The heat capacity of the binary liquid mixture triethylamine-water has been measured near its lower critical consolute point using a scanning, adiabatic calorimeter. Two data runs are analyzed to provide heat capacity and enthalpy data that are fitted by equations with background terms and a critical term that includes correction to scaling. The critical exponent a was determined to be critical exponents. These values, for the most part, agree very well with experimental results. _-3 Several universal amplitude ratios have also been predicted and many have also been experimentally tested with mixed results. 5 A particularly powerful observation is that only two critical exponents are linearly independent, and that the leading amplitudes are interrelated using only two scale factors.l-3 Thus the universality of the exponents could be used with two experiments to determine all the leading critical behavior of a given system.The heat capacity provides a delicate probe of the system near a critical point and can determine essential amplitude and exponent values. In particular, a precise measurement of the heat capacity of the binary fluid mixture triethylamine and water will help settle a dispute in the literature about the amplitude in the one-phase region and its effect on the universal ratio X, measure the universal ratio of the amplitudes above and below the critical temperature, andgive the first attempt in binary liquid mixtures at using a new "universal" amplitude relation R_, to reduce the number of fitting parameters while testing theoretical predictions.The heat capacity has a weak divergence near the critical point that is governed by the critical exponent _, has a critical contribution Be to the background heat capacity, and has correction to scaling terms that extend the theoretical description further from the critical point. 3'6 The critical point influences the system properties over a global region. 78 however, this experiment measures behavior near the critical point and we will use the simpler formalism that is appropri-8048