13 



ft. above, showed none of the characteristic burning effects. The 

 general physiological effects in these cases were so different from 



Fig. 7. Maple tree killed by direct current fro))i a trolley system, carry- 

 ing positive current through the rail, and return current through the feed 

 "ojirc in contact with branches. The largest amount of burning occur}-ed 

 slightly remote from the point opposite the rail, and in line with a large 

 root, lying diagonally luith, and just under the nearest rail. 



Fig. 8. Elm tree killed by a direct current from an electric railroad 

 system cartying positij'c current in the rail, and return current in the so- 

 called feed wire in contact with the branches. 



