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impressed with vegetable forms, which you will there find in great 
abundance. These you will frequently perceive to be so perfect, 
that our sceptical friend Wilton will no longer be able to hold out : 
he must, at last, give up the opinion, to which he has so long, and 
so pertinaciously, adhered, that these are the productions of the 
wanton and fanciful sports of nature ; and must admit them to have 
derived their forms from antediluvian vegetable remains. With the 
hope of securing a convert, and of augmenting the pleasure which 
you must all experience, in the contemplation of these wonders of 
nature, I shall, in this Letter, offer you a few observations on their 
origin and formation. 
In most of the strata which are found immediately above coal, 
decided marks and impressions of vegetables may be discovered: 
but it seldom happens, that any traces appear on the strata, on 
which the coal lays. A considerable difference also exists, between 
the several kinds of strata which lay immediately above coal, as to 
the quantity of vegetables they contain, and the strata in which they 
are found. The strata which, most commonly, form the matrices 
of these vegetable remains, are of the schistose kind ; sometimes of 
a bluish grey colour, nearly verging on black ; sometimes of a dark 
brown, but most frequently of a jet black. In these schisti, the 
impressions are often disposed as smooth and flat, as if the plants 
had been carefully placed between the leaves of an herharium. 
Where this is the case, and the vegetable remains thus form a sepa- 
rating medium of considerable extent between the laminae of the 
schist, the complete separation of these laminae is easily effected, by 
a small well-directed force ; and the impressions of the vegetables 
are thereby clearly displayed. 
The most beautiful specimens of this kind, are those, perhaps, 
which are found in the coal-pits of Lancashire. Dr. Woodward 
describes several fine specimens which he obtained from the Cannel 
coal-pits, near Haigh, in Lancashire. The colliers there, he says. 
