the Mode of Communication of Cholera
by John Snow, M.D.
London: John Churchill, New Burlington Street, England, 1855
CONTENTS (pp. 1-38)
(Click on to go to specific section)
Outline of the history of cholera
Cases proving its communication from person to person
Cholera not communicated by means of effluvia
The pathology of cholera indicates the manner in which it is communicated
Analysis of the blood and evacuations in cholera
Cholera is propagated by the morbid poison entering the alimentary canal
Evidence of this communication mode in the crowded habitations of the poor
Evidence of this communication mode amongst the mining population
Instances of the communication of cholera through the medium of polluted water in Horsleydown
Instances of the communication of cholera through the medium of polluted water at Albion Terrace, Wandsworth Road
Instances of the communication of cholera through the medium of polluted water at Rotherhithe
Instances of the communication of cholera through the medium of polluted water at Manchester in Hope Street, Salford
Instances of the communication of cholera through the medium of polluted water at Ilford and near Bath
Instances of the communication of cholera through the medium of polluted water at Newburn on the Tyne
Instances of the communication of cholera through the medium of polluted water at Cunnatore
Instances of the communication of cholera through the medium of polluted water in the Black Sea Fleet
HISTORY OF CHOLERA
The existence of Asiatic Cholera cannot be distinctly traced back further than the year 1769. Previous to that time the greater part of India was unknown to European medical men; and this is probably the reason why the history of cholera does not extend to a more remote period. It has been proved by various documents, quoted by Mr. Scot, that cholera was prevalent at Madras in the year above mentioned, and that it carried off many thousands of persons in the peninsula of India from that time to 1790. From this period we have very little account of the disease till 1814, although, of course, it might exist in many parts of Asia without coming under the notice of Europeans.
In June 1814, the cholera appeared with great severity in the first battalion, ninth regiment, N. I., on its march from Jaulnah to Trichinopoly; while another battalion, which accompanied it, did not suffer, although it had been exposed to exactly the same circumstances, with one exception. Mr. Cruikshanks, who attended the cases, made a report, which will be alluded to further on.
In 1817, the cholera prevailed with unusual virulence at several places in the Delta of the Ganges; and, as it had not been previously seen by the medical men practicing in that part of India, it was thought by them to be a new disease. At this time the cholera began to spread to an extent not before known; and, in the course of seven years, it reached, eastward, to China and the Philippine Islands; southward, to the Mauritius and Bourbon; and to the northwest, as far as Persia and Turkey. Its approach towards our own country, after it entered Europe, was watched with more intense anxiety than its progress in other directions. It would occupy a long time to give an account of the progress of cholera over different parts of the world, with the devastation it has caused in some places, whilst it has passed lightly over others, or left them untouched; and unless this account could be accompanied with a description of the physical condition of the places, and the habits of the people, which I am unable to give, it would be of little use.
There are certain circumstances, however, connected with the progress of cholera, which may be stated in a general way. It travels along the great tracks of human intercourse, never going faster than people travel, and generally much more slowly. In extending to a fresh island or continent, it always appears first at a seaport. It never attacks the crews of ships going from a country free from cholera, to one where the disease is prevailing, till they have entered a port, or had intercourse with the shore. Its exact progress from town to town cannot always be traced; but it has never appeared except where there has been ample opportunity for it to be conveyed by human intercourse.
There are also innumerable instances which prove the communication of cholera, by individual cases of the disease, in the most convincing manner. Instances such as the following seem free from every source of fallacy. I called lately to inquire respecting the death of Mrs. Gore, the wife of a Tabourer, from cholera, at New Leigharn Road, Streatham (lower right). I found that a son of deceased had been living and working at Chelsea. He came home ill with a bowel complaint, of which he died in a day or two. His death took place on August 18th. His mother, who attended on him, was taken ill on the next day, and died the day following (August 20th). There were no other deaths from cholera registered in any of the metropolitan districts, down to the 26th August, within two or three miles of the above place; the nearest being at Brixton (center right), Norwood (lower left), or Lower Tooting (lower center).
CASES PROVING PERSON TO PERSON TRANSMISSION
The first case of decided Asiatic cholera in London, in the autumn of 1848, was that of a seaman named John Harnold, who had newly arrived by the Elbe steamer from Hamburgh, where the disease was prevailing. He left the vessel, and went to live at No. 8, New Lane, Gainsford Street, Horsleydown. He was seized with cholera on the 22nd of September, and died in a few hours. Dr. Parkes, who made an inquiry into the early cases of cholera, on behalf of the then Board of Health, considered this as the first undoubted case of cholera.
Now the next case of cholera, in London, occurred in the very room in which the above patient died. A man named Blenkinsopp came to lodge in the same room. He was attacked with cholera on the 30th September, and was attended by Mr. Russell of Thornton Street, Horsleydown, who had attended John Harnold. Mr. Russell informed me that, in the case of Blenkinsopp, there were rice water evacuations; and, amongst other decided symptoms of cholera, complete suppression of urine from Saturday till Tuesday morning; and after this the patient had consecutive fever. Mr. Russell had seen a great deal of cholera in 1832, and considered this a genuine case of the disease; and the history of it leaves no room for doubt.
The following instances are quoted from an interesting work by Dr. Simpson of York (center left), entitled " Observations on Asiatic Cholera A: -----AThe first cases in the series occurred at Moor Monkton, a healthy agricultural village, situated to the northwest of York, and distant six miles from that place. At the time when the first case occurred, the malady was not known to be prevailing anywhere in the neighborhood, nor, indeed, at any place within a distance of thirty miles.
"John Barnes, aged 39, an agricultural laborer, became severely indisposed on the 28th of December 1832; he had been suffering from diarrhea and cramps for two days previously. He was visited by Mr. George Hopps, a respectable surgeon at Redhouse, who, finding him sinking into collapse, requested an interview with his brother, Mr. J. Hopps, of York. This experienced practitioner at once recognized the case as one of Asiatic cholera; and, having bestowed considerable attention on the investigation of that disease, immediately enquired for some probable source of contagion, but in vain: no such source could be discovered. When he repeated his visit on the day following, the patient was dead; but Mrs. Barnes (the wife), Matthew Metcalfe, and Benjamin Muscroft, two persons who had visited Barnes on the preceding day, were all laboring under the disease, but recovered. John Foster, Ann Dunn, and widow Creyke, all of whom had communicated with the patients above named, were attacked by premonitory indisposition, which was however arrested. Whilst the surgeons were vainly endeavoring to discover whence the disease could possibly have arisen, the mystery was all at once, and most unexpectedly, unraveled by the arrival in the village of the son of the deceased John Barnes. This young man was apprentice to his uncle, a shoemaker, living at Leeds. He informed the surgeons that his uncle's wife (his father's sister) had died of cholera a fortnight before that time, and that, as she had no children, her wearing apparel had been sent to Monkton by a common carrier. The clothes had not been washed; Barnes had opened the box in the evening; on the next day he had fallen sick of the disease.
"During the illness of Mrs. Barnes, her mother, who was living at Tockwith, a healthy village five miles distant from Moor Monkton, was requested to attend her. She went to Moukton accordingly, remained with her daughter for two days, washed her daughter's linen, and set out on her return home, apparently in good health. Whilst in the act of walking home she was seized with the malady, and fell down in collapse on the road. She was conveyed home to her cottage, and placed by the side of her bedridden husband. He, and also the daughter who resided with them, took the malady. All the three died within two days. Only one other case occurred in the village of Tockwith, and it was not a fatal case."
"A man came from Hull (where cholera was prevailing), by trade a painter; his name and age are unknown. He lodged at the house of Samuel Wride, at Pocklington (lower center); was attacked on his arrival on the 8th of September, and died on the 9th. Samuel Wride himself was attacked on the 1lth of September, and died shortly afterwards. These comprise the first cases.
"The next was that of a person named Kneeshaw, who had been at Wride's house. But as this forms one of a series connected with the former, furnished by Dr. Laycock, who has very obligingly taken the trouble to verify the dates and facts of the latter part of the series, it will be best to give the notes of these cases in that gentleman's own words.
" 'My dear Dr. Simpson: - Mrs. Kneeshaw was attacked with cholera on Monday, September 9th, and her son William on the 10th. He died on Saturday the 15th; she lived three weeks; they lived at Pocklington. On Sunday, September 16th, Mr. and Mrs. Flint, and Mr. and Mrs. Giles Kneeshaw, and two children, went to Pocklington to see Mrs. Kneeshaw. Mrs. Flint was her daughter. They all returned the same day, except Mr. M. G. Kneeshaw, who stayed at Pocklington, until Monday, September 24th, when he returned to York. At three o'clock on the same day, he was attacked with cholera, and died Tuesday, September 25th, at three o'clock in the morning. [There had been no cholera in York for some time.] On Thursday, September 27th, Mrs. Flint was attacked, but recovered. On Saturday, September 29th, her sister, Mrs. Stead, came from Pocklington to York, to attend upon her; was attacked on Monday, October the 1st, and died October the 6th.
"'Mrs. Hardeastle, of No. 10, Lord Mayor's Walk, York, was attacked with cholera on October 3rd, and died the same day. Miss Agar, residing with her, died of cholera on October 7th. Miss Robinson, who had come from Hull (lower center, Kingston upon Hull) to take care of the house, after the death of Mrs. Hardeastle and Miss Agar, was attacked, and died on October 11th. Mr. C. Agar, of Stonegate, York, went to see Mrs. Hardcastle on October 3rd, was attacked next day, and died October 6th, early in the morning. On Monday, October 8th, Mrs. Agar, the mother of Mr. C. Agar, was attacked, and on the same day, one of the servants; both recovered. They had lived with Mr. Agar. All the above dates and facts I have verified.
" 'I am, dear Dr. Simpson, yours very truly,
" 'T. LAYCOCK.
" 'Lendal, December 1st, 1849.' "
Several other instances of the communication of cholera, quite as striking as the above, are related in Dr. Simpson's work.
The following account of the propagation of cholera has been published, along with several other histories of the same kind, in a pamphlet by Dr. Bryson.
"Mr. Greene, of Fraserburgh, gives the following account of the introduction of cholera into two villages in Scotland. Two boats, one belonging to Cairnbulgh and the other to Inveralochy, met at Montrose, and their crews on several occasions strolled through the town in company, although aware that it was at that time infected with cholera. On their passage homeward, they were obliged to put into Gourdon, where one man belonging to the Cairnbulgh boat died on the 22nd of September, after an illness of fourteen hours, with all the symptoms of cholera. Several of the men of both boats were at the same time attacked with serous diarrhea, of which three of them had not recovered when they reached their respective homes; nor indeed until the first cases of the epidemic broke out in the villages.
"In Inveralochy the first case appeared on the 28th of September, three or four days after the arrival of the boat; the sufferer, the father of one of the crew, had been engaged in removing the cargo along with other members of his family. Two other cases occurred in this family; one on the 30th of September, and one on the 1st of October.
"In Cairnbulgh, the first cases appeared on the 29th and 30th of September respectively, and both patients had also been engaged in removing the cargo of the boat (shellfish) belonging to that village. No other cases appeared until the 3rd of October; so that from the 28th of September to the 3rd of October none were attacked in either village, but those who had come in contact with the suspected boats, or their crews.
"The subsequent cases were chiefly among relatives of those first attacked; and the order of their propagation was as follows. In Inveralochy, the first case was the father of a family; the second, his wife; the third, a daughter living with her parents; the fourth, a daughter who was married and lived in a different house, but who attended her father and mother during their illness; the fifth, the husband of the latter; and the sixth, his mother. Other cases occurred at the same time, although they were not known to have communicated with the former. One of them was the father of a family; the second his son, who was seized the day after his father, and a daughter the next day."
The following instances of communication of cholera are taken from amongst many others in the "Report on Epidemic Cholera to the Royal College of Physicians", by Dr. Baly.
"Stockport (upper left). (Dr. Rayner and Mr. J. Rayner, reporters). Sarah Dixon went to Liverpool (upper center), September 1st, to bury her sister, who had died of cholera there; returned to Stockport on September 3rd; was attacked with cholera on the 4th; was taken home by her mother to her mother's house, a quarter of a mile distant; was in collapse, but recovered. Her mother was attacked on the 1lth, and died. The brother, James Dixon, came from High Water to see his mother, and was attacked on the 14th.
"Liverpool. (Mr. Henry Taylor, reporter.) A nurse attended a patient in Great Howard Street (at the lower part of the town), and on her return home, near Everton (the higher part of the town), was seized, and died. The nurse who attended her was also seized, and died. No other case had occurred previously in that neighborhood, and none followed for about a fortnight.
"Hedon (lower right). (Dr. Sandwith, reporter.) Mrs. N. went from Paul, a village close to the Humber, to Hedon, two miles off, to nurse her brother in cholera; the next day, after his death, went to nurse Mrs. B., also at Hedon ; within two days was attacked herself; was removed to a lodging‑house ; the son of the lodging-house keeper was attacked the next day, and died. Mrs. N.'s son removed her back to Paul; was himself attacked two days afterwards, and died."
It would be easy, by going through the medical journals and works which have been published on cholera, to quote as many cases similar to the above as would fill a large volume. But the above instances are quite sufficient to show that cholera can be communicated from the sick to the healthy; for it is quite impossible that even a tenth part of these cases of consecutive illness could have followed each other by mere coincidence, without being connected as cause and effect.
NOT COMMUNICATED BY MEANS OF EFFLUVIA
Besides the facts above mentioned, which prove that cholera is communicated from person to person, there are others which show, first, that being present in the same room with a patient, and attending on him, do not necessarily expose a person to the morbid poison; and, secondly, that it is not always requisite that a person should be very near a cholera patient in order to take the disease, as the morbid matter producing it may be transmitted to a distance. It used to be generally assumed, that if cholera were a catching or communicable disease, it must spread by effluvia given off from the patient into the surrounding air, and inhaled by others into the lungs. This assumption led to very conflicting opinions respecting the disease. A little reflection shows, however, that we have no right thus to limit the way in which a disease may be propagated, for the communicable diseases of which we have a correct knowledge spread in very different manners. The itch, and certain other diseases of the skin, are propagated in one way; syphilis, in another way; and intestinal worms in a third way, quite distinct from either of the others.
PATHOLOGY INDICATES MANNER OF COMMUNICATION
A consideration of the pathology of cholera is capable of indicating to us the manner in which the disease is communicated. If it were ushered in by fever, or any other general constitutional disorder, then we should be furnished with no clue to the way in which the morbid poison enters the system; whether, for instance, by the alimentary canal, by the lungs, or in some other manner, but should be left to determine this point by circumstances unconnected with the pathology of the disease. But from all that I have been able to learn of cholera, both from my own observations and the descriptions of others, I conclude that cholera invariably commences with the affection of the alimentary canal. The disease often proceeds with so little feeling of general illness, that the patient does not consider himself in danger, or even apply for advice, till the malady is far advanced. In a few cases, indeed, there are dizziness, faintness, and a feeling of sinking, before discharges from the stomach or bowels actually take place; but there can be no doubt that these symptoms depend on the exudation from the mucous membrane, which is soon afterwards copiously evacuated. This is only what occurs in certain cases of hemorrhage into the alimentary canal, where all the symptoms of loss of blood are present before that fluid shows itself in the evacuations. In those rare cases, called "cholera sicca," in which no purging takes place, the intestines have been found distended with the excretion peculiar to the disease, whenever an examination of the body has taken place after death. In all the cases of cholera that I have attended, the loss of fluid from the stomach and bowels has been sufficient to account for the collapse, when the previous condition of the patient was taken into account, together with the suddenness of the loss, and the circumstance that the process of absorption appears to be suspended.
ANALYSIS OF THE BLOOD AND EVACUATIONS
The symptoms which follow the affection of the alimentary canal in cholera are exactly those which this affection is adequate, and, indeed, could not fail to produce. The analyses which have been made of the blood of cholera patients, show that the watery fluid effused into the stomach and bowels is not replaced by absorption, or is replaced only to a small extent. The analyses of Dr. O'Shaughnessy and others, during the cholera of 1831-32, show that the amount of water in the blood was very much diminished in proportion to the solid constituents, and that the salts of the blood were also diminished. The analyses of Dr. Garrod and Dr. Parkes, in the spring of 1849, were more numerous and exact. The amount of water in the blood of healthy persons is on the average 785 parts in 1000; whereas, in the average of the analyses performed by Drs. Garrod and Parkes, it was only 733 parts, while the amount of solid constituents of the blood, relatively to the water, was increased from 215 -- the healthy standard -- to 267. The globules, together with the albumen and other organic constituents of the serum, amount in the healthy state to 208 parts in 1000, while in the blood of cholera patients they amounted to 256 parts. The saline constituents in 1000 parts of blood are somewhat increased, on account of the great diminution of water; but, when estimated in relation to the other solid ingredients, or to the whole quantity existing in the healthy body, the amount is diminished. Dr. Garrod is of opinion that a chemical analysis will determine whether or not a specimen of blood has been derived from a cholera patient.
The stools and vomited matters in cholera consist of water, containing a small quantity of the salts of the blood, and a very little albuminous substance. The change in the blood is precisely that which the loss by the alimentary canal ought to produce; and, indeed, it is physically impossible that the alteration in the blood can be caused in any other way. The sweating which takes place in an advanced stage of the disease may increase the density of the blood to a trifling extent; but it does not come on till the blood is already altered, and it is only a consequence of the diminished force of the circulation, like the sweating met with in collapse from hemorrhage or severe injuries, and in faintness from venesection.
The loss of water from the blood causes it to assume the thick tarry appearance, so well known to all who have opened a vein in cholera. The diminished volume of the blood causes many of the symptoms of a true hemorrhage, as debility, faintness, and coldness; while these effects are much increased by its thick and tenacious condition, which impedes its passage through the pulmonary capillaries, thereby reducing the contents of the arteries throughout the system to the smallest possible amount, as indicated by the small thready pulse. The interruption to the pulmonary circulation occasioned by the want of fluidity of the blood, is the cause of the distressing feeling of want of breath. Proofs of the obstructed circulation through the lungs generally remain after death, in the distended state of the pulmonary arteries and right cavities of the heart. The deficient supply of blood to the various organs, and its unfitness to pass through the capillaries, are the cause of the suppression of the renal, biliary, and other secretions. The cramps appear to consist chiefly of reflex action, caused by the irritation, and probably the distension, of the bowels.
If any further proof were wanting than those above stated, that all the symptoms attending cholera, except those connected with the alimentary canal, depend simply on the physical alteration of the blood, and not on any cholera poison circulating in the system, it would only be necessary to allude to the effects of a weak saline solution injected into the veins in the stage of collapse. The shrunken skin becomes filled out, and loses its coldness and lividity; the countenance assumes a natural aspect; the patient is able to sit up, and for a time seems well. If the symptoms were caused by a poison circulating in the blood, and depressing the action of the heart, it is impossible that they should thus be suspended by an injection of warm water, holding a little carbonate of soda in solution.
It has often been contended that the collapse of cholera cannot be the mere result of the purging and vomiting, because, in some of the most rapid and malignant cases, the amount of the stools and vomited fluid is less than in milder and more protracted ones, or even in some cases in which the patients recover. But, in the most rapid and malignant cases, there is sufficient loss of aqueous fluid by the alimentary canal to alter the blood into the thick tenacious state peculiar to this disease; and the fact of more purging occurring in other cases which are more protracted, only proves that, in these latter, absorption from the stomach and intestines has not been altogether arrested, or that the stools have been diluted with fluids drank by the patient. The loss of fluid in every case of fully developed cholera must be sufficient to cause the thickened state of the blood, which is the cause of the algide symptoms; and the amount of malignancy of the case must depend chiefly on the extent to which the function of absorption is impaired.
If absorption were altogether arrested in every case of cholera from the beginning, the amount of discharge from the alimentary canal would not equal that of a fatal hemorrhage, for the thickened blood which remains is certainly not able to maintain life so well as the same quantity of healthy blood. Indeed, it is easy to calculate the amount of fluid separated from the blood, by means of the analyses previously quoted, and others which have been made of the cholera stools. In some analyses of these evacuations made by Dr. Parkes, the average composition in 1,000 parts was found to be 982.4 water and 17.6 solids; consequently, the problem is merely to find how much of such a fluid requires to be subtracted from blood consisting of water 785 and solids 215, in 1000 parts, in order to reduce it to blood consisting of water 733 and solids 267. The answer to this problem is that 208.5 parts would require to be subtracted from 1000 parts of blood. M. Valentin has estimated the average amount of blood in the human adult at thirty pounds; and, therefore, the whole quantity of fluid that requires to be effused into the stomach and bowels, in order to reduce the blood of a healthy adult individual to the condition in which it is met with in the collapse of cholera is, on the average, 100 ounces, or five imperial pints. This calculation may be useful as indicating the amount of fluid which ought not to be exceeded in the injection of the blood vessels.
PROPAGATED BY MORBID POISON ENTERING THE ALIMENTARY CANAL
Diseases which are communicated from person to person are caused by some material which passes from the sick to the healthy, and which has the property of increasing and multiplying in the systems of the persons it attacks. In syphilis, smallpox, and vaccinia, we have physical proof of the increase of the morbid material, and in other communicable diseases the evidence of this increase, derived from the fact of their extension, is equally conclusive. As cholera commences with an affection of the alimentary canal, and as we have seen that the blood is not under the influence of any poison in the early stages of this disease, it follows that the morbid material producing cholera must be introduced into the alimentary canal must, in fact, be swallowed accidentally, for persons would not take it intentionally; and the increase of the morbid material, or cholera poison, must take place in the interior of the stomach and bowels. It would seem that the cholera poison, when reproduced in sufficient quantity, acts as an irritant on the surface of the stomach and intestines, or, what is still more probable, it withdraws fluid from the blood circulating in the capillaries, by a power analogous to that by which the epithelial cells of the various organs abstract the different secretions in the healthy body. For the morbid matter of cholera having the property of reproducing its own kind, must necessarily have some sort of structure, most likely that of a cell. It is no objection to this view that the structure of the cholera poison cannot be recognized by the microscope, for the matter of smallpox and of chancre can only be recognized by their effects, and not by their physical properties.
The period which intervenes between the time when a morbid poison enters the system, and the commencement of the illness which follows, is called the period of incubation. It is, in reality, a period of reproduction, as regards the morbid matter; and the disease is due to the crop or progeny resulting from the small quantity of poison first introduced. In cholera, this period of incubation or reproduction is much shorter than in most other epidemic or communicable diseases. From the cases previously detailed, it is shown to be in general only from twenty-four to forty-eight hours. It is owing to this shortness of the period of incubation, and to the quantity of the morbid poison thrown off in the evacuations, that cholera sometimes spreads with a rapidity unknown in other diseases.
The mode of communication of cholera might have been the same as it is, even if it had been a disease of the blood; for there is a good deal of evidence to show that plague, typhoid fever, and yellow fever, diseases in which the blood is affected, are propagated in the same way as cholera. There is sufficient evidence also, I believe, in the following pages, to prove the mode of communication of cholera here explained, independently of the pathology of the disease; but it was from considerations of its pathology that the mode of communication was first explained, and, if the views here propounded are correct, we had a knowledge of cholera, before it had been twenty years in Europe, more correct than that of most of the older epidemics; a knowledge which, indeed, promises to throw much light on the mode of propagation of many diseases which have been present here for centuries.
The instances in which minute quantities of the ejections and defections of cholera patients must be swallowed are sufficiently numerous to account for the spread of the disease; and on examination it is found to spread most where the facilities for this mode of communication are greatest. Nothing has been found to favor the extension of cholera more than want of personal cleanliness, whether arising from habit or scarcity of water, although the circumstance till lately remained unexplained. The bed linen nearly always becomes wetted by the cholera evacuations, and as these are devoid of the usual color and odor, the hands of persons waiting on the patient become soiled without their knowing it; and unless these persons are scrupulously cleanly in their habits, and wash their hands before taking food, they must accidentally swallow some of the excretion, and leave some on the food they handle or prepare, which has to be eaten by the rest of the family, who, amongst the working classes, often have to take their meals in the sick room: hence the thousands of instances in which, amongst this class of the population, a case of cholera in one member of the family is followed by other cases; whilst medical men and others, who merely visit the patients, generally escape. The post mortem inspection of the bodies of cholera patients has hardly ever been followed by the disease that I am aware, this being a duty that is necessarily followed by careful washing of the hands; and it is not the habit of medical men to be taking food on such an occasion. On the other hand, the duties performed about the body, such as laying it out, when done by women of the working class, who make the occasion one of eating and drinking, are often followed by an attack of cholera; and persons who merely attend the funeral, and have no connection with the body, frequently contract the disease, in consequence, apparently, of partaking of food which has been prepared or handled by those having duties about the cholera patient, or his linen and
EVIDENCE OF THIS MODE OF COMMUNICATION IN THE CROWDED HABITATIONS OF THE POOR
Deficiency of light is a great obstacle to cleanliness, as it prevents dirt from being seen, and it must aid very much the contamination of the food with the cholera evacuations. Now the want of light, in some of the dwellings of the poor, in large towns, is one of the circumstances that has often been commented on as increasing the prevalence of cholera.
The involuntary passage of the evacuations in most bad cases of cholera, must also aid in spreading the disease. Mr. Baker, of Staines (lower left), who attended two hundred and sixty cases of cholera and diarrhea in 1849, chiefly among the poor, informed me, in a letter with which he favored me in December of that year, that "when the patients passed their stools involuntarily the disease evidently spread." It is amongst the poor, where a whole family live, sleep, cook, eat, and wash in a single room, that cholera has been found to spread when once introduced, and still more in those places termed common lodging-houses, in which several families were crowded into a single room. It was amongst the vagrant class, who lived in this crowded state, that cholera was most fatal in 1832; but the Act of Parliament for the regulation of common lodging houses, has caused the disease to be much less fatal amongst these people in the late epidemics. When, on the other hand, cholera is introduced into the better kind of houses, as it often is, by means that will be afterwards pointed out, it hardly ever spreads from one member of the family to another. The constant use of the hand-basin and towel, and the fact of the apartments for cooking and eating being distinct from the sick room, are the cause of this.
The great prevalence of cholera in institutions for pauper children and pauper lunatics, whenever it has gained access to these buildings, meets with a satisfactory explanation according to the principles here laid down. In the asylum for pauper children at Tooting, one hundred and forty deaths from cholera occurred amongst a thousand inmates, and the disease did not cease till the remaining children had been removed. The children were placed two or three in a bed, and vomited over each other when they had the cholera. Under these circumstances, and when it is remembered that children get their hands into everything, and are constantly putting their fingers in their mouths, it is not surprising that the malady spread in this manner, although I believe as much attention was paid to cleanliness as is possible in a building crowded with children. Pauper lunatics are generally a good deal crowded together, especially in their sleeping wards, and as the greater number of them are in a state of imbecility, they are no more careful than children in the use of their hands. It is with the greatest difficulty that they can be kept even moderately clean. As might be expected, according to the views here explained, the lunatic patients generally suffered in a much greater proportion than the keepers and other attendants.
EVIDENCE OF THIS MODE OF COMMUNICATION AMONGST THE MINING POPULATION
The mining population of Great Britain have suffered more from cholera than persons in any other occupation, -- a circumstance which I believe can only be explained by the mode of communication of the malady above pointed out. Pitmen are differently situated from every other class of workmen in many important particulars. There are no privies in the coal pits, or, as I believe, in other mines. The workmen stay so long in the mines that they are obliged to take a supply of food with them, which they eat invariably with unwashed hands, and without knife and fork. The following is a reply which I received from a relative of mine connected with a colliery near Leeds (lower right), in answer to an inquiry I made:
"Our colliers descend at five o'clock in the morning, to be ready for work at six, and leave the pit from one to half-past three. The average time spent in the pit is eight to nine hours. The pitmen all take down with them a supply of food, which consists of cake, with the addition, in some cases, of meat; and all have a bottle, containing about a quart of 'drink'. I fear that our colliers are no better than others as regards cleanliness. The pit is one huge privy, and of course the men always take their victuals with unwashed hands."
It is very evident that, when a pitman is attacked with cholera whilst at work, the disease has facilities for spreading among his fellow laborers such as occur in no other occupation. That the men are occasionally attacked whilst at work I know, from having seen them brought up from some of the coal pits in Northumberland, in the winter of 1831-2, after having had profuse discharges from the stomach and bowels, and when fast approaching to a state of collapse.
Dr. Baly, who has done me the honor of giving a very full and impartial account of my views in his "Report on Cholera to the College of Physicians", makes the objection to what I have said about the colliers, that the women and children who do not work in the mines, were attacked in as large numbers as the men. I believe, however, that this is only what ought to occur from the propagation of the cholera in the crowded dwellings of the pitmen, in the manner previously explained. The only effect of its communication in the pits would be, that the men and boys in a family would have the cholera a day or two earlier than the women and children; and if a special inquiry were made on this point, this would probably be found to be the case. It has often been said that, if cholera were a communicable disease, women ought to suffer in much greater numbers than the men, as they are employed in nursing the sick. I leave this objection and Dr. Baly's to combat each other.
It is very probable that, when cholera occurs amongst people who are employed in the preparation or vending of provisions, the disease may be spread by this means, although from the nature of the subject it is hardly to be expected that the fact would be discovered. The following cases, perhaps, afford as decisive proof of this variety of communication of cholera as can be expected. In the beginning of 1850, a letter appeared in the Provincial Medical and Surgical Journal, from Mr. John C. Bloxam, in the Isle of Wight (upper left), being an answer to the inquiry on cholera by Mr. Hunt. Among other interesting information, Mr. Bloxam stated, that the only cases of cholera that occurred in the village of Carisbrook, happened in persons who ate of some stale cow-heels, which had been the property of a man who died in Newport, after a short and violent attack of cholera. Mr. Bloxam kindly made additional personal inquiries into the case, in consequence of questions I put to him, and the following is a summary of the information contained in his letter:--
The man from whose house the cow-heels were sent for sale died on Monday, the 20th of August. It was the custom in the house to boil these articles on Monday, Wednesday, and Friday; and the cow-heels under consideration were taken to Carisbrook, which is a mile from Newport, ready boiled, on Tuesday the 21st. Eleven persons in all partook of this food, seven of whom ate it without any additional cooking. Six of these were taken ill within twenty-four hours after eating it, five of whom died, and one recovered. The seventh individual, a child, who ate but a 'small quantity of the cow-heels, was unaffected by it. Four persons partook of the food after additional cooking. In one case the cow-heels were fried, and the person who ate them was taken ill of cholera within twenty-four hours afterwards, and died. Some of the food was made into broth, of which three persons partook while it was warm; two of them remained well, but the third person partook again of the broth next day, when cold, and, within twenty-four hours after this latter meal, she was taken ill with cholera, of which she died. It may be proper to mention, although it is no unusual circumstance for animal food to be eaten in hot weather when not quite fresh, that some of the persons perceived the cow-heels to be not so fresh as they ought to have been at the time they were eaten, and part of them had to be thrown away a day or two afterwards, in consequence of being quite putrid.
It is not unlikely that some of the cases of cholera which spring up without any apparent connection with previous cases, may be communicated through articles of diet. It is the practice of the poor people, who gain a living by selling fruit and other articles in the streets, to keep their stock in very crowded rooms in which they live, and, when visiting the out-patients of a medical charity a few years ago, I often saw baskets of fruit pushed under the beds of sick patients, in close proximity with the chamber utensils. I need hardly say that if cases of disease were propagated in this way, it would be quite impossible to trace them.
If the cholera had no other means of communication than those which we have been considering, it would be constrained to confine itself chiefly to the crowded dwellings of the poor, and would be continually liable to die out accidentally in a place, for want of the opportunity to reach fresh victims; 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.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER IN HORSLEYDOWN
In 1849 there were in Thomas Street, Horsleydown (upper left), two courts close together, consisting of a number of small houses or cottages, inhabited by poor people. The houses occupied one side of each court or alley -- the south side of Trusscott's Court, and the north side of the other, which was called Surrey Buildings, being placed back to back, with an intervening space, divided into small back areas, in which were situated the privies of both the courts, communicating with the same drain, and there was an open sewer which passed the further end of both courts. Now, in Surrey Buildings the cholera committed fearful devastation, whilst in the adjoining court there was but one fatal case, and another case that ended in recovery. In the former court, the slops of dirty water, poured down by the inhabitants into a channel in front of the houses, got into the well from which they obtained their water; this being the only difference that Mr. Grant, the Assistant-Surveyor for the Commissioners of Sewers, could find between the circumstances of the two courts, as he stated in a report that he made to the Commissioners. The well in question was supplied from the pipes of the Southwark and Vauxhall Waterworks, and was covered in on a level with the adjoining ground; and the inhabitants obtained the water by a pump placed over the well. The channel mentioned above commenced close by the pump. Owing to something being out of order, the water had for some time occasionally burst out at the top of the well, and overflowed into the gutter or channel, afterwards flowing back again mixed with the impurities; and crevices were left in the ground or pavement, allowing part of the contents of the gutter to flow at all times into the well; and when it was afterwards emptied, a large quantity of black and highly offensive deposit was found.
The first case of cholera in this court occurred on July 20th, in a little girl, who had been laboring under diarrhea for four days. This case ended favorably. On the 21st July, the next day, an elderly female was attacked with the disease, and was in a state of collapse at ten o'clock the same night. This patient partially recovered, but died of some consecutive affection on August 1. Mr. Vinen, of Tooley Street, who attended these cases, states that the evacuations were passed into the beds, and that the water in which the foul linen was washed would inevitably be emptied into the channel mentioned above. Mr. Russell, of Thornton Street, Horsleydown, who attended many of the subsequent cases in the court, and who, along with another medical gentleman, was the first to call the attention of the authorities to the state of the well, says that such water was invariably emptied there, and the people admit the circumstance. About a week after the above two cases commenced, a number of patients were taken ill nearly together: four on Saturday, July 28th, seven or eight on the 29th, and several on the day following. The deaths in the cases that were fatal took place as follows: -- one on the 29th, four on the 30th, and one on the 31st July; two on August 1st, and one on August the 2nd, 5th, and 10th respectively, making eleven in all. They occurred in seven out of the fourteen small houses situated in the court.
The two first cases on the 20th and 21st were probably caused by the cholera evacuations contained in the Thames water, as it came from the waterworks, and they may be considered to represent about the average amount of cases for the neighborhood, there having been just that number in the adjoining court, about the same time. But in a few days, when the dejections of these patients must have become mixed with the water the people drank, a number of additional cases commenced nearly together. The patients were all women and children, the men living in the court not having been attacked; they may have been out at work all day and not have drank the water, but as the surviving inhabitants nearly all left the place immediately after the above mortality occurred, I was not able to ascertain whether this was so or not.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER AT ALBION TERRACE, WANDSWORTH ROAD
In Albion Terrace, Wandsworth Road, there was an extraordinary mortality from cholera in 1849, which was the more striking as there were no other cases at the time in the immediate neighborhood; the houses opposite to, behind, and in the same line, at each end of those in which the disease prevailed, having been free from it. The row of houses in which the cholera prevailed to an extent probably at that time quite unprecedented in this country, constituted the genteel suburban dwellings of a number of professional and trades-people, and are most of them detached a few feet from each other. They were supplied with water on the same plan. In this instance the water got contaminated by the contents of the house drains and cesspools. The cholera extended to nearly all the houses in which the water was thus tainted, and to no others.
These houses were numbered from 1 to 17, in Albion Terrace, and were supplied with water from a copious spring in the road in front of the terrace, the water of which was conducted, by a brick barrel-drain between Nos. 7 and 8, to the back of the houses, and then flowed right and left, to supply tanks in the ground behind each house, the tanks being made of brickwork and cement, covered with a flat stone, and connected with each other by stoneware pipes six inches in diameter. A leaden pipe conveyed water from each tank to a pump situated in the back kitchen. There was a cesspool behind each house, under the privy, and situated four feet from the water tank. The ground was opened behind the houses No. 1 and No. 7, and the drains examined under the superintendence of Mr. Grant, the Assistant Surveyor to the Commissioners of Sewers. The cesspools at both these places were quite full, and the overflow-drain from that at No. 1 choked up. At this house the respective levels of the cesspool and the water tank were measured, and the top of the overflow drain from the cesspool was found to be fifteen inches above the top of the tank, and the intervening ground was very wet. The overflow drain mentioned above had no bottom, or one so soft that it could be penetrated with a stick; and it crossed, at right angles, above the earthenware pipe of the water tank, the joints of which were leaky, and allowed the water to escape. Behind No. 7,. Mr. Grant found a pipe for bringing surplus water from the tanks, communicating with a drain from the cesspool; and he found a flat brick drain laid over the barrel drain before mentioned, which brought the water from the spring. It appears, from a plan of the property, that this drain, which was continued in a direction towards the sewer in Battersea Fields, brought surface drainage from the road, and received the drains from the cesspools, the house drains from the sinks in the back kitchens, and the surplus water, or some of it, from the tanks. There was every reason to believe that this drain was stopped up, but that was not ascertained: at all events it was unable to convey the water flowing into it during the storm on July 26th, as it burst near the house No. 8, and inundated the lower premises of that and the adjoining house, No. 9, with fetid water; and it was from this time that the water, which had occasionally been complained of before, was found by most of the people in these seventeen houses to be more or less impure or disagreeable. The water broke out of the drain again at No. 8, and overflowed the kitchens, during a heavy rain on August 2nd. It should be particularly remarked, that the tanks were placed on the same level, so that pumping from one would draw water from the others, and that any impurity getting into one tank would consequently be imparted to the rest.
The first case of cholera occurred at No. 13, on July 28th (two days after the bursting of the drain), in a lady who had had premonitory symptoms for three or four days. It was fatal in fourteen hours. There was an accumulation of rubbish in the cellar of this house, which was said to be offensive by the person who removed it; but the proprietor of the house denied this. A lady at No. 8 was attacked with choleraic diarrhea on July 30th: she recovered. On August 1st, a lady, aged eighty-one, at No. 6, who had had some diarrhea eight or ten days before, which had yielded to her own treatment, was attacked with cholera: she died on the 4th with congested brain. Diarrhea commenced on August 1st in a lady aged 60, at No. 3 ; collapse took place on the 5th, and death on the 6th. On August 3rd, there were three or four cases, in different parts of the row of houses, and two of them terminated fatally on the same day. The attacks were numerous during the following three or four days, and after that time they diminished in number. More than half the inhabitants of the part of the terrace in which the cholera prevailed, were attacked with it, and upwards of half the cases were fatal. The deaths occurred as follows; but as some of the patients lingered a few days, and died in the consecutive fever, the deaths are less closely grouped than the seizures. There was one death on July 28th, two on August 3rd, four on the 4th, two on the 6th, two on the 7th, four on the 8th, three on the 9th, one on the 11th, and one on the 13th. These make twenty fatal cases; and there were four or five deaths besides amongst those who were attacked after flying from the place.
The fatal cases were distributed over ten out of the seventeen houses; and Mr. Mimpriss of Wandsworth Road, who attended many of the cases, and to whose kindness I am indebted for several of these particulars, stated that cases occurred in the other seven houses, with the exception of one or two that were empty, or nearly so. There were five deaths in the house No. 6; and one of a gentleman the day after he left it, and went to Hampstead Heath. The entire household, consisting of seven individuals, had the cholera, and six of them died.
There are no data for showing how the disease was communicated to the first patient, at No. 13, on July 28th; but it was two or three days afterwards, when the evacuations from this patient must have entered the drains having a communication with the water supplied to all the houses, that other persons were attacked, and in two days more the disease prevailed to an alarming extent.
I had an opportunity of examining some of the water removed by Mr. Grant from the tanks behind the houses No. 1 and No. 7, and also some of the deposit which lay in the tanks to the depth of from six to nine inches. The water was offensive, and the deposit possessed the odor of privy soil very distinctly, I found in it various substances which had passed through the alimentary canal, having escaped digestion, as the stones and husks of currants and grapes, and portions of the thin epidermis of other fruits and vegetables.
Many of the patients attributed their illness to the water. This is here mentioned to show that they had drank of it, and at the same time found that it was impure. As explaining how persons might drink of such water before finding out its impurity, it may be stated that the grosser part of the material from drains and cesspools has a tendency, when mixed with water, to settle rapidly to the bottom. The only houses supplied with the same water, after passing the tanks in Albion Terrace, were four in Albion Street; but three of these had been empty for months, and the fourth was inhabited by a gentleman who always suspected the water, and would not drink it. There were two or three persons attacked with cholera amongst those who came to nurse the patients after the water was condemned, and who, consequently, did not drink it; but these persons were liable, in waiting on the patient, to get a small portion of the evacuations into the stomach in the way first pointed out; and there might be food in the houses, previously prepared with the tainted water. It is not here implied that every one of the cases in Albion Terrace was communicated by the water, but that far the greater portion of them were; that, in short, it was the circumstance of the cholera evacuations getting into the water, which caused the disease to spread so much beyond its ordinary extent.
The mortality in Albion Terrace was attributed by Dr. Milroy, in a published report to the General Board of Health, chiefly to three causes: first, to an open sewer in Battersea Fields, which is four hundred feet to the north of the terrace, and from which the inhabitants perceived a disagreeable odor when the wind was in certain directions; secondly, to a disagreeable odor from the sinks in the back kitchens of the houses, which was worse after the storm of July 26; and lastly, to the accumulation in the house No. 13, before alluded to. With respect to the open sewer, there are several streets and lines of houses as much exposed to any emanations there might be from it, as those in which the cholera prevailed; and yet they were quite free from the malady, as were also nineteen houses situated between the sewer and Albion Terrace. As regards the bad smells from the sinks in the kitchen, their existence is of such every-day and almost universal prevalence, that they do not help to explain an irruption of cholera like that under consideration; indeed, offensive odors were created in thousands of houses in London by the same storm of rain on July 26th; and the two houses in which the offensive smell was greatest, viz. Nos. 8 and 9 those which were flooded with the contents of the drain were less severely visited with cholera than the rest; the inhabitants having only had diarrhea, or mild attacks of cholera. The accumulation in the house No. 13 could not affect the houses at a distance from it. It remains evident the that the only special and peculiar cause connected with the great calamity which befel the inhabitants of these houses, was the state of the water, which was followed by the cholera in almost every house to which it extended, whilst all the surrounding houses were quite free from the disease. Indeed, the General Board of Health attributed the mortality at this place to the contamination of the water, in a manifesto which they published not long after Dr. Milroy's report.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER AT ROTHERHITHE
Dr. Lloyd mentioned some instances of the effects of impure water at the South London Medical Society, on August 30th, 1849. In Silver Street, Rotherhithe, there were eighty cases, and thirty-eight deaths, in the course of a fortnight early in July of that year, at a time when there was very little cholera in any other part of Rotherhithe. The contents of all the privies in this street ran into a drain which had once had a communication with the Thames; and the people got their supply of water from a well situated very near the end of the drain, with the contents of which the water got contaminated. Dr. Lloyd informed me that the fetid water from the drain could be seen dribbling through the side of the well, above the surface of the water. Amongst other sanitary measures recommended by Dr. Lloyd was the filling up of the well; and the cholera ceased in Silver Street as soon as the people gave over using the water. Another instance alluded to by Dr. Lloyd, was Charlotte Place, in Rotherhithe, consisting of seven houses, the inhabitants of which, excepting those of one house, obtained their water from a ditch communicating with the Thames, and receiving the contents of the privies of all the seven houses'. In these houses there were twenty five cases of cholera, and fourteen deaths; one of the houses had a pump railed off, to which the inhabitants of the other houses had no access, and there was but one case in that house.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER AT MANCHESTER IN HOPE STREET, SALFORD
The following instance, as well as some others of a similar kind, is related in the "Report of the General Board of Health on the Cholera of 1848 and 1849."
"In Manchester (upper left), a sudden and violent outbreak of cholera occurred in Hope Street, Salford. The inhabitants used water from a particular pump well. This well had been repaired, and a sewer which passes within nine inches of the edge of it became accidentally stopped up, and leaked into the well. The inhabitants of thirty houses used the water from this well; among them there occurred nineteen cases of diarrhea, twenty-six cases of cholera, and twenty-five deaths. The inhabitants of sixty houses in the same immediate neighborhood used other water; among these there occurred eleven cases of diarrhea, but not a single case of cholera, nor one death. It is remarkable, that, in this instance, out of the twenty-six persons attacked with cholera, the whole perished except one."
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER AT ILFORD AND NEAR BATH
Dr. Thomas King Chambers informed me, that at Ilford, in Essex (center right), in the summer of 1849, the cholera prevailed very severely in a row of houses a little way from the main part of the town. It had visited every house in the row but one. The refuse which overflowed from the privies and a pigsty could be seen running into the well over the surface of the ground, and the water was very fetid; yet it was used by the people in all the houses except that which had escaped cholera. That house was inhabited by a woman who took linen to wash, and she, finding that the water gave the linen an offensive smell, paid a person to fetch water for her from the pump in the town, and this water she used for culinary purposes, as well as for washing.
The following circumstance was related to me, at the time it occurred, by a gentleman well acquainted with all the particulars. The drainage from the cesspools found its way into the well attached to some houses at Locksbrook, near Bath (upper left), and the cholera making its appearance there in the autumn of 1849, became very fatal. The people complained of the water to the gentleman belonging to the property, who lived at Weston, in Bath, and he sent a surveyor, who reported that nothing was the matter. The tenants still complaining, the owner went himself, and on looking at the water and smelling it, he said that he could perceive nothing the matter with it. He was asked if he would taste it, and he drank a glass of it. This occurred on a Wednesday; he went home, was taken ill with the cholera, and died on the Saturday following, there being no cholera in his own neighborhood at the time.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER AT NEWBURN ON THE TYNE
There is no spot in this country in which the cholera was more fatal during the epidemic of 1832 than the village of Newburn, near Newcastle-upon-Tyne (center right) We are informed, in an excellent paper on the subject by Dr. David Craigie, that exactly one-tenth of the population died. The number of the inhabitants was five hundred and fifty; of these, three hundred and twenty suffered from the epidemic, either in the form of diarrhea or the more confirmed disease, and the deaths amounted to fifty- five. Being aware of this mortality, I wrote, about the beginning of the year 1849, to a friend in Newcastle -- Dr. Embleton -- to make inquiries respecting the water used at Newburn, and he kindly procured me some information from the Rev. John Reed, of Newburn Vicarage, which I received in February, as well as an answer from Mr. Davison, surgeon, of Newburn, to whom I had written in the meantime. I learnt from these communications that the people were supplied with water in 1832, as they still were, from three wells, two of which were very little used, and that the water in the third well was derived from the workings of an old coal mine near the village. The water of this well, as I was informed, although generally good when first drawn, became putrid after being kept two days. It was considered that the evacuations of the people could not get into any of the wells; but the vicar thought that the water of a little brook which runs past the village, and falls into the Tyne immediately afterwards, might find its way into that well which is chiefly resorted to. Putrefaction, on being kept a day or two, is so much the character of water containing animal matter, that, after receiving confirmation of my views respecting the communication of cholera by water from many other places, I wrote to Mr. Davison again on the subject, and he kindly took a great deal of trouble to investigate the matter further. He informed me that the brook was principally formed by water which was constantly pumped from coal pits in the neighborhood. About half a mile before reaching Newburn it received the refuse of a small village, and between that village and Newbum it ran through a privy used by the workmen of a steel factory. In Newburn this brook received the contents of the open drains or gutters from the houses. The drain which conveyed water from a coal mine or drift not worked for a great number of years, to the well mentioned above, passed underneath the brook at one part of its course, and from that point ran alongside of the brook to the well, -- a distance of about three hundred yards. Mr. Davison said that it was disputed whether there was any communication between the drain and the brook, but that it was highly probable that there might be; and that an occurrence which took place a few months previously seemed to prove that there was. Some gas-water from the steel manufactory mentioned above got by accident into the brook, and some of the people affirmed that the water in the well was strongly impregnated with it.
The first case of cholera in Newburn was that of a young man living close to the brook, about a hundred yards above the place at which it passes the well. He was taken ill on the 29th December, 1831, and died, in the stage of consecutive fever, on January 4th, 1832. There were some cases of diarrhea in the village, but no new cases of cholera till the night of January the 9th, during which night and the following morning thirteen persons were taken ill. During the night of the 12th four persons were attacked; by the 15th there were fourteen new cases, and on this day the late vicar died -- the Rev. John Edmonston. By the next day at noon there were at least fifty new cases. A few days after this the disease began to subside, and by the 2nd of February had almost disappeared. As several days elapsed between the first case of cholera and the great outbreak, it is probable that the water in which the soiled linen must have been washed, and which would necessarily run into the brook, was the means of communicating the disease to the thirteen persons taken ill on the night between the 9th and 10th of January; unless, indeed, the intermediate cases of diarrhoea could transmit the disease.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER AT CUNNATORE
The following passage is from the report of Mr. Cruikshanks on the outbreak of cholera in 1814, previously alluded to as occurring in a battalion on its march from Jaulnah to Trichinopoly.
" It was the belief of the natives, strenuously fostered and inculcated by their spiritual guides, that the epidemic was the immediate consequence of the wrath of Heaven, outraged and insulted by the pollution of certain sacred tanks, situated at the village of Cunnatore, in which sepoys of low caste and camp followers had indiscriminately bathed. Such we may not regard as affording a very satisfactory solution of the difficulty; yet it leads, I think, directly to the true point of inquiry. At Cunnatore, the force was so encamped, that while the 5th Native Infantry on the right had their supplies of water from wells, the puckallies of the 9th Native Infantry procured water for that battalion from tanks situated on low ground on the left of the line. The fact, that the disease first broke forth in a day or two after passing Cunnatore; the prevailing opinion of the natives, that it originated there, and that somehow it was connected with the tanks; a desire to discover some one cause confined in its influence and operation to one out of the two battalions; lastly, the difficulty or impossibility of lighting on any other; all these led to inquiry, and to ascertaining with a considerable degree of certainty, that each battalion was supplied with water from a source distinct from the other." The cholera was said not to be at Cunnatore at the time the infantry were encamped there, but this was probably a mistake.
INSTANCES OF THE COMMUNICATION OF CHOLERA THROUGH THE MEDIUM OF POLLUTED WATER IN THE BLACK SEA FLEET
The following quotation is from a letter by a medical officer in the Black Sea fleet, dated Baljik, August 23, 1854, and published in the Medical Times and Gazette of September 30th.
"A week after the return of the fleet to Baljik, on the 7th of August, about four thousand French troops encamped on the heights abreast our anchorage. These were part of the first division of the army that had marched to Kostenie, about ten days before. By it the first blood had been drawn on the part of the allied army. The loss in battle was small, but they had encountered an enemy more terrible than the Russians. The cholera had broken out among them, and attacking four hundred on the first night had destroyed sixty. The total loss had been something incredible. It was said, that out of eleven thousand men, not less than five thousand had perished in a few days. This dreadful calamity was attributed to drinking water from wells that had been poisoned by throwing in putrid carcasses.
"Putting aside the question of intentional poisoning, which always presents itself as the most ready way of accounting for such destruction, perhaps some support to the theory, that water is the medium by which cholera poison is conveyed, may be found in this circumstance, and in another of which I was witness. These soldiers, wearied by marching from a focus of cholera infection, were seen, many of them, washing their persons and clothing in the stream from which all the French ships of war, and the majority of the English fleet, obtained their supply of water. This was going on on the 7th and 8th, and, on the nights of the 9th and 10th, the disease burst out with great violence among the crews of several ships.
"Some English ships were the first to suffer, on the night of the 9th, and they proceeded to sea next morning. On the night of the 10th, other English ships, and some of the French, began to suffer; and the latter in an almost unparalleled manner.
"The two admirals' ships, Montebello and Ville de Paris, were terribly affected. On the previous day they had been in as healthy a state as usual; and in the night the cholera attacked, in the former, two hundred men, of whom forty lay dead in the morning; and in the Ville de Paris there were also many deaths. The French fleet sailed on the afternoon of the 1lth; and the following morning saw the English ships also at sea.
"On this day (the 14th), about noon, the Britannia, which had left port in a favorable condition, was attacked suddenly, and in twenty hours upwards of fifty of her crew had expired. We knew nothing of the calamity that had overwhelmed our leader until the following morning, when 9. reports of the sick' were sent from each ship to the admiral. By this time (the evening of the 16th), eighty had died, and more than two hundred remained in greater or less danger.
"The night of the 16th must have been one of great consternation on board her. The epidemic went on with unchecked violence; the officers were voluntarily attending on the sick; and the very few of the crew who had not been attacked, or who were not assisting their unfortunate messmates, were found quite insufficient to perform the duties of a ship when under sail; and the admiral, therefore, determined to return to Baljik, taking with him the Trafalgar and Albion, also badly affected.
"The crew of the Britannia were at once sent away from the ship, in small parties, into the numerous transports that remained idle; and it appears that, by this procedure, the epidemic influences operating among them have been greatly moderated, if not extirpated."
END OF READINGS (page 38)
Part One of Snow on Cholera
Click part 2 at left to proceed to pages 38-55
 Report on the Epidemic Cholera, 1824, p. 5.
 On the infectious Origin and Propagation of Cholera.
 See "London Journal of Medicine," May, 1849.
 London Journal of Medicine, loc. cit.
 In the so-called secondary fever there is toxicohemia, arising from suppressed excretion by the kidneys.
 See "London Gazette", 18th Sept. 1849.
 See Report in "Med. Gaz.". vol. ii, 1849, p. 429.
 Edin. Med. and Sur. Jour., vol. xxxvii.
 Scot, "Report on the Epidemic Cholera", p. 237.