2. FOR USE IN THE PRODUCING OF IRON CASTINGS OF THE CHARACTER DESCRIBED FROM A MOLTEN GRAY IRON MIX BY ADDING TO SAID MIX BEFORE POURING A PREDETERMINED LIMITED AMOUNT OF AN ALLOY OF MAGNESIUM, MISCH METAL AND COPPER, SUCH THAT UPON POURING SAID MOLTEN MIX INTO A MOLD, AND THEN REMOVING THE CASTING FROM THE MOLD, AND FINISHED CASTING, SAID CASTING WILL CONTAIN ITS GRAPHITIC CARBON IN SPHERICAL OR NODULAR FORM, WITHOUT SUBSEQUENT ANNEALING, AND SUBSTANTIALLY FREE OF THE USUAL FLAKE-LIKE GRAPHITIC CARBON OF GRAY IRON CASTINGS, AN ALLOY WHICH GOES INTO SOLUTION WHEN ADDED TO THE MOLTEN GRAY IRON MIX AS A LADLE ADDITION AND COMPRISING APPROXIMATELY 7 TO 30% MAGNESIUM, 3 TO 7% MISCH METAL AND 63 TO 90% COPPER, AND WHICH IS EFFECTIVE TO CAUSE PRECIPITATION OF THE GRAPHITIC CARBON IN SAID NODULAR OR SPHERICAL FORM.