This current work is presented to deal with the model of double diffusive convection
in porous material with variable viscosity, such that the equations for convective
fluid motion in a Brinkman type are analysed when the viscosity varies with temperature
quadratically. Hence, we carefully find a priori bounds when the coe cients depend
only on the geometry of the problem, initial data, and boundary data, where this shows
the continuous dependence of the solution on changes in the viscosity. A convergence
result is also showen when the variable viscosity is allowed to tend to a constant
viscosity.