304 
[Assembly 
Yellow Ochre. 
From trials which have been made with tliis form of ferruginous clay- 
in the porcelain furnace, it is found absolutely infusible. It appears, 
therefore, for no analysis has yet been made of the ochre, that the 
quantity of iron is not sufficient to operate as a flux, neither is there 
a mixture of silex, as it would in that case be fusible. The most re- 
markable character which appears in this ferruginous clay is, the bright- 
ness of its colour. On exposure to heat, it assumes a lively brown, 
which is superior to the common Spanish brown. We have, therefore, 
not only a fine clay, or one which may be employed for fire-bricks, 
crucibles, &;c. but one which furnishes a superior pigment. The com- 
position is evidently that of the porcelain clays, with the addition of 
iron, in a sufficient quantity to impart to it a fine yellow hue, and also, 
by burning, a bright reddish brown. It is now used in the Jersey City 
Works, and is found superior to any hitherto employed. 
Confirmation of former views, in relation to the pu7'ity of the Ore of 
the Sandford Vein. 
Since the preceding account of the Sandford vein was written, an ex- 
cavation has been made in it about its centre. This excavation is 10 
feet in perpendicular depth, and about 20 feet wide, and about 30 in 
length. After the removal of the surface, the whole excavation pre- 
sents entire layers of ore, without a particle of rock, a large portion of 
which is of the soft or granular kind, a variety much esteemed and 
sought for by bloomers, inasmuch as it requires no washing, and makes 
iron rapidly in the common forge. Without occupying farther time 
and space in the description of this or the other veins, I shall merely 
remark, that this improvement in the purity and goodness of the ore, is 
in accordance with the every day experience of miners. 
