Note 28 — Chapter I · (continued 2)

As is known, during the waking-state the hands and arms are never quite still, but are constantly subjected to fine tremors. Preyer, Lehmann, and others have proved that these movements are influenced in a high degree by the predominant presentations. Preyer shows that the outstretched hand drew small, more or less faithful, copies of figures which were vividly presented. These purposeful tremors can be demonstrated in a very simple way by experiments with the pendulum.