398 



EFFECT OF IRRITATION OF A POLARIZED NERVE. 



Time. 



Number of ex- 

 periment. 



Irritation without 

 polarization. 



Irritation during 

 poL'.rization. 



Remarks. 



h. m. 



178. 



Ist irritations. 

 2d irritations. . 

 3d irritations . . 

 4(h irritations. 

 5tli irritations. 

 6th irritations. 



179. 



1st irritations. . 

 2d irritations . . . 

 3d irritations . . . 

 4th irritations. . 

 5th irritations. . 

 6th invitations.. 

 7th irritations. . 

 8th iiTitations. . 

 9th irritations. . 

 lOtli irritations. 

 11th irritations. 



Irritation, 1 cell, rheo- 

 chord : 



1500 cent 5. 



1500 cent. 4. 



1500 cent 4. 



2350 cent 0.5 



2350 cent 1. 



2000 cent 2. 



Irritation, 1 cell, rheo- 

 chord : 



3003 cent 4. 



3003 cent 2. 



3003 cent 1.5 



3003 cent 1. 



3003 cent 0. 



3003 cent 0. 



3003 cent 0. 



3006 cent 0. 



3006 cent 0.5 



3006 cent 0.5 



2700 cent 1. 



Polarization, 2 cells, 

 rheochord: 



58 cent 5. 



58 cent 4. 



58 cent 4. 



40 cent 1. 



45 cent 2.5 



45 cent 3. 



Polarization, 2 cells, 

 rheochord : 



25 cent 5. 



25 cent 3. 



25 cent 1.5 



47 cent 3. 



52 cent 4. 



10 cent 3.5 



10 cent 1. 



55 cent 2. 5 



55 cent 2. 



10 cent 1.5 



55 cent 3. 



Kana temporaria. 



Kana temporaria. 



Of this last series of twenty experiments not one could be used as an 

 illustration of Pfliiger's theory, and almost all of them gave results di- 

 rectly opposite to what is demanded by this theory. In fifteen of the 

 experiments the polarizing current usually produced an increased exci- 

 tability of the nerves. 



Thus far one hundred and seventy-eight new experiments have been 

 recorded in this paper, in but seventy-two of which was the theory of 

 Pfliiger confirmed. This result convinced me that this theory could not 

 be true except in a modified state. For, if true, how will the directly 

 opposite results obtained in over one-half my experiments be explained. 

 Yet, as in so many of my experiments an increased excitability was found 

 in the katelectrotonic portion of the nerve, or a decreased excitability 

 in the anelectro tonic portion, I could not but believe that a grain of 

 truth was mingled with the peck of chaff which has been given us as 

 orthodox truth in the books of physiology under the name of " Pfliiger's 

 Laws of Electrotonus." The "grain of truth" consisted in the fact 

 that this condition sometimes did occur, and it was therefore necessary 

 to determine why it is not always present. 



On loolving more carefully over my experiments it occurred to me that 

 the effect of irritating a polarized nerve is influenced by the strength of the 

 polarizing and irritating currents. The experiments of Budge*, Munkf, 

 and Schiflf and Herzenf have already shown that the strengths of the cur- 

 rents did in some way influence the effect of the polarization on the 

 excitability of the nerve, but no one has thought of using this fact to 

 explain the varying results obtained by irritating a polarized nerve. 



For illustrations of this fact as respects the strengths of the polarizing 

 currents vide experiments 9 (irritations 2, 3, and 4), 11, 26 (iriitations 

 27 to 32), 28 (irritations 18 to 30), 46 (irritations 3 and 4), 52 (irritations 

 1 and 2), 53 (irritations 1 to 5), 58, 118, 121, 160, &c. 



*Loc. cit. 



tLoc. cit. 



tLoc. cit. 



