[en] Values of the concentration susceptibility, of liquid ³He/⁴He mixtures measured as the variation in ³He mole fraction with respect to the difference between molar chemical potentials of ³He and ⁴He have been determined near the lambda line and tricritical point from measurements of the differential osmotic pressure as a function of temperature T at four values of the ³He mole fraction, x = 0.594, x = 0.644, x = 0.680, and x = 0.706. In contrast to other determinations, results for the two values of x less than the tricritical value x/sub t/ = 0.675 show pronounced peaks at the lambda transition. Except perhaps for x < x/sub t/ in the normal-fluid region away from the transition, our data appear to be consistent with a simple tricritical scaling relationship