The Summary of Physics Restored

191How much this spiritual food contributes to animal life is shown by continual breathing, or drawing in outside air, which compels even an ordinary person to acknowledge it. Nature did not skilfully construct her bellows near the heart merely to cool it, as physicians commonly suppose. She also made them so that through their repeated fanning they might breathe in the ethereal air and offer the heart ethereal spirits to drink. By the breathing in and reception of these, the vital spirits are restored and multiplied.