adherent of science like Casiano de Prado can scarcely be appreciated except by those who have visited the Peninsula. Our associates Mr. Busk and the late Dr. Falconer, little more than two years ago, visited him at Madrid, and were impressed with his many excellent qualities. And it was only last year that my predecessor in this chair, in his annual address, gave an elaborate résumé of the chief writings of the Spanish geologist, and concluded with a reference to the difficulties encountered by him in the isolation of his work, and with a quotation of his last words, so applicable to his approaching end:-"I always started from Madrid, with my knapsack and hammer, cheerful and full of joy; on my return I never entered its gates without a vague feeling of sadness."

JACQUES AMAND EUDES-DESLONGCHAMPS was born at Caen in Normandy on the 17th of January, 1794. His parents were very poor, and imposed upon themselves severe privations in order to ensure to their son a liberal education. The deep sense of duty with which he was imbued enabled him to conduct to a successful issue a series of brilliant studies, so that at a very early age he obtained his first medical degree in his native town. Unfortunately a relentless European war obliged him to become a soldier; but having already rendered himself conspicuous through his medical studies, at the age of eighteen he received the title of assistant-surgeon to the Imperial Navy, and was on the 28th of October 1812, appointed to the frigate 'La Gloire.' He was a most skilful operator. In November 1815 he became Surgeon Assistant Major to the Military Hospital of Caen, but soon afterwards left the navy and went to Paris to take his degree of Doctor of Surgery. In May 1822 he was elected Surgeon to the Board of Relief of the town of Caen; and the number of poor that followed his funeral, as well as of the wealthier classes, is a proof of the high esteem in which his arduous services were held; indeed his noble mind was wholly bent on doing good and affording relief and encouragement to those who were in need of his aid or advice.

During his sojourn in Paris, however, medicine was not his only study; for comparative anatomy, botany, and physiology had occupied much of his attention; and in these sciences he made himself eminently proficient, as well as in the art of drawing. At that period the gypsum-quarries of Montmartre were disclosing to the genius of Cuvier a multitude of extinct mammalian remains; and these wonderful discoveries had so forcibly struck the ardent young naturalist, that on his return to Caen he lost no time in exploring the quarries in its neighbourhood. Great indeed was his surprise to find them replete with fossil remains of all kinds; and the discovery of a specimen of Teleosaurus Cadomensis so elated him that from that time comparative anatomy and palæontology became one of the chief pursuits of his long and well-employed life. So important and varied were his researches and publications that he was universally recognized as one of the most eminent palæontologists of his day. With Cuvier, E. Geoffroy St. Hilaire, Humboldt, and other

great masters of science he was upon the most intimate terms, and in constant correspondence. At Caen he met Lamouroux, and with him studied corals, and was one of the writers of the Encyclopédie Méthodique,' as well as of the Dictionnaire des Sciences Naturelles ;' he was likewise one of the principal founders of the Museum of Natural History of Caen, and of the Linnean Society of Normandy, which was established in 1823. He became Honorary Curator of that Museum, which he continually augmented by personal exertions; and the Transactions of the Linnean Society are enriched with many of his most important works. In 1825 he succeeded Lamouroux as Professor of Zoology to the Faculty of Sciences of Caen, and on the 22nd of October 1847 was named Dean of the said Faculty, which chairs he retained until the day of his death. No Professor could be more popular or more respected, and he inspired his pupils with a true love of science.

Honours of all kinds were heaped upon him; he was a Corresponding Member of the Institute of France and of numerous other academies and learned societies, an officer of the Legion of Honour, and a Medallist of St. Helena, and was in March 1858 elected a Foreign Member of the Geological Society of London. In 1861 he received a silver medal from the Minister of Public Instruction. In 1863 a gold medal was presented to him as a reward for the first portion of his work on 'Teléosaurus.' In 1864 another gold medal was awarded to him by the Academy of Sciences of Rouen. About two years ago M. Deslongchamps had the great misfortune to lose the sight of one of his eyes; and the other having become much impaired, the calamity produced on his active mind a feeling of deep depression. On the 15th of November last he assisted at the inaugural opening of the Session of the Faculty of Sciences of Caen, where his worthy and distinguished son was occupying his chair as Professor of Zoology. Feeling his end fast approaching, his last few days were spent in dictating to his son what was still necessary in order to enable him to complete the great work on the Fossil Crocodilian remains of Normandy, upon which he had laboured during so many years. Remembering with satisfaction, and frequently on his death-bed recalling to his family the compliment paid to him by the Geological Society of London, he desired that his last great work should be dedicated to that Society. On the 17th of January 1867 he expired, aged 73 years and one month. In him France has lost one of her most distinguished naturalists, and science one of her ablest votaries.

In addressing you a twelvemonth ago, my predecessor in this chair placed before you an account of the general progress of geology, as indicated in a long array of publications, the contents of which, gathered with an industry worthy of all praise, he offered to the Society in so readable a form as to attract and interest all its Fellows. But if my esteemed friend thought it necessary to claim your indulgence for the selection of certain works from amid a vast

body of literature, much more must I, elevated somewhat unexpectedly to the proud position of your President, crave your kind consideration in being allowed to select, as the subject of my address, only a comparatively limited district in the broad domain of our Science.

We retain, happily, among us still, perhaps the most active of our number, eminent men who joined our Society in what we may term its second generation. In their younger days geological science, although rapidly increasing in its dimensions, was not yet too extensive to forbid its entire ambit from being surveyed and explored by a single mind. But the amazing advance of the science within the last fifty years has rendered it necessary more than ever to recognize the limited power of the human intellect. Not only does the descriptive portion of physical geology carry us into a multiplicity of details culled from all parts of the earth, but the subdivision into numerous branches, all of them increasing with the growth of other conterminous sciences, has established the necessity, coupled with advantage to our progress, for working geologists to lay special stress on some particular portion of our subject.

The crowd of works which annually issue from the press of all civilized countries precludes the possibility of referring to the whole of them, except as a mere list of little more than their titles, and renders it incumbent on a President to seek out amongst them either those which may appear to be the more important, or which treat of those particular subjects with which he may happen to be most familiar.

In considering the nature and history of the rocks which form the crust of the globe, it appears to me that since Mr. Horner, a few years ago, gave a full summary of what had been recently done to elucidate the origin of the crystalline and metamorphic rocks, a number of works have appeared, some of them as contributions to our own Journal, others as independent treatises, which should excite more than a passing interest. Views of a very conflicting character have been brought forward: the Huttonian and Wernerian controversy seems almost to be revived in a modified form; and amid the results of observation and of experiment so many important facts have been elicited that I am induced to think it desirable to place before you, even if it be only as a reminder, some of the principal conclusions at which recent authors have arrived.

On looking round at the facilities offered to study by the constant multiplication and improvement of geological maps, I think it behoves me first to say a few words on the advancement of those surveys in which we are most nearly interested.

During the past year considerable progress in the field has been made by the Geological Survey of Great Britain. The mapping of the London Basin is now approaching completion, excepting on the north-east; and the last of the maps of the Wealden area, that of East Kent, is on the verge of being published. Five sheets of sections across the Weald are also being engraved, which, being on a

true scale both vertically and longitudinally, may help to clear up the still vexed question of the denudation of the Weald.

The mapping of the Lancashire Coal-field and adjoining areas is so far advanced that it is expected to be finished by the close of this year; and the coal-fields of Yorkshire, Newcastle, and Durham are also being mapped, and parts of them are already published. The Survey has also begun to make some progress in the exceedingly difficult country forming part of Westmoreland and Yorkshire near Kendal and Kirkby Lonsdale-a country complicated by great contortions of the Silurian strata, by numerous large faults, and by the concealment of the Silurian Old Red Sandstone and Carboniferous rocks by drift; and it is hoped that a beginning will soon be made to the issue of the geologically coloured maps of the district.

A large tract of Ayrshire has also been surveyed, consisting of Silurian Old Red Sandstone and Carboniferous rocks; and the finished maps are now in the hands of the engravers.

By way of showing the usefulness of these documents to the public I may mention that, in his Annual Report, Sir Roderick Murchison states that during the last ten years more than 36,000 maps and sections of the Geological Survey of Great Britain have been sold, not including, of course, the large numbers given away to learned societies.

The only memoir published by the Survey during last year is that on the Geology of North Wales, by Professor Ramsay. It commences in the 1st and 2nd chapters with an historical account of the nomenclature employed in regard to the formations of which the Silurian series of Britain consists, and sketches their extent and physical relations all through Wales and Shropshire. The remainder of the descriptive geological portion of this volume is occupied with a minute analysis of the structure of the Silurian region of North Wales; and to render this as clear as possible, besides the coloured plates of a map and sections, ninety-nine woodcuts are introduced, mostly illustrative of the physical relations of the rocks all over the country; and it is thus intended that by reference to the book any one may find enough of illustrative matter to enable him to understand the geological structure of almost every hill and valley in North Wales occupied by Silurian rocks. A brief sketch of the surrounding later formations is also given. The relations to each other of the igneous and stratified rocks of this remarkable region are explained according to the views held by Professor Ramsay and his colleagues on the Survey, views in the main held by the late Sir Henry De la Beche. It is shown, in accordance with these views, by the help of numerous sections, that the felspathic rocks consist to a great extent of intrusive bosses, and of great sheets of lava and of consolidated volcanic ashes on two horizons— one at the base of the Bala beds (Llandeilo), and the other on the horizon of the Bala limestone. These have been disturbed and faulted, thrown into anticlinal and synclinal curves, and denuded on a vast scale, whence arises the present physical configuration of the country, the hard rocks generally forming hills and mountains, and the softer slaty beds being apt to lie in valleys. Certain of the terms thus employed involve an assumption as to the origin of the alleged volcanic sub

stances, and some inquirers may dispute this nomenclature with respect to the Lower Silurian lavas and ashes; but practically it was found by the author of the book, and by his colleagues Professor Jukes, Mr. Selwyn, and Mr. Aveline, that until this conclusion was arrived at the igneous rocks could not be reduced to any systematic order, whilst as soon as it was come to the whole seemed to be intelligible, and, instead of presenting further difficulties, the interstratified igneous masses rather aided in the mapping and helped to explain the relations of all the parts to each other.

The second part of the volume consists of a description by Mr. Salter of the fossils illustrative of the memoir, accompanied by numerous plates. On the progress of that ably conducted survey in Canada which has produced such good results, Sir William Logan informs me that the late investigations have been devoted, in the first place, to working out in more detail the structure of that region on the south side of the St. Lawrence in Eastern Canada which is occupied by the Quebec group. That group, instead of including the "calciferous" and chazy," is now placed between them; and it has been found convenient to separate it into a lower, a middle, and an upper division, the lower comprehending nearly all the fossils by which the horizon. of the group is determined, and the middle containing all the magnesian rocks and metalliferous deposits which give the Lower Silurian formations an economic value.

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The geologists have also further followed out, on the westward of what was previously known, the distribution of the three great bands of limestone belonging to the Laurentian system, the upper band being that which holds Eozoon.

It had been already notified to us through Dr. Dawson that fragments of Eozoon had been found preserved in carbonate of lime. Both the large and small canals were in this case filled with calcspar. The specimens come from a micaceo-calcareous schist from the Laurentian of Madoc, where the rocks are not so much altered as they are in Grenville. This year one of the assistants, Mr. Vennor, in tracing this bed into Tudor, the next township to that of Madoc (which is north of Belleville, west of Kingston, Lake Ontario), has been so fortunate as to find a fossil whose white calcareous skeleton is preserved in a dark-coloured arenaceo-micaceous limestone, with minute grains of carbonaceous matter. The limit of the form is well preserved on one side; and although the minute structure is obscure, Dr. Dawson pronounces the fossil to be Eozoon Canadense. We may expect ere long to receive a further communication on this important subject from Sir William Logan himself.

The study of the numerous questions which arise from a careful examination of rocks has been much facilitated by the recent publication of several works treating specially of this branch of geology. Professor von Cotta's well-known treatise has been translated by Mr. Lawrence, one of our Fellows*, with the advantage of corrections and additions by the author, which make it, in fact, the third * Rocks classified and described, by B. von Cotta: an English edition, by Philip Henry Lawrence, F.G.S. Longmans, 1866.