No claim for legal services or for any other services rendered in respect of a claim or award for compensation under subchapter I to or on account of any person shall be valid unless approved by the Secretary; and any claim so approved shall, in the manner and to the extent fixed by the said Secretary, be paid out of the compensation payable to the claimant; and any person who receives any fee, other consideration, or any gratuity on account of services so rendered, unless such consideration or gratuity is so approved, or who solicits employment for another person or for himself in respect of any claim or award for compensation under subchapter I shall be guilty of a misdemeanor and upon conviction thereof shall, for each offense, be fined not more than $1,000 or imprisoned not more than one year, or both.