364 EXPERIMENT STATION RECORD. [Vol. 36 



milk which had been pasteurized by heating to 140° F. for from 25 to 30 minutes, 

 another group was fed upon raw certified mills, and a third was given milk 

 which had been boiled for 10 to 15 minutes. Symptoms of scurvy were produced 

 in most of the animals receiving an exclusive diet of raw, pasteurized, boiled, 

 or skim milk. A severe form of the disease was produced in the animals by 

 condensed milk, casein and water, and several proprietary infants' foods. 



A large number of the animals were also fed upon carrots, cabbage, lettuce, 

 and other green vegetables, with hay, for long periods. Symptoms of scurvy 

 were not observed when such a mixture of foods was given, but scurvy was pro- 

 duced in nearly all the young animals when milk was added to these diets of 

 green vegetables. This was rarely true in the case of the older animals. 



From a comparison of the results of this investigation with those of other 

 workers, it would appear that a ration which may be entirely adequate in 

 nutritive value for one species may be inadequate for another. "While there 

 is a marked individual variation toward diets in each species, the species varia- 

 tion is still greater." 



The paper is followed by a discussion. 



Chang'es in the urea content of blood and tissues of g'uinea pigs main- 

 tained on an exclusive oat diet, H. B. Lewis and W. G. Kaku (Jour. Biol. 

 Chetn., 28 {1916), No. 1, pp. 17-25). — Laboratory animals (guinea pigs), which 

 developed the so-called "scorbutus" as a result of an exclusive oat diet, showed 

 a urea content several times greater than the normal amount. When small 

 amounts of cabbage or oranges were added to the diet, no pathological conditions 

 developed for periods of from 2S to 42 days in the case of the cabbage and 24 to 

 63 days in the case of the oranges. Analyses of blood and tissues showed a 

 normal urea content. The addition of sodium citrate to the oat diet did not 

 influence the changes resulting from the exclusive oat diet. The changes in 

 the urea content of the organism are not attributed to partial starvation or to 

 lack of water alone, although these factors may be involved to some extent. 



The mechanism of the sparing action of ca'^bohydrates on protein meta- 

 bolism, R. A. KocHER {Jour. Biol. Chem.. 25 {1916), No. 3. pp. 577-576).— Ex- 

 periments with laboratory animals (dogs) were undertaken to determine the 

 sparing effect upon the output of nitrogen and of the ingestion of lactic and 

 pyruvic acids as compared with the sparing action of equivalent amounts of 

 undissociated carbohydrates. The acid or cane sugar was administered by 

 stomach tube to fasting dogs after the elimination of nitrogen had become con- 

 stant, and following this determinations were made of the nitrogen excreted 

 in the urine. 



The sparing action of lactic acid on protein metabolism was practically the 

 same as that of carbohydrates. That of pyruvic acid, however, was distinctly 

 less. The author states that one of the chief intermediate steps in the dissocia- 

 tion of glucose in the body is the formation of lactic acid, which can be 

 oxidized in the body to pyruvic acid. . Also, that lactic acid and pyruvic acid 

 can add on ammonia nitrogen to form alanin, and " when this process is op- 

 erative, nitrogen arising from catabolism of body proteins, instead of being 

 excreted, is utilized to synthesize new protein." Although the above reactions 

 are reversible, the normal catabolism of glucose gives rise to simpler molecules, 

 which may, in part, be combined with nitrogen to synthetize protein. 



These experiments tend to support the theory that the fixation of catabolized 

 nitrogen, by the dissociation products of glucose to form new proteins, is the 

 true mechanism of the sparing effect of feeding carbohydrates on the nitrogen 

 output. 



The effect on nitrogen partition of substituting alcohol for sucrose in an 

 otherwise fixed diet, F. S. Hammett {Jour. Biol. Chem., 25 {1916), No. 3. pp. 



