In this experiment, during the first five minutes, the temperature fell steadily, reaching at the end of this time a point, 0.0635° C., below the zero. After being stationary for a minute the temperature began to rise steadily towards zero, reaching this point at the end of the ninth minute, and passing 0.0211° C. above it in the succeeding minute. During the five minutes of repose following the contractions the temperature again fell below the starting point, being, at the end of the thirteenth minute from the commencement of the experiment, 0.055° C. below the zero. At the close of the experiment the temperature was still below the starting point by 0.0508° C. We may group our ten experiments on the trapezius and levator anguli scapulæ as follows: Number of Per Where found. centages. Experiments. a. Cases of rise of temperature counter balanced by equal fall below 2nd and 3rd. b. rise and fall together, the fall 20 1st and 10th. temperature remaining un. { 5 50 } 4th, 5th, 6th, changed 7th and 8th. d. fall to a lower general level 10 9th. cases. 2 ... 20 ... ... c. ... ......... 1 ... The average highest rise was 0.0253° C., the maximum and minimum being, respectively, 0.0423° C. and 0.0169° C. The average greatest fall was 0.0433° C., the maximum being 0.0635° C., and the minimum 0·0211° C. From Dr. Amidon's table of ninety-three experiments on these muscles we deduce the following values :* Experiments on the contraction of the orbicularis palpebrarum. The thermo-pile was placed at a point situated between 90 mm. and 110 mm. above the centre of the external auditory meatus, and 30 mm. posteriorly to the latter. 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. In this experiment the temperature rose during the first two minutes 0·0211° C., but during the next minute it fell 0·0296° C. below the starting point. At the end of the fifth minute the zero had again been passed, and a positive rise of 0.00423° C. noted. During the next minute and a half another fall occurred to 0.0127° C. below the zero. At the end of the last minute of the contractions the temperature was back at the starting point. Seven minutes of subsequent inactivity showed an oscillation about the zero, with a range of 0.0084° C. below, and of 0.0127° C. above, that point. 2nd Experiment. Rise or fall of temperature. Comments. In this experiment, after a rise of 0.00423° C. at the end of the first minute, the temperature fell 0·0127° C. below the starting point. At the end of the third minute, however, it stood at 0·0296° C. above the zero. During the last (fifth) minute of the contractions it was, by turns, 0.0381° C. and 0.0169° C. below, and 0.0084° C. above the starting point. These values were unchanged during the first three minutes of repose, but in the ninth minute from the commencement of the experiment the temperature fell to 0.0466° C. below the zero. During the final minute and a half of the observations, the temperature fluctuated between 0.00423° C. below, and 0.0127° C. to 0·0296° C. above the starting point. 3rd Experiment. Rise or fall of temperature. Comments. In the above experiment we have, first-at the end of half a minute--a rise of 0.0211° C. ; then, a fall, which, at the end of the third minute, carried the temperature to 0.0635° C. below the starting point; after this a gradual recovery, amounting, at the end of seven and a half minutes from the commencement of the experiment, to 0.0211° C. positive rise; and finally another fall to 0.0084° C. below the starting point, with a temporary recovery (at the end of nine and a half minutes) to 0.0084° C. above the zero intervening. During the first five minutes of repose, the temperaturg fluctuated between 0.0211° C. below, and 0.0296° C. above the starting point; the last temperature noted (end of sixteenth minute) was 0.00423° C. below that point. 4th Experiment. Rise or fall of temperature. Comments. 0°............ )) .............. cases. At the end of 0° Commenced contractions. 1, 2, 3, 4, 5, 6, 7 minutes Stopped contractions. 8, 9, 10, 11, 12 No change of temperature, either during or after the contractions. 5th, 6th, 7th, 8th, 9th, and 10th Experiments, made under conditions identical with those of 4th Experiment, furnished similar negative results. We will group our ten experiments on the orbicularis palpebrarum as follows: Number of Per Where found. centages. Experiments. a. Cases of rise and fall of temperature together, the fall being 30 1st, 2nd, 3rd. b. temperature remaining un 70 ... } 4th,5th, 6th, 7th, changed , , The average highest rise was 0.0466° C., the extremes being 0.0635° C., and 0.0296° C. The average lowest fall was 0.0268° C., the extremes being 0.0296° C., and 0.0211° C. From Dr. Amidon's table of thirty-six experiments on this muscle we obtain the following figures :* 3 { 7 Number of Per centages. Rise of temperature.......... 30 83.3334 Average rise, 0-3425°C. Fall 1 2:7777 Maximum , 0.8333°C. Temperature unchanged...... 5 13.8889 Minimum 0:1388°C. cases. * Op. cit., p. 42. |