On August 26, 1736, French physicist and mineralogist Jean-Baptiste Louis Romé de L’Isle was born. He is considered as one of the creators of modern crystallography. Driven by Carl Linnaeus‘ classification of living things , Romé de L’Isle tried to transfer this to inanimate nature and thus created the first systematics of crystals.
Romé de L’Isle – Youth and Travels
Jean-Baptiste Louis Romé de L’Isle was born in in Gray, Haute-Saône, in eastern France, into a respectable family attached to the military service, but practically without fortune. After his schooling at the college Sainte-Barbe of Paris, young Louis could only apply for a job as secretary of an artillery and engineering company leaving for the Indies. He visited India and it was during his travels and adventures in exotic landscapes that he developed a taste for natural sciences. He participated as secretary of an artillery company, with officer rank, in the Indian War, still called the Third Carnatic War. He was able to survey a dry and arid part of the East Indies. On January 15, 1761, he was taken prisoner during the capture of Pondicherry by the British and only decided to return in 1764 after three years of captivity and a long journey to Tranquebar, San Thomé and China, probably as a captive servant or hired on parole.
Natural Sciences and Mineralogy
The impressions of his time in India and China, as well as those of earlier travels, awakened his interest in nature, especially the earth sciences. Through his collaboration with the French chemist and mineralogist Balthazar Georges Sage (1740-1824), his interests shifted from chemistry and biology to mineralogy. He studied freshwater polyps, but his passion for one branch, mineralogy, developed as it explained the cutting of precious and semi-precious stones, as well as the shape of native metals, such as native copper. He established the catalogs of several private collections, in particular the Davila collection, at the time the richest in minerals of all Paris.
The Classification of Crystals
Driven by the classification of living things by Carolus Linnaeus, Romé de L’Isle tried to transfer this to inanimate nature and thus created the first systematics of crystals by distinguishing salt crystals, stone crystals, gravel crystals and ore crystals. Based on the discovery of the law of angular constancy on quartz crystals by Nicolaus Steno, Romé de L’Isle began, after construction of a suitable goniometer, with systematic investigations on further crystals or minerals. In doing so, he described numerous hitherto unknown or poorly determined minerals. When publishing his results, he was the first to use the term “crystallography”, which still describes the science of crystals today. His work also laid the foundation for the work of René-Just Haüy, who developed the law of symmetry and the law of decrescence, the precursor of the law of rationality, in crystallography.
Honors and Later Life
In 1775, famous for his initiation course considered remarkable in the Nordic world, he was appointed foreign member and correspondent of the Royal Academy of Sciences of Sweden. His Essay on Crystallography was translated into German in 1777. He was not widely read in France, if not always mocked. His protector Michelet d’Ennery died in 1786. Without resources, he received a double pension from the Treasury and from King Louis XVI, that is 600 + 400 Francs. In 1775 he was elected a member of the German Academy of Sciences Leopoldina. In 1780 he was accepted as a foreign member of the Prussian Academy of Sciences.
Jean-Baptiste Louis Romé de L’Isle died in Paris on July 3, 1790, at age 53.
Jeffrey C. Grossman, Introduction to Crystallography (Intro to Solid-State Chemistry) 
References and Further Reading:
-  Carl Linnaeus – ‘Princeps Botanicorum’, the Prince of Botany, SciHi Blog
-  Nicolas Steno and the Principles of Modern Geology, SciHi Blog
-  Chisholm, Hugh, ed. (1911). “Romé de l’Isle, Jean Baptiste Louis“. Encyclopædia Britannica. 23 (11th ed.). Cambridge University Press. p. 685.
-  Romé de L’Isle, Jean-Baptiste Louis de (1736-1790). Des caractères extérieurs des minéraux, ou Réponse à cette question, 1794
-  Jean-Baptiste Louis Romé de L’Isle at Wikidata
-  Romé de L’Isle, Jean-Baptiste Louis de, Cristallographie. Vol. 3. Paris: Imprimerie de Monsieur. 1783.
-  Romé de L’Isle, Jean-Baptiste Louis de,Cristallographie . Vol. 4. Paris: Imprimerie de Monsieur. 1783.
-  Jeffrey C. Grossman, Introduction to Crystallography (Intro to Solid-State Chemistry), Fall 2018, MIT Courseware @ youtube
-  Zdenek Johan, «Romé de Lisle Jean-Baptiste-Louis (1736-1790)», Encyclopædia Universalis, 2001.
-  Timeline of mineralogists, via Wikidata and DBpedia