LECT. XIV. XV. NO ELECTRIC CURRENT IN NERVES. 259 



present possess, no sign of the electric current is found in the 

 nerves of living animals. 



Some persons have asserted, that steel needles introduced 

 into the muscles perpendicularly to the direction of their 

 fibres, become magnetic, especially at the moment when 

 the muscles contract. From this it has been concluded, 

 that there existed an electric current in the nerves, and that 

 the circuit was established as in a spiral or an electro-dyna- 

 mic cylinder. 



I have repeated these experiments, by introducing steel 

 or iron needles into the muscles of living animals, and in. 

 all directions relative to their fibres. In order to convince 

 myself of the magnetization of the needles, thus plunged 

 into the muscles, I made use of those of a very good astatic 

 system, and even of those of the sideroscope of Lebaillif. 

 I never obtained an affirmative result. I placed the recently 

 prepared thigh and leg of a frog, in the interior of a spiral 

 of varnished copper wire, the extremities of which were 

 connected with those of a second smaller one, in which 

 there was a soft iron wire. I afterwards irritated the nerve 

 of the frog, observing, at the same time, if an induced 

 current transversed the spiral, and magnetized the iron 

 wire. All my researches were fruitless. 



I likewise tried the effect of introducing into an exposed 

 nerve of a living animal, the conductors of a very delicate 

 galvanometer by two points, as far apart as possible. I 

 operated upon animals under the influence of certain nar- 

 cotic poisons, and I excited strong muscular contractions 

 in them, at the moment when I placed the two wires of the 

 galvanometer in the nerve ; but I must confess that, when- 

 ever the experiment was well made, I never obtained evi- 

 dent and constant traces of the electric current. 



At the school of Alfort I made, in conjunction with 

 Longet, an experiment of this kind upon a horse. We 



