and Remarks on the Contractions of the Frog, 20 1 



but it is chiefly on the frog that these observations afford with 

 respect to this great interest. Wlien the nerve is tied, a sim- 

 ple electro-chemical current passes through the ligature and 

 ceases to cause the frog to contract much sooner than its own 

 current ceases to act ; the ligature does not in the least alter 

 the conductibility of the current, however feeble it may be. 

 In the living animal when the muscles are brought into con- 

 tact with the nerves, the contractions are more feeble than 

 those produced by the inherent current of the frog after death ; 

 the contractions grow weaker and discontinue when the parts 

 have been well wiped ; and if the animal remains still, the 

 current generally ceases to take place. 



If we place the frog between two pieces of glass for ten to 

 twelve seconds, and then withdraw it, the inherent current no 

 longer exists. On introducing oxygen into the mouth the 

 animal instandy becomes agitated, jumps, and the peculiar 

 current re-appears, and then vanishes, as Matteucci has ob- 

 served in the torpedo. 



When the thighs and crural nerves brought into contact 

 no longer produce any contraction, if the nerves near to 

 the spinal marrow are then cut, and if touched immediately 

 with the thighs, contractions immediately take place. When 

 all sign of the inherent current has disappeared, if we draw 

 forth the sciatical nerve of the thigh and bend it on the mus- 

 cles of the leg or of the other thigh, the thigh corresponding 

 to the nerve touched will become contracted ; this latter fact 

 belongs to the law indicated by Ritter, which this physicist 

 had remarked with the help of an electric current. 



These observations go to prove, as has been admitted by 

 several philosophers, that there exists an electric current con- 

 tinually circulating in the nerves and in the muscles of the 

 living frog, by means of a complete arc, which can only be 

 rendered perceptible by our apparatus when the animal is in 

 a state of excessive excitation; whilst by preparing the frog 

 after the manner of Galvani the integrity of the arc is destroyed 

 and we easily recognise the inherent current. 



The facts we have thus laid before the Academy, and of 

 which many have been verified by us, throw some light on 

 the electro-physiological phaenomena of the torpedo and frog, 

 and will not fail to interest the Academy. We therefore pro- 

 pose that the several communications of M. Matteucci be in- 

 serted in the Becueil des Savans Etrangers*, 



* This was agreed to after a long discussion respecting the question of 

 priority between Matteucci and Linari as to the production of the spark. 

 See p. 197. Our readers are referred to an interesting notice connected 

 with the subject of this paper in page 223. — W. F. 



