M. Wohler on Cocaine* 141 



In Peru and in other South American countries the coca leaf 

 (Erythroxylon coca) has long been extensively used as a narcotic. 

 As to its effects, accounts differ much. According to Von 

 Tschudi *, its use in moderate quantities is that of a beneficial 

 stimulant, and enables persons taking it to do without food for a 

 long time, and to bear great fatigue. But its immoderate employ- 

 ment produces effects analogous to those caused by excessive 

 use of opium. The peculiar physiological effects have been 

 ascribed to the presence of a narcotic principle, the existence of 

 which, however, has not been established. 



The plant (a supply of which was obtained through the Aus- 

 trian surveying frigate 'Novara') has been investigated by 

 Wohler f assisted by Niemann, who have established the ex- 

 istence in it of a peculiar crystallized organic base, to which the 

 name cocaine has been given. The investigation is not com- 

 pleted ; the formula is not fixed, nor has the chief point been 

 settled, whether the peculiar physiological effects are attributable 

 to this base. To obtain the base, the leaves were digested with 

 alcohol containing some sulphuric acid, the solution pressed and 

 mixed with hydrate of lime, by which a wax and part of the 

 chlorophyll were precipitated. The filtered alkaline solution 

 was neutralized with sulphuric acid, and the alcohol distilled off 

 in the water-bath. The addition of water to the residue caused 

 the precipitation of a semifluid mass which contained the re- 

 mainder of the chlorophyll. The supernatant liquid contained 

 sulphate of cocaine, from which the base was precipitated on the 

 addition of carbonate of soda. By treating this precipitate with 

 pther, the cocaine was dissolved out, and remained on evapora- 

 tion of the ether as a yellowish mass, which afterwards crystal- 

 lizes. By repeated treatment with alcohol it is obtained pure 

 and colourless. 



Cocaine crystallizes in small, white, colourless and inodorous 

 prisms. It is little soluble in water, more so in alcohol and in 

 ether. It has a bitter taste, and exerts a peculiar action on the 

 tongue ; the parts touched appear quite without feeling. It 

 melts at 98°, and solidifies crystalline. At a higher temperature 

 it decomposes with formation of ammoniacal compounds. Co- 

 caine is strongly alkaline; it completely neutralizes acids, but the 

 salts remain amorphous for some time before crystallizing. 



Cocaine most resembles atropine ; but it appears to differ in 

 composition, and in some properties. The gold salts of both 

 bases are precipitated from their cold hydrochloric acid solutions 

 on the addition of chloride of gold as amorphous masses, and 

 from their heated solutions in crystalline laminae. But the 



* Johnson's Chemistry of Common Life, chap. xx. 

 t Gbttinger Nachrichten, No. 10, 1860. 



