FALLACIES OF TESTIMONY. S79 



iostance of the application, to the phenomena of the divining-rod, of the very 

 simple test of closing the eyes, has lately been sent me by an American friend, 

 who was apparently unaware of its former application by Chevreul and Biot : 

 " An aged clergyman, of thorough integrity, has for many years enjoyed the 

 reputation of being specially skilled in the finding of places to dig wells by 

 means of the ' divining-rod.' Ilis fame has spread far ; and the accounts that 

 are given by him, and of him, must be, to those who place an implicit reliance 

 on human testimony, overwhelmingly convincing. He consented to allow me to 

 experiment with him, and I found that only a few moments were required to 

 prove that his fancied gift was a delusion. In his own yard there was known 

 to be a stream of water running a few feet below the surface, through a small 

 pipe. As he marched over and near this, the rod continually pointed strongly 

 downward, and several times turned clear over. These places I marked, and 

 then blindfolded him, and marched him about until lie knew not where he was, 

 taking him over the same ground over and over again ; and although the rod 

 went down a number of times, it did not once point to or near the places indi- 

 cated.'''' 



3. About twenty-five years ago, when the old phenomena of the oscilla- 

 tions of suspended buttons, developed by Dr. H. Mayo into a pseudo-scientific 

 theory of od-force, were strongly exciting public attention, a medical friend of 

 great intelligence, then residing in the south of France, wrote me long letters 

 giving the results of his surprising experiences, and asking what I regarded as 

 their rationale. My reply was simply, " Shut your eyes, and let some one else 

 observe the oscillations." In a short time I heard from him again, to the efiect 

 that his reinvestigation of the matter under this condition had satisfied him 

 that there was no other agency concerned than his own involuntary muscular 

 movement, directed by his mental expectancy of the results which would ensue. 



In the foregoing cases, the honest beliefs of the agents themselves brought 

 about the results; in the following these beliefs were taken up by the wit- 

 nesses to the performances of others, in spite of all common-sense probabil- 

 ity to the contrary, under the influence of their own strong "preposses- 

 sions." 



4. At a spiritualistic seance at which I was present, at an early stage of the 

 present epidemic, the " medium " pressed down one side of a large loo table sup- 

 ported on a pedestal springing from three spreading feet, and left it resting on 

 only two of its feet, with its surface at an angle of about 45. Having been 

 admitted to this seance under a promise of non-interference, I waited until its 

 conclusion ; and then, going over to the table, set it up and left it in the same 

 position. For I had observed, when this was done by the " medium," that the 

 edge of the broad claw of each foot, and the edge of its castor, bore on the 

 ground together, so as to afford a base which, though narrow, was sufficient for 

 the table to rest on, its weight happening to be balanced when thus tilted half 

 over. Several persons of great intelligence who were present at this seance (Mr. 

 Eobert Chambers among the rest) assured me that, if it had not been for my 

 exposure of this trick, they should have gone away in the belief that the table 

 was sustained by " spiritual " influence, as in no other way could they suppose 

 it to have kept its position against the force of gravity. 



5. So strong was the impression made by the rope-tying and other perform- 

 ances of the Davenport brothers, about twenty years ago, upon those who 

 were already prepossessed in favor of their " spiritualistic " claims, that I was 

 pressed by men of distinguished position to become a member of a coram'ttec 



