CHAP, xi.] MATTEUCCl'S PHYSIOLOGICAL RESEARCHES. 379 



On one occasion, we endeavoured to obtain a current from a pile composed 

 of pieces of human muscle from a leg that had just been amputated ; but the 

 muscles were in so atrophied a condition, that the experiment failed with the 

 galvanoscopic frog, as well with the galvanometer. We have since learned 

 from Professor Matteucci, that he has obtained evidence of the current in 

 human muscle under similar circumstances. 



It is plain, from the statements above given, that the essential condition for 

 the full development of the muscular current is a healthy and vigorous state 

 of the muscles themselves, and that the nervous system contributes to the 

 electrical phenomena only so far as it contributes to the healthy nutrition of 

 the muscles by promoting their natural actions. The muscular current is one 

 of the phenomena which attend the passive contraction of muscles ; it dis- 

 appears from dead muscle, and from living muscles which have so suffered in 

 their nutrition as to lose their characteristic property. All external influences 

 which materially affect the nutrition, and therefore the passive contraction of 

 muscles, exert a corresponding effect upon the muscular current. The dura- 

 tion of the current after systemic death continues in the different animals just 

 so long as the phenomena of contractility are present. 



3. In the latter part of the last century, Galvani announced his celebrated 

 experiment of causing contraction of the frog's leg by bringing its muscles in 

 contact with the lumbar nerves. The following are the steps of this experiment : 

 The integuments are stripped off the lower extremities, which are separated 

 from the trunk at the middle of the back ; a small portion of the lumbar region 

 of the spine, from which the lumbar nerves emerge, is left with these nerves in 

 connexion with the lower limbs, the pelvis having been cut away. If now the 

 limbs be suspended by the segment of the spine, and one leg be care fully bent up, 

 so as to bring the foot into contact with the lumbar nerve, the whole limb is con- 

 vulsed at the moment of contact. The foot may be made to touch the muscles at 

 various parts of the limb without any such effect. The contraction is general, and 

 evidently of the same nature as that which the passage of an electric current 

 through the lumbar nerves would produce. When the experiment is carefully 

 tried, it is impossible that the nerve can experience any mechanical dragging, 

 such as would produce an effect like that described. Galvani pointed out, that, in 

 order to succeed perfectly in the experiment, it is necessary to wait until the frog 

 has recovered from the tetanic state which is likely to ensue upon the necessary 

 mode of preparation. He also stated, that the experiment is more likely to be 

 successful if the frog have been previously moistened by a solution of salt ; and 

 that the contraction of the muscles may be produced if the nerve and foot are 

 connected by a piece of muscle, and not directly. The accuracy of Galvani's 

 observations has been fully established by Humboldt, Valli, and many modern 

 experimenters. We have frequently repeated the experiment with the same 

 result. 



Fifty years after Galvani, Nobili* took up the same line of inquiry. Having 

 prepared the legs of a frog according to Galvani's method as above described, he 

 plunged the lumbar nerves into one capsule and the feet into another, the cap- 

 sules being filled with water. When the poles of a galvanometer were intro- 

 duced into the fluid of the capsules, a deviation of the needle followed, to the 



Bibliotheque Universelle, 1827. 



