being again heated was converted into a bright yellow coloured mass, 

 which had its colour destroyed by water, and restored by muriatic 

 acid. With this acid the powder was digested for some time, then 

 well washed with water, carefully collected, dried, and ignited ; it 

 then weighed 50.06 grs. and exhibited the properties of Silex. 



The acid solution, united to the aqueous lixivia, was mixed with a 

 solution of subcarbonate of potash, which caused a powder of a dull 

 orange colour to fall down. This was repeatedly washed ; the wash- 

 ings set aside ; the residual powder dried, and then boiled in a silver 

 crucible, with successive portions of caustic alkali, until the alka- 

 line liquors ceased to afford any precipitate on the addition of 

 muriate of Ammonia. A powder of a deep brown colour remained 

 undissolved by the alkali. The alkaline washings collected were 

 decomposed by a solution of Muriate of Ammonia, a white powder 

 separated, which, washed carefully, and dried at a red heat, 

 weighed 22.75 grs. ; it was Alumine. (G). From the liquor re- 

 maining after the precipitation of the muriatic solution by subcar- 

 bonate of Potash, a brown flocculent powder was collected by 

 means of evaporation, and when dry, appeared of a yellowish 

 white colour; it weighed one grain, and consisted of oxide of 

 Manganese, equal to 0.50 grs. and oxide of Iron united to some 

 Lime, Magnesia and Silex, together equal to 0.50 grs. 



The substance mentioned above on ^vliicli caustic alkali had 

 no action, and of a deep brown colour, formed a partial solu- 

 tion with Muriatic Acid, and tliere were obtained from it 1.50 grs. 

 of oxide of Iron, 0..37 grs. of Silex, and of Alumine \mited to a 

 minute portion of Lime 0.94 grs. (^Ga). The oxide of Iron was ob- 

 tained from the solution bv Succinate of Aunnonia, the other ingre- 

 dients by the usual meani^. The nmriatic liquor formed during the 

 separation of the Alumine from its sokiiiun in ctiuslic potash by 



