This monograph covers three broad topics of Mietek's outstanding career, Heavy Fraction and Asphaltene Characterization, The Boduszynski Continuum Model, and Distillation. In his pioneering work, Dr. Boduszynski postulated that petroleum is a continuum of compounds having a wide variety of structural and elemental compositions. The model proposed that, unlike conventional wisdom at the time, petroleum transitions from individual molecules to high molecular weight components (i.e., asphaltenes), and that the molecular composition of petroleum is a continuously variable series of molecules without abrupt transitions. His work in this area forms the basis of the current model of petroleum. He predicted that the high-boiling residue after distillation was, in fact, a continuous extension of low molecular weight components, rather than (as was then thought) high-molecular weight "polymers."