194 CLINICAL DIAGNOSTICS. 



Method. Pour some of the urine into a conical glass, previ- 

 ously stirring the same with a glass rod to be sure to get an 

 average sample. The urine is then set away to allow the solid 

 particles to settle out; with horse urine this is a rather slow 

 process. To prevent decomposition during the process of sedi- 

 mentation, add a few drops of chloroform. Remove some of the 

 sediment with a pipette and examine a drop on a slide, under 

 the microscope. 



A. Crystalline Constituents of Urine. 



The reaction of the urine itself gives us a certain clue 

 as to the character of the sediments. The normal alkaline 

 urine of herbivora contains (see p. 151) carbonate of 

 lime and small quantities of neutral phosphates Ca 3 (P0 4 )o. 

 Such sediment does not dissolve when heat is applied, but the 

 addition of hydrochloric acid produces solution, and develop- 

 ment of CO,. The sediment which forms in the acid urine 

 of carnivora consists of acid urates and acid phos- 

 phates which dissolve on being heated. 



To determine accurately the nature of the crystalline 

 sediment a microscopical examination must be made ; the 

 forms of the crystals indicate their nature. Amorphous salts 

 can be recognized by micro-chemical tests only. 



a. Carbonate of lime crystallizes in globules with radi- 

 ate markings, if the globules are large a concentric marking 



Fig. 43. Fig. 44. 



Oxalate of Lime. Uric Acid. 



can also be observed. Carbonate of lime crystals also occur 

 in form of breakfast rolls, dumb-bells, whetstones and 

 crosses. Amorphous powder of carbonate of lime can be 



