Treasures at the Royal Society are protected from fire by a combination of carbon dioxide, nitrogen and argon - as Professor Poliakoff discovers. The Royal Society website is: http://royalsociety.org/ (thanks as always to Rupert!) More chemistry at http://www.periodicvideos.com/ Follow us on Facebook at http://www.facebook.com/periodicvideos And on Twitter at http://twitter.com/periodicvideos Periodic Videos films are by video journalist Brady Haran Brady's other channels include: http://www.youtube.com/sixtysymbols (Physics and astronomy) http://www.youtube.com/numberphile (Numbers and maths) http://www.youtube.com/DeepSkyVideos (Space stuff) http://www.youtube.com/nottinghamscience (Science and behind the scenes) http://www.youtube.com/foodskey (Food science) http://www.youtube.com/BackstageScience (Big science facilities) http://www.youtube.com/favscientist (Favourite scientists) http://www.youtube.com/bibledex (Academic look at the Bible) http://www.youtube.com/wordsoftheworld (Modern language and culture)