N-butyric acid is about the nastiest stuff I've ever smelled, and it's amazing how fast that stench can travel from one end of a large room to another. We had this stoner that started hanging around the chemistry lab a lot. One day I took him to the back room with a conspiratory air, and convinced him that this stuff was "soooo rad", and would "make you higher than a kite". I pumped him up enough that when I uncapped it he sniffed deeply without testing it first. He cried out, coughed, and vomited. Fortunately he was feeling too bad to catch me and do what he wanted, as I escaped back into the safety of the main room, laughing my head off. It didn't take long for the story to get around.