It always bugs my mind to think which comes first, it feels like the egg or the chicken problem. When i was reading about the discovery of the electron i found that the charge to mass ratio of the electron was discovered by J.J Thomson, with his cathode ray tube experiment. Which used the idea of electricity to come to his conclusion. and i also read the equations he used where the equation of Force due to the electric field and magnetic field. $F_m=Bqv$ and $F_e=Ed$. But where electric fields and there equations were discovered in his time. I mean does it seem logical that humans have discover the electric force before discovering the electron who are the causes for the electric field. I would like it if you can provide me what is discovered first and how the one is used for the other supported by a time line. Electric forces or properties of electrons
I mean how could J.J Thomson use equations that use the charge of electron like $F_m=Bqv$ before he even knows there existence. And how could a force of magnetic field due to a charge be thought before the discovery of this idea of a charged particle. Did the discovery of the electron led to the formulation of the equation of force by magnetic fields. Or did the magnetic field equations led to the discovery of the electron.