I received my Jacob's Ladder climbing arc apparatus a few minutes ago and fired it up! What a hoot! Mine has a 24 volt DC power supply and the unit has a multi-megavolt output for the two electrodes which creates the climbing arc - mine is purplish in color. It is not recommended that the device run more than five-minutes at a time as it produces both ozone and nitric oxide as by products of the ionization of the air. There is a safety cap on top of the acrylic tube enclosure with a sealing gasket and a valve to release the gases. Nitric oxide is the anhydride of nitric acid, which is obviously not good for the lungs!
Ah, deja vu!