Anthracite. 



281 



European geologists have satisfactorily traced the progress of veg- 

 etable matter from the living vegetable into peat, thence to bituminous 

 coal. They have, also, rendered it probable, that anthracite is only 

 another step in the process ; although some of them still doubt the 

 vegetable origin of this variety of coal. And in regard to plumbago, 

 the predominant opinion I believe is, that it has been produced from 

 elementary, rather than organized carbon. Dr. Macculloch, however, 

 says, that " the coal of secondary origin, containing vegetable remains 

 is converted into plumbago by the influence of trap; as wood has been 

 in my experiments, and as coal is, daily, in the iron furnaces ; so that 

 even the plumbago of the primary strata, no less than the anthracite, 

 might as well have originated in vegetables, as that each of them 

 should owe an independant origin to elementary mineral carbon."* 



Elie de Beaumont has also given an account of anthracite, which is 

 associated in the Alps with graphite in clay slate, reposing on lias. 

 " This graphite," says he, " is found in a bed of argillaceous slate 

 which contains vegetable impressions, similar to those which accom- 

 pany other deposits of anthracite in that country. This slate exhib- 

 its on the surface of these impressions minute veins of anthracite, and 

 it forms a part of a series, in which, both above and below, workable 

 anthracite shows itself : all which proves that the graphite is only a 

 modification of the anthracite. This modification appears to be con- 

 nected with the presence of certain feldspathic rocks, which are prob- 

 ably only the ramifications of a huge mass of feldspar situated near."f 

 If I mistake not, the circumstances under which these varieties of car- 

 bon occur in this country, throw some light on these enquiries, and 

 render probable the suggestions of Dr. Macculloch. The great num- 

 ber of vegetable remains found in connexion with the Pennsylvania 

 and Rhode Island anthracites, must, it seems to me, satisfy every 

 reasonable man of the vegetable origin of this mineral in these in- 

 stances. But a plumbaginous substance occurs with the Rhode Isl- 

 and coal, and the coal itself seems to be passing into plumbago. Still 

 more near to plumbago do we find the Worcester anthracite, and a 

 part of the bed is probably real plumbago. Here, however, we find 

 no vegetable remains, retaining their organized form, because the rock 

 belongs to the primary class ; being for the most part a bastard kind 

 of mica slate. Advancing one step farther, we find in the gneiss rock 



* System of Geology vol. 2. p. 297. 



t Annals des Sciences Naturelles, Tome 15. (1828.) p. 377. 

 36 



