Underpressurized, annular liquid jets have been studied under steady and transient conditions in order to assess the effects of Henry’s and Sievert’s solubility laws on mass transfer. It is shown that, in general, Henry’s solubility law predicts a higher, steady state mass absorption rate than Sievert’s law. The rate at which the under-pressurized, annular liquid jet tends towards an equilibrium, non-pressurized configuration is higher for Henry’s than for Sievert’s solubility law. Both this rate and the steady state mass absorption rate increase as the Weber number, the ratio of the solubility at the inner interface to that at the outer one, the product of the gas constant times the temperature and the solubility of the gases surrounding the jet, the ratio of the product of the pressure of the gases surrounding the annular jet times the annular jet’s mean radius at the nozzle exit to the liquid surface tension, and the nozzle exit angle are increased, and as the Froude and mass Peclet numbers, the annular jet’s thickness-to-mean radius ratio at the nozzle exit and the initial pressure of the gases enclosed by the annular jet are decreased.