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108 NATURAL HISTORY OF PRECIOUS STONES, &c.
Barbot
(' Taille du Diamant ') considers it an absurdity to suppose that the
action of one Diamond upon another could have been discovered by
accident, so much force being actually required to make one bite on the
other. This is true for the effective operation, but the idea
of their possessing such power may very possibly have been suggested by
observing the effect of slight and casual friction. Like a true Gaul,
Barbot solves the difficulty by making Berquem go to Paris to study the
art under Herman !
Laborde, to prove the antiquity of the art of diamond-cutting, adduces
the use of the diamond-point by the ancients for engraving gems.* This
is totally foreign to the purpose : nothing could have been done in the
way of reducing the Diamond to any given shape until the secret was
discovered how to get the diamond-dust to replace the emery,
that agent only effective for the softer gems; and this diamond-dust
could only then be obtained by nibbing one stone against the other ;
there was as yet no supply of small Diamonds good for pulverisation
alone. This then was the grand discovery of L. de Berquem ; and until a
genuine piece of mediaeval jewelry be produced, containing a Diamond
actually cut to a definite pattern, there is no reason why he should be
robbed of the honour he has so long enjoyed.
In
the modern art the first principles are the same. The stone, if of a
very irregular formation, is brought towards its required shape by
cleavage. A nick being scratched with a diamond-point along the
direction of its laminae, a smart blow with the knife severs the
projection, which can subsequently be itself cut into a shapely stone
of ap-
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