4601. When the sirens arrive, they constantly mutter something, and, at the same time, they observe whether the muttering becomes fixed anywhere. They at once note that there must be spirits in that place [where the sound becomes fixed]; and, forth with, by means of their execrable arts, they thrust themselves into their thoughts, and thus bind them. At first, they openly follow their thoughts, then they attempt to lead; and thus they obsess them. The spirits are then in a deplorable state, without the freedom of thinking; and, unless liberated by the Lord, they would spiritually perish; for they [the sirens] do not desist from their arts before they enter openly into the thoughts. This it was granted me to know from much experience, and I wondered how it could happen; but it was unavoidable, nor could they be expelled thence, because not approached, as was said, except by the Lord. When they have occupied the thought, then, in order that anyone who is not willing to follow them, may be without power to think except in agreement with them and also from them, they have certain cowbells into which they compel the spirit to speak, and this continuously, until he falls down as if hardly master of his own mind. In this manner they make the spirit to die, as it were; for they are most vicious.