Book II THE POXES AND MEASLES 75

appear certain scattered, red spots which soon grow more plain—
ly into pustules, sometimes rather moist and resembling 'vari'
(pimples), sometimes drier and resembling those exanthemata&
due to heat, which appear on children and are commonly call—
ed uffersurae'. Both kinds of pustules presently fill up with
a thin sort of pituita and matter,* and the malady is relieved
by these very means, easily enough in the case of children, not
so easily with adults. 'Therefore mothers often want their child—
ren to have these fevers while they are still of tender age. They
are contagious, because what exhales from the putrefaction is
very viseous, and is a germ of contagion for another individual
in the same manner as I have described in other contagious
diseases. In the majority of cases the patient recovers. For
this ebullition is a kind of purification of the blood, nor should
we scorn those who assert that infection contraeted by the
child from the menstrual blood in the mother's womb is localised
by means of this sort of ebullition and its putrefaction, and the
blood is thus purified by a sort of crisis provided by nature.
That is why almost all of us suffer from this malady, since we
all carry in us that menstrual infection from our mother's womb.
Hence this fever is of itself seldom fatal, but is rather a purgation.

But it is more benign for children than for adults, because
when people do not get rid of that infection of the blood at an
early age, that is a sign that it is of a kind not easy to separate.
And, later, when this separation occurs at a more advanced age,
it is very violent, and the patient has a more severe attack,
whereas it is less severe when the blood is more yielding,' and
better able to get rid of that taint. Hence when this process
has once taken place, the malady usually does not recur, be—
eause the infection has already been secreted. / Nevertheless,
eases of its recurrence a second time have been observed, and
in these the infection had not been completely secreted in the
previous attack. When the blood is pituitous, the variform
pustules are white, round, and full of a sort of mucus; if the
blood is bilious, the pustules that erupt are drier. 'This con—
tagion is analogous with that superfluous blood which has been
contracted from the menstrual blood; hence this sort of infec—
tion has analogy only for those persons whose blood has not
been purified; and this accounts for the fact that it does not in—
fect everyone, or all the humors.  This is all that I have to say
on this subject.