substances, as linen, woollen, silk, and leather. This property, which sometimes resides in the stem and branches, sometimes in the leaves and flowers, may be classed among those properties of plants, which, if we consider the actual state of society in all the civilized parts of the world, are productive of the greatest advantage to mankind. Hence, for instance, has arisen an art, the art of dying, which not only opens a wide field of employment to a numerous class of workmen, in every large city; but gives a degree of activity to general commerce, which cannot but surprise the mind of any one previously ignorant of the circumstance. Thus the quantity of indigo, accumulated in the extensive repositories of the EastIndia Company, is frequently so great as to make the occasional observer wonder that it should ever find a market: and the following statement will show how important this single substance is as an article of commerce. During the last five years, the quantity of indigo imported into London amounts to at least one hundred and twenty thousand chests; the average weight of the contents of each chest equalling 270 lbs., and the average price of each pound being five shillings. The estimated value therefore of the indigo contained in the 120,000 chests would be rather more than eight millions sterling.

If I am correct in supposing that blue, red, and yellow, are the colours most abundantly supplied by vegetables, it cannot fail to strike a mind of the least reflection, that these are precisely the elementary colours which a dier would have antecedently selected, in order to be enabled to practise his art to the greatest advantage; since from these three, all other colours or tints may be obtained. And with respect to black, which must practically be considered as a distinct colour, though not admitted as such theoretically, it is worthy of observation, that, although scarcely any vegetable substance yields it directly; yet, by the intervention of almost any form of iron, and this metal is in some shape or other present everywhere, it may readily be produced from a very numerous class of vegetable substances. In almost every instance where a vegetable substance has an austere and bitter taste, it will with iron give a die of a black colour. Thus the bark of the oak, and of many other trees, and that vegetable excrescence called the gall-nut, produce an ink by the addition of any saline form of iron.

From the earliest and least civilized times, and through every intermediate stage of society to the present period of refinement, the productions of the vegetable world have been in constant request for the most common purposes of life. The simplest dwellings not only of the uninstructed savage, but of the peasantry of many parts of modern Europe, are constructed almost entirely of wood; the simplest implements of husbandry, the plough, the spade, and the hoe, could hardly be employed without the aid of a wooden frame-work or handle; and the same observation holds good with

reference to the tools of the most necessary arts of life. How great would be the inconvenience, and how increased would be the labour of the carpenter, or the smith, or the mason, if, instead of wood, the handles of his implements were of iron! Nor are substances of vegetable origin of less importance, or less generally employed, in many of the higher arts of life. Examine the structure of a man of war-its hulk, of oak; its masts, of fir; its sails and ropes, of flax; its caulking, of tow and of tar. All is of vegetable origin from the top-mast head to the keel itself. With the exception indeed of the iron which is occasionally used in the construction, no metallic substance is necessarily employed; for the copper sheathing, though highly useful, is certainly not necessary.

It would require volumes to describe all the economical uses to which vegetables are applied. How many important trades arise from this source. How many families, now existing in opulence, originally derived their surnames from their occupation, and that occupation connected with vegetable materials; for instance, Cooper, Carpenter, Dier, Tanner, Turner, Wheeler, Weaver, Barker, Hayward, Gardener, Cartwright, Miller, Fletcher, Bowyer!

And then, to answer the various purposes to which they are to be applied, how widely do the qualities of different vegetable productions differ from each other! How well the rigid fibre and compact texture of the oak enable the bulky vessel to resist the buffeting of the waves! The ash, the beech, the fir, the yew, each has those appropriate qualities which make it individually preferable to the rest. The flexibility of the hemp and flax renders them capapable of being woven and formed into sails and cordage; and, exposed as the sails and rigging are to the vicissitudes of the weather, how well are they protected by being covered over with tar, itself of vegetable origin!

Some woods very readily split with that regularity of surface which we observe in common laths; and of the utility of that kind of material in almost every kind of building no one can well be ignorant. Other woods, as the willow, very readily bend, with a considerable degree of elasticity, in every direction; and hence are of value in the fabrication of what is known under the general name of wicker-work.*

In this department, again, though not to the same extent as in the case of some of the metals, is seen the effect of human labour in advancing the value of the original material. Compare, for in

The art of making wicker-work is often successfully cultivated at a very early period of civilization. Thus, in the neighbourhood of California, some of Captain Beechey's officers were supplied with water brought to them in baskets, which the Indians weave so close, that, when wet, they become excellent substitutes for bowls." (Beechey's Voyage, p. 385.) And we know that, not long after the conquest of Britain by Cæsar, the ornamental wicker-work of the natives was highly prized at Rome.

stance, the mercantile value of a piece of fine lace, with the original value of the material of which it is made.

There are many plants, which, though they neither produce fruit of any value nor are capable of being applied to any of the common purposes of the arts, are yet of the highest value as a natural defence to cultivated lands against the incursions of cattle; and sometimes even against the attacks of disciplined troops.

The quick set of our common hedges is an instance of the former application; and of its utility in this country no one can doubt, unless he happen to live exclusively in those districts, as in certain parts of the Cotswold and similar ranges of hills, where stone supplies a more ready material for a fence. Of the extent of its application, it would not be easy to make a correct estimate: but, when we consider how many public roads, and how many private enclosures are bounded by a fence of quickset, it becomes probable that the linear extent of hedges of this kind is, in England alone, equal to many times the circumference of the whole earth. In describing one of the most important fortresses in the Deccan, Captain Seely, in his account of the temples of Ellora, states that the town, which stands about 1020 yards from the fort, is surrounded by a hedge of prickly pear, nearly eighteen feet high, and thick in proportion. This natural defence round towns and villages on the western side of India is very common; and it offers to a predatory body of horse or foot a formidable barrier for the sharp and long thorns, which project from the stem and leaf, not only act as an immediate defence; but, if broken off, they exude a liquid which often produces severe inflammation.*

In a part of Normandy, lying between Caen and Falaise, is a district called "Le Bocage" (petit bois), which "derives its name from the high and bushy hedges with which it abounds; and which are designed to afford shelter from the stormy winds of the Atlantic. There are but few trees in those parts; but the hedges, being from eight to ten feet in height, are sufficient to protect the crops from the boisterous sea-breezes: and they thence bear the name of brisevent."+

The last point in the history of vegetables which I propose to consider is their application as fuel; and many nations entirely derive their supply of fuel, for culinary and other domestic purposes, from the vegetable kingdom alone: and even where such a supply is in a great measure needless, on account of the abundance of coal, yet, for many purposes, various forms of wood, either in a recent or in a charred state, are preferred, on account of the injurious effects arising from the sulphur with which coal is usually contaminated; in the heating of bakers' ovens, for instance, in the drying of malt, and in numerous processes of the arts. Around the shores

* P. 522.

Conversations on Vegetable Physiology, vol. ii. p. 232.

of the Arctic Ocean, where scarcely any traces of native vegetation are observable, the inhabitants are amply supplied by drift-wood (Sauer's account of Billings's Expedition, p. 104-259). And Captain Beechey says, that drift-wood is to the Esquimaux what forests are to us; being in such abundance and variety, that the inhabitants have the choice of several sorts of trees. All this drift-wood about the mouths of rivers, on the north coast of America, appears to be brought down by those rivers from the interior of America: but from the occurrence of many floating trees to the southward of Kamchatka, and from other circumstances, it is probable that much of the drift-wood, found at a distance from the mouths of rivers, comes very far from the southward. (p. 575-580).

Nor does the benefit, arising from vegetable forms of fuel, terminate with their consumption. The residuary ashes are useful, as a manure for the land, on account of the alkaline matter which they contain and that alkaline matter is also to many a poor peasant a substitute for soap; the lixivium, or ley, which may be obtained by filtering water through the ashes, owing its detergent quality to the alkali which it has dissolved in its passage. In those parts of the world indeed, as in North America, for instance, where it is requisite to clear the land of wood, for the purpose of bringing it into cultivation, the ashes of the forests, which are necessarily burned for this purpose, afford an enormous quantity of alkaline residuurn; and this is the source of much of that alkali of commerce, which, from having been obtained by evaporation of its solution in iron pans or pots, is commonly known under the name of potash.

That other alkali of commerce, called soda, is derived from a similar, though indeed a much more humble source; for, in this case, the alkali does not result from the combustion of stately and aboriginal forests, but from the combustion of heaps of sea-weed; which, in various parts of the coast of Europe, has been collected from the surfaces of the adjoining rocks.*

* In some instances loose stones are intentionally placed on the sea-beach for the purpose of affording a substratum for the growth of various sea-plants, which attach themselves to the stones so placed.

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CHAPTER IX.

ADAPTATION OF ANIMALS TO THE PHYSICAL CONDITION OF MAN.

SECTION I.

General Observations on the Animal Kingdom.

THE same remark may be made with regard to the general utility of animals, which has been made in the case of vegetables: for we have sufficient reason for believing, that, among the myriads of species of animals which exist upon the face of the earth, there is not one which does not act an important part in the economy of nature.* And yet, if it be correctly stated that out of about a hundred thousand species of animals, the number supposed to have been hitherto discovered, eighty thousand are of the class of insects;† it will be evident that the mass of mankind is ignorant of the very existence of nearly four fifths of the whole animal kingdom: for, with the excep tion of the fly, the bee, the wasp, the ant, and perhaps ten or twelve more species, few but professed naturalists are acquainted with the specific differences of this class of animals; so small are they in size, and so apparently insignificant to a common observer. But, if we have reason for believing that not a single animal species exists without its use in the general economy of nature, we have a certainty that there are many, the absence of which would be almost incompatible with the continuance of the existence of the human race. If, for instance, the duties of the shepherd and herdsman could no longer be exercised, in consequence of the extinction of the two species of which they have now respectively the care, into what misery would not the population of a great part of the world be plunged, cut off at once from some of the most substantial forms of animal food, and the most general and effectual sources of clothing!

And, if we consider the subject in another point of view, how fitly are the natures of these species, from the individuals of which such immense advantage accrues to man, accommodated to that end! If, for instance, the sheep and the ox were carnivorous, instead of herbivorous, how could the species be preserved: or, supposing for a moment that a sufficient quantity of animal food could be procured for

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It is the opinion of Mr. Scoresby, (Account of the Arctic Regions, vol. i. p. 179, 180,) that the olive-green colour of the water, observable in many parts of the Greenland sea, is owing to the presence of numberless quantities of very small medusæ and other minute animals. "These small animals," he says, apparently afford nourishment to the sepiæ, actiniæ, and other mollusca which constitute the food of the whale: thus producing a dependant chain of animal life, one particular link of which being destroyed, the whole must necessarily perish.

The number is probably greater.