CIRCULATION OF THE BLOOD. 139 



immersion in the cold water would repress their ebullition, but 

 with blood only, and such as could never make its way back 

 into the arteries, either by open-mouthed communications or 

 by devious passages ; it shows, moreover, how and in what way 

 those who are travelling over snowy mountains are sometimes 

 stricken suddenly with death, and other things of the same kind. 



Lest it should seem difficult for the blood to make its way 

 through the pores of the various structures of the body, I shall 

 add one illustration : The same thing happens in the bodies of 

 those that are hanged or strangled, as in the arm that is bound 

 with a fillet : all the parts beyond the noose, the face, lips, 

 tongue, eyes, and every part of the head appear gorged with 

 blood, swollen and of a deep red or livid colour; but if the 

 noose be relaxed, in whatever position you have the body, be- 

 fore many hours have passed you will perceive the whole of the 

 blood to have quitted the head and face, and gravitated through 

 the pores of the skin, flesh, and other structures, from the su- 

 perior parts towards those that are inferior and dependent, until 

 they become tumid and of a dark colour. But if this happens 

 in the dead body, with the blood dead and coagulated, the frame 

 stiffened with the chill of death, the passages all compressed or 

 blocked up, it is easy to perceive how much more apt it will be 

 to occur in the living subject, when the blood is alive and re- 

 plete with spirits, when the pores are all open, the fluid ready 

 to penetrate, and the passage in every way made easy. 



When the ingenious and acute Descartes, (whose honourable 

 mention of my name demands my acknowledgments,) and 

 others, having taken out the heart of a fish, and put it on a 

 plate before them, see it continuing to pulsate (in contracting), 

 and when it raises or erects itself and becomes firm to the touch, 

 they think it enlarges, expands, and that its ventricles thence 

 become more capacious. But, in my opinion, they do not ob- 

 serve correctly ; for, at the time the heart gathers itself up, 

 and becomes erect, it is certain that it is rather lessened in 

 every one of its dimensions ; that it is in its systole, in short, 

 not in its diastole. Neither, on the contrary, when it collapses 

 and sinks down, is it then properly in its state of diastole and 

 distension, by which the ventricles become more capacious. 

 But as we do not say that the heart is in the state of diastole 

 in the dead body, as having sunk relaxed after the systole, but 



