"Further remarks on the mode of communication of cholera; including some comments on the recent reports on cholera by the General Board of Health"

Medical Times and Gazette
(14 July 1855): 31-35
Part 1. A substantial portion of this essay was first read at the Epidemiological Society in May and June, 1855.

In a paper which I had the honour to read to this Society in 1851,* I enumerated various circumstances connected with the pathology of Cholera, and with its progress as an epidemic, which led me to the conclusion that it is propagated by the morbid poison which produces it being accidentally swallowed; that this morbid poison becomes multiplied and in-[31/32] creased in quantity on the interior surface of the alimentary canal and that it passes off in the ejections and dejections to produce fresh cases of the disease in those who happen to take the morbid matter into the stomach. I explained what great facilities there are for the cholera evacuations being accidentally swallowed in the crowded habitations of the poor, where the inmates cook, eat, live, and sleep in the same apartment, and pay little regard to washing the hands, since these evacuations are almost devoid of colour and odour, and are usually passed involuntarily in the latter stages of the disease. It is in the families of the poor that cholera is often observed to pass from one individual to another, while in cleanly dwellings, where the hand-basin and towel are in constant use, and where the rooms for cooking, eating, and sleeping are distinct from each other, the communication of cholera from person to person is rarely observed. In the houses of the poor, also, the disease is hardly ever contracted by medical, clerical, and other visitors, who do not eat or drink in the sick-room, while it often fares differently with the social visitor, who comes either to see the patient or attend his funeral. (*Published in Medical Times and Gazette, 1851, Vol. II.)

The cholera has visited the mining districts of this country with unusual severity, in each of the epidemics we have had. The following is the explanation of this circumstance:--The pits are without any privies, and the excrement of the workmen lies about almost everywhere, so that the hands are liable to be soiled with it. The pitmen remain under ground eight or nine hours at a time, and invariably take food down with them into the pits, which they eat with unwashed hands, and without knife and fork; therefore, as soon as a case of cholera occurs among any of the pitman, the disease has unusual facilities of spreading in the way I have pointed out.

In my former paper I also showed that the cholera evacuations have the property of communicating the disease after being mixed with the drinking-water of the people, and I related a number of instances in which sudden and severe outbreaks of the malady occurred in the epidemics of 1832 and 1849 among persons using the water of ditches and pump-wells contaminated with excrementitious matters. It is particularly to be remarked that, in those instances, there were one or two cases of cholera in the community where evacuations polluted the water, just before the great out-break. I also related a number of facts to show that cholera was communicated through the water supplied to many districts of London, and to several other towns where the water was obtained from a river receiving the sewage of the town. This division of my views on cholera which refers to its communication through the medium of drinking water, has apparently obtained a greater amount of attention from the Profession, than my views respecting its more immediate communication by the cholera poison being swallowed without the water. While I speak on this division of the subject, however, I must beg the Society to bear in mind also the other part of my views, first alluded to, for I am well aware that the part which relates to polluted water will not of itself explain the whole progress of the disease as an epidemic.

The epidemics of 1853 and 1854 have furnished numerous examples of the communication of cholera by means of water quite as striking as those which I related in my former paper; but I shall be content on the present occasion to describe only a single example which occurred on a large scale, and shall merely make such remarks on some other instances, as may be necessary to elucidate the way in which the water produces its effects.

The whole of the south districts of London, with the exception of the Greenwich district, and part of the Lewisham and Rotherhithe districts, are supplied with water by two water companies, one called the Lambeth Company, and the other the Southwark and Vauxhall Company. The population of the districts supplied by these two water companies, amounted in 1851 to nearly half-a-million. Now throughout the greater part of the districts supplied by these two water companies, the supply is intimately mixed, the pipes of both companies going down all the streets, and into almost all the courts and alleys. The water companies were at one time in active competition, and any person paying the rates, whether landlord or tenant, could change his water company as easily as his butcher or baker, and although this state of things has long since ceased, and the companies have come to such an arrangement that the people cannot change their supply, yet the result of the former competition remains. There is here and there a row of houses having the same supply, but very often two contiguous houses are supplied differently. There is no difference in the circumstances of the people supplied by the two companies; each company supplies both rich and poor alike.

In 1849 the water supplied by the two companies was nearly the same; that of the Lambeth Company was obtained from the Thames, close to Hungerford Suspension Bridge; and that of the Southwark and Vauxhall Company at Battersea-fields: each kind of water contained the sewage of London, and was distributed with very little attempt at purification, as the most superficial examination was enough to show. The cholera in 1849 was almost equally severe in the districts which were entirely supplied by the Southwark and Vauxhall Company, and those which were partly or chiefly supplied by the Lambeth Company. This latter company had no district, or even sub-district, exclusively to itself, and although it has since extended its supply to the sub-districts of Streatham, Norwood, Dulwich, and Sydenham, these villages are chiefly supplied by pump-wells.

Between the epidemic of 1849, and that of 1853, a very important change was made in the water supply of a great portion of the south districts of London. The Lambeth Company removed their works in 1852 from the neighbourhood of Hungerford Bridge to Thames Ditton, which is situated above Teddington Lock, and is, therefore, beyond the influence of the tide, and out of reach of the sewage of London.

Dr. Farr turned his attention to the influence of the water-supply on the mortality from cholera in London soon after my pamphlet, containing remarks on the subject, appeared in 1849. He returned to the subject in the latter part of 1853, and the weekly returns of that time contain some tables, showing that the districts, partly supplied with the improved water from Thames Ditton, suffered a lower mortality than those supplied exclusively with the water from Battersea-fields. It was desirable, however, to investigate this matter more in detail, and to find out, if possible, what was the actual water-supply in the houses in which fatal attacks occurred. I was unable to do this in the epidemic in the last quarter of 1853, but when the cholera returned to London in the following summer, I resolved to call myself at the houses in which deaths might occur, in the districts where the water-supply is intermingled in the way I have explained. The addresses of the persons who died of cholera during the first four weeks of the epidemic of 1854 were published in the weekly returns, and on applying to Dr. Farr, I was kindly permitted to copy those of the persons whose deaths were registered during the next three weeks. My inquiries thus extended over the first seven weeks of the epidemic, that is, from the 8th of July to the 26th of August. The number of deaths I inquired after personally amounted to 658; but as the water companies make no return of the number of houses they supply in particular parishes or districts, it was necessary, in order to find out the exact influence of the water, to extend the inquiry to all the districts to which the water of either company is distributed, in order that the number of fatal attacks might be compared with the entire number of houses supplied by each company, as shown by their returns to Parliament at the conclusion of l853, namely, 40,046 by the Southwark and Vauxhall Company, and 26,107 by the Lambeth Company.

I was assisted by a Medical man, Mr. Whiting, in making the inquiries respecting the water-supply in certain districts supplied only by the Southwark and Vauxhall Company; but I made the inquiry myself in all the districts to which the water of the Lambeth Company extends; so that Mr. Whiting's part of the inquiry, which he conducted very carefully, was merely to ascertain whether the houses, in which fatal attacks took place, were supplied by the Southwark and Vauxhall Company, or by a pump-well, or some other local supply. In the case where persons died in an hospital or a workhouse, to which they had been removed after the attack, the water-supply of the houses from which they had been removed was ascertained.

In stating the results of these inquiries, I shall divide the seven weeks over which they extended into two periods, giving the result of the first four weeks of the epidemic first, and then that of the succeeding three weeks, as the cholera was more exclusively caused by the water in the beginning of the epidemic than afterwards, for reasons that I shall state. I shall also treat separately of the groups of districts, accord-[32/33] ing as they were supplied by only one of the companies, or by the two combined.

In the first four weeks of the epidemic there was not a single death from cholera registered in the sub-districts supplied by the Lambeth Company, and not supplied by the other company. In the sub-districts, in which the supply of the two companies intermingled, in the way I have explained, there were 134 deaths from cholera registered during this period, and I ascertained, by calling at the respective houses in which the fatal attacks occurred that the water supply in 115 of the cases was that of the Southwark and Vauxhall Company, in 14 cases that of the Lambeth Company, in 2 cases from pump-wells, and 1 direct from the river, and in 2 instances it was not ascertained, as the place of attack was unknown. In the sub-districts which are supplied solely by the Southwark and Vauxhall Company, there were 200 deaths during the first four weeks of the epidemic, of which 171 had the supply of that company, and the rest had water direct from the river, or from pump-wells, or ditches.

In the next three weeks of the epidemic, from the 5th to the 26th of August, 18 deaths from cholera were registered in the sub-districts supplied by the Lambeth Company alone; of these 4 occurred in houses having the supply of that company, and the houses in which the others occurred were supplied from pump-wells or other sources. In the sub-districts in which the supply was intermixed, 518 of the fatal attacks of cholera occurred in these three weeks, of which I ascertained that 410 took place in houses having the supply of the Southwark and Vauxhall Company, and 80 in houses having the supply of the Lambeth Company, while the remaining 28 occurred in houses not supplied by either company, or of which the address was not known. During this period 644 fatal attacks occurred in the sub-districts supplied exclusively by the Southwark and Vauxhall Company, of which 567 happened to persons having the supply of the company, and the remaining 77 to persons obtaining water direct from the river, or from some other source.

It is to be regretted that we have not yet the exact number of houses supplied by each water company respectively, in those sub-districts in which the supply is intimately mixed up, as it is there that the investigation approaches completely to a crucial experiment. Dr. Farr has all the data for ascertaining this point, and I hope it will soon be worked out. In the mean time, however, we can arrive very nearly at the truth by the help of the Census tables. The entire number of inhabited houses in the sub-districts in which the water supply is intermixed was 44,686 at the time of the last census, and there were 3079 houses in the sub-districts which were supplied by the Lambeth Company to the exclusion of the other. These latter sub-districts, namely, Streatham, Norwood, Dulwich, and Sydenham, are chiefly supplied by private pump-wells, not more than one house in five at the utmost being supplied by the company; therefore, if we deduct one-fifth of the above from the entire number of houses which the Lambeth Company supplies, we shall have 25,491 as the number of houses which that company supplies out the 44,686 which were contained in the districts and sub-districts where the supply is intermixed; leaving 20,555 as the number supplied by the Southwark and Vauxhall Company. Some houses were built in a few of the less crowded sub-districts, between the time of the Census and the epidemic of 1854, but these are probably quite counterbalanced by a certain number of houses in Kennington and Brixton, which have a pump-well, and are not supplied by either company.

The 115 fatal attacks which occurred during the first four weeks of the epidemic in the 20,555 houses we have calculated to be supplied by the Southwark and Vauxhall Company, give 55 to every 10,000 houses, and the 14 fatal attacks which occurred in the 25,491 houses supplied by the Lambeth Company give 5 to each 10,000 houses; the cholera was therefore eleven times as fatal in the houses having one supply as the other. If we make a similar calculation with regard to the fatal attacks which occurred in the next three weeks in the sub-districts in which the water supply is intimately mixed, we find that the mortality of cholera was at the rate of 199 to each 10,000 houses supplied by the Southwark and Vauxhall Company, and 31 to each 10,000 houses supplied by the Lambeth Company. It was, therefore, between six and seven times as great during this period, to the population having one supply as to that having the other.

I will now state the results when the whole of the districts supplied by each of the companies are taken together, and compared with the entire number of houses supplied by each. In this way we get figures that are perfectly correct, and not merely a close approximation to the truth.

In the first four weeks of the epidemic there were 334 deaths from cholera in the districts to which the supply of the two water companies extends. Of these 286 were attacked while living in houses supplied by the Southwark and Vauxhall Company with water from the Thames at Battersea-fields, and only 14 in houses supplied with water from Thames Ditton. In 4 cases the houses were supplied with water from pump-wells, in 26 cases the water was drawn directly from the river or from ditches, and in 4 cases the supply could not be ascertained, as the place of attack was unknown. When the number of houses supplied by each of the companies respectively is taken into account, it is found that the cholera was 14 times as fatal in the houses receiving the water from Battersea-fields, and containing whatever might come down the sewers or over the side of a ship from cholera patients, as it was in the houses receiving the water from Thames Ditton.

I published the address of the houses in which the whole of the above 334 fatal attacks took place, appending the particulars of the water supply, and I have not heard that the correctness of the report has been called in question in a single instance.

The 286 cases occurring in the houses supplied with the water of the Southwark and Vauxhall Company were distributed over the whole area to which the water extends, reaching from Wandsworth to Rotherhithe inclusive; and this continued to be the case throughout the epidemic.

It is worthy of remark that while only 563 fatal cases of cholera occurred in the whole of this metropolis, containing over 300,000 houses, during the four weeks ending August 5th, 1854, 286, or more than one-half of the entire number, occurred in the 40,046 houses supplied by the Southwark and Vauxhall Company, while a great number of the remaining cases occurred in persons employed on the river, and drawing their drinking water from alongside the ship or barge. In the next three weeks of the epidemic, from the 5th to the 26th of August, 1180 deaths from cholera were registered in the districts of which I am treating. Of these fatal attacks, 977 took place in houses supplied with the water of the Southwark and Vauxhall Company, and 84 in houses supplied with the improved water of the Lambeth Company; there were 25 fatal attacks in houses supplied merely by pump-wells; in 76 cases, the water was obtained from the Thames, or from ditches, and in 18 cases the supply could not be ascertained, for the reason stated before.

When the number of houses supplied by each company respectively, is taken into account, it is found that in those three weeks, from the 5th to the 26th of August, the cholera was eight times as fatal in the houses supplied with water from Battersea-fields as in those supplied with the more pure water from Thames Ditton, the proportions being 241 fatal attacks in each 10,000 houses supplied with the former water, and 32 fatal cases in each 10,000 houses supplied with the latter.

An inquiry respecting the water supply in the house of attack, in all fatal eases of cholera, was made by the Registrar-General, through the district Registrars of all the south districts of London, beginning from the 26th of August, the day when my inquiry was left off. There were a considerable number of cases in which the supply could not be ascertained from the person registering the death, owing chiefly to the water-rates being "farmed," as the term is, but there is no reason to doubt that the returns were correct, so far as they went, and showed the same proportion as they would have shown if more complete. From the 26th of August to [33/34] the end of the epidemic, a period of ten weeks, 2443 cases were returned to the Registrar-General, in which the water supply in the house of fatal attack was that of the Southwark and Vauxhall Company, and 313 cases in which the supply was from the Lambeth Company; consequently, during this period, there were 610 fatal attacks in each 10,000 houses supplied by the former company, and 119 in each 10,000 houses supplied by the latter, and the malady was, therefore, more than five times as fatal to the population having water from the Thames at Battersea-fields, as to the population having the new supply, free from the sewage of London. (*[33]In my inquiries, I made use of a chemical examination of the water in all cases where the other evidence was not quite conclusive. The Lambeth water contained rather less than a grain of common salt in each gallon, while the water of the Southwark and Vauxhall Company contained nearly forty grains. I ascertained afterwards from the information of Mr. Quick, the Engineer to the latter company, and from some examinations I made of the Thames water taken direct from the river, that the common salt was nearly all derived from a mixture of sea-water, owing to the extreme dryness of the season, which caused it to flow higher up the river than usual. When, Messrs. Graham, Miller, and Hofmann examined the water of the Southwark and Vauxhall Company, at the latter part of January, 1851, it contained rather less than two [33/34] grains of common salt. It has been objected (Brit. and Foreign Med. Rec., April, l855) that the water of the two companies might alter from day to day, and that I ought to have examined that in their reservoirs; but, besides that it would be impossible for the sea-salt to be elevated over Teddington Lock, and extremely improbable that the Thames in London should take on, in the middle of a dry autumn, the character it had in a wet winter, an examination of numerous specimens throughout the district is as good proof of the nature of the water supply as one made at the reservoirs. I am, however, able to say that the two kinds of water existed throughout the district during the whole time of my inquiries, and were characteristic of their respective sources, for I examined very numerous specimens where the other evidence was conclusive, independent of that derived from chemistry. The mere appearance of the water was generally enough to indicate its origin, but I never relied on that alone.)

It will be observed that, while the disproportion between the number of fatal attacks in the houses supplied respectively by the two kinds of water remained very striking to the last, yet that it somewhat diminished with the progress of the epidemic, being fourteen times as great in one class as in the other, during the first four weeks of the epidemic, eight times as great during the next three weeks, and more than five times as great during the last ten weeks. The reason of this is, that as the number of cases increased, the opportunities of taking the disease directly from the patient in the manner I first pointed out, increased also. The proportion of deaths in houses supplied by the Lambeth Water Company increased during the progress of the epidemic, just as it did in parts of London having a water supply which took no share in the propagation of cholera, as the central and north districts supplied by the New River Company.

The Registrar-General calculated from the Census returns the number of persons living in the houses supplied by the two water companies mentioned above; and by this means we are enabled to compare the mortality of these parts of the population with that of the rest of London, which is estimated according to the number of the people, and not of the houses. The mortality of London generally in the late epidemic was 44 to each 10,000 inhabitants; among the population supplied by the Southwark and Vauxhall Water Company it was 157 to each 10,000 inhabitants, while it was only 27 to each 10,000 persons having the supply of the Lambeth Water Company. The preponderance of deaths in the south districts over the other parts of London, was caused entirely by the mortality among the customers of the Southwark and Vauxhall Water Company; and it is extremely deserving of notice, that the customers of the Lambeth Water Company, although intimately mixed up with those of the former company, retained an immunity from cholera throughout the epidemic, not only greater than that of London at large, but greater than that of any of its divisions, except the central and north districts above alluded to, which are supplied by the New River Company with water receiving no town drainage whatever, and not even navigated by people living in boats. This circumstance confirms me in the conclusion which I expressed in a former paper to this Society, that the remarkable relation of an inverse nature, which Dr. Farr discovered to exist between the elevation of the soil, and the mortality of cholera in the metropolis, depended entirely on the relative purity or impurity of the water; taking into account not only the supply of the companies, but also that drawn from the Thames and tidal ditches, and that of the pump-wells, which are most liable, to pollution in the low-lying districts.

In the Report of the late General Board of Health on the Water Supply of the Metropolis, published in 1850, the following passage occurs, at page 130: "We could find no evidence to justify the supposition that the aggravated effects of cholera, in the lower districts, was to be attributed to persons drinking pipe-water, which, in fact, very few people do habitually drink." The latter part of this passage I found in my inquiries last year in the South Districts to be erroneous, for there were very few pumps in use, until one came to the more distant and suburban parts; in the more densely peopled parts of Lambeth, Southwark, and Bermondsey, the people seldom had any other water to drink than that of the cistern or water butt, and the mortality was greatest among children and others who drank it unboiled. As regards the influence of the pipe-water itself, I believe that, since the inquiries of last summer above alluded to, especially that part of them made and published by the Registrar-General, it has been generally admitted. In the recent Report of Dr. Sutherland, published by the present Board of Health, both the author himself, and every one of the Inspectors whom he quotes on the subject fully admit the influence of the impure water of the Southwark and Vauxhall Company on the prevalence and mortality of cholera, although they do not admit the explanation which I give of this influence. It only remains, therefore, for me to prove that this impure water can increase the prevalence and mortality of cholera in no other manner than that which I explained at the beginning of this paper, and I shall have established my point. I should first like to remark, however, that although a scarcity of water for such purposes as washing out dirty courts and alleys had often been complained of, I am not aware that the quality of the water supplied from any water-works had ever been suspected of actually promoting the prevalence of cholera, or any other epidemic disease, before I published my views on its pathology and mode of communication in August, 1849. So far was this from being suspected, that the most approved measure for preventing cholera in London was that of abolishing common privies and cesspools, in order to remove offensive odours, and by substituting water-closets, to send the evacuations of both the sick and healthy, as quickly as possible into the Thames, although it was well known that about half the metropolis were drinking the water of this river.

As far as I am aware, it is these views which have led to a knowledge of the injurious effect of water under certain conditions, and I would therefore suggest that they are worthy, on this account, of some amount of consideration from those who do not yet admit their entire truth. I would even suggest that this result of the views I entertain affords of itself a presumption that they are correct.

But to proceed to the proofs to which I alluded. There are very numerous facts to show that mere impurity in the water does not of itself increase the prevalence of cholera, even when that impurity consists of the contents of sewers and cesspools. The greater number of the shallow pump-wells of this metropolis contain a good deal of organic matter from the neighbouring sewers, house-drains, and cesspools, in fact, the ground being covered up with houses and pavement, they are chiefly fed from these sources, but they do not, as a general rule, take any share in the propagation of cholera during an epidemic; it is only here and there, when one of them happens to receive what comes from a cholera patient, that it communicates the malady to those drinking the water. Persons often allow the water in their cisterns and butts to become extremely foul and dirty, but this has no effect in promoting the disease, provided the water be originally of a kind, like that of the New River, which never contains anything proceeding from cholera patients.

It follows, therefore, that mere impurity in the water does not predispose to, or in any way increase the prevalence of, cholera; and that the disease, when influenced by the water, is really due to the specific cause of cholera contained in the water.

Those who dissent from the opinion, that the water promotes the prevalence and fatality of cholera, by containing the specific cause of the disease, generally believe that the ordinary impurities in the water act as what they call a predisposing cause. But a predisposing cause is one which is supposed to prepare the patient to be acted on by some more direct cause; and it must, therefore, require a certain time for its operation. But I met with many instances last summer of persons being fatally attacked with cholera in the south districts of London, very soon after arriving from a healthy part of the country, and drinking the water of the Southwark and Vauxhall Company. Some of them were attacked within forty-eight hours after their arrival. Many cases occurred also in the neighbourhood of Broad-street, Golden-square, last autumn, of persons who were not in the habit of drinking the water of the pump in that street, who yet were fatally attacked with cholera after taking the water contrary to their [34/35] usual position. I have notes of many such instances, but will mention only one, that of a family of three persons, at 51, Poland street, who were all attacked on the 1st of September, and died on the same day. They were not in the habit of drinking the water from this pump, but had a jugful on the evening of August 31. My informant was the brother of the deceased woman. He fetched the water on one of those evenings, and saw a sister who survives go for it on the other evening. There were several instances also of families and individuals who were in the constant habit of drinking it at the time of the great outbreak of cholera, escaped the malady. The above circumstances show that the water did not act as a predisposing cause, but must have contained the real and efficient cause of the cholera.

Anything which is supposed to act as a predisposing cause is generally believed to produce its effects by lowering the general health and reducing the strength; but observation shows that cholera attacks individuals of all kinds indiscriminately, when they are exposed to the influence of its specific morbid poison. We may ascertain, from a table constructed by Dr. Guy, that in 1849, some of the occupations which suffered more from cholera that any others were those in which the men are extremely strong and robust, and follow an out-door employment. The seamen and ballast-heavers suffered excessively; 1 in 24 of their whole calculated number died; whilst the coalporters and coalheavers suffered nearly as much, since 1 in 32 of their number died. In the last epidemic also, the men in these occupations suffered severely, but the numbers have not yet been calculated. The reason of those persons suffering so excessively from cholera is, that they draw the water they drink from alongside the ship, and, therefore, have a greater chance of getting the cholera poison in a fresh and unimpaired state, than when it has to pass through the reservoirs and pipes of a water company. It is quite evident to any one acquainted with these men, that the Thames water does not produce cachexia, or gradually undermine the strength.

[Part 2 appeared in the 28 July issue.]