III. On certain ternary alloys. Part V. Determination of various critical curves, and their tie-lines and limiting points

The triangular method of graphical representation suggested by Sir G. G. Stokes, and described in Part IV (‘Roy. Soc. Proc.,’ vol. 49, p. 174), substantially amounts to the tracing out of a curve (“ critical curve”) which shall express the saturation of the solvent C with a mixture in given variable proportions of the other two constituents, A, B ; the variation being such that any given point on the curve is related to some other point (“ conjugate point ”) in a way given by the consideration that all mixtures of the three constituents, A, B, C, represented by points lying on the line (“ tie-line ”) joining these two conjugate points (“ ideal ” alloys, or mixtures), will separate into two different ternary mixtures corresponding with the two points respectively ; whereas any mixture of the same constituents, represented by a point lyingoutside the critical curve, will form a “ real ” alloy, or mixture, not separating spontaneously into two different fluids but existing as a stable homogeneous whole.