i82 Report of the Chemical Department of the 



much greater than that formed later, when the lactic acid organ- 

 isms have largely disappeared, if their respiration is the source of 

 any appreciable amount of carbon dioxide. The results secured 

 by us with our normal cheese do not show that there was any 

 such comparatively large amount of carbon dioxide produced at 

 the time the lactic acid organisms were most abundant. The 

 somewhat larger amount of carbon dioxide produced during the 

 first two weeks is undoubtedly due mostly to the decomposition 

 of milk-sugar and not to the respiration process of the living 

 cells present in the cheese. In the case of our chloroformed 

 cheese, we inhibited the activity of living organisms and this 

 source of carbon dioxide did not therefore exist in the cheese. 



(4) Chemical decomposition of compounds present in the cheese. — 

 Emerson" has lately shown that tyrosine, through the action 

 of the enzymes of the pancreas, can be converted into oxypheny- 

 lethylamine with simultaneous cleavage of carbon dioxide, in 

 accordance with the following representation of the reaction: 



HOC,,H, CH2 CHCNH^) COOH== 

 HO QH, CHo CH2 (NH2)+CO, 



Langstein^^ has also shown the same reaction in the case of a 

 long-continued peptic digestion of the coagulated portion of the 

 blood-serum of a horse. 



Ellinger^*^ has shown the formation of putrescine from ornith- 

 ine and of cadaverine from lysine, with the splitting ofif of car- 

 bon dioxide, by the action of bacterial ferments. The following 

 equations represent these reactions: 



CH,(NH2) CHo CH, CH(NH2)COOHc= 

 CH^CNH^) CH„ CH„ CH.CNHJ+CO^. 



CH^CNH.) (CR^), CH(NH2) COOH = 



CH^CNH.) (CH,)3 CH2(NH,)+CO,. 



Lawrow^^ found the same reaction taking place in an intense 

 peptic auto-digestion of the stomach. 



'^^Beit. t. chem. Physiol, tin d Pathol., 1 : 501 (1902). 



12 Ibid. 507 



13 ^m d. chem. Ges., 31 : 3183 (1898). 



'^^ Ztschr. Physiol. Chem., 33 : 312 (1901). 



