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Fusia dot  114. "Dr. Marshall Hall's method of artificial respiration"

Source: Snow, John. Medical Times and Gazette 14, 25 April 1857, p. 421 [Letter to Ed.].

To the Editor of the Medical Times and Gazette

Sir,--I shall be obliged if you will allow me to state, that I believe Dr. Marshall Hall's method of artificial respiration was quite efficient as a method of artificial respiration, in the case of death during the inhalation of amylene, which I related in the last number of the Medical Times and Gazette. That it was not efficient in restoring the patient is not to be wondered at, when his own natural respiration, continued for several minutes, had failed to restore the action of the heart. The artificial respiration was resorted to for want of anything else which could afford a chance of benefit. I asked Mr. Fergusson's advice respecting the propriety of opening the jugular vein, with a view to relieve the probable distention of the right cavities of the heart, but as the veins of the neck were shrunk, and did not contain any blood, he did not think it would be of any use to open them. In Mr. Paget's recent case of death during the inhalation of chloroform, the patient continued to breathe after the pulse had ceased, and the artificial respiration was not effectual in restoring him.

When the failure of the pulse is the consequence of the absence of breathing, as in drowning, artificial respiration is the proper remedy, and I believe the method of Dr. Marshall Hall to be a very efficient one. I had a few days ago the opportunity of seeing its good effects on a child born in a state of partial asphyxia. The child presented by the shoulder, but was easily turned by Mr. Edward Tegart while the mother was under the influence of chloroform. Being a large child, however, the circulation between it and the placenta was interrupted for a short time during the passage of the head, and when born, although there was a slow pulsation in the funis, it breathed only by distant gasps, its muscles were completely relaxed, and it was so insensible that dashing cold water on it had no effect on the respiration. The gasping was becoming less frequent and the pulse was failing, when Mr. Tegart and I began Dr. Hall's method. I could hear the air entering the larynx at every turn of the child. Its own inspirations soon became more frequent, it became of a florid colour, in place of the livid one it had previously presented; its muscles began to be tense and active, and in a very short time it was crying vigorously. I believe that inflation of the lungs from mouth to mouth might have restored this child, but, according to my experience, not with the same promptitude.

In any case of accident from chloroform or any other narcotic vapour, if the respiration were suspended by the over-action of the medicine on the brain, and the heart were not entirely paralysed, artificial respiration would, I believe, restore the patient. Such is the result of my experiments on animals; but where the heart itself is the organ chiefly or solely affected, artificial respiration, although affording a chance of benefit, is likely to be of little avail; and these apparently are the cases of accident which have ended fatally, notwithstanding prompt assistance.

I am, etc.

John Snow, M.D.

18, Sackville-street, April, 1857


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Fusia dot  115. "On some alleged ill effects of amylene"

Source: Snow, John. British Medical Journal 1, 2 May 1857, p. 381 [Letter to Ed.].

Letter from John Snow, M.D.

Sir,--I shall be obliged if you will allow me to make a few remarks on the case of operation for stricture by Mr. Syme's method, reported at page 331 of your last number. The operation was followed by some severe symptoms which the reporter of the case attributes to the amylene which had been inhaled. The symptoms, however, were such as are occasionally produced by operations on the urethra, more especially by the operation in question, and are not such as amylene, or any analogous substance has been known, or would be likely, to produce. I have seen very similar symptoms to those which occurred to Mr. Erichsen's patient follow the introduction of bougies, with some bleeding from the urethra--the convulsions only were wanting. I should wish, however, to call particular attention to the following passage in a paper by Mr. Syme on the treatment of strictures of the urethra by external incision. (Medico-Chirurgical Transactions, vol. 36, p. 260.) "A curious train of nervous symptoms sometimes present themselves, to the great consternation of all who have not previously witnessed them, or are unaware of their nature. They occur most frequently soon after the catheter is withdrawn, and appear to depend on the urine resuming its natural course, but have also been observed at an earlier period. They have never, so far as I know, lasted more than thirty hours, and seldom continue above half this time. They consist of rigors, bilious vomiting, coldness of the extremities, suppression of urine, and delirium. They require no treatment, and do not seem to admit of being alleviated or curtailed by opiates, stimulants, or other means of remedy, requiring merely a little time for their disappearance, so that the only cordial of any service is a confident assurance on the part of the surgeon that there is no ground whatever for the slightest alarm or uneasiness."

I have administered amylene in 146 cases without ever meeting with any of the symptoms which occurred in Mr. Erichsen's case, except simple vomiting without depression, and that not a quarter so often as happens after chloroform. Amylene has also been largely used in France without producing any such symptoms as those which Mr. Syme describes, and which occurred after the operation in question. Amylene resembles chloroform very closely in its effects--more closely, indeed, in one respect, than could be desired--that of its power to cause sudden accidents; but chloroform, so extensively as it has been used, has not been known to occasion suppression of urine, or the train of symptoms connected with, and caused by, the congestion of the kidneys and suppression of urine which occurred in Mr. Erichsen's case. Amylene bears a great resemblance to nitrous oxide gas, both in the symptoms it produces, and in the promptitude with which its effects come on and pass off; but although this gas has been breathed for amusement, during almost sixty years, it is not recorded to have produced such a train of symptoms in any case as were met with after the operation under consideration.

Apart from all the experience above alluded to, it would be extremely unlikely that a medicine, whose physical properties compel it to pass away in the breath, with the exception of a minute trace, in a few minutes, should produce a fresh set of serious symptoms hours afterwards, the patient having been well in the mean time. It would be as if the effects of alcohol or opium should return after a few weeks. With regard to the term poisoning of the blood which occurs in the report to which I have referred, the blood may be said to be poisoned as long as any trace of a medicine or condiment remains in it; but a few hours after a patient has inhaled amylene his blood is not more poisoned by it than that of the surgeon and his assistants was at the time of the operation. The important poisoning of the blood in Mr. Erichsen's patient arose from the retention of excrementitious materials which the kidneys failed to eliminate, and the convulsions seem to indicate that the urea was decomposed into carbonate of ammonia. Sufficient particulars are not related, with regard to the vomiting which followed the previous operations, to enable one to form an opinion as to whether it was caused by the chloroform or not; but it is not improbable that it was due in a great measure to the operation. Vomiting is a symptom which used to occur after operations, now and then, before chloroform was used; and this agent, besides the vomiting which it undoubtedly occasions, has often to take the blame of that produced by other causes, such as a dose of opium, loss of blood, morbid poisons, and derangement of the renal and other functions occasioned by an operation.

I am, etc.

John Snow

18, Sackville Street, April 1857.


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Fusia dot  116."On chloride of amyle"

Source: Snow, John. Medical Times and Gazette 14, 9 May 1857, p. 457 [Letter to Ed.].

By John Snow, M.D.

This compound was first made by M. Cahours, but was afterwards described more particularly by M. Balard, in the Annales de Chimie, in 1844. It is made by distilling equal quantities of amylic alcohol, or purified fusel oil, and perchloride of phorphorus. It is a colourless liquid, with a slight alliaceous odour, lighter than water, and boiling at 215º Fahr.

I prepared some of this substance a few months ago, and made some experiments with it on guinea-pigs and mice, and also inhaled a drachm of it myself. I ascertained from the experiments on the animals that they require to absorb one-fifth as much of the vapour as the blood is capable of dissolving, in order to be rendered quite insensible. This is exactly the same relative quantity as requires to be absorbed in the case of amylene, and it is not improbable that all the members of the amyle series will be found to possess the same relative physiological strength; for I found that this was the case with several substances of the ethyle series with which I made experiments some years ago. About one part in twenty-eight of what the blood would dissolve was the proportion which required to be absorbed, in order to cause complete insensibility with the compounds of ethyle.

The volatility of chloride of amyle is so moderate that it yields only three cubic inches and three-quarters of vapour at 60º Fahr. to 100 cubic inches of air, even when fully saturated by it. Owing chiefly to this circumstance it causes insensibility, slowly and with difficulty, and its effects pass off slowly; therefore I have not thought of applying it in surgical operations, although the symptoms it induced were very favourable. I think, however, that it might be tried with benefit in neuralgia, and other medical cases, and, possibly, in midwifery; it would, at least, have this advantage, that it could not possibly cause a sudden accident. I have not yet, however, sought an opportunity of applying it. The drachm of it which I inhaled took me ten minutes to consume; it produced a feeling of numbness and drowsiness, which slowly passed off without ill effects.

I should, probably, not yet have brought the subject of chloride of amyle before the Profession, except for what I believe to be a mistake which has been made respecting it. Dr. Simpson brought a substance which he called chloride of amyle before a recent meeting of the Medico-Chirurigical Society of Edinburgh, as a new anæsthetic.* He stated that it did not boil under 120º Fahr., and that it had anæsthetic properties equal to those of the hydride of amyle.

(*See Edinburgh Medical Journal, May, 1857, p. 1044.)

Now the latter is a powerful anæsthetic, very closely resembling amylene; and from this circumstance, and the very wide difference between the boiling points of chloride of amyle and the liquid which Dr. Simpson exhibited, I feel convinced that the latter was not the real chloride of amyle, but some other compound, or mixture of compounds.

The hydride of amyle is so very difficult to separate from the amylene, which is produced at the same time, that it could probably not be procured in sufficient quantity to apply to the human subject. Moreover, as it boils at 86º Fahr., and would be gaseous in sultry weather and in tropical climates, it would be extremely inconvenient in practice. It is, however, desirable to ascertain the properties of as many volatile narcotic substances as possible.

Sackville-street, May, 1857.


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Fusia dot  117. "On the adulteration of bread as a cause of rickets"

Source: Snow, John. Lancet, July 4, 1857, pp. 4-5.

By John Snow, M.D.

On commencing, in the year 1839, to see a considerable amount of practice amongst the poor of London, chiefly the out-patients of a public hospital, I was very much struck with the great number of cases of rickets. The complaint was shown more particularly in the bones of the leg, causing an outward curvature of the tibia and fibula; in children in their second and third year, it seemed almost the rule, and might be observed in the streets and the parks, as well as amongst children brought for advice. The complaint, moreover, was not by any means confined to the poor, but affected the children of the middle class to a considerable extent.

The usual causes to which rickets are attributed are of a somewhat general nature, such as vitiated air, want of exercise and nourishing food, and a scrofulous taint. These explanations, however, did not satisfy me, as I had previously seen a good deal of practice in some of the towns in the north of England, where the over-crowding and the other evils above mentioned were as great as in London, whilst the distortion of the legs in young children was hardly present; moreover, I noticed that the most healthy-looking and best-nourished children often suffered most from curvature of the bones of the legs, owing to their greater weight; and I afterwards found that this complaint was quite common in the villages around London as well as in the metropolis itself.

The bones owe their hardness to phosphate of lime, which exists ready formed in many articles of food, and only requires to be assimilated, whilst in rickets the phosphate of lime in the bones is known to be deficient; and therefore it seemed extremely probable that the want of this earthy salt in the food of the infants of this metropolis was the chief cause of the soft state of the bones. My attention was naturally directed to milk, which contains one chief supply of phosphate of lime, and which is somewhat scarce and dear, and not of the best quality in London; but I immediately recollected that in some of the mining and manufacturing districts in the northern counties of England milk was scarcely used at all in the families of the operatives, and yet I had hardly seen a case of curvature of the legs from rickets. On reflecting on the subject of bread, however, there seemed to be something which might explain the prevalence of this complaint in London. In the northern counties, where coals are cheap, it was the universal custom for every family to bake their own bread, and I believe still remains so; whilst in the south of England it is as much the custom to buy bread from the baker. Now, the bakers, so far as I have examined, all put alum in their bread, whilst this is never done in domestic practice, and the flour dealers rarely adulterate the flour with this substance. They are liable to a heavy penalty for adulterating flour, but the law is never enforced against the bakers. I have never examined a specimen of flour which contained alum, or a specimen of baker's bread which did not contain it.

When my attention was first turned to the subject of rickets, I thought it likely that the sulphuric acid of the alum would decompose the phosphate of lime of the wheat, and form sulphate of lime, which would not be available as nourishment for the bones; and I formed an intention to investigate the question both chemically and statistically; but this intention was long postponed, on account of other engagements and inquires. In the meantime, and without any regard to the question of rickets, Liebig has inquired into the action of alum in bread, and his investigation will justly have more weight with the reader than any inquiry of mine. He says, "Since phosphoric acid forms with alumina a compound hardly decomposable by alkalies or acids, this may perhaps explain the indigestibility of the London bakers' bread, which strikes all foreigners."*

(*Letters on Chemistry, third edition, p. 443.)

It is evident from the above passage that Liebig has ascertained that alum decomposes the phosphate of lime of wheat, and it is not likely that the bones would be able to nourish themselves with this salt out of phosphate of alumina and sulphate of lime; and where the baker's bread forms the chief and almost the only article of food, as it does amongst the children of the working classes in London and many other towns, one might expect the bones to be ill nourished, as regards their earthy and hardening materials. This appears to be the actual fact, as far as I have been able to extend my inquiries. The subject is capable of being decided by an exact numerical investigation, but I have thought it better to publish my inquiry in its present imperfect state, than to wait till I should be able to make such a complete research as I could wish, more especially as, by directing the attention of the profession to the question, it may be earlier decided. I expected to be able to contrast some of the large institutions containing young children in this metropolis with each other; but, so far as I have inquired, they are all supplied alike with bakers' bread containing alum. So far as I have been able to learn rickets are not common at present in the towns in the north and west, where home-made bread is chiefly used; and I was lately told, that in one town in Cornwall, where the people make their own bread, this complaint is almost absent; whilst in town a few miles off, where bakers' bread is consumed, the complaint is extremely common; but as my inquires have been only of a colloquial nature, I hesitate to mention places and persons. If it could be obtained, perhaps a return of the number of cases of rickets in the children under four years, as compared with the whole number, which are brought to the dispensaries, in towns where respectively the people buy chiefly flour or ready-made bread, would best help to decide the question.

It does not follow, if my conclusions are correct, that every child eating bread adulterated with alum ought to have rickets, or that every child fed with good bread ought to be free from the complaint; for, on the one hand, the other articles of food may often supply sufficient phosphate of lime without that of the bread, and, on the other hand, derangement of the digestive and urinary functions may prevent the phosphate of lime being assimilated when present. What we might expect, however, would be precisely what we observe--that rickets would be much more common in the children of the working classes fed almost entirely on bread than in those who have a greater variety of food. It can also be explained how the bones ultimately become hard from the gradual accumulation of the scanty supply of phosphate of lime derived from milk, potatoes, and other articles of food, whilst that which ought to be supplied in the bread is still withheld.

If the deformity in the bones of the legs does not proceed too far, it has a great tendency to diminish, and even disappear, as the children grow up; and the artificial support which is afforded by iron instruments and splints, both in the various hospitals for deformities, and under the advice of private medical men in London, diminishes very much the amount of permanent deformity which would otherwise be met with.

In my examinations of bakers' bread I have been much struck with the apparent universality of the practice of using alum, and with the large quantity employed--a quantity between twenty and thirty times as great as that usually stated by authors. I have met with alum, not only in the ordinary bread sold by bakers, but also in captains' biscuits, and in the so-called farm-house bread; and I was somewhat surprised to find that the high-priced bread, sold in the fashionable neighbourhood to the west of Regent-street contained more alum than the cheap bread sold in many of the poorer districts. I found that the bread supplied to me last autumn contained 10.13 grains of alum in 500 grains--i.e., 561 grains, or more than ounce and a quarter in the 4lb. loaf; whilst some bread obtained from a very noted baker contained 11.37 grains in the 500 grains, or nearly an ounce and a half in the 4 lb. loaf. The following is a brief account of the analysis of the latter bread:--500 grains, being carefully dried at the temperature of 100 Fahr., lost 128 grains of water, or more than one-fourth. Being carefully incinerated in a crucible, the ashes weighed 5.85 grains. The ashes yielded alumina, which, being washed, dried and ignited, weighed 1.2 grain, representing 11.37 grains of crystallized alum; with chloride of barium, they yielded 1.4 grains of sulphate of baryta, and with the nitrate of silver, 6.7 grains of chloride of that metal, representing 2.8 grains of common salt.

Dr. Hassall and some other authors have very properly pointed out that the only safe way to seek for alum is to incinerate the bread, and examine the ashes; but many writers go on repeating the statement that alum may be found by digesting the bread in distilled water, filtering, and applying tests to the water. In this way seldom more than a trace of alumina can be detected, even when the bread contains a large quantity; but it is probable that many persons take this short and easy method of examining it, and it is probably in a great measure owing to this circumstance that the bakers continue to use alum with so much impunity. An instance came under my notice not many months ago where a baker expected, with the utmost confidence, to have a satisfactory certificate to lay before the committee of a club-house respecting his bread, although it contained a great quantity of alum.

A probable way to break through what seems the universal practice of bakers to adulterate bread, would be for the committees of the public hospitals and the guardians of the poor to oblige the bakers who contract to supply their respective institutions to furnish an unadulterated article. No one pretends that alum is either nutritious or wholesome; and if the loaves without alum should cost a little more, owing to their carrying less water, no one can doubt that as much nutriment would be obtained for a given sum as under the present system.

Sackville-street, June, 1857.


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Fusia dot  118. "Cholera, and the water supply in the south districts of London"

Source: Snow, John. British Medical Journal 2, 17 October 1857, pp. 864-65 [Letter to Ed.].

By John Snow, M.D.

A passage, respecting the effect of water supply on cholera, in the recent document published by the General Board of Health, having been brought prominently before the British Medical Association, in a leading article of the Journal of October 10th, I think it highly desirable to point out that this passage does not by any means convey the whole truth, as regards the effect of the water supply on the epidemic of 1854. Instead of the cholera mortality in the houses supplied by the bad water being 3½ times as great as in the houses supplied by the better water (the statement of the Board of Health), it was in reality six times as great.

It may perhaps be asked, of what consequence are the exact proportions, so long as the principle is admitted? If the report were merely intended to produce in public authorities and private individuals a certain amount of scrupulosity with regard to the supply of drinking water, the exact numbers would perhaps not matter much; but, when the facts are laid before medical men, it is of the utmost importance that they should be correctly stated. Science cannot be advanced by incorrect quantities and numbers; and, in the present instance, the real facts have an important bearing on the question as to the nature of the material in the impure water which induces cholera, and the manner in which the same morbid material causes the disease in other cases, without the aid of water as a medium.

My attention had been closely applied to the particulars of the water supply of London for upwards of five years before the epidemic of cholera of 1854; and I had, from various sources, became [sic] acquainted with a number of circumstances which made it possible for a very conclusive personal inquiry to be made, in respect to that kind of influence of water supply on cholera which I had published in 1849. These circumstances were necessarily known to a number of workmen and several official persons, but probably not in their collective form to any other person interested in the mode of propagation of cholera, except myself. The particular circumstances of the water supply, and its adaptation to the kind of personal inquiry which I conceived and undertook, were first published by me in the Medical Times and Gazette of September 2nd, 1854, p. 247, and were alluded to in a leading article in the Association Medical Journal for October 27th of the same year.

I called myself at every house from which a cholera death had been registered, in the first seven weeks of the epidemic of 1854, in all the districts in which the supply of the two Water Companies in question was intermixed; and, if the illness had not commenced in the house in which the death took place, I then sought the real place of attack, and in either case I ascertained the water supply of the house. I did not rest satisfied with a mere verbal reply; but obtained, in all cases, such corroborative evidence as could leave no doubt on the point, and I have the notes of my result. As a proof of their general correctness, I may mention that Mr. Greenwood, the very intelligent registrar of Christchurch, Southwark, made an inquiry on the same point for the same seven weeks, in his district, and, on our comparing notes, our results were exactly the same in every instance, although our respective inquiries had been conducted in a different manner.

The result of my inquiry was that, in the first four weeks of the epidemic, the cholera was between thirteen and fourteen times as fatal in the population having the impure water supply of the Southwark and Vauxhall Water Company, as in the population having the improved supply of the Lambeth Company, taking into account the number of the population supplied respectively by each company. In the next three weeks of the epidemic, the mortality was nearly eight times as great in the one population as in the other.

Dr. Farr having been much struck with the results which I communicated to him of my inquiries, the Registrar-General, at the end of these seven weeks, directed the district registrars in the south districts of London, to furnish the water supply of each house in which a fatal attack of cholera might occur during the rest of the epidemic.

During this part of the epidemic, comprising ten weeks, and including its most severe period, the mortality was still more than five times as great in the population supplied by the first of the above mentioned companies as in that supplied by the other; so that the result of that part of the inquiry conducted through the office of the Registrar-General, afforded a strong corroboration of the correctness of the previous part. I have, moreover, shown in an article in the Journal of Public Health for October 1856, that the whole of the inquiry agrees with the relative mortality of the different districts and sub-districts supplied in varying proportions by the two Water Companies, both at different periods of the epidemic, and for the whole epidemic, in such a manner as could not happen unless the results of the inquiry were substantially correct. I have already stated that the relative mortality of the two populations differently supplied with water was six to one, when the whole epidemic is considered.

The results of the above inquiry having been canvassed by the Scientific Committee of the General Board of Health, a further inquiry was instituted, and was carried out within the eighteen months following the epidemic, and furnished the numbers quoted in the Journal of the Association. This further or supplemental inquiry was conducted as follows. Lists of the houses supplied by each Water Company were obtained from the two companies, and these lists were compared with the lists of deaths from cholera at the General Register Office. There are several reasons, however, why an inquiry thus conducted could only supply an approximation to the truth, and could bear no comparison, in point of accuracy, with a personal inquiry made on the spot, at the time of the epidemic.

The inquiry of the Board of Health is into the water supply of the house where the death took place, and not, like the previous inquiry, into that in which the fatal attack occurred; but many persons attacked with cholera in houses supplied by the Southwark and Vauxhall Company were removed to workhouses supplied by the Lambeth Company, whilst hardly any persons were attacked in houses supplied by the latter company, and then removed to a workhouse having the opposite supply, as I know from my personal inquiries in the first seven weeks of the epidemic.

Throughout the greater part of Lambeth, Newington, and the Borough, the houses were either without numbers, or numbered very irregularly; and the numbers were liable to frequent change, especially where new houses are constantly being added: therefore, numerous errors were liable to be made in comparing the lists. There were often two or three houses of the same number in the same street; thus it happened that, in the first fatal case I inquired about, the death did not occur at the first No. 6 I called at, but at the No. 6 down the other side of the way; and the water supplies of the two houses were different. Now this is particularly important; for, as the deaths were six times as numerous in the houses supplied with impure water as in those with the better supply, the result would be that, out of every six mistakes, five would transfer a death from the former houses to the latter, and only one would transfer a death from the latter houses to the former.

It so happened that the lists supplied by the Lambeth Water Company (that with the purer water) are so arranged and explained that every place might be made out, unless when the above mentioned difficulty about numbers occurs; but the lists supplied by the Southwark and Vauxhall Company are made out in such a manner as to be of only very partial service. They have a kind of alphabetical arrangement, but it is of no use. For instance, to put down such names as Albert Terrace and Providence Place, with no other information than that they are somewhere in a district which extends over ten or fifteen square miles, is to give very little information. Consequently, whilst all the deaths occurring in houses supplied by the Lambeth Company could be identified in the list, and others attributed to these houses from the sources of error above mentioned, it would necessarily happen that a great number of deaths occurring in houses supplied by the Southwark and Vauxhall Company could not be identified; and, in the Report of the Board of Health on Cholera, as affected by Impure Water, as many as 1,436 deaths, in the epidemic of 1853-54, are returned as occurring in houses supplied from unknown sources, although there were comparatively few houses which were not supplied by one company or the other.

The deaths in the epidemic of 1853 are included, with those of 1854, in the Report by the Board of Health which is quoted in the Journal of the Association; but this circumstance could not much affect the result, and certainly not in the direction in which it deviates from the original inquiry; for in 1853 there was but a small number of deaths, especially in the districts to which the water supply of the Lambeth Company extends.

For the various reasons stated above, we may conclude that the supplemental inquiry of the General Board of Health into the influence of water supply on cholera is of some value, and corroborates the original investigation, but ought by no means to be quoted as an exact exposition of facts, or be allowed to set aside the previous inquiry.


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Fusia dot  119. "On the outbreak of cholera at Abbey-Row, West Ham"

Source: Snow, John. Medical Times and Gazette 15, 24 October 1857, pp. 417-19.

By John Snow, M.D.

On seeing the notice in the Medical Times and Gazette of the 17th instant of the outbreak of cholera at West Ham, I called on Dr. Elliott, of Stratford, who was kind enough to take me to the place where the outbreak occurred, and to inform me of the various particulars connected with it. I also made some inquiries of the inhabitants, and the proprietor of the greater part of the property was good enough to give me some information respecting the drainage. The row of small houses in which the outbreak has occurred is situated, as was stated in the Medical Times and Gazette, about a hundred yards from the River Lea, and about two miles from the Thames. The row consists of eighteen dwellings: sixteen of these contain but two rooms, one over the other, and a small back kitchen; at the north-east end of the row, which is the farthest from the River Lea, is a house with four rooms, and at the opposite end of the row is a still larger house, occupied by the proprietor of the large flour-mills, a few paces further on, situated on the banks of the Lea, and partly overhanging it.

The only water which the inhabitants of Abbey-row used for every purpose was that of a pump-well near the middle of the row, and across the road. It is a shallow pump-well of not more than twenty feet deep, in the opinion of the proprietor. A few years ago, before this well was sunk, the inhabitants of the place had no other water than that of the Lea. Besides Abbey-row, the above pump supplied a dwelling in the above-mentioned flour-mill, a small dwelling just beyond the mill, and across the bridge, called the toll-house, and four very small cabins of one room a little way--perhaps thirty yards--from the mill, and situated under the bank of the Lea, and much below its level when the tide is up. When standing on the bank of the Lea, just above the water’s edge, one is almost on a level with the roofs of these cabins.

The number of inhabitants in the dwellings having the water supply of the above-mentioned pump was, at the beginning of the epidemic, 115, and they were distributed as follow; 93 in Abbey-row, 7 in the flour-mill, 2 in the small toll-house, and 13 in the four little cabins. The cases of cholera at West Ham have been confined to this population, with one exception to be mentioned afterwards. Out of the above-mentioned 115 persons, 6 died of cholera between the 3rd and 13th of the present month, being rather over 5 per cent. These 6 fatal cases indeed all occurred in Abbey-row, having but 93 inhabitants. Dr. Elliott informed me that there were also 6 or 7 very severe and decided cases of cholera which ended, or were in progress, of recovery. Cases which proceeded no further than diarrhœa, but which form a part of the same outbreak were numerous: by inquiry from house to house I found that, from September 29th, when the first case (not fatal) occurred, till October 16th, there had been 19 cases of illness with bowel complaint, sufficiently severe to require medical treatment, in addition to the fatal cases; so that above one-fifth of the inhabitants were more or less implicated in the epidemic. As some families were from home, or had removed, there might have been slight cases of illness that I did not hear of. I was only informed of one case of illness amongst the 13 inhabitants of the four little cabins mentioned above, so that they seem to have escaped rather better than the other inhabitants having the same drinking water. These cabins are inhabited by the families of labourers. The inhabitants of Abbey-row are clean looking and apparently industrious people. The men are chiefly employed in a large silk factory close by. The single case of cholera which occurred to any one at West Ham, or even near it, so far as is known, happened to the sister of a licensed victualler, living opposite to Abbey-row, and assisting in the business. The public house was supplied by a separate pump-well, on the premises. The public-house is distant from Abbey-row only the width of the road; and I may mention that, except where this public-house obstructs it the view extends from the front of the dwellings in Abbey-row across the marshes to the shipping at Blackwall and Greenwich.

The water of the pump which supplied the houses described above, was very impure, letting fall a copious deposit of dirty organic matter on standing. The nature of this deposit leaves no doubt on any one’s mind that it proceeds from the sewer and drains which pass within a few feet of the well: but whether the leakage is by percolation, or by a direct opening, has not yet been determined. There is a ditch or sewer which passes behind the pump-well, and within a few feet of it. The ditch is now covered at this spot, but Mr. Kayess of West Ham Abbey showed me a plan of it. This ditch or sewer flows into the Lea when the tide permits, but at other times the water from the Lea flows back up the ditch, as may be observed; for it is still open in a great part of its course between the river Lea and the pump. The drains from Abbey-row pass under the road, and pass very near to this pump-well, before entering the above-mentioned tidal ditch. The five houses in Abbey-row nearest to the house of the proprietor of the flour-mill belong to that gentleman; they are each provided with a privy over a cesspool; some, at least, of these privies have an overflow drain, which pass under the house and road to reach the tidal sewer. The remaining twelve houses belong to Mr. Kayess, mentioned above, and the privies of the first eleven of these were converted about a year ago into water-closets, the water being however carried from the pump and thrown down.*

(*It was in one of these houses (No. 8,) that the first case of cholera occurred on September 29th.)

These closets communicate, by means of drain pipes, with a large covered cesspool at the back of the row, which receives also all the water used in the cottages; the overflow from the cesspool passes into the tidal sewer, by a drain which passes under the floor of the first house (that adjoining the last of the five belonging to the proprietor of the flour-mill) and then passes under the road and near to the pump-well.

The impurity of the water of this pump-well was a chronic affair, and therefore, as mere impurity, would not account for the remarkably sudden and circumscribed outbreak of cholera which has occurred around it. Moreover, mere impurity in the water was never known to cause, or even aggravate, cholera. In all the sudden outbreaks of cholera which I have been able to connect with impure water, and have related in previous volumes of this Journal, and the two Journals from which it sprung, there has always been either absolute proof or strong presumption that the evacuations of a cholera patient had entered the water. In the fearful outbreak of cholera near Golden-square, which I described in the Medical Times and Gazette in Sept. 1854, I could myself only bring forward statistical and other evidence of the effect of the water, not having the power to open the well and adjoining drains; but when this was done by the parish authorities, at the suggestion of the Rev. Henry Whitehead, six months afterwards, the pump-well which caused the outbreak was found to be the recipient of the overflow from a cesspool, into which the evacuations of a child ill of cholera had been emptied within three days before the great irruption of the disease.

At Abbey-row, the contamination of the pump-well, forming the sole water-supply of the place, by the drains and sewer, which carry away the overflow from the water-closets and privies of that row, explains the way in which the cholera was propagated to so great an extent on the spot, when once it was introduced. Many of the persons attacked had had no personal communication with any previous patient. Some cases of illness followed a day or two after a previous case in the same family, and in these instances it is probable that the morbid matter of cholera was swallowed in the more ordinary way, without the medium of the water. I ascertained that a great number of the persons attacked were in the habit of drinking the water cold: but, in addition to the opportunity of taking the disease when it is first introduced into a household without the intervention of the water, it must be acknowledged that water, even before being boiled, enters in so many ways into the preparation of articles of diet, that every one is liable to take it.

Cholera prevailed in Abbey-row in 1832, 1849, and 1854, but not to the same extent as in the present month.

With regard to the introduction of the disease on the present occasion, the explanation I have to offer is somewhat circuitous, but is well supported by what has occurred in previous epidemics. In the Weekly Return of Births and Deaths for September 26 of the present year, the following death is recorded:–-"at Horselydown [sic], on board the Lütcken, on 22nd September, a seaman, aged 27 years, cholera Asiatica (nineteen hours)". The following note is added–-"The ship Lütcken arrived at Horselydown on the afternoon of the 21st instant from Harburgh (Hanover); she had touched at Glückstadt, and stopped there twenty hours, at which place cholera raged lately, and carried off five per cent of the inhabitants. The deceased had not been ashore at Horselydown." Glückstadt is on the Elbe, thirty miles below Hamburgh. The evacuations of the seaman who died at Horselydown [sic] would, of course, be thrown overboard, according to universal custom. There might also be other cases of cholera in the shipping from the ports on the River Elbe, lying in the Thames; but if not fatal, or occurring beyond the metropolitan boundary, we should not hear of them. From what occurred at the pump-well near Golden-square, in 1854, and at many other places in former epidemics, it is evident that the active material contained in the cholera evacuations is not destroyed by being mixed with water. Now, a morbid material which communicates any disease from one person to another, does so by the faculty of reproduction, which takes place during the so-called period of incubation, the disease which ensues being due, not to the matter first introduced, but to the resulting crop. But no one will deny that everything which multiplies and reproduces its kind must not only be organic, but organized. Even yeast is organized; and small-pox matter consists chiefly of cells. The morbid material of cholera, therefore, is not dissolved in water so long as it retains its properties, but is only distributed; and the amount of water in which it is so distributed ought merely to diminish the chances of its reproducing the disease, but not necessarily to prevent its doing so. Now, anything thrown into the Thames at Horselydown which can float goes backwards and forwards with the tide, ultimately, as a general rule, to reach the sea; but, in the meantime, it may pass up the Lea, or other tributaries, and also up any tidal ditches which communicate with these tributaries. If a sack of poppy seeds or mustard-seeds were thrown into the river at Horselydown, there is nothing more probable than that a few of them might find their way up the Lea, and the tidal sewer, and into the very pump-well at Abbey-row. I beg the attention of the reader to the following account of what occurred in previous epidemics. It will be remarked, in the meantime, that the first case of cholera at Abbey-row occurred seven days after the death of the seaman on board-ship at Horselydown.

The first case of Asiatic cholera in London in the autumn of 1848, was, according to an inquiry instituted by the then Board of Health, that of a seaman named John Harnold, who had newly arrived from Hamburg, where the disease was prevailing. The date of his death was the 22nd of September, like that of the seaman who died in the present year, and he died also at Horselydown, not, however, on board ship, but in a lodging near the shore. There was a severe case on September 30, in a man who came to lodge in the room in which Harnold died, but this man recovered. The first twelve fatal cases succeeding that of Harnold took place in the following situations. On September 30, a man was attacked in Lower Fore-street, Lambeth, and died on the following day; at the same time that this man was attacked, the first of a series of cases occurred in White Hart-court, Duke-street, Chelsea, near the river. A day or two afterwards there was a case at 3, Harp-court, Fleet-street; the next case occurred on board the hulk Justitia, lying off Woolwich; and the next to this in Lower Fore-street, Lambeth, three doors from where the previous case occurred. It was not till October 5, that a case was registered, as occurring in any other part of London. The inhabitants of Lower Fore-street, Lambeth, as well as those of White Hart-court, Chelsea, had no means of obtaining water in 1848, except by dipping a pail directly into the Thames. The inhabitants of Harp-court, Fleet-street, were in the habit, at that time, of fetching water from St. Bride’s pump, which was afterwards closed in consequence of its having been found that the well had a communication with the Fleet-ditch sewer, up which the tide flows from the Thames. When the cholera revived again in 1849, the first case in the sub-district of "Lambeth; Church, 1st part," was in Lower Fore-street; and on the commencement of the epidemic of 1854, the first case of cholera, in any part of Lambeth, and one of the earliest in London, occurred at 52, Upper Fore-street, where the people had no water but what they obtained from the Thames with a pail, as I ascertained by calling at the house.

Since 1854 the persons who drink Thames water, obtained within reach of pollution by the shipping and the London sewers, are diminished to a very small number. The water companies supplied from the Thames now obtain their supplies above the reach of the tide, and the river itself in London is become so foul that people are deterred from drinking it. It is chiefly for these reasons that we may hope that cholera will not at present become epidemic in London.

Sackville-street.

P.S. The river Lea divides near West Ham into several branches, which re-unite into one stream before entering the Thames. What Dr. Elliott and I have called the Lea is that branch of it furthest to the east. It is navigable, when the tide is up, as far as the flour-mill mentioned above. The handle of the pump at Abbey-row was removed on Monday, the 12th instant, and only one death occurred after this day; but the people had already begun to suspect the pump on Sunday, the 11th, and sought water elsewhere.

flashback Aside - Editorial Critique in BMJ of Snow's "West Ham" article flashback

Source: Editors. The cholera at West Ham, British Medical Journal, October 31, 1857, p. 916.

The outbreak of cholera at West Ham has, we are glad to say, ceased. The six deaths which took place in "Abbey Row," together with the decrease at Horsleydown, will, therefore, we trust, include the amount of the scourge for the present year. It was at first stated that in several of the cases there was no premonitory diarrhea; but Dr. Macloughlin has since carefully investigated the whole of them, and has arrived at the conclusion that diarrhea was present in every case.

Dr. Snow, whose ideas respecting the transmission of choleraic poison are well known, asserts tha the evauations of the seaman who died of the cholera on board ship at Horsleydown were thrown into the Thames, and that the poison was in this manner transferred to the well from which the people in Abbey Row drank, the well being subject to the overflows of the river Lea, which is several miles from the place where the organic choleraic evacuations were discharged into the Thames. If it be indeed possible to impregnate the immense mass of water in such a river by such apparently homopathic doses of choleraic matter, it seems to us that every person who drinks of that water, and not only every person who drinks of it, but every person who breathes the air on its banks loaded with its vapour, should be subject to an attack of the epidemic as well as the unfortunate people of Abbey Row, who at least had the advantage of receiving the affected water filtered through the earth.

Dr. Snow perhaps argue, inasmuch as the minute particles of cholera seed would become widely dispersed in the water of the Thames, the chances are that only a few of them would come into contact with the human stomach. This would indeed be one manner of explaining the difficulty; but we confess we can scarcely imagine one of these particles so perverse as to sail up the Lea, and actually seek out a certain pump through the very earth that lay below it, and the sewer it was supposed to have entered; for, be it remembered, it is not at all proved that the Lea water finds it way in any other manner into the well, if, indeed, it finds its way there at all. It is much more easy to believe that the cholera evaculations would float up and down the main stream, than they should enter a small well, as they must have done, according to Dr. Snow's hypothesis. Of course, it is impossible to disprove that the gentleman's explanation; but we must confess, with Dr. Lankester, that he does not, in our opinion, at all succeed in proving his case. What has become of all the other cholera seeds? Are they stil floating about the Thames, and only waiting for point between the North Foreland and the place where the tidal influences ceases? If indeed, these death-dealing germs are always laying in wait for us in the river, what guarantee have we that they may not be taken up by the pipes of the water company, and thus be distributed to us any morning as we wash our teeth? Dr. Snow may object, indeed, that the filters interpose between us and "pure death" in the form of this unfortunate seaman's floating dejecta, but he has already managed to percolate it through the earth at Abbey Row in order to get it into the well.

This theory is, we confess, a very alarming one, and calculated to keep Londoners from trusting water in any form. And why Londoners only? The cholea germs may escape out to sea, and ultimately poison somebody at the Feejee Islands -- for the germ, according to Dr. Snow, would appear to be indestructible. We trust Dr. Snow will pardon us for thus carrying out his theory to an absurd conclusion, and beg to assure him that it is far from our wish in any way to depreciate his labours with respect to cholera; they have been unsparing and able, and entitle him to the respect of his medical brethren. We fear, however, that he is carrying his theory of the manner in whch cholera is propagated too far, in thus attempting to clip and shape any new oubreak so that it shall fit the Procrustian bed he had made for it. That cholera evacuations may be conveyed from one person to another by means of water, and thus spread the disease, is most probably, under certain circumstances, the case; but Dr. Snow should scarcely have floated his cholera germs with such unerring accuracy for two miles up a great tidal river and its tributary, into a sewer, and thence into a well, in order to account for the deaths of six people from cholera in Abbey Row.

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Fusia dot  120. "On the origin of the recent outbreak of cholera at West Ham"

Source: Snow, John. British Medical Journal 2, 7 November 1857, pp.934-35 [Letter to Ed.].

Letter from John Snow, M.D.

Sir,--I have no complaint to make of the criticism of my views on the above subject, which is contained in a leading article of the Journal of Oct. 3lst; but I shall be glad to be allowed to make a few remarks by way of defending my opinions, and to allude to a case in connection with the outbreak that I was not acquainted with when speaking at the Medical Society of London.

In the first instance, I should like to say that I have not clipped or shaped this outbreak of cholera to fit the bed I had made for it; on the contrary, it came and shaped itself exactly to the conclusions which I had drawn from the observance of previous epidemics. This outbreak at Abbey Row, West Ham, took place in a community supplied by a particular pump-well; the water of this well was distinctly polluted by a sewer, which receives the overflow from the cesspools of this community; the tide flows up this sewer from the Lea, and up the Lea from the Thames. Moreover, there had been one case known and registered of death from cholera on board a ship in the Thames from a port where the cholera was very prevalent, a few days before this outbreak at West Ham. In treating of the early cases of cholera in 1848, occurring by the side of the Thames, and near St. Bride's pump, a few days after the death of a seaman from Hamburgh, I gave an explanation, some years ago, precisely like that which I now offer of the outbreak at West Ham. (See London Medical Gazette, vol. xlvii, p. 1051.)

The case connected with this outbreak, of which I was not previously aware, is one investigated by Dr. Ansell. At the time of the cases at West Ham, just beyond the borders of the metropolis, there happened in the whole of London just one case, which, by suddenly attacking a person in good health, and proving rapidly fatal, showed itself to be of the true Asiatic type. This case was that of a boy, aged 14, living at Bromley, about two miles from Abbey Row; he passed this place with his father, on October 7th, on their return from a long walk. He lagged behind, which attracted his father's attention, who looked back, and saw the boy drinking at the pump above alluded to. The boy was still quite well on the evening of the following lay, but at five o'clock in the morning of the 9th, he was seized “with diarrhœa, vomiting, great prostration, darkness of surface, thirst, loss of voice,” and he died in twenty hours. This case resembles two cases which occurred at West End, near Hampstead, in persons who drank water which was conveyed in a bottle from the pump in Broad Street, Golden Square, in 1854. In such cases there can be no doubt that the very matter which produced the attack was swallowed in the water; and they may well lead to an admission like that made in the Journal of today, “that cholera evacuations may be conveyed from one person to another by means of water, and thus spread the disease, under certain circumstances.” But this is to let in the small end of the wedge; and when once it is admitted, without pushing it to the Feejee Islands, it is difficult to prevent its going as far as circumstances require and permit. In the inquiry into the effect of water supply in cholera in the south districts of London, which I alluded to in a recent paper, I found that in the early part of the epidemic of l854, nearly all the cases of cholera occurred amongst persons having the impure water of the Southwark and Vauxhall Company. But if like causes act in the same manner when they produce like effects, on comparing the action of the polluted pump-wells with that of the Company's water, we must conclude that, in the latter case, the cholera evacuations passed first down the sewers, then up the Thames to Battersea, and afterwards through the water-pipes to the distance often of several miles. This, however, is a route quite as long and as circuitous as from a ship at Horsleydown to the pump-well at Abbey Row; but for my own part, if it is acknowledged that the morbid matter of cholera can be mixed with the water of a pump-well, and remain for even a few hours without being destroyed, I see no difficulty in its passing a few miles with the tide, which moves in the river almost as fast as a person walks.

There may have been other cases of cholera in the shipping in the Thames, from the Elbe and the Baltic, besides the one registered at Horsleydown, but if there were not, it is unnecessary to suppose that the quantity of cholera poison was so limited that it all required to go up the Lea and the tidal ditch to Abbey Row; or, on the other hand, that it was so plentiful as to be distributed in every pailful of water in the Thames; something between these extremes is what the circumstances of the recent outbreak and former epidemics suggest. I am ready to admit that the greater part of any impurity emptied into the Thames might go straight up and down with the tide, and reach in a few days the salt water, which nobody can drink; but it is a fact that a part of the water of the Thames does flow up the Lea, and a part of this also up the tidal ditch to Abbey Row, carrying with it more or less of every kind, of impurity which enters the Thames.

In an inquiry which the Rev. H. Whitehead made, in continuation of that which I commenced, respecting the water of the pump near Golden Square, he was led to conclude that, at one period, hardly anyone drank of the water without being attacked with cholera. The evacuations of one patient in that instance appeared to occasion above 600 fatal attacks within the space of a very few days. When the cholera evacuations enter a large river like the Thames, the result, as might be expected, is different. In the autumn of 1848 the first case imported was followed, in a few days, by several cases at different parts of the river's banks, amongst the population using water obtained directly from the river; and these cases were followed by others more numerous, chiefly amongst the population supplied with water obtained from the Thames at Battersea and Chelsea; and the fresh cases again supplied the morbid poison for a large number, and so the epidemic went on increasing. The like events followed in 1853, but in the present year, when few persons use water which is in any way connected with the tidal part of the river, the first imported case of cholera has been followed by other cases at one point only, and the disease has not spread further.

Since the last epidemic of cholera, the water supply of a great part of London has been entirely altered. At present no water company draws its supply from any part of the Thames which is within reach of pollution by the shipping, or the sewers of the town. The water supply of London is now different from its condition at any former period, and that has happened now which has not occurred before in the history of cholera in this metropolis. On every former occasion, when cholera prevailed in Hamburgh and other ports in the north of Europe, it extended to London; and the first cases were followed by others, and these again by more, till the disease was epidemic. This last summer and autumn cholera has again prevailed in the ports in the Baltic and the Elbe; it has again extended to London, and one well-marked imported case has been flowed by a group of cases on the borders of London, so well marked as to leave no doubt of their nature; but here the disease has left off for a period of already eighteen days, and, whatever may follow, this is a halt which occurred on no former occasion.

So far from it's being my opinion that the morbid matter of cholera is indestructible, I have from the first considered that it is very perishable, and that when mixed with water it cannot preserve its powers more than a few days; this being one cause why an epidemic often dies out so quickly. Dr. Wm. Budd advocated the same view in his able articles in the Association Medical Journal in 1854 and 1855. I believe that cholera poison, destructive as it is in certain circumstances to the human species, has many enemies, is easily destroyed, and, what is of more importance, is still more easily avoided.

I regret that I cannot enter fully into my views regarding the pathology and history of cholera in the short space to which it is necessary to confine this article; and I beg the reader to remember that, although I find it necessary to write most on that part of the subject which concerns the communication of cholera through the medium of water, its propagation by swallowing the morbid poison without this medium, plays a very important part in its progress, more especially in the crowded habitations of the poor.

I am, etc.

John Snow, MD.

Sackville Street, October 31st, 1857.


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Fusia dot  121. "On the case of congenital fissure of the sternum"

Source: Snow, John. Medical Times and Gazette 15, 28 November 1857, p. 561 [Letter to Ed.].

To the Editor of the Medical Times and Gazette.

Sir, --When I had the opportunity of examining the case of Eugene Groux, in the summer of 1855, I arrived at a conclusion respecting the cause of the pulsation seen and felt in the situation of the right auricle, which differed from the opinion which had been expressed on the case, so far as I am aware, and involved a point in the healthy action of the heart which was novel, so far as I know, though I may be mistaken. I recorded my conclusions in the book which M. Groux carries with him, and a little time afterwards sent a short communication to the Lancet on the subject.

I am very much gratified to find, from the Medical Times and Gazette of to-day, that Dr. Pavy has arrived at exactly the same conclusion as myself with regard to the cause of this pulsation, and I trust that it will not be unpleasant to Dr. Pavy to find that he and I are of the same opinion with regard to the cause of a phenomenon which exists, no doubt, in every healthy heart.

The following short passage from my communication will show that Dr. Pavy and I have given exactly the same explanation of the cause of the pulsation.

"When the ventricles contract, the portion of blood which is at their entrance is necessarily driven back into the auricles before the closing auriculo-ventricular valves, and the moment the ventricles become relaxed, the blood in the auricles is drawn onward again into them. It is the wave of blood so driven back into the right auricle by the tricuspid valve, as it is closed by the contraction of the right ventricle, which causes the pulsation seen and felt in the situation of the right auricle in the case of M. Groux, while the relaxation of the ventricle causes the sudden subsidence of the tumour."--Lancet, July 7, 1855, p. 17.

It is with regard to the pulsation, or rising up of the tumour, that we are entirely agreed, while there is a little difference between our explanations of its subsidence. Dr. Pavy has illustrated his conclusions, and possibly arrived at them originally, by vivisections on the dog, and he also makes some important remarks respecting the time when the auricles contract, a point on which I did not treat. I expressed the opinion, however, that "the filling of the tumour caused by the right auricle seems to be exactly synchronous with the first sound of the heart."

I made a remark respecting the time of the impulse of the apex of the heart and the pulsation of the aorta, which was not quite correct, as I find after I have had an opportunity, kindly offered me by Dr. Scott Alison, of examining the case with his sphygmoscope, but this slight error did not affect the main features of the case.

I am, etc.

John Snow, M.D.

Sackville-street, November 21, 1857.


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Fusia dot  122. "Drainage and water supply in connexion with the public health"

Source: Snow, John. Medical Times and Gazette 16, 13 February 1858, pp. 161-63, Part 1.

Part 1

By John Snow, M.D.

I was visiting a gentleman in the West of England some time ago, and he showed me the plan of the drainage of his house and garden. The drains received the proceeds from the water-closets of the house, and they were made to empty their contents into a brook, which flowed along the lower part of the grounds. I had observed that this brook turned a flour-mill in the estate, about a quarter of a mile lower down the stream, so I inquired whether the miller and his family had any other water for drinking and preparing their food besides that of the brook. The owner of the property replied that they had not. He said he had never thought of that subject, but he would try to get the miller some other water. I do not know whether or not he succeeded; and I have only alluded to the circumstance because it is an instance, on a small scale, of what is occurring nearly all over the country. In very many places the drinking water of the community is polluted by the drainage from water-closets, and the constituted authorities try, with more or less of temporary success, to procure other water.

None of the Water Companies which supply this metropolis have, for the last eighteen months, obtained any water which is polluted by the sewage of the town. Five of these Companies, however, still obtain water from the Thames, in the neighbourhood of Hampton and Thames Ditton, where the river becomes every year more impure, from the contents of the water-closets of houses and villages situated on its banks. It is probable, indeed, that from the subsidence of the water in large reservoirs, and from its filtration, it is incapable of communicating disease; but the inhabitants of London ought not to be satisfied with a probability on this point, they ought to have an absolute certainty that disease cannot be communicated by the water supplied to them. Except for the enormous quantity of water which is required to wash away the contents of water-closets, London would, no doubt, by this time have been entirely supplied with water from springs and wells at a distance, or from deep wells in the chalk formation under the metropolis.

The fact that water-closets cause the pollution of the rivers is not the greatest evil attending them, for rivers can never be entirely free from pollution; a greater evil is that they occasion the demand for such an inordinate quantity of water, that, in most cases, a supply from springs and wells cannot be obtained, and the polluted rivers have to be resorted to for the supply. Croydon and a few other towns of moderate dimensions are indeed supplied with water from deep wells, and Manchester and two or three towns in Scotland are supplied with surface water from extensive uncultivated moors; but a great number of towns are supplied with river water, which is more or less liable to pollution according to the situation at which the water is taken, and which is constantly becoming more impure, from the increasing adoption of water-closets, even in rural districts.

A great part of the water supply of most towns, and almost the entire supply of the rural districts, is derived from pump-wells, which are often very shallow, and are extremely liable to be polluted. It is my opinion that the absence of drainage, and its defective condition, are injurious to health only by the contamination they cause to pump-wells, or other supplies of water; and that when the health of the community is improved by improved drainage, either in town or country, it is by the amendment which is effected in the drinking water of the locality. I believe also that houses situated on gravel are generally more salubrious than those situated on clay, because organic matters are usually oxidized in passing through the gravel, and converted into mineral substances, chiefly nitrates, which have not the power of communicating disease. It is only when the source of pollution is very close to the pump-well that the gravel does not oxidize the organic matter.

I consider that the ordinary opinion which attributes the illness caused by absence, or imperfection of drainage, to effluvia given off into the air, is altogether a mistake. My reasons for this view of the subject are as follow. In the first place, whenever I have been able to separate the effluvia in question from real causes of disease, I have found an absence of effect. During the cholera year 1854, for instance, the Fleet-ditch was open for a considerable distance, and was covered in during the summer of 1855. The part open in 1854, and previously, passed through portions of the sub-districts of Saffron-hill, of the north sub-district of West London, and of St. James's, Clerkenwell. Now the mortality from cholera, in the Saffron-hill sub-district, was only at the rate of five in 10,000 inhabitants. The mortality in St. James's, Clerkenwell, was only eleven in 10,000; and the mortality in the north sub-district of West London was only five in 10,000, when the deaths in St. Bartholomew's Hospital are deducted.

In 1849 a part of Bermondsey, called Jacob's Island, was surrounded and intersected by ditches as wide as an ordinary canal, and covering several acres. The ditches were usually kept full, and emptied only at intervals. The water of the Thames admitted into them received the sewage of the surrounding population, either directly, from privies which over-hung the ditches, or through kennels [gutters] and drains. A number of the inhabitants of Jacob's Island, and the streets immediately surrounding the ditches, had access to no other water except that of the ditches. They usually allowed it to stand awhile, for a sediment to subside, before they drank it. The Metropolitan Commissioners of Sewers caused an inquiry to be made, at the end of the epidemic of 1849, into the effect of using the water of these ditches; and Mr. John Grant, the Assistant Surveyor to the Commissioners, was kind enough to favour me with the result. In the streets inclosed by the ditches, and immediately surrounding them, there were 7,286 inhabitants. Of these there were 865 individuals having no other supply of water than the ditches, and the remaining 6,421 had the supply of the Southwark and Vauxhall Company, or were supplied by private pumps. During the first nine months of 1849, 18 deaths took place from cholera, and eight deaths from other causes, amongst the 865 persons having no water supply but that of the ditches; and 95 deaths from cholera, and 46 from other causes, amongst the 6,421 persons having another supply. The mortality from cholera was, consequently, at the rate of 208 in 10,000 amongst the persons using ditch water, and 147 in 10,000 amongst the inhabitants who had the supply of the Southwark and Vauxhall Water Company, or that of private pumps. The mortality of the population living amongst and around the ditches, but not drinking the water, was, in fact, almost exactly the same as that of the other inhabitants further removed from the ditches, whilst that of the people who were obliged to drink the water was more than one-third higher, as is shown by the following figures from the report of the Registrar-General. St. James's, Bermondsey, in which Jacob's Island is situated, suffered a mortality from cholera of 142 in 10,000; St. Mary Magdalen, Bermondsey, a mortality of 159 in 10,000, and the Leather Market sub-district of Bermondsey, a mortality of 160 in 10,000. It is proved, therefore, that the population of Jacob's Island did not suffer in their health from the effluvia of the ditches amongst which they lived.

Between the cholera of 1849 and that of 1854, the ditches about Jacob's Island were all filled up, and the late Mr. Chas. Walsh reported that the cholera on that spot was not worse in 1854 than in the surrounding district. Bermondsey suffered more from cholera in 1854 than in 1849, owing to the Thames water, with which it was supplied, having become more impure in the interval. The greatest covering in or filling up of open sewers or ditches which had taken place anywhere in the Metropolis was in St. James's, Bermondsey; and yet the mortality from cholera in 1854 was 192 in 10,000, being higher than in any other parishes in the south districts of London, except St. Saviour's and St. Olave's, which had the same water supply, and contain also the two large Hospitals.

Mr. Glaisher, in his Report on the Meteorology of London, in relation to the cholera epidemics of 1853 and 1854, expresses his opinion that the disease was increased by the impure exhalations from the river Thames. An examination of the subject in detail does not, however, confirm this opinion. There are seven registration sub-districts situated at the river side, and extending from the sub-district of Charing Cross to that of the south-east sub-district of the City of London inclusive, and every one of these sub-districts had a mortality from cholera, in the epidemic of 1854, considerably below the average of that of the Metropolis. The gross population of these sub-districts was 86,815 in 1851, and the mortality from cholera in 1854 was 203, or 23 in 10,000; that of the entire Metropolis being 45 in 10,000. These seven sub-districts are supplied with water by the New River Company. The sub-districts situated at the river side on the south of the Thames had generally a high mortality from cholera, because they were chiefly supplied with unfiltered water by the Southwark and Vauxhall Company from the river at Battersea; but the sub-district of Lambeth Church, first part, which extends along the river side from Westminster-bridge to Vauxhall-bridge, and was chiefly supplied by the Lambeth Company with water from Thames Ditton, had a mortality from cholera of only 29 in 10,000. It should be observed, also, that districts situated at a good distance from the river had a high mortality, when they were chiefly supplied with water by the Southwark and Vauxhall Company. Thus Walworth, which is from a mile to a mile and a half from the Thames, had a mortality of 131 in 10,000; and Camberwell, more than two miles from the river, had a mortality of 136 in 10,000. Mr. Glaisher tries to explain this high mortality at a distance from the river, by supposing that the exhalations are confined by the neighbouring high grounds; but in another part of his report (p. 23), he has shown that Camberwell is beyond the influence of the Thames and the thick atmosphere of London, and that it enjoys a meteorology similar to that of the country near London. There is no situation in which the exhalations from the Thames would be more liable to be confined by the neighbouring high ground than in the valley of the Fleet river or ditch; and in 1854 this ditch was uncovered for a great distance, and was much more impure than the Thames, yet the districts in its neighbourhood suffered extremely little from cholera, as was before stated.

The fact that persons who work habitually amongst offensive animal substances do not appear to suffer in their health, confirms the view that no material injury arises from the effluvia of sewers and drains. The accompanying Table, No. 1, contains the mortality in 1851 amongst persons occupied in certain offensive trades in England and Wales, from the Fourteenth Annual Report of the Registrar-General. These trades comprise the second and third sections of the twelfth class of the Registrar-General, and comprise all the persons working in grease, bones, intestines, skins, hoofs, and horns. The deaths are arranged in decennial periods; and I have taken from the census report of the same year the number of persons living in these trades--both the entire number of 20 years and upwards, and the number living at each decennial period, and have calculated the deaths per thousand for each period of life. I have also done the same for males of all occupations, so as to draw a comparison between the population occupied in offensive trades, and the entire population of grown-up males. It will be observed that in the whole population of males of 20 years and upwards, the mortality was 20 per thousand in 1851, while among persons employed in offensive trades it was only 18.3 per thousand. In other words while the entire adult male population had an average duration of life of 50 years, the average duration of life in the offensive trades was 54 years and seven months. At each decennial period under 45 the proportion of deaths is considerably less in the offensive trades than in the rest of the male population; from 45 to 55 the mortality is precisely the same in both; and at ages above 55 it is slightly higher in the offensive trades.

Reference 122, TAble 1, Mortality Offensive Trades, Males, England and Wales

(Continue to PART 2)


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Fusia dot  123. "Drainage and water supply in connexion with the public health"

Source: Snow, John. Medical Times and Gazette 16, 20 February 1858, pp. 188-91, Part 2.

Part 2

By John Snow, M.D.

The material among the emanations from drains and sewers which is supposed by many persons to be most active in promoting zymotic disease is sulphuretted hydrogen gas; but it must be acknowledged that the chemist never catches any disease from this gas, when liberated in his laboratory; and that invalids drink a solution of it at Harrowgate and other places, without acquiring any tendency to zymotic disease, although the gas is undoubtedly absorbed into the blood. An instance occurred lately of this gas being set free on a very large scale, without its doing any injury to health. It is as follows:--

"At a certain point in Westerdale Head (North Riding) the process of jet-mining has been carried on for some time past, and a few weeks since it was observed that the heaps of shale excavated or turned over by the miners were giving out much smoke, and the smoke was accompanied by a noisome smell or stench. This smell, which is that of the sulphuretted hydrogen gas liberated from the decomposing alum shale, has been perceived at points not less than seven or eight miles, or even more, from the point of its origin; and every room in houses three or four miles distant is most offensively penetrated by it at all hours of the day and night. The burning heap is of large dimensions; many thousands of tons of the displaced shale lie in heaps more or less continuous. . . . It had been surmised that a mischievous effect on the health of the neighbourhood would be produced; but so far beyond the nauseous, suffocating fumes, which annoy everybody for miles in the direction of the wind from the burning heap, no harm seems to have been done; and it may be hoped, therefore, that none will now arise. Even among the inhabitants of the houses in the neighbourhood of the place no worse consequence than the annoyance from the almost intolerable stench has so far arisen."--Times, 7th January, 1858.

It is quite true that sulphuretted hydrogen will cause sudden death when breathed in a too concentrated state, but no argument ought to be adduced from this circumstance with regard to its causing illness, for carbonic acid gas will also cause sudden death, although it is a normal constituent of the atmosphere.

I have in former papers, in this Journal and elsewhere, been able to point out the very close connection which exists between the mortality of cholera and the contamination of the drinking water, by the contents of sewers and cesspools. It has very frequently been observed, that cholera was most fatal in situations where the ordinary mortality was highest; and, taking both these circumstances into consideration, there was reason to presume that the kind of pollution of the water mentioned above increased the ordinary mortality, at times when the cholera was not present. I am now able to show, from a set of statistics compiled and calculated from the Quarterly Reports of the Registrar-General, that this is the case. That part of this metropolis which is situated in the county of Surrey is supplied with water by two companies --the Lambeth Company, and the Southwark and Vauxhall Company. No other company supplied any portion of the metropolitan part of Surrey, except a very small portion of Rotherhithe, which is supplied by the Kent Waterworks Company.

The estimated population supplied by the Lambeth Company in 1854 was 166,906, and that supplied by the Southwark and Vauxhall Company 268,171. These numbers leave about 65,000 persons who were probably supplied by pump-wells, and lived chiefly in the more suburban districts, as Clapham, Wandsworth, Camberwell, and Norwood. The Lambeth Water Company, which supplied about one-third of the population of the metropolitan part of Surrey, obtained their water from the Thames in London, near the Hungerford Suspension Bridge, until January, 1852, when they moved their water-works to Thames Ditton, beyond the influence of the sewers of London. The Southwark and Vauxhall Company, which supplied more than half the population of that part of London which is situated in the county of Surrey, continued to obtain water from the Thames, between Vauxhall and Battersea, until July 22, 1855, when they obtained their supply from near the village of Hampton. I have shown, in the Table No. 2, the mortality in that portion of London which is in the county of Surrey, in every quarter of each year, commencing with 1850, and extending to June 1853, shortly after which period the cholera made its appearance. I have omitted the latter part of 1853 and the year 1854 from the table, as the cholera was present, and the mortality from this disease in this part of London has already undergone a very extensive and minute inquiry, extending to particular cases. Moreover, I do not wish on this occasion to inquire into the effect of water-supply on cholera, so much as on other diseases. The statement of the mortality in the table is, therefore, resumed at the beginning of 1855, and continued till the end of 1857. Throughout the table the mortality of the remainder of the metropolis during each year, and each quarter of a year, is shown side by side with that part of it which is situated in the county of Surrey.

Mortality of Metropolitan part of Surrey compared to rest of Metropolis - Part 1

Mortality of Metropolitan part of Surrey compared to rest of Metropolis - Part 2

It will be observed that in the years 1850 and 1851 the mortality of the metropolitan part of Surrey was considerably above that of the rest of the metropolis, being 1.8 per 1,000 above it in 1850, and 1.5 above it in 1851. In 1852, when a part of the water-supply of that part of London had been improved, the mortality still remained greater than that of the rest of the metropolis, but to a less extent than in the two previous years, only exceeding it by l.2 per thousand. In the first half of 1853, the mortality of the metropolitan part of Surrey exceeded that of the rest of London by only decimal 4 [0.4] per 1,000, or at the rate of decimal 8 [0.8] per 1,000 per annum. When the account of the mortality is resumed in 1855, after the cholera had passed away, it will be observed that the mortality of the metropolitan part of Surrey is still above that of the rest of London, in the two first quarters of the year; but on the 22nd of July, the Southwark and Vauxhall Company changed their source of supply from Battersea Fields to a point near Hampton, beyond the reach of the contents of the London sewers; then the whole of the metropolitan part of Surrey had an improved supply of water, and then, for the first time within the period of my inquiries, the mortality of this division of London falls, in that very quarter of the year, below the mortality of the remainder of the town. It remained below it in the last quarter of 1855, and also in the years 1856 and 1857, taking the mortality by the year together; and there are only two separate quarters in which the mortality of the Surrey Division of London rose a very little above that of the rest of the metropolis. I have not made any corrections for increase of population, because that of the metropolitan part of Surrey increased, from 1841 to 1851, exactly in the same ratio as that of the rest of London, and therefore the relative mortality of the respective divisions would have remained the same in the table, if the correction had been made.

The Chelsea Water Company removed their source of supply at the end of June, 1856, from Chelsea to a point of the river beyond the influence of the tide, and the mortality of the Chelsea and Westminster districts, which are supplied exclusively by this Company, has diminished in comparison with that of the rest of London. The diminution is, however, not so great as in the districts supplied by the Southwark Water Company, for the Chelsea Company used to separate a great past of the impurity from the water by subsidence and filtration before its distribution.

I have not had an opportunity to inquire into all the diseases besides cholera, which have been diminished by the improvement of the water supply; but I find that, since the change in the source of supply of the Southwark and Vauxhall Company, there has been a marked diminution in the deaths from diarrhœa and typhus, in the districts they supply. Since the commencement of 1855 the weekly reports of the Registrar-General have contained the deaths from these two diseases in the different districts of London, and I have compiled, in Table No. 3, the numbers of deaths from diarrhœa and cholera as they occurred respectively in that part of London situated in Surrey, and in the rest of London, from the beginning of 1855 to the end of 1857. It will be observed that in the two first quarters of 1855 the mortality both of diarrhœa and of typhus was higher in the metropolitan part of Surrey than in the rest of London; but that in the next quarter, that in which the supply of water was altered, the mortality of diarrhœa in this part of London fell below that of the rest of the town, and remained below it, with only two trifling exceptions to the end of 1857. The mortality of typhus in the Surrey part of London fell below that of the rest of the town, not in the quarter when the supply of water was improved, but in the following quarter, and has remained greatly below it ever since. I ought to remark, that the Registrar-General includes typhoid fever under the term of typhus.

I have in former papers adduced proofs that polluted water does not increase the prevalence of cholera by its acting in a general way, but only by conveying the special morbid poison of the disease, which must be present in the water, from a previous case or cases of the same malady. So, when polluted water increases the prevalence of other diseases, we must conclude from analogy that it acts in a similar manner, and that, when the water formerly supplied by the Southwark and Vauxhall Company increased the prevalence of diarrhœa and typhus, it acted by conveying the morbid material of these diseases from former patients.

Deaths from diarrhœa and cholera in Surrey and rest of Metropolis - Part 1

Deaths from diarrhœa and cholera in Surrey and rest of Metropolis - Part 2

The injury caused by impure water is by no means in proportion to the amount of impurity, but rather in proportion to the number of person who respectively contribute to, and partake of that impurity. Thus a pump-well supplying a single family may be grossly polluted for years, without causing or communicating any illness, and if it do so at last, the illness may not spread beyond the family. Or a pump may supply a large population, but if polluted only by the cesspool of a single house, may be a long time before it does any harm; like the pump-well in Broad-street, Golden-square, which caused no mischief during three epidemics of cholera, but caused a great mortality in 1854. It is when a river receives the excretions of a town and at the same time supplies the population with water that the mortality is greatest, as shown in Hull during the cholera of 1849; at Newcastle and Gateshead during the cholera of 1853, and in certain extensive districts of London in every epidemic. And that increase of mortality which is so striking in time of cholera goes on to a less extent at other times.

It follows from what I have said above that I should recommend the discontinuance of water-closets, or at least their diminution, instead of the continued increase of their numbers. A complete and well-regulated water-closet is so great a convenience that one cannot expect it to be discontinued in the better class of houses; but the so-called water-closet used by the working classes, who form the great bulk of the population, is according to the experience I have had, a worse nuisance than an open privy over a cesspool; as the recent excrement sticks about the pan and pipe, and is constantly disturbed by the water. In recommending the diminution of the number of water-closets, I of course do not suggest a return to the use of common cesspools; but some kind of moveable tank might be contrived, which should be charged with peat, or charcoal, or sawdust, or some other substance which would have the effect both of deodorizing the excrement, and bringing it into a state of disintegration, in which it could be more easily applied as manure. The tanks should be of a uniform size, so that a full one could be replaced by an empty one. It would be in new houses, and new neighbourhoods, that a plan of this kind could be best introduced. Dr. Hawkesley has contrived a plan for deodorizing the contents of water-closets, but he retains the use of the water.

As I have said above, the greatest evil of water-closets is the inordinate demand for water they occasion, and thus prevent most large towns being supplied otherwise than from the polluted rivers. If the general use of water-closets is to continue, and to increase, it will be desirable to have two supplies of water in large towns, one for the water-closets, and another, of soft, spring, or well water from a distance, to be used by meter, like the gas. Another evil of the general adoption of water-closets is the waste of manure. The sewage becomes diluted with such an enormous quantity of water that it is doubtful whether it can ever be profitably applied to agriculture. The quantity of the sewage is so great that it could not be detained in reservoirs, and it could not be constantly applied, as the ground is often oversaturated with rain; whereas, if the solid excrement were conveyed away in carts, by some plan similar to the one I have mentioned, the house drainage, which would contain a good deal of the urine of the community, together with solution of soap and other fertilizing materials, would be so moderate in amount that it might probably be applied as liquid manure. It would most likely be five times more fertilizing than the present sewage. By the present plan, the proper contents of the house drains are vastly diluted with water, whilst the solid excrement chiefly lodges in the sewers, and has to be carted away from time to time, or is washed into the rivers by a heavy rain.

As regards water supply, it is desirable that all the shallow pump-wells, situated in towns and among houses, should be closed from domestic use, as they are extremely liable to be polluted, and that, as rivers can never be entirely free from pollution, the supply of towns should be from springs or wells at a distance.

In detached houses in the country, where well-water must be used, the wells should not be sunk close to the house, but at a distance; and the water should be conveyed to a cistern in the house by pumping it through a pipe, or in some other suitable manner.

As regards the great question of the purification of the Thames, I believe the part of the river which most concerns the public health is that in the neighbourhood of Thames Ditton and Hampton. I consider that the river in London was never in a better state, regarding it in a sanitary point of view. Not a single water company now obtains a supply from it, hardly any of the inhabitants on the banks dip a pail into it, and I believe the water is much less used among the sailors and others on board ship than formerly. I look on the question of diverting the sewage of London from the Thames rather as a question of taste than a sanitary question; and I shall not attempt to decide whether the improvement in the appearance of the river would be worth the cost. I only hope that, if the measure is carried out, the pump-wells along the course of the operations will be closed, to prevent such a prevalence of epidemic disease as occurred at Croydon; and that if the river is made to look comparatively clean the population will not again resort to drinking the water. If the sewage of London can be conveyed all, or part of, the way to the sea without polluting the river, it is evident that the sewage of Oxford, Windsor, Reading, and other inland towns, cannot be dealt with in a similar manner. The great sewage difficulty arose out of the almost general adoption of water-closets, and I believe it will continue until they are very much diminished in number.

18, Sackville-street.


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Fusia dot  124. "The recent death from chloroform at Bristol,"

Source: Snow, John. British Medical Journal 1, 20 March 1858, pp. 223-25.

By John Snow, M.D.

The account of the accident from chloroform in the British Medical Journal of March 13th,* shows that death took place by paralysis of the heart. As Dr. Wm. Budd said, the patient "died from the primary action of the chloroform on the cardiac ganglia, whereby the action of that single muscle, on which all the functions of life depend, was instantly stopped."

*(Letter to Ed., British Medical Journal 13 March, 1858.)

But this has been the mode of death in every accident from chloroform, the particulars of which are related. In six of the recorded cases the paralysis of the heart took place, as in the recent case at Bristol, without insensibility having been previously induced. In the remaining cases, however, the patients were rendered more or less insensible before the fatal accident occurred; and in four cases there was an evident over action of chloroform on the brain, in addition to its fatal action on the heart. One of these four was the previous fatal case which occurred in the Bristol Infirmary, on January 21st, 1854. The patient was a woman, aged 59, with an old dislocation of the humerus. She inhaled one drachm of chloroform from a hollow sponge. "Nothing unusual occurring in the patient's condition during inhalation, a second drachm, in about five minutes from the first, was poured upon the sponge, and the inhalation was continued. Almost immediately after the addition of the second drachm, the chloroform was withdrawn, as the patient's breathing became stertorous; and immediately afterwards her pulse, which had hitherto continued pretty firm, was suddenly imperceptible, the respiration ceasing at the same time." (Association Medical Journal, 1854, p.109.) The chloroform in this instance acted directly on the heart, as well as on the brain, otherwise the pulse would have continued for some time after the natural and ordinary breathing had ceased. The pulse has continued after the breathing in one or two accidents from which the patients have been restored by artificial respiration; and it is most probable that it has done so in the three or four cases in which persons lost their lives by imprudently inhaling chloroform when no one was present.

The mode in which death takes place when the vapour of chloroform is continued of the strength in which it can safely be administered to a patient, is for the breathing to become embarrassed before it ceases, and for the pulse to go on beating for one, two or three minutes afterwards. An animal can easily be restored by artificial respiration during the interval whilst the heart is still beating; and there are besides often one or more deep gasping inspirations just at the moment when the heart is ceasing to beat, which often have the effect of restoring the creature to life if the chloroform have been withdrawn. The proper strength at which the vapour of chloroform should be inhaled, is four or five per cent of vapour to 95 or 96 per cent of air. With vapour of this strength, I feel very confident that no accident from chloroform would happen in the hands of a careful attentive medical man.

With air containing twice the above quantity of vapour of chloroform, animals can be killed by sudden paralysis of the heart, and they die exactly like the patients who have suffered fatal accidents from this agent. When small animals are placed in air containing ten per cent of vapour, they die suddenly in a state of agitation, if they have previously been made insensible by vapour of a weaker strength. There is every reason to conclude that all the patients who have died from chloroform in the presence of a medical man, have breathed the vapour just before the accident of much more than the proper strength; probably of not less than eight or ten per cent. I believe that there has been no death really due to chloroform in any case where the medical man was making any attempt to regulate the percentage of vapour in the inspired air. When a drachm of chloroform is poured in a hollow sponge, it is quite possible that a patient may breathe air containing eight or ten per cent of vapour. One hundred cubic inches of air at 60º Fahr. will take up fourteen cubic inches of vapour of chloroform when fully saturated, and the resulting compound will contain twelve per cent of vapour. It is quite true, that the air which passes over a sponge or handkerchief does not usually get fully saturated, and that the patient often breathes a good deal of air which has not come in contact with the wetted part of the handkerchief or sponge; the air passages, moreover, often refuse air which contains a large amount of vapour, and for these reasons patients may commonly breathe chloroform from a handkerchief or sponge without accident. There is, however, always some risk of accident when it is endeavoured to make a patient completely insensible in this way, as the amount of vapour in the inspired air cannot be regulated with any approach to accuracy. The persons who administer chloroform in this manner do not get uniform results; they are not aware that the effects of chloroform are as exactly in proportion to the quantity which enters the lungs of the patient, as the wound is in proportion to the depth to which the surgeon's knife enters the flesh. Patients are supposed to be more or less susceptible of the effects of chloroform irrespective of their evident physical condition, and when a fatal accident occurs, it is usually attributed to some peculiarity in the patient.

Out of fifty recorded cases of death from chloroform, however, eleven of the patients are related to have previously inhaled it, and been made insensible by it, without ill effects. It is not probable that more than twenty-two per cent of the persons who have hitherto inhaled chloroform, have inhaled it more than once; and, therefore, those with whom it has been proved to agree, seem quite as liable to accident as others, a circumstance entirely confirming the view, that accidents do not depend on any peculiarity of the patient who suffers them.

In the fatal case which occurred in Bristol in 1854, the coronary arteries were diseased, and a considerable proportion of the fibres of the heart were found in a state of incipient fatty degeneration. This amount of disease of the heart is, I believe, not at all uncommon in patients who inhale chloroform for surgical operations; and in the recent case in the Bristol Infirmary, the affection of the heart was so slight, that Dr. Budd says there was nothing in the slightest degree to account for the accident. The only patient I have lost whilst inhaling chloroform (Medical Times and Gazette, 1852, vol. ii. p.361), had, indeed advanced fatty degeneration of the heart, of which we were aware during his life. But it is my opinion that he died of his heart-disease, and not of the chloroform. His pulse ceased whilst he was straining to hold his breath, as if he were beginning to be affected by the pain of the operation. This case has not prevented me from administering chloroform to every other patient with symptoms of disease of the heart who has come before me, and has required to undergo a surgical operation. Whilst I admit that fatty degeneration of the heart is by no means a desirable accompaniment to the inhalation of chloroform, I consider that it offers a strong reason why the patient should not be subjected to a painful operation without the use of this or some other narcotic vapour. I have frequently observed that the pulse intermits, and the sounds of the heart are entirely suspended, for as much as five seconds at a time, when a patient is straining under the pain of a trifling operation, such as the ligature of the varicose veins, and I consider that such a state of the circulation would be much more dangerous to a weak or fatty heart than the effects of chloroform when carefully administered.

Some alteration in the condition of the heart can very often be found when looked for after death, and has been met with in many of the persons who have died from the effects of chloroform; but there are only four cases out of the whole fifty in which fatty degeneration of the heart is reported to have been decidedly present, and only in one of these in an extreme degree; and I think it not improbable that this complaint has been as frequently present in the patients who have inhaled chloroform without accident. According to my experience, extreme debility, and early infancy, and extreme old age, offer no objection to the use of chloroform. The patients who are least suited for it, in my opinion, are robust and athletic men; they are the most difficult to bring under its influence, and require the most care to avoid accident. They are, however, the persons who least require to be rendered insensible for slight operations. Out of fifty-one accidents which have happened from chloroform, thirty have occurred in the male sex, although females inhale the agent nearly twice as often as males, according to my experience. Infancy and old age have been singularly free from accidents from chloroform; and in proportion to the numbers living in each decennial period, the greatest number of accidents have happened between the ages of 35 and 45, when the frame is usually the strongest and most robust.

I am in the habit of using an inhaler which has been described in this Journal; but I do not consider that its use will prevent accidents, unless it is employed for the purpose of regulating the amount of vapour in the air. If the bibulous paper is arranged the same in July as in January, and the valves are employed in the same manner, it would be very likely that it might lead to accident. Persons who are unwilling to give the subject of chloroform any great scientific consideration, may yet cause insensibility with it by means of a handkerchief or hollow sponge, without risk of accident, if they first dilute it with an equal measure of rectified spirit. I have frequently used it in this way in operations of the face, and I have not found it cause headache, as Dr. Herapath states. Indeed, the spirit remains behind in the sponge, very few drops of it are inhaled; and in a protracted operation it is desirable to be provided with a dry sponge from time to time, on account of the spirit which remains. The effect of the spirit is to lessen the amount of vapour which the chloroform yields to the air. One hundred cubic inches of air, when saturated with vapour from a mixture of equal parts, by measure, of chloroform and rectified spirit of wine, only take up eight cubic inches of vapour, instead of fourteen. The air takes up enough vapour to cause insensibility, but not enough to cause sudden accident. I think it is Dr. Wilkinson, one of the Physicians to the Royal Infirmary at Manchester, who administers the chloroform in that institution, and he informed me that he had long administered it mixed with an equal measure of spirit with very satisfactory results. If headache had followed its use, I feel sure that he would have noticed the circumstance. Mr. Prichard, in commenting on his case, seems inclined to use the chloroform in future diluted with spirit.

I cannot agree with Mr. Prichard and others, who propose to diminish the number of accidents from chloroform by restraining its use to a few great operations, as I consider that accidents are more likely to be avoided by a constant familiarity with the agent. The medical officers of Guy's and St. Thomas's Hospitals had a strong objection to narcotism by inhalation for the first two or thee years after the practice was introduced, and chloroform was used much less frequently in these institutions than in the rest of the hospitals of London; yet it was in those two hospitals that two deaths from chloroform occurred, before any such accident had happened in any other hospital in this metropolis. The greatest benefit to be derived from causing insensibility during operations is, by extending the benefits of surgery. A surgeon could always advise an operation, but he could only perform it in those cases in which he obtained the consent of his patient. With the use of an anæsthetic, which he can confidently recommend on all occasions, however, he is able to perform almost every operation he recommends, and at the time, also, when it is most advisable.

It would, moreover, be very inconsistent to confine the employment of chloroform to great operations, as the only reason for giving it in any case is to avoid the strong odour, and other inconveniences, of sulphuric ether. It should be recollected, that the prevention of the pain of operations did not commence with chloroform. It was as thoroughly and completely established with sulphuric ether as ever it can be. The insensibility was induced in almost every operation in St. George's and University College Hospitals during the greater part of 1847 without a single failure, and in the time which is most desirable in employing chloroform, viz. in about four minutes. Sulphuric ether is apparently altogether incapable of causing sudden accidents like those which have occurred from chloroform. It is still very extensively used in America and some parts of the continent of Europe, and I believe that no accident has ever occurred from its use, unless it be one in France, which is, however, doubtful. It is a matter both for surprise and regret that those surgeons in England who do not feel that they can use chloroform with safety, do not again resort to the use of sulphuric ether. It should be used alone, not mixed with chloroform, which, being less volatile, would be left to the last, and inhaled when its great strength would be most objectionable. Indeed, one accident has been recorded as occurring in America from a mixture of ether and chloroform.

18, Sackville Street, 13th March, 1858.


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Fusia dot  125. "Death from chloroform"

Source: Snow, John. British Medical Journal 3 April 1858, p. 279 [Letter to the Ed.]

Letter from Dr. John Snow, M.D.

Sir,--I am surprised to find that Mr. Prichard has taken offence at my late-communication on chloroform,* and for a reason that is purely imaginary. He says that I referred to the two unfortunate cases which occurred in Bristol as if they were the only fatal instances on record.

(* "Death from chloroform," British Medical Journal, 27 March 1858, [ltr. to ed.]).

On the contrary, I referred to them only in comparison with all the other cases. Any one who has never heard of chloroform would perceive from my paper that there had been a number of other fatal cases, forty-nine of which, at least, had been recorded. I cannot perceive that there was any cruelty in referring to two cases which had been published in the Journal in which I was writing; but there would have been a cruelty in my neglecting to speak, on any suitable opportunity, of the advantages and perfect safety of chloroform, when properly and carefully managed, which I had witnessed almost daily for more than ten years. The proposal of Mr. Prichard to use anæsthetics only in a few great operations would almost abolish the greatest improvement that was ever made in surgery; for the fact of their application being so limited would make them a terror to the few patients who were allowed to inhale them.

I do not propose that any risk should be incurred by the administration of chloroform, but, on the contrary, that, unless a person is satisfied that he can give chloroform without risk, he had better use sulphuric ether. It was not merely because no one had recorded a death from sulphuric ether, that I spoke of its safety, but also because it will not cause those very sudden deaths in animals which depend on paralysis of the heart, and which chloroform can be made to produce at will. Only a small part of the dose of ether which it is necessary to inhale can be present in the lungs at one time; whilst a very large proportion, even the whole dose of chloroform, may be contained in the lungs at once. The question of the amount of vapour in the air under different circumstances is one of vital importance, and which every one must attend to who wishes to understand the action of narcotic vapours. Mr. Prichard must be wrong in supposing that it is the condition of insensibility that puts the patient in peril of his life. Hundreds of thousands of persons have been insensible without harm; whilst Mr. Prichard's own patient, and several others, died from chloroform without being made insensible at all.

I thought I had made my opinion sufficiently clear in my paper, that chloroform may be given with safety to every patient requiring a surgical operation; and that danger does not depend on the kind of patient, but on the way in which the agent is given. I am not aware of ever having written opinions which are inconsistent with each other. I have used the same kind of chloroform inhaler for upwards of ten years, with very slight alteration; and during the progress of operations on the face, when I cannot use the inhaler, I employ the mixture of equal parts by measure of chloroform and spirit, which I have thought it right to recommend to those who do not wish to study and adopt and inhaler. I use chloroform generally in preference to sulphuric ether, because it is more convenient, and can be made equally safe.

I admit that most persons who have written on chloroform are opposed to its use in cases of fatty degeneration of the heart; but they write without experience. I am opposed to the pain of the knife being inflicted on such patients; and I write from experience of the favourable action of chloroform on a great number of patients having all the symptoms of fatty degeneration well marked. In several cases, the disease was verified in patients who died a few days after great operations.

Mr. Prichard is welcome to his own opinion as to the cause of the death of the patient with fatty heart to whom I was administering chloroform; but he is wrong when he says that any one else than myself would come to an opposite conclusion from my own. The only medical man present besides Mr. Hawkins and myself when that patient died, was Mr. George Pollock. He had had great experience of the action of chloroform, and was well acquainted with the patient. He gave me his opinion, without being asked for it, that the patient died of his heart-disease, and not of the chloroform. That patient was benefited very much by previous inhalations of chloroform, and probably had his life prolonged by them. He was relieved of a stone in his bladder the year before his death, by lithotrity, under chloroform, when Mr. Hawkins was of opinion that he could not have borne the operation without being put in a state of anæsthesia.

I am, etc.,

John Snow.

18, Sackville Street, March 27th, 1858.

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