Fig. 1. An ancient Roman fragment of Glass
of the smeltz character. It was exhumed in the city of London, near
Moorfields, and is now possessed by Mr. Roach Smith: it is a melange of
yellowish-white enamel, with a very dark iron red. Specific gravity,
Fig. 2. Has the projecting Roman
pillars, as described in the manipulatory portion of this work, (see
;) and, like most of the Compound Glasses, has
scarcely undergone any decomposition whatever. Specific gravity, 2483.
Also Mr. R. Smith's.
Fig. 3. Is a very rare specimen from
Mr. R. Smith's collection, and displays the great perfection of
ancient Glass cutting. It formed part of an elegant drinking-cup.
One peculiarity is, its lightness; it being but little more than twice
its weight of water—viz., of a specific gravity 2049. It is
The ancients had their White Glasses both
of simple and compound character; the latter were by far the most
conservative. Specimens of the former, in the British Museum, and in
private hands, are in a state of considerable decomposition. The heat
of the burning lava which overwhelmed the devoted cities of Herculaneum
and Pompeii, may have had great effect in destroying part of the alkaline
properties, (much greater than the ordinary influence of the atmospheric
air,) and thus causing, in the partial decomposition, the