wick, whom he had known while partaking the hospitality of Mr. Allan, of Edinburgh.-The Marquis of Northampton remarked that Professor Haidinger had resided a long time in this country, and that he had, no doubt, added greatly to his geological knowledge while here. He (the noble marquis) hoped before long we should see in the British Museum a collection of minerals having especial reference to Great Britain.

Dr. Playfair proceeded to read a paper "On some new Oxides of certain of the metals of the Magnesian family." Chemists boasted of their acquaintance with the magnesian families, and yet our knowledge of them was at best very defective. What a vast hiatus

of

was there not in the knowledge of oxides alone! The oxides of copper had a striking analogy to the oxides of magnesia. Dr. Playfair then proceeded to show in what manner he had obtained peroxides copper, of iron, and of alumina. He was assisted by two diagrams, one showing the oxides of the magnesian metals, as far as we know them, the other showing the hydrates of peroxide of copper and of cupric oxide, with their cuprous analogues. These were given with their empirical and rational formulæ contrasted. In the course of his extempore address, Dr. Playfair expressed his opinion that the atomic weight of all unmagnesian metals might be doubled. -The vice president said the chemists present could not of course be expected to acquiesce in the new and curious statements respecting these peroxides, until they saw them proved by the analytic method, which Dr. Playfair could not adopt in a lecture. He had proposed some time ago that the atomic weight, for various reasons, ought to be doubled. He begged to express the great gratification he had derived from the statements of Dr. Playfair.-Dr. Daubeny expressed a similar feeling. Dr. Playfair had evinced great and minute chemical research, and had arrived at important general results. Dr. Apjohn said a few words to the same effect.

Mr. John Mercer's paper "On some peculiar instances of Catalytic Action," was then read by Dr. Playfair by the request of the author, who was present. Catalysis acts with a power so latent as seems to defy detection, yet Mr. Mercer explained on ordinary chemical principles some effects hitherto described as catalysis. The author had arrived by a wholly different process at results strikingly similar to those of Professor Playfair in the last lecture.

The vice president said, Mr. Mercer was well known in Lancashire for his practical application of chemistry to the useful arts, and particularly to calico printing. He had now shown a not less intimate acquaintance with chemical theory, and had established himself a chemical philosopher of high excellence. His explanation of catalysis was in his (the vice president's) opinion, better than that of Liebig. Dr. Playfair expressed himself of a different opinion on this latter point, but being referred by Mr. Mercer to the paper, and desired to read the passage again, he concurred with the vice president. The vice president said that Berzelius had invented the

1

term catalysis to express a power that he could not detect. There was reason to believe that as these effects were from time to time explained on ordinary chemical doctrines, the term catalysis would disappear.-Mr. Davies said the papers of Dr. Playfair and Mr. Mercer possessed an extraordinary value and interest, and he begged to move a vote of thanks to both gentlemen.-Dr. Playfair on behalf of himself and Mr. Mercer declined the proposed compliment. Both himself and Mr. Mercer were members, and the association could not thank its own members.

A paper was then read, communicated by Mr. R. Hunt, of Cornwall, entitled "Researches on the Influence of Light on the Germination of Seeds and the Growth of Plants." The subject had been entrusted to Mr. Hunt for experiment by the association. He had provided six boxes, so constructed that no light could enter except through glass of different colours: the first being deep red, the last deep green. In these boxes he had raised ranunculuses, tulips, and other plants. The tulips he found germinated the first under the orange glasses, and last under the blue and green. Under the blue glass the plants, although slower in germination, were more healthy, and promised to come to maturity, and be perfect flowers; while under the orange they were more forward but sickly. A curious result was noticed with respect to the red glass. Under all other circumstances plants bent towards the light, but those under the red glass bent away from the light. In nearly all cases germination had been prevented by the absorptive power of the yellow rays.

Dr. Daubeny, as one of the committee appointed to investigate the subject with Mr. Hunt, hoped the committee would continue the grant to the latter gentleman. The results at present obtained seemed indecisive; and without wishing to throw any discredit on the experiments, he thought Mr. Hunt ought to have a further opportunity of establishing his principle, that chemical rays produced a specific and positive influence on the germination of plants.

It being now two o'clock, the vice president adjourned the section to the following morning at eleven.

SECTION C.-GEOLOGY AND PHYSICAL GEOGRAPHY.

The president, R. I. Murchison, Esq., took the chair this morning shortly after eleven o'clock, and opened the proceedings by giving a brief verbal summary of a memoir communicated by Dr. Dale Owen, on the Western States of North America. Two large panoramic views of the geological structure of that country were hung up in view of the meeting, with well executed diagrams of the various fossil remains hitherto discovered in that region; distinguishing the strata from which they were taken. One of these views represented the various geological formations observed in that part of the country, extending from the Wisconsin river, and passing along the

Mississippi, Illinois, Sargamon, Kaskasia, Embaras, Wabash, White, Ohio, Green, Cumberland and Tennesse rivers, to the Allegany mountains. The other views commenced at Chickshawbluffs, Tennesse, and proceeded across the state of Kentucky, in a course nearly north east, through part of Ohio and Pittsburgh, to the Allegany mountains. The president said, he had only just read the memoir, and therefore, his account of its contents would be necessarily imperfect. The memoir in detail, with a collection of fossils, sent by Dr. D. Owen, would be submitted to the Geological Society in London. The author was a native of England, who studied in the university of London, under Dr. Turner, and afterwards went to America. The country to which the paper referred, embraced Illinois, Indiana, a portion of Kentucky and Ohio. In this large portion of country, there were two coal fields, one of which (the Illinois coal field) was nearly as large as Great Britain. This great tract of country was traversed at its southern termination by the river Ohio. The other coal field was called the coal field of the Ohio, and was also very extensive. These coal fields were separated from each other by an axis of much more ancient rocks, and the special object of the author in bringing the communication before the English public was, to have the identification established between those lower rocks on which the coal fields rest, and those which support our great carboniferous series in the British Isles. The president then pointed out on the map the places where the different fossils were found, and showed that in many respects there was a striking coincidence between the stratifications and the remains discovered in them, with those of our own country. One of the most remarkable coincidences was a cluster of fossil trees, the representation of which resembled those in Dixon Fold so much, that it was supposed by the meeting, until the president informed them to the contrary, that the diagram referred to that group. In the course of a conversation which afterwards ensued, Mr. Binney noticed one difference: the fossil trees in Dixon Fold had only four roots each, while the American fossils had many. Mr. Bassett, a gentleman who was present when the trees were sketched, stated that their respective diameters varied from one foot to eighteen inches. After some observations from Professor Sedgwick, Professor Phillips, Dr. Buckland, and Sir H. De La Beche, the thanks of the meeting were unanimously given to Dr. Owen for his communication.

Fossil Head of an Ox.-The president next exhibited the head of an ox, and read a letter from Professor John Knox, stating that the head was found a few days ago in excavating a sea-lock at the east end of the Forth and Clyde Canal, on the Frith of Forth, at twenty feet below high-water mark. Mr. Thompson, the engineer of the Canal Company, happening to be present at the moment it was discovered, had it placed in a box and forwarded to the association. -Dr. Buckland said it was apparently the head of a cow, and was found under a large quantity of mud, at the mouth of an estuary,

where it was not at all surprising that mud should have been accumulated.

British Belemnites.-Professor John Phillips, as one of the committee for advancing the knowledge of belemnites, reported what had been done in that respect since the last meeting of the association. He had been requested to prepare a series of drawings and descriptions, of an exceedingly numerous group of fossil shells, known by the name of belemnites. M. Du Blanville had already described a great number of these fossils, traced the analogy between their structure and that of other fossils, particularly the nautilus, to which the analogy was striking. M. Voltz, of Strasburg and Paris, also published a valuable work on this subject, and Dr. Buckland, in the Bridgewater treatise, had added much to our knowledge of those animals. Fifty pounds had been placed in the hands of Professor Phillips to defray the expense of drawings and engravings; and these were nearly completed, and would be distributed among geologists. He had already collected forty apparently distinct species of the belemnites. The belemnite had four aspects, two of which were alike, and two dissimilar; and he would have to make such drawings as would enable a person to see all the aspects in which they could be presented, in order that the species might be distinguished. He hoped he should soon be able to give a correct account of the forms of the belemnites, and the manner in which they are distributed in the stratified rocks.

Fossil Fishes.-Mr. L. L. B. Ibbetson read a report of Professor Agassiz on the fossil fishes of the Devonian, or old red sandstone formation. The learned professor commenced his paper by acknowledging the assistance which he had received from various quarters, particularly the late Lady Gordon Cumming, who had presented him with several splendid drawings of fossil fishes executed by herself and her accomplished daughter. These beautiful works of art were exhibited to the section, and greatly admired: six of them were representions of Pterycthys, or winged fishes. The views presented in this report are similar to those found in a popular little work by Mr. Hugh Miller, of Cromarty, entitled "New Walks in an Old Field."

Mud of Rivers.-The president informed the section that the committee appointed to report on the mud of rivers, had forwarded a communication from Belfast, stating that they had as yet made little progress, as the results were very unsatisfactory. With regard to earthquakes, they had nothing to report. A great number of those stories appearing in newspapers were nothing more than exaggerated accounts of storms.-The section adjourned at half-past two o'clock.

SECTION D.-ZOOLOGY AND BOTANY.

The Dean of Manchester, President.-Dr. G. Lankester, F. L. S., drew the attention of the meeting to a gigantic pair of the horns of

Wapeti deer brought from the western districts of America, which were exhibited by Mr. L. T. Gaskill, of Liverpool. Being placed in front of the chairman, they attracted great attention from their immense size; the head being nearly three quarters of a yard in length, with tufts of hair on each side, almost resembling the front mane of a lion; whilst the towering antlers were about six feet in length, from the base of the scull to the tip of the horn.-Mr. Gaskill stated that these immense antlers were brought hither by Mr. Daniel Mossinore, an eminent naturalist of the United States, along with the living male and female of the same species (young ones), which are now in the possession of her Majesty, in Windsor Park. It appeared from Mr. Gaskill's statement, that his Royal Highness Prince Albert, hearing of the arrival of the deer at Liverpool, instructed his secretary, the Hon. A. Murray, to make inquiries concerning them; but in the mean time they were purchased by the Earl of Derby, president of the Zoological Society, who also wished to become possessed of this extraordinary growth of animal nature; which had, however, become the property of the present owner. The noble earl hearing of her Majesty's desire to purchase the deer, with a proper feeling of loyalty, immediately presented them. The horns excited an interesting discussion.—Mr. Peach read a paper on the nidus and growth of Purpureus Capillus, the tea cup of Ellis.-Mr. Couch, of Cornwall, read a paper on the migration of birds and flowering of plants in that county.-Mr. Blackwall described a larva parasitic on spiders.-Mr. Strickland read the report of a committee, appointed by a late meeting, on the growth and vitality of seeds.

SECTION E. MEDICAL SCIENCE.

There were only three papers announced for reading in this section, and none of them possess any interest for non-medical readers.

FRIDAY.

SECTION G.-MECHANICAL SCIENCE.

The Combustion of Coal and the Prevention of Smoke.-Mr. Fairbairn read the report of a committee appointed at the meeting held at Glasgow, in 1840 (in consequence of a paper read by Mr. C. W. Williams), to make experiments upon the combustion of coal and other fuels, with a view of obtaining the greatest calorific effect, and avoiding the generation of smoke. In this report the subject of inquiry was arranged under the following heads :-1. The present state of knowledge as regards the combustion of fuel, particularly as applied to the furnaces of steam engines.-2. The due relations between the dimensions of the furnace and the boiler.-3. The dimensions and form of the chimney.-4. The best method of working the furnace. In reference to the general subject of the inquiry, the report stated that very great ignorance existed on the subject of combustion, and