This mutilated head, which had been so long the subject of observation, was united by the plane of the section to that of the other criminal, which had not been subjected to anatomical dissection. I then applied two arcs, making one of them to communicate with the summit of the pile and the right ear of one head, and the other with the bottom of the pile and the left ear of the second head. Both heads experienced contractions similar to those described in the 27th experiment; but in the head which had already been employed they appeared to be weaker. EXPERIMENT XXXII. After these experiments on the head, I proceeded to the trunk of the second criminal, which I conceived to be most proper for my purpose. I think it necessary here to observe, that the body had been exposed for about an hour, in an open court, where the temperature was two degrees below zero. The muscles of the fore-arm and the tendinous parts of the metacarpus being laid bare, an arc was established from those muscles to the spinal marrow. In consequence of this arrangement, the fore-arm was raised, to the great astonishment of those who were present. EXPERIMENT XXXIII. Having established an arc between the biceps muscle of each arm, which I had laid perfectly bare, I obtained similar contractions, but somewhat weaker than in the preceding case. EXPERIMENT XXXIV. Having laid bare the tendons of the fingers, on the back of the hand, I established an arc between that region and the spinal marrow, and obtained strong contractions in the fingers and in the whole hand. EXPERIMENT XXXV. Proceeding to the lower extremities, I formed an arc from the spinal marrow to the vastus internus, vastus externus, sartorius, and other muscles, and obtained strong contractions in all these muscles. Having removed the arcs and the pile, the muscles retained a small oscillatory motion, which continued for ten minutes. I observed the same phænomenon in the muscles of the neck, when I established an arc between the spinal marrow and various other parts of the trunk. EXPERIMENT XXXVI. Having applied the arc to the spinal marrow and the uncovered muscles of the under part of the tarsus of the right foot, the extensor muscles of all the toes, and particularly of the great toe, experienced very sensible contractions. I repeated the experiment with the arc applied, not to the spinal marrow, but to the uncovered muscles of the thigh, employed in the preceding experiment, and found the contractions excited to be much stronger. In like manner, the muscles of the soles of the feet, when I established an arc between them and the muscles of the thigh, manifested much stronger contractions than when the arc extended to any other distant part. EXPERIMENT XXXVII.