Page:The Harveian oration for 1874.djvu/50

 Second.—That while the arteries thus distribute everywhere the fresh pure blood, the veins with which they communicate bring back that same blood, no longer pure, to the right side of the heart, whence it is once more transmitted to the lungs, thence carried again revivified to the left ventricle, and then once more distributed throughout the body, its changes not being those of an ebbing and a flowing tide, but the ceaseless current of an onward rushing river.

We have no means of tracing step by step Harvey’s progress, or of knowing when the grand simplicity of the Circulation of the Blood first revealed itself to him as unquestionable truth. ‘I have found out that which will make my name immortal,’ exclaimed Charles Bell one day in hot haste, when the idea of the two systems of nerves, the motor and the sentient, presented itself to his mind as no vague fancy, but as the conclusion to which careful experiment and thoughtful reflection had brought him. Bell was fortunate in the Vates Sacer, the faithful companion, the ever-ready secretary; shall we say the muse who attended on his genius, or the angel guardian ever