COLMAN'S CONTINENTAL AGRICULTURE.

Wellington Independent, Volume VI, Issue 560, 22 February 1851, Page 4

COLMAN'S CONTINENTAL AGRICULTURE.

Crops. —In wine countries, it is known that in different localities, the same species of grape produces a wine of an altogether different quality and value from what it does in others. The kind of grape, the mode of culture, the degree of ripeness, the mode of making wine, the age of the wine, and doubtless in many cases, various artificial processes, affect to a degree the quality of the wive produced; but, beyond all this, there is something in the looality which is believed to determine its charaoter. The celebrated wine, known us Constantia, is the pro-

duct of a very limited territory at the Cape of Good Hope. In passing up the Rhine, there was pointed out to me the estate of Prince Metternich, where the celebrated Johannisberg wine is produced; and it is produced no where else; and from this circumstance its production is a source of immence profit. These facts seem to demonstrate the truth of the reply made always to my enquiries in relation to the subject, that there is something as yet unascertained, some peculiarity in the climate, aspect, or the soil, from whicli the product derived its characteristic properties. The same or similar circumstances may operate upon the quality of wheat; and it is obvious, as far as 'they are strictly local, dependent upon the climate and aspect, or upon any peculiarities of the soil which do not exist any where else, or upon any causes as yet ascertained they are beyond our reach. The farmers in France are behind no others in what may be called, technically, agricultural science ; aud some of those eminent men, who are sometimes called farmers of the closet, have gone into tho most exact and minute mathematical calculations as to the actual amount of certain mineral elements, which are supposed essential to the groivth of the crop, or of any particular crop : and next, as to the amount of these mineral substances, which any particular crop carries off in the straw and in the grain. They then proceed to determine the exact amount of these substances, which must be restored to the soil iv order to keep up its fertility. The first point is determined by analysing with great chemical exactness a portion of the soil; the second, by analysing a portion of the crop, of the straw, and the grain; and these premises being obtained, the third is of course matter of plain inference. These calculations are curious and ingenious, and if vegitation or the growth of plants were as simple an aflair, as well and as easily understood as many pretend that it is, these facts would have a most direct and immediate practical bearing. One of the most eminent of these calculators, however, himself admits that the application of these facts, or rather the rules deduced from them, is an operation difficult, dclii cate, and which only the most skilful persons can undertake. ! In the present very imperfect state of I our knowledge of vegitation, I am free to express my conviction, that they will answer no other purpose than that of mere curiosity and amusement. In the analysis of a soil, for example, if we suppose that a cubic foot is taken, this may be a very inadequate representative of other parts of the field. If the soil is taken from the surface, or that part of the soil which is cultivated, yet there is the soil under this, into whicli the roots of tho plants may extend themselves, and which may contain elements of which we are not apprised. In the chemical analysis of a soil, it is known likewise, that much of the active portion, all the vegitable portion, is dissipated by heat, and-no account is obtained of it but by the loss iv weight. The analysis of a soil, likewise, though it may give all its component parts, is sure to destroy their combinations, and disturb the relations which they held to each other. There is another great omission in this case. Notwithstanding all the analysis which have been given of soils and products, where the' amount of mineral elemeuts removed have been most particularly determined, yet I have met with no instance of the analysis of a soil immediately after the removal of the crop: by which on comparison with its condition at the time of sowing, the actual loss could be detected.