A critical dissertation upon the manner of the preparation of mercurial medicines, and their operation on human bodies, particularly those most in fashion : also, a demonstration that all the methods hitherto invented, in order to convey quick-silver internally into the blood, retaining its metalline texture and properties, have proved abortive : as also, a certain method of introducing the same metal in its essential or native dress internally into the blood : and the manner of it mechanically explain'd : not publish'd before