768 EXPEEIMENT STATION KECOKD. 



J 36, figs. Jf). — Work of previous experimenters is criticized on tlie ground that 

 sufficient account has not been taken of muscular activity. 



In the experiments here described graphic records of muscular activity were 

 made. The periods of observation vs^ere short and as far as possible vphile the 

 infants were asleep. The energy measurements were made indirectly by meas- 

 uring the gaseous exchange. 



A close relation was found between carbon dioxid production, pulse rate, and 

 muscular movements. The pulse rate in the younger infants was much less 

 stable than in the older infants, the slightest motion causing marked increase 

 of the rate. A description and a diagram of the apparatus used are given. 



A consideration of some chemical transfoiinations of proteins and their 

 possible bearing' on problems in pathology, F. P. Underiiill {Arch. Int. Med.^. 

 8 (1911), A'o. 3, pp. 356-381). — Chemical changes in proteins during the process 

 of digestion are considered, together with their possible relation to pathological 

 conditions. 



The sparing value of fats, A. Bartmann (Ztschr. Biol, 58 {1912), No. 8-11, 

 pp. 375-419, dgms. 5). — Experiments in which dogs were fed lard and later raw 

 fat pork showed that the sparing value of fat was constant, being about 7 per 

 cent. 



An efficiency curve of the fat was obtained by platting the sparing value 

 against, the amount fed. This curve reaches its maximum at about 150 per 

 cent of the necessary energy supply. Feeding large amounts of fat caused 

 increased elimination of nitrogen through the alimentary ti*act. 



Water balance in rest and in mountain climbing, G. Galeotti and E. SiG- 

 NORELLi {BiocJiciii. Zt-schr., 1,1 {1912), No. 3-.',. pp. 268-286).— Water excretion 

 through the kidneys, lungs, and skin was not affected by altitude alone, but in 

 mountain climbing as much as 4.2 liters passed through the skin in a day. The 

 weight so lost was quickly regained. 



The physiological significance of the segmented structure of the striated 

 muscle fiber, R. L. Lillie {Science, n. sen, 36 {1912), No. 921, pp. 2Jf7-255). — 

 In this paper two views of the cause of muscular contraction are conti'asted, 

 namely, that the process is analogous to the absolution of water by a sheet of 

 acidulated gelatin, and that the process results from transformation of surface 

 energy of the ultimate structural elements or colloidal particles (submicrons) 

 composing the fibrils. 



A comparative study of temperature fluctuations in different parts of the 

 human body, F. G. Benedict and E. P. Slack {Carnegie Inst. Washington 

 Pub. 155, 1911, pp. 73, figs. 38). — The purpose of these investigations was to 

 determine the best place for accurate and constant measurement of body tem- 

 perature, the temperature gradient of the body, and whether or not the tem- 

 perature fluctuations are uniform in different parts of the body. The thermal 

 junction apparatus used is described in detail. 



The conclusion is reached that, aside from the skin temperature, the tempera- 

 ture of the rectum or of the vagina is the best index of body temperature. 



A bicycle ergometer with an electric brake, F. G. Benedict and W. G. Cady 

 {Carnegie Inst. Washington Pub. 167, 1912, pp. 4), figs. 16). — An apparatus de- 

 signed to measure the amount of mechanical work done by a man, and essen- 

 tially the same as that in use at this Department (E. S. R., 21, p. 68), is de- 

 scribed. It consists of a bicycle the rear wheel of which is a copper disc, 

 rotating between the poles of an electro-magnet. The calibration of the instru- 

 ment is described and a study reported of the magnetic reactions in the disc. 



