18 METABOLISM OF ORGANIC AND INORGANIC PHOSPHORUS. 



these cases, the quantity of phosphoric acid in the urine is small. 

 Such a condition is found in herbivora, whose urine is habitually poor 

 in phosphates. The extent of the elimination of phosphoric acid by 

 the urine depends not only upon the total quantity of phosphorus in 

 the food, but also on the relative amounts of alkaline earths and the 

 alkali salts in the food. According to Preysz and Klug 6 and Olsav- 

 szky, the elimination of phosphoric acid is considerably increased by 

 intense muscular work. 



From the transformation of tissues rich in protein or phosphorized 

 nerve substances in the body, an equal relation between the nitrogen 

 and the phosphoric acid in the urine might be expected. Many 

 investigations have been made on this point, but the conditions which 

 affect the elimination of phosphoric acid are not yet sufficient ly 

 known to permit any definite conclusions being drawn from the obser- 

 vations thus far made. 



Of the various forms of phosphate compounds which appear in the 

 urine the following may be mentioned: Tricalcium phosphate, 

 Ca 3 (PO 4 ) 2 , which occurs only in alkaline urines; calcium diphosphate 

 (CaHP0 4 + 2H 2 O) occurs in neutral or only in very faintly acid 

 urines; ammonium magnesium phosphate, triple phosphate, may 

 separate, of course, from an amphoteric urine in the presence of a 

 sufficient quantity of ammonium salts, but it is generally charac- 

 teristic of a urine which has become ammoniacal through alkaline 

 fermentation; amorphous magnesium triphosphate, Mg,(PO 4 ) 2 , occurs 

 with calcium triphosphate in urine rendered alkaline by a fixed 

 alkali, and crystalline magnesium phosphate (Mg 2 (PO 4 ), + 22 H 2 O) 

 which has been observed in a few cases in human urine, and in horses' 

 urine. 



Phosphate calculi may consist of a mixture of the normal phos- 

 phate of alkaline earths with triple phosphate. They also are 

 composed of a mixture of earthy phosphate, triple phosphate, and 

 ammonium urate, surrounding a foreign bod}' as a nucleus. Calculi 

 consisting of triple phosphates alone and stones of simple acid calcium 

 phosphate are seldom obtained. 



SALTS IN THE ORGANISM. 



The body contains in its tissues and liquids a considerable amount 

 of inorganic material. When an} T organ is incinerated this material 

 remains as ash. If the bones, which are rich in mineral material, are 

 omitted the average amount of ash in the human body amounts to 

 about 0.1 per cent of its weight. It consists of clilorids, phosphates, 

 sulphates, carbonates, fluorids, silicates of potassium, sodium, calcium, 



Maly's Jahres-Ber., 1891 r Ji 



b Arch, gesam. Physiol., 1893, 54 :21. 



