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Transactions of the Sotietij. 



and will take first the " Shallow Seam " of Cannock Chase, for 

 samples of which I am indebted to Mr. A. H. Barnard, of Chase 

 Town. 



Section of the Shallow Sfam. 



The seam is divided by partings into three distinct beds of coal. 

 In the top one, called " Hardens," two layers could be defined by 

 degrees of lustre, a bright and a dull. In the latter minute specks 

 were detected, somewhat resembling iron rust. By pohshing a 

 portion, the specks were distinguished as macrospores, figs. 1 and 2, 

 plate VIII., and a microscopic section shows the spaces around to 

 be filled with microspores (fig. 3). In the bright layer spores 

 were also detected, but they were much less numerous, and 

 there was present, as the chief constituent, a structureless substance 

 to which I have given the name of hydrocarbon. Vegetable tissue 

 was also recognized. 



Between the top and middle beds of the seam comes a carbona- 

 ceous parting locally termed " spire," and in which was a quantity 

 of pyrites. The middle or bright coal is a cannel. It readily 

 polishes, and when this is done a few macrospores can be made out. 

 The mass of this coal is made up of the substance to which I have 

 referred under the name of hydrocarbon, and before proceeding 

 further it may be as well to say something respecting this substance. 

 It is generally structureless and presents a dark brown appearance, 

 and is an important constituent in the composition of some coals ; 

 the so-called bituminous varieties being the richest in the possession 

 of it. I believe it to constitute what has erroneously been termed 

 bitumen. I need, however, hardly say that coal contains no bitu- 

 men whatever, and the sooner we strike so misleading a term, as 

 applied to coal, out of our vocabulary the better. 



Below the " Bright Coal " is a second parting of " spire," with 

 an arenaceous stratum running through the centre. 



