The possibility of adapting the well-known mixing device shown in Fig. 1 for production of density gradients with retained hydrostatic equilibrium is investigated. It is shown that a specific form of the unstirred container can be found that gives a strictly linear density course. Instead of specifically shaped containers, specific plungers can be used in cylindrical containers. All pertinent equations arc given. The modified arrangement is useful for falling as well as for rising densities by use of exchangeable plungers.