Robert, this may be what you're referring to....

"The Lumier developer was frequently recommended and can also be used for modern Lippmann photographs. Development time was 1 to 3 minutes. Most often the image was fixed. However, it was sometimes recommended not to fix the developed image, since that would change the thickness of the emulsion and, change the colour of the image. Many Lippmann photographers used image intensification by a bleaching and redeveloping process, which compensated for the shrinkage introduced by the fixing step." - Bjelkhagen, 'Lippmann photography: its history and recent development', page 3, bottom paragraph.