Lazarus Ercker Collection

Recovery of gold from amalgum
863649 Recovery of gold from amalgum; (add.info.: Recovery of gold from amalgum. 7) chamois leather bag for separating amalgum from excess mercury

Purification of silver in muffle furnace
863683 Purification of silver in muffle furnace; (add.info.: Purification of silver in a muffle furnace. From 1683 English edition of Lazarus Ercker "Beschreibung allerfurnemisten mineralischen)

Assay laboratory with various forms of furnace
863682 Assay laboratory with various forms of furnace; (add.info.: Assay laboratory with various forms of furnace including and athanor or Slow Harry, 7, self-stoking furnace for cementation, 9)

Various muffles used in assay ovens
863648 Various muffles used in assay ovens; (add.info.: Assaying: Various muffles used in assay ovens for assaying gold and silver 1, 2, 3: 4, 5, 6, stopples, bottom plates and covers: 7)

Roasting gold ore
863652 Roasting gold ore; (add.info.: Roasting gold ore in order to recover the precious metal. From 1683 English edition of Lazarus Ercker "Beschreibung allerfurnemisten mineralischen Ertzt)

Assaying copper and lead
863650 Assaying copper and lead; (add.info.: Assaying copper and lead: prepared and weighed ore (1) and assay oven (2). From 1683 English edition of Lazarus Ercker "Beschreibung allerfurnemisten

Assay laboratory for gold and silver, 1574 (engraving)
863685 Assay laboratory for gold and silver, 1574 (engraving); (add.info.: Assay laboratory for gold and silver. 1) Furnace: 2) Sheet of iron onto which assays are poured: 3) Parting flask

Refining gold
863684 Refining gold; (add.info.: Refining gold: furnaces, 2, 2, and operator, 9. The man near 4 is gradually heating a crucible surrounded by a ring of burning coals)

Assaying of silver
863654 Assaying of silver; (add.info.: Assaying of silver: 1&3, moulds for making cupels: 2&4, the cupels: 8, man moulding cupels)

Assaying copper
863653 Assaying copper; (add.info.: Assaying copper: Furnaces (1, 4), ore (3), bellows (5), and aeolipile (6) to supply draught to furnaces. Pot in which flux is prepared (8)

Smelting copper
863647 Smelting copper; (add.info.: Smelting copper. From a 1683 English edition of Lazarus Ercker "Beschreibung allerfurnemisten mineralischen Ertzt- und Berckwercksarten" originally)

Refining of silver
863651 Refining of silver; (add.info.: Refining of silver, showing (2) a test put into the furnace and (3) burning the silver in a test

Interior view of a 16th century metallurgical workshop. Men are removing impurities from silver. From a book by Lazarus Ercker c 1539 - 1594, a Bohemian metallurgist who wrote treatises on metallurgy

Preparation of copper and silver to be alloyed for production of coins, 1683. Copper is melted (1) while an apprentice (9) soaks birch twigs in water

Crystallization of saltpetre (nitre, potassium nitrate, or KN03), 1683. Saltpetre is the principal ingredient in gunpowder, and is still used in the preservation of some foods

Checking the quality of saltpetre (nitre, potassium nitrate, or KN03), 1683. Saltpetre is the principal ingredient in gunpowder, and is still used in the preservation of some foods

Laboratory for refining gold and silver, showing typical laboratory equipment, 1683. 1) Athanor or Slow Harry, a self-feeding furnace maintaining a constant temperature

Production of saltpetre (nitre, potassium nitrate, or KN03), 1683. Nitre beds, heaps of manure mixed with chalky earth. These were watered with urine and manure water

Distillation of Nitric Acid, 1683. Also known as Aqua Fortis or Parting Acid, nitric acid was widely used in the refining and assaying of metals

Athanor or Slow Harry, a self-feeding furnace maintaining a constant temperature, 1683. Centre: 1) Athanor or Slow Harry ; 2) side chambers containing reagents; 3) glass receivers

Furnace for processes where protracted heat required, such as cementation, 1580
Furnace for processes where protracted heat required, such as cementation, 1683. This furnace is gravity-fed and self-stoking

Washing ore to extract gold, 1683. Water is fed into a sieve containing crushed ore. The solution containing ore in suspension is fed along collecting pans, often lined with dark woollen cloth

Assayer testing samples of gold or silver using a balance, 1683. Artist: Lazarus Ercker
Assayer testing samples of gold or silver using a balance, 1683. From English edition of Lazarus Ercker Allerfurnemisten mineralischen Ertzt und Berckwercksarten, originally published in Prague, 1574

Smelting of copper, 1683
Smelting of copper: making liquation cakes by reducing copper in furnaces and alloying with lead, 1683. From an English edition of German metallurgist Lazarus Erckers Beschreibung allerfurnemisten

Assayer testing samples of gold and silver, 1683. Copperplate engraving from the 1683 English edition of Beschreibung Allerfurnemisten Mineralischen Ertzt (Treatise on Ores and Asssaying)

Refining copper using the Hungarian process, 1683. Copperplate engraving showing cupellation cakes being roasted, releasing lead. The lead obtained is smelted at top left

Blast furnaces, 1683. Illustration from the 1683 English edition of Beschreibung Allerfurnemisten Mineralischen Ertzt (Treatise on Ores and Asssaying), by Lazarus Ercker, published in 1580

For sale as Licensed Images

Choose your image, Select your licence and Download the media

"Lazarus Ercker: Mastering the Alchemy of Metals in 1683" Step into the world of Lazarus Ercker, a renowned alchemist and metallurgist whose expertise revolutionized the production of coins and precious metals. In his laboratory, Ercker meticulously prepared copper and silver alloys for coinage, ensuring their durability and value. With great precision, Ercker demonstrated the crystallization process of saltpetre (potassium nitrate), a vital component in gunpowder production. His mastery extended to checking its quality, guaranteeing its potency for military purposes. Inside his well-equipped laboratory, Ercker showcased an array of tools used for refining gold and silver. From crucibles to retorts, each instrument played a crucial role in extracting pure precious metals from impurities. Ercker's ingenuity also encompassed the production of saltpetre itself. Through meticulous processes involving various chemicals and reactions, he ensured a steady supply for both warfare and medicinal applications. The distillation of Nitric Acid was another feat achieved by this brilliant scientist. With intricate apparatuses at hand, Ercker skillfully separated this powerful acid from other substances through careful heating techniques. At the heart of his laboratory stood an Athanor or Slow Harry furnace – an ingenious invention that maintained a constant temperature without external intervention. This self-feeding marvel allowed him to conduct experiments requiring prolonged heat exposure with ease. For processes demanding protracted heat such as cementation, Ercker employed specially designed furnaces capable of sustaining high temperatures over extended periods. These innovative contraptions facilitated complex metallurgical procedures with remarkable efficiency. Ercker's pursuit didn't stop at chemical transformations; he also delved into ore extraction methods to obtain coveted gold particles. By carefully washing ores through various techniques, he unlocked nature's hidden treasures while preserving their purity. As an assayer extraordinaire, Ercker tirelessly tested samples using precise balances to determine their gold or silver content.