Melting curves of indium samples of 99. 9999%, 99. 999%, and 99. 99% purity were obtained adiabatically. For the purest sample, the liquidus point temperature at the triple point pressure was found to be 156. 6298 degree C, and the latent heat of fusion was found to be 28. 53 J/g, with standard deviations of plus or minus 0. 4 mK and plus or minus 0. 02 J/g respectively.