154 THE POPULAR SCIENCE MONTHLY. 



tliem ; while, as a matter of fact, tlie laxity of most investiga- 

 tors in this regard is well known. These performances deceive 

 because people overlook the technical acquisitions needed to pro- 

 nounce upon the possibility or impossibility of a fastening being 

 undone and apparently restored without detection. If manufact- 

 urers of safes were equally credulous, and gave equally little time 

 to the study of the security of locks, " a safe " would be an ironi- 

 cal expression indeed. 



Passing next to the most interesting of spiritual manifestations, 

 those in which self-deception comes to the foreground, I need 

 hardly dwell at length upon the tilting of tables, the production 

 of raps by movements of which the sitters are unconscious ; for 

 these have been so often and so ably presented that they must now 

 be well understood. Suffice it to say that it has been objectively 

 proved that it is almost impossible not to give some indication of 

 one's thoughts when put upon the strain ; and that, when excited, 

 these indications may be palpably plain and yet remain unper- 

 ceived by the individual who gives them. The extreme subtlety 

 of these indications is met by the unusual skill of the professional 

 " mind-reader," who takes his clew from indications which his sub- 

 ject is " absolutely confident he did not give." The assurance of 

 sitters that they knoiv they did not move the table is equally 

 valueless, and here nothing but objective tests will suffice. The 

 most wholesome lesson to be derived from the study of these phe- 

 nomena is the proof that not all our intentions and actions are 

 under the control of consciousness, and that, under emotional or 

 other excitement, the value of the testimony of our consciousness 

 is very much weakened. Again, it is almost impossible to realize 

 the difficulty of accurately describing a phenomenon lying outside 

 the common range of observation. Not alone that the knowledge 

 necessary to pronounce such and such phenomenon impossible of 

 performance by conjuring methods is absent, but with due modesty 

 and most sincere intentions the readiness with which the observ- 

 ing powers and the memory play one false is overlooked. In the 

 investigation of Mr. Davies, above referred to, the sitters prepared 

 accounts of the " slate-writing " manifestations they had witnessed, 

 and described marvels that they had not seen but which they were 

 convinced they had seen — writing on slates utterly inaccessible by 

 Mr. Davies, and upon slates which they had noticed a moment be- 

 fore were clean. The witnesses are honest ; how do these mistakes 

 arise ? Simply a detail omitted here, an event out of place there, 

 an unconscious insertion in one place, an undue importance to a 

 certain point in another place — nothing of which any one need 

 feel ashamed; something which it requires unusual training and 

 a natural bent to avoid. The mistake lies in not recognizing our 

 liability to such error. 



