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Reprinted by permission of Dick Berg, University of Maryland, for use on this website.

The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources.

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Screw the 25 watt bulb into the socket and connect to the Variac.  Turn on the Variac to show that the bulb lights.  Turn off the Variac and using the slip joint pliers, break the glass envelope off the bulb leaving the filament exposed.  Fill the 1000 ml beaker with liquid nitrogen.  Dip the filament into the liquid nitrogen so that it is completely immersed and turn on the Variac.  The filament will glow and continue to do so until you take the filament out of the liquid nitrogen at which time it will burn out due to the rapid oxidation that take place in the oxygen laden atmosphere.