The lustre was vitreous to such a degree that the name _vitrum murrhinum_ was given to the artificial fabric, in Egypt. The splendour was not very great, for Pliny observes, “Splendor his sine viribus nitorque verius quam splendor.” The colours, from their depth and richness, were what gave these vessels their value and excited admiration. The principal colours were purple and white, disposed in undulating bands, and usually separated by a third band, in which the two colours being mixed, assumed the tint of flame: “Sed in pretio varietas colorum, subinde circumagentibus se maculis in purpuram candoremque, et tertium ex utroque ignescentem, velut per transitum coloris, purpura rubescente, aut lacte candescente.” Perfect transparency was considered as a defect, they were merely translucent; this we learn not merely from Pliny, but from the following epigram of Martial: Nos bibimus vitro, tu murra, Pontice: quare? Prodat perspicuus ne duo vina calix. Some specimens, and they were the most valued, exhibited a play of colour like the rainbow: Pliny says they were very commonly spotted with “sales, verrucæque non eminentes, sed ut in corpore etiam plerumque sessiles.” This, no doubt, refers to foreign bodies, such as grains of pyrites, antimony, galena, &c., which were often scattered through the substances of which the vessels were made. Such are all the facts respecting the vasa murrhina to be found in the writings of the ancients; they all apply to fluor spar, and to nothing else; but to it they apply so accurately as to leave little doubt that they were in reality vessels of fluor spar, similar to those at present made in Derbyshire.[81] [81] This opinion was first formed by Baron Born, and stated in his Catalogue of Minerals in M. E. Raab’s collection, i. 356. But the evidences in favour of it have been brought forward with great clearness and force by M. Roziere. See Jour. de Min. xxxvi. 193. The artificial vasa murrhina made at Thebes, in Egypt, were doubtless of glass, coloured to imitate fluor spar as much as possible, and having the semi-transparency which distinguishes that mineral. The imitations being imperfect, these factitious vessels were not much prized nor sought after by the Romans, they were rather distributed among the Arabians and Ethiopians, who were supplied with glass from Egypt. Rock crystal is compared by Pliny with the stone from which the vasa murrhina were made; the former, in his opinion, had been coagulated by cold, the latter by heat. Though the ancients, as we have seen, were acquainted with the method of colouring glass, yet they prized colourless glass highest on account of its resemblance to rock crystal; cups of it, in Pliny’s time, had supplanted those of silver and gold; Nero gave for a crystal cup 150,000 sistertii, or 625_l._ V.--DYEING AND CALICO-PRINTING.