Chemical Science, 203 



rated solution of salt, and in fact to consist of a saturated solution 

 of muriate of magnesia, mixed with a little muriate of lime ; the 

 salt which contains these cavities and fluids being itself perfectly free 

 from magnesia and from chloride of sodium. — N. Edin. Phil. Jour. 



7. On the Formation of Steel by means of Silica. — It is well 

 known to chemists, that silicum combines freely with iron, and 

 also, that certain persons have considered silica a substance 

 which possesses in common with carbon, and perhaps boron, the 

 power of converting iron into steel. M. Boussangault, if we 

 mistake not, put forth some views, in which he considered silicon 

 as the constant agent in the production of steel. 



The Editor of the Recueil Industriel has described several cases, 

 in which the presence of silicon appears to have an important 

 influence of this kind. Some time since. Dr. Eynard of Lyons, 

 having put some files into a mixture of five parts of water with 

 one of sulphuric acid, was astonished when he took them out, 

 to find, at the bottom of the glass vessel in which they had been 

 placed, a greyish-white and glairy substance. This, being col- 

 lected and dried, proved to be silica. 



In 1732, MM. Perru of Neufchatel established a manufactory 

 of steel cylinders at Lyons. These cylinders, which were highly 

 polished, and so hard as to be untouched by the file, had been 

 fused, it is said, with silica. They have never been imitated. A 

 pair of these cylinders, 5 inches in diameter, sell at this time for 

 2400 francs. 



Some years since, a person of the name of Ranquet, of Lyons, 

 formed vessels of white cast-iron of extreme hardness. M. Culhot 

 manufactured cylinders from the fragments of these vessels, and 

 the cylinders were of such hardness, it was impossible to shape 

 them by cutting instruments, so that they could be worked only 

 by emery, and similar substances, occupying months for the 

 purpose. This person made a secret of his process, but it is 

 said, used no charcoal in his process. 



M. Eynard found silica in cast iron, but not in forged iron j 

 its occurrence in the former, or rather the presence of silicon, 

 is a well-known circumstance. 



Upon these facts, the Editor founds some earnest recommenda- 

 tions to those who have the opportunity of ascertaining whether 

 the cementation of iron without charcoal, but with silica alone, 

 would produce steel, and in what proportions the silica ought to 

 be mixed, to obtain a very perfect and hard steel ; there are also 

 other points urged, which are either already upon the minds of 

 metallurgists, or are naturally suggested by the two above. 

 — xi. p. 311. 



8. Analyses of various Cast Irons and Steels. — These analyses 

 have been made by MM. Gay-Lussac and Wilson, at the works 

 of Charenton. They are appended to a work on chemistry by 

 M. Lassaigne. 



