Quote Originally Posted by DarkroomExperimente View Post
where would you get the alkali?....wood ashes?
The expression "taking the piss" comes to mind.

I'm not being rude, the expression comes from the old practice of taking the urine from the gents urinals in London by boat in wooden barrels to the North East coast of England, where it was hauled up a cliff face to a chemical works to extract the ammonia.

Urea breaks down to Ammonia, so that's one source of alkali