Note 1167 — BOOK XXXIII. THE NATURAL HISTORY OF METALS.647 (continued 2)

“Idem et Puteolani usus, præterque ad fenestras.” “The expression here, usus ad fenestras, has been misapplied by Lehmann, as a strong proof of his assertion; for he explained it as if Pliny had said that a blue pigment was used for painting window-frames; but glass windows were at that time unknown. I suspect that Pliny meant to say only that one kind of paint could not be employed near openings which afforded a passage to the light, as it soon decayed and lost its colour. This would have been the case in particular with lake, in which there was a mixture of vegetable particles.”—Beckmann, Hist. Inv. Vol. I. p. 480.