Section 90. Claims against the commonwealth for compensation under the provisions of section eighty-eight shall be referred to a board of three officers, including the state surgeon and the state judge advocate, appointed by the commander-in-chief. The board in consideration of the claim shall except as otherwise provided in section eighty-eight take into account any compensation received by the claimant or his dependents from the United States. The board shall have the same power to take evidence, administer oaths, issue subpoenas and compel witnesses to attend and testify and produce books and papers, and to punish their failure to do so as is possessed by a general court-martial. The findings of the board shall be subject to the approval of the commander-in-chief. The amounts so found due and so approved shall be a charge against the commonwealth and shall be paid in the same manner as other military accounts.