Page:Popular Science Monthly Volume 48.djvu/741

Rh where this malady strikes down the first cross—the mulatto or the half-breed—all further assimilation of the races is at an end.

The list of ethnic diseases might be greatly extended, but enough has perhaps been said to indicate the importance of eliminating it before entering upon the discussion of acclimatization per se. The predisposition of the negro for elephantiasis and tetanus, his sole liability to the sleeping sickness, so severe that in some localities the black is utterly useless as a soldier, his immunity from cancer and his liability to skin diseases in general, together with his immunity from yellow fever and bilious disorders, are well-recognized facts in anthropology. The Mongolian type appears to be likewise free from inflammatory diseases, and oftentimes from cholera to some extent; as well as from beriberi, which is so peculiar to the Malay stock that it may be traced in the Japanese kak ké. The Polynesians are immune from scarlet fever, and it is said that the Japanese can not even be inoculated with it. This again is an illustration of the same persistence of pathological predispositions, since the partial affinity of the Japanese to the Polynesian race is well established. Modern investigation is bringing out similar examples of the constancy of racial diseases among the modern peoples of Europe. Dr. Chibret affirms that the Celtic type is immune from "trachoma," or epidemic granular conjunctivitis, which has often seriously ravaged the rest of Europe. * Spreading in the Belgian army, it passed over the Walloons; and in the central plateau of France attacking strangers alone; it passed over southern Bavaria, even when contracted by a Celt, speedily becoming benign. The only exception to this racial immunity is that of the Piedmontese, otherwise it never extends above the two hundred metre Celtic boundary.