1917] FOODS HUMAX NUTRITION. 559 



product. In spite of the high ash percentage utilization by the pigs fed sweet- 

 ened condensed milk, their body gain contained less ash than did the gains of 

 either the normal or the evaporated-milli-fed-animals. Tricalcic phosphate 

 does not seem to be a particularly available form in which to furnish lime and 

 phosphoric acid." 



Although the authors state that definite conclusions can not be drawn on this 

 point, somewhat limited trials indicated that overdilution of the milk rations 

 tended to lessen their food value. 



In conclusion the authors discuss at length the principles of infant feeding in 

 light of these experiments and clinical evidence. Special attention is given to 

 the American, or percentage system, and the German, or calorific system, of 

 infant feeding and to suggestions for a combination of these two methods. 

 The compositions of human, cows', and sows' milks are compared. There is 

 also an extended discussion of the digestion of milk which touches mainly on 

 the following points: Casein digestion, the effect of colloids and cereals on 

 curd structure, the rate of coagulation in the stomach, digestion of milk serum, 

 and fat digestion. 



A bibliography of cited literature Is Included, together with an appendix, 

 which contains the clinical records of the animals used as subjects of the 

 experiments. 



Value of different grades of milk in infant feeding, R. M. Washbubn and 

 C. H. Jones {Vermont Sta. Bui. 201 (1916), pp. 32, pis. 4, figs. 6).— This is a 

 popular edition of Bulletin 195, noted above. 



Studies of infant feeding. — The chemical changes produced by the addition 

 of limewater to milk, A. W. Boswoeth and H. I. Bowditcu (Jour. Biol. Chem., 

 28 (1917), No. 2, pp. 431-435). — The results of this Investigation showed that 

 although the addition of limewater to milk Increases the total amount of CaO, 

 It results In a marked change In the arrangement of the salts, bringing about 

 the precipitation of calcium, phosphorus, and citric acid, a mixture of dlcalclum 

 (CaHP04) and tricalclum (CasPiOs) phosphates being the insoluble phosphates 

 formed. By the addition of limewater the reaction of the serum of milk is 

 brought toward the neutral point, the soluble alkalinity of the limewater being 

 used up In the precipitation of the insoluble calcium phosphates. 



" When milk to be used for infant feeding Is treated with limewater and 

 finally diluted to such an extent that it has twice the volume of the original 

 milk, or more, the soluble calcium and phosphorus may be reduced to amounts 

 less than those which are present In human milk." 



The influence of the coagulation by rennin upon the gastric digestion of 

 milk protein, J. T. Leaey and S. H. Sheib (Jour. Biol. Chem., 28 (1917), No. 2, 

 pp. 393-398). — The object of this investigation was to throw some light upon 

 the differences in results obtained by other workers regarding the Influence of 

 the coagiUatlon by rennin upon the subsequent gastric digestion of milk protein. 



The data obtained confirmed the results of Abderhalden and Kramm,^ who 

 found that clotted milk was more easily digested than milk In which coagula- 

 tion had been prevented by the use of an oxalate, but In the latter case peptic 

 digestion was believed to be Inhibited by the presence of the oxalate solution. 

 The Internal digestion of the paracasein curd by adsorbed pepsin is deemed of 

 rather minor Importance. Through a slightly different method from that 

 employed by Hawk (E. S. R., 15, p. 494), his conclusions were verified that 

 pepsin acts much more readily upon the protein constituents of milk where no 

 thick, elastic curd of paracasein Is formed. The formation of the curd of 

 paracasein was found to depend upon the strength of the hydrochloric acid 



iZtschr. Physiol. Chem., 77 (1912), No. 6, pp. 462-470. 



