BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 123 



egg-albumin or blood-serum, was able to change the protein 

 sufficiently without requiring ameba or bacterial digestion. 



The leprous nodule is cut in small slices and spread over 

 an albumin slant or Petri plate, and the surface covered with 

 i per cent, solution trypsin and placed in oven at 37 C. for 

 ten days. 



The growth is moist and becomes yellow after several 

 generations; it is on surface. 



Staining. B. lepra resist the decolorizing action of acids, 

 as the tubercle bacilli, but they are more easily stained, re- 

 quiring but a few minutes more with the ordinary watery solu- 

 tions. They take Gram's stain readily. 



Pathogenesis. Arning inoculated a prisoner with tissue 

 obtained from leprous patients and produced true leprosy, 

 but this was a susceptible native and the evidence is not 

 clear. Duval, by repeated injections of large amounts of 

 pure culture, has produced leprosy in mice, guinea-pigs, and 

 monkeys. 



Rabbits which have been infected through the anterior 

 chamber of the eye showed the lepra nodules (containing the 

 lepra bacilli) diffused through various organs. 



In man the skin and peripheral nerves are principally 

 affected, but the lymphatic glands, liver, and spleen can also 

 become the seat of the lepra nodules. The lepra cells which 

 compose these nodules contain the bacilli in large numbers. 

 By applying a vesicant to the leprous skin, the serum there- 

 by obtained will contain great numbers of bacilli. This is a 

 simple diagnostic test. 



Method of Infection. Not yet determined; the air, soil, 

 water, and food of leprous districts have been carefully ex- 

 amined without result. The nasal secretion is very infectious. 

 Intimate contact over a long period seems necessary, but the 

 records of leper asylums show that very few cases ever de- 

 velop among the attendants. 



Smegma Bacillus of Alvarey and Tavel. Lustgarten, in 

 1885, through a certain staining process, found peculiar 

 bacilli in syphilitic tissues which he thought had a direct 



