A broken achilles tendon for one of our team is an excuse to talk about plaster casts! About the graffiti on Sam's cast: http://periodicvideos.blogspot.com/2011/07/graffiti-on-sams-cast.html 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