Page:The Works of William Harvey (part 1 of 2).djvu/337

 both points are situated in the centre of the resolved fluid, and near the root of the veins which thence arise; hut they are never seen simultaneously: in the place of the white point there appears a red and palpitating point.

That portion of Goiter's sentence, however, where he says : ' ' the punctus saliens is now seen in the albumen rather than in the yelk/' is perfectly accurate. And, indeed, moved by these words, I have inquired whether the white point in question is turned into the blood-red point, inasmuch as both are nearly of the same size, and both make their appearance in the same situation. And I have, indeed, occasionally found an extremely delicate bright purple circle ending near the ruddy horizon surrounding the resolved liquid, in the centre of which there was the white point, but not the red and pulsating point ap- parent ; for I have never observed these two points at one and the same time. It were certainly of great moment to deter- mine : Whether or not the blood was extant before the pulse ? and whether the pulsating point arose from the veins, or the veins from the pulsating point ?

So far as my observations enable me to conclude, the blood has seemed to go before the pulse. This conclusion is supported by the following instance : on Wednesday evening I set three hen's eggs, and on Saturday evening, somewhat before the same hour, I found these eggs cold, as if forsaken by the hen: having opened one of them, notwithstanding, I found the rudiments of an embryo, viz., a red and sanguinolent line in the circum- ference ; and in the centre, instead of a pulsating point, a white and bloodless point. By this indication I saw that the hen had left her nest no long time before; wherefore, catching her, and shutting her up in a box, I kept her upon the two remaining eggs, and several others, through the ensuing night. Next morn- ing, very early, both of the eggs with which the experiment was begun, had revived, and in the centre there was the pulsating point, much smaller than the white point, from which, like a spark darting from a cloud, it made its appearance in the diastole; it seemed to me, therefore, that the red point emanated from the white point; that the punctum saliens was in some way engendered in that white point; that the punctum saliens, the blood being already extant, was either originally there produced, or there began to move. I have, indeed, repeatedly seen the