Mine ventilation and glasses: what they have in common

1. Step 1. Mine ventilation — is used in — Coal mine. Airing the workings.
2. Step 2. Coal mine — is used in — Coal. Extraction.
3. Step 3. Coal — is material for — Synthetic dye. Aniline from coal tar.
4. Step 4. Synthetic dye — is used in — Gram staining. Aniline dyes.
5. Step 5. Gram staining — uses — Microscope. For microscopy.
6. Step 6. Microscope — evolved from — Glasses. Spectacle makers assembled the first microscopes.

Open Evothings