622. These things being so - both these causes being apparently operative along the whole series of "scryers," or crystal-gazers, from the most unstable to the most scientific - one might be tempted to assume that these two clues, if we could follow them far enough, would explain the whole group of phenomena. Persons who have not seen the phenomena, indeed, can hardly be persuaded to the contrary. But the real fact is, as even those who have seen much less of crystal-gazing than I have will very well know, that these explanations cannot be stretched to cover a quarter - perhaps not even a tenth - of the phenomena which actually occur.

Judging both from the testimony of scryers themselves, and from the observations of Dr. Hodgson and others (myself included), who have had many opportunities of watching them, it is very seldom that the gaze into the glass ball induces any hypnotic symptoms whatever. It does not induce such symptoms with successful scryers any more than with unsuccessful. Furthermore, there is no proof that the gift of crystal-vision goes along with hypnotic sensibility. The most that one can say is that the gift often goes along with telepathic sensibility; but although telepathic sensibility may sometimes be quickened by hypnotism, we have no proof that those two forms of sensitiveness habitually go together.

The ordinary attitude of the scryer, I repeat, is one of complete detachment; an interested and often puzzled scrutiny and analysis of the figures which display themselves in swift or slow succession in the crystal ball.

This last sentence applies to the theory of points de repère as well. As a general rule, the crystal vision, however meaningless and fantastic, is a thing which changes and develops somewhat as a dream does; following, it may be, some trivial chain of associations, but not maintaining, any more than a dream maintains, any continuous scheme of line or colour. At the most, the scraps of reflection in the crystal could only start such a series of pictures as this. And the start, the initiation of one of these series, is often accompanied by an odd phenomenon mentioned above - a milky clouding of the crystal, which obscures any fragments of reflected images, and from out of which the images of the vision gradually grow clear. I cannot explain this clouding. It occurs too often and too independently to be a mere effect of suggestion. It does not seem to depend on any optical condition - to be, for instance, a result of change of focus of the eye, or of prolonged gazing. It is a picture like other pictures; it may come when the eyes are quite fresh (nor ought they ever to be strained); and it may persist for some time, so that the scryer looks away and back again, and sees it still.

It comes at the beginning of a first series of pictures, or as a kind of drop-scene between one series of pictures and another. Its closest parallel, perhaps, is the mist or cloud out of which phantasmal figures, "out in the room," sometimes seem to form themselves.

Moreover, the connection, if one can so call it, between the crystal and the vision is a very variable one. Sometimes the figures seem clearly defined within the crystal and limited thereby: sometimes all perception of the crystal or other speculum disappears, and the scryer seems clair-voyantly introduced into some group of life-sized figures. Nay, further, when the habit of gazing is fully acquired, some scryers can dispense with any speculum whatever, and can see pictures in mere blackness; thus approximating to the seers of "faces in the dark," or of illusions hypnagogiques.

623. On the whole it seems safest to attempt at present no further explanation of crystal-gazing than to say that it is an empirical method of developing internal vision; of externalising pictures which are associated with changes in the sensorial tracts of the brain, due partly to internal stimuli, and partly to stimuli which may come from minds external to the scryer's own. The hallucinations thus induced appear to be absolutely harmless. I at least know of no kind of injury resulting from them; and I have probably heard of most of the experiments made in England, with any scientific aim or care, during the somewhat limited revival of crystal-gazing which has proceeded for the last few years. We still want to know more on every point connected with these visions. How far, for instance, do they follow optical laws? Is there any tendency to complementary colouring, so that a green picture would be seen after a red? Are they magnified by the interposition of a magnifying glass? and, if so, is this a mere result of suggestion, or of the presence of something in the field of view which is really magnified? Would they be magnified if the scryer did not know that a magnifier was interposed, or, on the other hand, if he believed that a plain glass interposed was a magnifier? Some interesting experiments on these and kindred questions will be found in 623 A. I can imagine no fitter problem for research in a psychological laboratory.

624. A simpler experiment, which should be within the power of almost any one who has a good hypnotic subject, is the following: Describe some historic scene to the entranced subject, telling him that he will see the scene, as he conceives it, in a glass ball when he awakes. Awaken him, and make him look into the ball. He is then confronted with his own mental images, as though in an external picture, and he explains them as best he can. If these externalised pictures show a tendency to contain explanatory words, helping him to grasp their meaning, it will be needful to suggest in the trance that no such words should appear. In the experiments which I quote in 624 A, it will be seen that the hypnotic stratum sent up no such explanation along with the pictures; so that it was safe to offer these working lads large sums of money if they could tell me the subjects of pictures which they were actually drawing from memories of their own not five minutes old. These experiments, which I record at some length as eminently suitable for repetition, were made with two excellent hypnotic subjects with whom the late Edmund Gurney and Mrs. Sidgwick had long worked.

625. These experiments illustrate the gradual transition between the common forms of post-hypnotic hallucination, which, however surprising at first, are now undisputed, and the crystal-vision which I am anxious to present as no "occult practice" or superstitious fancy, but as the empirical development of processes more familiar but quite equally empirical.

But, indeed, as with automatic script, so here also we shall soon find that hypnotic experiments of this kind are not necessary in order to convince us that the crystal-pictures are, in their own sense, a reality. Quite apart from the veridicality of some of them; - the intrinsic evidence which they contain of knowledge outside the experimenter's ordinary knowledge; - they occur to a greater or less extent with so many persons of sanity and probity that we can no more doubt their existence than we can doubt the existence of the allied phenomena of hypnagogic hallucinations or of coloured audition already discussed. I give in Appendices an account of several important groups of these crystal-visions.