without iron. 
50 Dr. Schafhaeutl on the Different Species of Cast-Iron^ See, 
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 ^hite 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 nxjhite precipitate remained. The acid was re- 
moved and distilled w^ater 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.] 
