ALABASTER. 117 
forge amount, multiplied by this means at the head- 
quarters of the armies lately employed on the Continent. 
An artificial composition is sometimes used instead 
of lias. 
Considerable quarries of this stone are wrought in 
Germany. It is also found at Leixlip, near Dublin; 
in beds at Aberthaw, in Glamorganshire; in Dorset- 
shire, and near Bath. 
SULPHAT OF LIME. 
192. ALABASTER, or GYPSUM, is a kind of sulphat 
of lime, or of' lime in combination with sulphuric acid (24), 
which has a shivery and glittering texture ; and is of white 
colour tinged with grey or red> and sometimes stripcd t veined, 
or spotted. When crystallized, the primitiveform of its crystals 
is a regular four- sided prism (Fig. 14.) 
Being considerably softer than marble, this mineral 
is not capable of receiving a good polish. From this 
circumstance it is, however, the more easily worked. 
It is manufactured into chimney-pieces, columns, busts, 
ornamental vases, and lamps ; the latter of which trans- 
mit a soft and pleasing light. Such is sometimes the 
transparency of alabaster, that it has been employed 
for windows ; and, at Florence, there is now a church 
which receives its light through the medium of this 
substance. 
The ancients, though acquainted with the art of 
making glass, had not attained the knowledge of re- 
ducing it into thin transparent plates ; and frequently 
employed alabaster for windows. Of this stone the 
Temple of Fortune, which was built by order of the 
Emperor Nero, was erected. It had no windows what- 
ever, and received only a soft kind of light through its 
walls ; appearing rather as if the light issued from the 
interior, than that it was admitted from without. 
The hot springs of St. Philip, which supply the baths 
of Tuscany, are so strongly impregnated with alabaster, 
that artists take advantage of this to obtain impressions 
of bas-reliefs, by merely exposing their moulds to a 
