( m ) 



that the field inside a molecule of a crystal gains different intensities 

 it' an externa] field of constant intensity acts successively parallel to 

 the axes of the crystal. 



Ii is hue that in my former publications I have putg 1 =g a =g t , 

 because at that time there was no necessity to introduce more 

 complicated suppositions. But the abovementioned observations show 

 that generally </ l is different from g % and g t . 



If we do not accept this difference between the inner and outer 

 field, then we must fall back on the very complicated assumptions 

 of Becquerel and Onnes, that the apparent, probably electromagne- 

 tic mass of the electron is different parallel to t he three axes of 

 the crystal, and that the quasielastic forces in these directions are 

 proportional to these masses. This would lead to the hypothesis of 

 an immense number of different kinds of electrons, say of ellipsoidal 

 form, which during their vibration remain parallel to themselves. 

 The authors do not set forth how the law of the quasielastic forces 

 would be explained. As opposed to the difficulties of this hypo- 

 thesis 1 maintain that the above assumption of differences between 

 the inside and outside magnetic fields is much simpler. 



III. I should like to mention a general consideration arising from 

 the preceding. It seems to me that by the irresponsible introduction 

 of electrons which have forms masses and signs different from each 

 other, we should lose what has been up to the present one of the 

 chief advantages which characterise the electrontheory ; the simplicity 

 of the fundamental conception, and thus make the whole hypothesis 

 of less value. We would have to be content with this depreciated 

 value of the hypothesis, if we were compelled by undeniable results 

 of experience to do so. But up to the present I cannot recognise 

 any such evidence. 



The chief objection of J. Becquerkl to the hypothesis of inner- 

 molecular magnetic fields lies in the fact that the ZuKMAveffect is 

 notably independent of temperature. But as we do not know 

 anything definite about the cause of the inner field, it appears to 

 me, that one cannot assert anything about the sensibility to tempe- 

 rature with certainty. 



In this place I shall mention a consideration which seems to me 

 to carry some weight against the precipitate assumption especially of 

 /tositive electrons. 



We learn from the theory of light that in bodies electrons oscillate 

 about positions of equilibrium. Further the electron-theory permits 

 only of forces of electromagnetic nature: the quasielastic forces 



