Solution rates of 1h-, %-, and 1-in. cast benzoic acid spheres were measured under naturaland foreed-convection conditions. Upward-flowing streams of water and aqueous propylene glycol, in laminar and turbulent flow, were used to contact single spheres in either a 1.50-or 4.00-in.-diameter column. Sphere Reynolds numbers ranged from 10 to 16,920; Schmidt numbers from 987 to 69,680; sphere-to column-diameter ratios, ds/dc, from 0.123 to 0.497; and Grashof numbers from 5,130 to 125,200.The Sherwood number was found independent of the laminar-turbulent transition for pipe flow and the sphere-to column-diameter ratio when the Reynolds number is based on the average fluid velocity and sphere diameter.