Johann Friedrich Schweitzer
Johann Friedrich Schweitzer, also known as John Frederick Helvetius (1625–1709) was a Dutch physician and alchemical writer, of German extraction. He is known for his books Vitulus Aureus (The Golden Calf), published in 1667, Ichts aus Nichts, für alle Begierigen der Natur from 1655 and Miraculo transmutandi Metallica, Antwerp, 1667.
He is notorious for the story that he actually carried out transmutation of lead into gold. He is also said to have been physician to the Prince of Orange of the time. His birthplace is given as Cöthen, Anhalt. He is said to have known Baruch Spinoza.
- Joannes Fridericus Helvetius, in Latin, often known as Helvetius.
- See M. Nierenstein Helvetius, Spinoza, and Transmutation Isis, Vol. 17, No. 2 (1932), pp. 408-411.
- His great-grandfather, through Jean-Adrien Helvétius, 1662-1727, who introduced the use of ipecac in his position at the French court, father of another court physician Jean-Claude-Adrien Helvétius, 1685 – 1755, and grandfather to Claude-Adrien.
- Arthur Edward Waite, John Frederick Helvetius: The Famous Alchemist
- Works by Johann Friedrich Helvetius at Project Gutenberg
- The Golden Calf, Which the World Adores, and Desires at Project Gutenberg