I don't think any universal laws like gravity or friction effect gases so my bet would be that some would stay in an some would go out. Only way to know for sure is to open one. well wait, is it a...
You cant answer it because you dont give the price of the bottle just the case and the perfume itself
Stand the bottle upside down on its cap, so that the remaining perfume runs down to the opening.
Eau de Parfume (french) wich means perfume water...as i know it`s a little stronger than toilet water(EDT) . Somebody correct me if i`m wrong !