Aelius Galenus (Galen) – AD. 129-200:
- Galen was a prominent Greek-speaking Roman physician, surgeon end philosopher.
- Galen was the originator of the experimental method in medical investigation.
- He proved that urine was formed in the kidney.
- His most important discovery was that arteries carry blood. He explained the differences between venous and arterial blood.
- Galen explained the difference between motor and sensory nerves.
