In deacidification with magnesium bicarbonate solutions, papers from an old book took twice as long (80 minutes) to achieve the equilibrium alkali content in 2.13 g/l solutions as in 8.5 g/l solutions. Methanol (10%) in the solution greatly shortened the time required. Migration while drying concentrated the alkali at the surface of the paper (3:1 ratio, surface to interior). High humidity heat treatments increased the ratio, but freeze drying lowered it to 1. 5:1. In non-aqueous deacidification, poor solvents cause the alkali to lag behind the solvent front in penetrating the paper. The significance of the findings is discussed.