1822.] Scientific Intelligence, 465 



decomposed by acetate of barytas, the acetate evaporated, and by heat 

 converted into carbonate. All the lithia and potash were dissolved 

 by repeated boiling in water, the solutions evaporated to dryness, 

 and the residuum was repeatedly washed with cold water to remove 

 the potash, so that lithia only remained. 



Dr. Gmelin found that muriate of lithia gives a beautiful purple 

 colour to the flame of burning alcohol. The sulphate does the same 

 when first dissolved in water, and then thrown down by pure alcohol ; 

 the alcohol burns with a purple flame, and of course no strontian could 

 be present in this experiment. The flame with lithia from lepidolite 

 from Rozena, in Moravia, had green edges like that of the borates* 

 Lithia of the lepidolite from Utoen exhibited this phenomenon much 

 less distinctly. 



V. Analysis of the Red Lepidolite froyn Moravia. 



It had been, ascertained previously that this mineral, besides lithia 

 and potash, contained silica, alumina, oxide of manganese, and fluorip 

 acid. 1 



In order to determine the quantity of fluoric acid, 30 parts of lepi- 

 dolite were mixed with 100 parts of dry carbonate of soda, and kept 

 red-hot during an hour. The fused mass was repeatedly boiled with 

 water, until the water showed no trace of an alkali. Carbonate of 

 ammonia was now mixed with the solution, and while slowly evaporat- 

 ing, a small quantity of the same salt was occasionally added. Silica 

 and alumina fell down, and were separated by a filter. The liquid, 

 after having been saturated with muriatic acid, was kept warm for 

 some time to expel the carbonic acid, which the water might have dis- 

 solved, and then mixed with pure ammonia and muriate of lime in a 

 well-stopped vial. A white bulky precipitate appeared ; it was 

 washed with the same precautions against the influence of carbonic 

 acid, and, when dried, weighed 3*77 parts. Sulphuric acid occasioned 

 the appearance of copious vapours, that had the smell of fluoric acid, 

 and which corroded glass. 



Fluoric and phosphoric acid being so frequently associated in nature, 

 some experiments were made to detect the latter acid. By exposure 

 to heat, the fluoric and free sulphuric acid were expelled, and when 

 the alcohol was poured on the remaining sulphate of lime, and after- 

 ward evaporated, there remained a substance which., after fusion, had 

 a glass-like appearance, which deliquesced when exposed to the air, 

 and was dissolved with the greatest facility in pure water : in this solu- 

 tion, limewater caused a white precipitate. It was, therefore, phos- 

 phoric acid, and the phosphate of lime weighed 0*06 part, which, 

 deducted from the above quantity, leaves 3'71 of fluate of lime; accord- 

 gin to Berzelius, equal to 0-1033 of fluoric acid, or 3*44? per cent. The 

 phosphate of lime contained 0'00337 of phosphoric acid, or 0*112 per 

 cent. 



Thirty parts of lepidolite, fused in the usual way with potash, dis- 

 solved in muriatic acid, evaporated to dryness, and washed, gave 14<-717 

 silica, or 49*06 per cent. The liquid that held the soluble parts in 

 solution was mixed with excess of pure potash, and almost the whole 

 of the precipitate, which appeared at first, was redissolved. The alka- 

 line solution, when neutralized with muriatic acid, and precipitated by 

 carbonate of ammonia, gave 10*08 alumina = 3361 percent ; and the 



New Series, vol.iii. 2h 



