ther Question, _viz._ Whether it is not the _East_
Wind of it self that blights, without the help of _Insects_? But that may
be easily resolved on my side; for that if it was the Wind alone that
blighted, then every Plant in its way must unavoidably be infected with
its Poison; whereas we find the contrary on a single Branch it may be, or
some other distinct Part of Plants.

And again, to shew how reasonably we may conjecture that 'tis _Insects_
which thus infect the Trees, let us only consider, that every _Insect_ has
its proper _Plant_, or Tribe of _Plants_, which it naturally requires for
its Nourishment, and will feed upon no other kind whatsoever: Therefore
'tis no wonder to see one particular sort of Tree blighted, when all
others escape; as for Example, that Wind which brings or hatches the
_Caterpillars_ upon the _Apple-Trees_, will not any way infect the _Pear_,
_Plumb_, or _Cherry_ with _Blights_, because, were the Shoals of _Insects_
natural to the _Apple_, to light only upon those other Trees mentioned,
they would then want their proper Matrix to hatch in; or if they were
hatch'd already, they would Perish for want of their natural Food; so that
'tis morally impossible that all sorts of Trees should be blighted at the
same time, unless the Eggs of every kind of _Insect_, natural to each
Tree, could be brought at one time with the Wind, or that an Easterly Wind
could contain in it at once, as many differing Periods of Cold or Heat, as
would be requir'd to hatch and maintain each differing kind of those
Creatures.

The common People in the Country seem to be of my Opinion, that Blights
are brought by the East Winds, which they are so well satisfied brings or
hatches the _Caterpillar_, that to prevent the too great Progress of
Blights, it is common for them when the East Winds blow, to provide large
Heaps of Weeds, Chaff, and other combustible Matter on the Windside of
their Orchards, and set them on Fire, that the Smoak may poison either the
_Insects_ or their Eggs, as they are pass'd along. By this Contrivance I
have often known large Orchards preserv'd, when the neighbouring Parts
have suffer'd to the Loss of all their Fruit.

And I have also seen these Fires made with good Success to destroy the
_Caterpillars_, even after they were hatch'd, and had began to devour the
Trees, by suffocating them, and forcing them to drop to the Ground, where
they have been swept up in large Quantities, and kill'd. I have he