original programmes. A running gag throughout the series is the fastidious labelling of all items in Dymo tape, such as hairdryers, magnets, a bottle of maths, or a jar of nuts (which contained both types of nut: the foodstuff and fastener). Another recurring joke is the use of fictional apparatus and materials used in the experiments—items such as the "Besselheim plate" poke fun at real lab equipment, often named after their designers (e.g. Petri dish, Erlenmeyer flask). Pencils are always used to point at key elements of the experiments, as the 'scientists' do not speak: this is sometimes taken to ridiculous levels—pointing out pencils using a pencil; pointing at chocolates and then at a person to show they are a gift. Also, the series repeatedly instructs viewers to keep a notebook, described as a "copy book," and to inscribe random and essentially worthless details of the lessons taking place with the spoken instruction to "write this down in your copy book." The series was commissioned based on a 20-minute pilot episode (twice the length of an episode in the first series, but otherwise identical) in which Calcium is described as an amorphous gel prepared by grinding discarded teeth in massive milling machines; this is included on the DVD release of Series 1 as an "advanced double-length module". The DVD extras also include a music video for the song "Little Mouse" (as featured in the module on music), a selection of mock-Ceefax pages, and a creator's commentary. The joke is taken even further by presenting the DVD subtitles in exactly the same format as those broadcast via teletext. At the end of each episode, reference is made to the "next module"—although these episodes were never actually made. The episodes that are promised, but never seen are: "Champagne" "Cosmetics" "Dynamite" "Flowers" "Hitchhiking" "Italians" "Reggae" "Romance" On the DVD Ceefax pages there were also two unseen modules: "Blood" "Further Maths" Series two The second series is composed of six 30-minute episodes and is presented in the pop-science vein of programmes such as Tomorrow's World. The series was directed by Tim Kirkby, and Ash Atalla (producer of The Office) worked as executive producer. Running from 31 January to 7 March 2005 on BBC Two at 10 p.m., Series 2 comprised the following episodes: "Music 2000" "Health" "Sport" "Food" "Computers" "Live Inventor of the Year Final" The DVD commentary confirms that this was not the