WATER ANALYSIS 43 



That is, the 500 c.c. of sample water yielded ammonia 

 sufficient to match 7 c.c. of standard solution of ammo- 

 nium chloride. (1 c.c. = o-oi mgr. NH 3 ), hence 7 c.c. 

 standard solution equals 7 X o-oi 0-07 mgr. NH 3 , and 

 there is 



0-07 mgr. of free and saline NH 3 in 500 c.c. of sample. 

 or 0-014 mgr. of do. do. do. in 100 c.c. 

 or do. in 100 grm. 



or do. in 100,000 mgr. 



or 0-014 P ar t of do. do. do. in 100,000 parts. 



Note. In Nesslerizing, always add the AmCl solution 

 first to the trial glasses, and the Nessler later. If the order 

 is reversed, a turbidity is produced which prevents accurate 

 comparisons. 



Likewise always use distilled water, ammonia-free. 

 Pure natural water, ammonia-free, will not do, as it appears 

 muddy when compared with distilled water. 



The residue in the flask is used to determine the 

 " albuminoid ammonia," as now described. 



Albuminoid Ammonia is determined by breaking up 

 the nitrogenous organic matter in the water sample by the 

 action of an alkaline solution of potassium permanganate, 

 the nitrogen being converted into ammonia, which is distilled 

 off and estimated as described for free and saline ammonia. 

 All the nitrogenous organic matter is not so decomposed, 

 but the proportion of it which does so is sufficiently uniform 

 to form a basis for deductions. The albuminoid ammonia 

 is approximately ' one-tenth of the nitrogenous organic 

 matter in the water. Solution required is " alkaline 

 permanganate," made by dissolving 8 grm. of potassium 

 permanganate and 200 grm. of caustic potash in 1100 c.c. 

 of distilled water, and boiling down the bulk to 1000 c.c. 

 (1 litre). 



The amount of alkaline permanganate used should be 

 about one-tenth of the bulk of sample taken. It should 

 be mixed with three volumes of water, and boiled down to 

 three volumes. That is, in present case, take 50 c.c. of 

 alkaline permanganate, add to them 150 c.c. of water, and 

 boil down to 150 c.c, which are added to the residue in 



