On the Formation of Coal

Abstract

The previous theories of the formation of coal have never explained satisfactorily that there are two different kinds of bituminous coal, namely one has the caking property and the other not; however, from the above described observations, the following conclusions may be obtained, because it seems that there is the possibility of the formation of the caking component only when cellulose is in the original materials. Namely, caking coal should have been formed under such conditions, that there were still comparatively large amounts of the decomposition products of cellulose during the huminification processes and the degree of coalification was suitable; on the other hand, when cellulose was decomposed and diminished severely beyond a cirtain degree, sintering or non-caking coal should have been formed. In another words, Fischer's lignin theory may be able to explain only the extreme, or rather exceptional case of the coal formation, and as the general view of this subject the cellulose theory, that not only lignin but also cellulose are the important original material of natural coal, seems in any case to be reasonable.