Delpheline has the formula C25H39O6N and not C21H31O4N previously assigned to it. Delpheline, a base isolated from the alkaloids of Delphinium elatum, L., and assigned the formula C21H31O4N (Goodson, J., 1943, 139), has been found by potentiometric titration to have a molecular weight of 450, agreeing well with that required for the formula C25H39O6N and confirmed by the analytical figures found for the hydrochloride and nitrate previously recorded (Goodson, loc. cit., p. 141) and by the fact that six oxygen atoms can now be accounted for. Of these, three were known to be present in methoxyl groups, two are now found in a methylenedioxy-group, and one is shown to occur in a hydroxyl group, by the preparation of a monoacetyl derivative. The substance, like aconine (Jacobs and Elderfield, J. Amer. Chem. Soc., 1936, 58, 1059), contains an ethylimino-, not a methylimino-group as formerly assumed.