148 Account of the New Mineral Spring at Albany. 



Exp. 4. Tincture of galls when poured into a glass of the 

 water immediately strikes a purple color, which after stand- 

 ing for some time increases in intensity, till it becomes near- 

 ly black. 



Exp. 5. Prussiat of Potash. A few drops of this, poured 

 into a glass of this water, changes it to a green color, which 

 on standing for some time, gradually becomes quite blue and 

 deposits a blue sediment ; the effect of this test is, however, 

 repressed by the quantity of alkaline earth which the water 

 contains, for by previously adding a few drops of marine acid 

 to saturate the earths, I found that the color was much 

 more intense. When the water was previously boiled, neither 

 this test nor that of tincture of galls had any effect, which 

 showed that whatever iron was present was held in solution 

 by carbonic acid gas. 



Exp. 6. Solution of silver in nitric acid. When a few 

 drops of this solution are poured into the water, an immediate 

 white and ponderous precipitate falls to the bottom of the 

 glass, which after standing for some time, changes to a light 

 purple color. This precipitate is equally^ abundant, when 

 the water had been previously boiled, which shows the pres- 

 ence of marine acid ; indeed a very accurate estimate of the 

 quantity of this acid may be formed by the abundance of this 

 precipitate. 



Exp. 7. Solution of acetate of lead, when dropped into 

 this water, produces an immediate white cloud and a precipi- 

 tate. The color of this precipitate decides the absence of 

 sulphuretted hydrogen, as the smallest quantity of this gas 

 immediately changes the precipitate to a black ; in the pres- 

 ent case, the decomposition of the acetate was caused, either 

 by the sulphuric or the marine acid, and that it was produced 

 by the latter was evident both from the effect of the former 

 experiment, and from the fact that the precipitate was again 

 soluble in distilled vinegar, which would not have been the 

 case if it had been sulphat of lead, which is perfectly insolu- 

 ble.* 



Exp. 8. Muriat of Barytes, produces no change in the 

 transparency of the water, either when first taken from the 



* The muriat of lead is also perfectly soluble in boiling hot water, 

 largely added, which forms a good distinction between it and the sul- 

 phate and carbonate, the latter being also soluble in acids with effer- 

 vescence. — Editor. 



