Capillarity--The nature and thermodynamics of liquid interfaces--Surface films on liquid substrates--Electrical aspects of surface chemistry--Surfaces of solids--Long Range Forces--The solid-liquid interface-contact angle-nucleation--The solid-liquid interface-adsorption from solution--Friction and lubrication ; adhesion--Wetting, flotating and detergency--Emulsions and foams--The solid-gas interface-general considerations--Adsorption of gases and vapor on solids--Chemisorption and catalysis