Bordeaux Mixture ■ 77 



17. What is meant by copper in a positiv ion? 

 Copper in a negativ ion? 



18. In which ion is the copper in copper sulfate? 

 Positiv or negativ? 



19. Why is the hberation of soluble copper salt 

 from Bordeaux delayd by the presence of lime? 



20. How strong a solution of copper sulfate is 

 necessary to kill fungous spores? To kill plants? 



