150 PHYSICS OF THE ELECTRON 



the life of the atom. There is then no difficulty in conceiving how the 

 enormous evolution of heat by radium can be ascribed to its internal 

 energy. 



No atom being free from this loss of energy due to the radiation 

 of the electrons, one ought to expect on this hypothesis of decay a 

 universality of radioactive phenomena, the atoms which we con- 

 sider as actually stable suffering only an extraordinarily slow waste. 



IX. Electric Properties 



(42) Polarization. It remains now to show in a few words how 

 the preceding conceptions lend themselves easily to a representation 

 of the principal electric and magnetic properties of matter and make 

 possible for the first time a theory of the disruptive discharge and 

 of metallic conduction. 



A common property of all forms of matter is electrostatic polariz- 

 ation arising from the variation of the specific inductive power with 

 the nature of the substance. 



This polarization results in a manner quite natural by the modi- 

 fication which an external electric field produces in the motions of the 

 electron which constitute the atom. This modification is caused in 

 the mean by an excess of positive centres on the side where the field 

 tends to displace them and by an excess of negative centres on the 

 opposite side. The system takes then on the average an electrostatic 

 polarization. 



(43) Corpuscular Dissociations. If the electric field becomes suf- 

 ficiently intense, as, for example, during the passage of one of those 

 brief pulsations which constitute the Roentgen rays, or during the 

 passage through the atomic structure of an a or /? particle of very 

 great velocity, the modification produced may be very great, a cathode 

 corpuscle may be separated from the structure which remains posi- 

 tively charged; there is produced thus a corpuscular dissociation 

 which explains the conductivity acquired by insulating mediums 

 under the action of Roentgen or Becquerel rays, and which manifests 

 itself especially in gases, where the electrified centres thus freed can 

 move more easily, although by electrostatic attraction on the neutral 

 molecules, electrically polarizable, they surround themselves with 

 a group of molecules which accompany them during their motion. 



It seems well established that the negative ions in particular, also 

 produced in a gas, have a cathode corpuscle for centre, since the pene- 

 tration of cathode rays into a gas produces in it negative ions identical 

 with those of Roentgen rays, at least from the point of view of their 

 mobility or of their power of condensing supersaturated water vapor. 

 It seems, nevertheless, important to make sure, by measuring the 

 mobility of ions produced by different causes in the interior of gases, 



