Karl Friedrich Mohr (November 4, 1806 – September 28, 1879) was a German

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

famous for his early statement of the principle of the

conservation of energy The law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be Conservation law, ''conserved'' over time. In the case of a Closed system#In thermodynamics, closed system, the principle s ...

. Ammonium iron(II) sulfate, (NH₄)₂Fe(SO₄)₂.6H₂O, is named Mohr's salt after him.

Life

Mohr was born in 1806 into the family of a prosperous druggist in

Koblenz Koblenz ( , , ; Moselle Franconian language, Moselle Franconian: ''Kowelenz'') is a German city on the banks of the Rhine (Middle Rhine) and the Moselle, a multinational tributary. Koblenz was established as a Roman Empire, Roman military p ...

. The young Mohr received much of his early education at home, a great part of it in his father's laboratory. This experience may be responsible for much of the skill Mohr later showed in devising instruments and methods of chemical analysis. At the age of twenty-one he began to study chemistry under

Leopold Gmelin Leopold Gmelin (2 August 1788 – 13 April 1853) was a German chemist. Gmelin was a professor at the University of Heidelberg. He worked on the Potassium ferricyanide, red prussiate and created Gmelin's test, and wrote his ''Handbook of Chemistry ...

, and, after five years in

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

, Berlin and

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

, he returned with the degree of PhD to join his father's establishment. Mohr's father died during 1840 at which time Mohr assumed control of the family business. He retired from it for a life of scientific leisure in 1857, but at the age of fifty-seven some serious financial losses caused him to become a

privatdozent ''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualifi ...

in Bonn. In 1859, Mohr was one of the 56 founding members of the Freies Deutsches Hochstift (Free German Foundation). In 1867 he was appointed, by the direct influence of the government, extraordinary professor of

pharmacy Pharmacy is the science and practice of discovering, producing, preparing, dispensing, reviewing and monitoring medications, aiming to ensure the safe, effective, and affordable use of medication, medicines. It is a miscellaneous science as it ...

Work

Mohr was the leading scientific chemist of his time in Germany, and the inventor of many improvements in analytical methodology. He invented an improved

burette A burette (also spelled buret) is a graduated glass tube with a tap at one end, for delivering known volumes of a liquid, especially in titrations. It is a long, graduated glass tube, with a stopcock at its lower end and a tapered capillary tub ...

which had a tip at the bottom and a clamp (a 'Mohr's clip'), which made it much easier to use than its predecessors, which were more similar to a graduated cylinder. His methods of

volumetric analysis Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of Quantitative research, quantitative Analytical chemistry, chemical analysis to determine the concentration of an identified analyte (a substance to be ...

were expounded in his ''Lehrbuch der chemisch-analytischen Titrir-methode'' (1855) (Instructional Book of Titration Methods in Analytical Chemistry), which won special commendation from Liebig and ran to many editions. His ''Geschichte der Erde, eine Geologie auf neuer Grundlage'' (1866) (History of the Earth, a Geology on a New Basis), was also widely circulated. In a paper ''Über die Natur der Wärme'' (1837), Mohr gave one of the earliest general statements of the doctrine of the

Selected writings

* ''Lehrbuch der pharmaceutischen Technik.'' Braunschweig: Friedrich Bieweg, 1847. 1866 edition digitize

This was the first textbook of pharmacy. It was translated and adapted to English practice by Theophilus Redwood. The US version was translated and adapted by William Procter, Jr. * ''Commentar zur Preußischen Pharmacopoe nebst Übersetzung des Textes : nach der 6. Aufl. der Pharmacopoea Borussica bearbeitet ; für Apotheker, Aerzte und Medicinal-Beamte . Band 1'' . Vieweg, Braunschweig 184
Digital edition
by the

University and State Library Düsseldorf The University and State Library Düsseldorf (, abbreviated ULB Düsseldorf) is a central service institution of Heinrich Heine University. Along with Bonn and Münster, it is also one of the three State Libraries of North Rhine-Westphalia. ...

* ''Commentar zur Preußischen Pharmacopoe nebst Übersetzung des Textes : nach der 6. Aufl. der Pharmacopoea Borussica bearbeitet ; für Apotheker, Aerzte und Medicinal-Beamte . Band 2'' . Vieweg, Braunschweig 184
Digital edition
by the

* ''Commentar zur preussischen Pharmacopoe nebst Übersetzung des Textes : nach der sechsten Auflage der Pharmacopoea Borussica ; für Apotheker, Ärzte und Medicinal-Beamte'' Vol.1-2 . Vieweg, Braunschweig 2nd edition 185
Digital edition
by the

* ''Lehrbuch der chemisch-analytischen Titriermethode : für Chemiker, Ärzte u. Pharmaceuten, Berg- und Hüttenmänner, Fabrikanten, Agronomen, Metallurgen, Münzbeamte etc. ; nach eigenen Versuchen und systematisch dargestellt'' . Vieweg, Braunschweig 3. Aufl. 187
Digital edition
by the

* : - Based on Mohr's work

References

Attribution: *

Life

Work

Selected writings

See also

References

Further reading