a Vein of BLuminous Coal in the Islafid ofCitha, 165 



surfaces of the divisions or partiiifrs of the coal are brilliantly 

 shining. Its cross fracture is rough, and has a glimmering 

 pitchy appearance. 



We have now to advert to an external character which is 

 very common, and which, in fact, is of constant and universal 

 occurrence in this combustible; a feature which distinguishes it 

 from all other coals which have come to our knowledge in 

 any (juarter of the globe. Its horizontal fracture or surface is 

 marked, as shown in figure 2, by numerous concentric, or, 

 more properly speaking, excentric rings of various sizes, from 

 a twentieth part of an inch to a foot in diameter. They are 

 perfectly regular and uniform in shape, smooth, shining, con- 

 choidal, resembling the impressions made by a seal in black 

 wax, or when first seen, appear like the casts of the flat valves 

 of some shells. i 



This coal is exceedingly Fig. 2. 



friable, breaking into small Form of thelmpressions on the laminae 

 fragments under the ham- 

 mer. Its powder is brown, 

 and when pressed under the 

 pestle, takes a polish, like 

 certain resinous substances. 

 It burns with much flame 

 and a great deal of smoke ; 

 melts, and gives a light vo- 

 luminous cake, which, when 

 incinerated, leaves compara- 

 tively a small proportion of 

 cinders or ashes. 



The following analysis, 

 which was made by one of us, 

 gave per cent, as follows : 



Volatile matter (gas, &c.) 63*00 



Carbon \ 34-97 



Ashes and cinder 2*03 



of the Coal of Casualidad. 



100- 

 The foregoing examination of this bituminous coal (for we 

 see no reason to separate it from combustibles of that class) 

 fixes definitively the respective proportions of its component 

 parts ; consequently it determines the applications to which 

 that combustible would be the best adapted. Its quality of 

 burning with a long licking flame gives it obvious advantages 

 for evaporating, heating surfaces, &c., over man}' descriptions 

 of fuel which contain a smaller quantity of volatile matter. 

 For the generation of steam power, for boiling or concen- 



