Hi Tudor,
well as a retired analytical chemist myself I guess I should know as well -
but I don't! I agree about the peaty smell and wonder if it is connected
with humic acids being released.

Dave

"TudorHgh" wrote in message
...
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.