ECONOMIC USES OF LICHENS — LLANO 415 



ramosa^ is identical with methyl everninate resulting from the al- 

 coholysis of everninic acid, present in proportions of about 2.8 per- 

 cent, with a characteristic anise-seed odor. Walbaum and Kosenthal 

 (13) repeated the experiments of Gattefosse and arrived at different 

 results. They distilled the oil of Evemia prunastri and found that 

 at ordinary temperature it formed an oily crystalline mass of dark 

 color with a very powerful and agreeable odor. Further analysis 

 revealed Gattefosse's error, and orcinol monomethylether, not 

 lichenol (CioHi40), is the principal constituent of oak-moss. This 

 phenol, though not the main odoriferous part of the lichen oil, has a 

 pleasant, creosol-like smell, and an ester ^-orcinol methyl carboxylate 

 (C10H12O4) which does not enter into the odor of the oak-moss oil. 

 In the resinous precipitate Walbaum and Rosenthal found ethyl 

 everninate generated only during the extraction through esterification 

 of the everninic acid (C17H16O7) which was found to occur in a free 

 state in the lichen ; when boiled with baryta water it split into orcinol 

 and everninic acid with the liberation of carbon dioxide. This acid 

 is closely related to y8-orcinol monomethylether and would be con- 

 verted into it by the liberation of carbon dioxide. For these reasons 

 Walbaum and Rosenthal felt that the genesis of the principal con- 

 stituent of the odoriferous substances of oak-moss had a close con- 

 nection with the origin of everninic and evernic acids. Stoll and 

 Schener (13) found in the volatile fraction some compounds which 

 may also have a function in producing this odor, mainly thujone, 

 naphthalene, borneol, camphor, civeole, citronellol, guaniol, vanillin, 

 methylnonylketone, and stearic aldehyde. 



The multiplicity of types of essences and extracts may be due in 

 part to the diversity of substrata on which these lichens grow, as well 

 as to the varying mixtures of species offered to the manufacturer in 

 any lot, and the mode of extraction. This is also verified by the theory 

 of multiple substances in lichens, as proposed by Burkholder and 

 Evans (3). Hess (13) was able to extract atranorine and everninic 

 acid from a specimen of Evemia prunastri growing on oak, but not 

 from samples collected on beech or birch, while a sample from a 

 lime tree yielded some usnic acid. The whole problem is further 

 complicated by the fact that most constituents of oak-moss react upon 

 the solvent. Treatment of lichen extracts with alcohol is seldom 

 employed for preparation of essences, since it alters the evernic acid. 

 Thus the lichenol obtained by Gattefosse, using this method, was 

 everninate of ethyl. The synthesis of everninic, divarine, and other 

 acids has been performed in the laboratory but has not been applied 

 on a commercial scale. In the trade the oil is extracted by means of 

 low-boiling solvents, after which it is purified and decolorized, the 

 process yielding 0.2 to 0,3 kilo of the raw extract or 20 to 30 grams 



