164 



PA PA IN-PR TE OL YSIS. 



filtrate with the biuret test, giving due heed to the necessity 

 of adding sufficient potassium hydroxide to decompose all of 

 the ammonium salt present, an intense reaction for peptone was 

 obtained. Indeed, it was quite evident from the character of 

 the reaction that a fairly large percentage of true peptone had 

 been formed. 



A similar experiment was tried with coagulated blood-fibrin, 

 this form of proteid being warmed at 40 C. for two days 

 with 1 gram of papain in 800 c. c. of 0.4 per cent sodium 

 carbonate, a little thymol being present. On removal of the 

 proteoses with ammonium sulphate, as described above, a 

 strong biuret reaction was obtained in the filtrate, thus show- 

 ing the formation of true peptone. 



Obviously, one possible danger in experiments of this order, 

 where an alkaline fluid containing so much admixed proteid 

 is warmed at 40 C. for two or three days, is bacterial con- 

 tamination by which putrefaction may be incited. In the two 

 preceding experiments, thymol was made use of to obviate 

 this danger, but hi the next experiment chloroform and sodium 

 fluoride were likewise employed, as follows : 



These mixtures were placed in suitably stoppered flasks, 

 shaken thoroughly to insure complete solution of the sodium 

 fluoride, etc., and warmed at 40 C. for twenty hours, with 

 frequent agitation. At the end of the period the mixtures 

 were boiled and filtered, the 'filtrates neutralized, concentrated, 

 and the proteoses separated as already described by saturation 

 with ammonium sulphate. On testing the filtrates with the 



Coagulated blood-fibrin. 



