6o 



filter paper, was dropped into the glass vessel containing the freshly 

 mixed sulphuric acid and water. The box was quickly dropped into 

 position and made air tight around the base with dirt. 



Experiments With Carbon Bisulfid. 



No. 



3 



4 



5 

 6 



7 

 8 



9 



io 



1 1 



12 



13 



14 



*5 



Rate. 



10 gms. per cu. ft. 



15 " 

 10 



iS " 



20 " " 



25 " 



30 " " 



15 " 



20 " " 



10 " " 



10 " 



.2 gm. per cu. ft. 



Time. 



hour. 



5 minutes. 



10 



J 5 



10 



Results. 



\ Insects unaffected. 

 ^ Plant uninjured. 



Insects unaffected. 



Plant uninjured. 

 { Insects unaffected. 

 ( Plant uninjured. 

 ( Insects unaffected. 

 ( Plant uninjured, 

 j 1 or 2 p. c. insects killed. 

 I Plant uninjured. 

 \ 80 per ct. insects killed. 

 | Plant slightly injured. 

 j Insects all killed. 



Plant killed. 



Insects all killed. 



Plant badly injured, 

 f Insects all killed. 

 \ Plant killed. 

 \ 20 per ct. insects killed. 

 | Plant uninjured. 

 f 25 per ct. insects killed. 

 ( Plant uninjured. 

 \ Insects unaffected. 

 ( Plant uninjured. 

 \ 60 per ct. insects killed. 

 I Plant uninjured. 

 f Insects all killed. 

 ^ Plant slightly injured. 

 \ 75 per ct. insects killed. 

 ^ Plant slightly injured. 



I 



The eggs having all hatched at the time these experiments were 

 made, the effect on that stage could not be observed. The conclu- 

 sion to be drawn from the above is that for short exposures there is 



