Abundances of Interstellar CH and CH^{+} Radicals

The spectra of 30 0 and B stars were measured for the equivalent widths of the interstellar CR and CR+ lines. Conversion factors are determined between visual estimates of weak line intensities and equivalent widths. Column densities of CR and CR+ are determined with the use of the curve of growth. A brief consideration of molecular equilibrium shows that with favorable choices of parameters, both the radiative-association and surface-reaction models are able to explain, within a factor of 2, the observations in Oph, Per, and 20 Tau. Correlations between line intensity and color excess are searched for. Column densities of CN are determined from equivalent widths measured by Clauser and Thaddeus and by Dunham, and are compared with CR column densities.