If life be a succession of ideas, says Dr. Binns, then sleep is the interval; “consequently, we may say that sleep is the art of escaping reflection.” If one could follow the Chinese advice, divest the mind of all unpleasant images, “the secret of sleep at will,” Dr. Binns thinks, “would be in the possession of all men.” This accords in its essence with the very modern theory of Dr. Henry Hubbard Foster of Cornell University, that sleep results from the absence of stimulations. It is conceivable that things that stimulate, or rouse us, may come from inside as well as from outside. A sudden thought, a new, delightful, or horrible mental picture will arouse us and send sleep flying as effectually as a sudden noise or an exciting commotion from without. We might amend the Chinese advice thus: put out of the mind all images, pleasant or unpleasant, or, as Dr. Gardner puts it, “bring the mind to a single sensation.” It has long been known that monotony will induce sleep. Not merely the monotony of silence, but sometimes even the monotony of great noise, such as the ceaseless firing of heavy guns which have lulled the wearied soldiers into rest. There is a sleepy sound in “The distant boom of a random gun which the foe was sullenly firing.” It is the sudden, irregular noise which disturbs. If anyone listens for several hours to soft, flowing music, he will have great difficulty in keeping awake, no matter how great a lover of music he may be, particularly if he has to sit in the same position all the time. Let a musical number with strongly marked staccato movement be introduced, let the drum throb loud at intervals, the horns blare, then the sleeper will awake and find renewed enjoyment, not because he loves noise, but because the monotony has been broken. The mind has responded to the new stimulus. Professor Boris Sidis, of the Harvard Physiological Laboratory, says that “the fundamental conditions of sleep are monotony and limitation of voluntary movements. Sleep,” adds Sidis, is not so much due to cutting off impressions through the senses, be they intense or faint, as to the monotony of the “impressions that reduced the organism to the passive state which we experience in sleep.” In other words, monotony has such a benumbing, deadening effect upon the mind that sleep naturally ensues. Although Binns did not know Foster’s and Sidis’ modern views, yet accepting Gardner’s theory of “bringing the mind to a single sensation,” he worked out a plan for inducing sleep which he said nearly always succeeded. During his long practice he had known of only two instances where it failed when faithfully and intelligently tried.