The said commissioners, upon the completion of said hospital, shall surrender their trust to a board of managers or trustees, to consist of nine members, to be appointed by the Governor from the counties or parts of counties embraced in the said middle coal field; said managers or trustees shall be a body politic or corporate, by the name and style of “The Trustees of the State Hospital of the Middle Coal Field of Pennsylvania;” they shall serve without compensation, shall manage and direct the concerns of the institution, in consonance with the provisions of this act, and shall make all necessary by-laws and regulations not inconsistent with the Constitution and laws of the Commonwealth.