864 EXPERIMENT STATION EECOED. 



Feeding experiments with isolated food substances, T. B. Osborne, L. B. 

 Mendel, and Edna L. Ferry {Gm-negie Inst. Washington Puh. 156, 1911, pp. 53, 

 fig. 1, (Igms. 21). — In this paper, wbicli may be regarded as a progress report, 

 problems of nutrition are reviewed in tbe light of the newer knowledge of the 

 chemical structure of proteins. " The possibilities of protein synthesis in 

 animals and the conditions which this postulates; the significance of the avail- 

 ability, palatability, and physical texture of the food intake; the suggested 

 role of various accessories — inorganic salts, lipoids, etc. ; the distinction between 

 the nutritive demands during the period of growth and those of later adult 

 life, are brought within the range of discussion." 



A large number of experiments are reported with white rats to determine 

 whether animals can be maintained in nitrogen equilibrium and health for 

 long periods on a diet consisting of a constant mixture of pure foodstuffs, 

 including a single proteid. " Numerous experiments are reported in which 

 casein formed the sole nitrogenous constituent of the dietary. In this connec- 

 tion it is shown that the make-up of the inorganic constituents of the diet 

 exercises an influential effect on the nutritive efficiency of the dietary. From 

 the experience thus gained a ' basal ' ration was constructed on which rats were 

 kept many months in good health. Some of these experiments in which the 

 animals exhibited no noteworthy alterations in weight and showed a good 

 gain in nitrogen are, as far as the authors are aware, the most successful 

 recorded attempts at artificial nutrition with a constant mixture of pure 

 foodstuffs, containing only a single protein. Satisfactory experience also 

 followed the gradual complete substitution of the casein by other proteins, one 

 animal continuing more than 217 days on a diet in which the sole protein was 

 glutenin." 



Belation between the dig'estibility and the retention of ingested proteins, 

 D. D. Van Slyke and G, F. White {Jour. Biol. Chcm., 9 {1911), No. S-Ji, pp. 

 219-229). — The rate of nitrogen excretion was studied on different diets by col- 

 lecting urine at intervals and determining its nitrogen content, the rate of 

 nitrogen excretion being taken as an idex of the rate of absorption in the 

 intestine. Adding starch to the diet decreased the rate of nitrogen metabolism 

 but did not affect the completeness of absorption. With the foods tested nitro- 

 gen excretion occurred most rapidly after the ingestion of cod. The lower 

 cleavage products appear to be less capable than the higher cleavage products of 

 maintaining nitrogen equilibrium. 



The chemical and energy transformations in the dog after the ingestion 

 of different quantities of meat, H. B. Williams, J. A. Riche, and G. Lusk 

 {Proc. 8oc. Expt. Biol, and Med., 8 {1911), No. 3, pp. 61, 62).— Experimental 

 data are summarized and briefly discussed. 



Calcium metabolism. — II, The calcium content of human blood after oral 

 administration of large doses of calcium, N. Voorhoeve {Biochem. Ztschr., 

 32 {1911), No. 5-6, pp. 394-409) .—The daily administration of 2.727 gm. of 

 calcium oxid in the form of lactate or chlorid increased the calcium content of 

 the blood of a man on a diet rich in calcium. Under similar conditions 0.545 

 gm. of calcium oxid did not cause a very appreciable increase. 



Certain fundamental principles relating to the activity of bacteria in the 

 intestinal tract — their relation to therapeutics, A. I. Kendall {Jour. Med. 

 Research, 25 {1911), No. 1, pp. 117-187). — From a consideration of available 

 data and the results of a number of experiments with infants with bacillary 

 dysentery, the author concludes that carbohydrates protect protein in bacterial 

 growth, a conclusion similar to a theory quite commonly accepted in animal 

 nutrition. 



