Joseph Barlow Felt Osgood, The Charter and Ordinances of the City of Salem, Together with the Acts of the Legislature Relating to the City: Collated and Revised Pursuant to an Order of the City Council Page 67-68, Image 77-78 (1853) available at The Making of Modern Law: Primary Sources.

[Ordinances of Salem,] Fire, § 18. By an act passed March, 6 1847, the inhabitants of any town, and the government of any city in this Commonwealth, may order than no gun-cotton, or other substance prepared, like it, for explosion, shall be kept within the limits of such town or city, excepting under the regulations and penalties that were then applicable by law to gunpowder; and if it shall be considered necessary for public safety, they may restrict the quantity to be so kept to one-fifth of the weight of gunpowder allowed by law in each case provided for. . . § 22. The inhabitants of every town may order, that no gunpowder shall be kept in any place, within the limits of such town, unless the same shall be well secured in tight casks or canisters; and that no gunpowder above the quantity of fifty pounds, shall be kept or deposited in any shop, store, or other building, or in any ship or vessel which shall be within the distance of twenty-five rods from any other building or wharf; that no gunpowder, above the quantity of twenty-five pounds, shall be kept or deposited in any shop, store, or other building, within ten rods of any other building; and that no gunpowder, above the quantity of one pound, shall be kept or deposited in any shop, store, or other building, within ten rods of any other building in such town, unless the same be well secured in copper, tin, or brass canisters, holding not exceeding five pounds each, and closely covered with copper, brass or tin covers.