No. 3. We found a sycamore plane (Acer pseudo-platanus) in the same row with other sycamores, and about the same size, so exceeding hard that it could scarcely be cut down by mattock and hatchet, whereas the others adjacent were comparatively of moderate hardness, though differing considerably in hardness from each other; the soil in this case was very equable, being of Carse clay. The peculiar hardness of this tree could only be attributable to a harder variety. Indeed, the difference of quality in timber depends chiefly on the infinite varieties existing in what is called Species, though soil and {203} climate have no doubt considerable influence, both in forming the variety, and in modifying it while growing. Of varieties, those which have the thinnest bark, under equal exposure, have the hardest wood. No. 4. We have cut a number of large old ash trees, and found, with one or two exceptions, of what is called thunder-struck trees (which we consider only an obdurate variety), that they were invariably of very free, weak consistency, more especially the latter formed growths, but even the earlier growths had become _frush_ from age. This timber soon went to decay after being cut down:—one piece cut out into planks, and these being laid down in the order they occupied in the log, was in the course of some weeks rendered again entire by being agglutinated by Jew’s ears (a species of fungus.) The workmen were greatly startled at the fact, thinking the log bewitched. When immediately dissevered by wedges, the wood was so much decomposed, that its fibre was tenderer than the Jew’s ears, separating in a new course in most places, in preference to the saw draught occupied by the ears. We have found very old oaks have exactly the same friable character, so much so, as render their safe felling almost impossible; yet this oak timber had not lost much in weight {204} when compared after being dried with younger oak. No. 5. We cut a row of ash trees, about 50 years of age, in dry Carse clay, by the side of a deep ditch, and consequently of slow growth; the timber was excellent, hard, strong, and weighty, rather most so where the size was smallest. At one end, where the row approached a brook, and the soil became richer and moister, several of the trees were of good size, but rather inferior in quality of timber, excepting one (the largest, though not the nearest to the brook), which was of very hard, strong, and reedy fibre, evidently a variety differing much from the others. It is always easy to discriminate pretty accurately the quality of the wood, by examination of the saw cross section of the trunk, that is, provided the same saw be employed, and be kept equally sharp; the best timber having the glossiest, smoothest section.