Poindextrose
Poindextrose is a chemical that is emitted by geeks, dorks, and people with glasses.
History
When new girl Francine Rhenquist moved to Springfield Elementary School, Lisa was physically bullied by her. Lisa had no idea why Francine started bullying her, so she decided to figure out the cause. After reviewing security tapes of Francine finding and bullying her, Lisa realized that Francine was completely fine with her at the swimming pool due to her using a nose clip. Lisa realized that this meant the reason Francine bullied her was due to a smell-related cause.
Lisa had Database, Martin, and Milhouse, all of whom were victims of Francine, run on treadmills in the school gymnasium so she could gather their sweat from them. She then tested her theory on Drederick Tatum, who was giving a talk to Bart's class. Lisa wiped some of the sweat on Tatum's suit, which caused Nelson to get up and start bullying the heavyweight boxer, despite not wanting to.
At the 12th Annual Big Science Thing, Lisa presented her findings to an audience of scientists. They were initially dismissive of Lisa because she was a little girl, but Lisa brought out Francine, who had been put into a cage by her parents for the presentation. Lisa used a swab to apply Poindextrose to her and let Francine catch her scent. The bully immediately became aggressive and tried to get to Lisa. Lisa then had Professor Frink open the cage and the bully charged at her, only for Lisa to spray salad dressing over herself, stopping Francine in her tracks. Lisa explained to the confused scientists that the pungent vinegar and tangy Roquefort blocked Francine's smell receptors, rendering her harmless.
After Lisa's presentation, Francine smelled the Poindextrose on the other scientists and started attacking them. However, Lisa ran out of salad dressing so she couldn't stop her.[1]
Poindextrose was the element Pd on Lisa's Table of Geeky Delights.[2]
Appearances
Episode – "Bye, Bye, Nerdie" 
Book – Lisa Simpson's Guide to Geek Chic (mentioned)
