In this liquid limit we also find α α = κ κ T = 0 , namely that the vdW liquid is incompressible. Moreover, since ∂ ∂ T p = − − ∂ ∂ T v / ∂ ∂ p v = α α / κ κ T = ∞ ∞ , it is also mechanically incompressible, that is κ κ T → → 0 faster than α α .