The living cell almost always contains, locked in its interior, the visible or invisible products of its physiological activity or its nourishment.

The more the relationships of the nitrogen-rich substances to the cell nucleus were recognized, the more the question of the arrangement of the nitrogen and carbon atoms in the molecule came to stand out.

A person with good character has invisible enemies. Visible Goodness, Invisible Enemies.

A magician makes the visible invisible. A mime maks the invisble visible.

The true mystery of the world is the visible, not the invisible.

What delights us in visible beauty is the invisible.