This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
An official balsam obtained from Toluifera bal-samum. The tr. in 30-minim doses is a mild expectorant; the syrup is a pleasant flavor, and the balsam may be given in 10- to 15-grain doses in emulsion with acacia. While pleasant as a vehicle for more active agents, tolu possesses little therapeutic importance.