92 Geological Survey of Canada. 



gypsum, of which the water does not contain a trace, but consist of 

 carbonates, with silica and organic matter. Meanwhile the water be- 

 comes more highly colored, and now exhibits an alkaline reaction with 

 test papers. 



The recent water, mingled with hydrochloric acid and a salt of baryta 

 remains clear for a time, but after an hour a faint turbidness appears 

 indicating k irace of sulphate. With nitrate of silver and nitric acid, a 

 slight milkiness from the presence of chlorids is perceptible. The 

 amounts of sulphuric acid and chlorine were determined onportions of 

 two or four litres of the water reduced by evaporation to a small volume, 

 and acidulated. The precipitate obtained by the addition of a few 

 drops of nitric acid and nitrate of silver, was scanty and reddish color- 

 ed. After twelve hours of repose it was collected, dissolved from the 

 filter by ammonia, and the pure chlorid of silver thrown down by a 

 large excess of nitric acid, while the silver-salt of an organic acid re- 

 mained in the solution. 



When the precipitate obtained during the evaporation of the water is 

 boiled with a dilute solution of potash, the organic matter is dissolved, 

 and the akaline solution assumes a bright brown color which becomes 

 paler on the addition of acetic acid; acetate of copper produces no pre- 

 cipitate in the liquid thus acidulated ; but on adding carbonate of 

 ammonia and heating the mixture, a minute white flocculent precipitate 

 separates, having the characters of crenate of copper. Another portion 

 of the precipitate by evaporation was dissolved in hydrochloric acid, 

 and decolorized by boiling with chlorate of potash ; on evaporating the 

 solution a portion of silica separated, and the liquid gave with ammonia 

 a colorless precipitate, which was chiefly composed of alumina ; re-dis- 

 solved in hydrochloric acid however, it gave with a sulphocyanid, evi- 

 dence of the presence of oxyd of iron, and with molybdate of ammonia 

 an abundant yellow precipitate indicating phosphoric acid. The alumin- 

 ous precipitate heated on silver foil with caustic potash gave a slight 

 but decided reaction of manganese. 



When the concentrated water, with its precipitate, was evaporated 

 to dryness in a platinum capsule with excess of hydrochloric acid, and 

 the residue treated with acidulated water, a large amount of silica was 

 obtained, equal to one-third of all the solid matters present. This silica 

 was white after ignition, and perfectly pure. A portion of the water 

 Was evaporated to one-fortieth and filtered ; the residue being farther 

 evaporated to one-fourth, deposited on the platinum capsule an opaque 

 film, which was but imperfectly soluble in hydrochloric acid. The con- 

 centrated liquid was dark brown and alkaline, reddening turmeric paper; 

 it was now evaporated to dryness, ignited and treated with water. The 

 soluble portion was strongly alkaline to test papers, and perceptibly so 

 to the taste. The residue insoluble in water was treated with strong 

 hydrochloric acid, which dissolved a portion of lime without efferves- 

 cence, and left a residue of pure silica ; the acid solution contained no 

 magnesia. 



