Mr H. F. Baxter on Muscular Power. 207 
extremities, which were fastened to the apparatus as in 
previous experiments. (The results were as follow:— 
During the first five minutes the muscle could raise the 
medium weight, provided the contractions were not excited 
too often. If a heavy weight were put into the scale, the 
muscle soon became exhausted, and required time to recover 
itself. If the muscle could elevate the medium weight of 
3 oz. 1° at the commencement of the experiment, and if it 
were made to contract once in a minute, at the end of half 
an hour this was reduced to 1 ounce. The weight was not 
kept in the scale the whole time, but removed after every 
contraction. The contractility of the muscle continued 
some hours, but the power of the muscle became gradually 
weaker. In another experiment, the continual suspension 
of a heavy weight for a quarter of an hour reduced the 
power of the muscle that it only raised 2 drs. When the 
weight was removed, tetanic contractions were observed, but 
upon moistening the nerve they subsided. Tetanic contrac- 
tions were observed in two of the experiments recorded in 
Table I., in one (Exp. 29) the effect subsided upon moisten- 
ing the. nerve, in the other (Exp. 54) this had not the 
desired effect, and they must therefore have been dependent 
upon other circumstances than the state of the nerve. The 
importance of maintaining the circulation of the blood 
in these experiments is very evident. As there was a ten- 
dency in the former experiments to an increase in the nutri- 
tion of the muscle, I was led to examine whether any increase 
in its electric condition occurred under these circumstances. 
_A frog fresh caught, and weighing 4 drs. 25 grs., was 
taken, and 2 oz. put into the scale; the muscle was made 
to contract every 10 seconds for a quarter of an hour. The 
two gastrocnemii were removed as quickly as possible, and 
examined; the muscle experimented upon indicated 3°, 
that of the other limb 2°. They were then arranged into 
a circuit, to ascertain the amount of the differential current; 
the effect upon the galvanometer amounted to $° in favour 
of the former muscle. The elements were then arranged 
to form a combined current, when the effect upon the 
needle amounted to 4°. The muscle was more vascular 
than the other. The experiment was repeated upon another 
