This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Balsams arc vegetable juices, liquid, semiliquid, or concrete, which are characterized by containing, along with resin and volatile oil, either the cinnamic or benzoic acid. The balsam of Tolu, that of Peru, styrax, and benzoin, are more or less used, and require brief notices.