44 



active properties are no doubt to be found in the bitter principle, 

 which is combined with that nutritive and restorative amylaceous 

 gluten with which they abound. A long list of medicinal "Li- 

 chenes, quorum usus obsoletus est " may be found in Luyken and his 

 authorities. With the exception of what is above admitted, it is 

 probable that Spielmann (Inst. Mat. Med., p. 388) is correct in 

 saying that we know nothing with certainty of the particular 

 uses of lichens in medicine. The symbolical or physiognomistic 

 contemplation of nature which Porta reduced to a system, and by 

 which it was proposed to discover the virtues of plants through a 

 sort of homeopathy, so to speak, of nature itself extended to 

 lichens also, and hence, says Fries, the reputed (which are, perhaps, 

 not yet quite obsolete) virtues of Peltigera aphthosa, on account of its 

 soredia, to cure the thrush (aphthae); those of Usnea to strengthen 

 the hair, and cure diseases of it; and those of Sticta pulmonaria in 

 lung-complaints. And the Paracelsian school brought up at last that 

 "muscus cranii humani," which was so long a sort of philosopher's 

 stone among the adepts, no two of whom could agree upon what it 

 was, or whether any body had got it ; beyond which, in this regres- 

 sive series of our knowledge of the uses of lichens, we cannot go. 

 Auct. de Chresi : Fries, Lichenogr. p. cxi. ; L. Fl. Lapp. &c. 1. c. ; 

 Hagen, Hist. Lich. Pruss. Regiom. J782, p. 20, &c. ; Hoffmann, de 

 vario lich. usu, Erlang. 1786; Westring, Svenska Lafvarnas Fa'r- 

 ghistoria, Stockh. 1805; Luyken, Hist. Lich. in genere, Gotting. 

 1809, p. 22; Ntil, Art. "Lichen" in Edinb. Encyc. 1. c.; Hooker, 

 Tour in Iceland, Lond. 1813, I. p. 130; Id. Br. Fl. II. passim-, 

 Franklin, Narrative of a Journey, Lond. 1823, 1. c. 



VII. LICHENOLOGI. 



The name Lichen (x/u'v) was applied originally by Dioscorides 

 (lib. iv. cap. 53.), and after him by Pliny (lib. xxvi. cap. 3), to certain 

 species of this order, on account of their resemblance to the cuta- 

 neous disease, so called, whence, also, they were supposed to be 

 specifics for it. It was very long before these plants became ob- 

 jects of scientific study. Morrison and Ray reviewed all the cryp- 

 togamic tribes, and not in vain ; but they left them still confused. 

 It was TOURNEFORT (1719) who first more accurately limited the 

 class, and assigned to it, as a distinct division of the vegetable king- 

 dom, the name it bears. MICHELI (1729) followed, disposing the 

 species in admirable sections, and analyzing the fructification, which 

 he further illustrated by many good figures. These are the found- 

 ers of our science, and from their contemplative studies we come to 

 its second epoch (the descriptive) in Dillenius (1740). This great 

 cryptogamist devoted himself wholly to the limitation, description, 

 and delineation of the species, and his Historia Muscorum is clas- 

 sical. A new sun of Botany arose now in the North, whose rays 

 reached also the Lichenes. LINNJEUS, with his native genius, con- 

 joined the ideas of Micheli with the science of Dillenius, and from 

 him once more the study started anew. Among the more distin- 

 guished of those who continued to illustrate the Lichenes, were 

 Haller, Scopoli, Hudson, Necker, Weiss, Schreber, Lightfoot, 



