SHOOTING ACCIDENT AT PEEBLES.—Yesterday a party of horsemen who were to give a "Buffalo Bill" entertainment arrived in Peebles. The first two who arrived on Tweed Green were at once surrounded by a crowd of children. The men took the saddles and gun bags off their horses and placed them on the ground. While attending to their horses a boy got hold of a gun case and, raising it, pulled the trigger of the gun, which happened to be loaded. The bullet, after going through the leather in the gun case, passed through the thigh of a boy named Thomson, inflicting a severe flesh wound.