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Eilhard Mitscherlich
(7 Jan 1794 - 28 Feb 1863)
German chemist who spread the principle of isomorphism, did notable work on benzene compounds, made artificial minerals, and developed the Mitscherlich process to extract cellulose from wood, adopted by that industry.
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Science Quotes by Eilhard Mitscherlich (4 quotes)
[Mitscherlich Law of Isomerism] An equal number of atoms, combined in the same way produce the same crystal forms, and the same crystal form does not depend on the nature of the atoms, but only on their number and mode of combination.
— Eilhard Mitscherlich
Originally published in 'Om Förhållandet emellan chemiska sammansättningen och krystallformen hos Arseniksyrade och Phosphorsyrade Salter', (On the Relation between the Chemical Composition and Crystal Form of Salts of Arsenic and Phosphoric Acids), Kungliga Svenska vetenskapsakademiens handlingar (1821), 4. This alternate translation of the law appears is given by F. Szabadváry article on 'Eilhard Mitscherlich' in Charles Coulston Gillispie (ed.), Dictionary of Scientific Biography (1974), Vol. 9, 424; perhaps from J.R. Partington, A History of Chemistry, Vol. 4 (1964), 210.
Den förslags-mening: att olika element förenade med ett lika antal atomer af ett eller flere andra gemensamma element … och att likheten i krystallformen bestämmes helt och hållet af antalet af atomer, och icke af elementens.
[Mitscherlich Law of Isomerism] The same number of atoms combined in the same way produces the same crystalline form, and the same crystalline form is independent of the chemical nature of the atoms, and is determined only by their number and relative position.
[Mitscherlich Law of Isomerism] The same number of atoms combined in the same way produces the same crystalline form, and the same crystalline form is independent of the chemical nature of the atoms, and is determined only by their number and relative position.
— Eilhard Mitscherlich
Original Swedish from 'Om Förhållandet emellan chemiska sammansättningen och krystallformen hos Arseniksyrade och Phosphorsyrade Salter', Kungl. Svenska vetenskapsakademiens handlingar (1821), 4. In English as expressed later by James F.W. Johnston, 'Report on the Recent Progress and present State of Chemical Science', to Annual Meeting at Oxford (1832), collected in Report of the First and Second Meetings of the British Association for the Advancement of Science (1833), 422. A Google raw translation of the Swedish is: “The present proposal-sense: that various elements associated with an equal number of atoms of one or several other common elements … and that the similarity in: crystal shape is determined entirely by the number of atoms, and not by the elements.”
Certain elements have the property of producing the same crystal form when in combination with an equal number of atoms of one or more common elements, and the elements, from his point of view, can be arranged in certain groups. For convenience I have called the elements belonging to the same group … isomorphous.
— Eilhard Mitscherlich
Originally published in 'Om Förhållandet emellan chemiska sammansättningen och krystallformen hos Arseniksyrade och Phosphorsyrade Salter', (On the Relation between the Chemical Composition and Crystal Form of Salts of Arsenic and Phosphoric Acids), Kungliga Svenska vetenskapsakademiens handlingar (1821), 4. In F. Szabadváry article on 'Eilhard Mitscherlich' in Charles Coulston Gillispie (ed.), Dictionary of Scientific Biography (1974), Vol. 9, 424; perhaps from J.R. Partington, A History of Chemistry, Vol. 4 (1964), 210.
Every arsenate has its corresponding phosphate, composed according to the same proportions, combined with the same amount of water of crystallization, and endowed with the same physical properties: in fact, the two series of salts differ in no respect, except that the radical of the acid in one series in phosphorus, while in the other it is arsenic.
— Eilhard Mitscherlich
The experimental clue he used forming his law of isomerism. Originally published in 'Om Förhållandet emellan chemiska sammansättningen och krystallformen hos Arseniksyrade och Phosphorsyrade Salter', (On the Relation between the Chemical Composition and Crystal Form of Salts of Arsenic and Phosphoric Acids), Kungliga Svenska vetenskapsakademiens handlingar (1821), 4. Translation as shown in Joseph William Mellor, A Comprehensive Treatise on Inorganic and Theoretical Chemistry (1922), Vol. 1, 652. A very similar translation (“the same physical properties” is replaced with “nearly equal solubilities in water and acids”) is in F. Szabadváry article on 'Eilhard Mitscherlich' in Charles Coulston Gillispie (ed.), Dictionary of Scientific Biography (1974), Vol. 9, 424; perhaps from J.R. Partington, A History of Chemistry, Vol. 4 (1964), 210.
See also:
- 7 Jan - short biography, births, deaths and events on date of Mitscherlich's birth.
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- 
