808 Magnetic Rays in Different Gases. 



to the moving electrons contained in the structure of the ion ; 

 and beside it could easily happen that the electron satellite 

 would enter in the said structure, and so the neutral atom 

 might reconstitute itself. 



For instance, taking 10~ 8 as the order of size of the lineal 

 dimensions of an ion, it will he convenient to admit the average 

 radius of the orbit of the electron as at least equal to 10~ 6 *. 

 With this value, and with the values admitted for the charge 

 and the mass of the electron, we find that the velocity of the 

 satellite must not surpass 222 kilometres per second f. 



On the other hand, the said velocity must not he too small, 

 else the electron assumes so wide an orbit round the ion, that 

 the instability of the system becomes excessive, considering 

 the extreme facility with which the electron can be removed 

 and separated from the ion; Such a degree of stability of 

 the pairs ion-electron, consistent with the manifestation 

 of the phenomena that are supposed to be due to them, 

 requires then that the orbit of the electrons have a radius 

 neither too small nor too great, and therefore that the velocity 

 of the satellite has a value comprised within certain limits. 



Now it is evident that, according to the conditions in which 

 the discharge is produced, the average value of the velocity 

 of the electrons will be different, and therefore the number 

 of those whose velocity is comprised in the limits above 

 mentioned wdl be different. These limits depend on the 

 nature of the ions, and particularly on their dimensions ; 

 therefore the probability of the formation of the planetary 

 systems ion-eiectron, their stability, and the effect of the 

 magnetic field upon them, may vary with the nature of 

 the gas. 



If, for instance in an extreme case, it happens that the 

 distance between the two elements of the systems is in the 

 majority not great enough in comparison with the size of 

 the ions, the systems will cease to exist, not by separation, 

 but by formation of neutral atoms. In such a case evidently 

 the positive ions abandoned by the magnetic rays will be 

 absent, or will exist in very small quantity, and the virtual 

 anode will not be observed* 



To conclude, the negative results of some of the experiments 

 of Messrs. More and Bieman do not justify the supposition 



* Mem. of the R. Acad, of Bologna, ser. 6, t. vi. p. 7 (1909-10). 



t We deduce, that the slower cathode rays must contribute above all 

 to form the magnetic rays ; or rather those electrons with velocities 

 relatively small which, if the field did not exist, would not manifest 

 perhaps in a perceptible manner the characters of true cathodic rays, 

 these being constituted by electrons moving with much greater velocity. 



