156 Analysis of a Manganestan Garnet. 
fore, the moisture expelled by this treatment, was 0.02 
grammes on 3 grammes, or 0.66 per 100. sis 
. The residue of the preceding calcination, (A) was 
calcined, at a red heat ina platina crucible, during 30 min- 
utes with 15 grammes of sub carbonate of Soda, the mixture 
cible was also intensely green—an indication of a large 
quantity of Manganese. enan excess of muriatic acid 
was added to the liquor, chlorine was abundantly disenga- 
ged, the*solution was not perfect until the evaporation of 
the liquor was considerably advanced, it was then of a deep 
orange colour; to effect the separation of the silica it was 
evaporated in the usual manner to a dry gelatinous mass, 
then treated with water, acidulated with muriatic acid, and 
again moderately evaporated; more water was added, and 
the solution was filtered; the silica remaining on the filter, 
after edulcoration and calcination, weighed 1.075 grammes 
on 3 grs. Or 35.83 per 100.0% 2-9; ou, Ro et 
C. The silica having been separated, (B) the excess of 
acid was neutralized with caustic potash, the solution was 
treated with hydro-sulphate of potash, this occasioned a 
precipitate, which at first was black, but the latter portion 
of it was nearly colourless. The precipitate was well was 
ed and dissolved, in the humid state, in nitro-muriatic acid, 
D. The residue, which was separated from the alcaline 
liquor, (C) was of a dark red colour; it was treated while 
humid, with acetic acid, the solution was evaporated, at a 
moderate temperature, to perfect dryness, the dry mass was 
treated with water, the peroxide of iron, collected on 4 
filter. proved to be free from alumina and manganese, it 
weighed 0.486 grammes; a portion of'the pulverized min- 
eral was treated with nitric acid and calcined; the powder, 
which was flesh coloured, now became nearly black, this 
BL vee WALES eat AE Se I I gs Phe eA ee ee ene rE aT a 
