We can put the walls of our container anywhere inside the gas, and the force per unit area (the pressure) is the same. We can shrink the size of our "container" down to a very small point (becoming less true as we approach the atomic scale), and the pressure will still have a single value at that point. Therefore, pressure is a scalar quantity, not a vector quantity. It has magnitude but no direction sense associated with it. Pressure force acts in all directions at a point inside a gas.
Orthostatic purpura is a skin condition that results from prolonged standing or even sitting with the legs lowered (as in a bus, airplane, or train), which produced edema and a purpuric eruption on the lower extremities. : 827

See also
Skin lesion


== References ==