HISTORY 



diminished rapidly in the fourteenth and fifteenth centuries, since 

 when the disease has almost disappeared from many parts of Europe. 



But while abating in Europe, it appears to have been introduced 

 into Madeira and the Canary Islands about the end of the fifteenth 

 century, and perhaps also into America by the Spaniards. The 

 infection of the West Indies would appear, however, to have been 

 mainly due to the negro slaves brought from Africa about the middle 

 of the sixteenth century, after which the disease became common. 

 There is great doubt as to whether it did not exist in South America 

 in ancient times, but no clear evidence is forthcoming at present. 



In India, Japan, and probably China, leprosy is most ancient, 

 while it is very common in South China. During recent years the 

 Chinese have been moving about the world, and are accredited 

 with introducing the disease into Kamschatka, the Sandwich 

 Islands, Polynesia, Columbia, Cahfornia, Australia, New Zealand, 

 and also into Indo-China. 



Though very common in North and Tropical Africa, it appears 

 to have been unknown in South Africa until introduced in 1756 

 by the Dutch from Java, who carried it through Cape Colony and 

 the Orange Free State into the Transvaal. It must, however, be 

 stated that some people think it has existed for a long time in 

 South Africa. 



It is said that the numbers of lepers have markedly increased in 

 South Africa since the advent of the East Indian troops in the 

 middle of last century. 



As regards medical literature. Hippocrates says but little about the 

 disease, and perhaps really refers to psoriasis, while Aristotle defines 

 it better. It is not, however, until the first century that Aretaeus 

 of Cappadocia gives a clear description of the disease, and not till 

 1847 that the first modern clinical account by Danielssen and 

 Boeck appeared. The pathology of the disease has been carefully 

 studied by Virchow, Vandyke Carter, Leloir, Babes, Unna, Zam- 

 baco, Innes, Campana, De Amicis, Philipson, Mantegazza, and 

 Bergmann. In 1871 Hansen discovered the bacillus, and in 1877 

 definitely associated it with the causation of leprous lesions, and it 

 has subsequently been studied by Neisser in 1879, many others. 



Many attempts have been made to cultivate this bacillus, notably 

 by the Indian Commission, van Houten and Rost, and more recently 

 by Keebrowsky, Clegg, Bayon, and Dnval. In 1903 Stephansky 

 and Dean, and later Rabinowitsch and Tidswell, discovered a 

 peculiar leprosy-like disease in rats, the lesions of which contain 

 bacilli closely resembling Hansen's bacillus in appearance, and 

 not capable of cultivation. A diphtheroid bacillus has, however, 

 been cultivated by Dean from two cases, and is said by him to be 

 capable of being agglutinated by human leprous serum. There is 

 probably no connection between the human and the rat disease, 

 though some authorities admit it. The condition has been recently 

 investigated by Marchoux and Sorel, Bayon, and others. 



The method of infection is at present unknown, though there are 



