position. All this Dr. Harvey undertook to do; and with indefatigable Pains, traced the visible Veins and Arteries throughout the Body, in their whole Journey from and to the Heart; so as to demonstrate, even to the most incredulous, not only that the Blood circulates through the Lungs and Heart, but the very Manner how, and the Time in which that great Work is performed. When he had once proved that the Motion of the Blood was so rapid as we now find it is, then he drew such Consequences from it, as shewed that he throughly understood his Argument, and would leave little, at least, as little as he could, to future Industry to discover in that particular Part of Anatomy. This gave him a just Title to the Honour of so noble a Discovery, since what his Predecessors had said before him was not enough understood, to form just Notions from their Words. One may also observe how gradually this Discovery, as all abstruse Truths of Humane Disquisition, was explained to the World. Hippocrates first talked of the Usual Motion of the Blood. Plato said, That the Heart was the Original of the Veins, and of the Blood, that was carried about every Member of the Body. Aristotle also somewhere speaks of a Recur-rent