turned to the salts, a field where great progress had been made in recent years. The
composition of old, well-known salts had been determined, and many new salts
discovered, both in mineral, vegetable and animal materials. The “finest and most
remarkable of all hitherto known acids”, however, was common for all three
kingdoms of nature. Bergman was of course talking about his favourite subject,
carbonic acid (aerial acid), which he claimed could restore rotten meat, cure scurvy
and other deceases. He also touched upon the subject of mineral waters. He talked
about the phlogiston content of acids, and that the presence of phlogiston had only
been verified in hydrochloric acid (i.e. it was the only acid that could be oxidised).
Ammonia (volatile alkali) was composed of phlogiston (in this context hydrogen),
and as soon as this was removed an “elastic vapour” remained, insoluble in water
and which extinguished fire. This was nitrogen, and Bergman concluded that it had
so far not been possible to unite nitrogen and hydrogen to ammonia. Large scale
production of ammonia from hydrogen and nitrogen (the important
Haber-Bosch-process) would not be realised until the twentieth century.
Next topic was combustible materials. Sulphurs were substances composed of an
acid and phlogiston, e.g. common sulphur and phosphorus. Oils were probably
composed of phlogiston, aerial acid and water (correct, using the phlogiston theory). The finest oil in the mineral kingdom, petroleum (naphta) occurred in such a
plenty in the East that it often formed springs and streams; the source for that
information is unfortunately not specified. Amber was found to consists of oil, earth
and a special acid (now known as succinic acid).
The metals were the heaviest of all known bodies. The metals had been regarded
as compounds of an earth or calx with phlogiston, but it had recently been found
that arsenic consisted of an acid and phlogiston, and Bergman now suggested that
all metals could be composed in a similar way (Sect. 15.5). Bergman warned the
public of using copper ware for cooking; copper ware could be covered with tin, but
the problem was that tin occasionally was adulterated with toxic lead. Bergman also
mentioned a large lump of iron (weighing 680 kg) that had been found in Siberia.
This was almost certainly the Krasnojarsk meteorite, discovered in 1749; Bergman
believed that it had been formed by some kind of ancient volcanic activity.
After discussing water and its atomic nature (Sect. 22.3), Bergman turned his
attention to the atmosphere, which was not homogenous but composed of three
main components: foul air, good air and aerial acid. Bergman claimed that
inhalation of aerial acid could cure lung deceases. Fresh air was always healthier to
breath than indoor air, according to Bergman.
A number of substances from the vegetable kingdom were discussed by Bergman, e.g. sugar, which was used in “incredible amounts” and rubber. Bergman
hoped that rubber trees could be planted in Europe, and that rubber-coated clothes
and boots could protect people from rain in the future. He especially mentioned
military applications, trying to point at the impact chemistry could have in a large
number of important fields. Animal substances were different from substances
extracted from plants; for example, acids were less common. Bergman mentioned
formic acid, phosphorus, milk, cheese, fats and the study of bladder stones.
264
19 Scheele in Köping
composition of old, well-known salts had been determined, and many new salts
discovered, both in mineral, vegetable and animal materials. The “finest and most
remarkable of all hitherto known acids”, however, was common for all three
kingdoms of nature. Bergman was of course talking about his favourite subject,
carbonic acid (aerial acid), which he claimed could restore rotten meat, cure scurvy
and other deceases. He also touched upon the subject of mineral waters. He talked
about the phlogiston content of acids, and that the presence of phlogiston had only
been verified in hydrochloric acid (i.e. it was the only acid that could be oxidised).
Ammonia (volatile alkali) was composed of phlogiston (in this context hydrogen),
and as soon as this was removed an “elastic vapour” remained, insoluble in water
and which extinguished fire. This was nitrogen, and Bergman concluded that it had
so far not been possible to unite nitrogen and hydrogen to ammonia. Large scale
production of ammonia from hydrogen and nitrogen (the important
Haber-Bosch-process) would not be realised until the twentieth century.
Next topic was combustible materials. Sulphurs were substances composed of an
acid and phlogiston, e.g. common sulphur and phosphorus. Oils were probably
composed of phlogiston, aerial acid and water (correct, using the phlogiston theory). The finest oil in the mineral kingdom, petroleum (naphta) occurred in such a
plenty in the East that it often formed springs and streams; the source for that
information is unfortunately not specified. Amber was found to consists of oil, earth
and a special acid (now known as succinic acid).
The metals were the heaviest of all known bodies. The metals had been regarded
as compounds of an earth or calx with phlogiston, but it had recently been found
that arsenic consisted of an acid and phlogiston, and Bergman now suggested that
all metals could be composed in a similar way (Sect. 15.5). Bergman warned the
public of using copper ware for cooking; copper ware could be covered with tin, but
the problem was that tin occasionally was adulterated with toxic lead. Bergman also
mentioned a large lump of iron (weighing 680 kg) that had been found in Siberia.
This was almost certainly the Krasnojarsk meteorite, discovered in 1749; Bergman
believed that it had been formed by some kind of ancient volcanic activity.
After discussing water and its atomic nature (Sect. 22.3), Bergman turned his
attention to the atmosphere, which was not homogenous but composed of three
main components: foul air, good air and aerial acid. Bergman claimed that
inhalation of aerial acid could cure lung deceases. Fresh air was always healthier to
breath than indoor air, according to Bergman.
A number of substances from the vegetable kingdom were discussed by Bergman, e.g. sugar, which was used in “incredible amounts” and rubber. Bergman
hoped that rubber trees could be planted in Europe, and that rubber-coated clothes
and boots could protect people from rain in the future. He especially mentioned
military applications, trying to point at the impact chemistry could have in a large
number of important fields. Animal substances were different from substances
extracted from plants; for example, acids were less common. Bergman mentioned
formic acid, phosphorus, milk, cheese, fats and the study of bladder stones.
264
19 Scheele in Köping