FOODS HUMAN NFTRTTTON. 1071 



11 moderate diuretic to men and other aiiiiu.ils. 'i'lic diuresis is associated witii 

 vaso-dilatatiou of the kidney." 



The excess of energy due to the elimination of protein and its naeasure- 

 ment, A. ('iiai'VKau {('diiiiit. RcinL Acud. ,Sci. \l'(iris\. I)) {l!)l)7), Xo. ■'>, pi). 

 237-2 'i-i). — Tlie measurements of enei'f,'.v reported durinj: tlie digestion and 

 utilization of different nutrients showed, according to tlie author, that more 

 energy is given off as heat when protein is assimilated than is tlie case with 

 other nutrients. In general, the energy expenditure of a fasting subject is 

 augmented when the subject is fed, by the energy necessary for the digestion, 

 alisor])tion, and assimilation of nutrients. 



The difterent nutrients do not retiuire the same ( xpeiiditure. N'ariations of 

 this character are shown and exji'lained very well in tlie case of a.ssimilation, 

 which is accomplished by the incorporation of food iiotential into reserve fat. 

 With carbohydrates and fat tlie incorporation is accom])lislied eccmoniically, the 

 fat having only to be adapted to its new situation, while the carbohydrates 

 liave to be converted into fat by a simple process that is practically neutral 

 from a thermic point of view. With respect to protein the transformation into 

 fat is much more ditticult. The production of the fat reserves at the expense of 

 the food proteid explains, therefore, very well the greater energy expenditure 

 connected with the usage of the meat ration. This production residts in an in- 

 complete oxidation (to urea) of the potential proteid, an oxidation which 

 liberates a notalde quantity of energy without other utilization than that of the 

 chemical metabolism for which the energy is employed. 



With very large meat rations the actual energy thus employed for the forma- 

 tion of reserves of fat has a considerable value, but the ration need not be 

 excessive for the process of transformation of protein and fat to occur. Even 

 in small quantity the protein of the ration fulfills its double destiny of working 

 for the renovation of the tissues and of concurring in the maintenance of a 

 fat reserve. The result of this is that the greater expenditure of energy 

 connected with a meat diet manifests itself clearly in the case of subjects 

 nourished with rations capable only of maintaining an ecjuilibrium of nutrition. 



All of these facts are incompatible with the principle of isodynamie substitu- 

 tion. The nutritive value of the nutrients is not to be sought in their heats 

 of combustion. The theory of food and nutrition can no longer be presented in 

 such simple fashion. 



Concerning protein metabolism, .1. IIamalainen and W. IIelme (Skatid. 

 Arch. l']n/sii,l., 10 (]<K)7), Ao. l-.l. pii. IS 2-200). —When egg white. " protone," 

 and roast veal were each added to a liasal ratitm it was found that the excre- 

 tion of the extra nitrogen was slower on the egg diet tlian on tlie other diets. 

 Similar results were also noted with the sulphur excretion, the extra sulphur of 

 "protone" and veal being re<'Overed in 2 or 8 days as comjiared with G days 

 in the case of the egg wliitc The experimental dat.-i are not regarded as 

 sufticient for general deductions regarding the excretion of phosphorus. 



The chemical mechanism of protein assimilation, ('. 1na(;aki (Ztxclir. 

 I'lil/siol. Choii., 50 {1007), Ao. (>, /i/). .'i.'iD-Ji71). — Experiments made with cells 

 and isolated cell nuclei led to a number of geuex'al conclusions. According to 

 the author, nucleohiston iniites with albuinoses and forms salt-like bodies when 

 it is in a free or dissociated condition, and it follows that albumoses formed in 

 the body or artificially introduced into the circulation can be taken up or fixed 

 by the cell substance. 



Nitrogen balance on a mixed ration low in iirotein, U. Spadaro (Arch. 

 FisioL. 3 (I!)0<;\. Ao. .T. pp. o3-l-5.1s : ,//;x. //- Zriilhl. I'lnfsiol., 20 (.1906), Ao. 23, 

 p. ls!l). — The author found that in a 4-day expcriniciital jteriod he was prac- 

 tically in nitrogen e(piililiriuni on ;i mixed diet suiiplying l.").:{ gni. nitrogen per 



