was contaminated in various ways, but especially from an overflow pipe at the water works which permitted the occasional reflux of the water of the much polluted river Hiz into the tank.1

There are also instances in which the infection has been conveyed by milk, and in a few of these it has been demonstrated that the cans have been washed or the milk adulterated with polluted water.

(377) Prevention of Typhoid.

The doctrine is now firmly established that the infection is alone carried in the discharges from the bowels, hence there is no danger whatever in nursing cases of typhoid, nor in treating them at home, always provided that the nursing is skilled and efficient, and this cardinal fact is borne in mind. The motions themselves should always be passed into a strong disinfectant; and remembering that the typhoid bacillus on expulsion from the body is in the spore state, it is doubtful whether the sulphate of iron recommended by Dr. W. Budd is sufficiently trustworthy, for after all, ferrous sulphate is not a disinfectant of the highest rank, and it is preferable to use a 2 per cent. solution of corrosive sublimate, dissolved by means of ammonium chloride in water; this should always be placed in the bed-pan or receptacle, nor is it wise to cast immediately the discharges thus disinfected into drains, cesspits or sewers. All disinfection requires time, and at least two hours should elapse before the dejecta are thrown away. A supply of the usual weak corrosive sublimate solution 1 per 1,000 should be kept for the nurses to wash their hands in, if soiled; it is specially necessary that the hands before meals should be washed in this solution. It would naturally be far more efficacious to burn all excreta by receiving it in sawdust and cremating it in a special furnace, but this can only be done in hospitals or where special facilities are at hand. All bed-linen and bedding soiled by discharges should be thoroughly disinfected; the linen may be boiled,

1 The student may also peruse with profit the following Reports:-Report by Mr. Power on an Outbreak of Fever at Norwood, L. G. B. Med. Off. Rep. for 1882; Report by Dr. Blaxall on Enteric Fever at Sherborne, ibid.; Report by Dr. Airy on an Outbreak of Fever at Melton Mowbray, L. G. B. Med. Off. Rep. for 1881; Report by Dr. Page on Enteric Fever at Beverley, L. G. B. Med. Off. Rep. for 1884; Report by Mr. Shirley Murphy on the Outbreak of Enteric Fever at St. Albans. (In this case there was good evidence of specific contamination of the milk supply.) L. G. B. Med. Off. Rep. for 1884.

the bedding should go to the hot air or steam apparatus, and be exposed at least four hours to a heat of 115° to 120° F.

In country villages, where typhoid breaks out again and again every autumn, and no special sanitary defect is discovered, the whole area of the soil is probably infected, and the only way to deal with such places in the absence of obvious causes is, I believe, to close existing water supplies, no matter how pure they may seem to be, and to change them altogether, if this can be done. How far in these cases the application round each household of a powerful disinfectant to the soil itself, as well as to the drains may be of service has yet to be proved. A constant series of cases occurring regularly in the autumn among children, would point to the probability of the soil itself being infected, for as is well known children sit about on the ground, continually have earth-soiled hands, and in this way contaminate their food. In any case the presence or absence of typhoid in rural communities is an excellent test of sanitation. If present, it is the duty of the Medical Officer of Health to study very closely the water supply, the sewerage disposal, and the earth contamination of the area, and to remedy any defects which he may discover.

ASIATIC CHOLERA.

(378) History of Cholera in England.

The first description of cholera is generally held to have been given by Garcia del Huerto, a physician of Goa, about 1560. As a disease attacking a number of people, and when introduced into a community rapidly spreading, it is without doubt a modern disease. Had it prevailed in ancient times, there would certainly have been a record of its ravages. The date at which it appeared in India is put at 1777, but at this time it was not generally diffused. In 1817, cholera was more or less prevalent through the whole of India, and from this date India may be considered the home of cholera, and from this date onwards India has exported its cholera infection at irregular intervals to Europe.

The history of cholera is complicated and confusing, and its literature voluminous; in this work written for English readers, it will be best to confine the attention entirely to our own island.

Cholera has visited England four times, the dates being 1831, 1849, 1854, 1866. In 1831 it first appeared in October; at that time there was no registration of the causes of death, but the deaths of 52,547 persons from cholera were reported through various channels to the Board of Health. The important practical observation was made that cholera was usually preceded by preliminary diarrhoea; and house to house visitation with the early administration of medicine, seemed to arrest the farther development of the disease in not a few instances.

(379) Epidemic of 1848-9.

In the 1848-9 epidemic, the disease was studied by a number of observers well qualified to trace out cause and effect. This epidemic taught us to look closely on the water and the soil as the chief factors that had to do with diffusion. For instance, in London, the districts supplied with water taken from the Thames above Battersea, had a mortality of 15 per 1,000; districts supplied with water from the New River, the Lea, and the Ravensbourne, 48 per 1,000; districts supplied with Thames water taken below Battersea Bridge (between Battersea and Waterloo Bridge), 123 per 1,000; in other words, the populations drinking different portions of the same river, suffered from cholera in proportion to its pollution, for it is scarcely necessary to observe that the water of the Thames above Battersea was much

purer than below Battersea. Another discovery made in the 1849 epidemic with regard to London was the relationship of cholera mortality to elevation. Dr. Farre, writing his report of the epidemic said, "The elevation of the soil in London has a more constant relation with the mortality from cholera than any known element. The mortality of the nineteen highest districts was at the rate of 33 per 10,000, and of the nineteen lowest districts 100 in 10,000. The elevation in the two groups above the highwater mark of the Thames was as 71 to 10 feet (7·1). While the mortality was as 13 or in the inverse ratio . . . Cholera was excessively fatal in all the four districts which lie on a level with or below the Trinity high-water mark; it destroyed 144, 164, and 505 in 10,000 inhabitants. Notwithstanding the disturbance produced by the operation of other causes, the mortality from cholera in London bore a certain constant relation to the elevation of the

soil, as is evident when the districts are arranged in the order of their altitude. We place the districts together which are not on an average 20 feet above the Thames, and find on these bottoms of the London basin the mortality was at the average rate of 102 per 10,000; in the 2nd group at 20 and under 40 feet elevation, or on the second terrace, the mortality from cholera was at the rate of 65 in 10,000; in the 3rd group, or on the third terrace, 40-30 feet high, the mortality from cholera was at the rate of 34 in 10,000; in the 4th group 60-80 feet high, the mortality from cholera was at the rate of 27 per 10,000; in the 5th group 80 to 100 feet high, the mortality was at the rate of 22 per 10,000; in a district 100 feet high, the mortality was 17 per 10,000; in Hampstead, about 350 feet high, it was 7 in 10,000."

The system of registration had been in force since 1837, hence for the first time an accurate computation of the mortality was made. According to the official returns 53,293 died of cholera and 18,887 of diarrhoea.

(380) Epidemic of 1854.

In 1854, Sir Benjamin Hall was President of the Board of Health; he obtained the assistance of a medical council, aided by others well versed in chemistry and microscopy. This medical council or "scientific committee," studied more particularly and closely the distribution of cholera in the metropolis, and the result of their inquiries was summarised and expounded in a masterly report by Mr. Simon. "As often," said Simon, "as Asiatic cholera had been epidemic in London, it had been observed to prevail with especial severity in certain registration-districts on the south side of the river; viz., in St. Saviour's, St. Olave's, and St. George's, Southwark, in Bermondsey, Newington, Lambeth, Wandsworth, Camberwell, and Rotherhithe." He next proceeds to show that the conditions of these populations were precisely the same save in the quality of the water consumed in different households. "For throughout those southern districts of London, two great competing water companies had in past times canvassed house by house for their customers; their rival mains were still branching in the same area, often running parallel in the same streets; and during the late invasion of cholera, these two systems of pipes were respectively charged with very different waters.

"If, during the epidemic prevalence of cholera persons consuming pure water are less liable to suffer the disease than persons consuming foul water, surely there might be expected some striking difference between the death-rates of two populations respectively drinking from the Thames at Ditton and from the Thames at Battersea.

"And such were the sources of supply of the two companies referred to; the Lambeth Company pumping from the higher part of the river, the Southwark and Vauxhall Company from the lower; the former furnishing as good a water as any distributed in London, while the latter was purveying perhaps the filthiest stuff ever drunk by a civilized community. . . In the 24,854 houses supplied by the Lambeth Company, comprising a population of about 166,906 persons, there occurred 611 cholera deaths, being at the rate of 37 to every 10,000 living. In the 39,726 houses supplied by the Southwark and Vauxhall Company, comprising a population of about 208,171 persons, there occurred 3,476 deaths, being at the rate of 130 to every 10,000 living.

"The population drinking dirty water accordingly appears to have suffered three times as much mortality as the population drinking other water."

(381) The Broad Street Pump.

It was also in the epidemic of 1854 that the report of the water supply of the Broad Street pump exercised much influence on popular and scientific opinion. The water in the well, which was undoubtedly contaminated with sewage, was said to have been specifically polluted by the cholera excreta of a child who suffered from cholera from August 28th to the 30th. The cases of sickness and deaths among the consumers of this pump water are given as follows:

1 Report on Cholera Outbreak, St. James's, Westminster.