Studies have been made of the spectra given by strontium and barium in an oxy-hydrogen flame, in a `vacuum arc' in water vapour, in a `vacuum arc' in heavy-water vapour (D₂O), and in an arc in air at atmospheric pressure. For strontium, a band with some structure at 6050 Å and diffuse bands with maxima at 6460, 6590, 6675 and 6820 Å are attributed to SrOH, in agreement with James and Sugden's suggestion, the assignment being supported by small isotopic displacements with SrOD. Bands at 5950, 6050 and the far red, obtained best in the arc at 1 atmosphere, have a very complex structure suggesting a polyatomic emitter and variation of strength with concentration when strontium nitrate solution is sprayed into a flame supports assignment to the dimer of the oxide, Sr₂O₂. For barium, bands in the green and photographic infra-red are attributed to BaOH, the assignment again being supported by the isotopic shift. Diffuse complex bands near 4800, 5020 and 5500 Å in the arc in air may be due to the corresponding oxide dimer, Ba₂O₂.