420 University of California Publications in Agricuitural Sciences [Vol. 1 



particularly noted were those at which growth was retarded and 

 at wliieh it was arrested. 



Table XTII gives the data condensed from the experimental 

 records : 



TABLE XlII («) 



Toxic Effects of Copper upon Roots of Water Cultures 



First experimeut (1905) 



Cu in solution 



Indicating lessened toxicity in well water. 





iT^"^ 



Fig. 4. — Bean enltiires (eighth exp.), showing effects of varying con- 

 centrations of coi)per in distilled water and in solutions of mixed salts. 

 S, salt solutions; J), distilled water; IV, no copper, and .05 to 3. parts per 

 million of copper. 



TABLE XIII (h) 

 Eighth experiment (1905) 



Total 100 pts. per 100,000. 



