COAL-FIELD OF CLACKMANNANSHIRE. 127 



and each particular stratum which accompanies them. 

 I then described and exhibited the various organic 

 remains which are found in the strata, the most re- 

 markable of which are, the oysters contained in the 

 clay-ironstone, and the forms of exotic reeds in the 

 slate-clay. The impressions of minute plants are in 

 vast profusion. 



There is one remark regarding the stratification 

 deserving particular attention, which is, That the 

 immediate stratum or pavement on which the beds 

 of coal rest, is almost, without exception, a greyish- 

 black rock or fire-clay, which, when made into 

 bricks, strongly resists the effects of fire. This 

 fire-clay is found from the thickness of the tenth of 

 an inch to several fathoms. In no instance have I 

 seen the coal in direct contact with any other of the 

 strata, excepting where the coal was intersected 

 with numerous slips and dislocations : and this 

 particular observation I have found to hold, in 

 all the coal-fields I have examined in Great Bri- 

 tain. When this fire-clay is of any considerable 

 thickness, it abounds with the remains of the vege- 

 table kingdom, with a few kidney-shaped pieces of 

 clay-ironstone. 



The various strata represented in the section, lie 

 in a very regular manner ; and we very seldom find 

 one of these strata passing gradually into the other 

 adjoining. In general they are distinct and easily se- 

 parated at the line of junction, named by miners 

 the parting. This parting is sometimes composed 



