Jeremias Benjamin Richter | |
---|---|
Born |
Hirschberg, Prussia (present-day Poland) |
10 March 1762
Died | 14 April 1807 Berlin (present-day Germany) |
(aged 45)
Nationality | German |
Jeremias Benjamin Richter (German: [ˈʀɪçtɐ]; 10 March 1762 – 14 April 1807) was a German chemist. He was born at Hirschberg in Silesia, 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.
To him belongs the merit of carrying out some of the earliest determinations of the quantities by weight in which acids saturate bases and bases acids, and of arriving at the conception 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, and the quantities of acids saturating a given base a geometric progression.
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. 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. When Joseph Proust 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 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.