In Origen we find the two words οὐσία (essence, or substance) and ὑπόστασις (individual subsistence) accurately distinguished.  Quoting the description of Wisdom, as being the breath (ἀτμίς) of the power of God, and pure effluence (ἀπόρροια) from the glory of the Almighty, and radiance (ἀπαύγασμα) of the Eternal Light Wisdom of Solomon vii. 25, quoted by Origen, Fragm. in Epist. ad Hebræos, Lommatzsch, V. p. 300.,” he says that “Wisdom proceeding from Him is generated of the very substance of God,” and adds that “these comparisons most manifestly shew that there is community of substance between Father and Son.  For an effluence appears to be ὁμοούσιος, that is, of one substance with that body from which it is an effluence or vapour.”