We have measured insoluble particle size distributions covering the radius range 0.05--1.31 μm for six sections of ice core from Dome C, Antarctica. Two of the sections are from the Holocene, two are from the last glacial maximum (LGM), and another two are from the period that preceded it. Our measurements lead us to the conclusion that the southern hemisphere insoluble background aerosol size distribution, in the range of our measurements, has not changed significantly over the 26,000--year period that we studied. We also compared the concentration of diatoms in a sample of Holocene ice with that in two samples LGM ice and found that the concentration of diatoms whose largest dimension was equal to or greater than 10 μm was 20 times larger during the LGM, the same as the ratio we measured for the concentration of insoluble particles. We interpret this to mean that the higher dust levels were mainly due to an increase in wind strength rather than to increased continental aridity. ¿ American Geophysical Union 1988