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 consists of one part of the extract and eight of lard mixed. It is used for friction upon the skin, or as a dressing to blistered surfaces. For the latter purpose, not more than half a drachm or two scruples should be applied at first.