Which gas did Goldstein use to explain the formation of protons?

Goldstein explained the formation of protons using hydrogen gas. He passed electricity at high voltage through gas at a very low pressure taken in a perforated discharge tube. Streams of heavy particles were given out by the positive electrode i.e., the anode. These streams of heavy particles are called anode rays as these rays were directed away from the anode. These are also called positive rays since they consist of positively charged particles called protons.