419 



. D. HALL. Review on the Progress of the Chemistry of 

 Animal Nutrition during 1909. Annual Report of the Pro- 

 gress of Chemistry for 1909. Issued by the Chemical Society, 

 Vol. IV. London 1910, p. 198. 



" In this subject work continues to be very active on the part 

 of the pure physiologists ; eventually their work will be applied to 

 agricultural problems, but until the whole question of protein 

 hydrolysis and re-formation in the body has been cleared up no 

 great advance is likely to be made in the feeding of animals on 

 scientific principles. 



The evidence as to the specific character of the proteins of 

 each animal that had already been obtained from the experiments 

 of Miss Willcock and Hopkins (Ann. Report, 1907, 276) has been 

 strengthened by further work reported this year. V. Enriques, 

 (Zeitsch. physiol. Chem., 1909, 60, 105; A., ii, 594) experimenting 

 with rats, found that nitrogen equilibrium could not be maintained 

 when zein was the only nitrogen compound fed, although the loss 

 of body-nitrogen was less than on an entirely nitrogen-free diet. 

 Gliadin, which contains tryptophan but not lysine, maintains nitrogen 

 equilibrium, and can even lead to storage of nitrogen. E. Abder- 

 halden (Ibid. 61, 194; A., ii, 327, 817) also fed dogs on the clea- 

 vage products of casein from which the tryptophan had been removed. 

 Thereupon they lost body-nitrogen, but the equilibrium was main- 

 tained when either the unaltered cleavage products were fed or 

 tryptophan was separately added. While all these papers point to 

 the necessity of the tryptophan group in building up the proteins 

 contained in the organism, they go further, and show that no com- 

 plete understanding of the peculiarities of animal nutrition is pos- 

 sible until we have a full record of the syntheses of both animal 

 and vegetable proteins. On this latter point Osborne, Leavenworth, 

 and Brantlecht (Amer.J. PhysioL, 1908, 23, 180; A., i, 72) rather 

 abandon the hope of determining the monoamino-acids accurately, 

 and would differentiate the proteins by separating the hexone bases, 

 which can be obtained quantitatively. They give results for about 

 twenty-four vegetable proteins; histidine was present in all to the 

 extent of about 2.5 per cent, lysine was absent from the gliadins 

 but present in the proteins from leguminous seeds. Arginine va- 

 ried from i to 14 per cent., being least in oil seeds, but most 

 abundant in cereals. 



" The discussion continues of the part played by non-protein ni- 



