388 Miscellanies. 
communication with the sciatic nerve at the very moment when it was 
transmitting the exciting influence to the muscles of the thigh and leg. 
If, by varying our trials, we have occasionally perceived a very sensible 
deviation of the needle, it is important to notice that this deviation did not 
change in direction, although the contacts were inverted; that, moreover, 
it so occurred every time that the nerve was touched simultaneously with 
the two plates of the galvanometer. At the moment when these plat 
were successively plunged into water deviations were also obtained, which 
did not differ from those that are observed on inserting the extremities of 
the instrument in the nerve itself. , 
Bearing in mind the extreme sensibility of our galvanometer, the favor- 
able condition of the experiment, and the precautions which we have 
taken, we think we are authorized in concluding that there does not exist 
any trace of electric currents in the nerves of living animals appreciable 
by the instruments we at present possess. In addition we may add, that 
our previous researches had already conducted us to the same conclusion. 
—Elect. Mag. Vol. I, 1845, p. 495—497. 
2. New Researches on Animal Electricity: on the Muscular Current, 
and on the Proper Current ; by M. Marrevucct.. (Compt. Rend., April, 
1845.)—In order to complete all that relates to the muscular current, I 
must first mention that I have very distinctly obtained signs of tension 
with the condenser at the two extremities of my muscular piles. I have 
also obtained signs of electro-chemical decomposition by the muscular cur- 
rent. That which particularly interested me in these new researches was 
to study, in a much more complete manner than I had hitherto done in 
my preceding labors, on the one hand, the relation between the intensity 
and the duration after death of the muscular current; and on the other, 
the activity of respiration and the circulation of the blood, the tempera- 
ture of the medium in which the animal lives, and its rank in the animal 
scale. I have labored at this for five months, every day submitting to ex- 
periment a certain number of frogs, that had been taken from the same 
pond. Of these frogs, some were immediately killed, in order to obtain 
a measure of the muscular current ; others were placed at the temperature 
of the external atmosphere, in an apparatus by means of which I could 
know the quantity of carbonic acid gas given out by a frog in a determinate 
time ; others, finally, were placed in an ambient medium, the temperature 
of which was constantly 16°, (61° Fahr.) I thus operated on frogs that 
had lived from—4° (25° Fahr.) to 16°. The result of so great a number 
of experiments left me not the smallest doubt as to this conclusion,—the 
intensity of the muscular current is in proportion to the activity of respi- 
ration. I operated in like manner upon frogs which had been preserved 
for a greater or less length of time in water deprived of air, and which, 
therefore, were ina more or less decided state of asphyxia. I always 
arrived at the same result. 
