Contributions by the county for prior service annuity, widow's prior service annuity, age and service annuity and widow's annuity for all periods of time during which he was an employee of such county or such School of Nursing or its predecessor schools for which he has not received such credits. Such contributions shall be at the same rates as were in effect for employees under "The 1925 Act" during such periods of time, and shall bear interest at 4% per annum in the same manner as in the case of any other employee, and shall, together with all other amounts contributed by or for such employee for annuity purposes, be considered in computing the annuity for such employee or his widow.
Any period of employment for which credit is hereby provided shall also be counted as service for all other purposes of this Article, and any other county employee in the service on July 1, 1947, shall receive like credits for service theretofore rendered such schools.
The time and manner in which such additional contributions may be made shall be prescribed by the board.
40 ILCS 5/9-227