in the animal economy, is the function of the absorbent vessels, or that power by which they take up and propel substances. This power has been ascribed to the operation of different causes, according to the theories which physiologists have proposed. Some attribute it to capillary attraction, others to the pressure of the atmosphere, and others to Absorption an ambiguous or unknown cause, which they denominate suction; for this last is nothing else than the elastic power of one part of the air restoring the equilibrium, which has been destroyed by the removal or rarefaction of another part.