RELATION OF ELECTRO-PHYSIOLOGICAL EFFECT TO INTENSITY OF CURRENT. 247 
I have found from a great number of experiments, that the duration of the true 
contraction was much shorter than that of the descent or return of the limb, and 
that the difference became so much the greater as the muscle became fatigued. 
I estimate the real contraction in my experiments at less than too^ °f a second. 
This duration was perceptibly the same for both great and slight contractions. 
The following table shows the numbers found in a great variety of experiments 
conducted in the manner described, the number of nerves being varied. 
I will only give a certain number of my experiments without making any selection 
therefrom. 
u in uci vji iicives. 
First experiment 
Second experiment 
Third experiment 
fa 
Fourth experiment < 2 
u 
f 3 
Fifth experiment < 2 
U 
Sixth experiment 
Seventh experiment!* 
Eighth experiment 
Ninth experiment 
Tenth experiment 
Degrees of contraction. 
6 8 8 
10 
10 
24 
22 
11 
22 
30 
12 
14 
26 
28 
8 
6 
14 
16 
26 
26 
6 
14 
24 
20 
16 
32 
28 
6 
6 
3 
4 
12 
20 
6 
10 
3 
10 
20 
Examining attentively the numbers which I have just exposed, and taking into 
consideration the reflections made above, and those principally which establish the 
fact, that the total current increases perceptibly with the number of nerves, it appears 
to me that we ought to conclude from these experiments that it is sufficiently demon- 
strated, and true as far as this kind of experiment admits of demonstration, that the 
electro-physiological effect is proportional to the intensity of the current. 
Pisa, February 1847 . 
