By Dr. Noehden. 



follow. Yet the cause appears obvious ; but so does many a 

 truth, when it is once discovered. 



The dimensions, which both Mr. Williams and Mr. 

 Hempel assign to their rings, as best answering the purpose, 

 nearly approach to one another : and they may be taken as 

 rules to go by. But it is not to be said, that no deviation 

 from them should be allowed ; on the contrary, it may be ad- 

 visable to vary, according to the comparative strength of the 

 tree, and the quantity of sap, with which it may be pre- 

 sumed to be filled. The ring should never be cut so wide as 

 to defy the effort of the tree, in again covering the wound, 

 during the season ; for that deduction of fulness, which is 

 adequate to make up the loss of the bark removed, seems 

 just to place the treee in that medium of vigour, which is favour- 

 able to the production of fruit. Mr. Sabine has farther 

 favoured me with an account of a Pear-tree at Kew, whicli 

 I will transcribe in his own words. It will be seen, that 

 the remarks made before, are applicable in this instance. 

 The partial decay of that tree is attributable to the manner 

 in which the operation has been performed. 



" There is a Pear-tree," says Mr. Sabine, " against one 

 of the walls in the kitchen garden, belonging to His Majesty, 

 at Kew, which underwent this operation about 15 years ago. 

 The part operated on was near the root ; and as it was a 

 principal arm, about one half of the whole tree became 

 influenced by the operation. This half has uniformly borne 

 fruit, the other half has been nearly barren. The portion 

 of stem, which was laid bare, is about six inches wide, and 

 it has not been again covered by bark. That part just above 

 the ring is considerably larger than the part below it. The 

 ends of the branches appear in much decay, and there are 



