MUSCLES, NERVES, AND ELECTEICAL ORGANS. 165 



water which conveyed the current. When he applied a galva- 

 nometer to the parts intermediate between the submerged ones, 

 through which the current had passed, no action whatever was 

 observed. 



In consequence of this Peltier considered the cause of the polar- 

 isation to be the separation of hydrogen and oxygen in the sub- 

 merged parts, which he assumed from the analogy of metallic 

 electrodes, without however demonstrating anything of the 

 sort 1 . 



Peltier's observation was the starting-point of my own work 

 on this subject. On repeating his experiment with a solution of 

 ordinary salt instead of water, I actually found the surface where the 

 current entered the preparation giving an alkaline reaction, and 

 where it emerged giving an acid reaction 2 . Though this appeared 

 favourable to Peltier's explanation, yet, on the other hand, I 

 found, in opposition to his assertion, that every part of the pre- 

 paration through which the current had passed possessed, like a 

 secondary battery, a negative electromotive action. A portion, 

 then, of the negative polarisation possibly depends on the ions 

 collected at the points where the current enters and leaves the 

 preparation. The largest and by far the most important part 

 has its seat in the interior of the tissues, no doubt principally 

 in the muscles. 



3. Preliminary Studies on the internal Polarisation 

 of moist porous bodies. 



I was thus led to conceive the idea of an internal polarisation 

 of muscle. I soon, however, found other moist porous bodies 

 susceptible of internal polarisation, and then I first traced the new 

 phenomenon from a purely physical point of view through a long 

 series of moist porous bodies. These were either of an inorganic or 



1 Untersuchungen iiber thierische Elektricitat, vol. i. part i. p. 377; vol. ii. 

 part ii. p. 378. 



2 Humphry Davy saw acid and alkali set free in muscular flesh, pieces of living 

 plants, and even in the fingers to which distilled water had conducted the current. 

 (Philosophical Transactions for the Year 1807, Pt.I. pp. 52, 53 ; cf. Simon in Gilbert's 

 Annalen, 1801, vol. viii. p. 28 ; Hitter loc. cit., vol. ix. p. 329. I also saw acid and 

 alkali set free in a water-pad covered with violet-blue litmus paper between saline 

 pads. (Gesammelte Abhandlungen zur allgemeinen Muskel- und Nervenphysik, vol. i. 

 Leipzig 1875, P- II -) When I said here that this was contrary to Davy's statement 

 that test-paper only changes colour at the metal electrodes through ions, the above 

 experiments of Davy's were not before me. 



