Seybert’s Analysis of Chromat.of Tron. 321, 
C. The residue on the filter (.2,) supposed-to be molyb- 
die acid and sulphur, was washed and dried at.a- moderate 
temperature insufficient to sublime the sulphur ; it was then 
moderately calcined ; during the calcination there was not 
the slightest odour of sulphur—a proof that the nitric acid 
had completely acidified it. The molybdic acid, after the 
calcination, weighed 3.61 grammes, it dissolved ‘etitirely i in 
ammonia, and was therefore considered pure. The results — 
in (B and C.) give a total of molybdic acid, amounting to 
4.465 grammes, equivalent to 2.971 grammes of molydenura 
on five grammes, or pr 100 = 59.42, ( 
The constituents of the mineral according to this analysis, 
are, ; 
Per 100 Betsy. 
A. Sulphur, - 39.68 
-C, Molybdenum, - - 59.42 
99.10 
100.00 
000 90 Loss. 
Art. XIN. — Analysis of the ‘Whnbhibalt! Chromat of Tron ; by 
Henry Seysert, of Philadelphia. — 
Tis mineral was found at the Bare Hills, near Bama? 
in the State of Maryland ; the specimen submitted to anal-* 
ysis was amorphous, and incrusted with talc. Its colour 
was blackish-brown—colour of the powder deep reddish’ 
brown. Lustre metallic—opaque—fracture uneven—not 
very frangible—scratches glass—acts but very slightly on 
the magnet. The specific gravity , of a pure piece, wes, 
4.0639. Infusible before the blowpipe. 
Analysis. 
_ fl. 8 grammes of the mineral, after being carefully sepa+ 
rated from the talc, were reduced to a very fine powder, 
and exposed to a red heat in a platina crucible. The eal- 
cimed mineral was a shade darker. and weighed 7.87 Bram 
