Note 24 — XIII. SIR HENRY BESSEMER.

In Grüner's text-book on steel, he says: "In its properties, as well as in its manufacture, steel is comprised between the limits of cast and wrought iron. It cannot even be said where steel begins or ends. It is a series which begins with the most impure black pig iron, and ends with the softest and purest wrought iron. [Karsten stated this in these words in 1823.] Cast-iron passes into hard steel in becoming malleable (natural steel for wire-mills, the 'Wildstahl' of the Germans); and steel, properly so called, passes into iron, giving in succession mild steel, steel of the nature of iron, steely iron, and granular iron."