What Is the Milk and Charge Experiment?

Rutherford discovered the electron neutron and proton. I believe the next one was the positron, right? Was that an actual discovery or was that a thought? Um, I don't know. We understand they have a charge, some unit of charge. The way we can compare charges is by comparing the amount of electrons. And that combined with this nitrogen was found to produce this hella, a lot of energy.