Abstract: Particulate chromatography medium such as silica is packed into a chromatography column (2) along a feed conduit (16, 18) leading to a packing port (1) through the column wall. A motive flow of a liquid packing vehicle such as a non-polar organic solvent is established along a feed conduit by a pump (111). The medium, for example silica which is poorly compatible with low-polarity vehicles, is easily entrained in the motive flow by introducing it into the feed conduit (16, 18) via an ejector (30). This avoids subjecting the medium to the action of a mechanical pump.