Silver heart shaped box what is it?

This heart shaped box has a top opening lid, it is hallmarked Birmingham 1930, can someone tell me what it is called and what its worth?
it measures 4cm in diameter and 4cm in height.
heart box.JPG

Its from UK but purpose must be the same.

This is a danish speciality - especially from Sønderjylland. And it is called hovedvandsæg - its for smelling water. Used in the 1700-1800 hundreds - they didnt wash so they smelled. These were used for some water to take the bad smell.

Now yours is brittish but as i wrote purpose is similar.

And it is truely a collectors item. Some danes have huge collections of these.

Many thanks for the information you have provided me.