Page:Popular Science Monthly Volume 14.djvu/156

144 against the use of animal food, and warned them that it would produce a disease which, like original sin, could only be cured by baptism, i. e., frequent shower-baths and invocations of the Great Spirit; and Bernal Diaz tells us that the subjects of Montezuma were afflicted with an eruptive disease, more painful though less incurable than leprosy, but that fevers made their first appearance with the Spaniards, and were long limited to the district of Toltepec (in the valley of Anahuac) and the Spanish quarter of the city of Tlascala.

In our cotton States, too. Baton Rouge, Vicksburg, and Memphis, on their high and dry bluffs, and Chattanooga, at an elevation of seven hundred feet above the level of the Gulf, have suffered more in proportion to their population than any place this side of Vera Cruz; while the swamps of the Red River and the Arkansas bottom-lands had not much to complain of besides their chronic "chills," and the ne-plus-ultra swamp, called Florida, has been entirely spared.

It is also known that the miasmatic virulence of alluvial districts is aggravated by excessive moisture and diminished by dry seasons, especially long, dry summers, which convert festering bogs into harmless steppes, and confine the swamp-belt of large rivers to a narrow strip along the lower shores. Now, if yellow fever, typhus, and cholera, were depending upon what physicians call telluric causes, i. e., the condition of the soil, in our more or less immediate neighborhood, wet years would be the most dangerous, whereas experience shows that, on the contrary, epidemics generally follow upon dry, hot summers, like the last and those of 1873 and 1868. These facts, which agree with the experience of the remotest countries and times, only confirm what dietetic reasons might indicate a priori, viz., that the so-called zymotic diseases have subjective rather than objective causes: they are produced by the unhealthy condition, not of the country so much as of the inhabitants, and originate in dry cities oftener than in swampy forests.

During the long centuries of the Juventus Mundi, forests and swamps were almost synonyms, as they still are in the lower latitudes of America and Eastern Asia. Animal life swarms and revels in such regions. Herbivorous and carnivorous animals, and our cousins the anthropoid apes, thrive in the moist woodlands of the torrid zone, and the Asiatic Malays, the natives of Soodan and Senegambia, and the aborigines of our own continent, have inhabited the swampiest districts of the tropical bottom-lands for ages with perfect impunity. They do not employ any of the antidotes by which the stranger hopes to secure himself against what he calls climatic influences, and that their immunity is not the inherited privilege of a special race is demonstrated by the diseases of the Mexican Indians, who have adopted the diet of their Spanish masters, and of the West African negroes, who have been carried to the far less swampy islands of the West Indian Archipelago. Dietetic differences alone can, therefore, furnish a logical