^34 PHiLO«OPHlCAL TRANSACTIONS. [aNNO J 758. 



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 ima- 

 gine, 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 villas of the ancients, thinks ' that if this had not been the case, Palladius 

 would not have given directions to his husbandman to make specularia in the 

 olearium, or store-room, where the olives were preserved. For it appears, says 

 this author, from Pliny's describing a temple 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 pur- 

 poses mentioned above. 



Mr. N. does not pretend to decide on the weight of this argument of Mr. 

 Castells; but only observes, 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 com- 

 monly 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 fonner of these usages did actually subsist in the age of Pliny ; and therefore 

 before the destruction of Herculaneum, where he lost his life. 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. 



Mr. N. adds further, that this presumptive argument in favour of the anti- 

 quity of windows made of plates of glass, receives an additional force from the 

 close relation which must be allowed to subsist between them, and those com- 

 posed of the lapis specularis. The former must be cx)nsidered as an improve- 

 ment on the other, as they answered all the purposes of convenience, and at the 

 same time were more beautiful; and being the manufacture of Italy, might pro- 

 bably be purchased at a less expence. On all which accounts it seems reasonable 

 to conclude, that one of these inventions would naturally be introductory to the 

 other: and consequently, that as window-lights of the lapis specularis began to 

 be used within the memory of Seneca, who died under Nero, about Anno Christi 

 68, the original of those of glass may have fair pretensions to a place within 

 the period assigned in the foregoing paragraph, viz. some years before the de- 

 struction of Herculaneum, in whose ruins the plate before us was buried. 



