Trade card. A "snake oil" promotion for something a bit out of the ordinary. Rather than some medical health panacea, Kem-Kom promised miracles for your coal.
They claimed that one simply dissolve their powder in water, sprinkle it over coal, and all smanner of wonderful things would follow . . .
saving coal consumption by 25%, reducing labor and time and dirt, destroying deadly coal gas, causing the coal to ignite more quickly and last longer,
causing the coal to produce more intense heat, lessening the ashes, preventing clinkers and cinders, burning off the soot and much of the smoke,
and allowing inferior grades of coal to be mixed in. Right.