454 PHYSIOLOGY. 



BILE-PIGMENTS IN THE UKINE. It is usually in cases of icterus 

 that this condition exists when the urine becomes of a decided yel- 

 low color. The pigment usually found is bilirubin. 



Bile-pigment is readily detected by Gmelin's reaction, per- 

 formed by gently pouring the urine upon the surface of fuming 

 nitric acid, when a green-colored ring appears. 



CARBOLURIA. In this condition the urine is greenish brown, 

 becoming darker upon exposure to the air. It occurs either after 

 poisoning by carbolic acid or when the acid has been administered 

 as a drug. 



DRUG-PIGMENTS. After the administration of certain drugs the 

 urine is sure to be colored differently from normal. Those which do 

 this are rhubarb, hsematoxylin, santonin, and methylene blue. 



The Inorganic Constituents. These are derived either from the 

 aliments with which they are introduced into the body or they are 

 formed in the organism by combination with bases of the oxidized 

 sulphur and alimentary phosphorus. They are eliminated with the 

 urine in daily amounts from 16 to 24 grams. 



To these components belong: chlorine, combined chiefly with 

 sodium; phosphoric acid, uniting with potassa, soda, calcium, and 

 magnesia to form basic, neutral, and acid salts; sulphuric acid, in 

 part combined with alkalies and in part united to indol and phenol 

 in the form of aromatic substances (Baumann). The chlorides and 

 the major portion of the phosphates come from the blood; the 

 sulphates and the remainder of the phosphates from the activities 

 of metabolism. 



CHLORIDES occur in the form of sodic chloride. The average 

 quantity excreted is 180 grains daily. If the chlorides be in excess 

 in the food, not so much is given out in the urine as has been intro- 

 duced, since part passes off through the skin and rectum, while 

 another part accumulates in the tissues. Some is decomposed to 

 form the HC1 of the gastric juice. Sodium chloride is absent in 

 early stages of pneumonia. 



PHOSPHORIC ACID. This acid, combined to form the alkaline 

 (sodium and potassium) and earthy (calcium and magnesium) phos- 

 phates, appears in the urine in the daily quantity of about 2 grams. 

 The phosphoric acid of the urine is derived principally from the 

 alimentary phosphates. 



Hence there is an increase of phosphates after a meal composed 

 principally of meat, after muscular and nervous labor. There is 

 pathological increase in diseases of the brain and in osteomalacia; 



