12 



Present State of the Science of 



It is less necessary to enter into detail on this source of future 

 improvement, as the subject is fully treated in another part of this 

 Number ; while, in the single experiment therein detailed, 

 ground is shown for supposing that the prolificness of one species 

 of grain, the most important, namely, wheat, differs extremely in 

 its several varieties. 



But it is not enough for the farmer to know the best manage- 

 ment of an individual crop, even of all crops singly, unless he 

 know also in what order of succession they should follow each 

 other. It is by improved knov.ledge of this order, and a better 

 selection, that much improvement has already been effected in Bri- 

 tish agriculture. It is well known that crops of the same kind 

 following each other become rapidly less productive ; Avhether by 

 exhausting the land of some fertile property, or by depositing, as 

 has been lately supposed, some excrementitious matter injurious 

 to the growth of their own species, though favourable, perhaps, to 

 the luxuriance of some other tribe. Be this as it may, no one 

 would novr think of growing, as formerly, wheat, barley, and oats 

 in succession; and though Mr. Hitchins, land-surveyor, of Brigh- 

 ton, states that, in his recollection, the tenants of a gentleman 

 living in Sussex, when a clause was introduced into their leases 

 prohibiting them from growing more than two white crops in suc- 

 cession, com-plained that they could not hope to defray their rents 

 if fettered by such restrictions, few good farmers at present, on 

 light soils at least, come even up to those limits, by raising even 

 two white crops, as they are called, in immediate succession. It 

 is on these light lands, indeed, that a due rotation of crops has so 

 signally succeeded, that, whereas they were formerly considered of 

 very inferior value, they are now more readily occupied than those 

 heavier soils, which, being in their nature more suited to the 

 growth of wheat, were once valued more highly. And it is as 

 much by the slow and almost insensible amelioration of such land, 

 as by any increased breadth of cultivation, that the country has be- 

 come in any degree capable of supporting the vast numbers which 

 have been added to her population. A small parish might be 

 pointed out, in which an aged farmer remembers the time when a 

 single rick was all that it could produce of wheat in one year ; 

 whereas, without any increase of its ploughed ground, that same 

 parish now yields five or six yearly. Its sandy soil was then drifted 

 like snow before the Mind, and the scanty barley might be some- 

 times seen borne away also ; whereas the very fields, still called 

 ' The Sands,' are now, by that glutinous quality which high condition 

 imparts — by the droppings and the tread of the sheep which are fed 

 on the turnips that now grow in garden-like order where before was 



* See Paper VI. p. 39. 



