1819.] and the Analysis of a’ new Mineral. - 109 
is very compact, and its fracture hackly. Its specific gravity is 
pretty considerable, amounting to 8-750 after the metal has been 
fused. Itis very ductile, and may be hammered out into thin 
plates, both cold and hot, without the risk of cracking. Its 
cohesion appears to be pretty considerable, and to surpass that 
of tin. It belongs to the more fusible metals; for it melts 
before it is red hot; and an iron wire, heated to redness by a 
spirit lamp, readily melts it. It is likewise very volatile, rising 
up in the state of vapour, at a temperature not much surpassing 
that at which mercury boils. This vapour has no peculiar smell, 
and congeals, like mercury, in drops, which exhibit distinct 
traces of crystallization. 
This metal undergoes no alteration when exposed to the air; 
but, when heated, it burns very readily, and is converted into 
a yellow coloured oxide, the greater part of which sublimes in 
the state of a yellowish coloured smoke, and covers any body 
held over it with a yellow coating. Ifthe experiment be made 
before the blow-pipe upon charcoal, the charcoal is in like 
manner covered with a brownish yellow-coloured coat. It gives 
out no perceptible smell when it burns. It dissolves in nitric 
acid with the evolution of nitrous gas. Sulphuric acid and 
muriatic acid act upon it likewise, and hydrogen gas is given 
out ; but its solution in these acids is a very slow process. The 
solutions are quite colourless, and are not precipitated by water. 
This metal appears to combine with oxygen in only one propor- 
tion. The oxide has a greenish yellow colour; but by exposure 
to a strong red heat, it acquires a tint of yellow; and if the 
heat be very long continued, it becomes nearly brown. As the 
orange and brown oxides dissolve in acids, as well as the green- 
ish yellow, without the evolution of any gas, and form the very 
same kind of solutions, there is reason to believe that the alter- 
ation in the colour of the oxide is merely owing to the state of 
its aggregation, and not to any difference in the proportion of 
oxygen which it contains. This oxide withstands the strongest 
heat ; and when raised to a white heat in a covered platmum 
crucible, by means of Marcet’s lamp, it did not undergo fusion. 
When heated with charcoal, or any substance containing carbon, 
it is easily reduced to the metallic state’; and the reduction 
takes place when the heat just begins to get red. To borax, it 
communicates no colour. It does not dissolve in the fixed 
alkalies ; but a portion of it is taken up by ammonia. Towards 
the acids, it acts precisely as a salifiable base. The salts 
which it forms have almost all a white colour. Those with 
sulphuric acid, nitric acid, muriatic acid, and acetic acid, crys- 
tallize readily, and are very soluble. Those with phosphoric 
acid, carbonic acid, and oxalic acid, are insoluble. From the 
solutions of the first mentioned salts, it is thrown down white 
by the fixed alkalies, probably in the rs of an hydrate, and the 
