The Birmingham age-herald. [volume] (Birmingham, Ala.) 1902-1950, 1903-07-19
ELECTRIC FURNACE DIAMONDS.
Details of Professor Molssan's Remark
able Manufacturing Process.

Paris Letter to Electrical Review.
Professor Henri Moissan's experiments
In diamond making were begun after his
finding of microscopic diamonds In nature,
in the sblue earth" from the cape, in the
sands of Brazil and in several meteorites.
His researches showed that If carbon was
produced at low temperatures 1t was al
ways obtained In the amorphous condition
and no crystals were found. The details
of the manufacture are thus described:
For his experiment, Professor Moissan
utilized the pressure which Is produced in
iron when it passes from the liquid to the
solid state. 1t Is known in fact that solid
iron Is less dense than when In fusion, as
Is shown by the fact that when pieces of
the metal will float on the melted bath,
and 1t thus resembles water in this re-
spect lie melts the iron in the electric
furnace and saturates 1t with carbon, and
to carry this out 200 grammes of Swedish
iron cut into cylinders one-nalf inch long
and two-hfths inch in diameter we're
placed In a carbon crucible and completely
covered with powdered charcoal The
crucible was placed under the arc and
heated during three to six minutes with
current of $50 ampheres at 600 volts.
The cover of the furnace was removed and
the crucible seized with a pair of tongs
49,
! water The crucible and metal remain
red for a few moments, giving off gases
which come to the top; then the whole
cools off. 1t was not without apprehen-
sion that the experiment was made for
the first time as 1t was feared that an
explosion would be produced when the
melted mass at 1000 degrees came In con-
tact with the cold water. But no bad ef-
feet is produced with iron, although bis
mi hn me
violently and skaters everything.
The metallic mass is treated with hy-
drochloric acid until nothing more is dis
solved when there remain three kinds of
carbon; first, graphite second, a brown
ish colored carbon in very fine strips, APP
pearing to have undergone a strong pres
sure like that Of the Diablo Canyon me-
teorite; there remained a very small guam
tity of a more dense carbon which had to
be separated The two former varieties
Of carbon were dissolved out by treating
with aqua regia and hydroluoric acid,
then by placing the residue In sulphuric
acid at 200 degrees centigrade, into which
was projected nitrate of potash In powder
After further treatment all the anonymous
carbon is destroyed and the denser por-
tons which were examined by the micro
scope contained no graphite and consisted
of different varieties of carbon. BY plac-
Of 29, some pieces of high density fell to
the bottom and were separated. Then the
small residue at the bottom was placed
In a tube containing iodide of methylene, a
very dense liquid of 3.4. Some small par
ticles deposited and few black fragments
hoated on the liquid.
All these particles consisted of black and
transparent diamonds, which were exam
ined under the microscope The particles
which fioated were the Opaque or black
diamonds, having a rough surface. Their
density varies from to 3d. Some speci-
mems are smooth and have curved lines.
The transparent diamonds were next ex-
amined. They were of brilliant appear
ance ana had the same general aspect as
the natural rough diamond The surface
presented parallel striae and sometimes
triangular Impressions. The fragments Of
clear diamond were very often surrounded
by a layer Of black carbon, which was
difficult to dissolve off. Some of the dia-
monds had rounded surfaces, while 9TH
ers seem to be broken into small pieces.
One fragment had a yellow color. Other
specimens appear as cubes or have an ir-
regular form. Their density is near 3.5.
as proved by their sinking In iodide OF
methylene. They will scratch the ruby
without difficulty These specimens were
burned in oxygen and left practically no
ash. AS only very small quantity of
the crystals Is thus obtained. second
method was used which gave better re-
suits.
It seemed that the rapidity OF the cool
Ing had capital influence upon the form