Clemens Winkler
Encyclopedia
Clemens Alexander Winkler (December 26, 1838 – October 8, 1904) was a German chemist who discovered the element germanium
in 1886, solidifying Dmitri Mendeleev
's theory of periodicity
.
, Kingdom of Saxony
the son of a chemist who had studied under Berzelius. Winkler's early education was at schools in Freiberg, Dresden, and Chemnitz. In 1857 he entered the Freiberg University of Mining and Technology
, where his knowledge of analytical chemistry surpassed what he was being taught there. Sixteen years later, Winkler was appointed a professor of chemical technology and analytical chemistry at the university.
Winkler was elected a member of the Royal Swedish Academy of Sciences
in 1892.
In 1893, Winkler moved to Hamburg
where he married his childhood sweetheart Tanja Braun.
In 1902, Winkler resigned his professorship. He died in Dresden
two years later of carcinoma
at the age of 66.
According to Brunck, Winkler wrote poetry, and according to McCay, Winkler's talents extended to playing several musical instruments.
, was found by chemists to contain silver
and sulfur
. When Winkler subsequently analyzed the mineral, he found that the individual components only added up to about 93–94% of its total mass, leading him to suspect that a new and previously-unknown element must be present. After additional chemical purification steps over several months, Winkler isolated the pure element, germanium, on February 6, 1886 and published his results. The mineral argyrodite that was Winkler's start toward finding germanium is now known to be a double sulfide with formula GeS2 · 4Ag2S.
To place germanium into the periodic table
, Mendeleev suggested that it might be ekacadmium, an element he had predicted earlier. In contrast, Lothar Meyer favored an identification of germanium with ekasilicon, a different predicted element. Winkler isolated more of the pure material, and eventually obtained enough to measure some of its physical and chemical properties. His results showed unequivocally that Meyer's interpretation was the correct one and that nearly all of the new element's properties matched Mendeleev predictions. The close match between what had been predicted for ekasilicon and what was found for germanium was clear evidence for the utility and power of the periodic table and the concept of periodicity.
, SiO, and was the first to attempt to produce it by heating silica with silicon in 1890. However, he was unsuccessful because he was not able to heat the mixture to a high enough temperature using a combustion furnace. As no reaction occurred for him, Winkler incorrectly concluded that SiO does not exist, even though it was reported to have formed from the reduction of silica with charcoal three years earlier by C. F. Maybery. However, Henry Noel Potter, a Westinghouse engineer, repeated Winkler's experiment fifteen years later with an electric furnace, which enabled him to increase the reaction temperature by several hundred degrees and observe the generation of SiO.
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. The isolated element is a semiconductor, with an appearance most similar to elemental silicon....
in 1886, solidifying Dmitri Mendeleev
Dmitri Mendeleev
Dmitri Ivanovich Mendeleev , was a Russian chemist and inventor. He is credited as being the creator of the first version of the periodic table of elements...
's theory of periodicity
Periodic table
The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...
.
Life
Winkler was born in 1838 in FreibergFreiberg, Saxony
Freiberg is a city in the Free State of Saxony, Germany, administrative center of the Mittelsachsen district.-History:The city was founded in 1186, and has been a center of the mining industry in the Ore Mountains for centuries...
, Kingdom of Saxony
Kingdom of Saxony
The Kingdom of Saxony , lasting between 1806 and 1918, was an independent member of a number of historical confederacies in Napoleonic through post-Napoleonic Germany. From 1871 it was part of the German Empire. It became a Free state in the era of Weimar Republic in 1918 after the end of World War...
the son of a chemist who had studied under Berzelius. Winkler's early education was at schools in Freiberg, Dresden, and Chemnitz. In 1857 he entered the Freiberg University of Mining and Technology
Freiberg University of Mining and Technology
The Technische Universität Bergakademie Freiberg is a small German University of Technology with about 5000 students in the city of Freiberg, Saxony...
, where his knowledge of analytical chemistry surpassed what he was being taught there. Sixteen years later, Winkler was appointed a professor of chemical technology and analytical chemistry at the university.
Winkler was elected a member of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...
in 1892.
In 1893, Winkler moved to Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...
where he married his childhood sweetheart Tanja Braun.
In 1902, Winkler resigned his professorship. He died in Dresden
Dresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....
two years later of carcinoma
Carcinoma
Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...
at the age of 66.
According to Brunck, Winkler wrote poetry, and according to McCay, Winkler's talents extended to playing several musical instruments.
Discovery of germanium
In 1886, Winkler was provided with a new mineral from the Himmelsfürst mine near Freiberg. The mineral, called argyroditeArgyrodite
Argyrodite is an uncommon silver germanium sulfide mineral with formula Ag8GeS6. The color is iron-black with a purplish tinge, and the lustre metallic....
, was found by chemists to contain silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
and sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
. When Winkler subsequently analyzed the mineral, he found that the individual components only added up to about 93–94% of its total mass, leading him to suspect that a new and previously-unknown element must be present. After additional chemical purification steps over several months, Winkler isolated the pure element, germanium, on February 6, 1886 and published his results. The mineral argyrodite that was Winkler's start toward finding germanium is now known to be a double sulfide with formula GeS2 · 4Ag2S.
To place germanium into the periodic table
Periodic table
The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...
, Mendeleev suggested that it might be ekacadmium, an element he had predicted earlier. In contrast, Lothar Meyer favored an identification of germanium with ekasilicon, a different predicted element. Winkler isolated more of the pure material, and eventually obtained enough to measure some of its physical and chemical properties. His results showed unequivocally that Meyer's interpretation was the correct one and that nearly all of the new element's properties matched Mendeleev predictions. The close match between what had been predicted for ekasilicon and what was found for germanium was clear evidence for the utility and power of the periodic table and the concept of periodicity.
Other work
In addition to his isolation and study of germanium, Winkler investigated the analysis of gases. He published a book on the subject, Handbook of Technical Gas Analysis, in 1884. In that book Winkler describes his invention of the three-way stopcock. Clemens predicted the existence of silicon monoxideSilicon monoxide
Silicon monoxide is the chemical compound with the formula SiO. In the vapour phase it is a diatomic molecule. It has been detected in stellar objects and it has been described as the most common oxide of silicon in the universe....
, SiO, and was the first to attempt to produce it by heating silica with silicon in 1890. However, he was unsuccessful because he was not able to heat the mixture to a high enough temperature using a combustion furnace. As no reaction occurred for him, Winkler incorrectly concluded that SiO does not exist, even though it was reported to have formed from the reduction of silica with charcoal three years earlier by C. F. Maybery. However, Henry Noel Potter, a Westinghouse engineer, repeated Winkler's experiment fifteen years later with an electric furnace, which enabled him to increase the reaction temperature by several hundred degrees and observe the generation of SiO.
Further reading
– Extensive comments on Winkler from a student's point-of-view (English translation by George Lunge)External links
- The Clemens Winkler Medal (in German)