m^ 



INTRODUCTORY ESSAY. 



11 



paste of the same kind of clay as that of which the 

 bricks are made. Upon the application of heat^ the 

 whole becomes consolidated into one mass; and fur- 

 naces of this description 3 if the bricks be previously 

 well cured by exposure to the air^ will last many 

 yearSj although subjected to the very strong fires 

 employed in the manufacture of sugar. 



Masses of the calcareous formation, some of 



considei-able magnitude, are to be seen in Scot- 

 land. These are eitlior projections from the liigh 

 ridges, which have never been covered by the clay 

 formation ; or they are rolled fragments, of which 



there is an endless number. Some of these are at 

 a great distance from their origiual situation, to 

 which, however, they can gener^dly be traced. I 

 liave dib'geuily searched for the remains of animal 

 or vegetable substances, but have never been able 

 to find any in the minerals of this district. 



I cannot omit taking notice in this place of an 

 extinguished pseudo-volcanic hill, situate on tl)c 

 windward coast, in one of the estates belonging to 

 the Society for the propagation of Christian know- 

 ledge. It is to this day very properly denominated 

 the Burnt HiU^ and is mentioned by Hughes, as 

 having been accidentally set on fire by a slave, and 

 as having continued to burn for the space of five 

 years. It consists entirely of highly burnt clay, 

 and earth shsgj and the neighbourhood abounds 

 in bituminous shale, and mineral oil. 



