it began as a mistake.

The Black Death Plague Doctor: 

A plague doctor was a special medical physician who saw those who had the Bubonic Plague. In the seventeenth and eighteenth centuries, some doctors wore a beak-like mask which was filled with aromatic items. The masks were designed to protect them from putrid air, which (according to the miasmatic theory of disease) was seen as the cause of infection. The protective suit consisted of a heavy fabric overcoat that was waxed. A wooden cane pointer was used to help examine the patient without touching.

(via vintagegal)