G. H. Moore—Amorphous Mercurie Sulphie. 37 
cult to determine exactly on account of brittleness. Specific 
gravity 7-701 to 7-748, varying somewhat in different specimens, 
owing to intermixed cinnabar. 
_ Pyrognostic characters those of cinnabar. In the closed tube 
it sublimes totally except a slight residue of quartz and ferric 
oxide. The black sublimate yields a vermilion red powder 
when care has been taken, that, during the sublimation, the 
experiment suceeds best in vacuo; the residue is then not oxide 
but sulphide of iron. 
A qualitative analysis showed the presence of mercury and 
sulphur, with very small quantities of iron and silica. The 
quantitative analysis was made in duplicate, as follows: 
* In all of the six or seven specimens which I had examined previous to the 
publication of this paper, the mineral occurs, as stated, without a vestige of crys- 
talline structure. r. Emil Durand, of San ncisco, has, however, rvered 
Specimens in which minute black crystals occur, and published a notice of his dis- 
in the San Francisco papers. — 
Through the kindness of Prof. Geo. J. Brush, I have had the privilege of ex- 
ini , i stals are quite small, very irreg- 
sim 
pear to be aggregates of minute crystals. e habit is frequently almost | A 
and strikingly different from that of the long prismatic crystals of cinnabar 
which occur intermixed with and often implanted on them. : 
Unfortunately none of the specimens are sufficiently perfect to permit a deter- 
mination of the crystalline form. The difference in habit is. however, sufficiently 
= ne to warrant the supposition that they are probably not isomorphous 
Cinnabar, 
