Tudor,

I always thought it was a build up of various oils or secretions given off
from many plants and trees which accumulate in the top layer of the soil
during dry weather. When it rains there is a combination with iron compounds
in the soil which provide a catalyst to form the familiar rain odour. If you
could bottle it you would earn a fortune. It was dry and warm for several
days of late before the rains of yesterday. However not really having much
confidence with chemistry I may well be on the wrong track.
I was awoken but very loud thunder at 05.50hrs this morning in Coulsdon. The
storms of yesterday were very similar to a heat induced summer situation and
most unlike the normal April scenario as were the storms coming in from the
east last night. However there were some severe night storms over the
Southeast especially Sussex on the 14th April 1981. Some 91mm of rain fell
at Horsham.

Ian Currie -Coulsdon
www.frostedearth.com



Hello everybody,
Just had an email from my niece who's asking what the cause is of
that
nice smell you get when it rains after a warm spell. Told her I'd seek
advice,
so any suggestions would be welcome. My own guess is that it may well
be
a
man-made substance, as it is most noticeable over surfaces containing
tar
but I
can't quite understand why it needs wetting to release it. Being a
retired
industrial chemist I do know a bit about this sort of thing, but
obviously
not
quite enough, and I do need to retain credibility with my niece.

Tudor Hughes, Warlingham, Surrey.