Modern Witchcraft. 129 



" It is fortunate," said he, " that you have seen 

 it, for now I can believe it. If I had seen it 

 myself, I should not have believed it ! " The 

 commonest acts of perception are so liable to be 

 warped by hypothesis (a fact which conjurers 

 like Houdin consummately understand) that it is 

 quite useless to conjecture what our witnesses 

 may really have seen, unless we know much more 

 than they are likely to tell us of the physical 

 and mental conditions under which their seeing 

 was done. At a meeting of spiritualists in Bos- 

 ton, Mr. Robert Dale Owen once saw what he 

 took to be an "apparition in shining raiment," 

 being quite clear in his mind that no deception 

 or illusion was possible under the circumstances. 

 But Dr. Hammond, making a diagram of the 

 rooms from data contained in Mr. Owen's ac- 

 count, shows that, with the greatest ease, a 

 " woman in white " might have been brought 

 into the room and illuminated by means of a 

 dark lantern without awakening suspicion. The 

 case of Angelique Cottin, the famous " electric 

 girl," is equally instructive. After tipping tables, 

 repelling books, brushes, arid other small objects, 

 and disturbing magnetic needles before numer- 

 ous "intelligent audiences," her alleged powers 

 were carefully investigated by a committee of the 



