Silver halide compositions, layers and elements

Claim 1

A PHOTOGRAPHIC SILVER HALIDE EMULSION LAYER WHEREIN ANY HEAVY METAL SALT PRESENT IS SILVER HALID COMPRISING, BEFORE EXPOSURE TO ACTINIC RADIATION, LIGHT-SENSITIVE SILVER HALIDE CRYSTALS HAVING ASSOCIATED THEREWITH IN SUBSTANTIALLY GREATER THAN FOG-INHIBITING AMOUNTS, A SILVER MERCAPTIDE OF AN AROMATIC MERCAPTAN HAVING A SINGLE MERCAPTO GROUP ATTACHED TO AN AROMATIC HYDROCARBON RADICAL OF 6-10 CARBON ATOMS, SAID SILVER MERCAPTIDE BEING OF LOWER SOLUBILITY IN WATER THAN SILVER CHLORIDE, THE SILVER HALIDE CRYSTALS SO ASSOCIATED WITH THE SILVER MERCAPTIDE DISSOLVING MORE SLOWLY IN 10% AQUEOUS SODIUM THIOSULFATE THAN UNTREATED SILVER HALIDE CRYSTALS AT A PREDETERMINED PH, SAID MERCAPTAN BEING PRESENT IN SUCH AN AMOUNT, IN TERMS OF THE RATIO OF ITS WEIGHT TO THE SURFACE AREA OF SAID SILVER HALIDE CRYSTALS, THAT WHEN ADMIXED IN SUCH RATIO WITH AN AQUEOUS SILVER CHLOROBROMIDE (70/30 MOLE PERCENT) GELATIN DISPERSION CONTAINING 57 G. OF GELATIN PER MOLE OF AG AND .57 MG. OF AG PER ML., AND SAID SILVER CHLOROBROMIDE DISPERSION IS TREATED WITH 10%, BY WEIGHT, AQUEOUS SODIUM THIOSULFATE (SO THAT THE RESULTING MIXTURE CONTAINS 0.29 MG. OF SILVER AND 100 MG. OF SODIUM THIOSULFATE), AT LEAST THREE TIMES THE AMOUNT OF SILVER CHLOROBROMIDE REMAINS UNDISSOLVED AS COMPARED WITH A SIMILAR DISPERSION SUCCESSIVELY TREATED WITH 5%, BY WEIGHT, AQUEOUS SODIUM HYPOCHLORITE AND 10%, BY WEIGHT, AQUEOUS SODIUM THIOSULFATE, (SO THAT THE RESULTING MIXTURE CONTAINS 0.29 MG. OF SILVER, 25 MG. OF SODIUM HYPOCHLORITE AND 100 MG. OF SODIUM THIOSULFATE), AFTER VIGOROUS AGITIATION OF THE DISPERSIONS FOR 30 SECONDS AT 25*C.