Johann Christian Bernhardt

Johann Christian Bernhardt (* as Christian Wilhelm Gottlieb Bernhardt March 13, 1710 in Weiltingen , Middle Franconia; † December 23, 1758 in Langenbernsdorf ) was a German chemist , surgeon, and baker who lived in Langenbernsdorf in the mid-18th century.

For a long time little was known about him (Claus Priesner), except that he was the author of the book Chemical Experiments and that he was a doctor and fan of iatrochemistry . That only changed with an essay by Lothar Beyer in 2016.

He was the only son of the surgeon and Bader Gottlob Bernhardt (1683-1723) in Weiltingen near Ansbach and Maria Catharina Bernhardt (1688-1741). The father was accused of adultery, which is why he was prosecuted. In 1723, after the death of her father, the mother married the surgeon and bath surgeon Johann Conrad Häberlin in Weiltingen. He probably apprenticed to his stepfather and also took his first name Johann (he kept his first name Christian). He married Anna Martha Viebiger (died 1796) in Langenbernsdorf in 1749, the daughter of a draper from Zittau . With her he had three sons and a daughter Charlotte Henriette Bernhardt (born 1759), who married the bath surgeon and surgeon Johann Friedrich August Mayer from Potsdam in 1776 and had 14 children with him.

At the time of his marriage in 1749 he accompanied Count Rochus Friedrich Graf zu Lynar (1708–1781), who was the Danish ambassador to Russia, as a travel surgeon to Saint Petersburg. In 1751 he returned with the count and settled down as a bath and surgeon in Langenbernsdorf. In 1752 the first son was born. In 1754 he wrote his book on chemistry there. There was also a Johann Bernhard living in Langenbernsdorf, who was a Bader and died in 1754 and was the godfather of the firstborn (probably an uncle of Christian Bernhardt). It is not known where his laboratory was (there were larger ore processing plants nearby, and he obtained his vitriol gravel as the starting material for sulfuric acid production from mines in Beyerfeld near Schwarzenberg in the Ore Mountains).

Chemical experiments

In his book Chemical Trials (Leipzig 1755), Bernhardt deals in detail with the extraction of large amounts of highly concentrated sulfuric acid using the vitriol method , which is at the same time the first such description in the literature. Before the lead chamber process was developed, the vitriol process was the only known production method for sulfuric acid and was used to a large extent, especially in Bohemia and Saxony ( Nordhauser vitriol oil). Furthermore, the production of nitric acid and ethers from ethanol and sulfuric acid (one of the earliest precise descriptions of ether synthesis) is described. Bernhardt was the first to describe the difference between sulfur trioxide and pyrosulfuric acid . In addition to galley stoves , which are described in detail with detailed drawings, there are also descriptions of sand bath stoves .

Bernhardt spoke out against the secrecy of procedures and recipes and criticized the alchemical literature in this regard, which he made responsible for the most diverse harmful influences due to its dark expression . Literally he writes in the foreword of his book: The dark and puzzling way of writing of the alchemists has put quite a few people in great harm , and elsewhere: It might be better if the alchemists had never written anything about their art because they did not write more clearly . Perhaps not so many thousands of people would have lost their temporal happiness, nourishment, honor, body, and indeed their bliss. In his own words, Bernhardt does not feel bound by the confidentiality requirements of the adepts of alchemy, since he gained the knowledge through his own work and diligence . Bernhardt doubts the possibility of the alchemical conversion of metals in the book, but sees merits of alchemy in instructions for the production of medicines from minerals. The book also has medical histories from his practice, indicating that he is a doctor. Since only simple people are mentioned and nothing else is known about him, he was probably not a court doctor, but a country doctor. The foreword was written in Langenbernsdorf near Zwickau and dated October 1754.

The main aim of his book, as the title suggests, was the manufacture of medicines. With the help of sulfuric acid, he produced some drugs, such as an anodynous liquor , probably the Hoffmann drops (a mixture of ethanol and ether) and naphtha vitrioli ( diethyl ether ) , which had been known for a long time . The uses of Liquor anodynus (also for the production of herbal extracts) and of diluted sulfuric acid for plant extracts are described, but not the use of Naphta vitrioli .

Bernhardt evidently knew the chemical literature of the time, for example he cited Basilius Valentinus , Georg von Welling and Pierre-Jean Fabre as well as Hieronymus von Ludolf , Johannes Kunckel and Georg Ernst Stahl .

Fonts

• Chemical experiments and experiences to turn vitriole, saltpeter, furnace soot , mercury, arsenic, galbano , myrrh , the Peruvian fever bark and fly sponges into powerful drugs . Breitkopf, Leipzig 1755 ( digitized version ).

literature

• Winfried R. Pötsch, Annelore Fischer, Wolfgang Müller: Lexicon of important chemists . In: Lexicon of important chemists . Harri Deutsch, Frankfurt am Main 1989, ISBN 3-8171-1055-3 .
• Claus Priesner : Johann Christian Bernhardt and vitriolic acid. Life and work of an (almost) unknown doctor-chemist in the 18th century. In: Chemistry in Our Time . Vol. 16 (1982), H. 5, pp. 149-159, doi: 10.1002 / ciuz.19820160504 .
• Lothar Beyer: Biographical information about Johann Christian Bernhardt (1710–1758) - an important iatrochemist of the 18th century. In: History of Pharmacy, DAZ supplement, November 2016, pp. 61–65.

Remarks

1. ↑ Entry in the church book of Weiltingen. There, Christian Wilhelm Gottlieb Bernhardt is given as the birth name
2. ↑ The first description of the production of ethers from sulfuric acid and ethanol comes from the doctor Valerius Cordus in 1535, but was forgotten and was rediscovered by August Sigmund Frobenius in 1730 and the process published in 1741. Bernhardt does not seem to have known Frobenius.
3. ↑ Quoted from Priesner Johann Christian Bernhardt and vitriolic acid . In: Chemistry in Our Time. 1982, No. 5, p. 150.
4. ↑ Despite its medical effectiveness, Priesner, loc. cit. P. 158.