to the same species, but the cycle of development, instead of being accomplished in a single individual, would involve two or more acts of generation."*

I must, however, bring the subject to a close; not for want of material, for it is almost inexhaustible, but because I have already exceeded the limits I had anticipated. I trust I have fulfilled my pledge of justifying the criticism of M. Agassiz from the charges which have been brought against it; and I believe I may safely leave the matter in the hands of those who have listened to my vindication.

At the conclusion of the paper, the PRESIDENT said he would not invite discussion at that late hour (10.5). He desired to express the great interest and pleasure which he was sure had been felt by all who had listened to the many instructive matters which had been brought before them in the paper which had just been read by Dr. Collingwood, who, nevertheless, he thought, had altogether failed in showing the injustice of his strictures on the criticism of M. Agassiz. He would confine his remarks to two points, and, after all that had been said, he considered the illustration of the embryo snake and the embryo bird was an appeal to ignorance and not to science; and that M. Agassiz' petulant and offensive assumption of want of information on the part of Mr. Darwin and his supporters, on a subject unquestionably familiar to them, justified his censure of M. Agassiz' review as unworthy of so distinguished a philosopher. He (the Rev. H. H. Higgins) was not a supporter of Mr. Darwin's theory, but he deeply regretted the uncandid manner in which it had been in many quarters attacked.

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Dr. COLLINGWOOD observed that calling the similarities among embryos an appeal to ignorance" was simply begging the question. He did not consider it necessary to repeat his arguments, but he would cheerfully abide by what he had written, and was quite content that it should stand as the record of his defence of Agassiz.

*The passages in inverted commas I have quoted from Dr. Wright's edition of Agassiz and Gould's "Outlines of Comparative Physiology," London, 1851. I have considered myself justified in doing this, for these reasons; first, because although a work of Agassiz himself, two other names are associated with his in it;-secondly, because the statements are the most succinct and definite I have been able to meet with ;-and thirdly, because I believe they are still accepted as the correct and philosophical view of the subject of alternation of generations.

Dr. EDWARDS hoped the President would not leave the chair without affording him the opportunity of expressing the gratification he had received from Dr. Collingwood's able exposition of M. Agassiz' views, and he moved that the cordial thanks of the society be presented to him; for he felt sure that all present must have been pleased with the philosophical tone and highly instructive character of his paper, which, he considered, relieved M. Agassiz from the charge of wilful obscurity, and, at the same time, was exceedingly impartial on the general subject.

The Rev. C. H. BURTON seconded the motion, and confessed that he could not agree with the President's remarks, for he considered that Dr. Collingwood had successfully justified M. Agassiz.

SIXTH ORDINARY MEETING.

ROYAL INSTITUTION, 7th January, 1861.

The Rev. H. H. HIGGINS, M.A., PRESIDENT, in the Chair.

Mr. DAVID ANDERSON, of Egremont, was elected a member of the Society.

The PRESIDENT called attention to the magnificent illustrated works recently presented to the Royal Institution by the Emperor of the French, and the late King of Prussia, and which, having been handsomely bound, are now placed in the Library. Among the various works presented by the Emperor of the French was the beautiful one on the Catacombs of Rome; and the work of Lepsius on Egypt, from the late King of Prussia, was a very valuable addition. The town of Liverpool was indebted to Mr. T. C. Archer for these splendid donations.

The PRESIDENT also referred to Dr. Wallich's recently published "Notes on the Presence of Animal Life at Vast

Depths in the Sea," in which it is stated that in sounding not quite midway between Capes Farewell and Rockall, in 1,260 fathoms, a number of starfishes, belonging to the genus Ophiocoma, came up adherent to the lowest fifty fathoms of the deep sea line employed. Such facts as these were extremely interesting, because they are quite at variance with our existing ideas respecting the depth at which animal life can exist in the sea.

Mr. RICHARD BROOKE, F.S.A., then read a paper on"THE PROGRESS OF ART, SCIENCE, and useful INVENTIONS, SINCE THE MIDDLE AGES,"

in which he showed by an elaborate reference to the history of inventions, that most of our important and wonderful discoveries are of comparatively recent date.

SEVENTH ORDINARY MEETING.

ROYAL INSTITUTION, 21st January, 1861.

The Rev. H. H. HIGGINS, M.A., PRESIDENT, in the Chair.

The Rev. J. MACNAUGHT, M.A., and Mr. H. B. ROBERTS, were elected members of the Society.

Dr. COLLINGWOOD drew the attention of the meeting to the Reports of the Microscopical Section of the Literary and Philosophical Society of Manchester, in which it was stated that envelopes had been supplied by the society for distribution among captains of vessels to enable them to preserve soundings, and other similar materials, for microscopic examination; and, he further added, that directions for the

preservation of minute objects of natural history had been lately drawn up by Mr. William Weightman, with the object of calling the attention of captains to their collection under favourable circumstances.

The PRESIDENT referred to a lately published work by Professor Phillips, entitled "Life on the Earth, its Origin and Succession," which he strongly recommended to the notice of the members of the Society; and read a passage from it, which placed the difficulties of the developmental hypothesis in a very just and strong light.

Dr. COLLINGWOOD exhibited and remarked upon the valuable work just published by the Ray Society, on British Spiders, by Mr. John Blackwall. This work is copiously illustrated with beautifully coloured plates, and is the first of two volumes upon this hitherto neglected subject.

The Rev. J. ROBBERDS drew attention to a published paper by Mr. P. H. Holland, read before the Society of Arts, on the means of preventing coal-pit accidents, in which the writer urged the desirableness of compelling colliery-proprietors, by Act of Parliament, to insure the life of every miner employed, so as both to secure some provision for his family in case of accident, and also to make it the interest of the proprietors to enforce every known precaution against accidents, in order to reduce the rate of insurance. The writer calculated that an advance of only one penny per ton on the 66,900,000 tons of coal annually raised, would be sufficient to insure the life of every miner to the amount of £200.

The following paper was then read:

OBSERVATIONS ON AURORA.

BY DAVID WALKER, M.D., F.R.G.S., M.R.I.A., F.L.S.

(Late Surgeon and Naturalist to the "Fox" Arctic Exploring Expedition.)

IN bringing before you to-night some remarks as to the appearance, formation, and cause of Aurora, I shall confine myself to that which appears in the northern hemisphere, and is thence designated Aurora Borealis. I feel inclined to suppose that some of my remarks will apply to the Aurora Australis, but do not wish to encumber myself with reference to a phenomenon which I have never witnessed.

An appearance so remarkable as the Aurora could not fail to attract the attention of early observers, and afford cause for much conjecture. About the earliest theory respecting the cause was, that it was produced by the refraction of the Solar rays; another was, that it was identical with the tails of comets; another, that it depended on a mixture of the atmospheres of the earth and sun; while others ascribed it to the effects of the magnetic fluid. But as the science of electricity became better known and more fully developedwhen its luminous effects were shown-and especially when a resemblance was traced between the luminosity displayed by the passage of an electric current through a partially exhausted tube, and the appearance of Aurora, all previous hypotheses were set aside, and the theory of Eberhard and Cavendish. was adopted. They supposed that Aurora is dependent on electricity, transmitted through regions where our atmosphere is in a very rarified state; at the same time, it was also considered to have some connection with the magnetic forces of