quickstuff

GODDARD, John Frederick b. 1795; d. 1866 "...A second solution was to make the plate faster by double sensitizing, and here is where Goddard comes in. He used bromine vapour in addition to iodine to increase the sensitivity of the daguerreotype. Goddard's accelerator, which he called quickstuff, could reduce a 10 minute exposure to 1 minute."