On the Determination of Ammonia. 



137 



carbonate (6), practically one third of the ammonium remained 

 undisplaced. 



These observations gave strong support to our second conclu- 

 sion regarding the cause of the anomalous ammonia results that 

 prompted this study. 



Eighth Series. — This investigation was concluded with a deter- 

 mination of the effects of relatively very great excesses of sodium 

 carbonate in the aeration process. The results of this final test, 

 which are given in Table II, merely confirmed the conclusion al- 

 ready drawn that Folin's splendid method fails, in the case of triple 

 phosphate, to give perfectly accurate results for ammonia content. 



Table II. 



Eighth Series. Group R. 

 Pure, crystalline ammonio-magnesium phosphate (Eimer & Amend product), 0.5 

 gram. Sodium carbonate, 2-16 grams. Periods of aeration (2), 5 hours. Loss of 

 ammonia : maximum, 35.19 per cent; minimum, 12.04 pe r cent. 











Volume of Standard Acid Solution 













Required to Neutralize. 







Determi- 



Weight of 



Weight of 











Ammonia 



Group. 



nation. 



NH.MgP0 1 



Na 2 CO a 



After Aeration. 



If All NHj 



Lost, 



No. 



Gram. 



Grams. 









had been 



Per Cent. 











5 Hrs., 



5 Hrs., 



Total, 



Liberated, 













c.c. 



(a) <=.c. 



c.c. 



c.c. 





R 



85 



O.05 



2 



O.65 



O.05 



O.70 



I.08 



35-19 





86 



O.05 



4 



O.60 



O.15 



0-7S 



I.08 



30.56 





87 



O.05 



8 



O.70 



O.IO 



O.80 



I.08 



25.93 





88 



O.05 



16 



O.80 



O.I5 



0-95 



I.08 



I2.04 



Our paper on this subject will soon be published in the Journal 

 of Biological Chemistry. 



