A slow continuous change of the shape of solids or semi-solids under the action of gravity, or external force, is also by the extension of the term called viscosity, as the viscosity of ice, as observed in the slow movement of those rivers of ice, the glaciers.
The viscosity of liquids arises from the mutual attractions of the molecules and is diminished by the effect of the wandering molecules (C. D.). The viscosity of gases increases while that of liquids diminishes as the temperature is raised.
The viscosity of fluids presents a certain analogy with the malleability of solids.
Vis Viva is equivalent to active or living force; temperature is the Vis Viva of the smallest particles of a body; in bodies of the same temperature the atoms have the same vis viva, the smaller mass of the lighter atoms being compensated by their greater velocity.
This term, which is often met with in scientific treatises, was invented by Leibnitz. It is well known that water in rapid circulation will absorb more heat than when stagnant or moving slowly; this is caused by Vis Viva of the atoms.
CAPILLARY ATTRACTION.
Capillary attraction is the attraction which causes the ascent of fluids in small tubes. This word is derived from the Latin capillus—a hair.
The tubes must be less than one-tenth of an inch in diameter in order to produce the most satisfactory results, and tubes whose bores are no larger than a hair present the phenomenon the most strikingly. But though the rise of water above its natural level, is most manifest in small tubes, it appears, in a degree, in vessels of all sizes and shapes, by a ring of water formed around the sides with a concavity upward.