June 21, 2016:
(1) (1535) German physician, botanist and traveller Leonhard Rauwolf is born. He is remembered for his travels through Mesopotamia in 1573-1575 where he searched, and later wrote about, herbal medicines.
(2) (1811) Italian physicist and neurophysiologist Carlo Matteucci is born. He is known for his work on nerves and their use of electricity.
(3) (1880) American psychologist and pediatrician Arnold Gesell is born. His research focused on child development and proposed that mental conditions were not attributable to one cause; he suggested they were the result of genetics and environmental factors.