606 CONSIDERATION OF CARBON COMPOUNDS. 



Hyoscyamine differs from atropine by yielding with gold chloride 

 a precipitate which, when recrystallized from a hot aqueous solution, 

 acidified with hydrochloric acid, deposits lustrous, golden-yellow 

 scales. 



Hyoscine, C 17 H 21 NO 4 . Found together with hyoscyamine in 

 Hyoscyamus. The alkaloid is known only in an amorphous, semi- 

 solid state, but the salts, of which the hydrobromide is official, crys- 

 tallize readily. Hyoscine evaporated to dryness on a water-bath with 

 a few drops of fuming nitric acid leaves a nearly colorless residue 

 which turns violet on the addition of some alcoholic solution of 

 potassium hydroxide. 



Scopolamine hydrobromide, C 17 H 21 NO 4 HBr3H 2 O, is the hydro- 

 bromide of an alkaloid obtained from plants of the Solanacese, and is 

 chemically identical with hyoscine hydrobromide. 



Cocaine, Cocaina, C 17 H 21 NO 4 = 3OO.92. This alkaloid is found 

 in the leaves of the South American shrub Erythroxylon coca, in 

 quantities varying from 0.15 to 0.65 per cent. It is a white crystal- 

 line powder, soluble in about 600 parts of water, easily soluble in 

 alcohol, ether, and chloroform ; it fuses at 98 C. (208 F.). A frag- 

 ment of cocaine placed on the tongue causes the sensation of numb- 

 ness without acrid or bitter taste ; the solution in water is faintly bitter. 



Cocaine heated with acids in sealed tubes is decomposed into methyl alcohol, 

 benzoic acid, and ecgonine, showing it to be methyl-benzoyl-ecgonine : 



C 12 H 21 NO 4 + 2H 2 O = CH 3 HO + G 6 H 5 CO 2 H + C 9 H 15 NO 3 . 

 Cocaine. Methyl alcohol. Benzoic acid. Ecgonine. 



Ecgonine is found in the coca leaves as benzoyl-ecgonine, C 9 H I5 (C 7 H 5 0)N0 3 

 + 4H 2 O ; this is a white, crystalline substance from which cocaine may be 

 obtained by heating it with methyl-iodide. The mother-liquors obtained in 

 the manufacture of cocaine from the leaves contain the alkaloid in an amor- 

 phous state and possibly one or two other alkaloids, one of which has been 

 named hygrlne. Whether these alkaloids are contained in the coca-plant, or 

 are products of the decomposition of cocaine, are questions not yet decided. 



Of the various salts of cocaine, the hydrochloride, C 17 H 21 NO 4 HC1, 

 is official. This salt crystallizes from alcohol in short, anhydrous 

 prisms; from aqueous solution, however, with two molecules of water, 

 which are completely expelled at a temperature of 100 C. (212 F.). 

 The anhydrous salt fuses at 190 C. (374 F.) and is readily soluble 

 in water ; this salt solution has a somewhat more bitter taste than the 

 alkaloid itself. 



