[Myrddin]

My college chemistry professor accidentally dripped some methyl mercaptan on the lab floor and stepped on it with his leather sole Florsheim shoes. He didn't notice it while in the lab because the vent hood was fairly effective. As he walked from the lab to his car, he kept stopping to see if he had stepped in any dog crap. The shoes looked fine. When he got into his car, the stink was overwhelming. He realized that his shoes were contaminated with methyl mercaptan. He drove his car to the nearest trash can in the parking lot and deposited the shoes in the trash can. It was a $150 mistake.

[Ptarmigan]

Methyl mercaptan has to be one of the most potent smelling substance out there. Even a drop can do it and ruined a good shoe.