In addition to the power to establish and maintain in connection with the hospital and as a part of it, a training school for nurses, the board of trustees may enter into agreements with schools or educational institutions for the training of nurses and nurses’ assistants or may provide a training school for the preliminary training of nurses and nurses’ assistants and contract with schools or educational institutions for the further training of nurses and nurses’ assistants and such contracts may be on a continuing basis or for a definite term.