Portal:History of science/Selected anniversaries/June 15
- 763 BC - Assyrians record a solar eclipse that will be used to fix the chronology of Mesopotamian history.
- 1667 - The first human blood transfusion is administered by Dr. Jean-Baptiste Denys. He transfuses 12 fluid ounces (350 mL) of sheep blood to a 15-year-old boy. The boy later dies and Baptiste is accused of murder.
- 1752 - Benjamin Franklin demonstrates that lightning is electricity.
- 1755 - Birth of Antoine François, comte de Fourcroy, French chemist (d. 1809)
- 1768 - Death of James Short, Scottish mathematician and optician (b. 1710)
- 1915 - Birth of Thomas Huckle Weller, American virologist and Nobel Prize laureate
- 1917 - Birth of John Fenn, American chemist and Nobel Prize laureate
- 1917 - Death of Kristian Birkeland, Norwegian physicist (b. 1867)
- 1941 - Death of Otfrid Foerster, German neurologist (b. 1873)
- 1971 - Death of Wendell Meredith Stanley, American chemist and Nobel Prize laureate (b. 1904)