G. EH. Moore—Amorphous Mereurie Sulphide. 3 
phureted hydrogen with hydrochloric acid, but did not lose 
appreciably in weight. Furthermore, 3 grams of the mineral 
were fused with sodium carbonate and potassium nitrate; the 
hree grams were fused with sodium carbonate and potassium 
nitrate. The result, when treated after the usual routine of a 
qualitative analysis, gave no trace of arsenic, antimony or any 
other impurity. 
The powdered mineral yielded no bitumen to ether. 2,1751 
grams were, therefore, burned with lead chromate as in an or- 
ganic analysis and the resulting gases, after passing over a 
stretch of ignited metallic copper, conducted into baryta water. 
No precipitate was formed until, toward the end of the opera- 
tion, a current of air was passed through the apparatus. The 
trifling precipitate, which then came down, was quickly filtered 
off, washed and dissolved in hydrochloric acid, to which some 
chlorine water had previously been added, to oxidize any sul- 
phurous acid which might still be present. After standing 
some time, the fluid was filtered from the traces of barium sul- 
phate, which had precipitated, and the baryta thrown down as 
carbonate. The precipitate weighed 00155 grms., correspond- 
ing to carbon 0-0010 grms., or 0-04 per cent of the original min- 
eral, a quantity so small that it may be safely ascribed to the 
imperfect purification of the air used in the combustion. 
o chemical reason for the peculiar difference in properties 
from cinnabar could, therefore, be detected. fe 
Mercuric sulphide, as prepared in the laboratory, exists in two 
forms, which were first recognized by Berzelius as distinct iso- 
meric modifications, The first of these is the black precipitate 
produced by sulphureted hydrogen in solutions of mercuric 
salts. The second, obtained from the first by long continued 
agitation, treatment with alkaline sulphides, etc., is the crystal- 
lime red powder, vermilion. Only the latter variety, under the 
name of cinnabar, has hitherto been recognized in nature. The 
assumption lay near that I had to do with the one first named, 
especially, as the very low specific gravity could not be ac- 
counted for by the presence of traces of impurities. The nat- 
ural cinnabar has a specific varying from 8-0 to 8:2, in the mean 
81. Taking the latter number as a basis, the specific gravity 
calculated for a mixture like the one in question would be 
0165, whereas it is in fact 7-701. 
