his Mortality among the
Cows was at its height, that towards the End of the Summer, some Farmers
brought in fresh Cattel, and turning them into the same Fields, where many
Cows had died before, they took the Infection and died likewise; but the
following Spring those Fields were void of Infection, and the _Cows_ that
were put into them did very well, but what were then put into the
_Cow-Houses_, where the sick _Cows_ had been the Year before, were seiz'd
with the Distemper, and died; which seems to inform us, that it was the
Effect of _Insects_, which thro' the Warmth of those Stalls were preserv'd
from the Severity of the Winter's Frost; but such as were left in the open
Fields were destroy'd by the Cold. I have heard that a Woman about
_Camberwell_ cured Six in Seven of her _Cows_, by giving them once a Week
an Infusion of _Rhue_ and _Ale-wort_.

But it may be ask'd, why these infectious Distempers, subject to Men,
Cattle and Plants, are not universal? And why the Plague should not be as
well in _India_, _China_, the South Parts of _Africa_ and _America_, as in
these Parts of the World? (For I do not find it has ever been in those
Places.) This Query gives me a farther Opportunity to suggest, that
Insects are the Cause of it, and that they are brought with the Easterly
Winds. In the first place, so far as I can learn, there is not naturally
in _America_ any one Kind of Creature or Insect that is found in any other
Part of the World, and the Plants likewise are all different from those of
other Countries; as it is the same in _India_, _China_, &c. whose Products
are quite different from what we find elsewhere. Supposing then that these
pestiferous Insects are only the Produce of _Tartary_, let us consider to
what Parts of the World they may be carry'd from thence with the Easterly
Winds; and whether _India_, _China_, the South of _Africa_ and _America_,
are not beyond their Reach, or can reasonably be affected by them.

Whoever considers the Disposition of the Land and Water in the Globe, may
thus account for the Passage of these Insects, with an Easterly Wind from
_Tartary_, to all the Parts of _Europe_, _Asia-Minor_, _Palestine_,
_Barbary_, and other South Coasts of the _Mediterranean Sea_, whither,
'tis highly probable, they may come, without meeting any thing in their
Way to obstruct their Course.

The best Maps do not lay down any Mountains of Note between _Tartary_ and
the places which have been subject to the P