New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1897-10-16
ARTIFICIAL DIAMONDS.
RECENT EXPERIMENTS IN PRODUCING
WITH THE AID OF ELECTRICITY.

tnclal diamonds In connection with work on
calcium carbide and acetylene in America in
1874. | devised several forms Of apparatus and
processes. 70. which applied for patents in the
United States. Moissan had shown that arti-
nclal diamonds could be produced, although MI
croscOpic in size, by saturating a molten metal,
such as iron silver, with carbon. and then
cooling a globule of the same with great rapid
lty, whereby a cooled exterior portion or the
metal was caused to shrink strongly upon no.
interior portion. thereby causing the interior
portion 10 be cooled under considerable pressure.
BY dissolving away the metal, Molssan had
found that a portion Of the carbon held by the
molten metal In solution or in combination az
high temperature would. upon cooling under
great pressure separate from the metal in the
form Of small carbon crystals or diamonds, in
stead Of graphite, as in gray castiron.
Now. it is well known that the factor OF time
plays very important part In crystalline for
nations. much larger crystals being prodtced
when allowed to form slowly than when formed
with rapdty. To this end devised an
apparatus electric furnace. within whS.h the
metal. in the presence Of carbon. could beSused
ard raised TO exceedingly high temperature
by electric current in order that the maxi
mum Of carbon might be absorbed or taken up
Ivy the metal. the device being provided with
means for subjecting the molten metal to an
exceedingly nigh pressure. either by hydraulics
other suitable means. BY this method
pressure very many times great as attained
by Moissan could be applied To the molten
metal, and any desired length Of time permitted
To elapse in order 10 secure the maximum size
Of crystals. By Mcissan's method but a com.
best. limited by the tensile strength OF a thin
LAYER OF castron. while by my method oo'op To
100000 pounds to the square inch could II
requisite. be applied. Another method devised
by me was to pass a current Of sufficient guam
tity through a small body. rod or flament or
carbon in "A confined space. 10 cause its fusion
and then subject the same 10 great pressure anu
allow to cool slowly.
DIAMONDS or ELECTRO-DEPOSITION.
The method for the production Of artificial
diamonds which have always considered me
most promising IS by electrical deposition, 70;
by this means | am Of the opinion that dia,
nonds Of much larger size may be produced
and ~ a lower expense than by any olhei
method. I filed two applications tor patents IN
the United States in 1895 for processes ana APP
para'us for the production Of diamonds ny
deposition. but 1t was not until Septem-
Der year ago that had an 'pportuns,tyd 40 20
nerds In this manner and 10 verify my
theories Now, 1t is well known that If an cleo
tric current be passed through a carbon ma
ment immersed in an atmosphere of hydro-car-
bon a portion Of the hydro-carbon Is decpH-
posed and electrically deposited upon the ma
ment, the most rapid deposition taking place &C
the points Offering greatest electrical resistance
in other words in the hottest portions or the
hlament. this fact being taken advantage OF 10
secure uniformity OF electrical Teslstahce II,
electric lamp faments. Now. | have predicted
that If n carbon rod. immersed in q hydro-tar-
bon atmosphere. should be maintained at
very high incandescence by an electric current
for a considerable time, the electro -deposltloh
would assume crystalline form. While conduct
Ing some experiments at Faraday House. Char-
ing Cross Road. London. extending over Il
period OF three months. beginning carly IN Au-
gust a year ago I had an opportunity OF con-
Quoting a considerable scale large mum.
her Of experiments with 100 available electrical
horse power The experiments related ID the IN
vesilga ION OF various methods for the orpcuc-
tlon o. calcium carbide and other carhdes ny
the electric are, by incandescencr ana ny g &C.
irically superheatcd gases. and also TO the Ell
feet OF the electric current upon various gases;
In connecto, with this work ! conducted
sOile experiments to determine thc posS;p'I,Ls
md practicabty ~ producing diamonds oY
electro-depos!tion. The results OF these expert
Inents | have. until now. kept secret. for the
reason that publication prevents valid patents
being taken In most countries. but since DIT
Borchers has published some experiments con-
Quoted by him by which similar results were
attained. have determined to protect rlyselI by
patents in England and America only ana 10
publish an account Of what | have accom-
plished and what I expect 10 accomplish in the
production Of artificial! diamonds and the means
employed and Intended TO be employed. The
apparatus employed by me In my experiments
for the production Of diamonds by electro-depo-
sltlon was constructed as follows: large
graphite crucible. about = foot In dameter. and
twenty inches high with large hole cut
through the bottom. 70 admit the passage OF
fcur-inch carbon electrode, was inverted upon
heavy carbon bcdplatc. Inside OF the large
craVhite cruCibla was placed small gas car
bon crucibla abOu: four inches In diameter ana
six inches high, having It's bottom cut away;
the space intermediate o. the small and large
c-ucible was filed with finely broken charcoal.
4 carbon rod. about five-eiGhths OF an inch in
diameter. was interposed between the large YER
teal eiectrode and the carbon bedplate, in such
wise "a 10 pass through the centre OF the small
crucible without touching II. and make contact
with the vertically disposed electrode and the
hedpate. The large vertical electrode was care
fully insulated from the graphite crucible, and
the graphite crucible again insulated from the
carbon bedpl3te. The graphite crucible was
ESQ carefully wrapped upon the outside with
covering Of asbestos about half an inch thick. An
alternating current Of fifty volts. and varying IN
quantity from eight hundred TO fifteen hundred
nmperes was passed through the five -eighths
inch carbon rod Through n perforation made in
the bottom Of the carbon plate a strong blast OF
Get bon vapor emitted a. soon as the fur
race got heated up. and continued during the
who'll time the current remained on.
At the end Of about two hours the current
was turned of and the furnace allowed 10 cool
down when II taken 10 pieces The whole
surface Of the carbon rod wa, found 70 be COW
cred with n brilliant crystalline formation. the
crystals varying In sizr from pin point 10
large pins head. The crystals were pyram.dal
in form. and upon examination under micro
scope they were found 70 consist or n thin trans
parent casing with Interior and base portion
Of graphite. Tha crystals were found TO cut
Glass with the greatest ease. Under the OXy
hydrogen blowppe the crystals were wholly
Consumed. which seemed to show that they
were not composed Of any form OF carbide or
metallic salt The charcoal In the furnace was
nearly all voatiliZcd. aud at the top OF The FUR
mace was found n considerable quantity Of n
light hairy substance the fbres being quite
strong and resembling asbestos but capable
Of resisting temperature far above the fusion
point of asbestos. This was probably formed
from impurities or ash volatzed from the char
coal. This may serve as suggestion for the
production OF n nbr)us material which will
stand a much higher temperature than ashes
tos The next experiment was conducted in the
following manner The same form Of furnace was
employed as that above described. except that
no charcoal was used. the furnace being entire
" empty. Simultaneously with the passage Of
the electric curren. through the furnace.
rent OF Illuminating gas from the street main
was passed through the graphite crucible into
the furnace and out at the bottom. At the end
Of about two hours the electric current was
turned off, the furnace allowed to cool. when 1t
was taken apart as before. There found
Upon the carbon rod the same crystalline forma-
ton as In the first instance. and which an
r..a unLnI. mi 10 2 Hon be OF the