Hot Blast in the Smelting of Lead. 169 - 
cels of ashes ; it is sufficient, if it exists in ignitible quantities, 
and the particles are in ignitible proximity. It must be remem- 
bered, that we should add to this fine combustible matter the 
large coals and coarse powder separated by the sieve. 
_ It may be proper to add, that the wood we consume, is prin- 
cipally beech, sugar tree, and hickory. 
>» Thus it appears : 
1. That wood ashes contain a considerable quantity of finely 
divided coal. 
2. That the ashes may be sufficiently hot to ignite this coal, 
without themselves being at red heat. 
-3. That the progress of this ignition is slow ; and the cans ties 
tion may extend throughout a large mass of aaliaik without warn- 
ing, until it reach some inflammable material. 
__ I have assumed as true, for I suppose it will scarcely be denied, 
that the loss in the contents of the crucible, was owing to the 
consumption of carbon.* 
If my deductions from this humble, but I hope useful research, 
are correct, it is not safe to deposit hot ashes even in the middle 
of the largest bulk of cold ashes; for although the fresh ashes 
may not rest against wood, and nay appear securely remote from 
it, yet it is surrounded by and reposes upon combustible materi- 
als, which may, as in these two instances, conduct the invisible 
fire to inflammable bodies around, and box and pone be be in- 
eae in-sheets of flame.  , Joun. T. Prum 
une 12th, 1841. 
Arr. XX.—On the use of Hot Blast in the Smelting of Lead. 
_ Tue reduction of lead ore is effected in a great variety of fur- 
naces, many of them primitive and simple ; others requiring great 
expense in erection, and much practical experience in the man- 
agement, Yet these latter often give no better results than the 
original ‘log furnaces’ of our western pioneers. The great saving 
of labor and certainty of product effected by the furnace described 
meey induces the preparation of this article for publication. 
nor toexpel hygrometric moisture before weighing, which seems essenti 
‘the accuraey of the results.—Eds. mee 
Vol. x11, No. 1.—Oct.-Dec. 1841. 22 
