lichens: their economic role. 263 



and the lichen thaUi boiled and eaten in milk without mixture 

 with grains or potatoes. 



Quite a number of lichens have been used for medical purposes, 

 but few of the supposed medicinal qualities have been able to 

 stand the test of modern medical examination. Thus the " dog- 

 lichen," our common Peltigera canina, was formerly supposed to 

 be a curative of hydrophobia, hence the specific name. Likewise 

 our Sticta puliiioiiaria was supposed to cure pulmonary diseases, 

 while the well-known Usnca harhata was supposed to promote 

 the growth of hair and to be a sort of cure-all. And as the name 

 canina came from the Latin for dog, so we have in Evcrnia viil- 

 pina a specific name derived from z'ltlpcs, the Latin for fox, though 

 the plant is said to have been used mixed with other substances 

 to poison wolves rather than foxes. Lindsay, in his " Popular 

 History of British Lichens," states that Cetraria islandica fur- 

 nished preparations which were to be found in the drug stores of 

 England at the date of publication of his volume, 1865, as cura- 

 tives for dyspepsia, and we still find Cetraria given as a remedy in 

 our latest dispensatories. It is the bitter principle of the lichens 

 that is supposed to give the medicinal value, and it has been used 

 in fevers as a tonic and as a purgative as well as in the other ways 

 mentioned above. Also alcohol has been frequently made from 

 lichenin by fermentation. 



But turning from the use of lichens in medicine, it may be said 

 that their use as dyes is more worthy of our attention. Dyes of 

 various colors have been extracted from lichens and are still 

 being used in various ways. These colors are usually reds, pur- 

 ples, or blues, and they are used for coloring cloth, wood, paper, 

 etc. In Europe these dyes have been quite largely used in 

 coloring homespun cloth and }arn, our common ParuicUa sa.va- 

 fUis being commonly used and producing various colors accord- 

 ing to the method employed in making the dye. In Evcrnia vul- 

 pina the yellow coloring matter is ready-formed in the thallus, 

 and the same may be said of the beautiful yellows and oranges of 

 our Thcloschistcs and Placodiiinis. Brown colors are also ready- 

 formed in many lichen thalli, are easily extracted and have been 

 used for home consumption. But most of these are not to be had 



