Ox the different Jlates of Iron. 40 1 



'*■ crucible iron cut into fmall pieces, along with a mixture of 

 equal parts of carbonat of lime and argil, expofe them to 

 the degree of heat neceffary to weld iron, and maintain this 

 heat for an hour or more, according to the fize of the cruci- 

 ble ; the metal when poured into the ingot-mould will be 

 fteel fimilar to caft fteel. 



The oxyds of iron are equally fufceptible of paffing to a 

 ftate of foft iron, fteel, and caft iron, according to the pro- 

 portions of carbon employed. The black oxyd of iron, the- 

 ft-ate of which feems to be the molt unalterable, becomes 

 iron when treated in the crucible with an equal volume of 

 charcoal powder : by doubling that quantity you will have 

 fteel, and a progreffive augmentation gives it the characters 

 of white and grey caft iron. In a word, (3. Clouet obferved 

 the fame tranfitions, and always depending on the refpecf ive 

 quantities in treating caft iron and the oxyd of iron, caft iron 

 and forged iron, the oxyd of iron and iron, the oxyd of iron 

 and fteel. A fifth part only of caft iron is neceffary to ren- 

 der iron fteel. The iron and the oxyd do not unite inti- 

 mately ; the black oxyd mixed with a half lefs of carbon 

 than is neceffary for its redu&ion, gives a foft iron, but not 

 very tenacious, black and without a granulated fracture. A 

 fixth part of the oxyd brings back common fteel to the ftate 

 of iron, by treating them together either in the forge or by 

 cementation. 



At the end of his memoir C. Clouet gives fome obferva- 

 tions on the method of producing caft Heel, and the furnaces 

 proper for that purpofe. lie determines the proportions of 

 the fubftances to be fufed; the degree of beat; the precau- 

 tions to be employed in pouring them into the ingot-mould ; 

 the method of forging '.bis kind of fteel ; the procefles to be 

 employed for affayB, in a common forge, upon three or four 

 pounds of matter; and the proportions to be given to a re- 

 verberating furnace to operate at the fame time with four cruci- 

 bles, containing each frcAn twenty-three to twenty-fix pounds 

 of fted. He remarks, that ingredients of faline glafs cannot 



Vol. IN. Dd be 



