FOODS ANIMAL PEODUCTION. 871 



FOODS— ANIMAL PRODUCTION. 



Studies on the amount of nutrients required by man at rest, 



K. Elkholm {Shind. Arch. Plujswl., 11 {1000), Ms. 1-2, pp. 1-OG, 

 dkuja. 2). — The balance of income and outgo of nitrogen was studied 

 with students, soldiers, and aged men, the Sonden and Tigerstedt respi- 

 ration apparatus being used (E. S. R. , 8, p. 242). Tlie energy furnished 

 b}' the food consumed and utilized by the sul)jects is calcuhited. The 

 author discusses his results at length, comparing his experiments with 

 similar investigations made elsewhere. According to the author, the 

 students in these experiments required on an average 1,156 calories 

 per square meter of surface area; the soldiers, 1,186 calories; or taking 

 the average of the two groups of young men, 1,171 calories, A man 

 weighing 70 kg., whose surface area equals 2,0912 square meters, 

 would therefore need daily 2,150 calories net, while on the supj^osition 

 that 10 per cent of the fuel value of the food is lost in the feces, he 

 would need a total of 2,700 calories, or calculated on the basis of body 

 weight, 35 and 38. 6 calories, respectively, per kg. The author believes 

 further that the results of the numerous dietary studies which have 

 been made are in accord with these values. The article concludes with 

 an extended bibliography. 



On the elimination of nitrogen, sulphates, and phosphates after 

 the ingestion of proteid food, H, C, Sherman and P. B, Hawk 

 {Auur. Jour. Fhyslol., 4 {1000), No. 1, pp. 25~-Jtd, dgms. J).— The 

 authors (healthy 3'oung men under normal conditions of nutrition) 

 were themselves the subjects of experiments in which the amount of 

 protein was increased at different times in an otherwise practicall}^ 

 uniform diet. In one case the fat was correspondingly diminished. 

 The income and outgo of nitrogen were determined, as well as the heat 

 of combustion of the urine. The excretion of nitrogen, sulphur, and 

 phosphorus in the urine w^as determined at frequent intervals with 

 the object of ascertaining how soon after the consumption of protein 

 its cleavage products are excreted. 



"As measured by 3-liour periods, the rates of excretion of nitrogen and sulphates 

 run closely parallel and normally show a tendency to rise during the morning, 

 reaching a maximum after the midday meal, with a slight fall in the following period 

 and another rise after the evening meal. During the night the excretion usually 

 reaches the minimum. 



"The excretion of phosphates on the normal days described a curve altogether dif- 

 ferent from that of nitrogen and sulphates, rising steadily from the middle of the 

 morning until the time of retiring, then falling during the hours of sleep and con- 

 tinuing to fall for .3 hours after rising, reaching a minimum after breakfast. 



"When lean beef sufficient to furnish about 63.7 gm. of extra protein was taken 

 with breakfast, the nitrogen began to rise in the first 3 hours and reached a maxi- 

 mum between the sixth and ninth hours, after which it declined at first rapidly and 

 then more slowly, reaching the normal after about 36 to 39 hours. 



"The increased excretion of sulphates was proportional to that of nitrogen and 

 followed the same general course. It appeared, however, to begin a little later, and 

 certainlv regained the normal a little earlier. 



