Unknown Diodes or Lamps

Fellow Radiophiles, the following is an identification request from a RadioMuseum visitor.

Hello Ernst,
Happened to have your call sign written down from past.  Please see attached photo.
Photo shows (3) of these inside a unit.  Each measures approx 6 inches long x ¾ dia with single wire out each end…..”taped” down to surface.
Any idea what these may be ?  Unit had about 8 of these in parallel mounting and a selector switch to pick up each one individually for use in the electrical circuit. 
Thanks for any ideas as to what these are?  Surely don’t want to destroy.   Unit appears to be a piece of history.
Regards,
Leo
K8PYD/HZ1AB

To thank the Author because you find the post helpful or well done.

Hello Joe,

these is possibly a model for teaching different colors and spectrums with different gas fillings in cold discharge tubes. It needs a switch to drive each tube separately and a common pre resistor. The both darkened area inside of the bulbs near the electrodes shows a use with ac power.

Best regards,  Hans-Thomas

To thank the Author because you find the post helpful or well done.

Hello Hans:

Thank you for the explanation. I made a parallel post in the Tube Collector's Association Yahoo group and one of the members gave this response:

Looks like a quack medical device to me. Sometimes some of the tubes will be
filled with argon and some with neon, so the user can choose the healing blue
light or the magical red light.

- John KG4L

One way to describe a "quack medical device" might be a device that explores the Placebo Effect, but, for obvious reasons deceives the user into believing that something beyond the Placebo Effect is at play.

Best regards,

-Joe

To thank the Author because you find the post helpful or well done.