Aqueous solid particle dispersions in chemical sensitization

The invention is generally accomplished by providing a method of chemical sensitization comprising providing a silver halide emulsion, and adding to the silver halide emulsion aqueous solid particle dispersion of a chemical sensitizing agent having a water and organic solvent insolubility (i.e., 50 mg/100 ml or less), and heating said emulsion wherein said chemical sensitizing agent comprises at least one member selected from the group consisting of gold compounds represented by Formula I:{AuS2X}nI wherein X is PR2 (dithiophosphinates), P(OR)2 (dithiophosphates), COR (xanthates), CNR2 (dithiocarbamates), CR (dithiocarboxylates) R is alkyl or aryl n=1-6, tellurium compounds represented by Formula II:TeLnX2 wherein L is thiourea or substituted thiourea, n is 2 or 4, X is Cl, Br, I, OCN, SCN, SeCN, TeCN, or N3 and Formula IIA wherein X is COR, CSR, CNR2, CR, CAr, PR2, P(OR)2, (PR2)2N R is alkyl or aryl, and palladium compounds represented by Formula III:PdX2(TeR2)2 wherein X is Cl, Br, I, NCO, NCS, NCSe, NCTe, or N3 R is alkyl or aryl.