On Fri, Jan 17, 2003 at 12:22:33PM -0500, Mark A Mandel wrote: > Saltpeter forms at the bottom of dungheaps, which I think must be in > plentiful supply. A scarcity of sulphur, being elemental, would be a better hindrance. Unfortunately some laws of physics would have to be changed for that as well. (technogeek handwave)