Smithsonian Report. 1935. — Hurd-Karrer 



Relation between Selenium toxicity to Wheat and the Amount of 

 Sulphate Sulphur in the Nutrient Solution. 



The plants to the extreme right are killed by 3 p. p. m. selenium (as sodium selenate) in the absence of 

 sulphur. From right to left the plants show decreasing injury from this amount of selenium as the 

 sulphate increases, until the plants become normal with 36 p. p. m. sulphur. (The first control culture 

 to the extreme left shows injury from sulphur deficiency.) 



