This finding is fully confirmed by electrical phenomena in the realm of nature most remote from man (though it was an effort to solve the enigma of man which led to the discovery of this realm). Since Crookes's observations of the behaviour of electricity in a vacuum it is common knowledge that only the negative kind of electricity occurs as a freely radiating force (though it retains some properties of inertia), whereas positive electricity seems to be much more closely bound to minute particles of ponderable matter. Here again we find gravity-laden levity on the negative side, levity-raised gravity on the positive.