Catalytic extraction chamber

The Catalytic extraction chamber was a device for cannibalising life energy from others. Magnus Greel, a 51st century human, travelled to the 19th century where he experimented with the device. He used it on the local population to fuel his dying body. The Fourth Doctor threw Magnus into the device and it sucked out his life force. (DW: The Talons of Weng-Chiang)