280 THE SO-CALLED SECONDARY ELECTROMOTIVE 



it would certainly not be inferred with truth that under certain 

 circumstances a reversed induction occurs in addition to the ordinary 

 one, but it would be rather said that there must have been some 

 error, or that the cause of the phenomenon was something 1 wholly 

 unconnected with induction. In like manner, if in such compli- 

 cated structures as those of muscle and nerve, and with currents 

 of from 20-50 Groves', strengths of current repudiated for other 

 purposes, an after-effect similar in direction to the current were 

 found to exist, no one would think of describing- this effect as re- 

 versed polarisation. On the contrary, it would be said either there 

 is some source of error, or the phenomenon has nothing to do 

 with polarisation. Should the physics of the future indeed bring 

 to light a reversed (' positive ') polarisation, it will certainly not be 

 by means of experiments with such damaging strengths of current, 

 and made upon the most perishable objects in the world. The 

 cases of iron and zinc sulphate &c. before referred to will, on 

 closer investigation, undoubtedly show themselves to be based upon 

 something quite different from reversal of the law of polarisation. 



The author reproaches me (Sect. 15) that I have not discovered 

 the fundamental fact of the + intrapolar after-effect (the posi- 

 tive polarisation of du Bois-Reymond) in a realm in which I have 

 ' entered as a reformer ;' an entirely new method, by the way, of 

 making an attack upon irrelevant grounds. I might just as well 

 reproach him with not having discovered the extrapolar after-effect, 

 the law of the action current, or that of the secretion current, &c., 

 and particularly certain phenomena of this, his own special subject, 

 which will be brought to light in what follows. And how much 

 more indeed might not be discovered if some one would make up his 

 mind to go at muscle and nerve, not with the 20-50 Groves, which 

 we have hitherto used with apprehension, but with hundreds or 

 thousands of elements 1 



The most noteworthy point in the whole treatise is the manner 

 in which the new fact of the + intrapolar after-effect is made 

 use of. If it is true that my theory of electrotonus * so urgently 

 needed ' for its support the electrotonus currents in muscle dis- 

 covered by myself (du Bois-Reymond, Sect, i), 1 it is still more 

 evident that * positive polarisation ' is indispensable for du Bois- 



1 I ask myself in vain on what grounds du Bois-Reymond's theory of electrotonua 

 less urgently needs an electrotonus of muscle than my own. The molecular scheme 

 extends to both muscle and nerve, and what is correct for the molecules in nerve, 

 viz. their rotation by the current, must also be right for the molecules of muscle. 



