306 Chrome found combined with Irom, * — . 
and mean hardnefs, the fpecific gravity of which was found 
to be 4°0326. C. Pontier found>it in the department of 
Var, a la Baftide de la Carrade, near Gaffin, and confidered 
it as the brown blende, to which indeed it has a confider- 
able degree of refemblance, except that its fpecific gravity 
is far greater. This fubftance being analyfed in the labo- 
ratory of the mines by G. Taffaert, was found to be chromat 
of iron, that is to fay, a metallic falt formed by the combi- 
nation of iron with the acid arifing from the new metal dif- 
covered by C. Vauquelin, to pibich he gave the name of 
chrome. It feemed to contain, in 100 parts, 63°6 of that acid, 
36 of iron ; lofs, 1-4. Chemifts may now flatter themfelves 
that chrome, which hitherto has been found only in the red 
Jead of Siberia, in the ruby and the emerald, may be ob- 
tained in fufficient abundance to enable them to fubjeét it 
to new refearches. 
C. Vauquelin and Taffaert, by continuing their experi- 
ments on this fubftance, have afcertained the following 
oo, 
. It does not melt alone by the blow-pipe, but with 
aaa to which it communicates a green colour like that of 
the emerald. 
2. It is foluble in the muriatic acid, but flowly, and in fmall 
quantity. From its folution, which is of a greenifh blue 
colour, it is precipitated white by alkalies. 
3. Itis foluble in oxygenated muriatic acid. From this 
folution, almoft colourlefs, it is precipitated of a reddith 
brown by alkalies, and of an orange yellow by nitrat of lead. 
4. It is not decompofable by ‘potath, or the carbonat of 
potafh, without the affiftance of a degree of heat which cars 
ries it to incandefcence. 
5. It may eafily be reduced by the known means. It then 
gives an alloyed mais, having only an external metallic 
afpect, ealily fufed with borax ; brittle, but hard as fteel. 
6. This mafs is exceedingly difficult to be decompofed. It — 
muft be treated: fucceffively and feveral times with potath, 
which combines with the chromic acid and diffolves it, 
and with the muriatic acid, which diffolyes the oxyd of 
iron. 
7+ Other 
+,. ~ 
She 
