Ether

Contrelli was a prison planet which contained a thin layer of ether in its atmosphere. (COMIC: Station Zero)

Alfred Stahlbaum used ether to keep Bremm under permanent sedation. (AUDIO: The Silver Turk)

Behind the scenes

 * According to Inside a Skaro Saucer, "light ions in the ether" were the means by which the Daleks' Rad-etheric magniscopes were able to "see" at a distance of over a million miles. There, instead of the gas now called ether referenced in Station Zero and The Silver Turk, the writer was instead referring to the discredited scientific concept of "the ether", a thin gas filling all of the void of interplanetary space, allowing waves to travel through it.