INTRA-ATOMIl' ENERGY- 269 



told ill the time of Galvaiii that the enerj*'}' whicii wa.s used with diffi- 

 culty to twitch the lei^s of a frog and attract small fi'agments of paper 

 would one day set in motion enormous railway trains. 



Perhaps it will always l)e beyond our powers to completely dissoci- 

 ate the atom, because the difficulty would probably increase as disso- 

 ciation advances, yet to dissociate a very small part would suffice. 



If, as physicists still claim, matter, instead of being- an inunense 

 reservoir of energy, can only restore the energy comnmnicated to it 

 by some means or other — heat, for example — it is evident that in order 

 to produce the dissociation of matter there would be necessary' an 

 expenditure of work exactly equal to that which the results of the 

 dissociation would perform, conformably to one of the fundamental 

 principles of thermo-dynamics. 



It can not, however, be longer held that the energy exhibited by 

 the dissociated atom comes from without; it must be borrowed from 

 the enormous reserve that it possesses. Besides, even if it were 

 merelv an agent in the transformation of energy, the importance of 

 dissociation would still remain, since we can produce it by agents that 

 are to-day absolutel}' free to all and unutilized, such as light." 



MATTER CONSIDERED AS AN ENORMOUS CONDENSATION OF ENERGY. 



The indisputable fact that the atom is a reservoir of energy leads 

 immediately, in m}'^ opinion, to the hjqDothesis that matter is com- 

 posed onl}^ of condensed energy of a special mode, whence result its 

 weight, its form, and its fixity. It is to energy thus considered that 

 we give the name of matter. 



Some ancient facts, quite anterior to the discovery of the cathodic 

 rays, already pointed to this idea. Take, for example, the quantity 

 of electricity extracted from bodies bj' electrolysis. A gram of a 

 substance such as hydrogen contains a charge of 96,000 coulombs. 

 The electricity must be there in a state of very considerable condensa- 

 tion, since b}^ no means at our disposal can we make an insulated body 

 of the size we have mentioned hold more than a very small fraction of 

 this charge. -Foubert has observed that the quantity of electricity con- 

 tained in a cubic centimeter of h3'drogen would suffice to charge a 

 sphere as large as the earth with a potential of 6,000 volts. 



In my opinion electricity is only one of the manifestations of spe- 

 cial energy contained in the atoms. It is the state of prodigious con- 

 densation of this energy that permits the generation of the enormous 



«In a recent work (On ether and gravitational matter through infinite space) Lord 

 Kelvin expresses himself as follows: "The mechanical value of a cubic kilometer of 

 solar light is equal to 412 kilogram meters, equivalent to the work of a horsepower 

 for five and one-half seconds. This result may give some idea of the actual total of 

 the mechanical energy of the luminoun vil)rations and of the forces contained in our 

 atmosphere." 



