Page:An introduction to physiological and systematical botany (1st edition).djvu/65

 Rh that it might be slipped aside from the wood in the form of a hollow cylinder, the two ends being undisturbed. The edges of the bark were then united as carefully as possible, the wood covered from the air, and the whole bound up to secure it from external injury. After a few years, the branch was cut through transversely. The cylinder of bark was found lined with layers of new wood, whose number added to those in the wood from which it had been stripped, made up the number of rings in the branch above and below the experiment. For an account of this experiment I am indebted to Dr. Thomas Hope, the present Chemical Professor at Edinburgh.

Du Hamel engrafted a portion of the bark of a Peach-tree upon a Plum. After some time he found a layer of new wood under the engrafted bark, white like that of the Peach, and evidently different from the red wood of the Plum. Moreover, in this and other experiments made with the same intention, he found the layers of new wood always connected with the bark, and not united to the old wood. See his Physique des Arbres, vol. 2. 29, &c. It deserves