And this was the secret of much of his altered behaviour, of his mysterious absences, and more than all of his frequent pale looks and irritable moods.  The discomfort he felt when the cigarette was actually between his lips was nothing compared to the very disagreeable sensations that always followed.  He would feel sick and dizzy, and suffer from a headache for hours afterwards; but as soon as he recovered he would return to the charge and refuse to acknowledge himself beaten.