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Charles Bonnet

Born 1720
Died 1793

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French philosopher and natural scientist, born March 13, 1720, Geneva; died May 20, 1793, Genthod, near Geneva.

Biography of Charles Bonnet

Charles Bonnet was born to a French family driven into Switzerland by the religious persecution in the 16th century. His parents were Pierre Bonnet, a member of the Geneva council, and Anne-Marie Lullin de Châteauvieux. He went at least partially deaf when he was seven years old. Because he was teased at school he received his first education from private tutors.

In his sixteenth year he read the account of the ant-lion in Noël-Antoine Pluche's (1688-1761) Spectacle de la nature (Paris, 1732-1750) which turned his attention to insect life. He was also strongly influenced by René-Antoine Ferchault de Réaumur's (1683-1757) work Mémoires pour servir à l'histoire des insects (Paris, 1738).

Bonnet initially studied law, but the natural sciences occupied him more and more, and he was extremely successful. In 1740 he communicated to the academy of sciences a paper containing a series of experiments establishing what is now termed parthenogenesis (development of an egg without sperm) in female aphids, also known as tree-lice, lant louse, greenfly, or ant cow. This work made him, that year, the youngest corresponding member of the Académie des sciences in Paris. Parthogenesis is Greek for "virgin birth".

In 1741 he began to study reproduction by fusion and the regeneration of lost parts in the freshwater hydra and other animals. The following year he discovered that the respiration of caterpillars and butterflies is performed by pores, to which the name of stigmata has since been given. He also studied tapeworms. These investigations earned him a membership of the Royal Society of London in 1743, the same year he became a doctor of laws. That seems to be his last effort in that profession.

His discoveries regarding insects were published in Traité d'insectologie in Paris in 1745.

Bonnet also studied photosynthesis in plants and noted the emission of bubbles by a submerged illuminated leaf. This very visible production of oxygen by an illuminated leaf is still used regularly in school laboratories as a way of investigating rates of photosynthesis. In 1754 he published one of his most original works, Recherches sue l’usage des feuilles dans les plantes, in which he advances the idea that plants are endowed with powers of sensation and discernment.

At this time Bonnet devoted his energy entirely to work in philosophy and the natural sciences. However, a progressive visual impairment forced him to concentrate more on philosophy and the theoretical questions in biology.

In order to explain the fossil findings of extinct species, Bonnet, in his work La Palingénésie philosophique, advocated the view that the earth is periodically struck by global disasters. In these disasters most organisms die and the survivors climb the scala natura to reach new heights. According to this, mankind, the peak of evolution, would develop into angels after the next disaster, when plants would become animals, animals would become intelligent beings, and minerals would become plants. This disaster theory to explain evolution strongly influenced Erasmus Darwin (1731-1802), Charles Darwin's (1809-1882) grandfather. This makes Charles Bonnet one of the first biologist to use the term evolution in a biological context. However, he was stuck in the preformation theory, believing that each female organism contains within its germ cells an infinite series of preformed individuals, leading to an immortality and immutability of species.

Charles Bonnet described a lady who insisted of dressing in a death shroud and being put in a coffin. She demanded to be buried and when refused, remained in her coffin until she died several weeks later.

In 1755 Bonnet married Marie-Jeanne De la Rive, the daughet of Horace-Bénédict and Jeanne-Marie Franconis. He lived an uneventful life and he seems never to have left Geneva (which became a part of Switzerland in 1815). From 1752 to 1768 he was a member of the Grand Council (Grosser Rat) of Geneva, but then retired to his estate Genthod at the Geneva lake. Some of the sources below contain list of his works.

We thank Patrick Jucker-Kupper, Switzerland, for information submitted.

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