Section 1
SECTION 1. When a justice of the Supreme Court, who has rendered at least twenty years service either in the judiciary or in any other branch of the Government,or in both, (a) retires for having attained the age of seventy years, or (b) resigns by reason of his incapacity to discharge the duties of his office, he shall during the residue of his natural life receive the salary which is payable at the time of his retirement or resignation. And when a justice of the Supreme Court has attained the age of sixty years and has rendered at least twenty years' service in the Government, ten or more of which have been continuously rendered as a judge of a court of record he may retire, upon the salary of which he is then in receipt but a justice so retired may nevertheless be called upon by the President and be by him authorized to perform duties either-in the judiciary or in any other branch, agency, or instrumentality of the Government, without additional compensation. The refusal of such a justice to serve as required by the President, except for a justifiable cause, will work as a forfeiture of his retirement gratuity. It is a condition of the pension provided for herein that no retiring justice during the time that he is receiving said pension shall engage in private practice of law except as amicus curie without compensation.