URINARY APPARATUS. 193 



are assured of the quality of the yeast and that it is free 

 from traces of sugar. 



The phenylhydrazin test (C6H8N2) of V. Jacksch (Modifica- 

 tion of tsch'baum) is very reliable for the urine of the dog (Regen- 

 bogen) Mix 5 drops of phenylhydrazin, 20 drops of glacial acetic 

 acid and 50 drops of urine in a test tube and boil gently for one 

 minute; add 25 drops of officinal sodium hydrate solution and 

 again raise to boiling point. Allow the mixture to settle for 12-24 

 hours and then make a microscopic examination of the sediment. 

 If the urine contained sugar bunches of yellow, needle-like crystals 

 of phenylglukosazone will be found. 



Fig. 42. 



Carbonate-of Lime. 



Lactose occurs in the urine of cows advanced in preg- 

 nancy, disappears after calving and reappears when the milk 

 ducts become obstructed. 

 C. Microscopical Examination oftheUrine. 



If the examination thus far conducted reveals any im- 

 portant alterations, we complete the same with the micro- 

 scope. A microscopic examination of the urine 

 in diseases of the urinary organs is of even 

 greater importance than a chemical analy- 

 sis. 



