Cover Story
Carl Wilhelm Scheele and “fire air”
gas aktuell No. 44, 1993
Photo: Portrait plaque from the house where Carl Wilhelm Scheele was born (no portrait of Scheele made during his lifetime exists)
Cover Story
Carl Wilhelm Scheele and “fire air”
gas aktuell No. 44, 1993
Photo: Portrait plaque from the house where Carl Wilhelm Scheele was born (no portrait of Scheele made during his lifetime exists)
The 250th anniversary of the birth of Carl Wilhelm Scheele, one of the two people who discovered oxygen, is an occasion to look back at the history of this important element and its discovery. Oxygen is indispensable for respiratory and metabolic processes, and therefore essential to life. Moreover, it is the basis for combustion processes, which makes it important for a large share of our energy production. As a chemical element, oxygen was discovered and isolated by C. W. Scheele and J. Priestley independently from each other. A. L. Lavoisier recognized the fundamental significance of oxygen in combustion processes. Although the history of its technical application begins already with the unthinking use of fire some 300,000 years ago, the industrial-scale utilization of oxygen came into practice at the turn of the century with the discovery of air separation by low-temperature rectification. Messer Griesheim’s predecessors were also founded at that time. The history of oxygen technology is inseparably bound to the history of the company. With that in mind, this essay is dedicated to Dr. Hans Messer on his 50-year service anniversary.
Life and work of Carl Wilhelm Scheele
250 years ago, on December 19, 1742, Carl Wilhelm Scheele was born the son of the distinguished merchant Joachim Christian Scheele and his wife Margarethe Eleonore, née Warnekros, in Stralsund. Following elementary instruction in a private school, Scheele began, at the age of 14 and by his own volition, an apprenticeship in Göteborg as a pharmacist. From the pharmacist Bauch, who was connected with the family, he received his basic education there, expanding on it through intensive book study and autonomous experimentation. When the pharmacy was sold in 1765, Scheele moved to Malmö. There, in the “Zum Adler” pharmacy, he worked primarily in the laboratory and, with the support of his employer, continued his experiments. In Malmö, he also established a friendship with A. J. Retzius, who encouraged him to work systematically and to record the results of his experiments.
House in Stralsund where C. W. Scheele was born. At the time of his birth, Stralsund belonged to the Kingdom of Sweden.
In 1768, Scheele moved to Stockholm, where he continued his experiments and began his studies of gas chemistry. At his next stop, in Uppsala, he met his future sponsor, Torbern Bergman. This developed into a fruitful collaboration for both of them. Bergman profited from Scheele’s experiments and discoveries, while Scheele derived considerable benefit from Bergman’s theoretical knowledge, writing skills and worldwide reputation. Bergman was also the one who urged Scheele to conduct his manganese dioxide investigations, which would ultimately crown the air-fire experiments begun in 1768 with the discovery of oxygen and chlorine in 1771. Indeed, it was as a result of those manganese dioxide studies that Scheele was nominated to the Swedish Academy of Sciences and then elected to it in 1775, despite the lack of any certifiable academic training and therefore being considered only a “studiosus pharmaciae.” In April of that same year, he took over the pharmacy of the deceased pharmacist Pohl in Köping, which brought him a certain autonomy. It was also during this period that Scheele wrote his famous magnum opus “Chemical Observation and Experiments on Air and Fire”. He gave it to the publisher for printing at the end of 1775. Completion was delayed, however, and the book was not published until the fall of 1777.
Illustration of Scheele’s basic experiments from “Chemical Observation and Experiments on Air and Fire” published in 1777
Lavoisier’s equipment for gas technology experiments
He accepted neither his nomination to the Berlin Academy nor another from England. “I can eat no more than my fill, and when I can do so in Köping, then I need not look for my bread elsewhere,” he wrote to Bergman. As a condition from the takeover agreement for the pharmacy, he had to pass the pharmacist’s examination in November 1777. He used the opportunity to deliver his entrance address in Stockholm. During the subsequent examination, the examiners paid homage to the already famous researcher, who even figured on the list of nominees for the presidential election. Although someone else was selected by lottery to fill the office of the presidency, Scheele received, upon Bergman’s nomination, a grant of 100 riksdaler per year, which was paid out to him until his death. In 1781, he was able to purchase a new house, where he installed a well-equipped laboratory for the first time. Prior to this, he had made his greatest discoveries while huddled in nooks and crannies as a pharmacist’s apprentice and laboratory technician. In 1778, Scheele was named an honorary member of the “Berlin Society of Friends of Natural Science” and received other honors, some of which reached Köping only after his death on May 21, 1786, however. Scheele’s scientific work covered nearly all facets of chemistry in his day. Self-taught, he retained an unsystematic methodology and mostly pursued multiple investigations simultaneously.
Scheele only rarely conducted rigorous material balances, even though he was aware of the benefits of that approach from the work of Black and Lavoisier. Nevertheless, he was a master of qualitative and synthetic chemistry, and none of his scientific contemporaries possessed such comprehensive knowledge of the reactions of the substances known at the time.
Even 150 years ago, steel cylinders for compressed gases already very closely resembled the ones we use today. The illustration shows a configuration for filling CO₂ under pressure
He developed important fundamentals of analytical chemistry, preparative inorganic chemistry and organic chemistry. The outstanding work in his day in all of these fields testifies to his versatility. What made him truly famous, however, was the discoveries of chlorine, “dephlogistonized hydrochloric acid,” and most of all, oxygen, or “fire air.”