The Middlebury register. [volume] (Middlebury, Vt.) 1850-1882, 1877-08-17
Diamonds only Coal.

In the year 1894 il was discovered by
actual experiment at Florence that dia-
mond would burn. Cosmo LII had ono
fixed in the focus of burning glass,
and, after some exposure TO the rays of
the sun, it cracked, corruscatcd, and
finally disappeared like ghost, leaving
no traces behind. Experiments of this
kind were costly. They were long in
yielding any scientific results. II was
only sovereign prince who could af-
ford TO see his jewels vanish like the
gifts of fairy god-mother. Another
potentate, the Emperor Francis l, tried
q number of valuable diamonds in the
heat of smelling furnace, and may
have felt some qualification in finding
they had disappeared. This was in
1860, and about twenty years later
magnificent diamond was burned in
France. A jeweler named Leblanc de-
MED the possibility ofburning diamonds
and suspected some unfair play on the
part of Macquer, the chemist who had
conducted the operation. He had often,
he asserted, exposed diamonds to great
heat with the sole result of increasing
their brilliancy. Mr.. Streeter has done
the same with success. But Leblanc
only knew half of what Mr.. Streeter
knows, and when the chemists demand
ed that he should inclose some diamonds
in coal in crucible he rashly assented,
and in three hours they had all disap-
peared. Then another jeweler, Mail
ard by name, who seems to have had q
suspicion of the scientific truth, put
three diamonds into an earthen pipe
bowl, packed in powdered charcoal, and
exposed them without injury to intense
heat. Lavoisier, who was present,
proved in 177G that by shutting out the
air the diamond was preserved in fur
mace, but that the admission Of oxygen,
with which the carbon combines, allows
the diamond to burn like piece of coal.
Sir Humphrey Davy succeeded in prov
ing that the diamond contains no hy-
drogen; "and," adds Mr.. Streeter, 'iit
| is almost unnecessary to say that the
gas formed from the combustion of dia-
lnonds is carbon-dioxide (carbonic acid,
COZ, the gas yielded by every fire and
gas-burner, and by the combustion of
our own bodies; these latter, in the
combustion that attends their very liv-
ing, evolve carbon-dioxide by the lungs.
so that the old fable of the maiden from
whose lips fell diamonds may have a
really scientific basis after ALL" This is
very pretty, no doubt. But the coal
HEAVIER cXhales coz as well as the maid
oxide evolved by the London Gas Com
panies is not of quality TO suggest dia-
monds, or indeed anything of unusual
brilliancy. People who do not find gas
sufficiently expensive may learn in Mr.
Strecter's pages how to burn diamonds
and can take their choice of two or three
methods. AS there seems always to be
some uncertainty as TO the result, a little
refreshing excitement might be connect.
ed with these experiments, and while
they would not cost more than horse
racing, they. would generally leave as
little behind in the way of profit. A
burning diamond must be well wortl
seeing. Guyton dc Morveau consumed
one in oxygen gas under burning
glass: First he saw on that corner O
the diamond which was in the eXac
focus of the lens black point, then tho
diamond became black and carbonizcd
A moment after he saw clearly brigh
spark twinkling, as il were, on the darl
ground; and when the light was inter
ceptcd the diamond was red (rcd-hot
and transparent. A cloud now passct
over the sun, and the diamond wa
more beautifully white than at first ; bu
as the sun again shone forth in its ful
strength, the surface assumed n metal,i,
lustre. Up 10 this point The diamond
had scnsibly decreased in bulk Tn,
half-burnt gem was then repricved TO
a day or two, but on the resumption o
the process disappeared. Fourcroy wa
able TO make a black mark on pape
with diamond SCOT, and there seems {,
be no doubt that uncrystalline "blacl
carbon" may be produced in sufficien
quantities to be seen, while the darl
marks on some diamonds may be re
moved by intense heat, applied witt
care, 50 as not to complete the act q
combustion .-fThe SpectatOr.