TESTS OF GASES TO DESTROY SAN JOSE SCALE. 



799 



It does not appear that any of the gases that can be commonly 

 and simply generated will supersede hydrocyanic acid gas for 

 fumigating nursery stock. 



Table I. — Test of Gases for Fumigating Stock. 

 Experiments with Carbon Disulphide. 



Experiments with Carbon Tetrachloride. 



Experiments with Acetylene. 



I heated to ioo°C. 

 I " 

 I " 

 I " 



I " 



* Tree started to grow, then died. 



f More than one-fourth of liquid had not volatilized at end of period. 



X Of calcium carbide. 



