102 AEON AND HOCSON. 



finely ground in a mortar, the powder being kept in a closed bottle. Determina- 

 tions of total nitrogen (Kjeldahl) and phosphorus (Neumann's method) were 

 performed on all samples of foodstuffs, urines and faeces. The somewhat com- 

 plicated apparatus described by Neumann was not used for the destruction of 

 the organic material, but a simpler device of my own design was employed. 30 The 

 substance to be analyzed was placed in a 750 cubic centimeter Jena round flask 

 with a long neck, 10 to 15 cubic centimeters of sulphuric and nitric acids were 

 added at the beginning, whereas when the digestion approached completion, nitric 

 acid alone was added. 



The detailed records of the experiments are given at the end of this paper. 



The subject during the first experimental period (III) of four days 

 received 10.99 grams nitrogen and 1.67 grams phosphorus daily; he 

 excreted 10.61 grams nitrogen and 1.66 grams phosphorus per da} r , so 

 that nitrogen and phosphorus equilibrium practically existed, thus de- 

 monstrating that the food as given, . representing about 1,900 calories 

 and containing 70 grams of protein per day was sufficient to maintain 

 a man weighing 52.5 kilos and performing practically no .work. The 

 intake of phosphorus, 1.67 grams or 0.032 gram of P 2 5 per kilo of 

 body weight, was absolutely sufficient. This amount is doubtless lower 

 than the figure obtained as a result of experiments on Europeans, which 

 amount has been regarded almost as the minimum amount of phosphorus 

 permissible; but it corresponds approximately to the quantity of phos- 

 phorus demanded by dogs per kilo of body weight which, according to 

 the experiments of Meyer, 31 is -0.035 gram only. 



During the second period (IV) the man received very nearly the same 

 diet, with the difference that bran from polished rice was added. He 

 took 11.49 grams nitrogen per da}', of which 9.61 grams were in the 

 same form, namely, as rice, bread, and fish, as in the foregoing period, 

 whereas 1.88 grams were present in the darac. The quantity of nitro- 

 gen taken is slightly higher, but it was necessary to assume that the 

 nitrogen compounds in the darac are less digestible than those in the 

 other foodstuffs. The quantity of phosphorus (5.46 grams) was more 

 than three times as great as during the first period, but only 1.45 gram 

 of the phosphorus was present in the same foodstuffs as were employed 

 in the first experiment and 4.01 grams were in the darac (rice bran). 



The outgo of nitrogen was 10.92 grams; that of phosphorus, 4.84 

 grams; the nitrogen balance was only slightly higher in this experiment 

 than in the first one, but a retention of more than 0.5 gram phosphorus per 

 day took place. The observation is very common that during the 

 taking of a diet rich in phosphorus small amounts of the latter are 

 retained. 



The relative distribution of nitrogen and phosphorus in the urine 

 and faeces was as follows: In the first portion of the experiment 24.06 



3 °Handbuch der biochemischen Arbeitsmethoden. Berlin and Wien. (1909), 

 1, 388. 



