come from the momentum that his strong conviction had given to his movement onwards. For example, he says, "There is one experiment which I would have every one try who is anxious for truth, and by which it is clearly shown that the arterial pulse is owing to the impulse of the blood. Let a portion of dried intestine . . . be taken and filled with water, and then secured at both ends like a sausage: by tapping with the finger at one extremity, you will im- mediately feel a pulse and vibration in any other part to which you apply the fingers, as you do when you feel the pulse at the wrist." After referring to the manner in which such percussion may be made of use in distinguish- ing between air and fluid in the abdomen, he continues, Having brought forward this experiment I may observe, that a most formidable objection to the circulation of the blood rises out of it, which, however, has neither been observed nor adduced by any one who has written against me;" and then he falls back upon his observations which show that, in spite of this seeming difficulty, the circulation has been proved. He says that he had " already satisfac- torily replied to this difficulty;" and such is true, inasmuch as he had pointed out that all the blood did not pass through the vessels, but that some of it was detained for nutrition; he had spoken of the contractility of the arteries, and of the impulse wave; but his solution of the difficulty, that he himself alone had seen, was founded on his confidence in the truth of his main assertion.
6. Boldness was a great feature of Harvey's character, when he told any of the truths he knew. "It were," he says," disgraceful. . . . with this most spacious and admirable realm of Nature before us did we take the reports of others upon trust. Nature is herself to be addressed; and the paths she shows us are to be boldly
