616 INFECTION AND IMMUNITY. 



from Spain, and through these channels the disease 

 was carried to the southern states. The leprosy of 

 the western states seems to have been imported by 

 Norwegian immigrants chiefly. In 1902 the 

 United States leprosy commission found 278 cases 

 in this country. One hundred and eighty-six of 

 these individuals probably contracted the disease 

 in this country, 120 were born in foreign coun- 

 tries and 145 were native born. The disease also 

 extended around the globe in the opposite direc- 

 tion, reaching China, Japan and the East Indian 

 islands from India. The Sandwich Islands be- 

 came infected in the nineteenth century. 



The contagiousness of the disease appears to 

 have been recognized at a very early period. In 

 636 A. D. leprosy houses were instituted in Italy 

 and other countries, and the practice of segregat- 

 ing lepers soon became general. The hospitals 

 were called Lazarus houses in middle Europe and 

 St. George houses in Scandinavian countries. 

 Pipin and Charles the Great declared marriage be- 

 tween lepers illegal. The rapid disappearance of 

 leprosy in middle Europe during the sixteenth 

 century is ascribed largely to the segregation of 

 the patients. 



Bacillus of In 1872 Hansen announced that small rods, 

 sometimes intracellular and sometimes free, were 

 to be found constantly in teased preparations of 

 leprous tissue. These rods, leprosy bacilli, are 

 now universally recognized as the cause of the 

 disease, and in 1879 they were stained by Neisser 

 and a year later by Hansen. The organism is non- 

 motile, has about the dimensions of the tubercle 

 bacillus,, the same staining reactions, and fre- 



