124 



LECTURE VI. 



ELECT ROTON US {Cotitinned), 



Influence of acids and alkalies. Influence of carbonic acid and 

 of tetanisation. Influence of variations of temperature. 



The action-currents of polarised nerve. Bernstein's electro-tonic 

 decrement. Hermann's polarisation increment. 



InfltLence of Acids and Alkalies. — Turning back to 

 the kind of nerve upon which we have found that 

 experimental comparisons can be made systematically, 

 let me next direct your attention to some experiments 

 that at once suggest themselves when we have ad- 

 mitted that the extrapolar currents of nerve are 

 caused by electrolytic polarisation. 



Looking back to the series of effects represented 

 and summarised In ^<g. 47, p. 109, we naturally ask our- 

 selves what will be the effects of acids and bases upon 

 An. and Kat. 



Reviewing any considerable number of experi- 

 mental records in which A. and K. have been taken 

 before and after the nerve has been submitted to the 

 action of a weak acid or of a weak base, we shall 

 find :— 



