If a memorial building has been constructed for the purpose of a hospital pursuant to this chapter, additions for hospital purposes, and nursing homes to be operated in conjunction with the hospital may be erected or acquired by following the procedure outlined in chapter 347 and by issuing general county purpose bonds in accordance with sections 331.441 through 331.449, with the commissioners acting in the same manner and fashion as the hospital trustees under chapter 347, and with the procedure in all other respects to be identical.