The instrument is of the horse-shoe form, about ten inches in its long axis, and five in its short, composed of five layers of metal, the central being the longest, and the whole bound with stout ribbon. The patient was at the time apparently suffering considerable pain, _and unable to use his hand_. The _north_ pole of the magnet was gently passed five or six times down the sides and back of the middle finger, and then rested on the central joint. The result was such an immediate cessation of suffering, that he could gnash his fingers into the palm of his hand with ease and comfort, and he declared himself to be entirely relieved. The power of the instrument, however, did not cease here. Dr Blundell showed that it possessed the means of reproducing the pain in the most intense form. The _south_ pole of the magnet was directed along the finger. At the third pass the patient began to bite his lip and close his eyes with an expression of pain. At a few passes more his chin was spasmodically buried in his breast, and his wrinkled features expressed the acutest suffering. This was allowed to continue for a few seconds, when the _north_ pole was again presented to the finger, and the agony speedily subsided. The spectators then left the man lying with a countenance perfectly tranquil. At the extremity of the ward lay an elderly lady, a martyr to _tic douleureux_ in the lower jaw, extending to the ear, and affecting a large portion of the head. The disease, she stated, was of more than nine years' duration, and had never ceased to afflict her for a day during that period, up to her entrance into the hospital. Her appearance was proportionably miserable. The magnet had also been applied in her case, and with similar advantage, as she stated. On the present occasion it was found, on approaching her bed, that she was in consequence free from pain on that morning, and the further aid of the magnet was not needed. 'But cannot you show its power by producing the pain?' inquired a bystander. The suggestion was acted on. The _south_ pole of the magnet was passed from the centre of the chin along the lower jawbone up to the ear. At the third pass the poor woman indicated that the _tic_ was commencing, and in a few seconds more the affection was experienced intensely. The process was then stopped, as the experiment had been carried far enough to satisfy all present of its consummation; and after a brief space the presentation of the _north_ pole wholly freed the sufferer from pain. The operator subsequently stated, that by continuing the passes he could have carried the pain on to the production of delirium.