Hydrogen sulfide gas, a favorite of laboratory pranksters, appears to also induce a state of suspended animation in mice. Interestingly, it manages to lower the metabolic rate while maintaining normal blood pressure, something the researchers didn't expect, and which could have all sorts of applications in medicine. Known for its rotten egg smell, hydrogen sulfide gas occurs naturally in swamps, springs and volcanoes. While usually harmless, it can be toxic if breathed in sufficient quantity. The new study, presented at the recent American Physiological Society conference, built on earlier research which found that when mice breathed the gas, they went...