Another writer says of the clairvoyant perception of the human aura: "As he looks, the clairvoyant will see himself surrounded by the luminous mist of the aura, flashing with all sorts of brilliant colors, and constantly changing hue and brilliancy with every variation of the person's thought and feelings. He will see this aura flooded with the beautiful rose-color of pure affection, the rich blue of devotional feeling, the hard, dull brown of selfishness, the deep scarlet of anger, the horrible lurid red of sensuality, the livid grey of fear, the black clouds of hatred and malice, or any of the other hundredfold indications so easily to be read in it by the practiced eye; and thus it will be impossible for any persons to conceal from his the real state of their feelings on any subject. Not only does the astral aura show him the temporary result of the emotion passing through it at the moment, but it also gives him, by an arrangement and proportion of its colors when in a condition of perfect rest, a clue to the general disposition and character of its owner." Thought Forms. Another phase of clairvoyant phenomena of this class is that of the perception of "thought forms," as they are called by occultists. As all students of occultism know, a strong thought or emotion manifests a certain high vibratory motion, and takes upon itself a vibratory "form" which is plainly perceptible to the trained clairvoyant vision. These thought-forms manifest a great variety in appearance and character. Some appear in a faint wave-like form, something like the tiny waves caused by the dropping of a pebble in a pond of water. Others take on a whirlpool form, rotating and whirling as they move through space. Others appear like whirling rings, similar in general form to the "ring" puffed forth from the mouth of a cigar smoker, or from the funnel of a locomotive. Others glow like great opals. Others appear like jets emitted from the spout of a teakettle. Others twist along like a corkscrew. Others appear like exploding bombs. Others branch out arms like a devil-fish, which wriggle in all directions, as if striving to attach themselves to some object upon which they wish to take hold. The X-Ray Sense. Another phase of clairvoyant phenomena of this general class is that which may be called "the X-Ray Sense," for indeed it enables the clairvoyant to see through a brick wall, or other material obstacle, or through a sealed letter, etc. The higher psychic vibrations easily pass through the most solid object, just as do the X-Rays, and consequently the clairvoyant is able to see what is going on on the other side of a brick wall, or the walls of a house. Likewise, the clairvoyant vision is able to pierce through the dense earth, and to perceive veins of mineral or metal lying concealed beneath. Microscopic Vision.