It I, tad more than fifty years SiltIC rattlyc •s tUnte to be grit, 11;<:(1 in Scollthd, before that time grain being se p t;to•cl h olt the chaff by the action of wind operating ut_IN,cull the two doors nil a barn. In the windward door, a person stood dropping the grain from a siet c, or riddle, and in quantities proportioned to the force of the wind at the time ; a process not imperfect, when a good steady wind bIowed, but cot to be depend ed upon in ninny instances, when tl:e grain was wanted for seed, horse-co•n, or the purpose of marketing. In short, the inconveniences of that process of winnowing :Luc so evident, that they do not require to he enumera ted. They were, however, completely removed, iu Colth:tillenCe of OW introduction ut Linnet's, by which the husbandman might clean his corn when he pleased. Since thrashing machines were introduced, fanners al most in every case arc annexed to them, and in some instances, where powerful machines are used, fitted in ternally ith suitable riddles, it i.. perfectly practicable to measure and market the grain immediately as it comes from the machine.
On MAsuuk,s.
The practical farmer, without troubling himself con cerning the principles of vegetation, or inquiring about the food of plants, is perfectly satisfied, that by col lecting and applying what are called manures to the laud which he occupies, the fertility of the same is augmented, and greater crops, either of corn or grass, returned to him in the subsequent years, or so long as the strength of the manure is not exhausted; but he is equally satisfied, when the strength of the manure is exhausted, that a repetition becomes necessary, other wise the ground would become sterile and unproduc tive. It is our intention to treat of manures in this plain and expressive way, and chiefly to limit our in quiries to what may be of practical advantage. Manure is of the first importance to the farmer; and according to the quantity which he collects, and the judgment which guides the appropriation, his success will as suredly be regulated.
The term manure Is applied indiscriminately to all substances, which are known from experience either to enrich the different soils, or contribute in any other way to render them more favourable to vegetation.
Though little doubt can be entertained of the utility and necessity of such substances, yet the progress hi therto made, in ascertaining the mode in which they ought to be applied, the quantity that should be made use of, and the soils for which they are respectively best adapted, has not yet reached that perfection or certainty that could be wished.
The most superficial observation will serve to convince any intelligent person, that, in an agricultural point of view, the subject of manures is of the first magnitude. To correct what is hurtful to vegetation in the different Soils, and to restore what is lost by exhausting crops, are operations in agriculture which may be compared to the curing of diseases in the animal body, or supplying the waste occasioned by labour, or the ordinary evacua tions of nature.
The utility of manuring has, however, been question ed in some instances, particularly by Tull and hi3 disci ples, who assert that tillage alone, frequently and judi ciously applied, will produce every effect that can be expected from that practice.
That tillage is essential to the success of agricultural operations, is a point in which all good husbandnien are agreed; but that by tillage alone, the earth should be made to produce a succession of valuable crops of grain or vegetables, is a doctrine, which, fortunately fur the advancement of agriculture, has met with very few con verts. By such management poor lands would never become productive, and the richest soils would soon be exhausted.
Another opinion has been held forth to the public, that when land has once been put into good heart, it may be preserved in a state of constant fertility, merely by a proper rotation of crops, without any foreign ma nure.
In some particular spots, where the soil is uncom monly rich, and has been long undisturbed by the plough, and when great quantities of animal and vegetable mat ter have been accumulating for ages; this may, for a considerable space of time, be the case. But if the advocates for such a system assert, that any land, when once put into good order, will continue to pour forth an endless succession of valuable crops, by means of ju dicious rotations alone, without any manure being made use of, we pronounce the idea, with but very few ex ceptions, impossible. Indeed it might as well be sup posed, that any animal, after having made a full meal, would conthme to live, and perform every kind of la bour, without any farther supply of food. The con trary certainly is tile ease. both with regard to animals and vegetables; for if the nourishment supplied is less than the waste, the animal will di.•, and the soil become barren.
We need not extend our oLservations upon this sub ject farther ; for a gooe I trnier, who wishes to avail him self of every advaot.ge which experience points out, will, to a certain clegree, adopt, 1st, The tillage recom nzended by Tull, for the purpose 01 pulverizing the soil, and extirpating the weeds with which it may be infest ed; 2d, rgtilar ro ation of crops, in order that the va rious sorts of earth may, in their turn, according as they are calculated for different plants, become productive ; and, Sd, l ndeavour to gather a sufficient quantity we manure, not only to prevent the soil nom being exhaust ed, but, if possible, annually to make sonic addition to its former sources of fertility.