Harvey now rapidly advanced in general favour as a physician, and in 1615 was appointed Lumleian Lecturer at the College of Physicians, an office then held for life. His first lectures were given in April 1616, and in this and subsequent years he gradually unfolded the novel views on the heart and the circulation of the blood which he was acquiring, and which he published in 1628. The novelty of his views does not, however, consist in the idea that the blood actually moves in the vessels. This was known before, and Shakespeare gives expression to a current conception in the passage at the head of this chapter. Servetus, in 1553,[4] had asserted that the blood finds access from the right side of the heart to the left through the lungs, thus explaining the intermixture in the heart of the two kinds of blood appropriate to arteries and veins respectively. For a long time the partition between the ventricles was believed to be perforated like a sieve, so that a mixture of venous and arterial blood could take place. But this had been completely disproved by Berengarius and Vesalius. Consequently the two kinds of blood, according to this view, after meeting in the head, thorax, and abdomen, returned to the heart by the way they came, for a fresh supply of the exhausted or enfeebled spirits on which the principal functions of the body depended. Servetus, it is true, asserts a communication between the pulmonary artery and veins; but he particularly declares that “the vital spirit has its origin in the left ventricle, the lungs assisting especially in its generation,” and that “it is engendered from the mixture that takes place in the lungs of the inspired air with the elaborated subtile blood which the right ventricle of the heart communicates to the left.” The extent of his knowledge is further shown by his statement that “the blood is mixed in the pulmonary vein with the inspired air, and by the act of expiration is purified from fuliginous vapours, when having become the fit recipient of the vital spirit, it is at length attracted by the diastole.” Still very great credit is due to the man who first declared that “the crimson colour is imparted to the spirituous blood by the lungs, not the heart.” Servetus was, however, ignorant of the force by which the blood is impelled into the arteries, and the contractile functions of the heart were unknown. The ventricle was believed to dilate from some undiscovered cause, and thus to suck in the purified “spiritus vitalis.” But Servetus’s explanation, whatever it was worth, occurred in a theological work, the issue of which led to the author’s death at Calvin’s persecuting hands, and the work remained unknown—for Calvin carefully burnt every copy possible—until 1694, when Sir Henry Wotton disinterred it.