Our first sidelight on this question came in rather a surprising manner. It was taken for granted, almost as axiomatic, that if the conditions of savage life were such as to discourage, if not prevent, tuberculosis, certainly, then, the race which had been exposed to these conditions for countless generations would have a high degree of resisting power to the disease. But what an awakening was in store for us! No sooner did the army surgeon and medical missionary settle down in the wake of that extraordinary world-movement of Teutonic unrest, which has resulted in the colonization of half the globe within the past two or three hundred years, than it was discovered that, although the hunting or nomad savage had not developed tuberculosis, and the disease was emphatically born of civilization, yet the moment that these healthy and vigorous children of nature were exposed to its infection, instead of showing the high degree of resisting power that might be expected, they died before it like sheep. From all over the world--from the Indians of our Western plains, the negroes of our Southern States, the islanders of Polynesia, New Zealand, Hawaii, Samoa--came reports of tribes practically wiped out of existence by the "White Plague" of civilization. To-day the death-rate from tuberculosis among our Indian wards is from _three to six times_ that of the surrounding white populations. The negro population of the Southern States has nearly three times the death-rate of the white populations of the same states. Instead of centuries of civilization having made us more susceptible to the disease than those savages who probably most nearly parallel our ancestral conditions of a thousand to fifteen hundred years ago, we seem to have acquired from three to five times their resisting power against it. Not only this, but those races among us which have been continuous city-dwellers for a score of generations past have acquired a still higher degree of immunity. In every civilized land the percentage of deaths from tuberculosis among the Jews, who, from racial and religious prejudices, have been prisoners of the Ghetto for centuries, is about half to one-third that of their Gentile neighbors. In certain blocks of the congested districts of New York and Chicago, for instance, the Jewish population shows a death-rate of only one hundred and sixty-three per hundred thousand living, while the Gentile inhabitants of similar blocks show the appalling rate of five hundred and sixty-five. Similarly, by a strange apparent paradox, the highest mortality from tuberculosis in the United States is not in those states having the greatest urban population, but, on the contrary, in those having the largest rural population. The ten highest state tuberculosis death-rates contain the names of Tennessee, Kentucky, West Virginia, Virginia, and South Carolina, while New York, Pennsylvania, and Massachusetts are among the lowest.