Section 57. Every city having a population of fifty thousand or more, as determined by the last national census, shall establish and maintain within its limits a dispensary for the discovery, treatment and supervision of needy persons resident within its limits and afflicted with tuberculosis, unless there already exists in such city a dispensary satisfactory to the department. Every city having a population of less than fifty thousand, as determined as aforesaid, and every town may, and at the request of the department shall, establish and maintain a similar dispensary. Such dispensaries shall be subject to the regulation of the boards of health of the cities and towns where they are respectively situated, and shall be inspected by and be satisfactory to the department. A city or town which, upon the request of the department, refuses or neglects to comply with the provisions hereof shall forfeit not more than five hundred dollars.