Abstract: A silver halide emulsion of average grain size 0.2 .mu.m or less comprising silver halide grains having a core and an outer shell, the core comprising at least 85 mol % of the total silver halide content of the grain and at least 50 mol % of the silver halide in the core being silver bromide, and the outer shell comprising silver halide of which greater than 50 mol % is silver chloride; the emulsion either containing no rhodium dopant, or containing rhodium dopant such that the concentration of said dopant is at least as great in the core as in the shell.

Abstract: A medical X-ray film comprising a transparent base coated on at least one side with (a) a laminar grain silver halide emulsion and (b) a separate hydrophillic colloid layer containing a developing agent for silver halide in an amount corresponding to at least 0.5 moles per mole of the silver coated on that side of the base.

Abstract: Gelatin hardeners, suitable for use in hardening gelatin-containing photographic layers, of the formula: ##STR1## wherein: X is a member selected from the group consisting of O and S or is absent,each Y independently is a member selected from the group consisting of O, S and a bond,each R.sup.1 independently represents an aliphatic group of up to 10 carbon atoms or the two R.sup.1 groups together represent the necessary atoms to complete a 5, 6 or 7-membered ring,--NR.sup.2 R.sup.3 contains not more than 12 skeletal atoms andR.sup.2 and R.sup.3 are independently members of the group consisting of hydrogen, cyclic groups and acyclic groups or R.sup.2 and R.sup.3 together represent the necessary atoms to complete a heterocyclic ring.