178 NORTH AMERICAN INSECTS. 
These troughs ought not to be nailed to the trees, but 
should be supported by a few wooden wedges driven be- 
tween them and the trunks. A stuffing of cotton, cloth, 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 insects. 
These troughs will be found more economical and less trou- 
blesome than the application of tar, and may safely be rec- 
ommended and employed if proper attention is given to the 
precautions above named. Some persons fasten similar 
troughs, to contain oil, around the outer sides of an open 
box, inclosing 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.” 
In the Manchester Guardian, an English newspaper, of the 
Ath of November, 1846, is the following article on the use 
of melted India rubber to prevent insects from climbing up 
the trees: “ At the late meeting of the Entomological So- 
ciety of London, Mr. J. H. Pennel communicated the fol- 
lowing successful mode of preventing insects ascending the 
trunks of fruit trees: Let a piece of India rubber be burned 
over a gallipot, into which it will gradually drop in the 
condition of a viscid juice, which state, it appears, it will 
always retain; for Mr. Pennel has at the present time 
some which has been melted for upward of a year, and has 
been exposed to all weathers without undergoing the slight- 
est change. Having melted the India rubber, let a piece 
of cord or worsted be smeared with it, and then tied sey- 
eral times around the trunk. This melted substance is so 
very sticky that the insects will be prevented, and can be 
captured, in their attempts to pass over it. About three 
