The conviction of the genuineness of spirit photographs is a conviction which is founded on purely negative evidence (namely, that on very many occasions no fraud has been actually discovered), and held in the face of definite positive evidence (namely, the occasional actual discovery of fraud, as by Mr. Bush). But once formed it seems impossible to shake it, and just as always happens when emotion rather than reason is responsible for an opinion, every adverse indication is distorted into an additional corroboration. Just as a lover distorts the faults of his mistress into virtues--frivolity being regarded as gaiety, dulness as profundity and intransigeance as strength of mind--so the plain indications of fraud which leap to the eyes of the unbiassed student are gravely put forward as evidence of the wonderful ways in which the spirits work. Thus in _Light_ for January 29th I find advanced as “most evidential” the fact that whereas a plate which had been in the possession of the medium for several days showed an “extra,” others, simultaneously exposed, which had _not_ been in her possession, did not. (Note.--I am well aware that the plates sent to the medium for “impregnation by the psychic influence” were in a sealed packet which was certified intact when returned. But as anyone who has studied the subject of sealing knows, it is extremely difficult to devise a really fraud-proof method. Certainly no ordinary arrangement of strings and knots is reliable.)[14] Mr. Barlow, who writes the article, correctly argues that this result indicates that the lens of the camera used “had nothing to do with the formation of the psychic images which appear to have been printed on the photographic plate.” But instead of drawing the obvious conclusion that, in spite of the sealing, the plate which showed the “extra” had been tampered with, he adopts the view that a “psychic transparency” is used, that this is at some period applied to the sensitised surface of the plate by spirit agency and exposed to spirit light! Comment is needless.