120 



evaporating the liquid to a lioney consistence, extracting with 

 alcoliol and evaporating the solution. — Brown, transparent mass, 

 yielding a yellow powder; permanent at the air; of a faint smell, 

 a 'id of very bitter taste; softens when warm; dissolves readily in 

 water and alcohol, slightly in oils, not in ether, combines neither 

 with bases nor with acids. 



Liclieiiic Aci(l=:FuMARic acid. 



Liclieiliu=:Ci2 Hio Oio. In lichens and in algae, observed 

 for instance in the following genera : — Cetraria, Cladonia, Evernia, 

 Parmelia, Ramalina, Sticta, Usnea; Delesseria, Fucus, Helminto- 

 chorton. Is not distributed in isolated grains like stai-ch, but as a 

 turgid mass uniformly embedded between the cells. Free, for 

 instance Cetraria Islandica, from the bitter substance by macerating 

 with a weak solution of carbonate of soda and by washing; boil 

 with water for two hours, strain hot, press, collect the jelly, 

 separated after cooling, on a cloth; press, redissolve in little boiling 

 water; precipitate with alcohol and dry the deposit. — Colourless 

 or yellowish, hard, brittle, transparent mass of vitreous fractui'e 

 and difficult to pulverise, inodorous and tasteless, not volatile, 

 swells up considerably in cold water, dissolves in boiling water to 

 a thick slime, of a jelly-like appearance when concentrated; is 

 insoluble in alcohol and ether, becomes blue with iodine, dissolves 

 in wai-m nitric acid to a thin licpiid, and yields on heating oxalic 

 but no mucic acid; is converted into sugar when boiled with 

 water containing sulphuric acid. The aqueous solution, when 

 boiled by itself, loses its property of gelatinising. Alkalies and 

 alkaline earths dissolve the Lichenin likewise. 



Licli eiistarch = LicHENiN. 



Liclieiio-stearic Acid = C28 H23 O5 + HO. In Cetraria 



Islandica, also in Agaricus muscarius, and, doubtless, in numerous 

 other lichens and algae. Boil the Cetraria for half an hour 

 with alcohol and a little carbonate of potash, strain, mix the 

 liquid with an excess of hydrochloric acid and four to five times 

 its volume of water, wash the dejDOsit with water and boil it 

 several times with alcohol of 42 to 45 %. The alcoholic solutions 

 deposit, on cooling, a mixture of Licheno-stearin, Cetraric acid, 

 and another substance from which the Licheno-stearin acid is 

 dissolved by boiling petroleum and subsides after cooling, or better 

 when the petroleum is distilled off partly. It is purified by re- 

 crystallising in alcohol under aid of animal charcoal. — Loose, 

 white mass, consisting of fine, pearly, crystalline lamellse, inodo- 

 rous, of a rancid taste and affecting the throat; not bitter; fuses 

 at 120° without loss of weight; is not volatile; insoluble in water, 

 readily soluble in alcohol, ether, and oils. The Licheno-stearates 

 are permanent at the air, only soluble in water with aid of alkalies, 

 the solutions yielding a froth on boiling. 



