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THE ONYX.
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313
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1647,
testified from his own experience as to its power to stop bleeding from
the nose. At that time rings were cut entirely out of the Sard
stone,—to be worn with this same purpose in view. Such rings are still
made and worn in Italy ; the said benefit of arresting bleeding from
the nose being their reputed object.
Resuming
our notice of the Onyx, as to the Cameos formerly designed thereupon,
the darker shades were usually left to form the ground, whilst the
lighter shades were cut into figures. Onyxes, and Agates may readily be
stained to almost any colour by artificial means. For black, the stone
is first boiled in honey ; (and then in sulphuric acid, which
carbonises the grape-sugar). Only the porous parts of the stone absorb
the sugar, so that the carbonisation greatly heightens the contrast
between the white and black layers of the stone. The Nicolo variety of
Onyx has a deep brown ground, overlaid by a layer of bluish-white.
Honey is likewise employed for giving increased transparency to other
gems, if steeped in it for a time. Pliny relates that all gems are
brightened if boiled in honey (Mellis decoctu nitescunt), especially in the honey of Corsica, which was noted for its acridity. But all other acids are detrimental to precious stones.
Speaking
of honey, we call to mind the circumstance that in Tudor times honey
was poured over the meat at table in good houses. Furthermore, an
amazing quantity of sweets was eaten at dessert; for discussing which
refection the guests adjourned to another room ; or to the garden if it
were summer-time ; indeed, at that date sugar was eaten with almost
everything ; so that the teeth of most persons were black.
Lempriere relates that Polycrates (of classical times),
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