Cultivation 767 



lus upon media free from sodium chlorid. The technic of his 

 method is thus described by Rudolph*: "Small lumps of 

 pumice stone are washed and then dried in the sun, and then 

 allowed to absorb a mixture of i ounce of meat extract and 

 2 ounces of water. This pumice stone is then placed in 

 wide-mouthed bottles and placed in the autoclave. Each 

 bottle is provided with a stopper through which pass two 

 tubes, the one tube opening into the autoclave and reaching 

 nearly to the bottom of the bottle, and the other leading from 

 the top of the bottle into a condenser adjoining. When the 

 cover of the autoclave is adjusted and the steam admitted, 

 then in the case of each bottle, the steam passes by the one 

 tube to the bottom of the bottle, and rising through the 

 pieces of pumice stone, the steam, carrying with it the volatile 

 constituents of the meat-extract, reaches the condenser by 

 the second tube. The vapor in the condenser yields the 

 salt-free nutrient medium in the proportion of 2 liters to 

 each ounce of meat-extract originally used. The medium is 

 collected from the condenser in sterilized Pasteur flasks which 

 are kept plunged during the process in a freezing mixture 

 in order to condense some of the volatile alkaloids from the 

 beef that would otherwise escape. The nutrient fluid is 

 now inoculated with the bacillus of leprosy and the flasks 

 kept at 37 C. for from four to six weeks; at the end of this 

 period when examined the flasks should present a turbid 

 appearance with a stringy white deposit." 



Cleggt announced the cultivation of lepra bacilli from 

 human leprous tissue in symbiosis with ameba and other 

 bacteria. The organisms thus cultured he kept alive in 

 subcultures. The method devised by Clegg was the starting- 

 point of a more extended research by Duval, J who, after con- 

 firming the work of Clegg, found that the bacillus could be 

 cultivated directly from human lesions upon culture-media 

 containing tryptophan, without the symbiotic ameba or other 

 bacteria. The initial culture was somewhat difficult to 

 secure, but once the bacilli grew T , transplantation was easily 

 and successfully carried on for indefinite generations. He 

 further found that the lepra bacillus could be successfully 

 started to grow upon the ordinary laboratory media if bits 

 of leprous tissue were placed upon them, and at the same time 



* "Medicine," March, 1905, p. 175. 



f "Philippine Journal of Science," 1909, iv, 403. 



J "Journal of Experimental Medicine," 1910, xn, 649; 1911, xm, 365. 



