the water surface as experimental proof that water can transform into earth; [7] this
was important for Wallerius, who was searching the scientific means by which God
created Earth. According to Genesis, there was first water, then earth, and Wallerius
thought that Scheele’s work could be a clue to the underlying mechanisms of the
Creation. It is quite typical for Wallerius to pick out the facts that best fit his own
system and reject the rest. Gustaf von Engeström in a lecture (Sect. 9.6) in the
Royal Swedish Academy of Sciences, however, took Scheele’s work as an example
of what he saw as the unreliable nature of modern chemistry (Sect. 13.6) [8].
Scheele’s claim to have discovered a new mineral acid was his most controversial discovery, and he had to write two more papers to defend his ideas. In 1780,
he published the second paper on hydrofluoric acid disproving theories [9] put
forward by Monnet and Boullanger [10]. Scheele showed that all calcium (lime)
from the fluorite and all sulphuric acid added could be accounted for in the formed
calcium sulphate (gypsum), and that the acid was free from hydrochloric acid [9]
It was Scheele’s friend Johan Christian Friedrich Meyer (1739–1811)
1 in Stettin
who first prepared silicon-free hydrofluoric acid by performing the operation in an
apparatus made of lead in 1781, which he told Scheele in a letter. On March 9,
Scheele wrote to Bergman admitting that he had been wrong on believing that the
silicon was an integral part of the acid. He also admitted it in a letter to Ehrhart, who
printed the letter in his journal [11]. In a note, Ehrhart added that “Finally my friend
has surrendered and replaced his unintelligible idea with the truth”. Scheele was
probably not pleased by this comment since he did not send any more letters to
Ehrhart (at least not for publication). Scheele had to return a final time to his
hydrofluoric acid, in which he described the preparation of pure hydrofluoric acid
[12] in a glass-free apparatus [13].
Silicon tetrafluoride was later isolated by John Davy, brother of Sir Humphry
Davy, and when Berzelius passed silicon tetrafluoride over potassium, he became
the first chemist to isolate elemental silicon [14]. The isolation of fluorine from
hydrofluoric acid would be more troublesome, due to the extreme toxicity of
hydrofluoric acid. Scheele was actually very fortunate to survive his studies. Many
of the chemists who attempted to isolate fluorine had to pay a very high price,
including Humphry Davy, Gay-Lussac, and Thénard [15]. The two Irish brothers
George and Thomas Knox were seriously injured and both P Louyet and Jérôme
Nicklès died. Elemental fluorine was finally isolated by French chemist Henri
Moissan (1852–1907) in 1886 [16]. In part due this achievement, Moissan was
awarded the 1906 Nobel Prize in chemistry.
1
Not to be confused with chemist Johann Friedrich Meyer, who launched a theory of carbon
dioxide and lime (Chap. 18).
14.1 Hydrofluoric Acid
205
was important for Wallerius, who was searching the scientific means by which God
created Earth. According to Genesis, there was first water, then earth, and Wallerius
thought that Scheele’s work could be a clue to the underlying mechanisms of the
Creation. It is quite typical for Wallerius to pick out the facts that best fit his own
system and reject the rest. Gustaf von Engeström in a lecture (Sect. 9.6) in the
Royal Swedish Academy of Sciences, however, took Scheele’s work as an example
of what he saw as the unreliable nature of modern chemistry (Sect. 13.6) [8].
Scheele’s claim to have discovered a new mineral acid was his most controversial discovery, and he had to write two more papers to defend his ideas. In 1780,
he published the second paper on hydrofluoric acid disproving theories [9] put
forward by Monnet and Boullanger [10]. Scheele showed that all calcium (lime)
from the fluorite and all sulphuric acid added could be accounted for in the formed
calcium sulphate (gypsum), and that the acid was free from hydrochloric acid [9]
It was Scheele’s friend Johan Christian Friedrich Meyer (1739–1811)
1 in Stettin
who first prepared silicon-free hydrofluoric acid by performing the operation in an
apparatus made of lead in 1781, which he told Scheele in a letter. On March 9,
Scheele wrote to Bergman admitting that he had been wrong on believing that the
silicon was an integral part of the acid. He also admitted it in a letter to Ehrhart, who
printed the letter in his journal [11]. In a note, Ehrhart added that “Finally my friend
has surrendered and replaced his unintelligible idea with the truth”. Scheele was
probably not pleased by this comment since he did not send any more letters to
Ehrhart (at least not for publication). Scheele had to return a final time to his
hydrofluoric acid, in which he described the preparation of pure hydrofluoric acid
[12] in a glass-free apparatus [13].
Silicon tetrafluoride was later isolated by John Davy, brother of Sir Humphry
Davy, and when Berzelius passed silicon tetrafluoride over potassium, he became
the first chemist to isolate elemental silicon [14]. The isolation of fluorine from
hydrofluoric acid would be more troublesome, due to the extreme toxicity of
hydrofluoric acid. Scheele was actually very fortunate to survive his studies. Many
of the chemists who attempted to isolate fluorine had to pay a very high price,
including Humphry Davy, Gay-Lussac, and Thénard [15]. The two Irish brothers
George and Thomas Knox were seriously injured and both P Louyet and Jérôme
Nicklès died. Elemental fluorine was finally isolated by French chemist Henri
Moissan (1852–1907) in 1886 [16]. In part due this achievement, Moissan was
awarded the 1906 Nobel Prize in chemistry.
1
Not to be confused with chemist Johann Friedrich Meyer, who launched a theory of carbon
dioxide and lime (Chap. 18).
14.1 Hydrofluoric Acid
205