THE PA OE OF NA TUBE. 1 1 7 



and may be easily identified, even without the aid of its 

 characteristic fructification, by a peculiar pungent alka- 

 line smell, which is very disagreeable, especially when 

 the plant is moistened. In the Highland districts, many 

 an industrious peasant used to earn a comfortable living, 

 by collecting this lichen with an iron hoop from the 

 moorland rocks, and sending it to the Glasgow market. 

 The value of this lichen in Scotland is said at one time 

 to have averaged 10 per ton. Hooker states that at 

 Fort-Augustus, in 1807, a person could gain 14s. per 

 week by gathering it, estimating its market price at 

 3s. 4d. per stone of 22 Ibs. It appears also to have 

 been an article of commerce in Derbyshire ; the price 

 there given to the collector, who could gather from 20 

 to 30 pounds per day, being Id. per pound. This 

 source of remunerative employment in Britain has now 

 ceased, as the lichen is chiefly imported from Norway 

 and Sicily, where it occurs in greater profusion than 

 with us, and is said to contain a larger proportion of 

 colouring matter. The dye produced by the cudbear is 

 quite equal to orchil, and is capable of being so modified 

 as to give any tinge of purple or crimson. It is never 

 employed by itself to give fast colours to cloth, but merely 

 for the purpose of improving the hues already imparted. 

 It is sold to the dyers in the form of a purple powder. 

 Schunk, in his analysis of this plant, discovered a colour- 

 less crystalline acid, called erythric acid, which is soluble 

 in alkaline solutions, and converted by them into orcine 

 and carbonic acid, and which, under exposure to the air, 

 acquires first a red and at length a fine deep violet tint. 

 A species closely connected with the cudbear, and 



