The sun., 1896-10-28
MOISSAN MADE A DIAMOND.
WITH MS ELECTRIC FURNACE BE-
TORE NEW York AUDIENCE.

niIicn yoIntiiized Into Violet Gas
BriiiIant Demonstration by tho DIS
tineuIsbed French Chemist m the
College OF Physiciaus and Surgeons.
Before an nppreoative audience that COM
pletely flllsd the large lecture room of the Col
lcge OF Physicians and Surgeons. NJ. Henri
Molssan of the Institute OF Franco and of the
Academic dcs Sciences. who is known through
out tho world for his chemical Investigations
with very high temperatures and his researches
into the nature and applications OF the carbidcs,
delivered n lecture last night on tho
uses OF tho electric furnace and the re-
suits obtained by it, accompanied by some
brilliant experiments. The audience consisted
chiefly OF persons Interested In chemistry,
students, professors, electricians. and engineers
with sprinkling of ladies. and followed the
speaker with close attention during the hour
and half tnat the lecture lasted NJ Mossan
spoke in Fronch, and while some Of his hearers
understood his words. the rest understood the
chemical points he was sxpounding.
NJ Moisson 10 a man OF about forty-hve years.
of medium height and slender build. His face
10 striking one, his hair and beard are 1ct
black. streaked with gray, and his smile is very
pleasant. He spoke easily and unnfrectedly. in
clear. melodious voice.
He explained that while the carbon COM
pounds have been studied with great care by
organic chemists tHo phst hAbS SSe'9'
the study OF the different stages through which
carbon passes had been comparatively neglected
In his endeavors to obtain pure carbon, the or
dinary amorphous carbon. lempblack. contain
ing from 10 to 10 per cent of mpurities, he had
found It necessary to use very high temperatures
and had succeeded in obtaining one form of
pure carbon, graphite. High temperature
alone. however. would not yield the crystallized
form OF carbon, diamond. He set to work to
find out tho composition of diamonds by reduc-
ing some to ashes. In all. whether they came
from the Cape OF Good Hope or from Brazil. he
found iron. save In one very pure green hard
stone from Brazil. BY the study of the nature
of the ground and Of the geological formation In
which Capo diamonds are found, he found that
the earth. bosides graphite and microscopic dia-
monds, always contained granite. Granite Is
the product OF great pressure, and this fact led
him to tho idea that diamonds might also be
obtained by pressure. AS cast iron increases In
volume In passing from the liquid to tho solid
state he was led TO believe that IL an element
of carbon were enclosed in Globule Of cast
iron that was cooling 1t would be subjected to
the requisite pressure.
In order TO obtain n heat sufficiently great and
at the same time to be able to measure 1t, he
devised the simple form Of electric furnace
with which tho experiment last evening was
performed. 1t consists OF Two clay bricks, the
lower one about eighteen inches square and
foot deep, the upper one about six inches deep.
In the lower one is followed out an ell
liptical hole to contain the crucible,
whilo two carbon electrodes pass from tho
cavity to the exterior. where they connected
with tho electrical battery. The upper brick
serves for a cover. II. Moisson first sprinkled
tho cavity with magnesia In order to prevent
tho formation of calcium carbide. He then
placed 1t in the crucible. into which he had put
some soft iron filings and charcoal, covered 1t
with tho top brick, and turned on tho current.
In three minutes tho indicator showed q tenn
perature of 2,500s Fahrenheit. The clay was
boiling and flaming before the eyes Of the audi
enoe when NJ. Moisson put his hand on the top
brlck and kept 1t there to show that the heat
did not come through.
At the end of ten minutes the process was
complete. NJ. Moisson lifted the top with his
mass of hAme. and after holding 1t up for
while dropped it into some water.
The crucible he took out with tongs and also
dropped into cold water. He explained that tho
first time he had cooled the mass in that way he
had taken every possible precaution. expecting
an explosion but that after repeating tho process
three hundred times without an accident he
felt that the audience was safe.
On breaking the crucible he took out an ineot
the size OF q leaden bullet and explained the
processes by which the iron would havo to be
eliminated In order to get at the crystallized
carbon that was probably within it. The dia-
mond will have no commercial value. as tho
largest he has succeeded in making Is only ono
millimetre In diameter.