Stream 1 - Introduction

  31. "The fatal chloroform case at Newcastle,"

Source: Snow, John. Lancet 1, 26 February 1848, p. 239 [Letter to Ed.].

To the Editor of the Lancet

Sir,--The recent fatal case of inhalation of chloroform appears to confirm in a melancholy manner the remarks contained in my paper in the Lancet of the 12th instant, respecting the danger arising from the cumulative property of the agent when administered on a handkerchief. The alarming symptoms came on after the cloth with chloroform was removed from the patient's face. Some of Dr. Simpson's observations on this case confirm the view I have taken. He says -- "I have seen in a few cases such a blanched state of the lips and features come on, under the use of very powerful and deep doses of chloroform, stimulating syncope, and with the respiration temporarily suspended." It may be presumed, that the cases Dr. Simpson has seen were under his immediate superintendence; and this makes the danger still more evident; for if any one could prevent his patient from getting into a state which cannot be looked on therwise than as one of imminent peril, it would be the authority who introduced the agent, and recommended this method of its administration.

On January 10th, two days after I read the remarks at the Westminster Medical Society, respecting the effects of chloroform increasing after the inhalation was left off, M. Sédillot related, in the Academy of Sciences of Paris, that he had observed the pallor, smallness of pulse, feebleness of respiration, and coldness, to augment in an alarming manner after the employment of the chloroform had been discontinued. His observations were reported in the Gazette Médicale of January 15th.

I agree with Dr. Simpson, that it was not advisable to give brandy, or even water -- the more so, as I do not think with him that there was syncope; but that these liquids caused suffocation, filling up the pharynx, and being partially drawn into the larynx, seems improbable. This question, however, can be only determined by those who observed the symptoms at the time of death, and the nature of the froth found in the bronchi afterwards, as there is nothing in the reported evidence of the appearances on dissection which might not be caused by the kind of asphyxia liable to be induced when the effects of chloroform are carried too far; and these appearances are quite incompatible with Dr. Simpson's supposition that there was syncope. Preventing the recovery from syncope would not cause the state of the heart and lungs, which is characteristic of the opposite kind of death--that by asphyxia. In a certain number of those who are drowned, the heart and lungs are not congested, but the contrary, and it is believed by medical jurists, that those persons have fainted on falling into the water.

-- I remain, Sir, your obedient servant,

John Snow.

Frith-street, Soho.

  32. "On narcotism by the inhalation of vapors" (part 1)

Source: Snow, John. London Med. Gazette 41, 19 May 1848, pp. 850-54 (part 1).

By John Snow, M.D.

[Part 1]

Vapours when inhaled become absorbed. Method of determining the quantity in the blood in different degrees of narcotism. Experiments on animals for this purpose, with chloroform and with ether.

It is generally admitted that ether and chloroform, when inhaled, are imbibed and enter the blood, and this has been proved, as regards ether, in more ways than one. That substance has been detected in the blood of animals that have inhaled it; and I have proved its absorption as follows: -- I passed a tame mouse through the quicksilver of a mercurial trough, into a graduated jar containing air and ether vapour, and, after a little time, withdrew it through the mercury, and introduced it, in the same manner, into a jar containing only air. On withdrawing it, and waiting till the air cooled to its former temperature, I found that the mercury had risen considerably in the first jar, and become depressed to some extent in the second; vapour of ether having been absorbed from one jar and part of it exhaled into the other.

M. Lassaigne* (Comptes Rendus, 8 Mars, 1847; and Med. Gaz. vol. xxxix. p. 968.) endeavoured to ascertain the proportion of ether in the blood in etherization, by comparing the tension of the vapour of serum of the blood before and after inhalation, with that of an aqueous solution of ether in certain known proportions. This method would, no doubt, indicate the quantity of ether in the serum at the time it was examined; but part of the ether would escape from the blood, in the form of vapour, as soon as it came in contact with the air in its exit from the body. He made the quantity of ether in the blood to be 0.0008, or one part in 1250.

Dr. Buchanan† († Med. Gaz. vol. xxxix. p.717.), by considering the quantity of ether expended in inhalation, and making allowance for what is expired, without being absorbed, considered the quantity in the blood of the adult in complete etherization to be not more than half a fluid ounce; and this is, I believe, a pretty correct estimate.

I consider, however, that I have found a plan of determining more exactly the proportions of ether and of other volatile substances present in the blood in the different degrees of narcotism. It consists in ascertaining the most diluted mixture of vapour and of air that will suffice to produce any particular amount of narcotism; and is founded on the following considerations, and corroborated by its agreeing with the comparative physiological strength of the various substances.

When air containing vapour is brought in contact with a liquid, as water or serum of blood, absorption of the vapour takes place, and continues till an equilibrium is established; when the quantity of vapour in both the liquid and air, bears the same relative proportion to the quantity which would be required to saturate them at the temperature and pressure to which they are exposed. If, for instance, the liquid contains one per cent, and would require ten per cent to saturate it, the air will contain three per cent if thirty per cent be the quantity that it could take up. This is only what would be expected to occur; but I have verified it by numerous experiments in graduated jars over mercury. The intervention of a thin animal membrane may alter the rapidity of absorption, but cannot cause more vapour to be transmitted than the liquid with which it is imbued can dissolve. The temperature of the air in the cells of the lungs and that of the blood circulating over their parietes is the same; and, therefore, when the vapour is too dilute to cause death, and is breathed till no increased effect is produced, the following formula will express the quantity of any substance absorbed:--As the proportion of vapour in the air breathed is to the proportion that the air, or the space occupied by it, would contain if saturated at the temperature of the blood, so is the proportion of vapour absorbed into the blood to the proportion the blood would dissolve.

The plan which I adopted to ascertain the smallest quantity of vapour, in proportion to the air, that would produce a given effect, was to weigh a small quantity of the volatile liquid in a little bottle, and introduce it into a large glass jar covered with a plate of glass; and having taken care that the resulting vapour was equally diffused through the air, to introduce an animal so small, that the jar would represent a capacious apartment for it, and wait for that period when the effects of the vapour no longer increase.

Experiments with Chloroform

I will first treat of chloroform, and, passing over a number of tentative experiments, will adduce a few of those which were made after I had ascertained the requisite quantities. The effects produced in these experiments were entirely due to the degree of dilution of the vapour, for the quantity of chloroform employed was, in every instance more than would have killed the animal in a much shorter time than the experiment lasted if it had been conducted in a smaller jar. It is assumed that the proportions of vapour and air remain unaltered during the experiment, for the quantity absorbed must be limited to what the animal can breathe in the time, which is so small a part of the whole that it may be disregarded.

Exp.1. -- A Guinea pig was placed in a jar, of the capacity of 1600 cubic inches, and the cover being moved a little to one side for a moment, 8 grs. of chloroform were dropped on a piece of blotting paper suspended within. The animal remained in the jar twenty minutes, and was not appreciably affected any part of the time.

Exp.2. -- The same Guinea pig was placed in the same jar, on another occasion, and 12 grs. of chloroform were introduced in the same manner, being three-quarters of a grain for each 100 cubic inches. In about six minutes it seemed drunk. It was allowed to remain for seventeen minutes, but did not become more affected; occasionally it appeared to be asleep, but could be disturbed by moving the jar. On being taken out it staggered, and could not find the way to its cage at first, but it recovered in two or three minutes.

Exp.3. -- Two grains of chloroform were put into a jar containing 200 cubic inches; it was allowed to evaporate, and the resulting vapour equally diffused by moving the jar; and then the cover was withdrawn just far enough to introduce a white mouse. After a short time it began to run round continuously in one direction. At the end of a minute it fell down and remained still, excepting a little movement of one or other of its feet now and then. It remained in the same state, and was taken out at the end of five minutes: it flinched on being pinched, tried to walk directly afterwards, and in a minute or so seemed to be completely recovered.

Exp.4. -- A Guinea pig was placed in the jar of 1600 cubic inches’ capacity, and 20 grains of chloroform were introduced, as in the two first experiments, being a grain and a quarter for each 100 cubic inches. In two minutes the Guinea pig began to be altered in its manner. At the end of four minutes it was no longer able to stand or walk, but crawled now and then. After seven minutes had elapsed it no longer moved, but lay breathing as in sleep. It was taken out at the end of a quarter of an hour. It moved its limbs as soon as it was touched, flinched on being pinched, and in four minutes was as active as usual.

Exp.5. -- Three grains of chloroform were diffused in the jar of the capacity of 200 cubic inches, and a white mouse introduced. It was not affected at first, but in less than a minute became drowsy, and at the end of a minute appeared insensible, and did not move afterwards. It was allowed to remain two minutes longer; it breathed naturally, and its limbs were not relaxed. When taken out it was insensible to pinching; it began to recover voluntary motion in two minutes.

Exp.6 -- The same mouse was placed in the same jar on the following day with 3.5 grs., being a grain and three-quarters for each 100 cubic inches. I[t] ran round as before, but fell down in less than a minute, and before the end of the minute ceased to move. It continued breathing in its natural rapid manner till nearly four minutes had expired, when the breathing became very feeble, and immediately afterwards appeared to have ceased. The mouse was taken out just as four minutes had elapsed. It began immediately to give a few deep inspirations at intervals, after which the breathing became natural; it was perfectly insensible to pinching, and did not stand [851/852] for three minutes. At the end of five minutes it seemed to be recovered, but it did not eat afterwards, and it died on the following day. The state of its organs will be mentioned farther on. The stoppage of respiration and impending death did not seem to be the direct effect of the vapour, but the result of continued and very deep insensibility.

Exp.7. -- A white mouse was placed in the same jar, with 4 grs. of chloroform. At the end of a minute it was lying, but moved its legs for a quarter of a minute longer. When four minutes had elapsed the breathing became slow, and it was taken out. It was totally insensible for the first three minutes after its removal, and recovered during the two following minutes.

Exp.8. -- The same mouse was placed in the same jar on the following day with 4.5 grs. of chloroform, being 2 ¼ grs. for each 100 cubic inches. It became more quickly insensible, and at the end of two minutes the breathing was beginning to be affected, when it was taken out. It recovered in the course of five minutes.

Exp.9. -- A white mouse was put into this jar, after 5 grs. of chloroform had been diffused in it, being 2½ grs. to each 100 cubic inches. It was totally insensible in three-quarters of a minute; in a little more than a minute the breathing became difficult, and, before two minutes had expired, the respiration was on the point of ceasing, and it was taken out. The breathing remained difficult for five minutes, but in other five minutes the mouse recovered, and at the end of a quarter of an hour was very active.

It will be remarked that in these experiments, the mice became much more quickly affected than the Guinea pigs. The reason of this is, their quicker respiration and much more diminutive size. In the last experiment, the quantity of vapour was evidently sufficient to arrest the breathing by its direct influence.

It is evident from the second, third, and fourth of the above experiments, that about one grain of chloroform to each 100 cubic inches of air, suffices to induce the second degree of narcotism, or that state in which the correct relation with the external world is abolished, but in which sensation and ill-directed voluntary movements may exist. Now one grain of chloroform produces 0.767 of a cubic inch of vapour of the sp. gr. [specific gravity] 4.2 as given by Dumas; and when it is inhaled, it expands somewhat as it is warmed, from about 60° to the temperature of the body; but it expands only to the same extent as the air with which it is mixed, and therefore the proportions remain unaltered. But air, when saturated with vapour of chloroform at 100°, contains 43.3 cubic inches in 100; and

So that if the point of complete saturation be considered as unity, 0.0177, or 1-56th, will express the degree of saturation of the air from which the vapour is immediately absorbed into the blood; and, consequently, also the degree of saturation of the blood itself.

I find that serum of blood at 100°, and at the ordinary pressure of the atmosphere, will dissolve about its own volume of vapour of chloroform; and since chloroform of sp. gr. 1.483 is 288 times as heavy as its own vapour, 0.0177 ÷ 288 gives 0.0000614, or one part in 16,285, as the average proportion of chloroform by measure in the blood, in the second degree of narcotism.

From the fifth experiment it appears that a grain and a half per 100 cubic inches of air is capable of producing the third degree of narcotism; and by the sixth and seventh experiments, it is shewn that from a grain and three-quarters to two grains causes a very complete state of insensibility, which cannot be long continued without danger; but I may remark, that four minutes in a mouse represents a much longer period in the human being, in whom the circulation and respiration are so much less rapid. I think we may take two grains as the average quantity capable of inducing the fourth degree, -- the utmost extent of narcotism required, or that can be safely caused in surgical operations; and by the method of calculation above we shall get 0.0354, or 1-28th, as representing the degree of saturation of the blood, and 0.0001228 the proportion by measure in the blood.

A greater quantity than this seems to induce the fifth degree of narcotism, embarrassing the respiration; and two and a half grains have the power of directly stopping the respiratory movements. By calculation we obtain 0.0442, or 1-22nd, as the degree of saturation of the blood which has this effect.

Birds have generally a somewhat higher temperature than most mammalia, and therefore the following five experiments have been separated from the rest; but, in 13 and 14, the thermometer placed under the wing of the linnet, at the end of the experiment, indicated only 100°,--just the temperature in the groin of the Guinea pig when it was removed from the jar in the 4th experiment. These are the only occasions on which it occurred to me to apply the thermometer.

Exp.10. -- 4.6 grs. of chloroform were put into a jar containing 920 cubic inches, by sliding the glass which covered it a little to one side. The jar was moved about to diffuse the vapour; and thus each 100 cubic inches of air contained half a grain. A hen chaffinch was introduced, by again momentarily sliding the cover a little to one side. In less than two minutes it seemed rather unsteady in its walking at the bottom of the jar, but no further effect was produced, although it remained twenty minutes; when taken out, indeed, it did not seem affected. This experiment was repeated on the same bird, and on another chaffinch, and also on a green linnet, with the same result; that is, no decided effect was produced.

Exp.11. -- 9.2 grs. of chloroform were diffused through the air in the same jar, being one grain to each 100 cubic inches; and a chaffinch was put in. In less than two minutes it staggered about, and in two and a half minutes fell down, but still stirred. It did not get further affected, although it remained ten minutes. Sometimes it seemed perfectly insensible, but always stirred when the jar was moved, and occasionally it made voluntary efforts to stand. On being taken out it seemed sensible of its removal; it flinched on being pinched, and quickly recovered.

Exp.12. -- A chaffinch was placed in the same jar with 11.5 grs., being a grain and a quarter for each 100 cubic inches. In less than a minute it began to stagger, and shortly afterwards was unable to stand, but moved its legs and opened its eyes occasionally. It did not get further affected after two minutes had elapsed, although it remained three minutes longer. It seemed aware of its removal, but was not sensible to being pricked. In attempting to walk when placed on the table, immediately after its removal from the vapour, it fell forwards at every two or three steps. In a minute or two, however, it was able to walk.

Exp.13. -- A green linnet was put in the same jar, with 13.8 grs., being a grain and a half to each 100 cubic inches. In a minute it was unable to stand, and in half a minute more ceased to move. It remained breathing naturally, and kept its eyes open. It was taken out at the end of ten minutes, was insensible to having its foot pinched, and began to recover voluntary motion in three minutes.

Exp.14. -- Was performed on the same linnet, two or three days before the last, with a grain and three-quarters of chloroform to each 100 cubic inches, in the same jar.

It was affected much in the same way as detailed above, but was longer in recovering voluntary motion after its removal, at the end of ten minutes.

It will be perceived that these results coincide as nearly as possible with the effects of the same quantities on the Guinea pigs and mice; and I found that when the quantity of chloroform exceeded two grains to the 100 cubic inches, birds were killed very rapidly.

It occurred to me that if this method of ascertaining the amount of vapour in the blood were correct, then a much more dilute vapour ought to suffice to produce insensibility in animals of cold blood; and that experimenting on them would completely confirm or invalidate these views.

The following experiment has been performed on frogs several times with the same result, the temperature of the room being about 55°.

Exp.15. -- 4.6 grs. of chloroform were diffused through the jar of 920 cubic inches capacity, as in Exp. 10. In the course of a few minutes the frog began to be affected, and at the end of ten minutes was quite motionless and flaccid; but the respiration was still going on. Being now taken out, it was found to be insensible to pricking, but recovered in a quarter of an hour. In a repetition of this experiment, in which the frog continued a few minutes longer, the respiration also ceased, and the recovery was more tardy. On one occasion the frog was left in the jar for an hour, but when taken out and turned over, the pulsation of the heart could be seen. In an hour after its removal it was found to be completely recovered.

Now the vapour is absorbed into the blood of the frog at the temperature of the external air, whose point of saturation, therefore, remains unaltered; and as half a grain of chloroform produces 0.383 cubic inches of vapour; and air at 55° will contain, when saturated, 10 per cent. of vapour; 0.0383, or 1-26th, expresses the degree of saturation of the air, and also of the blood of the frog. And this is a little more than 0.0354, or 1-28th, which we considered as the greatest quantity that could with safety exist in the blood. But frogs are able to live without pulmonary respiration, by means of the action of air on the skin: consequently this experiment coincides exactly with the others, and remarkably confirms the accuracy of this method of determining the amount of chloroform in the blood.

At the College of Physicians, on March 29, when I had the honour of shewing the effects of chloroform at Dr. Wilson’s Lumleian Lectures, and briefly explained these views, I conjoined the last experiment and the 10th in the following manner. I introduced a chaffinch, in a very small cage, into a glass jar holding nearly 1000 cubic inches, and put a frog into the same jar, covered it with a piece of glass, and dropped 5 grs. of chloroform on a piece of blotting paper suspended within. In less than ten minutes the frog was insensible, but the bird was unaffected. Then, in order to shew that the effects depended entirely on the dilution of the vapour, another frog, and another small bird, were placed in a jar containing but 200 cubic inches, with exactly the same quantity of chloroform. In about a minute and a half they were both taken out,--the bird totally insensible, but the frog not appreciably affected, as from its less active respiration it had not had time to absorb much of the vapour.

As the narcotism of frogs, by vapour too much diluted to affect animals of warm blood, depends merely on their temperature, it follows that, by warming them, they ought to be put into the same condition, in this respect, as the higher classes of animals; and although I have not raise their temperature to the same degree, I have found that as it is increased, they cease to be affected by dilute vapour that would narcotize them at a lower temperature.

Exp.16. -- I placed the jar holding 920 cubic inches near the fire, with a frog and a thermometer in it; and when the air within reached 75°, 4.6 grains of chloroform were diffused through it. The jar was kept for twenty minutes, with the thermometer indicating the same temperature within one degree. For the first seventeen minutes the frog was unaffected, and only was dull and sluggish, but not insensible when taken out.

(To be continued)

  33. "On narcotism by the inhalation of vapors (part 2)."

Source: Snow, John. London Med. Gazette 41, 26 May 1848, pp. 893-95 (part 2).

[Part 2]

Experiments with Ether

We will now proceed to consider ether, and will begin with the brief relation of a few experiments, shewing the strength of its vapour required to produce narcotism to various degrees.

Exp. 17. -- Two grains of ether were put into a jar holding 200 cubic inches, and the vapour diffused equally, when a tam mouse was introduced, and allowed to remain a quarter of an hour, but it was not appreciably affected.

Exp. 18. -- Another mouse was placed in the same jar, with three grains of ether, being a grain and a half to each 100 cubic inches. In a minute and a half it was unable to stand, but continued to move its limbs occasionally. It remained eight minutes without becoming further affected. When taken out it was sensible to pinching, but fell over on its side in attempting to walk. In a minute and a half the effect of the ether appeared to have gone off entirely.

Exp. 19. -- A white mouse in the same jar, with four grains of ether, was unable to stand at the end of a minute, and at the end of another minute ceased to move, but continued to breathe naturally, and was taken out at the end of five minutes. It moved on being pinched, began to attempt to walk at the end of a minute, and in two minutes more seemed quite recovered.

Exp. 20. -- Five grains of ether, being two and a half grains to each 100 cubic inches, were diffused throughout the same jar, and a mouse put in. It became rather more quickly insensible than the one in the last experiment. It was allowed to remain eight minutes. It moved its foot a very little when pinched, and recovered in the course of four minutes.

Exp. 21. -- A white mouse was placed in the same jar with six grains of ether. In a minute and a half it was lying insensible. At the end of three minutes the breathing became laborious, and accompanied by a kind of stertor. It continued in the state till taken out at the end of seven minutes, when it was found to be totally insensible to pinching. The breathing improved at the end of a minute; it began to move at the end of three minutes; and five minutes after its removal it had recovered.

Exp. 22. -- The same mouse was put into this jar on the following day, with seven grains of ether, being 3.5 grs. to the 100 cubic inches. Stertorous breathing came on sooner than before; it seemed at the point of death when four minutes had elapsed; and being then taken out, was longer in recovering than after the last experiment.

Exp. 23. -- Two or three days afterwards the same mouse was placed in the jar, with eight grains of ether, being four grains for each 100 cubic inches. It became insensible in half a minute. In two minutes and a half the breathing became difficult, and at a little more than three minutes it appeared that the breathing was about to cease, and the mouse was taken out. In a minute or two the breathing improved, and in the course of five minutes from its removal it had recovered.

The temperature of the mice employed in the above experiments was about 100°. That of the birds in the following experiments was higher, as is stated; and they differ widely from the mice in the strength of vapour required to produce a given effect, although I found but little difference between the mice and the birds, in this respect, in the former experiments on chloroform. And one of the linnets was employed in both sets of experiments. Having seen MM. Dumeril and Demarquay’s statement of the diminution of animal temperature from inhalation of ether and chloroform, before the following experiments were performed, the thermometer was applied at the beginning and conclusion of some of them. I have selected every fourth experiment from a larger series on birds.

Exp. 24. -- 18.4 grs. of ether were diffused through a jar holding 920 cubic inches, being two grains to each 100 cubic inches; and a green linnet was introduced. After two or three minutes it staggered somewhat, and in a few minutes more appeared so drowsy, that it had a difficulty in holding up its head. It was taken out at the end of a quarter of an hour, quite sensible, and in a minute or two was able to get on its perch. The temperature under the wing was 110° before the experiment began, and the same at the conclusion.

Exp. 25. -- Another linnet was placed in the same jar, with four grains of ether to each 100 cubic inches of air. In two minutes it was unable to stand, and in a minute more voluntary motion had ceased. It lay breathing quietly till taken out, at the end of a quarter of an hour. It moved its foot slightly when it was pinched. In three minutes it began to recover voluntary motion, and was soon well. The temperature was 110° under the wing, when put into the jar, and 105° when taken out.

Exp. 26. -- A green linnet was put into the same jar with 55.2 grs of ether, being six grains to the 100 cubic inches. It was insensible in a minute and a half, and lay motionless, breathing naturally, till taken out at the end of a quarter of an hour. It moved its toes very slightly when they were pinched with the forceps, and it began to recover voluntary motion in two or three minutes. Temperature 110° before the experiment, and 102° at the end.

Exp. 27. -- A linnet was placed in the same jar, containing eight grains of ether to each 100 cubic inches. Voluntary motion ceased at the end of a minute. The breathing was natural for some time, but afterwards became feeble, and at the end of four minutes appeared to have ceased; and the bird was taken out, when it was found to be breathing very gently. It was totally insensible to pinching. The breathing improved, and it recovered in four minutes.

Exp. 28. -- 0.2 grs. of ether, being one grain to each 100 cubic inches of air, were diffused through the jar holding 920 cubic inches of air, and a frog was introduced. At the end of a quarter of an hour it had ceased to move spontaneously, but could be made to move its limbs, by inclining the jar so as to turn it over. At the end of half an hour voluntary motion could no longer be excited, and the breathing was slow. It was removed at the end of three-quarters of an hour, quite insensible, and the respiratory movements being performed only at long intervals, but the heart beating naturally; and it recovered in the course of half an hour. The temperature of the room was 55° at the time of this experiment.

We find from the 18th experiment, that a grain and a half of ether for each 100 cubic inches of air, is sufficient to induce the second degree of narcotism in the mouse; and a grain a half of ether make 1.9 cubic inches of vapour, of sp. gr. [specific gravity] 2.586. Now the ether I employed boiled at 96°. At this temperature, consequently, its vapour would exclude the air entirely; and ether vapour in contact with the liquid giving it off, could only be raised to 100° by such a pressure as would cause the boiling point of the ether to rise to that temperature. That pressure would be equal to 32.4 inches of mercury, or 2.4 inches above the usual barometrical pressure; and the vapour would be condensed somewhat, so that the space of 100 cubic inches would contain what would be equivalent to 108 cubic inches at the usual pressure. This is the quantity, then, with which we have to compare 1.9 cubic inches, in order to ascertain the degree of saturation of the space in the air-cells of the lungs, and also of the blood; and by calculation, as when treating of chloroform,

1.9 is to 108 as 0.0175 is to 1.

So that we find 0.0175, or 1-57th, to be the amount of saturation of the blood by ether necessary to produce the second degree of narcotism; and as by Exp. 21, three grains in 100 cubic inches produced the fourth degree of narcotism, we get 0.035, or 1-28th, as the amount of saturation of the blood in this degree. Now this is within the smallest fraction of what was found to be the extent of saturation of the blood by chloroform, requisite to produce narcotism to the same degree. But the respective amount of the two medicines in the blood differs widely; for whilst chloroform required about 288 parts of serum to dissolve it, I find that 100 parts of serum dissolve 5 parts of ether at 100°; consequently 0.05 x 0.0175 gives 0.000875, or one part in 1142, as the proportion in the blood in the second degree of narco-[894/895]tism, and 0.05 x 0.035 gives 0.00175, or one part in 572, as the proportion in the fourth degree.

In Exp. 28, the frog was rendered completely insensible by vapour of a strength which was not sufficient to produce any appreciable effect on the mouse in Exp. 17. This is in accordance with what was met with in the experiments with chloroform. Air, when saturated with ether at 55°, contains 32 grains; so that the blood of the frog might contain 1-32d part as much as it would dissolve, which, although not quite so great a proportion as was considered the average for the fourth degree in the mice, yet was more than sufficient to render insensible the mouse in Exp. 20.

There is a remarkable difference between the birds and the mice in respect to the proportions of ether and air required to render them insensible, a difference that was not observed with respect to chloroform. In some experiments with ether on Guinea pigs, which are not adduced, they were found to agree with mice in the effects of various quantities.

The birds were found to require nearly twice as much: five grains to 100 cubic inches, the quantity used in an experiment between the 25th and 26th, which is not related, may be taken as the average for the fourth degree of narcotism in these birds, with a temperature of 110°. By the kind of calculation made before, we should get a higher amount of saturation of the blood than for the same degree in the mice. But as serum at 110° dissolves much less ether than at 100°, the quantity of this medicine in the blood of birds is not greater than in that of other animals; and considered in relation to what the blood would dissolve at 100°, the degree of saturation is the same.

By Expts. 22, 23, and 27, we find that with ether as with chloroform, a quantity of vapour in the air somewhat greater than suffices to induce complete narcotism has the effect of arresting the respiratory movements. The exact amount which has this effect might be determined if necessary.

Before proceeding to consider some other vapours, and the general conclusions to be drawn from these inquires, it may be as well to consider how far the above results coincide with experience as to the quantities of chloroform and ether required to produce insensibility in the human subject.

The blood in the human adult is calculated by M. Valentin to average about 30 pounds. This quantity would contain 26 pounds five ounces of serum, which, allowing for its specific gravity, would measure 410 fluid ounces. This being reduced to minims, and multiplied by 0.0000614, the proportion of chloroform in the blood required to produce narcotism to the second degree, gives 12 minims as the whole quantity in the blood. And to produce narcotism to the fourth degree we should have twice as much, or 24 minims. More than this is used in practice, because a considerable portion is not absorbed, being thrown out again when it has proceeded no further than the trachea, the mouth and nostrils, or even the face-piece. But I find that if I put twelve minims into a bladder containing a little air, and breathe it over and over again, in the manner of taking nitrous oxide, it suffices to remove consciousness, producing the second degree of its effects.

In order to find the whole quantity of ether in the blood, we may multiply 410, the number of fluid ounces of serum, by 0.000875 for the second degree, and by 0.00175 for the fourth degree, when we shall obtain 0.358 and 0.71 of an ounce, i.e. foz ij. ɱl. [2 fluid ounces + 50 minims] in the first instance, and foz v. ɱxl. [5 fluid ounces + 40 minims] in the second,--quantities which agree very well with experience when we allow for what is expired without being absorbed.

(To be continued.)

  34. "On narcotism by the inhalation of vapors (part 3)."

Source: Snow, John. London Med. Gazette 41, 23 June 1848, pp. 1074-78 (part 3).

By John Snow, M.D.

[Part 3]

Experiments to determine the quantity in the blood, and illustrate the action of nitric ether, bisulphuret of carbon, and benzin.

Nitric ether, or nitrate of the oxide of ethyle, consists of nitric acid combined with ordinary or sulphuric ether. It is described as a colourless liquid of sp. gr. [specific gravity] 1.112, with a sweet taste and pleasant smell, and boiling at 185° Fah. Two specimens of it which I have answer to this description. One was made and presented to me by Mr. Bullock; and the other, which was made by Mr. Joseph Spence, was given to me by Dr. Barnes. Dr. Chambert, of Paris, related some experiments that he had performed on dogs with the vapour of this substance, in a work on Ether, published in autumn last; and Dr. Simpson afterwards mentioned it in his pamphlet on Chloroform, as one of the things that he had tried.

The two following experiments will serve to determine the quantity of nitric ether in the blood, when insensibility is induced by it: --

Exp. 29. -- Four grains were diffused through the air in a jar containing 800 cubic inches; and a common mouse was introduced in the same manner as in the preceding experiments. In ten minutes it became rather torpid, but could be disturbed by touching the jar. It was left in this condition when it had been in a quarter of an hour. On returning at the end of an hour from the commencement of the experiment, I found the mouse lying still. It was taken out, and it moved spontaneously, endeavouring to walk, but falling over; it was quite sensible to being pinched. In five minutes it had recovered power to walk, but was not yet conscious of danger, as it would have walked off the table if not prevented. In a few minutes longer it had recovered its usual state.

Exp. 30.-- Another mouse was placed in the same jar with eight grs. of nitric ether. It became affected in ten minutes, and at the end of a quarter of [1074/1075] an hour had ceased to move, but lay breathing naturally 160 times in the minute. It remained in this state till removed half an hour after the commencement of the experiment, when it was found to be relaxed, and totally insensible. It began to move in ten minutes; it could walk at the end of a quarter of an hour, and in a little time longer was quite active.

We perceive from the above experiments that half a grain of nitric ether to each 100 cubic inches of air suffices to induce the second degree of narcotism, and one grain the fourth degree. I have not met with a statement of the specific gravity of the vapour of this ether in any work to which I have referred, and consequently I endeavoured to determine it myself--not with great nicety, but with sufficient accuracy to satisfy the purpose of this inquiry. I made it to be 5.67; and half a grain of vapour in 100 cubic inches of air saturated with it at 100° is 15.7 cubic inches, and 0.284÷15.7 will give 0.018, or rather less than one fifty-fifth, as the relative saturation of the blood with nitric ether in the second degree of narcotism. One grain produces 0.568 of a cubic inch of vapour: and this, divided by 15.7, gives 0.0361, or very nearly one twenty-eighth, as the relative saturation of the blood in the fourth degree of narcotism. So we find that the quantity of the vapour in the blood, viewed in relation to what it would dissolve, is the same as in the cases of chloroform and sulphuric ether. In some experiments on birds, a rather larger quantity of vapour was required; but when their higher temperature was taken into account the relative proportion to what the air would take up was found to be the same, and, consequently, their blood was saturated to just the same extent.

One part by measure of nitric ether requires 52 parts of serum at 100° to dissolve it, and 52 x 56 = 2912; consequently, one part in 2912 is the proportion in the blood in the second degree of narcotism; and considering the average quantity of serum in the body, as before, to be 410 fluidounces, we get by calculation 67 minims as the whole quantity in the blood in this degree; and twice as much, or 2 drachms and 14 minims, in the fourth degree. These quantities agree with the little experience I have had of its effects on the human subject.

From its slight pungency, and the gradual way in which, owing to its sparing volatility, its effects are produced, nitric ether would be a very safe anaesthetic, suitable for minor surgical operations if its effects were agreeable, but such is apparently not always the case. M. Chambert met with vomiting in most of the dogs to which he gave it, and was deterred from inhaling it himself. Dr. Simpson states, in the Monthly Journal of April last, that he had found it to produce sensations of noise and fullness in the head before insensibility, and, usually, much headache and giddiness afterwards. I have inhaled a small quantity of it on two or three occasions, and it caused a disagreeable feeling of sickness each time. I have given it only to one patient, but in that instance it acted very favourably. A middle-aged man applied at St. George’s Hospital, on May 26, to have a tooth extracted. He inhaled from the apparatus I use for chloroform. Soon after he began his pulse became accelerated and increased in force, and his face rather flushed. He continued to inhale steadily for three minutes, when I found that the sensibility of the conjunctiva was considerably diminished, although voluntary motion continued in the eyes and eyelids, the expression of his countenance not being altered from that of complete consciousness and he held his head upright. The vapour was left off, and the tooth, which was firmly fixed, was taken out by Mr. Price, the dresser for the week, without any sign of the operation being felt; the man holding his mouth wide open in an accommodating manner. A minute afterwards he began to spit on the floor; and being questioned, he said that he had no knowledge of the removal of the tooth, and should have thought that he had never lost his senses, except for what he found had been done. His feelings were not unpleasant whilst inhaling, and he felt well, and walked away in a few minutes afterwards. A fluid-drachm and a half was employed, and it was not all used. There was perfect immunity from pain, whilst the narcotism of the nervous centres was not [1075/1076] carried further than the second degree: this, however, I do not look on as a peculiarity of nitric ether, for I have met with it occasionally from chloroform and sulphuric ether when the vapour was introduced slowly. The above case, I think, affords encouragement for further trials of this medicine.

Bisulphuret of Carbon.

This substance is well known to every one at all conversant with chemistry. It is a transparent colourless liquid, of sp. gr. 1.272, having a very fœtid odour, and boiling at about 113°. A paragraph copied from the Morgenblad went the round of the journals of this country about the end of February last, stating that M. Harald Thanlow, of Christiana, in Norway, had discovered a substitute for chloroform and ether, in a sulphate of carbon, a very cheap substance made from sulphur and charcoal. This, of course, could be nothing else than the bisulphuret of carbon. I immediately examined its effects of animals, and found that it causes convulsive tremors, but that the kind of narcotism such as ether produces may be recognized. On account of the great volatility and very sparing solubility of this substance, the point of relative saturation of the blood by it is soon reached.

The following experiments will shew both the action of the yapour [vapour] and the quantity of it in the blood.

Exp. 31. -- Two grains of bisulphuret of carbon were diffused through the air in a jar holding 200 cubic inches, and a white mouse was introduced. In three minutes it was altered in its manner, and no longer regarded the approach of the hand towards it. In six minutes tremors came on, which soon became violent, and lasted till after the mouse was taken out at the end of ten minutes; but voluntary motion continued along with the tremors. When taken out, it flinched on being pinched; attempted to walk, but fell over on its side: it had no appreciation of danger at first, but it quickly recovered.

Exp. 32. -- A common mouse was put into a jar holding 800 cubic inches, in which 12 grains of bisulphuret of carbon had been diffused, being a grain and a half to each 100 cubic inches. In a minute it began to have convulsive tremors whilst still walking. In half a minute more, voluntary motion ceased, but the tremors continued. It was removed at the end of ten minutes, was sensible to pricking and pinching, and in a minute or two began to recover voluntary motion, the trembling of the whole body continuing for a little time after it was able to walk.

Exp. 33. -- A white mouse was placed in the jar of 200 cubic inches capacity, with four grains of this substance in the form of vapour. It became quickly affected, and was lying powerless in less than half a minute. Convulsive tremors came on immediately after it fell, and lasted till death. At the end of four minutes the breathing became difficult, being performed only by distant convulsive efforts. The mouse was immediately removed, but only gave one or two gasps afterwards.

In another experiment, in which there were two and a quarter grains to each 100 cubic inches of air, the mouse, after running about for a minute, fell down, and stretched itself violently out, and died.

There is no stage of muscular relaxation prior to death by this vapour, as by those we have previously considered, when their effects are gradually induced; but tremulous convulsions of the whole body continue till death, which seems to be threatened almost as soon as complete insensibility to external impressions is established.

In Exp. 31, narcotism to the second degree was occasioned by one grain to 100 cubic inches. The sp. gr. of the vapour of bisulphuret of carbon being 2.668, it will be found that one grain of the liquid must produce 1.209 cubic inches of vapour; and I find that air, when saturated with it at 100°, expands to four times it former volume, so that 100 cubic inches contain 75 of vapour. Therefore 1.209 ÷ 75 gives 0.0161, or one part in 62 of what the blood would dissolve, as the relative saturation of the blood in the second degree of narcotism; and, as Exp. 33 may be regarded as the nearest approach to the fourth degree that we can get with this vapour, twice as much, or one part in 31, is the relative amount for that degree. These proportions do not differ much from those arrived at in the inquiries concerning the vapours previously examined.

Serum at 100° dissolves, as nearly as I can determine, just its own volume [1076/1077] of the vapour of bisulphuret of carbon; and, as the liquid is 408 times as heavy as its own vapour at the temperature of 100°, it will be found, by a similar calculation to that made with respect to the vapours treated of previously, that about 7½ minims is the average quantity that there should be in the whole blood of the human subject in the second degree, and 15 minims in the fourth degree of narcotism. When the great volatility of this substance is also taken into account, it will be perceived that its effects, when inhaled, must be most powerful. Indeed, I feel convinced, that, if a person were to draw a single deep inspiration of air saturated with its vapour at a summer temperature, instant death would be the result. Although its odour is offensive, it is not difficult to inhale; and Dr. Simpson has given it in a surgical operation and an obstetric case; he also informs us (op. cit.) that its effects were so powerful and so transient, that it was very unmanageable, and that it also cause some unpleasant symptoms, and he does not recommend its use.

Benzin or Benzole.

This substance was first discovered by Dr. Faraday, as a product of the distillation of compressed oil-gas, and named bicarburet of hydrogen; it was afterwards obtained by Mitscherlich, by distilling a mixture of benzoic acid and slaked lime; latterly Mr. Blatchford Mansfield has obtained it by the distillation of coal-tar. It consists of carbon and hydrogen, as its first name implied, the proportions being C12H6. It is a clear, colourless, and very mobile liquid, of sp. gr. 0.85, and having an aromatic odour. It has been described as boiling at 180°; and a portion with which Mr. Mansfield favoured me, boils, as he always found it to do, about 178°. There is no difference either in sensible properties or physiological effects between the benzin made from benzoic acid, and that obtained from coal-tar. Like the substance last treated of, it causes convulsive tremors in addition to the other symptoms of narcotism; they usually begin in animals before voluntary motion ceases, and continue as long as the vapour is applied, and during part of the recovery, and until death when animals are killed by it. The tremors are usually violent, affecting the whole body, and accompanied in birds with flapping of the wings.

One experiment will suffice to show the effects of this vapour.

Exp. 34. -- Six grains of benzin were diffused through the air in a jar holding 800 cubic inches, being three-quarters of a grain for each 100 cubic inches; and a half-grown white mouse was introduced. In less than a minute it began to shake and tremble, and ceased to move voluntarily, but every now and then gave a sudden start; this start could also be occasioned at any time by striking the jar so as to make a noise. This mouse continued in the same state till removed at the end of a quarter of an hour; it was totally insensible to pricking and pinching, which produced not the slightest effect on it, whilst at the same time a sharp noise near it cause it to start. Five minutes after its removal it began to recover voluntary motion, but the tremors continued a little longer. The mouse was soon as well as before the experiment. Less than half a grain of benzin to each 100 cubic inches of air, suffices to impair the voluntary motion, and alter the manner of an animal; rather more than half a grain causes convulsive tremors, and three-quarters of a grain and upwards produces complete insensibility, whilst two grains will take away life. In the experiment related above, the fourth degree of narcotism appeared to be induced by three-quarters of a grain, but one grain to the 100 cubic inches of air is the average quantity for that state in several experiments. The specific gravity of the vapour of benzin being 2.738, one grain of the liquid makes 1.179 cubic inch of vapour; and I find that air saturated with it at 100°, contains 20 per cent of it by measure: so 1.179 ÷ 20 will give the relative saturation of the blood. It is 0.058, or one-seventeenth part of what it would dissolve. This is a greater proportion than we arrived at in examining the vapours treated of above.

Benzin requires 270 parts of serum for its solution; consequently, by the kind of calculation made before, 42 minims is obtained as the average quantity that there would be in the human body, if narcotism were [1077/1078] carried to the fourth degree by this vapour. It follows from this that benzin must be powerful in its effects, and such I have found to be the case, but they are not so rapidly produced as the effects of chloroform, on account of its lesser volatility. I employed it in some cases of tooth-drawing, and in one amputation, in St. George’s Hospital, at the latter part of last year. Its action in the minor operations was very nearly the same as that of nitric ether, in the case related above; but in the amputation, where its effects were carried further, the patient had violent convulsive tremors for about a minute, which, although not followed by any ill consequences, were sufficiently disagreeable to deter me from using it again, or recommending it in the larger operations.

(To be continued.)

  35. On narcotism by the inhalation of vapors. (part 4)

Source: Snow, John. London Med. Gazette 42, 25 August 1848, pp. 330-35 (part 4).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 4]

On bromoform, bromide of ethyle, and Dutch liquid--General results of the experiments--The strength of narcotic vapours in the inverse ratio of their solubility in the blood.

Description of the physiological effects of chloroform.

Bromoform.

This is a volatile liquid of the same composition as chloroform, except that three atoms of bromine occupy the place of the same proportion of chlorine. It is made in the same way as chloroform, bromide of lime being used instead of chloride. I have repeatedly made it, but have never succeeded in obtaining more than a few grains in a purified state, although I used an ounce of bromine in making the bromide of lime on each occasion; consequently it is very expensive. It is extremely fragrant, having an odour that is, in my opinion, much pleasanter than that of chloroform or any other of this class of substances with which I am acquainted. It boils at about 184° Fah.; but, as its vapour is twice as heavy as that of chloroform, it is in point of fact nearly as volatile as that liquid. It is very pleasant to inhale, but I have never breathed in more than a few grains at a time, and, therefore, cannot speak of its operation on the human subject. Its effects on animals closely resembles those of chloroform.

The two following experiments will serve to illustrate the action of bromoform, and to determine the quantity in the blood. --

Exp. 35. -- A common mouse was placed in a jar containing 400 cubic inches, in which three grains of bromoform had been diffused. In the course of four or five minutes it became unsteady in its walking, and ceased to regard objects in its way. It did not get further affected, except to become rather sluggish, and, when removed at the end of twenty minutes, was capable of voluntary motion. It did not regard a slight pinch, but flinched when the soft part of its foot was pinched severely. It recovered gradually and was pretty well re-established in half an hour.

Exp. 36. -- Another mouse was placed in the same jar with six grains of bromoform: it was more quickly affected, and, at the end of five minutes, all voluntary motion had ceased, and it lay breathing naturally and rather deeply. It was removed at the end of a quarter of an hour, and did not stir on being pinched. It began to recover voluntary motion in ten minutes, but staggered at first. In a little more than half an hour it had recovered.

In the first of these experiments the second degree of narcotism was caused by three-quarters of a grain of bromoform to each 100 cubic inches of air. The specific gravity of the vapour of bromoform is stated, in Thompson’s Chemistry of Organic Bodies, to be 8.785 which gives 0.275 of a cubic inch as the quantity of vapour that three-quarters of a grain would yield; and I find that fifteen cubic inches of this vapour are contained in 100 of air saturated with it at the temperature of 100°; consequently the air of the jar contained 0.275 ÷ 15 = [0].00183, or nearly one fifty-fourth part of what it would take up if saturated at 100°, and according to the principles explained in a former part of these papers,* (* Vol. xli. p. 850 [first page of Part 1]) the blood of the mouse would contain just the same proportion--one fifty-fourth of what it could dissolve. In the other experiment, the fourth degree of narcotism was produced by twice the quantity--a grain and a half to each 100 cubic inches, which, by the same computation, gives about one twenty-seventh part of what the blood would take up. These proportions are nearly the same as in the case of most of the substances previously examined. I have not ascertained the exact solubility of bromoform, and consequently cannot compute the absolute quantity in the blood, but it resembles chloroform in being very sparingly soluble.

I have not heard that any one else has examined the effects of the vapour of bromoform; but Dr. Glover mentions an experiment in his valuable paper "On Bromine and its Compounds,"* (*Edin. Med. and Surg. Jour., Oct. 1842) in which bromoform in the liquid state was introduced into the stomach of a rabbit, with the same results as in other experiments with similar bodies: these were death, with congestion of the lungs and stomach.

Bromide of Ethyle.

Bromide of ethyle, or hydrobromic ether, is a very volatile liquid, boiling, as I have found, at 104°. It has a pleasant but somewhat pungent taste and smell. It was discovered by Seru[l]las in 1827, and is formed by the action of phosphorous on a solution of bromine in alcohol. I am not aware that its physiological effects have been examined except in a few experiments which I have performed with its vapour. I will cite two of them to illustrate its effects. The bromide of ethyle was made by myself.

Exp. 37. -- Eight grains of bromide of ethyle were introduced into a jar containing 400 cubic inches, and the vapour which instantly resulted was equally diffused by moving the jar. A mouse was then put in. In about four minutes it began to stagger and fall over, and was quite regardless of external objects. It did not get affected beyond this extent, except that it became rather feeble. It was taken out at the end of a quarter of an hour, having the power of voluntary motion, but rolling over in its attempts to walk. It flinched with severe, but not with slight pinching. In ten minutes it had pretty well recovered.

Exp. 38.--Another mouse was placed in the same jar with sixteen grains of bromide of ethyle. In two minutes it had ceased to move, not having shewn any signs of excitement. It lay motionless, breathing at first deeply, afterwards more naturally. It was removed at the end of a quarter of an hour, and was found to be totally insensible. In five minutes it began to move, but rolled over in its first attempts to walk. Twenty minutes after its removal, it appeared to have recovered from the effects of the vapour.

Connected with the great volatility of this liquid is the increased quantity of it required to be present in the air to produce a given effect,--in accordance with the law which requires that the blood must be impregnated to a certain extent relatively to what it could imbibe. In one experiment I performed with this substance, one grain to each 100 cubic inches of air produced no appreciable effect whatever on a mouse confined for twenty minutes in it, although with that quantity of several less volatile bodies complete insensibility would have been induced.

In experiment 37 two grains to each 100 cubic inches of air produced the second degree of narcotism; and in the following experiment four grains produced the fourth degree. The specific gravity of the vapour of bromide of ethyle is, I find 3.78, the atom being represented by two volumes. Two grains will consequently occupy 1.706 cubic inches in the form of vapour. At the temperature of 100° the vapour of bromide of ethyle almost excludes the air, and occupies 92.8 per cent of its place. So 1.706 ÷ 92.8 gives 0.0183, or nearly one fifty-fourth, as the relative saturation of the blood with this vapour for the second degree of narcotism; and there would be twice as much, or one twenty-seventh, for the fourth degree.

I have not ascertained by direct experiment how much bromide of ethyle serum will dissolve, but I find that water dissolves about one-sixtieth of its volume of it; and as the solubility of liquids of this kind is nearly the same in water as in serum, this may safely be taken as the standard;--when, if we consider the average quantity of serum in the human body to be 410 fluid ounces, as in a former part of these papers, and make the kind of calculation there made, we shall find that one fluid drachm and ten minims is the average quantity that there would be in the blood of a human subject in the second degree of narcotism; and two drachms and twenty minims in the fourth degree.

Dutch Liquid.

In recent works on chemistry this substance is called the hydrochlorate of chloride of acetyle. It is formed by the combination of equal volumes of olefiant gas and chlorine. It has a taste at once sweet and hot, and a pungent ethereal odour. It boils at 180°, [331/332] and not at 148°, as Dr. Simpson states in some brief remarks on it in the Edinburgh Monthly Journal for April last, where he informs us that its vapour, when inhaled causes so great irritation of the throat that few persons can persevere in inhaling it long enough to produce anesthesia; but that he had, however, “seen it inhaled perseveringly until this state, with all its usual phenomena, followed; and without excitement of the pulse or subsequent headache.” My experiments with it have been confined to animals; and the two following will serve as a sample of them: --

Exp. 39. -- One grain and a half of Dutch liquid was diffused through the air of a jar containing 400 cubic inches, and a mouse was introduced. After ten minutes had elapsed it began to stagger in its walk, and it continued to do so till it was removed at the end of half an hour. It was occasionally lying still, but always began to walk in an unsteady manner when the jar was move. It was sensible to pinching on its removal, and in a quarter of an hour had recovered from its inebriation. It continued well.

Exp.40. -- A mouse was put into the same jar after three grains of Dutch liquid had been diffused in it. It began to stagger sooner than that employed in the last experiment; and at the end of ten minutes had ceased to move, without having had any struggling or rigidity; and it was not disturbed on the jar being moved. It lay breathing naturally till it was taken out at the end of half an hour, when it was found to be totally insensible to pinching. In ten minutes after its removal it began to move, but rolled over in its efforts to walk; when half an hour had elapsed it appeared to have recovered entirely form the narcotism, but was less lively than before; and two or three hours afterwards it was observed to be suffering with difficulty of breathing, and it died in the course of the day. The lungs were congested and of a deep vermilion colour, probably the result of inflammation, occasioned by the irritating nature of the vapour. The right cavities of the heart were distended with dark-coloured coagulated blood. The same appearances were met with in another mouse that died in the same way after breathing this vapour.

In the first of these two experiments the second degree of narcotism was effected by three-eights of a grain of vapour to each 100 cubic inches of air; and as the specific gravity of this vapour is 3.4484, three-eights of a grain must occupy 0.35 of a cubic inch. I find that air, when saturated with vapour of Dutch liquid at 100°, contains 17.5 per cent., and therefore 0.35 ÷ 17.5 gives 0.02, or one-fiftieth, as the relative saturation of the blood in this degree. In the other experiment the fourth degree of narcotism was caused by twice as much vapour, or three-quarters of a grain to each 100 cubic inches, and, consequently, the blood would contain twice as much, or one twenty-fifth part of what it would hold in solution if saturated. I have ascertained that Dutch liquid requires about 100 parts of water for its solution, and taking its solubility in the serum to be the same, the blood would contain one part in 5000 in the second, and one part in 2500 in the fourth degree of narcotism, which in the human subject would be, on an average, 46 minims and 92 minims respectively.

General results of the experiments.

We have now seen the result of this experimental inquiry into the action of eight volatile substances, viz.: chloroform, ether, nitrite of oxide of ethyle, bisulphuret of carbon, benzin, bromoform, bromide of ethyle, and Dutch liquid. We find that the quantity of each substance in the blood, in corresponding degrees of narcotism, bears a certain proportion to what the blood would dissolve-–a proportion that is almost exactly the same for all of them, with a slight exception in the case of benzin, which I believe is more apparent than real. The actual quantity of the different substances in the blood, however, differs widely; being influenced by their solubility. When the amount of saturation of the blood is the same, then it follows that the quantity of vapour required to produce the effect must increase with the solubility, and the effect produced by a given quantity must be in the inverse ratio of the solubility, as I announced some time ago.* (*Medical Gazette, March 31.) This rule holds good with respect to all the substances of this kind that I have examined; including, in addition to those enumerated in this paper, bichloride of carbon, iodide of ethyle, acetate of oxide of ethyle, nitrate of oxide of methyle, acetate of oxide of methyle, pyroxilic spirit, acetone, and alcohol. The exact proportion in the blood, in the case of the three last mentioned [italicized in the table below], cannot be ascertained directly by experiments of the kind detailed above; for, being soluble to an unlimited extent, they continue to be absorbed as long as the experiment lasts: but from the large quantity of these substances that is required to produce insensibility, they confirm the rule stated above in a remarkable manner.

This general law, of course, does not apply to all narcotics; not, for instance, to hydrocyanic acid, but only to those producing effects analogous to what are produced by ether, and having, I presume, a similar mode of action. I am not able at present to define them better than by calling them, that group of narcotics whose strength is inversely as their solubility in water (and consequently in the blood). In estimating their strength, when inhaled in the ordinary way, another element has to be taken into the account, viz., their volatility; for that influences the quantity that would be inhaled. By multiplying together the number of parts of water that each substance requires for its solution, and the number of minims of each substance that air will hold in solution at 60°, we get a set of figures expressive of the relative strength of each, when breathed in the ordinary way; and by another method of calculation the time might be expressed, in minutes and seconds, that it would take, on an average, to render persons, breathing in the usual way, insensible by each substance: but I shall here confine myself to enumerating the bodies I have examined in two columns; arranging them, in the first column, in the inverse order of their solubility, which is the direct order of their actual potency; and in the second column, in the order in which they stand after their volatility is taken into the account, which is the order of their potency when mixed with air till it is saturated at any constant temperature.

The general law, stated above, respecting the solubility of these liquids in the blood, applies also, with certain modifications, to a number of bodies which are gaseous at ordinary temperatures, and there are several important conclusions to be deduced from it. But before proceeding further in the attempt to give a general history of narcotic vapours and gases, and to determine what substances should be included in the list or otherwise, it will be well for me to describe, more particularly than I have done, the nature of the narcotism produced by the class of bodies we are considering, of which chloroform may be properly be taken as the type. I shall, therefore, next proceed to give the best description that I can of the effects of chloroform, having especially in view the practical importance of the agent; and shall make all the remarks that I am able to include in a brief space, on the administration of chloroform in surgical operations, medicine, and midwifery.

Description of the effects of Chloroform.

I may premise, that in applying the term narcotic to chloroform and other volatile substances, I employ it in the extended sense in which it is used by writers on materia medica and toxicology, who make it include all the substances which act on the nervous system; and I apply the term narcotism to designate all the effects of a narcotic, as I am entitled to do by strict etymology, and do not confine it, as the practice has generally been, to express a state of complete insensibility. I do not object to the term anesthetic, but I use that of narcotic as being more comprehensive, and including the other properties of these vapours as well as that of annulling common sensibility.

To facilitate the description, I divide all the effects of chloroform short of the abolition of life, into five degrees. I use the term degree in preference to stage, as, in administering chloroform, the slighter degrees of narcotism occur in the latter stages of the process, during the recovery of the patient, as well as in the beginning.

The division into degrees is made according to symptoms, which, I believe, depend entirely on the state of the nervous centres, and not according to the amount of anæsthesia, which I shall give good reason for believing depends very much on local narcotism of the nerves.

In the first degree I include any effects of chloroform that exist while the patient possesses perfect consciousness of where he is, and what is occurring around him. As the sensations caused by inhaling a small quantity of chloroform have been experienced by nearly every medical man in his own person, I need not attempt to describe them. They differ somewhat with the individual, but may be designated as a kind of inebriation, which is usually agreeable when induced for curiosity, but is often otherwise, when the patient is about to undergo an operation: in such cases, however, this stage is very transitory. Although it is the property of narcotic vapours to suspend the functions of different parts of the nervous system in succession, yet they probably influence every part of that system from the first, but in different degrees.

I have found that my vision became impaired when inhaling chloroform, whilst I should have thought it as good as ever, had it not been that the seconds pointer disappeared from the watch on the table before me; and I could only discover it again by stooping to within a few inches within it. Common sensibility becomes also impaired, so that the pain of disease, which is generally due to a morbid increase of the common sensibility, is in many cases removed, or relieved, according to its intensity. And hence it is that patients are able to inhale chloroform and ether, without assistance, for the relief of neuralgia, dysmenorrhœa, and other painful affections; the latter, which acts less rapidly, being the best adapted for this kind of domestic use -- chloroform being perhaps not perfectly safe. The sufferings attendant on parturition, when not unusually severe, may generally be prevented, as stated by Dr. Murphy* (* Pamphlet on chloroform in the practice of midwifery.), without removing the patient’s consciousness; but I have met with no instance in which the more severe kind of pain caused by the knife was prevented, whilst complete consciousness existed, except in a few cases, for a short time, as the patients were recovering from the effects of the vapour, having just before been unconscious.

In the second degree of narcotism, there is no longer correct consciousness. The mental functions are impaired, but not altogether suspended. Generally, indeed, the patient neither speaks nor moves, but it is possible for him to do both; and this degree may be considered to be analogous to delirium, and to certain states of the patient in hysteria and concussion of the brain; and it corresponds with that condition of an inebriated person, who is not dead drunk, but in the state described by the law as drunk and incapable. It is so transitory, however, that the patient emerges to consciousness in a very few minutes at the farthest, if the chloroform is discontinued. This degree, any more than the others, cannot properly be compared to natural sleep, for the patient cannot be roused at any moment to his usual state of mind. Persons sometimes remember what occurs whilst they are in this state, but generally they do not. Any dreams that the patient has, occur whilst he is in this degree, or just going into, or emerging from it, as I have satisfied myself by comparing the expressions of patients with what they have related afterwards. There is generally a considerable amount of anæsthesia connected with [334/335] this degree of narcotism, and I believe that it is scarcely every necessary to proceed beyond it in obstetric practice, not even in artificial delivery, unless for the purpose of arresting powerful uterine action, in order to facilitate turning the fœtus. For, on the one hand, obstetric operations are less painful than those in which the knife is used, and, on the other, it is not so necessary that the patient should be perfectly motionless during their performance, as when the surgeon is cutting in the immediate vicinity of vital parts.* (*Mr. Gream and Dr. Wm. Merriman, who have done me the honour of quoting from my essays on ether and chloroform, in their pamphlets, have applied to midwifery, what I meant to apply only to delicate and serious surgical operations, and have grounded objections on the supposed necessity of producing a deep state of narcotism.) There is sometimes a considerable amount of mental excitement in this degree, rendering the patient rather unruly; but a further dose of the vapour removes this by inducing the next degree of narcotism, and there is less difficulty from this source with chloroform than with ether, since its action is more rapid, and two or three inspirations often suffice to overcome the excitement. Very often, however, the patient is quiet, and to a certain extent tractable in this degree, and if sufficient anæsthesia can be obtained, there are certain advantages in avoiding to carry the narcotism beyond it for minor operations, especially tooth-drawing, as I shall explain when I enter on the uses and mode of applying chloroform, at the end of this sketch of its physiological effects. The patient is generally in this degree during the greater part of the time occupied in protracted operations; for, although, in most cases, it is necessary, as I have formerly stated, to induce a further amount of narcotism before the operation is commenced, it is not usually necessary to maintain it at a point beyond this.

(To be continued.)

  36. "On narcotism by the inhalation of vapors." (part 5)

Source: Snow, John. London Med. Gazette 42, 8 September 1848, pp. 412-16 (part 5).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 5]

Description of the physiological effects of chloroform, continued--when inhaled it acts on the nerves as well as on the nervous centres. Phenomena attending death from chloroform--its action on the heart of the frog.

The advent of the third degree of narcotism is marked by cessation of all voluntary motion. Usually the eyes become inclined upwards at the same time; and there is often a contracted state of the voluntary muscles, giving rise to more or less rigidity of the limbs. This contraction is greater and more frequent from chloroform than from ether, and, by affecting the muscles of the jaw, it sometimes causes a considerable obstacle to operations on the mouth. As there are no signs of ideas in this degree, I believe that there are none, and that the mental faculties are completely suspended: consequently the patient is perfectly secured against mental suffering from any thing that may be done. It does not follow, however, that an operation may always be commenced immediately the narcotism reaches this degree, for anæsthesia is not a necessary part of it; and unless the sensibility of the part to be operated on be suspended, or very much obscured, there may be involuntary movements sufficient to interfere with a delicate operation--not merely reflex movements, but also coordinate actions, such as animals may perform after the cerebral hemispheres are removed, the medulla oblongata being left. Under these circumstances an operation usually causes a contraction of the features expressive of pain, and sometimes moaning or cries, but not of an articulate kind. Whether or not these signs are to be considered proofs of pain, will depend on the definition given to the word; and if they do not interfere with the operator, or influence the recovery, they can be of no consequence as there is no pain which has an existence for the patient. To obtain anæsthesia when it does not exist in this degree, and thus to prevent these symptoms if we desire, it is not necessary to carry the narcotism further, but only to wait at this point a few moments, giving a little chloroform occasionally to prevent recovery, and allow time for it to permeate the coats of the small vessels, and act more effectually on the nerves. The sensibility of the conjunctiva is a correct index of the general sensibility of the body; and until it is either removed or very much diminished, an operation of delicacy cannot be comfortably performed. Accordingly, in administering chloroform, as soon as the patient has inhaled sufficient to suspend voluntary motion, I raise the eyelid gently, touching its free border. If no winking is occasioned the operation may begin in any case, but if it is I wait a little time, till the eyelids either become quite passive or move less briskly. The state of the eye itself is observed, by this means, at the same time. It is usually turned up, and the pupil contracted, as Mr. Sibson has stated,* in the condition which I term the third degree of narcotism. (*Med. Gaz., Feb. 18. I think that the turning up of the eyes is not so constant as Mr. Sibson believes, as I have been unable to observe it in some patients at any stage.) The vessels of the conjunctiva, also, are sometimes injected, but more frequently they are not.

Dr. Hughes Bennet, in his able report on the properties of chloroform,† argues that the sensibility of the nerves is not suspended under its influence, because respiration, circulation, and uterine contractions continue, which could not be the case if the sensibility of the nerves connected with these functions were destroyed. (†Monthly Journal, Jan. 1848.) This argument would have some weight if the nerves of common sensibility did not differ from those of the organic system, or those which arise from the respiratory tract of the medulla oblongata; but as the case stands, it has none: and there is no more difficulty in conceiving a variable degree of susceptibility and of resistance to the effects of chloroform in different sets of nerves, than in different nervous centres. A careful observation of cases shows that the amount of local insensibility by no means keeps pace with the degree of sopor or coma, but [412/413] is later in coming on and going off, and varies in amount in different patients; and as we know that chloroform, like other narcotics, produces some effect on parts to which it is locally applied, the conclusion seems irresistible, that it acts on the nerves as well as on the nervous centres. This view of the subject explains some circumstances which before seemed inexplicable; such as that of the patient recovering his consciousness, and telling the bystanders that he does no feel what is being done. For, whilst the vapour is escaping from the blood by way of the lungs, there is no difficulty in understanding how the brain may recover its influence sooner than the branches and peripheral expansion of the nerves; since, in the brain, not only is the circulation more rapid, but there is little, if any, lymph external to the vessels; whilst, in the body at large, the chloroform, having transuded through the coats of the capillaries into the extra-vascular liquor sanguinis, remains there for a little time, acting on the nervous fibrillæ, before it can pass again by endosmose into the vessels. It is in young subjects, in whom, connected with the more active process of nutrition, the quantity of lymph external to the vessels is greatest, that the general insensibility most frequently remains, whilst the cerebral hemispheres are resuming their functions.

In the fourth degree of narcotism there is relaxation of the voluntary muscles, together with general insensibility. I am better acquainted with this degree as induced by ether than by chloroform, for with the latter agent the third degree appears to encroach somewhat on this; chloroform seeming to differ from ether, and approaching somewhat in its effects to benzin and bisulphuret of carbon, which, we have seen, are not attended with muscular relaxation at any stage of their effects. Accordingly, I am inclined to prefer the use of ether, to assist the reduction of dislocations and strangulated hernia. There is, however, often sufficient relaxation of the muscles to effect these objects even in the second degree of narcotism, especially if the effect have been kept up a little time. I was at one time inclined to believe that the functions of the spinal cord were more or less suspended in this degree, since reflex movements cannot be excited by any impressions made on the eyelids, or general surface of the body; but these reflex movements are absent in every degree of narcotism, when the common sensibility is abolished, and, thereby the circumstance is best explained attributing it to the narcotism of the nerves. Other functions of the spinal cord certainly remain; for the sphincters of the bladder and rectum continue contracted, and respiration goes on. The sensibility of the glottis continues, apparently unimpaired, in this degree of narcotism, but that of the pharynx is probably suspended; for, in operations on the mouth and nose, the blood sometimes finds its way into the stomach, without any visible act of swallowing. This takes place frequently, when the narcotism does not exceed the third degree. In these cases, it probably runs along the channel there is at each side of the epiglottis. The breathing is not unfrequently attended with some degree of stertor in the fourth degree; and the reason why one does not often meet with stertor in exhibiting chloroform, is, that one seldom carries the narcotism so far. There is a little stertor occasionally, even in the third degree of narcotism; and this symptom, and rigidity of the muscles, are met with altogether. There may be simple snoring in any degree of narcotism, and even in the natural sleep which often follows the state of insensibility; but it never comes on during the first minutes of the inhalation of chloroform, unless the narcotism reaches to the third or fourth degree. The iris is less sensible to light in this degree than under ordinary circumstances, and the pupil is about the usual size. I have never observed it widely dilated, or totally insensible to light.

I have not mentioned the pulse in the above outline of the action of chloroform on the human subject, as it is not indicative of the amount of narcotism. It is usually somewhat increased in force and frequency, as it is by a moderate amount of fermented liquor. This effect subsides with the effect of the vapour; but I have not remarked the pulse become slower after chloroform than it might be expected to be, in the same patient, in a state of perfect repose. 52 is the slowest pulse I have met with, and that was in a healthy man. This moderate acceleration is, I believe, the only direct effect of chloroform on the pulse. Indirectly, it may affect it in other ways. If, for instance, the breathing is interrupted by the pungency of the vapour, or from any other cause, the pulse becomes small and frequent, and when sickness is induced, it is diminished in force. If it is very frequent at the beginning of the inhalation, from mental perturbation, as is often the case, when the patient is about to undergo an operation, the frequency diminishes, as all anxiety departs with the loss of consciousness.

When animals are killed with chloroform, and not too abruptly, there is a stage between the fourth degree and the cessation of respiration in which the breathing is difficult, and sometimes slow and irregular. This I have named the fifth degree of narcotism. It is not every irregularity of breathing which is to be considered indicative of this degree,--for patients occasionally hold their breath for a short time, on account of the pungency of the vapour, and sometimes also, without any evident cause, in the second or third degree; but that need be no source of alarm. The fifth degree of narcotism, on the contrary, is the commencement of dying. I have only met with it in animals. It is sometimes accompanied with convulsive movements of the limbs--a result I never witnessed from ether.

Phenomena attending death from chloroform.

When the animal is made to breathe vapour of chloroform of such a strength that the respiration is stopped in the course of a few minutes, the heart continues to beat for a short time, and the circulation ceases only, as in asphyxia, for want of the respiration, without the heart having been brought under the influence of chloroform. The reason of this, as I explained, with respect to ether, on another occasion,* (*On the Inhalation of Ether, p.81.) is not that the vapour is incapable of affecting the heart, but because a smaller quantity suffices to arrest the respiration, and the process of inhalation ceases, without the heart and blood vessels being narcotized. The two following experiments illustrate and prove these points: --

Exp. 41. -- A nearly full-grown rabbit was placed in a jar containing 1600 cubic inches, with 64 grs. of chloroform, being four grains to each 100 cubic inches. At first it tried to get out, afterwards it struggled involuntarily, and then sank slowly down, and lay, when four minutes had elapsed, in a flaccid condition, breathing naturally. It did not stir afterwards, except from a slight convulsive twitch of its paw once or twice. In three or four minutes more, the breathing became slower, and ten minutes after it was put in, it breathed its last. It was immediately taken out, and the stethoscope applied to the chest. The heart was heard to beat for between two and three minutes, at first nearly as rapidly as before the experiment, but more slowly and less audibly towards the end. The chest was opened a few minutes afterwards, and feeble rhythmic contractions of both auricles and ventricles were observed, not strong enough to expel the blood with which the heart was filled, but not to distension. These contractions continued unabated during the half hour the inspection continued. The lungs were perfectly healthy, and not congested. Next morning the body was rigid, and the blood in the heart and adjoining vessels coagulated. The sinuses in the cranium were filled with blood, and the vessels on the surface of the brain were somewhat injected, but not those in its substance.

Exp. 42. -- Four and a half grains of chloroform were introduced into a jar containing 600 cubic inches, being three quarters of a grain to each 100 cubic inches, and, the vapour having been equally diffused, two frogs were put in. They tried to climb up the side of the jar, as if wishing to make their escape, and one or the other occasionally ceased to breathe for a minute or two, probably from disliking the vapour, but commenced to breathe again. In about five minutes the efforts to escape ceased, and they only moved to adjust their equilibrium when the jar was disturbed. They were now breathing regularly, and continued to do so till about ten minutes after their introduction, when all voluntary power ceased, and the breathing began to be performed only at intervals. They were allowed to remain till half an hour had elapsed, during the last ten minutes of which time no respiratory movement was observed in either of them. On taking them out, and laying them on their backs, the pulsation of the heart were observed on each side of the sternum. These pulsations were more distinct from the lungs being apparently empty. Now an experiment with chloroform on the frog does not necessarily cease with its pulmonary respiration, for it is capable of both absorbing and giving off vapour by the skin. Accordingly I continued the experiment on these frogs, placing one of them back again, in the course of two or three minutes, in the same jar, with three grains of chloroform, and the other in a jar of 400 cubic inches capacity, with five grains. They were laid on their backs, and the heart of the former one, in air containing half a grain of chloroform for each 100 cubic inches, continued to beat distinctly and regularly, 45 times in the minute, for four hours that it remained in the jar, and it was not observed to breathe during the whole time, although it was watched almost constantly. The respiration commenced again within half an hour after its removal. In about an hour it recovered its power of voluntary motion, and it was not injured by the [l]ong narcotism.

The pulsation of the heart of the other frog, in air containing a grain and a quarter of chloroform to each 100 cubic inches of air, became slower and more feeble, and in a quarter of an hour could not be observed. The frog was left in the jar a quarter of an hour longer, and removed when it had been in half an hour. The under part of the thorax was immediately opened sufficiently to expose the heart. It was moderately full of blood, but not contracting at all, and it did not evince the least irritability on being pricked, either now or after exposure to the air for some time. It is evident that the heart of this last frog became paralysed by the absorption into the blood of more vapour, in addition to the quantity that was sufficient to arrest the respiration. The temperature of the room during this experiment was 65.

The effect of chloroform on the heart of the frog is further shewn by the next experiment.

Exp.43. -- A frog was placed in the jar containing 600 cubic inches, with six grains of chloroform. In twenty minutes the respiration had ceased, but the heart continued to pulsate strongly. At the end of three-quarters of an hour the pulsations were more feeble, and had diminished from 40 to 30 in the minute. An hour and five minutes from the commencement of the experiment, no movement of the heart could be observed. The frog was taken out of the vapour, and a portion of the sternum and integuments removed, so as partly to expose the heart, when it was found to be still contracting, with a very feeble undulatory motion. This motion increased in force, and, in a quarter of an hour after its removal, the heart was pulsating regularly and strongly, the ventricle apparently emptying itself perfectly. When the frog had been out twenty minutes, it was placed again in the same jar, with the same quantity of chloroform. In about ten minutes the heart’s action began to fail again, and in about twenty minutes the slightest movement could no longer be perceived in it. The frog was immediately taken out, and the ventricle of the heart was pricked with a needle. In a few seconds a slight quivering was observed,--whether the result of the prick is not certain, and the action of the heart became gradually reestablished as before. It was arrested a third time by exposure to the vapour; and although, in its third removal, the anterior extremities of the frog had become rigid, the heart resumed its action partially, and continued to contract feebly for three or four hours after the rigidity of death had invaded the body and limbs of the animal.* The temperature of the room was 62° during this experiment. (*The setting in of rigidity in the frog is accompanied by a partial change of posture, and the contraction is sometimes strong enough to move the whole body.)

We learned from some of the experiments detailed in the early part of this paper, that the presence in the blood of one twenty-second part as much chloroform as it would dissolve, had the effect of arresting the respiration. From the last experiment we can determine how much it takes to stop the action of the heart. One grain of chloroform, as was stated before, produces 0.767 of a cubic inch of vapour; and at 62°--the temperature during this experiment--air, when saturated, contains 13.8 cubic inches. Therefore 0.767 ÷ 13.8 gives 0.0555, or one-eighteenth of what the blood would dissolve as the quantity which has the effect of arresting the heart’s action.

(To be continued.)

  37. "On narcotism by the inhalation of vapors." (part 6)

Source: Snow, John. London Med. Gazette 42, 13 October 1848, pp. 614-619 (part 6).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 6]

Phenomena attending death from Chloroform.--Post-mortem appearances.--The fatal cases of inhalation of Chloroform.

In my last communication it was shewn, that when an animal of warm blood is made to breathe the vapour of chloroform, well diluted with air, until death ensues, the heart continues to pulsate for some time after the respiration has ceased, the circulation being arrested, secondarily, by the failure of the breathing. It was also shewn, by some experiments on frogs, that chloroform has the effect of directly paralyzing the heart, when it is absorbed in a somewhat larger quantity than is required to stop the respiratory movements. It is possible, indeed, to narcotize the heart of warm-blooded animals by chloroform. When the vapour is exhibited to them in a concentrated form, the breathing and circulation appear to cease nearly together; probably, because the quantity of vapour in the lungs, at the time the breathing stops, is sufficient, when absorbed, and added to that already in the blood, to narcotise the heart. The two following experiments confirm this view.

Exp. 44. -- 120 grains of chloroform were put into a jar of the capacity of 600 cubic inches, which was kept accurately covered with a piece of plate-glass, and moved about to diffuse the chloroform over its sides. In a few minutes the chloroform was all converted into vapour. The temperature of the jar was 65°; the air in it was consequently nearly saturated with vapour, and contained 20 grains in each 100 cubic inches. A young rabbit was put into the jar. It was very quickly affected, and ceased to breathe in less than a minute. It was taken out immediately the respiration ceased, and the ear was applied to its chest, but no motion of the heart was audible. The thorax was opened as quickly as possible, and when the heart was first observed it was quite motionless; but it had not been exposed to the air for a minute, before it began to contract, the auricles beginning to move first, and shortly afterwards the ventricles,--and in three or four minutes it was contracting vigorously. This recommencement of the heart’s action no doubt resulted from the influence of the vapour. Soon after the chest had been opened, a drop of chloroform was allowed to fall on the heart, and its motion instantly ceased, but gradually commenced again in the course of a few minutes, and it continued to contract feebly for some time. The lungs, which collapsed as soon as the chest was opened, were, when first observed, of a vermilion tint. This colour of the lungs is an additional proof that the circulation had not continued after the respiration ceased. There was active vermicular motion of the intestines of the rabbit when they were exposed to the air, soon after death, and a drop of chloroform being put on the ileum at once stopped the contractions at the place of contact, whilst they continued as before in the rest of the intestine. The next morning the body of the rabbit was rigid, and the blood in the heart was coagulated. The right cavities were nearly full, and the left contained a small quantity of blood. The brain was quite healthy, its vessels not being congested.

Exp. 45. -- Two fluid drachms of chloroform were put into the same jar, which was placed near the fire, and moved about till the liquid was all converted into vapour, when the air within was of the temperature of 75°, saturated with chloroform, and containing about 29 grains in each 100 cubic inches. A young rabbit was put in. It first attempted to escape, then gave a little cry, and sank down on its side, and was dead three quarters of a minute after its introduction. It was immediately removed, and the ear applied to its chest, but no sound could be heard. The thorax was opened directly, and the heart observed to be perfectly motionless; but it commenced to contract after its exposure, as in the former ex-[614/615]periment, and in a few minutes was contracting vigourously. The rabbit was placed back again in the jar, in which the vapour was still retained, except a little that escaped during the momentary removal of the cover, and the heart became quickly affected from the absorption of the vapour by its moist surface. Its contractions became more and more feeble, and at the end of four minutes had entirely ceased, and could not be excited by pricking; yet they commenced again spontaneously about ten minutes after the removal of the rabbit from the jar, but were not so strong as before. The lungs of this rabbit were of a vermilion colour when the chest was opened, and the appearances on examination of the body next day were precisely the same as in the former experiment.

It has appeared to me that the respiration and circulation cease nearly together in those instances, also, in which an animal is slowly killed by the inhalation of vapour of chloroform of moderate strength. One experiment will suffice to relate in illustration of this.

Exp.46. -- A cat, which it was requisite to destroy, was placed in a jar holding 800 cubic inches, and a fluid drachm and a half of chloroform was put in, and the jar covered. The cat made efforts to escape for the first minute; it then became insensible, and was affected with spasmodic movements for about half a minute, after which it was quite motionless, and relaxed, and the breathing ceased about two minutes after the commencement of the experiment. It was taken out, and the stethoscope applied to the chest, and the sounds of the heart’s action were distinctly heard. At this moment the breathing began again, and the cat was put back into the jar, from which, however, the greater part of the vapour had escaped. It remained insensible, and the breathing after a time became very feeble, except at intervals, when it was laborious. In little more than half an hour the animal died. It was taken out as soon as the respiration ceased, but no movement of the heart could be heard. Next day the body was very rigid, the right cavities of the heart and the two cavæ were full, but not greatly distended; the left cavities of the heart were nearly empty. All the blood was dark coloured and fluid. The lungs were collapsed and of a bright red colour. They were not congested.

Post-mortem appearances.

As might be expected from these investigations concerning the mode in which chloroform causes death, the post-mortem appearances resulting from it are neither constant nor striking. I have preserved brief notes of the examination of 14 animals killed by chloroform--3 cats, 3 rabbits, 2 guinea pigs, 4 small birds (chaffinches and larks), and 2 mice. In every instance the right cavities of the heart were more or less filled with blood, and in five cases out of the fourteen they were much distended. The left cavities of the heart contained a little blood in every instance in which their state is mentioned. The blood was fluid in one instance-–that of the cat, related above. In the other instances it was coagulated-–generally firmly, but in three or four cases only loosely. The lungs were quite free from congestion in ten of the animals, in the other four they were congested in patches. The head was examined in only eight instances, and in these the substance of the brain was free from congestion, and the sinuses were not particularly distended, except in two.

The fatal cases of inhalation of chloroform.

After seeing how rapidly the vapour of chloroform kills animals when it pervades to a certain extent the air they breathe, and when we recollect that it came all at once to be generally administered without any previous teaching on the subject in the schools, it ought not to surprise us, however much we are called on to deplore the circumstances, that a few cases have occurred, in different parts of the world, in which the exhibition of chloroform has been attended with fatal results; especially when we consider that the vapour has usually been so administered that its strength could not be controlled. Reflecting, indeed, on the mildness and uniformity of the action of the vapour on animals, when more diluted, as shown in some of the experiments related in the first part of these papers, we ought to feel confident that it is capable of being used with perfect safety, certainty, and precision; and this view of the subject agrees with my experience, which has extended now over a great number of cases.

I offered some remarks at the time respecting the fatal case that occurred near Newcastle.* (*Med. Gaz. vol xli. p. 277.) The next case recorded is one at Cincinnati, U.S. in February last.† († See Med. Gaz. p. 79, present vol.) The remarks I made on the Newcastle case apply in great measure to this. Although the chloroform was not administered on a handkerchief, the vapour seems to have been inhaled in too concentrated a form, as its effects were produced very rapidly. The patient inhaled from a glass globe, containing a sponge of considerable size saturated with chloroform. "Breathing at first slow; inhaled 12 or 15 times, occupying from a minute to 75 seconds," and some stumps of teeth were then immediately removed. Now, it takes three or four moderately deep inspirations, and as many expirations, to replace all the air contained at one time in the lungs. Consequently, the patient was made sufficiently insensible for the operation by the effect of about 8 to 12 inspirations, whilst the chloroform of 3 or 4 inspirations more was in the lungs, waiting to be absorbed and increase the effect. I am aware that part of this would be expired again unabsorbed as the patient continued to breathe, but that is equally true of what was inhaled at the previous inspirations; so the fact remains, that the patient must have had from one-third to one-half more chloroform than was necessary to produce what was deemed sufficient insensibility. And according to what I have observed, insensibility to pain cannot be obtained in a very rapid manner without considerable narcotism of the nervous centres-–the third or fourth degree: therefore, that the patient should be in a dying state a few moments after the inhalation was discontinued, was only what might have been expected. The female friends of the patient considered that she died about two minutes after the commencement of the inhalation; and although the dentists who administered the chloroform thought that the patient lived a few minutes longer, yet, even according to their account, she was during this time in a dying condition. According to Mrs. Pearson’s account, which is clear and precise, the pulse became feeble and then stopped, and the breathing ceased about the same time. This agrees with what is stated above respecting the phenomena of death when rapidly caused by chloroform, and with what was observed in the rabbits in experiments 44 and 45.

On inspecting the body, the brain was found to be in a normal state, but the vessels and sinuses of the dura mater contained a larger quantity of blood than usual, which was liquid, and mixed with some bubbles of air. The lungs were considerably, but not intensely, congested. The heart was flaccid, and all its cavities entirely empty. It had been emptied, undoubtedly, after death. Artificial respiration was resorted to, and Mr. Sibson has remarked* that he has often known the heart to be emptied after death by artificial inflation of the lungs. (*Med. Gaz. p. 216, present vol.) Or if the head was first opened, as appears by the order in which the inspection is reported, part of the two or three ounces of fluid blood which flowed from the sinuses of the dura mater might have come from the right side of the heart, as I have seen the blood flow from the chest and out by the lateral sinuses in an inspection in which it was liquid. The blood in the case under consideration was as fluid as water in every part of the body, and the globules were thought to be altered in microscopic appearance. The cause which prevent the coagulation of the blood after death are not yet well understood, and although it is not correct, as was once supposed, that fluidity of the blood is a constant rule in certain kinds of sudden death, yet there are sufficient cases recorded where it was so, to show that it is not uncommon in the human subject when death takes place suddenly. The observations on animals, recorded above, as well as numerous others, show that it is not a characteristic property of chloroform to prevent the coagulation of the blood; and I think that the artificial respiration would assist, in more ways than one, to prevent its coagulation in this case, and one presently to be mentioned.

The next case that we have to notice occurred at Hyderabad.† († See Med. Gaz., present vol. p. 84.) The subject of it was a young woman, who required to have the distal phalanx of one of her fingers amputated.

The surgeon who operated says, "I administered a drachm of chloroform in the usual way--namely, by sprinkling it on a pocket handkerchief, and causing her to inhale the vapour. She coughed a little, and then gave a few convulsive movements." When these subsided, the operation was performed, and endeavours were made to recover the patient, but in vain. Scarcely a drop of blood escaped during the operation, and the surgeon remarks, "I am inclined to think that death was almost instantaneous; for, after the convulsive movements above described, she never moved, or exhibited the smallest sign of life." There was no inspection of the body.

The case which occurred at Boulogne,* is so like to above, that we may consider the two together. (*See Med. Gaz., present vol. p. 76 and 211.) The patient was a female, about 30 years of age, and took chloroform, for the opening of an abscess. M. Gorré, the operator, says, "I placed over the nostrils of the patient, a handkerchief moistened with from fifteen to twenty drops at the most of chloroform. Scarcely had she taken several inspirations, when she put her hand on the handkerchief to withdraw it, and cried with a plaintive voice, 'I choak!' [sic] Immediately the face became pale; (a symptom recorded also of the Newcastle case; and the one at Cincinnati) the countenance changed; the breathing embarrassed; and she foamed at the mouth. At the same instant, (and that certainly less than a minute after the beginning of the inhalation), the handkerchief moistened with chloroform was withdrawn." The operation was performed and then efforts were made to restore the patient, but she was dead; and M. Gorré remarks that the death was without doubt complete at the moment when he made the incision.

From experiments related in former parts of these papers, the conclusion was arrived at, that to produce a degree of narcotism that would arrest the respiration, the blood must contain about one twenty-second part as much chloroform as it would dissolve; and that to narcotise the heart so as to stop its contractility, the blood must contain about one-eighteenth part as much as it would dissolve. By a calculation similar to that made before,* I find that half a fluid drachm is the quantity that there should be in the whole of the blood of a person of average size, to stop the respiration, and 37 minims to arrest the heart’s action. (*Med. Gaz. vol. xli. p. 894.) In the case which occurred in India, a drachm of chloroform was placed on the handkerchief. We cannot easily suppose that more than half of this entered the patient’s lungs, since the expired air carries away a portion as it passes over the handkerchief. And since, as was estimated before, only about half of what enters the lungs becomes absorbed, the remainder being expired again, there could only be about fifteen minims in the blood. This quantity, supposing the young Hindoo female was but half the average size of the adult, and this is not improbable, would only be just sufficient to cause death by arresting the respiration, without immediately stopping the heart’s action, providing the chloroform were equally diffused through the whole of the blood. There is every reason, however, from the symptoms, to believe that the action of the heart was suddenly arrested; and the quantity used in the case at Boulogne would not have sufficed to cause death in any way, if it had been equally mixed with the blood. But it was not equally diffused through the circulation in either case,--there was not time for it to be so. Mr. Sibson, in treating the subject of death from chloroform,† makes some remarks in which I entirely agree. He says, "the poison penetrates to the heart from the lungs in a single pulsation, and at the beginning of the next systole the blood is sent through the coronary artery to the whole muscular tissue of the heart. The blood passing into the coronary artery is less diluted-–is more strongly impregnated with chloroform-–than is the blood in any other part of the system, except the lungs." († Med. Gaz., present vol., p. 109.) By experiments 42 to 45 on frogs and rabbits, it had been shewn that chloroform will act locally on the heart; consequently, if the blood passing from the lungs to the left side of the heart should happen to contain one-eighteenth part as much vapour as it would dissolve, the patient might be suddenly killed before [617/618] the nervous system in general were brought under the influence of the narcotic. A small quantity of chloroform might suffice to produce this result, if the vapour were mixed with only a limited portion of air.

The difficulty of inhaling the vapour in a concentrated form, on account of its pungency, and the further dilution of it when inhaled with the air already in the lungs, no doubt would usually prevent this kind of accident, and are in fact the reasons why it has not more often occurred. Still I believe that the patient is not safe unless the vapour is systematically mixed with so much air that no great quantity of it can be in the lungs at one time. I am of the opinion that ether is incapable of causing this kind of accident; for the blood may imbibe with safety so considerable a volume of its vapour, that the quantity which the lungs can contain at once, adds but little to the effect. And I consider that a patient could only lose his life by ether, from its careless continuance for several inspirations after well-marked symptoms of danger had set in.

M. Gorré says that he poured on the handkerchief not more than fifteen to twenty drops. The drops of chloroform are very small. When dropped from an ordinary phial, nine of them are equal to about two minims, and twenty drops would be less than five minims-–a very small quantity. But, as the chloroform was poured, he probably means as much as would be equal to fifteen or twenty drops of water-–in fact, about as many minims; and, indeed, as it was not measured, we have no means of being certain that there was not more- – say, half a fluid-drachm. However, fifteen minims might be amply sufficient to cause death in the way indicated above, even if but half of it entered the lungs; and the sudden paleness, and almost instantaneous death, clearly indicate that the circulation must have ceased suddenly.

The post-mortem appearances in the case at Boulogne were very nearly the same as in the case which occurred at Cincinnati, previously alluded to. Artificial respiration had been resorted to, and carried to the extent of permanently dilating the pulmonary vesicles. Air was met with in the sinuses of the dura mater in the American case, and in this case a good deal of air was mixed with the blood in the veins of almost all parts of the body. There can be but little doubt that this was a result of the artificial respiration, although one cannot tell precisely in what way the result was produced. The peculiar state of the blood, which was very fluid and dark-coloured, as in the American case, must have depended rather on the suddenness of the death, and the artificial respiration, than on any immediate action of the small quantity of chloroform--a quantity much less than is usually inhaled in a surgical operation.

A patient died whilst taking chloroform during an amputation at the hip-joint, at the Hôpital Beaujon, in Paris. But the death in this instance was probably not entirely due to the chloroform; for although the patient apparently got an overdose of the vapour when it was repeated during the operation, yet, as the pulse was occasionally appreciable for three-quarters of an hour afterwards, he would most likely have recovered, had it not been for the lesion occasioned by the operation, which it seems was never finished. So the four cases previously alluded to, and which happened at Newcastle, Cincinnati, Hyderabad, and Boulogne respectively, comprise the whole of the instances in which it appears to me that death has clearly and undoubtedly resulted from the inhalation of chloroform. There was a death at Aberdeen, but not from the professional administration of the agent. There is another case, however, in which the death is generally attributed to the chloroform; and occurring, as it did, in the practice of Mr. Robinson, who has had great experience, and deservedly earned a high reputation, connected with the administration of ether and chloroform, it has made a great impression both on medical men and the public. My reasons for doubting that death was caused by chloroform in this instance are these:--Mr. Robinson’s servant states, in her evidence, that the inhaler was not applied to the patient's face, but held at a little distance from it; and, with the kind of inhaler Mr. Robinson uses, it is impossible that the air the patient breathed could become strongly charged with vapour in this way; for it would pass into the mouth and nostrils by the side of the face-piece, and very little of it would pass over or through the sponge. Again, the patient was remarking that the vapour was not strong enough, just when the inhaler was removed, and the moment before he suddenly expired.* (*I do not understand why Mr. Robinson was proceeding to add more chloroform, having previously put a drachm and a half on the sponge, as applying the inhaler closer to the face would have made the vapour stonger.)

I consider that he would have made no such remark if there had been a quantity of vapour in his lungs capable of suddenly paralysing the heart. This condition of the patient is totally unlike the coughing and convulsions in the case in India, or the exclamation "I choke," in that at Boulogne. I am not inclined, however, to attribute the sudden death at that moment to a mere coincidence, as it might be occasioned by mental emotion. Fainting is not altogether peculiar to the female sex; and, supposing syncope to occur in a patient who has fatty degeneration of the substance of the heart, and an enlarged liver greatly encroaching on the space of the thorax, one can easily understand why he should not recover. In some of the reports it was stated that the patient did not appear alarmed, for he was laughing and talking the moment before he died; but I do not know why a patient should laugh in a dentist’s operating chair, unless to disguise or try to banish his apprehension. He had been led by his medical attendant in the country to believe that the chloroform would be attended with danger in his case; and again, just the moment before he died, Mr. Robinson was asking him to have his teeth taken out without proceeding further with the vapour. The post-mortem appearances are quite consistent with this cause of death; and, according to this view of the subject, the disease of the internal organs assists to explain the fatal occurrence; but I do not see how it can assist in explaining it, if it be attributed to chloroform, although I am aware that it is usually thought to do so.

If the heart were so thinned that it were in danger of being ruptured by the least distension, or if some of its orifices were so contracted that it could not maintain the circulation under increased exertion or excitement, I could understand how the inhalation might be attended with danger, if excitement and struggling were produced by it, as sometimes happens. And on these grounds I always looked on extensive disease of the heart as a contra-indication, to a certain extent, of inhalation, and have expressed opinions to that effect; but I cannot conceive how a moderate and gradual inhalation of chloroform should cause any person’s heart, however diseased, suddenly to cease beating. There are neither facts nor analogies in support of such an occurrence. Mr. Thomas Wakley, having met with great congestion of the heart and lungs in certain of the animals that he killed with chloroform, and mistaking, in my opinion, the consequence of the mode of dying for the cause of death, had expressed an opinion that this agent would be particularly dangerous in diseases of the heart and lungs; but this case, the only one of those where death was attributed to chloroform, in which any previous disease of these organs was found, cannot be considered to support an opinion founded on these grounds; for here there was no congestion of the heart, and but very little of the lungs. I am happy to find views similar to my own, respecting chloroform in disease of the heart, entertained by one whose opinion, both on account of the attention he has paid to this subject, and his great merit as a physiologist, is entitled to so much respect as that of Mr. Sibson. He says* that "persons the subject of heart disease, when the dread of a severe operation is great, may sometimes be peculiarly benefited by the careful and short production of anæsthesia during the cutting part of an operation." (*Loc. cit.)

(To be continued.)

  38. "On narcotism by the inhalation of vapors." (part 7)

Source: Snow, John. London Med. Gazette 42, 17 November 1848, pp. 840-844 (part 7).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 7]

On the administration of chloroform-–Objections to giving it on a handkerchief--Description of an apparatus.

The conclusion generally arrived at by those who have commented on the fatal cases of inhalation of chloroform, is one in which I do not agree. It has usually been concluded that there is danger necessarily attending the use of chloroform, and that it should therefore be confined to serious operations. Now a great part of the advantage attending the use of an anæsthetic consists in its preventing the patient's dread of the operation; but if the immunity from pain could only be obtained by incurring a danger of sudden loss of life, there would be a new source of fear. Many patients, again, have been readily induced to submit to a necessary operation, through the prospect of undergoing it without pain, who, otherwise, would have withheld their consent either altogether or till the prospect of a successful issue were much diminished. In this way, there is no doubt, many lives have been saved. But if the patient had to choose between pain and a risk, however small, of sudden death, this ready and early consent could not be expected. It is therefore necessary, for the sake of patients undergoing capital operations, to inquire whether there is any means of preventing the pain, which is free from danger, and to employ that means in preference to another. And if the skilful [sic] and careful administration of chloroform were really attended with danger, I would recommend that it should not be resorted to in any case; for we have in ether a medicine capable of affording all the benefits that can be derived from chloroform, and which never caused accidents of the kind we are considering, although it was the first used,--when the knowledge, consequently, of producing insensibility was less.* (*I am aware that ether was thought by some to have caused death in two or three instances in which the patients did not recover from the operation, but died two or three days afterwards; and in one of these instances a coroner's jury returned a verdict to that effect; but I believe the only instance on record in which the inhalation of ether was fatal, was one that occurred in France (see Gaz. Médicale, 4 Mars, and Med. Gaz. p. 432, last vol.), and in that case the inhalation was continued without intermission for ten minutes, although alarming symptoms were present nearly all the time; and it is probable that the result was owing as much to some defect in the inhaler, which limited the supply of air, as to the effect of ether.)

There is, however, no reason to doubt that chloroform is, when administered with care and a sufficient knowledge of its properties, unattended with danger,--or, at all events, with a degree of danger so small that it cannot be estimated;--not greater, for instance, than attends the minor operations of surgery, or the taking of ordinary doses of medicine. When the vapour of chloroform is well diluted with air, it is as safe as ether; and as it possesses some minor advantages over it,--such as being less pungent, and therefore more easily inhaled,--not leaving its odour in the breath for some time afterwards,--being more portable, on account of the smaller quantity required, and producing excitement less frequently in the early stages of its effects,--its use, by all medical men who are perfectly conversant with its effects and mode of administration, is quite allowable in every case in which there is much pain to be prevented.

But, without proper precautions, the inhalation of chloroform is undoubtedly attended with danger, on account of the rapidity of its action when not sufficiently diluted with air, and, also, on account of its effects accumulating for about twenty seconds after it is discontinued, which accumulation would be most formidable, if the air taken into the lungs just before, were highly charged with vapour. The exhibition of ether is not attended with this kind of danger, even if but little precaution is exercised, and the symptoms caused by both vapours being the same, I entirely agree in the recommendation of M. Valleix, physician to the Hôtel Dieu, that medical men who have not practiced anæsthesia should first study it from the action of ether.* (*See Med. Gaz. p. 305, present vol.) This advice will, perhaps, not generally be followed; but if practitioners are inclined to run any risk in administering chloroform before they are well prepared, they must recollect that they not doing it for the sake of preventing the severe pain and shock of the operation, but only to avoid the stronger odour, more pungent flavour, and other little inconveniences of ether.

It is quite obvious, that by merely placing the chloroform on a handkerchief or sponge, and getting the patient to breathe through it, we can have no control over the quantity of vapour in the air breathed. If the handkerchief be not applied close to the face, enough vapour will, most likely, not be taken to cause insensibility; and, if applied closely, the air breathed will probably be almost saturated, and that at a rather high temperature. In three out of the four fatal cases we have considered, the chloroform was administered on a handkerchief; and in the fourth case-–that in America-–no attention was paid to the proportions of vapour and air: the only endeavour appeared to be to make the patient insensible as quickly as possible. The handkerchief is advocated by some practitioners, on account of its supposed simplicity; but whenever I have had occasion to give chloroform in this way, I have felt it to be a very complicated process, on account of the difficulty of getting even an approximative knowledge of what I was doing, by the best calculation I could make.

Before administering chloroform, the surgeon should have as clear and distinct an idea of its vapour as of the blade of his knife; and as this will be read by students as well as practitioners, I shall be excused for introducing a brief explanation of the nature of a vapour. In a popular sense, this term is sometimes applied to the minute globules of liquid suspended in air, which result from the condensation of a vapour that has been mixed with it, as in what is called the steam or vapour from the spout of a tea-kettle. But chloroform cannot be taken in this form; if it were attempted, spasm of the glottis would ensue. A vapour is a dry aeriform condition of a substance differing from a gas only in the circumstances of temperature and pressure under which it takes the liquid to form. The vapour of chloroform has no separate existence under natural circumstances of pressure and temperature, or in any form of inhaler. No patient ever took any of it in this way, or ever will, and this is equally true of ether.*

(*Many practitioners, judging from their writings, seem to have very incorrect notions concerning these vapours. For instance, M. Boux, the eminent French surgeon, in objecting to the use of the handkerchief in the Academy of Sciences, says-–"In this manner the patient inspires the chloroform vapour without air." (See Med. Gaz. present vol. p. 214). Soon after the inhalation of ether was introduced, two veterinary surgeons in London endeavoured to try its effects on a horse in a pure state, and prevented the ingress of air. As they did not make the ether boil, the animal could get not vapour, except what combined with the little air that might get in through the leakage of the inhaler. The horse in fact was burked. The efforts at respiration were prodigious,--it shortly died,--and the heart and diaphragm were found to be ruptured. (See Lancet, April 10, 1847). This experiment has been recently quoted in a pamphlet opposed to chloroform in midwifery, as proof of the injurious effects of ether.)

Chloroform requires a temperature of 140° Fah., under the ordinary pressure of the atmosphere, to make it boil, and enable it to exist in the state of undiluted vapour; but mixed with air, it may have the form of vapour at inferior temperatures: the quantity that may exist in the air varying with the temperature directly as the elastic force of the vapour. The chloroform, in fact, that a patient breathes, is dissolved in the air, just as water is always dissolved in it, even in the driest weather, and the patient breathes his air with two vapours instead of one-–the new vapour being, to be sure, in much the largest quantity. As a proof that these physical considerations are worthy our notice, I may state, that if chloroform had boiled at 180° instead of 140°, its solubility and other properties remaining the same, the four fatal cases we had occasion to discuss would not have occurred.

The following table shews the result of experiments I made to determine the quantity of vapour of chloroform that 100 cubic inches of air will take up at various temperatures: --

The most perfect way of giving a vapour to animals is that adopted in the experiments I have related, the breathing not being interfered with, and the strength of the vapour being accurately known. This method is not applicable to patients, but our endeavour should be to approach to it as nearly as we conveniently can. The apparatus I employ is delineated in the subjoined engraving.* (*It is made according to my directions, by Mr. Matthews, 10 Portugal Street Lincoln's Inn Fields.)

a. Outer case containing water bath, screwed on -- b. Cylindrical vessel into which the chloroform is put; it is lined with a coil or two of bibulous paper up to the point c d. A cylindrical frame which screws into b - – it has apertures at the top for the admission of air, and its lower two-thirds are covered with a coil or two of bibulous paper, which touches the bottom of the vessel b, except where the notches e are cut in it. f. Elastic tube. g. Expiratory valve of face piece; the dotted lines indicate the position of this valve when turned aside for the admission of air not charged with vapour. h. Inside view of face-piece, pinched together at the top to adapt it to a smaller face. i. Inspiratory valve.

When the patient inspires, the air enters by the numerous and large apertures in the top of the inhaler, passes between the two cylinders of bibulous paper, wet with chloroform, through the notches in the bottom of the inner one, then up the centre of the apparatus, still in contact with the paper, and through the short tube, which is three-quarters of an inch wide in the inside. The air thus gets charged with vapour, whilst it meets with no obstruction whatever till it arrives at the inspiratory valve of vulcanized India-rubber, which weighs but a few grains, and rises at the beginning of the slightest possible inspiratory movement. The cylinder of thin brass in which the chloroform is placed is inclosed [sic] in a larger one containing water, which, by supplying the caloric that is removed in the vaporization of the medicine, prevents the temperature from being lowered. It also prevents it from being raised by the warmth of the hand, and thus keeps the process steady. If the temperature of the water be 60°, each 100 cubic inches of air passing through the apparatus might, according to the table above, take up 14 cubic inches, and become expanded to 114 cubic inches, when it would contain a little more than twelve per cent by measure. This is supposing it became quite saturated, which, however, it does not, and ten per cent of vapour, or eight minims of chloroform, is probably as much as the air contains. It is not desirable, however, to give it to the patient even of this strength, and the expiratory valve of the face-piece* is made to move to one side, so as to leave uncovered more or less of the aperture over which it is placed, and admit pure air to mix with and dilute that which has passed through the inhaler. By means of this valve, the vapour may be diluted to any extent, whilst, at the same time, one may have a knowledge of the strength of the vapour the patient is breathing; not exact, to be sure, but practically of great value. The valves in this face-piece act properly, and close of themselves, in every position in which a patient can be placed, except on his face, and even in this posture they will act of the head be turned on one side. (*It is the same face-piece I used in giving ether for three or four months before Dr. Simpson introduced the use of chloroform. By the removal of the peculiar expiratory valve, which is its most important part, and the introduction of a sponge, it has been made to constitute a chloroform inhaler by more than one practitioner. These inhalers are, undoubtedly, better than the sponge or handkerchief; but, besides the want of affording due command over the strength of the vapour, I consider that they are open to objection from the chloroform being so near to the mouth, that some of it might be inhaled, by a forcible inspiration, in the form of minute drops, when it would cause temporary spasm of the glottis.)

The position of the patient and inhaler have nothing to do with the specific gravity of the vapour, as some have supposed. If what the patient breathes were as heavy as the pure vapour, it would impose no appreciable labour on the muscles of respiration to raise it to the mouth; and although the vapour of chloroform is four times as heavy as atmospheric air, it does not increase the specific gravity of the air the patient inhales by more than one-fourth; and, indeed, air charged with vapour of chloroform is not so heavy as when charged with vapour of ether at the same temperature. The most convenient position of the patient taking chloroform is lying on the back or side, with the head and shoulders a little raised, as he is then duly supported in the state of insensibility, and can be more easily controlled if he shall struggle whilst becoming insensible. But there is no objection to the sitting posture, when that is most convenient to the operator.

In the next paper, I shall enter on the details necessary to be observed in giving chloroform in different kinds of surgical operations.

(To be continued.)

  39. "On narcotism by the inhalation of vapors."(part 8)

Source: Snow, John. London Med. Gazette 42, 15 December 1848, pp. 1021-25 (part 8).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 8]

Conditions of the patient which influence the action of chloroform--age--strength or debility--hysteria--epilepsy--renal convulsions--pregnancy--disease of the lungs--of the heart--tendency to congestion of the brain--diet previously to inhaling--- Administration of chloroform in amputations.

Before entering further on the subject of the administration of chloroform, it will be expedient to inquire what are the circumstances, if any, which forbid its use. And experience requires me to make the remark of this substance, which I made last year of ether,--that I know of no state of the patient, with respect either to age, constitution, or disease, which positively contraindicates the use of it, where it is required to prevent the pain of a severe operation, or, I may add, of one the patient greatly dreads. In making this statement, I must not be considered to be recommending the indiscriminate use of chloroform. On the contrary, I consider that everything connected with the patient should be taken into the account, and duly weighed, and the decision arrived at accordingly. And when I state that I have administered chloroform in almost every possible condition in which a patient could require an operation, it must not be considered that I have acted without discrimination, but rather, that going on gradually, and acting on previous experience, supposed objections have one by one vanished, and it has appeared that care in the mode of giving the vapour was the main guarantee, both of safety and success. This view of the subject is entertained by others as well as myself; for, it must be recollected, that I have never given chloroform or ether in an operation, without the concurrence of other medical men.

Chloroform acts more pleasantly, however, on some patients than on others; and we may therefore proceed to consider the circumstances which influence its mode of action. The period of life in which chloroform acts most pleasantly is childhood. In children, under thirteen years of age it scarcely ever causes either mental excitement, or any of the struggling which is not unusual in adults just before insensibility ensues, and immunity from pain is obtained with less narcotism of the nervous centres than in older subjects, as I stated before. It is never necessary to carry the narcotism further than the beginning of the third degree in children, at which time I believe their eyes are always turned up; and very often it is not requisite to carry the effects of the vapour beyond the second degree. Indeed, I have seen a child look about it, with a smile on its face, in the middle of the operation of lithotomy.

In a paper which I read at the beginning of the year, I recommended ether for children, in preference to chloroform, on account of the action of the latter being extremely rapid in young patients; but with the apparatus I described in the last paper, the vapour of chloroform can be so diluted with air as to become as mild and gradual in its action as one pleases, and since I have had small face-pieces suited for infants, I have generally given chloroform, and have administered it to a great number of children, from three weeks old upwards. But when the practitioner is only provided with a handkerchief or sponge, I still consider that the use of chloroform is not perfectly safe, and that ether ought to be employed.

As age advances, the action of chloroform, though equally safe and effectual, is less uniformly pleasant in appearance. In old age, indeed, there is frequently either groaning or a slight degree of stertor, not only during an operation, but even before it begins; so that the effect of the vapour, although quite as satisfactory to the patient, is less agreeable to friends who may be looking on, than in young subjects. I have often exhibited chloroform in extreme old age, and always with the best effects: indeed, I consider that age is not a source of danger when care is taken. Old people are generally rather longer than others in recovering their consciousness, probably because, owing to their circulation and respiration being less active, the vapour requires a longer time to escape by the lungs. They sometimes do not perfectly recover their former state till twenty minutes or half an hour has elapsed from the conclusion of the operation.

The general condition of the patient as regards robustness, or the contrary, has a considerable influence on the way in which chloroform acts. Usually the more feeble the patient is, whether from illness, or any other cause, the more quietly does he become insensible; whilst if he is strong and robust, there is very likely to be mental excitement in the second degree, and rigidity of the muscles, and probably struggling in the third degree of narcotism. This action of the muscles generally occurs when they are well nourished, whilst in the cases in which they are flaccid, and probably pale, it is usually absent.

The special condition termed diatheses, seem to have no regular influence over the action of chloroform, except the hysterical one, and this is apt to occasion a little trouble; for as soon as a patient who is subject to hysteria loses her consciousness, from the effect of the vapour, a paroxysm of the complaint is sometimes occasioned. This, however, can always be subdued by proceeding with the inhalation. But the hysterical state, in a few instances, returns, and becomes troublesome, as the effects of the vapour subsides. In two cases that I have met with, it continued for three or four hours. I saw one case, indeed, in which the hysteria lasted much longer, but it was kept up by the alarm of the practitioner in attendance, who was not well acquainted with the action of chloroform,--had given, I believe, an overdose in the first instance, and afterwards mistook the hysteria for the continued effect of the vapour. I was called upwards of thirty hours after the inhalation, when the anxious attendance on the young woman being discontinued, and some of the usual remedies for hysteria applied, she began to amend, but remained in indifferent health for some time. I believe that one or two cases of continued convulsions after chloroform and ether, related in the medical journals, were cases of hysteria. In trying to estimate how far the provocation of hysteria is a drawback from the benefits of chloroform, it must be remembered that the pain of an operation, and still more, perhaps, the anticipation of it, would cause an attack of hysteria in many patients; and I think the proper view to take of the subject is, that whilst a tendency to this complaint ought strictly to forbid the inhalation for amusement, which was at one time somewhat the fashion, it should not interfere with its use in a painful operation, or in any necessary operation, to which the patient cannot otherwise be induced to submit.

Persons subject to epilepsy are liable to have a fit brought on by inhaling ether or chloroform. This occurred in a young lady who had a tumor of the lower jaw, removed by the late Mr. Liston, and took ether, but I was able to subdue the convulsions before the operation began, by continuing the vapour, and with chloroform, this, of course, could be more quickly accomplished. It was stated, in one of the foreign medical journals, that chloroform is so certain to cause a fit in epileptic persons, that it may be used to detect impostors pretending to be subject to this disease; but Dr. Todd, who has used chloroform with some advantage in the treatment of epilepsy, in King's College Hospital, has informed me that it does not always produce an attack, even when carried to the extent of causing complete insensibility.

I may here mention a case, though not connected with a surgical operation, in which chloroform caused a recurrence of renal convulsions, from which the patient had been suffering: -- A working man, aged about 35, had been in ill health for some weeks before I was called to him on Feb. 19, on account of his being found insensible on the floor. He had in some measure recovered when I arrived, but was in a state of partial stupor, which on the following day was increased, and accompanied with violent convulsions. There was edema of the face and extremities, and his urine was albuminous, scanty, and of diminished specific gravity. He was bled from the arm, and took digitalis of potash, and on the 22nd, had quite recovered from the convulsions and stupor, and the urine was improved. On the 23rd, however, he became affected with delirium cum tremore, and in the evening I administered chloroform to him, having seen it apparently of service in two or three cases of this disorder. It no sooner began to take effect, however, than violent convulsions came on, of exactly the same kind as those with which he had been affected three days before, and accompanied with the same frightful distortions of the features. Although I did not deem it unsafe to continue the chloroform, I thought it more advisable to discontinue it, and to try the effect of opium. The chloroform having been left off, the convulsions almost immediately subsided, and in three or four minutes the patient was in his former state of delirium. He took twenty-five minims of tincture of opium, and the same dose three hours afterwards. He had a good night's rest, the next day was free from the delirium, and he gradually recovered his health. At the time the patient took the chloroform, there is no doubt that his blood still contained a certain amount of urea and other impurities, and the vapour seemed to act as an additional quantity of these impurities would have done, whilst opium had a different and beneficial effect.

Having noticed the general conditions of the patient, it remains to be inquired how far local disease interferes with the action of chloroform; but previously, the state of pregnancy may be noticed. I recollect two instances in which the patients were pregnant. One was that of a lady, about six months advanced, for whom Mr. Rogers removed some teeth. The chloroform had been recommended by her usual physician before I saw her. The other was a patient in St. George's Hospital, less advanced in pregnancy, on whom Mr. H. C. Johnson operated for the removal of a small fatty tumor. The result was quite favourable in both cases. The narcotism was carried only just to the third degree, and I think that care should be taken not to induce very profound insensibility in pregnancy.

Any affection of the lungs that would not prevent a surgical operation, would be no impediment to the administration of chloroform. I have exhibited it in a few cases in which there was evidence of crude tubercles, and in one case in which cavities existed, and the only result was, that the cough was generally relieved for a day or two afterwards. This has generally been the case also in chronic bronchitis, which has existed in a considerable number of patients. There is sometime a troublesome fit of coughing at the commencement of the inhalation, when any pulmonary affection exists, but this soon subsides. I have not seen the least injury to the respiratory organs result from the use of chloroform in any instance.

I have already alluded to affections of the heart, and have little to remark now, except that chloroform, carefully administered, is less likely to be prejudicial than severe pain. The patients, however, should be attended to afterwards, and if the chloroform is followed by sickness and coldness, as happens in a few cases, warmth should be applied externally, cordials given, and, if necessary, effervescing draughts, or an opiate. Patients with heart disease, it is well known, are unfavourable subjects for operation under any circumstances; and if they become infected with an animal poison during or sub-[1023/1024]sequent to the operation, have but little chance of recovery. A man, who had dilatation and thinning of the heart, took ether last year, in St. George's Hospital, whilst amputation of the leg was performed. He was attacked with sloughing phagedena, then prevalent, and died on the seventh day, in one of the cold fits attending the disease, there being apparently not strength enough in the heart to establish a reaction from the rigor. And in the case of a gentleman who inhaled chloroform this last summer for the removal of a tumor, and became affected with erysipelas and diffuse cellular inflammation, the symptoms took on a peculiarly low type, and he died on the fifth day. After death there were found dilation of the heart and thinning of its walls.

As narcotics are usually injurious when there is a tendency to congestion of the brain, it was apprehended by many practitioners that ether and chloroform would be unsafe for such patients; probably the transitory nature of the narcotism induced by inhalation, during an operation, is what renders it harmless. At all events, I have met with no ill results, although some of the patients had suffered from attacks of apoplexy, followed for a time by hemiplegia. This was the case in a man aged 66, on whom Mr. Keate operated, in St. George's Hospital, on the 3rd of August last, for the removal of a tumor situated on the thigh.

It is desirable to give some direction respecting the diet of patients about to inhale chloroform, for if it is inhaled immediately after a meal, there is increased liability to vomiting; and, on the other hand, it is not advisable to inhale after a long fast, for when sickness has occurred in this condition, it has been, in some instances, of considerable duration, and accompanied with more than usual depression. The best preparation appears to be a very moderate breakfast or luncheon two or three hours before the inhalation. The operations in the hospitals are usually performed soon after the patient's dinner hour. The most suitable arrangement in these establishments seems to be, that the subjects of operation should have no dinner, but should have a slender lunch during the forenoon; such as a little bread and butter, bread and milk, or gruel.

Chloroform in amputations

When moving the patient from his bed to the operating table would cause great pain, as in some cases of ulceration of the cartilages of the knee-joint, the chloroform may be administered with advantage, so as to induce insensibility prior to his being moved. In University and King's College Hospitals, I have exhibited chloroform in several cases of this kind, in the wards, previous to the removal of the patient to the operating theatre, and have afterwards given some more of the vapour just before the operation. In St. George's Hospital this has not been required, as patients so situated have been carried to the theatre on their beds. I have sometimes given just enough chloroform or ether to children to produce unconsciousness, merely to prevent the fright they would experience from seeing any of the preparations for an operation.

The position of the patient usually chosen by the surgeon in the larger amputations--that on the back, with the head and shoulders raised--is very convenient for the chloroform. If the sitting posture is preferred for amputations of the upper extremity, it is desirable to have the patient's back well supported, and the legs raised and supported, either on the couch, or another chair; otherwise he will be liable to slide of his seat when insensible. The tourniquet may be put on either before the inhalation, or after insensibility is induced, but, if before, the screw should not be tightened till afterwards. The tourniquet is occasionally applied during the inhalation in the hospital, in order to save time, and then I inform the patient of the nature of what is being done, that he may not be in dread of the premature use of the knife. It is a good plan to let the patient inhale in a comfortable posture, and then to draw him to the edge of the table, when this required, just before the operation is commenced.

If two fluid drachms of chloroform be put into the inhaler that has been described, they will usually more than suffice to last to the end of the operation. The face-piece should be at first applied with the expiratory valve turned aside, and this valve should be gradually moved over the aperture, more [1024/1025] or less quickly, according to the patient's power of inhaling the vapour, without coughing or complaining of its pungency. So long as he is conscious, his feelings should be attended to, and if nervous, he should be encouraged to persevere with the inhalation; but, when no longer conscious, his apparent dislike of the vapour must not prevent its continuance. The majority of patients become quietly insensible without offering any resistance; but, now and then, the patient, on entering the second degree of narcotism, feeling something unusual, and the purpose of it having escaped from his mind, tries to get rid of the apparatus, and it is necessary to hold his hands. Whilst any voluntary motion continues, either in the eyelids or any other part, all that is required is to go on giving the vapour steadily and gradually. It is seldom necessary to close the expiratory opening completely; it is usually sufficient if the valve cover three-fourths of it, and, if the patient breathe deeply it should not be more than half covered. When voluntary motion is no longer apparent, in order to become informed respecting the state of the patient, the eyelid should be gently raised, touching its free border. If he look up, it is evident that the narcotism has not exceeded the second degree. If no voluntary motion be excited, the third degree is probably attained, and if the eye be found turned up, this is pretty certain. But, notwithstanding this, if involuntary winking be occasioned by touching the edge of the eyelid, it is necessary to continue the vapour a little longer before the operation is commenced. In doing so, however, if the narcotism have already reached the third degree, and there be no particular rigidity or struggling, the valve may be opened a little further, so as to give the vapour in a more diluted form, or the inhalation may be intermitted for two or three inspirations at a time. In this way, insensibility of the nerves is obtained, without increasing the narcotism of the nervous centres. As soon as the sensibility of the conjunctiva is abolished, or so far blunted that the free edge of the eyelid, or the eye itself, can be touched without causing decided winking, the operation may be commenced with confidence that there will be no pain, and no involuntary flinching that will interfere with the operation. When there is struggling, or great rigidity, in the third degree of narcotism, it is requisite to continue the vapour a little longer till it subside. If there be any approach to stertorous breathing, the inhalation should at once be suspended, as was stated in a former paper. Stertor, however, never begins till the patient is perfectly insensible. The time occupied in the inhalation is usually from two to three minutes. The operation having been commenced, the medical man having charge of the chloroform should watch the patient's countenance, and if there be any sign of returning sensibility, give a little more vapour during the short time occupied in removing the limb. After the amputation is completed, the vapour need not be repeated until there is decided evidence of sensation. When the arteries to be tied are not numerous, it is requisite to give a little chloroform at intervals, and if cold water have to be applied to stop the oozing of blood, or the flaps have to be united by sutures, it is advisable to keep the patient partially insensible till this is done.

(To be continued.)

  40. "On the use of chloroform in surgical operations and midwifery." 

Source: Snow, John. London Jour. Med 1, January 1849, pp. 50-55.

By John Snow, M.D.

I.--Comparison of Chloroform with Ether.

II. Circumstances which forbid its use, or modify its action.

III. Mode of administering it.

IV. Description of its effects.

V. Results of its employment.

VI. The cases in which Chloroform is applicable in Midwifery.

VII. Directions for its employment.

I. It is now just two years since the news of the Inhalation of Ether for preventing the pain of surgical operations, reached this country; and a little more than a year, since Chloroform was introduced as a substitute for it. The result of experience has been, to show that either of these agents is capable of entirely preventing the pain of the most severe operations; and that when employed with care, and some little knowledge of their effects, they are free from danger. Although nothing can be effected with Chloroform which might not be accomplished by the aid of Ether, yet it possesses, as was stated by Dr. Simpson on introducing it, certain minor advantages,--in being less pungent, more portable, not leaving a disagreeable odour in the breath, and less frequently causing excitement previous to the insensibility; and these properties have been sufficient to enable it to be used, to the almost [50/51] total exclusion of Ether from practice. There are some surgical operations, however, in which I think that Ether should still have the preference. I allude to the reduction of dislocations and strangulated herniæ,-- operations in which complete relaxation of the muscles is required: as this is more easily obtained by the use of Ether. A degree of rigidity of the muscles, which gives place to a state of relaxation, by continuing the inhalation, is liable to be induced by both vapours; but is more frequent and intense, and less easily overcome, under the use of Chloroform than of Ether.

II. Any active inflammation in the head or chest ought, probably, to contra-indicate the use of Chloroform, in the present state of our knowledge respecting it; but, as surgical operations are not undertaken, and parturition seldom occurs, under these circumstances, they can hardly be considered as limitations of its employment. Chronic affections do not appear to offer any impediment to the careful use of it. I have, on three or four occasions, administered it to a patient in phthisis, requiring an operation, and several times when chronic bronchitis existed; when, so far from being injurious, it generally relieved the cough for a time. Disease of the heart have caused more dread of danger from Chloroform than those of any other organ,--especially since the death at Mr. Robinson's. But it appears, from the evidence adduced, that the exciting cause of the fatal event, in that instance, was rather the apprehension of what was about to be done, than the vapour which the patient had but just begun to inhale, in a very diluted state. I have seen Chloroform inhaled, without ill consequences, in several operations where the heart was more or less diseased; and have lately been informed by a medical man, that he had administered it with relief to the difficulty of breathing attending advanced valvular disease. Consequently, if a patient with disease of the heart is obliged to undergo a painful operation, the Chloroform, so far from being probably injurious, is likely to be of the greatest service, by preventing the emotion arising both from the pain and the anticipation of it. But it should be carefully administered, so as to excite the circulation as little as possible; and its effects carried no further, and continued no longer, than is necessary to prevent the severe part of the pain, in order to lessen the risk of subsequent sickness, and the depression which often attends it.

The general conditions of the patient, apart from acute disease, though they modify the action of Chloroform, are no obstacle to its employment or efficiency. I have had to administer it, several times, within a few weeks after birth, as well as in extreme old age, and have seen no ill effects from its use. Children are, indeed, very favourable subjects for its action, as it does not cause in them the excitement and muscular rigidity which are occasionally met with in adult patients; and immunity from pain can generally be obtained, without any thing like coma, whilst they are apparently in a dreaming state. They are quickly affected with the vapour, on account of the activity of their respiration and circulation. This should be borne in mind in practice.

Persons whose strength is somewhat reduced from any cause, also yield more quickly to the influence of Chloroform, than those in robust health. The greatest debility is no impediment to its use. Some of the patients in St. George's Hospital, who have undergone amputations, under both Chloroform and Ether, with a favourable result, were in such a feeble state, that, probably, the operations would not have been undertaken, except for the discovery of anæsthesia.

In patients subject to hysteria, a paroxysm is sometimes occasioned by the vapour, but it can always be quieted by continuing the inhalation.

III. Chloroform is recommended by Dr. Simpson to be given on a handkerchief: but in using such a powerful medicine as this, it is undoubtedly desirable that there should be some better means of regulating the quantity of it, in the air the patient breathes; and three cases have occurred, in different parts of the world, in which the inhalation of it, on a handkerchief, has been suddenly fatal; apparently from the air inspired containing so much vapour, as to impregnate the blood passing through the lungs, so strongly, that it caused paralysis of the heart, on entering that organ, and circulating through the coronary artery. There are several inhalers which permit of more or less regulation of the quantity of vapour. That which I employ, has been described in the Medical Gazette and Lancet. I never give Chloroform without the apparatus, except to keep up the insensibility during operations of the face or mouth, when it cannot be re-applied, and then I use a sponge squeezed out of cold water--putting on only ten or fifteen minims at a time.

The stomach ought not to contain much food when a patient inhales, as it would probably be vomited. The recumbent posture should be chosen when it is suitable for the operation; or if the patient must be seated, it should be on an easy chair, so that he may be duly supported, when insensible. In operations of the anus, lying on the side, with the knees drawn up, is much more convenient, as far as the Chloroform is concerned, than leaning over a table or bed, with the feet on the ground. The vapour should be much diluted at first, in order gradually to blunt the sensibility of the mucous membrane of the air passages, and thus avoid exciting cough.

IV. To facilitate the direction for giving Chloroform; the various effects it is capable of producing on the nervous centres, may be divided into five degrees. The first degree includes the slighter effects that are experienced by the patient, whilst he retains sufficient consciousness to appreciate his situation, and know what is occurring around him. The second degree is the dreaming, or wandering state of the mind, which is observed, when the patient is not silent, immediately to follow the loss of consciousness. In the third degree, there are no voluntary movements, articulate sounds, or anything indicating the presence of ideas; but there may be involuntary muscular contractions, or rigidity. The fourth degree is a state of absolute relaxation of the voluntary muscles, in which no contraction can be excited in them. The breathing is sometimes stertorous in this degree. The fifth degree is the state of impeded respiration observed previous to death, in animals killed by Chloroform. It must be stated, that the various degrees run gradually into each other, and cannot always be clearly distinguished; and that it is seldom necessary to carry the narcotism beyond the third degree, even in the most severe operations. The pulse is generally somewhat accelerated during the inhalation, but it is not a criterion of the action of the vapour.

The greater number of patients become quietly insensible, without offering any resistance; but, in a considerable part of them, there is some excitement, as soon as they lose their consciousness, and it is often necessary to hold their hands. A great number of female patients utter a singing sound at this stage of the inhalation. By continuing to administer the vapour the excitement is soon overcome. When voluntary motion, or talking, is no longer observed, it is desirable to examine the eye, to gain additional information as to the patient's state. If the eye be turned up, it is usually an indication that the narcotism has proceeded to the third degree, and the same is true of congestion of the vessels of the conjunctiva; but these symptoms are not met with in every case. The degree of sensibility of the conjunctiva is a better indication whether or not an operation will cause pain, than any other sign taken alone; but it is proper to take into consideration every symptom that can be observed. When the margin of the eyelid can be touched without causing contraction of the orbicularis muscle, or even when it causes but slight contraction, any operation can be performed without causing pain. As the effects of the vapour, unless very much diluted, continue to increase, for about twenty seconds, after the inhalation of it is discontinued, it is advisable, when the patient is nearly insensible, to intermit the vapour for two or three inspirations, now and then, or to dilute it with more air, if there be a valve for that purpose. Conducted in this way, the process of making the patient insensible usually occupies from two to three minutes; and this is safer than proceeding more expeditiously.

When the operation is not of very short duration, it is usually necessary to give a little Chloroform, from time to time, during its performance. Whilst important steps of an operation are in progress, it is best to prevent the least return of either voluntary motion or flinching; but in the subsidiary and concluding parts, we may wait till there is some clear sign of sensation. The loss of common sensibility generally outlasts the narcotism of the nervous centres, so that during the greater part of a protracted operation, the patient is usually in the second degree--often muttering unintelligibly, or talking in his dreams; and it now and then happens that arteries can be tied, or sutures introduced, without pain, after complete consciousness has returned. The protracted inhalation of Chloroform has a tendency to reduce the temperature of the body, consequently it is advisable to endeavour to keep the patient warm, both during the operation and afterwards; but this, of course, need not interfere with the exposure of the part that has been the seat of operation to the air, or making cold applications to it.

After the inhalation has been discontinued, the patient spontaneously recovers from its effects. Consciousness usually returns in a few minutes, - in some cases suddenly; in others, after a short period of incoherence or inebriation. It is best not to speak to the patient prematurely, but to quietly await the complete return of consciousness.

V. The patient, after a severe operation under Chloroform, is in a calmer and more cheerful state of mind than if he had suffered the pain; and after an amputation he seldom experiences nervous starting of the stump. These are circumstances that cannot fail to contribute to his [53/54] recovery; and as far as statistics of the larger operations have been collected, they are favourable to the practice of anæsthesia.

VI. The objections which have been made to the use of Chloroform in midwifery are nearly all à priori ones, and are capable of being met by replies of the same nature; but a question, concerning a line of medical practice, should be examined and decided on chiefly by experience. There are many labours so favourable, that the patient bears what pain there is cheerfully, and makes no complaint, unless it be for a few moments, whilst the child's head is passing through the external parts. In cases of this kind, which are probably the truly healthy ones, Chloroform does not seem to be indicated, and I have not seen it applied. The cases in which I have administered it, have been protracted, or attended with severe pain, or both these conditions have been combined, or they have been cases in which manual or instrumental aid has been required, and it has always afforded the greatest relief, and been attended with no ill effects, to the mother or her offspring. There was hæmorrhage after the birth of the child in one instance, but the patient had suffered from the same occurrence in previous confinements.

VII. The dose of vapour required at one time, in unassisted labour, is very much less than for a surgical operation. It is only to stop strong uterine action, in order to facilitate turning the child, that a full chirurgical dose of the vapour is required in obstetric practice; for, in instrumental delivery, there is less pain, and less necessity for the patient to be perfectly still, than in operations in which the knife is used. Chloroform should be given in midwifery, as in surgical operations, with an apparatus; or if the medical attendant be unprovided with one, he should put, only ten to fifteen minims on the handkerchief at a time. I feel obliged entirely to dissent from the practice recommended by Dr. Simpson, in the Monthly Journal of Medical Science for October last, of putting three or four drachms on the handkerchief to begin with. I do not dispute that he has tact enough to practice this plan without accident, but I feel sure that it will lead to fatal results in other hands. I also disapprove of his practice of handing over the handkerchief afterwards to the husband or nurse. This method of administering Chloroform is also objectionable from the quantity of vapour that becomes diffused through the air of the room; and from Dr. Simpson's account of the quantity employed, it must cost a shilling an hour more than the plan I employ. This I mention, merely to show that dispensing with the use of an apparatus is not a saving.

When the first stage of labour is tedious and painful, and the patient wearied and desponding, the greatest relief may often be afforded without altogether removing consciousness; and whilst the uterine contractions are not powerful, it is best to give but a very small quantity of Chloroform, or they become suspended, which, however, is of no great consequence, as they soon return. The best way of administering the vapour, is to let the patient inhale a little at the beginning of each pain. Commencing with the inhalation early in labour, does not entail a necessity of continuing it throughout; for the patient, knowing that she can have occasional relief, often bears the pain more cheerfully. And after the Chloroform is discontinued, it exerts sufficient influence, for a time, to counteract the persistent uneasiness there often is between [54/55] the pains, and thus to enable the patient to have short periods of refreshing sleep.

When the pains are stronger, rather more Chloroform can be given, without retarding the progress of the labour, but the effect of it should not exceed the second degree; and except in obstetric operations, the usual symptoms of labour ought to continue. The object should be only to prevent the patient's sufferings by making her unconscious; and whilst articulate complaints and loud cries are prevented, to allow the reflex or instinctive auxiliary action of the respiratory, and even voluntary muscles to continue, accompanied, perhaps, with some moaning. I believe that, with a little management, Chloroform may generally be administered without retarding the labour; and in cases rendered tedious by rigidity of the os uteri, or obstructed by an unyielding state of the perineum, Chloroform shortens the duration of labour very much, by causing the relaxation of these parts. There are instances, also in which a moderate exhibition of the vapour seems to strengthen the reflex bearing-down efforts, which had probably been diminished by fear of the pain.

Chloroform has been given with advantage by Mr. Landsdowne, of Bristol, and others, for the relief of severe after-pains. It may be used for this purpose in some cases where it has not been required during labour.

London, Frith Street, Soho Square, December 1848.

  41. "On narcotism by the inhalation of vapors," (part 9)

Source: Snow, John. London Med. Gazette 43, 9 February 1849, pp. 228-35, (part 9)

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 9]

1. Condition of patients subsequent to amputation under chloroform.

2. They are not more liable to secondary hæmorrhage.

3. Statistics of result of amputations under ether and chloroform.

4. Their administration in minor amputations.

5. In lithotomy.

6. Results of cases of lithotomy.

7. Chloroform in lithotrity.

8. In the treatment of stricture.

9. In operation for necrosis.

10. In the removal of tumors of the female breast.

11. In the removal of tumors of the maxillary bones, and other large operations on the face.

1. In amputations under chloroform, the patient is not only saved the immediate pain of the operation, but generally, also, the greater part of the subsequent smarting; for the common sensibility usually remains more or less blunted for some time after the return of consciousness, and the smarting is often not felt at all for half an hour after the operation, and then but slightly. In a few cases, however, pain is felt in the wound as soon as consciousness returns. In two or three cases in which the smarting was distressing, I have exhibited a little chloroform, from time to time, with complete relief, during the first hour or two that followed the operation; after which the pain shewed no tendency to return. I have tried the local application of chloroform over the wound, in one or two instances, but it was applied external to other dressings, and not much effect was observed from it. The nervous system is tranquilized by the chloroform inhaled during amputations, and the spasmodic starting [jerking] of the stump, that without its use would generally be distressing, hardly ever occurs.

2. One of the reports in circulation, soon after the inhalation of ether was introduced, was, that it gave rise to secondary hæmorrhage--probably some surgeon met with it in one or two cases. Secondary hæmorrhage, however, is by no means common after either chloroform or ether. Although I have administered one or other of these vapours in fifty-seven case of the larger amputations, there has not been secondary hæmorrhage of any consequence, except in two instances, and it has been equally uncommon after other operations. As inhalation prevents the fainting that would otherwise often attend an operation, and generally also stimulates the circulation more or less, we might expect that it would facilitate the tying of all the vessels, and thus be a means of preventing secondary hæmorrhage; and experience seems to confirm this view.

3. Preventing the severe pain of the larger operations may reasonably be supposed to have some effect in diminishing their danger: and as the result of the larger amputations had previously been made the subject of statistical inquiry, they at once suggest themselves as a means of comparing the present with former practice. But a statistical inquiry is evidently incapable of shewing what is the direct effect of the use of chloroform and ether on the mortality resulting from operations. For, if a slight difference should be found, it might be supposed to depend on the altered circumstances under which operations are sometimes performed since the introduction of anæsthetics; as, on the one hand, patients are occasionally induced to submit to them earlier, and when the circumstances are more favourable than they otherwise would be; and, on the other hand, an amputation is now and then undertaken, when the patient is so reduced, or his prospect of recovery from it so bad, that it would not [be] performed if the pain had to be inflicted. Still, it is proper to make a statistical inquiry, as it would be interesting to know whether the use of those agents has any appreciable affect, direct or indirect, on the mortality; and it may assist to dispel the fears of those, if any such remain, who think that the inhalation of them would be attended with notable ill consequences. With this view, I will here give the result of all the large amputations in which I have administered chloroform or ether. Although the number of cases I have to furnish is not large enough to determine this question, it will serve as a contribution towards that object.

The amputations in which ether was the substance employed , were 32 in number, and took place in 1847; those with chloroform were 25. Of these 57 amputations, five occurred in private practice; three of the thigh, of which two ended fatally; one of the leg, and one of the arm, both followed by recovery; 39 were performed in St. George's Hospital; 22 were amputations of the thigh, amongst which were six deaths; 13 of the leg, followed by three deaths; two of the arm, with one death; and two of the fore-arm, both ending in recovery. Eight of the amputations took place in University College Hospital; five of the thigh, all ending in recovery; two of the leg, in one of the which the patient died; and one of the arm, which terminated fatally. Four amputations of the thigh occurred in King's College Hospital, with one death; and there was one amputation of the leg in the Hospital of the Fusilier Guards, performed by Mr. Judd: the patient recovered. The deaths were each occasioned by some well recognized cause, which the inhalation could neither induce nor prevent: generally erysipelas of inflammation of the veins.

The following table shews the result of all these cases together. None of them remain under treatment; and all the patients who did not actually recover are included in the deaths, by whatever cause decease was occasioned:

If the two cases of amputation of the fore-arm be withdrawn, the total mortality will be 27 per cent. instead of 26. None of the above amputations were performed immediately after an accident, but were all either for disease or injuries sustained some time previously.* (*There have been eight amputations in St. George's Hospital performed immediately after injuries, in which ether or chloroform has been administered by one of the resident medical officers. Five of the patients recovered, two died, and one remains under treatment, going on favourably.) The mortality in the above cases is a little higher than shewn in a return by Dr. Lawrie of the amputations (primary ones being excluded) at the Glasgow hospital a few years ago,† (†Med. Gaz. vol. xxvii. p. 394.) but is much lower than a similar return by Prof. Malgaigne, from the Parisian hospitals.‡ (‡ Archiv. Gén. de Médecine, tom. lviii. p. 40.)

In a collection of cases of amputation, from various hospitals, under ether and chloroform, in the Monthly Journal of Medical Science, April 1848, by Dr. Simpson, the morality appeared much lower than in any previous tables; but as Dr. Simpson gave no instructions in his application for the return of amputations, that cases still under treatment should be excluded, there is reason to apprehend that he may have included such cases in his table, some of which may have since ended fatally. The return I furnished to him of operations under ether at St. George's Hospital is not correctly inserted in his table. Against the seven cases of amputation of the leg, there is a cipher in the column for deaths, where the number 1 ought to stand. This death arose from sloughing phagedena of the stump. I conclude that the discrepancy was occasioned by some mistake, and that, as I have mentioned it to Dr. Simpson, it will be corrected in his future tables; for I cannot suppose that it was intentionally withdrawn from the deaths, on account of the disease under which the patient succumbed.

4. In amputations at the ankle-joint, or tarsus, it is of course as needful to give chloroform as when the limb is divided higher up. Amputation of the finger or toe is an operation in which it is generally very desirable to inhale the vapour, as the pain of an amputation by no means diminishes in the same proportion as the size of the part on which it is performed. No particular directions are required respecting the mode of giving chloroform in the minor amputations, as what I have said concerning the larger ones is equally applicable to them.

5. Lithotomy is an operation in which I believe that every surgeon now considers it desirable, if not almost a duty, to have his patient made insensible. The practice of tying the hands and feet together with a bandage, to retain the patient in the required position, is still very properly resorted to. It is better to give the chloroform, so as to remove consciousness, before either the bandaging or introduction of the sound. This is especially desirable in the cases of children, and it is also the best plan in adults, as they begin the inhalation more at their ease. During the bandaging and sounding the effect of the vapour partially goes off, and therefore the inhalation must be resumed for a short time, so as to insure complete insensibility when the incision is made. The symptoms of insensibility were described in the last paper treating of the larger amputations. The patient should not be allowed to recover either consciousness or sensibility till the operation is completed by the extraction of the stone; and therefore, except when the operation is concluded in an unusually short time, it is necessary to give a little vapour from time to time, whenever the eyes shew that the patient is about to wake, or any slight shrinking or moaning indicates the beginning of uneasy sensations. It must not be supposed when there are obscure indications of sensations from time to time during an operation, that there is severe pain of which the patient is unconscious, for the truth is, that sensibility returns gradually, as we learn, by actual observation, in those cases where complete consciousness returns before the common sensibility. Under these circumstances, the patient, when first beginning to feel, describes as something pricking or pinching, measures that would without anæsthesia cause intense pain, and does not yet feel what at another time would be attended with considerable suffering.

6. The cases of lithotomy, in which I have administered ether or chloroform, are nineteen in number, of which fourteen ended in recovery, and five in death. Eight of the operations were performed at St. George's Hospital, the patients being all children. They all recovered but one, and in that case there was extensive disease of the bladder and kidneys, one of which was dilated so as to form a pouch. Five of the cases occurred in University College Hospital, under the late Mr. Liston; two of the patients were children, and recovered, and one--a very old man--died. Two of the cases were in King's College Hospital, both in children, and ended in recovery. And there have been four cases in private practice, all those of adults, three of whom died a few days after the operation, and one recovered. The three patients who died were far advanced in life, and their disease was of long standing. The patient who recovered could not have got through the operation had it not been for the chloroform: such was the opinion of Sir B. Brodie and Mr. Coulson. I alluded to this case in a paper I read last winter.* (*Lancet, Feb. 12, 1848.)

It will be observed that twelve of the above cases were those of children, and that all of them recovered but one, who had a mortal disease at the time of operation; and that of the seven adults, four died. This difference between the mortality of lithotomy in childhood, and in the later periods of life, is in accordance with the usual experience of surgeons. I may remark of the cases that were fatal, that death was the result of causes quite independent of the narcotic vapour, as in all the other cases that I have seen in which operations have ended unfavourably.

7. Chloroform is generally given in St. George's Hospital in lithotrity. As the pain of this operation is usually not excessive, inhalation would not be employed if the surgeons did not feel quite satisfied of its perfect safety, and freedom from all ill effects. I have always seen the operation very satisfactorily performed under chloroform, both in this hospital, and on two occasions when I assisted Mr. Henry Chas. Johnson with it, in private practice. Besides preventing what pain there would be, the surgeons find that the chloroform has the further advantages of preventing the straining efforts of the patient, and enabling them to seize and crush more fragments at one operation than they otherwise could.

The chief suffering from lithotrity is often in passing the fragments; and in dismissing this subject I may allude to the opinion of the late Mr. Liston, expressed to his class in 1847, that the discovery of etherisation would be a reason for choosing lithotomy in some cases, where otherwise crushing th calculus would be preferred, as the former operation at once frees the bladder from irritation, and is now stript of its greatest terror.

8. In the division of the urethra in the perineum, chloroform or ether is of course as necessary as in lithotomy. I have assisted with the inhalation in several such operations. One case may be alluded to here, on account of its important bearing on the treatment of stricture. It was a case in which this operation was about to be performed by Mr. Liston in University College Hospital, but was not required, owing to the relaxing effects of ether on the stricture.

John Willis, aged 42, had stricture of the urethra, caused by an injury twelve years before. He had passed his urine in a very small stream for the last three years, and latterly only by drops, and no catheter could be introduced, although it had been frequently attempted. When the patient was got fully under the influence of ether, a Number 1 catheter was introduced with the intention of passing it down to the stricture, preparatory to dividing it, by an incision in the middle line of the perineum; but it passed right on into the bladder, and the intended operation was not required. This took place on June 18, 1847; the catheter was retained in the bladder till the 23rd, when No. 2 was substituted for it, and subsequently larger catheters, and the patient went out cured on July 27th, being able to pass his urine in a good stream.

9. There are no operations in which the utility of narcotic vapours is greater than in those for necrosis--operations that are generally of considerable duration, and which are amongst the most painful in surgery, on account of the great sensibility of the inflamed bone surrounding the sequestrum. I have given ether and chloroform in nearly thirty operations for necrosis in St. George's Hospital, besides a number elsewhere. The action of the vapour has always been quite effectual in preventing the pain. The majority of the patients were children, and during a great part of the time occupied in the operation narcotism generally did not exceed the second degree; that is to say, there was a dreaming or wandering condition of the mind, and not a state resembling coma.

10. The extirpation of tumors is perhaps the most frequent operation in surgery; but tumors differ so much in size, situation, and every other respect, that there would be no advantage in stating the general result of their removal. Operations for the excision of tumors of the female breast, however, sufficiently resemble each other to admit of such a statement being given.

The number of cases in which I have had to give ether or chloroform, for the removal of tumors of the female breast, involving the gland, is thirty-four. Nineteen of them were in private practice, in seventeen of which the patients recovered from the operation, and in two cases the patients died--one of them of pleurisy, and the other, apparently, of exhaustion. The other fifteen patients were in St. George's Hospital: thirteen recovered from the operation, and two died -- one of peritonitis twenty-four days after the operation, the other of erysipelas.

By far the greater number of these tumors of the breast were of malignant nature. There has not yet been time to ascertain the ultimate effect of the operation on the disease; and, indeed, I am not able to give the results to the present period. The patients in the hospital leave when they have recovered from the operation, and generally are not heard of again; and I only hear now and then, through their surgeons, of some of those in private practice. I am able, however, to state that some of the patients are now in pretty good health, who must long since have died a lingering and painful death if no operation had been performed. Any objection that existed to the removal of malignant tumors must have been greatly diminished by the introduction of narcotic vapours. Each case must, of course, be judged on its own merits; but the number of cases in which an operation may be properly recommended, and in which it will be submitted to, when the whole question is laid before the patient, must be considerably increased by the discovery of the means of rendering it devoid of pain.

11. The only surgical operations that present any difficulty to the total prevention of pain during their performance, are operations of considerable magnitude and duration, which involve the cavity of the mouth or nose, such as the removal of tumors of the maxillary bones. The patient can be rendered insensible before the operation, in the usual way, as easily as in other cases; but the difficulty is in repeating the inhalation so as to preserve the immunity from pain till its conclusion. It is best, in operations of the face, to exhibit the vapour well diluted, so that insensibility may be induced gradually, by which means the fluids of the body get more thoroughly impregnated, and its effects are more permanent. When inhalation of chloroform extends over three or four minutes, and the third degree of narcotism is well established, with insensibility of the conjunctiva, it is generally about three minutes before there are distinct signs of pain from the use of the knife. The effects of ether are, I think, a little more lasting, and therefore it would be preferable in such operations, were it not that chloroform can be more easily reapplied during the operation. To effect this, I drop a few minims of it, from time to time, on a sponge that has been squeezed out of cold water, and as soon as the patient evinces any sign of pain, I apply it near to his mouth and nostrils for a moment, whenever the position of the surgeon's hands, and those of his assistants, will permit. In this way, if the pain cannot all be prevented, the patient can generally be kept so unconscious that he afterwards says that he felt nothing. It is only in protracted operations that the use of the sponge in this way is required, for the greater number of operations are concluded in two or three minutes.

There are some surgeons who think that chloroform in operations involving the mouth, and attended with considerable hæmorrhage, is not altogether free from the danger of blood getting into the trachea. This point requires to be very carefully considered, for whilst it would be improper to run a risk of this occurrence, the pain of large operations on the face is so frightful that the inhalation ought not to be interdicted on mistake grounds. There are good physiological reasons for believing that the sensibility of the glottis would last, under the influence of narcotics, as long as respiration continued to be performed; but the evidence will be that derived from experience. I have seen a great number of operations attended with considerable hæmorrhage into the mouth, in which ether or chloroform has been given, and no ill effects have followed in any case. The result of my observation consequently is, that there is no danger of blood getting into the air passages when these agents are carefully given, and the same attention is paid to the patient's position and breathing that would be in the absence of insensibility. There was one operation at which I assisted last summer, where the patient died soon after it was performed, and as I have heard that a report got abroad, in some parts of the medical world, that death was occasioned by blood entering the air passages, it may here be mentioned:

The patient was a young man, with a large fibrous tumor in the maxillary bone. For some time previous to the operation he had suffered occasionally from haemorrhage from the affected nostril, to an extent which had reduced him considerably. The vapour was given to him rather slowly, with the apparatus I commonly employ, and he became gradually insensible, without previous excitement or struggling. In about three minutes the inhalation was discontinued, the narcotism having reached the third degree. The patient was passive, but the muscles were not relaxed. The breathing was not stertorous. Some teeth were now extracted without causing any sign of pain. A little more chloroform was then given to him, and when the inhalation was discontinued a second time he was in the same state as before the teeth were drawn. The operation was immediately commenced. I took no notes of the method in which it was performed, but can state that the superior maxillary and malar bones of the left side were removed. During the first part of the operation, whilst the flaps were made, the patient was perfectly quiet and silent; but afterwards he began to groan and move his limbs, and he was not again rendered altogether insensible; for although a few minims of chloroform were from time to time sprinkled over a sponge, which was, now and then, held near his face, yet, owing to the hands of the operator and his assistants being in the way, and the cavity of the mouth and nostrils being laid widely open, he got very little of the vapour, and the only effect of it was partially to quiet him on one or two occasions. After the first two or three minutes of the operation the effect of the chloroform never exceeded the second degree. The patient executed voluntary movements of his arms and legs; sometimes it was necessary to hold his hands, and at one time he appeared conscious, for he folded his arms as if making an effort not to raise his hands to the seat of pain. He coughed now and then, and seemed somewhat embarrassed with the blood in his throat. He was seated in a chair, but as there was no window in the operating theatre except the skylight, his head was obliged to be inclined rather backwards. He was leaned forwards once or twice, to allow him to get rid of the blood, and it appeared that he vomited some on one of these occasions. Towards the conclusion of the operation, and at a time when he was very little under the influence of chloroform, he fainted. He was laid down, and brandy was given to him. No more chloroform was administered after this time. He partially rallied from the syncope, but again became faint. The actual cautery was applied, but oozing of blood continued until the moment of death,--about half an hour after his removal into another room. During this interval he was much exhausted; his pulse was small, and difficult to feel. He was tossing himself about in a restless manner, but there was no difficulty of breathing. He seemed quite conscious, doing as he was told, but, of course, could not speak, from the nature of the operation. I left a few minutes before the patient's death. When he ceased to breathe, tracheotomy was performed, and artificial respiration exercised by the opening, with no beneficial result. In my opinion this measure was not indicated, but of course it could do no harm.

After death, portions of the tumor were found still remaining attached to the posterior and upper part of the cavity, and projecting into the foramen lacerum of the orbit and right nostril, as well as in other directions. The trachea and bronchi contained some frothy blood. Numerous small dark spots of congestion were met with in the lung, resulting from some of the small bronchi being filled with blood.

It is evident that the chloroform did not contribute, either directly or indirectly, to this patient's death, for the following reasons:--1st. That the tracheotomy and artificial respiration sufficiently account for the small quantity of blood found in the bronchial tubes. (An eminent physician-accoucheur has informed me that in cases of still-born children, in which he has performed artificial respiration by an incision in the larynx, he has always found blood, after death, in the bronchi.) 2nd. If there had not been this reason for blood in the lungs, it would be more likely to have entered when the patient was moribund, or during the syncope, than at an earlier period. 3rd. That the symptoms did not indicate any impediment to respiration, but were such as I have seen in uterine hæmorrhage, and such as were met with after the removal of the superior maxillary bone by a very eminent operator in this metropolis, before the introduction of ether. 4th. That if the judicious use of chloroform caused a liability to the entrance of blood into the bronchi, there would have been some symptoms of it in the numerous patients who have recovered from similar operations in the narcotized state; but such is not the case. And 5th. That the quantity of blood met with in the lungs was not enough to cause rapid death.

In dismissing this case, I wish to state my belief that the operation was a very proper endeavour to cure the patient of a disease that must inevitably have been fatal in a short time; and that my reason for alluding to it is, that if I should leave it unnoticed, in treating of chloroform in operations on the face, I might be suspected of keeping back a material fact.

I will now enumerate the other operations, for the removal of larger tumors of the jaw, in which I have exhibited narcotic vapours.

In May 1847, Mr. Liston removed a large tumor of the lower jaw, in a young lady, dividing the bone far back, near the rami, on each side. He was assisted by Mr. Morton, Mr. Cadge, and others. The patient took ether.

On December 23, 1847, Mr. Henry Charles Johnson removed one of the superior maxillary bones of a young man, in St. George's Hospital, for a large tumor. This, and the remaining patients, inhaled chloroform.

A few days after the last operation, Mr. Fergusson removed a large tumor of the lower jaw, occurring in a gentleman. Sir B. Brodie was present.

Early in January 1848, Mr. Fergusson also removed a large tumor of the upper jaw of a middle-aged woman, in King's College Hospital. The tumor has been removed once before, but had returned.

In May last, Mr. Tatum removed a very large tumor of the lower jaw of a Spanish gentleman, in St. George's Hospital, dividing the bone near its symphisis, and disarticulating it on one side.

In November last, Mr. Fergusson removed a tumor of the superior maxillary bone in a little girl, in King's College Hospital.

In the same month, Mr. Fergusson also removed a tumor of the lower jaw in a young man, a patient in the same hospital.

The above patients all recovered favourably from the operation.

I have seen chloroform and ether employed, also, in a number of other operations in which a good deal of blood flows into the mouth and throat; such as operations for epulis, and polypi of the nose. Sometimes the patients can be observed to swallow the blood, with an act of deglutition; but usually it seems to flow down the pharynx and esophagus without distinct muscular effort; and if the quantity of it is not very large, it does not in any way interfere with the glottis.

When infants are laid on the back, during the operation for hare-lip, the blood is swallowed, whether they are narcotized or not; and when they are insensible, it goes down with less appearance of choking than when they are crying from pain.

  42. "On narcotism by the inhalation of vapors," (part 10).

Source: Snow, John. London Med. Gazette 43, 16 March 1849, pp. 451-56 (part 10).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 10]

1. Ether and Chloroform in operations on the teeth;

2. on the eye;

3. on the anus;

4. on the back.

5. Inhalation to facilitate the reduction of hernia;

6. of dislocations;

7. to aid diagnosis;

8. to save the moral feelings of the patient.

9. Occasional sequelæ of inhalation-–sickness;

10. its treatment.

11. Headache.

12. Hysteria.

1. Teeth. Chloroform is, I believe, not very generally employed in tooth-drawing in this metropolis. This is partly [451/452] owing to the circumstance, that the pain occasioned by the operation, though severe, is usually but momentary; but another reason appears to be, that the majority of dentists are not sufficiently acquainted with the application of the medicine to be satisfied that they can use it with perfect safety, and it is not always convenient to the patient to have another medical man present. It is only in the cases of children and very nervous persons, who have not resolution to keep the mouth voluntary open for the operation, that narcotism facilitates the work of the dentist; in other cases it adds to his trouble, and occupies more of his time. The introduction of ether and chloroform has been of service to the dental profession, having increased the practice of many of its members by relieving the springs of industry from the incubus of the dread of pain; for a number of the operations under these vapours would not have been performed except for their use. I allude to many of the cases in which the mouth is "cleared," as the term is, of a number of decayed teeth, and stumps of teeth, to make room for a set of artificial ones-–a process which is now generally performed at one or two sittings, without any pain, and which cannot fail to be, ultimately, of great benefit to the patients.

It is desirable not to carry the narcotism further than the third degree for the extraction of teeth, and in this stage there is generally some rigidity of the muscles of the jaw, but this can nearly always be overcome by pressing the chin down. It has been recommended that a wedge should be placed in the mouth before the inhalation, but I have never seen it necessary to have recourse to this plan, as I have always been able, with the assistance of the operator, to get the patient's mouth open. The few instances in which the mouth could not be at once opened were cases in which voluntary power was exerted under a dreaming condition of the mind, and in these cases the exhibition of a little more of the vapour enabled the desired object to be effected. There was one instance in which the addition to the dose of vapour was prevented by hysterical symptoms, till the lady recovered her consciousness, and then she had sufficient courage, and preferred to have her tooth removed without the repetition of the inhalation, which there is no doubt would have been effectual, as in every other case that I have seen. As it was, the pain was probably diminished. It has always appeared to me that there was a diminution of muscular power under the effects of chloroform and ether, in every variety of their operation; the voluntary efforts under excitement are much less powerful than those of an exasperated individual in an unnarcotised state, and the involuntary rigidity in the third degree is still more easily overcome. As there is usually less rigidity from the use of ether than chloroform, the former would be preferable in tooth-drawing, were it not for the strong odour that it leaves in the breath for the rest of the day. When teeth require to be removed from both jaws, those in the lower one, especially if they be molars, should be first extracted; otherwise, as the patient is unable to wash out his mouth, the blood will render them obscure. To clear the mouth of blood, whilst operating on the teeth of the lower jaw, it is sometimes desirable to use a sponge squeezed out of warm water. If the sensibility is found to be returning before all the teeth are extracted, the inhalation must be resumed for a short time before proceeding further. There is sickness after the use of chloroform in some instances of dental as of other operations, and it is here felt to be more annoying than after a great operation where the patient is necessarily an invalid. I shall have to speak of the treatment of sickness further on.

I am not an advocate for the use of chloroform in every instance of tooth-drawing, but I do not see how any rules can be laid down respecting its employment, as a good deal must depend on the wishes of the patient as well as on the presumed severity of the operation. One point, however, should be imperative, viz. that chloroform should not be given except by medical men who have made themselves well acquainted with its effects and mode of application. I have a strong feeling that severe pain ought not to be inflicted on children, since the means of preventing it have been discovered and act so favourably on them; and therefore, when a tooth is to be removed that is firmly fixed, I think that a child should be made insensible whenever there is the knowledge requisite to effect this with perfect safety.

2. Eye. In most operations on the eye, narcotism is of essential service. In the operation for strabismus, the amount of pain to be prevented is considerable; and as the patients are usually children, who would offer all the resistance in their power, the proceedings of the surgeon are very much facilitated, as Prof. Miller, of Edinburgh, has recently remarked.* (*Surgical Experience of Chloroform.) Chloroform or ether may be given with advantage to children, in operations on the eye unattended with pain, merely for the purpose of keeping the patient and the eye motionless. I have given the vapour of one or other of these medicines several times for Mr. Cæsar Hawkins and Mr. George Pollock, whilst operating on congenital cataract by the method of drilling. Two or three of the latter gentleman's patients were only a few weeks old. The operation was facilitated in all the cases. In the excision of cataract, it is not advisable to administer ether or chloroform, for if vomiting should be induced it would be likely to cause serious mischief; and although vomiting is not a frequent result of inhalation, when precautions are taken to prevent it, yet it is impossible, I believe, to predict with certainty in any case that it will not occur.

3. Anus. Operations on the anus are frequently required, and they are of a very painful nature, on account of the great sensibility of the part. It was the practice of most surgeons before the introduction of inhalation, to have the patient standing on the floor, in a stooping posture, and leaning over a table or bed; but this attitude could scarcely be maintained in a state of insensibility, and therefore the practice now is to let the patient lie on his side with the knees drawn up towards the abdomen; or when that is more convenient to the surgeon, the patient can lie on his back, as for lithotomy. The chief operations on the anus are that for fistula, the excision of hæmorrhoids, and the cutting away of loose folds of integument from the verge of the anus, for the cure of prolapsus. It is necessary to have the patient completely insensible in operations on this part, more especially in that for fistula, as any involuntary flinching during its performance would be a serious inconvenience.

4. Back. For the removal of tumors from the back, and the performance of any other operations in that situation, it is best to let the patient inhale whilst lying on his side, and when he is insensible to turn him over, in a great measure, on his abdomen, allowing his head to remain in its former position on the pillow: in this way the inhalation can be repeated, if required, during the operation.

It is unnecessary to enumerate other operations, as they do not require any special directions, as regards the chloroform or ether. There are some cases to be mentioned, however, in which narcotism is attended with signal benefits, in addition to the prevention of pain.

5. Hernia. There have been several cases of strangulated hernia, in which the inhalation of ether or chloroform has enabled the bowel to be replaced by the taxis, after previous efforts had failed, and where an operation must otherwise have been performed. I am not aware how soon etherisation was employed with this happy result, but the earliest case that I find recorded is that of a patient of Mr. White, in the General Hospital, near Nottingham: it occurred on March 22nd, 1847, and the ether was administered by Dr. Sibson.* (*See Med. Gaz. Vol. xi. p. 1009.) On July 10, 1847, there was a similar case under the care of Mr. Stafford, in the Marylebone Infirmary.† (†Med. Gaz. Vol. xi. p. 115.) On March 6th, 1848, a man, James S., was placed upon the operating table, in St. George's Hospital, with a strangulated inguinal hernia: I administered chloroform to him at the request of Mr. H. C. Johnson, who had the treatment of the case; and when the patient became completely insensible, and the muscular system relaxed, the hernia was readily reduced by means of the taxis, although it was previously quite incapable of reduction. If the taxis had not been successful, the operation, for which the instruments were arranged ready, would at once have been performed, whilst the patient was still insensible. In the case of another patient, a woman with femoral hernia, who was placed on the table immediately afterwards, Mr. Johnson performed the operation as soon as she was rendered insensible, without employing the taxis, being deterred by the tense and inflamed condition of the tumor. This case ended favourably, as well as the former one. There are several other cases recorded in the medical journals of this and other countries, besides the three above enumerated, in which the use of ether or chloroform has enabled the surgeon to reduce a strangulated hernia without the operation.

6. Dislocations. Narcotism by inhalation facilitates the reduction of dislocations of the bones, besides preventing the pain of the process; and it has enabled the surgeon to reduce dislocations of long standing, which could not otherwise have been relieved. On June 24, 1847, Mr. Tatum reduced a dislocation of the shoulder of ten weeks' standing, with the aid of the pullies, in St. George's Hospital, whilst the patient, Richard R., aged 31, was under the influence of ether. The dislocation, which happened in the country, had been first overlooked, and when detected, could not be reduced. On February 7th, 1848, a dislocation of the femur into the ischiatic notch, which had existed for about three weeks, was reduced with the aid of the pullies, in the same hospital, by Mr. H. C. Johnson; the patient, Patrick C., an Irish labourer, being made insensible, and his muscles being relaxed, with chloroform. Three days afterwards, Mr. Tatum reduced a dislocation of the hip, in the hospital, of five weeks' standing; the patient, Joseph G., a working man, being put under the influence of chloroform. I have also given the vapour, in St. George's Hospital, in some cases of old dislocation, in which the position of the parts has been improved by the efforts made during the state of insensibility and relaxation, although their condition did not admit of complete reduction: two cases of dislocation at the elbow-joint were of this nature. Some cases of recent dislocation have been reduced under the influence of narcotic vapours, when previous attempts at reduction had been unsuccessful. Two cases of dislocation of the thigh-bone, in which Dr. Sibson administered ether, at Nottingham, were of this nature. One into the ischiatic notch, reduced by Mr. White, April 7th 1847; the other on the dorsum ilii, reduced by Mr. Caunt, May 31st, 1847.* (*See Med. Gaz. Vol. xi. p. 1009.) I assisted Mr. H. C. Johnson by giving chloroform to a gentleman with a recent compound dislocation of the last phalanx of the thumb backwards. The previous efforts at its reduction had failed, on account of the pain occasioned by them being more than the patient could bear. When he was rendered insensible, the dislocation was soon reduced.

Chloroform was given in many of the above cases because it was in use at the time, and could be employed without the delay that getting the ether ready would have occasioned. It answered very well; but it is my opinion that ether is preferable, both in dislocations and strangulated herniæ, as it induces relaxation of the muscles more easily, and with less previous rigidity.

7. Aid diagnosis. The artificial production of insensibility is frequently of the utmost service in assisting the surgeon to form a diagnosis. I gave ether for this purpose at the request of the surgeons to St. George's Hospital, in February, 1847, to a little girl with disease of the knee and abscesses in the thigh. In this case, the great tenderness of the parts, and the nervous agitation of the patient, precluded every attempt to examine the state of the limb in the usual manner; but when the patient was rendered insensible, the condition of the limb was ascertained sufficiently to enable the surgeon to determine on amputation, which was performed on February 25th, by Mr. Henry James Johnson, the patient being again placed under the influence of ether. In several other cases of diseased joint and diseased bone, ether and chloroform have been employed in this hospital, to aid diagnosis in a similar manner. In sounding for stone, especially in children, it is of service to render the patient unconscious. I administered ether for this purpose in St. George's Hospital, as early as February 3rd, 1847, whilst Mr. Cutler sounded a little boy, aged four years. Dr. Thomas Smith, of Cheltenham, applied ether about this time, viz. on February 22nd, to [454/455] enable him to ascertain the state of the corneæ of a child labouring under strumous ophthalmia.* (*See Med. Gaz. Vol. xi. p. 676.)

8. Feelings of Patient. There are many operations on the female which medical students could seldom witness except at the expense of some shock to the feelings of the patient. They are now generally conducted in the hospitals in this wise:--The patient inhales and becomes insensible whilst only one or two surgeons and the nurse are present in the private ward, or behind the screen with her: the students then come in and witness the operation, and go away again before the consciousness of the patient has returned. In some operations in private practice, where the surgeon requires two or three assistants, they are not brought into the room till the patient is insensible, or she is made insensible in an adjoining room, and carried to the place selected for the operation.

9. Sickness. Narcotism by chloroform or ether, to the extent required in surgical operations, occasionally leaves some effects after the immediate influence of the vapour has subsided: these may be called sequelæ. I have not observed that they are more frequent after one of these agents than the other. The only after-effects of inhalation with which I am acquainted are sickness, headache, and hysterical symptoms in those predisposed to hysteria.

Vomiting is apt to occur during the narcotism, or just afterwards. It can be rendered less frequent by the precaution previously mentioned,† of not allowing the patient to inhale soon after a meal, and also not carrying the narcotism further, if possible, than the third degree,--thus avoiding stertor and complete relaxation of the muscular system; but I believe that it cannot always be prevented by all the care that can be used, more especially if the inhalation have to be repeated, in order to keep up the insensibility for more than a few minutes. (†Last Vol. p.1024) The vomiting no doubt depends on the action of the narcotic vapour on the brain, and is allied to that occasionally caused by opium and alcohol, and to that which occurs in some morbid conditions of the cerebrum. If the patient recover completely from the immediate effects of the vapour, without any feeling of sickness, he is not liable to it afterwards from that cause; and, in the greater number of cases in which vomiting does occur, the sickness goes off in a few minutes, and does not return; but in a few instances it continues for several hours, if nothing be done to relieve it, and in two or thee cases it has lasted, under these circumstances, for two or three days. I have met with more or less vomiting in about one-fifth of the patients operated on, under chloroform, during the last six months: many of them, however, had received no previous directions respecting their diet. The number of cases in which there has been troublesome sickness has been one in twenty-six operations during the same period. I have never found the sickness continue more than five or six hours when I have been taking measures to relieve it.

Diminished temperature of the surface generally accompanies the sickness: indeed, the depression of the respiration and circulation attending it has a tendency at all times to lessen the development of animal heat. But chloroform and ether, I am quite satisfied, have also the effect of diminishing the production of caloric, quite independently of their action on the respiration and circulation; and, when inhalation has been kept up for some time, I have remarked the patient to become rather cold in cases where no sickness was present.

10. Treatment. When sickness has continued after the immediate effects of the vapour have subsided, and the stomach has been quite emptied by vomiting, I have generally found that a little wine or weak brandy and water has removed the sickness. When the patient is cold as well as sick, warm wine and water, or brandy and water, are preferable; and other measures to restore warmth should be resorted to, such as warm covering, drawing the sofa near the fire, if it be winter, or applying a feet-warmer, if the patient be in bed. In two or three cases these measures did not afford relief, and ten or twelve minims of Battley's solution of opium were given, with the effect of completely and permanently removing the sickness: these, of course, were adult patients, and I have not found sickness continue very long in children. The horizontal posture should, if possible, be preserved till the sickness has subsided, and for some time afterwards. It is desirable, indeed, to let the patient remain, without being moved or spoken to, till the narcotism has completely passed off, in every instance where it is practicable. The necessary removal of hospital patients from the operating theatre immediately after the operation causes sickness in many cases where I believe that it would not otherwise come on. I have not perceived any appreciable benefit from effervescing draughts, and I have not had occasion to try hydrocyanic acid or creosote. The application of ammonia to the nostrils sometimes seems to refresh the patient, but internally I think it is not so beneficial as wine.

The wine and opium recommended above are not given to combat the direct effects of chloroform, and should not be administered till the immediate influence of the vapour has subsided, unless it be the former, when it is required to remove faintness from loss of blood, which, however, seldom happens during narcotism. The opium probably acts by removing irritability of the stomach, occasioned by the vomiting, which was induced in the first instance by the state of the brain.

11. Headache. Headache is not a common result of inhalation: few instances in which I have heard it complained of, occurred in persons in good health and inclined to plethora, and passed off spontaneously.

In describing the circumstances that modify the action of narcotic vapours, it was stated* that, in the hysterical diathesis, inhalation was liable to induce a paroxysm of the disorder, which might recur as the narcotism was diminishing. (*Last vol. p. 1022.) This usually soon subsides, but there are a few cases in which it remains troublesome for two or three hours. I have seen hysteria two or three times in the male, after ether and chloroform, in patients who had previously had the complaint. I have not found it to require any treatment, except in the case mentioned before;† and if it do, it should be treated in the usual way. (†Loc. cit.)

12. Hysteria. My own experience of hysteria, as a sequela of inhalation, is, that it forms no great impediment to its employment. Mr. Tomes,* however, has related three cases with which he had been made acquainted, where the disorder was more lasting and troublesome; and one case in which the use of chloroform was followed by worse effects than hysteria, viz. delirium, and subsequently an occasional vacancy in the patient's manner, leading her medical man to forbode insanity, sooner or later. (*See Review in Med. Gaz., last vol. p. 545.) In this last case, however, the patient had an overdose of the vapour, having been "almost pulseless-–scarcely breathing," with a ghastly countenance. The chloroform was given by a dentist who evidently did not understand its effects, having first asserted that the lady was "under its full influence," when she, in fact, heard what he said, and then having given an overdose. The case only confirms a maxim, now beginning to be better understood than when chloroform was first suddenly brought into universal notice-–viz. that it ought not to be used except by medical men who have studied its effects.

(To be continued.)

  43. "On the discussion respecting chloroform, in the Academie de Medecine de Paris."

Source: Snow, John. London Journal of Medicine 1, April 1849, pp. 324-326.

By John Snow, M.D.

The original conclusions arrived at by the Commission appointed to investigate the fatal case at Boulogne, and the general question of the safety or danger of chloroform, were ultimately adopted by the Academy, with very slight alteration (as was shown in the abstract of the proceedings in the last number of this Journal), but not till they had met with a very stout opposition, more particularly from MM. Blandin and Jules Güérin. With the first conclusion, which acquits chloroform of the death of M. Gorré's patient, I cannot agree, any more than these gentlemen, and a number of other speakers. The Commission commenced their investigation, with the assertion that chloroform always produces intoxication and insensibility before death; and their reporter, M. Malgaingne, adheres to their opinion to the end, in opposition to all contrary evidence, and even denies that chloroform can cause death by its direct action, and especially by poisoning.

Now the truth is, that the vapour, when inhaled of a certain strength, is just as sure to cause sudden death without premonitory intoxication or insensibility, as it is to cause its ordinary beneficial effect when inhaled of another strength, or to fail altogether of its desired action, if diluted beyond a certain point. I have several times made animals -- small birds, mice, and rabbits--breathe air saturated with vapour of chloroform at the ordinary room temperature of the atmosphere and the consequence has always been, that after attempting for a few seconds to escape from the capacious jar in which they were inclosed [sic], they suddenly exhibited signs of distress, and died without any interval of intoxication or insensibility, in periods varying from less than half a minute to a minute after their first exposure to the vapour. In these experiments, not more than one-sixth part of the air was displaced by the vapour diffused through the remainder. The vapour of chloroform never acts, as supposed by the Commission, by excluding the air, and so producing asphyxia. This is physically impossible. The same quantity of vapour of ether in the air causes a much slighter effect; and, of some vapours, a scarcely appreciable influence, even when the air is quite saturated with them. Chloroform acts by its narcotic properties alone; and when inhaled of the strength employed in the above experiments, it paralyzes the action of the heart at the same time as the respiratory movements. In two experiments of this nature previously related,1 I found the blood in the lungs still florid, immediately after death. (1 Medical Gazette, October 13, 1848.

In the case at Boulogne, artificial respiration was performed for upwards of an hour after death, and with force enough to cause permanent dilation of the air cells. At the subsequent inspection of the body, air was found in the pulmonary veins, in the heart, in the right carotid artery, and in the veins generally; a little frothy blood being found at the orifice of the vena cava. The conclusion of the report which has been adapted by the Academy, is, that death was probably caused by this mixture of gas with the blood. The report does just notice the idea that the air might have entered during the artificial respiration, but adds that this would not explain the cause of death, having prejudged, that it was not the narcotic action of the chloroform; and goes on to state that the froth at the orifice of the vena cava proves that the air entered during life, entirely overlooking the fact (and I do not see it alluded to by any of the speakers), that the froth would be produced by the churning of the blood backwards and forwards in the large vessels, during the artificial respiration which had introduced the air. The Commission suppose that the air or gas was suddenly developed in the vessels by some unknown cause, and curiously the speakers who oppose their conclusion, admit this sudden evolution of gas, but attribute it to the chloroform--to a peculiar action of ether on the blood. This is the weak point in their argument, for M. Malgaingne justly replies that this is only hypothesis.

One fact of importance has been brought to light by this inquiry. In the report previously published, it was stated that not more than from fifteen to twenty drops of chloroform had been employed; but by a judicial examination of what was left in the bottle, it was found that from five to eight grammes had been used--from 77 to 123 grains, or from one to two tea-spoonfuls, a quantity amply sufficient to cause death.

After thus treating the special case submitted to them, it is not surprising, that the conclusions of the Commission on the general question are vague and unsatisfactory. Part of them are commonplace remarks in which everybody agrees; but in what danger really consists, and how it is to be avoided, is nowhere pointed out. They state: "there is risk of asphyxia when the anesthetic vapour is not sufficiently mixed with air." The risk is not one of asphyxia, but of over-narcotism, which according to circumstances, may cause death by paralyzing the respiratory movements, and so bear a certain resemblance to asphyxia, or may arrest the action of the heart, and so resemble syncope. They lay down, as a rule: "To take care, during inhalation, that a sufficient quantity of air be mixed with the chloroform, and that respiration be entirely free"; but they do not state what is a sufficient quantity of air; whether 75 parts air to 25 vapour is sufficient, or whether it should be 95 parts air to 5 of vapour, we are left entirely in the dark. The truth is, it ought to be somewhere about the latter quantity, and the vapour cannot ever be breathed with safety in larger proportion than 10 parts by measure to 90 of air. The conclusion of the Commission means no more than that there should be sufficient air for the purposes of respiration, and this is a fatal mistake -- I say fatal, for there has been a death from chloroform in France, since the adoption of the report by the Academy. It occurred in a public hospital, and would, in all probability, have been prevented, by a different line of conclusions on the part of that learned body. The chloroform in this case was applied on lint, which was placed loosely over the mouth and nostrils. There was no impediment to free respiration, but the man suddenly expired, as in the previously recorded cases; and so long as so powerful an agent as this is given with no better means of regulating its strength than a handkerchief or sponge, such melancholy cases cannot fail, now and then, to happen. Many patients, who have not suffered, have narrowly escaped; several cases of syncope from chloroform were mentioned in the late discussion, and they have frequently occurred in this country under the use of the handkerchief, although it is not part of the action of chloroform, when carefully given, to cause syncope. The pulse may become small on account of struggling or altered breathing; and when sickness follows the inhalation, there is often a degree of depression attending it, but never sudden fainting, which, if caused by the vapour, must depend on a near approach to paralysis of the heart.

The last recommendation of the Academy is judicious enough, "to suspend the inhalation as soon as insensibility is procured", etc., but unless there be some means of regulating the strength of the vapour, there may be a dangerous increase of the narcotism after the inhalation is suspended, owing to absorption of a large quantity of vapour that may be present in the lungs at the moment, and which will take about twenty seconds to get absorbed and reach the brain; thus accumulating the effect during that period.

M. Roux remarked, that if he supposed it necessary to take all the precautions recommended by some surgeons, he would for ever renounce the use of chloroform. I would reply, that those who are not willing to take very great precautions in using this powerful medicine, should employ ether, in the use of which, danger can be avoided by only moderate precaution, as it cannot act so swiftly as not to give due warning.

54, Frith Street, Soho.

  44. "On narcotism by the inhalation of vapors," (Part 11).

Source: Snow, John. London Med. Gazette 43, 8 June 1849, pp. 983-85 (part 11).

By John Snow, M.D.

Vice-President of the Westminster Medical Society.

[Part 11]

The combination of chloroform and ether--of chloroform and alcohol--Chloric ether--Strong chloric ether--New mode of inhaling vapours.

It has been shown in former parts of this essay, that the action of chloroform can be rendered perfectly mild and safe by diluting it sufficiently with air. If the properties of this body were such, or if another body could be met with having such properties, that the relation between its intrinsic power and its volatility would prevent the air from taking up so much vapour, under the usual circumstances of temperature and pressure, as could enable a patient to get an overdose without ample warning, this would be an advantage; as there would then be no fear of accidents in the hands of medical men, even when not armed with a suitable inhaler, and special experience on the subject. This, however, is not the nature of chloroform, and although there are substances of this character, of which I intend to give a further account, they do not possess, at the same time, all the other convenient and agreeable qualities which would enable them to supersede chloroform in the majority of surgical operations. As the most desirable strength of a volatile narcotic liquid, not requiring great care in its use, is between that of chloroform and that of sulphuric ether, it might be supposed that by mixing the two medicines the desired end would be attained: but such is not the case; they have been so mixed by some practitioners, and I have tried them together, but the result is a combination of the undesirable qualities of both, without any compensating advantage. Ether is about six times as volatile as chloroform -- that is to say, if equal measures of each be placed in two evaporating dishes kept side by side, at the same temperature, the ether evaporates in about one-sixth the time of the chloroform; and when the two liquids are mixed, although they then evaporate together, the ether is converted into vapour much more rapidly; and, in whatever proportions they are combined, before the whole is evaporated the last portion of the liquid is nearly all chloroform: the consequence is that at the commencement of the inhalation the vapour inspired is chiefly ether, and towards the end nearly all chloroform: the patient experiencing the stronger pungency of ether when it is most objectionable, and inhaling the more powerful vapour at the conclusion, when there is the most need to proceed cautiously.

Chloroform was first employed for inhalation in the form of solution in alcohol, in which state it was called chloric ether. Mr. Jacob Bell was, I believe, the first person who exhibited it,* and it was afterwards employed occasionally in St. Bartholomew's Hospital, and in the private practice of Mr. Lawrence. (*See Pharm. Journ. Feb.). This so-called chloric ether contained from twelve to eighteen per cent of chloroform. When inhaled it yielded a little vapour of chloroform at the beginning of the process. Each hundred cubic inches of air passing over it, would take up, if saturated at 60°, from one and a half to two cubic inches, mixed with some vapour of spirit, and this was enough to produce insensibility if continued of the same strength, but by the time a third part of the liquid was inhaled, the quantity of vapour given off was reduced to less than half a cubic inch, which is insufficient either to induce or keep up insensibility; and when about half the chloric ether had evaporated, the remainder was reduced to spirit and water, with scarcely a trace of chloroform. Consequently, unless the inhaler were frequently emptied and replenished with fresh ether, insensibility failed to be induced; and under any circumstances the use of this preparation was troublesome and expensive.

In some able and interesting articles recently published in the Medical Gazette, Dr. John C. Warren, of Boston, U.S., has recommended a strong chloric ether, containing one part chloroform to two parts alcohol; this would be undoubtedly much more efficient than the ordinary chloric ether; but there is the same kind of irregularity in its effects, as in the case of the weaker preparation. The chloroform [983/984] evaporates chiefly with the first portion of spirit, and when a little more than half the liquid has been used, the remainder contains very little chloroform, and is, therefore, of no use for inhalation, since vapour of alcohol has very little effect.

I had often considered the subject of diluting chloroform with spirit, and since Dr. Warren's papers appeared have given the matter additional attention. I have mixed chloroform in various proportions with alcohol of 92.5 per cent and ascertained the quantity of vapour the compounds would give off. I have also placed these compounds in a current of air, in imitation of what takes place during inhalation, and by measuring the liquid from time to time, and weighing it in the specific gravity bottle, have been able to calculate the changes of composition which take place as evaporation proceeds. In so doing, a correction was made for the small quantity of water in the spirit, the proportion of which increases as the alcohol evaporates. The following table, which is as accurate as can be made without introducing fractions, shows how the proportion of chloroform decreases when it is mixed with an equal volume of alcohol, or with any other quantity marked in the table. For instance, when the hundred parts are diminished to sixty, they constitute the strong chloric ether of Dr. Warren, and the alterations in that compound are subsequently shown. The fourth column exhibits the quantity of chloroform in the mixed vapour that 100 cubic inches of air would take up, if saturated at 60°. The quantity that 100 cubic inches of air will thus take up from pure chloroform, is fourteen cubic inches.

Dr. Warren recommends the strong chloric ether, in order to prevent the accidents that have resulted from the too rapid action of chloroform. The quantity of vapour of chloroform that air would take up from this compound would, under the usual circumstances of inhalation, not exceed six per cent--a proportion which, I believe, would not cause any sudden accident; but unless the person using it have such skill as would enable him to avoid the risk of accident in using chloroform, he would be liable to fail in producing insensibility with its solution in spirit, owing to its rapidly decreasing strength, and the diminishing quantity of vapour that it gives off: indeed, Dr. Warren has himself experienced the irregularity of the action of strong chloric ether, having failed to induce insensibility with it in two or three cases; but he attributes the failure to a defect of susceptibility in the patients, and he advises the resort to chloroform in such cases. This is virtually yielding the point, and incurring in some cases the very risk which the proposed practice is intended to obviate. A case which occurred recently in Westminster, the account of which had not reached America when Dr. Warren's papers were written, shows that an apparent want of susceptibility does not protect the patient from accident. In that case,* a gentleman, who, as I am informed, had many times used chloroform in the same way before, employed half an ounce on a handkerchief without making the man insensible; but, a fresh supply being obtained an hour or two afterwards, the patient got an overdose, and lost his life, although the quantity used was not greater than on the previous occasion. (* See Lancet, Feb. 24.) When chloroform is given in such a way that the strength of the vapour can be regulated, it is found that there is no appreciable difference in the susceptibility to its action, whatever variety there may be in the symptoms induced previous to insensibility, and in the extent to which it is requisite to carry the narcotism in order to obtain relaxation or immunity from pain; and since it has been shown in the first three parts of these papers, that there is a definite rule for the proportion of chloroform [984/985] and other narcotic vapours in the blood, which applies alike to animals of different classes, it cannot be supposed that any human being could form an exception, since he would have to differ, not only from his own species, but from the animal kingdom in general.

When it is necessary to give chloroform on a sponge, during a surgical operation, it is not a bad plan to use it diluted with spirit, as recommended by Dr. Warren. In two or three recent cases of operation on the face, insensibility having been induced before the operation, by means of the apparatus as usual, it was requisite to employ the sponge to keep the patient insensible during its performance; and I employed a solution of chloroform in spirit, sometimes in equal parts, at other times in the proportion constituting the strong chloric ether. Both preparations answer the purpose very well, and can be employed more freely than undiluted chloroform. I poured, for instance, half a drachm on the sponge at once, in these cases, instead of a few minims.

If the strong chloric ether were used exactly as recommended by Dr. Warren, there would, I fear, be danger of accident from a cause independent of the action of the vapour inhaled. An ounce of the medicine is directed to be poured on a sponge only twice the size of an egg, which must thereby be rendered dripping wet, and should the patient be on his back, there would be risk of some drops of the ether being drawn into the glottis, in a liquid form. I have been informed by the operator of a case in which a patient was threatened with suffocation from a drop of chloroform falling into the throat from a sponge, and the solution of it in alcohol is scarcely less irritating, and would undoubtedly cause spasm of the glottis.

It follows from the above considerations, that, as a general rule, there can be no advantage in using a mixture of two or more substances of different volatility, by any ordinary method of inhalation, since the mixture cannot be uniformly introduced into the circulation. If, however, it should hereafter be found that there is any physiological advantage in combining any vapours, they could easily be given together in any uniform proportion, by a method which I have been employing lately for the exhibition of chloroform in cases in which I wished to be more than usually precise, or to gain a more exact experience. This method consists in putting a definite quantity of liquid to be inhaled into a balloon made of thin membrane, the capacity of which is known, and is not less than two thousand cubic inches, then filling the balloon with air by means of the bellows, and allowing the patient to inhale from it: the expired air being prevented from returning into the balloon, by one of the valves in the face-piece to which it is attached.

(To be continued.)

  45. "On the fatal cases of inhalation of chloroform."

Source: Snow, John. Edinburgh Medical and Surgical Journal 72, 1 July 1849, pp. 75-87.

Article V.

By John Snow, M.D.

(Read at the Westminster Medical Society, March 31, 1849)

Soon after the introduction of the inhalation of ether, two or three cases occurred in which it was rumoured that fatal effects had followed the practice; and in one case, that of Mrs Parkinson at Grantham, a coroner's jury returned a verdict to that effect, without much inquiry; the cause of death being taken for granted by the coroner in his charge. However, as the physiological effects of ether became generally known to the profession, it became evident that these deaths, which occurred two or three days after severe operations, could not be attributed to the inhalation. I know only one case where death was occasioned by the inhalation of ether.* (* See Gazette Medicale, Mars 4, 1848.) This occurred in France, and the process was continued for ten minutes, without intermission, although alarming symptoms existed a considerable part of that time, and the result was probably as much due to defective admission of air, as to the influence of the vapour.

At the time at which the inhalation of ether was introduced, two solutions of chloroform in spirit were in occasional use as medicines,--one of them bearing the name of chloric ether, and the other being called terchloride of carbon. The former of these preparations was used occasionally for inhalation, in St Bartholomew's Hospital and elsewhere, soon after the employment of sulphuric ether was introduced; but, besides being expensive, it was uncertain in its effects,--partly from its variable strength, but chiefly because the chloroform evaporated in largest quantity at first, leaving the spirituous solution weaker and weaker as the process continued. The composition of this so-called chloric ether was not generally known to the profession; but in the latter [75/76] part of the year 1847. Mr Waldie of the Apothecaries' Hall of Liverpool, being in Edinburgh, made known its nature, and recommended the chloroform, to which it owed its virtues, to Dr Simpson, who was at that time in search of new anæsthetics. Dr Simpson tried the chloroform in its separate state, as recommended by Mr Waldie, found it to answer, and introduced it into general employment, as is well known; and in a short time it almost superseded the use of ether throughout Europe, and became employed also, to a great extent, in America.

Chloroform is much more powerful than ether, and this is one reason why it is, in some respects, more convenient. Its greater potency depends, as I showed on a former occasion* on its being more sparingly soluble in the blood than ether. (* See Med. Gaz., March, 1848.) The quantity of chloroform required to induce insensibility is less than one-tenth as much by measure, as in the case of ether. Viewed in this manner, it is more than ten times as strong; but to ascertain their comparative physiological power, when inhaled in a similar manner, their volatility requires to be taken into account. In order to perceive the relative strength of these two medicines, we may suppose that the air which a patient breathes is saturated at 60°--the ordinary temperature of a dwelling room,--with one or other of the vapours, and see how much air he would have to breathe in either case, in order to be narcotized to the third degree,--the extent of insensibility usually required in a surgical operation. Thirty-six minims is about the average quantity of chloroform required to produce this degree of narcotism in the adult, and this would saturate 257 cubic inches of air at 60°, making it expand to nearly 300 cubic inches, which would be breathed in 12 ordinary respirations of 25 cubic inches each. The quantity of ether usually required to produce the same amount of insensibility in the adult, is about 7½ fluid drachms; this would saturate 440 cubic inches of air at 60°, and increase its volume to rather more than 800 cubic inches, which would require 32 ordinary respirations to breathe it. We see, therefore, that 12 inspirations of air charged with vapour of chloroform are equal to 32 similar inspirations of air charged with vapour of ether, at the same temperature; and that, consequently, chloroform is nearly three times as strong as ether. In actual practice the difference in strength is generally greater than this, for ether abstracts much more calorie than chloroform during its evaporation, thereby reducing the temperature of the air passing over it, and the sponge or whatever contains it, and limiting its own evaporation, in a greater degree. It follows, therefore, that the fact of accidents not occurring under the use of ether, could be no guarantee that they would not happen during the employment of chloroform.

Having, on a previous occasion, described the ordinary effects of chloroform, I shall now proceed at once to the consideration of the circumstances under which it is capable of causing death. When an animal, after it has become completely insensible, is allowed to continue breathing air charged with the vapour, the respiration shortly ceases; but if the air do not contain more than about five per cent of the vapour, the heart continues to pulsate for some time after the breathing has ceased, and the circulation is finally arrested for want of the respiration, as in all other cases when death takes place by apnœa. I have heard the pulsations of the heart, by means of the stethoscope, several times, for one or two minutes after the breathing has ceased, in cats and rabbits under the influence of chloroform. During this interval, life is easily recalled by means of artificial respiration; indeed, more than once, moving the animal, or pressing on its chest, whilst using the stethoscope, has apparently been the means of resuscitating it. This persistence of the heart's action, as I have elsewhere shown,* does not arise from any incapacity of chloroform to paralyze it, but from the circumstance that the sensibility of that part of the nervous system on which the motions of respiration depend, is abolished by a somewhat smaller quantity of the narcotic than is requisite to suspend the action of the heart. (* Med. Gaz., Vol. xlii. P. 415) When, however, an animal is made to breathe air containing a greater quantity of the vapour, ten per cent or upwards, death takes place rapidly in from half a minute to about two minutes, and the respiration and circulation cease about the same time. The reason of this is, that there is sufficient vapour in the lungs, at the moment when the breathing stops, to paralyze the action of the heart as soon as it is absorbed, and added to that already contained in the blood. Under these circumstances, it is evident that artificial respiration can be of no avail; and this is the manner in which, there is every reason to believe, the greater number of the fatal cases of inhalation of chloroform have occurred.

In order to give as clear an idea as possible of the cause of the accidents from chloroform that have happened in different parts of the world, I must direct attention to some considerations of the quantity of it, in the blood and in the lungs, under different circumstances. I have stated that the average quantity of chloroform required to be inhaled, by an adult, to induce the usual amount of insensibility required in an operation, is 36 minims; but about half of this is expired again without being absorbed, so that 18 minims is about the quantity existing in the blood. Indeed, about a year ago, I related to this Society* the result of some experiments, undertaken to ascertain the exact proportion in the blood, in the different degrees of narcotism, by which it was shown that about 12 minims is the quantity in the second degree, or the stage when the mind wanders and voluntary motion is unsteady; about 18 minims in the third degree of narcotism; about 24 minims in the fourth degree,--the stage of complete insensibility, with relaxation; a little more than 30 minims, the quantity that would be required to suspend the respiration; and about 36 or 37 minims to arrest the action of the heart, supposing the vapour to be equally diffused through the whole of the blood. (* Med Gaz., Vol. xli. p. 850) Now, let us ascertain what proportion of this latter quantity of chloroform may be present in the lungs at once, provided the air breathed by the patient be saturated at 60°. The quantity of air usually present in the lungs is about 250 cubic inches; this would contain 30 minims before it entered the lungs, but, as absorption and inhalation go on together, it is probable that, during ordinary respiration, only from half to two-thirds of this quantity would be present in the lungs at once, or from 15 to 20 minims; and, if the chloroform were removed from the patient's mouth, part of this would be expired again, and not more than from 10 to 15 minims would be absorbed into the blood after the discontinuance of the inhalation. But, supposing 12 minims were thus absorbed, they might cause a fatal result; for if the patient were narcotised to the third degree, and about 18 minims had been absorbed, when the inhalation was discontinued, the additional 12 minims would make half a drachm, which might suspend respiration; or, if the patient were already in the fourth degree, and twenty-four minims had been absorbed, twelve minims more would complete the quantity which I have estimated would be sufficient to arrest the action of the heart. These numbers are only approximations to the exact quantities; but the subject itself is not one of speculation, for that the effects of chloroform continue to increase during about twenty seconds after the inhalation is left off, owing to the further absorption of the vapour present in the lungs, may be observed daily in practice, even when the chloroform is largely diluted with air, and, of course, the greater the quantity of vapour in the air, the more formidable must be this increase of the narcotism. It will be recollected that I called the attention of the society to this increase or accumulation of the effects of chloroform, early in January last year,* before any fatal case had happened from its use, and recommended that the vapour should, by means of some suitable apparatus, be so diluted, that its effects should be gradually induced in not less time than about two minutes. (* See Med. Gaz. Vol. xli. p. 75, and Lancet, Feb. 12, 1848.)

Sometimes a patient begins all at once to breathe deeply during the inhalation; and, under these circumstances, if the vapour be not largely diluted, it will be inspired with dangerous rapidity. [78/79] The first incision by the surgeon's knife, when the patient is unconscious, but not totally insensible, sometimes has the effect of causing him to draw a deep inspiration, and to hold his breath at the end of it, retaining the air in his lungs: now, an inspiration of this kind might, on a moderate computation, introduce 100 cubic inches of air; and, if this were charged with vapour of chloroform, by passing over a handkerchief or sponge, it might contain ten or twelve minims; if the air or the handkerchief were warm, it might, indeed, contain much more; but this quantity, added to that already in the circulation, might cause a fatal accident.

It must be sufficiently evident, from these considerations, that, unless some means were used for regulating the strength of the vapour, fatal accidents would be liable to occur from the employment of chloroform. Unfortunately, Dr Simpson, to whom we are indebted for its introduction, recommended it to be used on a handkerchief, and even held it out as one of the advantages of the new anæsthetic, that it did not require any apparatus. This advice, coming from so high a quarter, could not fail to meet with numerous followers; and to this circumstance, many of the accidents that have occurred must, in my opinion, be partly attributed. It is not asserted, by the advocates of the handkerchief, that it affords any accurate means of regulating the strength of the vapour. This they seem to think unnecessary. They appear to consider that all that is required is, that the patient should inhale the chloroform till he is made insensible, and then leave off;--that the practice is not attended with danger; and that the deaths which have occurred, either were not caused by the chloroform, or depended on some idiosyncrasy, or the presence of organic disease. In order, however, to show the different effects of the vapour, according to the quantity of air with which it is diluted, I will make two experiments; in the first of which, a bird will die in about half a minute, although having sufficient air for purposes of respiration; and, in the second, another bird will become gradually insensible, and will as gradually recover, after its removal from the vapour.

Twelve grains of chloroform were poured into a glass jar holding 100 cubic inches, and covered with a plate of glass; the jar was moved about till the chloroform was converted into vapour, and equally diffused amongst the air, when a brown linnet was introduced. It made an attempt to escape, then appeared in distress; shortly afterwards it fell down, and it was taken out dead half a minute after its introduction. The same quantity of chloroform was then put, in a similar way, into a jar holding 600 cubic inches, and another linnet introduced. After a short time, it began to stagger as it walked, and soon afterwards was unable to keep on its legs; in about two minutes it appeared insensible, was allowed to remain a minute longer, when it was taken out and laid on the table. It shortly began to move, and in two or three minutes had quite recovered.

The jar employed in the first experiment holds enough air to support the respiration of a small bird, for ten or fifteen minutes, without distress. The chloroform introduced formed about nine cubic inches of vapour, displacing as much air, and leaving about 91 cubic inches; but the same quantity of vapour of ether would have acted much more mildly, gradually causing insensibility; and the same quantity of some vapours,--that of wood spirit, for instance,--would have scarcely had an appreciable effect on the bird in several minutes. Vapour of the strength employed in these two experiments does not act so rapidly on larger animals, but, by increasing its strength, it acts as quickly, and there is the same difference in its effects, with a similar difference in the proportion of vapour and air.

The first fatal case of inhalation of chloroform was that of Hannah Greener, which occurred near Newcastle, on the 28th of January last year. The patient was a girl 15 years of age, who required to have her toe nail removed. About a teaspoonful of chloroform was put on a cloth, which was applied to the mouth and nostrils. In about half a minute the patient's arm was rigid, and she appeared insensible. The operation was at this time commenced; she gave a kick, as if not quite insensible; at this time the lips became suddenly blanched, and she splattered at the mouth, as if in epilepsy. The breathing continued for upwards of half a minute after the cloth was removed from the face, but the patient was quite dead in two minutes from the first commencement of the operation.* (See Dr Meggison's Letter, Med. Gaz., Vol. xli. p. 254.) The spasm that occurred in this case at the moment of death, resembles what is often met with when animals are suddenly killed by vapour of chloroform not well diluted with air.† The most prominent appearance, found on inspection of the body, was a highly-congested state of the lungs. Sir John Fife attributed the death to this, but it ought rather to be attributed to the narcotic effects of an over-dose of chloroform on the brain and nerves. Both chloroform and ether, when in too strong a state, cause a temporary congestion of the lungs, as is evidenced by a momentary smallness of the pulse; but it may fairly be doubted whether this would cause death, and especially in so rapid a manner; whilst, on the other hand, the undoubted narcotic effects of the vapour explain it fully. There is no evidence to determine whether the action of the heart continued in this case after the respiration had ceased or not. There was dark fluid blood in its right cavities, and a very little in the left. († For a full account of the case of Hannah Greener, see the Edinburgh Medical and Surgical Journal, Vol. lxix. p. 498. April 1848.)

Dr. Simpson attributed the death in this instance to suffocation, by a small quantity of brandy given to the patient whilst she was dying, and which she swallowed, though with difficulty; but I believe that few medical men agree in this opinion. Some persons,--and there are medical men of eminence amongst them,--whilst they admit that the chloroform was the cause of death in this and similar cases, suppose that it acts mechanically, by excluding the air; but they do not distinguish between a vapour and a gas. Chloroform, when not admitted to mix with air, remains liquid until it is raised to the temperature of 140° Fah., unless the pressure of the atmosphere be partially removed from it by means of the air-pump. I have already alluded to the real cause of the accident, viz. that the air breathed by the patient contained too much vapour,--probably 10 or 15 per cent, when it ought to contain only about 5. There are others who think that the handkerchief applied too closely has caused death, by obstructing the respiration; but where death has happened so suddenly, this explanation is quite untenable. When ether was first introduced, I believe that some disagreeable symptoms were occasionally caused by obstructed respiration, from breathing for several minutes through a very narrow tube; and I have alluded to one case, in which this process being continued for ten minutes without ceasing, probably contributed to a fatal result. But the accidents from chloroform are of a different nature, and it must be borne in mind, that with this medicine air is required to dilute its vapour considerably over and above what would be merely required for the purposes of respiration.

The next accident from chloroform happened to Mrs Simmons, of Cincinnati, U. S., on Feb. 23, 1848. The limits of a paper will not allow of the cases being read in detail, consequently I can allude only to their chief features. The patient in America was 35 years of age, and in pretty good health. She required some stumps of teeth removed, and inhaled from a glass globe containing a large sponge saturated with chloroform. I believe that this is the only fatal case in which any kind of apparatus was used, and the dentists who employed it were not medical men; and their only endeavour appears to have been to make the patient insensible as quickly as possible. When the patient had drawn from twelve to fifteen inspirations, she appeared insensible, and the roots of teeth were extracted; she turned pale during the inhalation; groaned as the teeth were removed; and as the last root came out, her head turned to one side, her arms became rigid, and the body was drawn backwards. Mrs Pearson, a friend who accompanied the patient, at this moment placed her finger on the pulse and found it feeble, and that it shortly ceased to beat; the respiration ceased, she says, about the same time. She and [81/82] another female friend considered that the patient died at this time, about two minutes from the commencement of the inhalation,--the dentists thought that she lingered a little longer. Artificial respiration was performed after a time, and galvanism was also applied, which caused contraction of the voluntary muscles, but had no effect on the heart. In a medical inquiry which took place respecting this case, it was estimated that one-fourth part by measure of what the patient inhaled, might be vapour of chloroform; but this is evidently an over-calculation, for there could not be this quantity, unless the interior of the glass globe were maintained at a temperature of 80°; however, half the amount supposed might have caused the result.

At the post mortem examination, the blood-vessels of the head were moderately distended; some fluid blood mixed with air flowed from the sinuses of the dura mater,--this air had no doubt entered the blood-vessels during the artificial respiration. The lungs were considerably, but not intensely, congested; the heart was flaccid, and all its cavities were quite empty, but its lining membrane was stained with blood,--it had been emptied after death, either in opening the head, or else by the artificial respiration. Dr Sibson, in commenting on this case, last year, in the Medical Gazette, stated that he had seen the heart emptied after death, during experiments with artificial respiration in the human subject. The blood was very fluid in this case.

The next ease occurred at Hyderabad in Hindostan, in the person of a young woman, who had the distal phalanx of one of her fingers removed. A drachm of chloroform was put on a handkerchief and inhaled. The patient coughed a little, and then gave a few convulsive movements. The operation was then performed, but scarcely a drop of blood flowed, and no signs of life remained. The practitioner is inclined to think that death was almost instantaneous; for, after the convulsive movements, the patient was not observed to breathe or stir. There was no examination after death.

The next fatal case happened at Boulogne, in May last. The patient was a female, aged 30 years, in good health, but she had previously been in a state of anæmia. In the first account of the case, it was stated that only fifteen to twenty drops of chloroform had been put on the handkerchief; but a judicial examination of the bottle from which it had been taken, showed that from a drachm and a quarter to two drachms had been used,--five to eight grammes. "Scarcely had the patient taken several inspirations, when she tried to remove the handkerchief, and cried, 'I choke.' Immediately the face became pale; the countenance changed; the breathing embarrassed; and she foamed at the mouth; at the same instant (and certainly less than a minute [82/83] after the beginning of the inhalation), the handkerchief moistened with chloroform was removed," and the operation was performed by M. Gorré, his colleagues, in the meantime, trying in vain to remedy the state of the patient. Artificial respiration was kept up for a long time, and with such force as to cause permanent dilatation of the air-cells.

At the inspection of the body, the lungs were found visibly engorged in the lower lobes. The heart was quite empty, as in the American case, in which artificial respiration had been employed. The vessels of the head were not engorged, but air was found in the venous sinuses. It was met with also in the pulmonary veins (where no doubt it first entered by minute ruptures of the air cells and vascular tissue), in the heart, in the right carotid artery, and in the veins generally.

The members of the Academy of Medicine of Paris, attach great importance to the air in the veins; most of them attributing the death to it; some supposing that it was due to an unknown action of chloroform on the blood, and others thinking that it was spontaneously and suddenly developed. It is alleged that the air in the veins could not have been introduced by the artificial respiration, as the left ventricle had already ceased to act. But so soon as an opening was made into the pulmonary veins, the air would be urged forward, in the course of the circulation, by the forcible inflation. Moreover, the arteries possess the power of forwarding their contents after death, as is proved by their generally being found quite empty. The blood, in the case under consideration, was very fluid and black.

There was a statement in the Glasgow Herald at the beginning of the year, which was copied into the Medical and other Journals, that a gentleman inhaled chloroform, preparatory to having his toe-nail removed, by a surgeon in Govan, and expired almost instantly. As no account of this case has been given to the profession, we cannot discuss it; but there are two other cases which it is necessary to notice. The first of these occurred in the practice of Dr Barrier, at the Hotel Dieu at Lyons. The patient was a boy aged 17, on whom it was intended to perform amputation of the finger. A thin compress was placed on the face, and chloroform was dropped on gradually; in four or five minutes he was still speaking, and conscious of pain in the injured finger; a minute afterwards, he spoke again, and showed a little agitation. By this time, from one drachm and a half to two drachms had been poured on the lint, and it is to be supposed that a great deal of it went off by evaporation. The pulse had all the while been perfectly normal. All at once the patient rose suddenly, and threw about his limbs, but he was soon brought down again by the assistants. This excitement did not altogether last more than a quarter of a minute, when it was found that the artery at the wrist had ceased beating. The cloth was immediately taken off from the face, which looked haggard. The heart ceased to beat, and no pulse could he detected. Respiration was, however, carried on, but soon became weak, slow, and ceased completely in about half a minute. On the employment of very energetic restorative means, the breathing began again, with a certain amount of vigour; the pulse, however, could not be felt, and the respiration soon ceased again. Artificial respiration was employed amongst other means. After death, the heart was found empty. The lungs were collapsed, and of a slate colour.

It was especially noticed in this case that the heart ceased to beat before the respiration entirely left off. Dr Sibson made last year a suggestion which is particularly applicable to this case, viz., that the blood passing from the lungs to the heart, and through the coronary arteries, is more highly charged with the vapour than that in any other part of the body, and may cause paralysis of the heart, before even general insensibility is induced. Some experiments of mine on frogs and other animals* have shown that the vapour of chloroform has the power of acting locally on the heart, and suspending its action. (* Med. Gaz., vol. Xlii., p. 415.) It is therefore possible that, by means of very strong vapour, the blood passing through the lungs might be so impregnated with chloroform as to paralyze the heart, before the functions of the nervous system generally were abolished. To prevent this occurring, all that is required is that the vapour be uniformly and sufficiently diluted with air. In the case at Lyons, it appears that the patient got but little vapour into his lungs for several minutes, and then suddenly inhaled a considerable quantity, either from taking a deep inspiration, or some other cause.

The remaining case occurred very recently in Westminster, in a dispensary patient under the care of Mr Nunn's dresser. The subject of it was a labouring man who had his great toe amputated, on account of gangrene, following an accident. Half an ounce of chloroform was used on a handkerchief, with the effect of causing only excitement; insensibility was not induced; and a delay of two hours took place before fresh chloroform was procured. The second time the same quantity was employed as before. I understand that it was not all poured on the handkerchief at once, but was dropped on by portions; but of course it cannot be determined how much of the whole quantity was on the handkerchief at one time. In the account in the Lancet by Dr Arlidge, it is stated that, "after a period of excitement lasting two or three minutes, insensibility was induced, and the breathing. at first rather hurried, became now slower and rather sterto-[84/85]rous; the eyelids quivered on the approach of an object to the eye; the pupil became somewhat dilated; the pulse was at about 70, moderately strong. As soon as anæsthesia was produced the operation was proceeded with, and occupied not more than two minutes." I understand that the inhalation was continued during part of the time occupied by the operation. "At the close of the amputation no blood escaped when pressure was removed from the arteries. In the meantime the breathing became slower and less full, and a pallor with coldness diffused itself over the body, and showed itself in the lips, etc. The pulse receded in strength and frequency, and very shortly ceased at the wrist. The features assumed a ghastly expression, and everything betokened impending dissolution. A few respirations were noticed after the pulse ceased at the wrist, but in ten minutes (the time is probably greatly over-estimated) from the time of the inhalation respiration altogether ceased, and the chin dropped." The lungs and bronchial membrane were congested; the heart was rather large but flabby. There was an ounce of semi-fluid blood in the right ventricle, and a little in the left (artificial respiration had been employed). The contents of the head were natural.

This case shows in a striking manner the uncertainty of the employment of the handkerchief. In the first attempt to make the patient insensible, nearly all the chloroform was, wasted by evaporation into the air of the apartment, and but little entered the lungs; whilst, on the second occasion, he at some moment got an overdose, and was no more. The coroner's jury returned a verdict of death by chloroform properly administered, which is tantamount to an assertion that the inhalation of it is attended with danger, however well managed, than which nothing can be more untrue. I have no desire to blame the parties in whose hands this unfortunate case happened, and who had sufficient precedents for the way in which they proceeded, but I cannot admit that chloroform is properly administered when it leads to the death of the patient.

There have been two accidents from persons inhaling chloroform whilst no one was present; but I shall confine this paper to the cause and prevention of accidents occurring during its professional administration. There was an alleged death from it, which must be fresh in the minds of the fellows of the society, to which I have not alluded. I mean that which occurred in the practice of Mr Robinson, but which, I believe, was not caused by chloroform, for the following reasons. In the first place, the patient could have had but an extremely small quantity of the vapour, since, according to the evidence at the inquest, the face-piece, of which Mr Robinson's inhaler consists, was not fitted to the face, but held at a little distance from it; the air would therefore pass into the mouth and nostrils by the side, instead of going through the sponge it contained, and would consequently be but just flavoured with the chloroform. In the next place, the patient never exhibited any symptoms of the action of the vapour. He was talking one moment, and showing no signs of its effects, and the next moment his head and hand dropped, and he was dead. There was no convulsive action as in the cases in India and America, and that near Newcastle. No frothing at the mouth, as in the case at Boulogne, nor any exclamation respecting the strength of the vapour, such as, "I choke;" but, on the contrary, he was observing that the vapour was not strong enough, which, assuredly, he would not have done, if there had been a quantity of it in the lungs capable of causing sudden death. The decease of this patient seems to belong to a different class of deaths from those under consideration, viz, to those instances in which patients have suddenly expired when an operation was about to commence,--a kind of death from which patients are safe as soon as they become unconscious from the effects of chloroform. I look on Mr Badger's case as one of syncope, through fear of the operation or of the inhalation, concerning which he had been led to entertain apprehensions; and I believe that the syncope proved fatal from the fatty degeneration of the heart and the enlargement of the liver, which greatly encroached on the space of the thorax.

The death of a medical gentleman of Birkenhead, last year, was attributed to chloroform. He died of an attack of hæmoptysis, which came on two days after he had inhaled the vapour for the removal of a tooth. It is not surprising that, amongst the thousands of persons who have inhaled chloroform, one of them should have done so, a little time before he was about to have an attack of hæmoptysis. As the vapour has never caused hemorrhage from the lungs at the time of its employment, there is no reason to suppose that it could do so at an after period. There are other cases besides this, in which the death of patients, at periods more or less remote from an operation or confinement, have, by some persons, been attributed to chloroform. There is not time to consider these cases seriatim. I can only state generally my conviction, that the dangers, even of the mismanagement of chloroform, are chiefly confined to the moment when it is administered, and do not develop themselves afterwards.

The fatal cases we have been considering bear a considerable resemblance to each other. We have no particulars of the Glasgow ease; but in four out of the other six the insensibility was produced very rapidly, proving that the vapour must have been inhaled of great strength from the first; and in the other two cases, as well as in these, the dangerous symptoms set in very suddenly. [86/87] From the sudden paleness observed in most of the cases, it is probable that the circulation was arrested at once, by the direct action of the chloroform on the heart.

The appearances met with on dissection do not differ from those that are found in many other cases, especially of sudden death. There was no particular congestion of the head in any of the five bodies that were examined. The lungs were much congested in two of them, and somewhat congested in the other three. The heart was quite empty in three cases, in which inflation of the lungs had been made after death. The blood was generally fluid,--in two of the cases very much so. I think that this is mainly attributable to the sudden nature of the death; the blood in the human subject very often remaining liquid after sudden death. In animals, such as cats and rabbits, the blood is generally partially, if not well coagulated, after they have been killed by chloroform; and if a portion is allowed to flow by a wound made just after death, this coagulates very firmly, showing that, even if this medicine have the power of interfering with the coagulation of the blood in the vessels, it is not by effecting an alteration in that fluid.

As regards the treatment for an overdose of chloroform, I believe that artificial respiration, carefully performed, is all that could be done; it would save the patient in any case in which the heart is not paralyzed; and, in such a case, I believe that nothing would be of service.

The points which I have endeavoured to impress on the Society are, that, whilst chloroform is perfectly safe when carefully regulated, by means of a suitable instrument, it is not so under other circumstances. In the inhaler which I employ, the compartment containing the chloroform is surrounded with cold water to limit the quantity of vapour taken up by the air, and the expiratory valve of the face-piece is so adapted as to admit additional air to any extent to dilute the vapour still farther.

It will perhaps be asked, how it is that accidents are not more numerous from the use of the handkerchief, if it be really so dangerous, for it is still employed to a considerable extent, though much less frequently, in this metropolis at least, than the various kinds of inhalers which are in use. I think that the skill and adroitness of medical practitioners are the chief causes of this; but I have heard of several cases, such as one that I lately related to the Society, through the kindness of Mr. Henry Smith, in which the patient has had a narrow escape from impending dissolution during the use of the handkerchief.

Go to Group 4   (# 46-60)

Click to return to Stream 1 - d: John Snow's Publications