A compilation of experimental values of the infinite dilution partial molar Gibbs energy, enthalpy, and heat capacity of hydration, together with partial molar volumes in water at 298.15 K and 0.1 MPa is presented for aliphatic monoethers, diethers, and polyethers. These data are treated in the framework of the first- and second-order group additivity methods. However, third- and higher-order effects (i.e., interactions expressed beyond the nearest neighbors) are clearly present in aqueous ethers. The effects can be accounted for by the introduction of a number of corrections. For the second-order group contribution method, numerical values are determined for the following groups: C-(C)(2)(H)(O)(ether), C-(C)(3)(O)(ether), O-(C)(2), C-(H)(2)(O)(2), C-(C)(O)(2)(H), and corrections: a "ethoxyalkane" correction, {CH(3)-CH(2)-O-CH(2)}, and a "diether" correction, {O-(CH(2))(2)-O}. For the first-order group contribution method, in addition to the "ether" O group, a large number of corrections appears to be necessary for accurate reproduction of the compiled data: "ethoxyalkane", and "diether", corrections, two "acetal", {O-CH(2)-O} and {O-CH(CH(3))-O}, corrections, as well as "tertiary", {C(tert)-O}, and "ternary", {HC(tern)-O}, corrections, applied to monoethers that have direct contacts of tertiary and ternary carbon atom with oxygen.