154 APPLIED BACTERIOLOGY 



vera of leprosy still remains unsettled. There seems to be 

 some evidence to prove that it is not spread by contagion 

 or heredity, though there are examples which appear to 

 favour both. As recently as 1897, Ehlers of Copenhagen 

 has re-affirmed his belief in the contagiousness of leprosy, 

 whilst Virchow has declared that it is not highly contagious. 

 This matter was so carefully investigated by the Leprosy 

 Commission in India that it may be well to repeat here 

 their conclusions (Leprosy Commission in India Keport, 

 p. 384) : 



(1) ' Leprosy is a disease sui generis ; it is not a form of 

 syphilis or tuberculosis, but has strictly etiological analogies 

 with the latter. 



(2) ' Leprosy is not diffused by hereditary transmission, 

 and for this reason, and the established amount of sterility 

 among lepers, the disease has a natural tendency to die out. 



(3) ' Though in a scientific classification of diseases 

 leprosy must be regarded as contagious, and also inoculable, 

 yet the extent to which it is propagated by these means is 

 exceedingly small. 



(4) ' Leprosy is not directly originated by the use of any 

 particular article of food, nor by any climatic or telluric 

 conditions, nor by insanitary surroundings ; neither does it 

 peculiarly affect any race or caste. 



(5) ' Leprosy in indirectly influenced by insanitary sur- 

 roundings, such as poverty, bad food, or deficient drainage 

 or ventilation, for these, by causing a predisposition, in- 

 crease the susceptibility of the individual to the disease. 



(6) ' Leprosy in the great majority of cases originates de 

 novo, that is, from a sequence or concurrence of causes 

 and conditions, dealt with in the report, and which are 

 related to each other in ways at present imperfectly 

 known.' 



At thfe great Leprosy Congress held in Berlin, October, 



