220 MODERN VrEWR ON MATTER. 



('». The hypotheticiil part of the statement about the .size of an elec- 

 tron is the followino-. Whereas })oth the mass and the charo-e of an 

 electron are known, it is not yet quite certain that the mass is wholly 

 due to the charge. It is possible, but to mo very unlikely, that the 

 electron, as we know it, contains a material nucleus in addition to its 

 charge, so in that case it need not lie so concentrated, because :i portion 

 of its mass would be otherwise accounted for. 



I say ''accounted for," but it would be equally true to say " unac- 

 counted for." The mass which is explicable electrically is to a con- 

 siderable extent understood, but the mass which is merely material 

 (whatever that may mean) is not understood at all. We know more 

 about electricity than about matter, and the way in which electrical 

 inertia is accounted for electromagnetically and localized in the ether 

 immediately surrounding- the nucleus of charge is comparatr\'ely clear 

 and distinct. 



There may possibly be two different kinds of inertia which exacth^ 

 sinudate each other, one electrical and the other material, and those 

 who hold this as a reasonable possibility are careful to speak of elec- 

 trons as "corpuscles," meaning charged particles of matter of ex- 

 tremely small size, much smaller than an atom, consisting of a definite 

 electric charge and an unknown material nucleus, which nucleus, as 

 the}' recognize, l>ut have not yet finally proved, may quite possibly be 

 zero. 



The chief defect in the electrical theorj- of matter at present is that 

 the positive electron, if it exists, has never yet been isolated from the 

 rest of an atom of matter. It has never been found detached from a 

 mass less than the hydrogen atom; whereas the negative electron is 

 constantly and freel}' encountered flying about alone, its mass being 

 little more than the thousandth part of an atom of hydrogen. 



Until a positive electron can be similarly isolated, the hypothesis 

 that an atom is really composed solely of electricity — that is to sa}', of 

 equal quantities of positive and negative electricity associated together 

 in a certain grouping of little bodies, each of which is nothing more 

 than a concentrated charge of electricity of known amount — must 

 remain a hypothesis. 



7. It is a fascinating guess that the electrons constitute the funda- 

 mental sul)stratum of which all matter is composed; that a grouping 

 of, say, TOO electrons, 350 positive and 850 negative, interleaved or 

 interlocked in a state of violent motion so as to produce a stable con- 

 figuration under the influence of their centrifugal inertia and their 

 electric forces, constitutes an atom of hydrogen; that sixteen times 

 as many, in another stable grouping, constitute an atom of oxjgen; 

 that some 1»),000 of them go to form an atom of sodium, about 1(»0,- 

 000 an atom of barium, and 100,000 an atom of radium. 



