Any witness neglecting or refusing to appear in response to such summons or to answer any questions which such judge may require as material to such inquiry, shall be deemed guilty of a contempt and after a public hearing in open court and conviction of such contempt, shall be punished by a fine not exceeding $1,000.00 or imprisonment in the county jail not exceeding 1 year or both at the discretion of the court: Provided, That if such witness after being so sentenced shall offer to appear before such judge to purge himself of such contempt, the judge shall cause such witness to be brought before him and, after examination of such witness, the judge may in his discretion commute or suspend the further execution of such sentence.