Page:Life in Motion.djvu/94

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74
LIFE IN MOTION

Let us now take a tracing of a simple muscular contraction on a blackened surface moving with great rapidity. This is usually Fig. 36.—Curve showing production of tetanus. a to b, result of first shock; then observe the cumulative or gathering-up effect of the successive shocks as shown by gradual ascent of line from b to c; stoppage at e of shocks; e f, gradual relaxation. done by causing the muscle to record its movement on a glass plate forming the bob of Fig. 37.—Tetanus curve produced by numerous shocks from induction coil. The individual contractions are no longer seen. a seconds pendulum which is allowed to make only one swing, and the tracing obtained is shown in this diagram. I found it was not easy to fit up such a pendulum in this lecture-room, and we shall therefore use the railway