AND ANIMAL LIFE. 271 



merits V. and VI. the effects were almost instan- 

 taneous. The heart therefore is not protected by 

 being subject to the whole brain, but because the 

 sensorium has no direct influence through the ?ier- 

 vous system upon the action of the heart. 



CCXCI. If the heart were influenced by 

 the whole brain, in the sense understood by 

 some physiologists, we should naturally expect, 

 when the whole of this organ was removed, that the 

 action of the former would be materially affected, 

 which is not the case. If the connexion of these 

 organs be regarded as simply nervous, and of that 

 extensive description that the nerves of the heart 

 derive their power from every part of the brain,* 

 the possibility of completely destroying this re- 

 lation without injuring the contractions of the 

 heart, is completely at variance with such an 

 opinion. 



CCXCII. FONTANA destroyed the brain and 

 spinal cord of 24 frogs ; the same organs in 

 the same number of frogs were left entire. The 

 48 were made to swallow a certain quantity of 

 opium, for the purpose of observing whether the 

 action of the heart would be more influenced in 

 the one set than in the other ; but there was no 

 difference in the results. MONRO endeavoured 

 to affect the limb of a frog through the sciatic 

 nerve, which was isolated, but did not succeed.f 

 * WILSON PHILIP, p. 118. 



t Essays and Observations Physical and Literary, Art. XIII. 

 p. 295. Vol. III. Many experiments have been performed in 



