REMEDIES AGAINST THE CANKER-WORM. 469 
worms after they were hatched from the eggs, and were dis- 
persed over the leaves of the trees. It is said that some 
persons have saved their trees from these insects by freely 
dusting air-slacked lime over them while the leaves were wet 
with dew. Showering the trees with mixtures that are 
found useful to destroy other insects has been tried by a few, 
and, although attended with a good deal of trouble and ex- 
pense, it may be worth our while to apply such remedies 
upon small and choice trees. Mr. David Haggerston, of 
Watertown, Mass., has used, for this purpose, a mixture of 
water and oil-soap (an article to be procured from the manu- 
factories where whale-oil is purified), in the proportion of 
one pound of the soap to seven gallons of water ; and he 
states that this liquor, when thrown on the trees with a 
garden engine, will destroy the canker-worm and many other 
insects, without injuring the foliage or the fruit. This ap- 
plication may be found useful in protecting grafts 5 for if 
canker-worms attack these, they will very much injure, if not 
entirely destroy them. Jarring or shaking the limbs of the 
trees will disturb the canker-worms, and cause many of 
them to spin down, when their threads may be broken off 
with a pole ; and if the troughs around the trees are at the 
same time replenished with oil, or the tar is again applied, 
the insects will be caught in their attempts to creep up the 
trunks. In the same way, also, those that are coming down 
the trunks to go into the ground will be caught and killed. 
If greater pains were to be taken to destroy the insects in 
the caterpillar state, their numbers would soon greatly di- 
minish. 
Even after they have left! the trees, have gone into the 
ground, and have changed their forms, they are not wholly 
beyond the reach of means for destroying them. One per- 
son told me that his swine, which he was in the habit of 
turning into his orchard in the autumn, rooted up and 
killed great numbers of the chrysalids of the canker-worms. 
Some persons have recommended digging or ploughing un- 
