FLOOK.] 
SLADE COLLECTION. 
117 
specimens of Eoman glass are very numerous. The material was 
applied to a great number of uses, and the processes seem to have been 
quite as varied and well understood as in later times. The com- 
mon clear glass has generally a greenish or bluish hue, though some- 
times it is as white and brilliant as rock crystal; this latter kind was 
much valued by the Romans ; the other transparent colours are, gene- 
rally, various shades of blue, purple, yellow, and green. A delicate 
pink is supposed to derive its colour from gold. The opaque colours 
are less commonly employed singly, but they occur in shades of yellow, 
blue, green, and black. The beautiful iridescence with which many 
vases are covered is not intentionally produced, but is the effect of 
time, which has partially decomposed the surface of the glass. 
The simpler vases are only blown, with handles, feet, or ornamental 
fillets subsequently added ; others are blown into moulds, and exhibit 
various designs in relief ; some of the bowls have projecting ribs, and 
have been termed pillar-moulded. (No. 203). On some vessels, chiefly 
belonging to a late period, shallow engraving, executed on the wheel, 
has been added; others are cut in regular patterns (see 171 and 
321). Sometimes a coloured ground was coated with white opaque 
glass, which was afterwards cut away, so as to produce a cameo, 
as in the celebrated Portland Vase, exhibited in the Ornament Room, 
and in the Auldjo Vase (Case 58). In other instances, a number of dif- 
ferent colours were employed, sometimes, as in the Egyptian specimens 
above noticed, forming regular mosaic designs, sometimes blended into 
a mass of scrolls, rosettes, &c., and at others imitating onyx, agate, ma 
drepore marble, or porphyries and other hard stones, though generally 
in more brilliant colours. Of these designs the variety is inconceivable, 
as may be seen by two bowls (Nos. 86, 387,) and numerous polished 
fragments. Occasionally gold-leaf was introduced, and at a late time 
the insides of cups and shallow bowls were decorated with patterns in 
gold-leaf, sometimes on the surface, sometimes enclosed between two 
layers of glass. To this class belong the fragments with Christian 
designs found in the catacombs of Rome (Case H), as well as the remains 
of a large disc from Cologne (No. 317), on which, though much broken, 
eight Christian subjects may be distinguished. The mosaic glass, and 
especially that imitating various stones, was much used to line the 
walls, or to form the pavements of rooms. Very clever imitations of 
gems were made, and the glass intaglios and cameos have preserved to 
us designs of some of the greatest gem engravers ; being generally 
moulded from gems, and not themselves engraved. 
After the fall of the Roman empire the glass works of the West must 
have gone to decay ; of glass of the Anglo-Saxon period there are in the 
Slade Collection only three specimens, a tumbler with a convex base, 
from Selzen (No. 319), and two cups found in Kent. Those from 
the General Collection (Case 52, 53) are more numerous. In the 
East, glass making was still continued, probably in the neighbourhood 
of Damascus. There are in the collection some very fine specimens, 
all decorated with enamel and gilding. (Case 44, 45). Two lamps from 
mosques, made, according to the inscriptions, for Seifeddin Takuzde- 
