The petrographical analyses of the coal constituents separated by float-and-sink method were compared with densities, proximate analyses, ultimate analyses, calorific values and magnetochemical constants.It was suggested that the petrographic constituents (vitrite, clarite, durite etc.) by no means represent each specific structural constitution, but very complicated mixtures of inorganic ashes and organic molecules, these fundamental components being presumably characteristic of the coal species, and that the current definitions of coal petrog-raphy under the microscope would be due only to the relative proportions as well as binding states of these constitutional molecules and ashes.Thus, even the so-called pure vitrite could not be recognized, as purely organic, agglomerate, but appeared in practice to comprise a certain amount of inorganic ashes.
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