Iron . 
And, lastly, let the second variety of this genus of iron-stone be 
supposed to contain, silex 10, lime 7, clay 5 
To 4 troy ounces of the ore- 
add — — chalk 
3 bottle glass 
oi 
1 1 1 
1 
charcoal 
22 . 
or 1 920 grains, 
— 1680 
— 1440 
— 3,60 
5400 
Class of equalised mixtures, composed of, clay 7, lime 7, silex® 
r ~ 2i. 
To assay of this ore 4 troy ounces or 1920 grains, 
add 3 1- — — bottle glass — 
04- 
chalk 
charcoal 
1680 
1200 
240 
lO^. 
5040 
^ Such are the proportions requisite to obtain, from all the 
various iron-stones, an accurate assay ; the perfection of 
which is always indicated by the superior transparency of 
the flux, and the super- carbonatioir^ of the metallic but- 
ton. By scrupulously following these and similar pro- 
portions as the exigencies of the ore may point out, crude 
iron will always be obtained of the finest quality, carbona- 
ted beyond whatever is produced in the large way of ma» 
pufacture, and its surface covered with a beautiful carbu- 
ret of iron,f either in small shining specula, or in the state 
of a thin membrane. By a slight gradation of change in 
* That is, containing a portion of carbon or pure charcoal more 
than sufficient to produce perfect malleable iron, but producing 
uniform fusible cast iron. 
tBy a carburet of iron, is meant, iron combined with a large pro- 
portion of pure charcoal, or carbon. 
Malleable iron, is iron uncombined either with air or with carbon,, 
Blistered steel is iron with a small proportion of carbon. 
Fusible, hard, cast steel, contains still more carbon. 
Fusible smooth faced cast iron, still more than cast steel. 
T* C. 
