The contribution made by French physicist Jean Baptiste Perrin to the study of atomic physics was of the most fundamental kind: he helped to prove that atoms and molecules exist. This achievement, which quantitatively extended the original observations of botanist Robert Brown on the movement of pollen grains in water, and put scientific substance into Albert Einstein 's exquisite mathematical equations describing the distribution of those particles in solution, won for Perrin the 1926 Nobel Prize in chemistry.

Perrin was born in Lille, France, on September 30, 1870, and raised, along with two sisters, by his widowed mother. His father, an army officer, died of wounds he received during the Franco-Prussian War. The young Perrin attended local schools and graduated from the Lycée Janson-de-Sailly in Paris. After serving a year of compulsory military service, he entered the Ecole Normale Supérieure in 1891, where his interest in physics flowered...