Intelligence and Miscellaneous Articles. 393 



alcohol, which did not dissolve it entirely. A white powder re- 

 mained, which was thrown upon a filter, and this was found to be 

 carbonate of potash. The alcoholic solution, exposed to the air, 

 evaporated slowly, and deposited crystallized cinchonia, combined 

 with carbonic acid. 



The salts of quina, treated in the same way, yielded similar re- 

 sults ; and hence it may be concluded, that carbonates of organic 

 bases do not exist. — L'Instiiut, 28 Mars, 1839. 



MICA CONTAINING POTASH AND LITHIA. 



M. V. Regnault has analysed these micas ; they fuse easily at a 

 red heat, and without suffering any sensible loss of weight, and are 

 afterwards easily reduced to a fine powder. 



The analysis was performed by acting upon the mica, previously 

 fused and reduced to fine powder, with hydrochloric acid, and sepa- 

 rating the silica in the usual way. The alumina and peroxide of iron 

 were precipitated together by carbonate of ammonia; the liquors 

 being evaporated, after the addition of sulphuric acid, left a residue, 

 which, when calcined, yielded the alkaline sulphates, which were 

 dissolved in water, and decomposed by chloride of barium. The ex- 

 cess of barytes added was afterwards precipitated by dilute sulphuric 

 acid, added gradually; and the solution containing the alkaline 

 chlorides, after the addition of chloride of platina, were evaporated 

 nearly to dryness. By the addition of alcohol, the double chloride 

 of potassium and platina was separated ; the lithia was determined 

 by difference, and by the composition of the sulphates. 



In order to determine the fluorine, the mica was acted upon with 

 carbonate of soda, and then treated with boiling water. The alka- 

 line liquor was concentrated after filtration, and then subjected to a 

 current of carbonic acid gas, which produced an abundant precipitate 

 of glutinous silica. A solution of oxide of zinc in carbonate of am- 

 monia was afterwards added to the filtered liquor, and it was then 

 evaporated to dryness ; the last traces of silica and alumina were 

 thus separated. The saline mass was treated with a small quantity 

 of boiling water, and the liquor was supersaturated with hydrochlo- 

 ric acid in a platina capsule. The solution was suffered to remain 

 for twenty-four hours, in order to allow the carbonic acid to sepa- 

 rate perfectly. It was then saturated by ammonia, and the fluorine 

 precipitated by chloride of calcium. 



ROSE MICA LEPIDOLITE. 

 Tliis mica has the form of very small rose-coloured plates. It is 

 found disseminated in a kaolin, which is cmjDloyed in the porcelain 

 manufactures of Vienna. It is separated by washing from the kaolin. 

 The mean of four analyses gave 



Silica 52-40 



Alumina 26-80 



Potash 914 



Lithia 4-85 



Fluorine 4-40 



Dcutoxidc of manganese .... I'SO — 99-09. 



