14. Notwithstanding the very high esteem in which the Tyrian purple was held by the ancients, and the great encomiums which have been bestowed on it by many of the moderns, the loss of it is perhaps scarcely an object of regret. The shell fish which furnished the purple dye probably exist now, says Berthollet, in as great abundance as formerly. They have been so accu rately described, that they may be recognized ; and, in fact, Thomas Gage informs us, that shell fish have been found near Nicoya, a small Spanish town in South Ame rica, which possess all the properties described by Pliny, and other ancient writers. These shell-fish, it appears, are at present used in dyeing cotton on the coasts of Guagaquil and Guatimala. Cole, in the year 1686, dis covered some of them on the English coast, and Plu mier found a species of them at the Antilles. Rcaumur has made many experiments on the whelks which he ob tained from the coasts of Poitou, and Duhamel has mi nutely examined the colouring liquor of the purple shell fish which lie found in great abundance on the coast of Provence. He observed, that this liquor does not take a purple colour without the action of light, a circum stance which Reaumur had before remarked respecting that of the whelk ; that though at first white, it be comes of a yellowish green, which deepens to a sort of blue; that it afterwards reddens, and in less than five minutes becomes of a very fine deep purple. In all these respects, the colour produced possessed the cha racters of the ancient purple. If this method, therefore, of dyeing purple is no longer practised, it is not on ac count of our ignorance of the process, but because we are acquainted with more beautiful, as well as much less expensive dyes; though, as Dr Bancroft remarks, the purple afforded by the shell-fish in question, may still be applied with advantage in topical dyeing, for which but little colouring matter is required.
15. The art of dyeing seems to have made but little progress among the Greeks ; a fact which must undoubt edly be ascribed to the little estimation in which the arts that contribute to conveniency or Itivry were held by that warlike and high-minded people. Public opinion placed the fine and the useful arts at an immense dis tance from each other; for while the highest glory was connected with the former, the latter were degraded among the dishonourable and servile employments. Ac cordingly we find, that though the more opulent inha bitants of Athens preferred coloured clothes, the dress of the common people was made of cloth which had re ceived no dye. The art of dyeing linen appears to have been unknown in Greece before Alexander the Great in vaded India ; where, according to Pliny, his captains, in skirmishing on the banks of the Indus, first saw, to their astonishment, the enemy changing the ensigns of their vessels, and suddenly displaying others of different co lours. Even the dyeing of woollen stuffs seems to have made little progress at that time, as the same author, after declaiming against the luxury of his cotempora ries for wearing clothes dyed of colours which rivalled those of the finest natural flowers, observes, that none of these flowery colours were in use during the time of Alexander. It is probable, however, that the companions 4f that conqueror brought back from Persia and India some information respecting the rich dyes employed in those countries, which they afterwards diffused among their countrymen.
16. The Romans borrowed almost all the knowledge of dyeing which they possessed from the Greeks, toge ther with the same contemptuous notions with regard to the art. The sentiments of the Greeks and Romans in this respect, afford a remarkable contrast to the more liberal and enlightened views of the present clay, and furnish one of the most striking characters by which, the philosophy of the ancients is distinguished from that of the moderns. The ancients appear to have un dervalued every thing that contributed to domestic com fort and enjoyment ; and while they professed the most enthusiastic regard for the public good, to have forgot ten that the grand aim of all patriotism ought to be the promotion of individual happiness. They accordingly degraded the useful employments, and reserved their esteem for arts whose productions could seldom be brought in contact with ordinary affairs. The moderns, less actuated by feeling, and more influenced by reason, set a due value upon the fine arts, without underrating those which are subservient to the more common con cerns of lite. A philosopher of the present times does not affect the austere and reserved habits of the sages of antiquity : he mixes freely in society, and does not disdain to derive information from whatever nature or art may offer to his observation. The instruction he has received from the artist has been amply repaid, by the ligm which science has shed upon the arts, and the explanations which it has afforded of their various pro cesses.
17. Next to the Tyrian purple, the Romans valued most highly the colour obtained from the kermes, or coccus Weis. Pliny mentions that this dye was some times employed with the colour of murex and buccinum, (the shell-fish which gave the Tyrian purple) in pro ducing a sort of purplish crimson, called by the Romans hysgmus. He states, that this substance was brought from Galatia, or from the neighbourhood of Emeritia in Portugal, and that the latter was reckoned most valuable. We learn also from Pliny, that the kerrnes, like the Ty rian dye, was at last appropriated for dyeing the impe rial robes, though it must have yielded a colour greatly inferior to that which is obtained from it at present, as he insinuates that it was not durable. This last circum stance would lead us to suspect, that at that time the ancients were unacquainted with the use of alum as a mordant, though such an opinion is rather discounte nanced by other facts stated by Pliny. In his 35th book, chap. xv. De Sulphure, ?lumine, et generibus eorum, E.Tc. he describes several species of alum ; that of these the island of Cyprus afforded two, one white, and the other black ; and that though their colours differed but little, their uses were extremely different. The white alum, he adds, is principally used for dyeing wool with clear and bright colours ; the black, for dyeing brown and Clark colours. Ile afterwards notices five different kinds, and concludes with observing that all the different kinds of alum were possessed of an astringent property. Beck mann has endeavouree'to prove that the alum of the ancients was totally different from the triple compound to which the moderns apply the term alum, and consist ed in a combination of sulphuric acid, with either iron or copper, or perhaps zinc, formerly known by the names of green, blue, and white vitriols. In support of his opinion, he mentions that the Greek and Roman writers.