Johann Andreas Cramer (14 December 1710 – 6 December 1777) was a German

metallurgist Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the ...

and chemist who published some of the early ideas on metallurgy and chemistry in his books which included ''Elementa Artis Docimasticae'' (1741). Cramer was born in

Quedlinburg Quedlinburg () is a town situated just north of the Harz mountains, in the Harz (district), district of Harz in the west of Saxony-Anhalt, Germany. As an influential and prosperous trading centre during the early Middle Ages, Quedlinburg becam ...

where his father was a businessman involved in the iron ore industry. As a child he travelled to mines in the

Harz The Harz (), also called the Harz Mountains, is a highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The name ''Harz'' der ...

region along with his father and after the death of his father he was taken care of by his brother-in-law Christian George Schwalbe (1691-1791). Schwalbe was a physician with a circle of acquaintances who included chemists and botanists including Linnaeus. Cramer studied law for a semester at Hamburg before moving to Halle to study medicine in 1726. His teachers included George Ernst Stahl (1659-1734). He did not complete his medical studies and took an interest mainly in the chemistry subjects and them moved back to study law while attending chemistry courses at Halle by Juncker and Peter Gericke (1693–1750). He graduated and worked as a lawyer in Blankenburg, but continued to work on metallurgy. He moved to Helmstedt in 1734 and attended chemistry courses by Gericke. He also set up a laboratory at home began to train in assaying. He became acquainted with Gottfried Jacob Jänisch (1707–1781) who helped Cramer to move to Leiden where he also had a friend in

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

. Cramer moved to Leiden and met with several scholars in a "society of gentlemen" including

Jan Frederik Gronovius Jan Frederik Gronovius (also seen as Johann Frederik and Johannes Fredericus) (10 February 1690 in Leiden – 10 July 1762 in Leiden) was a Dutch botanist notable as a patron of Carl Linnaeus, Linnaeus. John Clayton (botanist), John Clayton, a pl ...

, Linnaeus,

Herman Boerhaave Herman Boerhaave (, 31 December 1668 – 23 September 1738Underwood, E. Ashworth. "Boerhaave After Three Hundred Years." ''The British Medical Journal'' 4, no. 5634 (1968): 820–25. .) was a Dutch chemist, botanist, Christian humanist, and ph ...

Gerard van Swieten Gerard van Swieten (7 May 1700 – 18 June 1772) was a Dutch physician who from 1745 was the personal physician of the Holy Roman Empress Maria Theresa and transformed the Austrian health service and medical university education. He was the f ...

(1700–1772), and Isaac Lawson (1704–1747). Lawson hired Cramer for his laboratory and helped in the writing of ''Elementa Artis Docimasticae'' published first in 1741. Cramer used the idea of "''menstrua''", an idea of a substance that he defined as ".. which being applied to others according to certain Rules, dissolve them so as to adhere themselves in a State of Division to the Particles of the Body dissolved, and cannot separate from them again of their own accord." These included what are now called fluxes including lead and arsenic. Cramer died at Berggieshübel near Dresden.

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External links

Elementa Artis Docimasticae
{{DEFAULTSORT:Cramer, Johann Andreas 1710 births 1777 deaths German metallurgists