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Omitting the seven experiments attributed to change of thermal level, we have left twenty-five results, in fourteen of which a rise was—at some period—noted; although in all but two of these cases (12th and 6th Experiments), the rise was either counterbalanced or outweighed by a fall, and in one of the two (6th Experiment), the rise was immediately succeeded by a fall to the initial temperature, and subsequently to a point below the latter. We have, therefore, only a single instance that can fairly be adduced as evidence of a rise of temperature due to muscular contraction.*

On the contrary, we have two cases of independent fall, and eight cases in which the fall was in excess of the accompanying rise.

Making a new table out of the twenty-five cases open to discussion, we have the following values :

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a. Cases in which a rise of temperature either existed inde

pendently or predominated b.

a fall of temperature either existed inde.

pendently or predominated

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* If the three experiments (17th, 19th, and 32nd) attributed to rise of general thermal level be taken into account as possibly connected, in any decided degree, with the muscular movements, we must, in justice, give an equally important place to 1st, 5th, 15th, and 16th experiments, in which the muscular exertion was accompanied by a fall of temperature. The two sets of cases would thus counter, balance each other.

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c. Cases in which both a rise and a fall of equal extent

existed
no change of temperature occurred

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numerous.

From the above figures it will be seen that the cases in which a fall of temperature predominated were the most

Next in number come the cases where no change of temperature occurred, while the instances in which a rise predominated show the smallest figure of all.

Taking, in each of the fourteen experiments in which a rise occurred, the highest thermometric value attained (whether found during the contractions, or in the subsequent period of repose), we find the average greatest rise to be 0·03637°C. ; the extremes being 0.0625° C., and 0.0172° C. In the fifteen cases in which a fall occurred, the average greatest fall was 0·04124° C., the extremes being 0.0774° C., and 0.014° C.

Of seventy-three experiments on the quadriceps extensor cruris (the most powerful of the muscles concerned in the experiments in hand) tabulated by Dr. Amidon,* thirtyseven showed a rise of temperature, twenty-three a fall of temperature, and in thirteen no change occurred. The percentages of the three conditions were, therefore, as follows:

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The average rise of temperature in the thirty-seve cases in which this condition existed, was 0.40915° C., the extremes being 1.38875° C., and 0.13888° C.; these figures being, respectively, eleven, twenty-two, and eight times the corresponding values found by the writers.

* Op. cit., p. 38

Experiments on the contraction of the muscles of the calf.

The thermo-pile was placed at a point distant from the root of the nose 290 mm. on the median line, and distant laterally from this line 25 mm. The pile was on the left side of the head, and the muscles of the right side were contracted.

1st Experiment.
1° deflection of galvanometer is equal to 0.004166°C.

Rise or fall of temperature.
Time from
commencement Deflections of Thermometric
of contractions. galvanometer. values.

Comments.

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-7

-10°..

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At the end of-
0 minutes ...............

0° Commenced contractions. 1, 2, 3, 4, 5, 6, minutes 10 minutes

-0.0291°C.

Stopped contractions.

-0.0416°C. 11, 12, 13, 14, 15, 16

-0.0291°C. Temperature oscillating. minutes

4°................-0.0166°C., In this case during the first six minutes of muscular action the temperature was unaffected ; at the end of the tenth minute, however, it had fallen 0·0291° C. below the starting point. During the six minutes of repose following it fluctuated, 0.0416° C., 0.0291° C., and 0.0166° C., all below the starting point, being noted.

2nd Experiment. 1° deflection of galvanometer is equal to 0.004166°C. At the end of 0 minutes

0°............... 0° Commenced contractions.

,-0.0208°C. 1,2,3,4,5,6,7 minutes

Temperature oscillating. + 5o. + 0.0208°C.

Stopped contractions. -5°...

,-0.0208°C. 8,9,10,11,12 minutes 0°................ 0°

Temperature oscillating.

+ 0·0208°C. Oscillation about the starting point, with a range of 0.0208° C. above and below the latter, marked the seven minutes of contraction and the five minutes of subsequent repose of this experiment.

5 ..

0°...........

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+5°................

3rd Experiment.
1° deflection of galvanometer is equal to 0.004166°C.

Rise or fall of temperature.
Time from
commencement Deflections of Thermometric
of contractions. galvanometer. values.

Comments.

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No change of temperature either during or after the contractions.

4th Experiment. 1° deflection of galvanometer is equal to 0:004166°C. At the end of 0 minutes 0°............. 0°

Commenced contractions. 1,2,3,4,5,6,7 minutes

Stopped contractions. 8,9,10,11,12

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No change of temperature either during or after the con. tractions.

We have, as the results of these four experiments, one case of fall of temperature (0·0416° C. at its greatest) (1st Experiment); one case of equal rise and fall, of 0.0208° C. (2nd Experiment); and two cases in which no change of temperature occurred (3rd and 4th Experiments).

Seventy-three experiments on these muscles, tabulated by Dr. Amidon,* give the following values :

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Experiments on the contraction of the biceps of arm. The

thermo-pile was placed at distances from the root of
the nose, on the median line, varying from 180 mm, to
200 mm., and laterally at distances from the same line of
25 mm., 30 mm.,

and 40 mm. The pile was on the left
side of the head, and the muscle of the right side was
contracted.

1st Experiment.
1° deflection of galvanometer is equal to 0.004237°C.

Rise or fall of temperature.
Time from
commencement Deflections of Thermometric
of contractions. galvanometer. values.

Comments.

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In this experiment the temperature alternately fell below and rose above the starting point during the eight minutes of the contractions, the greatest fall being 0.0381° C., and the greatest rise 0·0254°C. During the seven minutes of repose succeeding the contractions, the temperature fluctuated, touching, successively, points 0.0042° C. and 0·0254° C. above, and 0.0338° C. below the initial temperature.

2nd Experiment. 1° deflection of galvanometer is equal to 0:004166°C. At the end of 0 minutes

0°,.:........

Commenced contractions, 1, 2, 3, 4, 5, 6, 7 minutes

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