18 HOT SPRINGS, ARKANSAS. 



trated hydrochloric acid. One c. c. of sulphanilic acid (containing 1 



gram in each 100 c. c. of water) was then added, followed by 1 c. c. of a 

 solution of naptlrylamine hydrochloride (obtained by boiling 0.5 grams 

 of the salt with 100 c. c. of water for ten minutes at constant volume), 

 and the whole well mixed. The Nessler jar was then set aside for half 

 an hour, along with several other Nessler jars containing known amounts 

 of a standard nitrite solution (containing 0.0001 milligram of nitrogen as 

 nitrite in each c. c), made up to 100 c. c. with nitrite-free water, and 

 treated with hydrochloric acid, sulphanilic acid, and napthylamine 

 hydrochloride in the manner just described. By comparing the depth 

 of pink color in the known and unknown solutions the amount of 

 nitrite could be determined. 



Free ammonia. — A large flask of about li-liter capacity was con- 

 nected to an upright bulbed condenser by means of a rather large glass 

 tube and soft, new, rubber-stopper connections. In this was placed 5 

 c. c. of a saturated solution of sodium carbonate and 200 c. c. of ammonia- 

 free water. The water was distilled off in 50 c. c. Nessler jars until no 

 more ammonia was shown, when the jars were nesslerized. Five hun- 

 dred c. c. of the water under examination was now added and the dis- 

 tillation in 50 c. c. Nessler jars continued till ammonia ceased to be 

 given off. About four or five jars were usually necessary. These jars 

 were nesslerized and the depth of color compared with that in other 

 jars which contained known amounts of a standard ammonium chloride 

 solution (containing 0.01 milligram of NH 3 in each c. c), made up to 50 

 c. c. with ammonia-free water and nesslerized in the same manner. 



Total ammonia. — The same apparatus was used as that mentioned 

 in the paragraph above. In it were placed 200 c. c. of distilled water 

 and 50 c. c. of alkaline permanganate solution (prepared by dissolving 

 200 grams of potassium h) T droxide and 8 grams of potassium perman- 

 ganate in 1,250 c. c. of water and boiling the whole down to about 1 

 liter). The water was distilled off in 50 c. c. Nessler jars till ammonia 

 ceased to come over. Five hundred c. c. of water under examination was 

 now added and the distillation continued till ammonia ceased to come off. 

 Six jars were in all cases sufficient. These jars were nesslerized and com- 

 pared with nesslerized jars of known strength just as in the determination 

 of free ammonia. From the total ammonia thus found subtract the free 

 ammonia and the result is the albuminoid ammonia in 500 c. c. of water. 



Many precautionary details of the two above methods are not given, 

 but can be found by consulting any good book on water analysis. 



Oxygex-coxsuming capacitt. — In making this determination two 

 solutions were first prepared: (1) A standard solution of potassium 

 permanganate containing 0.3952 gram to the liter, each c. c. of which 

 has 0.1 milligram of oxygen available for oxydation; and (2) a stand- 

 ard solution of oxalic acid containing 0.7875 gram of crystalized oxalic 

 acid to the liter. The value of the oxalic acid in terms of the perman- 

 ganate was determined by boiling 10 c. c. of oxalic-acid solution and 200 

 c. c. of distilled water with 10 c. c. of sulphuric acid (1-3) and titrating 

 the fluid while boiling with the standard permanganate solution to the 

 appearance of a pink color. In the actual determination 200 c. c. of 

 the water in a porcelain dish was treated with 10 c. c. of sulphuric acid 

 (1-3) and the whole brought to the boiling point. Standard perman- 

 ganate was run in until the water was quite red and the boiling con- 

 tinued for ten minutes, adding permanganate every now and then to 

 keep the pink color about the same. The boiling was now stopped. 



