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effecting the reduction of certain earths into their respec- 
tive metalloids, especially silicium, and in that state that 
they become alloyed with the iron. 
The puddling furnace is a reverberatory furnace. The 
man who works it is called a puddler, and is assisted by an 
under hand. The bottom and sides of the improved puddling 
or boiling furnaces are made of cast iron plates, which are 
preserved from fusion by a thick coat of protoxide of iron. 
It is a great desideratum to find some more refractory sub- 
stance for the bottom of these furnaces. A very great num- 
ber of unsuccessful experiments have been made. I tried 
once to make a bottom of fire brick, but it wore away rapidly 
at the joinings of the bricks. I then attempted to make the 
bottom of a single huge brick, but although great precautions 
were taken in the admixture of powdered coke and in the 
drying, I did not succeed in getting my brick made without 
numerous small cracks, from the unequal contraction of so 
large a surface of fire clay. Platinum might probably 
answer, if it should ever become abundant and cheap 
enough. Hot blast pigs have a much greater tendency 
to destroy the bottom of the puddling furnace than cold 
blast pigs. I once tried a sample of hot blast pigs, which 
destroyed the bottom of the furnace so rapidly, that a hole was 
burned through, and the melted iron ran down into the ash 
pit. It was this property of hot blast iron of destroying the 
bottoms which rendered unsuccessful my attempt to intro- 
duce an improved description of puddling furnace at the 
large iron works in the south of France, in 1837. We 
account for this by guessing that hot blast iron contains 
silicium, and that, acting on the protoxide of iron which 
protects the iron plate of the puddling furnace, converts it 
into an extremely fusible matter, namely, silicate of iron. 
The operation of puddling is one which requires great care 
on the part of the workman in reference to the quality of the 
