Iron cement, used for filling up cracks and blowholes in iron castings by application with a hot iron, maybe made as follows. Take by weight 2 parts of sulphur and 1 part of fine blacklead. Place the sulphur in an old iron bowl and hold over a fire till the sulphur begins to melt; then add the blacklead, and stir till all is well mixed and melted. Then pour on an iron slab or smooth stone. To use the composition, a sufficient quantity is broken up, placed in the hole, and soldered in by means of a hot iron, in the same manner as a tinsmith solders sheets. As the fumes of sulphur are very annoying, the material must be melted in a good draught.