A theory is developed from first principles which includes all the important physical processes which affect the frequency of the free oscillations of a gas bubble. The components of the damping: viscosity, thermal conduction in the gas, and acoustic radiation are all determined. Numerical results for the damping are given for air bubbles in water. Since there is physical interest in the polytropic exponent, κ, (in pVκ = const.), the value of κ which gives the correct natural frequency is also determined. Numerical results for this κ for air bubbles in water are presented.