LECT. IX. ORGANIC CONDITIONS OF MUSCLES. 185 



after the other ; each one being deprived of the integuments 

 of the thighs and the legs ; and moreover, an incision being 

 made in the muscle of one of their thighs. 



The frogs being thus prepared, we easily succeed in put- 

 ting the leg of one into contact with the interior of the 

 muscles of the cut thigh of the next animal. In this way 

 we form, with living frogs, the pile already described. 

 The current which we then obtain is, as usual, directed 

 from, the interior to the external part of the muscle : its 

 intensity is, with an equal number of elements, more con- 

 siderable than with the muscles of dead frogs ; and it more 

 slowly becomes weaker. 



When we connect the interior and the surface of the 

 muscle, of a living or recently killed animal, by means of 

 a conducting arc, the existence of an electric current is then 

 rigorously demonstrated. This current is always directed 

 from the interior to the exterior of the same muscle ; its 

 duration after death varies, and is much longer in cold- 

 blooded animals than in those of a higher order. It ex- 

 ists without the direct influence of the nervous system, 

 and it is not modified, even when we destroy the integrity 

 of the latter. 



Influence of the organic Conditions of Muscle. It remains 

 for me to notice the investigations I have undertaken with 

 the view of discovering the influence which the organic 

 conditions of the living muscle have upon this current. 



When we examine the muscles of animals which have 

 been kept without food, or in which the blood either circu- 

 lates slowly, or is entirely interrupted, we see that the cur- 

 rent has lost much of its intensity. The same effect is 

 produced by employing frogs which have been left for some 

 time in water, more or less deprived of air by ebullition. 



If, on the contrary, the muscles have been for some time 

 the seat of inflammation, or have been gorged with blood, 



