207 



agree exactly in their nature is well known. Some difference, in- 

 deed, exists in the purity of these products ; but the same peculiar 

 foetid oil, and the same volatile acid, which are yielded only by 

 substances of this class, are produced in both cases. 



Equally powerful evidence appears to be derived, also, from the 

 fact of pure bitumen being found existing together with peat, in 

 such a mode of combination, as will warrant the conclusion, that 

 the peat has partially passed into a more perfect state of bitumini- 

 zation, so that a portion of it has become perfect bitumen. 



In some parts of Aberdeenshire, Dr. Anderson informs us, there 

 is found a certain kind of peat-moss, which when formed into peats 

 in the common way, are found to be more tender and brittle than 

 usual, so as to break down, during the process of drying, into irre- 

 gular lumps, called clods. When one of these clods is thrown into 

 the fire, it soon kindles, and burns with a clear bright flame, much 

 resembling that which would be produced by a lump of tallow or 

 butter, in the same circumstances ; these are therefore called creeshy, 

 i. e. greasy clods, though they discover no degree of unctuosity to 

 the sight, or smell, or feel. One of these clods continues to flame 

 for a long time ; and the use that is made of them by the natives 

 is to throw one clod into the fire at a time, for the purpose of giving 

 light, and another to supply its place when it is exhausted. This 

 kind of peat, the Doctor acquaints us, is very rare. 



The increased degree of inflammability observed in the peat 

 which is here described, can only be accounted for by the presence 

 of bituminous oils ; as the clear bright flame, resembling that of 

 a lump of tallow or butter, evidently points out. The presence of 

 any unctuous matter does not indeed appear to be pointed out by 

 any other sensible characters ; although, perhaps, even its separa- 

 tion might be obtained by the adoption of proper means. 



Monardes, an old Spanish writer on. medicine, says, that in 

 Collao, a province of Peru, there is a tract where neither tree nor 

 plant grows, in consequence of the earth being of a bituminous, 



