Reinforcing gelatin-silver negatives with iodide of mercury gives unstable images which assume a more or less uniform lemon-yellow color with accompanying loss of contrast. Once the authors had established the presence of salts of mercury and silver iodide in deteriorated old negatives, they set about reproducing these alterations by subjecting modern pliable negatives and glass plate negatives to accelerated aging. A method of restoration by development enabled them to regain the contrasts, and to stabilize the image. The image layer coming loose from its glass support during restoration was a risk they minimized by controlling the pH of the redevelopment bath. -- AATA