Two sets of these extracts from Darwin's letters to Henslow were printed while he was still abroad. The first of these was the series of "Geological Notes made during a survey of the East and West Coasts of South America, in the years 1832, 1833, 1834 and 1835, with an account of a transverse section of the Cordilleras of the Andes between Valparaiso and Mendoza". Professor Sedgwick, who read these notes to the Geological Society on November 18th, 1835, stated that "they were extracted from a series of letters (addressed to Professor Henslow), containing a great mass of information connected with almost every branch of natural history," and that he (Sedgwick) had made a selection of the remarks which he thought would be more especially interesting to the Geological Society. An abstract of three pages was published in the "Proceedings of the Geological Society" (Vol. II. pages 210-12.), but so unknown was the author at this time that he was described as F. Darwin, Esq., of St John's College, Cambridge"! Almost simultaneously (on November 16th, 1835) a second set of extracts from these letters--this time of a general character--were read to the Philosophical Society at Cambridge, and these excited so much interest that they were privately printed in pamphlet form for circulation among the members.
Many expeditions and "scientific missions" have been despatched to various parts of the world since the return of the "Beagle" in 1836, but it is doubtful whether any, even the most richly endowed of them, has brought back such stores of new information and fresh discoveries as did that little "ten-gun brig"--certainly no cabin or laboratory was the birth-place of ideas of such fruitful character as was that narrow end of a chart-room, where the solitary naturalist could climb into his hammock and indulge in meditation.
The third and most active portion of Darwin's career as a geologist was the period which followed his return to England at the end of 1836. His immediate admission to the Geological Society, at the beginning of 1837, coincided with an important crisis in the history of geological science.
The band of enthusiasts who nearly thirty years before had inaugurated the Geological Society--weary of the fruitless conflicts between "Neptunists"and "Plutonists"--had determined to eschew theory and confine their labours to the collection of facts, their publications to the careful record of observations. Greenough, the actual founder of the Society, was an ardent Wernerian, and nearly all his fellow-workers had come, more or less directly, under the Wernerian teaching. Macculloch alone gave valuable support to the Huttonian doctrines, so far as they related to the influence of igneous activity--but the most important portion of the now celebrated "Theory of the Earth"--that dealing with the competency of existing agencies to account for changes in past geological times--was ignored by all alike. Macculloch's influence on the development of geology, which might have had far-reaching effects, was to a great extent neutralised by his peculiarities of mind and temper; and, after a stormy and troublous career, he retired from the society in 1832. In all the writings of the great pioneers in English geology, Hutton and his splendid generalisation are scarcely ever referred to. The great doctrines of Uniformitarianism, which he had foreshadowed, were completely ignored, and only his extravagances of "anti-Wernerianism" seem to have been remembered.
When between 1830 and 1832, Lyell, taking up the almost forgotten ideas of Hutton, von Hoff and Prevost, published that bold challenge to the Catastrophists--the "Principles of Geology"--he was met with the strongest opposition, not only from the outside world, which was amused by his "absurdities" and shocked by his "impiety"--but not less from his fellow-workers and friends in the Geological Society. For Lyell's numerous original observations, and his diligent collection of facts his contemporaries had nothing but admiration, and they cheerfully admitted him to the highest offices in the society, but they met his reasonings on geological theory with vehement opposition and his conclusions with coldness and contempt.
There is, indeed, a very striking parallelism between the reception of the "Principles of Geology" by Lyell's contemporaries and the manner in which the "Origin of Species" was met a quarter of a century later, as is so vividly described by Huxley. ("L.L." II. pages 179-204.) Among Lyell's fellow-geologists, two only--G. Poulett Scrope and John Herschel (Both Lyell and Darwin fully realised the value of the support of these two friends. Scrope in his appreciative reviews of the "Principles" justly pointed out what was the weakest point, the inadequate recognition of sub-aerial as compared with marine denudation. Darwin also admitted that Scrope had to a great extent forestalled him in his theory of Foliation.
