Alexander Classen (13 April 1843, in

Aachen Aachen ( ; ; Aachen dialect: ''Oche'' ; French and traditional English: Aix-la-Chapelle; or ''Aquisgranum''; nl, Aken ; Polish: Akwizgran) is, with around 249,000 inhabitants, the 13th-largest city in North Rhine-Westphalia, and the 28th- ...

– 28 January 1934, in Aachen) was a German chemist, who is considered one of the founders of

electrochemical analysis Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outco ...

.Important Figures of Analytical Chemistry from Germany in Brief Biographies ...
by D. Thorburn Burns, R. Klaus Müller, Reiner Salzer, Gerhard Werner From 1861 he studied chemistry at the universities of

Giessen Giessen, spelled Gießen in German (), is a town in the German state (''Bundesland'') of Hesse, capital of both the district of Giessen and the administrative region of Giessen. The population is approximately 90,000, with roughly 37,000 univers ...

and

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

. In 1870 he became a lecturer of analytical chemistry at the polytechnic school in Aachen, where in 1882 he succeeded

Hans Heinrich Landolt Hans Heinrich Landolt (5 December 1831 – 15 March 1910) was a Swiss chemist who discovered iodine clock reaction. He is also one of the founders of Landolt–Börnstein database. He tested law of mass conservation which was given by Lavoisier. B ...

as professor of

inorganic chemistry Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disci ...

. At Aachen, he was appointed director of the Electrochemical Institute,

Published works

He was the author of ''Quantitative Analyse durch Elektrolyse'', a book that was published over numerous editions, and translated into English with the title
''Quantitative analysis by electrolysis''
He was editor of the last issue of Friedrich Mohr's textbook on

titrimetry Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant'' ...

("''Friedrich Mohr's Lehrbuch der chemisch-analytischen Titrirmethode''", 1914), and with English chemist Henry Enfield Roscoe, he authored a textbook on inorganic chemistry ("''Lehrbuch der anorganischen Chemie''"; 2 volumes, 3rd edition 1895–97). Other noted works by Classen are: * ''Tabellen zur Qualitativen Analyse'', 1876 – Tables for quantitative analysis. * ''Grundriss der analytischen chemie'' (2 volumes, 2nd edition 1879) – Outline of analytical chemistry. * ''F.L. Sonnenschein's Handbuch der gerichtlichen chemie'' (new edition of

Franz Leopold Sonnenschein Franz Leopold Sonnenschein (13 July 1817 – 26 February 1879) was a German chemist from Cologne. He taught himself pharmacy, and in the 1830s, established a small laboratory in Berlin. He worked with a physician as tutor for pharmacy students ...

's manual of

forensic chemistry Forensic chemistry is the application of chemistry and its subfield, forensic toxicology, in a legal setting. A forensic chemist can assist in the identification of unknown materials found at a crime scene. Specialists in this field have a wide ...

, 1881). * ''Handbuch der analytischen chemie'' (2 volumes, 4th edition 1889–91) – Handbook of analytical chemistry * ''Neuerungen in der quantitativen Analyse durch Elektrolyse'', 1895 – Innovations in quantitative analysis by electrolysis.HathiTrust Digital Library
(published works)

References

{{DEFAULTSORT:Classen, Alexander 1843 births 1934 deaths People from Aachen University of Giessen alumni Humboldt University of Berlin alumni Academic staff of RWTH Aachen University 20th-century German chemists 19th-century German chemists