Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/243

 in the lixivium rather than actually dissolved; for the solution being left at rest for some time, these particles subsided.

2. To the clear alkaline solution, muriat of ammonia was added, till no further precipitate took place; the precipitate was edulcorated and collected in a filter. It was white and gelatinous. Caustic potash being added to the clear fluid, ammonia was disengaged, showing that it contained an excess of muriat of ammonia; and acetic acid being added to another portion of the same liquor, no turbidness appeared, both circumstances showing that all the alumine was precipitated. This precipitate being dissolved in muriatic acid, in order to separate a minute portion of silica, which it contained, and being again precipitated by succinat of ammonia with excess of ammonia, formed a gelatinous mass, which being edulcorated, dried, and ultimately heated to redness, weighed 2,4 grains.

3. Another portion of residue, weighing thirty grains, being treated in a manner exactly similar to that just described, with this exception, that the redissolution of the alumine in muriatic acid and its subsequent precipitation by succinat of ammonia, were omitted, the gelatinous precipitate, heated to redness, weighed 1,4 grains , which afforded as close a coincidence with the former result as may be well expected: in processes of this kind.

4. Having never been able to obtain, by the mere evaporation of the water, any appearance of crystals resembling alum, I was