NUTRITIVE VALUES. 49 



investigations have shown that diarrhoea and other disorders follow 

 the feeding of peptones. The stimulating properties of the amido 

 acids are most valuable in that they create an appetite and prepare 

 the system for food. 



The scope of this report will not permit of the exhaustive treat- 

 ment of this' subject, but brief mention is made of the following con- 

 tributions as indicative of the tendency of the results obtained : 



Biirgi a states that meat extracts are not foods, and that all mate- 

 rial taken in this form is quickly eliminated. Only 4.57 per cent of 

 the nitrogen, 14.85 per cent of the carbon, and 17.55 per cent of the 

 energy content is retained. According to Rubner 6 meat extracts, 

 after they have served their purpose of stimulating digestion, are 

 eliminated from the body as rapidly as possible. W. H. Thompson 

 has fed arginin to dogs and found from 37.6 to 77 per cent in the 

 urine; on injecting arginin 82 per cent appeared in the urine. A 

 part of the arginin nitrogen appeared in the urine as ammonia. Voit d 

 claims that the value of meat extracts lies in their flavor, which pro- 

 motes the flow of the digestive juices. As the constituents of meat 

 extracts are largely in a form ready for elimination, Rubner e holds 

 that they have little food value. 



Pfeiffer, Einecke, and Schneider / have fed asparagin to cows and 

 report a favorable effect on the milk and its constituents, and W. 

 Yoltz^ claims asparagin can replace proteid without lowering the 

 quality of the milk and that it acts as a proteid sparer in herbivora. 

 In omnivora its proteid sparing power is small and it seems to have 

 no such power in carnivora but rather increases proteid cleavage. 

 In feeding experiments with mice on a zein ration Willcock and Hop- 

 kins * found that on adding tryptophane to the ration the lives of the 

 mice were lengthened. Henriques and Hansen* have maintained 

 nitrogenous equilibrium on feeding hetero-albumose. 



Rubner i discusses the alcohol-soluble and alcohol-insoluble por- 

 tions of fluid beef. The nutritive value of fluid beef is considered at 

 length and the author concludes that if enough of such product for an 

 entire ration were taken the cost would be enormous. The claim that 

 two teaspoonfuls of fluid meat have a nutritive value equivalent to 

 one and one-fourth pounds of cooked meat is deemed correct. Two 



a Arch. Hygiene, 1904, 51:1. 



»Ibid, p. 19. 



cj. Physiol., 1905, &*: 106. 



d Stoffwechsel, 1882, p. 449. 



«Zts. Biol., 1883, ^9:343. 



/Mitt, landw. Inst, konigl. Univ. Breslau, 1905, 5:179. 



^Fuhlings landw. Ztg., 1905, 54 (2) :41; (3) : 96. 



fcj. Physiol.. 1906, 35: 88. 



<Zts. physiol. Chem., 1906, 48: 383. 



iZts. Biol., 1879, 15:485. 



43689— Bull. 114—08 4 



