URINE. 117 



AMMONIA. 



Ammonia in the form of ammonium salts is present in 

 the urine of carnivora to the extent of 0.3-1.2 (average 0.7) 

 grms. for 24 hours. Its function in the body consists in 

 combining with and thus rendering non-toxic the mineral 

 and organic acids which appear in the organism, either after 

 their ingestion or their formation in metabolism. The 

 amount found in the urine is, therefore, markedly increased 

 in certain pathological states (e.g. diabetes) in which more 

 or less large quantities of organic acids make their appear- 

 ance in the blood as a result of disordered metabolism. 



Quantitative Estimation. 



Prepare two 500-cc. wide-mouthed Erlenmeyer flasks and 

 one tall cylinder (100 c.c. graduate) ; into the neck of each 

 insert a two-hole rubber stopper, one hole of which is pro- 

 vided with an L-shaped glass tube, each arm being about 3 

 inches long, the other hole provided with an L tube, the long 

 arm extending to within one-quarter inch of the bottom of 

 the vessels. A Folin absorption tube may be employed in- 

 stead of the long arm in the absorption flasks. 



Place 25 c.c. of urine in the tall cylinder with about one 

 gram of dry sodium carbonate; cover the urine with one-half 

 inch of crude petroleum to prevent foaming. 



To each flask add 20 c.c. ^ H 2 S0 4 , 200 c.c. of distilled 



water and a few drops of an indicator (Congo red or alizarin 

 red). Place the three bottles in series with the cylinder in 

 the middle, and connected in such a manner that the short 

 arm of one bottle is attached to the long arm of the succeeding 

 one. The long arm of the first flask is open to the air; the 

 short arm of the last bottle must be connected with a suction 

 pump. The purpose of the first flask is to insure the passage 



