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.
The camphorated soap liniment is essentially the same as the soap liniment just described, differing in the kind of soap employed, which in this preparation is the common white soap, made with animal fat, instead of the Castile soap, made with olive oil. The effect of the substitution is that the liniment is obtained of the consistence of a jelly, in consequence of the hot alcoholic solution of common soap gelatinising when it cools. It is usually sold in broad-mouthed bottles, containing about four fluidounces. Though of the consistence of a soft solid at ordinary temperatures, it assumes the liquid state when applied to the surface of the body. It is much used popularly, under the name of opodeldoc, in rheumatic pains, bruises, sprains, etc. It was, however, discarded from the U. S. Pharmacopoeia at the late revision.