INTRODUCTION, 1X

tivators of land in one part of the country are frequently incapable of profiting to any extent by the accounts that are given of what has been done by the exertions of thofe

inanother. This is fufficiently fhown in what has been done in refpect to the nature—

of foils; agriculturifts in general having given fuch defcriptions and definitions of them as coincided with the notions that they bad formed concerning their nature in their own particular diftrits or fituations, rather than fuch as marked their particular properties and compofitions*. Knowledge of this kind, however juft or accurate it may be in regard to the foil of the places from which fuch defcriptions are drawn, mutt, he contends, be very imperfect in refpect to others, and of courfe be incapable of any general application or utility. For it muft be obvious to every one who is in the leaft degree converfant with the bufinefs of cultivation, that foils do not only differ very materially in the nature of their principal ingre- dients, but alfo in the proportions or quantities in which thefe enter into fuch compofitions as are denominated foils. Thus the mere aflertion of a foil being clayey, loamy, gravelly,&c., conveys little information, as it does not make us in the leaft acquainted with either the properties or proportions of the fubftances from which they are thus denominated. Befides, it is known to every farmer that there is the greateft difference in the nature of clays and other fubftances. which conftitute the bafis of foils as they exift in the ftate of earth or mould; the clayey foil of one tra¢t of country being extremely fertile and productive, while that of another poffefles the higheft degree of fierility and barrennefs. There are likewife very confiderable differences in the loamy and gravelly foils of different districts, which are by no means diftinguifhed by fuch unqualified termst. For this reafon it probably is that experience in farming has had a lefs general effect in improving the fcience of agriculture than may have been fuppofed; and it is perhaps from the fame caufe that the principal improvements in the profeffion have been confined to particular fituations and diftriGs, from which they have extended themfelves by very flow and gradual means.:

The difficulty of determining the connexion of effects and their caufes, and the length of time that is requifite to fully afcertain any particular fact or circumftance in farming are alfo caufes that have confiderably impeded the fcientific progrefs of agriculture. After much labour, time and expenfe have been employed in order to elucidate and afcertain particular facts of this kind, it not unfrequently

* Anderfon’s Recreations in Agriculture,&c. Vol, I. 4+ Ibid a