notion of saving time, begin by transplanting such large Trees, as they find on their own estates, or that they can procure in their neighbourhood, and please themselves with the hopes of having fine plantations soon: But if, instead of removing these Trees, they would begin by making a Nursery, and raising their Trees from seeds, they would save a great expense, and much time, and they would have the constant pleasure of seeing their Trees annually advance in their growth, instead of growing worse, as will always be the case, where old Trees are removed; though many persons flatter themselves with the hopes of success, when they find their Trees shoot out the following sea

son.

"I have seen great numbers of tall Oaks transplanted, which have appeared to thrive for some years, when first planted; but, in five or six years after, they have begun to decay at top, and have leisurely died to the ground, than which nothing can be a more disagreeable sight to the owner. And the method, which is commonly practised in transplanting these Trees, would destroy them, were there a possibility of such large Trees surviving their removal, which is, that of cutting off all their branches: For, were the same practised on a Tree of the same age unremoved, it would stint the growth so much, as not to be recovered in several years, nor would it ever arrive to the size of such, as have all their branches left on them. But the reason given for this practice is, that, if the branches were left upon the Trees, they could not be supported; the winds would throw them out of the ground; and another (which is bad philosophy) is, that, as the roots have been greatly reduced by Transplanting, so the heads of the Trees should be reduced in the same proportion. As to the first, it must be allowed, that Trees, which are removed with great heads, are with great difficulty preserved in their upright situation; for the winds will have such power against the branches, as to overset the Trees, if they are not very strongly supported with ropes. Therefore, this may be brought as an objection to the Transplanting of large Trees, rather than in support of a practice, which is so prejudicial to them. And as to the other reason, it has no foundation For, if large amputations are made at the root,

there should not be the same practised on the head; because the wounded part of the head will imbibe the air at every orifice, to the great prejudice of the Tree.

"Besides this, if we pay any regard to the doctrine of the circulating of the juices in plants, we must allow, that the heads of the Trees are equally useful to nourish the roots, as the roots are to the heads; so that, if there is a waste of sap, both at the top and bottom of the Trees, it must weaken them in proportion. For, whoever will be at the trouble to try the experiment on two Trees of equal age and health, and cut the branches off from one, and leave them upon the other at the time of Transplanting, if the latter is well secured from blowing down, it will be found to succeed much better than the other. Or, if the same thing is practised upon two Trees left standing, the Tree, whose branches are cut off, will not make half the progress as the other, nor will the stem increase in its bulk half so fast. Therefore, where Trees are transplanted young, there will be no necessity for using this unnatural amputation, and the success of these plantations will always give pleasure to the owner." Gardener's and Botanist's Diction. in voc. "Planting."

I have particular satisfaction in quoting these sentiments from the great work of Miller, and I have little doubt of their being perused with equal satisfaction, by the discerning reader. In fact, no advocate of the system, which is attempted to be established in this Essay, could have given this material part of its principles with greater force and truth. It clearly shows, that, if the advancement of aboricultural science, in respect to this art, had not been stationary for a century in England, the giving Immediate Effect to Wood, instead of being, as it now is, a rude and uncertain practice, would long since have risen to the rank of a regular art, justly esteemed, and as generally cultivated.

NOTE III. Page 80.

It has been doubted, by some phytologists, whether Trees generate heat? I believe it is certain, notwithstanding what is

cursorily stated in the text, that frosts of very extraordinary severity will destroy Trees. The non-conducting property of wood may, in some measure, protect the juices; but their chemical composition is such, that they do not congeal, unless the cold be of the severest sort, and many degrees below the freezing point of water. In weather so hard, as to occasion the juices to freeze, the wood, in the act of congelation, is violently rent asunder: But, in the more common destruction of woody plants, it is not so much the degree of cold that kills them, as the too sudden reapplication of heat.

The ingenious Hassenfratz, to whom the chemical world is under some obligations, held, that vegetables are not fed by carbonic acid. In a Memoir, on the Nourishment of Vegetables, read in 1792 to the Royal Academy of Paris, having shown, as he conceived, that water and air are insufficient for all the purposes of vegetation, he attempted, in a second ingenious paper, to prove, that carbonic acid gas is not decomposed and digested in the organs of growing vegetables, and that they cannot be fed by it; because oxigen, escaping from combination in the decomposition of carbonic acid, and water escaping in vapour, in the state of gas, would absorb caloric, and produce cold: Whereas, by the experiments of the late John Hunter, living vegetables contain a degree of heat, greater than that of the surrounding atmosphere. The reason of this difference in opinion between these two accurate inquirers may possibly be, that Hunter's experiments were made only in the autumn, the winter, and early in the spring, when the activity of vegetation was suspended, which does not seem to have been the case respecting those of Hassenfratz.

It appears, however, that both Rüchert and Senebier ascertained, that vegetables do decompose carbonic acid, retaining the carbon, and emitting the oxigen. Dr Woodward made many experiments with plants of mint, growing in water, and found that a plant, in water from the Thames, which must certainly have contained a large share of carbonic acid, encreased considerably more in weight, than a plant growing in pure water. Schoppett, who examined the temperature of growing Trees in New York, found, that, from November to April, when the

bulb of a thermometer was put into a hole made in a Tree, the mercury rose higher than in the open air; and that, the colder the weather, the greater, of course, was this difference. From April to November, on the other hand, the thermometer showed a lower temperature in the Tree, than in the open air. And Ingenhoutz found, that a piece of green paper, hung on a Tree, in a warm summer-day, felt sensibly warmer than the leaves. Hunter likewise, who was fond of Trees, used to keep thermometers in them for months together, and obtained similar results. The subject is curious, and is the more deserving of the planter's investigation, that the state of the Bark, and its power, when thick and indurated, to protect the Sap-vessels, are so intimately connected with all facts, that tend to illustrate the subject.

NOTE IV. Page 82.

Of the close analogy, which subsists between the animal and vegetable kingdoms, many other examples respecting the former might be adduced, besides those mentioned in the text, in order to show, how universally Nature generates provisions for individuals, in order to fit them for the situations, in which they are placed. The general rule seems to be, as mentioned in the text, that, where there is a great external application of cold, an adequate non-conducting covering is supplied, to prevent the subtraction of internal caloric; and, in the same way, that covering is withdrawn, on a greater application of heat. Of the latter the Coach or Race-horse furnishes a familiar example, with his smooth and silky coat, enjoying the warmth and shelter of a well-constructed stable, when we compare it with the rough and shaggy one which he wears, when running out in winter. The coats of warm-blooded animals appear to be thick and fine, in proportion to the intensity of the cold they are destined to endure; and they are always thicker and finer in winter, than in summer. Accordingly (as stated in the text), the fur-bearing animals all inhabit high latitudes, and the value of their skins encreases, in proportion to the severity of the cold, in which they are killed.

Of the natural clothing of animals in cold countries, the Musk Ox of Melville Island, as observed by late voyagers, furnishes a striking instance; as the immense mass of non-conducting matter, which covers that animal, renders him capable of existing in a temperature, where even mercury freezes, and of which we can form no adequate conception. The long, hairy, and dense garb of the Kamskatcha Mammoth, that most powerful of quadrupeds, embalmed in ice, sufficiently proves the nature of such a coat, as enabled him to live in the coldest latitudes; and which the Elephant of tropical birth, with his unprotected hide, could not certainly have endured. In the same way, between the tropics, were the trunks of Trees not defended from the downward and burning rays of the sun, by a thick, expanded, and umbrageous foliage, there is reason to think, that their bark would be scorched, and severely injured: While the same vertical rays harmlessly descend on the woolly head of the Negro; who, without that light and natural turban, would, like the defenceless European, often fall a victim to the "Stroke of the Sun;" Coup de Soleil I will not call it, because the phenomenon is just as well and clearly expressed, in our own language.

NOTE V. Page 83.

Aristotle, who enjoyed the double honour of being the father of Natural History, as well as of Metaphysics, says (De Respirat. c. 10. and the same principle is frequently inculcated throughout his other works), Εν δὲ ἐφ ̓ ἂν ὄργανον χρήσιμον· ὡς ἐπεὶ μάτην ὁρῶμεν ουδὲν ποιοῦσαν τὴν φύσιν, δυοῖν δὲ ὄντοιν, θάτερον ἂν ἦν μάτην; meaning to intimate, that Nature bestows not, on either animals or vegetables, any thing in vain ; that, while she wisely effects her purposes by the easiest and most direct methods, she withdraws the interposition of the agents, as soon as their office is superfluous. This principle is exemplified in no instance better than in Trees, and in their uniform possession of Properties, which are best adapted to their peculiar circumstances.