Source:  Snow, John. London, J. Churchill, 1855, pp. 97-120.

Dr. Snow's Report," in Report on the Cholera Outbreak in the Parish of St. James, Westminster, during the Autumn of 1854

(July 1855) Snow dated his report, 12 December 1854. The Cholera Inquiry Committee asked him to read a paper, largely prepared in advance, that described his investigations of the Golden Square outbreak--significant expansions of what he discussed in MCC2, including a new feature to the map of deaths in the parish (see image p. 107).

[The original map had a tear in it, which remains in the image.]

Dr. Snow's Report.
[Constituting part 3 of the Cholera Inquiry Committee's Report to the Vestry of St. James, Westminster parish]

Having been requested by this Committee to draw up a Report on the water used in the locality so severely visited by Cholera, I beg to lay the following statement before you:--

The water supply of the district consists of that of the water companies and that of the street-pumps. The sub-district of Golden Square is supplied by the Grand Junction Company, with water from the Thames, facing Brentford, at Kew, which is almost entirely freed from animal and vegetable impurities before it is distributed. The sub-district of Berwick Street is supplied by the New River Company; the division between the companies being exactly that between the two sub-districts of the parish just named. The remaining districts supplied by the Grand Junction Company have been remarkably free from Cholera, both during the present year and in 1849; and most of the districts supplied by the New River Company have also been lightly visited by the malady on [97/98] both occasions; there is, therefore, in my opinion, no reason to suppose that the water of either of these companies contributed to the late outbreak of Cholera. One circumstance which remarkably confirms this view is, that the outbreak commenced on the same day, and almost at the same hour, in both sub-districts; and if it were possible that any pollution of the water supply of the two companies could have taken place, we cannot suppose that it would have occurred at the same time, and at two adjoining spots, in two systems of pipes in which the supply is derived from such very different sources.

With respect to the pump wells, I found some impurities in the water of each of those which I examined in the first week of September, in the Golden Square district, except the one in Vigo Street. The water of the pumps in Broad Street, Warwick Street, and Bridle Lane, all contained impurities visible to the naked eye on close inspection, in the form of minute, whitish, flocculent particles. The water of the pump in Marlborough Street contained a still larger quantity of organic impurities than the others, and most of the people in its neighbourhood avoided using the water, and sent to Broad Street. In my opinion, mere impurity in the water would not cause Cholera, unless it were of a special kind--unless, in fact, the impurity had proceeded from a Cholera patient. Dr. Lankester has, I believe, particularly examined [98/99] the water of the pump in Broad Street, which is situated in the centre of the area in which the mortality from Cholera occurred; and he will, no doubt, inform the Committee of the result of his researches. Dr. Hassall was good enough to examine some of this water, at my request, with the microscope, and he informed me that the particles I have mentioned above had no organized structure, and that he thought they probably resulted from the decomposition of other matter. He found a great number of very minute, oval animalculæ in the water, which are of no importance, except as an additional proof that the water contained organic matter on which they lived. I found that the water also contained a large quantity of chlorides--indicating, no doubt, the impure sources from which the spring is supplied. Mr. Eley of 38, Broad Street, informed me that he had long noticed that the water became offensive, both to the smell and taste, after it had been kept about two days. A person, at 6, Poland Street, also informed that he had noticed, for months, that a film formed on the surface of the water after it had been kept a few hours. These are characters of water which is contaminated with sewage.

I inquired of many persons whether they had observed any change in the character of the water about the time of the outbreak of Cholera, and was answered in the negative. I afterwards, however, met with the following important information on [99/100] this point:--Mr. Gould, the eminent ornithologist, lives near the pump in Broad Street, and was in the habit of drinking the water. He was out of town at the commencement of the outbreak of Cholera, but came home on Saturday morning, the 2nd of September, and sent for some of the water almost immediately, when he was much surprised to find that it had an offensive smell, although perfectly transparent, and fresh from the pump. He drank scarcely any of it. Mr. Gould's assistant, Mr. Prince, had his attention directed to the water, and perceived its offensive smell.

Whether the impurities of the water were derived from the sewers, the drains, or the cesspools, of which latter there are, I believe, a number in the neighbourhood, I cannot tell. I have been informed, by an eminent engineer, that whilst a cesspool in a clay soil requires to be emptied every six or eight months, one sunk in the gravel will often go for twenty years without being emptied, owing to the soluble matters passing away into the land-springs by percolation.

I requested permission, on the 5th of September, to take a list, at the General Register Office, of the deaths from Cholera registered during the week ending the 2nd of September, in the sub-districts of Golden Square and Berwick Street, St. James's, and St. Anne's Soho, which was kindly granted. Eighty-nine deaths from Cholera were registered during the week, in the three sub-districts. Of [100/101] these only six occurred on the first four days of the week; four occurred on Thursday the 31st of August; and the remaining 79 on Friday and Saturday. I considered, therefore, that the outbreak commenced on the Thursday; and I made inquiry in detail respecting the 83 deaths registered as having taken place during the last three days of the week.

On proceeding to the spot, I found that nearly all the deaths had taken place within a short distance of the pump in Broad Street. There were only ten deaths in houses situated decidedly nearer to another street-pump. In five of these cases, the families of the deceased persons told me that they always sent to the pump in Broad Street, as they preferred the water to that of the pump which was nearer. In three other cases, the deceased were children who went to school near the pump in Broad Street. Two of them were known to have drunk the water, and the parents of the third think it probable that it did so. The other two deaths, beyond the district which this pump supplies, represent only the amount of mortality from Cholera that was occurring before the eruption took place.

With regard to the 73 deaths occurring in the locality belonging as it were to the pump, there were 61 instances in which I was informed that the deceased persons used to drink the water from the pump in Broad Street, either constantly or [101/102] occasionally. In six instances I could get no information, owing to the death or departure of every one connected with the deceased individuals; and in six cases I was informed that the deceased persons did not drink the pump water before their illness.

The result of the inquiry consequently 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.

I had an interview with the Board of Guardians of St. James's parish on the evening of Thursday, 7th September, and represented the above circumstances to them. In consequence of what I said, the handle of the pump was removed on the following day.

Besides the 83 deaths mentioned above, as occurring on the three last days of the week ending September 2nd, and being registered during that week in the sub-districts in which the attacks occurred, there was a number of persons who died in the Middlesex and other hospitals, and a great number of deaths which took place in the locality during the two last days of the week, were not registered till the week following. The deaths altogether on the 1st and 2nd of September, which have been ascertained to belong to this outbreak of Cholera, were 197, and many persons who were attacked about the same time as these, [102/103] died afterwards. I should have been glad to inquire respecting the use of the water from Broad Street pump in all these instances; but I was engaged at the time in an inquiry in the south districts of London; and when I began to make fresh inquiries in the neighbourhood of Golden Square, after two or three weeks had elapsed, I found that there had been such a distribution of the remaining population, that it would be impossible to arrive at a complete account of the circumstances. There is no reason to suppose, however, that a more extended inquiry would have yielded a different result from that which was obtained respecting the 83 deaths which happened to be registered within the district of the outbreak, before the end of the week in which it commenced.

The additional facts that I have been able to ascertain, are in accordance with those above related; and as regards the small number of those attacked, who were believed not to have drunk the water from Broad Street pump, it must be obvious that there are various ways in which the deceased persons may have taken it without the knowledge of their friends. The water was used for mixing with spirits in some of the public houses around. It was used, likewise, at dining rooms and coffee shops. The keeper of a coffee shop which was frequented by mechanics, and where the pump water was supplied at dinner time, informed me on the 6th of September, that she was already aware [103/104] of nine of her customers who were dead! The water of this pump was also sold in various little shops with a tea-spoonful of effervescing powder in it, under the name of sherbet, and it may have been distributed in various other ways with which I am unacquainted. The pump was frequented much more than is usual, even for a London pump in a populous neighbourhood.

There are certain circumstances bearing on the question which deserve to be mentioned. The workhouse in Poland Street is more than three-fourths surrounded by houses in which deaths from Cholera occurred; yet, out of 535 inmates, only five died of Cholera - the other deaths which took place being those of persons admitted after they were attacked. The workhouse has a pump on the premises in addition to the supply from the Grand Junction Water Works, and the inmates never sent to Broad Street for water. If the mortality in the workhouse had been equal to that in the streets immediately surrounding it on three sides, upwards of 50 inmates would have died. There is a brewery in Broad Street near to the pump, and on perceiving that no brewer's men were registered as being dead of Cholera, I called on Mr. Huggins the proprietor. He informed me that there were above 70 workmen employed in the brewery, and that none of them had suffered from Cholera, at least in a severe form, only two having been indisposed, and that not seriously, [104/105] at the time the disease prevailed. The men are allowed a certain quantity of malt liquor, and Mr. Huggins believes they do not drink water at all, and he is quite certain that they never obtained water from the pump in the street. There is a deep well in the brewery in addition to the New River water.

At the wire cartridge and percussion cap manufactory, 38, Broad Street, where I understand about 200 work people were employed, two tubs were kept on the premises always supplied with water from the pump in the street for those to drink who wished, and 18 of those work people died of Cholera at their own houses - sixteen women and two men. Mr. Peter Marshall, surgeon, No. 53, Greek Street, was kind enough to inquire respecting seven workmen, who had been employed in the manufacture of dentists' materials at Nos. 8 and 9, Broad Street, and who died at their own homes. He learned that they were all in the habit of drinking water from the pump, generally drinking about half a pint once or twice a day, while two persons who reside constantly on the premises, but do not drink the pump water, had only diarrhea. Mr. P. Marshall also informed me of the case of an officer in the army who lived at St. John's Wood but came to dine in Wardour Street, where he drank the water from Broad Street pump at dinner. He was attacked with Cholera and died in a few hours. [105/106]

Dr. Fraser of Oakley Square, St. Pancras, kindly informed me of the following circumstance: - A gentleman in delicate health was sent for from Brighton to see his brother at No. 6, Poland Street, who was attacked with Cholera and died in twelve hours on the 1st of September. The gentleman arrived after his brother's death and did not see the body. He only staid about twenty minutes in the house, where he took a hasty and scanty luncheon of rump steak, taking with it a small tumbler of cold brandy and water, the water being from Broad Street pump. He went to Pentonville, and was attacked with Cholera on the evening of the following day, September the 2nd, and died the next evening.

The deaths of Mrs. E--- and her niece, who drank the water from Broad Street at West End, Hampstead, deserve especially to be noticed. I was informed by Mrs. E---'s son that his mother had not been in the neighbourhood of Broad Street for many months. A cart went from Broad Street to West End every day, and it was the custom to take out a large bottle of the water from the pump in Broad Street as she preferred it. The water was taken out on Thursday the 31st of 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, a high [106/107] and healthy part of Islington, was attacked with Cholera and died also. There was not Cholera at the time, either at West End or in the neighbourhood where the niece died. Besides these two persons only one servant partook of the water at West End, Hampstead, and she did not suffer, or, at least, not severely. She had diarrhea.

[Detail of the map enclosed with the original report. The Broad Street pump is indicated by a smudged area, center-left. The stippled line is "the inner dotted line" mentioned below that demarcates equal walking distances between the pump in Broad Street and the nearest rival pump at every point.]


There were some persons who drank the water from Broad Street pump about the time of the outbreak without being attacked with Cholera, but this does not diminish the evidence respecting the influence of the water, for various reasons.

The deaths which occurred during the fatal outbreak of Cholera are indicated in the accompanying map, as far as I could ascertain them. There are necessarily some deficiencies, for in a few of the instances of persons who died in the hospitals after their removal from the neighbourhood of Broad Street, the numbers of the houses from which they had been removed were not registered. The address of those who died after their removal to St. James's Workhouse was not registered, and I was only able to obtain it in a part of the cases, on application at the Master's office, for many of the persons were too ill when admitted to give any account of themselves. In the case also of some of the work people and others who contracted the cholera in this neighbourhood, and died in different parts of London, the precise house from which they removed is not [107/108] stated in the return of deaths. I have heard of some persons who died in the country shortly after removing from the neighbourhood of Broad Street, and there must no doubt be several cases of this kind that I have not heard of. The deficiencies I have mentioned, however, do not detract from the correctness of the map, as a diagram of the topography of the outbreak; for, if the locality of the additional cases could be ascertained, they would probably be distributed over the district of the outbreak in the same proportion as the large number which are known.

The outerdotted line on the map surrounds the sub-districts of Golden Square and Berwick Street, St. James's together with the adjoining portion of the sub-district of St. Anne's, Soho, extending from Wardour Street to Dean Street, and a small part of the sub-district of St. James's Square, enclosed by Marylebone Street, Tichborne Street, Great Windmill Street, and Brewer Street. All the deaths from Cholera which were registered in the six weeks from August the 19th to September the 30th within this locality, as well as those of persons removed into Middlesex Hospital, are shewn by black lines in the situation of the houses in which they occurred, or in which the fatal attacks were contracted. In addition to these the deaths of person removed to University College, St. George's, Charring Cross, and other hospitals, and to various parts of London, are [108/109] indicated in the map where the exact address was given in the Weekly Return of Deaths, or when I could learn it by private inquiry.

The pump in Broad Street is indicated on the map, as well as all the surrounding pumps to which the public had access at the time of the outbreak of Cholera. It requires to be stated that the water of the pump in Marlborough Street, at the end of Carnaby Street, was so impure that many persons avoided using it; and I found that the persons who died near this pump, in the beginning of September, had water from the Broad Street pump. The inner dotted lie on the map shews the various points which have been found by careful measurement to be at an equal distance by the nearest road from the pump in Broad Street and the surrounding pumps; and, if allowance be made for the circumstance just mentioned respecting the pump in Marlborough Street, it will be observed that the deaths either very much diminish, or cease altogether, at every point where it becomes decidedly nearer to send to another pump than to the one in Broad Street. At these points I ascertained that the people did generally send to the pump which was nearer. It may be noticed the deaths are most numerous near to the pump in Broad Street, where the water could be more readily obtained. The wide open street in which the pump is situated suffered most, and next the streets branching from it, especially those parts of them which are nearest to Broad Street. If there [109/110] have been fewer deaths in the south half of Poland Street than in some other streets leading from Broad Street, it is no doubt because this street is less densely inhabited.

I have made a distinct inquiry respecting the greater number of fatal cases of Cholera that occurred, at the time of the outbreak, within the outer boundary marked on the map, but in a situation very decidedly nearer to another public pump than to that in Broad Street, and the following are the results:--

On the 4th of September, a female, aged 42, died at 32, Great Marlborough Street. I learned from the persons with whom she lived that she habitually drank pump water, but did not get it from the pump opposite. She had it principally from Broad Street, but occasionally from Vigo Street. There were three deaths at 7, Great Marlborough Street, on the 2nd, 3rd, and 5th of September. This house is rather nearer to two other pumps than to the one in Broad Street, but water had been fetched from the latter pump, and had been drank at dinner for a fortnight previous to the attacks of Cholera.

On the 1st of September, a girl aged 8 years, died at 29, Carnaby Street. On calling a few days afterwards I was informed by other members of the family that they were in the habit of having water from Broad Street, and that deceased drank of it on the days preceding her illness. On the same day, [110/111] a female, aged 34, died at 31, Carnaby Street. I was informed, on making inquiry, that she used to send to Broad Street two or three times a-day for water to drink. On the 1st also, a female, aged 35, died at 40, Carnaby Street. I was informed that she sent nearly always to Broad Street for drinking water.

The houses in which the above three cases occurred are in that part of Carnaby Street which is near to the pump in Marlborough Street; and Tyler Street, in which the following cases occurred is also very near to the same pump.

Two widows who lived in the kitchen at No. 9, Tyler Street, were attacked with Cholera on the 2nd of September, and were taken to Middlesex Hospital, where they both died. The daughter of one of the deceased women, a girl aged 15, told me that she used to fetch water from Broad Street pump, as her mother did not like the water in Marlborough Street. Both the deceased persons used to drink the water up to the time of their illness. My informant also drank of it; she had a Diarrhea, but was not seriously ill. On the 2nd of September, a man and his wife died of Cholera at 8, Tyler Street. The landlord of the house made an inquiry of the grown-up children of the deceased persons for me, and I learned that they used to have water from the pump in Broad Street, as they considered the water in Marlborough Street not fit to drink.

On the 1st of September, a tailor, aged 50, and [111/112] his son, aged 12, died of Cholera, at 10, Cross Street, and within three days afterwards four more of his children died, two of them being grown up. This family were great drinkers of pump water, and used to send for it every day, but more especially to drink during the night, as they were thirsty in the warm weather, owing to the great number sleeping in one room. The children fetched the water from various pumps, but frequently from Broad Street. On the 2nd of September, a boy, aged 7 years, died at 4, Cross Street. This family sent frequently for pump water, both to Broad Street and Warwick Street.

On the 2nd of September, a carpenter, aged 30, died at 7, Upper John Street, Golden Square. He was a foreigner, and used to drink wine and water to his dinner. The water was procured by the people who kept the house, and they got it from Broad Street pump, as they thought the water better than that in Warwick Street, which is much nearer. Two other persons, who also drank the water, were taken ill at the same time as deceased, but recovered. One was the servant of the house, and the other was a young man in the family. My informants were the widow of the deceased man and the sister of the young man who recovered. It is worthy of notice, that the servant had an attack of Cholera a fortnight previous to the last one.

A girl, aged 5 years, died at 42, Ham Yard, on the 8th of September, having been attacked with [112/113] Cholera on September the 2nd. Deceased went to school in Dufour's Place, and a brother, a little older than herself, told me in the presence of his mother that he had seen his sister drink the water from the ladle at the pump in Broad Street. A girl, aged 7 years, at 3, Angel Court, Great Windmill Street, was attacked with Cholera on the 1st of September, and died on the 8th. She also went to school in Dufour's Place, and her parents think it probable that she drank the water of Broad Street pump. A boy, aged 9 years, died on the 2nd of September, at 9, Great Crown Court. He went to school near the pump in Broad Street, and was in the habit of drinking a good deal of the water.

At 13, Wardour Street, near to Oxford Street, the wife of a tradesman died on the 2nd of September. Her husband informed me that they used to have pump water which deceased used to drink. The boy was always directed to fetch it from Broad Street. The son of a chemist at 115, Wardour Street, which is about a dozen doors from Oxford Street, was attacked with Cholera, and went to Willesden, where he died on the 2nd or 3rd of September. He dined on the days preceding his attack at some dining-rooms in Wardour Street, where the water from Broad Street pump always stood on the table. He drank malt liquor with his dinner, but frequently took some water with the pastry or sweet pudding with which he concluded it. His father was my informant. [113/114]

The wife of a tailor at 2, Great Chapel Street, Soho, was attacked with Cholera on the 4th, and died on the 8th of September. I was informed by the person with whom she lodged, that she was a great drinker of pump water, and that she used to drink a good deal of cold water at the Baths and Wash-houses in Dufour's Place, where she had been at work on the days preceding her illness. On going to the Wash-houses I learned that some persons drank the water of the cistern there, and others that of the Broad Street Pump. The child of this woman was attacked on the 7th and died on the 11th of September.

There were three deaths at 14, Noel Street; two on the 1st of September, after a few hours' illness, and one on the 6th, after an illness of four days. Pump water was constantly drunk in this house. I saw the boy who fetched it in the presence of the family. He generally got it from Berner's Street, or Newman Street, but had occasionally obtained it from Broad Street, and had done so about two months before my inquiry, which was made at the end of October, but he could not remember the day or week when he last obtained it from Broad Street.

A young woman died at 39, Rupert Street, on the 5th of September, but she was taken ill in St. Anne's Court, where three other members of her family died. She was about to call in Rupert Street, but dropped down at the door; she was carried into the house, where she expired. [114/115]

On the 10th of September, a girl, aged eight years, died of Cholera after an illness of three days, at 7, Naylor's Yard, Silver Street; she went to the National School facing the end of Broad Street, and used to drink the water.

There were four fatal attacks of Cholera at No. 1, Brewer Street, in the beginning of September. One of the deceased persons was the master of the house, who used to send constantly to Broad Street for drinking water, and the others who were attacked were also in the habit of drinking it.

A cabinet-maker, who was removed from Philips' Court, Noel Street, to Middlesex Hospital, worked in Broad Street. A boy also who died in Noel Street went to the National School at the end of Broad Street, and having to pass the pump probably drank of the water.

A tailor who died at 6, Heddon Court, Regent Street, spent most of his time in Broad Street. A woman removed to the hospital from 10, Heddon Court, had been nursing a person who died of Cholera in Marshall Street.

There were eight fatal attacks at a considerable distance from the pump in Broad Street, but within the external boundary marked on the map, respecting which, I did not, on inquiry, trace any connection with the water of that pump.

Of the above 48 persons, it will be observed that 28 were ascertained to have drunk the water of Broad Street pump shortly before they were at-[115/116]tacked, whilst there is a greater or less probability that 10 of the others also drank it, and 2 more had been exposed to the malady, by residing in the same room with a patient who died of it. As regards the 8 cases in which I could trace no connection with the water of the pump in Broad Street, it may be observed that they form but a slight mortality for the large area in which they happened; a mortality not greater than was occurring in surrounding parishes, and probably not greater than would have taken place in this district if the great outbreak had not occurred.

I ought to mention, that in all the cases I have alluded to throughout the Report, the water from Broad Street was drunk cold, without having been boiled. It is the custom in this district, as elsewhere, always to use the cistern water for making tea, and other purposes where heat is employed, and to send for pump water only for the purpose of drinking it cold.* (* I should like to mention here, a fact that I met with in making a part of the house-to-house inquiry, which the Committee undertook in the winter. Out of the 14 houses in Cambridge Street, there were four in which I was distinctly told that none of the inmates ever sent to Broad Street for water, and that they did not do so in August last. There was no case of Cholera in any of these houses. In the other 10 houses, the water from the pump in Broad Street was more or less used by the inmates last August, and there was Cholera in all of them but one, and in that house there was Diarrhea--J. S., June 14, 1855.)

The following Table exhibits the chronological features of this terrible outbreak of Cholera:-- [116/117]

Date

No. of Fatal Attacks

Deaths

August 19

1

1

20

1

0

21

1

2

22

0

0

23

1

0

24

1

2

25

0

0

26

1

0

27

1

1

28

1

0

29

1

1

30

8

2

31

56

3

September 1

143

70

2

116

127

3

54

76

4

46

71

5

36

45

6

20

37

7

28

32

8

12

30

9

11

24

10

5

18

11

5

15

12

1

6

13

3

13

14

0

6

15

1

8

16

4

6

17

2

5

18

3

2

19

0

3

20

0

0

21

2

0

22

1

2

23

1

3

24

1

0

25

1

0

26

1

2

27

1

0

28

0

2

29

0

1

30

0

0

Date Unknown

45

0

Total

616

616


[117/118] The deaths in the above Table are compiled from the sources mentioned in describing the map; but some deaths which were omitted from the map, on account of the numbers of the houses not being known, are included in the Table. As regards the date of attack, I was able to obtain it with great precision, through the kindness of Mr. Sibley, in upwards of 80 deaths which occurred in Middlesex Hospital; for the hour of admission was entered in the hospital books, as well as the previous duration of the illness. In a few other cases also I had exact information of the hour of attack; and in the remainder I have calculated the date of attack by subtracting the duration of the illness from the date of death. There are 45 cases in which the duration of the illness was not certified to the registrars, and where I had no means of ascertaining it. The time of the attack in these cases is consequently unknown. These persons nearly all died on the first days of September, in the height of the calamity; and it is almost certain that they were cut off very quickly, like the others who died at this time.

It will be observed that the daily number of fatal attacks was already much diminished by September the 8th, the day when the handle of the pump in Broad Street was removed; and it is not improbable that the water had, from some cause or other, ceased to contain the cholera poison. At all events, the few attacks which took place after [118/119] September the 10th or 12th must have been occasioned in the usual manner, and not through the medium of the water.

I wish it to be understood that I do not attribute every case of Cholera to the use of polluted water. It is my opinion that every case is caused by swallowing the peculiar poison or morbid matter of Cholera, which has proceeded from a previous patient sick of the same malady; but this morbid matter need not be in water, and there are facilities for its being accidentally swallowed, and propagating the disease, without the aid of water. This is more especially the case in the crowded dwellings of the poor, where a number of persons live, sleep, cook, and eat in one room. I do not, therefore, attribute every case of Cholera in the parish to the water of the pump well in Broad Street, but certainly those which constitute the great outbreak which took place at the end of August, and which suddenly raised the mortality of this disease from about five in a week to nearly 500.

The reason why the water of this pump produced the great outbreak is, I feel confident, that the evacuations of one or more Cholera patients found their way, by some means, into the well. There were fatal cases of Cholera, a few days before the great outbreak, not far from the well, and there may have been other cases, not fatal, which are not recorded.

I published several instances, 1849, of sudden [119/120] and severe outbreaks of Cholera arising from the pollution of tanks, wells, and other local supplies of water, by the contents of cesspools and house-drains. In the outbreak at Albion Terrace, Wandsworth Road, in that year, the night soil was from six to nine inches deep at the bottom of the tanks that were examined. In some instances, in Horsleydown and Rotherhithe, the contamination of the water was equally well proved. In these instances, the dejections of a patient ill of Cholera entered the water before the great outbreak.

I have been making inquiries during the autumn just passed, in the South districts of London, which shew that the dejections of Cholera can reproduce the disease after passing down the sewers into the Thames, and being afterwards distributed through some miles of the pipes of a water company. Under these circumstances, the cases of Cholera are scattered over the whole of the districts supplied by the company; and become gradually more numerous, as each set of cases, the dejections of which pass into the river, produces new ones. In the instances, on the other hand, in which a pump well, or some other local supply of water is thus contaminated, the outbreak is always sudden and violent.

John Snow, M.D.

12th December 1854.

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