Kent wrote:

I use a product called "Private Preserve Wine Preserve", an aerosol N2 for
saving half consumed bottles of old wine. It would work fine for herbs. I
have old wines, and use it all the time. Buy it at "Bev. and More". I'm
going to try preserving herbs with it. You have to have an absolutely air
tight container, even though N2 is more dense than air. It will leak out if
you let it.

Actually, it's mostly a matter of O2 "leaking" in.
Since the partial pressure of O2 (~ 3 psi, as I recall) is greater
outside than inside (0 psi, if the package is filled with N2), oxygen
will diffuse in, displacing a small amount of the nitrogen you filled it
with.

Dave