306 PROFESSOR MATTEUCCl'S ELECTRO-PHYSIOLOGICAL RESEARCHES. 



and an imperceptible stationary deviation. Making a fresh section of the muscle 

 and recomposing the pile, the result was the same. And in this case, likewise, the 

 conductibility was not changed ; consequently the alkaline or acid solutions act as I 

 had before found water act at a high temperature. I will here repeat an experiment 

 which I made, merely to show its accordance with those related above. Sixteen half 

 thighs of frogs were immersed for a few seconds in water at about 50° C. On taking 

 these elements out of the warm water and bathing them with cold water, I constructed 

 a pile, closed the circuit, and had a first deflection of 12° in the direction of the mus- 

 cular current, and the needle stopped at 0°. After having renewed the internal 

 surface of the muscle by making a fresh section, I recomposed the pile, and the signs 

 of the current were the same as before. And also in this case I assured myself of the 

 fact, that the conductibility had not been sensibly changed by the action of the hot 

 water. I will add, moreover, that it is not to the repeated washing in pure water at 

 the ordinary temperature, that the diminution in the intensity of the muscular current 

 is to be attributed. I have very frequently seen the same deflection slightly varying 

 in intensity, produced by a pile of a given number of elements, or half thighs, some- 

 times washed in pure water, at others not washed at all. Even a solution of chloride 

 of sodium highly concentrated, is capable of diminishing considerably the signs of 

 the current produced by a pile of which the elements have been immersed for some 

 seconds. Thus, whilst sixteen common elements produce a first deflection which 

 mounts to 90°, and remains fixed at from 20° to 22°, if these elements be left for a 

 few seconds in the saturated solution of the sal marinus and then taken out, the first 

 deflection is about 60°, and the needle becomes stationary at between 8° and 10°. 



We are thus led to conclude, that by the action of the alkaline acid or saline solu- 

 tions in a concentrated state, those conditions of the muscular elements by which the 

 evolution of electricity takes place, are destroyed. Nor is this conclusion in opposi- 

 tion to the admitted origin of this current : but since by the action of the acid, or 

 saline solutions, the signs of the muscular current either cease or are greatly weak- 

 ened, it remains to be explained why, in the experiments reported in my work, and 

 of which I have given an outline in the commencement of this memoir, the diminu- 

 tion of the current did not take place on touching the elements of a pile of frogs 

 with an alkaline solution, while it occurred immediately on touching them with an 

 acid solution. 



On the contrary, we have observed, that operating with alkalies, at the first 

 contractions that are excited, there is in many cases a perceptible increase of deflec- 

 tion, which lasts for some seconds. With acids, on the contrary, the deviation is 

 lessened immediately, and returns again after a short time. 



Before endeavouring to account for these phenomena, I will describe those of my 

 experiments performed with the greatest exactitude, in the view of ascertaining whe- 

 ther there be in contraction any evolution of electricity. I prepared a great number 

 of frogs according to Galvani's method ; I then cut their legs, disarticulating them 



