Abstract: Particles suspended in a fluid carrier are differentially separated by, first, grading the particles into fractions of equal settling rates and, second, separating the equal-settling particles of each fraction according to the magnetic susceptibilities of the particles. The particulate sample to be separated is passed through a two-path parallel flow system. In one path, the sample is selectively graded, by elutriation, into equal-settling fractions. Each such fraction then flows directly to the second path, where it crosses a magnetic field at a velocity proportional to its settling rate. Such proportionality between settling rate and flow velocity provides a residence time which ensures that the degree of deflection, in response to gravitational and magnetic forces, required for separate recovery of magnetic particles, on the one hand, and non-magnetic particles, on the other hand, will be attained within the active length of the magnetic field.