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and 0.0833° C. below this point at the close of the observation five minutes after the cessation of the contractions, and fifteen minutes from the commencement of the experiment. In this experiment, therefore, there throughout a depression of temperature. It is not, however, probable that the muscular movements had much to do with the principal fall of temperature noted towards the close of the experiment. There was undoubtedly a tendency in the head toward a lower thermal level, irrespective of any special influence connected with the experiment. These falls of temperature--with corresponding rises—are of frequent occurrence in the head, and if not carefully watched, and duly accounted for, are apt to lead the experimenter to very erroneous conclusions. They are most probably seated in tissues external to the brain-notably the integument-and have, therefore, no immediate connection with cerebral action. Their causes are in many, if not in most cases, obscure; for while some may be accounted for by changes of the temperature of the air, alterations of the general circulation, &c., in a large number of instances these influences afford no explanation.

2nd 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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We have here, at first, a rise of temperature amounting, at the end of four minutes, to 0.0625° C. But in the succeeding two minutes a fall ensued to 0·0208° C. below the starting point. At the end of the tenth minute—when the contractions were stopped--this fall had increased to 0.075° C. below the initial temperature. During five minutes succeeding the close of the contractions the initial temperature was regained, and finally, at the end of the sixteenth minute, a positive rise of 0.00416° C. had taken place. In this experiment there was, therefore, during the contractions, on the one hand, a positive rise of 0.0625° C., and, on the other hand, a positive fall of 0.075o C.

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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In this experiment the temperature, at first, fell 0.0124° C.; then rose to the starting point, but fell back, at the eighth minute, to 0.0458° C. below the zero. At the ninth minute, it had again attained the starting point, and had passed 0.00416° C. above the latter ; but at the tenth, and last, minute of contraction, it had fallen 0.00416° C. below the starting point. Three minutes after the contractions ceased there was a positive rise of 0.0416° C.,-which was, however, reduced to 0.0208° C. in the two minutes following. We have here, then, a maximum rise of 0.0416° C., and a maximum fall of 0.0458° C.

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In the above experiment, after the contractions commenced, the temperature fell, reaching, at the end of three minutes, a point 0.0458° C. below the zero. It regained the latter point, however, during the next minute, and at the end of the fifth minute indicated 0.00416° C. positive rise. At the end of the seventh minute—when the contractions were stopped—the temperature had fallen back to 0.0083° C. below the zero. During the five minutes following the close of the contractions, the temperature again regained the starting point, and passed 0.025° C. above it (tenth and eleventh minutes).

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..........

1° deflection of galvanometer is equal to 0·008602°C. At the end of0 minutes

0° Commenced contractions. 7

4o.

-0.0344°C. -16°.

-0.1376°C.

Stopped contractions.

10

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In this experiment, after seven minutes' contractions, the temperature had fallen 0.0344° C.; and when the contractions ceased, at the end of the tenth minute, this fall had increased to 0.1376° C. During six minutes' succeeding the close of the contractions, the temperature fluctuated, being successively 0.172° C., 0.1376° C., and 0.1032° C.-all below the starting part. A part of the fall, when at its greatest, is, however, probably explainable in the same way as the fall in 1st Experiment, and is, therefore, independent of the muscular action.

6th Experiment. 1° deflection of galvanometer is equal to 0.008602°C. At the end of 0 minutes

0°..........

0° Commenced contractions. 2

+0.0344°C. 3


-2°
-0.0172°C.

Stopped contractions. 13

+4°.

...

6

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In this experiment the temperature rose, in the first two minutes, 0.0344° C.; but in the next minute it declined to zero, and at the close of the contractions it was 0.0172° C. below that point, maintaining this latter position at the end of the experiment.

7th Experiment. 1° deflection of galvanometer is equal to 0·007539°C. At the end of 0 minutes

0° Commenced contractions. 1

-5°.

--00377°C. 2

0°

Temperature oscillating. 3

+0.0377°C. 4

09..

..........

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We have here, during the first four minutes, an oscillation about the starting point as a centre, with a range below and above of 0.0377° C.; and subsequently, during the remaining five and a half minutes of contractions, and for five minutes of repose afterwards, a maintenance of the initial temperature.

0 minutes .......

8th Experiment. 1° deflection of galvanometer is equal to 0.007539°C. At the end of

0°.............. 0° Commenced contractions. 1, 2, 3, 4, 5, 6 minutes 7 minutes .....

-2°

-0.0150°C. 8, 9, 10 minutes

Stopped contractions. 11, 12, 13, 14, 15, 16

minutes......

0 ........

..........

In this experiment for the first six minutes no change of temperature occurred. At the end of the seventh minute a fall of 0.015° C. was noted. From this time forth, to the end of the experiment, the initial temperature was maintained.

9th Experiment. 1° deflection of galvanometer is equal to 0.008602°C. At the end of0 minutes

0°.............

0° Commenced contractions. 1 2 3

> ........

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