Book I CONTAGION 59

seated and confined putrefaction. 'This putrefaction, in its
relation to the air, is likewise not called contagion, since there
is not a precisely similar infection in the two things. But in
relation to some other thing which is second, third or fourth,
now it is called contagion, and the malady contagious. If,
however, the germs of contagion are transmitted directly by
the air to the first individual, one says that it is contagion, that
it has been received from the air, and it is adapted to pass on
to another person; for both the air and the person to whom it
has been carried have suffered the very same taint. We must
say the same about earth and water, because they transfer to
us, sometimes vapors only, sometimes also the very germs of
contagions. We may therefore consider that we know the
reasons why air, water etc. are infected, and now receive the
germs of contagions, now extraneous vapors, or again are merely
altered.

But perhaps we should proceed to enquire whether any con—
tagions per se depend on the sky and the heavenly bodies, since
astrologers?' often predict that certain diseases and epidemics
will arrive; for example, it is well known that they predicted
Syphilis (or the French Sickness, as it is called), long before
it had made its appearance. Certainly, since nothing that
touches us very nearly can be sent down to earth from the sky,
unless it be something spiritual like luminousness'*? or some—
thing else of the same sort, if we look back to what was said
aboves about the activities of spiritual things, we shall see
that no contagions per se can be produced by the sky; but
there is no reason why certain contagions should not be pro—
duced by it, by accident, and they might even be predicted by
astrologers. For since they know the phenomena most fre—
quently produced by the heavenly bodies per se, they can also
foresee what phenomena are most frequently connected with
them, by accident. Now the heavenly bodies may of them—
selves become heated, and this increase of heat results in the
rise of a great mass of vapors from the waters and the earth;
these vapors presently may produce various and diverse kinds
of corruption, some new, some familiar to us, some unusually
severe, according to the different constitutions of those heaven—
ly bodies. Astrologers and learned men observe these con—
ditions, and can foretell the effects that they usually produce.
Now these effects, though they occur by accident, under the