Hither likewise must be referred the cork or arcel[107], which is used by the Scotch, and others, to dye a purple or scarlet colour. The preparation of it is by powdering, and making it into a mass with urine. Parkinson tells us[108] the poor people in Derbyshire scrape it from the rocks, and make the same use of it. Mr. Ray[109] adds to this account, that the Welch, who call it _kenkerig_, have long been acquainted with this property, and have it in common use. The colour from this moss is but very dull; but if the same methods were taken to improve it, as have been with the _orchel_, it would undoubtedly be rendered much better, and more durable. Linnæus relates[110], that there is an immense quantity of this moss about the rocks of the isle of Aland in the Baltick; where the good women themselves make a yellow dye with it from a simple decoction of the plant, without the addition of any saline article. He adds, that those, who would heighten the colour, add a small quantity of _roucou_[111] to the decoction. Professor Linnæus tells us, that the Gothlanders manufacture a yellow dye from the common curled _lichenoides_ with yellow leaves and plates[112]. He adds, that it is a celebrated medicine in the esteem of the country people, as a specific in the jaundice[113]. Helwingius, in the Supplement to the _Flora Prussica_, affirms, that this moss will tinge paper and linen of a lively carnation colour, which too will stand the test of being exposed to the open sun for a long time without fading. It seems very probable, however, that he must mean some other plant of this genus, as Dillenius tells us he made the experiment unsuccessfully. Sweden affords a moss of this order, which, as far as hitherto appears, seems to be unknown to former botanists, and which Linnæus says will dye a deep purple colour[114]. 6. Lichenes erecti ramosi plani. _Such as consist of a firm tough matter, disposed into flat and thin ramifications growing erect, and bearing their scutellæ upon the edges, surfaces, and at the extremities._ This division comprehends the flat branched tree-mosses of authors; many of the fourth order of Haller’s lichens; the first part of the second division of series the second in Dillenius; and the _platisma_ of Hill. The plants of this division grow upon old trees, especially in thick and unfrequented woods; some of them upon rocks: they are many of them extremely common in England upon all kinds of trees. As they were some of the most obvious, so they were some of the first lichens noticed by the old writers, by whom they were called _lichenes arborum_.