The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Striations in Crookes Tube /  Hardening a Vacuum with a Tesla Coil This weekend I was testing a reproduction X-Ray tube Made in China.  It was an incredibly crude tube, but interesting still.  It was made from a modified light bulb.  When I tested it, instead of the normal yellow-green phosphorescence, I saw a Violet discharge - uh oh!  Geissler Vaccum.  That means either a pin-hole leak or something in the tube was liberating too much gas under operation. I remembered Tesla mentioned hardening a tube via high frequency currents only.  So I attached it to a Tesla X-Ray Coil for a while and took some pictures! After a while the Geissler Vacuum turned white, and then to striations.  Cool! The striations were unusually beautiful.  They always are, but the number are closeness was interesting! CLICK HERE FOR A MOVIE! I added a few extra jolts (15A) and tested it again... This time a dark space or two (ie, Tesla currents).  Might experiment with this tube some more!