Goethe, everyone, of course, dies unhappy at the end. Goethe had most probably
not read Bergman’s original work, and Bergman’s name is not mentioned in the
book. It has been suggested that Goethe probably read about elective attractions in
Physikalisches Wörterbuch written by Gehler in 1798 [13]. To make the story
chemically more relevant (a case of double elective attractions), Goethe should
have introduced Otto and Ottilie as a couple. Another similar reference to chemical
affinities is found in Swedish author August Strindberg’s autobiographical novel Le
plaidoyer d’un fou (The Defence of a Fool) from 1895: “It reminded of chemical
elective attractions, here active between living beings” [14].
20.2 Bergman’s Representation of Chemical Reactions
with Diagrams
Since the days of the alchemists, it was custom to represent chemical substances,
operations and laboratory equipment with symbols. Bergman used a modified set of
alchemical symbols in his notes and letters, and he used those symbols in his
affinity tables. For new substances (especially those that Scheele supplied at an
escalating rate), Bergman had to invent new symbols. Bergman’s symbols are
found, with Latin explanations, on fold out plates in The Chemical Lectures of H.T.
Scheffer and De attractionibus electivis.
In the eighteenth century, there were no reaction formulae in the modern sense.
Jean Beguin (1550–1620) had, however, used a diagram as early as 1615 to
describe the reaction between antimony(III) sulphide and mercury(II) chloride, but
he did not generalise the use of diagrams [15]. In the late 1750’s, William Cullen
used diagrams in his lectures to represent metatesis reactions [15], and according to
Thomas Thomson [16], it was Cullen who introduced the idea of using reaction
diagrams to Joseph Black. Neither Cullen, nor Black, who adopted the diagrams in
his own lectures, used diagrams in any publication.
Bergman independently introduced a system for representing chemical reactions
with diagrams. His system was introduced in The Chemical Lectures of H.T.
Scheffer in 1775 and then used more extensively in De attractionibus electivis.
These diagrams (the Opuscula version has a plate with 64 reactions) could express
both simple and double elective attractions in uniform diagrams, but were a
typographic nightmare, and are not found in any other of Bergman’s publications.
They received only modest use by other authors but were used by German chemist
and pharmacist Johan Trommsdorff (1770–1837), who replaced Bergman’s symbols with text [17, 18]. Similar diagrams were also used by British chemist William
Brande (1788–1866), but without the pointing brackets [19].
Two examples of Bergman’s reaction schemes are shown in Figs. 20.3 and 20.4.
The first example (Fig. 20.3) is the reaction between calcium chloride and
ammonium carbonate. The two reactants are shown to the left and right, respectively, and at the centre is the symbol for water, indicating a reaction in aqueous
solution (via humida). It is a reaction between two salts, so the attractions involved
274
20 Bergman’s Work on Elective Attractions
not read Bergman’s original work, and Bergman’s name is not mentioned in the
book. It has been suggested that Goethe probably read about elective attractions in
Physikalisches Wörterbuch written by Gehler in 1798 [13]. To make the story
chemically more relevant (a case of double elective attractions), Goethe should
have introduced Otto and Ottilie as a couple. Another similar reference to chemical
affinities is found in Swedish author August Strindberg’s autobiographical novel Le
plaidoyer d’un fou (The Defence of a Fool) from 1895: “It reminded of chemical
elective attractions, here active between living beings” [14].
20.2 Bergman’s Representation of Chemical Reactions
with Diagrams
Since the days of the alchemists, it was custom to represent chemical substances,
operations and laboratory equipment with symbols. Bergman used a modified set of
alchemical symbols in his notes and letters, and he used those symbols in his
affinity tables. For new substances (especially those that Scheele supplied at an
escalating rate), Bergman had to invent new symbols. Bergman’s symbols are
found, with Latin explanations, on fold out plates in The Chemical Lectures of H.T.
Scheffer and De attractionibus electivis.
In the eighteenth century, there were no reaction formulae in the modern sense.
Jean Beguin (1550–1620) had, however, used a diagram as early as 1615 to
describe the reaction between antimony(III) sulphide and mercury(II) chloride, but
he did not generalise the use of diagrams [15]. In the late 1750’s, William Cullen
used diagrams in his lectures to represent metatesis reactions [15], and according to
Thomas Thomson [16], it was Cullen who introduced the idea of using reaction
diagrams to Joseph Black. Neither Cullen, nor Black, who adopted the diagrams in
his own lectures, used diagrams in any publication.
Bergman independently introduced a system for representing chemical reactions
with diagrams. His system was introduced in The Chemical Lectures of H.T.
Scheffer in 1775 and then used more extensively in De attractionibus electivis.
These diagrams (the Opuscula version has a plate with 64 reactions) could express
both simple and double elective attractions in uniform diagrams, but were a
typographic nightmare, and are not found in any other of Bergman’s publications.
They received only modest use by other authors but were used by German chemist
and pharmacist Johan Trommsdorff (1770–1837), who replaced Bergman’s symbols with text [17, 18]. Similar diagrams were also used by British chemist William
Brande (1788–1866), but without the pointing brackets [19].
Two examples of Bergman’s reaction schemes are shown in Figs. 20.3 and 20.4.
The first example (Fig. 20.3) is the reaction between calcium chloride and
ammonium carbonate. The two reactants are shown to the left and right, respectively, and at the centre is the symbol for water, indicating a reaction in aqueous
solution (via humida). It is a reaction between two salts, so the attractions involved
274
20 Bergman’s Work on Elective Attractions