Iron . 
20 5 
following further remarks on this head are by Mr . 
Mushet—5 Phil. Mag. 128* 
When fine (No, 1.) or supercarbonated crude iron is 
run from the furnace, the stream of metal, as it issues 
from the fauld, throws off an infinite number of brilliant 
sparkles of carbon* The surface is covered with a fluid 
pellicle of carburet of iron, which, as it flows, rears itself 
up in the most delicate folds ; at first the fluid metal ap- 
pears like a dense, ponderous stream, but, as the collateral 
moulds become filled, it exhibits a general rapid motion 
from the surface of the pigs to the centre of many points ; 
millions of the finest undulations move upon each mould, 
displaying the greatest nicety and rapidity of movement, 
conjoined with an uncommonly beautiful variegation of 
colour, which language is inadequate justly to describe* 
Such metal, in quantity, will remain fluid for twenty mi- 
nutes after it is run from the furnace, and when cold will 
have its surface covered with the beautiful carburet of 
iron, already mentioned, of an uncommonly rich and bril- 
liant appearance* When the surface of the metal is not 
carburetted, it is smooth like forged iron, and always con- 
vex* In this state, iron is too rich for melting without the 
addition of coarse metal, and is unfit to be used in a cupo- 
la furnace for making fine castings, where thinness and a 
good skin are requisite* 
No. 4, or oxygenated crude iron, when issuing from 
the blast-furnace, throws off from all parts of the fluid 
surface a vast number of metallic sparks : they arise 
from a different cause than that exerted in the former in- 
stance. The extreme privation of carbon renders the me- 
tal subject to the combination of oxygen so soon as it 
comes into contact with atmospheric air. This truth is 
evidently manifested by the ejection of small spherules of 
iron from all parts of the surface ** the deflagration does 
notg however,, take place till the globule has been thrown 
