600 Hog-cholera 



of a nail with a flat head. There is nothing characteristic 

 about it. 



Agar-agar. Linear cultures upon agar-agar present a 

 translucent, circumscribed, grayish, smeary layer without 

 characteristic appearances. 



Potato. Upon potato a yellowish coating is formed, 

 especially when the culture is kept in the thermostat. 



Bouillon. Bouillon made with or without peptone is 

 clouded in twenty-four hours. When the culture is allowed 

 to stand for a couple of weeks without being disturbed, a 

 thin surface growth can be observed. 



Milk. Milk is* an excellent culture medium, but is not 

 visibly changed by the growth of these bacteria. Its reac- 

 tion remains alkaline. 



Vital Resistance. The bacillus is hardy. Smith found 

 it vital after being kept dry for four months. It ordinarily 

 dies sooner, however, and I have experienced difficulty in 

 keeping it in the laboratory for any length of time unless 

 frequently transplanted. The thermal death-point is 54 C., 

 maintained for sixty minutes. 



Metabolic Products. Gas-production. The hog-chol- 

 era bacillus is a copious gas-producer, capable of break- 

 ing up dextrose and lactose into CO 2 , H, and an acid, which, 

 formed late, eventually checks its further development. It 

 does not ferment saccharose. 



Indol. No indol and no phenol are formed in the culture 

 media. 



Toxin. In pure cultures of the hog-cholera bacillus 

 Novy* found a poisonous base with the probable composition 

 C 16 H 26 N 2 , which he gave the provisional name "suso toxin." 

 In doses of 100 mg. the hydrochlorid of this base causes con- 

 vulsive tremors and death within one and one-half hours in 

 white rats. He has also obtained a poisonous proteid of 

 which 50 mg. were fatal for white rats, and which immu- 

 nized them against highly virulent hog-cholera organisms 

 when administered by repeated subcutaneous injection. 



De Schweinitz f has also separated a slightly poisonous 

 base which he calls "sucholo toxin," and a poisonous proteid 

 that crystallizes in white, translucent plates when dried over 

 sulphuric acid in vacua, forms needle-like crystals with pla- 

 tinic chlorid, and was classed among the albumoses. 

 * "Medical News," 1900, p. 231. 

 | Ibid., p. 237. 



