Osmosis

Intuitively, if a liquid can soak through a solid, it should be able to seep through in any direction. Nollet found that you can have semipermeable membranes that allow one type of liquid but not another. Thus enables unidirectional fluid flow.
 Jean Antoine Nollet France 1748 Osmosis

Intuitively, if a liquid can soak through a solid, it should be able to seep through in any direction. Nollet found that you can have semipermeable membranes that allow one type of liquid but not another. Thus enables unidirectional fluid flow.