20 PRODUCTS OF DECOMPOSITION OF PROTEIDS. [BOOK I. 



The ammonia evolved, as well as the CO 2 in combination with barium, 

 were estimated and found to be in the same ratio as would result if urea 

 were treated in a similar manner. Although the boiling was continued 

 for some time, the decomposition still progressed and only terminated 

 when the liquid was heated in sealed tubes up to 150 C. The relative 

 amounts of CO 2 and NH 3 still remained the same. 



The substance thus treated did not give out any more ammonia, even 

 when heated to 200. Nearly the whole of the resulting mass could be 

 got into a crystalline form, and Schiitzenberger was able to identify the 

 following substances 1 : the elements of urea, (CO 2 and NH 3 ) : traces of 

 CO 2 , H 2 S, oxalic and acetic acid, tyrosine: amido-acids of the series 

 SH^ + NO 2n corresponding to the fatty series C n H 2n O 2 , from amido- 

 aenanthylic to amido-propionic acid : leucine, butalanine, and amido-butyric 

 acid predominated. There were also obtained one or two acids nearly 

 allied to aspartic and glutamic acid, and one or two related to Bitthausen's 

 leguminic acid; furthermore a small quantity of a substance resembling 

 dextrin. 



5. Action of hydrochloric acid and stannous chloride. When heated 

 with these reagents there are formed ammonia, aspartic acid, glutamic 

 acid, leucine and tyrosine. 



6. Action of various oxidizing agents, a. When oxidized by means of 

 manganese dioxide and sulphuric acid, or potassium bichromate and 

 sulphuric acid, the proteids furnish bodies belonging to the aromatic and 

 fatty groups. Amongst others the following: benzoic aldehyde, propionic 

 aldehyde, propyl cyanide, benzoic acid, valerianic aldehyde, butyl cyanide, 

 hydrocyanic acid, acetic acid, propionic acid, valerianic acid. 



b. By the action of nitric acid, there is first produced a yellow in- 

 soluble body (xanthoproteic acid) which dissolves on further action, 

 paroxybenzoic and oxybenzoic acids being ultimately formed. 



c. When oxidized by means of chlorine, the proteids yield, amongst 

 other products, fiimaric acid, oxalic acid and chlorazol. 



d. When heated with bromine and water, under pressure, there are 

 formed carbon dioxide, oxalic acid, aspartic acid, leucine, leucimide, 

 bromacetic acid, bromoform, bromanil and amidotribromobenzoic acid. 



SEC. 5. THEORETICAL VIEWS AS TO THE CONSTITUTION OF THE 



PROTEIDS. 



" Under the most diverse influences : action of water and strong 

 acids, action of bases, oxidations, putrefactions... &c. the proteid 

 bodies when decomposed yield : firstly amides, such as glycocine and 

 leucine, containing radicals derived from fatty acids, or from the 

 homologues of lactic acid, as well as more complex amides, such as 

 aspartic acid, C 4 H 7 N0 4 , the amide of malic acid, and glutamic acid, 



1 Sohutzenberger, Bulletin de la Soc. Chimique, 15 F6vrier, 5 Mars, et 15 Mars, 

 1875. 



