Secondly, there is what can best be described as an etheric pressure, somewhat corresponding to, though ”3 immensely greater than, the atmospheric pressure. In ordinary life we are as little conscious of one of these pressures as we are of the other but Etheric nevertheless they both exist, and if science were able to exhaust the ether from a given space, as it can exhaust the air, the one could be proved as readily as the other. The difficulty of doing that lies in the fact that matter in the etlieric condition freely interpenetrates matter in all^ sjates below it, so that there is as yet no means within the knowledge of our physicists by which any given body of ether can ,be isolated from the rest. Practical Occultism, however, teaches how this can be done, and thus the tremendous force of # etheric pressure can be brought into play. Thirdly, there ij a vast store of potential energy which has become dormant in matter during the involution of the subtle into the gross, and by Energy changing the condition of the