Page:The Harveian oration, 1875 (IA b22314611).pdf/28

 onward course of the blood, but preventing all regurgitation.

Having satisfied himself respecting the lesser circulation through the lungs, and taken note also of that other circuit by which the heart itself is nourished, Harvey proceeds to the greater circulation throughout the body, and has something so novel and unheard of to say about the quantity and source of the blood which passes from the veins into the arteries, that he fears to give it expression, lest he should stir up the envy of a few, and excite the enmity of mankind at large, in whom custom has become a second nature, doctrines once sown have struck deep root, and antiquity inspired respect. Still the die is cast, and Harvey, placing his trust in his own love of truth and the candour inherent in cultivated minds, proceeds to pass in review his stores of knowledge in terms I have already quoted; and laying special stress on his subtle and profound argument, based on the obvious impossibility of the circulating system —heart, veins, and arteries—holding together, unless there were “{{c|A motion as it were in a circle”, indulges in a lofty flight of poetic expressions. He compares the blood forced by the left ventricle into