THE PAGE OF NATURE. 105 



In medicine, lichens were at one time very highly 

 esteemed. In the days of Aldrovandus and Paracelsus, 

 Avho added the study of alchemy and the occult sciences 

 to that of plants, they were extensively employed in the 

 preparation of sympathetic ointments, and in the various 

 distillations connected with the search for the elixir vitse 

 and the universal solvent and nostrum. Wonderful cures 

 were ascribed to a particular application of them; and 

 in the works of the botanists of the middle ages, we find 

 long and elaborate observations upon the peculiar virtues 

 of species developed upon the oak, the pine, and the 

 beech. The common dog-lichen (Peltidea canind) a 

 species everywhere abundant on moist banks and turfy 

 walls, and easily distinguished by its livid brown wrinkled 

 leaves, and red, nail-like fructification was formerly 

 employed, at the suggestion of the celebrated Dr. Mead, 

 as a cure for hydrophobia (hence its specific name), and 

 in many instances with success; but whether the cures 

 were effected by an inherent power in the plant itself, 

 or merely by the aid of a strong imagination, may be left 

 an open question. Another species of the same family 

 (Peltidea apthosci), with a remarkably vivid green thallus, 

 growing by the side of mountain streams, was in high 

 repute at one time as a powerful anthelmintic, and is 

 still used by the Swedish peasants, when boiled with milk, 

 as a cure for the apthae or thrush in children. When 

 the primitive principle that " like cures like" formed the 

 basis of all medical treatment, several lichens were em- 

 ployed for the cure of diseases, on account of their fancied 

 resemblance to the organs or parts of the body affected. 

 Among such lichens the species in greatest favour 



