BUBBLES in the MUD: A Reminiscence and Perspective

I still feel a surge of excitement when, wading along some shore, my feet stir up an effusion of bubbles from the underlying muck. My thoughts ensue: Are they methane-rich, or perhaps composed of mixtures of nitrous oxide, hydrogen, carbon dioxide, and hydrogen sulfide? Do they contain exotics like ethane, dimethyl sulfide, trimethylamine, or even a methylated arsine? Suppressing an urge to grab a collection funnel, I resume my slog, leaving the unanswered questions for the next generation.