During Legs 127 and 128, we found a systematic error in the index property measurements, in that the wet bulk density, grain density, and porosity did not satisfy well-established interrelationships. We have found that an almost constant difference exists between the weight of water lost during drying and the volume of water lost. This discrepancy is independent of volume or water content of the sample. The water losses should be equal because the density of water is close to 1.0 g/cm**3. The pycnometer wet volume measurement has been identified as the source of the systematic error. The wet volume on average is 0.2 cm**3 too low. For the rare cases when the water content is negligible, there is no offset. The source of the wet volume error results from the partial vapor pressure of water in the pycnometer cell. Newly corrected tables of index properties measured during Legs 127 and 128 are included. The corrected index properties are internally consistent. The data are in better agreement with theoretical models that relate the index properties to other physical properties, such as thermal conductivity and acoustic velocity. In future, a standard volume sampler should be used, or the wet volume should be calculated from the dry volume and the water loss by weight
