Abstract
The diffusion coefficient for diffusion of HCl in the organic matrix of elephant's ivory dentine was determined for various concentrations by measuring the fractional uptake of H36Cl in decalcified, cylindrical specimens with concealed end surfaces using a Geiger-Müller counter. Values for the effective diffusion coefficient for sorption of HCl were greatly dependent on concentration (6.1 x l0–6 cm2/sec for 1.0 N HCl to 0.l8-10–6 cm2/sec for 0.01 N). On the basis of an approximate kinetic model the diffusion coefficient for simple diffusion was estimated (9-12 x 10–6 cm2/sec). The effect of stirring on the rate of sorption was negligible.