10 THE HARVEIAN ORATION, 1894. 



Ijocly suffers, the countenance changes, and the blood appears to 

 course hither and thither. In anger the eyes are fiery and the 

 pupils contracted ; in modesty the cheeks are suffused with 

 blushes ; in fear, and under a sense of infamy and of shame, 

 the face is pale, but the ears burn as if for the evil they heard 

 or were to hear ; in lust, how quickly is the n^ember distended 

 with blood and erected."* 



Harvey's great contemporary, Milton, though so violently 

 opposed to him in politics, would certainly not remain in 

 ignorance of Harvey's work, and he has noted the changes in 

 the colour of the face produced by emotions. In describing the 

 behaviour of Satan on his journey from Hell to Paradise, he 

 says : — 



" Thus while he spake, each passion dimm'd his face, 

 Thrice changed with pale, ire, envy, and despair; 

 Which marr'd his borrow'd visage." f 



But although these facts were known to Harvey so long ago, 

 it is only in comparatively recent years that the mechanism by 

 which they are brouglit about has been investigated, and it is 

 only within tlie last decade that physiologists have begun 

 regularly to believe that the cardiac muscle has a power of 

 rhythmic pulsation independent of its nerves, although Harvey 

 had noted that when the heart was cut into small pieces the 

 fragments would still continue to pulsate.J We may fairly, 

 indeed, compare the movements of the heart, as regarded by 

 physiologists of the present day, to those of a horse which is 

 capable of going independently, although its pace may be slowed 

 or accelerated by the reins or spur of the rider. TIjc power of 

 the vagus to act as a rein to the heart, and slow its movements 

 or stop them altogether, was first noted by Edward and Ernest 

 Heinrich Weber, while the effect that it sometimes has of 

 accelerating instead of slowing, like the effect of sliaking the 

 reins of the horse, was observed by Schiff, Moleschott and 

 Lister, and the transmission of excitation from one chamber to 

 another was experimented on by Paget. 



* The Works of William Harvey, Sydenham Society's edition, pp. 128— 

 129. 



t Paradise Lost, by John Milton, book iv. 



X The Works of JVilliam Harvey, Sydenham Society's edition, p. 28. 



