COMMENTARY. Celsus thus states the prognostics of a protracted fever: “Signa quædam sunt, ex quibus colligere possumus, morbum, etsi non interemerit, longius tamen tempus habiturum: ubi frigidus sudor inter febres non acutas circa caput tantum, et cervices oritur: aut ubi, febre non quiescente, corpus insudat: aut ubi corpus modo frigidum, modo calidum est, et color alius ex alio fit: aut ubi, quod inter febres aliqua parte abscessit, ad sanitatem non pervenit: aut ubi æger pro spatio parum emacrescit: item si urina modo liquida et pura est, modo habet quædam subsidentia; si lævia atque alba rubraque sunt, quæ in eâ subsidunt; aut si quasdam quasi miculas repræsentet; aut si bullulas excitat.” Galen has given a full exposition of these symptoms in his Commentary on the Prognostics of Hippocrates, from which Aëtius, Oribasius, and our author have borrowed largely. Rhases, Avicenna, but most especially Haly Abbas, treat at great length of this subject. See also Averrhoes (Commentaries on the Cantica of Avicenna.) SECT. VI.—HOW TO KNOW IF THE DISEASE WILL TERMINATE BY A CRISIS, OR BY RESOLUTION. This may be ascertained from what has been already said, namely, the species of the fever and its duration, and perhaps from the species of the fever alone. For hot and ardent fevers are of short duration, and usually terminate with some critical evacuation; whereas the gentler kinds prove more chronic, and have a tendency to abscess. From what has been said, it appears that we may prognosticate not only when the disease will come to a crisis, but also how it will terminate; for acute diseases generally terminate by critical evacuation, and the chronic by abscess. * * * * * COMMENTARY. A similar statement is made by Aëtius (v, 22.) See also Averrhoes (Comment. in Cantica Avicennæ.) SECT. VII.—ON CRITICAL DAYS.