material was first introduced by Schönbein in 1846, its distinctive qualities in comparison with gunpowder were recognized, although at that period they were far less well ascertained by experiment than they are at present. To the employment of gun-cotton as then known there was, however, a fatal drawback in its liability to spontaneous combustion. The elaborate experiments of General von Lenk have shown that this liability was due to imperfection in its preparation, and ceases altogether when suitable processes are adopted in its manufacture. Perfect gun-cotton is a definite chemical compound; and certain processes for the removal of all extraneous matter and of every trace of free acid are absolutely indispensable. But when thus prepared it appears to be no longer liable to spontaneous combustion, it can be transported from place to place with perfect security, or be stored for any length of time without danger of deterioration. It is not impaired by damp-and may be submerged without injury, its original qualities returning unchanged on its being dried in the open air and at ordinary temperatures.

A scarcely less important point towards the utilization of gun-cotton and the safety with which it may be employed in gunnery is the power of modifying and regulating its explosive energy at pleasure, by means of variations in the mechanical structure of the cartridge, and in the relative size of the chamber in which it is fired.

The experiments made by the Austrian Artillery Commission, as well as those for blasting and mining, were conducted on a very large scale; with small arms the trials appear to have been comparatively few.

There can be no hesitation in assenting to and accepting the concluding sentence of the Committee's report. "The subject has neither chemically nor mechanically received that thorough investigation that it deserves. There remain many exact measures still to be made, and many important data to be obtained. The phenomena attending the explosion of both gun-cotton and gunpowder have to be investigated, both as to the temperatures generated in the act of explosion and the nature of the compounds which result from them, under circumstances strictly analogous to those which occur in artillery practice."

I proceed to announce the awards which the Council has made of the Medals in the present year; and to state the grounds on which those awards have been made.

The Copley Medal has been awarded to the Reverend Adam Sedgwick, for his observations and discoveries in the Geology of the Paleozoic Series of Rocks, and more especially for his determination of the characters of the Devonian System, by observations of the order and superposition of the Killas Rocks and their Fossils, in Devonshire.

Mr. Sedgwick was appointed Woodwardian Professor of Geology in the University of Cambridge in the year 1818, since which time, up to a recent period, comprising an interval of upwards of forty years, he has

devoted himself to geological researches with an ability, a persistent zeal, and untiring perseverance which place him amongst the foremost of those eminent men by whose genius, sagacity, and labours the science of Geology has attained its present high position. To duly appreciate his earlier work as a geological observer and reasoner, we must recall to recollection the comparative ignorance which prevailed forty or fifty years ago, to the dispersion of which his labours have so largely contributed. Geology was then beset by wild and untenable speculations on the one hand, whilst on the other even its most calm and rational theories were received by many with distrust or with ridicule—and by others with aversion, as likely to interfere with those convictions on which the best hopes of man repose. Under such circumstances Geology needed the support and open advocacy of men who, by their intellect and acquirements, and by the respect attached to their individual characters, their profession, or social position, might be able on the one hand to repress wild fancies, and on the other to rebut the unfounded assertions of those who opposed the discussion of scientific truth. Such a man was Professor Sedgwick, and such was the influence he exerted. It may be well to make this allusion on an occasion like the present, because it often happens, not unnaturally, that those who are most occupied with the questions of the day, in an advancing science, retain but an imperfect recollection of the obligations due to those who laid the first foundation of our subsequent knowledge.

More than forty years have passed since Professor Sedgwick began those researches among the older rocks of England which it became the main purpose of his life to complete. In 1822 was begun that full and accurate survey of the Magnesian Limestone of the North of England which to this day holds its high place in the estimation of geologists as the foundation of our knowledge of this important class of deposits, whether we regard their origin, form of deposition, peculiarities of structure, or organic contents.

Contemporaneously with this excellent work, he examined the Whin Sill of Upper Teesdale, showed its claims to be treated as a rock of fusion, and discussed the perplexed question of its origin.

Advancing to one of the great problems which occupied his thoughts for many years, he combined in 1831 the observations of the older rocks of the Lake Mountains which he had commenced in 1822, and added a special memoir on the great dislocations by which they are sharply defined and separated from the Pennine chain of Yorkshire. Memoirs followed in quick succession on the New Red Sandstone of the Vale of Eden; on the stratified and unstratified rocks of the Cumbrian Mountains, and on the Limestone and Granite Veins near Shap. Thus, thirty years since, before the names of Cambrian and Silurian were ever heard, under which we now thankfully class the strata of the English lakes, those rocks had been vigorously assailed and brought into a lucid order and system which is to this day unchanged, though by the same hands which laid the

foundations many important additions have been made, one of signal value in 1851-the lower paleozoic rocks at the base of the carboniferous chain between Ravenstonedale and Ribblesdale. Perhaps no district in the world affords an example of one man's researches begun so early, continued so long, and ending so successfully. By these persevering efforts, the Geology of the Lake district came out into the light; and there is no doubt, and can be no hesitation in ascribing to them the undivided honour of the first unrolling of the long series of deposits which constitute the oldest groups of British Fossiliferous Rocks.

Still more complete, however, was the success of that work which was undertaken immediately afterwards on the coeval rocks of Wales; by which Professor Sedgwick and Sir Roderick Murchison, toiling in separate districts, unravelled the intricate relations of those ancient rocks, and determined the main features of the successive groups of ancient life which they enclose. These labours began in 1831-32, and in 1835 the two great explorers had advanced so far in their research as to present a united memoir to the British Association in Dublin, showing the progress each had made in the establishment of the Cambrian and Silurian systems, as they were then called; Professor Sedgwick taking the former, and Sir Roderick Murchison the latter for his special field of study.

In 1843 Professor Sedgwick produced two memoirs on the structure of what he then termed the Protozoic rocks of North Wales. Many excellent sections were given in detail in these memoirs; those exhibiting the structure of the western part of the district about Carnarvonshire being principally taken from his observations in 1831-32, while the more detailed sections of the eastern part were from those of 1842-43. These two papers gave the complete outline or framework, as it were, of the geological structure of this intricate region. In several subsequent years he continued to fill up this outline with further details, observed almost entirely by himself, giving numerous general and local sections, by which he determined the dip and strike of the beds, normal and abnormal, and all the great anticlinal and synclinal lines on which the fundamental framework depends.

Further and still minuter details were subsequently given, as was to be expected, by the Government Surveyors; but the general arrangement, finally recognized on the map of the Survey, is essentially the same as that previously worked out by his unaided labours.

It was a principle always advocated by Professor Sedgwick, that the geological structure of a complicated district could never be accurately determined by fossils alone without a detailed examination of its stratification. He always proceeded on this principle; nor (from the paucity of organic remains) would it have been possible on any other principle to have determined the real geological character of those older districts which he investigated so successfully. His arrangement and nomenclature of the Cambrian rocks in North Wales (the Lower Silurians of Sir Roderick

VOL. XIII.

D

Murchison) are given in his "Synopsis of the Classification of the British Palæozoic Rocks," 1855. It possesses the weight which must always be recognized as appertaining to the authority of the geologist who, by his own labours, first solved the great problem of the physical structure of the district.

There are other important memoirs of Professor Sedgwick's of which time forbids more than a very passing notice. The memoir "On the Structure of large Mineral Masses," published in 1831, was the first, and remains to this day the best descriptive paper which has yet appeared on joints, planes of cleavage, nodular concretions, &c.

.

Always attentive to the purpose of preparing a complete and general classification of the Paleozoic Strata, Professor Sedgwick at an early period in his career printed a memoir "On the Physical Structure of the Older Strata of Devon and Cornwall; " and another "On the Physical Structure of the Serpentine District of the Lizard." Of later date are several papers written by him, conjointly with Sir Roderick Murchison, respecting the Devonian System. The principal of these, published in 1840, comprised the work of several previous years, and made known the true nature of the Culm Beds of North Devon, as belonging to the Carboniferous series, and their position in a trough of the subjacent rocks, which rocks, on account of their position and their organic contents, were concluded to belong to the Devonian, or Old Red Sandstone period, a conclusion which was at first controverted, but was ultimately admitted. In another memoir by the same authors in 1828, they conclude that the coarse old red conglomerate along the north-western coast of Scotland and in Caithness is of about the same age as the Old Red Sandstone of South Wales and Herefordshire, and therefore of the Devonian period. They also published in 1840 an account of their general observations on the Palæozoic Formations of Belgium and the Banks of the Rhine, the results of which were considered to harmonize with those derived from other localities. Finally, we may notice another joint memoir. by these authors in 1830, "On the Structure of the Eastern Alps," which, however, had no immediate relation to the researches on the Paleozoic formations.

It will be observed that the memoirs which have been noticed are for the most part pervaded by a certain unity of purpose. The investigations were not on points of merely local interest, but were essential for the elucidation of the geological history of our planet during those early periods of which the records are most difficult to unfold. Few persons perhaps can have an adequate idea of the difficulties he had to contend with when he first entered North Wales as a geologist. Geologically speaking, it was a terra incognita of which he undertook to read the geological history before any one had deciphered the characters in which it is written. Moreover, besides the indistinctness and complexity of the stratification, and the obscurity which then prevailed as to the distinction between planes of stratification and planes of cleavage, there was also the

difficulty of what may be called "mountain geometry"-that geometry by which we unite in imagination lines and surfaces observed in one part of a complicated mountain or district with those in another, so as to form a distinct geometrical conception of the arrangement of the intervening masses. This is not an ordinary power; but Mr. Sedgwick's early mathematical education was favourable to the cultivation of it. We think it extremely doubtful whether any other British geologist forty years ago could have undertaken, with a fair chance of success, the great and difficult work which he accomplished.

Such are the direct and legitimate claims of Professor Sedgwick to the honour conferred upon him by the award of the Copley Medal. But there are also other claims, less direct, but which it would be wrong to pass altogether unnoticed. It is not only by written documents that knowledge and a taste for its acquirement are disseminated; and those who - have had the good fortune to attend Professor Sedgwick's lectures, or may I have enjoyed social intercourse with him, will testify to the charm and interest he frequently gives to geology by the happy mixture of playful elucidation of the subject with the graver and eloquent exposition of its higher principles and objects.

PROFESSOR Sedgwick,

Accept this Medal, the highest honour which it is in the power of the Royal Society to confer, in testimony of our appreciation of the importance of the researches which have occupied so large a portion of your life, and which have placed you in the foremost rank of those eminent men by whose genius and labours Geology has attained its present high position in our country.

The Council has awarded a Royal Medal to the Reverend Miles Joseph Berkeley for his researches in Cryptogamic Botany, especially in Mycology. Mr. Berkeley's labours as a cryptogamic botanist for upwards of thirtyfive years, during which they have been more especially devoted to that extensive and most difficult order of plants the Fungi, have rendered him, in the opinion of the botanical members of the Council, by far the most eminent living author in that department. These labours have consisted in large measure of the most arduous and delicate microscopic investigation. Besides papers in various journals on Fungi from all parts of the globe, and in particular an early and admirable memoir on British Fungi, the volume entitled Introduction to Cryptogamic Botany,' published in 1857, is one which especially deserves to be noticed here. It is a work which he alone was qualified to write. It is full of sagacious remarks and reasoning; and particular praise is due to the special and conscientious care bestowed on the verification of every part, however minute and difficult, upon which its broad generalizations are founded. Mr. Berkeley's merits are not confined to description or classification; there

་