FOODS ANIMAL PRODUCTION. 475 



assimilated. In the first experiment all the material excreted in the 

 feces came from the body. In the second experiment the author calcu- 

 lates that 4.27 gm. or 74 per cent per day of the feces came from the 

 body, and in the third experiment 8.56 gm. or 66 per cent. The per- 

 centage of nitrogen in the dry matter of the feces was 5.11 in the first 

 experiment, 4.17 in the second, and 4.35 in the third, being almost the 

 same whether no food or an abundance of nitrogen-free food was con- 

 sumed. When animal food or many vegetable foods are consumed the 

 greater part of the feces is believed to consist of metabolic products. 

 Therefore, since so much metabolic nitrogen leaves the body in the feces 

 it is not sufficient to consider only the nitrogen excretion in the urine 

 in determining the amount of protein required by the body, or similar 

 problems. In all such problems a considerable amount of metabolic 

 nitrogen in the feces must be taken into account. 



The author reviews at length the work of previous investigators on 

 the excretion of metabolic nitrogen and other products in the feces and 

 compares his results with those obtained by others. 



Contribution to the question of the formation of hippuric acid 

 in the animal organism, T. Pfeiffer and W. Eber et al. (Landw. 

 Vers. Stat, 49 (1897), N~o. 1-2, pp. 97-144).— The authors made a number 

 of experiments with horses on the formation of hippuric acid. The 

 influence of pentoses and of the putrefaction of protein on the formation 

 of hippuric acid and similar questions were studied. 



Among the conclusions reached were the following: The putrefac- 

 tion of protein can not be regarded as the sole source of the nitrogen - 

 free components of hippuric acid. The pentoses have an influence upon 

 the formation of hippuric acid, though some other factor which has not 

 hitherto been taken account of is concerned in it also. More definite 

 conclusions could not be drawn from the present experiments. The 

 authors are continuing their investigations. 



Chronic oxalic acid poisoning, W. Caspari (Inaug. Diss., Berlin; 

 abs. in Gentbl. agr. Ghem., 26 (1897), Xo. 8, pp. 529-533).— The author 

 made a number of experiments with rabbits on the effect of feeding 

 beet leaves and a ration to which oxalic acid neutralized with calcium 

 carbonate or sodium carbonate was added. The following deductions 

 were drawn from the results: Food containing oxalic acid in small 

 quantity and in a comparatively insoluble form is not harmful if fed 

 for a short time, but is beneficial, since it improves the appetite. 

 When fed in large quantities or in soluble form serious injury is caused 

 and chronic oxalic poisoning induced. The addition of calcium carbon- 

 ate to rations containing oxalic acid is regarded as a preventive of 

 poisoning. 



Experiments were also made with dogs. Oxalic acid was found to 

 increase the excretion of calcium in the urine and feces. 



The assimilation of iron, E. Hausermann (Ztschr. pliysiol. Ghem., 

 23, No. 6, pp. 555-592). — The author reports experiments made with rats, 

 10078— No. 5 6 



