TREES AND THE GARDEN. 



225 



in allowing any alternat- 

 ing current wires to be at- 

 tached to a tree. 



Direct Currents are 

 probably the more dan- 

 gerous of the two, as a 

 direct current seems to 

 have a characteristic 

 physiological effect upon 

 protoplasm and causes 

 disintegration of the cells. 

 It is believed that a direct 

 current can kill a tree even 

 if its strength is not suffi- 

 cient to cause burning, al- 

 though it sometimes does 

 cause local burning, as 

 with the alternating cur- 

 rent. These injuries usu- 

 ally occur from the di- 

 rect currents from trolley 

 lines, and instances have 

 been known where the 

 trunk of the tree has been 

 girdled to the distance of 

 ten feet or more from the 

 base by leakage from trol- 

 ley lines, and trees have 

 died from electrocution. 



Effect of Lightning. 

 It is a well-known fact 

 that lightning affects trees 

 in different ways, and it is 

 surmised that some trees 

 are more susceptible than 

 Others, but little is known MAPLE TREE, KILLED BY DIRECT 

 aboutthis. Feeble lightning 



strokes often cause ridges on trees, and in such cases 

 the discharge affects only a small part of the vital layer. 



