During the eighteenth century, as it became clear that metals gained mass when they were oxidized, phlogiston was increasingly regarded as a principle rather than a material substance.
خلال القرن الثامن عشر، وأصبح واضحًا أن المعادن تكتسب كتلة عندما تتأكسد، إعتبر فلوجيستون بشكل متزايد على أنه 'مبدأ' بدلاً من جوهرا ماديا .