286 
Between the top and middle beds of the seam came a 
carbonaceous parting locally termed ‘‘Spire,” and in which was 
a considerable quantity of pyrites. The middle, or “ Bright 
Coal,” is a true cannel. It readily polishes, and when this 
is done a few macrospores may be distinguished. A micro- 
scopic section shows the presence of microspores, but they 
were scarce, compared to the quantity in the upper bed. The 
main mass of this coal was made up of the material which 
I referred to under the name of hydrocarbon, and before pro- 
ceeding further it may be as well to say something respecting 
this substance. It is generally structerless and presents a 
dark brown appearance. It is an important constituent in the 
structure of some coals; the so called bituminous varieties 
being the richest in the possession of it. I believe it to 
consitute that which has erroneously been termed bitumen. 
I need, however, hardly say that coal contains no bitumen 
whatever, and the sooner we strike such a misleading 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. 
Next comes the “ Best Coal,” or bottom bed, which is the 
chief one of the seam. The lustre is fairly bright which 
appears to be due to the numerous thin bright layers which 
travers the dull portion. In the dull layers macrospores and 
microspores were numerous, but in the bright hydrocarbon 
was the chief constituent. 
The variations in the beds which constitute the “ Shallow 
Seam,” illustrate the importance of investigators taking a 
complete stratagraphical section of each seam to which they 
turn their attention. The top bed is not a freely combustible 
fuel, but when combustion has fairly commenced considerable 
heat is generated. The “Bright Coal” is mainly worked for 
gas purposes, and the “Best” for gas and household use. A 
mixture of the ‘“ Hardens” and “Best” beds makes an 
economical house coal, but requires a good draught. 
I next take the Welsh “Four Feet Seam,” celebrated 
throughout the world for its smokeless properties. For samples 
