been under the plough for some years, it is found in proportion to the quantity of putrid dung that had been laid upon them, making an allowance for the crops they have sustained. To set this matter in a clear light, let us attend to the effects of manures of an oily nature, and we shall soon be satisfied that oil, however modified, is one of the chief things concerned in vegetation. Rape dust, when laid upon land, is a speedy and certain manure, though an expensive one, and will generally answer best on a lime-stone land, or where the soil has been moderately limed. This species of manure is much esteemed by the farmer. It contains the food of plants ready prepared; but as it is not capable of loosening the soil by any fermentation, the lands upon which it is laid ought to be in excellent tilth. At present, that useful article of husbandry is much diminished in goodness, owing to the improved methods of extracting the oil from the rape. Heat and pressure are employed to a double degree more than formerly.

Farmers, who live in the neighbourhood of large towns, use abundance of soot. It is an oily manure, but different from the former, containing alkaline salt in its own nature, calculated as well for opening the soil as for rendering the oily parts miscible with water. It is observed that

pigeon's dung is a rich and hasty manure. These animals feed chiefly upon grains and oily seeds; it must, therefore, be expected that their dung should contain a large proportion of oil. The dung of stable-kept horses is also a strong manure, and should not be used until it has undergone the putrid ferment, in order to mix and assimilate its oily, watery, and saline parts. Beans, oats, and hay, contain much oil. The dung of horses, that are kept upon green herbage, is of a weaker kind, containing much less oil. Swine's dung is of a saponacious and oily nature, and perhaps is the richest of the animal manures. When made into a compost, and applied with judgment, it is excellent for arable lands. The dung of ruminant animals, as cows and sheep, is preferable to that of horses at grass, owing to the quantity of animal juices mixed with their food in chewing. And here we beg leave to remark in general, that the fatter the animal, cæteris paribus, the richer the dung. Human ordure is full of oil and a volatile alkaline salt. By itself, it is too strong a manure for any land; it should therefore be made into a compost before it is used. The dung of carnivorous animals is plentifully stored with oil. Animals that feed upon seeds and grains come next, and after them follow those which subsist upon grass only. To suit these different manures to their proper soils requires the greatest judgment of the farmer, as what may be proper for one soil may be detrimental to another.

In order to strengthen our argument in favour of oil being the principal food of plants, we observe that all vegetables, whose seeds are of an oily nature, are found to be remarkable impoverishers of the soil, as hemp, rape, and flax; for which reason, the best manures for lands worn out by

these crops are such as have a good deal of oil in their composition; but then they must be laid on with lime, chalk, marl, or soap ashes, so as to render the oily particles miscible with water. The book of nature may be displayed to show that oily particles constitute the nourishment of plants in their embryo state; and, by a fair inference, we may suppose that something of the same nature is continued to them as they advance in growth. The oily seeds, as rape, hemp, line, and turnip, consist of two lobes, which, when spread upon the surface, form the seminal leaves. In them the whole oil of the seed is contained. The moisture of the atmosphere penetrates the cuticle of the leaves, and, mixing with the oil, constitutes an emulsion for the nourishment of the plant. The sweetness of this balmy fluid invites the fly, against which no sufficient remedy has, as yet, been discovered. The oleaginous liquor being consumed, the seminal leaves decay, having performed the office of a mother to a tender infant. To persons unacquainted with the analogy between plants and animals, this reflection will appear strange. Nothing, however, is more demonstrable. The leguminous and farinaceous plants keep their placentia, or seminal leaves, within the earth, in which situation they supply the tender germ with oily nutriment, until its roots are grown sufficiently strong to penetrate the soil.

It is usual to talk of the salts of the earth; but chemistry has not been able to discover any salts in land which has not been manured, though oil may be readily obtained from every soil, the very sandy ones excepted. Marl, though a rich manure, has no salts. It is thought to contain a small portion of oleaginous matter, and an absorbent earth, of a nature similar to limestone, with a large quantity of clay intermixed. Lime mixed with clay comes nearest to the nature of marl of any factitious body that we know of, and may be used as such, where it can be had without much expense. By increasing the quantity of clay it will make an excellent compost for a light sandy soil; but to make the ground fertile, woollen rags, rotten dung, or any oily manure, should be incorporated with it some time before it is laid on.

It is a received opinion that lime enriches the land it is laid upon, by means of supplying a salt fit for the nourishment of plants; but by all the experiments that have been made upon lime, it is found to contain no kind of salt. Its operation, therefore, should be considered in a different light by the fermentation that it induces, the earth is opened and divided, and, by its absorbent and alkaline quality, it unites the oily and watery parts of the soil. It also seems to have the property of collecting the acid of the air, which it readily forms into a neutral salt, of great use in vegetation. From viewing lime in this light, it is probable that it tends to rob the soil of its oily particles, and in time will render it barren, unless we take care to support it with rotten dung, or other manures of an oily nature. As light sandy soils contain but a small portion of oleaginous

particles, we should be extremely cautious not to overdo them with lime, unless we can at the same time assist them liberally with rotten dung, woollen rags, horn shavings, and other manures of an animal kind. Its great excellence, however, upon a sandy soil, is by mechanically binding the loose particles, and thereby preventing the liquid parts of the manure escaping out of the reach of the radical fibres of the plants. Upon clay the effect of lime is different; for, by means of the gentle fermentation that it produces, the unsubdued soil is opened and divided; the manures laid on readily come into contact with every part of it; and the fibres of the plants have full liberty to spread themselves. It is generally said that lime answers better upon sand than clay. This observation will undoubtedly hold good as long as the farmer continues to lime his clay lands in a scanty manner. Let him treble the quantity, and he will then be convinced that lime is better for clay than sand. It may be justly answered, that the profits will not admit of the expense. We agree. But then it must be understood that it is the application, and not the nature of the lime, that should be called in question. Clay, well limed, will fall in water and ferment with acids. Its very nature is changed. Under such agreeable circumstances, the air, rain and dues, are freely admitted, and the soil is enabled to retain the nourishment that each of them brings. In consequence of a fermentation raised in the soil, the fixed air is set at liberty, which, in a wonderful manner, promotes vegetation. It is the nature of lime to attract oils and dissolve vegetable matters. Upon these principles we may account for the wonderful effects of lime in the improvement of black moor land. Moor earth consists of dissolved, and half dissolved, vegetable substances. It is full of oil. Lime assimilates the one and dissolves the other. Such lands, not originally worth one shilling per acre, may be made, by paring, burning, and liming, to produce plentiful crops of turnips, which may be followed with oats, barley, or grass seeds, according to the inclination of the owner. These observations, however, are rather foreign to the present argument, to which we shall now return. To the universal principle, oil, we must add another of great efficacy, though very little understood: we mean the nitrous acid of the air. That the air does contain the rudiments of nitre, is demonstrable from the manner of making salt petre in the different parts of the world. The air contains no such salt as perfect nitre: it is a factitious salt, and is made by the nitrous acid falling upon a proper matrix. The makers of nitre form that matrix of the rubbish of old houses, fat earth, and any fixed alkaline salt. The universal acid, as it is called, is attracted by these materials, and forms true nitre, which is rendered pure by means of crystallization, and in that form it is brought to us. In very hot countries the natural earth forms a matrix for nitre, which makes the operation very short. It is observed, that nitre is most plentifully formed in winter, when the wind is northerly; hence we may

understand the true reason why farmers and nurserymen lay up their lands in high ridges during the winter months. The good effects of that operation are wholly attributed to the mechanical action of the frost upon the ground. Light soils, as well as the tough ones, may be exposed in high ridges, but with some limitation, in order to imitate the mud walls in Germany, which are found, by experience, to collect considerable quantities of nitre during the winter. After saying so much in praise of nitre, it will be expected that we should produce some proofs of its efficacy, when used as manure. We must confess that experiments do not give us any such proofs. Perhaps too large a quantity has been used ; or rather, it could not be restored to the earth with its particles, so minutely divided, as when it remained united with the soil, by means of the chemistry of nature. We shall, therefore, consider this nitrous acid, or as philosophers call it, the acidum vagum, in the light of a vivifying principle, with whose operation we are not fully acquainted.

A curious observer will remark, that there subsists a strong analogy between plants and animals. Oil and water seem to make up the nourishment of both. Earth enters very little into the composition of either. It is known that animals take in a great many earthy particles at the mouth, but they are soon discharged by urine or stool. Vegetables take in the smallest portion imaginable of earth, and the reason is, because they have no way to discharge it. It is highly probable that the radical fibres of plants take up their nourishment from the earth, in the same manner that the lacteal vessels absorb the nutriment from the intestines : and as the oily and watery parts of our food are perfectly united into a milky liquor, by means of the spittle, pancreatic juice, and bile, before they enter the lacteals, we have all the reason imaginable to keep up the analogy, and suppose that the oleaginous and watery parts of the soil are also incorporated, previously to their being taken up by the absorbing vessels of the plant. To form a perfect judgment of this, we must reflect that every soil, in a state of nature, has in itself a quantity of absorbent earth, sufficient to incorporate its inherent oil and water; but when we load it with fat manures, it becomes essentially necessary to bestow upon it, at the same time, something to assimilate the parts. Lime, soap ashes, kelp, marl, and all the alkaline substances, perform that office. In order to render this operation visible to the senses, dissolve one drachm of Russia potash in four ounces of water; then add one spoonful of oil. Shake the mixture, and it will instantly become an uniform mass of a whitish colour, adapted to all the purposes of vegetation. This easy and familiar experiment is a just representation of what happens after the operation of burn-baking, and consequently may be considered as a confirmation of the hypothesis advanced.

Let us attend to the process. The sward being reduced to ashes, a fixed alkaline salt is produced. The moisture of the atmosphere soon

reduces that salt into a fluid state, which, mixing with the soil, brings about an union of the oily and watery parts, in the manner demonstrated by the experiment. When the under stratum consists of a rich vegetable mould, the effects of burn-baking will be lasting. But when the soil happens to be thin and poor, the first crop frequently suffers before it arrives at maturity. The farmer, therefore, who is at the expense of paring and burning a thin soil, should bestow upon it a portion of rotten dung, or shambles manure, before the ashes are spread, in order to supply the deficiency of oily particles. In consequence of this prudent management the crop will be supported during its growth, and the land will be preserved in health and vigour.

Hitherto we have considered plants as nourished by their roots; but they are also nourished by their leaves. An attention to this part of the vegetable system is essentially necessary. Vegetables, that have a succulent leaf, such as vetches, peas, beans, and buck wheat, draw a great part of their nourishment from the air, and on that account impoverish the soil less than wheat, oats, barley, or rye, the leaves of which are of a firmer texture. Rape and hemp are oil-bearing plants, and, consequently, impoverishers of the soil; but the former less so than the latter, owing to the greater succulency of its leaf. The leaves of all kind of grain are succulent for the time, during which period the plants take little from the earth; but as soon as the ear begins to be formed they lose their softness, and diminish in their attractive power. The radical fibres are then more vigorously employed in extracting the oily particles of the earth for the nourishment of the seed.

SPECIMENS OF THE VOCAL POETRY OF FRANCE.

THE song has always been popular among our lively neighbours. Tacitus says of the ancient Gauls: "Cantilenis infortunia sua solantur,"—they console themselves in misfortune by singing. Every one knows that the metrical romances of the Troubadours, called "Les Fabliaux," constituted the original poetry of France, nor has the polish of modern language rendered those old productions discordant to the ear of taste. Henry the Fourth was no mean composer, and sang the charms of the beautiful Gabrielle in verse worthy of her tenderness. The refinement of the court of Louis the Fourteenth carried this style of lyrical poetry to perfection. It degenerated under the regency, when the profligate Orleans outraged the modest decencies of life by the bacchanalian orgies of the Palais Royal, and his infamous minister, Cardinal Dubois, sanctioned impiety by his irreligious example. The characteristic of French songs is gallantry, though in our days Beranger has tuned his sweet and animating lyre to patriotism and liberty. His works are too familiar to require any