KIMMERIDGE SHALE. 



183 



Comparative Table of the Value of the Illuminating 

 Matters contained in some of the Gas Coals and Cannels 

 Usually Employed for Gas Manufacture in England. 



The Blackstone has au advantage over common coal in requiring 

 half the time only in the production of an equal amount of gas, and 

 consequently a considerable economy of fuel. The supply at 

 Kimmeridge is inexhaustible, and the position of tlie beds favour- 

 able for working. Science has shown the value of these shales, 

 the volatile matter of the best bed (Blackstone) being 73 percent., 

 leaving 27 only solid matter. Their capacity for the production of 

 valuable oils and other ingredients must remain undeveloped until 

 a system of deodorization has been discovered in the chemist's 

 laboratory, and until then every attempt to bring the sliale into a 

 marketable condition must as hitherto end in disappointment. 



