And as (according to this learned writer) there is nothing in the term _specular_ itself, which hinders it from being extended to windows made of other materials besides those above-mentioned; so others imagine, that there are some intimations in ancient authors, which require, that it should actually be so extended. Thus Mr. Castells, the ingenious illustrator of the villa’s of the ancients, thinks[56], that “if this had not been the case, Palladius would not have given directions to his husbandman to make _specularia_ in the _olearium_[57], or store-room, where the olives were preserved. For it appears (says this author) from Pliny’s describing a temple[58] built of the _lapis specularis_, or phengites, as the greatest rarity in his time, and the mention Plutarch makes of a room in Domitian’s palace lined with it, that it was not common enough for husbandmen to purchase;” _viz._ in such quantities, as were required for the purposes mentioned above. I shall not take upon me to decide upon the weight of this argument of Mr. Castells; but only observe, that if any one should be induced by it to think, that the use of glass for windows may be of much greater antiquity than is commonly allowed, or even as old as the fragment, which occasions these remarks, he may find other probable reasons to corroborate his opinion. As, first, that there seems to have been a natural and obvious transition from the practice of using glass plates for the ornamenting the walls of apartments to that of introducing light into those apartments, (as we find the _lapis specularis_ was in fact employed at the same time for both those purposes) and consequently it seems reasonable to suppose, that the latter of these applications could not be long in point of time after the former. But it appears from the authorities produced above, that the former of these usages did actually subsist in the age[59] of Pliny; and therefore before the destruction of Herculaneum, where he lost his life[60]. From whence we may draw no improbable conclusion, that the latter destination of plates of glass, (_viz._ for window-fences) did likewise precede the same event.