The egg from the bottle

https://www.setthings.com/wp-content/uploads/2017/04/egg.jpg Put a fresh egg in a glass of vinegar. Leave the egg in the vinegar until the hard crust dissolves and remains only an elastic membrane. Put the egg thus obtained in water. In 3-7 days, the egg will increase its volume.
The experiment is even more fun if we put the egg from vinegar into a bottle...

https://www.setthings.com/en/the-egg-from-the-bottle/