The history of cyanide dates back to ancient times, but its modern discovery and understanding are tied to the development of chemistry in the 18th and 19th centuries. Cyanide's name comes from the Greek word "kyanos," meaning "dark blue," referring to the dark blue color of a compound derived from it. Its development involves key discoveries in the fields of both chemistry and industry.
Key Historical Milestones in the Invention and Discovery of Cyanide:
1. Early Knowledge and Use of Cyanide Compounds:
- Ancient Times: Some cyanide compounds existed in the natural world, such as cyanogenic glycosides found in plants (e.g., the pits of cherries and almonds). These plants, when ingested or chewed, can release small amounts of hydrogen cyanide (HCN).
- Prussian Blue Pigment (1706): The discovery of Prussian blue (a dark blue pigment) by the German color maker Johann Jacob Diesbach is one of the earliest recorded events involving cyanide compounds. Prussian blue was accidentally produced when Diesbach was working with potash (potassium carbonate) contaminated with animal blood. The blood contained iron, which reacted with the potash, creating the pigment. Though not understood at the time, the pigment contained iron cyanide compounds (ferric ferrocyanide), marking cyanide's first significant use in a material.
2. Discovery of Hydrogen Cyanide (Prussic Acid) – 1782:
- Carl Wilhelm Scheele: A Swedish chemist, Scheele was the first to isolate hydrogen cyanide (then called "Prussic acid") in 1782. He did this by heating Prussian blue pigment with acids, which led to the release of hydrogen cyanide gas. Scheele is credited with recognizing this gas as a distinct chemical substance.
Hydrogen cyanide (HCN) quickly became recognized for its highly poisonous nature, and Scheele's discovery laid the groundwork for later developments in cyanide chemistry.
3. Identification and Naming of Cyanide – Early 19th Century:
- Joseph Louis Gay-Lussac (1815)**: Gay-Lussac, a French chemist, gave hydrogen cyanide its modern chemical name, "cyanogen," meaning "producer of blue," due to its link with the blue Prussian pigment. He also worked extensively on understanding the molecular structure of cyanogen and other cyanide compounds, helping to clarify their composition.
- Jean-Baptiste Dumas: In the 1830s, Dumas, another French chemist, further explored cyanide compounds and helped categorize them into organic and inorganic cyanides, enhancing the scientific understanding of their properties.
4. Development of Cyanide in Industry:
- 19th Century Industrialization: As chemistry advanced during the Industrial Revolution, cyanide compounds found numerous industrial applications. In the 19th century, cyanide salts such as potassium cyanide (KCN) and sodium cyanide (NaCN) began to be synthesized in laboratories for various uses. These salts were discovered to be effective in metallurgical processes.
- Gold and Silver Extraction: Cyanide's ability to form stable complexes with gold and silver revolutionized mining. In 1887, the MacArthur-Forrest process was developed by Scottish chemists John Stewart MacArthur and the Forrest brothers (Robert and William Forrest). This process involved using dilute solutions of cyanide to extract gold from low-grade ores, making cyanide pivotal to the mining industry. This marked a significant development in the large-scale industrial use of cyanide.
5. Cyanide in Warfare and Poisonings:
- Chemical Weapons: Cyanide’s highly toxic properties led to its use as a chemical weapon. During World War I, hydrogen cyanide (HCN) was used as a chemical weapon, though it was not as effective on the battlefield as other chemical agents like mustard gas due to its rapid dispersion.
- Assassination and Espionage: Cyanide has also been notoriously used in espionage and assassinations. Secret agents in World War II carried cyanide capsules to commit suicide if captured, and notable figures such as Nazi officials used cyanide to avoid capture after the fall of the Third Reich. Cyanide's lethal nature made it the substance of choice in various high-profile cases of suicide and political assassinations.
6. Mass Suicides and Accidental Poisonings:
- Jonestown Massacre (1978): One of the most famous instances of cyanide poisoning occurred during the Jonestown Massacre, where more than 900 members of the Peoples Temple, a cult led by Jim Jones, committed mass suicide by drinking a cyanide-laced drink. This tragic event drew significant attention to cyanide as a fast-acting and deadly poison.
Summary of Cyanide’s Historical Impact:
- Scientific Advancements: The discovery of cyanide and its compounds was pivotal in advancing chemistry, especially in the understanding of chemical bonding and molecular structures.
- Industrial Uses: Cyanide’s role in gold and silver extraction remains one of its most important applications in modern industry. Its application in electroplating, plastics, and synthetic fibers also highlights its industrial significance.
- Lethal Legacy: Despite its industrial importance, cyanide’s notoriety stems from its use as a deadly poison, both in warfare and in numerous incidents of mass suicide and assassination. Its potent toxicity has led to tight regulations and safety protocols in industries where cyanide is used.
In summary, the invention and discovery of cyanide involve key figures in chemistry like Carl Wilhelm Scheele and Joseph Louis Gay-Lussac, who helped identify and understand its composition. Over the centuries, cyanide transitioned from a chemical curiosity to a critical industrial tool and a feared poison.
