The coniferæ differ much in the internal arrangement of their woody structure from the hard wood species, having tissue of much larger cells, and being generally destitute of the large lineal tubes, which in hard wood constitute the more porous inner part of the annual layer. When these tubes occur in the pines, they also differ in position, being in the outer part of the layer. Owing to the resin of the pines becoming fixed in the cells of the outer part of the annual layers, inspissated, we think, by the summer’s heat and drought (others say congealed by the cold), these cells are filled up, and this part of the growth rendered much denser than the inner part of the layer, being from solidity semi-transparent. We would attribute the abundance of resin in the Georgian pitch pine to the heat and long summer of that country, probably in concert with damp richness of soil, not only occasioning this deposit under these circumstances, but perhaps inducing a disposition in this species to the formation of this product[44]. The absence of the large tubes, {207} and the presence of oleaginous resin, render pine timber, when old and small growthed, not so brittle, nor so liable to decay, as that of deciduous trees; but it becomes very deficient in lateral adhesion. From the same cause we find the external layers of matured pine timber comparatively superior to the quality of the inner layers: in hard wood the exterior layers are generally much inferior to the inner. Boards of sap-wood of fast grown Scots fir, particularly of the outside layers are much better suited—stronger and more lasting, for boxes used as carriage packages, or for machinery or cart lining much exposed to blows and friction; than boards of the best matured red wood of Memel, Swedish, or Norway pine. This is principally owing to the fast grown alburnum possessing much greater lateral adhesion than the matured wood of old pines. To have these sap-wood boards in greatest perfection, the tree must {208} not lie in the bark after felling, and the boards must be well dried soon after being cut out. To expose the tree, peeled, either standing or felled, to the sun and dry air for some time, will considerably increase the strength of this alburnum. The wood, while in the state of sap-wood, of many kinds of timber is as strong and much tougher than the same wood after being matured, and would be equally valuable were any process discovered of rendering it equally durable; its insufficiency often arises from partial decay having occurred while in the log. The same sap-wood of oak, which, allowed to lie on the grass after being peeled in spring, will be so much decomposed in autumn that it may be kicked off with one’s heel; if cut out and dried immediately on being felled, it will be tougher than the matured, and, kept dry as cart-spokes, and defended by paint from the worm, will last and retain its toughness for an age. The tilling up, which to a certain