Paris-green experiment Xo. 1, April 19, 1889. 





Check lot. 



1 1 1 

 1 lb. to 100 gals. 1 lb. to 200 gals. , 1 lb. to 300 gals. 1 lb. to 500 gals. 



Died. 



Number used, 

 24. 



Number used, 

 12. 



Number used, 

 12. 



Number used, 

 9. 



Number used, 

 12. 



April 22 





3 



o 



3 



1 

 2 

 2 

 2 



2 



23 



2 



3 



24 



1 . 



3 

 4 

 2 



1 



25 





2 

 1 

 2 



3 



26 



3 

 2 



2 



I 



27 



1 

 1 



1 



29 





1 











Total 



10 



12 



12 



9 



.2 



May 4 this experiment was repeated with a fresher lot of beetles, with 

 more marked results, curculios commencing to die two days after treat- 

 ment in all the poisoned lots but one, all of one lot being dead in nine 

 days, and in ten days all of every poisoned lot but a single beetle. In 

 the check lot, meanwhile, only one had died. 



Paris- green experiment Xo. 2, Mag 4, 1889. 





i i 



Check lot. 1 lb. to 100 gals. 1 1 lb. to 200 gals. 



! 

 1 lb. to 300 gals, j 1 lb. to 500 gals. 



Died. 



Number used, 

 12. 



Number used, 

 12. 



Number used, 

 12. 



Number used, 

 22. 



Number used, 

 22. 



Mav 0. 



7 





3 



1 

 1 

 2 

 3 



1 



2 





1 







4 

 2 

 3 

 4 

 

 2 

 1 



2 



8 



9 



2 

 3 



1 



1 

 3 



10 



11 



1 



4 

 4 



13 





4 



5 



14 





1 



1 











Total 



1 



12 



12 | 22 



21 



In both the above experiments, as also in the following, peach leaves 

 were used as food, and these were sprayed but once. 



All strengths of the poison mixture here killed the beetles feeding 

 on it, the difference being seen in the rapidity with which they took 

 effect. In four days from poisoning the ratios killed were 42 per cent, 

 in lot two, 33 per cent, in lot three, 27 per cent, in lot four, and 18 per 

 cent, in lot five. 



Finally, May 17, a still more extensive experiment was begun with 

 London purple, three hundred and forty-seven curculios being divided 

 into five lots as before, their treatment differing from that of the fore- 

 going only in the substitution of London purple for Paris green. The 

 results were rendered, however, somewhat less satisfactory by the late- 

 ness of the season, which probably accounts for the number of deaths in 

 the check. Other parallel observations led to the conclusion that spent 



