ulphureted hydrogen
being evolved. On examining the porcelain boat in which the boron had
been placed, a non-volatile black substance is found, which appears to
consist of a lower sulphide of the composition B_{4}S. The same
substance is obtained when the trisulphide is heated in a current of
hydrogen; a portion volatilizes, and is deposited again further along
the tube, while the residue fuses, and becomes reduced to the
unalterable subsulphide B_{4}S, sulphureted hydrogen passing away in
the stream of gas.

Two selenides of boron, B_{2}Se_{3} and B_{4}Se, corresponding to the
above described sulphides, have also been prepared by M. Sabatier, by
heating amorphous boron in a stream of hydrogen selenide, H_{2}Se. The
triselenide is less volatile than the trisulphide, and is pale green
in color. It is energetically decomposed by water, with formation of
boric acid and liberation of hydrogen selenide. The liquid rapidly
deposits free selenium, owing to the oxidation of the hydrogen
selenide retained in solution. Light appears to decompose the
triselenide into free selenium and the subselenide B_{4}Se.

Silicon selenide, SiSe_{3}, has likewise been obtained by M. Sabatier
by heating crystalline silicon to redness in a current of hydrogen
selenide. It presents the appearance of a fused hard metallic mass
incapable of volatilization. Water reacts most vigorously with it,
producing silicic acid, and liberating hydrogen selenide. Potash
decomposes it with formation of a clear solution, the silica being
liberated in a form in which it is readily dissolved by alkalies.
Silicon selenide emits a very irritating odor, due to the hydrogen
selenide which is formed by its reaction with the moisture of the
atmosphere. When heated to redness in the air it becomes converted
into silicon dioxide and free selenium.

* * * * *

NATURAL SULPHIDE OF GOLD.

By T.W.T. ATHERTON.

The existence of gold in the form of a natural sulphide in conjunction
with pyrites has often been advanced theoretically as a possible
occurrence, but up to the present time this occurrence has, I believe,
never been established as an actual fact.

During my investigations on the ore of the Deep Creek Mines, I have
found in them what I believe to be gold existing as a natural
sulphide. The description of this ore will, no doubt, be of interest
to your readers.

The lode is a large irregular one of pure arsenical pyrites,