Book III TREATMENT OF CONTAGIONS 187

shall now prescribe. For once the germs are killed, the disease
will progress no further.  'The same is true of rabies, syphilis,
scabies and the rest. Nay, more; when you are called in at an
advanced stage of the disease, if you resort to general remedies
and clear away the catarrh in phthisis and concoct its substance,
you will still accomplish nothing, unless you unceasingly direct
your attention and treatment to the germs. Moreover, in the
case also of fevers called pestilent, why do we not employ those
remedies which we are in the habit of employing in other fevers?
Why does everyone forthwith cry out that we must halt the
putrefaction?  And this is not done by clearing away obstruc—
tions or evacuating plethora (of the humors), but by seeking
for certain special means which may oppose the putrefaction.
It is because there is in these fevers a definite mode of putre—
faction which demands special attention. Now it seems that
our ancestors did hand down to us the treatment for certain
contagions, to the extent at least of some remedies, but that
not all of these remedies were designed to fight contagion as
contagion, but were either discovered by some chance or from
its resemblance to other things, such as poisons and the like.
"This will become more evident from what I shall have to say
about each disease separately. This I shall now undertake,
and begin with the universal method and form of treatment.
Now there are two ways of treating disease, the one prophy—
lactic, while the other frees the patient from it. For the sake
of brevity I shall begin my enquiry with the latter, the curative
method, and I promise that, once this has been correctly under—
stood, everyone will be able to take the easiest road to the
prophylaetic method also. Well then, he who wishes to cure
contagions must pay attention to the following points.^ First
let him observe what sort of contagion it is, whether it is one of
those that come to us from without, and if so whether it has
been contraeted from the air or from another person; or whether
it is one of those which develope originally in us; whether it
infects by direct contaet only, or also by fomes, or infects also
at a distance. 'Then let him consider whether it is acute or
slugeish; in what humor it is seated, and what is its analogy
(selective property); also how far it has progressed, whether it
is in the initial stage, or has progressed far; also what parts of
the body are mainly attacked, whether it is wholly internal, or
wholly external, or everywhere; whether it has taken hold of