Cast Steel , 
351 
la the public instructions drawn up by order of the com- 
mittees of safety, that they could offer nothing but con- 
jectures on the subject*, in this situation was the know- 
ledge of the chemists and manufacturers of France, when 
Citizen Clouet resumed his experiments on a larger scale 
at the house of the Conservatory of Arts, and the minera- 
logical school at Paris, on the fusion of various kinds of 
steel, and the immediate conversion of iron into cast- steel. 
On this subject, the author delivered a memoir to the 
Institute of France, which forms the subject of Guyton’s 
report. He first treats of the combinations of iron and 
charcoal. One thirty- second part of charcoal is sufficient, 
as he affirms, to convert the iron into steel ; one-sixth 
part of the weight of the iron affords a steel which is more 
fusible, but still malleable ; and, after this term, it be- 
comes nearer to the state of cast-iron, and no longer pos- 
sesses enough of tenacity. By augmenting the dose of 
charcoal the fusibility is increased ; and, at last, it ac- 
quires the state of grey cast-iron. 
The particular cast-iron, which results from the com- 
bination of iron and glass, forms the second object upon 
which the attention of Citizen Clouet was fixed. The 
glass enters but in a small quantity into this compound, 
notwithstanding which, the properties of the mass are 
changed. This iron, though very soft to the file, if heat- 
ed merely to cherry red, Hies in pieces under the hammer : 
the cast ingot contracts greatly in cooling ; and when, by 
careful management, it has been made into bars, the opera- 
tion of hardening gives them the grain of steel, and renders 
them brittle, without adding to their hardness. 
Charcoal in powder, added to the glass, changes the 
result, and increases the fusibility ; but the nature of the 
product is greatly influenced by the close of these ingre 
* Nichols. Phil. Journal II. 102, 
