OPTICAL INACTlVITY OF GELATIN lN THE ADSORBED STATE AT THE LIQUID/LIQUID INTERFACE AND ITS USE AS A MEASURE OF ADSORPTION.

Optical rotation for transparent emulsions of amyl acetate in gelatin-water.glycerol sots of various concentrations have been found experimentally and compared with those calculated from Beer's law for mixtures. The observed rotations are found to be less than the calculated from which it is inferred that the gelatin particles on being adsorbed on the oil globules become optically inactive. The optical inactivity of adsorbed gelatin has been used as a measure of its adsorp­tion at the liquid/liquid interface in transparent emulsions as well as such milky emulsions as could be made transparent by the addition of glycerine. From the difference between the calculated and observed values, the values of \(x/m\) (quantity of gelatin adsorbed by one g. of the oil) have been calculated and found to be nearly constant for the different quantities of the adsorbent used. The value of \(x/m\) increases with the increase in initial concentration. It has been experimentally proved that the gelatin in the adsorbed state at the liquid/liquid interface loses optical activity only temporarily