Gold rose modestly and silver slipped on the Comex division of the New York Mercantile Exchange Thursday. Gold added $2.50 to close at $1,589 per troy ounce. Silver lost 11 cents to reach $28.79 per ounce. The dollar index fell 0.4 percent to 82.59 in the International Exchange. Against the dollar the euro rose to $1.3004 from Wednesday\'s $1.2961. Against the yen, the dollar was lower at 96.09 yen from 96.11 yen. The British pound rose to $1.5079 from Wednesday\'s $1.4923. The dollar fell to 1.0223 Canadian dollars from 1.0276 Canadian.