On Jul 1, 7:58 am, Thomas Prufer prufer.pub...@mnet-
online.de.invalid wrote:
On Sat, 30 Jun 2007 21:37:46 +0100, Mike D wrote:
My house is about 100 years old and has various old redundant gas
pipes, imbedded in the walls and under the floors, but the only pipe
which is supposed to be live is teh one going directly from the meter
to my central heating boiler. And that is all at thoe opposite end of
the house from where the slight gas smell has been commented on.

Old gas pipes can give of the smell of gas -- it's a powerful scent, and a
little goes a long way.

I don't know how deadly the stink additive is but none of the
paraffins are noxious. Unvented, they seem to have an effect on
driving ability though, no doubt, copious amounts of the assassin's
drug of choice: hashish, might be involved there though.

All paraffins aka alkanes are heavier than air.
They run from Methane at 4 carbon atoms through to Octane with ten, a
volatile liquid through to turps at about 16 IIRC, all the way down to
the really heavy waxes used in tarmac.

There is no limit to the length of the molecule chain. But the density
remains about the same all the way through. I have no idea why.

The long strands seem to have no particular affinity -or more
importantly aversion, for each other other than as liquids they are
miscible and as solids their threads remain interwoven -hence
demonstrating very little of a crystalline matrix.

It could be argued that hydrogen is the first one in this family but
of course it would be the first in all the organic families of
hydrocarbons and be a pointless inclusion except to say that hydrogen
too is not noxious.