Cast Steel . 
379 
From this we see that when a proportion of charcoal 
equal to one fortieth part, and above, the weight of the 
iron is used, the latter always gains in weight ; but when 
a more sparing proportion is introduced, room is left for 
the exertion of another affinity upon the metal, and it con- 
sequently and invariably loses in weight proportioned to 
the diminution of the carbon. I have here further to re- 
mark upon the foregoing experiment, and upon the nature 
of experiments by synthesis performed in this way in ge- 
neral, that the results as to quality will differ materially 
when different portions of matter are used. So that an 
operator repeating the above experiments either in cruci- 
bles smaller or larger, or with a greater or less weight of 
mixture, would not obtain the same results. 
The formation of cast steel in the large way, founded 
upon the results of the foregoing experiments, affords an 
incontestable proof of this. In fusions of 18, 22, and 
25 lbs. of iron each, we are obliged to increase the dose of 
carbon considerably beyond that requisite in small expe- 
riments. To form steel equal to that obtained in experi- 
ment XIII. wherein one ninetieth of charcoal was used, 
one fifty-fifth part is requisite to be introduced. For 
steel similar to that in experiment XIV. one sixty-fifth 
and one seventieth part are used. For softer steel one 
ninetieth, whereas in the small experiment 1 one hundred 
twentieth part was sufficient. If in the manufacturing a 
small extra quantity of carbon is requisite, this is saved 
by the comparatively small loss sustained in the transmu- 
tation of the iron into steeh 
Many instances have occurred in the first fusion from a 
cast steel pot in the large way, where 251bs. of iron, and 
its requisite proportion of carbon, not exceeding one se- 
ventieth, have afforded an ingot of cast steel weighing 
24ibs. 12, 13, 14, and 15 ounces, being a loss equal to 
no more than 1 one hundred tenth, 1 two hundredth, 1 
