1688. CONCERNING THOSE WHO CONSTITUTE THE PROVINCE OF THE DURA MATER There were a number of spirits above me at a medium distance overhead, about the region of the cerebrum, who acted by a sort of common pulsation, which was at first a reciprocal undulation, as it were, downwards and upwards with a certain cool kind of breathing upon my forehead. Their motion, as I have remarked, was a kind of reciprocal one, such as I have sometimes experienced from a multitude of spirits. From this species of up and down motion, I could infer that they were not of the more interior class, as their movement is that of gyres.