[619] In Pliny’s time people coloured a white earth with indigo, or only with woad, _vitrum_, in the same manner as coarse lakes and crayons are made at present, and sold it for indigo. One of them he calls _annularia_, and this was one of the sealing earths, of which I have already spoken in the first volume. In my opinion it is the same white pigment which Pliny immediately after calls _annulare_: “Annulare quod vocant, candidum est, quo muliebres picturæ illuminantur.” These words I find nowhere explained, and therefore I shall hazard a conjecture. Pliny, I think, meant to say that “this was the beautiful white with which the ladies painted or ornamented themselves.” [620] Plin. lib. xxxv. § 12, p. 684.--Vitruv. lib. vii. cap. 14. [621] Tavernier, ii. p. 112. We are told so in Malta Vetus et Nova a Burchardo Niederstedt adornata. Helmest. 1659, fol. lib. iv. cap. 6, a work inserted in Grævii Thesaurus Ital. vi. p. 3007. This man brought home with him to Germany, after his travels, a great many Persian manuscripts, which were purchased for the king’s library at Berlin. Niederstedt, however, is not the only person who speaks of indigo being cultivated in Malta. Bartholin, Epist. Med. cent. i. ep. 53, p. 224, says the same. [622] It is entirely different from the molybdate of tin, the laborious preparation of which is described by J. B. Richter in his Chemie, part ii. p. 97. [623] It deserves to be remarked, that the Greek dyers, speaking of a fermenting dye-pan covered with scum, used to say, like our dyers, that it had its flower, ἐπάνθισμον. In Hippocrates the words ἐπάνθισμα ἀφρῶδες denote a scum which arises on the surface. Among the Latins _flos_ in this sense is very common. [624] Caneparius de Atramentis, Rot. 1718, 4to, v. 2. 17.--Valentini Museum Museor. i. p. 225.--Pomet, i. p. 192. [625] See his edition of Dioscorides, Colon. 1529, fol. p. 667. [626] Lib. xxxvii. 10. sect. 61, p. 791. [627] Lib. xxxv. cap. 6. [628] _Perfici_ is a term of art which is often used to express the finishing or last labour bestowed upon any article: _Vasa sole perficiuntur_. When vessels of earthen-ware have been formed, they must be suffered to dry and become hard in the sun. See Hardouin’s index to Pliny. [629] Gum and gummy substances of every kind used to make ink thicker and give it more body, were called _ferrumen_. See Petronius, cap. 102, 15. [630] Vitruv. vii. 10, p. 246. [631] Lib. xxxv. cap. 7. [632] Exercitat. Plin. p. 816, b. And in the Annotationes in Flavium Vopiscum, p. 398, in Historiæ Augustæ;, Paris, 1620, fol. [633] De Composit. Pharmac. secundum locos, lib. iv. cap. 4. Edit. Gesn. Class. v. p. 304. [634] Lib. iv. cap. 7. [635] Salmasii Exercitat. Plin. p. 908, a. [636] Pauli Æginetæ libri vii. Basiliæ, 1538, fol. p. 246, lib. vii. [637] Parabilium lib. i. 161, p. 43.