As a tertian paroxysm commences with a rigor, and a quotidian without one, the fever composed of both brings on a degree of shivering, which is less than a rigor, and greater than chillness, as being a mixture of these two extremes. Whence, this fever has not improperly got the name of semi-tertian. These fevers are formed in two ways, either the two paroxysms uniting into one, or being mixed together from the commencement. When, therefore, the tertian prevails, the fever is attended with a strong shivering, and has even a certain degree of rigor at the attack. Such a fever also soon becomes hotter and more ardent, and brings on some vomiting of bile, or a discharge of it downwards, or by a sweat. When the other, the pituitous, prevails, there is coldness of the extremities, but little shivering; neither are they accompanied with thirst, nor are they ardent. But when the tertian intermittent and continual quotidian are equal in magnitude, the commencement of the paroxysm is with shivering; and when that from phlegm prevails, there are contractions and shiverings; but if the hotter species prevail, they soon acquire heat. This is the true semi-tertian, being a fever formed from an equal combination of both, a tertian intermittent, and a continual quotidian. But that which is not the true semi-tertian has either more of the bilious, or of the pituitous character; which species is of easiest cure, the smaller humour being readily overcome by the prevalence of the greater, or by the aid of art. When the pituitous state prevails, we must use especially the remedies mentioned for the quotidian; or, if yellow bile, those for the tertian, always bestowing most attention upon that which is most urgent, but not neglecting the other entirely. * * * * * COMMENTARY. The reader may find histories of the semi-tertian in the Epidemics of Hippocrates, where see the Commentary of Galen. Our author’s account is condensed from Galen (de Diff. Febr. ii, 2, and de Typis, 4.) See Aëtius (v, 81); Actuarius (Morb. Dig. ii, 1); Nonnus (142); Celsus (iii, 8); Palladius (21.) Celsus describes it as the second species of tertian in the following terms: “Alterum longe perniciosius, quod tertio quidem die revertitur, ex octo autem et quadraginta horis fere sex et triginta per accessionem occupat, interdum etiam vel minus, vel plus; neque ex toto in remissione desistit, sed tantum levius est. Id genus plerique medici ἠμιτριτᾶιον appellant.” He approves of bleeding at the commencement, and of a diet that is nutritive without being heating.