"The spirit of harmony and union will depart from the elements, disturbed by the imprudent hand; and the currents of blind forces will become immediately infested by numberless creatures of matter and instinct--the bad demons of the theurgists, the devils of theology; the gnomes, salamanders, sylphs, and undines will assail the rash performer under multifarious aerial forms. Unable to invent anything, they will search your memory to its very depths; hence the nervous exhaustion and mental oppression of certain sensitive natures at spiritual circles. The elementals will bring to light long-forgotten remembrances of the past; forms, images, sweet mementos, and familiar sentences, long since faded from our own remembrance, but vividly preserved in the inscrutable depths of our memory and on the astral tablets of the imperishable 'Book of Life.'"--(P. 343, vol. I.) Paracelsus speaks of _Xeni Nephidei_: "Elemental spirits that give men occult powers over visible matter, and then feed on their brains, often causing thereby insanity. "Man rules potentially over all lower existences than himself," says the author of _Art Magic_ (p. 333), "but woe to him, who by seeking aid, counsel, or assistance, from lower grades of being, binds himself to them; henceforth he may rest assured they will become his parasites and associates, and as their instincts--like those of the animal kingdom--are strong in the particular direction of their nature, they are powerful to disturb, annoy, prompt to evil, and avail themselves of the contact induced by man's invitation to drag him down to their own level. The legendary idea of evil compacts between man and the 'Adversary' is not wholly mythical. Every wrong-doer signs that compact with spirits who have sympathy with his evil actions.