Evidently I have no explanation to offer. The apparition of these human forms raises a problem, which is far more complicated than the problem of raps and movements without contact, and I think the study of this problem cannot be profitably undertaken at present. Nothing authorises me to consider these curious phenomena as demonstrating the exactness of the spirit hypothesis; I think their cause lies elsewhere than in the intervention of the spirit of a deceased person; but I am not yet able to formulate any rational opinion on this subject. However, I will point out the close connection, which appears to me to exist between the production of these forms, and the production of raps and movements without contact. These relations tend to persuade me, that all these phenomena belong to the same order, and depend upon the same agent, and the same cause. Before, however, analysing summarily the observations on which I base this opinion, I ought to describe a series of experiments, which have given me most curious results. These experiments were made with a medium, a man of deep intelligence and refined nature, of whose medianity I have already spoken, pages 74, 79, 81-2, 101-3. I obtained with him: (_a_) raps, faint at first, but very clear and well verified, with and without contact; (_b_) movements without contact of feeble amplitude, but very well observed; (_c_) faint luminous phenomena; (_d_) finally, the production of diverse forms. The first two categories of facts have already been dealt with, I will now describe the last two. They confirm, to a certain extent, the experiments already related in this chapter. The first time luminous phenomena were seen, we were holding a seance in a small room, but were not using a table. The medium perceived several lights and even faces on the wall in front of him. These lights and faces were not visible to me. Sometimes I thought I saw lights, but extremely faint ones, and at the limit of visibility; I think these lights were subjective. And yet, I have often asked the medium where he saw the light, to describe its shape, and the direction it took if it moved about, and I have remarked that the indications given by the medium concorded with my own observations; but, curiously enough—and it is my duty as a witness to point this out—I could often see these lights, just as well when my eyes were closed, as when they were open. This circumstance seems to me conclusive, and makes me think these lights were subjective. In reality, I do not think that the light emitted by the gleams I saw was of such a nature, that its rays could penetrate through closed eyelids. This interior visibility should exist in every case; now this is not so, and I have only observed it with this particular medium, though I had once or twice suspected it in a former series of experiments.