408 



ECONOMIC AND TECHNICAL 



whether it has been at all instrumental in keeping off that disorder." Belief in 

 the efficacy of the powder died out before the end of the century but the echo 

 of the famous remedy remains in the name Peltigera canina, the dog lichen. 



d. POPULAR REMEDIES. Lichens with very few exceptions are non- 

 poisonous plants. They owed their repute as curative herbs to the presence 

 in the thallus of lichenin and of some bitter or astringent substances, which, 

 in various ailments, proved of real service to the patient, though they have 

 now been discarded in favour of more effective drugs. Some of them, on 

 account of their bitter taste, were frequently used as tonics to replace 



Fig. 132. Perttuaria amara Nyl. on hark (S.H., Photo.}. 



quinine in attacks of fever. Several species of Pertusaria, such as the bitter 

 P. amara (Fig. 132), and of Cladonia as well as Cetraria islandica (Fig. 128), 

 were recommended in cases of intermittent fever; species of Usnea and 

 others, as for instance Evernia furfuracea, were used as astringents in 

 haemorrhages; others were given for coughs, Cladonia pyxidata (Fig. 69) 

 being supposed to be specially valuable in whooping cough. 



One of the most frequently prescribed lichens was the tree lung-wort 

 (Lobaria pulmonaria) (Fig. 72). It was first included among medical plants 

 by Dorstenius 1 , a Professor at Marburg; he gives a good figure and supplies 



1 Dorstenius 1540. 



