1919] FOODS HUMAN NUTBITIOIT. 469 



the rate of development. No difference was noted between dextrin and .starch 

 as to the effect either on growth or development. 



The results as a whole are thought to indicate definitely the possibility of so 

 adjusting the diet by means of variations in such nutrients as fat, protein, and 

 vitamins, as to alter the size of the tadpole and the rate of metamorphosis. At- 

 tention is, however, called to other factors, such as temperature and food con- 

 trol, which also play an Important part. 



A biological analysis of pellagra-producing' diets. — VI, Observations on 

 the faults of certain diets comparable to those employed by man in pel- 

 lagrous districts, E. V. McCollum, N. Simmonds, and H. T.. Parsons {Jour. 

 Biol. Chem., 38 {1919), No. 1, pp. 113-146, pi. 1, figs. 10).— In continuation of the 

 series of studies on pellagra-producing diets previously noted (E. S. R., 40, p. 

 69), the authors present the results of feeding experiments with rats on diets 

 comparable to those employed by man in pellagrous districts, together with 

 similar experiments in which such diets were supplemented by food additions 

 containing the factors (proteins, certain salts, and fat-soluble A) which previous 

 study had shown to be deficent in the so-called pellagra-producing diets. 



The results of the studies reported show that in no case was a condition 

 analogous to pellagi'a in man produced in the rats, although all showed a gen- 

 eralized poor condition as evidenced by slight deformities, early aging, and in- 

 ability to produce and rear young successfully. This condition was remedied in 

 varying degrees by the addition to the diet of salts, leafy vegetables, meat pow- 

 der, and milk or milk powder. 



In connection with the interpretation of these results a detailed discussion is 

 given of previous work by the authors and other investigators on the relation of 

 diet to pellagra. The evidence as a whole is considered by the authors to 

 support the conclusions of Siler, Garrison, and MacNeil (E. S. R., 31, p. 858) 

 " that pellagra is caused by an infectious agent, and that unless it has been in- 

 troduced into a district there may develop such a condition of lowered vitality 

 from faulty diet or other debilitating influence as would predispose one to an 

 attack, without the appearance of the disease. The debilitating effects on ani- 

 mals of diets derived from cereals, tubers, roots, and any food products formed 

 from the milling of grains, together with legume seeds and meats, are so striking 

 that we believe similar diets would produce in man a susceptibility to infectious 

 diseases such as tuberculosis or pellagra. We have come to hold the view . . . 

 that the predisposing influence for both is in general the same, and the char- 

 acter of the unsanitary conditions surrounding the individual may determine 

 which of these two diseases he will develop." 



In discussing the relative values of several foods as correctives in the diet of 

 the pellagrous, the authors recommend the regular and liberal use of leafy 

 vegetables, and above all the inclusion in the diet of a suitable amount of milk 

 because of its cheapness. 



Biochemical studies of the saliva in pellagra, M. X. Sxtllpvan and K. K. 

 Jones {Pub. Health Rptn. [U. >S'.], 3^ {1919), No. 20, pp. 1068-1080).— A study 

 of the mixed saliva of individual pellagrins at the pellagra hospital of the 

 U. S. Public Health Service at Spartanburg, S. C, was undertaken to detei-mine 

 whether the saliva, from a biochemical standpoint, differed from that of normal 

 individuals. 



The rate of flow and diastatic power were found to vary within the limits 

 established by normal controls. The specific gravity was slightly higher than 

 that of the controls. Total solids, ash, organic matter, and mucin were also 

 higher, but the differences are thought to bear no relation to the mouth symp- 

 toms. The sulphocyanate content was much less marked, indicating that in 

 pellagra patients there is both a lessened protein intake and a detoxicating 



