Peach-Blossom Coloured Mica. 201 



■a. The mass was soaked in the crucible with water as much 

 as possible, and put into a glass ; the rest, firmly adhering 

 to the crucible, was dissolved by muriatic acid, which was 

 quickly heated and poured off again, that it might not act 

 too much upon platina by its evolving chlorine. The whole 

 mass was now dissolved in muriatic acid. The red solution 

 formed was evaporated to full dryness in a porcelain dish. 

 The dry mass being soaked in water, some muriate of platina 

 and potash, together with silica, was left undissolved. The 

 silica was put upon a filter, and washed. It weighed, after 

 ignition, 0.7526 gr. = 52.259 per cent. 



b. The liquid was then precipitated by sulphuric acid, the 

 sulphate of barytes put upon a filter, and washed out. It was 

 now again precipitated by caustic ammonia, the precipitate dis- 

 solved in muriatic acid, and the muriatic solution boiled with 

 an excess of pure potash. From the alkaline solution alumine 

 was thrown down in the usual manner. It weighed, after ig- 

 nition, 0.3974 gr. = 28.345 p. c. When dissolved in sul- 

 phuric acid, and mixed with sulphate of potash, it crystallized 

 entirely into alum. 



c. The residue left undissolved by potash was reckoned to 

 be pure oxide of manganese, without sensible traces of iron ; 

 it weighed, after ignition, 0.057 gr. = 4.065 p. c. of oxide 

 of manganese = 3.663 p. c. of protoxide of manganese. 



d. The liquor (in b) from which barytes by means of sul- 

 phuric acid, and then alumine and oxide of manganese, by 

 means of ammonia, had been thrown down, was evaporated, 

 and the residue ignited. The fused mass being dissolved in 

 water by the assistance of a few drops of muriatic acid, was 

 mixed with hydrosulphuret of ammonia. The sulphuret of 

 manganese precipitated was decomposed by muriatic acid, the 

 acid solution precipitated by carbonate of potash, and the 

 oxide of manganese obtained, already accounted for in No. c. 

 The liquor separated by the filter from the sulphuret of man- 

 ganese was evaporated, and the residue melted ; there remain- 

 ed 0.394 gr. of a salt, which was dissolved in a little water 

 By adding muriate of platina to this solution, a considerable 

 precipitate was formed, composed of muriatic acid, oxide of 

 platina, and potash. The solution, freed from potash, was 

 now evaporated, and strongly ignited. The fused salt was 



