COMMENTARY. We mentioned, in the 18th Section, that the ancients held quartans to be occasioned by an accumulation of black bile. Hence, says Hippocrates, they prevail most in autumn, and attack persons between the ages of twenty-five and forty-five. (De Nat. Hum. 29.) He recommends principally for them emetics, purgatives, and the warm bath. (De Affect. 19.) By wandering fevers, of which mention is made by our author, is meant fevers, the paroxysms of which return after an interval of many days. See Hippocr. (Epidem.); Rhases (ad Mansor. x, 8.) Our author’s description is condensed from Galen (Therap. ad Glauc. i), or probably copied direct from Oribasius (Synops. vi, 12.) Galen states that quartans are of a less inflammatory nature than tertians, and hence the pulse is slower and smaller. Ruffus (ap. Aëtium, v, 83) refers the origin of certain quartans to the spleen. Alexander says that quartans arise from yellow bile overheated, or from feculent blood, these humours being lodged either in the vessels or in the spleen. Palladius, Nonnus, Synesius, and, in a word, all the Greek authorities, give a similar account of the nature of quartans. Constantinus Africanus says that a paroxysm lasts for twenty-four hours, and is succeeded by an interval of forty-eight hours. The urine is at first white and watery, but in the decline becomes black. He mentions that it is connected with induration of the spleen. Actuarius gives a similar account of the nature of the disease, and of the characters of the urine. The disease, he says, is generally connected with some affection of the liver or spleen, and passes off by a discharge of black urine. He relates an interesting case to this effect. (De Urinis, ii, 17.) It may be proper to mention that in all other acute diseases, a discharge of black urine was reckoned a very mortal symptom. (De Urinis Comment. ed. Ideler.) As there is nothing original in the theory and descriptions which the Arabians give of quartans, we shall not enter upon them minutely. Averrhoes states that the fever invades with a great sense of cold, so that the patient’s teeth chatter. The colour of the urine at first inclines to green, or is somewhat white; but afterwards it becomes gross, black, or reddish. The interval between the paroxysms is two days. The most of those affected with quartans have disease of the spleen. Alsaharavius gives exactly the same account of these fevers. Avicenna’s description is most ample and comprehensive, but contains no additional facts to those we have already mentioned. Haly Abbas, Avenzoar, and Rhases, in like manner, adopt the views of the Greeks. SECT. XXIII.—THE CURE OF QUARTANS.