LICHENS AS DYE-PLANTS 415 



of rock- or soil-lichens, is chiefly used in Scotland and Sweden (hence the 

 name "Swedish moss") to furnish a red or crimson dye. In Scotland all 

 dye-lichens are called " crottles," but the term " cudbear " was given to 

 Lecanora tartarea (either the lichen or the dye-product); it was acquired 

 from a corrupt pronunciation of the Christian name of Dr Cuthbert Gordon, 

 A chemist, who, according to Bohler 1 , obtained a patent for his process of 

 producing the dye, or who first employed it on a great scale in Glasgow. 

 Johnson 2 remarks that the colour yielded by cudbear, if well prepared, is 

 a fine, clear, but not very bright purple. It is, he alleges, not permanent. 

 Like other orchil substances it is without effect on cotton or linen. 



e. PREPARATION OF ORCHIL. A general mode of treatment of dye- 

 lichens recommended by Lauder Lindsay 3 for home production of orchil, 

 cudbear and litmus is as follows : 



i. Careful washing, drying and cleansing to separate earthy and other 

 impurities. 



?-. Pulverization into a coarse or fine pulp with water. 



3. Repeated addition of ammoniacal liquor of a certain strength, obtain- 

 able* from several sources (e.g. putrid urine, gas liquor, etc.). 



4. Frequent stirring of the fermenting mass so as to ensure full exposure 

 of every part thereof to the action of atmospheric oxygen. 



5. Addition of alkalies in some cases (e.g. potash or soda), to heighten 

 or modify colour ; and of chalk, gypsum and other substances to impart 

 consistence. 



/ BROWN AND YELLOW DYES. The extracting of these colours from 

 lichens is also a very old industry. Linnaeus found during his journey to 

 Lappland 4 , undertaken when he was quite a young man, that the women in 

 the northern countries made use of a brown lichen for dyeing which is 

 evidently Parmelia omphalodes (Fig. 135). He describes it as a "rich 

 Lichenoides of a brown stercoraceous colour," and he has stated that it grew 

 in such abundance in the Island of Aland, that every stone was covered, 

 especially near the sea. In the Plantae tinctoriae 6 there is a record of six 

 other lichens used for dyeing : Lichen Roccella, L. tartarens, L. saxatilis, 

 L. juniperinus, L. parietinus and L. candelarius. The value of Lichen om- 

 phalodes was also emphasized by Lightfoot ; the women of Scotland evidently 

 appreciated its dyeing properties as much as other northern peoples. 



A series of memoirs on the utility of lichens written by Willemet 6 , 

 Amoreux and Hoffmann, and jointly published at Lyons towards the end 

 of the eighteenth century, represents the views as to the economic value 

 of lichens held by scientific botanists of that time. All of them cite the 



1 Bohler 1835, N. 10. 2 Johnson 1861. 3 Lindsay 1855. * Linnaeus 1711. 



5 Linnaeus 1760. 6 Willemet etc. 1787. 



