384 



EXCRETION 



febrile patients. It is characterized by a well-marked spectroscopic ab- 

 sorption band at the junction of green and blue. Those who believe urobilin 

 to be identical with hydrobilirubin suppose that the bilirubin is reduced by 

 the putrefactive processes in the intestines, and is conveyed in its reduced 

 form by the blood stream to the kidneys. 3, Uroerythrin, occasionally found. 

 And, 4, Uromelanin. 



Mucus. Mucus sediment in the urine consists principally of the 

 epithelial debris from the mucous surface of the urinary passages. Parti- 

 cles of epithelium, in greater or less abundance, may be detected in most 

 samples of urine, figure 297. As urine cools, the mucus is sometimes seen 

 suspended in it as a delicate opaque cloud, but generally it falls. In inflam- 



FIG. 297. 



FIG. 



FIG. 297. Urinary Deposit of Mucus, etc. 



FIG. 298. Urinary Sediment of Triple Phosphates (large prismatic crystals) and Urate of 

 Amonium, from urine which had undergone alkaline fermentation. 



matory affections of the urinary passages, especially of the bladder, mucus 

 is secreted in large quantities and speedily undergoes decomposition. 



Saline Matter. Sulphuric acid, in the form of salts, is taken in 

 very small quantity with food. Sulphur is also a constituent part of the 

 proteid molecule; hence its elimination, like that of nitrogen, gives a certain 

 measure of proteid metabolism. It is excreted as inorganic sulphates of 

 sodium and potassium, and as ethereal sulphates, compounds of phenol, 

 cresol, skatol, i.e., cresol sulphuric acid (C 7 H ? OSO 2 OH), etc. 



The phosphoric acid in the urine is combined partly with the alkalies, 

 partly with the alkaline earths about four or five times as much with the 

 former as with the latter. In blood, saliva, and other alkaline fluids of the 

 body phosphates exist in the form of alkaline, neutral, or acid salts. In the 

 urine they are acid salts, viz., the sodium, ammonium, calcium, and magne- 

 sium phosphates, the excess of acid being (Liebig) due to the appropriation 

 of the alkali with which the phosphoric acid in the blood is combined, by the 

 several new acids which are formed or discharged at the kidneys, namely the 

 uric, hippuric and sulphuric acids, all of which are neutralized with soda. 



