THE MUSCULAR CURRENT. 289 



the atmosphere. I oppose the two piles to one another in the manner I have de- 

 scribed in my work quoted above, for the purpose of discovering the differential 

 current. This done, I determine the intensity of the muscular current in each of the 

 piles, taking note of the first deflection, and of that which the needle indicates after 

 the circuit has been closed ten minutes. In another experiment performed in exactly 

 the same manner, I confronted the current of one muscular pile, the elements of 

 which had been in hydrogen, with another, the elements of which had been in air 

 highly rarefied. Finally, before putting the muscular elements in hydrogen gas and 

 in rarefied air, I measured the muscular currents of each of these piles, in order to 

 compare them with those which were to follow. I should be too long if I were to report 

 all the numbers of the different experiments which I performed. The conclusion to 

 be drawn from them all is extremely simple. Hydrogen gas does not act differently 

 upon the muscular elements from oxygen, and atmospheric or rarefied air, or in other 

 words, these different gaseous media do not exert any influence upon the intensity 

 and duration of the muscular current. 



It only remained for me to determine precisely the cause of the singular effect ex- 

 hibited by hydrogen; and as I could not doubt that this effect was owing to the 

 action of hydrogen gas upon the secondary polarities evolved upon the platinum, I 

 tried the following experiment. I introduced a platinum wire into a tube of glass, 

 and with the blow-pipe I soldered it to the upper and closed end of the tube. I con- 

 structed a pile of twenty elements, and closed the circuit, as seen in fig. 4. The tube 

 filled with water is inverted in the liquid contained in the extreme cavity of the 

 pile, in which the outer surface of the muscle is immersed. When the circuit was 

 closed the first deflection was 90°, then the needle retrograded as usual. When 

 the deflection was at 20°, I introduced hydrogen into the tube A, and the needle in- 

 stantly began to rise to 25°, 30°, 40°, 50°. I allowed the hydrogen to escape, filling 

 the tube again with water and closing the circuit, and after ten minutes the needle 

 was at 5°. Again, I filled the tube with hydrogen and the needle rose to 20°, 25°, 

 30°. Finally, I transferred the hydrogen tube to the other cavity in which the inner 

 surface of the muscle was immersed, and instead of advancing the needle only fell 

 more rapidly. 



The effect then of the hydrogen gas is to act upon the oxygen which tends to be 

 evolved upon the platinum which transmits the muscular current, which passes, as 

 is well known in the muscular element itself, from the interior of the muscle to the 

 surface. It is a case analogous to the gas-pile of Grove. These researches seem to 

 prove that the cause of the rapid diminution, both of the muscular and proper current, 

 from the circuit being kept closed, lies in the secondary polarities of the platinum 

 extremities, which generate a current that circulates in a direction contrary to that 

 of the muscular pile. I have yet to mention the experiments attempted by putting 

 the muscular elements in contact with carbonic acid for different lengths of time. I 

 have performed three experiments of this nature, in each of which I have confronted 



