134 LEPROSY AND SYPHILIS. 



daylight, has succeeded on fish agar in producing a markedly 

 chromogenic growth, varying in color from a pale lemon yellow 

 to a dark chocolate brown. The culture has a sticky, tenacious 

 consistence and dries out rapidly at incubator temperature, 

 less so at room temperature or in a cool place. After the or- 

 ganism has once been started on the artificial media it seems 

 to grow with more or less readiness on nearly all media. 



The Bacillus leprce stains very readily with the anilin dyes, 

 and also by Gram's method. It very greatly resembles the 

 tubercle bacillus in retaining its color when subsequently 

 treated with strong solutions of mineral acids. 



An interesting point about the staining of the Bacillus 

 leprce which will permit differentiation from the Bacillus tuber- 

 culosis is that the lepra bacillus is rapidly stained by the 

 Gram method, while the tubercle bacillus stains with great 

 difficulty by it, and must remain at least twenty-four hours 

 in the color dish before taking the stain. 



Baumgarten's differentiation between these two bacteria is 

 to subject cover-glass preparations which have been smeared 

 with scrapings from leprous nodules or ulcers for five minutes 

 in the Ehrlich solution, and afterward to decolorize with solu- 

 tion of nitric acid in alcohol, 1 part of acid to 10 parts of 

 alcohol. The bacillus of Hansen will be stained, while the 

 tubercle bacillus will not. 



A number of investigators have by inoculation with fresh 

 extirpated leprous tissue succeeded in reproducing the disease 

 in the lower animals. Tedeschi inoculated a monkey under 

 the dura mater, and death resulted in six days. Many lepra 

 bacilli were found in the spleen and spinal cord at the 

 autopsy. 



Nature of Leprosy. Besnier, with many others, contends 

 that leprosy is a bacterial disease exclusively limited to man, 

 and that the microorganisms will reproduce themselves in 

 man alone, and not in animals. 



Dyer, from observation of leprosy in fifty cases in Louis- 

 iana, concludes positively that the direct cause of the disease 

 is the lepra bacillus. The indirect cause is contagion. The 

 disease therefore is not hereditary. 



