Page:Popular Science Monthly Volume 64.djvu/491

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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.

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 C, 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 themselves 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