Ludwig Ferdinand Wilhelmy (25 December 1812, Stargard in Pommern – 18 February 1864, Berlin) was a German scientist who is usually credited with publishing the first quantitative study in

chemical kinetics Chemical kinetics, also known as reaction kinetics, is the branch of physical chemistry that is concerned with understanding the rates of chemical reactions. It is to be contrasted with chemical thermodynamics, which deals with the direction in ...

Scientific work

Wilhelmy studied at

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

, earning a doctorate in 1846. He worked as a Privatdozent from 1849 to 1854 before moving to Berlin. Wilhelmy's work in chemical kinetics concerned the acid-catalyzed conversion of a sucrose solution into a 1:1 mixture of fructose and

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

, a reaction that he followed with a polarimeter. He wrote a differential equation to describe the reaction, integrated it, and used it to interpret his experimental results. Wilhelmy found that the reaction's rate was proportional to the concentrations of sucrose and of acid present. He also examined the influence of temperature on the reaction. According to Moore, Wilhelmy received little credit from his contemporaries for his early investigations in the field of chemical kinetics. It has been speculated that the strong physical-chemical orientation of Wilhelmy's work, the new method of

polarimetry Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves. Typically polarimetry is done on electromagnetic waves that have traveled through or ...

, and the fact that Wilhelmy was relatively unknown all led to this situation. Similar laboratory results were published by Jacobus Henricus van 't Hoff and

Svante Arrhenius Svante August Arrhenius ( , ; 19 February 1859 – 2 October 1927) was a Swedish scientist. Originally a physicist, but often referred to as a chemist, Arrhenius was one of the founders of the science of physical chemistry. He received the Nob ...

30 years later, with a much greater impact.(Subscription required for electronic access) Wilhelmy is also known for the

Wilhelmy plate A Wilhelmy plate is a thin plate that is used to measure equilibrium surface or interfacial tension at an air–liquid or liquid–liquid interface. In this method, the plate is oriented perpendicular to the interface, and the force exerted on ...

method for measuring surface tensions.

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External links

- describes and pays tribute to Wilhelmy's early work {{DEFAULTSORT:Wilhelmy, Ludwig 19th-century German chemists 1812 births 1864 deaths Heidelberg University alumni Academic staff of Heidelberg University People from Stargard

Scientific work

See also

Notes and references

Further reading

External links