A manometric method of determining the density of a liquid is described. After calibration of the densitometer only remote observations need be made of a setting to a fiducial line and of the pressure of an applied gas. No confining fluid is used. This makes the densitometer particularly suitable for liquids at high temperatures. The densities of the following inorganic salts above their melting points have been found: sodium nitrite, potassium thiocyanate and potassium chlorate.