The salaries, expenses and other allowances, including mileage, mentioned in this chapter, Chapter 1 (§ 2.2-100 et seq.) of this title and Chapter 1.1 (§ 30-19.11 et seq.) of Title 30 shall, except where otherwise specifically provided, be paid out of the state treasury after being duly audited, and the Comptroller shall draw his warrants on the State Treasurer for the payment thereof. Salaries shall be paid every two weeks, semimonthly or monthly, at the discretion of the Comptroller, upon such dates as the Comptroller may prescribe. Expenses shall be paid when they have been incurred, and the other allowances shall be paid when the services have been rendered or the travel has been performed however, members of the General Assembly and others traveling to the seat of government who would be entitled to mileage for traveling home may receive such mileage before going home.