TROPICAL PLANTS USED FOR INDUSTRIAL PURPOSES.
Cotton—Its Cultivation in the United States—Caoutchouc and Gutta Percha—Manner in which these resins are collected—Indigo—The British Logwood cutters in Honduras—Brazil Wood—Arnatto.
Under the Plantagenets and the Tudors, wool formed the chief export of England. The pastoral races that inhabited the British Isles, unskilled in weaving, suffered the more industrious Flemings to convert their fleeces into tissues; and the dominions of the Duke of Burgundy, enriched by manufactures and by the stimulus they gave to agriculture, became the most prosperous part of Europe. At length the islanders began to discover the sources of the wealth which rendered Ghent and Bruges, Ypres and Louvain, the marvel and envy of the mediæval world; and gradually learning to keep their wool at home, invited the Flemings to the shores of England.
The bigoted oppression of Spain came in aid of this more enlightened policy: our wool ceased to be sent abroad, and English cloth eventually became the chief of our exports. But, like all human affairs, trade is subject to eternal fluctuation, new wants are constantly created, new markets opened, new articles introduced, and thus, almost within the memory of living man, the wool-manufactory has ceased to be the great staple of our189 industry; and, thanks to the inventive genius of our Arkwrights and Cromptons, a vegetable fibre furnished by a plant totally unknown to our forefathers, now ranks as the first of all the world-wide importations of England.
There are many different species of the cotton-plant, herbaceous, shrubby, and arboreal. Their original birthplace is the tropical zone, where they are found growing wild in all parts of the world; but the herbaceous species still thrive under a mean temperature of from 60° to 64° F., and are capable of being cultivated with advantage as far as 40° or even 46° N. lat. The five-lobed leaves have a dark green colour, the flowers are yellow with a purple centre, and produce a pod about the size of a walnut, which, when ripe, bursts and exhibits to view the fleecy cotton in which the seeds are securely embedded.
It is almost superfluous to mention that the United States is the first cotton-producing country in the world. The area suitable for cotton south of the thirty-sixth degree of latitude, comprises more than 39,000,000 acres, of which less than one-sixth part is now devoted to the plant. The yield depends in part upon the length of the season. Seven months are required for an average crop, and the average periods in which the last killing frost of spring and the first killing frost of autumn occur are March 23, and October 26. Cotton is cultivated in large fields, and when the soil is superior, the plant rises to a height of six or eight feet, although in the richest cane-brake soil, exhausted by successive crops, it dwindles down to a height of three or four feet only. The aspect of a cotton field is most pleasing in the autumn, when the dark-coloured foliage and bright yellow flowers, intermingling with the snow-white down of the pods when burst, produce a charming contrast. At that time all hands are at work, for it is important to pluck as much as possible during the first hours of morning, since the heat of the sun injures the colour of the cotton, and the over-ripe capsules shed their contents upon the ground, or allow the wind to carry them away.
The collected produce is immediately carried to the steam-mill to be cleansed of the seeds, and then closely packed in bales, which in the seaports are further reduced by hydraulic presses to half of their previous volume, thus causing a great saving in the freight. Large clippers frequently carry eight or ten190 thousand of these bales to Liverpool, whence, perhaps on the day of their arrival, they are conveyed by rail to the next manufacturing town, which returns them in a few days to the port, ready to clothe the Australian gold-digger or the labourer on the banks of the Ganges.
India, which still in the last century provided Europe with the finest cambrics and muslins, now yearly receives from England cotton goods to a large amount. Thus the stream of trade may be said to have rolled backwards to its source, for though the wants of the Hindoo are easily satisfied, and cotton grows at his very door, yet his hand-loom is unable to compete with the machinery and the capital of England. Even in the exportation of the raw material he labours under great disadvantage when compared with America, though railroads and a better system of culture have done much to improve the quality and facilitate the transport of Indian cotton.
When we consider the luxuriance of vegetation in the tropical zone, it is not to be wondered at that so many plants of those climes abound with juices of a variety and richness unknown to those of the temperate latitudes. The resins and gums which our indigenous trees produce, either in smaller quantities or fit only for common uses, are there endowed with higher virtues, and ennobled, as it were, by the rays of a more powerful sun. Sometimes they exude spontaneously through the rind and harden in the atmosphere; more frequently a slight incision is required to make the sap gush forth in which they are dissolved, but in every case they require but trifling labour for their collection. Many of them have medicinal qualities, others are esteemed for their aromatic odour, but none ranks higher in a commercial and technical point of view than caoutchouc or India-rubber, which was first brought from South America to Europe as a great curiosity at the beginning of the last century, and is now absolutely indispensable for a thousand different uses. Nothing was known even of its origin until the year 1736, when the French naturalist La Condamine, while exploring the banks of the Amazon, discovered that it was chiefly produced by the Siphonia elastica, a large tree growing wild in the primitive forests along the borders of the rivers in Guiana and North Brazil.
The resin is collected by the Indians in a very simple191 manner. With a small hatchet they make deep and long incisions in the rind, from which a milky sap abundantly exudes. A small wooden peg is then fixed into each aperture to prevent its closing, and a cup of moist clay fastened underneath, which in about four or five hours is filled with as many table-spoonfuls of the juice. The produce of a number of incisions having been gathered in a large earthen vessel, is then spread in thin coatings upon moulds made of clay, and dried, layer after layer, over a fire, until the whole has acquired a certain thickness. When perfectly dry, the clay form within is broken into small fragments, and the pieces are extracted through an aperture, which is always left for the purpose.
Besides the Siphonia elastica, many other American trees, belonging to the families of the Euphorbiaceæ and Urticeæ, afford excellent kinds of caoutchouc; and since it is become so valuable an article of commerce, the East Indies, and Java likewise, yield considerable quantities, chiefly from the Urceola elastica and the Ficus elastica.
The Icosandra Gutta, which furnishes the gutta percha of commerce, is a native of the Eastern Archipelago and the adjacent lands. A few years since, this substance, now so celebrated and of such wide extended use, was totally unknown in Europe, for though from time immemorial the Malays employed it for making the handles of their hatchets and creeses, it was only in the year 1843 that Mr. Montgomery, an English surgeon, having casually become acquainted with its valuable properties, sent an account of it, with samples, to the Royal Society, for which he was most justly rewarded with its gold medal. The fame of the new article spread rapidly throughout the world; science and speculation seized upon it with equal eagerness; a thousand newspapers promulgated its praises; it was immediately analysed, studied, and tried in every possible way, so that it is now as well known and as extensively used as if it had been in our possession for centuries.
The Icosandra Gutta is a large high tree, with a dense crown of rather small dark green leaves, and a round smooth trunk. The white blossoms change into a sweet fruit, containing an oily substance fit for culinary use. The wood is soft, spongy, and contains longitudinal cavities filled with brown stripes of gutta percha. The original method of the Malays for collecting192 the resin consisted in felling the tree, which was then placed in a slanting position, so as to enable the exuding fluid to be collected in banana leaves. This barbarous proceeding, which from the enormous demand which suddenly arose for the gutta would soon have brought the rapidly rising trade to a suicidal end, fortunately became known before it was too late, and the resin is now gathered in the same manner as caoutchouc, by making incisions in the bark with a chopping knife, collecting the thin, white, milky fluid which exudes in large vessels, and ............