An article caught my attention, enhanced by the mention of a Smelly Lab. It talks of recent technology furthering the findings of Stanley Miller's famous 1953 experiment, his creation of primordial soup of organic molecules. New York Times article, 26 March 2011 click here
Re: hydrogen sulfide -
"It's very smelly," Hazen explained. "Just a trace of it will make your lab absolutely uninhabitable — and make you enemies up and down the hall for months."
An article of 27 October 2008 mentions that hydrogen sulfide, with its noticeable rotten egg smell, may actually regulate blood pressure ... click here
... something soakers of sulfur mineral springs have long known!