INSECTS. 173 



and I have little doubt that it actually decomposes and de- 

 stroys the insect in the chrysalis state ; at least I hope that 

 this is the case. 



" There are many reasons, which should encourage a 

 repetition of this experiment. The digging round the trees 

 is highly useful to them, while tarring is very injurious. 

 The expense is not great. A man can dig round fifty trees 

 in one day. The lime is a most salutary manure to the 

 tree. After the spot has been once opened and limed, the 

 labour of keeping it open will not be great. Three hogs- 

 heads of air-slaked lime, or the sweepings of a lime-store, 

 will suffice for fifty trees, and will cost three dollars. As 

 it is done but, once a year, I think it'cannot be half so ex- 

 pensive as tarring. 



" I repeat it, that I mention my experiments with great 

 diffidence, as being the first of my own knowledge. It 

 may induce several persons to try it in different places, and 

 where trees are surrounded w r ith others, which are treated 

 differently. All I pray is, that it may prove successful, and 

 relieve us from this dreadful scourge, which defaces our 

 country, while it impoverishes and disappoints the farmer." 



The remedies proposed by Professor Peck were, 1st, 

 Turning up the ground carefully in October, as far as the 

 branches of a tree extend, to half a spade's depth, or five 

 inches, so as completely to invert the surface. A great 

 number of chrysalids would thus be exposed to the air and 

 sun, and of course destroyed. 2dly, Breaking the clods, 

 and smoothing the surface with a rake, and passing a heavy 

 roller over it, so as to make it very hard, and without cracks. 

 In grass-grounds, the sods should be turned with the grass- 

 side down, and placed side by side, so -as to be rolled. 

 The winter's frosts would heave and crack a smooth sur- 

 face, but it might be smoothed and hardened by the roller, 

 or by other means, in March, with much less trouble, time, 

 and expense, than rolling requires. As lime, when sla- 

 ked, is reduced to an impalpable powder, and is thus well 

 adapted to close the openings in the surface, Mr. P. was 

 inclined to think its good effects ere produced this way as 

 well ashy its caustic qualities. Thacher's Orchardist, p. 93. 



John Kenrick, Esq., of Newton, Mass., proposed, be- 

 tween the time in June after the worms had disappeared 

 and the 20th of October, to take the whole of the soil sur- 

 rounding the trees, to the extent at least of four feet from 

 the trunk, and to a suitable depth, and cart it away to a 

 distance from any trees, which the canker-worms are in the 

 15*- 



