Eucain, like cocaine, is a methyl ester of a benzoylated-oxypiperidine, carbo-oxylic acid. It is, however, a synthetic product, while cocaine is obtained exclusively from coca leaves; only, in the exhaustion, synthesis has been introduced for the purpose of completely exhausting the cocaine in the leaves.

The formula of cocaine and of eucain is the same.

Eucain, like cocaine, is insoluble in water, or nearly so, but the neutral salts formed by combinations with acids are soluble.

The hydrochloric salt of eucain appears in two forms.

One modification crystallises from water in small shining plates, which contain a molecule of water of crystallisation, and the formula for it is

C19H27NO4HCLH2O.

It dissolves in water to the extent of 6 per cent.

The second modification crystallises from a solution in methyl alcohol in shining prisms, which contain two molecules of methyl alcohol in crystallised form.

For anæsthetic purposes the first modification crystallised from water is to be preferred. A solution of it in water differs from a solution of cocaine in water in this respect, that it remains unchanged, while the cocaine solution, after a time, undergoes decomposition.

The appellation ‘eucain’ has no meaning. It is used simply to dispense with the complex chemical nomenclature which has been mentioned.

Eucain hydrochlorate is not so expensive as cocaine hydrochlorate.