334 Mr. Ci-ienevix's Analysis oj Corundum, and of 
bottom, which had all the properties of silica, and, when washed 
and ignited, weighed 42,5 grains. 
2. Into the liquor which had served to wash the above 
powder, 1 poured ammonia. A copious precipitate was thus 
formed, which was separated by filtration, and well washed. 
3. Carbonate of potash also caused a precipitate in the liquor 
of No. 2. This precipitate was found to be carbonate of lime, 
and weighed 23,5 grains, = 15 of lime. 
4. The precipitate of No. 2. was redissolved in muriatic acid ; 
then boiled with an excess of potash, and filtered. There re- 
mained undissolved, 3 grains, which were iron. 
5. The liquor of No. 4. was precipitated by muriate of am- 
monia, and afforded alumina ; which, being washed and ignited, 
weighed 37,5 grains. 
I could also perceive a trace of manganese. 
The proportions therefore are, 
Silica - - - 4 2 >5 
Alumina - - ~ " 37>5 
Lime - - “ - 1 d?° 
Iron - - ” 3 ’° 
Loss, with a trace of manganese - 2 >° 
By a similar treatment, the following substances, contained 
in this matrix, afforded the under-mentioned results. 
100,0. 
Felspar , 
Lime 
Iron 
Loss 
Alumina 
Silica 
64 
24 
6 , 25 
2,00 
3 >75 
100,00 
