[8] As crystal-gazing seems to me one of the most curious phenomena to study, I will take the liberty of mentioning that well-made crystal balls may be found at Leymarie, 42 Rue Saint-Jacques, Paris; at the Society for Psychical Research, 20 Hanover Square, London, W.; or Mrs. Venman, Sugden Road, Lavender Hill, London, S.W. The price of the globes varies from 6s. to 9s.; those of ovoids, from 8s. to 10s. The best thing to do would be to look for a ball in rock-crystal, the price of which would vary from 4s. to £8. They must be cut to order, for it is extremely difficult to find any ready made. M. Servan, jeweller at Bordeaux, furnishes good ones. When looking into the ball, it should be sheltered from reflection, as it should offer a uniform tint, without any brilliant points. To obtain this result, it may be enveloped in a piece of dark foulard or velvet, or held in the hollow of the hand, or even at the fingertips, provided the conditions mentioned above have been observed. The object ought to be placed within the range of normal vision; the gaze should not be directed on to the surface of the crystal, but _in the crystal itself_. The knack of gazing inside the crystal is speedily acquired. Mirrors also give very good results. They can be made like ordinary mirrors, or black like the famous mirrors of Bhatta, which are made of a special composition. Sensitives say that the mirror should not reflect anything: it should present a uniform tint, _e.g._ that of the sky, blue or grey, but without the mixture of these colours as would be the case with a cloudy sky; in a room the ceiling may be reflected, if it be monochrome. Under these conditions of operation I have sometimes observed results so extraordinary, as to confound the imagination. They appeared to me to tend towards demonstrating Kant’s idea of the relativity and contingency of time and space. It is very difficult to admit, that these two ordinates of our perceptions are exactly what they seem to be, unless we push the theory of coincidence to the absurd. But this would be shutting the door on all discussion, and on all intelligent examination of a fact apparently abnormal. My observations have been made with different persons, and a great many have been pointed out to me. Sensitives, possessing the faculty of seeing in the crystal, are not rare. The analysis of the facts I have observed, or of which I hold first-hand reports, allows me to class these ‘hallucinations’(?) under six categories of increasing interest:— _A._ Imagination—images, ordinary hallucination. _B._ Forgotten souvenirs, recalled to memory in the form of visions. _C._ Passed events, of which the sensitive affirms to have always been ignorant. _D._ Present events, certainly unknown to the sensitive. _E._ Future events. _F._ Facts of doubtful interpretation.