The Art of Invigorating the Health, and improving the Strength of Man, has hitherto only been considered for the purpose of training him for Athletic Exercises, but I have often thought that a similar plan might be adopted with considerable advantage, to animate and strengthen enfeebled Constitutions, prevent Gout, reduce Corpulency, cure Nervous and Chronic Weakness, Hypochondriac and Bilious Disorders, to increase the Enjoyment, and prolong the duration of Feeble Life, for which Medicine, unassisted by DIET AND REGIMEN, affords but very trifling and temporary help. The universal desire of repairing, perfecting, and prolonging Life, has induced many ingenious men to try innumerable experiments on almost all the products of the Animal, Vegetable, and Mineral kingdoms, with the hope of discovering Agents, that will not merely increase or diminish the force or frequency of the Pulse; but with an ardour as romantic as the search after the Philosopher's Stone, they have vainly hoped, that Panaceas might be found possessing the power of curing "all the evils that flesh is heir to." Let not the uninitiated in Medical Mysteries imagine for a moment, that the Editor desires to depreciate their Importance, but observe once for all, that he has only one reason for writing this Book, which is, to warn you against the ordinary causes of Disorder and to teach you the easiest and most salutary method of preventing or subduing it, and of recovering and preserving Health and Strength, when, in spite of all your prudence, you are overtaken by sickness, and have no Medical Friend ready to defend you.