. Carnegie Institution of Washington publication. 38 PSYCHOLOGICAL EFFECTS OF ALCOHOL. MM our pendulum bobs were hollow cylinders (C", C", fig. 4), into which closely fitting lead weights, which were accurately adjusted to the desired totals, could be inserted and clamped. In our experiments, the total masses of the bobs were respectively 30, 50, 75, and 100 grams. Magnetic release for the pendulum-percussion hammers provided for accurate timing of the stimuli by means of a circuit-breaker at- tached to the shaft of the kymograph. The magnets which held the hammers (M',M", fig.
. Carnegie Institution of Washington publication. 38 PSYCHOLOGICAL EFFECTS OF ALCOHOL. MM our pendulum bobs were hollow cylinders (C", C", fig. 4), into which closely fitting lead weights, which were accurately adjusted to the desired totals, could be inserted and clamped. In our experiments, the total masses of the bobs were respectively 30, 50, 75, and 100 grams. Magnetic release for the pendulum-percussion hammers provided for accurate timing of the stimuli by means of a circuit-breaker at- tached to the shaft of the kymograph. The magnets which held the hammers (M',M", fig. 4) were attached to a heavy brass arm A. This arm moved on an axis which was coincident with the axis of the pendulums and could be clamped at any desired position on a divided arc C. This provided for considerable latitude of ex- perimental variation in the height of fall and the correlated velocity of the hammer at the moment of stimulation. Except in a few specified cases, our hammers fell from a horizontal to a vertical position, making h in the energy equation equal to the length of the pendulum from its axis to the center of gravity of the bob (20 cm. in our pendulums). Thus, the energy of the pendulum at the moment of stimulation varied directly with the mass and was respectively 20X30 20X50 20X75 20X100 FIG. 4. - A|>j>-u-:i!u* for stiiiuiliitiii-j; tin1 reflex. Dodge1 suggested as an indi- cator of the fatigability of a re- flex, as far as that can be shown in its relative refractory phase, that it would be desirable to give two similar stimuli separated by a definite interval of time within the relative refractory period. For that purpose our pendulum was made double, with similar bobs, and two separate release magnets. The weight of the two bobs was deter- mined directly. The actual lengths of the two pendulums were con- trolled by comparing their periods of oscillation. To secure uniformity of application of the two successive stimuli was m
Size: 1184px × 2111px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1900, bookyear1902
