Towards the end of the year 1730, the captain of an English vessel, which came from the Cape de Verde islands, brought a bag of archil to Santa Cruz by way of trial. He discovered his secret to some Spanish and Genoese merchants, who, in the month of July 1731, resolved to send a ship to these islands. They landed on that of St. Anthony and St. Vincent, where in a few days they obtained five hundred quintals of this lichen, which they found in such abundance, that it cost them nothing more than a piastre per cent. by way of present to the governor. The archil of the Cape de Verde islands appears larger, richer, and longer than that of the Canaries, and this, perhaps, is owing to its not being collected every year[83]. Adanson, in 1749, found also the greater part of the rocks in Magdalen island, near Senegal, covered with this lichen. Though the greater part of our archil is at present procured from the Canary and Cape de Verde islands, a considerable quantity is procured also from the Levant, from Sicily, as Glass says, and from the coast of Barbary; and some years ago the English merchants at Leghorn caused this lichen to be collected in the island of Elba, and paid a high price for it[84]. Our dyers do not purchase raw archil, but a paste made of it, which the French call _orseille en pâte_. The preparation of it was for a long time kept a secret by the Florentines. The person who, as far as I know, made it first known was Rosetti; who, as he himself tells us, carried on the trade of a dyer at Florence. Some information was afterwards published concerning it by Imperati[85] and Micheli the botanist[86]. In later times this art has been much practised in France, England, and Holland. Many druggists, instead of keeping this paste in a moist state with urine, as they ought, suffer it to dry, in order to save a little dirty work. It then has the appearance of a dark violet-coloured earth, with here and there some white spots in it. The Dutch, who have found out better methods than other nations of manufacturing many commodities, so as to render them cheaper, and thereby to hurt the trade of their neighbours, are the inventors also of lacmus[87], a preparation of archil called _orseille en pierre_, which has greatly lessened the use of that _en pâte_, as it is more easily transported and preserved, and fitter for use; and as it is besides, if not cheaper, at least not dearer. This art consists, undoubtedly, in mixing with that commodity some less valuable substance, which either improves or does not much impair its quality, and which at the same time increases its weight[88]. Thus they pound cinnabar and smalt finer than other nations, and yet sell both these articles cheaper. In like manner they sift cochineal, and sell it at a less price than what is unsifted.