1916] FOODS HUMAN NUTRITION. 473 



of sulphur compounds was gradually diminished. The body weight decreased 

 1.5 lbs., probably owing to the monotony of the diet. 



Relative toxicity of substances found in foods, A. N. Cook and Sylvanna 

 Elliott {Jour. Indus, and Engin. Chem., 8 {1916), No. 6, pp. 503, 50 Jf). — Experi- 

 mental data are reported indicating the comparative toxicity of such sub- 

 stances as sodium benzoate, alum, caffein, carbolic acid, etc., in the case of 

 laboratory animals (frogs and goldfish) living in solutions of these chemicals. 

 The authors conclude that " experiments of this nature, at least upon animals 

 so distantly related to man, do not furnish conclusive evidence of the effects 

 of such substances upon the human system." 



The fate of inorg'anic nitrogen in the metabolism of the dog, W. Caldwell 

 and H. R. S. Clotwokthy {Biochem. Jour., 10 {1916), No. 1, pp. 14-25). — A 

 number of feeding experiments with laboratory animals (dogs) are reported, 

 which were undertaken to determine whether the protein of food may be re- 

 placed by inorganic nitrogen in the form of ammonium salts. The animals 

 received a basal ration consisting of potatoes, dog biscuit, flour, dried milk, 

 salt, and water during a preliminary period until nitrogen excretion was 

 approximately constant. The dogs then received, in addition to the basal 

 ration, known amounts of different ammonium salts, the fate of which was 

 investigated by urine analysis. 



A uniform retention of the added nitrogen was not observed nor was the 

 extra nitrogen always excreted in the same form. Although urea was some- 

 times found in the urine, the authors were not convinced that it was synthe- 

 sized from ammonia nitrogen. In the authors' opinion the form in which the 

 added nitrogen is excreted depends on the ammonium salt ingested, and ap- 

 parently on the ions into which the ammonium salt is dissociated. 



Nitrogen metabolism during pregnancy, K. M, Wilson {Bui. Johns Hop- 

 kins Hosp., 21 {1916), No. 303, pp. 121-129, figs. 3). — Observations were made on 

 the nitrogen metabolism in three normal pregnancies, in one case from the 

 tenth to the fourteenth week, and in two other cases for the last 133 and 101 

 days of the pregnancy and also for a short time in the puerperal period. 



From the data reported it is evident that " in the perfectly normal pregnant 

 woman, storage of nitrogen begins at a much earlier period than has hitherto 

 been supposed ; possibly the organism may acquire the capacity for storing 

 nitrogen from the very beginning of the pregnancy. In the early months this 

 storage is far in excess of the actual needs of the developing ovum, and the 

 excess must be added to the general maternal organism. Storage of nitrogen 

 continues throughout the entire duration of pregnancy, being most marked 

 during the last few weeks, when the fetal needs are at a maximum. 



" The nitrogen stored is greatly in excess of the actual needs of the develop- 

 ing ovum, so that, apart from the amount needed for the hypertrophy and 

 development of the genitalia and breasts, a large proportion of the nitrogen 

 stored is added to the general maternal organism as ' Restmaterial ' . . . 

 [although no positive statement is made] concerning the form in which this 

 reserve is stored. . . . The nitrogen capital of the maternal organism is thus 

 increased, though the reserve supply may possibly be entirely exhausted during 

 the puerperium and period of lactation." 



There was a relative, though not necessarily an absolute, increase in the 

 percentage of urinary nitrogen excreted as amino acids, and also a tendency 

 for the percentage of ammonia nitrogen to increase during the last weeks of 

 pregnancy. 



Acidosis in diabetes, R. T. Woodyatt {Jour. Amer. Med. Assoc, 66 {1916), 

 No. 25, pp. 1910-1913) .—The author summarizes and discusses in this paper 

 information regarding the underlying causes of acidosis as related to the 



