202 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



At tlie same time an explanation was necessary for the curious 

 distribution of the hnes in the spectrum. According to the work of 

 Balmer, of Kayser, of Runge, of Rydberg, these hnes are distributed 

 into definite series and each series obeys simple laws. We might at 

 fu"st expect to fuid these laws those of harmonics. Just as a cord, 

 vibrating Avith infinite degrees of freedom, gives an infinite series of 

 harmonics whose frequencies are multi})les of the fundamental 

 frequency of the cord, and just as a sonorous body of more complex 

 form also gives out an analogous though less simple series of har- 

 monics — for instance, a Hertz resonator is susceptible of an infinite 

 number of cUfferent periods — so might an atom, for identical reasons, 

 give out an infinite series of cUfferent wave lengths of hght. You 

 know that this simple explanation failed, because with the spectro- 

 scopic phenomenon it is the frequency and not its square for wliich 

 the expression is simple; for the frequency does not become infinite 

 for harmonics of an infinitely high order. The idea must either be 

 modified or abandoned. All attempts at modification have been 

 futile; the method refuses to be adapted. Accordingly Ritz aban- 

 doned this theory and represented the vibrating atom as formed of 

 a rotating electron and several magnetons placed end to end. Then 

 the mutual electrostatic attraction of the electrons no longer deter- 

 mines the wave length; that depends on the electromagnetic field 

 formed by tlie electrons. 



I^ is rather difiicult to accept this idea because it seems somewhat 

 artificial. However, we must resign ourselves to it for the time being 

 since continued search for another has so far proved futile. How 

 does the atom of hydrogen produce lines of several different wave 

 lengths ? It is not because each one of the atoms could produce any 

 of the lines m the spectrum of hydrogen and does produce this or 

 that one of the lines according to the initial condition of the vibration. 

 It is because there are several kinds of hydrogen atoms, difteiing 

 among themselves by the number of magnetons in line, each atom 

 producing a different wave length. Can these different atoms change 

 from one kind to another, and if so, how 1 How can an atom lose a 

 magneton as does seem to happen when w^e pass from one allotropic 

 form to another ? Is it that a magneton escapes from an atom or do 

 some of the magnetons in alignment change and become iiregularly 

 distributed ? 



This disposition of magnetons, end to end, is a peculiar character- 

 istic of the theory of Ritz. The ideas of Weiss must seem to us in 

 every way less strange. The magnetons must be placed either end 

 to end or at least parallel smcc theii" resultant eft'ects combine arith- 

 metically, or rather algebraically, not geometrically. 



Now what is a magneton ? Is it a simple thing ? No, pj-ovided we 

 w^ish to retain the hypothesis that they result from special amperian 



