The relation of our sense-organs to the several degrees of matter, to solids, fluids, gases, atmospheric and etheric motions, vary in different individuals to such a wide extent that the average wool-sorter leaves many an artist behind in his perception of colour-shades. The same odour is perceptible by one person and unrecognisable by another. In the gradation of sound, too, the same differences of perception will be commonly noticed. But quite apart from the scale or range of perception, the _quality_ of a sense-impression is found to vary with different persons. By this we mean that the same body will affect different persons in dissimilar manner. Hence arises the variety of "tastes" in regard to forms, colours, flavours, scents, sounds, fabrics, etc., what is agreeable to one being highly objectionable to another. The experience is to common to need illustration; but the conclusion to which we are led is that, in relation to the nervous system of man, every material body has a variable effect. And this clears the ground for a statement of our views in regard to the Crystal and its effects upon the seer. The Crystal itself is a clear pellucid piece of quartz or beryl, sometimes oval in shape, but more generally spheroidal. It is accredited by Reichenbach and other researchers with highly magnetic qualities capable of producing in a suitable subject a state analogous to the ordinary waking trance of the hypnotists. It is believed that all bodies convey, or are the vehicles of, a certain universal magnetic property, variously called Od, Odyle, etc., which is regarded as an inert and passive substance underlying the more active forces familiar to us in kinetic, calorific, and electrical phenomena. In this respect it bears a position analogous to the Argon of the atmosphere. It is capable of taking up, sympathetically, the vibrations of those bodies or elements to which it is temporarily related. But of itself it has no activity, although in its still, well-like, and calm depths it holds the potentiality of all magnetic forces. This Odyle, then, is particularly potent in the quartz or beryl, when brought into activity by the intention of the seer. It produces and retains more readily in that form the various images communicated to it from the soul of man. And the soul, in this connection, must be regarded as the repository of all that complex mass of emotions, thoughts, impressions, perceptions, feelings, etc., included in the inner life of man; for the soul of man is not the less a scientific fact because there are those who bandy words concerning its origin and nature. Reichenbach has shown by a series of experiments upon sensitive and hypnotised subjects that metals and other substances produce very marked effects in contact with the human body. Those experiments showed, too, that the same substance affected different patients in diverse manner. The hypnotic experiments of Dr. Charcot, the well-known French biologist, also demonstrate