Philosophical transactions, Vol. L. Part II. For the year 1758. / Giving some account of the present undertakings, studies, and labours, of the ingenious, in many considerable parts of the world.

by Various; Royal Society

[40] Pliny mentions a kind of glass or jet called obsidianum:—nigerrimi coloris, aliquando et translucidi, crassiore visu, atque in speculis parietum pro imagine umbras reddente. Nat. Hist. lib. xxxvi. c. 26. §. 67.

And that the practice of staining glass was known in his time, appears from what he says concerning the obsidianum mentioned above:—Fit et genere tincturæ—totum rubens vitrum, atque non translucidum. Ibid.

[41] Panciroll. Rer. Mem. p. 288.

[42] These glass balls had sometimes water within them: Cùm additâ aquâ vitreæ pilæ sole adverso in tantum excandescant, ut vestes exurant. Plin. lib. xxxvi. c. 22. §. 45.

Invenio medicos, quæ sunt urenda corporum, non alitèr utilius id fieri putare, quam crystallinâ pilâ adversis positâ solis radiis. Plin. Nat. Hist. lib. xxxvii. c. 6. §. 10.

[43] Vid. Mons. Renaudot Memoires de l’Acad. des Inscript. tom. I.

[44] Vid. infra, not. 11.

[45] Theatrum Scauri——scena ei triplex in altitudinem CCCLX columnarum.——Ima pars scenæ e marmore fuit: media e vitro: summa e tabulis inauratis. Nat. Hist. lib. xxxvi. c. 15.

[46] A. V. 678. Hard. not. Plin. lib. xxxvi. c. 8.

[47] Agrippa in thermis, quas Romæ fecit, figlinum opus encausto pinxit, in reliquis albaria adornavit: non dubiè vitreas facturus cameras, si prius inventum id fuisset, aut a parietibus scenæ—Scauri pervenisset in cameras. Lib. xxxvi. c. 25. §. 64.