Cocaïne

Cocaïne is prepared by digesting coca leaves with 85 per cent. alcohol containing a small quantity of sulphuric acid, mixing the expressed mass with milk of lime, neutralising the filtrate with sulphuric acid, evaporating off the alcohol, mixing the residue with water, precipitating the resulting yellow-brown solution with carbonate of sodium, treating the brown precipitate of impure cocaïne with ether, and evaporating. Cocaïne then remains, partly amorphous, partly crystalline, and may be purified by repeated treatment with alcohol.

Cocaïne.—Let us mention, finally, cocaïne as the most recent mydriatric we possess.

When cocaïne is injected beneath the skin, the filaments of the sensory nerves which ramify throughout its substance lose their power of conduction, and local anesthesia is the result.

Cocaïne, in addition to its action as an anæsthetic, produces a very marked change in liver, which is characterised by a great increase in the volume of that organ and a specific degeneration of the liver cells.

On account of its use as a local anæsthetic, cocaïne is the best known of the alkaloids present in coca-leaves (Erythroxylon coca).

When boiled with water, cocaïne is hydrolyzed into benzoylecgonine, C₁₆H₁₉NO₄, and methylic alcohol.

Cocaïne is used in medicine usually in the form of its hydrochloride, as a rapid local anæsthetic.