MUSCLES, NERVES, AND ELECTRICAL ORGANS. 197 



ation holds good, that the resulting- polarisation, which is the 

 difference between two component polarisations, is no measure of 

 their strength, for this may be many times as great as the observed 

 difference. For, obviously, the various kinds of phenomena of 

 nerve-polarisation lead unavoidably to the assumption that in 

 nerves as well as in muscles there are present at the same time 

 two polarisations, a positive polarisation which at once attains 

 almost its full amount although it continues to increase slowly and 

 is very persistent, and a negative polarisation which increases with 

 the time of closure, and rises more and more above the former, 

 but disappears more quickly after the opening of the battery- 

 circuit. Opening currents of the ordinary inductorium of an 

 adequate strength produce purely positive polarisation. 



In regard to the finer details of the phenomenon, the various 

 maxima of polarisation-curves recognised in muscles, and the influence 

 on the position of these maxima of current-density, time of closure, 

 and time of opening, it is desirable to await further investigations, 

 although even in this respect the old nerve-table, with all its 

 incompleteness, has a certain resemblance to the new table of 

 muscle. We know nothing as yet about the proportional strength 

 and duration of polarisation in muscle and in nerve with an equal 

 current-density, &c., and it would be very difficult to form a 

 reliable conception of it. 



14. Matteucci's Experiments on Nerve Polarisation. 



I first gave an account of internal negative polarisation of nerves 

 in 1856, in my paper upon this phenomenon in moist porous bodies 

 generally 1 . In 1867 I again returned to it as a circumstance 

 which is opposed to the constancy of currents in circuits containing 

 nerves 2 . That nerves possess, in addition, internal positive polari- 

 sation, although perhaps in a manner only apparent to persons well 

 informed on the subject 3 , I have often pointed out when speaking 

 of the secondary electromotive actions of electrical organs. 



Although my papers on polarisation of electrolytes and moist 

 porous bodies found their way into French and Italian journals 4 , 



1 Monatsberichte etc., August 4, 1856, p. 457; Gesammelte Abhandlungen etc., 

 vol. i. p. 19. 



2 Archiv fur Anatomie, Physiologie, etc., 1867, p. 262 ; Gesammelte Abhandlungen 

 etc., vol. ii. p. 192. 



3 Monatsberichte etc., 1858, p. 106; Untersuchungen am Zitteraal etc., p. 206. 



4 II nuovo Cimento ec., vol. v. Maggio e Giugno, Pubbl. il 9 Luglio, 1857, P- 33$ J 

 Annales de Chimie et de Physique, 3 me Sdrie, 1860, vol. Iviii. pp. 314, 318. 



