URINARY APPARATUS. 181 



which precipitate in the bladder as the fluid becomes more 

 or less condensed from reabsorption processes. When ex- 

 posed to the air in a vessel the turbidity increases because 

 the soluble acid calcium carbonate (C0 3 H),Ca after giving 

 off CO, H 2 is converted into insoluble calcium carbonate 

 C0 3 Ca. This conversion occurs most rapidly at the surface 

 of the liquid, causing the formation of a thin fragile mem- 

 brane at that place (crystals of calcium carbonate). Small 

 granules of lime also precipitate and constitute a part of the 

 sediment. Not infrequently these lime granules are im- 

 bedded in cylindrical masses of mucus that were molded in 

 the uriniferous tubules. This normal turbir' urine has an 

 alkaline reaction. 



Clear urine of the horse is always abnormal 

 and usually has an acid reaction ; upon cooling, however, it 

 may become turbid. The turbidities consist of precipitated 

 phosphates, oxalate of lime, and crystals of gypsum and uric 

 acid salts ; these dissolve upon heating the fluid. These salts 

 can be recognized by means of a microscopical examination. 



Abnormal turbidity may be due to the presence 

 of organized elements (cells) ; recognized by means of mic- 

 roscopical examination. 



In the ox, sheep and goat the normal urine is 

 clear when voided but becomes turbid on standing ; precipita- 

 tion of monocarbonates. 



The urine of the dog is clear in health, becom- 

 ing slightly turbid after standing ; due to precipitation of 

 uric acid salts. 



d. Consistency of urine. Normal urine of the horse 

 is a rather thickish, slimy, viscous fluid ; the viscosity being 

 due to an admixture of murine which occurs in the bladder. 

 Besides this the cast off epithelial cells undergo a process 

 .of swelling and thus increase the consistency of the urine. 

 Acid horse urine is always less viscid than such ajs sjivts 



