IMMUNITY 179 



anthrax or glanders when fed with large quantities of infected material, 

 but this is not comparable with natural infection. Smith reports 

 tuberculosis, due to human bacilli, in a tame bear whose master had the 

 disease. Possibly with closer association such cases would be more 

 frequent. Man seems to possess complete immunity to rinderpest, and 

 apparently none of our domestic animals are susceptible to scarlet 

 fever or measles. The immunity of the lower animals to cholera and 

 typhoid fever may be due to their normal intestinal bacteria. 



When we confine our attention to man, variations in susceptibility 

 among the races is not so great as was once believed. Livingstone 

 found no trace of syphilis among the Africans and believed these people 

 to be immune to this infection, but as early as 1867, Fritsch reported 

 it rare but saw occasional cases which he attributed to contact with the 

 white man. More recently, this disease has become common in the 

 Congo and coast colonies, and in Uganda it is said to have become a 

 veritable plague. Mense states that the bearers of culture have car- 

 ried the gifts of civilization and the scourge of venereal disease to 

 trustful savages. However, venereal diseases are not the only ills 

 which have been disseminated by the white man. Indeed, if the pres- 

 ent opinion concerning the introduction of syphilis into Europe be true, 

 it was one of the jewels borne to Spain by the sailors who accompanied 

 Columbus on his first voyage. Smallpox did much to aid the Spaniard 

 in his conquest of Mexico, and measles and tuberculosis have played 

 important roles in reducing the red man in America. According to 

 Calmette, the white man has done much in spreading tuberculosis to 

 other races and conditions of men. 



Hahn points out that in countries occupied by two races or by 

 peoples of different religions, apparent differences in susceptibility are 

 due to material conditions in life. One race lives more hygienically 

 and more intelligently than the other. This is especially true of those 

 infections which afflict principally the poor and ignorant classes. In 

 India and in the Philippines plague and cholera prevail quite exclu- 

 sively among the natives, while Europeans and Americans live for the 

 most part in safety. In the cholera epidemic in Astrakhan in 1892, 

 the Armenians suffered but little while the Tartars died in great num- 

 bers. Much has been written about the comparative freedom of the 

 Jew in Western Europe and in America from tuberculosis and this 



