DESTRUCTIVE INSECTS. 305 



some of what we consider vegetable sweets. It has 

 been affirmed that potato water showered on goose- 

 berry and other fruit trees preserves them from 

 caterpillars. 



Connected with this subject may be mentioned the 

 protection of old ornamental trees, which suffer, or 

 are supposed to suffer, from certain insects which 

 breed in timber. Many stately trees in the gardens 

 of colleges, palaces, and in public malls in cities, have 

 been prematurely killed, it is said, by the larva of the 

 Scolytus destructor. Whether they cause the injury 

 in the first place, or are only attracted by the already 

 decaying members of the tree, is variously under- 

 stood, but the latter circumstance is the most pro- 

 bable*. Trees in public places are liable to many 

 accidents which such as stand in the forest escape. 

 The former are exposed to injuries from the knives 

 of silly people, bruises from the roller, spade, or 

 sithe ; these induce decay ; this invites the insects ; 

 their depredations increase the wounds and prevent 

 recovery. That such accidental bruises may not 

 increase to endanger the life of the tree, the best 

 thing to be done is scooping out all the decayed parts 

 both of bark and wood, and covering the wound with 

 a good coat of tar, in which a little tallow and salt- 

 petre is added, to be renewed, from time to time, if 



* This has been satisfactorily proved in an excellent paper, by 

 the ingenious Mr. Denson, senior, of Water Beach, near Cam- 

 bridge, author of the " Peasant's Voice." 

 X 



