Multiply -chaYged Atoms. fiCO 



parabola must have eight times the maximum amount of 

 energy possessed by the normal atoms. This could be 

 accounted for if some of the mercury atoms in the discharge- 

 tube had lost 8 corpuscles, for then the energy communicated 

 to the atom by the electric field would be eight times the 

 energy communicated to an atom with the normal charge. 

 Eight is a Very large number of corpuscles to lose, much 

 larger than the number lost by the other elements which 

 get multiple charges; I had previously to these experiments 

 never found a case in which this number exceeded three ; 

 so that in my paper in the Phil. Mag. for August 1912, I 

 suggested another explanation of the behaviour of the 

 mercury line; A study of the plates taken with large 

 electrostatic deflexions has revealed the existence of 7 para- 

 bolas due to mercury > corresponding to the mercury atom 

 with 1. 2, 3, 4, 5, 6, 7 charges respectively, the parabola 

 corresponding to 8 charges has not been detected, but as the 

 parabolas get in general fainter for each additional charge 

 on the atom, it is probably there but too faint to be detected. 

 PL XV. fig. 1, taken from a photograph when the gas in the 

 tube was the residual gas left after exhaustion by the Gaede 

 pump, shows these lines very well. The measurements of 

 mle for these parabolas gave the following values : — -- 



m e. 







200 







102 

 66-3 

 50*4 

 44 



200/2 

 200/3 

 200/4 

 this not ii 



mercury line but is 



39-8 

 33-7 

 2&6 



200/n 

 200/6 



200/7 



[due to C0 2 . 



It will be noticed that the heads of the parabolas corre- 

 sponding to 1, 2, 3 charges respectively lie on a straight line 

 passing through the origin, indicating that the velocities of 

 the particles producing the heads of these parabolas are all 

 equal, and therefore, since each particle is an atom of mercury $ 

 that the kinetic energy of the particles at the heads of the 

 parabolas is constant. This is what we should have expected, 

 for the heads of all the parabolas are due to particles which 

 had originally lost 8 corpuscles, the particle at the head of 

 the parabola corresponding to one charge has regained 7 

 of these after passing through the cathode, that at the head 

 of the parabola corresponding to two charges, six, and so on; 

 these particles when in the discharge- tube were all in the 



