55 



LECTURE III. 



CONTENTS. 



On the production of CO„ by tetanised nerve. 



Hypothesis and experiment. Three stages. Comparison between 



the effects of CO2 and of tetanisation. 

 Direction of further inquiry. Significance of the staircase effect. 



Summation. " Bahnung." 

 Postscript. 



It was comparatively early in these experiments — 

 during the month of October, 1895 — that the nerves 

 under study presented some puzzling- features in their 

 mode of response, that for some time were a grievance 

 and a stumbling-block. The nerves said "check," 

 just as this month (February) they are again saying 

 " check." My disgust at their enigmatical conduct 

 came to its climax on October 27 with plate 672, and 

 vanished in the evening of the same day with the 

 appearance of plate 675. 



I will venture to tell the story of these two plates, 

 for I think that it illustrates what so often happens in 

 the course of an inquiry as almost to be the rule, viz., 

 that "check" in the course of some otherwise smooth 

 and glib interrogation, although at first disliked as a 

 stumbling-block, ought in reality to be welcomed as a 

 stepping-stone in disguise, a sign that some unexpected 

 bit of truth has cropped up. 



I had undertaken to show a friend the stimulant 

 action of carbon dioxide, and had announced it as an 



