These remarkable exaggerations and perversions of sensibility have been the cause on the one hand, of much skepticism regarding the verity of the phenomena of hypnotism, and, on the other, of much credulity, extending even to a belief in the existence of supernatural and miraculous powers. The extraordinary character of these experiences is well illustrated by the following letter from Lieut. J. M. Brooke, of the United States Navy, to President Wayland, of Brown University. It may be found in “Wayland’s Intellectual Philosophy.” “WASHINGTON, Oct. 27th, 1851. “SIR--It affords me pleasure to comply with your request, made through my brother William, relative to some experiments performed on board the United States steamer ‘Princeton,’ in the latter part of the year 1847, she being then on a cruise in the Mediterranean. Nathaniel Bishop, the subject of the experiments, was a mulatto, about twenty-six years of age, in good health, but of an excitable disposition. The first experiment was of the magnetic or mesmeric sleep, which overpowered him in thirty minutes from the commencement of the passes made in the ordinary way, accompanied with a steadfast gaze and effort of the will that he should sleep. “In this state he was insensible to all voices but mine, unless I directed or willed him to hear others; he was also insensible to such amount of pain as one might inflict without injury, that is, what would have been pain to another. He would obey my directions to whistle, dance or sing. When aroused from this sleep he had no recollection of what occurred while in it. That such an influence could be exerted, I was already aware, having previously witnessed satisfactory experiments. Of clairvoyance I had never been convinced; indeed, considered it nothing but a sort of dreaming produced by the will of the operator. I became aware of its truth rather through accident than design. “It happened, one day, that some of my brother officers asked a question which the others could not answer. Bishop, who had been a few moments before in a mesmeric sleep, gave the desired information, speaking with confidence and apparent accuracy. As the information related to something which it seemed almost impossible to know without seeing, we were very much surprised. It struck me that he might be clairvoyant; and I at once asked him to tell me the time by a watch kept in the binnacle, on the spar or upper deck, we being on the berth or lower deck. He answered correctly, as I found upon looking at the watch, allowing eight or nine seconds for time occupied in getting on deck. I then asked him many questions with regard to objects at a distance, which he answered, and, as far as I could ascertain, correctly.