And now a word or two about the disposition and attitude of the subject. The visions do not occur in the crystal itself. They may appear to do so, but this is due, when it occurs, to the projection and visualization of the mental images. The visions are in the mind or soul of the seer and nowhere else. It is a matter of constitutional psychism as to where the sense of clear vision will be located. Personally I find the sense to be located in the frontal coronal region of the brain about 150 to the right of the normal axis of vision, which may be regarded as the meridian of sight. Other instances are before me in which the sense is variously located in the back of the head, the nape of the neck, the pit of the stomach, the summit of the head, above and between the eyes, and in one case near the right shoulder but beyond the periphery of the body. The explanation appears to be that the nervo-vital emanations from the body of the seer act upon the static odyle in the agent, which in turn reacts upon the brain centres by means of the optic nerves. And this appears to be sufficient reason why the crystal or mirror should be kept as free as possible from disturbing elements. Water is extremely odylic and should never come in contact with the agent employed as it effectually carries off all latent or stored imports. I am forced to use a crude terminology in order to convey the idea in my mind, but I recognize that the whole explanation may appear vague and inadequate. It is of course at all times easier to observe effects than to offer a clear explanation of them. Yet some sort of working hypothesis is constructed when we collate our observations, and it is this that I have sought to communicate. For similar reasons, when in use the crystal or mirror should be shaded and so placed that no direct rays from sun or artificial light may fall upon it. The odyle, as Reichenbach so conclusively proved by his experiments, rapidly responds to surrounding magnetic conditions and to the vibrations of surrounding bodies, and to none more rapidly than the etheric vibrations caused by combustion or light of any kind. There should be no direct rays of light between the agent and the seer. The room in which the sitting takes place should be moderately warm, shady, and lit by a diffused light, such as may be obtained by a light holland blind or casement cloth, in the daytime. The subject should sit with his back to the source of light, and the illumination will be adequate if ordinary print can be read by it. It is important that all persons sitting in the same room with the seer should be at least at arm's length from him. Silence should be uniformly observed by those present, until the vision is attained. It will then be found convenient to have two persons present to act as Interrogator and Recorder respectively.