330 ELECTRO-PHYSIOLOGY. 



gas was found to result from the action of the gas on the secondary polarity 

 of the platina extremities of the galvanometer. It is possible that the action 

 of these gases on the nutrition and on the muscular respiration may eventually 

 have a certain influence on the electro-motor power of the muscles; but this 

 effect will be slow in manifesting itself. The action of nitrous gas and of sul- 

 phuretted hydrogen is, on the other hand, distinct. On causing frogs and even 

 animals of warm blood to die by inhaling these gases, it is found that the elec- 

 tro-motor povv^er of their muscles is enfeebled. The same may be said of frogs 

 which have died after many hours, confinement in water boiled and deprived 

 of air. 



It has finally been inquired what effect ensued from the immersion of mus- 

 cles in different liquids upon their muscular electro-motive power. The first 

 effect realized from such immersion, if very brief, in saline water and in a 

 solution of sulphate of soda or of magnesia, is the augmentation of the power 

 in question. On using in effect the differential method, and comparing a muscle 

 which has not been, Avith another which has been, immersed in these liquids, if 

 a differential current has been observed, as is in fact often the case, this current 

 has been in the direction of the muscles which had undergone immersion. It is 

 impossible to explain this effect solely by the increase of conductibility due to 

 the liquids ; we are obliged to recur to the augmented electro-motive force. It 

 is to be noticed also that these liquids maintain the red color of the globules of 

 the blood, and must therefore increase the chemical action of nutrition. From 

 prolonging for a greater time the immersion of a muscle in any liquid, the con- 

 stant and general efi'ect is the weakening, and finally the disappearance of the 

 electro-motive power much sooner than would be tlie case if the muscles were 

 left in air. 



After having stated the laws of muscular electricity, it would remain to pro- 

 pound the theory of this animal electro-motor. What is its form? What its 

 manner of acting? With which of the electro-motors known in physics has tlie 

 living muscle an analogy ? We are forced to confess that, notwithstanding the 

 many investigations which have been devoted to muscular electricity, we are 

 yet unable to give any satisfactory reply to these questions W^e know that a 

 piece of muscular elementary fibre, however small, if taken from an animal 

 living or recently dead, is an electro-motor, of which the current has a deter- 

 minate direction in the muscular fibre luider examination. We know that this 

 electro-motor power increases with the length of the fibre, and with the number 

 of the muscular elements organically combined. We know, finally, that this 

 same power varies with the muscular irritability. We are thus led to conclude 

 that the electro-motive power of the muscles has its origin in the chemical actions 

 of the muscular respiration. But all this conveys no information respecting the 

 form of the nutscular electro-motor, nor whether the currents which we detect 

 with the galvanometer are derived currents — that is, whether the muscular 

 electro-motors being always in action, their currents are discharged through the 

 liquids or the tissues which envelop the muscle. Certain it is that the currents 

 obtained in the frog which still retains the skin are weaker than those which 

 occur at the same points in the same frog when the skin is removed, and this is 

 also the case on covering a muscle with any liquid stratum whatever. 



We should not forget that there is in the muscular electro-motor a funda- 

 mental character which distinguishes it from the common electro-motors. The 

 extremities of an entire muscle have the same electrical state, as two artificial 

 transverse sections also have the same state, which can never be the case either 

 in a battery, an electro-dynamic spiral, or in a Leyden jar. We cannot, in the 

 actual state of the science, form any precise idea of this difference, nor is it more 

 easy to understand why the half thigh, which is a muscle terminated by two 

 transverse sections, one natural and the other artificial, which should have, it 

 would seem, the same electrical state, is, notwithstanding, a powerful electro- 



