233 



yond the operation, attract the sap to the 

 very edges of the wound, as ah'eady de- 

 scribed ; while, in the former case, we 

 have nothing beyond the w ound to cause 

 such attraction ; and, therefore, in old 

 trees, they cannot heal. When such are 

 made into Pollards, the idea of timber is 

 gone; and, therefore, it is of little conse- 

 quence if they afterwards grow hollow, as 

 they may live in that state for ages. How- 

 ever, when persons are particularly careful 

 of such subjects, cutting off the head, 

 slopingli/, as near a live branch as possible, 

 and afterwards capping the wound with 

 lead, is the best preventive of decay. 



In every other case, where branches 

 are too large for the knife, we find the 

 saw not only the best, but the only prac- 

 ticable tool for pruning upon a large scale: 

 (cutting down trees is another thing ;) be- 

 cause it is expeditious, and an}^ one may 

 soon learn the use of it, so as to cut off 

 the branches exactly to the required de- 



Q 



