73 



EinetinrrCio H30 1^2 Oio. Alkaloid of the different kinds of 

 the Ipecacuanha-root, from Cephgelis Ipecacuanha and possibly in 

 roots of other Rubiacese of emetic property. Boil with water, 

 evaporate the decoction to dryness, treat with alcohol, filter and dis- 

 til off the alcohol, evaporate again to dryness and exhaust with water 

 acidulated with hydrochloric acid. Precipitate the solution with 

 chloi'ide of mercury, wash the deposit with cold water and dissolve 

 in alcohol, precipitate the mercury with sulphide of baryum, 

 remove the latter with sulphuric acid, dilute with water, distil off 

 the alcohol, throw down the E. with ammonia, wash with cold 

 water and dry. — White powder, slightly bitter, of alkaline 

 reaction, fuses at 50° and is destroyed in higher temperatures, 

 dissolves slowly in cold, a little more in hot water, readily in 

 alcohol, not in ether and oils, readily in acids, not in the hydrates 

 and carbonates of alkalies ; becomes dark olive-green with concen- 

 trated sulphuric acid. Its salts are not crystallisable. 



[Glenard prepares Emetin by mixing the pulverised root or the 

 extract with lime, exhausting with ether, evaporating the ethereous 

 solution to dryness, dissolving the residue in dilute hydrochloric 

 acid and precipitating the E. with ammonia. The composition of 

 the E., dried at 110°, was found to be C30 Hgj NO4. The chloride 

 forms tufty, united needles, and is almost colourless.] 



EmO(lill=C4o H15 O13. In the root of Rheum Emodi, 

 probably also in other species of this genus of Polygonete. 

 Macerate the root with water, dry again and exhaust with benzol, 

 ■distil off most of the benzol, press the remnant converted into a 

 crystalline pulp after cooling, treat again with benzol, which 

 dissolves chrysophanic acid and leaves intact a reddish, sparingly 

 soluble substance ; dissolve the latter in hot benzol, leave to cool 

 and purify by recrystallising in hot and highly concentrated acetic 

 acid and in hot alcohol. — Lustrous, deej) orange-red, brittle, 

 klinorhombic prisms ; does not fuse below 250° and sublimates to 

 a slight extent in yellow fumes. It dissolves, similar to chry- 

 sophanic acid, in liquor of ammonia with violet-red colour, more 

 readily in alcohol and amylalcohol, not so readily in benzol. 



ElUUlsill. The peculiar albuminous matter of almonds and of the 

 seeds of some trees allied to Prunus Amygdalus; exists dissolved in 

 the emulsions of these seeds, and causes their milky apjijearance by 

 suspending the fat oil. To the E. belongs the remarkable property 

 of decomposing amygdalin into hydrocyanic acid and other pro- 

 ducts. It is obtained, when an emulsion of SAveet almonds is 

 agitated with four times its volume of ether, and allowed to rest 

 for a few days; the clear aqueous solution is separated from the 

 supernatant ether, and from insoluble particles; precipitated with 

 alcohol and dried in a vacuum. — Horny substance, or when tritu- 

 rated white powder without smell or taste, soluble in cold water; 



