2* 

 2. 



arsenious acid. 



Fig. 9. Photograph showing the action of arsenious acid on barley iu the presence 

 of nutrient salts. (March 16th May 9th, 1911.) 



1. Control. 

 1/50,000 

 1/100,000 



1/1.30,0110 



1/200,000 

 1/250,000 



6. 1/500,000 



7. 1/1,000,0(10 



8. 1/5,000,000 



9. 1/10,000,000 



10. 1/25,000,000 



11. 1/50,000,000 



