EXPERIMENTS WITH LIVING HUMAN BEINGS. 619 



ment of error from the expectation of the experimenter was eliminated, 

 it was quickly shown that the contractions were entirely subjective. Mr! 

 Edison, I may say, is not only an inventor of phenomenal genius, but 

 likewise a skilled and practiced experimentalist, and, as I found when 

 making these and similar investigations with him, extraordinarily fertile 

 in resources of method and device for wresting the secrets from na- 

 ture, and usually alert against subtile sources of error ; but, when drawn 

 . into the province of the involuntary life, he found himself, like men 

 of science in general, insufficiently equipped with knowledge to even 

 surmise, not to say provide for, the errors that may arise from the un- 

 conscious or involuntary action of mind on body. 



In some instances the reverse mistake is made, and phenomena of 

 the involuntary life are supposed to be volitional. In the case of the 

 " Maine jumpers " or so-called " jumping Frenchmen " of Canada and 

 the Maine woods— the incredible performances of which I have elsewhere 

 described— it had for years been assumed, both by men of science and 

 by the laity, that the movements were intentional, and within control. 

 This conclusion, though most erroneous, was quite a natural one for 

 those who have no knowledge of the relation of mind to its physical 

 substratum. 



An illustration of the second method of deception — doing nothing 

 when the subject supposes we are doing something— is professing to 

 apply electricity, putting the electrodes in position, and going through 

 the motions, when no current is running, or when the connection is 

 broken ; in this way I have several times proved that patients were 

 mistaken in inferring that electrical applications injured them; and, 

 conversely, I have been able in one striking case to prove that the pa- 

 tient was right, and that a certain symptom was temporarily aggravated 

 by the application. 



Third Source of Error : Intentional deception on the part of the, 

 subject.— T\i\^ element of error is so obvious that it would seem to be 

 quite needless to refer to it ; and yet it is constantly overlooked even 

 in researches conducted by physiologists. To assume, as is often or 

 usually done, that the subject on whom the experiment is made is hon- 

 est in his relation to that experiment, because he has a general charac- 

 ter for honesty, is always unscientific ; and all experiments where such 

 assumption is made must be ruled out of science. 



Intentional as well as unintentional deception on the part of the 

 subject can only be scientifically met by deception on the part of the 

 experimenter. The methods of deceiving already described suffice to 

 guard against all deception on the part of the subject, whether inten- 

 tional or unintentional. 



It is clear proof of the non-expertness of Zollner, Wallace, Charcot, 

 and Westphal, that in their published accounts of experiments with 

 living human beings they assumed that, if the subjects were honest, the 



