C 2 93 ] 
in which the plague raged, abounded unufually with 
all forts of flies j which fhews at leaft, that the con- 
ftitution of the air doth at thofe times greatly fa- 
vour the production of fuch creatures. This con- 
jecture will feem the more probable, as the ufual 
prefervatives againft infection, namely vinegar, to- 
bacco, rue, wormwood, &c. arc endued with very 
acrid and pungent particles, with which perhaps they 
fling and kill the invifible flies before they can lay 
their eggs, and by thefe means preferve us from 
contagion. 
Be this however as it will, it is certain there is 
fuch a conftitution as we are here fpeaking of, in 
refpeCt both to diftempers and infeCts. But whence 
this proceeds, whether from the fun alone, or from 
the joint influence of other neighbouring planets, 
or the tranfudations of mineral vapours, or fermen- 
tations in the foil of the earth ; and further, whe- 
ther this fort of climacteric in the feafons be fta- 
tionary or cafualj I leave better naturalifts to judge. 
I only infift, that fuch a conftitutional tempera- 
ment there is, which, running thro’ all nature, doth 
at certain times give more than ordinary energy to 
the prolific powers of fuch plants or animals as are 
of nature fimilar thereunto. 
This plainly appears to us in plants of all kinds, 
even excluding the confideration of warmer or 
colder, of drier or moifter feafons, which, it is ma- 
nifeft, have only their fhare in the calualties to 
which the vegetable world is liable. They frequently 
bear more bloffoms and fruit in a bad, and lefs in 
a good feafonj and what puts the matter beyond 
all queflion, that feafon which is favourable to one 
Q^q kind 
