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pecially Westring in his Svenska Lafvarnas Farghistoria, Stockh. 

 J805, the classical work. Many lichens, among which the Archil, 

 Parelle, and Cudbear, are most distinguished, abound in coloring 

 matter of equal elegance and tenacity, and those mentioned are 

 articles of commerce. Westring distinguishes between those 

 lichens which impart color to pure water, which he calls essential 

 pigments, and those which require a peculiar treatment to yield 

 color preparable pigments. A single species, with different treat- 

 ment, affords very different colors, which he exhibits in every case. 

 He considers that the colors afforded by lichens are remarkably 

 efficacious in staining marble durably. There is no brief view of 

 the uses of lichens as dye-stuffs so comprehensive as that given by 

 Mr. Neil in his admirable article in the Edinburgh Encyclopedia. 

 Coloring matter may be said, says Fries, to exist in all lichens, but 

 it abounds especially in the crustaceous, the tartareous, and coria- 

 ceous kinds, and is almost deficient in those which are more deli- 

 cate, or subgelatinous. And it is most remarkable, that not only 

 the quantity, but the kind of color, differs in different states of evo- 

 lution of species. Isidioid forms, he adds, are most rich in color; 

 next to them are the Variolarioid ; and the powdery, gonimous, and 

 hypothalline states are the poorest. The color seems to depend on 

 the resinous principle Erythrinum, already referred to, said to be 

 peculiar to lichens. This affords red, purple, and brown hues, 

 which differ very much, according to the treatment. The mucilage 

 of lichens was proposed by Lord Dundonald to be applied to thick- 

 ening the mordants, and fixing the colors in calico-printing. From 

 Umbilicaria pustulata excellent Chinese ink has been made. Paper 

 has been made from the gray foliaceous Parmelise. A gum as trans- 

 parent as gum arabic was obtained by Georgi and by Amoreux, by 

 evaporation of the mucilage of Parmelia, Peltigera, and Rama- 

 lina. In Siberia, the Lungwort lichen (Sticta pulmonaria) is a 

 common substitute for hops, in the making of ale ; and is also reck- 

 oned edible by Georgi, yielding " a yellow, nearly insipid muci- 

 lage," which may be eaten with salt. And this species, and many 

 others, from the tannin which they contain, are employed in some 

 countries for tanning leather. Many cruslaceous lichens contain 

 oxalic acid in greater or less abundance; and according to M. 

 Braconnot, this occurs in the bitter Variolaria (Pertusaria pertusa, 

 ft. sorediata, c. orbiculata, Fr.) in such quantity that 100 parts yield- 

 ed 18 of lime, combined with 29.4 of oxalic acid ; and the lichen is 

 now employed in France in the manufacture of the acid on a very 

 extensive scale. 



In medicine, the uses of lichens were formerly so much thought 

 of, that there was scarcely a disease for which some lichen or other 

 was not regarded specific. Those still received are reckoned as- 

 tringent, febrifugal, and stomachic ; and more rarely they seern to 

 be purgative and anthelmintic. Parmelia parietina was some years 

 since declared to be a sufficient substitute for Peruvian bark, an 

 opinion which gained same credit in Europe, and even now, I was 

 assured by a competent person, is not wholly given up. That many 

 lichens may be useful as febrifuges is hardly doubtful, and their 



