1916] FOODS — HUMAN NUTRITION. 767 



In the animal body the change of creatin to creatinin takes place at its 

 maximum velocity, since the creatinin is rapidly removed. The fact that mus- 

 cular tissue has the power to convert creatin into creatinin is important evidence 

 in support of the theory that muscle creatin is the source of urinary creatinin 

 with a creatin- and creatinin-free diet, and also that the transformation of 

 creatin into creatinin takes place in part at least in the muscular tissue. 



The influence of diet on the development and health of the teeth, J. I. 

 DuEAND (Jour. Amer. Med. Assoc, 67 {1916), No. 8, pp. 564, 565). —Studios of 

 other investigators reviewed here indicate that the teeth of children fed during 

 six months of the first year on sweetened condensed milk showed a higher per- 

 centage of caries (about 72 per cent) than those of children fed upon breast milk 

 or modified cows' milk (about 42 per cent). The author states that "a poorly 

 balanced diet, high in carbohydrate and low in fat, protein, and mineral con- 

 stituents, fed during the period in which the teeth were developing and calcify- 

 ing in the jaws, seems to have rendered them doubly susceptible to decay after 

 they erupted." 



Emphasis is also laid upon the advantage of tough and hard foods, which 

 develop the muscles of mastication and enlarge and strengthen the jaws, and 

 upon the cleaning effect of such foods as meat, fresh vegetables, acid fruits, 

 and fibrous foods. Also, the ptyalin content and alkalinity of the saliva 

 secreted vary with the flavor, acidity, or hardness of foods. Acid fruits, pro- 

 ducing a highly alkaline saliva with a high ptyalin content, are recommended 

 as valuable foods with which to finish a meal. 



Dietary deficiency as the etiological factor in pellagra, E. B. Vedder 

 (Arch. Int. Med., 18 {1916), No. 2, pp. lS7-172).—In this paper the author 

 considers the analogies which exist between pellagra and the two deficiency 

 diseases beri-beri and scurvy, and also the question of whether the evidence 

 pointing toward infection can be explained on the deficiency hypothesis. An 

 extended study is reported of the diets of a large number of pellagrins, in order 

 to determine whether or not a deficiency could be demonstrated in these diets. 

 The author considers also a number of changes which have occurred during the 

 past 10 years in the South which may account for the increa.se in pellagra. 

 The following conclusions are drawn from the investigation : 



" There is a certain similarity between pellagra and other known deficiency 

 diseases, namely, beri-beri and scurvy. Much of the evidence that has been 

 presented as a proof of the infectious nature of pellagra can be reasonably 

 explained in accordance with a deficiency hypothesis. 



"A deficiency is demonstrable in the diets of most pellagrins. This deficiency 

 appears to . . . [the author] to result from the too exclusive use of wheat 

 flour, in association with corn meal, salt meats, and canned goods, foods that 

 are known to be deficient in vitamins. 



" Changes in the diet of the people of the South have occurred during the 

 past 10 or 15 years. Since . . . [all the changes that have occurred are not 

 known and the importance of the known changes can not be judged accurately], 

 it is unscientific to assume that the recent increase in pellagra can not be due 

 to such changes. 



" The hypothesis that pellagra is caused by a deficiency is very plausible and 

 must be taken into consideration in subsequent studies of this disease." 



Some metabolic effects of bathing in the Great Salt Lake, II, Helen I. 

 and H. A. Mattill {Amer. Jour. Physiol. U {1916), No. 2, pp. US-152).— 

 This investigation was made to determine whether the findings in an earlier 

 study (E. S. R., 33, p. 367) were significant and constant. 



" Two subjects were maintained on a uniform diet for twelve days. A bath- 

 ing period of four days followed a fore period of five day», with a tJiree-day 



