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 scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...

famous for his early statement of the principle of the

conservation of energy In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be ''conserved'' over time. This law, first proposed and tested by Émilie du Châtelet, means tha ...

. 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: ''Kowelenz''), spelled Coblenz before 1926, is a German city on the banks of the Rhine and the Moselle, a multi-nation tributary. Koblenz was established as a Roman military post by Drusus around 8 B.C. Its nam ...

. 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 red prussiate and created Gmelin's test, and wrote his ''Handbook of Chemistry'', which over successi ...

, and, after five years in

Heidelberg Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of students ...

, Berlin and

Bonn The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ru ...

, 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 qualific ...

in Bonn. In 1859, Mohr was one of the 56 founding members of the

Freies Deutsches Hochstift The Freies Deutsches Hochstift (Free German Foundation) is a literary association based in Frankfurt, Hesse, Germany. It is the owner of the Goethe House, the place where the playwright and poet Johann Wolfgang von Goethe was born and spent his ...

(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 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 tube at the stopcock's outl ...

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 chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant' ...

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 Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at t ...

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

Mohr, Friedrich – Lehrbuch der chemisch-analytischen Titrirmethode, 1870 – BEIC 12226093

* ''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. William Procter Jr. (May 3, 1817 – February 10, 1874) was an American pharmacist. He graduated from the Philadelphia College of Pharmacy in 1837. He is known for his role in establishing the American Pharmacists Association and his work on th ...

* ''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 (german: Universitäts- und Landesbibliothek Düsseldorf, abbreviated ULB Düsseldorf) is a central service institution of Heinrich Heine University. Along with Bonn and Münster, it is also one of t ...

* ''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 ed. 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