119 



solid fat after the gi-een colour has disappeared; dissolve in warm 

 alcohol, and precipitate by evaporating and mixing with water. — 

 Snow-white, voluuiinoiis, easily friable, inodorous mass, consisting 

 of concentrically united needles; fuses at 45°, dissolves sparingly 

 in cold, better in hot alcohol, readily in ether. 



Lecaiioric Acid = C32 H13 O13 + HO. In various licliens of the 

 genera Evernia, Lecanora, Roccella, Variolaiia. Extract with 

 ether, evaporate, wash the remnant with cold ether until the 

 latter passes ofi' uncoloured, boil with water to remove orsellic 

 ether, and recrystallise in alcohol. — White, radially united crystal- 

 line needles without taste or smell, of acid reaction; not volatile; 

 dissolve in 2500 parts of boiling water and crytallise on cooling- 

 yield when boiled with water, oi'sellic acid = Cie H7 O 7 + HO, the 

 latter yielding orcin by continued boiling under evolution of 

 carbonic acid; dissolve in 150 parts cold alcohol of 80^, in 15 

 ■parts of boiling alcohol under formation of orsellic etherrr 

 C4 H5 O + C16 H7 7 ; in 80 parts of ether. Lecanoric acid forms 

 with alkalies easily crystallising salts. 



Ledum-Tannic Acid = Cu HgOe. In the leaves of Ledum 

 palustre. Add to the aqueous decoction solution of acetate of 

 lead by drops, until a sample of the pi-ecipitate dissolves com- 

 pletely in acetic acid, filter and precipitate with subacetate of 

 lead. The deposit, after washing, is decomposed with sulphiu'et of 

 hydrogen, the sulphide of lead is removed and the liquid evapo- 

 rated. — Reddish powder, dissolves in water and in alcohol, the 

 solutions becoming dark-green by chloride of iron; throws down 

 on boiling with diluted acids a yellow or red powder (Ledoxanthin). 



Le2,'Ulllillt Peculiar protein substance, occurring principally 

 and in large quantity (up to 20°/^ or 30°/o) in the seeds of the 

 leguminous plants. To prepare it, treat peas, &c., with warm 

 water, precipitate with acetic acid, wash the deposit with a little 

 cold water, treat with alcohol and ether, redissolve in potash-ley, 

 precipitate ^vith acetic acid and wash again with water, alcohol 

 and ether. — White powder with a yellowish tinge, dissolves in 

 cold and hot water. The solution becomes covered with a pellicle on 

 evaporating, and the Legumin is thereby converted into the 

 insoluble modification. Acetic acid throws down Legumin, and 

 does not redissolve it when added in excess; sulphuric acid 

 behaves in the same manner, while oxalic, tartaric, citric and malic 

 acids do not precipitate the Legumin from solutions. For other 

 properties see Protein substances. 



Lepidill. Peculiar substance, occurring in every species of the 

 genus Lepidium, prevailingly in the younger parts and in tlie seeds. 

 It is obtained by boiling with water acidulated with sulphuric 

 acid, saturating the decoction with carbonate of lime, filtering, 



