CONTENTS. 



PAGE 



Diseases of trees, ........... 188 



Diagnosis of disease, . . . . . . . . . . 189 



Fungous diseases of trees, ......... 190 



Wood-destroying fungi, ......... 196 



Slime-flux 198 



Treatment of fungous diseases of trees, . . . . . . .198 



Winter injuries, ........... 199 



Winter injuries of roots, ......... 200 



Winter injuries above ground, ........ 204 



Frost cracks, ........... 204 



Winterkilling of cork cambium, ........ 206 



Sun scald, 207 



Drought, 208 



Sun scorch and bronzing of leaves, ........ 210 



Mechanical injuries, ....... . 212 



Earth fillings around trees, ......... 214 



Bleeding of trees, 215 



Injurious chemical substances, 216 



Kerosene oil, ........... 216 



Gas oil, 216 



Paint 218 



Miscible oils, ........... 218 



Road oil, 218 



Creosote, 218 



Coal tar 218 



Salt, 219 



Other injurious substances 219 



Banding substances, .......... 219 



Effects of illuminating gas on trees, ........ 220 



Effects of atmospheric gases on vegetation, ...... 228 



Electrical injuries, ........... 233 



Effects of alternating currents, ........ 235 



General effects of direct currents, . . . . . . . . 236 



Death of trees from direct current, 238 



Electrolysis 241 



Lightning, 241 



Earth discharges, .......... 242 



Susceptibility of different trees to lightning stroke, .... 244 



Injuries to trees from arc lamps, ........ 245 



Injury to trees from wires, ..... . 246 



The spraying of shade trees, ......... 249 



Valuation of shade trees, 255 



Court decisions concerning damages to trees, 258 



Codified shade tree laws of Massachusetts, 1915, 261 



PUBLICATION 1 " OF THIS DOCUMENT 



APPROVED BY THE 

 SUPERVISOR OF ADMINISTRATION. 



