Hi 
F 
— 
366 J. Lawrence Smith on Eimery. 
— ble in water, and in the future operations of the analyses there is 
eno embarrassment from a deposit of alum. 
The bisulphate of soda was prepared by adding an excess of 
pure sulphuric acid to the pure carbonate or neutral sulphate of 
soda and heating it in a capsule until all: the water had been ex- 
pelled and sufticient of the acid to allow of the mass becoming 
solid on cooling. ‘That obtained 1 in commerce is not sufficiently 
The: pulverized emery is placed in a large platinum exuciblés 
with six or eight times its weight-of bisulphate of soda, and the 
mixture is-heated over a lamp in the same manner and with the 
same precatifions.as are employed when using the bisulphate of 
potash. From ‘fifteen to thirty minutes suffice for the operatten 
The mass is allowed. to cool, ee water with a few drops of. éul- 
alien ane are 6 added to it and the whole heated, when it solr 
tion: and when treated with water and a Joke or two of eee’ 
ric acid all except the silica is dissolved. ‘The liquid which passes 
ov filter in this case is added to the first and the analysis contin- 
ed. The silica obtained is diminished by the quantity taken up 
from the mortar in order to arrive at what is actually contained 
in the mineral. The filtered solution i is heated with a little nitric 
alkali ; this redissolves the alumina first precipitated and thus sep- 
arates it from the oxyd of iron and a trace of lime. The iron 
and lime are separated in the ordinary way; the alkaline solution 
of alumina was poe and the alumina precipitated with car- 
bonate of amm 
Thus analyzed, dee emery from different places gave the fol- 
lowing results :— 
oe aes i is Speci Chemical composition, 
| en Ts eo ee | Water (Alumina. Pion, Lime. | Silica. | ‘Total. 
1 {kK 57 =e “190 | 6350 | 33-25 | 0-92 | 1°61 | 10118 
2 56 3:98 | 210 | 70°10 | 29°21 | 0°62 | 400 | 99°03 
3 56 3°75 | 2°53 | 71-06 | 20°32 | 1:40 | 41 
4 53 4-02 | 2°36 | 68°00 | 30°12 | 050 | 236 | 98°34 
5 47 382 | 311 | 77°82 62 | 1:80 | 81 
6 46 8-75 | 472 | 68:53 | 2410 | 086 | $10 | 10131 
aah 46 3-74 75°12 | 13°06 | O72 | 688 | 
8 44 | $87 | 547 | 69-46 | 19:08 | 281 | 241 | 9928 
a 42 4°31 | 5°62 | 60°10 | 33°20 | 0-48 | 180 eee 
10 3-89 | 200 | 61-05 | 27-15 | 1:30 | 9°63 | 10113 | 
