96 POLARIZED CONDITION OF THE CHAP. IX. 



, condition ; and it does not appear that, by merely 

 passing a current through it, we should be able to 

 produce the effect we wish. 



Instead of a constant, an intermitting current, from 

 an ordinary medical electro-magnetic machine, was 

 employed, and made to traverse the muscular or 

 nerve fibre as before. In these instances, there was 

 no indication of an increase in either of the muscular 

 or nerve currents. 



The limbs of a galvanoscopic frog were now placed 

 in separate glass vessels, employing the current from 

 the batteiy of six cells, the current being inverse in 

 one limb and direct in the other, as in Matteucci's 

 experiment. When tetanic contractions were pro- 

 duced in the inverse limb, an attempt was made to 

 ascertain whether any difference existed between the 

 muscular and nerve currents of both limbs. No 

 decided difference between the two limbs could be 

 detected ; differences were occasionally observed, but 

 the nerve current in the direct limb was apparently 

 as frequently increased as that of the inverse limb, 

 but the muscular and nerve currents of both limbs, 

 and in other parts of the SEime frog, generally indi- 

 cated a greater amount of deflection previous to the 

 passage of the current from the battery than afterwards. 



It may be asked, Do not these tetanic contractions 

 indicate an increase in the polarized state or con- 

 dition of the nerve? Do Bois Ebtmond' states, 



' On Animal Electricity. Edited by H. Bence Jones, M.D. 

 p. 213. 



