[456] Einleitung in die Lehre von den Regalien. Rostock, 1757, 4to, p. 494. [457] Chronicon Canon, reg. ord. August. capituli Windesemensis; auctore Joh. Buschio. Antv. 1621, 8vo, p. 73. [458] Schrevelii Harlemum. Lugd. Bat. 1647, 4to, p. 181. [459] This letter of Fulbert may be found in Maxima Bibliotheca Veterum Patrum. Lugduni 1677, fol. tom. xviii. p. 9. [460] In Labbei Biblioth. Manuscr. i. p. 132. [461] Traités de la Police, ii. p. 151. VERDIGRIS, OR SPANISH GREEN. Respecting the preparation of verdigris, various and in part contradictory opinions have been entertained; and at present, when it is with certainty known, it appears that the process is almost the same as that employed in the time of Theophrastus, Dioscorides, and Vitruvius[462]. At that period, however, every natural green copper salt was comprehended under the name of _ærugo_. Dioscorides and Pliny say expressly, that a substance of the nature of those stones which yielded copper when melted, was scraped off in the mines of Cyprus; as is still practised in Hungary, where the outer coat of the copper ore is collected in the like manner, and afterwards purified by being washed in water. Another species, according to the account of Dioscorides, was procured from the water of a grotto in the same island; and the most saleable natural verdigris is still collected by a similar method in Hungary. The clear water which runs from old copper-works is put into large vessels, and after some time the green earth falls to the bottom as a sediment.