The Winslow mail., 1897-04-03
HE MANUFACTURES DIAMONDS,
Prof. Moisson Uses Carbon and Iron
and CrucibIe Furnace.

ard CrucibIe Furnace.
Referring to the recent lecture In
New York of Prof. Henry Moisson, the
French scientist. who makes diamonds.
the Evening World says:
Prof. Moisson told how he had dis
covered the composition of diamonds
by reducing specimens of diamonds to
ashes.
The scientist found out by the process
that in all these diamonds, save one
very pure green gem from Brazil, there
was iron, while the Cape diamonds
came from earth that contained granite
and graphite.
Granite is the effect of great pressure.
AS cast iron increases in volume in
passing from the liquid to the solid
state, he was led to believe that If an
element of carbon were inclosed in a
globule of cast iron that was cooling It
would be subjected to the requisite
pressure. He had experimental to as
certain the different stages through
which carbon passes and had obtained
pure carbon-graphite-by very high
temperature.
High temperature alone, however.
would not yield the crystallized form
of carbon known to commerce as "dla-
mond." Heat at sufficient pressure
would, he believed. and he at last sue
ceeded in proving it.
In order to obtain a heat sufficiently
great and at the same time measurable,
he devised a simple electric furnace,
and there it was before his audience.
1t consisted of two clay bricks, one
eighteen inches square on the surface
and a foot thick, with another above Il
half as thick. In the lower brick was
a hollow large enough to contain the
crucible, while two carbon electrodes
connected with a battery entered the
cavity, which was sprinkled with mag
nesla to prevent the formation of cal
cium carbide.
In the crucible were placed soft-iron
filings and charcoal. The furnace was
covered up and the current turned on.
In three minutes the Indicator showed
that things inside the little furnace
were $500 degrees hot The clay was
boiling and flaming before their eyes.
Prof. Moisson carelessly laid his hand
on the top brick and kept it there-just
to show that the heat didn't come
through.
At the end of ten minutes the little
wizard turned off the current, lifted the
| cover, the under side a white mass of
flame, and dropped it in some water.
He took out the crucible with tongs and
dropped it into cold water
When the crucible was cold he broke
it and took out an ingot as big as a
common bullet. He explained the proc
ess which he must go through to elm
mate the iron, in which was imbedded
the crystallized carbon-the diamond.
Then the slender Frenchman spoiled
it all by telling his audience that he had
never been able to make a diamond
larger than one millimetre in diameter
and of no commercial value, but he
hoped later on TO produce a regular
''searchlight" Then the Sign "DIa.
monds made while you watt VIII be-
come familiar.
He told n lot of interesting things
about diamonds. He said the little
black specks found in diamonds, called
'crapauds'' in France, 'pogs" in New
York which detract from the value Of
the stones, were the first proof to him
that he had got OH natures track.
He said that when cooling the cruci-
bic in molten lead O. the crystal takes
the shape of rectangular figure, but
when mercury is used in cooling tho
crucible the diamonds are octahedron.
These latter, like similar diamonds
found at the Cape fields, split when ex.
posed to the air-an additional proof to
Moisson that diamonds are produced
by pressure. These pressures are prin
cipally expansion power