FOODS HUMAN NUTRITION. 373 



lack of M better and more definite term, may be called iudividual idiosyncrasy." 

 ("»\vin,ii to the severity of the symptoms produced ricin was not satisfactory for 

 snch experimental studies. 



Protein requirements of man, D. J. R. Carracido (Vet. Espai'i., 53 (1909), 

 Aon. IS7'i, iJi). ',S2-',S.',; 1S75, iip. 500~o02; 1877, pp. 532-53J,) .—From the data 

 summarized and discussed the author recommends 110 gm. protein per man 

 per day. 



Protein cleavage in the digestive tract in man, Alice Stauber (Biochem. 

 Ztschr., 25 (1910), A'o. 2-3, pp. 187-203). — Accoi'ding to the author's results, 

 the urea excretion determined at hourly intervals after taking food does not 

 give a constant curve with normal individuals. In cases where there was a 

 previous flushing out of urea the maximum urea excretion was observed in the 

 fourth or tifth hour after taking a normal diet containing nitrogen. When 

 nitrogen was fed in the form of products of deep-seated protein cleavage the 

 maximum excretion was noted in one to two hours. 



The author also reports data obtained under pathological conditions. 



The synthesis of fat in the animal body, J. B. Leathes (Enjcb. PhysisoL, 

 S (1909). pp. 356-370). — A digest of data and discussion of the formation of 

 fat in the animal body. See also previous articles by the author (E. S. R., 20, 

 p. net)). 



The mother substance of glycogen, E. Pfluger and P. Junkersdorf (Arch. 

 PJnj.siol. ll'fliujvv^. 131 (1910), No. 5-6, pp. 201-301).— From the large amount 

 of experimental data recorded and discussed the authors conclude that there 

 is a strong probability that the glycogen formed on au abundant proteid diet 

 is derived from protein itself and not from fat. 



[Note on glycogen formation], E. Pfluger (Arch. Physiol. [Pfliiycr], 131 

 (1910), \o. 5-6, pp. 302-305). — The data presented supplement the paper noted 

 above. 



Note on overnutrition and mineral metabolism, E. Biernacki (Zciifbl. 

 Gcsam. Physio}, u. Path. Stofficcchscls, ii. scr., 5 (1910), No. 6, p. 2-^0). — Tht 

 author gives a number of corrections of the figures published in his article 

 previously noted (E. S. R., 22, p. 370). 



Some colloid-chemical aspects of digestion, with ultramicroscopic observa- 

 tions, J. Alexander (Jour. Amcr. Chem. Soc, 32 (1910), No. 5, pp. 680-687). — 

 From a digest of data obtained by other investigators, his own observations 

 with the ultramicroscope of the action of diastase upon potato starch grains 

 and the action of pepsin upon coagulated egg albumen, and other information, 

 the author discusses the principle of colloidal protection in digestion, and 

 particularly the effect of gelatin or some similar substance on the digestion of 

 protein. 



According to his summary, " bald chemical analysis can not express the 

 digestibility and availability of a food any more than it can express or explain 

 the action of the digestive juices, or in fact any other physiological process. 

 In all these processes can be traced the influence of the colloidal substances 

 everywhere present in the body, whose effects are quite out of proportion to 

 their small mass. Striking examples are the enzyms which catalyze and direct 

 chemical and physical changes, and the protective colloids which oppose 

 crystallization, precipitation and coagulation, emulsify fats, and facilitate 

 diffusion and absorption. As soon as we approach the chemistry of living 

 organism, we are confronted with problems of colloid chemistry, and there is 

 no doubt but that a correct understanding and application of its principles 

 will throw much light upon many other obscure problems in biology, physiol- 

 ogy and medicine." 



