YORKSHIRE ALUM WORKS. 245 



of a double convex fofm. Two or three species of nautili 

 occur, these last are rarely found in a perfect state. The 

 belemnitae are very abundant. The trochita? are found, but 

 not i, great abundance. The fossil vertebra: and other 

 bones of animals are frequently found, the form of which 

 has been but little devauged. I found a part of the o& 

 fenioris of an animal with the trochanter and the foramina 

 very evident ; the part where it was broken measured 4-2 

 inches in diameter, so that its length when in a perfect state 

 may be inferred to have been at least 4 feet. The sbells are 

 numerous, of various puecies, and some of these are in a state 

 of ^reat preserva'tj'^'i. 



Naphtha is soaietimes found enclosed in an ironstone of a 

 globular form. Jet is found in abundance, frequently the 

 bituminization is not pe'fect, and one part of the substance 

 presents us with pure jet, while the other is still in the state 

 of pet'ified wood: in this state it is most commonly found, 

 in breaking up large masses of iron ore. 



There is an immense quantity of red iron ore, found in 

 strata, at the depth of about 200 feet from the top of the 

 aluminous strata : the thickness of these seams of ore vary 

 from about a few inches, to about 2 feet. In some situf- 

 tions four or ifive of these strata are found alternating with 

 schistus. The specific gravity of this ore is from 3'4 to 4*2. 

 It.contains, upon analysis, from 30 to 60 per cent of iron, 

 combined with oxigen, yjhosphoric acid, lime, alumine, and 

 silex. Considerable quantities of this ore are collected, and 

 carried down to ISewcastle, and smelted at the founderies 

 erected there for this purpose. 



Sulphate of lime is found crystaUized in radiated and 

 striated crystals; but this is at considerable depths in the 

 i'ocks. 



Carbonate of lime is generally found crystallized, filling 

 -the veins which intersect the aluminous schiiptus. The thick- 

 ness of these veins of crystallized carbonate of lime is gene- 

 rally O'o of an inch, and they are of considerable depth. 



An ingenious landscape painter, and a good mineralogist, New variety of 

 Mr. Bird, of this place, has recently discovered a new vari- ^^^"^ ^o'lk. 

 ety of alum rock, containing silex and sulphur, with oxide of 

 -iron. This rock effloresces on exposure to the atmosphere, 



and 



