Gonverfion of Iron into Steel. 204 
fhrinkace and expanfion. The whole was expofed to 4 mo- 
derate white heat for nearly. an hour, and for forty minutes 
further a heat equal to the whole power of the furriace. The 
crucibles were fafely withdrawn, and, nen examined, the 
following facts prefented themfelves :— 
cc The outer crucible rernained entire; the fand, next, 
formed an entire veffel confiderably connected. The ‘feeond 
erucible was alfo found, but in the bottom of it I found an ir- 
regular metallic mafs, A {mall hole in the fide of the interior 
pot had allowed nearly one-half of the original weight of iron 
to pafs; the remainder of it, forming a very beautiful circular 
button, refted upon the bottom. The furface was cryftallifed 
in radii, fhooting from a central point upon the upper fur- 
face of the button. The colleétive weight was 1858 grains : 
lofs, 17 grains, = ;1, part the weight of the iron. When the 
metal was lodged i in the fmall crucible, the fides and bottom 
were glazed, as in the former experiment. 
III. “‘ The fame experiment was repeated with bottle 
glafs, and a fimilar length and degree of heat applied. The t¢~ 
duétion of the glafs was entire. Rheewixt the exterior and mid- 
dle crucible, the glafs appeared as an entire interpofed veffel, 
completely furrounding the two fmaller ones. Upon exa- 
minirig the interlor crucible, I found that the contaé of the 
bottle- -alats had fufed the cover of fire-clay fitted over the iron, 
and that the promifcuous fufion of the glafs and clay formed 4 
very fine dark-green tranfparent mafs, ‘beneath which lodged 
the metallic bution, The upper furface ftill preferved the 
acutenefs of the original angles upon one piece of iron; the 
others had refolved theists by fufion into a very fine i ingot 
of foft fteel with partially cryftallifed edges. The w eight of 
the whole was 1759 graing; lefs fon. when put in, five 
grains; ¢qual to ,:, + part of the whole.—I am convinced 
that by prolonging the heat ten minutes, the whole iron would 
haye entered into fufion. I would from this and other expe- 
Timents infer, that the iron is of more difficult carbonation 
‘when a fufed medium is made ufe of, than when either pure 
fand, pure lime, or clay, are ufed. 
IV. “ In order that no proof might be further wanting to 
eftablith the faét of the iron receiving the carbon from its fo- 
Dd2 lution 
