LICHENS. 



171 



In the arts, and in domestic economy, many of this order 

 are most useful. A species of one genus (Variolaria faginea) 

 contains oxalic acid so largely, that it is now employed in 

 France on an extensive scale for its production.* Then, as 

 an article of food, the lichens produce the Tripe de Roche 

 (Gyropkora genus), which is so much eaten by the Canadian 

 hunters, and which proved so serviceable to Sir John Franklin 

 and his brave companions during a season of want to which few 

 have been subjected; but it is very bitter and nauseous, and 

 can only be employed in the absence of more salutary food. 



Tripe de Roche. 



ESTHER. 

 Is not the Iceland moss also a lichen 1 ? 



Iceland Moss. 



* Hooker, in vol. v. of English Flora, from which much of this is 

 taken. 



