OF THE WOOD. 35 



that it might be slipped aside from the Vvood 

 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 whxole 

 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 w^hich it had 

 been stripped, made up the number of rings 

 in the branch above and below the experi- 

 ment. For an account of this experiment 

 I am indebted to Dr. Thomas Hope, the pre- 

 sent Chemical Professor at Edinburgh. 



Du Hamcl engrafted a portion of the bark 

 of a Peach-tree upon a Plum. After some 

 time he found a layer of new w^ood 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 Arhresy vol. 2. 29, <&c. It deserves 



D ^ 



