Electrical discharge experiments. Diagrams of electrical discharge experiments in vacuum tubes carried out by the British amateur scientist John Peter Gassiot (1797-1877). This work, titled 'Experimental investigations on the stratified appearances in electrical discharge', was published in 1862. Gassiot was the first to show that electrical discharges in thin gases may be deflected by magnetic and electrostatic influence, work which later led to the concept of cathode rays.