RELATIONS OF BACILLI TO THE DISEASE. 265 



vations have been made, but one after another has proved 

 to be erroneous. A similar statement may be made with 

 regard to experiments on animals. If a piece of leprous 

 tissue be introduced subcutaneously in an animal, such as 

 the rabbit, a certain amount of induration may take place 

 around it, and the bacilli may be found unchanged in appear- 

 ance weeks or even months afterwards, but no multiplica- 

 tion of the organisms occurs. The only exception to this 

 statement is afforded by the experiments of Melcher and 

 Orthmann, who inoculated the anterior chamber of the eye 

 of rabbits with leprous material, the inoculation being 

 followed by an extensive growth of nodules in the lungs 

 and internal organs, which they affirmed contained leprosy 

 bacilli. It has been questioned, however, by several 

 authorities whether the organisms in the nodules were 

 really leprosy bacilli, and up to the present we cannot say 

 that there is any satisfactory proof that the disease can be 

 transmitted to any of the lower animals. 



It would also appear that the disease is not readily 

 inoculable in the human subject. In a well-known case 

 described by Arning, a criminal in the Sandwich Islands 

 was inoculated in several parts of the body with leprosy 

 tissue. Two or three years later, well-marked tubercular 

 leprosy appeared and led to a fatal result. This experiment, 

 however, is open to objections, as the individual before 

 inoculation had been exposed to infection in a natural way, 

 having been frequently in contact with lepers. In other 

 cases inoculation experiments on healthy subjects, and 

 inoculations in other parts of leprous individuals have given 

 negative results. It has been supposed by some that the 

 failure to obtain cultures and to reproduce the disease 

 experimentally may be partly due to the bacilli in the 

 tissues being dead. That many of the leprous bacilli are 

 in a dead condition is quite possible, in view of the long 

 period during which dead tubercle bacilli introduced into 

 the tissues of animals retain their form and staining reaction. 

 There is also the fact that from time to time in leprous 

 subjects there occur attacks of a certain amount of fever, 



