The board of supervisors in each county may establish and maintain a county hospital, prescribe rules for the government and management thereof, appoint a county physician and other necessary officers and employees thereof, who shall hold office during the pleasure of the board and authorize said hospital to be a member of and maintain membership in any local, state or national group or association organized and operated for the promotion of the public health and welfare or the advancement of the efficiency of hospital administration and in connection therewith to use tax funds for the payment of dues and fees.