Mesmerism--Experiment during a trance--I submit to being mesmerised--My observation upon it--I myself start to mesmerise--Experiment made in a diligence--Another experiment in the house of the _procureur de la République_ of Joigny--Little Marie D---- --Her political predictions--I cure her of fear Between the representation of my play and Casimir Delavigne's, the scientific world was much taken up with an important event which established the power of magnetism, that had been under dispute since Mesmer's day. One of the cleverest surgeons of the time, Jules Cloquet, had just performed an operation on Madame Pl--- for cancer in the breast, without her feeling the least pain, she having been put into a trance by mesmerism. One word about mesmerism. Let us leave actualities and turn to abstractions. Madame Pl---, upon whom this strange experiment had just been made, was between sixty-four and sixty-five years of age; she had been a widow ten years and had suffered for two or three years from glandular swellings on the right breast. Doctor Chap---- was her medical adviser; he had practised magnetism for some time and found himself apt at it. He attempted to apply it to the cure of Madame Pl---, but the disorder had gone too far, and he decided to try if it might be possible to lessen her pain while the operation was being performed. Jules Cloquet was consulted, and it was proposed that he should operate on the sleeping patient. He consented, welcoming the opportunity of seeing for himself a phenomenon concerning which he was sceptical, and also, at the same time, glad to be able to spare the patient the suffering inevitably connected with one of the most painful of surgical operations. Doctor Chap---- magnetised Madame Pl--- and rendered the whole of her right side completely insensible to pain. The ablation of the breast began by an incision eleven inches long, followed by another nine inches long. By means of these two incisions they could get at several glands under the armpit, which were carefully dissected. During the operation, which lasted ten minutes, the patient gave no signs of sensibility. To use the surgeon's own words-- "It seemed as though he were _operating on a dead body_; save that, when the operation was over and the patient's wound was being bathed with a sponge, she twice cried out, without coming out of her state of trance, 'Be quick and finish, and do not tickle me like that!'"