Dr Turner on Lithion-Mica. 267 



I may here notice one circumstance which should not be 

 lost sight of in performing the process for fluoric acid. If 

 manganese existed originally in the mica, a portion of it is 

 sometimes retained by the alkaline solution, and remains in it 

 even after the fluate of lime has subsided, without communi- 

 cating any colour by which its presence might be suspected. 

 It is a good precaution, therefore, to drop a little hydrosul- 

 phuret of ammonia into the liquid, which will separate the 

 manganese if present. It is also advisable to evaporate the 

 solution to dryness, after separating the fluate of lime, to 

 ascertain if all the silica had been separated in the former part 

 of the process. 



The substance which was supposed in all these cases to be 

 lithia, has of course been proved to be such. Its characters 

 are quite distinct. It forms a salt with muriatic acid, which is 

 easy of fusion, deliquesces with surprising rapidity, and dis- 

 solves in alcohol. It forms, with sulphuric acid, a neutral sul- 

 phate, which fuses readily, and afterwards dissolves completely 

 in water. Acetic acid combines with it, and the acetate is deli- 

 quescent. When its solution is evaporated, it becomes tena- 

 cious like mucilage while drying ; and when quite dry is very 

 brittle. When the acetate is ignited, a carbonate is left, which 

 has decided alkaline properties, dissolves with difficulty in 

 water, fuses with great readiness, and shoots into a crystalline 

 mass on cooling. It stains the surface of platinum when fused 

 upon it. These properties leave no doubt whatever of its 

 being lithia. 



Professor Gmelin was the first, so far as I know, to show 

 that the alcoholic solution of the muriate of lithia had the 

 property of burning with a red flame ; and he even observed 

 that both the sulphate and supersulphate of lithia could cause 

 alcohol to burn in the same manner. This property may, I 

 find, be made apparent in various ways. Perhaps the neatest 

 mode of producing the effect with the muriate of lithia is to 

 dip a little bibulous paper into the alcoholic solution, and set 

 fire to it. If a fragment of the solid muriate or acetate of li- 

 thia, slightly moistened, be taken upon the point of a knife, 

 and be made to touch the flame of a candle, a redness will be 

 instantly communicated to it. The carbonate can be made to 



