FOODS — HUMAN NUTRITION. 861 



The comparative chemistry of m.uscle — the partition of nonprotein water- 

 soluble nitrogen, D. W. Wilson {Jour. Biol. Cfiem., 17 (1914), ^"o. 3, pp. 385- 

 JfOO). — The author reports the results of studies of the distribution of nitrogen 

 in the muscles of invertebrates, namely, lamprey, limulus, squid, clam, scallop, 

 and periwinkle. 



"The lamprey muscle contained a minimum of total extractive nitrogen, most 

 of which was nonamino nitrogen. The values for the total amino nitrogen 

 rose from a minimum in the lamprey which was only 4 per cent of the total 

 extractive nitrogen, to a maximum in the clam and scallop which was over 

 50 per cent of the total extractive nitrogen. . . . 



" The nonamino nitrogen is high in all the extracts examined. The major 

 portion is in the diamiuo-acid fraction in which it greatly exceeds the amino 

 nitrogen. Of the compounds isolated from these and similar extracts, betain, 

 urea, prolin, arginin, histidin, and creatin contribute all or part of their 

 nitrogen to the nonamino nitrogen fraction. The various qualitative and quan- 

 titative relations indicate that betain is probably an iDiportant constituent of 

 extracts of muscles from these types of animals." 



The total sulphur was also determined in the total extracts. 



" The great qualitative and quantitative variations between the extracts of 

 muscles from different vertebrates and invertebrates suggest fundamental dif- 

 ferences in the tissue metabolism of these animals. . . . Comparative studies 

 on the extractives of these simpler forms of life may throw some light on their 

 role in the animal economy and aid in solving some of the problems of inter- 

 mediary metabolism. Experiments like the above, besides furnishing inter- 

 esting data, suggest points of attack where the variations are sufficiently large 

 to furnish fruitful investigations." 



The necessity relation of lipoids to life. The behavior of such essential 

 substances to reagents which will extract lipoids, W. Stkpp (Ztschr. Biol., 

 62 {1913), No. 9-10, pp. JfOo-Jill). — According to the author's conclusions, these 

 important lipoid substances can not be extracted from a feeding stuff by ether 

 but are readily extracted by alcohol. 



Meeting the body food requirements during a 24-hour cycle, J. BEEcoNifi 

 {Compt. Rend. Acad. Sci. [Paris], 158 {1914), No. 15, pp. 1019-1082, figs. S).— 

 From observations of the daily distribution of the energy requirement of the 

 body and the fact that the period of maximum availability of the energy in the 

 meals occurs about three hours after eating, the author recommends that the or- 

 dinary diet furnishing 1 part of fat. 1 part of protein, and from 4 to 5 parts 

 of carbohydrate should be taken in 3 meals as follows : A heavy meal supplying 

 from 1,400 to 1,500 calories at about 7.30 a. m. ; a light meal supplying 300 to 

 400 calories at 4.30 p. m. ; and a dinner supplying 700 to 800 calories at 8.00 p. m. 



Rational utilization of human energy — scientific study of manual labor, 

 J. Amae {Genie Civil, 64 {1914), No. 19, pp. 373-377, figs. 10).— The author 

 emphasizes the fact that to secure the greatest efficiency from the human motor 

 its normal limit of fatigue must not be exceeded so that overfatigue results. 

 Continuous action is contrary to the laws governing the human motor and rest 

 periods of proper length must be provided to secure the maximum efficiency. 

 In most systems for studying the efficiency of the human motor the physi- 

 ological element is disregarded. 



To determine the proper length and distribution of rest periods, as well as the 

 most efficient way in which the human motor can be utilized, an experimental 

 study was made of the energy expended in performing a number of different 

 tasks. 



The energy expended was measured by means of the oxygen consumption, this 

 factor being determined by a respiration apparatus provided with a double 



