204 Prof. Latham, Further observations, &c. [March 6, 



and as this is specially so in the case of methyl hydantoic acid and 

 its conversion into methyl hydantoin, this latter substance might 

 possibly exist in the urine after the internal administration of 

 sarcosine. Salkowski has o-iven great care and attention to this 

 point, without however arriving at any definite proof." 



" This then was the state of the question, when Professor Bau- 

 man informed me that methyl-hydantoin reduces sulphate of 

 copper in an alkaline solution and asked me to make some fresh 

 experiments with sarcosine founded upon this reaction." 



Schiffer then describes the experiments which he performed to 

 demonstrate the existence of methyl hydantoin in the urine, and 

 thus sums up the result of his investigations: — 



" Our knowledge therefore of the destination of sarcosine in the 

 organism may be formulated as follows : By far the greatest part 

 is excreted unchanged : a smaller jDortion, one-fifth to one-sixth, is 

 transformed ■ into the uramido-acid we have been discussing, or 

 rather into its anhydride (methyl hydantoin), and a smaller portion 

 is oxidized into methyl urea." 



Schultzen's experiments therefore here receive some confirma- 

 tion — and possibly further investigation may show how the dis- 

 crepancies among the various investigations have arisen. The 

 conditions under which the different animals have been kept may 

 not have been the same, and we know that hippuric acid is not 

 always excreted by an animal after the administration of benzoic 

 acid. " When horses are kept in the stable or only lightly worked, 

 their urine contains hippuric acid, but when they are put to hard 

 work, it contains benzoic acid*," and we may conceive that it 

 is possible under certain conditions for sarcosine to pass through the 

 system unchanged, and under other conditions to combine with the 

 molecule CONH 2 and appear in the urine as methyl hydantoin. 

 That this takes place to some extent Schiffer's experiments prove, 

 and that it results from the combination of sarcosine instead of 

 NH 3 with an alcoholic carbamate appears to be the most reason- 

 able explanation. These experiments then it seems to me are a 

 strong proof that in the living system the amido acids glycocine, 

 leucine, &c. are transformed into the metameric urethanes or 

 alcoholic carbamates, which may then be further decomposed on 

 meeting with ammonia into urea and the corresponding alcohol. 



* Watts, Diet. in. p. 156. 



