CHAPTER XXVIII. THE METALLIC AND NON-METALLIC ELEMENTS OF CAST IRON. Having described processes followed in making cast iron and qualities affecting its character, etc., tip to the time it arrives in pig form at foundries, ready for re-melting to make castings, as seen in Chapters I. to XXVII., we will -now treat of qualities which can affect cast iron when in the hands of founders, and of information which they should possess in order to make mixtures best suited for different kinds of gray and chilled castings; also on subjects pertaining to testing, etc. While the effects of silicon and sulphur, manganese, phosphorus, and carbon have been referred to somewhat in the preceding chapters, it has only chiefly been done in a manner.incidental to the manufacture of cast iron. It is when pig or cast iron is in the hands of founders that its peculiarities or characteristics are best displayed. For this reason, the second part of this work will be found the more important in imparting information on cast iron to those employed in the manufacture of castings or interested in their use. In taking up this second part of the work, it will be well to first treat of the metallic and non- metallic elements of cast iron. An element is a substance composed of only onehorus. Manganese.