Book II PESTILENT FEVERS t 85

acts per se, and the putrefaction occurs just the same, whether
they be present or not. In faect it may happen that, in an in—
dividual, either the phlegm or the bile is predisposed to putrefy,
according to the principles mentioned above, but that they
nevertheless are not infected by the contagion so much as some
other humor is infected, because the analogy with them is lack—
ing. Hence not all the putrefactions that arise about the earth
or in the air, but only certain ones, dispose us to that contagion
which accompanies the plague.

If, then, what I have said about contagion is correct, the
principles of contagions per se are the germs themselves, about
whose nature I have said so much. And although, by virtue of
a certain common principle, they concur in action with vapors
and local!l heat, they are nevertheless endowed with a special
nature and method of causing putrefaction. For, as I have
said, first, they possess great force and activity, secondly a
strong and well—worked combination, and moreover that com—
bination has a viscous constitution, and finally, they have not
only a material but also a spiritual antipathy to the natural
heat of the body, and to the soul itself. When these conditions
are present, these fevers produce a putrefaction very different
from that in other fevers, inasmuch as in others there is & super—
ficial sort of putrefaction, not deep—seated and foul; whereas in
these it is very deep—seated and reaches to the innermost parts
of the thing that putrefies. And this happens because, in the
first place, the germs are not endowed with slight power of
action, like simple vapors, but with a much greater power, on
account of their strong combination, for which cause they are
not quickly or easily altered, but last and keep up their activity;
'also, on account of their viscosity, they adhere fast to the humor
with which they have analogy; they attack it and quickly dis—
solve it, since they are very active and moist; and therein they
are much helped by the spiritual antipathy which drives out
and expels the natural heat, so that the humor, deprived of this
heat, quickly contraets deep—seated putrefaction. 'This putre—
faction, moreover, is not only deep—seated, but also very ex—
tensive, that is, it extends to many parts of the body, since the
germs are scattered on all sides, and generate some here and
others there, which are, so to speak, their progeny. Montanus,
then, was right in saying that great putrefaction occurs in pesti—
lent fevers, but he did not explain the cause per se of its occur—