274 On the Cause of the Structure of Spectra. 



8. Summary. 



The structure of spectra is traced to the two facts, first that 

 atoms vibrate as deformable, but practically incompressible, 

 bodies of finite calculable rigidity, so that their surfaces have 

 stationary waves corresponding to the fundamental mode of 

 vibration and its harmonics, and second that electrons in 

 describing nearly circular orbits round an atom, out of an 

 infinity of such orbits possible, have orbits of certain 

 frequencies made predominant by resonance. An electron 

 can make 1, 2, 3 .... m revolutions between two occasions 

 when it gets its energy renewed by striking the atom at the 

 middle of one of its vibrating internodes, or it can make 1 -\-jjl, 

 2-hfi . . . . m+fi where /ul is generally an harmonic fraction. 

 The orbits for a positive electron are different from those for 

 a negative, and therefore a relative motion between positive 

 and negative electron is set up. This is the direct cause of 

 the vibrations of light. This relative motion can be represented 

 by giving the positive and negative electron different angular 

 velocities round the circumference of a circle. By such 

 motions Banner's and Bydberg's formulas can be explained, 

 and Bydberg's laws lead to the conclusion that the fundamental 

 angular velocity of all electrons associated with all atoms is a 

 constant representing a frequency of 33 X 10 14 per second. 



From the rigidities of the metals at absolute zero the 

 mechanical periods of vibration of the atoms are calculated 

 and proved to exhibit simple harmonic relations, and probably 

 to possess a common harmonic of a frequency of the same 

 order as that of ordinary light. It is probable that the 

 common harmonic of the atoms and the fundamental mode of 

 motion of the electron are identical or harmonically related. 



The spectra of different elements thus appear to be caused 

 by practically one and the same form of electrical appliance 

 (pair of electrons) which is supplied with energy by the atom 

 at various internodes. One spectrum is only a slight 

 kinematical variation of another. 



The principles of the kinetic theory of gases and of the 

 electromagnetic theory of light are brought into natural relation. 

 Bigidities at absolute zero calculated according to the Kinetic 

 Theory of Solids are shown to be connected with the structure 

 of spectra, and molecular resonance is shown to play a striking- 

 part in the melting of the metals. The atoms in a compound 

 molecule are more intimately united than is usually supposed. 

 Melbourne, May 190] . 



