188 On the Combination of Silicium with Platina, 
the silex in the analysis which I have made of several of the pro- 
ducts of the foundry of La Berardiere. | 
I dissolved the steel in sulphuric acid, diluted with six times 
its weight of water. The insoluble residue was then dried, 
weighed, and burned, and the proportion of carbon was inferred 
by the loss in burning. It deserves to be noticed that this car- 
bonaceous residue takes fire long before the platina erucible is 
red-hot ; sometimes even when it is no hotter than the hand can 
bear. The residue after combustion was then digested with di- 
lute muriatic acid, which dissolved the metallic oxides, leaving 
the silex pure, which last was then calcined and weighed when ~ 
warm. 
In this procedure the estimate of carbon is far from being ri-. 
gorously accurate, but my principal object was directed to that 
of the silex. Experiments were made with four different sam- 
ples, namely, Ist. Iron (derive) ; 2d. Cemented steel; 3d. Cast- 
steel; 4th. Steel from Monkland near Glasgow, made with Dan- 
nemora Swedish iron. 
The products were as follow: 
Iron. Carbon. Silicium. Mang. & Copper.: 
Nos 15:)/99°825 cossiadiactrace sade) OAT. cue eatrace 
2, 99325. 6..4...0°490 2.244. 0225 2.205. ditto 
By 9O442 08 fais) OP3BBis ci;.04.6. OF225) i. oa oe ditto 
4, 99°375. .. 0006 0:500 2. vi 10125) oe ais ov ditto 
It appears, therefore, that during the cementation of iron into 
steel, it absorbs a small quantity of silicium as well as carbon ; 
but I state this with some doubt, as it requires a greater num- 
ber of analyses with the same iron both before and after cemen- 
tation. 
The combination of iron with silicium was long ago hinted at 
by Clouet. He says expressly that iron combines with glass 5 
and of all the experiments that could be imagined to prove the 
property possessed by silicium to convert iron into steel, none 
would be more conclusive than that of this eminent chemist 5 
but such is the force of preconceived opinion, that he interpreted 
his result in favour of carbon,—His process was, to melt soft iron 
with a mixture of clay and chalk, and it turned out good cast- 
steel: and being satisfied that steel must contain carbon, he in- 
ferred that his product contained it, and explained its presence 
from the decomposition of the carbonic acid of the chalk by the 
iron at a high temperature, without ever ascertaining by analysis 
whether carbon was really present in his steel. 
To be satisfied of this fact, I repeated Clouet’s process, fol- 
lowing with scrupulous accuracy the description which he has 
given in his report to the Institute. (Jowrnal des Mines ee 
ne 
