The nature of an intermitting fever and ague consider'd wherein is explain'd, the cause of each succeeding symptom, and their periodical returns: with the best and most rational method of cure. Such Cures also are accounted for, as have been obtain'd by Spirits, Acids, Charms, Frights, Emeticks, Catharticks, Sudorificks, Hot and Cold Bathing. With Reasons and Cases to prove, How the Bark in many Instances doth cure, and why in many others it doth not, and when judiciously given seldom fails; in Order to obviate the Mistakes of those who are prejudic'd against that Incomparable Medicine. To which is added, An Extraordinary Case of one Widow Sparkes, of Eighty Years of Age, who upon the Cure of an Ulcer in her Leg, had her Menses return, after they had left her Thirty Years, and they continu'd their regular Periods. By Simon Mason, of Cambridge