Nucleon-nucleon scattering data from 0 to 274 Mev are discussed by means of a boundary-condition approximation. For internucleon distances greater than the core radius, which may depend on the state under discussion, the nucleon-nucleon interaction is assumed to vanish, while at the core radius the logarithmic derivative of the wave function or the reaction matrix satisfies a boundary condition. Assuming charge independence, it has been found possible to fit most of the experimental data with all but one boundary condition energy-independent. The core radius for the $^{1}S_{0}$ state is assumed to decrease with increasing energy. We find that $p\ensuremath{-}p$ scattering is composed mostly of scattering in the $^{1}S_{0}$ and $^{3}P_{0}$ states, both of which give isotropic distributions. The scattering from the $^{3}P_{0}$ state is close to the scattering by a repulsive sphere of radius 1.32\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}13}$ cm. The scattering in the isotopic singlet state below 100 Mev, assuming that the $n\ensuremath{-}p$ angular distribution is symmetric about 90\ifmmode^\circ\else\textdegree\fi{}, is entirely determined by the low-energy fit to triplet ($^{3}S_{1}+^{3}D_{1}$) $n\ensuremath{-}p$ scattering. Above 100 Mev the ($^{3}S_{1}+^{3}D_{1}$) states make the major contribution to the isotopic singlet scattering. The predicted cross sections fail significantly in only one detail: they are not sufficiently large for $n\ensuremath{-}p$ scattering near 180\ifmmode^\circ\else\textdegree\fi{}. Regardless of the validity of this particular fit, the boundary-condition approximation is found to provide a comparatively simple method for the broad correlation and understanding of the experimental results.