without iron, 



SO Dr. Schafhaeutl 07i the Different Species of Cast-Iron^ &c. 



This light precipitate consisted therefore of 

 Silica, 

 Carbon, 

 Hydrogen, 

 Sulphur, 



and was, in all probability, a carburet of silicon mixed with a 

 carburet of sulphur. 



The same quantity of steel filings from a razor made by 



Rogers of Sheffield, gave nearly the same result, with the ex- 



. ception, that the sediment was darker, and there remained 



more of the white sulphurous precipitate, covering not only 



the sides, but, in a thick layer, the bottom also of the test tube. 



Iron which I made at Axat, in the Oriental Pyrenees, from 

 a mixture of spathose iron and iron glance, differed only 

 from the foregoing specimens in this, that the sediment ap- 

 peared of a lighter colour and the sides of the tube remained 

 uncovered by the \sdJiite precipitate. 



The first decanted liquid of this iron treated with sulphu- 

 retted hydrogen let fall a reddish yellow precipitate, soluble 

 in ammonia, leaving white sulphur. 



Further, I treated powdered cast iron from the Maesteg 

 iron-works, near Neath in South Wales, with caustic potash 

 in a test tube. After the evolution of ammonia had ceased, 

 the mass was dissolved in distilled water, and a part of the 

 iron was found remaining. Half of this powder was dissolved 

 in hydrochloric acid ; hydrogen escaped, and a whitish gray 

 flocky precipitate remained. The other half of the remain- 

 ing iron being again melted with caustic potash, and am- 

 monia was again disengaged, leaving also a black granulated 

 mass of iron, which was rather tough under the hammer, 

 and afterwards being likewise dissolved in hydrochloric acid, 

 a perfectly 'wJiite precipitate remained. The acid was re- 

 moved and distilled water substituted, until no trace of hy- 

 drochloric acid was to be found. I considered it to consist 

 of sulphur and silica; but on heating it carefully over a 

 spirit lamp, a very volatile vapour was disengaged, having 

 some distant resemblance to the smell of cyanic acid gas. 

 A little white powder remained on the bottom, and the 

 sides of the test tube were covered by a dew of a perfectly 

 transparent liquid. Having poured a few drops of distilled 

 water i ito the tube, and afterwards a drop of solution of 

 nitrate of silver, a white precipitate fell which retained its co- 

 lour on exposure to the rays of the sun ; a proof that it was 

 not chloride of silver. 



[To be continued.] 



