On 18 Mar, 18:35, (Nick Maclaren) wrote:
God alone knows what sodium oxide is
like, but I don't want to get anywhere near even a small quantity!

You do right.
http://msds.chem.ox.ac.uk/SO/sodium_oxide.html
"Reacts violently with water, acids and with many other compounds.
Store under dry inert gas. May lead to fire in contact with
combustible material."