92 



POPULAR HISTORY OF LICHENS. 



in many Lichens to a large extent, and in garden rhubarb, 

 sorrel, and other phanerogams ; and of an oil similar to the 

 furfurol of bran and the fucusol of seaweeds, which is pro- 

 ducible by distilling Cetraria Islandica, Usnea harhata, and 

 other Lichens with certain proportions of sulphuric acid 

 and water. Brownish colouring matters, ready formed in 

 the thallus, also exist abundantly in many Lichens, and are 

 easily extracted ; they are the basis of various dyes prepared 

 by the peasantry of this and other countries, but they are 

 not of sufficient value ever to have been manufactured or 

 applied on the large scale. It will thus be remarked that 

 the only matters really valuable in dyeing are the product 

 of the chemical metamorphosis of colourless compounds, 

 which usually exist in species devoid of vivid or deep tints. 



Lichens, in consequence chiefly of imaginary virtues, were 

 at one time employed in various arts, in which their use 

 is now totally abandoned. Prom their alleged aptitude for 

 imbibing and retaining odours or scents, the powder of se- 

 veral filamentous and fruticulose species formed the basis of 

 certain perfumes which were celebrated in the seventeenth 

 century, and of which the chief was designated the " Poudre 

 de Chypre" (Pulvis Ci/prius), or Cyprian hair-powder : 

 these were popularly believed to remove scurf, and to clean 



