mate those remaining unmounted at about 2500 species. With regard to the scientific arrangement to be ultimately adopted, there are some difficulties in the way. Dr. Woodward's manual, though excellent as far as it goes, represents only the state of our knowledge of the subject some fifteen or twenty years ago. On the other hand the Messrs. Adams and Dr. Gray in their elaborate treatises unfortunately disregard the well-known and well-estab. lished laws of zoological nomenclature. In the meantime, until the whole collection is mounted, the arrangement is one of mere convenience. When mounting my own shells, all the duplicates were put into the Society's collection, and in this way over fifty species have been added to it. The work of editing the Society's Journal has led this year to a much larger amount of general correspondence than last, which has taken up time that would otherwise have been devoted to work in the Museum. Under many disadvantages and difficulties, and with many deficiencies and shortcomings to regret, it is yet hoped that the work done during the past session has not been altogether barren of results but that it may have tended in some small degree to help to popularize the study of the natural sciences in the city. The various reports were ordered to be printed, the usual votes of thanks to the retiring officers duly passed, and the meeting proceeded to elect officers for the current year with the following result: OFFICERS FOR THE YEAR 1871-72. President.-Mr. Principal Dawson (re-elected). Vice-Presidents.-Dr. Hunt, Rev. Dr. De Sola, Sir W. Logan, Dr. Carpenter, Messrs. Billings, Selwyn, Leeming and Barnston, Dr. Smallwood. Treasurer. Mr. J. Ferrier, jun. (re-elected). Cor. Secretary.-Prof. Darey (re-elected). Council.-Messrs. Marler, Watt, McCord, R. Bell, Shelton, Edwards, Drummond, Murphy and Joseph. After naming the sub-committees, the meeting adjourned. Dr. THE NATURAL HISTORY SOCIETY OF MONTREAL IN ACCOUNT WITH JAMES FERRIER, JR., Treasurer. Cr. H. Passmore, 100.00 "Rent of Lecture Room By Government Grant. Members Yearly Subscriptions "Donation towards liquidation of Debt, J. F., Jr. "Subscription to "Naturalist" Insurance 39.00 "Interest from Treasurer one year on $886.15 62.03 THE CANADIAN NATURALIST AND Quarterly Journal of Science. ABSTRACT OF PROCEEDINGS OF THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE, At its Forty-First Meeting, at Edinburgh, August, 1871. The Presidency of the Association was resigned by Prof. Huxley, and assumed by Sir William Thompson, who delivered the usual Presidential Address. After dwelling on the origin of the Association, and the eminent scientific career of several of its early founders, the President gave a review of the present work of the Association, and suggested, in connection with it, the importance of establishing a British Year Book of Science. He also urged upon the Government the necessity for the foundation of National Colleges of Research, on a scale commensurate with the importance of Scientific Education, and in some degree corresponding with similar institutions on the continent of Europe. He then proceeded to give a general sketch of the recent progress of Physical Science, from which we give the following extracts:— 1. SPECTRUM ANALYSIS. The prismatic analysis of light discovered by Newton was estimated by himself as being "the oddest, if not the most considerable detection, which hath hitherto been made in the oper ations of nature." Had he not been deflected from the subject, he could not have failed to obtain a pure spectrum; but this, with the inevitably VOL. VI. No. 2, consequent discovery of the dark lines, was reserved for the nineteenth century. Our fundamental knowledge of the dark lines. is due solely to Fraunhofer. Wollaston saw them, but did not discover them. Brewster laboured long and well to perfect the prismatic analysis of sunlight; and his observations on the dark bands produced by the absorption of interposed gases and vapours laid important foundations for the grand superstructure which he scarcely lived to see. Piazzi Smyth, by spectroscopic observation performed on the Peak of Teneriffe, added greatly to our knowledge of the dark lines produced in the solar spectrum by the absorption of our own atmosphere. The prism became an instrument for chemical qualitative analysis in the hands of Fox Talbot and Herschel, who first showed how through it the old "blowpipe test," or generally the estimation of substances from the colours which they give to flames, can be prosecuted with an accuracy and a discriminating power not to be attained when the colour is judged by the unaided eye. But the application of this test to solar and stellar chemistry had never, I believe, been sug gested, either directly or indirectly, by any other naturalist, when Stokes taught it to me in Cambridge, at some time prior to the summer of 1852. The observational and experimental foundations on which he built were: (1) The discovery by Fraunhofer of a coincidence between his double dark line D of the solar spectrum and a double bright line which he observed in the spectra of ordinary artificial flames. (2) A very rigorous experimental test of this coincidence by Prof. W. H. Miller, which showed it to be accurate to an astonishing degree of minuteness. (3) The fact that the yellow light given out when salt is thrown on burning spirit consists almost solely of the two nearly identical qualities which constitute that double bright line. (4) Observations made by Stokes himself, which showed the bright line D to be absent in a candle-flame when the wick was snuffed clean, so as not to project into the luminous envelope, and from an alcohol flame when the spirit was burned in a watch-glass. And (5) Foucault's admirable discovery (L'Institut, Feb. 7, 1849), that the voltaic are between charcoal points is "a medium which emits the rays D on its own account, and at the same time absorbs them when they come from another quarter." The conclusions, theoretical and practical, which Stokes taught me, and which I gave regularly afterwards in my public lectures in the University of Glasgow, were :— (1) That the double line D, whether bright or dark, is due to vapour of sodium. (2) That the ultimate atom of sodium is susceptible of regular elastic vibrations, like those of a tuning-fork or of stringed musical instruments; that like an instrument with two strings tuned to approximate unison, or an approximately circular elastic disc, it has two fundamental notes or vibrations of approximately equal pitch; and that the periods of these vibrations are precisely the periods of the two slightly different yellow lights constituting the double bright line D. (3) That when vapour of sodium is at a high enough temperature to become itself a source of light, each atom executes these two fundamental vibrations simultaneously; and that therefore the light proceeding from it is of the two qualities constituting the double bright line D. (4) That when vapour of sodium is present in space across which light from another source is propagated, its atoms, according to a well-known general principle of dynamics, are set to vibrate in either or both of those fundamental modes, if some of the incident light is of one or other of their periods, or some of one and some of the other; so that the energy of the waves of those particular qualities of light is converted into thermal vibrations of the medium, and dispersed in all directions, while light of all other qualities, even though very nearly agreeing with them, is transmitted with comparatively no loss. (5) That Fraunhofer's double dark line D of solar and stellar spectra is due to the presence of vapour of sodium in atmospheres surrounding the sun and those stars in whose spectra it had been observed. (6) That other vapours than sodium are to be found in the atmospheres of sun and stars by searching for substances producing in the spectra of artificial flames bright lines coinciding with other dark lines of the solar and stellar spectra than the Fraunhofer line D. The last of these propositions I felt to be confirmed (it was, perhaps, partly suggested) by a striking and beautiful experiment, admirably adapted for lecture illustrations, due to Foucault, |