146 Prof. Johnson’s Report on the Bradford Coal Feld. 
It loses by calcination, - - - - 22.7 per cent. 
And gives of iron, - - i. oy 20:4 bak 
Earthy matter, - - - - ¢ 867010 
Volatile matter, oxygen, &c., > - es Hen? 
; 100.0 
“No. 7. This is the middle ply of the ore in the bed near Mason’s 
coal mines. It is found in a stratum of kidney-shaped balls, five inches 
thick. Its color, in fresh fractures, is dark bluish gray, surface splintery, 
occasionally giving conchoidal fractures, compact, and of uniform texture, 
Its specific gravity is 3.763 
Heated to 320°, it loses but - - - 0.2 per cent. 
Fully calcined, it loses in addition, - =; 298% 
Treated with pure lime, it yields at once malleable 
iron with a little oxide, - - | ts 
Earthy impurity, Sere - => § Se 
Oxygen, - Mo.“ 
* This stratum affords the siehest ore hich has fallen under my notice 
from any coal formation, for the sample above analyzed was not a surface 
specimen reduced to the state of a hydrate, but a well marked solid car 
bonate, with only a thin surface coating of hydrate. It will probably be 
found expedient to work it with either No. 1 or No. 3, or with both to- 
gether, in order to obtain a good soft pig metal. 
“No. 8. This ore is found in the upper of the three bands already 
mentioned. It generally presents the appearance of nearly square blocks, 
or brick-shaped masses, seven inches thick. Above this ply of ore, is @ 
course of balls separated from it only by a few inches of friable sandstone. 
A coarsé quartzose grit lies a little higher. The aspect of this ore, when 
it has not undergone any decomposition by atmospheric influences, is 4 
dark gray color, a rather rough surface, and a mixture of shining metallic 
particles interspersed through the body of the ore, as well as on its SUrI- 
face. Its specific gravity is 3.4783. . 
At 320°, it loses, - 0.4 per cent. 
At a white heat it undergoes decomposition, = 
loses, O58 ss 
It dietia withont difficulty, and yields of pigiron, 43.3 
Tt contains of earthy ea bee into a ald 
white cinder, - 64. 
And the oxygen is, - - . bean & = 
~ 100.0 
= a The pig metal obtained was soft, gray and tough. There is no doubt 
mind, that this ore will be found to work well either by itself, oF 
