CH. III.] THE CARDIAC NERVES. 91 



are propagated downwards along the same nerve (129, 131), 

 and, consequently, may not only have an influence on the 

 movements of the heart (7), but may excite sentient actions (97). 

 In the same way, the sensational conceptions, desires, and 

 aversions, sometimes excite cardiac movements, which are 

 sentient actions produced through the nerves by various 

 material external sensations (66, 93) : examples of this kind 

 are numerous, as when ideas, foreseeings, and emotions change 

 the movements. It is acknowledged by the most eminent 

 physiologists, that the action of the heart generally is not 

 mechanical, but animal; yet that it is absolutely a sentient 

 action is undoubtedly erroneous, since it will continue and 

 be re-excited even after the heart has been removed from 

 the body (164, iii). Neither is it any proof thereof, that an 

 external impression on the terminal fibrils renews the move- 

 ments of the heart, since the action of that impression be- 

 comes sentient only after reaching the brain, and not before 

 (98, 1 62) . If it be asked, whether the motion of the heart is 

 not sometimes changed by numerous impressions made on the 

 origin of its nerves in the brain, and consequently that many a 

 change in its motion maybe a sentient action (97)? — I answer, 

 — this by no means proves the contrary, for no change in the 

 heart's movement is subject to the will (162, 163). It is much 

 more indisputable, that such a change is a sentient action, when 

 an external sensation or another spontaneous conception excites 

 the change. Now the mind actually feels many external im- 

 pressions on the nerves of the heart. It feels its palpitation, 

 or wounds and other irritants ; and violent actions result from 

 these, which are necessarily direct sentient actions of its ex- 

 ternal sensations (129). That its nerves do not respond to all 

 stimuli, is a peculiarity they have in common with all other 

 nerves. Further, it is indisputable, that although the will has 

 no power over the heart, still many sensational conceptions have, 

 and particularly the instincts and emotions; and it is clear 

 from this, that many changes in the heart's action are true 

 sentient actions, in so far as they are produced by conceptions 

 by means of their cerebral impressions (97, 163). Lastly, 

 although the movement of the heart is neither weakened nor 

 ceases, when the brain is compressed, or the nerves tied, 

 nothing more can be inferred therefrom, than that the entire 



