Method of making a silver halide emulsion

Claim 1

A PROCESS WHICH COMPRISES ADMIXING, IN ANY ORDER, AN AQUEOUS DISPERSION OF LIGHT-SENSITIVE SILVER HALIDE IN A WATER-PERMEABLE AMPHOTERIC PROTEIN PROTECTIVE COLLOID AND AN AQUEOUS SOLUTION CONTAINING FROM 3% TO 20% BY WEIGHT, BASED ON SAID COLLOID, A WATER-SOLUBLE, ACIDSOLUBLE ORGANIC POLYMER OF HIGH MOLECULAR WEIGHT TAKEN FROM THE GROUP CONSISTING OF POLYVINYL ACETALS, ALKYLVINYL ETHER/MALEIC ANHYDRIDE COPOLYMERS, POLYGALACTANS AND PHOSPHATES OF POLYGLYCIDYL METHACRYLATES CONTAINING A PLURALITY OF RECURRING OXY GROUPS SELECTED FROM THE GROUP CONNSISTING OF ETHER, ACETAL, AND ALCOHOLIC HYDROXYL GROUPS AND RECURRING GROUPS TAKEN FROM THE CLASS CONSISTING OF FREE ACID GROUPS AND THEIR ALKALI METAL AND AMMONIUM SALTS, SAID POLYMER BEING SOLUBLE BOTH IN WATER AND 1% NITRIC ACID TO THE EXTENT OF AT LEAST 1%, BY WEIGHT, AND BEING CAPABLE OF FORMING A COMPLEX WITH AN AMPHOTERIC PROTEIN COLLOID BELOW ITS ISOELECTRIC POINT, ADMIXING AN ACID TO LOWER THE PH BELOW THE ISOELECTRIC POINT OF SUCH COLLOID THEREBY FORMING A COMPLEX OF THE POLYMER AND SAID COLLOID AND RECOVERING THE PERCIPITATED COMPLEX OF SAID POLYMER AND COLLOID CONTAINING DISPERSED SILVER HALIDE.