The vitreous phlegm being the coldest of all, if it accumulate in the body, and remain free from putrefaction, it occasions the rigor without heat, which is not attended with fever. In those fevers which are kindled by the humours, it is putrefaction for the most part which kindles febrile heat. If it become putrid, and that through its whole substance, which is rarely the case, owing to its great coldness, it occasions quotidian fever. But when it is half putrid, and not equally through its whole substance, but some parts of it being putrid, and others not, it gives rise to the fever called hepialus, in which those affected have rigors and fever at the same time; for the parts of the humour which are not putrid being scattered through the veins all over the body, occasion rigor; but the putrid parts kindle fever. The word hepialus is either derived from ἡπίας ἁλος, i. e. the sea, which is mild in appearance, although formidable in reality; or from ἡπίως ἁλεάζειν, i. e. warming gently. And, as this fever is of the quotidian kind, being formed by phlegm, it is to be treated in the same manner; only that it requires remedies as much hotter and more incisive than the quotidian, as its phlegm is colder than that of the other. The rigor without heat stands in need of heating things still more than the hepialus. Wherefore, the composition of three peppers, that from calamint, and still more that from Cyrenaic juice are particularly suitable to this complaint, as also the remedies prepared from castor and the like. You will find a fuller account of these matters in the 46th section, “on immoderate rigor and cold.” The fevers called lipyriæ, and the typhoid or smoky, and whatever others are mentioned besides those described, being all of the same kind as the above mentioned, will require the same methods of cure as those which have been mentioned, or will soon be described. * * * * * COMMENTARY. Hippocrates applies the term hepialus to a fever occasioned by amenorrhœa. He briefly notices the lipyria in several parts of his works, (as Coac, 32, 27.) Galen enters minutely into the consideration of the nature and causes of the hepialus, which appears to be a variety of the quotidian intermittent. He says the fever derives its origin from the putrefaction of a thick phlegm resembling melted glass. Its distinguishing characteristic is, that the patient experiences a sensation of heat and rigor at the same time. Aëtius, and the other subsequent authorities, treat of the fever in the same terms. They recommend, principally, sudorifics and calefacients.