CHAPTER XIII
THE SIGNS OF CONTAGIONS

Contagions have their own peculiar signs, of which some an—
nounce beforehand contagions to come, while others indicate
that they are already present. 'The signs that are called pre—
monitory come from the sky or the air, or from the vicinity of
the soil or water; and among these some are almost always,
others are often, to be trusted.

Therefore one ought not to consider them all as prognostica—
tions, but only as signs of probability. For instance, when
you see in the sky that several of the stars called planets are
assembling into one quarter, (as it often happens, for instance,
that several planets are in the north or south and are entering
into conjunction reciprocally), then be sure that in that quarter
important changes will take place on the earth. First there
will be very great humidity due to masses of vapor rising from
the earth and water, soon followed by severe droughts, when
the vapors are at length consumed by the scorching heat about
the earth and in the atmosphere. 'These phenomena usually
bring putrefactions also.  If the conjunction of several of these
stars occurs under the influence of the greater stars which are
called 'fixed', then you may predict that some remarkable con—
tagion is portended. Further, there are certain aspects of the
planets to which astronomers assign these portents, aspects
which must not be wholly ignored, though they need not al—
ways be feared.

"TThe air again gives us signs of its own; first when numerous
and frequent conflagrations appear, of the sort that happen in
the uppermost region, the so—called zenith, such as falling
stars, comets, fiery beams (aurora), tempest—flares and the like,
which indicate that putrefaction is occurring around the earth.
For all these arise from an unctuous (oily) and viscous fomes.
'TThis shows that there are present also and are rising from the
earth, vapors of this unctuous and viscous kind, which nearly
always happens in connection with putrefactions. We ought

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