Any person other than an Indian of the full blood who shall attempt to reside in the Indian country, or on any Indian reservation, as a trader, or to introduce goods, or to trade therein, without a license, shall forfeit all merchandise offered for sale to the Indians or found in his possession, and shall moreover be liable to a penalty of $500: Provided, That this section shall not apply to any person residing among or trading with the Choctaws, Cherokee, Chickasaws, Creeks, or Seminoles, commonly called the Five Civilized Tribes: And provided further, That no white person shall be employed as a clerk by any Indian trader, except as such trade with said Five Civilized Tribes, unless first authorized so to do by the Commissioner of Indian Affairs. (R.S. 2133, as amended; 25 U.S.C. 264)