URINE. 3OI 



from day to day, thus allowing of the preparation of both a nitrogen 

 and a phosphorus balance, 1 a definite ratio may be established. In 

 experiments upon dogs, which were fed an exclusive meat diet, the 

 ratio of nitrogen to phosphorus, in the urine and feces, was found 

 to be 8.1 : i. 



Pathologically the excretion of phosphoric acid is increased in 

 such diseases of the bones as diffuse periostosis, osteomalacia and 

 rickets ; according to some investigators, in the early stages of pul- 

 monary tuberculosis ; in acute yellow atrophy of the liver ; in diseases 

 which are accompanied by an extensive decomposition of nervous 

 tissue and after sleep induced by potassium bromide or choral hy- 

 drate (Mendel). It is also increased after copious water-drinking. 

 A decrease in the excretion of phosphates is at times noted in febrile 

 affections, such as the acute infectious diseases ; in pregnancy, in the 

 period during which the fcetal bones are forming, and in diseases 

 of the kidneys, because of non-elimination. 



EXPERIMENTS. 



i. Formation of " Triple Phosphate." Place some urine in a 

 beaker, render it alkaline with ammonium hydroxide, add a small 



FIG. 96. 



" TRIPLE PHOSPHATE." (Ogden.) 



amount of magnesium sulphate solution and allow the beaker to 

 stand in a cool place over night. Crystals of ammonium magnesium 

 phosphate, " triple phosphate," form under these conditions. Ex- 



1 In metabolism experiments, a statement showing the relation existing between 

 the nitrogen content of the food on the one hand and that of the urine and feces 

 on the other, for a definite period, is termed a nitrogen balance or a " balance 

 of the income and outgo of nitrogen." 



