42 METABOLISM OF ORGANIC AND INORGANIC PHOSPHORUS. 



According to Ehrstrom, who studied phosphorus elimination, from 

 50 to 88 per cent of the phosphoric acid is eliminated in the urine by 

 the human organism, but the average amount given by different inves- 

 tigators varies from 70 to 80 per cent. With animal food almost all 

 the phosphorus is eliminated in the urine, while with vegetable food 

 a larger proportion of the phosphorus is found in the feces. The 

 amounts of calcium and phosphorus present in the food stand in 

 close relationship to one another. The rabbits eliminated from 27 

 to 50 per cent of the ingested phosphoric acid in the urine, a con- 

 siderably lower percentage than ir the case of carnivorous animals. 



ETHER- ALCOHOL-SOLUBLE PHOSPHORUS BALANCES. 



The ether-alcohol soluble phosphorus balances were determined 

 during the principal feeding period. The amount of phosphorus 

 ingested in this form was practically the same in all cases. It is 

 interesting to note the small portion of the 29 per cent of organic com- 

 bined phosphorus in phytin, which is soluble in ether and alcohol. 

 The figures show that 0.59 per cent of the phosphorus was present in 

 phytin as ether-alcohol soluble phosphorus. This shows that the 

 ether-alcohol extracted phosphorus may represent but a small pro- 

 portion of the total organic combined phosphorus. 



The presence of organic phosphorus in the urine has been discussed, 

 but it is interesting to note that the average figures in Tables V and 

 VI show a slightly larger amount of the so-called organic, or ether- 

 alcohol soluble phosphorus in the urine in the case of the rabbits fed 

 on inorganic phosphorus. 



TABLE V .Ether-alcohol-soluble phosphoric acid balances Principal period. 



RABBITS FED ORGANIC PHOSPHORUS. 



aSkan. Arch. Physiol; 1903, 14: 82. 



