etheric may be regarded as synonyms for the subtle body.
There is ample evidence that the Etheric Double can come adrift from the dense body, consciously, accidentally, or in sleep; it can be detached in trance or by hypnosis and sent on its way, but its powers and its appearances vary greatly.
Sometimes, as in Swedenborg's case, the Double can report what is happening at its distant rendezvous through the lips of its abandoned self that lies within the powers of many sensitives.
That distinguished Medium, Mrs. Eileen Garrett, explains the procedure in My Life as a Search for the Meaning of Medium-ship.
I shall endeavour, as far as possible, to keep Mediumship and the professional use of psychic power out of this volume; not because a Medium is necessarily an untrustworthy person, but because this business of the Double is essentially an affair of quite ordinary contrivance; you may encounter it once in a lifetime or it may be an everyday performance. All that it requires is an easily detachable Etheric, but on what that depends we are still in ignorance. From my own experience I should say that, lacking the needful looseness, no recipe for detachment is of the slightest use unless it involves some special cultivation of your psychic powers.
In Mrs. Garrett one has that rather rare product, a Medium with outstanding abilities, who is anxious, for her own satisfaction and for the sake of humanity, to understand them.
In 1932, when working with several well-known psychiatrists and scientists in America who were interested in the problem of telepathy at a distance, a test was arranged for her in New York.
From a room there she was asked to communicate with a