Eucalyptus. - The leaves of Eucalyptus globulus Labillardiere (nat. ord. Myrtaceae), collected from the older parts of the tree.

Habitat

Australia; cultivated in subtropical countries.

Characters

Petiolate, lanceolately scythe-shaped, from 15 to 30 cm. long, rounded below, tapering above, entire, leathery, grayish-green, glandular, feather-veined between the midrib, and marginal veins; odor strongly camphoraceous; taste pungently aromatic and somewhat cooling, bitter and astringent.

Composition

1) A volatile oil {see below); (2) Cerylic Alcohol; (3) A crystallizable Fatty Acid; (4) A crystallizable Resin.

Dose, 1/2 to 2 dr.; 2. to 8. gm.

Preparation

Extractum Eucalypti Fluidum. Fluid Extract Of Eucalyptus

By maceration and percolation with Alcohol and Water, and evaporation.

Dose, 1/2 to 2 fl. dr.; 2. to 8. c.c.

Oleum Eucalypti. Oil Of Eucalyptus

A volatile oil distilled from the fresh leaves of Eucalyptus globulus Labillardiere, Eucalyptus oleosa F. v. Mueller, and some other species of Eucalyptus (nat. ord. Myrtaceae).

Characters

A colorless or faintly yellowish liquid, having a characteristic, aromatic, somewhat comphoraceous odor, and a pungent, spicy, and cooling taste. Sp. gr., 0.915 to 0.925.

Solubility

In all proportions, in Alcohol, Carbon Disulphide, or Glacial Acetic Acid. The oils from different species of Eucalyptus vary very much.

Composition

The chief constituents are - (1) Eucalyptol C10H18O or Cineol (about 70 per cent.); (2) Cymene, Cl0H14; (3) Eucalyptene, C10H16; (4) Tannic Acid.

Incompatibles. - Alkalies, mineral acids, and metallic salts.

Dose, 5 to 30 m.; .30 to 2.00 c.c.

Eucalyptol. Eucalyptol

C10H18O=l53.66. A neutral body obtained from the volatile oil of Eucalyptus globulus Labillardiere, and of some other species of Eucalyptus (nat. ord. Myrtaceae).

Source

In the distillation of Eucalyptus leaves, crude Eucalyptol comes over between 338° and 352.4o F.; 170o and 178o C, and is purified by re-distillation from Caustic Potash or Calcium Chloride.

Characters

A colorless liquid, having a characteristic, aromatic, and distinctly camphoraceous odor, and a pungent, spicy, and cooling taste. Sp. gr. ,0.930.

Solubility

In all proportions, in Alcohol, Carbon Disulphide, and Glacial Acetic Acid.

Dose, 5 to 30 m.; .30 to 2.00 c.c.

Action Of Eucalyptus

External

Oil of eucalyptus is much less irritant when applied externally than other volatile oils, but if its vapor is confined it will produce vesication and pustulation. It is powerfully antiseptic and disinfectant. Old oil is more antiseptic than new, probably from the greater amount of ozone it contains.

Internal

Gastro-intestinal tract. - In medicinal doses oil of eucalyptus is stomachic, having the same action as oil of cloves. In large doses it produces severe gastro-intestinal irritation, as shown by vomiting, diarrhoea, and abdominal pain.

Circulation. - It, like quinine, arrests the movements of the white blood-corpuscles; and it likewise resembles this drug in its antipyretic and its antiperiodic actions, and also, it is said, in causing contraction of spleen; but quinine is in all respects the more energetic. In medicinal doses the heart is stimulated by oil of eucalyptus, and the blood-pressure rises; probably these effects are reflex from the stomach. After large quantities the action of the heart is enfeebled, and temperature falls.

Respiration. - Small doses slightly accelerate, poisonous doses slow respiration.

Nervous system. - Large doses are powerfully depressant to the brain, to the medulla, and to the spinal cord, abolishing reflex action. Death occurs from paralysis of respiration.

Mucous membranes, kidneys, and skin. - Like other volatile oils, eucalyptus is excreted by all these channels. It imparts its odor to and disinfects the breath and the urine. It stimulates the organs by which it is excreted, consequently it is a diaphoretic, a stimulating expectorant, a diuretic, and a stimulant to the genitourinary tract. Large doses cause renal congestion.

Therapeutics Of Eucalyptus

External

It is used as an antiseptic for wounds, sores, and ulcers. It is three times as powerful as carbolic acid, and is therefore preferred by some surgeons. A eucalyptus gauze has been prepared as a dressing for wounds, which may be washed with a weak solution of the oil in alcohol. An ointment of oil of eucalyptus, 8; iodoform, 1; hard paraffin and vaseline, of each 40, is applied to chancres. An emulsion of the oil is used as an urethral injection. It would probably be an efficient parasiticide.

Internal

A vapor or the spray of oil of eucalyptus has been recommended for diphtheria and fetid bronchitis, and it is sometimes given by the mouth to correct the foetor of the expectoration. Occasionally it is used for its stomachic and carminative effects, especially if the faeces are very foul smelling, and some employ it in cystitis and pyelitis. It has been prescribed in septicaemia. As an antiperiodic for ague and an antipyretic it is far inferior to quinine. In most cases eucalyptol can be substituted for the oil with advantage.