40mm Hg Violet streamers appear between electrodes
10mm Hg A pink glow fills the tube, concentrated around the anode
3mm Hg Discharge becomes faint blue, Faraday's dark space appears
1mm Hg Faraday's dark space expands
0.10mm Hg Cathode begins to fluoresce
0.02mm Hg Cathode rays emerge, causing the tube sides to fluoresce
Both electrodes on these premium tubes have a full glass envelope. A plastic stand, insulated electrode and connecting wire with clip are included (as shown in product photo). A 50mm induction coil is the recommended power supply.