The third type was composed of irregular aggregates of sand and rock. An addition
to the second edition is a long description of the different inorganic bodies in the
Earth crust: salts, earths, combustible bodies and metals. The work with Gahn in the
late 1760s on crystals (Sect. 25.9) also inspired him to write a paragraph on
crystallography and crystallisation.
The formation of the magnetic core was difficult for Bergman to discuss, as no
knowledge of its nature was available. It was clear, however, that the surrounding
crust once had been liquid or at least soft enough for the centrifugal force to flatten
the Earth at the poles. It appeared unlikely to Bergman that God had designed the
Earth that way. The mechanism behind the creation of the chemical elements was
completely unknown, but it was clear that they initially had been very finely divided
so that they could be dissolved or suspended in water. At this point Bergman does
not seem to differentiate between the concept of element and particle. Bergman
regarded the mountains as the skeleton of the Earth, which prevented the surface
from collapsing and flattening. Valleys had once been carved out by water perhaps
fluctuations of the location of the Earths centre of gravity had been a driving force.
Bergman continued the discussion of petrifications from part 1, and the questions why fossilised rhinoceroses were found in Siberia. Some authors had argued
that the climate once had been much warmer in Siberia, which Bergman concluded
was astronomically impossible. This was long before there was any evidence
suggesting the continental drift. The only possibility, according to Bergman, was
that their dead bodies were brought there by the Deluge. When discussing the
formation of minerals, Bergman concluded that there did not appear to be any
formation of new minerals in the present day. He also briefly mentioned alchemy
and the possibility of preparing gold. Bergman argued that it would be ridiculous to
establish rules for what nature can or cannot do; there were, however, no evidence
for transmutation [51]. Bergman concluded that “Thus, water has been the most
prominent reason to the state, which the Earth’s surface has adopted” [52]. The
Deluge, which other more traditional authors attributed a great importance, is only
discussed briefly on the last page of the chapter.
The last, sixth, part of the book is devoted to organic bodies: plants and animals.
Of special interest is the discussion of the nutrients of plants. Bergman discussed
the famous willow tree experiment of van Helmont, where a willow tree was found
to increase in weight although only water was added and without reducing the
weight of the soil. Bergman rejected the idea that the soil merely supports the roots,
as he had found lime, magnesia, clay and silica in the ashes from plants [53].
Although it was clear that water was the main nutrient for plants, it was also clear
that they took up air and light. Fertilisers caused plants to grow faster, as the plant
did not have to prepare vital substances by themselves. In the second edition,
Bergman also referred to Priestley’s finding that green plants can refurbish foul air
(i.e. converts carbon dioxide to oxygen).
7.2 Physical Description of the Earth
91
to the second edition is a long description of the different inorganic bodies in the
Earth crust: salts, earths, combustible bodies and metals. The work with Gahn in the
late 1760s on crystals (Sect. 25.9) also inspired him to write a paragraph on
crystallography and crystallisation.
The formation of the magnetic core was difficult for Bergman to discuss, as no
knowledge of its nature was available. It was clear, however, that the surrounding
crust once had been liquid or at least soft enough for the centrifugal force to flatten
the Earth at the poles. It appeared unlikely to Bergman that God had designed the
Earth that way. The mechanism behind the creation of the chemical elements was
completely unknown, but it was clear that they initially had been very finely divided
so that they could be dissolved or suspended in water. At this point Bergman does
not seem to differentiate between the concept of element and particle. Bergman
regarded the mountains as the skeleton of the Earth, which prevented the surface
from collapsing and flattening. Valleys had once been carved out by water perhaps
fluctuations of the location of the Earths centre of gravity had been a driving force.
Bergman continued the discussion of petrifications from part 1, and the questions why fossilised rhinoceroses were found in Siberia. Some authors had argued
that the climate once had been much warmer in Siberia, which Bergman concluded
was astronomically impossible. This was long before there was any evidence
suggesting the continental drift. The only possibility, according to Bergman, was
that their dead bodies were brought there by the Deluge. When discussing the
formation of minerals, Bergman concluded that there did not appear to be any
formation of new minerals in the present day. He also briefly mentioned alchemy
and the possibility of preparing gold. Bergman argued that it would be ridiculous to
establish rules for what nature can or cannot do; there were, however, no evidence
for transmutation [51]. Bergman concluded that “Thus, water has been the most
prominent reason to the state, which the Earth’s surface has adopted” [52]. The
Deluge, which other more traditional authors attributed a great importance, is only
discussed briefly on the last page of the chapter.
The last, sixth, part of the book is devoted to organic bodies: plants and animals.
Of special interest is the discussion of the nutrients of plants. Bergman discussed
the famous willow tree experiment of van Helmont, where a willow tree was found
to increase in weight although only water was added and without reducing the
weight of the soil. Bergman rejected the idea that the soil merely supports the roots,
as he had found lime, magnesia, clay and silica in the ashes from plants [53].
Although it was clear that water was the main nutrient for plants, it was also clear
that they took up air and light. Fertilisers caused plants to grow faster, as the plant
did not have to prepare vital substances by themselves. In the second edition,
Bergman also referred to Priestley’s finding that green plants can refurbish foul air
(i.e. converts carbon dioxide to oxygen).
7.2 Physical Description of the Earth
91