132 



trated. It was brought to me from Scotland by Dr. Peter 

 Murray. 



The lower figure is similar to the uppermost, except being 

 externally in a state of decomposition, probably from expo- 

 sure to the atmosphere among the tumblers (as they call the 

 stones in common) in the river Tees, We received it from 

 the Rev. Mr. Harriman. Its redness is caused by the oxy- 

 genization of its iron. The outside is so far decayed as to 

 expose the divisions of carbonate of lime. These are called 

 septariums, of which there are various sorts j and besides 

 those of iron stones there are to be found some of marie of 

 various sizes, at Bristol, the Isle of Sheppy, Richmond, and 

 many other places. 



The sort in the upper figure is often so much admired after 

 being split that it is frequently cut and polished. The frac- 

 ture is conchoidal, earthy, and the component parts more 

 or less regular in their mixture, holding 



Iron, 



Clay, 



Lime, 



Silex, and 



Manganese. 



