Dug, Alrignt! But the final word should be ruff! Now we need a second verse, maybe about CO2 flooding? And a third about brines? a fourth about partial melts? eric When Eugster buffered fO2 > Its value could not vary, > But now a more permissive crew > Defines things quite contrary. > They claim a buffer need not buff; > It can slide aside when the going gets ruff. > >Slainte, Dugald