Page:The Harveian oration - delivered at the Royal College of Physicians June 24, 1882 - by George Johnson (IA b21517046).pdf/24

 ries and veins, was supposed to be of a to-and- fro character. From the time of Aristotle to that of Cesalpino, and, as we shall presently see, by Cesalpino himself, this movement was compared to the tides of Euripus--that is, to the ebb and flow of the tide in a narrow channel. This, then, was the state of knowledge, or rather of igno- rance, with regard to the movement of blood in the systemic vessels before the publication of Cesalpino's writings. We have now to inquire to what extent he succeeded in throwing light upon the subject.

With regard to the structure of the heart and its valves, Cesalpino says that it is so arranged as to allow of continuous motion from the veins to the heart, and from the heart to the arteries.¹ In these statements there was nothing new. In the chapter ' De Pulmonis Constitutione' lie 2 the says

¹ 'Ut continuus quidam motus fieret ex venis in cor et ex corde in arterias.'--Speculum Artis Medice, lib. vi. cap. xix., ed. 1670, P. 473.

2 Fertur igitur ex corde sanguis fervidus per arteriam ex dextro ventriculo, quam Galen venam arterialem vocat, in pulmonem iterumque cordi redditur per venam ex sinistro ventriculo pro- deuntem, quam Galen arteriam venalem vocat. Interim in itinere contemperatur ab aere frigido inspirato in asperas arterias juxta venas et arterias, ut circulatione quadam sanguis perficiatur in naturam spiritus, prins in dextro ventriculo deinde in sinistro.