Carl Auer von Welsbach (9 September 1858 - 8 April 1929) was an Austrian scientist and inventor who had a talent for not only discovering advances, but turning them into commercially successful products. He is particularly well known for his work on the rare earth elements, which led to the development of the flint used in modern lighters, the gas mantle which brought light to the streets of Europe in the late 1800s, and the development of the metal filament light bulb.
Welsbach was born in Vienna, son of Therese and Alois Ritter Auer von Welsbach, director of the Imperial printing office (Staatsdruckerei) in the days of the Austro-Hungarian Empire. Carl went to secondary school in Mariahilf and Josefstadt before graduating in 1877, and joining the Army as a second lieutenant.
In 1878 he entered the University of Vienna, studying math, general chemistry, engineering physics and thermodynamics. He then moved to the University of Heidelberg in 1880, where he continued his studies in chemistry under the direction of Robert Bunsen (inventor of the bunsen burner). He received his PhD in 1882, and returned to Vienna to work as an unpaid assistant in Prof. Lieben's laboratory, working with chemical separation methods for investigations on rare earth elements.
In 1885 he used a method he developed himself to separate didymium for the first time. He saw several different colored versions which he named praseodymium (green) and neodidymium (pink), the later then became the more common name for the element, neodymium.
Later that year he received a patent on his development of the gas mantle, which he called Auerlicht, using a chemical mixture of 60% magnesium oxide, 20% lanthanum oxide and 20% yttrium oxide which he called Actinophor. To produce a mantle, guncotton is impregnated with a mixture of Actinophor and then heated, the cotton eventually burns away leaving a solid (albiet fragile) ash which glows brightly when heated. These original mantles gave off a green-tinted light and were not very successful, and his first company formed to sell them failed in 1889.
In 1890 he introduced a new form of the mantle based on a mixture of 99% thorium oxide and 1% cerium oxide which he developed in collaboration with his colleague Dr. Haittinger. These proved both more robust as well as having a much "whiter" light. Another company founded to produce the newer design was formed in 1891, and the device quickly spread throughout Europe.
He then started work on development of metal-filament mantles, first with platinum wiring, and then osmium. Osmium is very difficult to work with, but he developed a new method which mixed osmium oxide powder with rubber or sugar into a paste, which is then squeezed through a nozzle and fired. The paste burns away, leaving a fine wire of osmium.
Although originally intended to be a new mantle, it was during this period that electricity was being introduced into the market, and he started experimenting with ways to use the filaments as a replacement for the electric arc light. He worked on this until finally developing a workable technique in 1898, and started a new factory to produce his Auer-Oslight, which he introduced commercially in 1902. The metal filament light bulb was a huge improvement on the existing carbon filament designs, lasting much longer, using about 1/2 the electricity for the same amount of light, and being much more robust.
In 1903 he won another patent for what is today known as a "flint", although the term is not well-applied. Welsbach's flints consisted of pyrophoric alloys, 70% cerium and 30% iron, which when scratched or struck would give off sparks. This system remains in wide use in cigarette lighters today. In 1907 he formed Treibacher Chemische Werke GesmbH to build and market the devices
Over the rest of his life he turned again to "pure" chemistry and publshed a number of papers on chemical separation and spectroscopy. He presented a major paper on his work on the separation of radioactive elements in 1922.