254 PHILOSOPHICAL TRANS ACTIONS, [aNNO 1758. 



is the orchel,* or argol, as it is commonly called. This enters more into eco- 

 nomical uses among us than any other of the whole genus. How considerable 

 an article it forms in the dyeing trade, in which its uses are various and exten- 

 sive, is very well known. Its tinging property has been known from ancient 

 times ; and some of our most celebrated botanic writers are of opinion, that it 

 was used as a dye even in the days of Theophrastus. That father of botany 

 mentions a fucus, which he says grew on the rocks about the island of Crete ; 

 and that they dyed woollen garments of a purple, or rather a red colour, with 

 it. It grows on the rocks by the sea-coast in many parts of the Archipelago, and 

 in the Canary Islands ; whence we generally import it, as well as from the Cape 

 Verde, which afford it in plenty. The demand for orchel is so great, that M. 

 Hellot,-J~ of the Royal Acad, of Sciences, informs us, they gather yearly on an 

 average, from the isle of Teneriffe 500 quintals, which amounts to 25 ton 

 weight; from the Canary Islands 400 quintals, from Forteventura 300, from 

 Lancerota 300, the same from Gromera, and from Ferro 800. 



The way of manufacturing the orchel for the uses of dyeing, was for a consi- 

 derable time a secret in few hands; but it is now done in London, and other 

 parts of Europe, to great perfection. Mr. Ray, from Imperatus, gives a brief 

 account of the process. :|: Micheli has since delivered a more exact detail of it. 

 His at least seems to be the method ^ which the dyers at Florence used. From 

 both these accounts, urine and pot-ash appear to be the principal ingredients 

 used in extracting its colour. Many other plants of this genus contain the same 

 tophaceous matter as the orchel ; and on trial have been found to strike a good 

 colour. 



3. LiCHENES PyXIDATI. 



Such as consist of a firm tough flexible matter, formed into simple tubular 

 stalks, whose tops are expanded into the form of little cups. 



This division contains the cup-mosses of authors; the 2d order of coralloides 

 of Dillenius; great part of the first order of lichens in Haller; the 7 th, 8th, 

 Qth, and 1 0th order in Micheli; and the Hchenes schyphiferi of Linneus. Dr. 

 Hill has constituted a genus entirely of these cup-mosses, under the name of 

 pyxidium. They are common with us on heaths, and other dry and barren 

 places. Some of them are proliferous, even to the 3d degree, and form a very 



• Coralloides corniculatum fasciculare tinctorium foci teretis facie Dillen- Hist. Muse. p. 120. Cla- 

 donia tophacea Hill. Hist. PI. p. 93- Fucus capillaris tiiictorius Rail Hist. i. p. T*- Lichen (Ro- 

 cella) fruticulosus solidus aphyllus subramosus tuberculis alternis Lin. Sp. PI. 1154. — Orig. 



+ L'Art de la Teinture des Lains et des EtofFes de Lain, Paris 1760, p. 543. — Orig. 



X Raii Hist. PI. i. p. 74. — Orig. 



( Nova Plant. Gener. p. 78. — Orig. 



