"Thereupon St. Theophilus made a pact with the Devil." --ACTA, S. S., 4 February. Many forms of insanity, it is well known, are accompanied by the fixed idea that the sufferer is continually associated with another being, a friend or an enemy, a man, an animal, or a mere shadow. Somnambulists, also, not unfrequently fancy that they obtain their exceptional knowledge of hidden things, not by intuition or instinct, but through the agency of a medium, whom they look upon as an angel or a demon. There is, however, a third class of cases, far more formidable than either of those mentioned, in which the mind is disturbed, and magic phenomena are produced by an agency apparently entirely independent of the patient himself. Such are possession, vampirism and zoanthropy--three frightful forms of human suffering, which are fortunately very rare, being limited to certain localities in space, to a few short periods in time, and to men of the lowest grade only. Possession is that appalling state of mind which makes the patient believe that he is in the power of a foreign evil being, which has for the time full control over his body. This power it abuses by plaguing the body in every imaginable way, by distorting the features till they assume a scornful, diabolical expression, and above all, by causing the sufferer to give utterance to cynical remarks and horrible blasphemy. All these phenomena are based upon the division of the patient's individuality, which cannot be remedied by any effort of his own, and which makes him look upon the evil principle in his nature as something outside of himself, and no longer under his control. The phenomena which accompany possession are too fearful in their nature, and yet at the same time too exceptional to keep us altogether and easily from believing, as many thoughtful and even pious men have thought, that in these cases a real demon takes possession of the afflicted. The bitter hatred against religion, which is always a symptom of possession, would naturally tend to enforce such a presumption. The possessed know not only their own sins, but also those of the bystanders, and use this knowledge with unsparing bitterness and cruel scorn; at the same time they feel the superiority of others with whom they may come in contact, as the demoniacs of the Bible never failed to recognize in Christ the Son of God. From the numerous cases of modern possession which have been investigated, we derive the following information as to its real nature. Possession is invariably a kind of insanity, which is accompanied by exceptional powers, producing magic phenomena; it is also invariably preceded by some grave disorder or dangerous disease. The former may be of purely mental nature, for violent coercion of will, sudden and subversive nervous shocks or long-continued enforcement of a hateful mode of life, are apt to produce the sad effect. Hence its frequent