This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This is a very concentrated tincture of the root of belladonna, intended exclusively for external use. It may be applied by means of a camel's-hair pencil, or may be diluted with two or more measures of soap liniment, and rubbed upon the part. It is peculiar to the British Pharmacopoeia.