134 BACTERIAL POISONS. 



the chemical products of the germs x, a, and A of Booker's 

 list in the following manner and with the results as stun <! 

 below. 



Of these germs, BOOKER makes the following statements : 



" x was found almost as a pure culture in the feces of a 

 fatal case of diarrhoea, a was strongly pathogenic when 

 tested last winter. A was isolated last summer ; liquefies 

 gelatin, and belongs to the proteus group." 



Beef-tea cultures of each of these germs were made and 

 kept in an incubator at 37 for forty-eight hours. At the ex- 

 piration of this time these cultures were used for inoculating 

 flasks of sterilized beef-broth. Eight flasks, each contain- 

 ing about ten ounces, were employed for each germ. These 

 cultures were kept in the incubator at 37 for ten days. 

 They were then twice filtered through heavy Swedish filter- 

 paper. The second filtrate was allowed to fall into a large 

 volume of absolute alcohol feebly acidified with acetic acid. 

 A voluminous, flocculent precipitate resulted in each case. 

 After the precipitates had subsided the supernatant fluid 

 was decanted. The precipitates were then treated with dis- 

 tilled water, in which those from x and a were soluble, 

 while that from A proved insoluble. A large volume of 

 absolute alcohol was again added, and the mixture allowed 

 to stand for four days. The precipitates from x and a com- 

 pletely subsided, leaving the supernatant fluids perfectly 

 clear; but in the case of A the subsidence was not com- 

 plete. The precipitates were collected, by decantation and 

 filtration, on porous plates, and dried over sulphuric acid. 

 These substances are proteid in composition, but differ from 

 known proteids and from one another That from x is 

 slightly yellow, as seen deposited in the alcohol, but be- 

 comes grayish on exposure to the air. It is readily soluble 

 in water, from which it is not precipitated by heat or nitric 

 acid, singly or combined. 



It gives the biuret and xantho-proteid reactions. It is 

 precipitated by saturating its aqueous solution with ammo- 

 nium sulphate, and therefore cannot be classed with the 

 peptones. Sodium sulphate and carbonic acid fail to throw 



