igneous rock of dark-crimson ground thickly dotted with small
crystals of felspar. Though there are other colours of precisely
the same stone, as far as its chemical composition goes, yet the
ancient Porphyrites, " purple stone," designated exclusively the
first-named kind. It took also the epithet Leptopsephos from its
speckled texture. Egypt alone produced it in Pliny's age, and in
masses of sufficient dimensions for the largestworks. But under
the Lower Empire the Romans obtained an inexhaustible supply of
the finest material from nearer home ; Valéry observed on the
coast of Sardinia vast quarries of Porphyry with shafts of
columns lying about, merely roughed out as they were left by the
workmen. The earliest works in it seen at Rome were statues of
Claudius brought from Egypt by his deputy Vitrasius Pollio, a
novelty, which Pliny remarks, was not received with approbation,
at least no one had up to that time followed his example. Under
the Lower Empire, however, it was largely employed in the most
sumptu