STRUCTURE AND FUNCTION OF THE KIDNEYS. 



361 



The Urine. 



Physical Properties. Healthy urine is a perfectly transparent, 

 amber-colored liquid, with a peculiar, but not disagreeable odor, a bit- 

 terish taste, and a slight acid reaction. Its specific gravity varies from 

 1015 to 1025. On standing for a short time, a little mucus appears in 

 it as a flocculent cloud. 



Chemical Composition. The urine consists of water, holding in so- 

 lution certain organic and saline matters as its ordinary constituents, 

 and occasionally various other matters; some of the latter are indications 

 of diseased states of the system, and others are derived from unusual ar- 

 ticles of food or drugs taken into the stomach. 



Table of the Chemical Composition of the Urine. 



Water, 



Solids- 

 Urea, ....... 



Other nitrogenous crystalline bodies 

 Uric acid, principally in the form of 

 alkaline Urates, a trace only free. 

 Kreatinin, Xanthin, Hypoxanthin. 

 Hippuric acid, Leucin, Tyrosin, Tau- 

 rin, Cystin, etc., all in small 

 amounts and not constant. 

 Mucus and Pigment. 



Salts: 



Inorganic 



Principally Sulphates, Phosphates, "] 

 and Chlorides of Sodium, and 

 Potassium, with Phosphates of 

 Magnesium and Calcium, traces of 

 Silicates of and Chlorides. I 



Organic 



Lactates, Hippu rates, Acetates, and 

 Formates, which only appear occa- 

 sionally. 



Sugar, 



Oases (nitrogen and carbonic acid principally). 



. 967 

 14.230 



10.635 



8.135 



33 



a trace sometimes. 



1000 



Reaction. The normal reaction of the urine is slightly acid. This 

 acidity is due to acid phosphate of sodium, and is less marked soon after 

 meals. The urine contains no appreciable amount of free acid, as it 

 gives no precipitate of sulphur with sodium hyposulphite. After stand- 

 ing for some time the acidity increases from a kind of acid fermentation, 

 due in all probability to the presence of mucus and fungi, and acid 



