Section 24. The department may publish for general distribution such parts of its annual report to the general court and such other matter as it may deem adapted to promote the interests of the public health in the commonwealth. The department shall publish every five years for distribution among boards of health and other health agencies a manual of the laws relating to boards of health in the commonwealth, containing such information upon the same subject as it may deem expedient. The cost of any publications referred to in this section shall be paid out of the appropriation for the general expenses of the department.