Experimental data of Cantelow on the time-dependent transmission of 133Xe in air flowing steadily through fixed beds packed with activated charcoal adsorbent are reinterpreted on the basis of a dispersion model in terms of a dimensionless dispersion number and an effective adsorption capacity for the gas-adsorbent system. The transmission is the ratio of the concentration at the outlet of the adsorber bed to the concentration at the inlet to the bed. The dispersion model provides an alternative interpretation to the theoretical plate model for the transport of a gas through a packed bed. For the range of dimensionless dispersion numbers represented by the data, the two models lead to the same values for the effective adsorption capacity. The reciprocal of the dimensionless dispersion number is equal to twice the theoretical plate number.