Biology, so called, is one peculiar feature, or form, of mesmerism. "These experiments," says Dr. Richmond, "attracted much attention some three years since, in Ohio, and other places, and such was the intense excitement of the public mind that, in some places, parents and the public were obliged to interfere and stop children from biologizing each other." It was found that not only muscular motion, but the exercise of the senses, could be destroyed by the will of the operator. Taste was obliterated, or changed, memory destroyed, and any picture presented to the mind of the subject would be seen. Tell him he saw snakes, and he would become frightened, and rush with violence over the seats and benches. Tell him he was sleigh riding, and he would instantly seize the reins, and drive the horses with great glee. Tell him he was a witch--an old woman in rags--and he would own the character, and confess all the crimes with which you had charged him. Tell him he was a gay young lady, and another subject was about to court him, and a love scene would commence. Tell him he was cold, and he would shiver, his teeth chatter; he would stamp, and thresh his hands to keep them warm. Tell him it was summer--very hot, and he would begin fanning himself, fling off his coat, and, unless prevented, would divest himself of all garments tell him that a tree of fruit was before him, and he would begin to fill his pockets. Sweep the room before him, and open the sky, and say that the river of life and a white throne were before him, that the judgment was set, and instantly he would assume the attitude of devotion; he would gaze with burning eye and rapt delight into the scene of glory. Take him to a lake side, tell him a child was drowning in the water, and he would wade in, take it in his arms, and lay it carefully down, and weep over it in deep pity. Bring before him the lightning's flash, the thunder's roll, or proclaim a God in grandeur, and a world on fire, and, as once actually took place in Covington, Kentucky, a dozen subjects fell in intense fright: some on to the floor, some on benches, others sought to fly, and all declared to the audience that a shower of fire seemed to be around them. Any image the operator sees fit to plant in the subject's mind is readily done; any passion readily assumed; reverence, revenge, vanity, love, hate, fear, mirth, joy, grief, or ecstasy, are all _imitated_ at his bidding, and safely dispersed and reproduced with the rapidity of thought, changing in an instant both the actions and motions of the subject. Tell the person he is suffocating in water, and he _will_ suffocate, unless you prevent him. Tell him he is struck on the head, and he falls, as if stricken down with a hammer. No doubt a subject might be killed by a mental impression--by saying to him he was shot through the heart, or was struggling in water. This is the opinion of all operators in the art. The subject at the time is, to all