(Solid + liquid) phase diagrams have been constructed for (trichloromethane + N,N-dimethylformamide, or pyridine, or N,N-dimethylaniline). Congruently melting solid addition compounds form with the empirical formulae : HCON(CH3)(2) . CHCl3, and C5H5N . CHCl3. The HCON(CH3)2 . CHCl3 is interesting in that a metastable form can be made to crystallize from solution. No solid addition compound forms in {(1 - x)CHCl3 + xC(6)H(5)N(CH3)(2)}.