Peter Cooper Hewitt, an American, invented the first commercial mercury vapor lamp in 1901. It was the first of its kind to have an acceptable color of light and it is the blueprint for modern fluorescent light fixtures.
Peter Hewitt’s first mercury-filled fixtures, developed in the late 1890s, were used for lighting in photography studios because the light the fixtures produced was unappealing for home use. The first commercial product was developed when he teamed up with George Westinghouse to form a company.
The invention was developed from earlier discoveries by German physicists Julius Plücker and Heinrich Geißler. These discoveries showed that passing an electric current through a glass tube with small amounts of gas could produce light.