that acid； and the other saltish； and many other varieties； and
again there is cold combined with other qualities。 These are what
proves injurious； heat； it is true； is present also； possessed of
strength as being that which conducts； is exacerbated and increased
along with the other； but has no power greater than what is peculiar
to itself。
18。 With regard to these symptoms； in the first place those are most
obvious of which we have all often had experience。 Thus； then； in such
of us as have a coryza and defluxion from the nostrils； this discharge
is much more acrid than that which formerly was formed in and ran from
them daily； and it occasions swelling of the nose； and it inflames；
being of a hot and extremely ardent nature； as you may know； if you
apply your hand to the place； and； if the disease remains long； the
part becomes ulcerated although destitute of flesh and hard； and the
heat in the nose ceases； not when the defluxion takes place and the
inflammation is present； but when the running becomes thicker and less
acrid； and more mixed with the former secretion； then it is that the
heat ceases。 But in all those cases in which this decidedly proceeds
from cold alone； without the concourse of any other quality； there
is a change from cold to hot； and from hot to cold； and these
quickly supervene； and require no coction。 But all the others being
connected； as I have said； with acrimony and intemperance of humors；
pass off in this way by being mixed and concocted。
19。 But such defluxions as are determined to the eyes being
possessed of strong and varied acrimonies； ulcerate the eyelids； and
in some cases corrode the and parts below the eyes upon which they
flow； and even occasion rupture and erosion of the tunic which
surrounds the eyeball。 But pain； heat； and extreme burning prevail
until the defluxions are concocted and become thicker； and concretions
form about the eyes； and the coction takes place from the fluids being
mixed up； diluted； and digested together。 And in defluxions upon the
throat； from which are formed hoarseness； cynanche； crysipelas； and
pneumonia； all these have at first saltish； watery； and acrid
discharges； and with these the diseases gain strength。 But when the
discharges become thicker； more concocted； and are freed from all
acrimony； then； indeed； the fevers pass away； and the other symptoms
which annoyed the patient； for we must account those things the
cause of each complaint； which； being present in a certain fashion；
the complaint exists； but it ceases when they change to another
combination。 But those which originate from pure heat or cold； and
do not participate in any other quality； will then cease when they
undergo a change from cold to hot； and from hot to cold； and they
change in the manner I have described before。 Wherefore； all the other
complaints to which man is subject arise from powers （qualities？）。
Thus； when there is an overflow of the bitter principle； which we call
yellow bile； what anxiety； burning heat； and loss of strength prevail！
but if relieved from it； either by being purged spontaneously； or by
means of a medicine seasonably administered； the patient is
decidedly relieved of the pains and heat； but while these things float
on the stomach； unconcocted and undigested； no contrivance could
make the pains and fever cease； and when there are acidities of an
acrid and aeruginous character； what varieties of frenzy； gnawing
pains in the bowels and chest； and inquietude； prevail！ and these do
not cease until the acidities be purged away； or are calmed down and
mixed with other fluids。 The coction； change； attenuation； and
thickening into the form of humors； take place through many and
various forms； therefore the crises and calculations of time are of
great importance in such matters； but to all such changes hot and cold
are but little exposed； for these are neither liable to putrefaction
nor thickening。 What then shall we say of the change？ that it is a
combination （crasis） of these humors having different powers toward
one another。 But the hot does not loose its heat when mixed with any
other thing except the cold； nor again； the cold； except when mixed
with the hot。 But all other things connected with man become the
more mild and better in proportion as they are mixed with the more
things besides。 But a man is in the best possible state when they
are concocted and at rest； exhibiting no one peculiar quality； but I
think I have said enough in explanation of them。
20。 Certain sophists and physicians say that it is not possible
for any one to know medicine who does not know what man is ＇and how he
was made and how constructed＇； and that whoever would cure men
properly； must learn this in the first place。 But this saying rather
appertains to philosophy； as Empedocles and certain others have
described what man in his origin is； and how he first was made and
constructed。 But I think whatever such has been said or written by
sophist or physician concerning nature has less connection with the
art of medicine than with the art of painting。 And I think that one
cannot know anything certain respecting nature from any other
quarter than from medicine； and that this knowledge is to be
attained when one comprehends the whole subject of medicine
properly； but not until then； and I say that this history shows what
man is； by what causes he was made； and other things accurately。
Wherefore it appears to me necessary to every physician to be
skilled in nature； and strive to know； if he would wish to perform his
duties； what man is in relation to the articles of food and drink； and
to his other occupations； and what are the effects of each of them
to every one。 And it is not enough to know simply that cheese is a bad
article of food； as disagreeing with whoever eats of it to satiety；
but what sort of disturbance it creates； and wherefore； and with
what principle in man it disagrees； for there are many other
articles of food and drink naturally bad which affect man in a
different manner。 Thus； to illustrate my meaning by an example；
undiluted wine drunk in large quantity renders a man feeble； and
everybody seeing this knows that such is the power of wine； and the
cause thereof； and we know； moreover； on what parts of a man's body it
principally exerts its action； and I wish the same certainty to appear
in other cases。 For cheese （since we used it as an example） does not
prove equally injurious to all men； for there are some who can take it
to satiety without being hurt by it in the least； but； on the
contrary； it is wonderful what strength it imparts to those it
agrees with； but there are some who do not bear it well； their
constitutions are different； and they differ in this respect； that
what in their body is incompatible with cheese； is roused and put in
commotion by such a thing； and those in whose bodies such a humor
happens to prevail in greater quantity and intensity； are likely to
suffer the more from it。 But if the thing had been pernicious to of
man； it would have hurt all。 Whoever knows these things will not
suffer from it。
21。 During convalescence from diseases； and also in protracted
diseases； many disorders occur； some spontaneously； and some from
certain things accidentally administered。 I know that the common
herd of physicians； like the vulgar； if there happen to have been
any innovation made about that day； such as the bath being used； a
walk taken； or any unusual food eaten； all which were better done than
otherwise； attribute notwithstanding the cause of these disorders；
to some of these things； being ignorant of the true cause but
proscribing what may have been very proper。 Now this ought not to be
so； but one should know the effects of a bath or a walk unseasonably
applied； for thus there will never be any mischief from these
things； nor from any other thing； nor from repletion； nor from such
and such an article of food。 Whoever does not know what effect these
things produce upon a man； cannot know the consequences which result
from them； nor how to apply them。
22。 And it appears to me that one ought also to know what diseases
arise in man from the powers； and what from the structures。 What do
I mean by this？ By powers； I mean intense and strong juices； and by
structures； whatever conformations there are in man。 For some are
hollow； and from broad contracted into narrow； some expanded； some
hard and round； some broad and suspended； some stretched； some long；
some dense； some rare and succulent； some spongy and of loose texture。
Now； then； which of these figures is the best calculated to suck to
itself and attract humidity from another body？ Whether what is
hollow and expanded； or what is solid and round； or what is hollow；
and from broad； gradually turning narrow？ I think such as from
hollow and broad are contracted into narrow： this may be ascertained
otherwise from obvious facts： thus； if you gape wide with the mouth
you cannot draw in any liquid； but by protruding； contracting； and
compressing the lips； and still more by using a tube； you can
readily draw in whatever you wish。 And thus； too； the instruments
which are used for cupping ar