FOODS — HUMAN NUTRITION. 463 



Studies of pellagra {Jour. Amer. Med. Assoc, 65 {1915), No. 21, pp. 1818, 

 1819). — This article summarizes in a concise form the results of recent Investi- 

 gation Into the cause of pellagra. 



Contribution to the physiology of the stomach. — XXI, The secretion of 

 gastric juice in man. A. J. Carlson {Amcr. Jour. Physiol., 87 {1915), No. 1, pp. 

 50-73, fig. 1). — Observations are reported of the amount ami character of gastric 

 juice secreted under varying conditions by a man having a gastric fistula and 

 complete cicatricial stenosis. The author's conclusions are as follows : 



" The fluid content of the ' empty ' stomach varies from S to 50 cc. with an 

 average of 20 cc. The quantity is greater in the morning than at noon or at 

 6 p. m. It is on the whole greater in the summer than in the winter months. 

 The most important factor in these daily and seasonal variations is probably the 

 tonicity of the empty stomach. 



" The gastric glands in the normal person are never completely quiescent. 

 The continuous secretion varies from 2 to 50 cc. per hour. The higher figures 

 are exceptional, but may obtain for several days in succession, again to revert 

 to the lower figures. The vagus secretory tonus is a possible, and the auto- 

 digestion of the gastric juice itself is a probable, factor in this continuous gastric 

 secretion. The secretion itself is rich In pepsin, but when the secretion rate Is 

 very low it is poor in hydrochloric acid. 



" Chewing of indifferent substances and stimulation of the nerve endings la 

 the mouth by substances not related to food do not cause secretion of gastric 

 juice, that is, these processes do not augment the continuous gastric secretion. 



" Seeing, smelling, and possibly thinking of palatable food usually cause a 

 slight, but very transitory secretion of gastric juice. 



" The rate of secretion of gastric juice on mastication of palatable food is 

 directly proportional to the palatability of the food. During- mastication the 

 average rate is 3.5 cc. per minute (minimum rate, 1.4 cc. ; maximum rate, 10.8 

 cc). On cessation of chewing the secretion rate diminishes rapidly so that 

 from 15 to 20 minutes the gastric glands reach the level of the continuous gastric 

 secretion. The chemistry of this appetite gastric juice has been practically con- 

 stant during the three years of observation. 



" The latent period of the appetite secretion varies Indirectly with the rate 

 of the continuous secretion, so that when the continuous secretion is abundant 

 the appetite secretion shows no latent period at all, while with the lowest rate 

 of the continuous secretion the latent period varies from 2 to 4 minutes. This 

 latent period is therefore one of the processes of secretion in the gland cells, 

 and not In the nervous mechanism. 



" On the basis of these experiments on Mr. V., on the reports of other gastric 

 fistula cases in man, and on the w^ork of Pawlow on dogs, it Is estimated that an 

 adult normal person secretes at an average meal (dinner) 700 cc. gastric juice, 

 or an average total of 1,500 cc. gastric juice In 24 hours." 



A study of the action of bitter tonics on gastric secretion has been noted from 

 another source (E. S. R., 32, p. 858). 



On the secretion of bile, S. Okada {Jour. Physiol., 49 {1915), No. 6, pp. 457- 

 482). — The experiments herein reported were made with dogs, which were pro- 

 vided with a permanent fistulous opening, so that the total secretion of bile 

 passed out by the fistula. A number of tests were conducted to determine the 

 effect of diets of bread, butter, and meat on the quantity of bile secreted. Other 

 experiments concerned the effect of protein, carbohydrate, and fat administered 

 In the form of white of egg, cane sugar, and olive oil, respectively. Tests were 

 also made with peptone, extract of meat, acids, drugs, etc. The author's con- 

 clusions are, in part, as follows : 



