12 IRON COMPOUND IN THE FORM OF POWDER AND PASTE USED AS A CEMENT IN PIPE-JOINTS AND FOR STOPPING LEAKS IN STEAM, HYDRAULIC, AND OTHER FLUID AND VAPOR CONDUCTORS AND CONTAINERS, AND FOR WATERPROOFING AND OIL-PROOFING FOUNDATIONS, FLOORS, WALKS, WALLS, AND LIKE SURFACES, AND FOR MAKING HARD CONCRETE SURFACES