The medium in whose presence the phenomena were produced was the well-known "Dr." Slade. This medium has been demonstrated to have resorted to fraud with a certainty that admits of no dispute.
But, as Mr. Hereward Carrington points out, we ought not to allow this fact to influence us in the consideration of any particular case. In the first place it is fairly certain that mediums who are capable of producing genuine phenomena under suitable conditions are also liable to resort to trickery when the genuine thing does not come off. (Cp. the case of Eusapia Palladino.) In the second, too great a reliance on antecedents is apt to produce an unreliable a priori prejudice. Every case should be considered on its merits alone and the medium's past history should only be allowed to influence our judgment if it can be shown that fraud has not been rigorously excluded and that the only argument against it is the argument from moral integrity.
In this case the argument from integrity is obviously inadmissible and as a matter of fact the precautions taken to guard against fraud were so very inadequate that we cannot accept the experiments in question as worth anything at all from the scientific point of view.
Zöllner's account of his experiments is to be found in his book "Transcendental Physics," translated into English by Mr. C.C. Massey in whom the author found an able and enthusiastic champion against his many critics.
Among the more important of his experiments were:
Production of knots in an endless string.
Slate writing under "test" conditions.
Disappearance and reappearance of solid objects.
Coins transferred from closed and fastened boxes.
Other instances of the apparent penetration of matter by matter.