 Volume viscosity was introduced in 1879 by Sir Horace Lamb in his famous work "Hydrodynamics".Although relatively obscure in the scientific literature at large, volume viscosity is discussed in depth in many important works on fluid mechanics, fluid acoustics, theory of liquids, and rheology.The negative-one-third of the trace of the Cauchy stress tensor at the equilibrium is often identified with the thermodynamic pressure,

which only depends upon the equilibrium state potentials like temperature and density (equation of state).