Page:The Harveian oration delivered at the Royal College of Physicians June 26, 1889 (IA b22361285).pdf/10

 pulsate together, and by successive strokes, because they all depend upon the heart.’ These words produced no impress on the physiology of the day, and we find authors wandering darkly around the great fact which it was Harvey’s mission to bring to light. For eighteen hundred years after Aristotle, no advance was made worthy of note; for Servetus, who wrote in 1553, and of whose labours too much has been made by commentators, did little more than offer a conjecture on the pulmonary circulation. It is worthy of notice, however, that at this date the necessity for contact of atmospheric air with the blood coming from the right ventricle was recognised.

It was by this contact, the Vital Spirit, as it was called, was produced or engendered: the colour of the blood changed to crimson, and, purified by the inspiratory act from fuliginous vapours, the vital fluid became fitted for the preservation of life and health. The blood of the right ventricle was known to require great purification, and it is to be hoped physiology will soon help us to a more complete knowledge of the changes effected by the respi-