on the Agency of Galvanism. 81 



which has nothing in common with the eflfects of any chemical 

 ag-ent. We also perceive, during life, a well-marked line of 

 distinction between these two sets of functions. While the ani- 

 mal enjoys health, the sensorial functions are subject to intervals 

 of inactivity. In the most perfect sleep, these functions, with 

 the exception of that part of them which is necessary to respira- 

 tion, cease ; while the functions which 1 have termed nervous, 

 on which, in conjunction with the muscular function, the life of 

 the animal depends, have no such intervals ; and, by their con- 

 stant activity, support that part of the sensorial functions with 

 which they are intimately connected in respiration. This is the 

 only function, as appears from what is said in the tenth chapter 

 of the second part of my Inquiry, essential to life, in which the 

 sensorial power is concerned, and which, consequently, forms 

 the only connexion essential to life, between the sensorial and 

 nervous powers. 



The extent and nature of this connexion I have endeavoured 

 to define by many experiments, which demonstrate the indepen- 

 dent action of the sensorial and nervous, as well as the muscular 

 power, in the function of respiration * ; shewing that, although 

 they all conspire in its performance, so that it ceases if any one 

 is withdrawn, yet that, after withdrawing any one, we can still 

 prove by experiment the presence of the others in unimpaired vi- 

 gourf, although rendered inefiFectual, as far as relates to respi- 

 i^tion, by the absence of a power, which must co-operate with 

 them in this complicated function. 



These observations led me to point out, that, as the sensorial 

 powers are always the first whose operation ceases in dying, 

 unless death be instantaneous throughout the system, by the 

 sudden and total destruction of the nervous power I it is by 

 destroying respiration, that all other causes of death finally de- 

 stroy the nervous and muscular powers §. These powers can- 



* See the Tenth Chapter of the Second Part of the above Inquiry, and 

 the experiments there referred to. 



\ See page 210, ct scq. of that Inquiry. 

 X lb. page, 213 et seq. 

 § lb. page 206, ct scq. 

 Vol.. VIII. G 



