I have said that although our imaginative friend is given to wild speculations, he is not always necessarily wrong. We know too little about the laws of brain-force to be dogmatic with reference to it. I am, myself, therefore, fully in sympathy with the psychological investigators. When it comes to the various pretended sciences by which men and women make large profits, attempts at investigation are very apt to be used as lucrative advertisements for the charlatans. But a series of investigations of the significance of certain popular beliefs and superstitions, a careful study of the relations of certain facts to each other,--whether that of cause and effect, or merely of coincidence,--is a task not unworthy of sober-minded and well-trained students of nature. Such a series of investigations has been recently instituted, and was reported at a late meeting held in the rooms of the Boston Natural History Society. The results were, mostly negative, and in one sense a disappointment. A single case, related by Professor Royce, attracted a good deal of attention. It was reported in the next morning's newspapers, and will be given at full length, doubtless, in the next number of the Psychological Journal. The leading facts were, briefly, these: A lady in Hamburg, Germany, wrote, on the 22d of June last, that she had what she supposed to be nightmare on the night of the 17th, five days before. “It seemed,” she wrote, “to belong to you; to be a horrid pain in your head, as if it were being forcibly jammed into an iron casque, or some such pleasant instrument of torture.” It proved that on that same 17th of June her sister was undergoing a painful operation at the hands of a dentist. “No single case,” adds Professor Royce, “proves, or even makes probable, the existence of telepathic toothaches; but if there are any more cases of this sort, we want to hear of them, and that all the more because no folk-lore and no supernatural horrors have as yet mingled with the natural and well-known impressions that people associate with the dentist's chair.” The case I have given is, I am confident, absolutely free from every source of error. I do not remember that Mr. Rathbone had communicated with me since he sent me a plentiful supply of mistletoe a year ago last Christmas. The account I received from him was cut out of “The Sporting Times” of March 5, 1887. My own knowledge of the case came from “Kirby's Wonderful Museum,” a work presented to me at least thirty years ago. I had not looked at the account, spoken of it, nor thought of it for a long time, when it came to me by a kind of spontaneous generation, as it seemed, having no connection with any previous train of thought that I was aware of. I consider the evidence of entire independence, apart from possible “telepathic” causation, completely water-proof, airtight, incombustible, and unassailable.