300 



THE SO-CALLED SECONDARY ELECTROMOTIVE 



which prevented du Bois-Reymond (p. 348) from using polarising 

 as leading-off electrodes is in this way completely avoided l . 



When one such double electrode lies upon a living, the other 

 upon a dead portion of muscle, then, as might be expected, the 

 + after-current only appears following such currents as are directed 

 from the former to the latter, i. e. from living to dead tissue. In 

 every way the above arrangement presents itself as the most favour- 

 able one for obtaining the + after-effect of muscle, even when both 

 double electrodes lie upon living tissue, since in all cases the leading- 

 off is from the most effective portion of the anodal intrapolar region. 



Examples. Sartorius muscle, with one end A in heat-rigor. 

 Leading in and off by means of double electrodes at cc'. 



|c cr 



Example I. 



Example 2. 



1 In this, as in all experiments of this nature, if a rheochord be used in order to 

 obtain weak polarising currents, the break must lie between the tissue and the 

 rheochord, not between the latter and the battery. (See Pfltiger's 'Archiv,' vol. vi. p. 318.) 



2 The fractions in the brackets indicate the relative delicacy in each particular 



