Multicomponent-Fluid Tricritical Points

Phenomena in "ordinary" fluid mixtures (such as C${\mathrm{H}}_3$OH-${\mathrm{H}}_2$O-C${\mathrm{O}}_2$) which are analogous to tricritical points in ${\mathrm{He}}^3$-${\mathrm{He}}^4$ mixtures, metamagnets, etc. have been reported for some years in the Soviet physical-chemistry journals. References to these papers are given, together with a brief explanation of why the two types of phase transition are analogous, and reasons why further experiments on the "ordinary" mixtures would be of interest.