18 POISONOUS PKOTEINS 



secured evidence of the presence of xanthine 

 bases. 



Bacterial cellular substance responds to all 

 the protein reactions. Proteins are detached 

 from the substance by both alkalis and acids, 

 but the properties of the bodies thus obtained 

 indicate that they are split products obtained 

 by the cleavage of more complex molecules, and 

 do not exist free in the cellular substance. Di- 

 lute mineral acid splits off. the nitrogenous car- 

 bohydrate and when this extraction is carried 

 on at high temperature much of the second car- 

 bohydrate is converted into a reducing sub- 

 stance. The acid extracts when dropped into a 

 large volume of alcohol give a precipitate which 

 after purification by resolution in water and re- 

 precipitation with alcohol yields more than 

 seven per cent of phosphorus. The line of 

 cleavage through the large molecules in the cel- 

 lular substance followed by acid action seems 

 to be definite and the same products are ob- 

 tained with one per cent and 0.1 per cent sul- 

 phuric acid. More concentrated acids after 

 prolonged heating break deeper into the molec- 

 ular structure and cleave the biuret bodies with 

 the liberation of amino acids. Wheeler and 

 Leach have made special studies of the action 

 of mineral acids on bacterial cellular substance. 



