In 1851 G. G. Stokes obtained a relaxation wave equation, which has been overlooked by many modern-day researchers, but nevertheless, its form has been applied to a variety of problems of weak waves propagating in relaxing gases. The present contribution is to elucidate features of the Stokesian relaxation wave equation in a straightforward manner and to point out other physical problems relatable to the Stokesian relaxation wave equation.