brown
crystals, some of which were of considerable dimensions. They were
brilliant, transparent, and harder than quartz. They were examined by
MM. Thenard and Dumas.
Submitted
to an intense heat in contact with the air, the crystals experienced
not the slightest change, a proof sufficient in itself that they were
not of the nature of the diamond. Besides, notwithstanding their
considerable hardness, they were easily scratched by the latter gem.
The conclusion of the academical savants was, that the pretended
diamonds were merely silicates or artificial precious stones.
The
experiments of Gannal gained more renown. Specimens of his productions
were sent to M. Champigny, director of the workrooms of the jeweller
Petitot, who examined them with care; and having satisfied himself that
they scratched steel, and could be scratched by no metal, that they
were of pure water, and displayed a brilliant lustre, concluded that
these little bodies were nothing else but diamonds. This declaration,
emanating from a man well versed in the special trade, created an
excitement and even a panic in the diamond trade.
The process by which Gannal obtained his diamonds was very simple.
He introduced carbon disulphide and water into a matrass, with morsels of phosphorus, which in the
