I? POPULAR SCIENCE MONTHLY. 



outside, thus forming Lenard's rays, they are likewise only the same 

 or similar corpuscles in the space outside rather than inside the vacuum 

 tube. Finally it has been proved that these electrified corpuscles are 

 present as well in the mass of a gas through which Rontgen rays have 

 passed, also in the mysterious radiation called Becquerel rays which 

 proceeds from uranium and other radio-active substances, also in all 

 flames, near all very hot bodies and in the air near certain metallic 

 surfaces on which ultra-violet light falls. In every case the corpuscle 

 is charged with an electron charge of negative electricity. If a cor- 

 puscle originates as a fragment chipped off from an electrically neutral 

 atom and is negatively charged, it follows that the remainder of the 

 atom of matter is left positively charged. 



The word ' atom ' therefore, as far as it signifies something which 

 cannot he cut, is becoming a misnomer as applied to the chemical unit 

 of matter, because this latter is capable of being divided into two parts 

 of very unequal size. First, a small part which is negatively electrified 

 and which is identically the same, no matter from what chemical 

 atom it originates, and secondly, a much larger mass which is the re- 

 mainder of the atom and is positively electrified, but which has a 

 different nature depending on the kind of chemical atom broken up. 

 The question has then begun to be debated whether we can distinguish 

 between the corpuscle and the electric charge it carries and if so in 

 what way. In other words, can we have an unelectrified corpuscle 

 or is the corpuscle so identified with its electric charge that they are 

 one and the same thing? It has been shown experimentally that an 

 electric charge in motion is in effect an electric current, and we know 

 that an electric current possesses something equivalent to inertia, that 

 is, it cannot be started and stopped instantly, and it possesses energy. 

 We call this electric inertia inductance, hence the question arises 

 whether the energy of the corpuscles when in motion is solely due to the 

 electric inductance or whether it is partly due to what may be called 

 the ponderable inertia of the corpuscle. 



This very difficult question has not yet been even approximately 

 settled. At the present moment we have no evidence that we can sepa- 

 rate the electron charge from the corpuscle itself. If this is the case, 

 then the corpuscles taken together constitute for all practical purposes 

 negative electricity, and we can no more have anything which can be 

 called electricity apart from corpuscles than we can have momentum 

 apart from moving matter. For this reason it is sometimes usual to 

 speak of the corpuscle carrying its charge of one electron of negative 

 electricity simply as an electron, and to drop all distinction between 

 the electric charge and the vehicle in or on which it is conveyed. 



It is remarkable that so far no one has been able to produce or find 

 a corpuscle positively electrified. Positive electricity is only known in 



