Eucalyptus (U. S. P).—Eucalyptus.

Fig. 108. Leaves and fruit of Eucalyptus globulus. Photo: Eucalyptus 1. Preparations: Ointment of Eucalyptus - Fluid Extract of Eucalyptus
Related entries: Eucalyptol (U. S. P.)—Eucalyptol - Oleum Eucalypti (U. S. P.)—Oil of Eucalyptus

"The leaves of Eucalyptus globulus, Labillardière;" "collected from the older parts of the tree"—(U. S. P.).
Nat. Ord.—Myrtaceae.
COMMON NAME: Blue-gum tree.
ILLUSTRATION: Bentley and Trimen, Med. Plants, Plate 109.

Botanical Source and History.—The genus, Eucalyptus, is noted as being an extensive and almost exclusively Australian family of trees; for, although 134 species are recorded by Bentham (Flora Australiensis), as natives of that continent, only 2 or 3 species are found to grow in any other lands. The Eucalyptus trees are very numerous in their native country, and constitute an important feature in every landscape. They are sometimes shrubs, but generally trees, which often attain gigantic size. Most of the species secrete a resinous substance, and hence are known to the Australian colonists as "gum trees." The leaves, which are always entire, are very variable in shape and position. In the young trees they are always opposite and horizontal, but, in older trees, they generally become alternate, and, by a peculiar twist of the leaf-stalks, present the edges instead of the flat surfaces to the ground, thus giving the Eucalyptus a strange appearance, different from that of any of our American trees. The flowers of the Eucalyptus trees are generally in umbellate clusters. The calyx is partially adnate to the ovary, and furnished in the bud with a conical lid or cap, covering the stamens, but which, when the flower-expands, separates from the lower part of the calyx by a circular dehiscence, and falls off entire. There are no petals, but the stamens are numerous, and are sometimes united into 4 sets. The fruit, which is dry and enclosed in the hardened calyx, contains 3 or 4 cells, and usually ripens but 2 or 3 seeds to each cell.

The botanical history of the genus, Eucalyptus, is not yet thoroughly established. The leaves of the same species, at different stages of their growth, are extremely variable, and the species are so numerous and so closely allied, that positive specific differences are very difficult to find. The colonists classify them by the bark, which is either smooth, rough, or sometimes scaly.

Eucalyptus globulus.—This is one of the most valuable of Australian trees, on account of the timber, which is strong and durable. It is a large tree, often exceeding 200 feet in height, and known to colonists as "blue-gum," although the name is applied to at least 6 other species. The Eucalyptus globulus is placed, by Bentham (Flora Australiensis), in the series Normales, which have "perfect stamens with globular anther cells, opening longitudinally." The flowers are large, sessile, and produced in axillary clusters of 1 to 3. The mature leaves are from 6 to 12 inches long, and borne on wrinkled, twisted stalks, about 1 inch in length. They are narrowly lanceolate and falcate, with entire and thickened edges; they are obtuse or cordate at the base, and gradually tapering at the apex to an acuminate point. Their texture is very firm, so that the leaves retain their shape without wrinkles when dried. The veins are confluent near the margin. The entire leaf is thickly sprinkled with pellucid oil dots, and the surface, when dry, with minute black specks.

The leaves of Eucalyptus globulus constitute, in Australia and adjacent countries, the popular remedy against fevers, and especially in obstinate palustrial fevers. They are firm, coriaceous, and, in the green state, resist the attacks of grasshoppers and locusts. They have a strong, agreeable, aromatic odor, and a warm, bitterish, and aromatic taste, which, as with peppermint leaves, is followed by a cool sensation in the mouth.

Description.—The mature leaves, which are gathered from the older parts of the tree, are thus described by the U. S. P.: "Petiolate, lanceolately scythe-shaped, from 15 to 30 Cm. (6 to 12 inches) long, rounded below, tapering above, entire, leathery, grayish-green, glandular, feather-veined between the mid-rib and marginal veins; odor strongly camphoraceous; taste pungently aromatic and somewhat cooling, bitter and astringent"—(U. S. P.).

Chemical Composition.—The leaves have been analyzed by Cloez, Faust and Homeyer, M. F. A. de Hartzell, and Prof. E. S. Wayne. According to Cloez, they contain tannin in quite a large proportion, resinous matter, and an essential oil (see Oleum Eucalypti), which has been found to consist chiefly of eucalyptol (cineol, C10H18O) (see Eucalyptol). Rabuteau failed to discover a basic principle after having freed all alcoholic extract of the leaves from oil, tannin, and resin. H. Weber found a white crystalline body, mixed with an amorphous resinous mass, both of acid reaction; an acid yellow resin, of bitter taste; an acid named eucalyptic acid; and a neutral, crystallizable, bitter substance, soluble in ether and alcohol, and only slightly soluble in water. Prof. E. S. Wayne obtained a crystallizable acid resin, capable of producing, with ferric chloride, a brown-red reaction.

Action, Medical Uses, and Dosage.—The oil of eucalyptus (which is chiefly eucalyptol) and eucalyptol, in small doses, are gentle stimulants; in large doses, they occasion irritation of the throat and fauces, with increased flow of saliva; cephalagia, with extreme fatigue; frequency of the pulse; increased temperature; diminution of vascular tension; gastric irritability, and, not unfrequently, diarrhoea, accelerated respiration, the peculiar odor of the oil being exhaled with the breath; and increase of the urinary excretion. In some instances a sort of intoxication results from large doses (20 drops) of eucalyptol, and large doses of it and of eucalyptus produce some drowsiness and lack of power over the limbs. The chief eliminatory organs appear to be the lungs and kidneys, the drug causing an increased elimination of urea. Locally, the oil is irritant, particularly if not allowed to evaporate.

Eucalyptus globulus has for a long time been known as a remedy for intermittent fever among the natives of the countries of its origin. It is stated that more than 40 years ago the corvette, "La Favorite," being in the vicinity of Botany Bay, had her crew nearly decimated by a pernicious fever, and that a perfect recovery ensued among those remaining upon using an infusion of the leaves of Eucalyptus; the credit of this discovery is given to Dr. Eydoux and M. de Salvy. Dr. Ramel, of Valencia, is said to have introduced the remedy into Europe, in a statement made to the Academy of Medicine, in 1866; since which period its therapeutical virtues have been examined by many investigators. The emanations from this tree have, it has been reported, a strong antagonistic influence against those conditions termed malarial, and, on this account, it has been cultivated in various places in Europe where these conditions appear to have had a permanent existence.

Notwithstanding the high encomiums passed upon this agent as an antipyretic by the majority of those who have tested it, there are certain other investigators who are less enthusiastic; thus, Dr. Burdell, who tested it in the miasmatic fevers encountered in the marshy district of Sologne, France, states that, though eucalyptus has been sometimes found a febrifuge nearly equal to quinine, at other times it has proven to be discouragingly inefficient. (Indeed, the same may be observed of quinine and all other remedies, unless specifically indicated.) After thoroughly testing it in 123 cases, be concluded that it possessed but little or no antimalarial power. He states that the cures effected by it have been more frequent in the hospital than in the palustral localities, and which may be readily accounted for. Very often, as Chomel has shown, persons attacked with intermittent fever are cured in the hospital without any medicines having been employed. Dr. Carlotti, of Ajaccio, considers a quickly made decoction of the leaves to be of great value in those cases of intermittent fever that do not yield to quinine. He gives the decoction in doses of from 2 to 5 fluid drachms. Prof. Locke states that it is not so useful in recent ague as cinchona bark, but better in chronic ague, "in cases attended with excessive discharges or drain upon the system, as diarrhoea, dysentery, etc." He recommends 10-drop doses of specific eucalyptus in chronic obstinate diarrhoea, when no ague is present.

Aside from its alleged utility in intermittents, this agent has had other virtues attributed to it, as follows: The leaves and their preparations have been successfully used as a tonic and gently stimulating stomachic, in atonic dyspepsia, and in catarrh of the stomach and typhoid fever; also advised in mucous catarrhal affections generally; in pseudo-membranous laryngitis, in asthma, with profuse secretion, and in chronic bronchitis, with or without emphysema, and in whooping-cough; it has likewise proved efficient in chronic catarrh of the bladder, where the urine is high-colored, contains an abnormal amount of mucus, or, perhaps, some purulent matter, and micturition is attended with much pain. More recently it has been recommended as a diuretic in the treatment of dropsy. Both the leaves and the oil, as well as eucalyptol, are excitants and deodorizers, and, as such, have been successfully employed as local applications in bronchial affections with fetid expectoration, in ozena, in fetid or profuse mucous discharges, in vaginal leucorrhoea, offensive lochial discharges, gonorrhoeal discharges, indolent, fetid wounds or ulcers, cancerous ulcerations, in septicemia, and in gangrene. An excellent application in leucorrhoea, with relaxation of the vaginal walls, is prepared as follows: Rx Sea salt, 1 lb.; fluid extract of eucalyptus, fl℥ss. Place the salt in an earthenware or tin vessel, and pour upon it the extract and mix thoroughly. A half ounce of this preparation may be added to 1 pint of hot water and injected by means of a glass or metallic syringe. M. Bucquoy has found eucalyptus to exert a happy influence in the treatment of pulmonary gangrene. M. Luton, and others, have derived considerable benefit from it, when locally applied in cancerous affections, in the form of a compress of lint moistened with the tincture. It has likewise been advised to prevent putrefaction of organic substances, and to deodorize sickrooms and apartments containing unhealthy air. The leaves may, in some cases, be applied alone, directly to the part, in form of cataplasm; or they may be combined with other articles to form a poultice. The oil may be applied of full strength, or diluted with some other agent. In throat and pulmonary maladies, a tincture diluted, or a medicated water, may be inhaled in the form of spray; if the oil be employed, it may be dropped on some cotton placed in a small tube, from which the vapor may be inhaled. As a deodorizer, the tincture or the oil may be sprinkled or sprayed upon the offensive body, or the atmosphere of an apartment may be frequently sprayed with the same. Eucalyptol acts very much like the oil and both somewhat resemble turpentine in their effects. Like eucalyptus, it is used in foul and purulent respiratory diseases, particularly fetid bronchorrhoea, chronic bronchitis, pulmonary gangrene, and pulmonary tuberculosis, etc.

The dose of eucalyptol and of the oil is from 2 to 10 drops, and it is more convenient to administer it in capsules. One part of either combined with 100 parts of cod-liver oil has proved serviceable in phthisis; it removes the offensive taste and odor of the fish oil. Eucalyptol is now given in many instances where the oil was formerly administered on account of the greater definiteness of the dose, as the oil depends for its virtues upon the percentage of eucalyptol present. Both have been given for the relief of migraine, and, externally applied, give relief in some forms of neuralgic and rheumatic pains.

The leaves of eucalyptus, made up into cigars or cigarettes, and smoked, have been advised to afford relief in bronchial catarrh, asthma, and other affections of the respiratory organs. The question has been asked, may not the small amount of benefit that might be derived from the minute proportion of oil remaining intact, be more than overcome, and even prove injurious, from the irritating action of the smoke and of the empyreumatic products?

The most agreeable and convenient forms of administration are the tincture, in doses of 10 to 30 drops; or the fluid extract in doses of 5 to 30 drops, in syrup; or, preferable to all, specific eucalyptus, from 10 to 30-drop doses in malarial troubles, and from 5 to 10-drop doses in other troubles. It may be given with glycerin or syrup, as it does not mix well with water. The dose of the oil and of eucalyptol is from 5 to 10 minims, preferably in capsules.

EUCALYPTUS HONEY, gathered by bees from eucalyptus flowers, is quite active, and has been recommended for parasitic and putrescent conditions, gonorrhoea, fevers. and catarrhal diseases. It is sedative to the heart, actively diuretic, and increases the elimination of uric acid.

Specific Indications and Uses.—Sensations of coldness and weight in the bowels; cold extremities; cold perspiration; perspiration during chill; chronic catarrhal diarrhoea; chronic vesical catarrh, the urine containing pus; unhealthy fetid secretions from any part; relaxed mucous tissues, with profuse secretion; pasty, badly-smelling coating upon the tongue; fetid false membranes; sore throat, with fetid odor; fetid and catarrhal states of the broncho-pulmonic tract; and, in large doses, in chronic ague with exhausting discharges.

Related Drugs.—EUCALYPTI GUMMI. This new addition to the British Pharmacopoeia is furnished by the bark of Eucalyptus rostrata, Schlechtendal, as well as other species of eucalyptus. It is an exudation from the bark and has a ruby-red color, and is the so-called red gum from these trees. It resembles kino, though less astringent and possessing a brighter appearance. It has a bitter taste. When pure, it is almost entirely dissolved by alcohol, and, added to water, forms a solution containing from 80 to 90 per cent of the drug, having a neutral reaction (see Botany Bay Kino). Dose, 2 to 10 grains. For an account of the properties of this gum, see P. L. Simmonds, Amer. Jour. Pharm., 1895, p. 132.

Anacharis Alsinastrum.—This plant is a native of Canada, and is credited with anti-malarial properties. When introduced into districts where malaria and malarial diarrhoea are prevalent, it is said to diminish the number of cases of these disorders (Medical Bulletin).

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.