689. The nineteenth century has commenced with a much more scientific mode of planting and managing trees than formerly existed. Excellent modes of pruning have been pointed out and practised by Pontey, Monteath, Billington, Blaikie, and others, which will render future plantations much more valuable than where this operation and thinning have been so generally neglected as hitherto. At the same time, it deserves to be remarked, that the practice of close pruning large trees, introduced by some of these writers, though it has added to the bulk and exterior beauty of the timber of the trunk, has been found, on cutting down the tree, to have materially injured the timber. The wound formed by the amputation of large branches heals over, but the wood below, probably from its not being intimately united with that which grows over it, is often found to decay.