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exactly in their nature is well known. Some difference, indeed, 
exists in the purity of these products ; but the same peculiar fetid 
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 bituminization, 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 bi- 
tuminous 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 separation 
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 
