FREE AND ALBUMINOID AMMONIA 219 



into the distilling flask, and about i gram of recently 

 ignited sodium carbonate is added. The flask is then 

 closed and the contents boiled. In the first case four 

 Nessler glasses of distillate (each containing 50 c.c.) are 

 collected. The distillation is then stopped and to each 

 of the cylinders is added 2 c.c. of the Nessler reagent, 

 the solutions mixed thoroughly by rotating 

 the glasses, and the latter then placed in the 

 order of collection on a white tile or piece of 

 dull white paper. 



Into five other Nessler glasses are now 

 run respectively i, 2, 4, 6, and 8 c.c. of the 

 dilute standard solution of ammonium chlo- 

 ride ( = 0-01, 0'02, etc., mg. of NH3); the 

 volume is then made up to 50 c.c. in each 

 case with ammonia-free water, and to each 

 is added 2 c.c. of Nessler . reagent. After 

 standing for a few minutes the colours of the Nessler glass, 

 distillates are compared with those of the 

 standards, and the number of cubic centimetres of 

 ammonium chloride solution required to match the 

 colour of the sample distillate in each case is noted 

 down. The total number of cubic centimetres re- 

 quired is the number of hundredths of a milligram 

 of free or saline ammonia contained in 500 grams of 

 water. 



Albuminoid Ammonia. — After the above estimation, 

 50 C.C. of alkaline permanganate solution are added to 

 the water remaining in the distilling flask and the 

 distillation is continued until at least three more 

 Nessler glasses of distillate have been collected. These 

 are treated in the same way as before and compared, 

 with the standards. 



Example. — Five hundred c.c of water taken for 

 analysis. 



