YOUTH CONFESSES TO BRUTAL MURDER-----SLAIN GIRL’S BODY FOUND IN FURNACE OF STORE ROOM WHERE BOTH WORKED.Portland, Maine, July 14 —f/P)—A 22 year old youth, alleged by po lilt; to have confessed tlie* brutal slaving of a 20 year old girl when! she repulsed his advances, today* pleaded hot guilty to a charge of murder.James M Mitchell was arrestedtyesterday a few hours after the charred body of Miss Lillian 1 MacDonald was found in a furnace in the basement of a Congress street stationery' store, where both were employed.The young woman was last seen alive Saturday morning when she went to the basement to distribute pay envelopes. She hud approximately $SOO, and Mitchell, accord iug to County Attorney Ralph M. Ingalls, said he took his own payand burned the remainder withthe body. I