Farther, the reason why the lungs have such ample vessels, both arteries and veins, (for the capacity of the pulmonary veins exceeds that of both the crural and jugular vessels,) and why they contain so large a quantity of blood, as by experience and ocular inspection we know they do, admonished of the fact indeed by Aristotle, and not led into error by the appearances found in animals which have been bled to death,—is, because the blood has its fountain, and storehouse, and the workshop of its last perfection in the heart and lungs. Why, in the same way we find in the course of our anatomical dissections the arteria venosa and left ventricle so full of blood, of the same black colour and clotted character, too, as that with which the right ventricle and pulmonary artery are filled, inasmuch as the blood is incessantly passing from one side of the heart to the other through the lungs. Wherefore, in fine, the pulmonary artery or vena arteriosa has the constitution of an artery, and the pulmonary veins or arteriæ venosæ have the structure of veins; because, in sooth, in function and constitution, and everything else, the first is an artery, the others are veins, in opposition to what is commonly believed; and why the pulmonary artery has so large an orifice, because it transports much more blood than is requisite for the nutrition of the lungs.
All these appearances, and many others, to be noted in the course of dissection, if rightly weighed, seem clearly to illustrate and fully to confirm the truth contended for throughout these pages, and at the same time to stand in opposition to the vulgar opinion; for it would be very difficult to explain in any other way to what purpose all is constructed and arranged as we have seen it to be.
AN ANATOMICAL DISQUISITION
ON THE
CIRCULATION OF THE BLOOD
TO
JOHN RIOLAN, Jun., of Paris
A MOST SKILFUL PHYSICIAN; THE CORYPHÆUS OF ANATOMISTS REGIUS PROFESSOR OF ANATOMY AND BOTANY IN THE UNIVERSITY OF PARIS; DEAN OF THE SAME UNIVERSITY AND FIRST PHYSICIAN TO THE QUEEN MOTHER OF LOUIS XIII.
BY WILLIAM HARVEY, AN ENGLISHMAN
PROFESSOR OF ANATOMY AND SURGERY IN THE ROYAL COLLEGE OF PHYSICIANS OF LONDON; AND PRINCIPAL PHYSICIAN TO HIS MOST SERENE MAJESTY THE KING.