The etheric double is primarily a body of magnetic stresses in the framework of whose meshes every cell and fibre of the physical body is held as in a rack. But intermediate between this and the dense physical body as we know it, there is what may be called the raw material out of which dense matter is condensed. This was called by the ancients hyle, or First Matter, and by the moderns, ectoplasm. It is this projected ectoplasm which produces the phenomena whenever physical manifestations are in question. It may be projected as long rods, which will operate up to a distance of a dozen feet or so; or it may be projected as a nebulous cloud, connected with the medium by a tenuous thread. This cloud can be organised into distinct forms, having the semblance of life and acting as vehicles for conscious wills.
See also: Etheric plane