Prof. Johnson’s Report on the Bradford Coal Field. 143 
regular texture, being sometimes uniform, and at others, conglomerated 
of clay, and fragmentary masses of iron ore with a calcareous cement. 
The weathered specimens are commonly of a dark brown color approach- 
ing to black, and are obviously changed from the character of carbonates 
of the protoxide, to hydrated peroxides of the metal. As in passing 
through this change some portions of earthy matter are commonly sepa- 
rated and washed away, the ore in this latter condition is richer than in 
its previous state of a carbonate, the Joss in carbonic acid and earthy mat- 
ter being greater than the gain in oxygen and water.. This remark will 
also apply to the other carbonates, as compared with the hydrated parts of 
the balls or blocks of ore. In the process of decomposition the hydrate 
is often accumulated in the form of a shell, more or less regular upon the | 
exterior of a nucleus of spongy earthy matter, nearly destitute of j iron ; 
such shells are occasionally found in the bed now under consideration. 
The following are the results of my examination of this ore 
. 1. A specimen of this ore from near the gutcrop: was selected, 
having the elongated kidney form, a shell enclosing white earthy matter, 
its color in recent fractures of the shell, dark brown. 
“Its specific gravity was 3.2264 at a temperature of 56° Fah. It lost 
at 320°, 2) per cent. in water; and by the application of a white heat for 
some time, the combined water expelled, amounted to 21.1 per cent. 
“ An assay of this ore in the dry way, without any admixture whatever, 
gave of metallic iron, 32.5 per cent., and of earthy cinder, 29.8 per cent.; 
oxygen, 14.1 per cent.; water, 23.6 per cent.; of which 2.5 per cent., as 
above stated, was uncombined. 
“The pig metal obtained in this assay was of a light gray color, and 
rather brittle. This trial proves that the ore will not actually require the 
use of any flux for its reduction. 
“ No. 2.. This sample was taken from under the fall, below the lower 
bed of coal and was in the original state 6f-the «mineral. not changed to 
hydrate, as in the preceding example. Its color is light blue, its texture 
amorphons, or foliated, its fracture irregular ; some shining particles, 
probably pyritous, are distributed through it. 
“Its specific gravity is 3.0549. At 320° it Toses 0.5 per cent. It lo- 
ses when heated to whiteness, 10.5 per cent. of carbonic pay with prob- 
ably a little sulphur. The amount of iron contained in this ore, was 24.2 
per. cent. ; of earthy materials, 49.2. e state in which the iron exists 
in this ore is doubtless that of a proto-carbonate. The cinder was brittle, 
of = green color, and perfectly fused. 
“ No. 3. This ore was taken from the fifth ply of a bed about 10 feet 
in thickness, and at an elevation of 1080 feet above the Susquehanna, and 
64 feet above the 371 inch bed already described. The ply is 18 inches 
thick. 
