To test the semi-permeable qualities of the inner membrane of an egg shell, I place one egg in a hypertonic solution (corn syrup) and one egg in a hypotonic solution (water).  

Using time-lapse footage, you can watch one egg shrink in size and one egg increase in size due to osmosis (the movement of water through a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration) in order to reach dynamic equilibrium (a state in which all regions have an equal solute concentration).