RECENT ADVANCES IN SCIENCE 2; 



matter are small compared with that of light, but on several 

 grounds it has recently been borne in on the mind of the 

 physicist that it cannot be accepted as more than an approxi- 

 mation in cases where the velocities are large, and that in 

 consequence the motions of cathode particles, radioactive 

 particles, and electrons within the atom, where the speed is 

 comparable with that of light are subject to a wider body of 

 dynamical laws than those propounded by Newton. Such an 

 admission, while not removing the difficulties mentioned above, 

 does, at least, encourage the hope of resolving them by methods 

 of attack unthought of until recent years. For example, Bohr 

 in 191 3, by applying the Quantum hypothesis of Planck to 

 the Rutherford model, scored a remarkable initial success in 

 accounting for the spectral series of hydrogen and helium, 

 and in giving a rough, general explanation of the Rydberg 

 law for the series of lines in the spectra of other elements. 

 Considerable work has been carried on in connection with 

 Bohr's theory during the years of the war, especially directed 

 towards the high-frequency or X-ray spectra of the elements, 

 and I understand that Bohr himself is shortly to publish the 

 results of a prolonged research which, it is stated, has extended 

 very considerably the success of its earliest applications. Of 

 course, it must be borne in mind that all this success depends 

 on the application of the Quantum hypothesis. Now this 

 hypothesis is not a system of dynamics. Its success in explain- 

 ing the nature of" Full " Radiation, the relation between specific 

 heat and temperature, the photoelectric law, etc., may be 

 reasonably held to support the view that it will one day be 

 embraced within the scope of our future laws of dynamics as 

 an important deduction from them — as important, perhaps, as 

 the principle of energy is to-day with respect to the Newtonian 

 laws from which it is deducible. 



That being the state of affairs, considerable interest still 

 attaches to all attempts to explain atomic structure on the 

 older and more orthodox views, and it may be of interest to 

 readers of Science Progress to become aware of an attempt 

 recently made by A. L. Parson to overcome difficulties of 

 atomic structure by postulating a new structure for the elec- 

 tron. His paper entitled " A Magneton Theory of the Structure 

 of the Atom " was published in the Smithsonian Collections, 

 vol. lxv. No. 11 (1916). On grounds which cannot be entered 



