

ELECTRICAL BREAK-EXCITATION. 117 





To this I have a double answer. If by experiments and 

 reflection any one reaches a new conception of a complicated process, 

 he has no time to enquire whether his new view is in agreement 

 with older views of the same subject. He has only to ask whether 

 his view is in agreement with the facts. Though the older view 

 may have brought into harmony a whole series of diverse pheno- 

 mena in the most simple and complete manner, it may yet per- 

 haps be erroneous, and, however dearly won, have to be abandoned 

 and to make way for the others, as has more than once occurred 

 in the history of science. A new theory, therefore, cannot be 

 rejected for the mere reason that it is not entirely in agreement 

 with old ones. 



But in the second place I do not at all see in what way 

 Pfliiger's fundamental law, that the excitation is due not to the 

 current itself but to a definite change of state produced by it in the 

 nerve electro tonus is abandoned on my theory. For, according to 

 my view just as much as according to that of Pfliiger, the appear- 

 ance of catelectrotonus acts as a stimulus; for Pfliiger it is in 

 addition the stronger stimulus ; while the disappearance of anelec- 

 trotonus is for Pfliiger the weaker, but for my theory no stimulus 

 at all. The extremely important fact that the stimulus occurs at 

 the cathode on closure, at the anode on opening, is however also 

 explained by my theory. Besides, if with this fact we often pro- 

 ceed to associate the assertion that the appearance of catelectro- 

 tonus and disappearance of anelectrotonus act as stimuli, this 

 conclusion is justified only if it can be shown that nothing occurs 

 on closure except the appearance of catelectrotonus, and nothing 

 on opening except disappearance of anelectrotonus. But if it be 

 shown that on opening catelectrotonus appears in addition to 

 anelectrotonus disappearing, the former being an event which is 

 known to act as a stimulus, while it is not known whether the 

 latter also does so, the assumption that in both cases the same 

 cause produces the effect is the more probable and logical. Time 

 will decide whether my theory constitutes an advance or not. The 

 conditions are certainly not made to appear more complicated by 

 it; it acknowledges only one part of Pfluger's law of excitation, 

 and, so far at least as I can see, does not essentially contradict it. 

 A nerve is excited only if it is moved from its position of equi- 

 librium in a certain direction ; on returning it is not excited. By 

 this return it changes in the one case from a structure of increased, 

 in the other, case from one of diminished excitability to one of 



