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638 they drink. The same was shown in Egypt in I880, in France in 1884, and again in the department of Finistère almost at the present time.

In Italy, Naples has afforded one of the most striking examples of the same thing. Commencing in August, 1884, the epidemic spread by rapid strides until September 11th, and then rapidly fell. Between August 23d and November 9th some 12,345 cases and 7,086 deaths occurred among a population of 402,908. At that period the water supply of Naples was mainly derived from trenches running from house to house underground, and was exposed to direct contamination not only by soakage of filth, but by the reckless practice of washing in the trenches linen soiled by choleraic discharges.

In the following year Naples was supplied with pure water from a distant mountain stream (the Serino), and there followed a marked immunity of the city from cholera, notwithstanding the presence of the disease in the neighborhood. In 1887, however, an injury to the Serino water conduit led to a temporary return to the old system, and two sharp explosions of cholera at once ensued, but ceased on the resumption of the purer supply. Even more demonstrative was the case of Genoa, a city provided by means of three aqueducts with an excellent supply of a naturally good water. After a few scattered cases a sudden and widespread explosion of cholera occurred between September 21st and 24th, the rich and the poor being indiscriminately attacked. It was soon found that of the first three hundred cases ninety-three per cent were in houses supplied by one of those aqueducts (the Nicolay), and on following that watercourse to its commencement near the village of Busalla, thirteen miles distant, a colony of workmen was found encamped. Cholera had broken out in Busalla on September 14th, and inquiry disclosed the fact that the clothing of the workmen, both of the sick and the healthy, was washed in the river Scrivia, which feeds the Nicolay aqueduct. The supply of this water to Genoa was promptly stopped on September 28th, and the epidemic at once rapidly declined.

Everywhere the same tale is told, but my present immediate object is to insist that also in India, the "home of cholera," it is now clear—to me at least—that water is the agent by which the infection is carried from one human being to another.

The experiences of Calcutta, as observed by Dr. W. J. Simpson, the able health officer of that city, show that those persons who have an abundant and pure water supply—namely, the Europeans and better-class natives—escape cholera epidemics, except in isolated instances which can generally be accounted for; while the natives who depend on tank water suffer severely when a tank becomes polluted by the excreta of a cholera patient.