Ignorance of the influence of the imagination upon the nervous system has given rise to many superstitions. We will give a few statements of facts to establish and illustrate this position. Some time previous to 1784, a gentleman in Paris, by the name of Mesmer, professed to have discovered a universal remedy for all diseases; and this remedy consisted in being _magnetized_ under peculiar forms and circumstances. M. Mesmer became so noted for his discovery, and he performed such extraordinary cures, that, in 1784, the French king appointed a committee, consisting of four physicians and five members of the Royal Academy of Sciences, to investigate this matter. The committee, as soon as they had examined the whole apparatus employed in magnetizing, and taken cognizance of the manoeuvres of Mesmer, and his partner, Deslon, proceeded to notice the symptoms of the patients while under the influence of magnetism. These were various in different individuals. Some were calm and tranquil, and felt nothing; others were affected with coughing and spitting, with pains, heats, and perspirations; and some were agitated and tortured with convulsions. These convulsions were sometimes continued for three hours, accompanied with expectoration of a viscid phlegm, ejected by violent efforts, and sometimes streaked with blood. They had involuntary motions of the limbs, of the whole body, and spasms of the throat. Their eyes wandered in wild motions; they uttered piercing shrieks, wept, laughed, and hiccoughed. The commissioners observed that the great majority of those thus effected were females, and that these exhibitions did not begin until they had been under the operation of magnetism one or two hours, and that, when one became affected, the rest were soon seen in the same situation. In order to give the magnetizer the fairest opportunity to exhibit the power of his invention, and to give the most satisfactory evidence to the public, the commissioners all submitted to be operated upon themselves, and sat under the operation two hours and a half, but without the least effect upon them, except the fatigue of sitting so long in one position. They were magnetized three days in succession, but without any sensible effect being produced. The magnetizing instruments were then removed to Dr. Franklin's house, away from public view, parade, and high expectation, and fourteen persons were then magnetized, all of them invalids. Nine of them experienced nothing, five appeared slightly affected, and the commissioners were surprised to learn, in every instance, that the poor and ignorant alone were affected. After this eight men and two women were magnetized, but without the least effect. At length a female servant submitted to the same operation, and she affirmed that she felt a heat in every part where the magnetized finger was pointed at her; that she experienced a pain in her head; and, during a continuation of the operation, she became faint, and swooned.