The Book of Dreams and Ghosts

If thinking of friends and lovers, lost or dead, could bring their forms and voices before the eye and ear of flesh, there would be a world of hallucinations around us. "But it wants heaven-sent moments for this skill," and few bridal nights send a vision and a voice to the bed of a wakeful lover far away. Stories of this kind, appearances of the living or dying really at a distance, might be multiplied to any extent. They are all capable of explanation, if we admit the theory of telepathy, of a message sent by an unknown process from one living man's mind to another. Where more than one person shares the vision, we may suppose that the influence comes directly from A to B, C and D, or comes from A to B, and is by him unconsciously "wired" on to B and C, or is "suggested" to them by B's conduct or words. In that case animals may be equally affected, thus, if B seems alarmed, that may frighten his dog, or the alarm of a dog, caused by some noise or smell, heard or smelt by him, may frighten B, C and D, and make one or all of them see a ghost.