Looking closely at pepper spray and an explosive mouthful.

People may think that blogs — even those about chemistry — only cover what the blogger had for breakfast and the occasional picture of cute kittens. Hopefully this column has dispelled some of those thoughts in the past few years, but if anyone still needs persuading, Deborah Blum's post About Pepper Spray (http://go.nature.com/iV1eQb) should do the trick. Written shortly after a “shocking incident involving peacefully protesting students at the University of California-Davis”, Blum took her readers through the chemistry behind the innocuously named weapon. For those familiar with the Scoville scale, pepper spray is about 1,000 times hotter than jalapeños and up to 25 times hotter than habaneros. But if you think that the effect is similar to the stinging eyes you may have experiences after not being careful in the kitchen, Blum warns “we're not talking about cookery but a potent blast of chemistry”. Capsaicins, the compounds that confer heat on both chillies and pepper spray, “inflame the airways, causing swelling and restriction” making it particularly dangerous “to people with asthma and other respiratory conditions”. So dangerous, in fact, that it has been linked to around 75 deaths.

Blum's post about such a newsworthy topic gathered so much attention it's been re-posted in many venues, including Scientific American where it was the most popular item on the site for days. She even appeared on the Rachel Maddow show on MSNBC to discuss pepper spray (the segment can be found via http://www.msnbc.msn.com/id/26315908/).

On a less controversial, although slightly more explosive, topic, Derek Lowe treated us to another thing he won't work with, hexanitrohexaazaisowurtzitane. Hiding behind that mouthful are six nitrogen atoms, each bonded to one of six nitro groups. If you dare to even imagine making it, Lowe suggests that you “picture a bunch of guys wheeling around drums of fuming nitric acid while singing the Anvil Chorus from Il Trovatore”.