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النشر الإلكتروني

THE

MONTHLY REVIEW,

For J A N U AR Y, 1758.

Continuation of the Account of the Compleat Body of Husbandry ;

wish Remarks. See Vol. XVII, page 406.

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ANY of our Readers may, posibly, think us somewhat tedious in the confideration of the Treatise before

us; but when the vast importance of the subject, and the high expectations which have been artfully raised, as to the merit of this compleat work, are duly considered, we flatter ourselves, any further apology will be deemed unnecessary.

We are now arrived at the sixth book of the Compleat Body of Husbandry, which treats of Tillage, in fix parts, viz.

ist, Of Plants, and their Nourishment. 2. Of the Advantages of Tillage. 3. Of the Implements of Husbandry, and their feveral Ures, 4. Of the different Manners of Sowing. 5. Of Drill and Harsehoeing Husbandry. 6. Of the Benefits of Drill and Horsehoeing Husbandry.

The firft part treats, ift, of Rests. Their forts(1); the exe tent to which they sometimes run; either perpendicularly (2),

(1) Which are two ; Spreading roots, and tap roots.

(2) They say, that the first roots of every seed are always of the perpendicular kind; and in soft deep foils will penetrate many yarda into the earth, if uninterrwted: which we really believe, it'they le not too short.

VOL. XVIII.

or horizontally; their tendency towards the surface of the ground (3); the advantage which the often stirring that surface produces, in increasing their quantity, and causing them to spread to a great extent (4): and that heat is a great article in

the process of roots of plants obtaining their nourishment.' For, by its constant variation, contracting and expanding, it

gives motion and presure between the roots and the small particles of earth continually,--and is, indeed, the true fource of the nourishment and growth of vegetables.':

2dly, Of Leaves. We are told that these are the organs of transpiration, and are so necessary to the greatest part of vegetables, that they cannot subsist without them; for if all the leaves of a flourihing tree are pulled off, it will commonly die. That, from the number of veficles filled with air contained in leaves, many have concluded them to be the lungs of plants ; and Mr. Papin's experiments, it is said, seem to favour this doctrine. Plants transpire only in the day :-during the night

they revive, and by their leaves; 'imbibe the dews and rains,' which contributes greatly to their growth.'

There are many more curious observations here, collected chiedy, it seemts, from Grew, Papin, Tull, and Du Hamel.

3dly, Our Authors treat of the Nourishment of Plants; and bestow five chapters in endeavouring to prove that all

plants are nourished by the same substance: that this sub

stance is no other than earth in very fine particles, carried • into their vessels by water :' that it there undergoes that

change which gives it the particular taste, colour, and form, ' which belong to the plant;' which is evident from the com• mon effects of grafting trees.'-An instance of Mr. Du Hamel's in the Memoirs of the French Academy proves this, it is said, in a very particular manner. A young citron, of • the bigness of a pea, was let in by the stalk to a branch of an orange tree,

The citron grew to its full bignels, and became * perfectly ripe, but was, to all intents and purposes a citron ;

having nothing of the orange at all in its nature, fors, taste, or • appearance. Further, that every plant will exhauft the earth ' of its [that] nourishment which would be fit for others of ' the same growth.' And that a piece of land which was once « fit for the nourishing and supporting of a crop of any plant,

(3) Caused by the effect, they say, of the rains, and dews, and influence of the sun's rays: wnich alio makes them grow to a greater ength. (4) This is illufrated by an experiment from Mr. Tull.

will continue to support and nourish crops of that plant for ever, if it be properly tilled and managed, &c.'

These opinions are acknowleged to be Mr. Tull's; and our Authors not only approve, but have farther fupported them by experiments and authorities, from Mr. Hales, from Du Hamel, and from common observations(5); and, to our apprehensions, with great truth and reason. This very curious subject, is here largely discussed, and well explained.

4thly, Of Changing Crops, and of the Distribution of the Nourishment of Plants in the Earth.

Here our Authors observe, that though there is a great advantage in fowing successively different species upon the fame land,'-—-yet'this is not owing to the commonly supposed

cause, that each exhausts the earth only of its peculiar nou• rishment, leaving the proper juices for the others. But the good effects of changing crops is, by them, attributed to three causes; it, the different quantity of nourishment different plants require; 2d, the different constitution and formation 'of' parts in plants, fome being much more delicate than • others ;' 3d, the different quantity of tillage which each kind -requires’ (6). Thus poor land will nourish rye, but not

wheat,

(3) One of our Author's observations is, that Wbeat, requiring a great deal of nourishment, succeeds beter after Oars than afier Bärley ; because Oats exhauft the ground less than Barley. Now here, if we appeal to experience, we believe our Authors will be found misaken, in supposing that Wheat succeeds better after Oats than after Barley, and ibat the former exhaust the ground less than the latter. For generally, in the compass of our knowlege, where Wheat is fown on Rubbles, they are almost always either bean or pea stubble, on heavy land; or Barley ftubble, on light dry land: but rarely, we had almost faid nerer, Oat ftubble on any fort of land. For it is the general opinion of Farmers, that no grain impoverishes ground like Oats : and it is a general rule with them, when about leaving a farm, to sow a great many Oats, to get, as they say, their pennyworths out of the ground.

And the nature of the Oat seems to confirm the truth of the Farm. ers opinion, for it is a hot, hardy plant, which is seen by its growing, and even delighting, in cold climates, as the Highlands of Scotland, &c. and wet foils, as the Fenns, &c. And it is the most fibrous rooted planc of any common grain that grows : by which it is properly qualified to gather the great quantity of food its hot conftitution, trong digestion, and situation in such cold climates, and wet foils, requires.

(6) These three causes seem to be needlessly wire drawn out of each other ; for, to our underslanding, they appear to be no more

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'wheat, nor, they say, oars(7). And ' oats will penetrate hard • land better than barley, and, therefore, -will grow with less

Hage,' &c.

Take a small specimen of our Authors manner of accounting for the infertility of soils. When the pores (of a Soil) are in too small number,' they say, there is, frequently, no communication between them; and the roots are thus • stopped in their par

age, and cannot get at the nourishment that is ready for them in other places, nor obtain enough for the support of the plant : this is the fault of too fliff soils. On the other hand, when the pores are too Jarge, the roots go through them almost without touching the earth, they, therefore, can take no

nourishment from it: this is the fault of too light foils. Thefe sarethe defects of the generality of foils, and these may be re• medied by culture properly conducted : for the earth contains ** so great a quantity of nourishment, that there is no need to * fear exhausting it; the only business is to put the roots in a * condition of getting at it.' Well, Gentlemen, and when you have remedied those defects by culture,' that is, when you have increased the pores of gif joils, and made those of light foils smaller; and thus put the roots into a condition of get

ting that great quantity of nourishment, you say, the earth

contains; you will ftill have only flow, inadive, earth; which will do but little towards vegetation, until a proper degrce of heat be introduced, even according to your own account, in Chap. HII. of this part, that heat is the true source • of the nourishment and growth of vegetables. Nor yet, will fire and earth of themselves suffice for vegetation; the other two elements, air and water, muft join their good offices, or nothing can be done, after all. In fine, to forward vegetation, in the higheft degree, it seems rcquifite, there should be a proper conjunction of all the four elements(8), in fuch due and proportional quantities, as the peculiar nature and constitution of the particular fpecies of plants require. And that land is the riches

than this, that different plants having different conftitutions, and tex. sure of parts, require different quantities of nourishment, and, of course, different degrees of tillage.

(7) We cannot agree with them in this, because we know that the worlt land, if it will bear any thing, will bear Oats: which, by their conflicucion, and by the liriciure and make of their roots, as ob. ferved before, are better fitted to live on the poores foils, than any o her common grain.

(8) We have, here, nothing to say to the artificial elements of the Chemists, and Cartefisns: we want only thofe plain fimple ones of Nature, Fire, Water, Earıb, and Air, to explain the principles and phænomena of vegetation.

which has the greatest share of all these four elements, in such due proportion to each other as the nature of the particular ipecies of plants to be nourished, requires.

Therefore, land may be poor, i. e, afford but little nourishment to plants, in two respects. ift, It may have a large share of all the four elements conjunctis, but in such an undue pro, portion to each other, as is mof unsuitable to the particular ipecies of plants to be nourished. So clays have a large thare of earth and water ; but too little heat and air: and gravels and fands, have a large Mare of heat and air; but too little water and earth. 2dly, Land may have too small a fare of all the elements conjun&tly. As chalk has too little of fine earth; for it is conposed of a coarse dry earth that will not enter the vesícis of plants ; for plants will not grow on it: too little of air ; tuo little of fire, for it has no heat in it: too little of water, for it lets that through like a sieve. Such, we apprehend, with due fubmiffion, is the nature of chalk (9).

Now a due proportion of manure(10) actually supplies plants with these elements, and conveys them to their roots. For the fermentation of the manure cauies a heat, or gentle fire (the first element) in the earth, which divides and pulverizes it(ul), in the same manner with cillage, tho' in a much greater degree; and thus produces fine earth, another element) which our Authors call, and which is, indeed, the primary part of the food of plants. Again, this heat and fermentation occasions a rarefaction of the air contained in the earth, and in the roots of the plants; this causes the internal air to expire, and the external to inspire, and thus produces a circulation which supplies the plant with a continued succession of fresh air, (a third element). Lastly, The falcs contained in manure, that are lodged at or near the surface of the ground, attract the dews, by cooling the ambient air, which condenses and precipitates the vapours floting in it; and thus, perhaps, in no small measure, supplies the

(9) These are, we believe, all the entire pure soils we have ; and, we humbly conceive, that most of our orher foils, are only a compound of some, or all of these. But our confined limi's will not allow us to persue this theory any further at present.

(9) This due proportion is well known to the experienced Hyfbandman.

(11) It is probable, that the fermentation, by its agitation and intersice motion, breaks and divides the earth into a great oumber of small congeries of pares; and that the heat, by rarefying the air contained in each, again subdivides every part ; fo that their joint effc& in pulverizing the ground, is, no doubt, much greater than inat of village san be.

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