DBook II PHTHISIS 121

are being stealthily invaded by that sort of decay; but when
the pituitous dischaäarges in the region of the lungs are merely
beginning to be corrupted, but the lungs themselves are not yet
affected, then the man ought not to be called 'phthisical!', but
'dyspnoeic', ?5 or something of that sort.

As for the causes of the form of phthisis that arises originally
within us, I think they are sufficiently well known to doctors.
None of these causes is of necessity previously present in that
form which is contraected by contagion. For it may happen
that a man who has never suffered from catarrh, who has no
ruptured blood—vessels, has never been afflicted with an ulcer
in the chest, never had pleurisy, in short has never had any
serious illness, but is in excellent health, nevertheless contracts
the disease either from association with or living with a sufferer
from phthisis, or from fomes; for it is really astonishing with
what tenacity and for how long a time that virus is preserved
in fomes. In fact it has often been observed that the clothes
which a phthisical person has worn have conveyed the contagion
even after the lapse of two years. Furthermore, the rooms,
beds, and floors where a sufferer from phthisis has died, also
become fomes. We must therefore conclude that in that sort
of fomes are left behind the very germs of contagion that evapo—
rate from the putrefaction produced in phthisis. 'These germs
have a surprising analogy (selective affinity), for they are not
contagious to the eyes, or the palate, or to any other organ ex—
cept the lungs. 'The reason for this, generally speaking, I
have stated above.?* — In faet all things do not act on all things,
but only certain ones on certain others, under certain condi—
tions of activity, substance, and application, and hence they
are called 'analogous'.

Now the signs which indicate that the lungs are already
diseased are often evident to the eye, for often tiny particles of
the lung itself are thrown up in the patient's sputum. But
when the lungs are beginning to decay and are in the flaccid
stage, the signs are not so evident. However, when you ob—
serve that the illness is prolonged, that the sputa are disgusting
in appearance, have an offensive smell, and resemble matter;
when, moreover, the cheeks take on a rosy tinge, then you
may conclude with certainty that the lungs have already be—
gun to decay, especially if the phthisis has been contracted by
contagion. And you can discover proofs that this sort of con—