How

imation to our limit of price for importing. far it would be politic to increase the minimum of import duty, and thus to let our exchequer share the rise with the foreigner is I admit a subject worthy of consideration, as not enhancing the price to the consumer, but insomuch as it would help the payment of taxes, would benefit the country at large. The variation of duty and prices are the only safe limits for admission or exclusion of import, and there should be none except when needed, of which price will usually be the most certain index. I am afraid I am occupying too much space in your columns, but the subject must be my apology. I am, Sir, yours, Holderness, Dec. 10. R. IVESON.

GRAND PLOUGHING MATCH.

On Tuesday, the 5th December, one of the most animated and patriotic exhibitions ever witnessed took place near Murthly Castle. The late Sir John Archibald Stewart, of Grandtully, last year had intended, in order to stimulate the agricultural energies of the tenantry of his numerous estates, to present them with a splendid silver medal and other prizes, to be competed for at a ploughing match. Death has since deprived the country of the worthy Baronet who originated the patriotic scheme, but his brother and successor has nobly carried his predecessor's intentions into effect, and again has the skill and science of our ploughmen been called into exertion. The field selected for the display was the large haugh, nearly opposite Murthly Castle on the north bank of the Tay. Long ere day dawn, seventy pairs of horses had passed Dunkeld Bridge for the combat, and by eight o'clock nearly a hundred competitors had arrived, and a concourse most numerous of the inhabitants of the surrounding country had assembled to witness the contest, eager, if possible, to anticipate the award of the judges. The gentlemen appointed to this difficult office were Messrs. Inches, Marlee House; Constable, Hill of Errol; and Jack, West Mill of Kinnaird, The prizes were awarded as follows:1st, to Donald Stewart, Lagg of Grandtully. 2nd,-John Stewart, Meikle Tombaue, Strathbraan. 3rd,-Robert Dow, Dalbathie.

4th,-Donald Keir, Ballanleek, Strathbraan. 5th,-James Robertson, Pitleoch, do.

6th,-George M'Farlane, servant to Mr. Campbell, Mains of Grandtully.

7th,-Alex. Chapman, Airntully. 8th, Wm. M'Kenzie New Delvine. 9th,-John Tyrie, servant to Mr. Sime, Airntully. 10th,-Peter Duff, Lednaskae, Grandtully. 11th, James M'Laren, Airntully.

12th,-James Duff, servant to Mr. Robertson, Ballanloan, Strathbraan.

13th, David Malcolm, servant to Mr. Bruce, Airntully.

14th, -John Robertson, do.

do.

do.

AGRICULTURAL CHEMISTRY.

No. III.*

BY HENRY R. MADDEN, ESQ., L.R.C.S., EDINBURGH.

(From the Quarterly Journal of Agriculture.)

We

From the remarks we have made on vegetable nutrition, I am sure it must appear self-evident to all, that the action of the "permanent" constituents of soil, namely, silica, alumina, carbonate of lime, &c., must be purely mechanical; and that it is the organic matter only, which is added to the soil, that can have any physiological or chemical influence upon vegetation. It is clear, therefore, that the success of all farming operations will in a great measure depend upon requisite attention being paid to the supply of these " transient" ingredients, as they have very properly been denominated. Nevertheless, it is absolutely necessary that the proper texture of the soil shonld be continually preserved, which can only be done by having constant recourse to various mechanical operations, which have from time immemorial been used for this purpose. These may be advantageously divided into two classes. First, those which are employed to alter the natural texture or condition of the soil, as draining, paring, and burning, &c.; and, secondly, those by which the natural texture is restored, after it has been altered by the various processes which have been carried on in the soil, as ploughing harrowing, &c. shall now therefore, say a few words with regard to the theory of these operations. First, with regard to draining. That certain plants only can grow in soil which is constantly wet and boggy, is a fact that must be known to all those who have taken the trouble to look about them; and to such it must be equally evident, that the plants which do generally inhabit such situations, are far from being the most useful. To grow those vegetables, therefore, which are most prized by the agriculturist, the very first point to be examined into is the condition of the land with respect to water; without due attention to which, no soil, however well constituted in other respects, will be found capable of being cultivated by any means to the greatest advantage. When a farmer therefore intends to bring any new piece of ground into cultivation, he must first examine its natural herbage; and to one who has any knowledge of " country matters," this will be quite sufficient, since the general character and appearance of the sward of a wet soil is so distinct, that it is impossible to mistake it. For example, wherever the grass is coarse interspersed with rushes and carices, we may conIclude that the soil is wet, and that the water it contains is frequently stagnant; if however, these symptoms are not very evident, the farmer must proceed further,―let him see if the herbage is the same in all parts of the field, or whether it,s coarser in some places than in others; should this be the case, let him next determine the position of the coarser parts, whether they occur on the rising ground or in hollows. Should the latter be their prevailing position, more particularly should the grass of all the lower parts of the fields appear to be in a less thriving state than that on the more elevated portions, there will be good reason to believe that it is owing to some defect in the texture either of the soil or subsoil, by which the water

* In No. 2 of this series, p. 348, line 19, delete (common salt) after carbonate of soda.

that naturally falls on it is prevented from getting easily away. Again, should any spot show evidence of moisture, that should at once be examined, and its cause if possible ascertained, more particularly as to whether it depends upon the existence of a spring, since it frequently happens that soil, which of itself is of the very best texture, may be rendered bad, and nearly useless, by such an occurrence. When the fact is once ascertained, there is no want of remedies. Draining has, I am happy to say, attracted so much attention of late, that it is now brought to a very fair degree of perfection,-in fact, the difficulty is not how to drain, but how to persuade the farmers and landlords to have their fields drained; for strange as it may appear, still it is "not less strange than true," there are many farmers who are so devoted to their old ways, that although they cannot look around them without the practical advantages of draining presented to the eye, still they are content to grow rushes instead of grass, rather than be at the first expense of having their land rendered permanently fertile: by which means, instead of annually losing the rent of such land, they would be receiving a large profit upon the outlay which was necessary to effect the cure.

On account of so much having been already written in this Journal upon the principles and practice of draining, I shall not occupy my limited space with a recapitulation of the various methods of performing this valuable operation, but shall merely, in the briefest manner possible, give an outline of the scientific principles upon which it is founded.

The fundamental law upon which the success of all draining operations depends is simply this, that water, in common with all other fluids, cannot support itself in an inclined position, but will always endeavour to obtain a horizontal one, unless opposed by insurmountable obstacles; hence, so long as the surface upon which water rests is in the slightest degree inclined, it will continue to move onwards. All therefore, which is required to be done, in order that land should be thoroughly drained, is to ensure a permanent oblique channel for the water, the lower end of which must of course ultimately terminate in some proper receptacle, as a pond, river, or the like. In securing this channel there are various circumstances to be considered, the neglect of any of which will inevitably produce a failure :-These are

I. From whence does the water proceed, from above or below? Or, in other words, is the moisture owing to retained surface water, or emitted spring water? 2. The texture of the soil must be particularly attended to, If it be a stiff clay, and the cause of the damage surface water, the first thing to be done is, by constant tillage, to render the clay as loose as possible,-to raise the land in ridges, and to furrow-drain, as it is termed. If again the clay is of a lighter kind, as a good clay loam, for example, or still more, if the soil be sandy, the subsoil likewise possessing an open texture, the fault will almost invariably depend upon the existence of a spring; in this case, the highest parts of the land should always be drained first, as it sometimes happens that this effectually cures the evil without incurring the expense of draining the whole. There are other cases, however, in which, without an intimate knowledge of geology, it would be useless to attempt draining; for example, in those perplexing instances where the subsoil consists of irregular strata of clay and sand. Many other cases, too, might be mentioned

all of which prove that, to practise draining successfully, a man must make it his chief study, and depend upon it, it will always, in such cases, be found more economical in the end for farmers to employ a professional drainer, than for them to run the risk of a failure, by attempting it themselves. Before concluding this subject, I may just enumerate the cases in which draining may be required.

I. TO GET RID OF SURFACE WATER.-1. In all stiff horizontal clays.

2. In horizontal lands of all textures, if reposing on a subsoil of impervious clay.

3. In ferruginous soils of any texture, where there exists the moor-pan, as it is termed,-by which is meant a peculiar impervious stratum, composed chiefly of iron, which often exists betweeen the soil and subsoil in such situations. Here, however, the breaking of the pan might greatly assist the subsequent draining of the land. II. TO GET RID OF SPRINGS.-Wherever these exist, it is clear that the only way to prevent them injuring the land, is by giving their contents a free exit, in some direction where they can do no harm.

PARING AND BURNING.-This operation is recommended by several writers as the readiest way of bringing many kinds of waste land into a fit state for immediate cultivation; and yet there is no process upon which the opinion of different scientific men appears to be more at variance,— some strangly opposing it as an unwarrantable waste of manure, and others recommending it as strenuously on the score of economy! It is evident therefore, that one or other of these two sects must either be guided by erroneous principles, or neither of them have sufficiently investigated into all the particulars of the subject upon which they have written. The latter of these, I think, we shall be able to prove to be the cause of this, as of many other cases, in which directly opposite opinions are held by different men upon the same subject. We shall therefore, carefully discuss the point under the two following heads.

First, We shall state the different theories which have been propounded to explain the action of this process, and mention the various ways in which it may possibly act: and, secondly, See how, and in what cases it may be advantageously applied to practice. The various theories which have been promulgated with reference to this subject are chiefly the following, namely, 1st, That it acts by altering the texture of the soil; 2d, That its aetion depends upon the heat decomposing inert vegetable matter; 3d, That the cause of the improvement depends upon the formation of vegetable alkali (carbonate of potass) which acts as manure; and 4th, That the good effects are caused by the destruction of certain injurious substances which previously existed in the soil.

The first of these theories is the one proposed by Sir Humphrey Davy, and has certainly the merit of being founded upon strictly scientific principles; for example he states that it is injurious, except upon clayey soils, but that, in the latter case, the effect of the heat is to alter the constitution of these soils-in fact, to render them in texture much more similar to sands; to use his own words, "It may, when judiciously applied, convert a matter which was stiff, damp, and, in Consequence, cold, into one powdery, dry, and warm, and much more proper as a bed for vegetable life." Now that this statement concerning the alteration of texture is strictly true, needs no

other proof than a reference to the process of brick-making, which essentially depends upon the above fact. If for example, we powder a brick, we shall find that in this state, the clay possesses properties extremely similar to those of sand, namely, that when mixed with water its particles do not adhere together, and form a cohesive plastic mass. The chemical change which it has undergone is simply its being deprived of water, and as I stated in my first 66 paper, dry alumina cannot be made to unite with water, except through the medium of chemical solvents;" so that having once completely deprived it of that substance, there is extremely little chance of its ever resuming the form of a hydrate. Moreover, during the process of burning, the alumina enters into chemical union with the silica and iron of the soil, should any exist, and forms with them insoluble compounds, which are decomposed with great difficulty; and hence it may be extremely useful in lands where the iron is liable to become soluble, in which state as before mentioned, it acts as a powerful poison to almost all vegetables. An objection might here be raised, that although paring and burning altered the texture of the soil actually exposed to the fire, still this quantity would be too small, when spread and mixed with the remainder, to produce any material difference of texture; but upon calculation, it will be found, that even if the turf lost one half of its weight by burning-which could only take place when a large quantity of vegetable matter was present-as it is generally cut two or more inches thick, there would be added at least 142 per cent. of altered alumina (having the mechanical properties of silica) to the soil; six inches being taken as the average depth of tillage. Sir Humphrey Davey likewise takes notice of the second method by which paring and burning might be useful, namely, by decomposing inert vegetable matter. He says, "Although it destroys animal and vegetable matter, nevertheless this is more than compensated by the good it effects upon the texture, and in fact, the carbon of the ashes may be more useful than the original vegetable fibre." Here however, it is not so easy, fully to comprehend the author's meaning; for we have already seen that, in order for any substance to be absorbed by plants, it must either be soluble in water, or in an extremely minute state of division; whereas, carbon, when fully developed, or, in other words, when completely disorganised is capable of being dissolved by no known agent except fire; and as to a spontaneous formation of carbonic acid, by a union taking place between it and oxygen in the cold, if such is the case, it certainly is a new chemical fact; and lastly very little if any of the carbon left after the incineration of turf, will be in a sufficiently minute state of division to admit of its being absorbed in the solid form. The good effects, however, may depend upon the burning acting in the following way upon the inert vegetable fibre of the soil. Although a great part of the organic matter must be completely disorganised by the intensity of the heat, still a portion of it may not suffer decomposition to the same extent, and this, when acted upon by the carbonate of potass, produced during the process, may be easily converted into soluble organic food, which, of course, would act as manure; moreover, it is very well known that an accumulation of undecomposed vegetable fibre is injurious to plants; in fact, is one of the most frequent causes of" loss of heart" in old pasture land, so that its destruction might be beneficial.

Thirdly, The utility of the process being dependent upon the formation of carbonate of potass has already been shown. In calcareous soils there would moreover be formed, in addition, a certain quantity of "hot lime," which of course would act in the same manner as if applied after it had been burned in the kiln. The great objection which has been made to the process of paring and burning, will be best considered here, as it is this "waste of organic matter" that is so severely reprobated. Those who hold this opinion, state that the quantity of alkali which is formed, is by no means sufficient to compensate for the immense loss sustained by the large quantity of organic matter which is necessarily destroyed during the process; and in its place they propose paring the land, and forming the part removed into compost heaps, in order to be decomposed by means of lime. That this might possibly be applicable in a few cases there can be no doubt; but to adopt it as a general principle, would be extremely dangerous; for I fear that, practically, it would be the very reverse of economical; for when the price of the lime, the expense of making the heaps, and all the other minutiæ, are taken into consideration, it will be found that, in fact, such a procedure would be attended with far more expense than would be compensated by the quantity of manure gained. I have heard a remark by a very sagacious farmer, which I think will apply extremely well here, namely, that, "in the management of a farm there is a certain point, beyond which if a man goes he will find himself a loser instead of a gainer; for it will never answer to keep a market farm like a garden." So also there are many things, which when considered abstractedly, might appear economical, when put into practice would be found to be exactly the reverse.

The last method in which paring and burning has been supposed to act, is that promulgated by Professor Rennie: according to his hypothesis, the advantage derived from this process depends chiefly upon the heat decomposing certain pernicious matters contained in the soil. This statement was made on account of the importance that has been attached by many late writers to some experiments performed some years ago by M. Macaire, by which he endeavoured to prove that plants ejected from their roots substances which were injurious to them, or, in other words, that plants passed excrementitious matters into the soil. By this means they have accounted for the necessity of a rotation of crops, and many other circumstances, the causes of which had before been wrapped in obscurity. Now, whatever may be the merits of this theory-and we shall have an opportunity of discussing it fully when speaking of the rotation of crops-it, like all others, has been made use of, by some at least, to explain almost every operation in husbandry: for example, Professor Rennie would have us believe that the chief if not the only beneficial effects to be derived from the various operations of paring and burning, fallowing, irrigation, and the like, depended upon their freeing the soil from this excrement. These, with the exception of the first, will be considered afterwards; we shall, however, here make a few remarks upon how far the effects of paring and burning can be explained upon this hypothcsis. One of the chief arguments which he adduces in support of this statement, namely, that it is not the formation of ashes, and their action as manure, which is the cause of the improvement, but

that the whole amelioration depends upon the decomposition of the excrementitious matters-is, that when fires have been lighted upon grass, the sward is afterwards most luxuriant for a certain distance round the spot occupied by the burning mass, or, in other words, as far as the heat of the fire has been sufficient to decompose the excrement." Now a moment's consideration will, I think, be sufficient to show the fallacy of this argument. First, is it likely that the spot itself on which the fire stood should have a luxuriant herbage, when every root and seed contained in the soil must have been completely destroyed by the intense heat? And again, how is it possible that the heat could be sufficient to decompose the excrement (an organic compound) for some distance round the spot, and yet that the roots of the grass (organized bodies likewise) should not be in the least degree injured? Moreover, although this alone would be sufficient to show the instability of the argument-the fact related by no means proves that it is not the effect of the ashes of the plants burned; for, since the active part of these ashes is extremely soluble, the very first rain would carry it into the soil, and unless it were either extremely loose, or perfectly horizontal, a portion of it would most certainly spread for some distance round the spot, and hence the increased luxuriance. So much for all the theories which have deduced as explanatory of this process. We shall now shortly recapitulate the various methods in which it may possibly act.

1. In stiff clays, paring and burning may be of value, by depriving a certain portion of alumina of its chemically combined water, thus giving to it the mechanical properties of sand, and hence to a certain extent altering the texture of the 'soil.

2. In cases where iron exists in the soil, which is liable to become soluble, this process may act beneficially, by causing a chemical union to take place between this substance and the alumina and silica, and thus rendering it incapable of being again dissolved; and in this manner doing away with one cause of "loss of heart."

3. By destroying a large quantity of inert vegetable matter, the land may be greatly cleaned and improved; by which means another cause of "loss of heart" is overcome.

4. By the formation of alkaline ashes (carbonate of potass), and the subsequent action of these upon the remaining organic matters of the soil; thus converting them into soluble food.

5. In calcareous soils the chalk will be reduced to lime, thus increasing the quantity of alkali found in this particular instance, the subsequent effects of which will of course be the same as in the preceding case.

6. By destroying the seeds of useless plants, and at the same time most probably the larva of innumerable injurious insects.

7. The process of paring and burning being of course followed by ploughing, the land will thus be thoroughly stirred up, and fully prepared for the subsequent operations of husbandry.

Thus we have at least seven excellent reasons in favour of this operation, and only one against it, which we have already seen to be in a great measure futile. We shall proceed therefore to say a few words in reference to its practical application. These remarks will require to be indeed very brief, since it is clear that what has been already said concerning the methods in which the process may act, will at once suggest to the thinking farmer the cases in which it may be applicable. I shall

merely, therefore, take this opportunity of remarking how impossible it is to lay down practical rules upon any one operation in husbandry, which can be applicable to all cases; in fact, I am convinced that the chief cause of practical agriculturists not giving in to the suggestions of men of science, is, that the latter are so extremely apt to lay down general rules, without at first considering carefully all the various circumstances, local or individual, which may influence greatly the feasibility of the plan proposed. For example, with reference to the suggestion of making compost heaps after paring, instead of burning the mass, the following circumstances would have to be carefully considered,-1st, Whether there is a scarcity of manure, and consequently that great care must be taken to husband all that can be got at; 2nd, Whether lime can be obtained with facility, and at a trifling expense; 3rd, Whether on examination the soil is not already full of calcareous matter; 4th, Whether the trouble and expense of carting the lime, making the heaps, turning them, and allowing the land to lie useless until the compost is fully formed, will be compensated for by the value of manure gained. Without due attention to all these circumstances the farmer would very possibly find in the end that he was a loser instead of a gainer, and that, in endeavouring to carry his economy to the greatest possible extent, he had, in point of fact, greatly increased his expense. Thus we see that paring and burning is the easiest, quickest, and most economical way of bringing poor cold clays into a fit state for cropping, particularly if stocked with undecomposed vegetable matter, unless under the peculiar circumstances above mentioned; and that likewise it may be useful for sandy soils, should these be liable to "loss of heart," either from the existence of iron in a soluble state, or, as in the former case, from the accumulation of vegetable fibre, more particularly if the soil has already a sufficiency of lime; but should this not be the case, unless lime were expensive, it should be tried first, as in many cases it will be found the most economical. The above methods are those chiefly in use for altering the natural texture of soils, and, as has been shewn, are extremely useful for that purpose. In addition to these, however, there has been a great deal said of late concerning the judicious admixture of soils in order to improve their fertility, as, for example, adding clay to sand, and vice versa. Now, however plausible these suggestions may at first sight appear, it is very doubtful whether they will ever prove of any great practical value; for there are such a variety of collateral circumstances to be taken into consideration, that it is difficult to see how they could possibly be put in practice, without incurring a much greater outlay of capital than the increased fertility of the soil would ever recompense; for, when we consider the immense quantity of sand or clay, as the case might be, which would be necessary to effect the requisite alteration of texture,*-when we calculate the time and expense

* About 120 cubic yards of earth would be required to cover each English acre, one inch thick, which, as before stated, taking six inches as the average depth of tillage, would, when thoroughly mixed, only add 142 per cent. of sand or clay to the soil. This shews in a forcible light the practical advantages of paring and burning, over artificial admixture in all cases where the texture of the soil is too stiff.

of digging, carting, and spreading the soil,-the repeated tillings requisite to mix it properly,-and, morcover. when we consider that, unless the soil added were surface-soil (which could extremely seldom be the case), we are adding so much inert mineral matter, which will necessarily impoverish the original soil to a great degree, and hence require large quantities of manure to be added ;when, I repeat, we take these and many other circumstances into consideration, I conceive that, however plausible the idea of an artificial mixture of soils may be in theory, it will not, in the present state of husbandry at least, be found applicable to practice in any instance where economy is a consideration.

We shall now proceed to consider the various methods which are had recourse to by farmers, in order to restore the natural texture to soil, after that has been altered by the various processes which have been carried on in it.*

When earth has been for a long period exposed to the weather, however well pulverized it may have been at first, it will-unless it consist almost entirely of siliceous matter become consolidated to a greater or less extent, and thus be rendered unfit for many of the operations of husbandry. Moreover, if, in addition to mere exposure, the soil should have had an abundance of vegetation upon it, the root fibres of all these plants will of course remain in it, and thus tend in a still greater degree to bind it together. To obviate these difficulties, as well as to facilitate various other processes, farmers have, from time immemorial, had recourse to various mechanical operations for restoring the soil to its original state: these are ploughing, harrowing, and the like, by means of which the earth is fully broken up, the root-fibres which it contains completely separated, and the soil thus reduced to a comparatively fine powder. This preparation of soil, of course, differs in degree according to the foulness of the land; for example, much more preparation is requisite after a grain than a fallow crop, and for this obvious reason, that the latter is in most cases entirely removed from the soil, roots and all, whereas in the former case the root is almost invariably left behind: grain crops too, from not permitting of hoeing, &c., during their growth, tend greatly to promote the increase of weeds, on which account a longer and more careful cleaning is of course rendered necessary. In a slight sketch of the science of farming, like the present, it would of course be quite out of place to enter into any of the minutiae of practice connected with the mere mechanical operations of husbandry. A very few words will therefore suffice on the subject of ploughing and harrowing.

These operations, as before mentioned, are had continual recourse to by the farmer, in order to keep his land clean and open, and at the same time render it fit for the reception of seed; and the principles upon which they act are purely mechanical, the plough being merely a modification of the spade, so as to admit of the substitution of draught for manual labour; and the harrow again merely a horse

* Of course these remarks refer only to land which has already been subjected to cultivation, since it is evident that soil which has never been broken up for agricultural purposes must have remained for so great a length of time in grass, or some such state, that this may legitimately be termed its natural condition; and consequently pulverizing such soils may be considered as altering their texture.

rake. It will be, therefore, quite superfluous to occupy any space in explaining the principles of such well known operations.

Not so, however, with regard to the various kinds of fallowing, which are used by farmers as aids to ploughing, &c. in cleaning and preparing their land; for here a great many circumstances require attention, all of which must be examined scientifically. Fallowing, it is well known, implies subjecting soil to various ploughings, barrowings, grubbings, &c., and at the same time allowing it to remain for a certain period, either without sowing any crop upon it, as in perfect fallows; or arranging the seed sown in such a manner that they will suffer the land to be continually cleaned during the whole period of their growth, as in fullow crops. These two of course are mere modifications of each other.

The pure fallows will be best considered under two heads, Winter and Summer, because, although a complete fallow occupies both these seasons, still the changes effected in the soil are extremely different during the oarly and latter parts of the process. WINTER-FALLOW.-All land which is to be either thoroughly fallowed, or prepared for a fallow-crop, is well ploughed in Autumn, after the harvest is completed, and this should be as deep as possible, eight or nine inches at least, or even the trench plough may be used if it appear necessary. Great care should be taken in this operation that the land be laid in such a manner as to keep as dry as possible, more especially to prevent the surface-water from stagnating on any one spot; for which purpose the method of cleaving with open furrows, as it is called, is the most effectual, as by this means the ridges are divided in two, and hence the number of water-courses doubled; in other cases again, gathering up may be had recourse to for the same purpose. After this ploughing, the land is allowed to rest until the following spring, and during this interval various changes take place, which it will be necessary for us to consider carefully; these are the destruction of weeds, and probably insects, and the more complete pulverization of the soil. One of the chief advantages to be gained by fallowing is undoubtedly the destruction of weeds, and consequently, if the land be ploughed in the Autumn to a considerable depth, and the under surface exposed to all the severity of the winter, the tender fibres of the roots of these weeds are thereby destroyed, and the plants themselves of course die; so that, for perennial weeds, the winter-fallow is an effectual remedy; the annual ones, however, have, long ere this period, shed their seeds, and consequently a great many of these may escape injury. In addition, however, to the destruction of weeds, the Winter-fallow is supposed to clear the land of many insects, which during these months retire below the surface of the soil, to protect themselves from the severity of the season. This, however, is not found to be strictly correct, and I doubt if the winterfallow is ever very effectual in promoting the destruction of insects, and for this reason, very few of these animals penetrate to any considerable depth into the soil, the average being from three to four inches; if, then, the ploughing is carried to the depth of eight or nine inches, it follows that by this means the insects are even better protected from the inclemency of the weather than if the land had been left untouched; and the spring cross-ploughing,

*Of course this refers only to the greater number of the insects, for some of them will undoubtedly be exposed between the furrow-slices, and thus most probably be destroyed.