Until Now
MedicineScience

Al-Razi

A physician distinguishes smallpox from measles and tells doctors to trust observation.

When
Duration
25 years
Known to
± 15 years
Era
Post-Classical, Holocene

Al-Razi, working in Baghdad around 900 CE, writes the first clear clinical differentiation of smallpox and measles, compiles the vast Comprehensive Book of Medicine recording his own cases including failures, and insists that experience overrides authority — he wrote a book titled Doubts about Galen. He also ran hospitals and is said to have chosen the site of one by hanging meat around Baghdad and building where it rotted slowest.

Just before

Just after