All payments and disbursements payable out of the appropriation to the Department of Military Affairs shall be made by the State Treasurer upon warrants of the Comptroller issued upon vouchers signed by the Adjutant General or such person as the Adjutant General may designate for such purpose. Expenditures not specifically provided for but manifestly for the benefit of the military service may be made by the Adjutant General with the written approval of the Governor.
Va. Code § 44-14