Summary: A diagram of the relationship between d174 and % forsterite in olivines is presented in fig. 1 of the preceding paper by Jambor and Smith. In this note, statistical aspects of Jambor and Smith's data are considered in detail and compared to equivalent data by Yoder and Sahama (1957). This analysis leads to the conclusion that the relationship of mol. % Fo and d174 or d130 can be expressed as a straight line for Fo > 30 %. Olivines with Fo < 10 % are not related to this straight line.