Dieudonné Sylvain Guy Tancrède de Gratet de Dolomieu usually known
as Déodat de Dolomieu (23 June 1750 – 28 November 1801) was a
French geologist; the mineral and the rock dolomite and the largest
summital crater on the
Piton de la Fournaise
Piton de la Fournaise volcano were named after
Biography and career
Déodat de Dolomieu was born in Dauphiné, France, one of 11 children
of the Marquis De Dolomieu and his wife Marie-Françoise de Berénger.
As a child young Déodat showed considerable intellectual potential
and special interest in the natural surroundings of his home in the
Alps of southeastern France. De Dolomieu began his military career in
the Sovereign and Military Order of the
Knights of Saint John
Knights of Saint John (also
Knights Hospitaller or the Knights of Malta) at the age of
12. His association with the Maltese Order caused him difficulties
throughout his life, beginning with a duel, which he fought at the age
of 18, when he killed a fellow member of the Order. For this
infraction he was sentenced to life in prison but due to the
Pope Clement XIII
Pope Clement XIII he was released after only 1 year.
During the years prior to the
French Revolution De Dolomieu took full
part in the intellectual ferment of
France and the rest of Europe. He
maintained numerous social contacts among the nobility and although he
never married, De Dolomieu had something of a reputation as a ladies'
man. Through his friend and mentor, the Duke de La Rochefoucauld, De
Dolomieu was made a corresponding member of the Royal Academy of
Sciences. He spent his spare time taking scientific excursions
throughout Europe collecting mineral specimens and visiting mining
areas. His particular interests included mineralogy, volcanology, and
the origin of mountain ranges. Although De Dolomieu was greatly
interested in volcanoes, he became convinced that water played a major
role in shaping the surface of the Earth through a series of
prehistoric, catastrophic events. De Dolomieu was not a uniformitarian
geologist. His contemporary, James Hutton, did not publish the
principle of uniformitarianism until 1795. De Dolomieu was an
observationalist and spent much of his time collecting and
categorizing geological data. Unlike Hutton, no scientific principles
or theories are credited to him, although he left his permanent mark
on geology in another way: that is by discovering the mineral that
would be named after him.
During one of his voyages to the
Alps of Tyrol (today part of
northeastern Italy) De Dolomieu discovered a calcareous rock which,
unlike limestone, did not effervesce with weak hydrochloric acid. He
published these observations in 1791 in the well-known French science
magazine "Journal de Physique". In March 1792, the rock was named
dolomie (or dolomite, in English) by Nicolas-Théodore de Saussure.
Today both the rock and its major mineral constituent bear the name of
De Dolomieu, as do the Dolomites, the mountain range of northeastern
Italy. De Dolomieu was not the first to describe the mineral dolomite.
Most probably it was Linnaeus, who was the first to note the fact that
this rock resembled limestone but does not effervesce with dilute
acid. In his book "Oryctographia Carniola, oder physikalische
Erdbeschreibung des Herzogthums Krain, Istrien und zum Theil der
benachbarten Länder", published by J. G. I. Breitkopf, Leipzig in
1778, the Austrian naturalist
Belsazar Hacquet also observed this
distinction between limestone and a rock that Hacquet described as
lapis suillus. The two men met in Laibach in 1784, when De
Dolomieu visited Sigmund Zois. However, Hacquet was well aware of
the fact that the description of a limestone that would not effervesce
with acid (and therefore had to be different from normal limestone) by
the famous Carolus Linnaeus in 1768 preceded his own. On p. 5 of
the second volume of his "Oryctographia Carniola", which appeared in
1781, Hacquet stated that the white powder he had found near the town
of Vorle ("unterm Teil der Oberkrain") a white powder that strongly
resembled limestone but would not react with dilute hydrochloric acid,
reminded him of the Marmor Tardum described by Linnaeus.
In addition to his scientific activities De Dolomieu continued to
advance in rank in the Knights of Malta and was promoted to Commander
in 1780. However, he continued to have difficulties as a result of his
liberal political leanings which were unpopular among the conservative
nobility who controlled the Order. De Dolomieu retired from active
military service in 1780 to devote all of his time to travels and
De Dolomieu was at first a strong partisan of the French Revolution,
which began in 1789. However, the murder of his friend the Duc de la
Rochefoucauld, a near-escape from the guillotine, and the beheading of
several of his relatives, turned him against the revolution. During
this time De Dolomieu became a supporter of
Napoleon Bonaparte. In
1795, having lost his fortune in the revolution, De Dolomieu accepted
the position of Professor of Natural Sciences at the École Centrale
Paris and started to write the mineralogical section of the
Encyclopédie Méthodique. The following year he was appointed
Inspector of Mines and Professor at the École Nationale Supérieure
des Mines de Paris, where his portrait still hangs in the library. His
extensive mineral collection is today housed at the Muséum National
d'Histoire Naturelle of Paris.
By 1798 De Dolomieu had developed an international reputation as one
of the leading geologists in the world and was invited to join the
scientific expedition accompanying Bonaparte's invasion of Egypt, as
part of the natural history and physics section of the Institut
d'Égypte. In March 1799 De Dolomieu became ill and was forced to
Alexandria, Egypt for France. His ship, caught in a storm,
sought refuge at the port of Taranto, Italy where De Dolomieu was made
a prisoner of war. General Thomas-Alexandre Dumas, the father of
Alexandre Dumas, the author, was also captured and held. The city was
part of the Kingdom of the Two Sicilies, which was then at war with
France. De Dolomieu had previously made a powerful enemy of the Grand
Master of the Maltese Order when he helped negotiate the surrender of
the island of Malta to Napoleon. The Grand Master denounced De
Dolomieu and he was transferred to Messina, Sicily and imprisoned
under horrible conditions, in solitary confinement, for the next 21
The imprisonment of a world-famous scientist, under such conditions,
was abhorrent to the intellectual community of Europe. Even the
scientific community of England (who was at war with France) protested
the confinement. Talleyrand, the French foreign minister, attempted to
negotiate Dolomieus release through the Pope. Napoleon, who was First
France at the time, felt that asking for such an
intervention by the Pope would be dishonorable. The future Emperor's
approach to the problem was more direct. In the spring of 1800
Napoleon led the French army into Italy, delivering a crushing blow to
the Austrians and their Italian allies on 14 June at the Battle of
Marengo. All of Italy then came within Napoleon's sphere. One of the
terms dictated by
Napoleon in the peace treaty of Florence (March
1801) was the immediate release of De Dolomieu.
Upon his liberation De Dolomieu resumed his scientific studies and
field excursions. But his health, broken by the long imprisonment in
Sicily, gave way during a trip to the Alps. Déodat de Dolomieu died
on 28 November 1801 at the home of his sister at Châteauneuf.
George F. Kunz
George F. Kunz wrote about his contributions to mineralogy.
^ Saussure le fils, M de. (1792): Analyse de la dolomie. Journal de la
Physique, vol.40, pp.161-173. Gardien, Guy (2002). "Introduction".
Déodat Gratet de Dolomieu
Déodat Gratet de Dolomieu (in French). Editions Publibook. p. 9.
^ On p.41 of part 3 of his book "Systema naturae per regna tria
naturae, Secundum Classes, Ordines, Genera, species cum characteribus
& differentiis" published in 1768 by Laurentii Salvii, Homiae, 236
p., Linnaeus stated clearly: "Marmor tardum - Marmor particulis
subimpalpabilius album diaphanum. Hoc simile quartzo durum, distinctum
quod cum aqua forti non, nisi post aliquot minuta & fero,
effervescens". In translation: "Slow marble - Marble, white and
transparent with barely discernable particles. This is as hard as
quartz, but it is different in that does not, unless after a few
minutes, effervesce with "aqua forti""
^ Felizardo, Alexandre. "Baltazar Hacquet (1739–1815)". Cavernas em
Foco (in Portuguese). Bookess. p. 119.
^ Kranjc, Andrej (2006). "Balthasar Hacquet (1739/40-1815), the
Pioneer of Karst Geomorphologists". Acta Carsologica. 35 (2).
^ Šumrada, Janez (2001). "Žiga Zois in Déodat de Dolomieu".
Kronika: časopis za slovensko krajevno zgodovino [The Chronicle: the
Newspaper for the Slovenian History of Places] (in Slovenian and
English). Association of Slovenian Historical Societies, Section for
the History of Places. 49 (1/2): 65–72. ISSN 0023-4923.
^ Kunz, George F. “Déodat Dolomieu.” Science Monthly. Volume 8,
pages 527–536. June, 1919. (Based on Alfred Lacroix. “Notice
Historique sur Déodat Dolomieu,1750–1801.” 88 pages, portrait,
^ Kunz, George F. “Un Manuscrit [sic] inédit de Dolomieu sur la
Minéralogie du Dauphiné.” Science. Volume 50, number 373, pages
373–374. October 17, 1919.
Wikisource has the text of the 1911 Encyclopædia Britannica article
Dolomieu, Déodat Guy Silvain Tancrède Gratet de.
Carozzi, A. V.; Zenger, D. H. (1981). "On a type of calcareous rock
that reacts very slightly with acid and that phosphoresces on being
struck (translation, with notes of Dolomieu's paper, 1791)". Journal
of Geological Education. 29: 4–10.
Dolomieu, D. G. de (October 1791). "Sur un de pierres trés-peu
effervescentes avec les acides of phosphorescentes par la collision".
Jour. Physique. 39: 3–10.
Zenger, D. H., Bourrouilh-Le Jan, F. G. and Carozzi, A. V. (1994).
"Dolomieu and the first description of dolomite". In Purser, B.;
Tucker, M.; Zenger, D.
Dolomites A volume in honor of Dolomieu.
International Association of Sedimentologists:
Special Publication 21.
pp. 21–28. ISBN 0-632-03787-3. CS1 maint: Multiple
names: authors list (link)
Charles-Vallin, T. (2003). Les aventures du chevalier géologue
Déodat de Dolomieu. Presses Universitaires de Grenoble, Grenoble.
pp. 296 p.
Gaudant, J., ed. (2005). Dolomieu et la géologie de son temps. Les
Presses de l'École des Mines de Paris, Paris. pp. 200 p.
Caminada, P. (2006). Das abenteuerliche Leben des Forschungsreisenden
Déodat de Dolomieu 1750 - 1801. Projekte Verlag, Halle. pp. 285
ISNI: 0000 0000 7977 2732
BNF: cb12433033f (d