However, we may with greater probability propose another use, for which the ancients might employ such plates of glass, as are now under consideration, _viz._ the adorning the walls of their apartments by way of wainscot. This I take to be the meaning of the _vitreæ cameræ_ mentioned by Pliny[44]; who intimates, that this fashion took its rise from glass being used by M. Scaurus[45] for embellishing the scene of that magnificent theatre, which he erected for exhibiting shows to the Roman people in his ædileship[46]. And we may collect from the same author[47] (what is further confirmed by his contemporary [48]Seneca), that this kind of ornament had been admitted, in his time, into chambers in houses, baths, _&c._ Whether the plates used for this purpose were stained with various colours (as mentioned above), or had tints of divers kinds applied to the back part of them, I shall not pretend to determine: but in either way they would have a very agreeable effect. The last destination, which the obvious congruity of the thing itself, countenanced by the practice of many ages past, as well as of the present time, would induce one to ascribe to such plates of glass, is that of windows for houses, baths, portico’s, _&c._ But I am sensible, that whoever should be hardy enough to advance such an hypothesis, would be censured as an innovator, in opposing the general opinion of the connoisseurs in antiquity. These gentlemen are almost unanimous in asserting, that whenever we meet with mention made of _specularia_ in ancient writers (especially those _of_, or near _to_, the age, to which we must refer this fragment), we are to understand by that term nothing but fences made of _laminæ_, either of a certain stone called from its transparent quality _lapis specularis_[49], brought first from Hispania Citerior, and afterwards found in Cyprus, Cappadocia, Sicily, and Africa; or of another stone of the same nature, _viz._ the phengites. These, tho’ expressly distinguished from each other by Pliny[50], are yet reckoned by some moderns[51] as one and the same thing; and thought to have been nothing but a kind of white transparent talc, of which (according to Mons.[52] Valois) there is found a great quantity in Moscovy at this day. Now that this _lapis specularis_, or phengites, was really used for windows by the ancient Romans in their houses, _&c._ cannot be denied; since (according to the opinion of the learned[53] in antiquity) this usage is mentioned by Seneca[54] among other improvements in luxury introduced in his time. But whether it was so used exclusive of other materials (particularly glass), may, I think, admit a doubt. Salmasius is of opinion[55], that nothing can be determined upon this point from the word _specular_ itself, which seems to be a generical term, equally applicable to windows of all kinds, whether consisting of the _lapis specularis_, or any other transparent substance.