Abstract Valuable information about the specific surface area, the size, and the shapes of pores, the setting in of reversible capillary condensation and of complete filling of pores may be obtained by plotting the experimental volumes of adsorbed nitrogen, V a , as a function of the statistical thickness, t , of the adsorbed layer, as given in Paper I of this series. The V a − t plot, together with the experimental adsorption and desorption isotherm gives a very good picture of the whole pore system.