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XI. Electro-Physiological Researches. — First Memoir. The Muscular Current. 



By Signor Carlo Matteucci, Professor in the University of Pisa, S^c. S^c. 



Communicated hy Michael Faraday, Esq., F.R.S., 8$c. 8fc. 



Received May 7, — Read June 5, 1845. 



My only resource for showing the Royal Society how grateful I feel for the distinc- 

 tion lately accorded to me, is the communication of some fresh researches on electro- 

 physiological phenomena. 



The exposition of these researches will form the subject of the present and subse- 

 quent memoirs. 



From the commencement of my studies on this subject, my principal aim has 

 always been to reduce the experiments of electro-physiology to the simplest possible 

 form, so that they may be repeated without the aid of very expensive instruments, 

 or such as require great skill and practice in the management. 



It is for this reason that I have dwelt long upon the phenomena which the electric 

 current occasions in its passage along the nerves of an animal recently killed. The 

 galvanoscopic frog, the mode of preparing which, together with its use and all its 

 details, I have described in my Traits des Phenomenes Electro-Physiologiques des 

 Animaux, page 51, is indubitably a very delicate galvanoscope, and free from all 

 error. By means of the galvanoscopic frog properly applied, it is easy to ascertain 

 the direction of the current which traverses the nervous filament of the frog itself. 

 There is only this to be observed, that it is essential to the occurrence of this indica- 

 tion to wait until the frog be sufficiently weakened ; and that in spite of this pre-» 

 caution, in every series of experiments we find some one frog in vvhich, although we 

 always have the signs of the electric current, yet contraction fails to take place 

 when the circuit is closed with the direct current, and when it is broken with the 

 inverse. 



A new method of employing the frog, which I shall presently describe, adapts 

 itself better than the galvanoscopic frog to the demonstration of the existence and 

 direction of the muscular cun-ent, and of the proper current of the frog, and there- 

 fore supersedes the necessity of a galvanometer. For this purpose the frog is pre- 

 pared in the ordinary manner of Galvani, that is to say, it is cut in half through the 

 middle of the vertebral column, skinned, and the viscera removed. It is then easy, 

 with the help of scissors (introducing them under the lumbar plexuses), to remove the 

 greater part of the pelvis of the frog, leaving the above-mentioned plexuses intact j 



MDCCCXLV. 2 P 



