The following offices, positions and places of employment are hereby exempted from the provisions of this Division: officers elected by the people; the officers and employees whose appointment and removal is otherwise provided for by law; attorneys and other employees whose necessary qualifications, in the judgment of the commission, include admission to the practice of law in the state. The chief deputy assessor, deputy assessor in charge of administrative service division, deputy assessor in charge of real estate division and deputy assessor in charge of personal property division, the appointment of whom shall be made by the County Assessor of Cook County, shall not be included in the classified service of Cook County. The superintendent of the Cook County Hospital Mental Health Clinic and the purchasing agent, the appointment of whom shall be made by the President of the Board of Commissioners of Cook County, with the advice and consent of the Board of Commissioners of Cook County, shall not be included in the classified service. Provided, that the Board of Commissioners of Cook County may contract with any recognized training school for the nursing of any or all of the persons who are sick or mentally ill.