It's our favourite reaction - the barking dog - but in a newly uncovered 3m high tube! Barking Dog Playlist: http://bit.ly/Barking_Dog Featuring Sir Martyn Poliakoff and Neil Barnes. Previous videos Barking Dog Slow Motion: https://www.youtube.com/watch?v=c3fJRRCAIdk Horizontal Barking Dog: https://www.youtube.com/watch?v=b32gnEgoQlw 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 From the School of Chemistry at The University of Nottingham: http://bit.ly/NottChem Periodic Videos films are by video journalist Brady Haran: http://www.bradyharan.com/ Brady's Blog: http://www.bradyharanblog.com/ Join Brady's mailing list for updates and extra stuff --- http://eepurl.com/YdjL9