NATURAL PHILOSOPHY. 139 



" This is the interpretation I give to these phenomena : When I 

 held the pendulum in my hand, a muscular motion of my arm, al- 

 though insensible to me, moved the pendulum from its repose, and 

 when once the oscillations had commenced they were soon augmented 

 by the influence exercised by the sight, so as to put me in that partic- 

 lar frame of disposition or tendency to the motion. Now, it must be 

 acknowledged that the muscular motion, even when it is increased by 

 this same disposition, is nevertheless weak enough to stop, I will not 

 say under the empire of the will, but when it has simply the thought 

 of trying to see whether this or that will stop it. 



" So, then, there is an intimate connexion between the execution 

 of certain motions and the act of the mind relative to them, although 

 this mental act is not the will which commands the muscular organs. 

 In this regard, it seems to me that the phenomena I have described is 

 interesting in connexion .with psychology, and even the history of 

 sciences ; they prove how easy it is to take illusions for realities, 

 whenever we turn our attention towards a phenomenon wherein our 

 bodies play a part, especially in circumstances which have not been 

 sufficiently analyzed. 



" In truth, if I had contented myself with making the pendulum 

 oscillate above certain bodies, and with the experiments where these 

 oscillations were arrested when glass, resin, &u., were interposed be- 

 tween the pendulum and the body which seemed to determine its mo- 

 tion, then certainly I would have had no reason not to believe in the 

 divining rod, or any other thing of the same sort. Now, it may be 

 easily conceived how honest and educated men are sometimes led to 

 recur to very chimerical ideas to explain phenomena which are not in 

 reality removed from the physical world we know. 



" Consequently, I conceive without difficulty that an honest man, 

 whose whole attention is fixed upon the motion a rod which he holds 

 in his hands may take from a cause unknown to him, may receive 

 from any the least circumstance the tendency to motion necessary to 

 superinduce the appearance of the expected phenomenon. For ex- 

 ample, if that man seeks a spring, and he has not his eyes blindfolded, 

 the sight of a green plat of grass over which he is walking may, un- 

 known to himself, determine in him the muscular motion capable of 

 disarranging the rod by the established association between the idea 



o o / 



of active vegetation and that of water. 



" The preceding facts, and the interpretation above given of them, 

 have led me to connect them with others which we may daily observe. 

 From this connexion the analysis of them becomes both more simple 

 and more precise than it was, at the same that time they form an ensem- 

 ble of facts, whose general interpretation is susceptible of a great exten- 

 sion. But, before going further, let us distinctly remember that my 

 observations present two leading circumstances : 



" First. To think that a pendulum held in hand may move, 

 and that it moves without our having the consciousness that the mus- 

 cular organ gives.it the least impulsion. This is the first fact. 



" Secondly. To see this pendulum oscillate, and its oscillations 

 13* 



