ANIMAL ELECTRICITY. LECTURE VI. I 35 



agents — acid, heat, and action — which presumably 

 provoke a chemical disruption of living- matter — 

 have as their common effect an augmented kathodic 

 polarlsability. 



And please notice with reference to this record, 

 that there can be no question here of any fallacy by 

 alteration of resistance. This point has of course 

 been carefully examined by other experiments into 

 which it is not necessary to enter now ; but in the 

 present case, with a raised temperature (40°), i.e., 

 with increased conductivity, there are diminished 

 currents, and the inc7'eased K. is with a falling 

 temperature, and cotemporary with a diminished A. 

 Comparing the relation between A. and K. before 

 and after the rise of temperature, there is a very 

 evident diminution of the ^/k quotient ; as was the 

 case in consequence of acidification, and in conse- 

 quence of tetanisation. 



The Eledrotonic decrement. The Polarisation 

 increment. — There are two more cardinal experiments 

 belonging to our subject that I am anxious to demon- 

 strate and to explain as clearly as I am able, and that 

 will bring to its conclusion this preliminary exposition 

 of the principal data concerning the electromotive 

 reactions of nerve. 



The first experiment is to show that an electro- 

 tonic current, like a current of injury, is diminished 

 during excitation — undergoes a negative variation. 



