ELLER VON BROCKHAUSEN, JOHANN THEODOR.

Sur la Nature et les Proprietés de L'Eau. (+) Sur les Phenomenes qui se manifestent, lorsqu'on dissout toutes sortes de Sels dans L'Eau commune separément. (2 papers).

(Berlin, Haude et Spener, 1752). 4to. No wrappers, as issued in "Memoires de L'Academie Royale des Sciences et Belles Lettres" tome VI (1750), pp. 67-82 and pp. 83-97 and with the section-titlepage "Memoires ....Classe de Philosophie Experimentale".

First printing of Eller's most importent chemical works.

"A really importent investigation is Eller's on the soluability of salts in water. He found that most salts cause a fall in temperature when dissolved in water, but some...cause a rise in temperature....He discusses the theory of solution - the interpostion of salt particles between water particles, attraction, etc..."(Partington II, pp. 716-17).

When Frederick the Great became king in 1740, he made Eller his personal physician and appointed him director of the Berlin Academy of Sciences. Eller’s wife died in 1751, and in 1753 he married Henrietta Catherine Rosen. In 1755 Frederick made Eller a privy councillor, a position he held until his death. Eller held the highest positions in Prussia, professor of anatomy, dean to the Collegium Medico-Chirurgicum, director of the Berlin Academy of Sciences and physician-in-ordinary to Frederick the Great. Together with Georg Ernst Stahl he was responsible for laying the foundation for all subsequent developments in medical services in Prussia.

Order-nr.: 44742