44 OF THE A\OOD. 



the barks of growing trees, carefully binding up their 

 wounds, and, after some years, on cutting them across, 

 he found the layers of new wood on the outside of the 

 tin. His original specimens I have examined in the 

 public museum at Paris. 



Dr. Hope, the late worthy Professor of Botany at 

 Edinburgh, instituted an experiment, if possible more 

 decisive, upon a branch of Willow three or four years 

 old. The bark was carefully cut through longitudinally 

 on one side for the length of several inches, so 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 possi- 

 ble, 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 ac- 

 count 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 Arbrcs, 

 vol. 2. 29, Sec. It deserves also to be mentioned, that 

 by performing this experiment of engrafting a portion of 



