returning energy is exactly equal to that radiated away cannot be determined by observation alone, but it appears to be of the same order of magnitude, and explains why the flux of energy observed is so very much greater than the amount indicated by physical measurements. “As shown above, the use of the mathematics of wave-mechanics by physicists has disclosed the existence of a sub-ether which is fully confirmed by magnetic vision, but this magnetic vision further discloses a series of such sub-ethers, so that sub-ether number 2 performs the same function for sub-ether number I, as sub-ether number I performs for ordinary electro-magnetic waves. Now the difference between ordinary vision and developed vision lies in the faculty of developed vision to tune in to the vibrations of the sub-ethers which underlie the ordinary electro-magnetic ether. It is the difference between a wireless receiving ‘set tuned to one wavelength, and a receiving set which can be set to any wavelength. This power of tuning the consciousness to these different orders of vibratory systems is latent in all, and will eventually be developed in all. It is the next step in human evolution. “As the author has stated in Chapter I, it is the purpose of this volume to give illustrations of the use of this new power of vision, both for physical, investigation and for the medical sciences. The following examples are taken from records of experiments on electricity and on the atom, and medical investigations are recorded later. These recorded observations arc compared with facts as far as they are known, and with current theories where facts are absent. Observations in connection with physics are handicapped by having largely to be compared with theories, but physical theories have changed so rapidly in recent years, that one theory is superseded by another almost before the first can obtain publication. For instance, Eddington published his ‘Internal Constitution of the Stars’ in 1926, and Jeans his ‘Astronomy and Cosmogony’ in 1928. Now both these writers assume the truth of Bohr’s theory of the atom, and many of their most important conclusions in connection with the stars, and with astrophysics, are based on the truth of Bohr’s theory. Yet Prof. Eddington, in his latest work, ‘The Nature of the Physical World’ (p. 204), tells us that by 1925 Bohr’s model of the atom had quite definitely broken down. “It is evident from the above that the test of magnetic vision, by comparing it with the results of physical theories, may lead to uncertainties, and the only reliable test of magnetic vision is by comparing it with other observations where theories do not intervene.