1 4 6 D O C U M E N T 1 2 5 D E C E M B E R 1 9 2 5 Phone the League for Human Rights, Zentrum 8131, and tell them that I cannot give my signature in the Wandt case since I am not familiar enough with the matter, and I cannot put blind faith in these oafs.[12] I am also enclosing a letter addressed to Dr. Courvoisier Neubabelsberg Observatory.[13] Please send it right away. Ehrenfest was greatly surprised that you, on your own, promised by telegram a lecture by me. In any case, it is impossible for me to lecture there later.[14] 125. From Hendrik A. Lorentz Haarlem, 8 December 1925 Dear Colleague, I have been thinking some more about the question you posed to me yesterday[1] and unfortunately come to the conclusion that constructing a proper electron this way does not work. The difficulty is that the forces dependent on the vector product are more or less similar to the centrifugal force, and for that reason are not able to hold the mutually repellent charges together. 1. This can already be seen when considering simple cases. The rotating charged system forms a system of circular convection currents. If all of them are in the direction indicated by the ar- row in this circle K, then the general direction of the induced magnetic field is orthogonal to the plane of the drawing toward the front and the resulting forces drive the current elements (moving charges) toward the outside. 2. This consideration can be dressed more prettily and generally. Let us only as- sume that everything is symmetric, let’s say, around the z-axis and that the state is stationary. Nothing more is assumed about the charge distribution its density ρ can change from one circle around the z-axis to the next, and it can even change in sign. The system does not even need to rotate as a whole at a common angular velocity, either each circle can revolve at its own velocity v. In these circumstances, the electric lines of force as well as the magnetic ones lie on the meridional plane. As a consequence, Maxwellian potentials exist on such a plane, in particular, the two resp. portions dependent on E and H under normal pressure that seeks to separate the halves to the right and left away from the plane. Assuming , then one arrives at a contradiction. v H] ⋅ [ K E 1 c -- - v H] ⋅ [ + 0 =