Note 309 — Chapter IV

Considering the very long period during which physiology has been studied, it is remarkable how little the physiologists have contributed towards the great and final object of all science, namely, the power of predicting events. To me it appears that the two principal causes of this are, the backwardness of chemistry, and the still extremely imperfect state of the microscope, which even now is so inaccurate an instrument, that when a high power is employed, little confidence can be placed in it; and the examination, for instance, of the spermatozoa has led to the most contradictory results. In regard to chemistry, MM. Robin and Verdeil, in their recent great work, have ably proved what manifold relations there are between it and the further progress of our knowledge of the animal frame; though I venture to think that these eminent writers have shown occasionally an undue disposition to limit the application of chemical laws to physiological phenomena. See Robin et Verdeil, Chimie Anatomique et Physiologique, Paris, 1853, vol. i. pp. 20, 34, 167, 337, 338, 437, 661, vol. ii. pp. 136, 137, 508, vol. iii. pp. 135, 144, 183, 281, 283, 351, 547. The increasing tendency of chemistry to bring under its control what are often supposed to be purely organic phenomena, is noticed cautiously in Turner's Chemistry, vol. ii. p. 1308, London, 1847; and boldly in Liebig's Letters on Chemistry, 1851, pp. 250, 251. The connexion between chemistry and physiology is touched on rather too hastily in Bouilland, Philosophie Médicale, pp. 160, 257; Broussais, Examen des Doctrines Médicales, vol. iii. p. 166; Brodie's Lectures on Pathology, p. 48; Henle, Traité d'Anatomie, vol. i. pp. 25, 26; Feuchtersleben's Medical Psychology, p. 88; but better in Holland's Medical Notes, 1839, p. 270, a thoughtful and suggestive work. On the necessity of chemistry for increasing our knowledge of embryology, compare Wagner's Physiology, pp. 131, 132 note, with Burdach, Traité de Physiologie, vol. iv. pp. 59, 168.