§ 1. The powers conferred on city councils of cities and selectmen of towns by chapter one hundred and two of the Revised Laws, to regulate the keeping, storage, use, manufacture or sale of gunpowder, dynamite or other explosives and inflammable fluids, shall hereafter be exercised by the fire marshal’s department of the district police. § 2. The fire marshal’s department of the district police may make regulations for the keeping, storage, use, manufacture or sale of gunpowder, dynamite or other explosives, crude petroleum or any of its products, or other inflammable fluids; and may prescribe the materials and construction of buildings to be used for any of the said purposes.