352 On Crystallized Oryd of Chromium. 
larged views of two of them, give a perfect idea of the originals, 
the prismatic form of which is obvious to the eye and perfeetly 
distinct with a glass. If we judge from the figures in Mr. Alger’s 
paper in this volume, (p. 14,) the prismatic preci of his crys- 
tals is much less strikin 
Mr. Alger has described the mineral in his specimens, as mica. 
I have been able to obtain only a very small pag of the min- 
eral from one’ or two protruding curves on m cimen. It 
readily cleaves parallel to the terminal plane, is reais softer 
than mica, and is easily reduced by the pressure of a knife on 
_ white paper, into a fine, coherent powder, of a greenish tint. It 
has no elasticity, and before the blowpipe gives off an abundance 
of water. From these decided characters, and the rarity of such 
an association of mica, and the quite frequent one of chlorite and 
quartz, it seems altogether probable that this mineral is chlorite. 
If these several minerals were at one time in solution in, the 
fluid quartz, they-must have crystallized previous to. it. The rutile 
prisms are so straight or so gracefully curved and bent, that they 
~ would seem to have experienced but slight resistance. They in- 
tersect- and cross each other, and pass through the loops in the 
chlorite crystals or touch them on the outside, and they peo 
cae first. Around most of these convolutions of chlorite 
ere is a burr, or a minute spot of imperfectly radiating fractures, 
Ssmictlly iridescent, which suggests that they were formed 
before me: solidification of the quartz, and that’ they had occa- 
e pressure or disturbance and a sligh racture. But as 
the: Sahlcrite: uniformly, and ‘the rutile in very many cases, must 
have: been ‘without any attachment,’ the ee of eit fluid 
quartz to have sustained them was probably gre 
On removal of the rutile. and chlorite: rig the gang gue the 
vertical strie of the former.and the transverse strie of the latter 
are found figured on the quartz, making it eertain that the latter 
was last solidified. 
There must be somewhere in this region north, ‘a rich deposit, 
for which mineralogists will earnestly seek, until it is Sse and 
- its treasures are transferred to appt cabinets. 
Arr. XXXIV.— Occurrence of Crystallized Oxyd of Chromium 
in furnaces Ped the manufacture of Chromate of Potash ; by 
W. P. Brak 
Read before the American Association for the Advancement of Science, New 
Haven, August, 185 
i reice of the sesquioxyd of specie have been obtained 
in small quantities by Wohler, by passing the vapor of cio? 
—— acid through a tube heated to nF 
