descending scale of the animal kingdom, and the connexion between its development and a general increase of sensuous perception, seem to have been little studied; but Dr. Grant (
Comparative Anatomy, p. 252) thinks that the lens exists in some of the rotifera; while in regard to its origin, I find a curious statement in
Müller's Physiology, vol. i. p. 450, that after its removal in mammals, it has been reproduced by its matrix, the capsule. (If this can be relied on, it will tell against the suggestion of Schwann, who supposes, in his
Microscopical Researches, 1847, pp. 87, 88, that its mode of life is vegetable, and that it is not ‘a secretion of its capsule’). As to its probable existence in the hydrozoa, see
Rymer Jones's Animal Kingdom, 1855, p. 96, ‘regarded either as a crystalline lens, or an otolithe;’ and as to its embryonic development, see
Burdach,
Traité de Physiologie, vol. iii. pp. 435–438.
204
Torricelli first weighed the air in 1643. Brande's Chemistry, vol. i. p. 360; Leslie's Natural Philosophy, p. 419: but there is a letter from Descartes, written as early as 1631, ‘où il explique le phénomène de la suspension du mercure dans un tuyau fermé par en haut, en l'attribuant au poids de la colonne d'air élevée jusqu'au delà des nues.’ Bordas Demoulin, le Cartésianisme, vol. i. p. 311. And Montucla (Hist. des Mathémat. vol. ii. p. 205) says of Descartes, ‘nous avons des preuves que ce philosophe reconnut avant Torricelli la pesanteur de l'air.’ Descartes himself says, that he suggested the subsequent experiment of Pascal. Œuvres de Descartes, vol. x. pp. 344, 351.
205
Dr. Whewell, who has treated Descartes with marked injustice, does nevertheless allow that he is ‘the genuine author of the explanation of the rainbow.’ Hist. of the Induc. Sciences, vol. ii. pp. 380, 384. See also Boyle's Works, vol. iii. p. 189; Thomson's Hist. of the Royal Society, p. 364; Hallam's Lit. of Europe, vol. iii. p. 205; Œuvres de Descartes, vol. i. pp. 47, 48, vol. v. pp. 265–284. On the theory of the rainbow as known in the present century, see Kaemtz, Course of Meteorology, pp. 440–445; and Forbes on Meteorology, pp. 125–130, in Report of British Association for 1840. Compare Leslie's Natural Philosophy, p. 531; Pouillet, Elémens de Physique, vol. ii. p. 788.
206
The Hebrew notion of the rainbow is well known; and for the ideas of other nations on this subject, see Prichard's Physical History of Mankind, vol. v. pp. 154, 176; Kame's Sketches of the History of Man, vol. iv. p. 252, Edinb. 1788; and Burdache's Physiologie, vol. v. pp. 546, 547, Paris, 1839.
207
Thomas calls him ‘le plus grand géomètre de son siècle.’ Œuvres de Descartes, vol. i. p. 89. Sir W. Hamilton (Discussions on Philosophy, p. 271) says, ‘the greatest mathematician of the age;’ and Montucla can find no one but Plato to compare with him: ‘On ne sauroit donner une idée plus juste de ce qu'a été l'époque de Descartes dans la géométrie ancienne… De même enfin que Platon prépara par sa découverte celles des Archimède, des Apollonius, &c., on peut dire que Descartes a jetté les fondemens de celles qui illustrent aujourd'hui les Newton, les Leibnitz, &c.’ Montucla, Hist. des Mathémat. vol. ii. p. 112.
208
‘Descartes joint encore à ses autres titres, celui d'avoir été un des créateurs de notre langue.’ Biog. Univ. vol. xi. p. 154. Sir James Mackintosh (Dissert. on Ethical Philos. p. 186) has also noticed the influence of Descartes in forming the style of French writers; and I think that M. Cousin has somewhere made a similar remark.
209
Thomas says, ‘Descartes eut aussi la gloire d'être un des premiers anatomistes de son siècle.’ Œuvres de Descartes, vol. i. p. 55; see also p. 101. In 1639, Descartes writes to Mersenne (Œuvres, vol. viii. p. 100) that he had been engaged ‘depuis onze ans’ in studying comparative anatomy by dissection. Compare p. 174, and vol. i. pp. 175–184.
210
Dr. Whewell (Hist. of the Inductive Sciences, vol. iii. p. 440) says: ‘It was for the most part readily accepted by his countrymen; but that abroad it had to encounter considerable opposition.’ For this no authority is quoted; and yet one would be glad to know who told Dr. Whewell that the discovery was readily accepted. So far from meeting in England with ready acceptance, it was during many years most universally denied. Aubrey was assured by Harvey that, in consequence of his book on the Circulation of the Blood, he lost much of his practice, was believed to be crackbrained, and was opposed by ‘all the physicians.’ Aubrey's Letters and Lives, vol. ii. p. 383. Dr. Willis (Life of Harvey, p. xli., in Harvey's Works, edit. Sydenham Society, 1847) says ‘Harvey's views were at first rejected almost universally.’ Dr. Elliotson (Human Physiology, p. 194) says, ‘His immediate reward was general ridicule and abuse, and a great diminution of his practice.’ Broussais (Examen des Doctrines Médicales, vol. i. p. vii.) says, ‘Harvey passa pour fou quand il annonça la découverte de la circulation.’ Finally, Sir William Temple, who belongs to the generation subsequent to Harvey, and who, indeed, was not born until some years after the discovery was made, mentions it in his works in such a manner as to show that even then it was not universally received by educated men. See two curious passages, which have escaped the notice of the historians of physiology, in Works of Sir W. Temple, vol. iii. pp. 293, 469, 8vo., 1814.
211
‘Taken by Descartes as the basis of his physiology, in his work on Man.’ Whewell's Hist. of the Induc. Sciences, vol. iii. p. 441. ‘Réné Descartes se déclara un des premiers en faveur de la doctrine de la circulation.’ Renourd, Hist. de la Médecine, vol. ii. p. 163. See also Bordas Demoulin, le Cartésianisme, vol. ii. p. 324; and Œuvres de Descartes, vol. i. pp. 68, 179, vol. iv. pp. 42, 449, vol. ix. pp. 159, 332. Compare Willis's Life of Harvey, p. xlv., in Harvey's Works.
212
‘Les veines blanches, dites lactées, qu'Asellius a découvertes depuis peu dans le mésentère.’ De la Formation du Fœtus, sec. 49, in Œuvres de Descartes, vol. iv. p. 483.
213
Even Harvey denied it to the last. Sprengel, Hist. de la Méd. vol. iv. pp. 203, 204. Compare Harvey's Works, edit. Sydenham Soc. pp. 605, 614.
214
M. Cousin (Hist. de la Philos. II. série, vol. i. p. 39) says of Descartes, ‘Son premier ouvrage écrit en français est de 1637. C'est donc de 1637 que date la philosophie moderne.’ See the same work, I. série, vol. iii. p. 77; and compare Stewart's Philos. of the Mind, vol. i. pp. 14, 529, with Eloge de Parent, in Œuvres de Fontenelle, Paris, 1766, vol. v. p. 444, and vol. vi. p. 318: ‘Cartésien, ou, si l'on veut, philosophe moderne.’
215
‘Descartes avait établi dans le domaine de la pensée l'indépendance absolue de la raison; il avait déclaré à la scholastique et à la théologie que l'esprit de l'homme ne pouvait plus relever que de l'évidence qu'il aurait obtenue par lui-même. Ce que Luther avait commencé dans la religion, le génie français si actif et si prompt l'importait dans la philosophie, et l'on peut dire à la double gloire de l'Allemagne et de la France que Descartes est le fils aîné de Luther.’ Lerminier, Philos. du Droit, vol. ii. p. 141. See also, on the philosophy of Descartes as a product of the Reformation. Ward's Ideal of a Christian Church, p. 498.
216
For, as Turgot finely says, ‘ce n'est pas l'erreur qui s'oppose aux progrès de la vérité. Ce sont la mollesse, l'entêtement, l'esprit de routine, tout
