of Sheffield
1804 Patented a process for producing malleable cast iron by partial decarbonisation, involving exposure of the castings for several days to high temperature in a closed vessel, packed with iron ore or other metallic oxides capable of abstracting a portion of the carbon in the iron. The process was said (in 1864) to be 'substantially that which has been followed for the purpose ever since the time of his description.'[1]
'The process of decarbonizing iron in order to give it malleability has been known for about two hundred years. It was first described by Reaumur, the distnguished French metallurgist and philosopher, in 1722. From that time until 1804, when patents were issued to Samuel Lucas, of Sheffield, England, the process of making malleable iron was more of a theoretical than a practical method. At the shops of Samuel Lucas the process was worked out, but not as we have it now. .....' [2]