Lisa A. Romankiw John R. Evans Patrick G. Hatcher 1985 Coalified wood was examined by SEM and CPMAS**1**3C NMR to delineate chemical and physical alterations responsible for gelification. Early coalification selectively degrades cellulosic components, preserving lignin-like components that are eventually transformed to coal. Cellular morphology persists until the chemical composition becomes uniform, at which point the cells coalesce under compaction and gelify. application/pdf en Pergamon Press GELIFICATION OF WOOD DURING COALIFICATION. text