g£ ALUMINOUS CHALYBEATE SPRING IN I. OF WIGHT. 



white and gelatinous. Caustic potash being added to the 

 clear fluid, ammonia was disengaged, showing that it con- 

 tained an excess of muriate of ammonia; and acetic acid 

 being added to another portion of the same liquor, no tur- 

 bidpess 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 

 succinate of ammonia with excess of ammonia, formed a 

 gelatinous mass, which being edulcorated, dried, and ulti- 

 mately heated to redness, weighed 2*4 grains. 

 Another por- 3. Another portion of residue, weighing thirty grains, 

 timK being treated in a manner exactly similar to that ju-.t de- 



scribed; with this exception, that the redissolution of the 

 alumine in muriatic acid and its subsequent precipitation 

 by succinate of ammonia, were omitted ; the gelatinous pre- 

 cipitate, heated to redness, weighed 1*4 grain f, which 

 afforded as close a coincidence with the former result as 

 may be well expected in processes of this kind. 

 Crystals of 4. Having never been able to obtain, by the mere evapo- 



*!um obtained ration of the water, any appearance of crystals resembling 

 potash, alum, I was desirous for the sake of obtaining farther evi- 



dence on the subject, to bring the sulphate of alumine to 

 a crystallized state, by artificially supplying what I con- 

 ceived to be wanting for the completion of that process. 

 For this purpose, having dissolved about thirty grains of 

 residue in distilled water, I added to the filtered solution 

 two or three drops of a solution of carbonate of potash, and 

 evaporated it very slowly; crystals were thus obtained, 

 dispersed in the saline mass, which, though of a size scarcely 

 exceeding that of a pin's head, had a distinct octohedral 



* The particulars of the manner in which the silica is separated, by 

 the intervention of muriatic acid, will be detailed uader the head 

 Silica, in another part of this paper. 



f The real weight was 1-6 grain, but 02 of a grain were deducted, on 

 account of the quantity of silica known, by other experiments, to have 

 been present, as will be seen under the head Silica. It may be pro- 

 per to mention, that the gelatinous precipitate, during its gradual 

 desiccation, shrunk into small fragments resembling coarsely pul- 

 verized glue, an appearance which is well known to characterize 

 alumine. - 



form 



