Page:Popular Science Monthly Volume 29.djvu/315

Rh case of the former is local and not climatic, and is due to the circumstance that the site of the city is "a bowl in the mountains," so that drainage from it is now, and always has been, very difficult. And, as years have passed, and the population living within the bowl has multiplied, the evil has continually increased, until Lake Tezcoco, which borders the city, and on which Cortes built and floated war galleys, has been nearly filled up with drainage deposits which have been carried into it through an elaborate system of city sewers. If these sewers ever had fall enough to drain them, they have, as the result of the filling up of this lake, little or none now, and the result is that they have become in effect an immense system of cess-pools; while the soil, on which from 250,000 to 300,000 people live, has become permeated throughout with stagnant water and filth inexpressible. And were it not for the extreme dryness and rarefaction of the air, which, as before pointed out, prevent the putrefaction of animal substances, and seem to hinder the propagation of the germs of disease, the city must long ago have been visited with plague, and perhaps have been rendered absolutely uninhabitable. And, even under existing circumstances, the average duration of life in the city of Mexico is estimated to be but 26·4 years. Typhoid fever prevails all the year round, and is especially virulent at the end of the dry season, when the heat is the greatest. And, surprising as it may seem, with a climate of perpetual spring and an elevation of 7,500 above the sea-level, lung and malarial diseases hold a prominent place among the causes of death. According to the reports of the Board of Health of the Mexican capital for April and May of the present year (1886), thirty-three per cent of the weekly mortality at that season was to be referred to typhoid and other forms of gastric fever, and twenty per cent to consumption and pneumonia. In the year 1877, when a typhus epidemic prevailed, the city's mortality was reported to have been as high as 53·2 per thousand as compared with an average death-rate of 24*6 in Paris for the same year. "A distinguished member of the medical faculty of Mexico has lately published a report, in which he demonstrates, by comparative statistical tables, that the annual mortality of the city is increasing to such an extent as already to counterbalance the natural movement of the population, and, if not checked in time, as threatening the race." —"United States Consular Reports," No. 3, 1881, p. 18.

This condition of affairs is not due, as some might infer, to any improvidence or want of enterprise on the part of the Mexicans, for