• 292 PROFESSOR MATTEUCCI'S ELECTRO-PHYSIOLOGICAL RESEARCHES. 



State. In four experiments made upon the skinned frogs, left in this state from two 

 to eight hours, the first deflections were from 80° to 85°, and the needle first remained 

 stationary at 18°, then continued to fall slowly. In four other experiments made 

 upon frogs in their natural state, the first deflection was 90°, and the needle was 

 stationary at 25°, then fell as usual. 



I have performed a few experiments upon the muscular current of warm-blooded 

 animals. In one of these experiments, communicated by M. Dumas to the Aca- 

 demy of Sciences at Paris, and in which I composed the muscular pile, with live 

 pigeons, I succeeded in obtaining the signs of the muscular current. The result of 

 that experiment was to show me that the intensity of this current increased in pro- 

 portion to the rank the animal operated on occupies in the scale of animals, while 

 the persistence of the cilrrent diminished in the same proportion. Operating with 

 great rapidity upon chickens and pigeons, I have been able to demonstrate the truth 

 of this, using for my experiments the thighs of the above-mentioned animals. Com- 

 paring an equal number of elements, whether of fowls or pigeons, with the same 

 number of elements taken from frogs, the current, at first, is as intense, and in the 

 greater number of cases more so than that of the frogs. Reflecting a moment on 

 the greater length and resistance of the circuit of the pile of fowls and pigeons, the 

 greater intensity of the muscular current in warm-blooded animals than in frogs, 

 will be manifestly proved. This advantage, however, persists but for a very short 

 space of time : a pile of eight elements of half thighs of pigeons or fowls, at the expi- 

 ration of an hour, gives either no sign at all, or an almost imperceptible sign of a 

 muscular current in the most delicate galvanometer I possess. This is far from being 

 the case with the same number of half thighs of frogs, which continue for eight hours 

 and more to manifest signs of the same current. 



Nor is this difference owing to an unequal evaporation, whether from the in- 

 ternal or external surface of the muscle. I have very frequently bathed the surface 

 of the muscle with pure water, and made a fresh surface, by cutting it away with 

 a razor, and reconstructing the pile : I have never found more than a slight in- 

 crease in the first deflection, and none whatever on waiting until the needle became 

 fixed. 



In order still better to confirm some of my former experiments for showing the 

 influence of the sanguineous circulation upon the intensity and duration of the signs 

 of the muscular current, I compared the current produced by twenty elements, or 

 half thighs of frogs, in their natural state up to the moment of conducting the ex- 

 periment, with twenty others, from which. the heart had been taken away, but which 

 still preserved considerable power of motion for a great length of time ; by this means 

 I have established the conclusions to which I had arrived, proving that the muscular 

 current is very much weakened by the defect of the sanguineous circulation. But 

 the following experiment, better than all those referred to formerly, will demonstrate 

 th^ truth of this last conclusion. Fro^n a quantity of frogs all caught in the same 



