Eucalyptus

u-ka-llp'tus, a genus of trees peculiar to Malaysia, Australia, and Tasmania. They are known also as gum trees and stringy barks. There are numerous species--about 150 in all. The eucalyptus is of rapid growth. One tree is mentioned with a height of 480 feet and a diameter of 81, surpassing even the gigantic sequoias of California. The wood is valuable as fuel. It possesses strength and durability. In Australia, Eucalyptus lumber takes the place of American pine for bridges and general building purposes. Blocks of eucalyptus are used for paving the streets of Sydney and other Australian cities. An illuminating gas may be obtained from the wood by destructive distillation. A ton of wood yields 10,000 cubic feet of gas. The bark is used in tanning. The leaves are leathery. Those of many species turn their edges to the sun, a position which enables the tree to stand severe drouth. A fragrant oil is distilled from the leaves. It resembles camphor in some respects. It makes valuable varnish. The tincture of eucalyptus has an odor like that of cubebs. It is a remedy for asthma, bronchitis, and whooping cough. It also takes the place of quinine as a remedy in case of fever, and is an excellent antiseptic dressing for wounds. Because of its medicinal properties the culture of the eucalyptus tree has been recommended in malarious districts for the purpose of counteracting miasmatic influences. One species of eucalyptus, the blue gum, has been introduced widely in warm countries, notably in Spain, Algeria, Egypt, India, Florida, and southern California. This tree is cultivated for its timber. It withstands drouth well, but cannot endure frost. The flowers are without petals. They resemble those of the myrtle. Consul Henry D. Baker, of Hobart, gives an interesting report of the extensive use to which the leaves of the eucalyptus tree are put in Tasmania:

I recently paid a visit to Port Esperance, about fifty miles journey by water southwest of Hobart, for the special purpose of observing an interesting use to which eucalyptus leaves are being put in the preparation of an extract for the prevention of corrosion and encrustation of boilers. The plant at Port Esperance is said to be the only one of its kind in the world. It is owned by a company in Liverpool, England, and its product is sold at profitable prices to leading steamship companies engaged in trans-Atlantic and Mediterranean service.

There are many plants in the Commonwealth of Australia where eucalyptus oil is distilled for medicinal purposes, and there is a plant in New South Wales where acetic acid is an important by-product in the distillation of the oil; but at the Port Esperance plant the eucalyptus oil itself is considered merely a by-product in the preparation of the more valuable extract for use in preventing deterioration of boilers.

This extract has the appearance and consistency of tar when prepared for export to England. It is shipped with no more liquid in it than is necessary to prevent caking in the casks en route, it being thinned, however, with the addition of water on its arrival at Liverpool. The extract is said to diffuse itself through the water of boilers and cleanse them of any acid, greasy, or saline matter, forming with such deleterious ingredients a harmless sediment which sinks to the bottom, and it prevents any formation of crust around the water line.

Four tons of eucalyptus leaves will produce about one ton of the extract for boilers, and about seventy to eighty pounds of eucalyptus oil. This plant is located in the vicinity of extensive forests of the blue gum eucalyptus which is also grown to some extent in Florida and California. Twigs of the leaves are taken off the trees irrespective of the age or height of the tree, except that old trees are not preferred owing to the great preponderance of woody matter. They are placed in large bags and, by an iron hook arrangement, are slid down the hillsides along telegraph wire especially strung for their easy transportation to the mill. The leaves are for the most part about ten inches long and from one inch to one and a half inches wide. The leaves most used at this plant are taken from an underbrush of trees in "bush" destroyed by fire about two years ago. The same trees may be considered good for another crop of satisfactory leaves in about three years after the first leaves have gone to the mill. The leaves are poured into a large cauldron, called a digester, and steam is applied for four hours. During this steaming the acetic acid in the leaves passes off into vapor, the eucalyptus oil is carried out by the steam to the condenser, the waste water being then separated by use of a syphon.

The residuum in the digester is then subjected to steam pressure, by means of which the valuable extract is obtained, being first, however, boiled down to the consistency of tar. . . . It is a curious fact that the acetic acid and the boiler extract, both obtained from the same leaves, have an exactly opposite effect on iron, the former destroying and the latter preserving it. In order to prevent the digesters from being eaten by the acid in the leaves the digesters are painted with the boiler extract before the leaves are put in and the steam applied.

The local consumption of eucalyptus oil for medicinal purposes is quite large. It is a favored remedy for colds, rheumatism, asthma, and other bronchial affections, skin diseases, toothache, burns, bruises, etc. It is frequently sprinkled over bedroom floors to drive away mosquitoes. It is used most commonly, with sugar, often in the form of lozenges. It is occasionally taken in overdoses, and I have heard of several deaths from this cause in Tasmania quite recently. The exportation of oil appears small compared with the local consumption. The value of the exports of oil from Tasmania last year was only $4,560.

An illuminant known as "gum gas" can be produced from the leaves and is said to give a bright light. A local authority has estimated that 10,000 feet of gas can be obtained from a ton of leaves. The eucalyptus bark is said to contain a fiber suitable for paper; also tanning. Eucalyptus flowers contain a nectar especially good for bee food, though the flavor of honey from the eucalyptus is somewhat peculiar and might not please every taste. Eucalyptus woods are considered very valuable for railway sleepers and for piles. Some of this wood was exported to England for the Dover harbor works about ten years ago, and is said to be in excellent condition still.