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.
Blue-gum Tree, Eucalyptus globulus. The leaves and Oil of Eucalyptus, official in the U. S. and several other countries. Eucalyptus rostrata, or Red Gum, official in the British Pharmacopeia. It contains kino-tannic acid and is used in troches and as a gargle in sore throat.
The action is similar to that of the terebenes. See "Abies." Many fantastic claims have been made regarding eucalyptus. The antimalarial and anti-periodic influences are too slight to be of any importance, and it does not contract the spleen. The fluidextract, unless made of recent leaves, is nearly inert. Kobert has shown euca-lyptol to be only a "medium strong" antiseptic.
This is purely that of the tere-binthinates, already described under "Abies," plus a greater antiseptic influence than that possessed by most agents of the class. Cineol is identical with eucalyptol, and cineol is not a remarkable agent. Either eucalyptol or cineol may be given in an average dose of 5 minims in affections of the mucous surfaces of the respiratory and genito-urinary organs. But the chief employment of eucalyptol is in nasal sprays and inhalations and as an ingredient of antiseptic mixtures. It is a mild antiseptic rubefacient incorporated into ointments used in the treatment of eczema. It is not nearly so potent an antiseptic as it was at one time thought to be. The fluidextract is hard to manage pharmaceutically and it is disagreeable to take.