Abstract: It was found that 1,7,10,16-tetraoxa-4,13-dithiacyclooctadecan (2S-1 8-C-6)and 1,7,10,16-tetraoxa-4,13-diazacyclooctadecan (2N-18-C-6)can act as modifiers when epitaxial deposition occurs to nonisomorphic silver salt, while 1,4,7,10,13,16-hexaoxacyclo-octadecan (18-C-6)can ont.They have no effect on the epitaxial growth of the isomorphic crystals.The aza-and thiacrown ethers can also etch the host grains, and their etching abilities decrease in the order of 2S-18-C-6, 2N-18-C-6and 18-C-6, they are the same as complexing abilities with Ag⁺.In fact,18-C-6 does not etch the octahedral AgBr emulsion.The modification of epitaxial deposition by the crown ether is related much to the comlexing between the crown ether and Ag⁺ and therefore, the solubilization of the crystal in the crown ether.

Key words: epitaial emulsion, modifier, crown ether