1895 - 96 .] 
Dr Charteris on Action of Eucain . 
167 
The Physiological Action of Eucain. By M. Charteris, 
M.D., Professor of Materia Medica, University of Glasgow, 
and William MacLennan, M.B., C.M. 
Eucain, like cocaine, is a methyl ester of a benzoylated- 
oxypiperidine, carbo-oxylic acid. It is, however, a synthetic pro- 
duct, 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 
c 19 h 27 no 4 iiclh 2 o. 
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 anaesthetic purposes the first modification crystallised from 
water is to be preferred. A solution of it in water differs from a solu- 
tion 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 hydro- 
chlorate. 
Physiological Experiments . 
Assisted by Dr MacLennan, I commenced in May last a series 
of experiments on the physiological action of solutions of the 
