The grant of powers in this act contained to county hospital boards and to the duly authorized officers and agents thereof shall be liberally interpreted and construed as a broad and general grant of powers to the end that the operation and administration of county hospital properties may be efficient, economical and successful; the enumeration of certain powers that would be implied without such enumeration shall not be construed as a denial or exclusion of other implied powers necessary for the free and efficient exercise of the powers expressly granted.