MM. Wohler and Lossen on Cocaine. 25 



treatment submitted to fractional distillation, by which it was 

 resolved into three hydrocarbons, hydride of amyle, amylene, 

 and allyle, the latter being the most abundant. It boils at 59°, 

 and is easily separated from the two others which boil at 30° and 

 35° respectively. These are separated by treatment with bro- 

 mine, with which amjdene forms a compound, while hydride of 

 amyle is quite unattacked. 



The formation of amylene is effected by a simple addition of 

 the radical ethyle to the radical allyle, 



G 2 H 5 + G 3 H 5 =€ 5 H 10 , 



and is thus a sort of mixed radical, ethyle- allyle, analogous to 

 those described by Wurtz some years ago. 



The investigation of cocaine, the new base in the coca leaf, 

 begun by Niemann under Wohler's direction*, has been con- 

 tinued by Lossen j\ When the base is treated with hydrochloric 

 acid, it undergoes a simple metamorphosis : it separates into 

 benzoic acid, and a new base, for which Wohler proposes the 

 name Ecgonine (e/cyovos, sprout). The analysis of this new base 

 indicated that its formula was C 18 H 16 NO 6 , and hence that the 

 decomposition of cocaine by hydrochloric acid took -place in the 

 manner represented by the following equation : — 



C 32 H 20 NO 8 + 2HO = C 18 H 16 NO 6 + C 14 H 6 O 4 . 



Cocaine. Ecgonine. Benzoic acid. 



The decomposition is best effected by heating the solution of 

 cocaine in a sealed tube for some time to a temperature of 100°. 



The new base is soluble in water, and is not precipitated by 

 carbonate of soda nor by bichloride of platinum. But if to a 

 mixture of the base with bichloride is added a large quantity of 

 alcohol, the double salt crystallizes in long orange-yellow needles. 



The above deportment of cocaine explains why, on extracting 

 the leaves with dilute acid, in many cases no base is obtained. 

 The best method of obtaining cocaine is, according to Lossen, 

 the following : — The leaves are digested with rain-water for some 

 hours between 60° and 80°, the infusion poured off, and the ope- 

 ration repeated several times. The united infusions are heated 

 with acetate of lead, the precipitate filtered off, and the excess 

 of lead removed by the addition of sulphate of soda. The liquid 

 filtered from the precipitated sulphate of lead is made alkaline 

 with carbonate of soda, and exhausted four to six times with 

 ether. The greater part of the ether is distilled off from the 

 etherial extracts ; on spontaneous evaporation cocaine is left in 



* Phil. Mag. vol. xx. p. 141. 



f Liebig-'s Annalen, March 1862. 



