1885.] creatine and urea in muscular tissue. 271 



Again, by combining two molecules of CH 2 jp N 2 we should 

 have by Tieman's formula 



CH 2 - CN 

 2CH 2 {™*=^>NH + NH 3 



CH 2 - CN 

 which when hydrated with weak acids would give 



c,H,<NH){«xm 



a body having the same composition as aspartic acid, but differing 

 in that it is an imido instead of an amido body. Similarly 



C 2 H 4 - CN 



CH 2 {™* + C 2 H 4 1™ 2 = y NH + NH> 



CH 2 - CN 



(OOOTT 



which hydrated would give C 8 H 6 (NH) jp OOT T a body having the 



same composition as glutamic acid, differing only in structure. 

 But by strong HC1 and high temperature these ' imido-nitriles ' 

 seem always to give aldehyde, HCN and an amido acid. It is not 

 improbable therefore that under certain conditions we may have 



2CH 4cN 2 converted int0 CH *- CH ( NH *) {coOH 



aspartic acid 



and CH 2 {™* + C 2 H 4 {^ converted into C 3 H 5 . (NH 2 ) {^^ 



glutamic acid. 



Lastly, a few words as to the formation of glucose. In plants 

 C0 2 entering by the leaves combines with H 2 sent up from the 

 roots, and from these starch is said to be formed, a volume of 

 oxygen equal to that of the C0 2 absorbed being exhaled by the 

 plant. 



MM. Loew and Bokorny, and Pringsheim have shown that 

 there is a substance in living plasma which has the property of 

 reducing silver salts and for this reason is regarded as an aldehyde. 

 The aldehyde resulting from the combination in the plant of C0 2 

 and H 2 0. Pringsheim gives the following as the reaction ; the 

 volume of C0 2 absorbed and of given out, being the same ; 



' C0 2 + H 2 = H.CHO + 2 



methyl 

 • aldehyde 



19—2 



