Before this country was so much overrun by men and oxen, a great deal of timber had existed, covering much of the superior land which is now under tillage. This consisted chiefly of the oak, Scots fir, birch, hazel, and alder,—the oak extending northward and to elevations, and ripening seed, and attaining to a size which it does not now do, either wild or cultivated, in the same latitude, neither here nor in any other portion of the world; which, along with some other facts, lead to the supposition, that the climate has changed a little,—in part, possibly, as we have before stated, from the gradual formation of peat, to which, overthrown oak forest, from the abundance of the tannin principle, has a great disposing influence, even under a warmer climate than present Scotland. The highest latitude to which a tree, or any other kind of plant, reproducing by seed, {357} naturally extends, depending on the ripening of the seed, and also on the power of occupancy, is however different from that where it will grow, when ripe seeds are procured from the coldest place where they ripen, and all the competitors removed; and under the system of shelter belts, hardy pine nurses, and seeds from the nearest place where they ripen, we have no doubt that oaks may be extended to a colder situation than Nature herself would have placed them in. For the higher more bleak portion of the country, we would recommend acorns grown in Scotland, in preference to those imported from England. We have several times observed wheat, the seed of which had been imported from England, sustain blight and other injuries in a cold moist autumn, when a portion of the same field, sown of Scots seed, at the same time as the other, and under the very same circumstances, was entirely free from injury. English acorns are also frequently heated in the casks in which they are imported, which must impair their vigour[66]. {358} The part of Mr Cruickshank’s volume which we have analyzed, does not extend much beyond the first half: this portion is well worth a perusal. We have merely glanced over the remainder: it is a make-up scarce worth noticing. The language, on the whole, is easy and plain; and although the volume contains a considerable number of errors, in the pointing out of which we have not been sparing, yet will it form an excellent planter’s assistant to people who have ground to plant, and are ignorant of the process of planting. * * * * *