Abstract
The effect of certain “neutral“ salts in accelerating the washing of hypo from film emulsions is found to occur not only at the concentrations used for hypaeliminating baths but through the range of concentrations to be expected In normal water supplies. Pure water is a relatively poor washing medium and the difficulties of hypo elimination In peaty-water areas can be accounted for by the comparative purity of the local supply. Bicarbonate Ion appears to be the most important single determinant of the washing power. The differences are Important when aluminium hardening has been used.