212 BOARD OF AGRICULTURE. 



do with destroying the insect as the Paris-green, by stopping 

 np the breathing-apparatus of the insect ? 



Dr. Fisher. That, perhaps, woukl be true, if it did stop up 

 the breathing-apparatus ; which it does not. It cannot do it. 

 If it was of the nature of oil, it would close up the breathing- 

 pores ; but no dry powder like that can have any such effect. 



Question. How frequently do you find it necessary to 

 repeat the application ? 



Dr. Fisher. As often as you find the bug; that is to 

 sa}^, you go over your field, and the next day, if you have 

 effectually applied the green, you will see scarcely any potato- 

 bugs : within forty-eight hours every one will have dis- 

 appeared. If you have not put it on effectually, if you have 

 left spots where there are bugs, of course it will take some 

 time for them to reach the green ; but, when they do reach 

 it, they will die, and it is only the next crop to which you 

 are to apply it. With regard to the use of children, if it is 

 any benefit to the children, I should use them m that way. 

 But it is the most expensive mode possible to raise potatoes 

 by hand-labor in picking the bugs. I have known many 

 people who have tried it. They had a prejudice against 

 Paris-green, and they picked faithfully and effectually every 

 bug they found during the season : but I never knew a per- 

 son to continue it two seasons; the education of one year 

 was sufficient. The labor is altogether too much. The game 

 is not worth the powder that it costs. 



Question. Is there any objection to using it in water? 

 For two years I have simply put a teaspoonful of Paris-green 

 in a large watering-pot of water ; and it has been perfectly 

 effectual, without injuring the potato. 



Dr. Fisher. That might answer, if it did not require so 

 much labor to carry the water. It costs so much to dilute it 

 and carry it through a field, that it seems to me that it is not 

 profitable to do it. Another thing : the green is not soluble 

 in water at all. ■ It is only by keeping it constantly stirred 

 that you can have and hold it reasonably well mixed with 

 the water ; and you never can be sure but what one leaf is 

 going to get ten times as much as another; and then it is 

 very difficult to apply it so that the greater part of your 

 water will not go upon the ground. You cannot apply it in 

 small enough quantities. It wants simply a spray, and you 



