184 



Remarkable 

 fchiflus, 



from Iceland, 



contifting very 

 much of alder 

 leaves. 



External cha- 

 rafters. 



MR. hatchett's OBSERVATIONS 



formed, without the abfolute obliteration of the original 

 vegetable characters ; and, although I have fele&ed the 

 Bovey coal as an example, becaufe it is found in this country, 

 we muft recolleclthatfimilar fubftances, orftrata of bituminous 

 wood, are found in many parts of our globe; fo that the 

 example which has been more immediately chofen, is neither 

 rare nor partial *. 



The nature, however, of the various kinds of bituminous 

 wood, may in fome refpe&s be different ; but this I have not 

 as yet had the means of afcertaining ; I mail therefore only 

 ftate the fa&s refulting from experiments made on Bovey coal, 

 and more efpecially on a peculiar bituminous fubftance with 

 which it is accompanied. But, before I enter into thefe 

 particulars, it will be proper to mention a very remarkable 

 fchiflus, with which I was, fome months fince, favoured by 

 the Right Hon. Sir Jofeph Banks. 



§ HI. 



This fchiflus was found by Sir Jofeph, in the courfe of his 

 tour through Iceland, near Reykum, one of the great f pouting 

 hot fprings, diftant about twenty-four Englifh miles from 

 Hafnifiord ; but circumfiances did not permit him to afcertain 

 the extent of the flratum. 



The Angularity of this fubftance is, that a great part of it 

 confifts of leaves, which are evidently ihofe of the alder, inter- 

 pofed between the different lamellae. I do not mean mere 

 impreffions of leaves, fuch as are frequently found in many of 

 the flates, but the real fubftance, in an apparently half charred 

 irate, retaining diftinclly the form of the leaves, and the 

 anangement of the fibres. 



The fchiflus is light, brittle, of eafy oxfoliation, in the 

 tranfverfe fracture earthy, and of a pale brown colour; but, 

 when longitudinally divided, the whole furface conftantly pre- 

 fents a feries of the leaves ,which have been mentioned, 

 uniformly fpread, and commonly of a light gray on the upper 

 furface, and of a dark brown on the other; the fibres on the 



* Strata of bituminous wood are found in various parts of France, 

 in the vicinity of Cologne, in HefTe, Bohemia, Saxony, Italy, 

 and efpecially in Iceland, where it is known under the name of 

 Surturbrand. 



light 



