The magnetic susceptibilities of MBBA, p-quinquephenyl, and the cyano-biphenyl compounds NCB where N ranges from 5 to 9 have been measured as a function of temperature in the nematic range. In the nematic range the susceptibility is anisotropic and Δ = (χ ≥ - χ ⊥) should be proportional to the order parameter S. The coefficients of proportionality S/Δ χ have been calculated using information available in the literature concerning the susceptibility of similar organic compounds. These results are in good agreement with values obtained by the procedure which Haller has suggested, which involves extrapolation of the experimental data to zero temperature i.e. to S = 1. Our scaled results for S, which should be accurate to within 3 % in absolute terms, are in general agreement with the results of previous investigators in the case of MBBA