152 



HUMAN PHYSIOLOGY. 



URINE. 



Normal urine is of a pale yellow or amber color, perfectly transparent, 

 with an aromatic odor, an acid reaction, a specific gravity of 1020, and a 

 temperature when first discharged of 100 F. 



The color varies considerably in health, from a pale yellow to a brown 

 hue, owing to the presence of the coloring-matter, urobilin or urochrome. 



The transparency is diminished by the presence of mucus, the calcium 

 and magnesium phosphates, and the mixed urates. 



The reaction of the urine is acid, owing to the presence of acid phosphate 

 of sodium. The degree of acidity, however, varies at different periods 

 of the day. Urine passed in the morning is strongly acid, while that passed 

 during and after digestion, especially if the food is largely vegetable in 

 character, is either neutral or alkaline. 



The specific gravity varies from 1015 to 1025. 



The quantity of urine excreted in twenty-four hours is between forty and 

 fifty fluidounces, but ranges above and below this standard. 



The odor is characteristic, and caused by the presence of taurylic and 

 phenylic acids, but is influenced by vegetable foods and other substances 

 eliminated by the kidneys. 



COMPOSITION OF URINE. 



Water ' 



Urea 



Other nitrogenized crystalline bodies, uric acid, } 



principally in the form of alkaline urates, 

 Creatin, creatinin, xanthin, hypoxanthin, 

 Hippuric acid, leucin, tyrosin, taurin, cystin, all in 



small amounts, and not constant, 

 Mucus and pigment, 



Salts 



Inorganic: principally sodium and potassium sul- 

 phates, phosphates, and chlorids, with magnesium 

 and calcium phosphates, traces of silicates and 

 chlorids, 



Organic: lactates, hippurates, acetates, formates, 

 which appear only occasionally, 



Sugar 



Gases (nitrogen and carbonic acid principally). 



967.0 

 14.230 



10.635 



8-135 



a trace 



1,000.000 



