growth of green crops, hay and oil-cake should be resorted to for that purpose.

In other cases, lime, chalk, marl, and various other mineral substances, have been resorted to as auxiliaries; but the effect of some of these tending more to stimulate vegetation than to enrich the wasted powers of the soil, it has frequently happened that ground which at one time had been greatly benefited by their application, has afterwards been injured when repeated under the erroneous notion that its powers might be restored by the same operation. Land, thus forced, has in many cases been so much impoverished as to render it incapable of producing any thing but a poor pasture, and to require a great length of time to pass away before it can be restored to its original condition. It should, indeed, be observed, that the application of fossil manures requires more judgment and consideration than any other; for vegetable and animal manures contain the fertilizing property within themselves, and, however injudiciously applied, cannot fail to impart ultimate benefit to the land, if not to the immediate crop; but the power of fossils consists in their action upon the constitution of the soil, and if this be improperly directed, the greatest mischief may ensue.

None of these has, perhaps, produced more injury in some cases, or greater benefit in others, than lime-of which very striking instances may be found in those parts of the country where it is either very abundant or scarce. In the former it has been not uncommonly laid upon the land without the aid of putrescent manure, until the soil has become worthless; while in the latter, as its scarcity renders it expensive, it has only been moderately used by farmers of judgment and capital, and the effects, after a number of years, are still apparent in the improvement of the soil. While writing this, we have under our eye a farm of 400 acres of strong clay, which has not been limed within the memory of man. The tenant, who is conscious of the advantages which might be derived from the use of limeas demonstrated in the condition of adjoining land of the same quality—is yet prevented by circumstances from its employment; and thus, not only are his own profits, but the value of the soil to the landlord also, equally reduced.

On the subject of burnt clay, we have recently had an opportunity of making some inquiries in the neighbourhood of the late General Beatson's farm, in Sussex; and we have learned, that although several practical farmers in that part of the country adopted his plan, yet very few of them have found it to answer their expectations. One of them, who has followed it extensively, confirms us in the opinion which we have already stated, that much depends upon the mode in which the operation of burning is performed; for if the clay be calcined to the consistence of brick, it yields nothing in the shape of that soft ash which is proper for manure; and if not sufficiently burned, it will return to its original condition. In the former state it may, however, act in some degree as an alterative of the soil; and in the latter, it will at least afford some nutriment to the crop to which it is actually applied. It therefore does not appear, from past experience, that it can ever be made to supersede the use of lime on land which has not been formerly dressed with the latter; but in such cases, or in parts of the country where lime cannot be procured, it may yet be employed to a certain extent with advantage.

As to paring and burning, there can be no doubt that the earth, if combined with fibrous roots and other vegetable matter, will answer the purpose of manure when burned; yet shallow soils are thus frequently more injured by the abstraction of too large a portion of the surface, than improved by

the temporary addition of the manure. We have lately seen down-land, which was broken up during the war, and has been now during several years returned to pasture, yet still bears nothing like the sward of a fine sheep-walk on the poorest chalks, and probably will require half a century to bring it back to its former condition. We therefore cannot but again caution all farmers and owners of land against bringing such soils under the plough*.

With regard to gypsum and salt we have nothing to add, except to repeat our recommendation of experiments on their effectst. Though quite aware of the common sentiment that gentlemen may use their superfluous cash for this purpose, but farmers have uses enough for their money in the regular routine of their business, and few are so overburdened with capital as to afford the risk of its diminution by uncertain speculation'-yet we entreat them to reflect, that experiments may be tried with those two articles upon a single acre; that the expense, if unsuccessful, can only occasion the loss of a few shillings; but if they succeed, may be productive of incalculable advantage.

Neither respecting the various miscellaneous substances which we have enumerated have we any further observation to make upon their respective properties. The fluid or dissolved parts of animal matter require some preparatory process to fit them for manure, the great object being to blend them with the soil in a proper state of minute division; for when they have been applied in a rank or unreduced state, bad effects have followed. Trainoil, blubber, and similar refuse, should therefore be made into composts with a large body of earth. Rape and malt dust, requiring no mixture, are very commonly laid upon the land as top-dressings-the difference between which and manure ploughed into the ground, is, that the former are applied chiefly with a view to the sole benefit of the immediate crop, without regard to the further improvement of the soil; though there can be no doubt that if the crop be increased, the soil will also feel their good effects. In this manner soot is also almost invariably used; but its fertilizing properties are solely referable to the ammonia contained in it, which is an active stimulant of vegetation. The practice of laying it upon land which has been limed, or of mixing it, as sometimes done, in composts with lime, is therefore injudicious §.

It has long been a disputed question, whether all plants extract the same nutritive juices from the soil, and convert them into the kind of sap adapted to their peculiar qualities, or whether each is nourished by a different substance. It would at first appear improbable that plants differing from each other in form, smell, taste, and properties as food, should be produced by the same matter; yet, when we reflect that different plants deprive each other of nourishment, by extending their roots into the same soil in which various kinds are planted, we cannot but conclude that their first nutriment must be of the same nature, though the sap

* A treatise has been just published by Professor Rennie, on Paring and Burning, in which he attributes whatever value it may have to the effects of the fire, considering it in the light of an instantaneous fallow.' Were this principle to be relied upon, it would follow that paring and burning might, within a few years afterwards, be advantageously repeated; whereas experience proves that, with whatever benefit the operation may be attended in the first instance, a repetition of it is always found to impoverish the soil.-See the Quart. Journ. of Agric., No. XXV.

† See Chapters xiv. and xviii.

Tallow and oils received in a crude state by the roots may clog the pores of the plant, repel the aqueous fluid, and obstruct the free communication of the leaves with the atmosphere.'-Sir H. Davy's Lect. on Agric. Chem., 4to. p. 112.

§ Hornby on Limè, p. 26.

probably acquires different properties in its progress towards perfection. This, however, is one of the secrets of vegetation with which we are unacquainted; but as we also see that some soils are better adapted than others for the growth of particular kinds of grain and vegetables, and that those crops to which they appear the most favourable yet become deteriorated if repeated, even though regularly dressed with one species of manure, it seems evident that there must be some advantage in the change of manures, as well as in the system of cropping tillage land. This will be gained by every farmer who has at his command manures of an unusual kind, and who understands their use, for he may then adopt many plans of cropping which are out of the power of others not similarly situated, and vary his rotations according to circumstances of the moment, or to his own convenience.

We have already touched upon the properties of alkaline manures, so far as they have been tested by experience: the solution of the effects of acids upon the soil must be still left to future experiments, for those already made by chemists, in many instances, present different results. Whatever may be the food of plants-whether gases, oils, salts, or acids-the farmer, however, need not puzzle himself about their chemical qualities, for he may either satisfy himself from the experience of others, or by small trials of his own, whether the effects of any particular species produce fertility or not. Farm-yard manure has been justly called the farmer's magic wand;' and the oftener that wand is waved, the more will it contribute to his prosperity. He sees that wherever it has been judiciously used, it causes abundant crops, and that wherever it has been withheld, sterility seizes upon the soil: his chief efforts should therefore be directed to its increase.

Although the time and manner of applying every description of manures depend so much upon the nature of the soil and season, as well as of the crops to be sown, that no precise rules can be laid down for their employment, yet the following general hints may be found useful.

SUMMARY.

When manures of any kind are to be used as top-dressings for grass, the best season for that purpose is as early as practicable in the month of February, as the vernal showers will then wash them into the soil. If for arable land, at the same time as the sowing of the seed, or immediately after; but if for wheat, when vegetation is about to acquire force in the spring.

If dung be applied to a wheat crop, it should be ploughed in during the course of a summer fallow; if compost, at the last ploughing before the seed furrow; but composts of lime and earth only may be laid upon the land during any period of the year.

The land should be laid dry; and the manure should be equally and speedily spread over every part of it, in proportion to the nature of the soil; but if ploughed in, though it should be well mixed with the ground, it should not be too deeply buried.

The stronger and the colder soils are, the more manure they require ; and, as such land is generally applied to the production of crops which do not speedily attain their full growth, the application of dung which has not been completely decomposed by the putrefactive process may be there admitted; for although the progress of vegetation may not be so rapidly

* Sir H. Davy, Agric. Chem. 4to. p. 273. Doncaster Report on Bone Manure, p. 27. See also the recent Theory of the Rotation of Crops, by M. De Candolle.

forwarded, yet the manure will at length decay, and afford a more gradual degree of nutriment to the present, and greater support to the land for the production of future crops. On adhesive land, long manure from the farm-yard also acting mechanically, by keeping the soil open, is not so binding as short dung; but on dry, sandy, hot soils, the dung should, on the contrary, be perfectly decomposed, or rotten; and manure of any description should, on such land, be only laid on in moderate quantities at one time. One general observation may be made regarding all dissertations on manure, which is that as there will be different gradations both of soils and the substance of which manures are composed, we can never speak but in general terms of their application.

The following table will explain how many heaps of manure—each containing an equal quantity of any given amount-are required to dress any field, per acre, at certain regular distances: so that, by calculating the solid contents of the manure in cubical yards, each containing 27 bushels, and dividing it by the number of heaps, the exact quantity to be laid on in each heap may be correctly ascertained:

IMPERFECT as was the knowledge of husbandry in former times, yet our forefathers were enabled to distinguish the qualities of the soil with great accuracy; for those parts which were the most anciently cultivated, and which formed the infield land around their villages, are found at the present day to consist of the best ground when in its natural state, though much of that which has been since broken up has been greatly improved by the application of manures, and the progress of successful cultivation.

The difference in quality of the fruits of the earth-more particularly remarkable in grain-though distinguished in many places by the names of the districts in which the corn is grown, yet does not arise from any other cause than dissimilitude of soil and climate; and the utmost exertions of cultivation can only to a certain degree improve, but never effect, any absolute change in the indigenous nature of its productions. This, indeed, is generally admitted, so far as regards soils; but although they may be apparently of the same kind, yet their fertility is materially affected by climate, notwithstanding they may be situated in nearly the same part of the country, and with little variation of level; for although the heat indicated by the thermometer may correspond, yet the temperature of the air is varied according to the aspect of the land-whether exposed to the north or south, and the prevailing winds occasioned by the position of adjacent highlands and vales-and the seasons are thus rendered earlier or later. The natural situation of a farm-independently of its local connexion with roads and markets-is therefore an object of the first importance, and affects its value much more than is commonly supposed; for the estima

tion of all the vegetable products of this country depend, with very few exceptions, upon the degree of heat which they enjoy during their growth; and it is well known that when the soil is dry, and the harvest early, corn of the same weight yields more saccharine matter than that which is produced under less favourable circumstances*.

No two farms can indeed be found precisely situated, in point of soil, situation, climate, and exposure, and a very small difference in any of these circumstances will occasion a great diversity in their fertility; consequently no rules can be strictly applied to their management. It has, however, been justly observed, that farms thus variously soiled are spurs to ingenuity-obliging their occupiers to break through those confined opinions and narrow prejudices which are too frequently contracted in countries where a uniformity of soil and regular routine of management prevailt.'

From the vague manner in which soils are frequently described, and the various acceptation of the same terms in different counties, it is difficult for a farmer who reads an account of the agriculture in any other district than that in which he resides, to judge what relation such a soil may bear to that which he himself occupies. In some parts of England, any loose clay is called marl, and in others it is called loam; while this is defined by one to be a fat earth; and by another, a mixture of clay, sand, and calcareous earth, without stating the proportions. Regarding the latter, it has indeed been remarked by the late Mr. G. Sinclair, that, on referring to books on husbandry and gardening, we are directed to a hazel loam, a brown loam, clayey loam, or to a humid sandy soil, peat earth, garden mould, &c.; but the want of proper definitions of those terms is so perplexing, that it is really impracticable to determine what kind of soil is meant thus, of upwards of fifty different kinds of soil and composts examined by him in various parts of the kingdom, those under the same name were found to differ greatly in their respective qualities. The method of determining the nature of soils by chemical analysis has, however, been of late years so much simplified by Sir Humphry Davy, that it is now in the power of every practical person to ascertain their properties, without much risk of being mistaken‡.

This has been clearly established by the application of the saccharometer-an instrument invented for the use of maltsters, brewers, and distillers, for the purpose of ascertaining the strength and value of worts. The common standard by which the value of grain, of apparently equal quality, is usually estimated, is that of the weight in proportion to its cubical measure; and when the corn is to be manufactured into meal, this must ever be a primary object, though subject to many deductions, which also enter into the consideration of the miller. But among those who require it for the purpose of brewing, the saccharometer is a more certain criterion-as, whatever the weight of the grain may be, its strength, or nutritive power, will be in proportion to the quantity of saccharine matter which it contains.

Marshall's Rural Econ. of Yorkshire, 2nd edit., vol. i. p. 281,

All soils contain sands of various degrees of fineness, and impalpable earthy matter; when, therefore, the exact proportions in which these are combined in a soil are ascer tained, it shows directly to what class it belongs-whether the loamy, clayey, calcareous, sandy, peaty, &c. Sir H. Davy, however, states, in his Agricultural Chemistry, 'that the term sandy should never be applied to any soil that does not contain at least seven-eighths of sand. Sandy soils that effervesce with acids should be distinguished by the name of calcareous sandy soil, to note the difference which exists between them and those that are silicious. The term clayey should not be applied to any land that contains less than one-sixth of impalpable earthy matter, not considerably effervescing with acids. The term loam should be limited to soils containing at least one-third of impalpable earthy matter; and a soil to be considered as peaty ought to contain at least one-half of vegetable matter. These may be considered as the genuine characters of soils, and determined by a very simple process-that of washing the impalpable earthy matter of