Surface excess, definition interpretation

It is the objective of this paper to discuss fundamental aspects of the thermodynamics of adsorption at the solid-liquid interface, with emphasis on providing proper definitions of experimental variables such as the surface excess, selectivity, amount adsorbed, and the relationships among them. Types of surfactant adsorption isotherms for binary systems are discussed, and it is shown that an extreme caution must be taken when interpreting isotherms for surfactant mixtures. It is hoped that this discussion will facilitate a better understanding and interpretation of experimental results reported in the literature. 

The ratio 1.63 of the rosin soap is also rather lower than that of water however experiments of 248, by showing us that this liquid, at least such as I prepared, gives caps which never have a colorless phase, made known to us that its surface viscosity, although with positive excess, is not very energetic there is thus here agreement between the indications provided by the ratios and those which one deduces from results more definitely interpretable. 

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