mixing said used fixer solution with an aqueous solution of hydrosulfide that provides 0.5 to 1.0 moles of hydrosulfide ions per mole of dissolved silver, whereby said dissolved silver is converted to {HEAD ~ a precipitate} of {TAIL ~ silver sulfide} 
of
mixing said used fixer solution with an aqueous solution of hydrosulfide that provides 0.5 to 1.0 moles of hydrosulfide ions per mole of dissolved silver , whereby said dissolved silver is converted to { HEAD ~ a precipitate } of { TAIL ~ silver sulfide }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL