Section 5. The department shall take cognizance of the interests of life, health, comfort and convenience among the citizens of the commonwealth; shall conduct sanitary investigations and investigations as to the causes of disease, and especially of epidemics, and the sale of food and drugs and adulterations thereof; and shall disseminate such information relating thereto as it considers proper. It shall advise the government concerning the location and other sanitary condition of any public institution. It may produce and distribute immunological, diagnostic and therapeutic agents as it may deem advisable, and may sell such portions of such materials produced in its laboratories as constitute an excess over those required for its use within the commonwealth.