4345. Zenzes, A. Feb. 24. Cast iron, special treatment of; Bessemer or pneumatic processes; silicon steel.-Molten Bessemer or haematite pig iron is blown in a converter till the silicon and manganese are largely oxidized, and the charge is reduced to a "white iron." 200 per cent. of pig iron, rich in silicon, is added at a high temperature, and a grey cast iron of high tensile strength is produced containing 1À5 per cent. silicon and less than 3 per cent. carbon.