This section is from the book "A Practitioner's Handbook Of Materia Medica And Therapeutics", by Thos. S. Blair. Also available from Amazon: A Practitioner's handbook of Materia Medica and Therapeutics.
Eucalyptus, Blue gum tree. The preparations of this valuable drug are many, but Eucalyptol is probably the most definite and generally useful. Tinctures and fluid-extracts depend in value upon how recent a leaf is used in making them up, since the eucalyptol soon evaporates from the dried leaves. The antimalarial influence of the drug seems to be better represented in a good fluidextract, and the antiseptic properties in eucalyptol. Eucalyptus is antimalarial, antiperiodic, febrifuge, and tonic, producing great increase of urea and possessing antiseptic properties. In large doses (f.e. or ec. tr., 20 to 30 I) it is anti-malarial, rather slow in action, but peculiarly well adapted to cases where quinine irritates the nervous system, and to masked intermittents and so-called "dumb ague." Malarial neuralgia and ague with jaundice yield nicely to its persistent use. In low forms of fever, such as typhoid or scarlet fevers, its antiseptic and tonic properties are often of very distinct value, and it serves to keep the kidneys active.
In small doses (f.e. or ec. tr., 3 to 10 I) it appears to be eliminated by the skin to just sufficient degree to stimulate it, producing a feeling of warmth, while very large doses are known to cause vaso-constriction, which makes a cold surface. The secreting mucous membranes of the respiratory and gastro-intestinal system are affected similarly. Hence, this agent is useful in a cold and clammy skin and a heavy, inert sensation in the viscera. It should be combined with other indicated agents to remove the underlying cause of these subjective symptoms.
Eucalyptol is a very valuable antiseptic as well as possessing, in almost full measure, the virtues of eucalyptus. A few drops upon the surface of hot water is, next to calomel, the best inhalation to loosen diphtheritic membrane. At the same time give eucalyptus and jaborandi internally. As a gargle, spray, or inhalation (properly diluted), it is of value in bronchial catarrh, asthma, phthisis, etc. In chronic ulceration of the stomach and in septic, renal, and vesical troubles, as well as in most of the indications for eucalyptus, it is of value. Dose, 5 to 15 I. in capsules or on sugar. Locally, it can be used combined with oils.