The practice of burning the surface, and applying the. ashes as nranure, to the soil that remains, has in e it long prevalent in Bi itain ; and though it has been cowl, nined, nay reprobated by many chemical writers, anu prohib ited in numerous instances by proprietors, yet, by pro fessional people, who judged of the utility the prac tice, from the nature and consequences of its it has, almost in every case, been supported, and considered as the most advantageous way of bringing in and im proving all soils, where the surface Lamed a coarse sward, and was composed of peat-earth, or °the r inactive substances. The burning of this surface has been view ed as the best way of bringing such soils into action ; the ashes, furnished by the burning, serving as a stimulant to raise up their dormant powers, thereby rendering them fertile and productive in a superior degree, than could othertt isc be accomplished.
These have been the sentiments of husbandman for many generations, and are not to be overturned by the force of abstract reasoning, however plausibly and for eddy urged. Were a field to he burned, and the ashes thus produced to be removed to another, the objections of chemists would be well founded ; but so long as these ashes are spread upon the surface, and an effect pro duced upon the remainder of the soil and subsoil, equal, if not superior, to that which is occasioned by calcareous manure, no evil can be dreaded. Tile soil, in place of being thinned by the burning, is, in fact, thickened ; be cause a portion of the subsoil is impregnated and brought into action, whereby the staple is deepened, and its pro ductive powers inc reared. It must be remarked, how ever, that, as the effects of burnt ashes, though instan taneous, arc hot of long duration, a dressing of dung, in the third year, becomes highly necessary, after which, land so treated should be restored to grass. The great object to be attended to, when stimulants are employed, is to use gentle and lenient cropping' afterwards ; other wise, what with justice might have been considered as a meritorious improvement, may turn out to deserve a Con trary character.
What we have said relates to what is generally called paring and burning- ; that is, paring the surftee to the deepness of one, two, or dire e inches, gathering it into heaps, and burning it. We shall now speak of ashes burnt and used in a different manner ; that is, when per t earth is Jigged and burnt in quantities, and afterwards applied to a field of a different sort of soil or quality.
The edicts of ashes, used in this way, are precisely the w ith those of , though their operation is wore• violent, and therefore sooner over. The first crop is commonly very luxuriant • but, unless dung is after wards administered, the soil w ill be rather exhausted than enriched by die applicatinn of the ashes.
In the agricultural memorandums of Robert Ainsiie, land-steward to ttn lcbrated John earl of Stair, on his estate of Cuihnial, in some account of the operation of • i es, and the method of making them from peat-eattn. described.
According t n Ainslie, it appears, that Lord Stair, in 17'23, sent s . al Lards if earthy ashes from Lon don, of a hind a Itch used by homers in the south of Engla ls Inp dretsi: n•• their grass and tillage lands. These ashes, agreeaoly to his lordships direc t iere,, were ;in \VD 1111011 two different pieces of ground ; viz. on a piece intended for hay, and On a piece sown with barley, while a proportion of them was reserved till their yetlities were analysed and ascertained. Both the grass and barley were greatly improved by the dres sing ol ashes bestowed ; and upon analysing the part reserved, it was found, that with a great proportion of earthy substance, the ashes contained many particles of lime or shelly matter. Hence, .Nlr Ainslie concluded, that these ashes were either made by carefully burning moss that was strongly incorporated with snell marl, or that lime had been mixed with them ; by means of which, and the salts, na.ural to all ashes, it was sup posed that their great fertilizing quality was produced.
Mr Ainslie recehed certain directions for burning moss, along with the ashes, which are of considerable importance. Ile was directed to begin the fire with dry faggots, furze, or straw, then to put on dried moss finely minced and well beaten with a clapper ; and when that was nearly burnt down, to put on moss less dry, but well minced and clapped, making holes with a prong to carry on the fire, and so adding more moss, till a hill ()lashes, something of the size of a wagon load, was accumulated, which, when cold, he was directed to carry to the bins, or store heaps, before the ashes gut wet. Agreeably to t hcsc directions, a good deal of moss was burnt by Mr Ainslie at a very small expense, the people employed soon becoming very expert in the several operations of cutting and burning the moss, and of managing, in the most advantageous manner, the kilns in which it was prepared.