But modern physical science is today offering corroborative proof (though the same is not needed by the occultist who has the astral vision) to the general public, of the existence of the human aura. In Europe, especially, a number of scientists have written on the subject of the aura, and have described the result of the experiments in which the aura has been perceived, and even photographed, by means of fluorescent screens, such as are used in taking X-Ray photographs, etc. Leading authorities in England, France, and still more recently, in Germany, have reported the discovery (!) of a nebulous, hazy, radio-active energy or substance, around the body of human beings. In short, they now claim that every human being is radio-active, and that the auric radiation may be registered and perceived by means of a screen composed of certain fluorescent material, interposed between the eye of the observer, and the person observed. This aura, so discovered (!) by the scientists, is called by them the "human atmosphere," and is classified by them as similar to the radiations of other radio-active substances, radium, for instance. They have failed to discover color in this atmosphere, however, and know nothing, apparently, of the relation between auric colors and mental and emotional states, which are so familiar to every advanced occultist. I mention this fact merely as a matter of general interest and information to the student, and not as indicating, even in the slightest degree, any idea on my part that the old occult teaching, and the observed phenomena accompanying the same, regarding the human aura, require any proof or backing up on the part of material scientists. On the contrary, I feel that material science should feel flattered by the backing up by occult science of the new discovery (!) of the "human atmosphere." A little later on, material science may also discover (!) the auric colors, and announce the same to the wondering world, as a new truth. CHAPTER II. THE PRANA-AURA. Many writers on the subject of the human aura content themselves with a description of the colors of the mental or emotional aura, and omit almost any reference whatsoever to the basic substance or power of the aura. This is like the play of Hamlet, with the character of Hamlet omitted, for, unless we understand something concerning the fundamental substance of which the aura is composed, we cannot expect to arrive at a clear understanding of the phenomena which arises from and by reason of the existence of this fundamental substance. We might as well expect a student to understand the principles of color, without having been made acquainted with the principles of light.