562 fairchild: mineral sulphide water 



of a solution of 5 cc. CdClo and set aside for the moment 

 and stoppered. Connection was then made to the regular 

 carbon dioxide train (with the chromic acid tube), air free 

 from carbon dioxide was drawn through the train and 15 

 cc. i-i acetic acid was introduced into the ammoniacal cadmium 

 chloride, partly precipitated as cadmium sulphide together with 

 barium catbonate, by means of a small separatory funnel attached 

 to the Peligot tube. The tube was immersed in a boiling water 

 bath, and the aspiration continued for 30 minutes. Any un- 

 neutralized ammonia fumes may now be caught in the chromic 

 acid. After the test the soda-lime tube showed no increase in 

 weight. The flask containing the non- volatile hydrogen sul- 

 phide and carbon dioxide was next replaced, 4 cc. i-i acetic acid 

 was added to decompose the normal carbonate, and the solution 

 was boiled for a few minutes and cooled 30 minutes more in a 

 current of air free from carbon dioxide. The soda-lime tube 

 showed a gain of 0.0407 gm., whereas 0.0415 gm. was present. 

 Therefore no carbonate formed in this water, a fact confirmed 

 by repeated tests. 



Inasmuch as no half-bound carbon dioxide was formed in the 

 above mixture a new solution was made up of a like amount of 

 sodium hydrosulphide, but containing 0.84 gm. of NaHC03 per 

 liter, the chemical equivalent of the sodium hydrosulphide pres- 

 ent. The first test on 100 cc. boiled as above described in a 

 current of hydrogen showed that 0.0078 gm. CO2 had been 

 driven over into the Peligot tube, as against a possible 0.022 gm. 

 An iodometric determination of the volatilized sulphide gave 

 0.0098 gm., or 38.8 per cent of the total present. Below is a 

 table of the results obtained by decreasing the ratio of the sul- 

 phide to the bicarbonate present in the generator. This ratio 

 was effected by using smaller aliquot portions, and at the same 

 time keeping the amount of sodium bicarbonate nearly constant. 

 Although the water mixture was kept under a layer of toluol in 

 a well-stoppered bottle, its sulphide concentration grew less 

 within a week, hence an occasional check on the sulphide value 

 was necessary. 



