Jeremias Benjamin Richter (; 10 March 1762 – 4 May 1807) 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 t ...
. He was born at
Hirschberg in
Silesia
Silesia (, also , ) is a historical region of Central Europe that lies mostly within Poland, with small parts in the Czech Republic and Germany. Its area is approximately , and the population is estimated at around 8,000,000. Silesia is split ...
, became a mining official at
Breslau in 1794, and in 1800 was appointed assessor to the department of mines and chemist to the royal porcelain factory at
Berlin, where he died. He is known for introducing the term ''
stoichiometry
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions.
Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equal ...
''.
Developer of titration
He made some of the earliest known determinations of the quantities by weight in which
acids
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
saturate
bases and bases acids. He realised that those amounts of different bases which can saturate the same quantity of a particular acid are equivalent to each other (see ''
Titration'').
He was thus led to conclude that chemistry is a branch of applied mathematics and to endeavour to trace a law according to which the quantities of different bases required to saturate a given acid formed an
arithmetical progression
An arithmetic progression or arithmetic sequence () is a sequence of numbers such that the difference between the consecutive terms is constant. For instance, the sequence 5, 7, 9, 11, 13, 15, . . . is an arithmetic progression with a common differ ...
, and the quantities of acids saturating a given base a
geometric progression
In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of non-zero numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the ''common ratio''. For ex ...
.
Law of definite proportions (
stoichiometry
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions.
Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equal ...
)
Evidence for the existence of atoms was the law of definite proportions proposed by him in 1792. Richter found that the ratio by weight of the compounds consumed in a chemical reaction was always the same. It took 615 parts by weight of
magnesia (MgO), for example, to neutralize 1000 parts by weight of
sulfuric acid
Sulfuric acid ( American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...
. From his data,
Ernst Gottfried Fischer calculated in 1802 the first table of chemical equivalents, taking sulphuric acid as the standard with the figure 1000.
[ John Theodore Merz, '' A History of European Thought in the Nineteenth Century'' (1903) Vol.1] When
Joseph Proust
Joseph Louis Proust (26 September 1754 – 5 July 1826) was a French chemist. He was best known for his discovery of the law of definite proportions in 1794, stating that chemical compounds always combine in constant proportions.
Life
Joseph L ...
reported his work on the constant composition of chemical compounds, the time was ripe for the reinvention of an atomic theory. The
law of definite proportions
In chemistry, the law of definite proportions, sometimes called Proust's law, or law of constant composition states that a given
chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source ...
and constant composition do not prove that atoms exist, but they are difficult to explain without assuming that chemical compounds are formed when atoms combine in constant proportions.
Publications
His results were published in ''Der Stochiometrie oder Messkunst chemischer Elemente'' (1792–1794), and ''Über die neueren Gegenstände in der Chemie'' (1792–1802), but it was long before they were properly appreciated.
This was partly because some of his work was wrongly ascribed to
Carl Wenzel by
Jons Berzelius through a mistake which was only corrected in 1841 by
Henri Hess, professor of chemistry at
St. Petersburg
Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...
, and author of the laws of constant heat-sums and of
thermoneutrality.
Later work
Between 1792 and 1794 he published a three-volume summary of his work on the law of definite proportions. In this book Richter introduced the term
stoichiometry
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions.
Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equal ...
, which he defined as the ''art of chemical measurements, which has to deal with the laws according to which substances unite to form chemical compounds''.
Richter was fascinated with the role of mathematics in chemistry. Unfortunately his writing style has been described as ''obscure and clumsy''. His work therefore had little impact until 1802, when it was summarized by
Ernst Gottfried Fischer in terms of tables.
Notes
See also
*
Equivalent weight
In chemistry, equivalent weight (also known as gram equivalent) is the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance. The equivalent weight of an element is ...
References
* (Link not working)
;Attribution
*
{{DEFAULTSORT:Richter, Jeremias
1762 births
1807 deaths
People from Jelenia Góra
People from the Province of Silesia
19th-century German chemists
18th-century German chemists