The ordinary photographic plate represents colours differently to their relative values as seen by the human eye, and in order to get the true effect certain dyes are mixed with the emulsion of the plates, or dyed screens which eliminate certain rays are interposed between the lens and the object. The normal individual cannot see the aura, but a simple chemical device will put him on a par with the best natural aura discerner. If a narrow glass trough or an oblong clear crystal glass bottle is filled with a dilute solution of the dye di-cyanin[50] which dissolves readily in absolute alcohol; that is all the apparatus necessary. The subject whose aura is to be inspected should be placed against a black or neutral background opposite a source of illumination, preferably a north-facing window. The observer then takes the bottle of blue solution and gazes through it at the clear sky for a period of some minutes. This serves to eliminate the retinal impression of certain of the normal light rays and renders the observer’s eyes sensitive to vibrations or rays not normally perceptible and stimulates an abnormal acuteness of vision. The room should now be entirely darkened, and as soon as the eyes have recovered their “owl sight” the body of the subject will be seen to be surrounded by an envelope of vibratory exhalations whose colour varies with different individuals and changes under stress of emotion. Suggestion or hypnosis exercises very peculiar effects on this aura, which would seem to be, if not an ectoplasm a psychoplasm in itself, yet the invisible vehicle which is capable of being separated from the material body and forming the astral body. The aura vibration and the Becquerel or N-rays are closely connected, and the scientific hypothesis suggests that these rays are in the scale just above the infra-violet. The simple instrument indicated above has certain therapeutic values in the diagnosis of illness, but is also invaluable for the psychic analysis of hauntings, cases of unconscious mediumship, and other matters. FOOTNOTES: [45] See _The New Revelation_. Sir A. C. Doyle. [46] For details of leverage, etc., see: _The Reality of Psychic Phenomena and Experiments in Psychical Science_. By W. T. Crawford. [47] Author’s note, 1912. [48] Valuable data were gained by experiment with this disastrous relic. They are not suitable for publication at this stage, and I learnt recently of similar objectionable attributes associated with a battlefield souvenir from near Ypres. [49] _The Evolution of Forces._ Gustave le Bon. [50] Used in colour screen making for photography, and poisonous. Some glasses used in bottle making are not suitable, but a trial of one or two suitably shaped ones will always reveal one that works all right. CHAPTER XI ORIENTAL OCCULTISM