Fig. 2. Photograph showing the action of copper sulphate on barley in the presence 

 of nutrient salts. (March 5th— April 19th, 1907.) 



1. Glass distilled water. 



2. Copper distilled water. 



3. 1/12,500 copper sulphate. 



4. 1/25,000 



r,. 1/30,000 



C. 1/100,000 



7. 1/250,000 



8. 1/500,000 



9. 1/1.000,000 



