ALBUMINS OR PROTEINS. 



245 



products can be combined in like manner. Thus, on administering ben- 

 zoic acid to birds we obtain a definite amount of ornithine. In this case 

 hippuric acid does not appear in the urine, being replaced by ornithuric 

 acid, the dibenzoyl compound of ornithine. As previously stated, we can 

 unite cystine with brombenzene, in a dog, thus protecting it from further 

 oxidation. All of these discoveries indicate that the disintegration of 

 albumin in the tissues proceeds in an analogous manner to that of the 

 fats or carbohydrates. Glycogen is first split up into its components and 

 then consumed. The same kind of action takes place with the fats. 



We might ask ourselves whether the glycocoll withdrawn from the body 

 by the benzoic acid administered can be directly derived from the amount 

 of decomposed albumin. An answer to this question must be obtained 

 by studying the increased elimination of hippuric acid caused by the 

 administration of benzoic acid, and tracing at the same time the dis- 

 integration of the albumin. Such experiments have been made, 1 and it 

 appears that more glycocoll is excreted than can be derived from the dis- 

 integrated albuminous substance. Such results are to be very cautiously 

 accepted, as we know comparatively little about the decomposed albu- 

 mins in the intermediate metabolism. We must always consider the 

 possibility that the animal cell may be capable of producing glycocoll from 

 other amino acids. We have already called attention to a striking example 

 of this by showing that it was impossible to change the composition of the 

 individual amino acids in the serum-albumins by feeding a protein which 

 was especially rich in a certain amino acid. 2 In the case indicated, the 

 " normally " constituted serum-albuminous bodies were evidently produced 

 from gliadin. A glance at the following table will show the changes 

 which must have taken place. We find it necessary to state, in order to 

 prevent any misunderstanding, that our conclusions were naturally only 

 superficial and incomplete. The configuration and stereochemistry will 

 at some time undoubtedly be taken into consideration in studying such 

 changes. 



1 Cf. W. Wiechowski: Arch. exp. Path. Pharm. 53, 435 (1905). 



2 E. Abderhalden and F. Samuely: loc. cit. 



