Cast Iron, Steel, and Malleable Iron. 523 



The quantities of manganese and silicon are as 2*54 to 1 ; 

 now, if we follow the process during the transition of this 

 cast iron into steel, both those bodies have to burn away with 

 the same quantity of carbon. By chemical analysis we find 

 in the first two- thirds of the process, the quantity of man- 

 ganese very rapidly diminishing in comparison with the car- 

 bon, leaving the silicon quite untouched. On the contra- 

 ry, when manganese is replaced by silicon, this last is oxi- 

 dized so very rapidly, as it is in relation to manganese only 

 like 1 : S'S-i, so that the greatest part of the silicon is oxi- 

 dized when more carbon is present than is necessary to pre- 

 vent the iron from fusion at a white heat. When the carbon 

 is so far diminished, that the iron begins to become suffici- 

 ently solid for the hammer — all the silicon is oxidized, which 

 gives, as we shall soon perceive, a hardness and tenacity to 

 the steel. 



Before we take leave of these three specimens of cast iron, 

 I must return to the solution of acetate of lead of specimen A, 

 in which the sulphuretted hydrogen had been collected. 



The precipitated sulphuret of lead, as before mentioned, was 

 not crystallized in scales; on the contrary, it had a viscous 

 dark brown appearance; and after some days standing, I found 

 it to contain rhomboidal columns of white crystals deposited 

 on the bottom of the bottles in needle-like aggregations, and 

 in a vertical position on the sides. On first inspection I 

 considered them as crystallized acetate of lead, but their dif- 

 ficult solubility, however, in distilled water, induced me to ex- 

 amine them more closely; and by trying them with the blow- 

 pipe, the rising copious white fumes covering the charcoal 

 immediately showed the presence of antimony, and the well- 

 known yellow ring around the crystals on the charcoal 

 plainly signified the presence of lead. The crystals them- 

 selves, treated with concentrated sulphuric acid, disengaged 

 acetic acid, and the crystals therefore consisted of antimony, 

 lead, and acetic acid. 



The above-mentioned treatment of 60 grains of white iron 

 with hydrochloric acid of the specific gravity 1*103, left 2*92 

 grains of sulphuret of lead mixed with antimony and acetate 

 of lead, and the precipitate contained 0*833 antimony. 



It is remaikable, that not only almost all the antimony 

 escaped with the hydrogen, butthatthe antimony was likewise 

 deposited in the acetate of lead, being also oxidized and con- 

 verted into an acetate, and that no trace of antimony followed 

 the hydrogen after it had passed the second bottle. 



[To be coiitiiuied,] 



