CHAPTER XVII. Frontier Desperadoes and Savage Ferocity. Original Friendliness of the Indians .-- The River Pirates, Culbert and Magilbray .-- Capture of Beausoliel .-- His Rescue by the Negro Cacasotte .-- The Cave in the Rock .-- The Robber Mason .-- His Assassination .-- Fate of the Assassins .-- Hostility of the Apaches .-- Expedition of Lieutenant Davidson .-- Carson's Testimony in his Favor .-- Flight of the Apaches..