History of Civilization in England, Vol. 2 of 3

by Henry Thomas Buckle

[1123] Dr. Lindley (Third Report of Brit. Assoc. p. 33) says, that Desfontaines was the first who demonstrated the opposite modes of increase in dicotyledonous and monocotyledonous stems. See also Richard, Eléments de Botanique, p. 131; and Cuvier, Eloges, vol. i. p. 64. In regard to the steps taken by Adanson and De Monceau, see Winckler, Gesch. der Botanik, pp. 204, 205; Thomson's Chemistry of Vegetables, p. 951; Lindley's Introduc. to Botany, vol. ii. p. 132.

[1124] It is curious to observe how even good botanists clung to the Linnæan system long after the superiority of a natural system was proved. This is the more noticeable, because Linnæus, who was a man of undoubted genius, and who possessed extraordinary powers of combination, always allowed that his own system was merely provisional, and that the great object to be attained was a classification according to natural families. See Winckler, Geschichte der Botanik, p. 202; and Richard, Eléments de Botanique, p. 570. Indeed, what could be thought of the permanent value of a scheme which put together the reed and the barberry, because they were both hexandria; and forced sorrel to associate with saffron, because both were trigynia? Jussieu's Botany, 1849, p. 524.

[1125] The Genera Plantarum of Antoine Jussieu was printed at Paris in 1789; and, though it is known to have been the result of many years of continued labour, some writers have asserted that the ideas in it were borrowed from his uncle, Bernard Jussieu. But assertions of this kind rarely deserve attention; and as Bernard did not choose to publish anything of his own, his reputation ought to suffer for his uncommunicativeness. Compare Winckler, Gesch. der Botanik, pp. 261–272, with Biog. Univ. vol. xxii. pp. 162–166. I will only add the following remarks from a work of authority, Richard, Eléments de Botanique, Paris, 1846, p. 572: ‘Mais ce ne fut qu'en 1789 que l'on eut véritablement un ouvrage complet sur la méthode des familles naturelles. Le Genera Plantarum d'A. L. de Jussieu présenta la science des végétaux sous un point de vue si nouveau, par la précision et l'élégance qui y règnent, par la profondeur et la justesse des principes généraux qui y sont exposés pour la première fois, que c'est depuis cette époque seulement que la méthode des familles naturelles a été véritablement créée, et que date la nouvelle ère de la science des végétaux…. L'auteur du Genera Plantarum posa le premier les bases de la science, en faisant voir quelle était l'importance relative des différents organes entre eux, et par conséquent leur valeur dans la classification…. Il a fait, selon la remarque de Cuvier, la même révolution dans les sciences d'observation que la chimie de Lavoisier dans les sciences d'expérience. En effet, il a non seulement changé la face de la botanique; mais son influence s'est également exercée sur les autres branches de l'histoire naturelle, et y a introduit cet esprit de recherches, de comparaison, et cette méthode philosophique et naturelle, vers le perfectionnement de laquelle tendent désormais les efforts de tous les naturalistes.’

[1126] Hence the removal of a great source of error; since it is now understood that in dicotyledons alone can age be known with certainty. Henslow's Botany, p. 243: compare Richard, Eléments de Botanique, p. 159, aphorisme xxiv. On the stems of endogenous plants, which, being mostly tropical, have been less studied than the exogenous, see Lindley's Botany, vol. i. pp. 221–236; where there is also an account, pp. 229 seq., of the views which Schleiden advanced on this subject in 1839.

[1127] On the arrangement of the leaves, now called phyllotaxis, see Balfour's Botany, p. 92; Burdach's Physiologie, vol. v. p. 518.

[1128] The classification by cotyledons has been so successful, that, ‘with very few exceptions, however, nearly all plants may be referred by any botanist, at a single glance, and with unerring certainty, to their proper class; and a mere fragment even of the stem, leaf, or some other part, is often quite sufficient to enable him to decide this question.’ Henslow's Botany, p. 30. In regard to some difficulties still remaining in the way of the threefold cotyledonous division of the whole vegetable world, see Lindley's Botany, vol. ii. pp. 61 seq.

[1129] Mr. Swainson (Study of Natural History, p. 356) says ‘mineralogy, indeed, which forms but a part of chemistry.’ This is deciding the question very rapidly; but in the meantime, what becomes of the geometrical laws of minerals? and what are we to do with that relation between their structure and optical phenomena, which Sir David Brewster has worked out with signal ability?

[1130] The difficulties introduced into the study of minerals by the discovery of isomorphism and polymorphism, are no doubt considerable; but M. Beudant (Minéralogie, Paris, 1841, p. 37) seems to me to exaggerate their effect upon ‘l'importance des formes crystallines.’ They are much more damaging to the purely chemical arrangement, because our implements for measuring the minute angles of crystals are still very imperfect, and the goniometer may fail in detecting differences which really exist; and, therefore, many alleged cases of isomorphism are probably not so in reality. Wollaston's reflecting goniometer has been long considered the best instrument possessed by crystallographers; but I learn from Liebig and Kopp's Reports, vol. i. pp. 19, 20, that Frankenheim has recently invented one for measuring the angles of ‘microscopic crystals.’ On the amount of error in the measurement of angles, see Phillips's Mineralogy, 1837, p. viii.

[1131] He says, ‘depuis plus de vingt ans que je m'occupe de cet objet.’ Romé de Lisle, Cristallographie, ou Description des Formes propres à tous les Corps du Règne Minéral, Paris, 1783, vol. i. p. 91.

[1132] See his Essai de Cristallographie, Paris, 1772, p. x.: ‘un de ceux qui m'a le plus frappé ce sont les formes régulières et constantes que prennent naturellement certains corps que nous désignons par le nom de cristaux.’ In the same work, p. 13: ‘il faut nécessairement supposer que les molécules intégrantes des corps ont chacune, suivant qui lui est propre, une figure constante et déterminée.’ In his later treatise (Cristallographie, 1783, vol. i. p. 70), after giving some instances of the extraordinary complications presented by minerals, he adds: ‘Il n'est donc pas étonnant que d'habiles chimistes n'aient rien vu de constant ni de déterminé dans les formes cristallines, tandis qu'il n'en est aucune qu'on ne puisse, avec un peu d'attention rapporter à la figure élémentaire et primordiale dont elle dérive.’ Even Buffon, notwithstanding his fine perception of law, had just declared, ‘qu'en général la forme de cristallisation n'est pas un caractère constant, mais plus équivoque et plus variable qu'aucun autre des caractères par lesquels on doit distinguer les minéraux.’ De Lisle, vol. i. p. xviii. Compare, on this great achievement of De Lisle's, Herschel's Nat. Philos. p. 239: ‘he first ascertained the important fact of the constancy of the angles at which their faces meet.’