288 DISEASES OF VEGETABLES. 



the bark with the point of a pruning knife, in two 

 or three places. This, if performed about Midsum- 

 mer, evidently relieves the tree, as its future growth 

 is much increased. The result is perfectly natural ; 

 if the envelope has its expansive action cramped, it 

 will every summer struggle for a vent ; and when the 

 constricting bark is separated, the envelope will im- 

 mediately be increased in volume, and a new impetus 

 given to the secretions of the tree. 



To such length has this remedy been applied, that 

 the whole outer bark has been, by some 'arboricul- 

 turists, removed, to the manifest advantage of the 

 tree. Indeed the same practitioners maintain, that 

 the general barrenness and failure of old apple and 

 pear orchards, is chiefly to be attributed to constric- 

 tion of the bark ; and the only way to renovate these, 

 or other old trees, is to strip them of their old hardened 

 covering *. It is said that cork-trees are invigorated 

 by the loss of their bark, and that the same trees are 

 stripped periodically without detriment to their health 

 or natural magnitude. 



Attending to the rationale of this practice, it is 

 true, as has been before shown, that only a few of the 

 recently formed layers of inner bark are absolutely 

 necessary to the vital processes of the system. All 

 those on the exterior are dead, and may be removed 



* It should be observed here, that if fruit-trees be sound at the 

 heart, and stunted or stationary in growth, they may be assisted by 

 disbarking ; but it is impossible to renovate old hollow trees much 

 by such means. 



