that _feu fixe_, caloric, the nervous fluid, and
the electric fluid "are only one and the same substance occurring in
different states."

FOOTNOTES:

[107] Charles Bonnet (1720-1793), a Swiss naturalist, is famous for his
work on Aphides and their parthenogenetic generation, on the mode of
reproduction in the Polyzoa, and on the respiration of insects. After
the age of thirty-four, when his eyesight became impaired, he began his
premature speculations, which did not add to his reputation. Judging,
however, by an extract from his writings by D'Archiac (_Introduction a
l'Etude de la Paleontologie stratigraphique_, ii., p. 49), he had sound
ideas on the theory of descent, claiming that "la diversite et la
multitude des conjunctions, peut-etre meme la diversite des climats et
des nourritures, ont donne naissance a de nouvelles especes ou a des
individus intermediaires" (_Oeuvres d'Hist. nat. et de Philosophie_,
in-8vo, p. 230, 1779).

[108] See his remark: "_On a dit avec raison que tout ce qui a vie
provient d'un auf_" (_Memoires de Physique_, etc., 1797, p. 272). He
appears, however, to have made the simplest organisms exceptions to this
doctrine.

[109] _Elementa physiologiae corporis humani_, iv. Lausanne, 1762.

[110] _Theoria generationis_, 1774.

[111] _Memoires de Physique_, (1797), p. 250.

[112] _Memoires de Physique_, etc. (1797), p. 272.

[113] Huxley's "Evolution in Biology" (_Darwiniana_, p. 192), where be
quotes from Bonnet's statements, which "bear no small resemblance to
what is understood by evolution at the present day."

[114] Buffon did not accept Bonnet's theory of preexistent germs, but he
assumed the existence of "_germes accumules_" which reproduced parts or
organs, and for the production of organisms he imagined "_molecules
organiques_." Reaumur had previously (1712) conjectured that there were
"_germes caches et accumules_" to account for the regeneration of the
limbs of the crayfish. The ideas of Bonnet on germs are stated in his
_Memoires sur les Salamandres_ (1777-78-80) and in his _Considerations
sur les corps organises_ (1762.)

[115] _Memoires de Physique_, etc., pp. 318, 319, 324-359. Yet the idea
of a sort of continuity between the inorganic and the organic world is
expressed by Verworn.

[116] _General Physiology_ (English trans., 1899, p. 17). In France
vitalism was founded by Bordeu (1722-1766), developed further by Barthez
(1734-1806) and Chaussier (1746-1828), and form