adverse, had, until recently, no communication for thousands of years with the races of the Old World, among whom tuberculosis arose. Hirsch lays much stress on the susceptibility of Africans, as may be seen from the following:—
"No race or nationality enjoys a decided immunity from consumption; but in respect to the frequency of its incidence, the negro race takes first place. Proof of this is furnished by the medical reports from all those parts of the world to which the negro has migrated, and in the mixed population of which he forms a considerable ingredient: such as the United States, the West Indies, the Mosquito Coast, Brazil, the Argentine Republic, Peru, and Bolivia, Algiers, Egypt, the East African Islands, Ceylon and the East Indies.
"In the convict prisons of the United States, from 1829 to 1845, the average mortality from phthisis among the prisoners of the white race was 11·16 per 1000; but among the negroes confined in. the Eastern Penitentiary of Pennsylvania it was 4074, and in the Maryland Penitentiary 28·49; while among the coloured population living at large in New York it was 11 per 1000. At Wilmington, N.C., 0·9 of the whites died of phthisis in 1880, and of the blacks 2·6 (Wood). 'It is a remarkable fact,' says Bartolacci in his work on Ceylon, 'that of 9000 Kaffirs (negroes from the East Coast of Africa) who had been imported at various times by the Dutch Government into Ceylon, and had been drafted into regiments, scarcely a trace of their descendants remains; they would certainly not be recognized at all among the present population of the island. In the years 1803 and 1810 the British Government imported three or four thousand negroes from Mozambique into Ceylon to form into regiments, and of these in December 1820 there were left just 440, including the male descendants.'
"Whether this preponderance of phthisis among negroes is an affair of physiological predisposition due