FOODS — HUMAN NUTKITION. 169 



cated yeast from whicb the bitter principle had been removed by treatment with 

 soda was added to a basal ration in a digestion experiment with a man, 86 per 

 cent of the protein from the yeast was resorbed and 88 per cent of the energy 

 utilized. The calculated physiological nutritive value was 74.8 per cent of the 

 total energy. The coefficients of digestibility were organic substances 90, fat 

 70, cellulose 40, and nitrogen-free extract 100 per cent. 



The place of retention or reconjugation of the amino acids in the body, 

 A. WoELFEL {A^ncr. Jour. Physwl., 29 (1912), No. .J, Proc. Amrr. Physiol. Soc, 

 2It {1911), pp. XXXVIII, ZXZ/Z).— Dogs, which had been operated on a few 

 days previously for Eckfistulse, were used in these experiments. Their hepatic 

 arteries were tied, and solutions of amino acids introduced into their washed 

 out intestines. 



All the urine excreted was collected and the animals bled completely. The 

 blood was defibrinated and centrifuged, and the serum thus obtained had its 

 albumin removed and was otherwise prepared for formol titration to test it for 

 an increase in its amino nitrogen content over normal serum. The ammonia 

 and the amino nitrogen in the urines were determined. 



"The small increases of amino nitrogen in the blood and the small increases 

 of formol titratable nitrogen in the urines were far from commensurate with the 

 amounts of amino acid shown by determination to have been absorbed by the 

 intestine. ... 



" That the amino acids are not removed from the blood with the fibrin in the 

 defibrination, or that some constituents of the plasma or the blood corpuscles 

 are not responsible for their disappearance, was shown by control determination. 



"Tissues other than the liver, intestinal mucosa, and blood cells can take up 

 amino acids from blood plasma. Since the tissues in general seem to have such 

 an avidity for amino acids, it is fair to suppose that in them the amino acids 

 can be utilized for the regeneration of albumins." 



The physiology of phosphorus during growth, A. LrpscHxJTz (Pflilger's 

 Arch. Physiol., I'lS (1911), Xo. 1-3, pp. 91-9S). — Basing his opinion on experi- 

 ments with young dogs fed a diet low in phosphorus, the author concludes 

 that the growing organism is able to make use of all available phosphorus, 

 whether it is supplied in small quantities by the food or deposited in the less 

 important organs of the body. 



Biological signifi.cance of casein phosphorus for the growing organism, 

 A. LiPSCHtJTz (Pfliigcr\s Arch. Physiol., l',3 (1911), No. 1-3, pp. 99-108).— The 

 author conducted experiments with growing dogs whose food contained no phos- 

 phorus except that supplied by casein. In his opinion the work is too incom- 

 plete to be conclusive, but indicates that the growing organism can obtain the 

 inorganic phosphorus necessary for its supply from the organic phosphoric acid 

 resulting fi-om the cleavage of casein. 



Microscopic studies on living smooth muscle, E. B. Meigs (Amer. Jour. 

 Physiol., 29 (1912), No. 4, Proc. Amer. Physiol. Soc, 2^ (1911), pp. XIV, 

 XV). — The experiments reported were made with amphibians and were in- 

 tended to throw light on the question whether smooth muscle cells decrease 

 in volume during contraction ; the results " confirm this view." 



The chemical constituents of the ash of smooth muscle, L. A. Ryan and 

 E. B. Meigs (Amer. Jour. Physiol., 29 (1912), No. 4, Proc. Amer. Physiol. Soc., 

 2k (1911), pp. XV, XVI). — The smooth muscle of the bullfrog's stomach was 

 analyzed for potassium, sodium, phosphorus, and chlorin. together with jparallel 

 analyses of the ash of striated muscles from the same frogs. "The work indi- 

 cates that smooth muscle contains somewhat less potassium and phosphorus 

 and somewhat more sodium and chlorin than striated muscle, but the differ- 

 ences are much less marked than has sometimes been supposed. 



