NATURAL PHILOSOPHY. 141 



the prime cause of a great number of our actions, takes place only 

 when we are in a certain state, which is exactly that which magne- 

 tisers call faith. 



" The existence of this state is perfectly demonstrated by my ex- 

 periments. So long as I believed the motion of the pendulum 

 which I held in my hand possible, it took place ; but, after having dis- 

 covered the cause 'of it, it was impossible for me to reproduce it. It 

 is because we are not always in the same state, that we do not con- 

 stantly receive the same impression from the same thing. 



" Thus the gaping of another does not always make us gape ; laughter 

 is not always communicated from the laugher to his neighbor, &c. The 

 great orator who wishes to make the crowd share his passion does not 

 reach at one leap his object ; he commences by disposing his audience 

 to it, and it is only after he has made himself master of them, that he 

 gives his last argument, his last trait. The great poet, the great writer 

 constantly resort to the same artifice ; they first prepare their reader 

 for their final impression. 



" Nothing is more curious in the study of the causes which determine 

 man's actions, than the knowledge of the means employed by the shop- 

 keeper to attract and fix the buyer's attention upon the qualities of the ar- 

 ticle he would have him take ; or the knowledge of the means employed 

 by the ' necromancer ' to have one rather than another card drawn 

 from a pack, or to divert the spectator's attention upon one thing so' 

 as to withdraw it from another, a diversion without which the ' necro- 

 mancer ' would cause no surprise, which is the great object of his art 

 It results from these considerations that the most different professions 

 employ quite analogous although excessively varied means to attain 

 the same end, that of first fixing man's attention so as afterwards to 

 produce on him a determined effect. 



" I think my observations are connected with the history of the 

 faculties of animals'; that some of their acts attributed to instinct are 

 really of the class just spoken of. This seems to me especially true of 

 gregarious animals ; and it seems to me that it would be very interest- 

 ing to study in this regard the influence of their leaders upon the 

 subordinate members. 



" Do not the instances above mentioned throw some light upon the 

 cause of the fascination one animal exerts over another." 



OX THE NATURE OF HEAT. 



WITHIN the past few years some new views respecting the nature 

 of heat have been brought forward. They are highly interesting theo- 

 retically, and important in their practical application, inasmuch as they 

 modify in a considerable degree the theory of the steam-engine, the 

 air-engine, or any other in which the motive power is derived imme- 

 diately from heat. 



A theory which proposes to explain the thermal agency by which 

 motive power is produced, and to determine the numerical relations 

 between the quantity of heat and the quantity of mechanical effect 



