PHYSIOLOGY. 81 



one case than in another ; we can impute it to the manner in 

 which the experiment was made, to their not cutting through 

 all the nerves at once, and, as the heart is supplied with nerves 

 from various sources, to some of these being left uncut which 

 might support its action. But, in another way we remove the 

 difficulty, by saying that it is true that the action of the heart 

 may, hi some degree, subsist after all such communication is 

 destroyed ; that there is an inherent power to this effect we 

 readily allow; and in a living and entire animal, with a very 

 few nerves, or, if you will, with none at all, it may give some 

 action ; but this does not disprove that the nerves are constantly 

 necessary ; for in these experiments the actions were disordered, 

 the pulse became intermittent, and the slight palpitations which 

 continue in the heart after it is separated from the nervous sys- 

 tem, are not that vigorous action which is necessary to the func- 

 tions of life. From all these considerations together, I think 

 it should appear that some energy of the brain is required even 

 in the involuntary motions, where it appears to be less neces- 

 sary, and where a renewed action does not indeed always concur, 

 as in the voluntary muscles. I could make a like remark with 

 respect to the stomach, where we cannot shew such proofs of 

 the brain exciting or diminishing its action ; we know that the 

 stomach requires the constant action of the nerves, the constant 

 energy of the brain ; for by destroying its nerves it becomes 

 paralytic immediately, an effect which was commonly found 

 to occur in the experiments made upon the heart by cutting 

 the par vagum : the appetite was destroyed, the contents of the 

 stomach stagnated and were variously corrupted, &c. In cer- 

 tain diseases the same accident has happened. With regard to 

 the voluntary muscles the matter is more clear : if the nerve 

 belonging to a muscle is tied, it becomes paralytic, in so far as 

 the will has no more any power over its motions. But Dr. Hal- 

 ler says, 'motus insitus superest nervo revincto,'* ( 404). 

 Stimuli applied will indeed renew its contraction ; but these 

 contractions are not so vigorous and full as when they are pro- 

 duced by the power of the will, i. e. by the animal power. From 

 Haller's own experiments it is evident that the motion is consi- 

 derably weakened in consequence of ligatures upon the nerves. 

 He refers to two authors, Du Bois and Jausserand, who found 

 VOL. i. F 





