THE BOOK OF DIAMONDS
large,
the publications have not been as extended as one would at first
expect. It appears, without doubt, that many of the workers have
considered more the synthetic preparation of carbon for the diamond
than the study of the different allotropic forms of carbon.
Among
the first attempts to make synthetic diamonds may be mentioned that of
J. B. Hannay of Glasgow, who commenced his experiments in 1879. After
many trials, some of which resulted in violent explosions, he is said
to have succeeded. The method adopted by Mr. Hannay is described as
follows:
A
tube twenty inches long by four inches in diameter was bored so as to
have an internal diameter of half an inch. In the tube was placed a
mixture of ninety per cent of rectified bone oil, and ten per cent of
paraffin spirit, together with four grams of the metal lithium. The
open end of the tube was welded air-tight, and the whole mass was
heated to redness for fourteen hours; on opening it a great volume of
gas rushed from the tube, and within was a hard, smooth mass adhering
to the sides of the tube. It was quite black, and appeared to be
composed of iron and lithium, but on closer inspection small
transparent pieces were found imbedded in it. The mass was dissolved,
and the small transparent pieces proved to be 'crystalline carbon',
exactly like diamonds but almost microscopic.
Out
of eighty complex and extensive experiments only three succeeded.
Violent explosions were frequent, steel tubes burst, scattering their
fragments around, and furnaces were blown up. 'The continued strain on
the nerves', writes Mr. Hannay, 'watching the temperature of the
furnace, and in a state of tension in case of an explosion, induces a
nervous state which is extremely weakening, and when the explosion
occurs it sometimes shakes one so severely that sickness supervenes'.1
1 Williams, Gardner F., The Diamond Mines of South Africa, B. F. Buck and Co., N. Y., 1906, Vol. II, p. 138.
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