the char ad eristic Properties of l^annint 109- 



process, therefore, independent of these circumstances must 

 have taken place, in order that the vegetable substances, such 

 as ligneous matter, resin, oil, &c. should become coal and 

 bitumen. 



In a former paper I have endeavoured to show that these 

 changes are progressive, and, having noticed the perfect state 

 of the submerged wood at Sutton and other places, 1 next 

 described the qualities of the ditTerent kinds of Bovey coal, 

 which exhibit a series of gradual changes from bodies which 

 retain the vegetable structure and texture, although imper- 

 fectly carbonized, to others in which almost the complete 

 characters of the common mineral or pit coal are absolutely 

 established. 



From the alder leaves in the schistus from Iceland I ob- 

 tained extractive vegetable matter ; and although this was 

 not afforded by the varieties of Bovey coal, yet these, as 

 well as the alder leaves, and also a coal like that of Bovey, 

 found in Sussex, at Newick Park, (an estate belonging to 

 sir Elijah Impey,) and also the surturbrand of Iceland, 

 yielded some resin, which at Bovey is likewise found ia 

 distinct masses, intermixed with the strata of coal, and com- 

 bined with asphaltum, in the proportion of about 41 parts 

 of the latter with 55 of resin *. 



Now, exclusive of the other vegetable characters which 

 are so evident in many of the varieties of Bovey coal, of the 

 Sussex coal, of surturbrand, &c. &c. the presence of resin 

 must be regarded as a strong fact; for this substance has al- 

 ways been attributed to the organized bodies, particularly to 

 those of the vegetable kingdom, and I do not know of any 

 instance, previous to my own experiments, in which resin 

 had been discovered as constituting part of any of the dif- 

 ferent species and varieties of coal. 



From the external vegetable characters possessed by the 

 Bovey coal, the Sussex coal, the surturbrand, and many 



in ilie surturbrand or fossil wood of Iceland, and which Scheuchzer remarked 

 adso in tlie fossil wood fouiidin tlic neighbourhood of the lake of Thun, in 

 Switzerland." Phil. 'I'rans. 179!), p. 147. 



* Obnervations on the Chanj^e of some of the proximate Principles of Ve- 

 getables into Bitumen. Phil. Trans. 1804, p. -lOJ. 



3 Others, 



