Who discovered plasma?

Plasma was first discovered by Sir William Crookes in 1879. He used an electrical discharge tube that became known as a "Crookes tube." He first labeled plasma as "radiant matter" because of its luminous quality.

Plasma is the most common of the four types of matter. It comprises more than 99 percent of all matter in the universe. Plasma occurs when a state of matter contains a large amount of ionized particles and generates its own magnetic field. When under the influence of a magnetic field, it may form structures such as filaments, beams and double layers. The sun is made of plasma.