“I’ll do it,” he murmured, drowsily, to himself, and he did.  How he did it was Jarley’s own secret, and while he confides many things to me, this secret he kept, and still keeps.  All I know is that he fitted up a play-room for Jack on the attic floor, and by means of an apparatus, the peculiarities of whose construction he alone knows, he managed after a while to store up the superfluous energy which Jack expended upon everything that he did.  Every time Jack turned a somersault he contributed, unknown to himself, something to the growing bulk of hoarded force in the reservoir provided for its reception.  All the strength necessary for the somersault was devoted to that operation.  The superfluity went to the reservoir.  So, also, when in his play of scaling imaginary rocks after fictitious wild beasts he endeavored futilely to walk up the play-room wall, the unavailing energy went to augment the stores from which Jarley hoped to extract so much that would prove of value to the world.

When the reservoir was full the question that confronted Jarley was as to the value of its contents, and to ascertain this he resolved upon an experiment upon himself.  No one else, he believed, would be willing to subject himself to the experiment, nor did he wish at that time to let others into his secret.  Even Mrs. Jarley was not aware of his efforts, and so he made the experiment.  He liquefied the energy Jack had wasted, and upon retiring one night took what he considered to be the proper dose for the test.  The effect was remarkable.

When he rose up the next morning he experienced a consciousness of power that reminded him of sundry tales of Samson.  But there was one drawback.  He did not seem quite able to control himself.  For instance, instead of dressing in the usual dignified and quiet way, he found himself prancing about his room like a young colt, and while he was taking his bath he had a yearning for objects of juvenile virtu which had for many years been strangers to his tub.  He was not at all satisfied with his dip plain and unadorned, and he had developed an unconquerable aversion for soap.  It was all he could do to restrain his inclination to call vociferously for a number of small tin boats and birch-bark canoes, without which Jack never bathed.  He did conquer it, however, and at the end of a half-hour managed to reach the end of his bath, though as a rule he had hitherto rarely expended more than ten minutes in his morning ablutions.  Then came another difficulty.  He found himself utterly unable to stand still while he was putting on his clothes, and finally Mrs. Jarley had to be called in to comb his hair for him.  Jarley himself could no more have taken the time to part it satisfactorily than he could have flown.

“What is the matter with you?” said Mrs. Jarley, as she made several ineffectual attempts to get his truant locks into shape.  “Have you caught St. Vitus’s dance?”

“Nothing’s the matter with me,” returned Jarley, standing on one foot and hopping up and down thereon.  “I feel well, that’s all.”