1688. About those constituting the province of the dura mater
There were numerous spirits above me at a moderate distance overhead, over the region of the cerebrum. They were working as if by a general pulsation, at first like a alternating undulation down and up, accompanied by a mildly cool breathing on my forehead. Their motion seemed like a collective alternation, for I have sometimes experienced such motions coming from a multitude of spirits. In this case it was alternating, downward and upward, which made me think that they were not inward spirits, whose motion goes in whirls.