Background
Johann Theodor Eller was born on November 29, 1689, in Plôtzkau, Germany. His father, Jobst Hermann Eller, was an eminent military man under the prince of Anhalt; his mother belonged to the Behm family, an ancient family in Livonia.
University of Jena, Fürstengraben 1, 07743 Jena, Germany
Eller had an excellent education in law at Quedlinburg College and Jena University, but he changed to the study of medicine while at Jena.
German Academy of Sciences Leopoldina, Halle, Germany
Eller was a member of the German Academy of Sciences Leopoldina.
Potsdamer Straße 33, 10785 Berlin, Gremany
Eller was a member of the Royal Prussian Academy of Sciences.
Johann Theodor Eller was born on November 29, 1689, in Plôtzkau, Germany. His father, Jobst Hermann Eller, was an eminent military man under the prince of Anhalt; his mother belonged to the Behm family, an ancient family in Livonia.
Eller had an excellent education in law at Quedlinburg College and Jena University, but he changed to the study of medicine while at Jena. In 1711 he left Jena to search for better instruction in anatomy, going to Halle, then Leiden, and finally in 1712 to Amsterdam, where he found the most capable anatomists in Europe, Rau, and Ruysch.
When Rau moved to Leiden, Eller went with him and performed public dissections for him until 1716. Eller was not prepared at this point to settle down to the practice of medicine, but turned to the study of mineralogy and chemistry, first with Lemery and Homberg in Paris, and then with Hauksbee and Desaguliers in London.
Upon his return to Anhalt-Bernburg in 1721, Eller was made court physician by the prince. In 1724 King Frederick William I called Eller to Berlin and made him professor of anatomy and permanent dean of the Medical College, as well as physician to the army. When Frederick the Great became king in 1740, he made Eller his personal physician and appointed him director of the Berlin Academy of Sciences. In 1755 Frederick made Eller a privy councillor, a position he held until his death.
Eller held the highest medical positions in Prussia during his lifetime. His writings reflect his medical knowledge and consist largely of compilations of case histories, like the one he published in Berlin in 1730, based on his experiences in the Charité Hospital in Berlin. He carried out some studies on human blood, examined human calculi, and warned about the dangers of using copper kitchen utensils, but he is not noted for any significant development in medicine.
Eller’s theoretical chemistry is characterized by the central role given to heat (fire). His writings clearly place him in the Continental tradition that considered heat to be material in nature. With Eller, the Stahlian principle of phlogiston became simply another name for the primary element fire in the fixed state. In this state, fire is chemically combined with most substances and generally is released during chemical reactions. In the active state fire is the sole cause of the fluidity of water and fluids in general (air included). This principle is also integrated into his main practical chemical work, which dealt with the solubility of salts in water. Eller argued that since solubility generally increased with temperature, it must be because the fire in the water, whose activity in-creased with temperature, could more readily break up (dissolve) the salts.
Eller was a member of the German Academy of Sciences Leopoldina and the Royal Prussian Academy of Sciences.
Eller is said to have been a very competent doctor and administrator.
Eller married Catherine Elizabeth Burckhard in 1721. His wife died in 1751, and in 1753 he married Henrietta Catherine Rosen.