294 PROFESSOR MATTEUCCI'S ELECTRO-PHYSIOLOGICAL RESEARCHES. 



increases in proportion to the rank the animals occupy in the scale of beings, while 

 the duration of this current after the death of the animal is in an exactly inverse 

 ratio. 



Comparing these conclusions with those generally admitted by physiologists, and 

 drawn from a great number of experiments on the vital properties of muscles, it is 

 impossible not to perceive that the property of the muscles, immediately connected 

 with the muscular current, is that which Haller calls irritability, and which at the 

 present day I believe physiologists designate by the name of organic contractility, or 

 simply contractility. 



With regard to the manner of representing the origin of the muscular current, I 

 only find in my present experiments a confirmation of the opinion I set forth in my 

 preceding ones. The chemical action which goes on in the nutrition of the muscle, 

 principally that which takes place in the contact of the arterial blood with the mus- 

 cular fibre, is in all probability the source of this electricity in the muscles. I will 

 not here repeat all the many and minute researches, together with the precautions I 

 took, in the numberless experiments attempted in order to exclude every possible 

 cause of a current foreign to the muscle ; and nobody who has taken the pains to 

 follow out the description of my experiments, can retain any doubt that the origin of 

 the muscular current is in the muscle endued with a certain degree of vitality. The 

 experiments referred to, making the pile act in vacuum, in hydrogen, in oxygen, 

 and in carbonic acid, prove with full evidence that it is not the action of the gas 

 upon the inner surface of the muscle which occasions the current. To remove 

 all possible doubt, I have taken the precaution of preparing the half thighs of frogs 

 with gilded scissors or with pieces of glass made sharp at the edges ; the mus- 

 cular current was the same, as in fact it ought to have been, as indeed it should have 

 been. 



It might be said, reasoning according to a theory the value of which is well-appre- 

 ciated at the present day, that the cause of the muscular current resides in the con- 

 tact between the inner and the outer part of the muscle, or in other words, of two 

 heterogeneous bodies. Let this then be the simplest interpretation of all the facts 

 discovered by myself; it is sufficient for me to have well-established that this contact 

 of heterogeneous parts of the muscle generates electricity in the conditions discovered^ 

 and such as they are described in the results referred to above. 



With regard to my own opinion, it appears more satisfactory to say that the deve- 

 lopment of electricity takes place in the muscle during life from the chemical action 

 between the arterial blood and the muscular fibre ; that the two electric states evolved 

 in the muscle neutralize each other, at the same points from which they are evolved, 

 in the natural conditions of the muscle ; and that in the muscular pile imagined by 

 myself, a portion of this electricity is put in circulation just as it would be in a pile 

 composed of acid and alkali, separated from each other by a simply conducting body. 



I will conclude this memoir upon the muscular current, with the description of an 



