By using non-wetted and inert calcium fluoride substrates as plates or crucibles (cups), it is possible to extend the sessile drop method and its more precise version 'large drop' method for surface tension measurement of highly chemically active alloys. The Surface tension and density of copper titanium alloys over a wide range of titanium concentration (up to 70 at%) at temperatures between 1000 and 1250degreesC were measured. The surface tension-concentration dependence for Cu-Ti melts deviates positively from the Zhychovitsky theoretical isotherm for ideal solutions. The compression of alloys is observed. The copper-titanium melts deviate negatively from Raoult's law. The work of adhesion of Cu-Ti melts to CaF2 was also determined and it was found to be 820 +/- 65 mJ/m(2) for Cu + 70 at% Ti.