Not immediately related to CP, but do we all mean the same thing by
'Matural Gas'? Most gas in the UK used to be made from coal - I
assume its main component was Carbon monoxide (certainly bad for
humans, don't know about plants) and it no doubt had lots of other
things in it which might have tarnished silver (Sulphur?).
For several decades now, all our gas has come from under-sea
reserves. This is mainly Methane, and we refer to it as 'Natural
Gas'. I doubt it being harmful to plants.
-- Clarke Brunt (clarke@brunt.demon.co.uk)