REMEDIES AGAINST THE CANKER-WORM. 467 
found to answer the purpose. A belt of cotton-wool, which 
it has been thought would entangle the feet of the insects, 
and thus keep them from ascending the trees, has not proved 
an effectual bar to them. 
Little square or circular troughs of tin or of lead, filled 
with cheap fish-oil, and placed around the trees, three feet or 
more above the surface of the ground, with a stuffing of 
cloth, hay, or sea-weed between them and the trunk, have 
long been used by various persons in Massachusetts with 
good success ; and the only objections to them are the cost 
of the troughs, the difficulty of fixing and keeping them in 
their places, and the injury suffered by the trees when the oil 
is washed or blown out and falls upon the bark. Mr. Jona- 
than Dennis, Jr., of P ortsmouth, Rhode Island, has obtained 
a patent for a circular leaden trough to contain oil, offering 
some advantages over those that have heretofore been used, 
although it does not entirely prevent the escape of the oil, 
and the nails, with which it is secured, are found to be inju- 
rious to the trees. These troughs ought not to be nailed to 
the trees, but should be supported by a few wooden wedges 
driven between them and the trunks. A stuffing of cloth, 
cotton, or tow should never be used ; sea-weed and fine hay, 
which will not absorb the oil, are much better. Before the 
troughs are fastened and filled, the body of the tree should 
be well coated with clay paint or whitewash, to absorb the 
oil that may fall upon it. Care should be taken to renew 
the oil as often as it escapes or becomes filled with the in- 
sects. ■ These troughs will be found more economical and 
less troublesome than the application of tar, and may safely 
be recommended and employed, if proper attention is given 
to the precautions above named. Some persons fasten simi- 
lar troughs, to contain oil, around the outer sides of an open 
box enclosing the base of the tree, and a projecting ledge is 
nailed on the edge of the box to shed the rain ; by this con- 
trivance, all danger of hurting the tree with the oil is en- 
tirely avoided. 
