MESMERISM, ODYLISM, TABLE-TURNING, ETC. 15 



evidence of their higher marvels has invariably broken down when 

 submitted to the searching tests imposed by the trained experts whom 

 I maintain to be alone qualified to pronounce judgment upon the 

 matter. 



Nothing is more common than to hear it asserted that these are 

 subjects which any person of ordinary intelligence can investigate for 

 himself. But the chemist and the physicist would most assuredly 

 demur to any such assumption in regard to a chemical or physical 

 inquiry; the physiologist and geologist would make the same protest 

 against the judgment of unskilled persons in questions of physiology 

 and geology; and a study of mesmerism, odylisra, and spiritualism, 

 extending over more than forty years, may be thought to justify me 

 in contending that a knowledge of the physiology and pathology of 

 the human mind, of its extraordinary tendency to self-deception in re- 

 gard to matters in which its feelings are interested, of its liability to 

 place undue confidence in persons having an interest in deceiving, and 

 of the modes in which fallacies are best to be detected and frauds ex- 

 posed, is an indispensable qualification both for the discrimination of 

 the genuine from the false, and for the reduction of the genuine to its 

 true shape and proportions. 



And I further hold, not only that it is quite legitimate for the in- 

 quirer to enter upon this study with that " prepossession " in favor of 

 the ascertained and universally admitted laws of Nature which believ- 

 ers in spiritualism make it a reproach against men of science that they 

 entertain, but also that experience proves that a prepossession in favor 

 of some " occult " agency is almost sure to lead the investigator to the 

 too ready acceptance of evidence of its operation. I would be the last 

 to affirm that there is not " much more in heaven and earth than is 

 known to our philosophy ;" and would be among the first to welcome 

 any addition to our real knowledge of the great agencies of Nature. 

 But my contention is, that no new principle of action has any claim 

 to scientific acceptance, save upon evidence as complete and satisfac- 

 tory as that which would be required in any other scientific investi- 

 gation. 



The recent history of Mr. Crookes's most admirable invention, the 

 radiometer, is pregnant with lessons on this point. When this was 

 first exliibited to the admiring gaze of the large body of scientific 

 men assembled at the soiree of the Royal Society, there was probably 

 no one who was not ready to believe with its inventor that the driving 

 round of its vanes was effected by light ; and the eminent physicists 

 in whose judgment the greatest confidence was placed, seemed to have 

 no doubt that this mechanical agency was something outside optics 

 properly so called, and was, in fact, if not a new force in Nature, a new 

 modus operandi of a force previously known under another form. 

 There was here, then, a perfect readiness to admit a novelty which 

 seemed so unmistakably demonstrated, though transcending all previ- 



