Mineral Subfiance from New South Wales. $t 
fumed not to have owed its fufion, in the above experiments, 
to the fame caufe to which fome of the common fimple earths, 
in certain circumftances, owe theirs, namely, their union with 
the matter of the vefle.1 or fupport, that is, with an earth or 
earths of a different kind from themfelves ; but to poflefs a 
fufibility ftridtly its own, which takes place in afire of 150 
degrees, or perhaps lefs. 
As charcoal in fine powder affumeS a kind of fluidity in the 
fire, fulfil ar to that which powdered gypfum exhibits in a fmali 
heat, its furface had changed from concave to horizontal, and 
the bead had funk to the bottom ; it was rough and black on 
the outfide, and whitifh within. On repeating the experiment 
in a cavity fcooped in a piece of charcoal, the refult was a 
blackifh bead like the former, only fmooth on the outfide, with 
fomething of metallic brightnefs, not unlike that of black- 
lead. Both beads were very light, and had a confiderable ca- 
vity within. All the internal part was whitifh, without the 
leaft metallic afpeft ; and the external gloffy blacknefs appeared 
to be only the fcain which charcoal powder communicates, in 
ftrong fire, to fome earthy bodies that have a tendency to 
vitrify. By boiling in concentrated marine acid a part of the 
beads was diffolved, precipitable as at firft by water ; but an, 
accident prevented the procefs from being continued fufficiently 
to determine whether the whole could be diffolved or not. 
By this fufibility in the fire ; folubility in one only of the 
Common mineral acids, and parting with the acid in a heat 
below ignition ; precipitability by water, and non-precipita- 
bility by Pruffian lixivium ; this fubftance is ftrongly diferimi- 
nated from all the known earths and metallic calces. And as 
it fuffers no decompofition from any of the alkalies, in any of 
T t 2 the 
