J. Lawrence Smith on Emery. 367 
- T ought to mention that the analysis afforded other substances’ 
in small quantities in some of the emeries ; as titanic acid, oxydof 
manganese, oxyd of zirconium, and sulphur (existing in pyrites) ; 
but these substances are unimportant in the composition of“emery, 
and are in such minute quantities, that it is necessary to operate 
on a considerable quantity of the mineral to obtain satisfactory 
results concerning them. a . 
+ The analyses marked 6 and 8 were made by decomposing the 
emery as it. came from the sieve, without pulverization in the 
agate mortar. It was by accident that it occurred and I was not 
aware of the neglect until it was fused with the bisulphate of 
soda, but not wishing to lose the analysis, the operations were 
coutinuied as in the other cases, only using a little more of the 
bisitphate in the second decomposition ; aud somewhat to my sur- 
prise, the decomposition was quite as perfect as in the other cases. 
I had nearly completed all my analyses in the manner detailed, 
_ when*his fact became known, so that I have but these two cases 
to report. It will simplify the analysis of corundum if pulver- 
ization in a diamond mortar be found sufficient, and I propose 
examining specially into this question. 
The water which was found in the emery comes from the 
corundum, a fact which will be shown when the analysis of pure 
corundum is given, which will be in the second part of the 
memoir. A very minute quantity of what has been estimated as 
water might bea little oxygen lost by the oligiste which is some- 
times found in emery. Those emeries which contain the least 
water, every thing else alike, are the hardest, as instanced by that 
from Kulah, notwithstanding the quantity of iron it contains. 
The silica existing in emery is most often in. combination with 
alumina or the oxyd of iron or with both, for this reason we mus 
not always regard the quantity of alumina as an indication of the 
quantity of corundum in the emery. 
which differs from these ores of iron, and besides the surface 
exposed is of a lighter color. From the numerous observations 
ade, I may set it down as a general rule, that any blackish 
oe or dark blue rock of a strong argillaceous smell, that scratches 
agate easily, with a specific gravity in the neigborhood of 4, is 
Sure to be emery. 
The mining of Emery. 
The mining of this substance is of the simplest character. 
= The natural decomposition of the rock in which it occurs facili- 
