Page:The Philosophy of Creation.djvu/246

 tion operative under certain conditions. It is due to the fact that the molecules of the fluid lie loosely and are in a state to respond to a slight force. The fluid ascends the sides of an immersed solid because the attraction between the particles of the solid and of the fluid is stronger than the attraction between the particles of water for themselves. Mercury is depressed because the attraction between the particles of the mercury is stronger than the attraction between the mercury and the immersed solid.

Cohesion is the attraction between the molecules which form the mass. Its great strength, as in brass and other solidified bodies, is due to the ability of the component particles to receive and to appropriate the power of attraction, and to the form of the constituent parts whereby they interlace and lock.

Adhesion is chiefly distinguished from cohesion by its taking place between surfaces brought into contact.

Osmosis, the passing of liquids through a porous partition and their diffusion, is due to the capillary