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72 
to induce a concert of action amongst agriculturists. This could 
be accomplished by planting only the earliest varieties of pota¬ 
toes. If this method were universally put in practice, there 
wonld be no potatoes after mid-summer for the insects to feed upon 
and they would probably all perish from starvation. And even if 
a small proportion of them should subsist upon other plants till 
fall, they would be of too old a brood to survive the winter and 
perpetuate the race another year. 
But it is now generally admitted that the most effective remedy 
foi the Colorado Potato-beetle, so far as human agency is con¬ 
cerned, is the application to the vines of the poisonous substance 
commonly known as Paris-green, and chemically designated as 
the Arsenite of Copper. This substance proves fatal to the insects, 
not by coming in contact with them, but by being eaten by them. 
Indeed, these creatures have a very pertinacious vitality under 
all the ordinary applications which prove destructive to insects. 
I have thoroughly sprinkled the infested vines with copperas water, 
one ounce to the quart, which has been highly recommended ; 
and with fish brine, one quart to two gallons of water, but both 
applications hurt the vines much more than they did the insects. 
I have also immersed the beetles in diluted carbolic acid, and then 
rolled them over and over in Paris-green, and put them in a box, 
and some oi them were alive on the next day. But when this 
article is eaten by them with the foliage, it proves speedily and 
certainly fatal. 
Hie first time that I knew of this substance being used on a 
large scale, was in the summer of 1869, by Mr. E. W. Grosvenor 
ot Hastings, Minnesota. This gentleman used twelve dollars worth 
of Paris-green, diluted at about the rate of one quarter of a pound 
to half a peck of flour, and.saved his potato crop. Upon the older 
vines it had to be repeated, but upon vines three or four inches 
high, he thought it affected them in some way which rendered 
them thenceforward repugnant to the insects. But upon this point 
it is proper to remark that the'testimony is conflicting. Mr. Gros¬ 
venor also mentioned the interesting incident that in stripping 
the bark trom some old fence posts in the winter time, near the 
fields that had been infested by the bugs, he found thousands of 
them, which had availed themselves of this shelter for the winter, 
I 
