Stinky Science: Why the Smelliest Smells Smell So Smelly

Going where no nose wants to go, this fearlessly fun and fascinating nonfiction book explores the science behind smells. The witty preface sets the odor-ometer bar high: a cartoon caricature of the author, standing waist deep in a steaming puddle of green goo, surrounded by buzzing flies, ceremoniously announces, “You hold in your hands a veritable guide to the gross, a manual of the malodorous, a syllabus of stenches.” Indeed, the chapters that follow do not disappoint.

In a conversational style that includes lots of gross facts, Edward Kay explains the biology behind our keen sense of smell. Six million scent receptors, covered with mucus, allow us to identify “10 000 unique smells”. Our olfactory system also protects us by detecting things that are dangerous, like smoke and rotten meat (“many things that are bad for us smell bad to us, too!”). Not only is our sense of smell strongly linked to memory, it can “change your mood by triggering good or bad memories.”

A scent by scent rundown of some of the smelliest animals and plants you’d never want to encounter is provided. Steer clear of the polecat – this member of the weasel family can blind an attacker with its spray that “smells like a mixture of burned rubber, garlic, rotten eggs and a dirty gym locker.” Bombardier beetles, green wood hoopoe birds and sloths are also notorious for their noxious fumes. The durian fruit’s scent is described by a food writer as being akin to “turpentine and onions, garnished with a gym sock.” While most flowers attract insects by smelling sweet, the corpse plant takes the opposite approach and lures insects that prefer the heady aroma of rotting meat and dung.

The chemical combinations that make up stinks are described in suitably putrid details. Bad breath and rotting cabbage smell the same because they both contain methyl mercaptan. Also sharing similar chemistry are “farts and swamps full of rotting vegetation” which both contain hydrogen sulfide. The final section looks at creatures with superior senses of smell, like vultures (who have hundreds of millions of scent receptors), sharks (who can “detect a single drop of blood in the water from 3.2 km away”) and the Eastern American mole (who smells in stereo).

Mike Shiell’s exuberant cartoon illustrations are full of requisite bathroom humour as well as diagrams of digestive systems, and brains. A glossary and a thorough index round out this informative nonfiction title.

Once readers get a whiff of this scent-ational science book, they won’t be able to get their nose out of Stinky Science.