"Section 1. Any person employed in the Philippines by the Government of the United States, or any agency thereof, to whom authority is delegated by the said Government or agency, to administer oaths and affirmations, tod claimants for benefits granted by the United States in the preparation and presentation of their claims, and to make investigations and examine witnesses, shall have authority to administer oaths and affirmations during his employment in the Philippines in any investigation or matter connected with the performance of his duties and functions: Provided, however, That for any oath or affirmation administered by him, no fee shall be charged or collected."