62 REPORT—1868. 
Chenot, Clay, Renton, and others) to produce iron directly from the purer 
ores, by reducing the ore in the first instance to a metallic sponge, and ball- 
ing up this sponge, which is a loose porous mass somewhat similar to spongy 
puddled iron, on the bed of a furnace; but all these attempts have failed, 
simply on account of the great waste of iron, a waste amounting to from 25 to 
50 per cent. in balling up the sponge. Indeed the loss in an ordinary pud- 
dling-furnace would probably be greater than 20 per cent. if the metal were 
not partly protected from the flame by the bath of cinder in which it lies; 
for in one instance in which the cinder accidentally ran out of a puddling- 
furnace during the balling up of the charge, leaving the iron exposed to the 
flame, I found the yield reduced from the average of 413 Ibs. down to 370 
lbs., showing an increased waste of 43 lbs., or over 10 per cent., due to the 
more complete exposure of the metal to the oxidizing action of the flame. 
In order to realize the theoretical result, a sufficient amount of oxides must 
have been supplied to effect the oxidation of the silicon and carbon of the 
pig iron, and to form a tribasic silicate of iron (8FeO, SiO’) with the silieie 
acid produced. 
The amount of oxide required may be readily ascertained. 
In taking the expression Fe’ 0+, the atomic weight of which is 
3x 28+4 x 8=116, 
while that of the three atoms of iron alone is 
3 x 28= 84, 
it follows that 
ae x 46=63°5 Ibs. 
of cinder or oxide of iron are requisite to produce the 46 Ibs. of reduced irom 
which were added to the bath. There must, however, remain a sufficient 
quantity of fluid cinder in the bath to form with the silicon (extracted from 
the iron) a tribasie silicate of iron, or about 60 Ibs., making in all 124 Ibs. of 
fettling, which would have to be added for each charge, a quantity which is 
generally exceeded in practice, notwithstanding the inferior results univer- 
sally obtained. 
There remain for our consideration the sulphur and phosphorus, which being 
generally contained in English forge pig in the proportion of from -2 to °6 
per cent. each, can hardly affect the foregoing quantitative results, although 
they are of great importance as affecting the quality of the metal produced. 
It has been suggested by Percy that the separation of these ingredients 
may be due to liquation. This I understand to mean that the erystals of 
metallic iron which form throughout the boiling mass when the metal ‘ comes 
to nature,” exclude foreign substances in the same way that the ice formed 
upon sea-water excludes the salt, and yields sweet water when remelted. 
According to this view, pig metal of inferior quality will really yield iron 
almost chemically pure, to which foreign ingredients are again added by me- 
chanieal admixture with the surrounding cinder, or semireduced metal. 
It may be safely inferred that the freedom of the metal from impurities 
thus taken up will mainly depend upon the temperature, which should be 
high, in order to ensure the perfect fluidity and complete separation of the 
cinder. 
Led by these chemical considerations, and by practical attention to the 
subject, extending over several years, I am brought to the conclusion that the 
process of puddling, as practised at present, is extremely wasteful in iron and 
fuel, immensely laborious, and yielding a metal only imperfectly separated from 
its impurities. 
How nearly we shall be able to approach the results indicated by the che- 
