the Mode of Communication of Cholera
by John Snow, M.D.
London: John Churchill, New Burlington Street, England, 1855
CONTENTS (pp. 98-139 [The End])
(Click on to go to specific section)
Effect of water supply on the mortality of cholera in Birmingham, Leicester, etc.
Effect of water supply on the mortality of cholera in Exeter.
Effect of water supply on the mortality of cholera in Hull.
Effect of water supply on the mortality of cholera in York.
Effect of water supply on the mortality of cholera in Dunfries, etc.
Effect of water supply on the mortality of cholera in Nottingham and Glasgow.
Effect of water supply on the mortality of cholera in Paris and Newcastle upon Tyne
Limited inquiry respecting the effect of the water supply at Newcastle
Assent of the medical profession to the influence of polluted water on the mortality from cholera
True explanation of this influence
Answers to certain objections
Circumstances connected with the history of cholera explained by the principles advocated in this treatises, as --
The duration of the epidemic is each place usually bears a direct relation to the number of the population
The effect of season on the prevalence of cholera
Proportion of the sexes who die of cholera at different periods of an epidemic, and under different circumstances
Proportion of deaths from cholera in certain occupations
Evidence that plague, yellow fever, dysentery, and typhoid fever are communicated in the same way as cholera
Instances in which ague was caused by impure water
Measures required for the prevention of cholera and other diseases which are communicated in the same way
APPENDIX, containing a list of the deaths from cholera which were registered in the four weeks ending 5th August 1854, together with the water supply of the houses in which the fatal attacks took place, in all the sub-districts to which the supply of either the Southwark and Vauxhall or the Lambeth Water Company extends
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN BIRMINGHAM, LEICESTER, ETC.
The prevalence of cholera has been very much under the influence of the water supply in other towns besides London. The cholera has prevailed to a considerable extent in the crowded habitations of the poor in Liverpool (upper center) and some other towns, where the general supply of water was not in fault, but I know of no instance in which it has spread through all classes of the community, except where the general supply of water has been contaminated with the contents of the drains and sewers; and all the towns with which I am acquainted that have enjoyed an almost complete immunity from this disease, have a water supply quite free from any chance of contamination. Birmingham (1856 map: upper middle) , Bath, Cheltenham (1856 map: middle left), and Leicester (1856 map: lower left) have nearly escaped the cholera in every epidemics The few cases that have occurred being chiefly those of persons newly arrived from places where the disease was prevailing, and a few others who came in communication with them. All these towns have a supply of water quite free from connection with the drains and sewers, and the small rivers which flow through them are so impure that it would be impossible to drink the water. Leicester is crowded with a poor population, and has hardly any physical advantage except its water supply.
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN EXETER
The first cases of cholera in Exeter in 1832, were three in the same day, besides one in St. Thomas's, a suburb of Exeter, in a gentleman just arrived from London, where the disease was prevailing. The other three were a woman and her two children; the former, with one of her children, had returned from Plymouth the previous day, where she had been nursing a child that had died of the cholera. Within five days from this time, there were seven fresh cases in as many different parts of the town, amongst persons having no intercourse with each other or the first cases. The disease soon became very prevalent, and in three months there were 1,135 cases, and 345 deaths. Exeter is situated on ground which rises from the edge of the river to an elevation of one hundred and fifty feet. In 1832 the inhabitants were chiefly supplied with river water by water-carriers, who conveyed it in carts and pails. Dr. Shapter, from whose work  the above particulars are obtained, kindly furnished me with information concerning the sewers, and with maps of their position. The water-carriers, by whom Exeter was very greatly supplied, obtained their water almost exclusively from certain streams of water, diverted from the river in order to turn watermills; and one of the chief sewers of the town, which receives such sewage as might come from North Street, in which the first cases of cholera occurred, empties itself into the branch from the river which divides into the two mill-streams just mentioned. It must be remarked that the parish of St. Edmund, in which these streams of water were situated, had a lower mortality from cholera than other parts of the town like it, densely populated and on low ground near the river. Dr. Shapter attributes this lower rate of mortality, and I believe rightly, to St. Edmund's being freely intersected by running streams of water. The people would probably not drink more of the water than in parts of the town where it was less plentiful, and had to be paid for, but they would have much better opportunities for personal cleanliness: so that whilst they would be exposed to only the same number of scattered cases, they would be less likely to have the malady spreading through families, and by personal intercourse. After the cholera of 1832, measures were taken to afford a better supply of water to Exeter; not, so far as I can find by Dr. Shapter's work, that its impurity was complained of, but because of its scarcity and cost. Waterworks were established on the river Exe, two miles above the town, and more than two miles above the influence of the tide. Exeter has since been very plentifully supplied with this water, and Dr. Shapter informed me that in 1849 there were only about twenty cases of cholera, nearly half of which occurred in strangers coming into the town, and dying within two or three days after their arrival. This last summer there was only one death from cholera in Exeter.
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN HULL
We will now consider the town of Hull, in which, together with other sanitary measures adopted since 1832, there has been a new and more plentiful supply of water, but with a far different result to that at Exeter. In 1832 Hull was scantily supplied with water conveyed in pipes from springs at Anlaby, three miles from the town. About 1844, new waterworks were established to afford a more plentiful supply. These works were situated on the river Hull, at Stoneferry, two miles and three quarters from the confluence of that river with the Humber. About half the sewage of the town is delivered into the river of the same name, the rest being discharged into the Humber, as appears from information and a map kindly furnished me in 1849 by Dr. Horner of Hull, who was making great efforts to have better water obtained for the town. The tide flows up the river many miles past the waterworks, carrying up with it the filth from the sewers. The supply of water was, to be sure, obtained when the tide was down, but as the banks of the river are clothed with sedges in many parts, and its bottom deep with mud, the water can never be free from sewage. Moreover, there are some parts of the river above Stoneferry much deeper than the rest, and where the deeper water is, according to the testimony of boatmen, nearly stagnant; thus allowing the water carried up by the tide to remain and gradually mix with that afterwards flowing down. There are also boats, with families on board, passing up the river to the extent of five thousand voyages in the year. The water when taken from the river was allowed to settle in the reservoir for twenty-four hours, and was then said to be filtered before being sent to the town. In 1832 the cholera was confined almost exclusively to the poor, and the deaths amounted to three hundred.
In 1849 the deaths in Hull (including the suburb of Sculcoates) were 1834, although 8,000 or 10,000 left the town, it is said, to avoid the ravages of the disease. Dr. Horner informed me that the deaths occurred amongst all classes of the community, and that the town was much better drained in 1849 than in 1832.
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN YORK
When the cholera made its appearance at York, about the middle of July 1849, it was at first chiefly prevalent in some narrow streets near the river, called the Water Lanes. The inhabitants of this spot had been in the habit, from time immemorial, of fetching their water from the river at a place near which one of the chief sewers of the towns empties itself; and recently a public necessary had been built, the contents of which were washed every morning into the river just above the spot at which they got the water. In a short time from twenty to thirty deaths occurred in this locality; but the medical men considering the impure water injurious, the people were supplied from the waterworks, with water obtained from the river at a point some distance above the town, and the cholera soon ceased nearly altogether in this part of the city, but continued to spread in some other parts. The cholera having thus abated in the Water Lanes, the gratuitous supply of water was cut off, and the people went to the river as before. There were still cases of cholera in the town, and it soon broke out again in this locality, and in the first few days of September eight deaths occurred among the persons who used water obtained direct from the river. The tap for general use was again opened, and I the river water interdicted, and the cholera again ceased, and did not recur. These circumstances were communicated to me by a friend on whose accuracy I can rely.
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN DUNDFIES, ETC.
The inhabitants of Dumfries drink the water of the river Nith, which flows through the town, and into which the sewers discharge their contents, which float afterwards to and fro with the tide. In 1832 there were 418 deaths from cholera out of a population of 11,606, being at the rate of 360 in 10,000, or I in every 28 of the inhabitants. The cholera again visited Dumfries at the close of 1848, and carried off 431 persons, or I in every 32, out of a population now numbering 14,000; so that the mortality was excessive on both occasions.
Preston and Oldham, in Lancashire, are supplied with water from surface drainage on the neighboring hills, and there was scarcely any cholera at either of these places in 1849. The greater part of the town of Paisley is supplied in a similar way; and I was informed that the cases of cholera which occurred there in 1849 were confined to a quarter of the town to which this supply of water does not extend.
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN NOTTINGHAM AND GLASGOW
Nottingham (1856 map: middle left) is supplied with filtered water obtained from the river Trent, some distance above the town. In 1832 this supply did not extend to all the inhabitants, and the cholera was somewhat prevalent amongst the poor, of whom it carried off 289; the population of the town being 53,000. After that time the water was extended copiously to all the inhabitants, and there were but thirteen deaths from the epidemic in 1849. The local Sanitary Committee placed the supply of water amongst the chief causes of this immunity from cholera, and I believe justly. There were but seven deaths from cholera in Nottingham last summer.
Glasgow has been supplied, since the early part of the present century, with the water of the Clyde, obtained a little way above the town, but within the influence of the tide, and consequently mixed with the contents of the sewers. It is imperfectly filtered through sand. In 1847, however, the parish of Gorbals, which forms the south part of Glasgow, was furnished with a supply of water collected on the neighboring hills; and Dr. Leech, of Glasgow, speaks as follows respecting the influence of this water on the prevalence of cholera: "During the late cholera there was a remarkable circumstance, which deserves notice as compared with the epidemic of 1839. Since the former period, the population of Glasgow, south of the Clyde, has nearly doubled; and with this exception, and the introduction of the softwater supply, the circumstances might be considered as the same at both periods. In one district, the parish of Gorbals, the attack in 1832 was fearful; while Glasgow, north of the Clyde, also suffered severely. During the late epidemic (that of 1848-49], Gorbals parish furnished comparatively a small number of cases; while the epidemic in other parts of Glasgow was very severe. The unanimous opinion of the Medical Society was, that this comparative immunity was to be attributed to the soft-water supply." 
I was informed that when the cholera was prevalent in Glasgow last winter, the parish of Gorbals again enjoyed a similar immunity from the disease.
EFFECT OF WATER SUPPLY ON THE MORTALITY OF CHOLERA IN PARIS AND NEWCASTLE UPON TYNE
The following passage respecting the water-supply of Paris is from Dr. Farr's "Report to the Registrar-General on the Cholera of 1848-49": --"The supply of Paris is from various sources, but four-fifths of the water is from the Canal de l'Ourque, which, by the decision of Napoleon, was also appropriated to navigation. The water for some years, and in 1832, when the epidemic was so fatal, was drawn from the dirty basin in which the boats and barges of the canals rested; but is now drawn from the canal before it enters the basin .... The mortality of cholera in Paris was excessive, and in 1832 varied from 80, of 10,000 inhabitants, in the elegant Chaussée d'Antin and in Montmartre on the heights, to 530 and 520 in the low quarters of the Hôtel de Ville and the Cití." (p. lxxviii)
The town of Newcastle-upon-Tyne (1856 map: center right) affords a remarkable instance of the influence of the water supply on the prevalence of cholera. In 1831-32 there were no waterworks at Newcastle; it was supplied, in an insufficient manner, with spring water, which generally had to be carried some distance to the houses from "pants" in the streets. The epidemic was pretty severe at this time. From November 1831 to November 1832 there were 801 deaths from cholera out of a population of 42,760. The disease prevailed chiefly amongst the poor, and was worst in the least elevated parts of the town, near the river. Subsequently to 1832, waterworks were established on the river Tyne, a little above the town; but these were abandoned, in 1848, in favor of a supply from a rivulet and springs at Whittle Dean, about ten miles distant. In 1849, there were but 295 deaths from cholera in a population then increased to 71,847. In the beginning of July 1853, two months before the reappearance of cholera in England, the Whittle Dean Water Company found their proper sources insufficient for the demands of the population and the various factories, and they made use of the former waterworks, mentioned above, to obtain water from the Tyne. The point at which they obtained water from the river, is scarcely a mile above Newcastle, and the tide flows for six miles above the town, carrying the contents of the sewers with it. There are also villages, containing several thousands of colliers and iron-founders, on the banks of the Tyne, above the waterworks. The water from the Tyne was mixed, without filtration, with that from Whittle Dean, to the extent of one-third; and the mixed water, so supplied, was discolored, and contained the large quantity of 7.1 grains of organic matter per gallon.
In the autumn of 1853, the cholera was prevailing extensively at Hamburgh, and in nearly all the ports of the Baltic, whence a number of ships were arriving every day in the Tyne. The first cases of cholera commenced, with diarrhea, on the 27th and 28th August, at Bell Quay, on the banks of the Tyne, three miles below Newcastle. One of the patients' from Bell Quay was taken worse whilst on a visit to her mother at Newcastle: she died on 2nd September. Her mother was taken ill the same evening, and died on the following day. Other cases occurred in Newcastle on the 1st and 2nd of September, having no connection with these. A ship from Bremen was lying at Bell Quay, opposite the house where the first cases occurred; but there had been no illness on board this ship, and the precise way in which the cholera was introduced on this occasion, is not known.
The disease soon spread to an extent almost unprecedented in this country: by the 15th of September the deaths exceeded a hundred a day. In nine weeks there were 1,533 deaths from cholera in a population of 86,114, being 178 to each 10,000 inhabitants; but the greater number of these deaths occurred in a few days, as 1001 took place from the 13th to the 23rd Sept. inclusive. 
Gateshead (1856 map: center right), which is situated opposite to Newcastle, on the other side of the Tyne, is supplied with the same water; and in 1849 it shared with that town a comparative immunity from cholera, whilst in the autumn of 1853, 433 persons died of that disease out of a population of 26,000, or thereabouts, being 166 to each 10,000 inhabitants.
The lowest streets in Newcastle and Gateshead are about five feet above high-water mark; and only a few streets are situated at this level, for the banks rise very abruptly, at a little distance from the river, on both sides. A great portion of each town is elevated nearly 200 feet above the river, and some parts are nearly 300 feet high ; yet the Water Company supplies all these districts, and all were severely visited by the cholera, which on this occasion spared no class of the community. In the districts which are most crowded, the mortality was greatest, the deaths being much more numerous, in the parishes which contained a great number of tenements consisting of a single room, than in those which consisted chiefly of houses occupied by one family. This, however, is quite in accordance with the principles which I am throughout endeavoring to explain. A great deal of stress is laid, very properly, by the Commissioners who have reported respecting this outbreak, on the ill-arranged buildings, the defective drainage, and want of privy accommodation, in Newcastle; but it must be remembered that all these evils existed in 1849, when Newcastle escaped with less cholera than most towns, --to a greater extent than they did in 1853, for many improvements had taken place in the meantime.
In consequence of a great outcry on the part of the public, who naturally connected the great fatality of cholera in some measure with the turbidity and offensive smell of the drinkingwater, the Company entirely ceased to draw water from the Tyne on the 15th September; and although the Tyne water was not entirely out of the pipes for a day or two, the deaths, which had been rapidly increasing, began to diminish on the 17th, and were lessened considerably by the 20th. The following is the course of the mortality in Newcastle, in the most fatal part of the epidemic; and it began to decline at exactly the same time in Gateshead:
LIMITED INQUIRY RESPECTING THE EFFECT OF THE WATER SUPPLY AT NEWCASTLE
The late General Board of Health directed one of their medical inspectors, Dr. Waller Lewis, to make minute inquiry as to the relative effects produced by the use of pure spring water, and that of the Water Company, during the epidemic of cholera in Newcastle; and it is much to be regretted that the inquiry was not carried out. To have conducted the inquiry through the whole of Newcastle and Gateshead would not have entailed a quarter as much labor as my investigations in Lambeth, Newington, and the Borough. Dr. Lewis called on Mr. Main, the secretary of the Water Company, and they made an inquiry in certain houses, taken at random, through three streets, and also in Greenhow Terrace, where a severe outbreak of cholera had occurred, although it was not supplied by the Company, but had what was reported to be good spring water. Dr. Lewis gave up the inquiry because he could not find two places exactly alike in all their physical conditions, – one place supplied with spring water, the other by the Company. He made no report of what he had done; but Mr. Main sent a paper on the subject of this commenced inquiry to the Pathological Society of Newcastle, an abstract of which appeared in the Medical Times and Gazette". By adding Greenhow Terrace to the streets partly supplied by the Company, and by including cases of cholera, fatal or otherwise, with those of mere diarrhea, Mr. Main was able to show a result apparently in favor of the Company's water. He was good enough, however, to send me a copy of his paper, which contains the details of the inquiry as far as it extended; and I found, on perusing it, that, leaving out Greenhow Terrace, which is not supplied by the Company at all, there was no case of cholera, either fatal or otherwise, and no case, even of approaching cholera, in any house which was not supplied with the Company's water. All the deaths and all the cholera occurred in the houses having this water, whilst in the houses having only pump water, there was simply diarrhea. In the workhouse, supplied by the Water Company, and having five hundred and forty inmates, there were twelve cases of cholera, or approaching cholera, and seven deaths; whilst in the military barracks, supplied from wells on the premises, and having five hundred and nineteen inmates, although there was a good deal of harmless diarrhea, there was no cholera, nor any case of approaching cholera.
The communication of cholera by means of the water is well illustrated by the instance of Moscow, which was severely visited by that disease in 1830; but much less severely in the second epidemic. Subsequently to 1830 the greater part of the town, which is situated to the north of the Moscow river, obtained a supply of excellent water, conducted in pipes from springs at a distance; and the cholera in 1847 was chiefly confined to those parts of the town which lie to the south of the river, to which the new supply of water did not extend, and where the people had still only impure riverwater to drink.
The above instances are probably sufficient to illustrate the widely-spread influence which the pollution of the drinking water exerts in the propagation of cholera.
ASSENT OF THE MEDICAL PROFESSION TO THE INFLUENCE OF POLLUTED WATER ON THE MORTALITY FROM CHOLERA
After the Registrar-General alluded, in the "Weekly Return" of 14th October last, to the very conclusive investigation of the effects of polluted water in the south districts of London, there was a leading article, in nearly all the medical periodicals, fully admitting the influence of the water on the mortality from cholera. It may therefore be safely concluded that this influence is pretty generally admitted by the profession. It must not be disguised, however, that medical men are not yet generally convinced that the disease is actually communicated from person to person by the morbid matter being swallowed in the drinking water, or otherwise. It used to be the custom of medical authors to speak of three kinds of causes of a disease, viz. predisposing, exciting, and proximate causes. The proximate causes have been given up, as being the diseases themselves; but authors still divide causes into predisposing and exciting ones. It may be remarked, however, that in treating of certain communicable diseases, the cause of which is thoroughly understood, as syphilis and the itch, predisposing causes are never mentioned; and that they are rarely alluded to in treating of smallpox, measles, and scarlet fever, whilst they continue to be appealed to in explanation of the various continued fevers. Now many medical men, whilst they admit the influence of polluted water on the prevalence of cholera, believe that it acts by predisposing or preparing the system to be acted on by some unknown cause of the disease existing in the atmosphere or elsewhere. The following amongst other reasons prove, however, that opinion cannot long halt here, and that, if the effect of contaminated water be admitted, it must lead to the conclusion that it acts by containing the true and specific cause of the malady.
TRUE EXPLANATION OF THIS INFLUENCE
In my inquiries in the south districts of London I met with several instances in which persons, especially maid-servants and young men, died of cholera within a few days after coming from the country to a house supplied with water by the Southwark and Vauxhall Company. The Registrar of Waterloo Road (2nd) remarked as follows on this point, on 26th August last:_" This is the third successive case of fatal cholera, where the patients have recently come from the country. Similar instances have frequently attracted the Registrar's notice." I found that the houses in which these cases occurred were supplied by the above-named Company. The outbreak of cholera in the Baltic fleet, related at page 36 (see Part 1) occurred within forty-eight hours after the polluted water had been taken on board. And lastly, if the contaminated water merely acted by predisposing or preparing the system to be affected by some other cause, it would be impossible to explain why nearly all the persons drinking it should be attacked together, in cases where a pump-well or some other limited supply is polluted, while the population around experience no increase of the malady.
All the evidence proving the communication of cholera through the medium of water, confirms that with which I set out, of its communication in the crowded habitations of the poor, in coal_mines and other places, by the hands getting soiled with the evacuations of the patients, and by small quantities of these evacuations being swallowed with the food, as paint is swallowed by house painters of un- cleanly habits, who contract lead-colic in this way.
ANSWERS TO CERTAIN OBJECTIONS
There are one or two objections to the mode of communication of cholera which I am endeavoring to establish, that deserve to be noticed. Messrs. Pearse and Marston state, in their account of the cases of cholera treated at the Newcastle Dispensary in 1853, that one of the dispensers drank by mistake some rice-water evacuation without any effect whatever. In rejoinder to this negative incident, it may be remarked, that several conditions may be requisite to the communication of cholera with which we are as yet unacquainted. Certain conditions we know to be requisite to the communication of other diseases. Syphilis we know is only communicable in its primary stage, and vaccine lymph must be removed at a particular time to produce its proper effects. In the incident above mentioned, the large quantity of the evacuation taken might even prevent its action. It must be remembered that the effects of a morbid poison are never due to what first enters the system, but to the crop or progeny produced from this during a period of reproduction, termed the period of incubation; and if a whole sack of grain, or seed of any kind, were put into a hole in the ground, it is very doubtful whether any crop whatever would be produced.
Dr. Thiersch is of opinion, as appears by a discussion which has recently taken place at Munich, that the cholera evacuations are not at first capable of generating the disease; but that a decomposition takes place in them, and that in from six to nine days they become in a state to induce cholera. He founds this opinion on experiments which he performed by giving small quantities of the cholera evacuations to white mice. Although it is not contrary to all analogy that some change or development should take place in the cholera poison in the interval between its leaving one person and entering another, it is most probable that the fatal bowel complaint produced in white mice by Dr. Thiersch was not a specific disease, but the ordinary effect of putrefying ingesta. Many of the best attested instances of the communication of cholera are those, such as were related at the commencement of this work, where the patient is attacked in from twenty-four to forty-eight hours after first being near another patient, and although an interval of a week or so, often elapses between one case of the disease and those which follow, it is extremely probable that, in these instances, the evacuations remain the greater part of this time in a dry state on the soiled linen, without undergoing any change.
An objection that has repeatedly been made to the propagation of cholera through the medium of water, is, that every one who drinks of the water ought to have the disease at once. This objection arises from mistaking the department of science to which the communication of cholera belongs, and looking on it as a question of chemistry, instead of one of natural history, as it undoubtedly is. It cannot be supposed that a morbid poison, which has the property, under suitable circumstances, of reproducing its kind, should be capable of being diluted indefinitely in water, like a chemical salt; and therefore it is not to be presumed that the cholera-poison would be equally diffused through every particle of the water. The eggs of the tape-worm must undoubtedly pass down the sewers into the Tharnes, but it by no means follows that everybody who drinks a glass of the water should swallow one of the eggs. As regards the morbid matter of cholera, many other circumstances, besides the quantity of it which is present in a river at different periods of the epidemic, must influence the chances of its being swallowed, such as its remaining in a butt or other vessel till it is decomposed or devoured by animalcules, or its merely settling to the bottom and remaining there. In the case of the pump-well in Broad Street, Golden Square, if the cholera poison was contained in the minute whitish flocculi, visible on close inspection to the naked eye, some persons might drink of the water without taking any, as they soon settled to the bottom of the vessel.
It is not necessary to oppose any other theories in order to establish the principles I am endeavoring to explain, for the field I have entered on was almost unoccupied. The best attempt at explaining the phenomena of cholera, which previously existed, was probably that which supposed that the disease was communicated by effluvia given off from the patient into the surrounding air, and inhaled by others into the lungs; but this view required its advocates to draw very largely on what is called predisposition, in order to account for the numbers who approach near to the patient without being affected, whilst others acquire the disease without any near approach. It also failed entirely to account for the sudden and violent outbreaks of the disease, such as that which occurred in the, neighborhood of Golden Square.
Another view having a certain number of advocates is, that cholera depends on an unknown something in the atmosphere which becomes localized, and has its effects increased by the gases given off from decomposing animal and vegetable matters. This hypothesis is, however, rendered impossible by the motion of the atmosphere, and, even in the absence of wind, by the laws which govern the diffusion of aeriform bodies; moreover, the connection between cholera and offensive effluvia is by no means such as to indicate cause and effect; even in London, as was before mentioned, many places where offensive effluvia are very abundant have been visited very lightly by cholera, whilst the comparatively open and cleanly districts of Kennington and Clapham have suffered severely. If inquiry were made, a far closer connection would be found to exist between offensive effluvia and the itch, than between these effluvia and cholera ; yet as the cause of itch is well known, we are quite aware that this connection is not one of cause and, effect.
Mr. John Lea, of Cincinnati, has advanced what he calls a geological theory of cholera. he supposes that the cholera poison, which he believes to exist in the air about the sick, requires the existence of calcareous or magnesian salts in the drinking-water to give it effect This view is not consistent with what we know of cholera, but there are certain circumstances related by Mr. Lea which deserve attention. He says that, in the western districts of the United States, the cholera passed round the arenacious, and spent its fury on the calcareous regions; and that it attacked with deadly effect those who use the calcareous water, while it passed by those who used sandstone or soft water. He gives many instances of towns suffering severely when river water was used, whilst others, having only soft spring water or rain water, escaped almost entirely; and he states that there has been scarcely a case of cholera in families who used only rain water. The rivers, it is evident, might be contaminated with the evacuations, whilst it is equally evident that the rain water could not be so polluted. As regards sand and all sandstone formations, they are well known to have the effect of oxidizing and thus destroying organic matters; whilst the limestone might not have that effect, although I have no experience on that point. The connection which Mr. Lea has observed between cholera and the water is highly interesting, although it probably admits of a very different explanation from the one he has given.
CIRCUMSTANCES CONNECTED WITH THE HISTORY OF CHOLERA EXPLAINED BY THE PRINCIPLES ADVOCATED IN THIS TREATISE, AS --
THE DURATION OF THE EPIDEMIC IN EACH PLACE USUALLY BEARS A DIRECT RELATION TO THE NUMBER OF THE POPULATION
There are certain circumstances connected with the history of cholera which admit of a satisfactory explanation according to the principles explained above, and consequently tend to confirm those principles. The first point I shall notice, viz., the period of duration of the epidemic in different places, refers merely to the communicability of the disease, without regard to the mode of communication. The duration of cholera in a place is usually in a direct proportion to the number of the population. The disease remains but two or three weeks in a village, two or three months in a good-sized town, whilst in a great metropolis it often remains a whole year or longer. I find from an analysis which I made in 1849 of the valuable table of Dr. Wm. Merriman, of the cholera in England in 1832, that fifty-two places are enumerated in which the disease continued less than fifty days, and that the average population of these places is 6,624. Forty-three places are likewise down in which the cholera lasted fifty days, but less than one hundred; the average population of these is 12,624. And there are, without including London, thirty-three places in which the epidemic continued one hundred days and upwards, the average population of which is 38,123; or if London be included, thirty-four places, with an average of 78,823. The following short table will show these figures in a more convenient form: –
There was a similar relation in 1849 between the duration of the cholera and the population of the places which it visited; a relation which points clearly to the propagation of the disease from patient to patient; for if each case were not connected with a previous one, but depended on some unknown atmospheric or telluric condition, there is no reason why the twenty cases which occur in a village should not be distributed over as long a period as the twenty hundred cases which occur in a large town.
Even the duration of the cholera in a street, when compared to its duration in the individual houses, points to the same conclusion. A table has been published  in the report of the late discussion on cholera at Munich, which shows that whilst the epidemic remained three or four weeks in a street, it only remained six or seven days in houses where several people were attacked. Dr. Pettenkofer remarks, that "if the proximate cause of the disease had been generally diffused over a certain number of streets or a certain district, and its invasion had been opposed by individual disposition alone, one might have expected that both the cases of disease and the instances of death would have occurred in single houses, where many such appeared together, at similar periods of time throughout the whole street; but, supposing that the proximate cause of the disease was not general, but local, then it would act in such a manner that the period of time within which the disease would show itself in single houses would be very different from that which was applicable to the entire street." The local cause in a house we know to be the illness of some individual, who, in many cases, has newly arrived from some place where the disease was prevailing.
THE EFFECT OF SEASON THE PREVALENCE OF CHOLERA
Each time when cholera has been introduced into England in the autumn, it has made but little progress, and has lingered rather than flourished during the winter and spring, to increase gradually during the following summer, reach its climax at the latter part of summer, and decline somewhat rapidly as the cool days of autumn set in. In most parts of Scotland, on the contrary, cholera has each time run through its course in the winter immediately following its introduction. I have now to offer what I consider an explanation, to a great extent, of these peculiarities in the progress of cholera. The English people, as a general rule, do not drink much unboiled water, except in warm weather. They generally take tea, coffee, malt liquor, or some other artificial beverage at their meals, and do not require to drink between meals, except when the weather is warm. In summer, however, a much greater quantity of drink is required, and it is much more usual to drink water at that season than in cold weather. Consequently, whilst the cholera is chiefly confined in winter to the crowded families of the poor, and to the mining population, who, as was before explained, eat each other's excrement at all times, it gains access as summer advances to the population of the towns, where there is a river which receives the sewers and supplies the drinking water at the same time; and, where pump-wells and other limited supplies of water happen to be contaminated with the contents of the drains and cesspools, there is a greater opportunity for the disease to spread at a time when unboiled water is more freely used.
In Scotland, on the other hand, unboiled water is somewhat freely used at all times to mix with spirits; I am told that when two or three people enter a tavern in Scotland and ask for a gill of whiskey, a jug of water and tumbler-glasses are brought with it. Malt liquors are only consumed to a limited extent in Scotland, and when persons drink spirit without water, as they often do, it occasions thirst and obliges them to drink water afterwards.
There may be other causes besides the above which tend to assist the propagation of cholera in warm, more than in cold weather. It is not unlikely that insects, especially the common houseflies, aid in spreading the disease. An ingenious friend of mine has informed me that, when infusion of quassia has been placed in the room for the purpose of poisoning flies, he has more than once perceived the taste of it on his bread and butter.
PROPORTION OF SEXES WHO DIE OF CHOLERA AT DIFFERENT PERIODS OF AN EPIDEMIC, AND UNDER DIFFERENT CIRCUMSTANCES
Dr. Farr gives the following very important information respecting the sex of persons who died of cholera at different periods of the epidemic.
It is worthy of remark, that at the beginning of the epidemic, the deaths of males exceeded the deaths of females very considerably; the numbers in the months of October, November, and December, 1848, were, – males 612, females 493; or in the proportion of 100 to 80....
"As a general rule, when the mortality from cholera attained a very high rate, the number of deaths among females exceeded the deaths among males.
"In London a remarkable change was observed in the proportion of the sexes affected in the course of the epidemic. In four weeks of October 1848, the deaths of 80 males and of 42 females by cholera were registered; in the thirteen last weeks of the year the deaths of 258 males and 210 females were registered; and there was an excess of males at all ages, but particularly in the ten years of age 15-25. In the quarter ending March 1849, the deaths of males amounted to 250, of females to 266: at the age of 25 and upwards the excess of deaths among females was considerable. In June, at the commencement of the great outbreak, the males again furnished the most numerous victims. At the close of July the females died in greater numbers than the males, and continued to do so to the end. In the week that the mortality was highest, the deaths of 895 males and of 1131 females were returned. In the September quarter the deaths of males under the age of 25 exceeded the deaths of females; but after that age the proportions were reversed."
The greater part of the female population remain almost constantly at home, and take their meals at home, whilst a considerable number of the men move about in following their occupations, and take both food and drink at a variety of places; consequently, in the early part of an epidemic, when the disease only exists in a few spots, the male part of the population is most liable to come within the operation of the morbid poison; but at a later period of the epidemic, when the cholera is more generally diffused, it may reach those who stay at home as readily as those who move about; and in addition to the risk which the women share with the men, they have the additional one of being engaged in attending on the sick.
It is a confirmation of this view of the matter that, when the cholera poison is distributed through the pipes of a Water Company, the above rule does not hold good, but a contrary one prevails, owing, probably, to females being less in the habit of drinking beer than men, and being therefore more likely to drink water. Of the 334 deaths detailed in the Appendix to this work (286 of them amongst the customers of the Southwark and Vauxhall Water Company), only 147 were males, whilst 187 were females. The deaths occurred in the first four weeks of the recent epidemic. On the other hand, out of the 229 deaths from cholera which occurred in all the rest of London during this period, 140 were males and only 89 females. When the mortality of the whole of the metropolis during this period is taken together, there is a slight preponderance on the part of the males; the numbers being, -- males 287, females 276: total 563.
The deaths from cholera in England in 1849 were 53,293; of those, 14,718, or 27 per cent of the whole, occurred in children under 15 years of age. Of the 334 deaths which are recorded in the Appendix to this work, 127, or 38 per cent., are those of children under 15, whilst of the remaining 229 which occurred in the rest of London during the first four weeks of the epidemic, only 61, or 26 per cent., took place before the age of 15, -- a proportion nearly the same as in the whole of England in 1849. The higher proportion of deaths amongst children in the houses supplied with the impure water from the Thames at Battersea Fields, probably arose from the circumstance that children are very fond of drinking water in warm weather. I often heard such remarks as the following, in making my inquiries in the south districts of London: – "My children like water better than tea or anything else, I cannot keep them away from the water-butt;" or, "the child that is dead used to drink a great deal of that water, she was big enough to reach to the butt herself."
PROPORTION OF DEATHS FROM CHOLERA IN CERTAIN OCCUPATIONS
Dr. Guy, physician to King's College Hospital, made a table showing the occupations of 4,312 males, of fifteen years of age and upwards, who died of cholera in London in the epidemic of 1848-49; together with the ratio which the deaths bear to the living, as well as it could be ascertained from the census of 1841. I have not room for the whole table, but have selected the occupations which suffered most, and those which suffered least. The following abstract of Dr. Guy's table contains all the occupations where the deaths from cholera equaled one-fiftieth of the number living, and all those in which the deaths did not exceed one in two hundred and fifty living.
In some of the occupations which show a high relative mortality, the number of living is too small to allow of any reliable statistical result, and the relative mortality is probably clue to accidental circumstances quite unconnected with the occupation. In other cases, however, the numbers are so considerable as to indicate something more than accident. The 299 sailors, for instance, constituted one twenty-fourth of the whole estimated number in that occupation. The 7 ballast-heavers form just the same proportion of the whole in that occupation, and the 53 coal-porters and coal-heavers constituted one in 32 of those so employed. Now all those persons lived or were employed on the river, where it is the habit to drink water drawn by pailfuls from the side of the ship. The 67 hawkers are one in 22 of the whole number. These persons are constantly moving about, and are in the habit of living in crowded lodging-houses, and consequently must be extremely liable to contract any communicable disease. Tanners nearly all live in Bermondsey and Lambeth, supplied in 1849 with none but very impure water, as was previously explained. The weavers probably suffered the high rate of mortality from the crowding of their apartments in Spitalfields, and the uncleanness of their habits.
The persons who suffered less from cholera than any other part of the male population, are footmen and men-servants; and it is impossible to conceive a class less exposed to the disease. They live in the best parts of London, and go from home much less than their masters. The low rate of mortality amongst medical men and undertakers is worthy of notice. If cholera were propagated by effluvia given off from the patient, or the dead body, as used to be the opinion of those who believed in its communicability; or, if it depended on effluvia lurking about what are by others called infected localities, in either case medical men and undertakers would be peculiarly liable to the disease; but, according to the principles explained in this treatise, there is no reason why these callings should particularly expose persons to the malady.
CLICK FOR TABLE XIV
There is one remarkable circumstance connected with Dr. Guy's table (see Table XIV). One master-brewer died of cholera, being 1 in 160 of the trade; but no brewer's man or brewer's servant is mentioned as having died of this malady, although these men must constitute a very numerous body in London. There must be a few thousands of them. I have, indeed, met with the deaths of two or three of these persons, in looking over the returns of some of the most fatal weeks in 1849 ; but the brewers' men seem to have suffered very slightly both in that and the more recent epidemics. The reason of this probably is, that they never drink water, and are therefore exempted from imbibing the cholera poison in that vehicle.
The great prevalence of cholera along the course of rivers has been well known for a quarter of a century; and it meets with a satisfactory explanation from the mode of communication of the disease which I am inculcating. Rivers always receive the refuse of those living on the banks, and they nearly always supply, at the same time, the drinking water of the community so situated. It has sometimes been objected to the propagation of the disease by the water of rivers, that the epidemic travels as often against the stream as with it. The reply to this is, that people travel both against the stream and with it, and thus convey the malady from village to village and from town to town on the banks, whilst the water serves as a medium to propagate the disease amongst those living at each spot, and thus prevents it from dying out through not reaching fresh victims.
The principles I have laid down afford a satisfactory explanation of the circumstances, that absence of drainage promotes the prevalence of cholera, and that it flourishes better on a clay soil than on primitive rocks, sandstone, or gravel. Without drainage, the refuse of the population permeates the ground, and gains access to the pump-wells. Merthyr Tydvil, with 52,863 inhabitants, is entirely without drainage, and the people derive their supply of water from pump-wells. This place has suffered severely from cholera in every epidemic. In 1849 there were 1,682 deaths from this disease, being 234 to each 10,000 inhabitants, – a rate of mortality as high as in Hull and certain of the south districts of London, where the morbid poison of cholera was distributed by the steam-engines of the water companies. The primitive rocks, sandstone, and gravel, generally cause the purification of the water by the separation or oxidation of organic matters, whilst clay does not exert this salutary influence to the same extent.
EVIDENCE THAT PLAGUE, YELLOW FEVER, DYSENTERY, AND TYPHOID FEVER ARE COMMUNICATED IN THE SAME WAY AS CHOLERA
Since the latter part of 1848, when I first arrived at my present conclusions respecting the mode of communication of cholera, I have become more and more convinced that many other diseases are propagated in the same way.
When the plague visited this country, it was most fatal in London, York, Winchester, and certain other towns having a river of fresh water passing through them. It resembled cholera also in being twice as fatal in the districts on the south of the Thames as in those on the north. The following passage from Stow's "Survey", published in 1633, shows the way in which Southwark was supplied with water about the time of the great visitations of plague: "Southwark useth chiefly the water of the Thames, that falls into a great pond at St. Mary Overies, that drives a mill called St. Saviour's Mill, the owner whereof is one Mr. Gulston. The revenue thereof is supposed by some to be worth 1,300 pounds a year."
Although some of the lower parts of the City were supplied with water from the Thames, at the latter part of the sixteenth and throughout the seventeenth century, yet the greater part of London north of the Thames was supplied by fountains and conduits, conveying spring water from a distance. The following quaint but poetic account of the conduits of London cannot fail to be interesting: "As nature, by veins and arteries, some great and some small, placed up and down all parts of the body, ministereth blood to every part thereof; so was that wholesome water, which was necessary for the good of London, as blood is for the good and health of the body, conveyed by pipes, wooden or metalline, as by veins, to every part of this famous city .... They were lovely streams indeed that aid refresh that noble city, one of which was always at work pouring out itself when the rest lay still. Methinks these several conduits of London stood like so many little but strong forts, to confront and give check to that great enemy, fire, as occasion should be. There, methinks, the water was entrenched and in-garrisoned. The several pipes and vehicles of water that were within these conduits, all of them charged with water, till by turning of the cock they were discharged again, were as so many soldiers within these forts, with their musketry charged, ready to keep and defend these places. And look how enemies are wont to deal with these castles, which they take to be impregnable, and despair of every getting by them, -- that is, by attempting to storm them by a close siege: so went the fire to work with these little castles of stone, which were not easy for it to burn down (witness their standing to this day); spoiled them, or almost spoiled them, it hath for the present, by cutting off those supplies of water which had vent to flow to them, melting those leaden channels by which it had been conveyed, and thereby, as it were, starving those garrisons which it could not take by storm. As if the fire had been angry with the poor old tankard-bearers, both men and women, for propagating that element which was contrary to it, and carrying it upon their shoulders, as it were, in state and triumph, it hath even destroyed their trade, and threatens to make them perish by fire who had wont to live by water."
Dr. Farr makes the following remarks on the plague, in his report on the cholera of 1848-9: "It is endemic in the Delta of the Nile, and periodically decimates the popu_ lation of Cairo and Alexandria .... It grows gradually less fatal up the Nile, and is less frequent and destructive in Upper than in Lower Egypt, in the high lands and in the desert, than on the low lands on the shores of the Mediteranean." Speaking of Cairo, he says: "Through the midst of it passes the Great Canal, into which the sewers are discharged over carrion, excretion, and mud. At the yearly overflow of the Nile, its waters, filling this canal, are distributed over the city, and drunk by its wretched inhabitants."
The plague resembles cholera in being much promoted by crowding and want of personal cleanliness. The natives of Gurhwal, a province in the northwest of British India, in which the plague has been present for the last thirty years, believe that it may be transmitted from one place to another in articles of diet, such as a jar of ghee.
Yellow fever, which has been clearly proved by Dr. M'William and others to be a communicable disease, resembles cholera and the plague in flourishing best, as a general rule, on low alluvial soil, and also in spreading greatly where there is a want of personal cleanliness. This disease has more than once appeared in ships sailing up the river Plate, before they have had any communication with the shore. The most probable cause of this circumstance is, that the fresh water of this river, taken up from alongside the ship, contained the evacuations of patients with yellow fever in La Plata or other towns.
It was long ago observed, that dysentery was apparently propagated by the drinking of water containing excrementitious matters. The frequent appearance of this disease in Millbank prison, when the Thames water was used, is a confirmation of this; and Dr. Bryson has lately related a number of instances where both dysentery and fever seemed to be occasioned by the water of the Yangtse-Kiang, the Canton river, and other rivers of China. What very much confirms this view of the case, is, that nearly all the patients were afflicted with great numbers of intestinal worms (lumbrici); for it cannot be supposed that the worms could proceed from malaria, miasmata, or any of the causes which are frequently believed to occasion dysentery and fever. The eggs of the lumbrici were no doubt contained in great numbers in the water of the densely populated Chinese rivers.
There are many facts which indicate that one at least of the continued fevers – the typhoid fever with ulceration of the small intestines -- is also propagated in the same way as cholera. Dr. Jenner called my attention some time ago to an instance occurring at the village of North Boston, Erie County, N.Y., in which typhoid fever was probably communicated to a number of families by the contamination of the water of a well which they used. The epidemic which prevailed so extensively at Croydon two years ago was of this character, as was verified by a Committee of the Epidemiological Society, of which Drs. Sankey, Jenner, and A. P. Stewart were members. Mr. Carpenter, of Croydon, has lately shown very ably that this epidemic was connected with the pollution of the pump-wells of the town, owing to the disturbance of the ground, and of many old cesspools during the drainage operations of the Local Board of Health. The Board had supplied the town with good water from a deep well in the chalk, but the population had a prejudice against it and persisted in resorting to the water of the shallow pump-wells. In the autumn of last year diarrhea was very prevalent in Croydon (1872 map: middle left), and Mr. Carpenter found that this also was caused by the impure water of the pump-wells. Nine-tenths of the people of Croydon were drinking the new water supplied by the Board of Health, but, out of thirty-two patients with diarrhea who came under the notice of Mr. Carpenter, twenty-five were drinking well-water entirely, five drank water from both sources, and the other two could not decidedly say that they had not drank well-water.
INSTANCES IN WHICH AGUE WAS CAUSED BY IMPURE WATER
Intermittent fevers are so fixed to particular places that they have deservedly obtained the name of endemics. They spread occasionally, however, much beyond their ordinary localities, and become epidemic. Intermittent fevers are undoubtedly often connected with a marshy state of the soil; for draining the land frequently causes their disappearance. They sometimes, however, exist as endemics, where there is no marshy land or stagnant water within scores of miles. Towards the end of the seventeenth century, intermittent fevers were, for the first time, attributed by Lancisi to noxious effluvia arising from marshes. These supposed effluvia, or marsh miasmata, as they were afterwards called, were thought to arise from decomposing vegetable and animal matter; but, as intermittent fevers have prevailed in many places where there was no decomposing vegetable or animal matter, this opinion has been given up in a great measure; still the belief in miasmata or malaria of some kind, as a cause of intermittents, is very general. It must be acknowledged, however, that there is no direct proof of the existence of malaria or rniasmata, much less of their nature.
That preventive of ague, draining the land, must affect 'the water of a district quite as much as it affects the air, and there is direct evidence to prove that intermittent fever has, at all events in some cases, been caused by drinking the water of marshes. In the " General Report of the Poor Law Commissioners on the Sanitary Condition of Great Britain," Mr. Wm. Blower, surgeon, of Bedford, states that typhus and ague, which had long infested the village of Wootton, near Bedford, had been much diminished by digging a few wells, and obtaining good water. He also states that, in the neighboring parish of Houghton, almost the only family which escaped ague, at one time, was that of a respectable farmer who used well water, whilst all the other families had only clitch water.
M. Boudin  relates a very marked instance in which intermittent, and apparently also remittent, fever were caused by drinking marsh water. It is as follows: --
"In July 1834, 800 soldiers, all in good health, embarked on the same day in three transports at Bona, in Algeria, and arrived together at Marseilles; they were exposed to the same atmospheric influences, and were, with one essential 'difference, supplied with the same food, and subjected to the same discipline. On board one of the vessels were 120 soldiers: of these, 13 died on the passage, from a destructive fever, and 98 more were taken to the military hospital of the lazaretto at Marseilles, presenting all the pathological characters proper to marshy localities. On seeing the physiognomy of these patients, altogether so unusual for Marseilles, one would have said that the Gulf of Mexico, the Delta of the Ganges, and the marshes of Senegal and of Holland, had supplied passengers to this ship. In short, by the side of a simple intermittent, there was a pernicious fever. On an inquiry being instituted, it was ascertained that on board the affected ship the water supplied for the soldiers, owing to the haste of the embarkation, had been taken from a marshy place near Bona; whilst the crew, not one of whom was attacked, were supplied with wholesome water. It further appeared that the nine soldiers who had escaped had purchased water of the crew, and had consequently not drunk the marsh water. Not a single soldier or sailor of the other two transports, who were supplied with pure water, suffered."
Mr. Grainger, who quotes the above circumstance in his Appendix to the Peport on Cholera, also says:  "Dr. Evans, of Bedford, related to me an equally well-marked instance. A few years ago, he was staying at Versailles, with his lady, when they both became affected with the ague, and, on inquiry, the following facts were disclosed. The town of Versailles is supplied with water for domestic purposes from the Seine, at Marli. At the time in question, a large tank, supplying one particular quarter, was damaged, and the mayor, without consulting the medical authorities, provided a supply of water, consisting of the surface-drainage of the surrounding country, which is of a marshy character. The regular inhabitants would not use this polluted water; but Dr. and Mrs. Evans, who were at an hotel, drank of it unwittingly, and it was also used by a regiment of cavalry. The result was, that those who drank the water suffered from intermittent fever of so severe a type, that seven or eight of the soldiers, fine young men, died on one day, Sept. 1, 1845. On a careful investigation it was ascertained that those only of the troops who had drunk the marsh water were attacked; all the others, though breathing the same atmosphere, having escaped, as did also the townspeople."
In all the instances I have just quoted, the cause of ague, whatever it may be, was swallowed with the water, not inhaled with the air; and on questioning two patients, ill with this complaint, in St. George's Hospital, after harvesting in Kent, they told me that they had often been obliged to drink water from the ditches. The disease of the liver and spleen, to which persons are subject after attacks of intermittent fever, also confirms the view that its material cause enters the system by the alimentary canal, and not by the lungs; and it is of importance to remark, that Hippocrates observed, that drinking stagnating waters caused hard swellings of the spleen.
Whether the unknown cause of ague has been produced in the system of a previous patient, like the pus of smallpox and the eggs of tapeworm, or whether it has been produced externally, there is, at present, no sufficient evidence to show. In the case first supposed, the disease would be a communicable one, in the second it would not.
There is one circumstance which seems to indicate that the specific cause of intermittent fevers undergoes a development or multiplication within the system of the patient, – it is, that a period of dormancy, or incubation, has been observed, in many cases, between the visit to the unhealthy locality and the illness which followed; for, as I have already remarked, every poisonous or injurious substance causes symptoms as soon as it has been absorbed in sufficient quantity.
The communication of ague from person to person has not been observed, and supposing this disease to be communicable, it may be so only indirectly, for the materies morbi eliminated from one patient may require to undergo a process of development or procreation out of the body before it enters another patient, like certain flukes infesting some of the lower animals, and procreating by alternate generations.
MEASURES REQUIRED FOR THE PREVENTION OF CHOLERA AND OTHER DISEASES WHICH ARE COMMUNICATED IN THE SAME WAY
The measures which are required for the prevention of cholera, and all diseases which are communicated in the same way as cholera, are of a very simple kind. They may be divided into those which may be carried out in the presence of an epidemic, and those which, as they require time, should be taken beforehand.
The measures which should be adopted during the presence of cholera may be enumerated as follows :_
1st. The strictest cleanliness should be observed by those about the sick. There should be a hand-basin, water, and towel, in every room where there is a cholera patient, and care should be taken that they are frequently used by the nurse and other attendants, more particularly before touching any food.
2nd. The soiled bed linen and body linen of the patient should be immersed in water as soon as they are removed, until such time as they can be washed, lest the evacuations should become dry, and be wafted about as a fine dust. Articles of bedding and clothing which cannot be washed, should be exposed for some time to a temperature of 212 degrees or upwards.
3rd. Care should be taken that the water employed for drinking and preparing food (whether it come from a pump-well, or be conveyed in pipes) is not contaminated with the contents of cesspools, house-drains, or sewers; or, in the event that water free from suspicion cannot be obtained, is should be well boiled, and, if possible, also filtered.
Works are in progress for supplying a great part of London with water from the Thames, obtained, like that of the Lambeth Company, above Teddington Lock. Although this is not the best possible source for supplying a large town, it is a great improvement on the practice of many of the water companies; and the water, owing to filtration, and especially to its detention in large reservoirs, will probably be quite salubrious: at all events it will be much safer than that of the shallow pump-wells of London, which are fed from very polluted sources. It is very desirable that the handles of nearly all the street-pumps of London and other large towns should be fastened up, and the water used only for such purposes as watering the streets. A proper supply of water for the shipping in the Thames is much wanted. Water acquires a flat taste by being boiled; but if it is filtered after it becomes cold, it gets re-aerated, and the flat or vapid taste is entirely removed.
4th. When cholera prevails very much in the neighborhood, all the provisions which are brought into the house should be well washed with clean water, and exposed to a temperature of 212 degrees Fahrenheit; or at least they should undergo one of these processes, and be purified either by water or by fire. By being careful to wash the hands, and taking due precautions with regard to food, I consider that a person may spend his time amongst cholera patients without exposing himself to any danger.
5th. When a case of cholera or other communicable disease appears among persons living in a crowded room, the healthy should be removed to another apartment, where it is practicable, leaving only those who are useful to wait on the sick.
6th. As it would be impossible to clean out coal-pits, and establish privies and lavatories in them, or even to provide the means of eating a meal with anything like common decency, the time of working should be divided into periods of four hours instead of eight, so that the pit-men might go home to their meals, and be prevented from taking food into the mines.
7th. The communicability of cholera ought not to be disguised from the people, under the idea that the knowledge of it would cause a panic, or occasion the sick to be deserted.
British people would not desert their friends or relatives in illness, though they should incur danger by attending to them; but the truth is, that to look on cholera as a "catching" disease, which one may avoid by a few simple precautions, is a much less discouraging doctrine than that which supposes it to depend on some mysterious state of the atmosphere in which we are all of us immersed and obliged to breathe.
The measures which can be taken beforehand to provide against cholera and other epidemic diseases, which are communicated in a similar way, are --
8th. To effect good and perfect drainage.
9th. To provide an ample supply of water quite free from contamination with the contents of sewers. cesspools, and house-drains, or the refuse of people who navigate the rivers.
10th. To provide model lodging-houses for the vagrant class, and sufficient house room for the poor generally.
The great benefit of the model lodging-houses arises from the circumstance that the apartments for cooking, eating, and sleeping, are distinct, and that all the proper offices which cleanliness and decency require are provided. The very poor who choose to avail themselves of these institutions. suffer a rate of mortality as low as that of the most opulent classes. The public wash-houses, which enable poor persons to wash the soiled linen of the sick or the healthy, without doing it in the midst of the plates and dishes and provisions of the family, are well calculated to prevent the spread of disease.
11th. To inculcate habits of personal and domestic cleanliness among the people everywhere.
12th. Some attention should undoubtedly be directed to persons, and especially ships, arriving from infected places, in order to segregate the sick from the healthy. In the instance of cholera, the supervision would generally not require to be of long duration.
In the autumn of 1853, certain German emigrants, on their way to America, who had crossed the sea from Hamburgh and Rotterdam, where cholera was prevailing, to the port of Hull, and had gone thence, by rail, to Liverpool, were seized with cholera (some of them fatally) in the latter town; and it is most likely to the well-regulated Emigrant's Horne, in which these cases occurred, that the town of Liverpool owed its freedom from the epidemic at that time. And a little medical supervision, and the detention of some of the emigrants for a short time in Liverpool, before their embarkation, would probably have prevented the great mortality which occurred in some of the emigrant ships during their passage to America.
The measures which are intended to prevent disease should be founded on a correct knowledge of its causes. For want of this knowledge, the efforts which have been made to oppose cholera have often had a contrary effect. In 1849, for instance, the sewers of London were frequently flushed with water, – a measure which was calculated to increase the disease in two ways: first, by driving the cholera evacuations into the river before there was time for the poison to be rendered inert by decomposition; and second, by making increased calls on the various companies for water to flush the sewers with, -- so that the water which they sent to their customers remained for a shorter time in the reservoirs before being distributed. It should be remarked, also, that the contents of the sewers were driven into the Thames by the flushing, at low water, and remained flowing up the stream for four or five hours afterwards. Flushing the sewers was not repeated during the recent epidemic, but increased quantities of water were distributed by some of the Companies, and at more frequent intervals, causing the water-butts to overflow for hours together into the drains, and producing nearly the same effect as flushing the sewers; in addition to which, the water in the butts of the Southwark and Vauxhall Company's customers was prevented from settling, as it might have done if less frequently disturbed.
I feel confident, however, that by attending to the above-mentioned precautions, which I consider to be based on a correct knowledge of the cause of cholera, this disease may be rendered extremely rare, if indeed it may not be altogether banished from civilized countries. And the diminution of mortality ought not to stop with cholera. The deaths registered under the name of typhus consist chiefly of the typhoid fever mentioned above. Its victims are composed chiefly of persons of adult age, who are taken away from their families and connections. In 1847 upwards of 20,000 deaths were registered in England from typhus, and in 1848 upwards of 30,000 deaths. It is probable that seven times as many deaths have taken place from typhus as from cholera, since the latter disease first visited England in 1831; and there is great reason to hope that this mortality may in future be prevented by proper precautions, resulting from a correct knowledge of the mode of communication of the malady.
Containing the number of deaths from cholera registered in the four weeks ending 5th August, 1854, together with the supply of water in the houses in which the fatal attacks took place, in all the sub-districts to which the water supply of either the Southwark and Vauxhall or the Lambeth Company extends. (See Table VII, page 84 [Part 3]) The registers of deaths are copied from the Weekly Returns of the Registrar General.
ST. SAVIOUR, SOUTHWARK. Christchurch.
At 34, Charlotte Street, on 29th July, a stock-maker, aged 29, " Asiatic cholera 18 hours" Lambeth.
At 45, Gravel Lane, on 1st August, the widow of a farmer, aged 48, " cholera 12 hours". Southwark and Vauxhall.
At 1, Alpha Place, on 1st August, a barrister's clerk, aged 57, " cholera 24 hours". Southwark and Vauxhall.
ST. SAVIOUR, SOUTHWARK. St. Saviour.
At 1, Park Street, on 25th July, the wife of a laborer aged 35, " Asiatic cholera 14 1/2 hours". Southwark and Vauxhall.
At 40, Bankside, on 25th July, the son of a locksmith, aged 5 years, " cholera 12 hours" Southwark and Vauxhall
At same house, on 26th July, the daughter of a locksmith, aged 9 yrs., " cholera 12 hours". Southwark and Vauxhall.
At same house, on 28th July, the daughter of a locksmith, aged 13 yrs., " cholera 12 hours". Southwark and Vauxhall.
At 97, Bridge Road, on 28th July, a hatter, aged 36, Asiatic cholera 24 hours". Southwark and Vauxhall.
At 49, Great Guildford Street, on 29th July, a coalporter, aged 44, " cholera 151 hours".Southwark and Vauxhall
At 20, Zoar Street, on 31st July, a female, formerly a domestic servant, aged 79, diarrhea 2 days, "cholera 12 hours" Southwark and Vauxhall.
At 22, America Street, on Aug. 1, the wife of an engine-driver, aged 38, "cholera 12 hours". Southwark and Vauxhall.
At 5, Pleasant Place, August 1, the daughter of a coalporter, aged 5 years, "Asiatic cholera 13 hours". Southwark and Vauxhall.
At 10, Castle Street, on 1st August, the son of an engineer, aged 7 years, "cholera 12 hours". Southwark and Vauxhall.
At 86, New Park Street, on 1st August, the son of an artist, aged 2 years, "Asiatic cholera 10 1/2 hours". Thames water from the tank of a sawmill.
At 54 1/2, Great Guildford St., on 2nd Aug., a laborer, aged 51, "Asiatic cholera 47 hours". Southwark and Vauxhall.
At the same house, same day, the wife of a laborer, aged 48, "Asiatic cholera 12 1/2 hours". Southwark and Vauxhall.
At 2, Emerson Place, on 3rd August, the wife of an engineer, aged 30, "cholera 2 days". Southwark and Vauxhall.
At 29, Norfolk St., on 2d Aug., the son of a laborer, aged 8 years, "Asiatic cholera 12 1/2 hours". Southwark and Vauxhall.
At 68, Great Guildford St., on 3rd Aug., the widow of a laborer, aged 40, "cholera 19 hours". Southwark and Vauxhall.
At 10, Castle Street, on 3rd August, the daughter of a laborer, aged 4 years, "cholera 12 hours". Southwark and Vauxhall.
At White Hart Inn Yard, on 3rd August, the wife of a porter, aged 49, "cholera 14 hours". Southwark and Vauxhall.
At 22, America Street, on 3rd August, an engine-driver, aged 35, "cholera 9 hours". Southwark and Vauxhall.
At 15, Essex Street, on 4th August, a packer, aged 65, diarrhea 4 days, "cholera 11 hours ". Southwark and Vauxhall.
In the original publication the list of deaths is continued in this form for a total of twenty-five pages.
 History of the Cholera in Exeter in 1839.
 Report of the General Board of Health on the supply of Water to the Metropolis, 1850, p. 55.
 See Report of Commissioners on the Cholera at Newcastle, etc., p. 474.
 Opus cit., p. xxv.
 Report of Swedish Commissioners, quoted in the Second Report of the Metropolitan Sanitary Commission, 1848..
 Medical Times and Gazette, Lancet, and Association Journal..
 Various conditions are requisite for the production of a disease, as they are for the production of a crop of wheat or turnips, but it is not necessary to dignify these conditions with the name of causes.
 Medical Times and Gazette, 1854, vol. i, p. 182.
 Med. Times and Gazette, Nov. 25th, 1854.
 Report on the Cholera of 1848_49, p. xl.
 Rolle's Account of the Buring of London in 1666.
 Official Reports on the Province of Kurnaon, by J. H. Batten, Esq., C.E. Agra, 1851.
 Dr. Cheyne on Dysentery, Dublin Hospital Reports, vol. iii.
 Statistical Reports on the Health of the Navy. Part 11. 1853.
 Association Journal, October 6, 1854.
 Svo., 1842, p. 66..
 Essai de Géographie Médicale, p. 52.
 De Aere, Aquis, et Locis
END OF READINGS
Part four (final) of Snow on Cholera