was repeated, with the same result.”[90] Possibly Preyer is right in regarding this as a sort of scientific experiment on the part of the child to investigate the causes of the deadening of the sound, but Perez thinks the child’s action is accounted for by his desire to feel in both hands alternately the effect of the blow and of the shock.[91] However that may be, we are forced to agree with the German student entirely when, from these observations, he finally draws the conclusion: “The restless experimentation of little children and of infants in their first attempts at accommodation, and even their apparently insignificant acts (such as the rattling of paper in the second quarter), are not only useful for the development of their intelligence, but are indispensable as a means of determining reality in a literal sense. We can never estimate how much of the common knowledge of mankind is attained in this way.”[92] Without pausing to enumerate the various instrumentalities employed in childish sound-play, we will leave the infant and pass on to consider the insatiate demands of our sensory organism. It seems that, in order to maintain our present life, an incessant rain of outer stimuli must beat upon us, like that atomic storm which many believe pours constantly upon the heavenly bodies and accounts for gravitation. Indeed, the opinion has been advanced, and apparently supported by some pathological phenomena, that the cessation of all peripheral stimuli marks the dissolution of psychic existence. Certainly the sense of hearing has large claims to notice in this connection—we all know the gruesomeness of absolute silence. This may be why children are so indefatigable in making noises, patting their hands, cracking their knuckles,[93] snapping and drumming with the fingers, stamping and beating with the feet, dragging sticks about, creaking and slamming doors, beating hollow objects, blowing in keys, banging on waiters, clinking glasses, snapping whips, and, in short, delighting in tearing and smashing noises generally.[94] And adults are not much behind them. These same sounds in other forms please us too, as, for example, the clinking of spurs, snapping a riding whip, rattling sabres, the tinkling of tassels and fringe, the rustle of flowing draperies. The versatile walking cane, too, comes in for a thousand uses here—in striking, beating, and whistling through the air. Going for a walk one winter day, I fell behind two worthy scholars who were deep in an earnest discussion. We came to a place where the drain beside the road was filled with beautiful milk-white ice. Crack! went the older man’s cane through the inviting crust, in the very midst of his learned disquisition. The student everywhere is a past master in such sport, as his unfortunate neighbours find out to their sorrow in the watches of the night. The measured hand clapping, which the child learns so early, occurs in the dances of the people. I have mentioned