The chemicals we off-gas change when we watch something funny or thrilling

Ars Technica: In cartoon worlds, squiggly lines over characters are reserved for the exceptionally smelly. But, in reality, everyone deserves those little squiggles: each of us is constantly emitting a steady stream of gases and microbes, as well as smells. And those gases may be able to reveal more about us than what we last ate (and whether it agreed with us). Our gases may also divulge what we think about movies.