RECENT DISCOVERIES IN RADIATION. 487 



Cathode Ray Particles Much Smaller than the Smallest Known Atom. 



But the most remarkable result of experiments upon cathode rays is 

 the conclusion that while they consist of rapidly moving particles, these 

 particles are not ordinary atoms or molecules, but are instead bodies 

 whose mass is only about one one-thousandth of the mass of the smallest 

 atom known, namely, the atom of hydrogen. The calculation by which 

 this conclusion is obtained is based upon a comparison of the amount 

 of deflection which is imparted to the rays by a magnet of known 

 strength, and the amount of deflection which is produced by electric 

 charges of known size on D and E. It can also be based upon other 

 experiments which will not here be described. Suffice it to say that 

 more than a dozen well-known physicists have made the observations 

 and the calculations upon which they are based, and that, although 

 they have worked by as many as three different methods, the results are 

 all in substantial agreement. 



A New Theory as to the Constitution of Matter. 

 Furthermore, since experiments of the kind mentioned above always 

 lead to the same value for the mass of the cathode ray particle, no 

 matter what be the nature of the gas which is used in the bulb and no 

 matter what be the nature of the metal constituting the cathode Cj 

 physicists have found it necessary to conclude that these minute 

 particles are constituents of each and every one of the different metallic 

 elements at least, and probably of all the other elements also. In view 

 of these discoveries, the suggestion has been put forward by several of 

 the greatest living physicists, that these cathode particles are them- 

 selves the primordial atoms out of which the 70 odd atoms known to 

 ordinary chemistry are built up. According to this suggestion, the 

 chief difference between the different atoms of chemistry would consist 

 simply in differences in the number of the primordial atoms which enter 

 into them. Thus the hydrogen atom would be composed of about a 

 thousand of these minute corpuscles, or electrons, as they have been 

 called, the oxygen atom of 16,000, the mercury atom of 200,000, and 

 so on. It is necessary to assume, however, that these electrons are 

 half plus and half minus, for otherwise we can not account for the 

 uncharged condition of ordinary atoms. Since, however, no evidence 

 has as yet appeared to show that positively charged electrons ever 

 become detached from atoms, J. J. Thomson has brought forward the 

 hypothesis that perhaps the positive charges constitute the nucleus of 

 the atom, while the negative electrons are on the outside and are 

 therefore more easily detachable. It is too early to assert this theory 

 as correct; it is introduced here merely as a profoundly interesting 

 speculation brought forward by men high in authority in the scientific 

 world. It differs radically from most other speculations of the same 

 general nature, in that it is based upon a certain amount of experi- 



