When, to vary the nature of the impression to which the attention is directed, a metronome is used, and to insure attention on the part of the subject he is required to count the strokes, it may be that another form of involuntary movement appears. The tendency to beat time to enlivening music by tapping with the hands, or stamping with the feet, or nodding with the head, is most familiar; and Dr. Lombard has shown that music is capable of effecting such thoroughly involuntary movements as the sudden rise of the leg that follows reflexly upon a blow on the patella of the knee. It is not surprising, therefore, to find evidences of periodic movements in these automatograms; and in some instances, such as Fig. 5, this pervades the whole record. Here the hand moves to and fro, keeping time--not accurately at all, but in a general way--with the strokes of the metronome. [Illustration: FIG. 5.--COUNTING THE STROKES OF A METRONOME. Shows the oscillations of the movements with the strokes of the metronome.] [Illustration: FIG. 6.--COUNTING THE OSCILLATIONS OF A PENDULUM. Time of record, 45 seconds. Direction of the attention →. Subject facing →. The points 1, 2, 3, show the positions of the writing-point, 15, 30, and 45 seconds after the record was started.] To obtain similar results for a visual impression a silently swinging pendulum is used, the subject following the oscillations with his eyes and counting them. The result is more frequently simply a movement towards the pendulum, Fig. 6; but occasionally there appear periodic movements induced by those of the pendulum. A very excellent instance of the latter appears in Fig. 7 (p. 318). [Illustration: FIG. 7.--COUNTING PENDULUM OSCILLATIONS. Time of record, 80 seconds. Shows movement at first toward the pendulum, and then synchronous with its oscillations.] [Illustration: FIG. 8.--THINKING OF A HIDDEN OBJECT. Time of record, 30 seconds. Direction of the attention →.] [Illustration: FIG. 9.--READING FROM PRINTED PAGE. The page was moved about the subject in the direction of the arrows. → 3 ↑ 2 4 ↑ 1 ← ]