118 



Laevo-<i'liico.se=FRuiT Sugar. 



Lapathiii = Chrysophanic Acid. 



Laricill==Ci4 H12 O4. The purgative ingi'edient of the 

 Larch-agaric, Polyporus officinalis. It is se2:)arated with difficulty 

 from the accompanying resin. — Is in the pure state a white, 

 amoi'phous powder of bitter taste, dissolves readily in alcohol and 

 oil of turpentine ; forms with boiling water a paste. 



Laseri>itill. = C4s Hoc O14. Bitter substance of the root of 

 Laserpitium latifolium. Ti-eat with alcohol of 80%, distil off the 

 alcohol from the tinctures, separate the upper resinous layer of the 

 residue from the aqueous lower one; allow the former to stand at 

 the air until it is converted into a crumbly crystalline pulp; 

 collect it in a filter, remove most of the resin by washing with 

 weak alcohol; next dissolve in alcohol, precipitate the rest of the 

 resin with subacetate of lead dissolved in alcohol; remove from the 

 filtered liquid the excess of lead by sulphuret of hydrogen, and 

 leave the liquid to evapoi'ate spontaneously. At first a flocky 

 matter is formed, the pure siibstance crystallising later. 



The Laserpitin crystallises in colourless prisms, has neither 

 smell nor taste, only the resinous L. has a bitter taste ; is insoluble 

 in water, readily soluble in alcohol, ether, chloroform, sulphide of 

 carbon, oil of tui'pentme, benzol, and fixed oils; the alcoholic 

 solution has a neutral reaction and strongly bitter taste. It fuses 

 at 114° without loss of weight, and sublimates in higher tem- 

 l)eratures undecomposed. It does not dissolve in alkalies and 

 diluted acids; dissolves in concentrated sulphuric acid with cheny- 

 red colour, also in fuming nitric acid. The alcoholic solution is 

 not precipitated by acetate of lead, nitrate of silver, chloride of 

 mercury, iodide of potassium, and alkalies. It separates when 

 heated with a concentrated aqueous or better alcoholic solution of 

 caustic potash, into angelic acid, and into a brown resin (Lasei-ol). 



Laui'ic Acid = C24 H23 3 + HO. In the fat of the fruit of 

 Laurus nobilis, Ocotea Pichurim, Tetranthera calophylla, Irvingia 

 Barteri, Cocos nucifera, Croton Tiglium, combined with glyceryl 

 oxyd. Saponify the solid fat of the bay -berries (the laurostearin) 

 with soda-ley, separate the soap with common salt, and decompose 

 with tartaric acid. The Laurie acid, which rises to the top, is 

 purified by repeatedly melting with water and by recrystallising in 

 alcohol. Appears in white, tuft-like, brittle, crystalline needles of 

 0-883 density at + 20°; fuses at 43 'S"; volatile with the vapours 

 of boiling water; is insoluble in water, readily soluble in alcohol 

 and in ether, the solutions having an acid reaction. The Laiirate 

 of baryta contains 71*38%, the Laurate of lead 63 '12% acid. 



Laui'OSteariu = C54 H50 Os. As to occui-rence see Laurie 

 Acid. Expose the fixed bay-oil to the sunlight, and press ofi" the 



