Around 1772, a German-Swedish pharmaceutical chemist discovered oxygen and identified it as 'fire air' but failed to report it in time: How Carl Wilhelm Scheele discovery made a difference?

Around 1772, a German-Swedish pharmaceutical chemist discovered oxygen and identified it as 'fire air' but failed to report it in time. The chemist was Carl Wilhelm Scheele, who worked as an apothecary and pharmacist in Sweden. He conducted chemical experiments with basic equipment available in pharmacies. Scheele prepared oxygen independently of Joseph Priestley and studied its ability to support combustion. He called the gas “fire air” because he believed in the phlogiston theory that was used by many chemists at the time. His work later became part of the history of modern chemistry.

A discovery made before its publication

Carl Wilhelm Scheele was born on December 9, 1742, in Stralsund, Pomerania, a region that was under Swedish jurisdiction at the time. He was the son of a German merchant. In 1757, Scheele became an apprentice to a pharmacist in Gothenburg, Sweden. His interest in chemistry developed during this period. He read books and carried out experiments with chemicals available in the pharmacy.


Scheele completed his apprenticeship in 1765 and moved to Malmö. He worked at a pharmacy there and began making contacts with people connected to academic science. One of these contacts was Anders Jahan Retzius of Lund University. In 1768, Scheele moved to Stockholm. He wanted another pharmacy position and greater contact with scientific circles. In 1770, he moved to Uppsala, where he worked at another pharmacy.

At Uppsala, Scheele met Swedish chemists Johan Gottlieb Gahn and Torbern Bergman. His friendship with Bergman continued until Bergman's death in 1784. Scheele later moved to Köping. He became an apothecary and operated his own business. In 1775, he formally passed an apothecary examination and became a member of the Royal Swedish Academy of Sciences. The Academy also provided him with a yearly pension, allowing him to continue his experiments.

Around 1772, a German-Swedish pharmaceutical chemist discovered oxygen and identified it as 'fire air'

Scheele's work on oxygen began through experiments designed to understand air and combustion. Chemists of the period believed that air contained more than one type of gas. Scheele studied the part of air that supported combustion. He calculated that this part made up about one-fourth of ordinary air.

He tried to obtain this gas from different substances. His experiments included heating mercury oxide and black magnesia. Through these experiments, he produced a gas that supported combustion. Scheele called it “fire air.” His name came from his observation that the gas helped substances burn.

His explanation was based on the phlogiston theory. This theory proposed that a substance called phlogiston was involved in combustion. According to the theory, a material lost phlogiston when it burned. Scheele completed much of this work around 1772. However, he did not publish his findings immediately. His work appeared in his book Chemische Abhandlung von der Luft und dem Feuer, published in 1777.

Joseph Priestley published his independent oxygen experiments earlier. This meant Priestley received publication credit for the discovery, although Scheele had produced and studied the gas independently.

How did Scheele's discovery make a difference?

The study of oxygen changed the understanding of air and combustion. It later became part of the work that helped chemists move away from the phlogiston theory. Scheele's experiments showed that air was not a single substance. His work contributed to the growing study of gases and chemical reactions.

Scheele did not explain oxygen using the chemical theory that became accepted later. Antoine Lavoisier and other chemists later developed explanations that rejected the phlogiston theory and placed oxygen at the center of a new understanding of combustion. Scheele's work therefore became part of the transition from older chemical ideas to modern chemistry.

What did Carl Wilhelm Scheele discover?

Scheele's work covered many areas of chemistry. He is associated with oxygen, chlorine and manganese, along with studies involving barium, molybdenum and tungsten compounds. In 1774, he treated black magnesia, also known as pyrolusite, with muriatic acid, now known as hydrochloric acid. The experiment produced an unknown gas.

Scheele called it “dephlogisticated muriatic acid.” The gas was chlorine. He did not understand its nature in the way modern chemistry does. Scheele also studied black magnesia and recognized that it contained a substance associated with manganese. He was unable to isolate manganese as the metal.

His work also involved barium oxide, molybdenum compounds and tungstic acid. His research on tungsten contributed to the later identification of tungsten as an element, although Scheele did not isolate the metal itself.

Work on acids and organic substances

Scheele studied many acids. He was the first to isolate and describe several organic acids. His work included tartaric acid, oxalic acid, lactic acid, citric acid and malic acid. He called malic acid the “acid of apples.”

He also studied mucic acid, uric acid, prussic acid, gallic acid and pyrogallic acid. His research extended to casein, aldehyde and glycerol. His work showed how an apothecary could contribute to chemical research through the study of substances used in medicine and other areas. Scheele also studied mineral acids. His work included arsenic acid, molybdic acid and tungstic acid. He examined hydrofluoric acid and its salts and studied phosphorus and its compounds.

Scheele's Green and photographic experiments

Scheele also developed a copper arsenite pigment known as Scheele's Green. It was produced using copper compounds and arsenic trioxide. The pigment became used in the 18th and 19th centuries. Later investigations showed that arsenic in the pigment could pose a health risk.

Scheele also studied the effect of light on silver salts. He observed that light could darken silver chloride. He demonstrated that ammonia could help fix images by removing certain silver compounds. This work became part of the early history of photographic chemistry.

How did he conduct his experiments?

Scheele worked under conditions that were different from those of modern laboratories. He did not have access to modern laboratory equipment. He lacked a proper oven capable of producing the heat required for some mineral experiments. He used equipment from pharmacies and often borrowed or improvised instruments.

For experiments involving gases, he used tubes and retorts. He also used a prepared oxen bladder to collect and study gases. His ability to conduct chemical experiments with these materials became an important part of his scientific work.

Scheele developed skill in chemical analysis through repeated experiments. His laboratory notes are believed to contain details of between 15,000 and 20,000 experiments, although only a small part of this work was published.

His relationship with other scientists

Scheele's early work was not always organized through formal laboratory records. Retzius helped him develop a more systematic approach. His friendship with Torbern Bergman also influenced his work. Bergman encouraged Scheele to publish important research and benefited from Scheele's ability to analyze substances.

Scheele, in turn, continued to seek Bergman's advice on chemical theory. Scheele focused on experiments. Other scientists played a larger role in developing the theories used to explain the results.

The delayed report and its impact

Scheele's oxygen discovery became known through his 1777 book. By then, Joseph Priestley had already published his independent work. This delay affected how the discovery was credited in scientific history. Scheele had prepared oxygen before Priestley's published report, but his failure to publish his findings in time meant that Priestley received publication priority.

Scheele's case shows why publication became important in science. Making a discovery was one part of scientific work. Recording and reporting the result also became necessary for establishing priority.

His final years and death

Scheele remained active in chemistry after moving to Köping. His pharmacy provided him with a place to continue his research. His experiments sometimes involved substances that were dangerous. These included cyanide and arsenic. His work was carried out without the ventilation and safety equipment available in modern laboratories.

Scheele died on May 21, 1786, in Köping, Sweden. He was 43 years old. On his deathbed, Scheele married the widow of the town's former apothecary. She had remained as his housekeeper. The marriage allowed the pharmacy and other assets to pass to her.

What is Carl Wilhelm Scheele's legacy?

Carl Wilhelm Scheele is remembered for independent work on oxygen, chlorine and manganese, along with research into many chemical substances. His career began with an apprenticeship in a pharmacy. He later became an apothecary, member of the Royal Swedish Academy of Sciences and a contributor to chemical research.

His oxygen experiments became one of the main parts of his scientific legacy. His other work also helped expand knowledge of acids, minerals, gases, organic substances, pigments and light-sensitive compounds.

His story also explains the importance of scientific publication. Scheele had prepared oxygen before Priestley published his findings, but the delay meant that his role was not immediately recognized in the same way.