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and the same lichen would yield different chemical compounds de- 

 pending upon a difference of .locality and substratum. French and 

 Scandinavian chemists employed lichens (especially Cladonia 

 rangifcrina] in the manufacture of alcohol. 



These chemical investigations were primarily conducted with a 

 view to improve the dye industry dependent upon the various color- 

 ing substances derived from lichens. France, more than any other 

 country, improved upon the methods of extracting the dye, as well as 

 of applying it. Orseille was especially recommended in dyeing 

 woolen and silken goods. Innumerable methods for extracting the 

 dye as well as for improving its durability were employed. Some 

 of these methods were patented. 



Lichens also found a wider use as an article of diet. Cetraria 

 Islandica, because of its high percentage of lichen-starch (lichenin), 

 was especially recommended as already mentioned. The inhabit- 

 ants of Iceland, Norway and Sweden mixed this lichen with various 

 cereals and mashed potatoes, from which an " uncommonly palata- 

 ble and healthful bread was prepared." Sir John Franklin and his 

 companions made use of this lichen during their Arctic voyages. 

 Its use to prevent the peculiar disease known as " Iceland scurvy' 

 continued. In general, however, it may be stated that lichens were 

 used as an article of diet onlv in the case of a famine or in those 



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countries where the cereals are not abundant, principally because all 

 lichens contain a bitter principle, which is very disagreeable to the 

 taste and difficult to remove and which has a deleterious effect upon 

 the digestive tract, producing a form of intestinal inflammation. 



As to the use of lichens in medicine it was found that they were 

 not reliable, and other drugs soon supplanted them. They were, 

 however, recommended as an article of diet for convalescents, espe- 

 cially "Iceland moss" (Cetraria Islandica"). The peasantry of 

 various countries still believe in the healing properties of various 

 lichens. We have already mentioned Peltigcra canina. In Sweden 

 Pcltigera aphthosa was boiled in milk and given to children afflicted 

 with " thrush." Decoctions of various lichens (especially Parmelias 

 and Cladoniai] were employed in intermittent fevers. The purga- 

 tive properties of most lichens (particularly the Umbilicarias) are 

 well known ; various species of Gyrophora and Umbilicaria were 

 the cause of severe illness among members of the Franklin expedi- 

 tion. 



