860 EXPERIMENT STATION RECORD. 



chemical action, tlie liver and kidneys are relatively twice as large in fish-eating 

 and insect-eating as in carnivorous and herbivorous animals. 



The minimum requirement of protein supplied by a bread diet, M. Hind- 

 HEDE (Skand. Arch. Physiol., 31 {1914), No. 4-6, pp. 259-320) .—The author 

 reports the results of a series of digestion experiments from which he draws 

 the following conclusions: 



The minimum protein requirement is about the same for bread and potatoes 

 and is in the neighborhood of 20 gm. of digestible protein for 3,000 calories. 

 Potato and bread protein appear to have about the same value as meat protein 

 and can replace the body tissue gram for gram. See also a previous note (B. S. 

 R., 31, p. 263). 



Protein requirement and the food value of meat, Kisskalt {Miinchen. Med. 

 Wchfischr., 61 (19U), No. 20, pp. 1121, 1122).— The author believes in a gen- 

 erous protein ration as opposed to the paper noted above. 



Calcium deficiency in the diet, R. Emmerich and O. Loew (Ztschr. Hyg. ti. 

 Infelctionslci-anlc, 77 {WW, No. 2, pp. 311-328). — Data from their own investi- 

 gations and those of others are summarized, which led the authors to conclude 

 that the calcium content of the daily food may vary within wide limits on a 

 mixed diet and that there is a possibility of calcium deficiency. In some locali- 

 ties there is a marked decrease in the use of milk and vegetables, the foods 

 which are richest in calcium, while there is a corresponding increase in meat, 

 potatoes, and bread, and other foods made from flour, which are poorest in this 

 constituent. Such conclusions have led the authors to recommend the addition 

 of calcium chlorid to fiour in bread making. See also a previous note (E. S. R., 

 29, p. 565). 



Concerning calcium bread advocated by Emmerich and Loew, Kunebt 

 {Ztschr. Gesam. Getreideic, 6 {1914), No. 4, pp. 73-80).— A critical discussion of 

 the work noted above. 



On age and metabolism and the significance of the excretion of creatin, 

 R. A. KRArsE {Quart. Jour. Expt. Physiol., 7 {1913), No. 1, pp. 87-101; ahs. in 

 Zenthl. Expt. Med., 5 {1914), No. 8, p. 350). — According to the author's observa- 

 tion, the urine of children on a creatin-free diet contained creatin. This con- 

 dition ceases with boys in the fifth and sixth year, but continues longer with 

 girls. The amount of creatin nitrogen in millimeters per kilogram of body 

 weight is much smaller with children than with adults, Increasing rapidly 

 through the earlier years and then more slowly. When given to children 

 per OS in even small quantities part was excreted. 



The conclusion was reached that children have less ability to break down 

 creatin than adults, and that creatin is to be regarded as an intermediary 

 product of metabolism which can be further utilized under normal conditions. 

 The appearance of creatin in urine is dependent upon whether the process of 

 creatin formation or creatin destruction dominates, a condition similar to that 

 found with uric acid. 



On the influence of preliminary heating upon peptic and tryptic prote- 

 olysis, A. H. BizARRo {Jotir. Physiol, 46 {1913), No. 3, pp. 267-284, figs. 6; ahs. 

 in Zenthl. Physiol., 28 {1914), No. 2, pp. 101, JO'2).— Artificial digestion experi- 

 ments were made with egg white, fibrin, gelatin, beef, and casein. No definite 

 conclusions could be drawn as to the digestive power of trypsin, but the experi- 

 ments afforded additional evidence that this ferment induces cleavage of the 

 amino groups vex'y slowly. A preliminary heating of egg white to from 120 to 

 140" C. increases the proteolytic action of the trypsin. Similar results were 

 obtained when fibrin, casein, and beef were heated, and contrai-y results with 

 gelatin. An increase in amino cleavage products was noted after 15 hours' 

 tryptic digestion. 



