Stream 5 - Additional Items

a: Overview of Snow's Significance

In his past book, King Cholera, Norman Longate (1925-2016) provides a fine overview in an engaging tone of John Snow's life and contributions, summarizing much of what has been presented in this website. His 10 pages in Chapter 19 on John Snow reflect his writing style, crafted in 31 books during an active life time.

Source: Longmate, Norman. Victory in Sight, Chapter 19, 201-211 in Longmate N. King Cholera - The Biography of a Disease, publisher H. Hamilton, London,1966.

I resolved to spare no exertion which might be necessary to ascertain the exact effect of the water supply on the progress of the epidemic.

- SNOW, M.D., On the mode of communication of cholera, 1855

Victory in Sight

The main burden of the fight against cholera in the British Isles had been borne by the humble, and usually underpaid, general practitioner. It was appropriate that the great discovery of how cholera was spread should have been made not by a high-powered official committee, or some flamboyant master of medicine, but by a shy, unfashionable doctor, who never achieved real eminence in his profession. Dr. John Snow had been born at York, the son of a farmer, in 1813, and at fourteen had been apprenticed to a surgeon in Newcastle.

He had learned his trade in a tough school, as assistant to a succession of village surgeons, which involved "many rough rides and a fair share of night work."

In 1831 he had gained his first experience of cholera when he fought an epidemic at Killingworth colliery single-handed. Five years later, like a nineteenth-century Dick Whittington [English folklore Dick Whittington and His Cat has been popular  since pre-Victorian times], Snow set out for London on foot to make his fortune. For months he "walked the wards" at the Westminster Hospital, and in 1838, having qualified as a Member of the Royal College of Surgeons and of the Apothecaries Company, "nailed up his colors" as a general practitioner at his lodgings at 54 Frith Street, Soho.

Snow at this time was a very serious-minded young man, very different to the traditional medical student. His recreations were swimming, walking and collecting geological specimens and his idea of a merry Easter Monday was to challenge a fellow student to a fifty mile walking match. At the age of seventeen he had become both a teetotaller and a rigid vegetarian, though in later life he took an occasional glass of wine on social occasions, and he eventually abandoned his vegetarianism also. A fellow student described Snow in his early twenties: "Not particularly quick of apprehension, or ready in invention, he yet always kept in the foreground by his indomitable perseverance and determination.... The object of this steady pursuit with him was always truth."

Snow was by temperament quiet and reserved and many of his contemporaries considered him "peculiar." In his first years in London his practice did not prosper, largely, according to a friend, because he had "no personal introduction to the bedsides of dowagers" and there was "not the least element of quackery in all his composition." Snow supported himself from his fees as medical officer to four sick clubs [members paid monthly or annual contributions for medical care] , work involving many night calls and little pay, and filled in his time with research and study, ultimately adding both B.M. (Bachelor of Medicine) and M.D. (Doctor of Medicine) to his qualifications. The turning point in his career came in 1846, when ether began to be used in Britain as an anesthetic. This discovery, which was, in his own words, both "practical" and "humane," made an immense appeal to Snow, and soon he became recognized as an authority on it and its successor, chloroform. Before long his income had risen to 1,000 pounds a year and his name was finally made in 1853, when he was summoned to give chloroform to Queen Victoria at the birth of Prince Leopold — an occasion which convinced the doubters that it was not contrary to God’s will to reduce the pains of child-birth.

In 1848 Snow had turned his attention to cholera, for as an authority on respiration he had begun to doubt that it was conveyed by the air. He soon came to suspect that water was the responsible agent and the result was the first edition of On the mode of communication of cholera, which appeared in 1849. During the next six years "Dr. Snow’s theory" was frequently referred to but not generally accepted, partly no doubt because the miasmatists were so well entrenched, but also perhaps because Snow was not the man to command attention by force of personality. He was of no more than average height and slim build; his voice was husky and often hard to follow; and in the daily affairs of life he was punctilious to the point of fussiness, rising and retiring early and being exceedingly tidy in his habits. Snow lacked altogether the colourful touches that attract attention. He read nothing for pleasure except scientific works and was notoriously shy, the reason perhaps that he never married. His recreations in middle age were playing with his friends’ children, listening to his friend and biographer Dr. Richardson read aloud from Thackeray and Dickens, and occasionally going to the opera. In a profession whose leading members were often forthright to the point of rudeness, Snow was consistently reserved. He lacked altogether the ruthless determination that carries many men to the top. Often, says Richardson, he would make the long journey from Soho to Mortlake to see one of his friend’s poor patients, to the humblest of whom he was unfailingly courteous and kind. He was too compassionate, unlike many of his contemporaries, to carry out any experiment on an animal out of mere curiosity and, in an age of vigorous if not brutal controversy, too gentle ever to review a book critically: if he disapproved of it he refused to review it at all. All these features of his character help to explain why, when Dr. John Snow had at last found the truth about cholera, it took a generation for his ideas to be accepted.

The 1855 edition of On the mode of communication of cholera in which Snow modestly offered his great discovery to the world, is virtually a different book from the previous essay with the same title and its 139 pages are a model of lucid exposition and convincing argument. Snow began by deducing certain basic facts about the disease. It had, he declared, nothing to do with the lungs, being in fact an "affection of the alimentary canal." It was the violent purging and vomiting which this produced which were the real clue to the disease for they led to the loss of fluid which caused all the other symptoms: the thick tarry blood, which made circulation difficult and thus caused the patient to feel cold, the weakened pulse and impaired breathing, the cramps, and even the dreaded collapse itself. From this introduction Snow went on to the root of the matter, the way in which cholera spread. "The morbid material producing cholera," he concluded, "must.., be swallowed accidentally, for persons would not take it intentionally." "Swallowed," that was the key word, and once it was accepted all else became plain. Cholera spread fastest among the poor, not because their homes were unventilated but because they were crowded and badly lighted. Under these conditions the other members of a patient’s family constantly came in contact, unknown to themselves, with the odorless and colorless "ejections and dejections" containing the cholera poison, and, since the poor rarely had facilities for washing, transferred it to their mouths when next they ate. At once the facts which had puzzled the world for twenty years were explained: the near immunity enjoyed by doctors, who washed before meals, and did not eat in their patients' homes; the liability to cholera of nurses and those who laid out the dead, who ate on the premises, and the infection of those who visited the sickroom or attended the funeral, occasions usually accompanied by food or drink. The cholera explosion in the child farm at Tooting in the 1848-9 epidemic was easily explained: the victims had been huddled together two or three in a bed, and like all children had constantly put their fingers in their mouths. The reason why the miners of Merthyr [Merthyr Tydfil is a town in Wales where 1 in every 25 inhabitants died of cholera in 1849] had suffered so badly was also clear. "The pitmen," wrote one of Snow’s informants, a relative connected with a Yorkshire colliery, "all take down with them a supply of food.... The pit is one huge privy and of course the men always take their victuals with unwashed hands."

All this was useful enough, but it was in the next section of his book that Dr. Snow made his vital contribution to medical knowledge. "If the cholera had no other means of communication he wrote, "it would confine itself chiefly to the crowded dwellings of the poor.... But there is often a way open for it to extend itself more widely and to reach the well-to-do classes of the community; I allude to the mixture of the cholera evacuations with the water used for drinking and culinary purposes, either by permeating the ground, and getting into wells, or by running along channels and sewers into the rivers from which entire towns are sometimes supplied with water." In these few lines the veil of mystery was at last ripped away from the disease which had bewildered governments and defeated doctors for a generation. Cholera was spread not by the air but by the water supply. The terrified mobs of St. Petersburg and Paris, who had raised riots and murdered strangers in the street, the fear-crazed peasants of Hungary who had stormed the castles of the nobility, all had alleged that they were being poisoned — and all had been right. But those responsible were not the sinister agents of some international conspiracy but themselves.

In support of his theory, Snow mustered an impressive array of evidence. There was, he pointed out, the significant case of the battalion of Native Infantry in India who had been stricken with cholera while on the march. "It was the belief of the natives..." reported a British doctor, "that the epidemic was the immediate consequence of the wrath of heaven, outraged and insulted by the pollution of certain sacred tanks... in which sepoys of low caste and camp followers had indiscriminately bathed" — the same tanks from which the troops had drawn their drinking water. There was the savage outbreak at the village of Newburn near Newcastle, the worst, in relation to population, of the whole 1831 epidemic. Snow, through correspondence with a friend in Newcastle and the vicar and surgeon at Newburn, succeeded, twenty years later and 300 miles away, in establishing its cause — a brook which, having been contaminated by the refuse of a village and a steel works, had half a mile further on infected a well. The outbreak in the Black Sea fleet was also full of clues for those with eyes to see them, a doctor on the spot having noted that the infected ships had drawn their drinking water three days before from a stream in which soldiers, wearied by marching from a focus of cholera infection, were seen... washing their persons and clothing."

The heart of Dr. Snow’s book lay in the seventeen pages in which he recorded his investigation into the affair of the Broad Street pump. Snow prepared a large-scale map of the area, with houses which had suffered cholera deaths indicated by black lines. The most casual glance showed at once the tremendous concentration of deaths in the immediate vicinity of the suspect pump, which enjoyed a high local reputation for taste and purity, and the virtual absence of deaths near the other eleven pumps in the district. "The result of the inquiry..." wrote Snow, "was, that there had been no particular outbreak or increase of cholera, in this part of London, except among the persons who were in the habit of drinking the water of the above-mentioned pump-well.... The deaths either very much diminished, or ceased altogether, at every point where it becomes decidedly nearer to send to another pump than to the one in Broad Street."

To support this conclusion, Snow gave some striking examples.

Seven workmen employed at No. 8 and 9 Broad Street and all died, though they lived outside the district, while two people who lived on the premises, but did not drink the water, escaped. In a nearby brewery, not one of 70 men caught cholera, because they were supplied with free beer, or water from the brewery’s own well. An army officer from St. John’s Wood dined in Wardour Street, drank the Broad Street water with his meal and was dead in a few hours. "The keeper of a coffee shop in the neighborhood, which was frequented by mechanics, and where the pump-water was supplied at dinner-time, informed me (on 6th September) that she was already aware of nine of her customers who were dead." The case which Snow considered "perhaps the most conclusive of all" was that of a widow who had formerly lived in Soho and, having developed a great taste for the Broad Street water, had a large bottle of it sent out on the carrier’s cart every day to her new home in Hampstead. "The water was taken on Thursday 31st August and she drank of it in the evening and also on Friday. She was seized with cholera on the evening of the latter day and died on Saturday. A niece, who was on a visit to this lady, also drank of the water; she returned to her residence in a high and healthy part of Islington, was attacked with cholera and died also." Later enquiry, not by Dr. Snow, established that the well had probably been infected by a cesspool, which served No. 40 Broad Street, the house nearest to the pump, where a baby had been attacked by cholera on the 28th August.

Much of Dr. Snow’s book consisted of a study of a more widespread but less sensational outbreak in South London between July and October 1854, the area on which he had concentrated his enquiries in 1849. Since that time an important change had taken place in South London: while the Southwark and Vauxhall Company, one of the two undertakings which supplied water to the area, still drew its supplies from the Thames at Battersea, the other, the Lambeth Company, had moved its source up-river to Thames Ditton, where the water was unquestionably purer. "The intermixing of the water supply ... over an extensive part of London," wrote Snow, "admitted of the subject being sifted in such a way as to yield incontrovertible proof on one side or the other... The pipes of each Company go down all the streets and into nearly all the courts and alleys.... In many cases a single house has a supply different from that on either side.... No experiment could have been devised which would more thoroughly test the effect of water supply on the progress of cholera.... No fewer than three hundred thousand people of both sexes, of every age and occupation, and of every rank and station, from gentlefolks down to the very poor, were divided into two groups without their choice and, in most cases, without their knowledge; one group being supplied with water containing the sewage of London and, amongst it, whatever might have come from the cholera patients, the other group having water quite free from such impurity. To turn this grand experiment to account, all that was required was to learn the supply of water to each individual house where a fatal attack of cholera might occur."

The results, achieved by patient door to door enquiry, completely bore out his theory. During the first four weeks of the epidemic "in 286 cases the house where the fatal attack of cholera took place was supplied with water by the Southwark and Vauxhall Company, and in only fifteen cases was the house supplied with the Lambeth Company’s water." Since the Southwark Company supplied 40,000 houses with water and the Lambeth Company 26,000 houses, "the proportion of fatal attacks to each 10,000 houses was as follows. Southwark and Vaushall, 71. Lambeth, 5. The cholera was, therefore, 14 times as fatal at this period, amongst persons having the impure water of the Southwark and Vauxhall Company.

In the closing section of his book John Snow demonstrated how the water-borne theory of cholera could explain many lesser mysteries about the disease. Sailors, dockers and coal-heavers suffered badly because they constantly drank contaminated river water, while brewers’ men rarely caught cholera for they usually drank beer. Women were more susceptible than men, because they drank more water, especially the contaminated water of their own homes. Their families suffered for the same reason. 'I often heard such remarks as the following in making my enquiries in the South districts of London: "My children like water better than tea or anything else, I cannot keep them away from the water-butt".'

There is a wealth of tragedy in another mother’s remarks which he recorded: ' "The child that is dead used to drink a great deal of that water, she was big enough to reach the butt herself".'

The supporters of the atmospheric theory of cholera had found a good deal of difficulty in explaining why in London it was almost invariably a summer disease, while in Scotland there had been several epidemics at the height of winter. Here, too, Snow had the answer: "The English people, as a general rule, do not drink much unboiled water, except in warm weather. They generally take tea, coffee, malt liquor or some other artificial beverage at their meals. In Scotland, on the other hand, unboiled water is somewhat freely used at all times to mix with spirits... and when persons drink spirits without water, as they often do, it occasions thirst and obliges them to drink water afterwards."

There remained unexplained only those mysterious cases where cholera had leaped across miles of countryside between places which were not linked either by travelers or by a shared water supply. Snow had not investigated this type of epidemic but suggested with astonishing perspicacity: "It is not unikely that insects, especially the common houseflies, aid in spreading the disease."

Hundreds of doctors before Snow had painstakingly tried to trace out the course of past epidemics, throwing suspicion in turn on the air, the water, physical contact between the sick and flies.  What they had not understood was that all these causes might be superimposed one upon another in the same outbreak. It was Snow’s good fortune that he selected for study two epidemics which were solely water-borne, but it was his genius which led him on to see beyond the immediate circumstances of his own experience to the wider, universal truth.

The history of cholera is full of ironies and not the least remarkable was that within a few weeks of the appearance of his book, at the beginning of John Snow, instead of being hailed as a public benefactor, was under attack as an enemy of sanitary progress. His insistence that cholera was caused by a specific substance and not spontaneously generated by evil-smelling rubbish caused him to be branded as a reactionary defender of nuisances.

The unfortunate coincidence that Dr. William Budd of Bristol had published in 1849 a pamphlet advancing the water-borne theory of cholera almost simultaneously with the first edition of Snow’s book, also led to endless confusion which irritated both parties. It must have been infuriating to Snow when early in 1856 the great sanitarian and educational reformer, Sir James Kay-Shuttleworth, in a speech to an audience of medical students, compared the man who had discovered how cholera was spread to Jenner, the conqueror of smallpox, Magendie, the brain specialist, and Semmelweiss, victor over puerperal fever, and then named him as William Budd. According to his biographer, Snow’s courageous action over the Broad Street pump led to ‘much sneering and jeering even.... The abstruse science men.., wanted to discover the cause of a great natural phenomenon in some overwhelming scientific problem’. On the whole the ordinary G.P.s (general practitioners) who had actually coped with epidemics came out of the affair better than the leaders of the profession, who had only theorized about them. More than one humble parish medical officer wrote to The Lancet or The Association Medical Journal to report how outbreaks had been halted, as if by magic, when a contaminated well was abandoned, while the curate of St. James’s parish in Soho made a handsome public apology to Snow, whose theory he had attempted to disprove by three months of house to house enquiry in Broad Street itself. All his labor had achieved was to prove that Snow was right.

Beside those who questioned whether Snow’s theory was true, there were others who argued that if true it was not original. It was recalled that as long ago as 1817 Army medical officers in India had realized that one way to halt an epidemic was to find a new source of water. Then in February 1832 an anonymous pamphlet published in Edinburgh contained the emphatic statement that "water is clearly the medium through which the unknown cause may be introduced into the stomach." Later that year, Dr. John Parkin, writing in The London Medical and Surgical Journal, hit on the truth almost by chance while trying to justify a private theory about the use of charcoal as a filter. "I have," he wrote, "been induced to draw the conclusion that a noxious matter of poison being generated in the earth has been diffused in the different springs... and that this matter being conveyed into the stomach.., produces that train of symptoms." Curiously enough, later in life Parkin became a fanatical opponent of the water-borne theory and ridiculed the suggestion that cholera was caused by a living organism.

John Snow’s claims were really established in the memoir of him published shortly after his death by his friend Benjamin Richardson, who wrote that: "It was my privilege during the life of Dr. Snow to stand on his side. It is now my duty on his death...to claim for... the entire originality of a connection between impure water supply and choleraic disease."  William Budd, the Bristol doctor who was the real co-discoverer of the water-borne theory, was less fortunate. He had to wait till 1936, 56 years after his death, to find a champion and biographer.

In 1856, the year after the publication of John Snow’s book, valuable support for his theory came from two very different quarters. The official Report on the last two cholera epidemics of London as affected by the consumption of impure water, submitted to the Board of Health by its medical officer, entirely bore out his findings.

In the same year appeared Charles Kingsley’s novel, Two Years Ago. Kingsley was usually described as a Christian Socialist but was at heart a reforming Conservative who wished to encourage the nobility and squirearchy to feel a sense of responsibility towards the poor, and favored government intervention only where private benevolence was inadequate. The story of Two Years Ago, which runs to 500 pages, begins in the Berkshire village of Whitbury in 1840, which possess a lovable local physician, Dr. Thurnall. His son Tom, after being apprenticed to another local practitioner, goes off to study medicine in London and to set off on a series of adventures round the world. Off the Cornish coast on his way home the ship is wrecked and Tom is washed ashore at the village of Aberalva, which is clearly based on Clovelly, where Kingsley spent much of his boyhood. Tom’s life is saved by the heroine, Grace, the beautiful and virtuous village schoolmistress, although his life savings mysteriously disappear during the rescue. A penniless castaway, he soon finds his feet as an assistant to the village doctor, an ill-qualified and drunken man, who considers that "this new fangled sanitary reform... is all a dodge for a lot of young government puppies to fill their pockets and rule and ride over us."  Tom becomes convinced that Aberalva is in great danger, because of its insanitary and crowded state, with 1,400 people packed into only 100 houses. He attempts to rouse the neighborhood, assisted by the schoolmistress, the young curate, a nobleman, Lord Scoutbush, whose yacht has, in the most timely fashion, anchored in the harbor, and an Army medical officer traveling with him, Major Campbell. Tom gives a lecture in the schoolroom, illustrated with enlargements of the "abominations" found in local wells and water butts, and the curate preaches a sermon on sanitary reform, only to be denounced by a local dissenting preacher because he "impiously pretended to explain away the Lord’s visitation into a carnal matter of drains." 

In chapter 16, entitled " Come at last" the story reaches its climax with the arrival of cholera. Among the first to be carried off are all who opposed the reformers, including the doctor, who had been wandering about the streets begging people to forgive him for his past neglect. Tom throws the Methodist minister out of a house, lest he should "kill the poor wretches before their time, by adding to the fear of cholera the fear of hell," and Major Campbell interrupts a revivalist meeting to such good purpose that the congregation change their minds about repenting and decide instead to throw their pastor in the harbor. He is rescued by Tom in the nick of time but duly catches cholera: "In two hours more he was blue; in four he was a corpse." Finally, all ends happily. Tom goes off to the Crimea as a secret agent; the schoolmistress as a nurse; both, and Tom’s money, are reunited after the war at Whitbury and marry with his old father’s blessing. The curate makes a good match with Lord Scoutbush’s sister and returns to Aberalva as its rector, while Major Campbell, unlucky in love, perishes gallantly on the battlefield.

Two Years Ago was a great success and enabled Kingsley to pay off his debts. John Snow was not so fortunate. His book left him 200 pounds out of pocket and for the greatest British medical discovery since vaccination he received neither professional acclaim nor public reward. He died of a stroke only three years later, in 1858, at the tragically early age of 45, while at work on a new book on chloroform, laboring to the last to add to scientific knowledge and to reduce the pain of suffering humanity.

Sources:

The source for Snow’s life is John Snow, M.D., On Chloroform and other Anaesthetics. With a Memoir of the Author by Benjamin W. Richardson, M.D. (1858). A very thorough account of the Broad Street pump episode by H. H. Scott, Some Notable Epidemics (Edward Arnold, 1934), supplements Snow’s own book. The Kay-Shuttleworth incident and other aspects of the confusion of Budd with Snow are described in The Association Medical Journal for 26th January, 9th February, 16th February and 29th March 1856 and support for the water-borne theory appears in the issue for 17th September. Relevant remarks by or about Snow also appear in The Lancet for 10th March, 21st April, 4th June and 1st December 1855, and in The Edinburgh Medical Journal for January 1856. John Parkin’s early advocacy of the water-borne theory, and his later recantation, are quoted by E.W. Goodall, M.D., William Budd, p. 98-99 (Arrowsmith, 1936).

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