1100 EXPERIMENT STATION RECORD. 



probable that fat protects iirotein as well as an isodynamic quantity of carbohydrates, 

 both in a condition of nitrogen hunger and nitrogen abundance. It was noted that 

 under certain conditions fat exhibited less than one-half its protective power when 

 carbohydrates were absent. This the author believes is exi)lained by the fact that 

 when carbohydrates are no longer supplied some must be formed in the body from 

 protein, and that fat can not serve for this purpose in the place of j^rotein. In other 

 words, as soon as the glycogen is no longer present in the body fat is inferior to 

 carbohydrates as a protector of protein. 



This question and related topics, including the cleavage of })rotein during fasting, 

 are discussed at length with special reference to the author's results and those 

 obtained by otherjnvestigators. 



Concerning- the metabolism of phosphorus in adult man, E,. Ehhstrom 

 {Skaiitl. Ari-Ii. Plii/sioL, 14 [1903), No. ]-.i, iq,. SJ-1 11, fig>i. i:-).— The author's experi- 

 ments were made with 3 men, and the foods and excretory products were analyzed. 

 The excretion of nitrogen and of phosphorus were not found to be parallel, the 

 quantity of nitrogen being influenced by the protein content of the body and the 

 quantity of phosphorus by the quantities of phosphates dissolved in body fluids, the 

 amount in the skeleton, and also by the amount of lecithin and protein containing 

 phosphorus. 



The author concludes, therefore, that it is not necessary in metabolism experi- 

 ments to calculate the ratio of nitrogen to phosphorus. As regards the metabolism 

 of this element, the author notes that the amount of j)hosphorus present in food is 

 one of the factors which affects the amount metabolized. The body has not the 

 same tendency to accumulate phosphorus and reach a condition of equilibrium as is 

 observed with nitrogen. Within limits at least, the metabolism of phosphorus is 

 thought to be regulated in the same way as that of fat. That is, it can be stored uj) 

 in the body or drawn upon, according to circumstances, for comparatively long 

 periods. Further experiments on this point are regarded as essential. Ajiparently 

 there is a minimum ph()si)horus recjuirement which varies within rather narrow 

 limits, 1 to 2 gm. per day, supplied l)y an ordinary mixed diet, being, in the author's 

 opinion, about the needed (juantity. 



The amount of phosphorus digested, the form in which it is best fitted for resorp- 

 tion in the body, the form in which phosphorus f>ccurs in urine, the metabolism of 

 nitrogen, and other tojjics are discu.ssed. 



The effect of different variables upon the excretion of carbon dioxid dur- 

 ing- positive muscular work, J. K. .Ioiiansson and (i. Koraex [Skand. Arch. 

 Physiol., 14 [190,1), Xo. 1-.1, pp. GO-SI, dgm. 1). — Continuing earlier work (E. S. 11., 

 14, p. 992) experiments in which the respiratory (juotient was determined are 

 reported on the effects of training, duration of work, speed at which it is performed, 

 and some similar factors upon positive muscular work, which consisted in raising 

 and lowering a weight with the aid of apparatus of special construction. The authors 

 conclude that in harmony with earlier observations the carbon dioxid excretion is 

 directly proportional, within certain limits determined by practice or training, to 

 the number of nuis(-ular contractions. It also appeared that with positive muscular 

 work the carbon dioxid excretion was dependent upon the manner and duration of 

 the muscular motion as well as the amount of external work i)roduced. The effect 

 of duration is greater in so far as it represents the duration of tlie muscular c-on- 

 tractions in successive phases of motion. The experimental data are further discussed 

 at some length. 



The artificial method for determining- the ease and rapidity of the dig-estion 

 of meats, H. S. (tRixdley and T. Mojonniek {Univ. Illinvis, Uuir. Stadie.i, 1 {190^i), 

 No. 5, pp. 3-20). — The results of a considerable number of digestion experiments with 

 raw and cooked beef are rejjorted and the experimental methods described. Accord- 

 ing to the authors the results indicate that there is a difference in the ease and rapidity 



