PAGE 



Rclatiou.s between aniuunts of copper in root systems and injury 



to plants 215 



Pathological effects ' 216 



Soil conditions relating to toxic effects of copper upon plants ...- 217 



Stimulation 219 



Field observations 221 



Effects of river sediments 222 



Effect of cultivation upon alfalfa ,- 223 



Summary 227 



Part III. — Appendix 229 



Methods of analysis , 229 



Reagents and apparatus 229 



Manijiulation 229 



The determination of copper in small amounts of plant ashes 232 



Bibliography 236 



