The plague resembles cholera in being much promoted by crowding and want of personal cleanliness. The natives of Gurhwal, a province in the north-west 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.[[34]]
MODE OF PROPAGATION OF YELLOW FEVER.
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.[[35]] 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.[[36]] 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.[[37]] 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.[[38]] 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 diarrhœa was very prevalent in Croydon, 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 diarrhœa 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.
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 miasmata, much less of their nature.
CAUSE OF INTERMITTENT FEVERS.
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,”[[39]] 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 neighbouring 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 ditch water.
M. Boudin[[40]] 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.”