144 Influence of Low Temperatures upon Ensymes [March, 



metaprotein in the reacting mixture was: at 40° C, i^ to 2 hr. ; 

 at 16.5° C, 2^ hr.; at 10° C, 3 to zYa hr.; at 5 to 6° C, 8 hr.; at 

 0° C, 2 to 3 days. 



In Flaum's final series of experiments, the artificial gastric juice 

 was prepared with mucous membranes from the fundus of pig 

 stomachs, and purified until free from proteoses and peptones. In 

 this series, the study of proteolysis was continued until the acid meta- 

 protein disappeared. At 40° C, decomposition of the coagulated 

 protein began in 30 min. After 50 min., soluble protein was pres- 

 ent; after 2 hr., acid metaprotein. Traces of proteoses were noted 

 after 2 hr. and peptone was present after 2^ hr. Acid metaprotein 

 disappeared after 48 to 50 hr. At 16° to 17° C, acid metaprotein 

 formed after 2% hr., and proteoses and peptone after 2^- hr., 

 while 4 days (about 94 hr.) were required to carry digestion to the 

 stage at which acid metaprotein was no longer present. At 10° to 

 10.5° C, after the lapse of 4 to 5 hr., acid metaprotein made its ap- 

 pearance. After 5^ to 6 hr., proteoses and traces of peptone were 

 detected; and acid metaprotein disappeared at the end of the 5th 

 day. At 5° to 6° C, 8 to 10 hr. were required for the formation 

 of acid metaprotein, and about 20 hr. for the definite appearance of 

 Proteose and peptone, while 7 to 8 days elapsed before acid metapro- 

 tein completely vanished. At 0° C. in 3 to 4 days the coagulated 

 protein was decomposed with the formation of acid metaprotein, 

 Proteose and peptone; after 14 to 15 days, acid metaprotein was no 

 longer present. 



Flaum also prepared an artificial gastric juice from frog stom- 

 achs by extraction with 2 percent hydrochloric acid sol. at 0° C. 

 This juice digested both fibrin and ovalbumin at 0° C, and at 

 16° to 17.5° C. (room temp.). However, when the stomachs 

 of living frogs were flushed, and coagulated tgg white was then 

 introduced, no digestion of the protein took place in the living ani- 

 mals held at 0° C. for as long as 14 days, or at 4° to 5° C. for 6 days. 

 Digestion occurred in i day in frogs held at 10° C. The failure of 

 digestion to occur in vivo at the lower temp. is ascribed by Flaum to 

 the fact that no gastric juice was secreted, the lower temp. limit for 

 its secretion being 8° C. 



"Müller (15) permitted the gastric protease of pike to act on 100 

 mg. of heavy fibrin particles. The same volume of enzyme extract 



