An Act amending the act of August 9, 1955 (P.L.323, No.130), known as The County Code, in preliminary provisions, further providing for applicability; in county officers, further providing for enumeration of elected officers, providing for appointment of district attorneys in counties of the first class; and, in district attorney, assistants and detectives, further providing for district attorney, qualifications, eligibility and compensation and for filling of vacancies.