1 have likewise determined that these answers cannot be dictated by the mind of the medium, whose scientific and literary knowledge were not always equal to the message received. This observation coincides with the facts observed among pretended Demonomaniacs, who had in their attacks the gift of language, responding in Latin to the exorcists, making entire discourses in this language, of which they knew not the first elements. Under the name of _phenomena of ecstasy_, Dr. Gibier described, after his experiments with the medium Slade, his displacement by a stronger spirit to that of his usual control. Says Gibier, the phenomena produced from thence were “a certain discoloration of the medium’s face, which became red, a sort of grin contracting the muscles of the visage, the eyes were convulsed upwards, and after some nystagmatic movements of the ball of the eye the eyelids closed tightly, gritting of the medium’s teeth was heard, and a convulsive sign, indicating the commencement of his _possession_ by a strange spirit. After this short phase, which was painful to behold, the medium’s face fell into a smile and the voice, as well as the attitude, was completely modified to that of a different person. Slade thus transformed to his regular control, saluted all our party most graciously.” Among the experiments made by Dr. Gibier to control this condition of _incarnation_ (the English call it _trance_), we might cite that of a comparison of the dynamometric force of the medium in his natural condition and the _trance_ state. In the first case, by reason of two previous attacks of hemiplegia, Slade’s muscular force gave 27 kilos to the right and 35 kilos to the left. In the second state there were 63 kilos to the right and 50 kilos to the left. Meantime, Dr. Gibier, no more than ourselves, deems it proper to consider the trance state other than a hypothesis, “a foreign element, introduced in the scene, and like it present in the experiences of suggestion and catalepsy.” If we cannot give a scientific explanation of these phenomena, it is our duty to examine them as others and retrace their history, especially seeking those points of coincidence with the proofs furnished by the history of demonomania and diabolic possession of the Middle Ages; for we are convinced that these phenomena were dominated by the same unknown force, interpreted differently by reason of the philosophic and religious ideas of the epoch at which they were studied. CLASS XIII.—_Varied cases of a complex character._