SUGAR IN THE NUTRIENT MEDIUM. 135 



1. Bacterial Proteins (Buchner). This term refers 

 to certain albuminoid substances which produce fe- 

 ver (pyogenic) and inflammation (phlogogenic). 

 They are obtained by boiling, for several hours, po- 

 tato cultures together with one-half-per-cent potash 

 lye (about fifty volumes potash to one volume bac- 

 terial substance). The clear fluid, filtered through 

 paper, allows the precipitation of the proteins after 

 careful feeble acidulation. The proteins may then 

 be washed, dried, and, before using, dissolved in a 

 weak solution of soda. 



The best-known protein is Koch's tuberculin. Mal- 

 lein also belongs to this category. According to 

 Buchner and Hoemer all bacterial proteins have es- 

 sentially the same action. According to Mathes deu- 

 teroalbumose, which is obtained by the action of 

 pepsin on albumin and has no connection whatever 

 with bacteria, produces the same effects on tubercu- 

 lous guinea-pigs. 



2. " Toxalbumins." C. Fraenkel and Brieger 

 (Deut. med. Wschr. , 1890, 4 and 5) confirmed in great 

 measure the statements of earlier observers (Christ- 

 mas, Koux and Yersin, Hankin) that measures which 

 precipitate albumin will also precipitate from the 

 bouillon cultures of many bacteria amorphous poisons 

 which exert an intense and usually specific (similar 

 to the living culture) toxic action. They called these 

 poisons toxalbumins and considered them analogous 

 to the toxic albuminoid bodies in many plants (ricin 

 in ricinus communis, abrin in abrus precatorius, 

 etc.). The majority of investigators regarded and 

 some still regard these poisons as " labile" albumi- 

 noids, which are derived from the bacterial cell. 



