Excess molar volumes, V-m(E) have been measured for binary mixtures of butanol (n-C4H9OH) + pentane (n-C5H12), + hexane (n-C6H14), + heptane (n-C7H16), + octane (n-C8H18), + 2,2,4-trimethylpentane (2,2,4-TMP), and + carbon tetrachloride (CCl4) at 288.15 K and 298.15 K, and refractive indexes, n(D), have been measured for these mixtures at 298.15 K. At both temperatures V-m(E) has been found to be positive throughout the entire range of composition for xn-C4H9OH + (1 - x)n-C7H16 and + (1 - x)n-C8H18. At both temperatures 288.15 K and 298.15 K, V-m(E) is positive at low mole fractions of n-C4H9OH and negative at its higher mole fractions in the case of mixtures of n-C4H9OH with n-C5H12, n-C6H14, 2,2,4-TMP, and CCl4. Values of V-m(E) and n(D) for the various mixtures of n-C4H9OH have been fitted in smoothing equations.