Causon was due to putrefaction of bile in the smaller vessels of
the heart, diaphragm, stomach or liver, and was an acute fever
characterized by furred tongue, intolerable frontal headache, tinnitus
aurium, constant thirst, delirium, an olive-colored face, redness and
twitching of the eyes and a full, frequent and rapid pulse. Epiala
and lipparia were febrile conditions concerning which there seems to
have been much difference of opinion, even in the days of Gilbert.
Apparently they were distinguished by variations of external and
internal temperature, or by chills combined with fever. Febris ethica
is our modern hectic fever. In the discussion of this last variety we
are introduced to the "_ros_" and "_cambium_" of Avicenna, apparently
varieties of hypothetical humors.

All these fevers are regarded from the standpoint of Humoralism,
and depend upon variations in the quantity, quality, mixture or
location of the four humors, blood, phlegm, bile and black-bile
(_melancholia_).

In the general treatment of febrile diseases, so-called preparatives
and digestives are first employed to ripen the humors, after which
evacuatives (emetics, cathartics, sudorifics, and occasionally even
venesection) are utilized for the discharge of these peccant humors.
Much emphasis is laid upon the dietetics of fevers, and this branch of
treatment is highly elaborated. Complications are met by more or less
appropriate treatment, and the condition of the urine is studied with
great diligence. Venesection is recommended rather sparingly, and is
never to be employed during the _dies caniculares_ (dog-days) or _dies
Aegyptiaci_, nor during conjunctions of the moon and planets, nor upon
the 5th, 15th, 17th, 25th, 26th, or 27th days thereafter, etc.

Among the complications of fevers discussed by Gilbert, two seem
sufficiently important to justify special attention. On folio 74b we
find a section entitled "_De fluxu materie per parotidas venas_,"
in which he remarks that "Sometimes matter flows through the parotid
veins behind the ears down to the neck and nares, and obstructs the
passages for air, food and drink, so as to threaten suffocation." He
cautions us against the use of repressives, "lest the matter may run
to the heart," and recommends mollitives and dissolvents, such
as butter, dyaltea, hyssop and especially newly shorn wool (_lana
succida_), which, he says, is a strong solvent. Is this a reference
to the septic parotitis not unfreq