5+ i fee cae Pe Bia STA et vie fy Ae PROCEEDINGS THE ROYAL SOCIETY OF DECEMBER 1844 to APRIL 1850. EDINBURGH : PRINTED BY NEILL AND COMPANY. MDCCCLI. be A Mie ere nD) Dea CONTENTS. ~ Account of the late Earthquake at Demerara. By W. H. Camp- bell, Esq. Communicated by M. Ponton, Esq.,_- On the Existence of an Electrical Apparatus in the Flapper Skate and other Rays. By Dr Stark, - : > Observations on the Comet, visible now or lately in the Constella- tion of the Whale. By C, Rumker, Esq. Communicated by Sir T. M. Brisbane, Bart., a 7 : P . On a Possible Explanation of the Adaptation of the Eye to Dis- tinct Vision at Different Distances. By Professor Forbes, Notice of an Ancient Beach near Stirling. By Charles Maclaren, _ Esq., : a : - ; : - Farther Remarks on the Electrical Organs of the Rays. By Dr Stark, Ps 2 - 4 ‘ : ; Observations on the same subject. By Professor Goodsir, C “Note on the Form of the Crystalline Lens. By Professor Forbes. Included in the former Abstract, 2 a On the Cause which has produced»the Present Form and Condi- tion of the Earth’s Surface. By Sir George S. Mackenzie, Bart., “Some Account of the Magnetic Observatory at Makerstoun, and of the Observations made there. By J. A. Broun, Esq. Com- - municated by Sir T. M. Brisbane, Bart., 3 - ‘ Description of a Sliding Scale for Facilitating the Use of the Moist- bulb Hygrometer. By James Dalmahoy, Esq., : : Account of Experiments to Measure the Direct Force of the _ Waves of the Atlantic and German Oceans. By Thomas Stevenson, Esq. Communicated by David Stevenson, Esq., _ A Verbal Communication in regard to Chevalier’s Experiments on the Decomposition of certain Salts of Lead by Charcoal. By Dr Traill, . ; : : ° : : On a Peculiar Modification of the Doubly Refracting Structure of Topaz. By Sir D. Brewster, K.H., : + “ Extracts from Letters to the General Secretary, on the Analogy of the Structure of some Voleanic Rocks with that of Glaciers. _ By C. Darwin, Esq., F.R.S, Specimens were exhibited. With Observations on the same subject, made by Professor Forbes, Letter from Professor Gordon, of Glasgow, on the subject of the ~ Viscous Theory of Glaciers, Read by Professor Forbes, Jo Page 1 10 13 13 15 16 17 19 iv CONTENTS. On the Existence of peculiar Crystals in the Cavities of the Topaz. Part I. By Sir D. Brewster, K.H., On the Use of Colourless Ink in Writing. By on George 8. Mac- kenzie, Bart., On the Use of Metallic Reflectors for Gomtants! and on ‘the Deis mination of the Errors arising from Non-Parallelism in the Mirrors and Sun-Shades of Reflecting Instruments. By John Adie, Esq., On the Existence of peculiar Crystals in the Gayinee of Topas Part II. By Sir David Brewster, K.H., . On the Extraction of pure Phosphoric Acid from Bones, and on a New and Anomalous Phosphate of Magnesia. By Dr Gregory, On the Improvement of Navigation in Tidal Rivers. By David Stevenson, Esq., . c On the Solvent Action of Tieeaeee Water on Soils. By John Wilson, Esq., F.G.S. Communicated by Dr Gregory, : Observations on the Temperature of the Earth at Trevandrum, in Lat. 8° 30’ 32”. By John Caldecott, Esq. Reduced, with some Remarks, by Professor Forbes, - - 2 Miscellaneous Observations on Blood and Milk. By Dr John Davy, : An Account of some of Mr Bain’ s spplieations “of Electricity as as a moving power to Clocks, On Dr Wollaston’s Argument from the limitation of the Earth’s Atmosphere as to the Finite Divisibility of Matter. By Dr George Wilson, . Biographical Notice of the late Professor Henderson. “By Profes- sor Kelland, On the Chemical Relations of Creosote. By Dr Gregory, On the Thermometric Correction of Magnetic Instruments. By J. A. Broun, Esq., . On the Constitution of Bebeerine.” By Dr ‘Douglas Maclagan, and Thomas G. Tilley, Esq., Birmingham, On the Sums of the Digits of Numbers. By Bishop Terrot, Notes on the Topography and Geology of the Cuchullin Hills in Skye; and on the Traces of Ancient Glaciers which they pre- sent. Part I. By Professor Forbes, Notes on the Topography and Geology of the Cuchullin Hills i in Skye ; and the Traces of Ancient Glaciers which ae Preeti (concluded). By Professor Forbes, On the recent Eruption of Hecla, and the Volcanic “Shower. in Orkney. By Dr Traill, On a new variety of Gamboge from the Wynaad. By Dr Christison, Results of the Makerstoun Observations, No. 1. On the Relation of the Variations of the Earth’s Magnetism to the Solar and Lunar Periods. By J. A. Broun, Esq. Communicated We Sir T. M. Brisbane, Bart., 3 Experiments and Investigations as to ‘the influence exerted over some Minerals by Animal and Vegetable matter, under certain conditions. By Mrs Margaret Henrietta Marshall. Communi- cated by Sir T. M. Brisbane, Bart., : : 21 21 58 59 CONTENTS. On the Action of Soluble Lead Salts on Natural Waters. ie Pro- fessor Connell, . Claudia and Pudens; an attempt to shew that the Claudia men- tioned in St Paul’s Second Epistle to Timothy, was a British ; Princess. By Archdeacon Williams, On the Decomposition and Dispersion of Light within Solid Bodies. : By Sir David Brewster, K.H., A few Remarks suggested by Professor Forbes’s ; Description of the ¥ effects of Glacial Action among the Cuchullin Hills, and Mr Maclaren’s views of the facts observed by him at the Gareloch. By Sir G. 8. Mackenzie, Bart., 4 Remarks on certain grooved surfaces of Rock on Arthur's Seat. By the Rev. Dr Fleming, . Biographical Notice of the late Sir er ohn Robison, K. H., See. R.S. Ed. By Professor Forbes, . On a method of rendering Magnetical Instruments Self- Registering. By J. A. Broun, Esq. Communicated by Sir T. M. Brisbane, Bart., Verbal Notice respecting the Thyroid, Thymus, and Supra-renal Bodies. By Professor Goodsir, On the recent Scottish Madrepores, with Remarks on the Climatie Character of the Extinct Races. By the Rev. Dr Fleming, On the principle of Vital Affinity, as illustrated by recent Obser- vations in Organic Chemistry. Part I. By Dr Alison, On the Personal Nomenclature of the Romans, with an especial re- ference to the Nomen of Caius Verres. By the Rey. J. W. Donaldson. Communicated by Bishop Terrot, On the appearance of the Great Comet of 1843, at the Cape of Good Hope, with illustrative Drawings. By Professor Smyth. Communicated by the Secretary, On the Existence of Fluorine in the Bones from Arthur’ s "Seat. By Dr G. Wilson, : On the Composition of the Bones from Arthur’ s Seat. By Dr Gheiskicenis On the Description of Oval Curves, and those haying a plurality of Foci. By Mr James Clerk Maxwell; with remarks by Pro- fessor Forbes. Communicated by Professor Forbes, On the Influence of Contractions of Muscles on the Circulation of the Blood. By Dr Wardrop, _ On the Solubility of Fluoride of Galeium i in Water, and the relation of this property to the occurrence of that Substance in Minerals, and in recent and Fossil Plants and Animals. By Dr G. Wilson, _ On the Constitution and Properties of Picoline, a new organic base from Coal-Tar. By Dr T. Anderson, Notice of Polished and Striated Rocks recently disoovered on Arthur’s Seat, and in some other ree near Edinburgh, By David Milne, Esq., . i Results of the Pehenaess Observations, No. II. On the Relation of the Variations of the Vertical Component of the Earth’s Mag- netic Intensity to the Solar and Lunar Periods. By J. Allan _ Broun, Esq. Communicated by Sir T. M. Brisbane, Bart., . Two Verbal Notices. (1.) On the Geology of Arthur Seat. (2.) On the Dentition of the Walrus. By the Rey. Dr Fleming, 94 95 vi CONTENTS. On the Mean Height of the Barometer in different Latitudes. By Professor Hansteen of Christiania. Communicated in a Letter to the Secretary, 101 On the Extent to hie Fluoride of Calcium i is Soluble i in 1 Water at 60° F. By Dr George Wilson, : 102 New Observations on the Glaciers of Savoy. Part IL By Professor Forbes, - 103 New Observations on the Glaciers of Savoy. (Concluded). By Pro- fessor Forbes, ; 107 On General Differentiation. Part II, By the Rev. " Professor Kelland, . 108 Extracts from a Letter of Baron Berzelius. Consnedtantind by Dr T. Anderson, 108 On the presumed lon: dontinaed Presence of Arsensic in the Human Stomach. By Dr Gregory, 110 Notes on the Superficial Strata of the N eighbourhood of Eainburgh, By the Rev. Dr Fleming. (Commenced.) . 110 An Attempt to Elucidate and Apply Mr Warren's Doctrine re- specting the Square Root of Negative Quantities. By Bishop Terrot, 111 Notes on the Superficial Strata of the Neighbourhood of Edinburgh. (Coneluded.) By the Rev. Dr Fleming, - 111 Speculation respecting the origin of Trap-Tuff, the Canze: of Farth- quakes, and of Partial Changes of the Bed of the Ocean. Part I. By Sir G. S. Mackenzie, Bart., = $ : . 114 On the Principle of Vital Affinity. Part IJ. By Dr Alison, . 114 Speculation respecting the origin of Trap-Tuff, the Cause of Earthquakes, and of Partial Changes of the Bed of the Ocean. Part II. By Sir G. S. Mackenzie, Bart., : : ALS On Vital Affinity. Parts I. and III. By Dr Alison, 117 On the Co-existence of Ovigerous Capsules and Spermatozoa in the same individuals of the Hydra Viridis. By Dr Allen Thomson, 123 On the Parallel Roads of Lochaber; with Remarks on the Change of relative Levels of Sea and Land in Scotland, and on the De- trital Deposits in that Country. Part I. By David Milne, Esq., 124 On the Course of Observation to be pursued in future at the Royal Observatory of Edinburgh. By Professor Smyth, : 126 Observations of Terrestrial Temperature made at Trevandrum Ob- servatory, from May 1842 to December 1845. By John Cal- decott, Esq. Communicated by Professor Forbes, . 127 On the Temperature of Wells and Springs at Trevandrum in India (Lat. 8° 31’, Long. 5° 8™). By Major-General Cullen, Madras Artillery. Communicated a a Letter to Professor Forbes, ees Chemical Notices. By Dr Gregory, . 129 Remarks on the Hypothesis of Progressive Development 4 in the Or- = ganic Creation. By Sir G. S. Mackenzie, Bart., 2 130 On the Parallel Roads of Lochaber; with Remarks on the Change of relative Levels of Sea and Land i in Scotland, and on the De- trital Deposits in that Country. Part II. By David Milne, Esq., 132 Verbal Communication on Fossils of the Lias Formation, from South Africa. By the Rey. Dr Fleming, : : 7 S158 CONTENTS. On Certain Products of Decomposition of the Fixed Oils in Contact with Sulphur. By Dr T. Anderson, On the Structural relation of Oil and Albumen in the Animal Eco- nomy. By Dr J. H. Bennett, F Experiments on the Ordinary Refraction of Light, by Iceland Spar. By W. Swan, Esq. Communicated by Professor Kelland, On the Boulder Formation and Superficial Deposits of Nova Scotia. By J. W. Dawson, Esq. Communicated by Dr Gregory, _ On the Mode of Occurrence of Gypsum in Nova Scotia, and on its Probable Origin. By the Same, On certain Anomalous Deviations of the Transit Instrument at the Royal Observatory. By Professor Smyth, . ; Results of Makerstoun Observations, No. III. On the Solar and Lunar periods of the Magnetic Declination. By J. A. Broun, Esq. Communicated by Sir T. M. Brisbane, Bart., : Notice of Two Ores of Copper, one of them a New Mineral. By Professor Connell, . : Biographical Memoir of the late Dr Hope. By Dr Traill, ¢ Note on the Constitution of the Phosphates of the Organic Alkalies. By Dr Thomas Anderson, Examination of some Theories of German Writers, and of Mr Grote, on the Authorship of the Iliad and sea By Pro- fessor Dunbar, : On Algebraical Symbolism. By Bishop Terrot, : Account of a Geological Examination of the Volcanoes of the Wis varais. By Professor Forbes, : Geological Notices. By the Rev. Dr Fleming, Verbal Notice. By the Rev. Dr Fleming, On the Preparation of Kreatine, and on the Amount of it in the Flesh of different Animals. By Dr Gregory, _ Notices of a Flood at Frastiinz, in the Vorarlberg, in Sasi mrdiere of 1846. By William Brown, Esq. Contributions to the Phenomena of the Zodiacal Light. By Pro- fessor Smyth, a - Practical Illustration of the Adjustments of the Equatorial Instru- ment. By Professor Smyth, _ On the Vertebral Column, and some Chinraetens that hess been overlooked in the Descriptions both of the Anatomist and Zoolo- gist. By Dr Macdonald, : ; : On the Theory of the Parallel Roads of Lochaber. By James Thomson, Esq., jun., vier Communicated by Professor ___ Forbes, : ~ On an Instrument for measuring the extensibility of Elastic Solids. By Professor Forbes, _ On the Anthracite of the Calton Hill. By the Rev. Dr Fleming, ‘On some Phenomena of Capillary Attraction observed with Chloro- form, Bisulphuret of Carbon, and other Liquids. ae Dr George Wilson, Notice of the Orbit of the Binary Star a Centauri, as recently determined by Captain W. S. Jacob, Jane ga es = Professor Smyth, vii 178 Vill CONTENTS. On the Colouring Matter of the Morinda citrifolia. By Dr Thomas Anderson, An attempt to Improve the present Methods of determining the Strength and Direction of the Wind at Sea. By Professor Smyth, On the Action of the Dry Gases on Organic Colouring Matters, and its relation to the Theory of Bleaching. By Dr George Wilson, - On the Products of the Destructive Distillation of Arniiial Sub- stances. PartI. By Dr Thomas Anderson, Note respecting the Refractive and Dispersive Power of Chloro- form. By Professor Forbes, Geological Notes on the Valleys of the Rhine and Rhone. By Robert Chambers, Esq., , : : On the Classification of Colours. By Professir Forbes, = Description of a Mud-slide at Malta. oo, A. Milward, Esq. Com- municated by the Secretary, . : : An attempt to explain the “ Dirt-bands” of Glaciers. a A. Mil- ward, Esq., On the rate of Progression of the Himalayan Glaciers. By Lieu- tenant R. Strachey, Bengal Engineers, Observations on the preceding Communications, and especially 0 on the Cause of the Annual Rings of Glaciers. By Professor Forbes, An Account of Carnot’s Theory of the Motive Power of Heat, with Numerical Results deduced from Regnault’s Experiments on Steam. By Professor William Thomson of Glasgow, Theoretical Considerations on the Effect of Pressure in Lowering the Freezing-Point of Water. By James Thomson, Esgq., jun., Glasgow. Communicated by Professor W. Thomson, On the Early History of the Air-Pumpin England. By Dr George Wilson, 2 : On the Classification of Colours. Part II. By Professor FF orbes. (See p. 190), ? Verbal Notice of Sclicidas Stalactites on Arthur's Seat. By the Rey. Dr Fleming, On some peculiar Impressions on the Surface of certain Strata of Greywack$ Schist, at Goldielands, in Roxburghshire. By James Elliot. Communicated by David Milne, Esq., 3 On the Causes of Local Peculiarities of Temperature in different parts of Great Britain. By James Elliot. Communicated by David Milne, Esq., . : : : Verbal Notices. By the Rev. Dr Fleming, ; Notice by Professor Smyth of Locke’s Electric Observing Clock, Abstract of a Communication on Rolling Curves, On the Extraction of Mannite from the Dandelion. By Messrs Smith ; with an Analysis of the Mannite by Dr Stenhouse. Com- municated by Dr George Wilson, é On some new Voltaic Arrangements with Chlorous and Chromic Acids, with an Account of a Battery, yielding electricity of great intensity, in which the negative as well as the positive element is Zinc. By Dr Thomas Wright. Communicated by Dr G. Wilson, : : - ; z ~ 214 216 217 218 219 223 CONTENTS. 1x Biographical Notice of Dr Chalmers. By the Very Rev. E. B. Ramsay, . 226 An Attempt to compare ‘the Exact and Popular Estimates of Pro- : bability. By Bishop Terrot, 228 On the Gradual Production of Luminous Impressions on “the E ye, and other phenomena of Vision. By William Swan, Esq., . 230 Note on the Refractive and Dispersive Powers of the Humours of . _ the Eye, determined by Experiment. By John Adie, Esq., . 232 On Grooved and Striated Rocks in the Middle Region of Scot- land. By Charles Maclaren, Esq., . . 233 On a Simple Form of Rain-Gauge. By the Rev. Dr Fleming, . 234 On a Method of Cooling the Atmosphere of Rooms in a raps, ge Climate. By Professor Smyth, é . 285 Notice of a Shooting-Star. By Professor Smyth, . 236 A few Unpublished Particulars SORT the late Dr Black. By Dr George Wilson, 238 On a New Voltaic Battery of Intense Power. By Dr Wright. Communicated by Dr George Wilson, 239 On a New Species of Manna, from New South Wales. By Dr Thomas Anderson, 239 _ Account of a Peculiar Structure ‘found i in 1 the Vagmares Telandious: By Dr John Reid. Communicated by Professor Goodsir, . 241 _ Notes to a Paper on the Motive Power of Heat. By Professor William Thomson, 241 Note regarding an Experiment suggested by Professor Robison. By Professor Forbes, 244 Personal Observations on Terraces, and other Proofs of Changes in the relative Level of Sea and Land in Scandinavia. By Robert Chambers, Esq., = 247 _ Note respecting the Dimensions and Refracting Power of the Eye. _ By Professor Forbes, 251 On the Intensity of Heat reflected from Glass, By Professor Forbes, 256 On the Solution of. certain Differential Equations. By Professor Kelland, . i : .) 257 On the Muscular Substance of the Tongue. By Mr Zaglus. Com- municated by Professor Goodsir, ~ . 258 - On the Volcanic Formations of the Alban Hills, near Rome. By Professor Forbes, . ; - 259 On the Gamboge Tree of Siam. By Dr Christiaon, ‘ - 263 Notice respecting a Deposit of Shells near Borrowstounness. By Charles Maclaren, Esq., : é : - 265 _ An Account of some Monstrosities. By the late Dr J. Reid. Com- municated by Professor Goodsir, : 267 The Effect of Pressure in Lowering the Freoxing-Point: of Water experimentally demonstrated. By Prof. W. Thomson, Glasgow, 267 On the Extinction of Light in the Atmosphere. By W. S. Jacob, Esq., H.E.I.C. Astronomer, Madras. Communicated by Pro- fessor Smyth, . 271 Abstract of a Paper on the Hypothesis of Molecular Vortices, and _ its Application to the Mechanical Theory of Heat. By W.J.M. _ Rankine, Esq., Civil Engineer, ; - 275 x CONTENTS. On Probable Inference. By Bishop Terrot, : : ‘ On the Ante-Columbian Discovery of America. By Dr Elton. Communicated by Dr Traill, : Z . ; On the Equilibrium of Elastic Solids. By Mr James Clerk Maxwell. Communicated by the Secretary, : Two Letters from W. E. Logan, Esgq., to Earl Catheart, Notes on Practical Chemical Subjects. By Alexander Kemp, Eg. Communicated by Dr Gregory, Analysis of the Anthracite of the Calton Hill, Edinburgh. By Dr A. Voelcker. Communicated by Dr George Wilson, On the Proportion of Fluoride of Calcium present in the Baltic. By Professor Forchammer of Copenhagen. With some Prelimi- nary Remarks on the presence of Fluorine in different Ocean Waters. By Dr George Wilson, On an Application of the Laws of Numerical Hafnionic Ratio to Forms generally, and particularly to that of the Human Figure. By D. R. Hay, Esq., Note regarding the American Electric- Observing Clocks. By Pro- fessor Smyth, Account of a Bemarkaila Meteor, seen 19th December 1949, By Professor Forbes, : Notes on the Purification and Properties of Chloroform. By Dr Gregory, ‘ On a Peruvian Musical ‘Tnsteanaent, like the ancient Syriix; By Dr Traill, : Some Remarks on Cometary Physics. By Professor Smyth, Abstract of Professor Kelland’s Exposition of the Views of D. R. Hay, Esq., on Symmetric Proportion, “ On the Constitution of Codeine, and its Products of Decomposition: By Dr Thomas Anderson, . On the Physical and Scottish Statutory ‘Limits of Sea and River, as applicable to Salmon Fisheries. By the Rey. Dr Fleming, On the Combined Motions of the Magnetic Needle, and on the Aurora Borealis. By J. A. Broun, me Communicated by Sir T. M. Brisbane, Bart., : : : OE —— ss ———<—_ ——— PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. VOL. IL. 1844-5. No. 25. SixtTy-SECOND SESSION. Monday, 2d December 1844. Sir T. M. BRISBANE, Bart., President, in the Chair. The following Communications were read :— 1. Account of the late Earthquake at Demerara. By W. H. Campbell, Esq. Communicated by M. Ponton, Esq. 2. On the Existence of an Electrical Apparatus in the Flapper Skate and other Rays. By James Stark, M.D., Fellow of the Royal College of Physicians, Edinburgh. The author, after noticing the fishes in which an electrical ap- paratus had been discovered, stated that, with the exception of Geoffroy St Hilaire, no writer had endeavoured to shew that Skates possessed electrical organs. The organ to which that writer al- ; luded, the author regarded as nothing else than muciparous ducts, identical with the very same organs in the Torpedo, and quite distinct from the electrical organs, The circumstance was then mentioned which directed the author’s attention to the tail of the skate, and led him to suppose that an electrical organ might exist in it. On removing the skin from the tail of a Flapper Skate, an organ was discovered occupying the place of the lateral muscles, extend- ing from near the base to the very tip of the tail, and possessing all the anatomical characters of the electrical apparatus of fishes. It was about 14 inches in length, and about half an inch in diameter for nearly one-half of its length ; was composed of columns or four-sided _ membranous tubes, about the twelfth of an inch in diameter, divided VOL, II. A 2 by cross membranous septa into compartments varying from the twentieth to the thirtieth of an inch in diameter. These compart- ments were filled with a transparent gelatinous matter. The columns were so arranged as to form layers, which, on a transverse sec- tion, were seen to have a concentric arrangement, but on a longi- tudinal section, were seen to form hollow cones placed one within the other. This arrangement allowed about three-fourths of the wide extremity of every cone-shaped layer to come in contact with the skin. The microscope shewed the walls of the columns and their cross septa to be composed of dense fibrous and filamentous tissue, on which the blood-vessels and nerves were minutely ramified. The gelatinous matter which filled the compartments was seen to be com- posed of very minute cells, the walls of which were composed of a fine transparent membrane, over which the nerves were seen to ramify in the most beautiful manner. The interior of these very minute transparent cells was filled with a transparent jelly. A rough chemical examination shewed the organ to be composed principally of gelatine, and in small part of albumen. No fibrin was observed in it. The organ was supplied with nerves from three sources, viz., from the lateral branch of the eighth pair, and from the anterior and pos- terior caudo-spinal nerves. This organ did not exist in equal development in every species — of Ray. In most of them it was merely rudimentary, not being thicker than a crow-quill or common pen, and consisted of only four or five columns, similarly divided into cells by cross membranous septa. The author formed the conclusion that this was an electrical ap- paratus from the following purely anatomical considerations, as he had not an opportunity of ascertaining the occurrence of electrical discharges from the organ by an examination of living specimens, 1. The structure of the organ was the same as that of the electrical apparatus of the Torpedo and Electrical Eel—consisting of membranous tubes or columns arranged in layers, each column being divided into distinct compartments filled with a gelatinous fluid. 2. All the layers of tubes communicated with the skin, and that skin was abundantly supplied with mucus. 3. The organ was supplied not only with spinal nerves, but with the descending branch of the eighth pair, which, along with a branch of the fifth pair, is the electrical nerve of the allied genus Torpedo ; 3 whereas, in other fishes, this nerve is solely distributed to the in- significant muscles which move the fin of the tail. 4, The microscopic structure is the same as that of the electrical organs of the Torpedo and Electrical Eel. 5. The chemical constitution is the same as that of the electrical organs of the Torpedo, consisting of gelatine and albumen, but no fibrin. The paper was concluded with a few remarks on the probable uses to the Rays of an electrical organ; and by directing the atten- tion of naturalists to the probable existence of electrical organs in many soft-bodied fresh and salt water animals, as Polypi, Asterias, &e. 3. Observations on the Comet, visible now or lately in the Constellation of the Whale. By C.Rumker, Esq. Com- municated by Sir T. M. Brisbane, Bart. The following Donations were announced :— Transactions of the American Philosophical Society, held at Phila- delphia, for promoting Useful Knowledge. Vol. ix., Part 1. —By the Society, Bulletin de la Société Geologique de France. Tome xiiii—By the Society. __ Memoirs and Proceedings of the Chemical Society. Parts 7, 8, 9. : — By the Society. " Journal of the Statistical Society of London. Vol. vii., Parts 1, 2, 3— By the Society. Journal of the Asiatic Society of Bengal, 1843. No. 142.—By the Society. ‘Det Kongelige Danske Vindenskabernes Selskabs Naturvidenska- belige og Mathematiske Afhandlingar. Deels ix. and x.—By 3 the Society. _ A System of Mineralogy, comprising the most Recent Discoveries. ; By James D, Dana.—By the Author. ‘The Journal of Agriculture, and the Transactions of the Highland and Agricultural Society of Scotland, 1844, July and October. “ — By the Society. ‘Scheikundige Onderzoekingen, gedaan in het Laboratorium der ¥ Utrechtsche Hoogeschool. 2d Deel. 5d Stuk.— By the Editors. rt of the Thirteenth Meeting of the British Association of the 4 Advancement of Science, held at Cork in August 1843.— By the Association. The Eleventh Annual Report of the Royal Cornwall Polytechnic Society, 1843.—By the Society. The Journal of the Royal Geographical Society of London. Vol. xiv., Part 1.— By the Society. Proceedings of the Royal Astronomical Society. Vol. vi., Nos. 1-6. —By the Society. The Electrical Magazine, conducted by Mr Charles V. Walker. Vol. i., No. 5.—By the Editor. Journal of the Asiatic Society of Bengal. No. 143.—By the Society. Journal of the Bombay Branch Royal Asiatic Society. Nos. 5 and 6. — By the Society. Annales des Sciences Physiques et Naturelles, d’Agriculture et d’Industrie, publiées par la Société Royale d’ Agriculture, &., de Lyon. Tome vi— By the Society. Geologische Bemerkungen iiber die Gegend von Baden bei Rastadt. Von J. F, L. Hausmann.—By the Author. Memoire sur le Daltonisme. Par Elie Wartmann.—By the Author. Astronomische Nachrichten, herausgegeben, von H. C. Schu- macher.—By the Editor. Versuch einer objectiven Begrundung der Lehre von den drei Di- mensionen des Raumes. Von Dr Bernard Bolzano.—By the Author. Magnetische und Meteorologische Beobachtungen zu Prag. Von Karl Kreil—(vierter Jahrgang). By the Author. Astronomical Observations made at the Royal Observatory, Green- wich, in the year 1842, under the direction of George Bid- dell Airy, Esq., M.A., Astronomer-Royal.—By the Royal Society. Catalogue of the Places of 1439 Stars, referred to the Ist of January 1840; deduced from the Observations made at the Royal Observatory, Greenwich, from 1836, January 1, to 1841, December 31.—By the Royal Society. Proceedings of the Geological Society of London. No. 98.—By the Society. Memoires de la Société Geologique de France. (Deuxieme Serie). Tome i., Partie 1.—By the Society. Sixth, Seventh, and Eighth Letters on Glaciers. By Professor Forbes.— By the Author. 5 Proceedings of the Zoological Society of London. Nos. 120 to 134.—By the Society. Abhandlungen der Koniglichen Akademie der Wissenschaften zu Berlin—ans dem Jahre 1842.—By the Academy. Bericht iiber die zur Bekantmachung geeigneten Verhandlungen der Konigl. Preuss. Akademie der Wissenschaften zu Ber- lin. Juli 1843 bis Juni 1844.—By the Academy. Tijdschrift voor Natuurlijke Gescheidenis en Physiologie—Uitge- geven door J. van der Hoeven en W. H. De Vriese, M.D. Deel. xi. St. 2.—By the Editors. Archief voor Geneeskunde—Uitgegeven door Dr J. P. Heije. Deel. iii, St. 4.—By the Editor. Het Instituut of Verslagen en Mededeelingen, Uitgegeven door de vier Klassen van het koninklijk Nederlandsche Instituut van Wetenschappen, Letterkunde en Schoone Kinsten over den Jare 1842, St. 4. 1843, St. 1, 2, 3—By, the Royal Institute of Holland. ~ Niewe Verhandelingen van het Bataafsch Genootschap, der Proe- fondervindelijke Wijsbegeerte te Rotterdam. Deel. ix., St. 1, 2, 3.— By the Society. Memoire de l’Academie Imperiale des Sciences de Saint Peters- bourg—(Sciences Politiques, &c.) Tome vi., Liv. 4, 5, 6. Tome vii., Liv. 1, 2, 3. Ditto ditto, Sciences Mathematiques. Tome v., Liv. 4, 5, 6. Tome vi., Liv. 1. Recueil des Actes de la Seance Publique de I’ Academie Imperiale des Sciences de Saint Petersbourg, tenue le 29. Dec. 1843.— By the Imperial Academy. Nouveaux Memoires de la Société Helvetique des Sciences Na- turelles. ‘Tomes i—vi.—By the Society. Actes de la Société Helvetique des Sciences Naturelles.—By the Society. Verhandlungen der Schweirischen Naturforschenden Gesellschaft bei ihrer Versammlung zu Zurich, 1841. Ditto ditto, zu Altdorf, 1842.—By the Association. Specimens of Printing-Types in the Establishment of Neill & Co., Printers, Edinburgh.—_By Messrs Neill § Co. Comptes Rendus Hebdomadaires des Séances de l’Academie des Sciences. Tome xviii., Nos. 15-26, and Tome xix., Nos. 1-16.—By the Academy. ’ Maps of the Irish Ordnance Survey, containing the County of Lime- rick, 62 sheets.— By the Lord Lieutenant. Monday, 16th December 1844. Sir GEO. MACKENZIE, Bart., in the Chair. The following Communications were read :— 1. On a Possible Explanation of the Adaptation of the Eye to Distinct Vision at Different Distances. By Profes- sor Forbes. The idea suggested in this paper, occurred to the author three years ago, from reflecting that the destruction of spherical aber- ration in the eye might be effected by a modification of the curva- ture of the lens, as well as by the variable density which it is known to possess, and which has usually been accounted for as in- tended for that purpose. The author considering the probability to be almost infinite against the sphericity of the surfaces (a necessary evil in our instru- ments, but inexplicable in a natural organ), a conviction which he atterwards found to be reduced to certainty by experiments which have actually been made on the figure of the lens—he conceived. that the variable density of this part of the eye must have some other cause. He considered it likely that it might contribute to the focal adjustment of the eye in the following way :—The lens is composed of coats more firm and tenacious, as well as more refractive, towards the centre, and less so at the sides. These coats are also nearly spherical in the centre, forming a nucleus of considerable resistance. Hence the author supposes, that if the lens be compressed in any manner by a uniform hydrostatic pressure, it will yield most readily in a plane at right angles to the axis of vision, and hence the lens will become more spheroidal, and, consequently, more refractive ; that is, adapted for the vision of objects at small distances. The hydrostatic pressure in question is believed to be conveyed from the humours of the eye, between which the lens is delicately suspended, and to originate in the compressing action of the muscles which move the eye-ball acting simultaneously on the tough sclerotic coat. The author thus sums up the evidence which he thinks gives pro- bability to this explanation :— 1. The form of the surfaces of the lens might have been such as to correct aberration without any variation of density whatever. But, on the contrary, it has a form which exaggerates the ordinary spherical aberration, A form which, therefore, appears to be 7 adapted to the rapid variation of density in the lens, which must, therefore, be presumed to have some distinct mechanical utility. 2. The effort to view near objects is accompanied in most, if not all persons, by a sensible muscular effort. ‘3. This theory is free from the various conclusive objections urged by Dr Young against all explanations which do not turn upon a change of figure of the lens; and it is also free from the difficul- ties to the admission of Dr Young's theory,—the muscularity of the lens itself. 4, When the lens is reproduced, after the operation for cataract, the power of adjustment is greatly diminished or wholly lost, since the variable elasticity will be wanting. 5. The diminution of the adjusting power of the eye in old age is explained by the increased rigidity of the lens, and consequent in- compressibility. 6. The crystalline lens polarizes light in a manner similar to that exerted by glass and other uncrystallized substances in a state of constraint, that is, possessing unequal elasticity in different direc- tions, 2. Notice of an Ancient Beach near Stirling. By Charles Maclaren, Esq. This beach presents the appearance of a terrace, extending along the north side of the Carse of Stirling, from the foot of Abbey Craig westward to Lecropt Church, and beyond it. Its length is about two miles; its breadth, at Lecropt Church, is about 200 feet, at Airthrey Mineral Well 900 feet, and at Airthrey Castle near alfa mile. Its upper surface is nearly a dead level in both direc- tions, except where breaches have been made in it, by streams or other agents. The elevation of this surface above the Carse in ~ about 85 feet, and above the Forth at Stirling probably 110 feet. Rock is seen under the terrace at the village of Causeyhead, in the bed of the River Allan, at the Bridge, and at the bottom of the acclivity under Lecropt Church. Everywhere else the terrace seems to consist of stratified sand and gravel, constituting a mass similar in form and materials to our present beaches. Its preservation may be attributed to the high rock of Abbey Craig, which protected it from the action of the ancient tides when the sea stood at a con- siderably higher level than it does at present. A remnant of a similar beach is seen on the south side of the Carse, about a milo southwest from Stirling. It consists of a hill of alluvial matter, a 8 furlong south from Whitehouse Farm, and about 70 or 80 feet in height. A small portion of a lower terrace about 30 or 30 feet above the Carse, is found at the southwest foot of the rock of Stir- ling Castle ; and a portion of a terrace of the same height is seen in connection with the higher terrace, extending for a short distance eastward of Lord Abercromby’s south gate. The following Donations were announced :— Annuaire de l’Academie Royale des Sciences et Belles Lettres de Bruxelles, 1844, Bulletin de l’ Academie Royale de Bruxelles. Tome x., Nos. 8-12. Tome xi., Nos. 1-8. Memoires Couronnés et Memoires des Savants Etrangers, publiés par l Academie Royale des Sciences et Belles Lettres de Bru- xelles. Tome xvi. Annales de l’Observatoire Royale de Bruxelles, publi¢ées par le Directeur, A. Quetelet. Tome iii—By the Academy. Annuaire de ]’Observatoire Royale de Bruxelles, par A. Quetelet, Directeur de cet Etablissement, 1844.— By the Author. Recherches Statistiques, par A. Quetelet.— By the Author. Notices sur Pierre Simons, Alexis Bouvard, et Antoine Reinhard Falck, par A. Quetelet— By the Author. Bulletin de la Société Géologique de France. Tomei. Feuilles 28-33.—By the Society. Novi Commentarii Academiz Scientiarum Instituti Bononiensis. Vols. i., ii., ii., iv., v— By the Academy. Opere Edite et Inedite del Professore Luigi Galvani, raccolte e pubblicate per cura dell’ Accademia delle Scienze dell’ Insti- tute di Boloona.— By the Academy. On the Excision of the Eyeball in cases of Melanosis, Medullary Carcinoma, and Carcinoma, with Remarks by J. Argyll Ro- bertson, M.D., F.R.S.E.—By the Author. Monday, 6th January 1845. Sir T. M. BRISBANE, Bart., President, in the Chair. The following Communications were read :— 1. Farther Remarks on the Electrical Organs of the Rays. By Dr Stark. 9 ©. Observations on the same subject. By John Goodsir, Esq. 3. Note on the Form of the Crystalline Lens. By Professor Forbes. Included in the former Abstract. 4, On the Cause which has produced the Present Form and Condition of the Earth’s Surface. By Sir George Mackenzie, Bart. The author first described, generally, the appearance of the loose materials covering the surface; and referred to some districts in the north of Scotland, especially the central one on the borders of Perth and Inverness shires, as demonstrating the effects of vast currents of water having passed over the surface. He also referred to the valleys of the river Conan and its tributaries, in Ross-shire, as presenting an epitome of all the phenomena which may be supposed to result from a vast flood gradually subsiding, and taking the direction of the val- leys. He then shortly alluded to the theories proposed to account for the present condition of the surface, which appear to resolve them- selves into the effects of a remote cause. It being generally admitted that the crust of the earth now ap- pears broken, some portions having been elevated, and some having sunk ; and that this breaking up of the strata, causing them to take various positions, the broken portions being inclined at different angles, some being vertical ; and that this dislocation of the strata is observed everywhere ; it is obvious that a tremendous force must "have been exerted to produce these effects. The elevation of the ~ former ocean bottom, and the sinking of much of the former land, ~ would occasion an agitation of the waters such as would have caused the waves to overtop the mountains ; and as the waves subsided cur- ~ rents would have been directed with great violence through all the valleys, sufficient to produce all the phenomena we observe, except those which may be fairly attributed to a subsequent gradual rising of the land, and to partial convulsions. Sir George concluded by observing that, probably, Man had not appeared on the earth previous to the great convulsion by which the order of the strata had been so greatly disturbed ; - for, besides no human fossil remains having yet been found, man, without such disturbance of the rocks, could not have enjoyed what external nature offers to his senses, nor have discovered the minerals and organic remains which have contributed so much to his wealth and comfort, as well as to the noblest exercise of his mental faculties. 10 The following Candidates were duly elected Fellows of the Society :— Dr James Andrew, F.R.C.P. Dr Geo. Wilson, Lecturer on Chemistry. The following Donations were announced :— The Journal of Agriculture, and the Transactions of the Highland and Agricultural Society of Scotland, for January 1846.— By the Society. Arsberiittelse om Zoologiens Framsteg under aren 1840-42. Af S. Loven. Arsberiittelse om Framstegen i Kemi och Mineralogafgiven, den 81 Mars 1844. Af Jac. Berzelius. Arsberiittelse om Botaniska Arbeten och Upptackter for ar 1838. Af J. E. Wikstrom. « Kongl. Vetenskaps-Academiens Handlingar, for ar 1842. Ofversight af Kongl. Vetenskaps-Academiens Forhandlingar, 1844. Nos. 1 to 7.— By the Academy. The Journal of the Royal Asiatic Society. No. 15, Parts 1, 2.— By the Society. Observations Meteorologiques faites & Nijne-Taguilsh (Monts Oural) Government de Perm. Annee 1842. Mittlere Oerter von 12,000 Fix-Sternen, von Carl Rumker. Part 1, containing pp. 1-47.— By Sir Thomas Brisbane. Monday, 20th January 1845. The Right Reverend Bishop TERROT, V. P., in the Chair. The following Communications were read :— 1, Some Account of the Magnetic Observatory at Makerstoun, and of the Observations made there. By J. A. Broun, Esq. Communicated by Sir T. M. Brisbane, Bart. The observatory is situated on a rising ground forming the left bank of the Tweed, and is at a distance of about fifty yards from the Astronomical Observatory. It is built of wood ; copper nails were used, and all iron carefully excluded from the building. The plan of the observatory is rectangular, 40 feet long by 20 broad: it is divided into one large room to the north, 40 feet by 12, i et he el i ee ae > ll and two ante-rooms to the south, with the lobby and entrance doors between. The magnetometers and telescopes in the observatory are placed on stone pillars of about 20 inches diameter, having good foundations, and being completely disconnected with the floor, so that no tremor can be communicated to the instruments by walking past them. The instruments in the observatory are of two classes, Magnet- ical and Meteorological. Belonging to the former class, there are, 1. The Declination Magnetometer, used for determining the variations and absolute values of the angle formed by the astronomical and magnetic meri- dians. 2. The Bifilar Magnetometer, by means of which the varia- tions of the horizontal component of the earth’s magnetic force are obtained. 38. The Balance Magnetometer, which gives the varia- tions of the vertical component. 4. The Inclinometer, used for ob- taining the magnetic dip, or the angle formed by the direction of the earth’s total intensity, and a horizontal plane, namely, in the mag- netic meridian. 5. An extra Declinometer in a small wooden build- ing, at a distance from the observatory, is used for obtaining the absolute value of the horizontal component of the earth’s magnetic force, according to the method of Gauss. The second class of instruments is the Meteorological. These are,—1, The Barometer, a standard by Newman, similar to that belonging to the Royal Society. The tube is 0°552 inches in diameter. 2. Thermometers. The dry and wet bulb thermometers, by Messrs Adie and Son, are placed on a revolving wooden frame opposite one of the north windows. They are always read from within the observatory, the frame being moved by means of cords and pullies. Maximum and minimum register thermometers, by Adie and Son, are placed on the north side of the observatory. Self-registering black bulb thermometers, for solar and terrestrial radiation, are placed in an enclosed space at a distance from the observatory. 3. Anemoscope and Anemometer. 4. The Rain-Gauge. In 1841 and 1842, daily observations were made at the Gdéttin- gen hours of 8 and 11 a.m., and 2 and 5 p.m.; in 1843 at 6, 8, 10, a.m.; Noon; 2, 4,6, 8,and 10, p.m. Another observation was made at 11 a.m., after October 1843; in 1844, at every hour of the twenty-four ; and this system is being continued in 1846. The instruments observed at these hours were, the declination, the 12 horizontal force, and vertical force, magnetometers,—the barome- ter, its height and temperature.—the dry and wet bulb external thermometers, and the thermometers of the two force magnetometers. To these were added observations of the weather. The magnetic inclination, or dip, has been observed since the com- mencement, with a few exceptions, twice a-week. Since July 1841, the monthly periods, named Terms, have been regularly kept. The terms are periods of twenty-four hours, which occur once a-month, on days previously agreed upon, and during which simultaneous observations of the magnetometers are made in all the magnetic observatories. At present, the three magnetome- ters are observed every five minutes of the 24 hours, meteorological observations being made hourly. In this way, each term produces 388 observations of each magnetometer, comparable with the obser- vations made at the same instant in the other observatories. Finally, observations for the absolute declination and absolute horizontal intensity of the earth’s magnetism have been made as regularly as possible at different periods of the year. The second class of observations is irregular, and comprise all those observations of phenomena which are irregular in their pe- riods. The most important of this class are the extra magnetic ob- servations. Whenever the magnets are found to have assumed posi- tions differing unusually from those at the previous observations, they are watched, and if found to be moving, extra observations are im- mediately commenced. When the disturbance is moderate, the three instruments are observed every five minutes, as on term days; if it be considerable, an instrument is observed every minute. Much attention has been paid to the magnetic disturbances in 1844. Upwards of 60,000 extra-readings of the magnetometers having been made in that year, giving about 25,000 mean posi- tions. The aurora borealis is as carefully observed as due attention to the magnetic disturbance with which it has here been found invariably accompanied, will allow. Attention is paid to the measurement and description of halos, parhelia, and paraselene. The reductions are at present in a considerable state of forward- ness ; and it is expected that the volume for 1848 will be ready to place in the printer’s hands as soon as that for 1841 and 1842 is issued. . 13 2. Description of a Sliding Scale for Facilitating the Use of the Moist-bulb Hygrometer. By James Dalmahoy, Esq. The instrument described in the paper is made of German silver, ___and is about a foot in length, and 4; of an inch in breadth; along __ the middle of it there is a groove for a slider. On the right edge : of the groove is engraved a scale of inches, and on the left the de- grees of temperature from 0° to 85° Fahrenheit, each being placed exactly opposite that point of the scale of inches which measures the corresponding tension of vapour. On the left edge of the slider is engraved a scale of equal parts, each 4% of an inch; on the right edge, and having the same zero, is a vernier, applicable to the scale of inches. The lines on these scales are ten times larger than those which the symbols in the dew-point formula represent, but their nu- merical designations are not changed. The instrument is to be used as follows :—Find on the slider the number which expresses the difference between the indications of the dry and moist bulb thermometers, and bring it opposite the num- ber on the left scale, denoting the temperature of the moist-bulb; then zero on the slider will indicate, on the left scale, the tempera- ture of the dew-point ; and on the right scale, the corresponding force of vapour. . The paper concludes by shewing that the ordinary hygrometric _ formula, which suggested the idea of the sliding scale, indicates also a geometrical construction for finding the temperature and tension of vapour at the dew-point, which, however, would not be practically applied with convenience. 3. Account of Experiments to Measure the Direct Force of the Waves of the Atlantic and German Oceans. By Thomas Stevenson. Communicated by David Stevenson, Esq. The author has attempted to supply a great desideratum in the _ practice of marine engineering, by instituting a series of experiments to ascertain what force the waves exert against opposing barriers. For this purpose he suggests, in some peculiar situations, the use _ of columns of water or of air, by which the force of each wave can be ascertained ; in the one case by the rise of the water-column, or _in the other by a pressure-gauge, shewing the same result in atmo- spheres by compression. But in all the observations as yet made he has used an instrument which may be termed a “ self-registering 4 14 Marine Dynamometer.’ This dynamometer is contained in an iron cylinder, which is fixed to the rock where the experiments are to be made. The instrument consists of a plate or disc attached to a powerful spring, which is lengthened by the action of the waves. In graduating the instrument, the pressure required ‘to lengthen the spring, a given quantity is ascertained by loading the dise with weights, so that when the quantity that the spring has yielded by the action of the sea is known, the pressure due to the area exposed is known also. The discs employed varied from 3 to 9 inches in diameter, and the resistance of the springs from about 10 lb. to about 50 Ib. for every 3} inch of elongation. With a view to check the results, three instruments, of very different powers of springs, were besides placed each other on an exposed rock, for a space of about six months, and the results were found to be remarkably concordant As the action of a wave may be supposed to combine the effects of a sudden impact with a subsequent continuous pressure, an objection might be urged against estimating these effects statically ; and the author has accordingly made some remarks relative to this subject, which it is not, however, necessary hére to state. The results obtained are, up to this date, 260 in number, and these embrace a continuous register of the agitations of the Atlantic (as ascertained at the Skerryvore Rocks, Aryyllshire,) for the last 22 months ; together with a later train of similar observations, on the German Ocean, made at the Bell Rock Lighthouse. The fol- lowing is a digest of the results obtained :— Atlantic Ocean. Average of results for 5 swmmer months, during the years 1843 and 1844, is 611 lb. per square foot. Average of results for 6 winter months during the same years is 2086 lb. per square foot, or thrice as great as in the summer months. Greatest result yet obtained at Skerryvore, being on the 20th December 1844, is 4835 lb. per square foot. German Ocean. Greatest result yet obtained at the Bell Rock, being on the 9th October 1844, is 3013 lb. per square foot. The greatest effect of the sea, which has been observed, is, there- fore, that of the Atlantic, which is equal to about 2 tons per square foot. There are also a few observations (made in April and June 1842) upon the Irish Sea, on the coast of Kirkcudbright, but the weather ee : 15 was unfavourable for such observations ; the highest result was 840 lb. on a square foot, ‘The communication concludes with an ac- count of several instances of the effects of the waves in the eleva- tion of spray, and in the transportation of heavy masses of rock. The greatest observed elevation of spray was at the Bell Rock Lighthouse, on the 20th November 1827, during a calm with a ground swell. On this occasion the spray was projected to the height of 106 feet, which shews the existence, on the large scale, of a pressure of about 3 tons. The pressure which projected this column of spray exceeds, therefore, the greatest result obtained by the Marine Dynamometer. The largest stone that is mentioned in the paper, as having been moved by the sea, is 42 tons weight. This stone, which is on the shores of one of the Hebrides, was seen to move under the influence of each wave. 4, A Verbal Communication in regard to Chevalier’s Expe- riments on the Decomposition of certain Salts of Lead by Charcoal. By Dr Traill. The following Donations were announced :— _ Journal of the Royal Asiatic Society of Bengal. Nos. 144, 145.— . By the Society. On the Nature of the Nervous Agency. By James Stark, M.D., ; F.R.S.E.— By the Author. Researches on the Brain, Spinal Cord, and Ganglia, with Remarks on the Mode by which a continued flow of Nervous Agency is 4 excited in, and transmitted from, these organs. By James Eis Stark, M.D., F.R.S.E.— By the Author. Philosophical Transactions of the Royal Society of London for . 1844. Part ii. _ Proceedings of the Royal Society of London, No, 59.—By the 2 Royal Society. “Magnetical and Meteorological Observations made at the Royal Observatory, Greenwich, in the year 1842, under the direc- ___ tion of George Biddell Airy, Esq., M.A., Astronomer-Royal. _ —By the Royal Society. Outlines of Chemistry for the use of Students, By William Gre- gory, M.D., Professor of Chemistry in the University of Edinburgh, By the Author. 16 Monday, 3d February 1845. Sir T. M. BRISBANE, Bart., President, in the Chair. The following Communications were read :— 1. On a Peculiar Modification of the Doubly Refracting Structure of Topaz. By Sir D. Brewster, K.H. While examining, in polarised light, some of the crystals which he had discovered in Topaz, the author observed certain optical phe- nomena, depending on a peculiarity of structure. This peculiarity is manifested either inthe depolarisation of light, when it gives rise to four quadrants of light, separated by the radiiof ablack rectangular cross si- milar to the central portion, or the tints of the first order in the uni- axal system of polarised rings, or in the unequal refraction of com- mon light, which gives rise to the mirage of a luminous point, in the form of concentric circles surrounding the centre of force. In every case there was found a quadrangular cavity in the centre of the in- tersection of the cross, generally dark and opaque, but in one case having a luminous spot in the centre. These cavities are from the so0y to the zz/55 of an inch in diameter. These cavities are quite distinct from all those formerly described by the author ; and from the phenomena above described, he con- cludes that the contents of each cavity have exerted an elastic force on the surrounding mineral while in a plastic state. In some cases fissures are seen proceeding from the central cavities, but these are supposed to have been produced after the mineral had become indu- rated, and had already been subjected, in the plastic state, to the pressure or force above indicated. These cavities never accompany the cavities with two fluids, but occur in specimens containing numerous embedded crystals, differ- ing little from Topaz in refracting power. Since the mineral must have been plastic when it yielded to the pressure here noticed, it cannot have been formed by the aggrega- tion of molecules having the primary form of the crystal. These considerations, along with others connected with the crys- tals, which occur in the cavities of Topaz, have ledthe author to adopt the idea of a new and peculiar kind of crystallization, to which he will soon direct attention. 17 2. Extracts from Letters to the General Secretary, on the Analogy of the Structure of some Voleanic Rocks with that of Glaciers. By C. Darwin, Esq., F.R.S. Specimens were exhibited. With Observations on the same sub- ject, made by Professor Forbes. “I take the liberty of addressing you, knowing how much you are interested on the subject of your discovery of the veined struc- ture of glacier ice. I havea specimen (from Mr Stokes’s collection) of Mexican obsidian, which, judging from your description, must resemble, to a considerable degree, the zoned ice. It is zoned with quite straight parallel lines, like an agate; and these zones, as far as I can see under the microscope, appear entirely due to the greater or lesser number of excessively minute, flattened air cavities. I can- not avoid suspecting that in this case, and in many others, in which lava of the trachytic series (generally of very imperfect fluidity) are laminated, that the structure is due to the stretching of the mass or stream during its movement, as in the ice-streams of glaciers. * * * * Tf the subject of the lamination of volcanic rocks should interest you, I would venture to ask you to refer to p. 65-72 of my small volume of * Geological Observations on Volcanic Islands.’* I there _* The laminated, volcanic rocks of Ascension, consist, as described by Mr Darwin, of excessively thin, quite parallel layers of minute crystals of quartz (determined by Professor Miller) and diopside ; of atoms of an oxide of iron, and of an amorphous, black angitic mineral ; and, lastly, _ ofa more or less pure feldspathic stone, with perfect crystals of feldspar _ placed lengthways. The following is a portion of the passage referred to : _ —* Several causes appear capable of producing zones of different tension in masses semiliquified by heat. In afragment of devitrified glass I have _ observed layers of spherulites, which appeared, from the manner in _ which they were abruptly bent, to have been produced by the simple _ ¢ontraction of the mass in the vessel, in which it cooled. In certain dykes on Mount tna, described by M. Elie de Beaumont, as bordered _ byalternating bands of scoriaceous and compact rock, one is led to sup- _ pose that the stretching movement of the surrounding strata, which ori- _ of moving glaciers is stretched and fissured. In both cases, the zones _ may be compared to those in the finest agates ; in both, they extend in the direction in which the mass has flowed, and those exposed on the surface are generally vertical. In the ice, the porous lamine are rendered VOL. 1. B 18 throw out the idea, that the structure in question may perhaps be explained by your views on the zoned structure of glacier ice, the layers of less tension being, in the case of the Ascension obsidian- rocks, rendered apparent, chiefly by the crystalline and concretionary action superinduced in them, instead of, as in zoned ice, by the con- gelation of water. * * * ** How singular it at first appears, that your discoveries in the structure of glacier ice should explain the structure, as I fully believe they will, of many voleanic masses. I, for one, have for years been quite confounded whenever I thought of the lamination of rocks which have flowed in a liquified state. Will your views throw any light on the primary laminated rocks? The lamine certainly seem very generally parallel to the lines of disturbance and movement. Be- lieve me, &c. C. Darwin.” To Professor FORBES. Professor Forbes confirmed the previous remarks by others, made by himself on the specimens transmitted to him by Mr Darwin, and on specimens from Lipari and Iceland in the collection of the Royal Society, as well as by direct observations made by himself on the lava streams of Aftna. distinct by the subsequent congelation of infiltrated water ; in the stony feldspathic lavas by subsequent crystalline and concretionary action. The fragment of glassy obsidian in Mr Stokes’s collection, which is zoned with minute air-cells, must strikingly resemble, judging from Professor Forbes’s description, a fragment of the zoned ice; and if the rates of cooling and the nature of the mass had been favourable to its crystalliza- tion, or to concretionary action, we should here have had the finest pa- rallel zones of different composition and texture. In glaciers, the lines of porous ice and of minute crevices seem to be due to an incipient stretch- ing, caused by the central parts of the frozen stream moving faster. than the sides and bottom, which are retarded by friction. Hence, in glaciers of certain form, and towards the lower end of most glaciers, the zones become horizontal. May we venture to suppose that, in the feldspathic lavas with horizontal lamine, we see an analogous case? All geologists who have examined trachytic regions have come to the conclusion, that the lavas of this series have possessed an exceedingly imperfect fluidity ; and as it is evident that only matter thus characterized would be subject to become fissured, and to be formed into zones of different tensions, in the manner here supposed, we probably see the reason why augitic lavas, which appear, generally, to have possessed a higher degree of fluidity, are not, like the feldspathic lavas, divided into lamine of differ- ent composition and texture. Moreover, in the augitic series, there never appears to be any tendency to that kind of concretionary action, which, we have seen, plays an important part in the lamination of rocks of the trachytic series, or, at least, in rendering that structure ap- parent.” : General View of the Brochken Headed Barrel of Stockholm Pitch. eee ae Elevation. — = Biularged Krew a “the Lttch as GaPerveL. Stoner Qarried atong by the Stream pe id Fe Schereok Sith. Clin? 19 8. Professor Forbes then read the following Letter from Professor Gordon, of Glasgow, also on the subject of the Viscous Theory of Glaciers. GLaAsGow, January 31. 1845. _ * * * When you requested me to give you a memorandum of _ what appeared to me to be the very glacier-like motion and appearance of Stockholm pitch flowing from a barrel, I considered my observation to have been too casual to be worth writing, and having foreseen that I could arrange an experiment at Gateshead in the beginning of the year, I delayed giving you the memorandum you wished. I had hoped to have been able to inspect and report on my experiment about this time ; but I cannot go to Gateshead for some time to come, nor have I had any report of the progress of my pitch glacier since _ the 6th January, when I was informed it had not moved since the day after I left it, on the 28th December. Your note of yesterday _ induces me to offer you the following still perfectly vivid impressions of the analogy between ice and Stockholm pitch. Allow me, in the first place, to mention that I read your travels in a the Alps, in May last. That on the 24th of June I spent almost 20 hours on the glaciers of the Grindewald. I went up by the lower glacier, prepared with poles to prove the motion, and actually _ observed a progress of about 12 inches in the course of 13 hours, _ from 6 a.m. to 7 p.m. I traced the “dirt bands” on the surface. I was let down into several crevasses, oné of them to a depth of 30 _ feet and could trace the slaty structure of the ice. The alternate clear blue thin veins, and the transition to opaque grey or even white. I descended from the glacier with a much better appreciation _ of the theory of glaciers than I had had, and a strong conviction * that the facts I had observed, could not be otherwise accounted for __ than by the mechanical theory you have given. In passing through _ Gateshead in August, a broken headed barrel of Stockholm pitch at _ the Wire Rope Factory, attracted my attention. Its general appear- ance is represented in Fig. 1. A mass of Stockholm pitch broken from a barrel in August (at _ the time of the observations I am about to mention) presented a dark- _ brown colour, a glassy lustre, translucent edges. The substance is fragile, fracture conchoidal, and very uniform. A mass, Fig. 4., which was brought to me by the workman having charge of this department, and which he had broken from the end of such a m as I have represented coming from the barrel, presented generally the same appearance as a mass broken from an entire 20 barrel,* but had this remarkable peculiarity, that there were lines —structural lines, @ a a a—whose texture and colour were dif- ferent from the general colour of the mass recognisable on such points as b b b, between any two such structural lines. Fig 2. is an elevation of the stream of pitch, shewing pretty nearly the dimensions and outward appearance of the stream. The striated slaty structure appears here on the outside, as is more dis- tinctly (intended to be) shewn in Fig. 3. There were certain well- defined lines, and on either side of these for some little distance, other small lines or cracks (but not open cracks or fissures), and then a space of smooth glassy-looking pitch. I am strongly impressed with the idea, that the structural lines are a result of the motion, and that they correspond with the veins of glaciers. The lines incline most when the surface is steepest, as at h, Fig. 3., and are very faint and nearly horizontal at i, where the surface of the stream is nearly so too. I left Gateshead with- out having an opportunity of getting a sectional view of this stream. I can get no real Stockholm pitch in Glasgow, else I should have made the experiment you have incited me to attempt here. Iam, &c. Lewis Gorpon. To Professor FORBES. The following Candidates were duly elected Fellows of the Society :— Dr John Burt, F.R.C.P., Edinburgh. “3 Dr Thomas Anderson, Lecturer on Chemistry. The following Donations were announced :— The Electrical Magazine, conducted by Mr Charles V. Walker, for October 1844.— By the Editor. Memoir of Francis Baily, Esq., D.C.L., Oxford and Dublin. By Sir John F. W. Herschel, Bart.— By the Royal Astronomi- cal Society. Inest de Stella Lyre variabili Disquisitio. Per F. G. A. Arge- lander.— By the Royal Astronomical Society. Description of Bones, &c., found near the River Ohio, 1786, with an Engraving, and Observations on the Aunual passage of Herrings. By Mr John Gilpin. From the Columbian Ma- gazine, December 1786.—Anonymous. Three Volumes in the Chinese Character on Astronomy and Geo- graphy.— By Professor Forbes. * The pitch is fragile at the same time that it fows—L.G. PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. VOL. 11. 1844-5. No. 26. Srxty-SEconD SESSION. Monday, 17th February 1845. Riegur ReverenD BISHOP TERROT in the Chair. a The following Communications were read :— 1. On the Existence of peculiar Crystals in the Cavities of the Topaz. PartI. By Sir D. Brewster. 2. On the Use of Colourless Ink i in Writing. By Sir George Mackenzie. hn xtany years ago, the author had attempted to separate the com- pon ent parts of common ink, with the view to get rid of its incon- venience in soiling everything with which it came in contact, by committing some of the parts to paper, and some to the pen. Work- ing with solutions, he found that, in all his trials, the paper was, sooner or later, discoloured more or less, so as to unfit it for the market, and he abandoned the attempt. He afterwards tried salts of iodine, but failed to fix the colour which they yielded. After an- other interval, the subject again recurring, he was led, by an acci- al circumstance, to think he might attain the long sought-for ect by using dry powders for the paper, instead of solutions. The irst trial satisfied him that he was, at length, to succeed; and, ifter persevering a considerable time, he brought certain processes 0 far as to yield good paper. With an almost colourless ink, wepared with permuriate of iron, traces were instantaneously pro- d, dark a for ordinary purposes. The powder introduced D 22 into the machine for preparing the paper, is compounded of galls, anhydrous ferro-prussiate of potassium, and carbonate of lime, so diluted with rice flour, that enough, and no more of the powder than enough, remains among the fibres of the paper. The paper is sized before being passed through the machine, and is afterwards finished in the usual manner. Specimens of different qualities of paper were laid on the table, and written on with the colourless ink by the members present. 3. On the Use of Metallic Reflectors for Sextants, and on the Determination of the Errors arising from Non- Parallelism in the Mirrors and Sun-Shades of Reflect- ing Instruments. By John Adie, Esq. The object of this communication was to shew that, by the use of metallic reflectors for sextants, greater accuracy was obtained in the observed angles, and also that larger angles could be observed. Objects were seen reflected by metallic mirrors, which could not be seen when glass was used; and that when the alloy was formed of pure metals, it was not subject to rust or tarnish, even when exposed to action of the sea air. The author then exhibited a sextant fitted with these mirrors, which had been employed for a season in the survey of the north coast of Scotland, under Mr Mossman, and read extracts of letters from that gentleman. In the second part, he describes methods by which the non- parallelism in mirrors and shades may be determined with great accuracy, before they are applied to reflecting instruments. A Ballot then took place for the following Candidates, recommended by the Council at last Meeting for filling places in the Foreign Honorary list :— RIM. GCanctiyss. 02, oe seemeess tae ee Paris, Car péistiory: : nic gcusepietmnas 6 Bex, Bhirenber gts asa Geass sass 0% Berlin, Elie de Beaumont,........ bars. LS 10 gael or Cae a Om Paris, IEansteen eee eens ake Christiania, ee Oti cheese lites act Konigsberg, WWamontsec eres cence Munich, Dba dbbtasitics

10 a.m. till 45™ ad noon, and as much to the east from the latter epoch till 11" p.m.; from 11 PM, . till 2" 35 a.m., the north end of the needle moves 0 7 towards the west, Seana: to the east again about as much by 6 a.m. The epoch of the greatest westerly declination seems to be connected with its annual period, or with the value of the mean westerly declination, nd the epoch of the principal mininum, with the sign of the secular change. The author considers that the diurnal oscillation is double at all seasons of the year. : 2. The Moon’s hour angles. The following are the result, Moon in opposition north of the equator; mean of 13 lunations ; scillation single; range= 08. _ Maximum 1° before inferior transit. Minimum 4+ or 5" before aperior transit. Moon in opposition south of the equator; mean of 12 lunations; Nation double ; range= 0-6. Maximum 23}, and minimum 6 after superior transit. Second- ‘maximum at inferior transit. Minimum 5" after it. oon in opposition northward, south of equator ; mean of 25 lu- ; oscillation double ; range=0'6. econdary maximum 43", and minimum 8" after superior transit, xximum at superior transit, minimum 6° after it. 146 3. Notice of two Ores of Copper, one of them a new Mineral. By Professor Connell. The first of the two ores here described, found in Cornwall, is a new combination of chloride of copper, sulphate of copper, and water. It occurs in beautiful small deep blue acicular crystals, of high lus- tre, grouped in bundles. The quantity was too small for a quanti- tative analysis. The other is essentially a double carbonate of zinc and copper. It is from Matlock. It is pale-green, with a laminated structure and pearly lustre. In the qualitative examination of it, the author observed indications of one, or even of more than one, metallic oxide, which he could not identify satisfactorily with any known substance. — This oxide was found to adhere to the copper, when that metal was precipitated by sulphuretted hydrogen. When the sulphuret was dissolved in aqua regia, and precipitated at a boiling heat by potash, the new oxide remained dissolved in the alkali, and the solution yielded on evaporation a small quantity of a soluble salt of a beauti- ful orange-yellow colour. The solution of this salt, when acidulated, — gave, with sulphuretted hydrogen, a red-brown precipitate, which, — when dry, was insoluble in muriatic acid, but soluble in aqua regia, On comparison with other known oxides yielding yellow compounds with bases, it appeared to differ from all; but the author had so mi- nute a quantity to operate on, that he cannot pronounce decidedly till he has made further investigation. The analysis of 316 grains of the mineral gave for 100 parts, Carbonic acid and water, : : Dy Oxide of copper, ° : : 32°5 Oxide of zinc, : F 3 ol 42°7 Magnesia, . A - : > Drace Lime, . . ; . . Trace 102-7 2 This might give the formula, eS 0) CO, + HO, that is, n ; 1 atom of dicarbonate of copper aud zinc, combined with 1 atom of | water, which gives 27:9 per cent. of carbonic acid and water to- gether ; but the smallness of the quantity analysed, prevented the determination of the relative proportions of carbonic acid and water. PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. ' VOL. II. 1847-8. No. 381. Monday, May 3, 1847. Tue following Donations of Books to the Library were announced :— Memoirs and Proceedings of the Chemical Society. Part 20. 8vo. — By the Society. ‘The American Journal of Science and Arts. Conducted by Profes- sors Silliman and J. D. Dana. For March 1847. 8v0.— By the Editors. On three several Hurricanes of the Atlantic, and their relations to the Northers of Mexico and Central America, with notices of other storms. By W. C. Redfield. 8vo.—By the Author. 26,1846. 8v0.—By the Academy. [he Fourteenth Annual Report of the Royal Cornwall Polytechnic Society, 1846. 8vo.— By the Society. Magnetical and Meteorological Observations made at the Royal Observatory, Greenwich, in the year 1844, Under the direction _ of George Biddell Airy, Esq., M.A., Astronomer-Royal. 4to. _ —By the Royal Society. 148 Sixty-Firta SESSION. First Ordinary Meeting, 6th December 1847. Sirk THOMAS MAKDOUGAL BRISBANE, Bart., President, in the Chair. The following Communications were read :— 1. Biographical Memoir of the late Dr Hope. By Dr Traill. 2. Note on the Constitution of the Phosphates of the Organic Alkalies. By Dr Thomas Anderson. The author had been led to investigate the phosphates of the organic alkalies, with the view of determining the accuracy of an analysis of the phosphate of strychnia by Reonault, which gave results incompatible with the known constitution of the inorganic phosphates. He alluded to the investigation of the phosphates of aniline by Nicholson, and proceeded to the statement of his own observations. Phosphate of Strychnia, with one equivalent of Strychnia, was obtained in long truncated needles, by digesting strychnia in tribasic phosphoric acid. It dissolved readily in water, and was acid to test-paper. By analysis it gave results corresponding to the formula (C 44 Hos No O, HO) 2 HO PO; The crystallized salt was found to contain 4 equivalents of water of cerystalization. Phosphate of Strychnia, with two equivalents of Strychnia. By long-continued digestion of strychnia with the foregoing water in solution, an additional atom of the alkaloid is dissolved, and the solu- tion on cooling deposits rectangular tables of a salt which is neutral to test-paper. It is less soluble in water than the acid phosphate, and its constitution was found to be represented by the formula 2 (Cy, H2; N, O, HO) HO PO; Phosphate of Brucia, with two equivalents of Brucia, is obtained by the solution of Brucia in phosphoric acid, and crystallizes from the concentrated solution in short prisms. The crystals are neutral to test-paper, and contain a large quantity of water of crystallization, which they lose by efflorescence. The formula of the salt is 2 (Cy, H.; N, O; HO) HO PO; 149 _ A double phosphate of Brucia and soda was also formed, but could not be obtained perfectly pure. | Phosphate of Quinine, with three equivalents of Quinine, By _ digesting quinine with phosphoric acid, a solution of this salt is obtained, which becomes a solid mass of silky needles on cooling. They are extremely soluble in hot water, and are quite neutral to test- 5 paper. They gave, by analysis, a result corresponding with ; 3 (Cy) Hj, NO, HO) PO; _ These results the author considered sufficient to establish the fact, that the phosphate of the organic alkalies agree in their constitution _ with the inorganic salts of that acid ; and he concluded his paper by _ observing, that the relations of these bases to phosphoric acid might be made use of as a means of classifying them. Thus quinine, which _ replaces three equivalents of water in phosphoric acid, might be com- _ pared to oxide of lead and the oxides of the heavy metals. Brucia ag represent the inorganic alkalies. While strychnia, which, under ordinary circumstances, replaces only one equivalent of water, belongs to a class which has no analogue among the series of inor- ga * ic bases. The following Donations to the Library were announced: nnals of the Lyceum of Natural History of New York. Vol. IV., No. 87. 8vo.— By the Society. vay Society of London, on the 19th February 1847. By Leonard Horner, V.P.R.S., President of the Society. 8vo.—By the Author. Proceedings of the American Philosophical Society. Vol. IV., No. Bay 6384. 8vo. ransactions of the American Philosophical Society, held at Phila- ; 3 -delphia, for Promoting Useful Knowledge. Vol. IX., Part 3. -. — By the Society. A Treatise on Atmospheric Phenomena. By Edward Joseph Lowe, Esq. 8vo.— By the Author. Annales de I'Observatoire Royal de Bruxelles. Tom. V.—By M. A. Quetelet. Mémoires Couronnés et Mémoires des Savants Etrangers, par I’ Aca- _ démie Royale de Bruxelles. Tom. IX., 1845 et 1846; Tom. XX., 1846, 2 Parties; Tom. XXI., 1846. 4to—By the _ Academy. 150 Nouveaux Mémoires de Académie Royale des Sciences et Belles . Lettres de Bruxelles. Tom, XIX. 4to.—By the Academy. Mémoires de l’Académie Royale dés Sciences, des Lettres, et des Beaux Arts de Belgique. Tom. XX. 8vo.—By the Academy. Bulletin de Académie Royale des Sciences, des Lettres, et des Beaux Arts de Belgique. Tom. XIII. (complete) et Tom. XIV., Nos. 1, 2, 3, 4, 5,6. 8v0.—By the Academy. Bulletin de la Commission Centrale de Satistique de Belgique. Ext. de Tom. III., sur les Anciens Recensements de la Population Belge, par M. Quetelet ; et la méme livraison, De Influence du Libre Arbitre de ’Homme sur les Faits Sociaux. Par M. A. Quetelet. 8vo.—By the Author. Bulletin de la Société Impériale des Naturalistes de Moscou. Nos, 3, 4 (1846); No. 1 (1847). 8vo. Séance Extraordinaire de la méme Société, du 22 Février 1847. 8vo. —By the Society. Berichte Uber die Mittheilungen von Freunden der Naturwissen- schaften in Wien. Von W. Haidinger. Band I., Nos. 1—6, und - Subscriptions Liste. 8vo.—By the Author. Bulletin der Kénigl. Akademie der Wissenschaften zu Berlin, Nos. 1-77. 8vo.—By the Academy. Gelehrte Anzeigen, von der Akademie der Wissenschaften zu Berlin, Bde. 16-23. 8vo.—By the Academy. Abhandlungen der Mathematisch-Physikalischen Classe der Kénigl. Bayerischen Akademie der Wissenschaften. 4 Band. 3 Abthei- lung. 4to,—By the Academy. Uber das Studium der Griechischen und Rémischen Alterthiimer. Von Ernest von Lasaulx.—By the Author. Uber die Ordealien bei den Germanen in ihrem Zusammenhange mit der Religion. Von Georg Phillips. 8vo.— By the Author. Die Uberbleibsel der Alteegyptischen Menschenrace. Von Dr Franz Pruner. 6vo.—By the Author. Almanach der Akademie der Wissenschaften zu Gottingen, fiir 1847. 8v0.— By the Academy. Annuaire de l’ Académie Royale de Belgique, 1846 & 1847. 8v0.— By the Academy. Annuaire de l’Observatoire Royale de Bruxelles. Par M. Quetelet. 1847.— By the Author. 151 _ Journal of Agriculture, and Transactions of the Highland and Agricultural Society of Scotland. No. 17 (July) and No, 18. (October) 1847. 8vo.—By the Society. Journal of the Statistical Society of London, Vol. X., Part 3. 8vo. — By the Society. Quarterly Journal of the Geological Society. No. 2 (August). 8vo. —By the Society. Monthly Journal of Medical Science. No. 81 (September). 8vo. —By the Editor. Thirteenth Annual Report of the Royal Cornwall Polytechnic Society. 8vo.—By the Society. _ Journal of the Royal Asiatic Society. Vol. X., Parts 2 and 3. 8vo. —By the Society. Journal of the Asiatic Society of Bengal. Edited by the Secretary. a Nos. 171, 172, 173. 1846. 8vo.—By the Editor. e Do. do. Edited by the Secretaries. New Series. Nos. 174, . 175, 176, and 181; with Supplementary Number published January 1847. 8vo.— By the Editors. _ American Journal of Science and Arts. Conducted by Professors | Silliman and Dana, Second Series. Nos. 5, 8; 9, 10, 11. 8v0o.— By the Editors. _ Philosophical Transactions of the Royal Society of London. Part 1, . 1847. 4to—By the Society. Kongelike Danske Videnskabernes Selskabs Naturvidenskabelige og * Mathematiske Afhandlinger. Tolvte Deel. 4to.—By the Royal Society of Sciences of Copenhagen. Flora Batava. No. 147. 4to— By the King of the Netherlands. ~ Handbuch der Mineralogie. Von J. F. L. Hausmann. 2 Theil. j 8v0.—By the Author. _ Astronomische Beobachtungen der Kénigl. Universitiits-Sternwarte Beat in Konigsberg. Von F. W. Bessel. 19 and 21 Abtheilung. _ -Fol.— By the Author. Annales de la Société Royale d’ Agriculture de Lyon. Tom. VIII. 1845.— By the Society. Recherches sur les Mouvements de la Planéte Herschel. Par M. Le Verrier. 1846.—By the Author. Ankuendigung und Probe einer Neuen Kritischen Ausgabe, und Neuen Uebersetzung der Syrischen Chronik, des Gregor Bar-Hebraeus. Von G. H. Bernstein. 1847, 8vo.—By the Author. 152 Sur la Publication des Monuments de la Géographie. 8vo.—By the Author. Satistique Générale. Rapport au Ministre de l’Intérieur sur les Travaux de la Commission Centrale, et des Commissions Provinciales de Satistique—By M. A. Quetelet. Rapport sur les Travaux de ’ Académie Royale des Sciences et Belles Lettres de Bruxelles, pendant l’année 1842-43. Par A. Quetelet. Svo.— By the Author. Rapport sur les Travaux et les Titres Scientifiques de M. Daponchel, lu A la Société des Enfants du Nord. 2 copies. 8vo.—By the Society. Bulletin des Séances de la Société Vaudoise des Sciences Naturelles. Nos. 14 & 15. 8vo.—By the Society. Censura Commentationum Soc, Reg. Danicz Scientiarum, anno 1846, ad premium reportandum oblatarum.—By the Society. Ofversigt éver det Kongelike Danske Videnskabernes Selskabs Forhandlinger, og dets Medlemmers Arbeider i Aaret, 1846, af H. C. Orsted. 8vo.—By the Author. On the Nucleus of the Animal and Vegetable “ Cell.”’, By Martin Barry, M.D. 8vo.—By the Author. Memoirs and Proceedings of the Chemical Society. Part 21. 8vo. —By the Society. On the Origin of Continents. By James D. Dana. 8vo. Origin of the Grand Outline Features of the Earth. By James D. Dana. 8vo.—By the Author. Greenwich Astronomical Observations. 1845. 4to.—By the Royal Society. Medico-Chirurgical Transactions. Vol. X1II. 8vo.—By the Editor. Everest’s Measurement of the Meridional Arc of India. With Plates, 4to.— By the Directors of the East India Company. Results of Astronomical Observations at the Cape of Good Hope. By Sir J. F. W. Herschel, Baronet. 8vo.— By the Duke of Northumberland. Researches for a Remedy against Communism. By Baron Dersenyis. 8v0o.— By the Author. Turner’s Chemistry. 8th Edition. By Liebig and Gregory. 8yo. —By the Editors. Description and Conquest of Ceylon. By Henry Marshall. 8vo. —By the Author. 153 Elements of General and Pathological Anatomy. Second Edition. By David Craigie, M.D. 8vo.—By the Author. Observations on the Famine of 1846-7 in the Highlands of Scot- land and in Ireland. By W. P. Alison, M.D. 8vo.—By the Author. The Acts of the Parliaments of Scotland. Vol. I. (1124—1423.) Fol. Acta Dominorum Concilii. Oct. 5, 1478 ad Nov. 15,1495, Fol. Acta Dominorum Auditorum. Oct. 9, 1466 ad Dec, 16, 1494. Fol.— By the Lords Commissioners of the Treasury. Proceedings of the Royal Society. No. 67, 1846, and No. 68, 1847. 8vo.—By the Society. Memorie della Reale Academia delle Scienze di Torino. Ser Seconda. Tom. III.,1V., V., VI. 4to.—By the Academy. Memoirs and Proceedings of the Chemical Society. Part 22. 4to. — By the Society. Journal of the Statistical Society of London. Vol. X., Part 4. 8vo, —By the Society. Observations on the Temple of Serapis. By Ch. Babbage. 8vo.—By the Author. Bulletin de la Société de Géographie. 3itme Série, Tom. VII. 8yo. —By the Society. Etudes d’Astronomie Stellaire. Par M. Struve. 1847. 8vo—By the Author. Die Cephalopoden des Salzkammergutes, aus der Sammlung Seiner Durchlaucht Fiirsten Von Metternich. Von F.R. Von Hauer. 4to.— By Prince Metternich. _ Journal of the Asiatic Society of Bengal. Nos. 178 and 179, for May and June 1847; and Index to Vol. XV. 8vo.— By the ; Society. _ Proceedings of the Zoological Society of London. Nos. 155, 177. : 8yvo. * Reports of Council and Auditors of the Zoological Suciety of ; London, for April 1847. 8vo. 7 A List of the Fellows, &c., of the Zoological Society of London, for April 1847. 4.— By the Society. A large Collection of the Admiralty Charts of Great Britain —By the Lords Commissioners of the Admiralty. 154 Monday, 20th December 1847. Rieut Rev. BISHOP TERROT, V.P., in the Chair. The following communication was read : Examination of some Theories of German Writers, and of Mr Grote, on the Authorship of the Iliad and Odyssey. By Professor Dunbar. In the first part of the paper the question was examined, whether the art of writing was known and practised at the time in which Homer is supposed to have lived? It was found that there was no evidence, either in the Iliad or Odyssey, that it was practised at that time; but that these poems must have been transmitted orally by the Bards for a period of nearly three centuries. It was then con- sidered whether poems of such a length as the Iliad and Odyssey could have been composed and committed to memory by one man; and it was shewn, from several examples, that there was no impos- sibility in the matter. Mr Grote’s theory, “ that no such poet of the name of Homer ever existed,’’ was then examined, and shewn, from the testimony of several of the most eminent Greek authors, to be fallacious. It was stated that lays, containing the history of the ancestors of powerful chiefs, were composed by the Bards attached to their families, and that Homer, in all probability, availed himself of them in working up the Iliad and Odyssey. The mode in which these poems were circulated through Greece by the Nomads, was next pointed out, by their reciting them on public occasions in every part of Greece. It was shewn that they were not committed to writing till a little before the age of Solon and Pisistratus. Wolfe and Lachmann’s theories were then examined, aud shewn to be altogether fallacious. The opinion of Mr Grote that the Iliad was first an Achilleis, and that the books, including the second and the subsequent ones to the eleventh, were the compositions of a later or later poets, was examined, and it. was shewn, by a reference to several incidents in these books, that they must have been composed by the same author, and formed a necessary part of the story of the Iliad. It was stated, contrary to Mr Grote’s opinion, that the Iliad possessed more unity than the Odyssey, and that internal evidence proved that it was in all probability composed by the author of the Iliad, and not by a piecing together of the lays of later poets. The opinions of some German critics, that the Odyssey was of a later date ‘than the Iliad, _—— — 155 was then examined, and shewn to be well founded. It seemed likely to have been composed in Homer's old age, and bore the same resem- blance to the Iliad in point of execution as the Paradise Regained of Milton to that of the Paradise Lost of the same poet. The paper concluded with a quotation from Mr Grote, in which he seemed to have departed from his original opinions. The following Gentlemen were duly elected Ordinary Fellows : Joun Witson, Esq., F.G.S. Moses Sreven, Esq. The following Donations to the Library were announced :— Emploi de l’Airain 4 défaut du Fer chez la plupart des peuples des cing parties du monde, &c. Notice intéressant les Peintres d’Histoire et les Archéologiques, Extraite du livre intitulé, Déconvertes dans la Troade. Par A, F. Mauduit. 3 copies. F 8vo.— By the Author. _ Défense de feu Le Chevalier, et du feu Comte EN Choiseul Gouftier contre M. P. B. Webb. Par M. Mauduit. 4 copies—By the Author. _ Appendices du livre Découvertes dans la Troade, publié en 1840 par . M. Mauduit ; Défense de Le Chevalier et du Comte Choiseul Gouffier, &e. 4to.—By the Author. _ Verhandlungen der Schweizerischen Naturforschenden Gesellschaft e bei ihrer Versammlung zu Chur. 1844. 4to. — By the Society. _ Actes de la Société Helvétique des Sciences Naturelles. Trentiéme * Session. 4to.—By the Society. Journal of the Asiatic Society of Bengal ; Edited by the Secretaries. d September, No. 182. 8vo.— By the Society. - Scheikundige Onderzeckingen, gedaan in het Laboratorium der -__Utrechtsche Hooge-school. 44 Deel, 44e Stuk. 4to.— By the University. ‘Mittheilungen der Naturforschenden Gesellschaft in Bern, aus dem Jahre, 1844-46. Nos. 13-38, 57-86.—By the Society. Bulletin de la Société des Sciences Naturelles de Neuchatel. 1844— 45-46. Tom. 1. 8v0.— By the Society. ‘9 eh de la Société des Sciences Naturelles de Neuchatel. Tom. Be h,, 11., 111. “4to. —By the Society. 156 Abhandlungen der Kénigl. Akademie der Wissenschaften zu Berlin, aus dem Jahre 1845. 4to— By the Academy. Bericht iiber die zur Bekanntmachung geeigneten Verhandlungen der Kénigl., Preuss. Akademie der Wissenschaften zu Berlin. Juli—December 1846, und Januar—Juni 1847. 4to— By the Academy. Bemerkungen iiber Gyps und Karstenit, von J. F. L. Bateau 4to.— By the Author. Nachrichten von der Georg-Augusts-Universitiit und der Kénigl. Gesellschaft der Wissenschaften zu Gottingen. 1846.——By the Society. Tradescant der Aeltere 1618 in Russland. Von Dr J. Hamel. 4to.—By the Author. Annuaire Magnétique et Météorologique du Corps des Ingénieurs des Mines de Russie, ou Recueil d’Observations Magnétiques et Météorologiques, par A. T. Kupffer. Année 1844. Nos. 1 & 2.—By the Editor. An Engraving of the late Principal Robertson.—By John Russell, Esq. Monday, 3d January 1848. Rieut Rev. BISHOP TERROT, V.P., in the Chair. The following communication was read :— 1. On Algebraical Symbolism. By Bishop Terrot. The author commenced by proving the propriety of the adoption of the minus sign for quantities of an affection opposite to those affected by the plus sign, and detecting the limits within which this use of the absolute minus was reasonable and effective. He observed that this was merely a particular case of the nota- 3 tion which symbolizes the inclination of lines by the factor 177, namely, the case where 0=180°, and proceeded to shew within what limits the algebraical rules for the treatment of exponential quanti- ties are applicable to the symbols of inclined lines. After referring to the use of this notation in all the problems of plane Trigonometry, especially those which treat of the sines and cosines of multiple ares, he gave some examples of its applicability 157 to some elementary propositions in the first and fourth books of Euclid. The following Donations to the Library were announced :— 4 The American Journal of Science and Arts, conducted by Professors Silliman and Dana, Vol. IV., No. 12. November, 1847. 8v0o.— By the Editors. The Journal of Agriculture. N.S, No. 19. January, 1848. 8vo. —By the Publishers. On certain Laws of Cohesive Attraction. By James D, Dana. 8vo. A General Review of the Geological Effects of the Earth’s Cooling from a State of Igneous Fusion. By James D. Dana. 8vo. Conspecius Crustaceorum. Auctore Jacobo D. Dana. 8vo0.—By the Author. Leeds Philosophical and Literary Society. Annual Report. 1846-7. 8vo.— By the Society. _ The Mathematical Analysis of Logic. By George Boole. 8vo.— By the Author. Kénigl. Vetenskaps Handlingar, for Ar 1845. Hft. 1 & 2 Stockholm, 1847. 8vo.— By the Academy. Ofversigt af Kénig]. Vetenskaps-Akademiens Férhandlingar. 1846. Nos. 7-10. 1847. Nos. 1-6. Stockholm. 8vo.—By the Academy. Arsberiittelse om Zoologiens Framsteg under Aren 1843-44. Af - C. J. Sunderall. Stockholm, 1846. 8vo.—By the Editor. Tal Hiillet vid Praes. Nedliiggande uti Kénigl. Vetenskaps-Akade- mien, den 7 April 1841. Af N. G. Sefstrém. Stockholm, 1846. 8vo.— By the Editor. _ Beriittelse om Framstegen i Fysik, éren 1843 and 1844, afgiven till Konig]. Vetenskaps-Akademien, af A, F. Svanbergoch, och a P. A. Siljestrém. “Stockholm, 1847. 8vo.—By the Editors. _ Memoirs of the Royal Astronomical Society. Vol. XVI. 4to. ‘a Proceedings of the Royal Astronomical Society. Vol. VII., Nos. a 1-17. 8vo.—By the Society. Monthly Journal of Medical Science, No 85. January, 1848, 8vo. _—- — By the Editors. Monday, 17th January 1848. Dr CHRISTISON, Vice-President, in the Chair. The following Communications were read :— 1. Account of a Geological Examination of the Volcanoes of the Vivarais. By Professor Forbes. The author having, on former occasions, stated some results of his travels in Auvergne and the Cantal, gives a more detailed descrip- tion of the volcanoes of the Vivarais, which have been less fre- quently and less accurately described. He first gives an account of the journey from Le Puy across the chain of the Cevennes which culminate at the volcanic summit of the Mezeuc, by the course of the Loire, to Montpezat in the department of the Ardéche. The best descriptions of the Vivarais are those of Foujas de St Fond and Mr Scrope. The plates illustrating the work of the lat- ter leave almost nothing to desire. These authors have described more or less fully the following volcanic orifices—Coupe de Jaujac, Souillolsor Neyvac, Mouleynes or Thuez ; Montpezat and Aysac. Other writers have described the cone of Bauzou, and the (so-called) crater of Elevation of Pal, which are generally supposed not to have given birth to any lava stream. The present author has given a more minute and detailed account of each of these volcanoes, and of the great beds of basaltic lava to which they have respectively given birth. He discusses the relative age, the remarkably columnar strue- ture, and the surprising erosion by water of these (comparatively modern) lava flows, which he illustrates by an exact map of the formations, based upon Cassini’s, and by very numerous levels baro- metrically determined. He has also been able to add to the list of known voleanoes in this district, two craters which he believes never to have been described, occurring in remarkable positions, and giving rise to extensive lava streams, one in the valley of Budzet, the other in that of la Bastide. The former he believes to be unparalleled amongst ancient or modern lavas for the length and slenderness of its stream, shewing a surprising liquidity, which he illustrated by some experi- ments on the powers of melted iron solidifying in narrow channels. A series of specimens illustrating the paper had formerly been presented to the Society. 159 2. Geological Notices. By Dr Fleming. (1.) Additional example of Diluvial Scratches on the Rocks in the neighbourhood of Edinburgh. The author stated that, recently, an opportunity had presented itself of observing, at a newly-opened sandstone quarry, dressed and scratched surfaces, at an elevation above the level of the sea greater than any examples of the same kind of diluvial action as yet re- corded, as occurring in the neighbourhood. The locality is east- ward of the east Cairn Hill, in the Pentland Hills, at a place termed * Thomson’s Walls,’’ and its elevation, according to Knox’s map of Mid-Lothian, is 1400 feet. Dr Fleming then stated, that, last autumn, in addition to the ex- ample of a dressed and scratched surface 130 yards westward of Granton Pier, on a level with the beach, he had observed a similar occurrence at the east side of the harbour of North Berwick, near the “ Auld Kirk,” on the surface of a rock of amygdaloid; and added, that he had found similar scratches, at the sea-level, on the south side of Montrose Basin. The author next adverted to an example of dressed vertical surfaces, with horizontal scratches, on the northern base of North Berwick-Law. He likewise referred to the horizontal scratches on a vertical face of rock recently exposed at the Hadderwick Lime Quarries, north from Montrose. Dr Fleming next called the attention of the Society to the Black- ford Hill example of a dressed and scratched surface, and intimated _ that the scratches had a dip to the eastward, reaching, in some cases, _ to 50°. He stated it as probable, that the phenomena, instead of having resulted from diluvial action, had been produced by the abrading operations of the Braid Burn. Verbal Notice. (2.) On the Fluor-Spar of Aden. Dr Fleming exhibited to the Society several beautiful examples of quartz and calcedony, in the form of cakes or circumscribed ‘ ereamnites, from the fort of Aden in the Red Sea, which had been u 160 sent to him by Dr Buist of Bombay. They were remarkable as having a few minute crystals of fluoride of calcium, the matter of which aggregated during the evaporation of the water, which had furnished, in greater quantity, the siliceous materials forming the support. The following Gentleman was duly elected an Ordinary Fellow :— James Top, Esq., W.S. The following Donations to the Library were announced :— Ordnance Survey. Account of the Measurement of the Lough Foyle Base in Ireland. By Capt. William Yolland. 4to.— By the Honourable Board of Ordnance. Natural History of New York. Botany. By John Torrey. Vol. f.,"Part 2.’ Vol: Al. Part 2. Ato: Do Do. Agriculture. By E. Emons. Part 5, 4to. — By the State of New York. Flora Batava. Parts 148 and 149. 4to.—By the King of the Netherlands. Journal of the Asiatic Society of Bengal, No. 183. October, 1847. 8v0.— By the Secretaries. A Collection of Fossii Plants from the Neweastle Coalfield—By Sir G. S. Mackenzie, Bart. Monday, 7th February 1848, Sir THOMAS MAKDOUGAL BRISBANE, Bart., President, in the Chair. The following Communication was read :— 1. On the Preparation of Kreatine, and on the amount of it in the flesh of different Animals. By Dr Gregory. After some remarks on the present state of animal chemistry, the author commenced by giving a brief account of the recent discoveries of Liebig in regard to the constituents of the “ juice of flesh,” or the liquid contained in the substance of the muscles, which is distin- 161 guished from the blood by the large proportion of free acid it con- tains. This remarkable animal fluid has been found, by Liebig, to contain phosphoric and lactic acids in large quantity, inosinic acid in small proportion, and some other acids not yet studied ; also, potash in large quantity with a little soda, a considerable proportion of magnesia, and a little lime, chloride of potassium, with a little q _ chloride of sodium, and, besides some compounds of animal origin not yet investigated, the new base Kreatinine, and the very remarkable substance, Kreatine, first discovered by Chevreul, but in vain sought for by Berzelius and other chemists. He then described the process, essentially that of Liebig, by which kreatine is extracted from the flesh of quadrupeds, birds, and fishes, in all of which hitherto tried, it has been found, although in small and variable quantity. A table was exhibited, shewing the per- centage obtained from different kinds of flesh and fish, and the re- sult was, that this interesting substance may be most easily and cheaply prepared from fish, especially cod, herring, salmon, and _ mackerel, all of which yielded much more than beef or horse-flesh, q and nearly as much as fowl, which was the most productive. The ‘ maximum proportion of kreatine was 3*2 per 1000 parts of flesh. 4 The average about 1°5 per 1000. The author stated that he had found inosinie acid only in the ~ flesh of fowl and turkey ; and he is informed, by Baron Liebig, that it is quite possible that this acid may also have been confined to _ the flesh of fowls in his experiments, as it was often absent, although — he cannot now ascertain the cases in which it was present. _ He concluded by stating, that as kreatine is found in the urine, _ along with kreatinine, it appears to be, in part at least, a substance _ intended for excretion. Its crystalline character renders this proba- ble; and, at all events, if it has any function to perform in the body, that function is not yet known. It must be regarded, in the mean time, as one of the numerous series of less complex products derived from the decomposition, in the body, of the effete tissues ; and al- though we cannot yet produce it artificially, yet, from the rapid pro- "gress recently made in the study of the products of decomposition of the albuminous substances, we may hope “soon, not only to do this, - put also to discover, from these products, the true formulz of the al- buminous compounds. 162 2. Notices of a Flood at Frastanz, in the Vorarlberg, in the Autumn of 1846. By William Brown, Esq. The author noticed the general effects of running water, in dis- solving, rubbing down, and transporting to a lower level, the solid parts of the earth’s surface; and referred to the gradual change which it is producing on the relative level of sea and land. He then described an occurrence which he had witnessed in the Vorarlberg, during the autumn of 1846. After a hot and dry summer, a succession of heavy rains for nearly a fortnight, awelad all the streams flowing into the river Ill, flooded the lower grounds, and inflicted a great deal of injury on the fields, roads, and bridges, At Frastanz, a small stream brought down from the mountains an enormous quantity of gravel, which continued for at least three weeks after the rains had ceased. When first seen by him, on the 6th of September, the volume of water in the stream was not very great, nor was its velocity unusual; but immediately beneath the surface of the water, which was quite transparent, in- numerable stones were seen to be in motion. These stones were generally of the size of an egg. The quantity of gravel brought down was so great, that the bed of the stream was elevated to the height of 25 feet in one part. The village of Frastanz was consi- dered to be in danger, from this curious torrent of stones rolled along by the water; and several hundreds of men were employed to bank it in by large trees laid lengthwise, and supported by strong posts driven into the ground. In the course of the following year, a wooden canal was formed in the lowest part of the stream, by which about a third of the mass of gravel has been washed down. This has raised the level of the Ill, into which the Frastanz stream flows, for two or three miles. The quantity of loose stones in the upper part of the ravine is still so great as to threaten a renewal of the catastrophe at any time when an unusual flow of water shall set it in motion. 3. Contributions to the Phenomena of the Zodiacal Light. By Professor C. Piazzi Smyth. The purport of this paper was to place on record certain observa - tions made during the years 1843—4—5, in the southern hemisphere, Ee ee 163 at those times of the year when the Zodiacal Light cannot be seen in the Northern hemisphere ; to test, by means of these new data,— which, besides the novelty of the geographical position, had the fur- ther one of being determined by instrumental measurement,—what laws of the phenomena may be considered to have been satisfactorily made out, and what required further elucidation; and to recommend these latter to the attention of observers situated in more favourable parts of the world than those commanded by European Observatories generally. After discussing the history of the subject, and mentioning the results arrived at by different observers, the author mentions the manner in which his attention was first particularly directed to the subject, describes the particular course of observation which he then commenced, and which consisted principally in observing the right ascension and declination of the apex of the light, by means of a small equatorial instrument of particular construction, which gave results not affected with more than 2° of probable error. Combin- ing his own observations with those of former investigators, the author concludes, that the hypothesis proposed by Cassini, and subsequently maintained by La Place, Schubert, Poisson, Biot, and Humboldt, viz., that the Zodiacal light is in the form of a ring encircling the sun, is _ decidedly untenable, but that it is rather, as first suggested by Mairan _ and since affirmed by Olbers and Sir John Herschel, in the form of a ~ lenticular mass. Mairan’s idea, too, of the body being excentrically _ disposed about the sun, being endued with a rotation, and occasionally crossing the earth’s orbit, seems to be confirmed. But the exact _ quantity of such excentricity, the period of rotation, the position of _ the plane of the body, the question of any actual periodical increase _ in the size and brightness of the Zodiacal light, and the physical na- ture of that light, whether entirely reflected, or whether, as rendered _ probable by some observations, partly direct, are matters, for the sa- - tisfactory determination of which more data are required. For the assistance of those who may be inclined to prosecute the inquiry, the author adds descriptions, both verbal and pictorial, of what the - Zodiacal light is like, what observers may expect to see; and men- _ tions the times of the year at which, in different latitudes, the phe- “nomenon may be best seen, together with a number of other atten- dant cireumstances which are necessary to be complied with, in order to procure undeniable observations. ' VOL. I. P 164 The following Donations to the Library were announced :— Observations made at the Magnetical and Meteorological Observa- tory at St Helena, Vol. I. 1840-43. 4to—By H. M. Government. Fusinieri (A.) sulle Ipotesi del Signor Melloni circa il Calore Raggiante. 4to.—By the Author. Astronomical Observations made at the Royal Observatory, Edin- burgh. By the late Thomas Henderson. Reduced and Edited by C. P. Smyth. Vol. VII. for 1841. 4to.—By the Royal Observatory. Fellenberg (L. R. de), Fragmens de Recherches comparées sur la Nature constitutive de différentes sortes de Fibrine du Cheval dans l'état Normal et Pathologique. « 8vo. Analyse de l’Eau Minérale de Weissenburg. 8vo. Ueber die bei der Consolidation des Faserstoffes stattfindenden Veriinderungen der elementar -analytischen Bestandtheile desselben. 8vo.—Bby the Author. Bulletin des Séances de la Société Vaudoise des Sciences Naturelles. No 13. 8vo.— By the Society. Journal of the Royal Geographical Society of London. Vol. XVII., Part 2. 1847. 8vo.— By the Society. The London University Calendar for 1848. 12mo,—By the University. Acta Academie Ceesareze Leopoldino-Carolinze Naturze Curiosorum. Vol. XXI., Pars 2. 4to.—By the Academy. ~ Monday, 2\st February 1848. Rigut Rev. BISHOP TERROT, V.P., in the Chair. The following Communications were read :— 1. Practical Illustration of the Adjustments of the Equatorial Instrument. By Professor C. Piazzi Smyth. The object of this paper was partly to introduce to the notice of travellers and residents in tropical countries, a small equatorial in- strument, specially contrived for observing the Zodiacal light ; and partly to bring forward before amateur astronomers, prominently, ee F 165 the advantage of equatorial mountings in general; as well as to ex- _ emplify the best and easiest methods of adjusting and rectifying the instruments, and placing the telescopes in every respect in the most favourable circumstances for yielding good results. After describing | how, in the history of astronomy, equatorial or parallactic stands : were twice taken up and abandoned again, from the erroneous estimate formed of the purposes to which they were adapted, the author mentioned the impracticable nature of the altitude and azimuth mountings which followed; and dated the present era of the perfection and the rational employment of equatorials to have commenced in 1820, when Sir J. Herschel, in conjunction with Sir J. South, erected one of these instruments, to give, by its A. R. and Declination circles, absolute places roughly ; and, by means of a mi- crometer applied to the focus of the telescope, small differences very exactly : the old error having been, to attempt to determine abso- lute places with the utmost precision. After particularising the various merits and imperfections of the two grand divisions of equatorials, viz., the English and the Ger- man, and mentioning a new construction in progress for the Edin- burgh Observatory, combining with the single-pier and short polar axis of the German form, the advantage which the English possesses, _ of large circles, and a position for the telescope between the two bearing ends of the polar axis, together with an exceeding degree of firmness and stiffness,—the author proceeded to describe the six errors of adjustment to which all equatorials are subject, and to shew, by means of a model placed within a representation of the - celestial sphere, contrived for the purpose, how all the rectifications ‘might be made by means of observations of stars. The application of clock motion to equatorials, for the purpose of keeping a celestial object stationary in the field, was next entered - into; and the plan explained by which the hitherto ungovernable _ fits of “ knocking”’ of the revolving balls in the later form of English clocks, has been remedied in the case of the Edinburgh Equatorial ; —viz., by having three pendulum-balls 120° apart, attached to the vertical spindle of the governor, instead of only two at 180°. As a proper micrometer to be used for very faint objects, in place of the ring micrometer,—which the author unhesitatingly condemned, as never having furnished accurate results either in A, R. or Decl., but more especially in the latter, in any person’s hands, though so 166 strongly recommended, and extensively used, on account of the beauty and truth of one of the theoretical principles involved in it,—he recommended a bar-micrometer, wherein right ascensions were mea- sured by transits across three parallel bars, marking both the immer- sions and emersions, so as to get rid of error of focus and irradiation of light; and declinations were measured by a bar at right angles to the former, the objects being bisected alternately with either edge of the bar. Observers already provided with position-micrometers might easily have some of these bars inserted, which in one position might be used for A. R., and in another for Decl. Such a micro- meter has been found to require no illumination on the darkest nights, even in telescopes of small aperture, and to produce results, with the amorphous masses of faint comets, almost equal in accuracy to those obtained from stars observed with fine wires in an illuminated field. The paper concluded with a short special description of the Zod. Light-equatorial, which, for economy, lightness, and general effec- tiveness, seemed well fitted for scientific travellers. 2. On the Vertebral Column, and some Characters that have been overlooked in the Descriptions both of the Ana- tomist and Zoologist. By Dr Macdonald. After noticing that the vertebral skeleton has usually been com- pared to a column, of which the basis (in man) is formed by the sa- erum and coccyx, the shaft or columnar part being the bodies of the true vertebrz, as they are usually styled, and ‘surmounted by the splendid composite capital the cranium, the author proposed re- stricting the observations to the columnar portion, usually divided into 7 cervical, 12 dorsal, and 5 lumbar vertebra. This division was denounced, and beginning at the summit, he shewed that the upper or cervical region consisted only of 6 vertebrae, as the 7th, in its normal position in the mammal class, had a rib partly articulated to its body, and therefore acquired the character of a dorsal vertebra. Restricting the cervical to six, the arrangement of the atlas and axis indicates the tendency to a combination into pairs in the course of the vertebral axis. The body of the atlas is almost entirely re- placed by the intrusion of the odontoid process of the axis; and thus, ————— ee ee 4 3 167 by their combined form and articulations, the head resting on them is provided with an equatorial and azimuth motion, as the astrono- mers say. The pairing of the 1st and 2d osteologically, is further strengthened neurologically, which is also applicable to the next pair | of the 3d and 4th. These two pairs are more properly to be consi- dered as the acostal cephalic portion, as the cervical plexus is princi- | pally distributed to the upper region of the body, as far as the moto- sensory part of the system is concerned, although it also contributes _to the thoracic and abdominal portions of the nutrient or splanchnic system. The third pair, formed by the 5th and 6th cervical ver- tebre, are the acostal constituents of the humero-brachial regions, and with the 7th, 8th, 9th, and 10th, are neurologically connected to- gether in supporting the nerves, forming the brachial plexus as they emerge fromthe spinal canal. This arrangement completes the cervical region in all the mammals except the Bradipus tridactylitis ; which is also illustrative of the coupling or pair principle here proposed, as the additional vertebra only form another pair. The idea of the dif- ferent classes of vertebrae composing the cervical region, as proposed by De Blainville and Knox, was examined, and shewn to be incom- plete, as it considered the 7th vertebra to be a class by itself. As De Blainville’s view coincided with that now submitted, in separating the 7th from the upper vertebrae, it was pro tanto adduced in evidence ; but the most striking corroboration was found in the examination of the skeletons of many of the mammals, several of which were ex- hibited and demonstrated, where it was shewn that in many, if not all, mammals, the normal position of the head of the rib was opposite the intervertebral space, and that as 12 ribs require 12 spaces, there must be 13 costal vertebrae. This additional thoracic or costal _ vertebra is provided by the 7, which is only (in man) deprived of jts costal connection possibly by the traction of the subclavian artery, which is the remains of one of the primitive reptiléid branchial arches, even here the first rib is occasionally in its normal situation, and when it is found that, in all cases, there are in man eight and generally nine of the ribs in their normal situation, and, also, that an undue share is given to the 8th vertebra, as the whole of the Ist, and part of the 2d, rib is connected to it, we are surely authorised to consider this as the normal position in all mammals. The impor- tance attached to this osteological discovery is, that it corrects an 168 error in the universally assumed character of mammals, which Dau- benton and Cuvier first applied, with the sole exception above no- ticed of the Sloth, which, however, still remains the exception to the number, while it corroborates the principle of coupling or pairing the cervical vertebree, which is of considerable use in unravelling the cranial vertebrae, and which De Blainville speaks of as still un- intelligible “ to those who have been unable to elevate themselves to this kind of questions” (the signification of the skeleton transcen- dentally considered) “ partly on account of the nature of their minds, and partly from the want of proper and sufficient subjects of contemplation.” In this view of the cervical vertebre, there was no examination of what are known as floating or cervical ribs, first pointed out and deseribed by Vieq d’Azyz in the Memoirs of the Academy of Paris for the year 1774, and which lately, Professor T. Bell of King’s College, London, has described in the case of the Bradypus. This class of ribs ought to be regarded as quite different from the thoracic ribs; and there was a beautiful example exhibited on the table, which the kindness of Professor Goodsir enabled the author to shew to the Society, and which forms part of a series collected and described by Dr Knox, in the London Medical Gazette, some years ago. In va- rious classes there are similar ribs, quite unconnected with, and dif- fering from, the thoracic ribs, which are rather homotypes of the sty- loid process of the temporal bone, and possibly of the lower floating or the 10th, 11th, and 12th, or abdominal ribs. (?) The consideration of these, in the next part of the communication, with the exposition of the cranial vertebra, will form a subject for a farther communica- tion, Having demonstrated that the 7th rib is attached to the 7th ver- tebra in the Mammal class, as in the Monkeys; the Carnivora, as far as examined ; the Elephant, Hog, and Horse, among the Pachyder- mata; the Deer, Elk, Giraffe, Camel, Ox, Sheep, among the Rumi- nants; and the Dugong, Porpese, and Whale, among the Cetacea,— the only exception being the Seal and Walrus, in the specimens of the Barclay Museum of the Royal College of Surgeons of Edin- burgh; and also having assigned a sufficient cause for the abnormal situation of the lst rib in Man on the 8th vertebra, instead of be- tween the 7th and 8th,—the enumeration of the cervical region will I 169 be 6 instead of 7, as hitherto described by all systematic naturalists, who depend on organic structure for the characters of their classifi- cation. The following Donations to the Library were announced :— An Attempt to discover some of the Laws which govern Animal Torpidity and Hibernation. By Peter A. Browne, LL.D. 8v0o.—By the Author. Cambridge and Dublin Mathematical Journal. Nos. 13 and 14. 8yo. —By the Editor. Journal of the Asiatic Society of Bengal. No. 184. 8vo.——By the Society. Journal of the Indian Archipelago and Eastern Seas. Nos. 1, 2, 3. 8v0.—By the Editor. Guyot (A.) Note sur la distribution de Roches dans le Bassin Erra- tique du Rhone. 8vo. Note sur le Bassin Erratique du Rhin. 8vo. Note sur la Topographie des Alpes Pennines, &c. 8vo.— By the Author. Monday, 6th March 1848. Tue Very Rav. PRINCIPAL LEE, V-P., in the Chair. The Chairman, after a brief account of the Keith Founda- tion, presented to General Sir Thomas M. Brisbane, Bart., _ GO.B., President of the Society, the Keith Prize Medal, awarded to him by the Council, for the Makerstoun Obser- _ yations on Magnetic Phenomena, made at his expense, and ‘published i in the Transactions of the Society. The Chairman also announced that the Council had also 4 eranded, independently of the Keith Prize, a Silver Medal _ toJ. A. Broun, Esq., in token of their sense of his merits, in _ conducting and superintending the Makerstoun Observa- The following Communication was then read :— On the Theory of the Parallel Roads of Lochaber. By James Thomson, Esq. jun., Glasgow. Communicated by Professor Forbes. The author, after briefly stating the views of Mr Milne, and the remarks of Sir G. S. Mackenzie, gave his reasons for agreeing with the former, that the terraces were the beaches of lakes, formed by barriers across the valleys; and, with the latter, in holding that these barriers could not have been formed of earthy detritus. He then proceeded to shew that the theory of Agassiz, according to which the barriers were formed of glaciers, was the most probable yet advanced, and while it required some modification in the details to render it consistent with recently observed facts, was strongly supported by the researches of Professor Forbes, both in regard to the former exis- tence of glaciers in our latitudes, as demonstrated in the case of the Cuchullin Hills, and in regard to the laws of the motion of glaciers, as developed in Professor Forbes’s papers on the Glaciers of the Alps. He pointed out that all the difficulties of the theory of earthy bar- riers were connected with the notion of their being composed of earthy detritus, and that both Sir T. D. Lauder and Mr Milne ad- mitted the great difficulty of accounting for their disappearance. He then explained the modifications which were required to ren- der the theory of Agassiz capable of explaining all the facts hitherto observed. The highest shelf in Glen Roy stops short just above the opening into Glen Glaster, and this would have been the result had the bar- rier which formed that shelf blocked up Glen Roy above the latter glen, and thus forced the water to be discharged by the water-shed at the head of the valley of the Spey. It must also have blocked up Glen Collarig nearly to the Gap. To form the middle shelf, this barrier had only to retire a little, so as to open up Glen Glaster, when the water would discharge itself by the ancient river-course leading from the water-shed in Glen Glaster, first pointed out by Mr Milne. The lowest shelf would be formed when the glacier retired to near the mouth of Glen Spean. j 171 The blockage of Glen Gluoy seems to have been unconnected with that of the other glens, The author ascribes it to a glacier occupying the site of Loch Lochy, and fed from the high mountain to the north. He explains the occurrence of a lower shelf in Glen Gluoy, which stops short of the mouth of the glen, by a reference to analogous . phenomena observed by Professor Forbes in the Lac de Combal. . The shelf in a glen near Kilfinnan observed by Mr Darwin, is accounted for by the glacier supposed to have occupied the site of Loch Lochy. Mr Milne objects, to the notion of a glacier descending from Ben- Nevis, and crossing Glen Spean to block up Glen Roy, that the in- equalities of the intervening ground are so great as to render the existence ofa glacier in this direction highly improbable, more espe- cially as the ice had a comparatively easy outlet northward towards Fort-William. The author, however, endeavours to shew, that, if we assume a climate intermediate between that which produces the glaciers of the Alps, and that which forms the glaciers of the arctic and antarctic regions, there is no real difficulty in imagining the existence of a great expanse of ice descending from Ben-Nevis, at a level consider- _ ably higher than that of the intervening hills, as well as of the high- _ est shelf in Glen Roy. That such a climate may very probably have existed, the author considers as proved by the researches of Professor Forbes among _ the Cuchullin Hills, the elevation of which is much less than that of _ Ben-Nevis. There is, in the phenomena of the great erratic blocks of the Alps, proof of the former prodigious horizontal extension of glaciers, _ although, in the existing climate of the Alps, the glaciers no longer _ exhibit the same horizontal development. The author also referred to the indications of glaciers found in many parts of Great Britain, a of them in the Lochaber district, to the occurrence of organic remains of an arctic character, and to the marks of the supposed Bakion of icebergs, as supporting the view of the existence of a gla- cial climate at some remote period, The diluvial theory of Sir G, S. Mackenzie was briefly examined, Mn d certain objections urged against it. _ The author also alluded to the objection urged by Mr Lyell to the glacial theory, on the score of the changes of relative level on sea VOL, IL. Q 172 nd; and denied that there was any evidence of such changes ermination of the supposed glacial period. district of Locha- and la: having occurred since the t The paper was illustrate ber, enlarged from that of § d by a large map of the ir G. 8S. Mackenzie. The following Gentlemen were duly admitted Ordinary Fellows :— Dr James Aian, Deputy Joun Hatt Maxwett, Esq. of Dargavel. Tuomas STEVENSON, Esq., Civil Engineer. Inspector of Hospitals. The following Donations to the Library were announced : Lalande’s Catalogue of Stars. 8yvo. Lacaille’s Catalogue of Stars. 8v0.— By the British Association. The Journal of Agriculture, and Transactions of the Highland and Agricultural Society of Scotland. No. 20, March 1848. 8vo. — By the Society, PROCEEDINGS ROYAL SOCIETY OF EDINBURGH. emails Jina 3) ot Dedjms ole 0 ei de VOL. II. 1847-8. No. 32. eg Ae tal it mt toes Srxty-S1xtH SESSION. Monday, 20th March 1848. Dr CHRISTISON, V.P., in the Chair. The following Communications were read :— 1. On an Instrument for measuring the extensibility of Elastic Solids. By Professor Forbes. Tis instrument is almost a faithful reproduction of S’Graves- ande’s apparatus described in his ‘ Physices Elementa Mathema- tiea’’ 1742 (but not in the previous editions). It is described or alluded to by few modern writers, except Biot in his “ Traité de Physique.” It consists of a strong wooden table or frame, with a vice at each end, between which a wire or lamina may be stretched with a determinate tension by means of a weight attached by a cord, pass- ing over a pulley in the manner of the musical apparatus, called a Monochord. After the tension is adjusted both vices are screwed fast, the space included between them being exactly 50 inches. If now, any deviation of the middle point of the wire included by the vices be made (similar to the action of sounding a harp-string), the force required to pull it a certain distance aside will depend, lst, on the length of the wire; 2d, on its tension ; 3d, on its extensibility, or the modulus of elasticity. _ §’Gravesande employed his apparatus to verify Hooke’s law, that the extension is as the extending force within the limits of per- fect elasticity. But it does not seem to have occurred to him, nor (singularly enough) to later experimenters, to deduce from the forces required to produce given deviations, the specific extensibility, or what Dr Young calls the Modulus of Elasticity of the body. VOL. Il. R 174 It is essential that the deviation from the rectilinear position of the wire should be ascertained with great nicety, and S’Gravesande’s contrivance effects this in a very neat and satisfactory way. of a second, is almost exactly ;, of the brightness of the light when seen by un- interrupted vision ; and it is also ascertained that light requires about the tenth part of a second to produce its full effect on the eye. (4.) It is found that lights of different intensity act on the eye with equal rapidity, so that even the light of the sun produces an impres- sion with no greater rapidity than that of a common gas flame. (5.) Rays of different refrangibility act on the eye with equal ra- pidity. (6.) Since Professor Wheatstone’s experiments have proved that 232 the light of the electric spark of high tension continues for less than the millionth part of a second, and it has been shewn that the bright- ness of the impression, produced by light on the eye, increases in the exact arithmetical proportion of the time during which it con- tinues to act on the retina, it follows that the apparent brightness of the electric spark is only zg54555 of what it would become if the duration of the spark could be prolonged to j5th of asecond. From the great apparent brilliancy of the nearly instantaneous electric spark of high tension, when compared with the sensibly continuous light of Voltaic electricity, it is inferred that the brightness of elec- trical light increases with the tension of the electricity. 3. Note on the Refractive and Dispersive Powers of the Hu- mours of the Eye, determined by Experiment. By John Adie, Esq. The author’s object in undertaking these experiments, was to dis- cover if the achromatism of the eye could be accounted for by the differences in the dispersive ratios of the fluids forming that organ. The indices for several of the fixed lines were determined in the aqueous humour ; with the crystalline no satisfactory result could be obtained, In subjecting the vitreous humour to experiment, only the strongest of the fixed lines could be seen, and that with great difficulty ; one remarkable feature, however, was observed, viz., that on dividing the mass of humours two spectrums were formed, the one placed over the other, having a greater deviation, and, consequently, refractive power. Thus proving, that that humour is not of equal density throughout, as has heretofore been supposed. The following Donations to the Library were announced :— The London University Calendar for 1849. 8vo.—By the Uni- versity. The Ethnological Journal, No. 10. 8vo.—By the Editor, Suite of the Collection of Hydrographic Charts, with Sailing Direc- tions, &c.— By the Lords Commissioners of the Admiralty. 233 Monday, 2d April 1849. General Sir T. MAKDOUGALL BRISBANE, Bart., President, in the Chair. The following Communication was read :— @ 1. On Grooved and Striated Rocks in the Middle Region of Scotland. By Charles Maclaren, Esq. In this paper an account was given of grooved, striated, and abraded rocks in various parts of Scotland, from Glen Spean on the north, to the Pentland and Lammermoor Hills on the south, After indicat- ing the direction in which the groovings pointed, it was shewn,—that the appearance of these grooved and striated rocks is irreconcilable : with the hypothesis which ascribes the phenomena to a supposed . great Atlantic wave or transient flood, of which one part swept across the low lands of Scotland, while another part was turned back by the mountains,—that in the district between the Clyde and the Spean, where the largest and best marked groovings were observed, there is satisfactory evidence to prove, that they were produced by bodies of vast depth occupying the valleys, moving from the mountain group as a common centre, toward the coast and the Lowlands in all direc- tions, and exerting an immense force of pressure vertically and la- terally,—that this quaquaversal motion, as well as the form, position, and size of the groovings, are conclusive against the idea that they were caused by currents of water loaded with stones and gravel, since no collected mass of water exists, or could exist, of the requi- site magritude and elevation, to send out streams in all directions capable of acting powerfully at the height of a thousand feet or more above the bottoms of the valleys,—that the effects mentioned, there- fore, can only be accounted for by the agency of glaciers, as exemplified in the Swiss Alps, where glacier ice is found covering immense areas, filling the valleys, and grooving and abrading their sides to the height of one or two thousand feet,—finally, that the strie, groovings, and abrasion seen in the great central valley of Scotland, and on the Pent- land Hills, are probably due to icebergs or rafts of ice, to which also the transportation of many travelled boulders may be ascribed. 234 The following Donations to the Library were announced :— Annuaire Météorologique de la France pour 1849, Par MM. J. Haeghens, Ch. Martins, et A. Bérigny. 8v0o.— By the Authors. Bulletin des Séances de la Société Vaudoise, No. 19. 8vo.— By the Society. Memorie della R. Accademia delle Scienze di Torino. Serie 2da, Ten Vil val TX. 4to.— By the Acadmy. ; Ofversigt af Kongl. Vetenskaps-Akademiens Forhandlingar. 1847, No. 10; 1848, Nos. 1, 2, 3, 4, 5, 6, 7, 8,9. 8vo. Kongl. Vetenskaps-Akademiens Handlingar for Ar 1846. 8v0.— med Plaucher. 4to. Arsberittelse om Zoologiens F ramsteg under Aren 1833-44. Tredje Delen, af S. Lovén. 8vo. Arsberattelse om Zoologieus F ramsteg under Aren 1845 och 1846, af C. H. Boheman. 8vyo. Arsberittelse om Framstegen i Kemi och Mineralogi,af Jac. Berzelius. 8v0.—By the R. Academy of Stockholm. (Euvres de Laplace. Tom. V., VI., VII. 4to.—By the French Government. Aanteekeningen, &c. van het Provinciaal Utrechtsch Genootschap van Kunsten en Wetenschappen. 1847 & 1848. 8vo. Verslag, &c. van het Provinciaal Utrechtsch Genootschap van Kunsten en Wetenschappen. 1847 & 1848, 12°—By the Society. Report on the Epidemic Cholera at Madras in 1824. By William Scot. 8vo.—By the Author. Monday, April 16, 1849. Dr CHRISTISON, V.P., in the Chair. The following communications were read :— 1. On a Simple Form of Rain-Gauge. By the Rev. Dr Fleming. The author began by stating, that during a calm, when the rain- drop was under the influence of the centripetal force only, the form 235 and position of the rain-gauge were unimportant. The case, how- ever, was widely different when the drop was likewise influenced by wind, for then any object raised above the surface, such as a rain- gauge projecting three or four feet from the ground, occasioned de- flections and eddies, whereby the regular fall of the rain into the collector was prevented. The Author then recommended, that in all cases the gauge should be placed on the ground, with its mouth on a level with a regularly trimmed grass plot, so as to prevent eddies and evaporation. The form which he considered unexception- able (an example executed by Mr James Bryson, 66 Princes Street, being exhibited) was that of a copper cylinder, with a funnel-form partition placed about an inch and a half below the mouth, having an aperture for the index of a float, which rises as the rain passes into the receiving portion of the lower part of the cylinder, at the bottom of which is a stopcock for letting off, at times, the accumu- lated water. A second cylinder of copper, closed at bottom, is pro- vided, to be inserted into the ground for the reception of the gauge, the latter having a shoulder or flange to prevent the entrance of earth. By this arrangement the collector and receiver are equal in area, so that errors of workmanship are avoided. The state of the gauge is known by simple inspection of the index of the float, and extreme facility of emptying and adjusting the instrument secured. | 2. On a Method of Cooling the Atmosphere of Rooms in a ; Tropical Climate. By Professor C. Piazzi Smyth. } : After stating the case distinctly, and dwelling emphatically on its importance, as shewn by individual instances in private life, and by the statistics of the world at large, the author proceeded to describe _ the various methods adopted at present in India, and shewed their | incapacity to meet the end proposed, as they merely agitated the air already in a room, or perniciously overloaded it with moisture. To take the most difficult case that could occur, he chose that of a country where the mean temperature of day and night, and sum- mer and winter, is never below 80°, and where there could, conse- quently, be no coolness in springs or rivers, or in the night air; _ where also the atmosphere being saturated with moisture, no cold could be produced by evaporation; and under such circumstances 236 proposed that a method should be found of lowering the temperature of the air in a room; doing, in fact, there, the reverse of what is effected in a cold room by lighting a fire. The principle of the plan which he brought forward was dependent on the property of air to increase in temperature on compression, and to diminish on expansion; the air was to be compressed by a forcing pump into a close vessel, then cooled or rather deprived merely of its acquired heat of compression, and then being allowed to escape into the room desired to be cooled, would issue at a temperature as much below that of the atmosphere as it had risen above on com- pression. That this was a vera causa there was no doubt ; the suficiency and the practicability were the only matters of doubt. These the author attempted to solve, by shewing the quantity of increase of heat due to a certain amount of compression; and by devising the most con- venient form of the necessary apparatus, and concluded that a one- horse power should supply a room with 30 cubic feet of air per minute, cooled 20° below the surrounding atmosphere. The various sources of mechanical power likely to be met with in warm countries, were then described; and particularly a new and simple, and at the same time, a remarkably compact and effective form of windmill ; as the wind is everywhere so cheap and abundant, and in the tropics so certain a species of moving power. Methods also of ventilating the cooled room, z. ¢., of keeping it constantly supplied with cooled fresh air, and removing the vitiated, were explained, as well as a natural principle for meeting the residual difficulty that might be expected to arise in some cases, viz., the too great moisture of the cooled air. 3. Notice of a Shooting-Star. By Professor C. Piazzi Smyth. The object of this notice was merely to call attention to the im- portance of observing the phenomena of shooting-stars more carefully and rigidly, and of applying to them more correctly than has generally been the case hitherto, the measurement of time and of space, and to exemplify what may be done in this way by the calculation of a recent instance. This instance, the rare one of an ascending shoot- ing-star, was furnished by Captain W. S. Jacob, Bombay Engineers ; and he having given the place where the body first appeared, that 237 where it disappeared, and the time, the author of the paper, who had great faith in his friend’s exactitude, considered the opportunity favourable for trying what results would be given by the application of Sir J. Lubbock’s theory. Some dissatisfaction has been felt about theories of shooting-stars, inasmuch as no one of them will explain al/ the observed phenomena. But though this is undoubtedly a necessary characteristic of a true theory, still great allowances are necessary here where so many dif- ferent classes of cosmical and atmospherical objects may be con- founded even by practised observers ; and where the greater number of observers are utterly unpractised, and their senses wholly unedu- cated for scientific observation. Allowing that some electrical and magnetical effects have been mistaken for shooting-stars, but ex- eluding the baseless electrical, chemical, and lunar hypotheses, a great proportion are undoubtedly of a cosmical nature, and belong properly to astronomy ; and these may be divided into two classes of small bodies. 1st, Those which are circulating round the sun as a primary ; and 2dly, Those which are revolving round the earth as such. The first we may occasionally see when passing near them in their orbits, but are not likely to come within sight of the same again, unless, indeed, they approach so near the earth as to gravitate towards it instead of the sun, and so become satellites or shooting- stars of the second class, Sir J. Lubbock’s theory is, that the shooting-stars shine by reflected light, and are extinguished by entering the earth’s shadow ; and he has given formule on this supposition for computing the dis- tance of the body from the spectator by noting the place in the sky where, and the time when, the extinction occurs. These formule have been rendered more convenient for computa- tation by Mr Archibald Smith, Phil. Mag., March 1849; and, computed according to them, Captain Jacob’s observation gives, for the distance of the body from the observer, 1721 miles; and that entry into the earth’s shadow was the true cause of the disappear- ance, is borne out by the fact that the direction of motion was towards _ the axis of the earth’s shadow. And, on account of the extremely - small distance of the body, its change of place during flight would sufficiently account for its gradually appearing in the lower part of _ the sky when coming out of conjunction, increasing in brilliancy dur- ing its flight (reaching, at its maximum, the brightness of Venus), and VOL, II. x 238 then slowly vanishing as it entered first the penumbra and then the umbra of the earth’s shadow, in a slanting direction ; and lastly, the body can hardly fail of being a satellite, as its distance is so much less than that of a shooting-star, which M. Petit of Toulouse has pretty well identified as revolving about the earth in 3" 20™, or at about 3000 miles from the surface. 4. A few unpublished particulars concerning the late Dr Black. By Dr George Wilson. The object of this communication was to lay before the Society a few characteristic incidents concerning Dr Black, gathered from Mrs Elizabeth Wordsworth, who was a servant in his household during the five last years of his life. The facts recorded do not admit of abridgment, but they com- pletely confirmed the accounts contained in the published biographies of Black, concerning his valetudinarian and methodical habits, whilst they gave no countenance to the statement which had been credited in some quarters, that the great chemist was an avaricious or penu- rious man. Some interesting particulars were adduced illustrative of the amiability and gentleness which characterised Dr Black; and the author concluded by noticing that an error had been committed as to the date of the philosopher’s death, which was not the 26th of November 1799, as stated by Robison, but the 6th December of that year, a fact which Mr Muirhead first pointed out (Watt's Corre- spondence, p. xxii.), but which is confirmed by the newspapers of the period. (Vide Edinburgh Mercury of 14th December 1799.) Dr Christison then exhibited some interesting Specimens of Alum-Slate, illustrative of the Manufacture of Alum, and described both the natural and artificial processes. The following Donations to the Library were announced :— Journal of the Asiatic Society of Bengal. Edited by the Secretaries. Nos. 196 and 197. 8vo.— By the Editors. Proceedings of the Royal Astronomical Society. Vol. IX., No. 5. 8v0.— By the Society. 239 Monday, April 30, 1849. Bishop TERROT, V.P., in the Chair. The following communications were read :— 1. On a New Voltaic Battery of Intense Power. By Dr Wright. Communicated by Dr George Wilson. The author placed on the table a battery of four pairs, each con- sisting of a rod of coke 2} inches long by 14 in diameter, surrounded by a cylinder of amalgamated zine, 2} inches high by 2} inches in diameter ; the different pairs were firmly attached to the same bar of wood, and could be immersed in jars of stoneware at once. The arrangement was charged with a mixture of nitric acid one part, sulphuric acid four parts, water eight parts. The author stated that he considered the power of the battery, which was twice that of Grove’s, was due to the heat generated on the surface of the zine by the local action of the nitric acid. 2. On a New Species of Manna, from New South Wales. By Thomas Anderson, M.D. About thirty years ago a species of manna, obtained from the Eucalyptus Mannifera, was brought from New South Wales, and was examined by Dr Thomas Thomson, and afterwards by Professor Johnston, both of whom ascertained it to contain a new species of sugar, different from the mannite which exists in ordinary manna. The author had, through the kindness of Mr Sheriff Cay, an oppor- tunity of examining a very different species of manna, remarkable both from its chemical constitution, and from its possessing a defi- nitely organised structure. This substance was discovered by Mr Robert Cay in 1844, in the interior of Australia Felix, tothe north and north-west of Melbourne, where it occurs at certain seasons on the leaves of the Mallee plant, Eucalyptus Dumosa, and is known to the natives by the name of Lerp. It consists of numerous small conical cups of the average diameter _ of a sixth of an inch, more or less distinctly striated, and covered 240 on the outside with hairs of considerable length. The cup resembles some of the smaller species of patella, and its mouth is perfectly smooth and round. Several of the cups are frequently attached to one another by the edges, and always so that their mouths form a plane, by which it would appear they have been attached to the leaves. The hairs, when examined under the microscope, were found to con- sist of uniform tubes, with a granular structure, and indistinct traces of transverse stric; they are coloured uniformly blue by iodine. The cups are made up of a confused mass of closely-compacted cells resembling starch globules, and coloured blue by iodine. The taste of Lerp is distinctly saccharine, but this is confined entirely to the hair, the cup having merely a mucilaginous taste. The chemical examination shewed it to consist of an uncrystallisable sugar similar in its character to that found in fruits, of starch, gum, inulin, and cellulose, the absolute identity of the latter two of which was determined by ultimate analysis. There were also found minute traces of resinous matter and nitrogen, and 1:13 per cent of ash. The following is the result of its quantitative analysis :— Water, : : ; j 15°04 Sugar with a little resinous matter, - 49°06 Gum, i : F : 5°77 Starch, : : - : 4:29 Inulin, : 3 : : 13°80 Cellulosa, : - : : 12°04 100-00 Ash, . : : - : 1:13 The author, in concluding his paper, remarked that all the species of manna before observed consisted of soluble substances, and were considered to be produced by the puncture of an insect, which caused the exudation of their constituents in the fluid form, and that they gradually dried up upon the surface of the leaf, but that the exist- ence in Lerp of the insoluble cellulose and starch, and the sparingly- soluble inulin, seemed scarcely compatible with such an explanation of its origin. 241 3. Account of a peculiar Structure found in the Vagmarus Islandicus. By Dr John Reid. Communicated by Pro- fessor Goodsir. 4. Notes to a Paper on the Motive Power of Heat. By Pro- fessor William Thomson. (1.) On the Values of u derived from Observations on the Vapours of various Liquids. An important test of the truth of the axiom on which Carnot’s Theory is founded, will be afforded by comparing the values of deduced from observations on various liquids. I am informed by Mons. Regnault, that, by the end of this year, data as complete as those which we at present possess for water, will be supplied for five or six different liquids, from certain investigations with which he is now occupied, Carnot gives values of u for the temperatures of the boiling of sulphuric ether, alcohol, water, and essence of turpentine, derived from various observations upon those liquids. The compari- son of these with the values of 4, deduced from Regnault’s continu- ous series of observations on water, are exhibited in the following table :— Values of u Carnot’s de- |\deduced from duced values| Regnault’s Differences. of pw. Experiments on Water. Names of the Boiling- Liquids. points. Ft. lbs. Sulphuric Ether, 4°48 Alcohol, . . ; 3°96 Water, . . 3°66 Essence of Tur- | 3:53 pentine, The coincidences of the results obtained by such very different experiments are very striking, The differences certainly lie within the limits of the errors of observation ; for it happens that the dif- ference of the two results deduced by the different experimenters, from water at the boiling-point, is greater than any of the other differences. It is very remarkable that the feature of the gradual 242 decrease of 4 with the temperature should be so clearly brought out by observations performed on different liquids, at different tempera- tures. (2.) On the Heat developed by the Compression of Air. Carnot demonstrates the following proposition :— Equal volumes of all elastic fluids, when compressed to equal smaller volumes, disengage equal quantities of heat. This very remarkable proposition, given as a theorem by Carnot, was enunciated as a probable experimental law by Dulong; and it therefore affords a very powerful confirmation of Carnot’s funda- mental principle. Mr Joule of Manchester has made some important experiments on this subject. The view which he takes of a thermal “ equiva- lent” for motive power is at variance with Carnot’s theory, but his experimental results agree with its indications in a very satisfactory manner. In endeavouring to effect a comparison, I found that the following propositions are a consequence of Carnot’s Theory. 1. In compressing a gas of which the temperature is kept in- variable, the amount of work spent is exactly proportional to the quantity of heat developed. 2. The amount of work necessary to produce a unit of heat in this manner is the same, whatever be the gas operated on, but de- pends upon the temperature, being determined by the expression [7 +E t). K (3.) On the Specific Heats of Gases. Carnot proves, as a theorem, that the excess of the specific heat* under a constant pressure above the specific heat at a constant vo- lume is the same for all gases at the same temperature and pressure. This result agrees well with the experimental results obtained by Dulong. Carnot’s theory affords the following determinate expression for the difference alluded to in the enunciation : E2 p #(1+E t? * i.e. The “capacity for heat” of a unit of volume, 243 (4.) Comparison of the Relative Advantages of the Steam-Engine and Air-Engine. In the steam-engine, with the expansive principle pushed to the utmost, as Carnot points out, the effective range of temperature, or the fall utilised, is from the temperature of the boiler to that of the condenser. The superior limit of temperature is restricted by the circumstance, that the pressure of saturated steam is enormously great for high temperatures ; so that in practice, the temperature in the boiler is not in any ordinary engines so high as 150° per cent., but is in general very much below this limit. Carnot points out, that in this respect, the air-engine has a vast advantage over the steam- engine ; as there is no limit to the temperature in the hot part, ex- cept such as the preservation of the materials requires ; and, there- fore, in it an enormously greater portion of the whole fall, from the temperature of the coals to that of the atmosphere, may be made use of. In other respects, we have no reason a priori for giving a preference to one kind of engine above the other. We cannot, how- ever, feel confident that any air-engine has yet been constructed, which is capable of economising the fall actually used, as well as is done by steam-engines, with their comparatively limited range of temperature, or even that the duty for fuel consumed has in any actual air-engine exceeded or even come up to the duty performed by the best steam-engines. (5.) On the Economy of Actual Steam-Engines. The following table affords a synoptic view of the performances and theoretical duties, in various actual cases.* When heat is transmitted from a body at 140°,+ through an engine, to a body at 30°, the work due to each unit of heat is 439 foot-pounds. This is the “theoretical duty’ referred to in the last column in the table. * I am indebted to the kindness of Professor Gordon, of Glasgow, for the experimental data. t+ Pressure 3} atmospheres; 37 lb. on the square inch of the safety-valve. 244 Tasre A.—Various Engines in which the Boiler is at 140°, and the Condenser at 30°. Work pro- | Werk pro- | Work pro- sce duced for each|duced for each|duced for each ee 4 CASES. lb. of coal | 1b. of water | unit of heat “A 8 consumed. | evaporated. transmitted. aoe uty. ei Deciat « se ae cared, bai | Ft.-lbs. Fi.-Ibs. | Ft.-lbs. (1.) Fowey Consols | Experiment, re- 1,488,000 | 175,000 283 642 ported in 1845, { (2.) Taylor’s Fag, at the United | Mines, working in ( 1840, (3.) French Engines, | according to con- > tract, (4. ) English Engines | according to con- i 565,700 66,550 | 108 242 a 1,167,000 | 137,300 222 504 eK eX 98,427 | 159 36 tract, (5.) Average re performance Cornish ae, (6.) Common En- gines, consuming 12 lb. of coal per hour, per horse- power. (7.) Improved En- gines, with expan- | sion cylinders ; using an eqniva- } 495,000 | 58,240 943 | 2124 lent to 41b. of best | coal per horse- power, per hour. 631,000 | 74,240 | 120 273 —~--—-— 165,000 | 19,410 31-4 74 5. Note regarding an Experiment suggested by Professor Robison. By Professor J. D, Forbes. In his memoir of Dr Chalmers, lately read to this Society, Mr Ramsay has referred to an experiment which Dr Chalmers was anxious to have performed on the tide-wave in the Bay of Fundy. The object was to determine the earth’s density by the attraction of the tide-wave on a plummet or spirit-level, on the same principle as 245 _Maskelyne’s experiment on Schiehallion, but with the superior ad- _ vantages arising from the perfect homogeneity of the attracting mass, and from the circumstance that all the observations might be made ata single station. The experiment might, in short, appear to unite _ the advantages both of Maskelyne’s and Cavendish’s methods of de- termining the earth’s density. The suggestion was Dr Robison’s, and Dr Chalmers had it from him. It is contained in the Elements of Mechanical Philosophy, _ Edit. 1804, page 339, and is given in the following words :—* Per- haps a very sensible effect might be observed at Annapolis-Royal in Nova Scotia, from the vast addition of matter brought on the coast twice every day by the tides. The water rises there above 100 feet at spring tide. Ifa leaden pipe a few hundred feet long were ‘Jaid on the level beach, at right angles with the coast, and a glass pipe set upright at each end, and the whole filled with water, the water will rise at the outer end, and sink at the end next the land as the tide rises. Such an alternate change of level would give the ‘most satisfactory evidence. Perhaps the effect might be sensible on a _very long plummet, or even a nice spirit-level.”’ It is needless to observe that the methods proposed by Dr Robison are not the best which might be suggested ; but that, in consequence of the extreme simplicity of the observation, considered as a purely astronomical one, a deviation of the direction of gravity of only a very few seconds could be ascertained within small limits of error.* t I thought it worth while to make the calculation approximately for an assumed height of the tide-wave. Had the result been at all encouraging I should have taken pains to ascertain, on good autho- rity, the exact rise of the tide, and the circumstances of the locality whence the rise is greatest. Thave calculated the horizontal attraction of a semicylinder of water 100 feet thick, and of about two, four, and eight miles radius upon ‘a point at the extremity of the axis of such a semicylinder ; because hese conditions can easily be reduced to calculation, and because The micrometric observation of a plumb-line, as in a zenith sector, would be sufficient ; or, as Professor Smyth has suggested to me, the view of the wires of a transit instrument, with a collimating eye-piece, as reflected in a mercury trough,—an observation, the accuracy of which may, he states, be brought within dy of a second. VOL. U. ¥ 246 they represent very approximately the circumstances of an attracted point placed at high water-mark on a vertical sea-wall facing a basin or estuary. The radius of the attracting mass of water being repre- sented (more accurately) by 10,000, 20,000, and 40,000 feet, I find the influence of a tide-wave 100 feet thick upon a plumb-line to produce a deviation of only 0-’44 (forty-four hundredths of a second), 0-50, and 0-53; the effect increasing extremely slowly with the radius, as might be expected. If the tide rose only fifty feet, the first effect would be reduced to 0°”246. Even the greatest of these calculated deviations affords no ground for hoping that the method of Robison could be applied with any success to determine the earth’s density. It is rather singular that this ingenious suggestion is not once al- luded to, so far as I am aware, by any writer on the figure and den- sity of the earth; yet surely it was as worthy of notice as Dr Hutton’s proposal to measure the attraction of an Egyptian pyramid.—(Phil. Trans. 1821.) The following Donations to the Library were announced :— American Journal of Science and Arts. Conducted by Professors Silliman and Dana. 24 Ser. Vol. VII., No. 20. 8vo.— By the Editors. Ethnological Journal. No, 11. 8vo.—By the Editor. Passages in the History of Geology. By Andrew C. Ramsay, F.G.S. 8vo. (2 copies.) —By the Author. On the Nature of Limbs. By Richard Owen, F.R.S. 8vo.—By the Author. Proceedings of the Philosophical Society of Glasgow. Vol. II. 1844-8. 8vo.—By the Society. The Philosophy of Trade ; or Outlines of a Theory of Profits and Prices. By Patrick James Stirling. 8vo.—By the Author. 247 PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. VOL. Il. 1849-50. No. 35. Sixty-E1GutTn SEsston. Monday, 3d December 1849. Hon. Lord MURRAY, V.P., in the Chair. The following Communication was read :— 1. Personal Observations on Terraces, and other proofs of Changes in the relative Level of Sea and Land in Sean- dinavia. By Robert Chambers, Esq., F.R.S.E., &. In this paper were given descriptions of alluvial formations of a terassiform character in the valley of the Lir river, near Drammen, in Norway, and of similar objects in valleys near the foot of the Midsen lake. The author then described a remarkable terrace which runs for fully fourteen miles at one elevation along the upper part of the valley of the Logan, in the Dovre field. It is composed on the left side of the valley of water-laid sand, and is believed to be about 2150 feet above the level of the sea. On the Dovre field, several hundred feet higher, are morasses containing the remains of much greater trees than are now growing in that district, the highest vegetation of which is a dwarf birch; and Mr Chambers remarks, that when the terrace was on the sea-level this district would enjoy a temperature fit for the production of such large timber. Mr Chambers next described some remarkable terraces in the valleys _ near Trondhiem, and particularly the great terrace of erosion which overlooks that city at an elevation of 522 feet above the sea. The remainder of the paper was chiefly devoted to an account of a remarkable couple of terraces, which are traceable along the coasts of Nordlands and Finmark, apparently at one level (57 and 143 feet above the sea), excepting in the sounds near Hammerfest ; where, throughout a space of twenty-five miles, they are upon an = VOL. I. Z 248 inclination. This portion of the phenomena fell under the attention of M. Bravyais, of the French Scientific Expedition of the North, by whom they were measured barometrically and described. The pre- sent observer took measurements of these inclined terraces by the level and staff, in eighteen or twenty places, and thus confirmed the views of his predecessor. By Mr Chambers’s observations, the fol- lowing new points are ascertained: 1. The terraces, as being in- clined, form an exceptive case, in contrast with those of a neighbour- ing district of coast of much larger extent (at least 180 geographical miles). 2. The disturbed district has moved on an axis of rest near Neeverfiord, where the two terraces are about the normal height. 3. A line, 14° west of north, (being nearly the line of the magnetic meridian), being drawn across the disturbed district, the inclination is shewn to be equable throughout equal spaces of that line, which is thus proved to be the meridian of the movement. 4. The northern extremity of the dip of the upper line at Hammerfest is 58 feet below, and the southern extremity, abreast of the Alten terraces, is 96 feet above the axis of rest. The author then described visits which he paid in September 1849 to two of the places in the Gulf of Bothnia where marks have been made in order to detect the rate of movement of the land; at the rock near Lofsgrund he found the sea about six inches below the mark made sixteen years before by Sir Charles Lyell; while, on the eliffs of Grasée, where Flumen made a mark in 1820, the water was exactly eleven inches lower. His Grace the Duke or AreyLi was duly elected an Ordinary Fellow. The following Donations to the Library were announced :— Address delivered at the Anniversary Meeting of the Geological Society of London, 16th February 1849. By Sir H. de la Béche. 8v0.— By the Author. Proceedings of the American Philosophical Society. Vol. V., No. 41. 8v0.— By the Society. Journal of the Statistical Society of London, Vol. XII., Pt. 2. 8vo. —By the Society. Scheikundige Onderzoekingen, gedaan in het Laboratorium der Utrechtsche Hoogeschool. 5% Deel, 1ste, 34¢, & 44¢ Stuk. 8vo.—By the University. 249 The American Journal of Science and Arts. Vol. VII., No. 21. 8vo. Edited by Professors Silliman and Dana.—By the Editors. Journal of the Asiatic Society of Bengal. Edited by the Secretaries. New Series, No. 25. 8vo.—By the Editors. Quarterly Journal of the Geological Society of London. No. 16. 8vo.—By the Society. Bulletin de la Société Géologique de France. Tom. XIV., & Tom. I. & II, 2% Série. 8vo.—By the Society. Sixteenth Annual Report of the Royal Cornwall Polytechnic Society, 1848. 8vo.—By the Society. The Journal of Agriculture and Transactions of the Highland and Agricultural Society of Scotland. No. 25, N.S., July 1849. 8vo.—By the Publishers. The Journal of the Royal Geographical Society of London. Vol. XIX., Part 1, 1849. 8vo.—By the Society. Verhandelingen der Eerste Klasse van het K. Nederlandsche Insti- tuut van Wetenschappen, Letterkunde, en Schoone Kunsten te Amsterdam. 34¢ Reeks, 1ste= Deels, 24¢ Stuk. 4to. Tijdschrift voor Wis-en Natuurkundige Wetenschappen, uitgegeven door de Eerste Klasse van het K. Nederlandsche Instituut van Wetenschappen, Letterkunde en Schoone Kunsten. 2% Deel, 3° & 4e Afleverings. 8vo.—By the Institute. Report of the Eighteenth Meeting of the British Association for the Advancement of Science, held at Swansea, in August 1848. 8vo.— By the Association. Neue Denkschriften der Allgemeine Schweizerischen Gesellschaft fiir die gesamten Naturwissenschaften. Bde.8 & 9. 4to. Verhandlungen der Schweizerischen Naturforschenden Gesellschaft bei ihrer Versammlung zu Winterthur 1846 & 1847. 8vo. Mittheilungen der Naturforschenden Gesellschaft in Bern. Nos. 87-134. 8yo. Die Wichtigsten Momente aus der Geschichte der drei ersten Jahr- zende der Schweizerischen Naturforschenden Gesellschaft. 1848. 8vo.—By the Society. Antiquités Celtiques et Antidiluviennes. Mémoire sur |’Industrie primitive et les arts dleurorigine. Par M. Boucher de Perthes. 8vo.— By the Author. 250 Meteorologische Beobachtungen angestellt auf Veranstaltung der , Naturforschenden Gesellschaft in Ziirich. 1837-46. 4to. Denkschrift zur Feier des hundertjahrigen Stiftung festes der Na- turforschenden Gesellschaft in Ziirich am 30 November 1846. 4to.—By the Society. Mittheilungen der Naturforschenden Gesellschaft in Ziirich. Heft I., (No. 1-13). 8vo.— By the Society. Proceedings of the American Philosophical Society. Vol. V., January, March, 1849. No. 42. 8vo.—By the Society. The Progress of the development of the Law of Storms, and of the Variable Winds, with the practical application of the sub- ject to Navigation. By Lieut.-Colonel William Reid. 8v0.— By the Author. On the Geological Structure of the Alps, Apennines, and Carpa- thians, more especially to prove a transition from Secondary to Tertiary Rocks, and the development of Eocene Deposits in Southern Europe. By Sir Roderick Impey Murchison. 8vo.—By the Author. Account of the effect of a Storm on Sea-Walls or Bulwarks on the coast near Edinburgh, as illustrating the principle of the con- struction of Sea-Defences. By W. M. Rankine. 8vo. An Equation between the Temperature and the maximum elasticity of Steam and other vapours. By W. M. Rankine. 8vo.— By the Author. The American Journal of Science and Arts. Conducted by Pro- fessors Silliman and Dana. 2d Series, No. 22, July 1849. 8vo.— By the Editors. Journal of the Asiatic Society of Bengal. Edited by the Secretaries. No. 200, February 1849. 8vo, and N.S., No. 28, April 1849, and No, 203.— By the Editors. Journal of the Statistical Society of London. Vol. XII., Parts 3 and 4. 8vo.— By the Society. Journal of the Geological Society of Dublin. Vol. IV., Part 1. 8vo.— By the Society. Catalogue of the Calcutta Public Library. 8vo.—By the Council. Flora Batava. 159 Aflevering. 4to— By the King of Holland. A Letter addressed to the Earl of Rosse, President-Elect of the Royal Society. By Marshall Hall, M.D. 8vo. 251 On the Neck as a Medical Region, and on Trachelismus ; on Hid- den Seizures; on Paroxysmal Apoplexy, Paralysis, Mania, Syncope, &c, By Marshall Hall, M.D. 8vo.——By the Author. Astronomical Observations made at the Radcliffe Observatory, By Manuel J. Johnson. 1842, 1848, 1844, 1845, 1846, 1847. Vol. I1I.— VIII. 8vo.—By the Radcliffe Trustees. Quarterly Journal of the Geological Society, No. 18, 1849. 8vo. —By the Society. Journal of the Indian Archipelago and Kastern Asia, Vol. III. Nos. 1, 2, 3, 4. 8vo.—By the Editor. The American Journal of Science and Arts. Conducted by Profes- sors Silliman and Dana. Second Series. No. 23. 8vo,—By the Editors. Memoirs of the Ganglia and Nerves of the Uterus. By Robert Lee, M.D. Ato. On the Ganglia and Nerves of the Heart. By Robert Lee, M.D. 4to.—By the Author. Atheneum. Rules and Regulations, List of Members, &c. 1847. 12mo. Annual Report—General Abstract of Accounts. 1848.— By the Atheneum. Description of a Machine for Polishing Specula, with Directions for its use. By W. Lassell, Esq. 4to.—By the Author. Monday, 17th December 1849. Right Rev. Bishop TERROT, V.P., in the Chair. The following Communications were read :— 1. Note respecting the Dimensions and Refracting Power of the Eye.* By Professor J. D. Forbes. “ Whilst lecturing lately on the subject of Vision, I consulted some recent authorities on the dimensions and curvatures of the refracting apparatus of the eye; and having calculated from them the con- * Printed here in full by permission of the Council. 252 vergence of rays within the eye, it may save trouble to others to put them on record. 3 ‘The measures of the eye given in almost every English work on the subject, are those given by Young on his own authority, or that of Petit. In the fifth volume of Dove’s Repertorium, I find a series of measures collected by Treviranus from his own and preceding ob- servations, which I have converted below from French lines into deci- mals of an English inch. In these the curvatures are supposed sphe- rical, In the same work of Dove, I find a series of measures by Dr Krause of Hanover, on eight recent human eyes, which seem to have been made with uncommon care, and in which the deviation of the surfaces from sphericity is noticed. I have preferred these last for the purpose of calculation, because al/ the measures are taken from the same eye, which is not the case with the numbers collected by Treviranus. [ have consulted the original paper of Krause in Pog- gendorff’s Annalen, vols. xxxi. and xxxix., where it appears, (1.) That the cornea is thicker at the sides than in the centre; (2.) The anterior curve of the cornea is nearly spherical, the posterior parabolic ; (3.) The anterior surface of the lens is elliptical, the lesser diameter being in the axis of vision, the posterior surface is parabo- ic; (4.) The figure of the retina, or the posterior surface of the vitreous humour, is an ellipsoid. “ The following are those given by two eminent German authori- ties, Treviranus and Krause, when reduced to English inches :— Mean ofseveral Mean of eight Authors by measures by Treviranus. Krause. Inches. Inches. Thickness of cornea (central part), é 0-032 0-040 Distance of first surface of lens from back sur- face of cornea, j ‘ ‘ 0-104 0-107 Pupil behind cornea, : : . 0-096 0083 Thickness of lens, : 2 : 0-181 0-181 Axis of vitreous humour, 0°548 0°567 Axis of the eye from interior of the cornea to the retina, : - : 0.833 0°855 Radius of first surface die cornea, : 0-301 0°348 Radius of first surface of lens, : : 0-280 0°369 of second do., ; - : 0°196 0-201 Curvature of retina near the axis, : 0°534 0°5238 These numbers agree tolerably well, only that the radius of eur- 253 vature of the first surface of the lens is disproportionately great in the last column. This arises from the circumstance, that it is de- rived by calculation, for the curvature of an ellipse at the lesser axis, the two axes of which are alone given by Krause. Now, it is evi- dent, that if we regard the lens as a whole, or even any considerable breadth of it, its mean radius of curvature will be sensibly smaller. In fact, Krause finds that it may be tolerably represented by a cir- cular curvature, having a radius of -329 inches. It occurred to me, however, that by taking the greatest density of the lens, as given by Brewster, and the curvature of the middle part, both anterior and posterior, as given by Krause, I ought to arrive at a close approxi- mation to the course of the axial pencil. ‘I have adopted for the refractive indices of the parts of the eye, those given by Sir D. Brewster in his original paper in the Edin- burgh Philosophical Journal, vol. i., page 44, with the exception of that of the densest part of the lens, which is almost certainly mis- printed. - They are as follow :— Aqueous humour, “ : ‘ 1°3366 =p, Crystalline, outer coats, F - 1°3767 —— middle coats, : ‘ 1°3786 —— central coats, s - 1:3990*= 4, the whole, , = 1°3839 Vitreous humour, 2 : : 1:3394 =p, * Calculating from the preceding data, with Sir D. Brewster’s in- dices of refraction, the author finds the positions of the foci, towards which the rays converge, after refraction at the successive surfaces, to be the following (reckoning from the interior surface of the cornea, the thickness of which has been neglected)— For rays falling For rays diverging parallelonthe froma point 10 inches cornea, distant. , Inches. Inches. After first refraction at the eovictl — 1-382 1541 humour, : : 2 After second refraction at first sur- } — 1-260 1:377 face of the lens, 3 “ After third refraction into ae — 1-060 1135 humour, i 4 * In the Edinburgh Phil. Journ., we find 1:3999. But I take this to be a _ misprint, as in Sir D, Brewster’s own subsequent writings, we always find 1:3990. 254 “‘ Now the measure of the axis of the eye we have seen to be only ‘833 inch, according to Treviranus, and -855 according to Krause ; consequently, rays of mean refrangibility (to which Brewster’s mea- sures refer) converge to a point no less than -227 inch behind the retina, when the rays fall parallel on the cornea, and *302 when the object viewed is at 10 inches’ distance. The axis of the eye, as even measured by Dr Young, though somewhat greater than we have reck- oned it above, (Dr Young makes it 91), does not come up to the requisite dimensions; and Dr Young, with his usual acuteness, ascribes the difference to the gradually varying density of the strata or coats of the lens,* the dense small nucleus evidently acting as a lens of comparatively short focus ; and this explanation is probably the correct one, to which we may add, that the configuration of the coats of equal density, which, near the surface of the lens, are very elliptical, become, near its centre, gradually nearly spherical. On this account, it is all but impossible to predict the exact course of the rays through a structure of so much complication. “Dr Young had considered the case with his usual attention and penetration. He investigates the focus of a spherical lens, or lens with surfaces which are segments of spheres, and whose density is variable, and the result may be recalled here as one which, perhaps, has not been sufficiently remarked. ‘“ On the whole,” he says, “ it is probable that the refractive power of the human crystalline in its living state is to that of water nearly as 18 to 17 [gives index refr.=1:415]; that the water imbibed after death from the humour of the capsule reduces it to the ratio of 21 to 20 [1:403], but that, on account of the unequable density of the lens, its effect on the eye is equivalent to a refraction of 14 to 13 [1-439] for its whole size.’ t * On the whole, these calculations, as well as the considerations into which I entered in a former paper, read to the Society in 1844,} on the mechanism of the focal adjustment, have left on my mind the conviction that the optical and mechanical structure of the organ of sight is even less understood than it is commonly believed to be. Simple as are its general arrangements, and comparable, in some respects, to those of artificial combinations, we perceive surfaces figured in a complex manner, and structures of varying refractive * Nat. Phil., vol. ii., p. 580. + Nat. Phil., vol. ii., p. 82. { Transactions Royal Society of Edinburgh, vol. xvi., p. 1. 255 density combined in a very complicated manner. Krause’s measures of the curvature of the surfaces of the lens confirm the inadmissibi- lity of the all but universal opinion of the variation of density of the crystalline being intended to correct the aberration of spherical surfaces, when, in reality, no such surfaces exist. We are quite un- able to trace the exact course by which the rays’of light are focalised on the retina, since it depends on the internal constitution of the lens that they do not meet very far behind it; and it still remains at least doubtful how the adjustment to distinct vision of objects at different distances is effected. ** Finally, the question of achromatism of the eye has its own diffi- culties. It is not now contended that the eye has the power of con- verging equally rays of different refrangibilities; but it is not un- reasonable to suppose that the chromatic aberration is at least par- tially corrected. One result of the calculations into which I have entered (which were first in part undertaken at my request, by Mr James Clerk Maxwell, and since entirely repeated and extended by myself), is a clear exhibition of the physical conditions of perfect achromatism in the eye. The form is simpler than I have else- where seen, and may at once satisfy any reasonable person of the possibility that the eye might be rendered achromatic, at least for objects at a certain distance; to prove which, so much has been written, and at so great length. The result may be stated in two lines. If we calculate the effect upon the final focal distance of the whole refracting system of the eye (q’), of a variation in the re- fractive index of each of its three humours (denoted by j,, “i, 4). We find this equation when the incident rays are parallel, or reach the eye from a very distant object :— 6g’ = 1:579 8 fey + 1150 6, — 2-788 6 fly. Let the coefficients 64,, 65, 6, denote the dispersion or differ- ences of the indices of refraction for extreme rays, corresponding to the three media, then it is evident, from the negative sign of the third term on the right hand, that they may be so chosen as to annihi- late the second side of the equation, or make the variation of focal distances nothing, for the differently refrangible rays. “If the rays proceed from a point 10 inches distant from the eye, the equation for the variation of the focus will be 6q” = 1873 64,+1°402 64,-3°298 du, 256 and the condition which makes this equal to zero, or the focus inde- pendent of small variation of the refrangibility of the ray may be satisfied, at the same time that the former equation is satisfied also ; consequently, with three media, as in the eye, we may have perfect achromatism for any two distances ; which would also be sensibly perfect for the intervening ones. Of course by perfect achromatism, we here mean a union of the extreme red and violet rays; the irra- tionality of dispersion does not concern this question.” 2. On the Intensity of Heat reflected from Glass. By Pro- fessor J. D. Forbes. The author, after referring to a communication made to this So- ciety, on the 18th March 1839, on this subject, and noticed in the ** Proceedings”’ of that date, stated, that being about to recommence his observations on radiant heat, so long and unavoidably inter- rupted, he had carefully examined the unpublished observations on which the previous notice was founded, with a view to ascertain what might be the numerical discrepancy which they present from Fresnel’s Theoretical Law. The variation in the results of experiment for each of the angles was very considerable, arising from a multitude of causes as yet imperfectly estimated, but which appear to have been encountered by other observers, who, since that time, have undertaken the same research. Under the circumstances, the mean of the whole observations made between November 1838 and March 1839, have been taken for each angle of incidence ; and the results being pro- jected in the usual manner, the angles of incidence forming the line of abscissz, and the intensities the ordinates, an interpolating curve was drawn through the whole. The numbers thus obtained (which are presented as only a rude first approximation), are shewn in the following table, and compared with Fresnel’s Formula, calculated for an index of refraction of 1°50. i Proportion of Fresnel’s Numbers. Eneidence. Heat Reflected. when « = 1°50. : etl bt eer ees FOSS it sO ioc “040 1) a ee, “O20 settusreas “040 2OtTR. Fen. “eee. -040 SC eae “Uo Saw che. “042 Re 257 nie ra yar nity eer able a xy ae a a 17 eee eye “046 OU eer eds as MD mate tareege “058 BU i Mesias Shee cures “089 HO RR SLSR Ua ‘171 GO hl sees. Ss Se ek PL “388 BG tral ake ia deists US ns ger 613 | ae 1 eee mea 1-000 | The results of experiment are generally in excess. This may be due to the impossibility of obtaining rays of heat quite parallel from terrestrial sources. To avoid this and other difficulties, experiments have recently been made in Germany by M. Knoblauch, and in Paris by MM. Provostaye and Depains. The results of the last named observers are very conclusive in favour of the accuracy of Fresnel’s law. Their memoir had not reached the author of this paper until his calculations were almost completed. 3. On the solution of certain Differential Equations. By Professor Kelland. Until recently, general solutions of several classes of equations, such as that which occurs in the theory of the figure of the earth, could not be arrived at. An ingenious transformation lately ren- dered it a matter of comparative ease to arrive at a solution of these _ equations in those forms in which they are presented in the solution of physical problems ; but still much remains to be done. The ob- ject of the present paper is to supply some portion of the deficiency in this respect, by the introduction of a new transformation, and the adoption of the function r. The solutions thus obtained are perfectly general, and are arrived at with the greatest facility. The Most Noble the Marquis or TWEEDDALE was duly elected an Ordinary Fellow. The following Donations to the Library were announced :— The Astronomical Journal. Vol. 1., No. 1. 4to.—By the Editor. Athenzeeum—Annual Report—General Abstract of Accounts from Ist January to 31st December 1848. 8vo.—By the Athe- neum. 258 Twenty-Ninth Report of the Council of the Leeds Philosophical and Literary Society. 1848-49. 8v0.—By the Society. Smithsonian Contributions to Knowledge. Vol. I. Published by the Smithsonian Institution. 4to. Report, &c. of Smithsonian Institution. 1849. 8vo.—By the In- stitution. Fauna Antiqua Sivalensis, being the Fossil Zoology of the Sewalik Hills, in the North of India. By Hugh- Falconer, M.D., and Proby T. Cautley, F.G.S. PartsI.and 1X. Fol. Do. do. Letter-Press, Part I. 8vo.—By the Author. United States Exploring Expedition during the years 1838, 1839, 1840, 1841, and 1842, under the command of Charles Wilkes, U.S.N. Atlas. Zoophytes. By James D. Dana, A.M. Imp. Fol.— By the Author. Astronomical Observations made at the Royal Observatory, Green- wich, in the year 1847, under the direction of George B. Airy, Esq. 4to.—By the Observatory. Philosophical Transactions of the Royal Society of London for the year 1849. PartsI. and II. 4to. List of Fellows, &c. of the Royal Society, 30th November 1848. Ato. Proceedings of the Royal Society. 1848. Nos. 71 and 72. 8vo. By the Society. Monday, 7th January 1850. Sir THOMAS M. BRISBANE, President, in the Chair. The following Communications were read :— 1. On the Muscular Substance of the Tongue. By Mr Zaglus. Communicated by Professor Goodsir. Professor Goodsir communicated an abstract of a paper by Mr Zaglus on the muscular structure of the tongue. The author of the paper had found the muscular substance of the tongue to consist of a cortical Re wc } J 259 layer, which surrounds the organ on all sides, except its posterior attachment, and in the middle line of its inferior surface. The cortex consists of a complicated network of fibres, derived from the hyoglossi, styloglossi, lingualis, chondroglossi, and a pair of new muscles, named by the author Notoglossi. The minute details of the arrangement of these muscles have now been ascertained by the author, and their actions in producing the peculiar volubility of the organ. The cavity of the cortex is occupied by a medulla of transverse and perpendicular muscles, some of which are limited to the cavity itself ; others pass into it from without. The transverse system consists of transversales proprii, with the palatoglossi and glossopharyngei, the perpendicular of external or proper, perpendicular muscles, and internal or geneoglossi. The transverse and perpendicular muscles are arranged in the medulla, in transversely parallel lamine, which consist alternately of perpendicular and transverse systems, which pass through the muscles of the cortex to the mucous membrane. It was also stated, that the human tongue and the ruminant form two types, the latter presenting root, body, and tip, the former want- ing the tip. These two types, also, differ in the former possessing, and the latter wanting, a mesial fibro-cartilaginous septum. 2. On the Volcanic Formations of the Alban Hills, near Rome. By Professor J. D. Forbes. The author thus sums up the general results of his memoir :— “In the first place, it appears that the Alban volcano (for it is essentially one) has acted throughout a great period of time ; for not only has it evidently repeatedly changed its form and materials of eruption, but it is surrounded by knolls of basaltic formations which seem to indicate very ancient and very repeated ejections, without taking the regular form of craters. Such are probably Monte Algido, Civita Lavinia, Monte Giove (Corioli), the Capuccini of Albano, Rocca Priore, Colonna, and perhaps even Capo di Bove, and several open craters, such as one a little below Albano, the Lago Cornufelle near Frascati, the Lake of Gabii, and one near Colonna, 260 which, on the authority of Ponzi, appear to have ejected peperino. The horse-shoe form of the old crater of the Alban Mount, which, whether formed by the elevation process or not, appears to be com- posed of beds of basalt, lapilli, tuff, or peperino, and here and there of the lava called Sperone, gave way, like that of Somma, on the western or seaward side, and I cannot but think it in no small de- gree probable, that the vast lava beds which lie under Nemi and Genzano, and which dip at a small angle under Monte Cavo, are part of the dislocated walls of the ancient crater displaced by the convulsion which rent it on the western side, and which was accom- panied by a prodigious fluid discharge of peperino, which then formed the strata of La Riccia and Albano, and which, overwhelm- ing the broken-down wall of the ancient crater, formed at the same time the Monte Gentile, and the peperino beds above Nemi. This is confirmed by the prodigious lava blocks imbedded in these rocks, which bespeak the violence of the convulsion during which they were formed. Ages later, the present summit of Monte Cavo and the crater of the Campo d’Annibale were formed, and the latter gave out its cur- rents of tefrine or grey basalt, and raised the crater of La Tartaruga and others in the valley of La Molara, and in the central crater; at the same time ejecting great volumes of pulverulent lapilli. It may have been coeval with these perfectly regular and comparatively modern eruptions, or it may have preceded them, that, after a period so long that the surface of the ancient eruptions of peperino were covered with vegetation and timber, the tremendous outbursts which forced open the craters of Albano and Nemi took place, the former pro- ducing some slight ejections of peperino or boiling mud, near Castel Gaudolfo ; and at the same time a separate orifice, opening at the foot of Monte Cavo, may have discharged into the valley of Marino the remarkable variety of peperino described in this paper, and containing vegetable stems. A long, perhaps even a final, repose succeeded this paroxysm. Even from the very dawn of Italian history these scenes of previous turmoil and desolation appear to have enjoyed profound ranquillity, and to have been immemorially covered with impenetra- ble groves sacred to the sports of Diana. *« Tt will be seen, then, that we admit tufas or peperinos of three very different periods, one of which is coeval with, or even anterior to, the formation of the exterior cone, another largely developed, which P 261 accompanied the great breach in it towards the sea; and a third, which probably produced some local streams, such as that of Marino, which has evidently flowed since the ground took its present con- figuration, and was covered with plants. Of lavas, likewise, we must admit at least three periods ; 1st, the compact basalts of the outer circuit, which, if Von Buch’s theory be correct, have flowed under a less inclination than they at present have; 2dly, The well-marked leucitic, or partridge-eyed lavas, which form the interior circuit ; and, 3dly, the compact basaltic lava which flows past Rocca di Papa towards Grotta Ferrata, which is possibly coeval with the dikes oe- __eurring at Capo di Bove and elsewhere. This leaves the origin of the lava sperone still uncertain. It is undoubtedly one of the more recent products, for it not only overlies the whole of the old basaltic _ series at Tusculum and Nemi, but the leucitic lavas of the newer cone at Rocca di Papa. The easiest solution would be to consider it as a _ scoriform basalt ; but even to this there are difficulties, not only mine- ralogical, but from position, For how can we connect the mantle- shaped covering of Monte Cavo up to its highest point, with the basalt, which nowhere attains a height (so far as I know) within several hundred feet of it ? It is still more difficult to conceive any contin- uity between the sperone of the central cone and that of Tusculum, which is separated from it by the great valley of La Molara. The following gentleman was duly elected an Ordinary Fellow :— W. J. M. Rankine, Esq., C.E. The following Donations to the Library were announced :— The Phenomena Diosemeia of Aratus, translated into English verse, with Notes. By John Lamb, D.D. 8vo.—By the Author. _ Abstract of Exposition on the Strength of Materials. Read before the Royal Scottish Society of Arts at the request of the Coun- cil. By George Buchanan, F.R.S.E. 8vo.—By the Author. _ Sopra alcuni punti della Teoria del Moto dei Liquidi. Memoria del Prof. P. Tardy. 4to.—By the Author. Annalen der K. Sternwarte bei Miinchen, herausg. von Dr J. La- mont. Bde. 1 & 2. 8v0.—By the Observatory. 262 Journal of the Asiatic Society of Bengal. Edited by the Secretaries. Nos. 204 and 205. 8vo.—By the Editors. Journal of Agriculture and Transactions of the Highland and Agri- cultural Society of Scotland. No. 27, N.S., January. 8vo. — By the Society. Mémoires de l’Académie R. des Sciences, &c. de Belgique. Tom. XXVIII. 4to. Annuaire de Académie R. des Sciences, &c., de Belgique. Tom. XV., 2me partie. Tom. 16™¢, lve partie. 8vo.—By the Academy. 263 PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. VOL. II. 1850. No. 36. Monday, January 21, 1850. Dr CHRISTISON, V.-P., in the Chair. The following Communications were read :— 1. On the Gamboge Tree of Siam. By Dr Christison. Although Gamboge has been known in European commerce for nearly two centuries and a half, and its applications in the arts have been extended in recent times, the tree which produces it is still _ unknown to botanists. The late Dr Graham, in 1836, was the first to describe accurately a species of Garcinia, which inhabits Ceylon, and which is well known there to produce a sort of Gamboge, not, however, known in the commerce of Europe. Resting on a peculiarity in the structure of the anthers, which are circumscissile, or open transversely by the _ separation of a lid on the summit, he constituted a new genus for this plant, and called it Hebradendron cambogioides. At the same _ period the Author examined the properties of this Gamboge, and found that it possesses the purgative action of the commercial drug in full intensity, and that the two kinds agree closely also, though not absolutely, in chemical constitution. _ At an earlier period Dr Roxburgh described, in his Flora In- dica,” another species of Garcinia, under the name of Garcinia pic- toria, which inhabits the hills of Western Mysore, and which also VOL. I. 2A ; oo EPP i en Rl Whe 264 was thought to produce a sort of Gamboge of inferior quality. In 1847 specimens of the tree and its exudation were obtained near Nuggur on the ghauts of Mysore by Dr Hugh Cleghorn of the East India Company’s service ; and the author, on examining the Gam- boge, found it all but identical with that of Ceylon in physio- logical action, in properties as a pigment, and in chemical con- stitution. The same plant, with its Gamboge, was about the same time observed by the Rev. F. Mason, near Mergui in Tavoy, one of the ceded Burmese provinces. A third species, inhabiting the province of Tavoy, and also pro- ducing a kind of Gamboge, was identified by Dr Wight in 1840 with Dr Wallich’s Garcinia elliptica, from Sylhet, on the north-east frontier of Bengal. Its exudation was long thought to be of low quality. But, although this substance has not yet been examined chemically, it has been stated by Mr Mason to be, in his opinion, quite undistinguishable as a pigment from Siam Gamboge. It is a matter of doubt whether Graham’s character is sufficiently diagnostic to be a good generic distinction. But it was shewn by Dr Wight in 1840, that a well characterised section at least of the genus Garcinia consists of species which have “ sessile anthers, flat- tened above, cireumscissile, and one-celled ;” and that all these spe- cies, and no others, appear to exude a gum-resin differing probably very little from commercial Gamboge. Still the tree which produces Siam Gamboge, the finest and only commercial kind, continues unknown, A strong presumption how- ever arose, that the last species was the Siam tree, as it grows in the same latitude with the Gamboge district of Siam, and not above 200 miles farther west. But if the information recently communi- cated to the author be correct, the Siam tree is a fourth dis- tinct species of the same section. In December last he received from Mr Robert Little, surgeon at Singapore, specimens taken from two trees which were cultivated there by Dr Almeida, a resident of the colony, and which were obtained by him “ direct from Siam” as the Gamboge tree of that country. These specimens are not such as to allow of a complete description ; yet they are sufficient to shew that the plant presents the characters of Wight’s Gamboge- bearing section of the genus Garcinia ; but that it is not any of the species hitherto so fully described as to admit of comparison with it. The fruit is round, not grooved, crowned by a four-lobed knotty stigma, 265 and surrounded hy numerous sessile or subsessile aborted anthers, and by a persistent calyx of four ventricose fleshy sepals. The male flowers consist of a calyx of the same structure, a corolla of four ven- tricose fleshy petals, and a club-shaped mass of about forty subsessile anthers, closely appressed, connected only at the mere base, one- celled, flattened at the top, and opening by a circular lid along a line of lateral depressions ; and there is no appearance of an aborted ovary amidst them. These are the characters of the three species presently known. These three species very closely resemble one another in general appearance and special characters. The new species presents the same close resemblance to them all; and, in particular, its foliage is undistinguishable from that of Garcinia ellip- tica, the leaves being elliptic, acuminate, and leathery, exactly as described and delineated by Wight. But it differs from them all in the male flowers and fruit being peduncled. The male flowers are fascicled, and have a slender peduncle three-tenths of an inch in length. The single young fruit attached to one of the Specimens has a thick fleshy peduncle, like an elongated receptacle, half as long as the male peduncle. All the other species hitherto described have both male and female flowers sessile or subsessile. As this difference cannot arise from a mere variation in the same species, the plant must be a new one. The evidence however that it produces Gam- boge, and more especially the commercial Gamboge of Siam, is not yet complete ; and, until further information on this point be obtained, which the author expects to receive in the course of the year, it ap- pears advisable not to attach to it a specific name. A question may even arise whether the male flowers and the fruit here de- scribed may not belong to two species instead of one ; but this is far from probable. 2. Notice respecting a Deposit of Shells near Borrowstoun- ness. By Charles Maclaren, Esq. This deposit of shells is situated about a mile and a half west from Borrowstounness, where the Carse of Falkirk terminates in a strip of flat land a furlong in breadth. The shells are exposed in two openings, each about 300 feet long, made in the soil to procure limestone for Mr Wilson’s iron-works. The bed can be traced in these openings along lines having an aggregate length of 1000 feet. Over all that space the shells form an unbroken stratum of 266 very uniform depth (nearly three inches), and almost perfectly ho- rizontal. They are covered by a bed of dark-brown sandy clay, from two to three feet thick, and rest on a deposit of the same sub- stance, which closely resembles the mud spread over the present beach. The shells are all of one species, the cockle, or Cardium edule, and of various sizes down to the most minute. They are mixed with a portion of the clay which covers them, but lie so com- pactly, that they present to the eye the appearance of a layer of chalk nodules. Very few of them are fractured, and the two valves are generally united. The openings reach within 12 or 15 yards of the high-water line; but the number of broken shells seen on the beach shews that the bed had once extended farther northward, and that part of it has been cut away by the sea. The bed is at present about the level of high water, or a little above it, while the natural abode of the cockle, according to Mr Broderip, is from the low-water line to a depth of 13 fathoms. The continuity of the bed, its re- gular level, its ‘remarkable uniformity, its composition confined to a single species, and the state of the shells, which are generally entire, and have the two valves united, shew that they are in their native locality, and prove that they could only have been brought to their present position by an upheaval of the land. This upheaval must have been to the extent at least of 18 feet, which is the differ- ence betwixt high and low water, but very probably it was to the extent of 20, 30, or 40 feet. Inundations of the sea, caused by storms, have been called in to account for such deposits, but in my opinion very inconsiderately. That a sudden and violent movement of the sea should sweep away a bed of shells from its ori- ginal locality, is intelligible enough; but that, while transporting them over some hundred feet or yards, it should preserve them un- broken, with the valves still united,—that the rushing water, in- stead of ploughing up the dry land it invaded, should smooth and level an area of more than an acre, then spread out the shells upon it with mathematical regularity, in an uninterrupted stratum of nearly uniform depth,—that, finally, it should cover them with a bed of clay two or three feet thick, and then withdraw ;—these seem to me to be effects utterly irreconcileable with the known agency of floods. I would as soon believe that the West India hurricane, instead of levelling the planter’s house, transports it en masse, with its walls, roof, and furniture all entire, from one end of a field to the other. . 5 267 3. An Account of some Monstrosities. By the late Dr J. Reid. Communicated by Prof. Goodsir. 4. The Effect of Pressure in Lowering the Freezing-Point of Water experimentally demonstrated. By Professor W. Thomson, Glasgow. On the 2d of January 1849, a communication, entitled “Theo- retical Considerations on the Effect of Pressure in Lowering the Freezing-Point of Water, by James Thomson, Esq., of Glasgow,” was laid before the Royal Society, and it has since been published in the Transactions, Vol. XVI., Part V. In that paper it was demonstrated that, if the fundamental axiom of Carnot’s Theory of the Motive Power of Heat be admitted, it follows, as a rigorous con- sequence, that the temperature at which ice melts will be lowered by the application of pressure; and the extent of this effect due to a given amount of pressure was deduced by a reasoning analogous to that of Carnot from Regnault’s experimental determination of the latent heat, and the pressure of saturated aqueous vapour at various temperatures differing very little from the ordinary freezing-point of water. Reducing to Fahrenheit’s scale the final result of the paper, we find t=n x 0:0135; where ¢ denotes the depression in the temperature of melting ice pro- duced by the addition of n ‘ atmospheres” (or n times the pressure due to 29-922 inches of mercury), to the ordinary pressure expe- rienced from the atmosphere. In this very remarkable speculation, an entirely novel pbysical De ee phenomenon was predicted in anticipation of any direct experiments on the subject ; and the actual observation of the phenomenon was pointed out as a highly interesting object for experimental research. To test the phenomenon by experiment without applying excessively great pressure, a very sensitive thermometer would be required, since for ten atmospheres the effect expected is little more than the tenth _ part of a Fahrenheit degree; and the thermometer employed, if _ founded on the expansion of a liquid in a glass bulb and tube, must be protected from the pressure of the liquid, which, if acting on it, Bitar 2 268 would produce a deformation, or at least a compression of the glas that would materially affect the indications. For a thermometer of extreme sensibility, mercury does not appear to be a conve- nient liquid; since, if a very fine tube be employed, there is some uncertainty in the indications on account of the irregularity of capillary action, due probably to superficial impurities, and observ- able even when the best mercury that can be prepared is made use of ; and again, if a very large bulb be employed, the weight of the mercury causes a deformation which will produce a very marked difference in the position of the head of the column in the tube ac- cording to the manner in which the glass is supported, and may therefore affect with uncertainty the indications of the instrument. The former objection does not apply to the use of any fluid which perfectly wets the glass; and the last-mentioned source of uncer- tainty will be much less for any lighter liquid than mercury, of equal or greater expansibility by heat. Now the coefficient of expansion of sulphuric ether, at 0° C., being, according to M. I. Pierre,* “ 00151, is eight or nine times that of mercury (which is 000179, according to Regnault) ; and its density is about the twentieth part of the density of mercury. Hence a thermometer of much higher sensibility may be constructed with ether than with mercury, without experiencing inconvenience from the circumstances which have been alluded to. An ether thermometer was accordingly constructed by Mr Robert Mansell of Glasgow, for the experiment which I pro- posed to make. The bulb of this instrument is nearly cylindrical, and is about 3} inches long and 3th of an inch in diameter. The tube has a cylindrical bore about 63 inches long: about 53 inches of the tube are divided into 220 equal parts. The thermometer is entirely enclosed, and hermetically sealed in a glass tube, which is Just large enough to admit it freely. On comparing the indications of this instrument with those of a thermometer of Crichton’s with an ivory scale, which has divisions, corresponding to degrees Fahren- heit, of about ,1;th of an inch each ; I found that the range of the ether thermometer is about 3° Fahrenheit; and that there are about 212 divisions on the tube corresponding to the interval of pressure from 31° to 34°, as nearly as I could discover from such an unsatisfactory standard of reference. This gives 7; of a degree * See Dixon on Heat, p. 72. 269 for the mean value of a division. From a rough calibration of the tube which was made, I am convinced that the values of the divisions at no part of the tube differ by more than 5th of this amount, from the true mean value ; and, taking into account all the sources of uncertainty, I think it probable that each of the divisions on the tube of the ether thermometer corresponds to something between 4s and 7, of a degree Fahrenheit. With this thermometer in its glass envelope, and with a strong glass cylinder (Crsted’s apparatus for the compression of water), an experiment was made in the following manner :— The compression vessel was partly filled with pieces of clean ice, and water: a glass tube about a foot long and 4th of an inch in- ternal diameter, closed at one end, was inserted with its open end downwards, to indicate the fluid pressure by the compression of the air which it contained: and the ether thermometer was let down and allowed to rest with the lower end of its glass envelope pressing on the bottom of the vessel. A lead ring was let down so as to keep free from ice the water in the compression cylinder round that part of the thermometer tube where readings were expected. More ice was added above, so that both above and below the clear space, which was only about two inches deep, the compression cylinder was full of pieces of ice. Water was then poured in by a tube with a stopcock fitted in the neck of the vessel, till the vessel was full up to the piston, after which the stopcock was shut. After it was observed that the column of ether in the thermo- meter stood at about 67°, with reference to the divisions on the tube, a pressure of from 12 to 15 atmospheres was applied, by forcing the piston down with the screw. Immediately the column of ether descended very rapidly, and in a very few minutes it was below 61°. The pressure was then suddenly removed, and immediately the column in the thermometer began to rise rapidly. Several times pressure was again suddenly applied, and again suddenly removed, and the effects upon the thermometer were most marked. The fact that the freezing-point of water is sensibly lowered by a few atmospheres of pressure, was thus established beyond all doubt. After that, I attempted, in a more deliberate experiment, to deter- mine as accurately as my means of observation allowed me to do, the actual extent to which the temperature of freezing is affected by determinate applications of pressure. 270 In the present communication, I shall merely mention the results obtained, without entering at all upon the details of the experiment. I found that a pressure of, as nearly as I have been able to esti- mate it, 8:1 atmospheres produced a depression measured by 7} divisions of the tube, on the column of ether in the thermometer ; and again, a pressure of 16°8 atmospheres produced a thermometric depression of 163 divisions. Hence the observed lowering of tem- 7k 5 perature was Al or ‘106° F. in the former case, and oe or 232° F. ? 3 in the latter. Let us compare these results with theory. According to the con- clusions arrived at by my brother in the paper referred to above, the lowering of the freezing-point of water by 8-1 atmospheres of pres- sure would be 8:1 x ‘0135, or ‘109° F.; and the lowering of the freezing-point by 16-8 atmospheres would be 16°8 x ‘0135, or -227° F. Hence, we have the following highly satisfactory compa- rison, for the two cases, between the experiment and theory. | | ovener e-| Dezsenion svering | Observed Pressures. | eaecaaes that the Pressures were | Differences. | * | truly observed. oo | pute ole Uthat | | } | 81 Atmospheres.) -106°F. | “109° F. —-003° F. | 16-8 Atmospheres. °232° F. | 227° F. +°005° F. | | | | | It was, I confess, with some surprise, that, after having completed the observations under an impression that they presented great dis- crepancies from the theoretical expectations, I found the numbers I had noted down indicated in reality an agreement so remarkably close, that I could not but attribute it in some degree to chance, when I reflected on the very rude manner in which the quantitative parts of the experiment (especially the measurement of the pressure, and the evaluation of the division of the ether thermometer) had been con- ducted. I hope, before long, to have a thermometer constructed, which shall be at least three times as sensitive as the ether thermometer I have used hitherto; and I expect with it to be able to perceive the effect of increasing or diminishing the pressure by less than an atmosphere, in lowering or elevating the freezing-point of water. F. If a convenient minimum thermometer could be constructed, the effects of very great pressures might easily be tested by hermetically sealing the thermometer in a strong glass, or in a metal tube, and putting it into a mixture of ice and water, in a strong metal vessel, in which an enormous pressure might be produced by the forcing 271 pump of a Bramah’s press. In conclusion, it may be remarked, that the same theory which pointed out the remarkable effect of pressure on the freezing-point of water, now established by experiment, indicates that a corresponding effect may be expected for all liquids which expand in freezing; that a reverse effect, or an elevation of the freezing-point by an increase of pressure, may be expected for all liquids which contract in freezing ; and that the extent of the effect to be expected may, in every case, be deduced from Regnault’s observations on vapour (provided that the freezing-point is within the temperature-limits of his observa- tions), if the latent heat of a cubic foot of the liquid, and the altera- tion of its volume in freezing be known. 5. On the Extinction of Light in the Atmosphere. By W. S. Jacob, Esq., H.E.I.C. Astronomer, Madras. Com- municated by Prof. C. Piazzi Smyth. Ina letter dated Madras, November 1849, Captain Jacob says, ** T have been much interested in reading, lately, Professor Forbes’s paper in the Philosophical Transactions, 1842, Part 2, on the Ex- tinction of Light and Heat in the Atmosphere.” As his results agree very closely with those of my experience on the Trigonome- trical Survey of India, and which, though not founded on any pre- cise measures, being still the conclusions of some years’ experience, are perhaps worth noticing, particularly when they agree with the _ results of more exact measures. On commencing work with heliotropes in 1837, I soon found that _ for long distances it was necessary to enlarge the apertures more than in the simple ratio of the distance (though such was Colonel Eyerest’s practice) ; and before the end of the first season, I had formed a scale of apertures for corresponding distances, which after- wards needed very little alteration, but when finally corrected by subsequent years’ observation, stood as follows :— 272 Aperture. Maximum Distance. Maximum Distance Inches. Miles. without Absorption. 0°5 15 15 10 23 30 2°0 33 60 4:0 45 120 80 60 240 Our heliotropes were circular glass mirrors, 8 inches in diameter ; and for the smaller apertures, diaphragms were used between the heliotropes and the observer. At the distances stated the light was just visible to the naked eye in clear weather, and when seen over a valley: if the ray grazed near the surface, the light was much re- duced. On one occasion I employed a heliotrope at 64 miles, and used an aperture of } of an inch, and found it rather brighter than usual, so that probably 63 or 7 miles would be the normal distance for that size. This agrees well enough with the rest of the scale, but there is no need to employ a conjectural quantity ; and if the rate of absorption corresponding to the above be computed, so close an agreement will be found, as may entitle the numbers to be looked on as something better than mere estimates,—as the results, indeed, of a species of observation. The mean of the whole shews a loss of 0610 in passing through one mile of atmosphere ; with the barometer at 27-0 inches (that being about the average height of my stations), but reduced to 30-0 inches, the quantity will be :0671. Hence the loss of light in passing from the zenith through a homo- geneous atmosphere of 5-2 miles will be -303, or only about one per cent. less than Professor Forbes’s result, And as my air was con- siderably drier than his (the mean humidity being not much above ‘30 instead of ‘56), this will probably account for the difference ; and, at any rate, the agreement is much closer than could have been expected. I once mentioned this matter to Captain Waugh, the present Surveyor-General of India, then my fellow-assistant ; but he not only had not noticed the thing, but did not even apprehend my mean- ing. He assented to my remark on the loss of light in passing through the atmosphere, but asserted that the aperture should vary as the distance, thus allowing for no loss! 0°1 inch per mile answered, 4 he said, for all distances that he had tried! So it might answer for the distances most usually occurring on the Survey; for 4 inches would be proper for 40 miles, and 2 inches not much too bright at 20, and it is not often that these limits would be passed. Yet it is hardly possible to conceive that he should not have noticed the different intensity of the lights; had not his opportunities been per- haps rather unfavourable, as his work lay chiefly in plains, where, as mentioned above, the light of a grazing ray is very much re- duced, and the atmospheric effect would therefore be mixed up with disturbing local causes. I myself was much astonished at first discovering that the air had so great absorbent powers, and many ideas are suggested by the fact. We see at once how easily many of the planets may be ren- dered habitable to beings like ourselves. Mars, e. g., may enjoy a 273 temperature little inferior to our own, by having a less absorbent envelope ; and Venus may be kept as cool as we are, by having one more so. The following Gentlemen were duly elected Ordinary Fellows :— Mr Atex. K. Jonnston. Dr Joun Scort, F.R.C.P. Dr Sueripan Mouspratt, Liverpool. The following Donations to the Library were announced : Annuaire Magnétique et Météorologique du Corps des Ingénieurs des Mines ; ou Recueil d’Observations Météorologiques et Mag- nétiques faites dans l’entendue de l’empire du Russie, par A. T. Kupffer. Nos. 1 & 2, 1849. 4to.—By the Russian Government. _ Verhandelingen der Eerste Klasse van het K. Nederlandsche In- stituut van Wetenschappen, Letterkunde, en Schoone Kunsten te Amsterdam. 384 Reeks, Deel 1, Stuk 3 en 4. 4to. _ Tijdschrift voor de Wis-en Natuurkundige Wetenschappen uitge- geven door de Eerste Klasse van het K. Nederlandsche In- stituut van Wetenschappen te Amsterdam. 34° Deel,.1 & 2 Afleverings. 8vo.—By the Academy. 274 Jaarboek van het K. Nederlandsche Instituut van Wetenschappen, Letterkunde, en Schoone Kunsten te Amsterdam, 1847, 1848, 1849. 8vo.—By the Academy. Catalogue of 2156 Stars, formed from the Observations made during Twelve Years, from 1836 to 1847, at the Royal Observatory, Greenwich. 4to.—By the Royal Society, Lond. Proceedings of the Philosophical Society of Glasgow, 1848-9. Vol. III., No. 1. 8vo.—By the Society. Quarterly Journal of the Chemical Society of London. No. 8. 8vo. By the Society. Proceedings of the Royal Astronomical Society. Vol. X., No. 2. 8vo. —By the Society. 275 PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. VOL. Il. 1850. No. 87. Monday, 4th February 1850. The Hon. Lord MURRAY in the Chair. The following Communications were read :— 1, Abstract of a Paper on the Hypothesis of Molecular Vor- tices, and its Application to the Mechanical Theory of Heat. By William John Macquorn Rankine, Civil Engineer, F.R.S.E., F.R.S.S.A., &e. The object of this paper is to shew how the laws of the phenumena of Elasticity and Expansion, as connected with heat, may be re- duced to mechanical principles by means of an hypothesis called that of Molecular Vortices. The author ascribes the first distinct statement of an hypothesis of this kind to Sir Humphrey Davy, and refers to Mr Joule as hay- ing supported it; but he states that its consequences, to the best of his knowledge, have not hitherto been developed by means of the _ principles of Analytical Mechanics. The author has endeavoured to do this, so far as the present state of experimental knowledge enables him, introducing such modifica- _ tions into the hypothesis as are necessary in order to connect it with the undulatory theory of radiation. His researches were commenced in 1842, but were laid aside for nearly seven years from the want of experimental data, which, however, have at length been to a great extent supplied, so far as gaseous bodies are concerned, by the ex- VOL. I. 2B 276 periments of M. Regnault. The author has thus been enabled to resume his investigations, and has obtained formule, agreeing with experiment, and applicable to practice, for the expansion and elas- ticity of gases,—the elasticity of vapours in contact with their liquids,—the specific heat of gases,—tho heat produced by their compression,—the latent and total heat of evaporation,—the expan- sive action of vapours,—the power of the steam-engine,—and the mechanical value of heat in general. One of the most useful in practice of those formule,—that for cal- culating the elasticity of steam and other vapours in contact with their liquids,—was published separately in the Edinburgh New Philosophical Journal for July 1849, with tables and a diagram, shewing its agreement with experiment, but without any account of the reasoning from which it is deduced. The theory of radiant heat, like that of light, having been re- duced to a branch of mechanics by means of the hypothesis of undu- lations, it is the object of the hypothesis of Molecular Vortices to reduce the theory of stationary heat also to a branch of mechanics, and thus to make a further step towards the fulfilment of the wish of Newton,—“ UTINAM CHTERA NATURZ PHZZNOMENA EX PRIN- CIPIIS MECHANICIS DERIVARE LICERET.” The hypothesis of molecular vortices is defined to be that which assumes, that each atom of matter consists of a nucleus or central point, enveloped by an elastic atmosphere, which is retained in its position by attractive forces, and that the elasticity due to heat arises from the centrifugal force of those atmospheres, revolving or oscillating about their nuclei or central points. According to this hypothesis, quantity of heat is the vis viva of the molecular revolu- tions or oscillations. The author, for the present, leaves indeterminate the following questions, as he has not as yet found it necessary to make any definite supposition respecting them. First, Whether the elastic molecular atmospheres are continuous, or consist of discrete particles? This includes the question, Whether expansive elasticity is wholly the result of the mutual repulsions of particles, or is, to a certain extent, a primary quality of matter ? Secondly, Whether, at the centre of each atom, there is a real nucleus or extremely small central body, or a mere centre of con- densation and force ? a i i a ee ae 277 Thirdly, What are the figures of the orbits described by the par- ticles of the atomic atmospheres in their revolutions or oscillations ? The author introduces into the hypothesis of molecular vortices a supposition peculiar to his own researches, for the purpose of con- necting it with the undulatory hypothesis as to radiation. It is this : That the vibration which, according to the undulatory hypothesis, constitutes radiant light and heat, is a motion of the atomic nuclei or centres, and is propagated by means of their mutual attractions and repulsions. The absorption of light and of radiant heat, accord- ing to this supposition, is the transference of motion from the nuclei or centres to their atmospheres, and the emission of light and ra- diant heat, the transference of motion from the atmospheres to the nuclei or centres. The author enumerates several advantages which he conceives that this hypothesis possesses over the common supposi- tion of a luminiferous ether pervading the spaces between ponderable particles. The present paper refers solely to the condition of bodies in the state of gas or vapour. It is divided into two parts, the first of which treats of the Statical Relations of Heat and Elasticity, or their relations when both are invariable; and the second, of their Dynamical Relations, which take place when gaseous bodies expand or contract, and involve the principles of the mutual conversion of heat and expansive power, and those of the latent heat of expan- sion and evaporation. The first section of the first part explains the general principles of the hypothesis, of which a summary has just been given. The second section contains the mathematical investigation of the general equation between the heat and the elasticity of a gas. The total elasticity is divided into two parts, —the superficial atomic elasticity, being the elasticity of the atomic atmospheres at the bounding surfaces of the atoms, which is always expansive, and a function of density and heat, and an elasticity arising from the mutual forces exerted by separate atoms, which may be expansive _ or contractive, and in the perfectly fluid state is a function of den- sity only. The more substances are rarefied, that is to say, the more the forces which interfere with the operation of the elasticity of the _ atomic atmospheres are weakened, the more nearly do they approach _to a condition called that of perfect gas, in which the total elasticity 278 at a given temperature, is simply proportional to the density. This is therefore assumed to be the law of the elasticity of the atomic at- mosphere of any given substance; so that the superficial atomic elasticity is held to be proportional to the density of the atomic atmosphere, at its bounding surface. It is shewn, that although the form of such bounding surfaces in a perfect fluid is a rhombic dodecahedron, it may be treated without sensible error, in calculation, as if it were spherical, and the atmo- sphere of each atom may be conceived to be composed of concentric spherical layers, the density being uniform for each layer, but varying for different layers. An oscillatory movement is supposed to be propagated from the nucleus or atomic centre in an inappreciably short time, to every part of the atmosphere, so that the mean velocity of movement is uniform throughout. The quantity of heat in one atom, or any other mass of matter, is expressed in terms of the force of gravity, by the weight of that mass, multiplied by the height through which it must fall at the earth’s surface, in order to acquire that velocity. This oscillatory movement is conceived to be resolved into two com- ponents, one in the direction of radii passing through the atomic centre, the other performed in spherical surfaces described round that centre. The latter component alone produces centrifugal force; and it is afterwards shewn to be probable, that the ratio which the vis viva of this latter component bears to the whole wis viva of the oscillations, depends on the chemical constitution of the substance. The centri- fugal force thus arising, has a tendency to increase the superficial density and elasticity of the atomic atmosphere, and must, at each layer of that atmosphere, be in equilibrio with the forces arising from the elastic pressure of the adjacent layers, and from the attraction towards the nucleus or centre. The condition of this equilibrium is expressed by a differential equation, which at the same time shews it to be stable. By the integration of that equation, there is ob- tained a general expression for the elasticity of a gas, in terms of its density and heat. The first and largest term is simply proportional to the density of the gas, multiplied by a function, which varies as a certain fraction of the heat increased by a constant. In a perfect gas, this term constitutes the whole elasticity. It is followed by an approximative converging series, chiefly ne- eo] 279 gative, in terms of the reciprocals of the powers of the function of the heat before mentioned, representing the effect of the actions of the nuclei or centres in modifying the superficial-atomic elasticity. The numerators of the terms of this series are functions of the density, diminishing along with it, and requiring to be determined by experiment. The last term of the expression represents the effect of the mutual action of separate atoms, and is a function of the density, to be determined by experiment. The third section treats of Temperature and of Real Specific Heat. Bodies are defined to be at the same temperature, when the powers of their atoms to communicate heat are equal ; and the proper mea- sure of temperature is defined to be the elasticity of a perfect gas at constant volume, or its volume under constant pressure. Those quantities are, in all perfect gases, proportional to the temperature, as measured from a point 274-6 centigrade degrees, or 494-28 de- _ grees of Fahrenheit’s scale, below the temperature of melting ice. This point is called the absolute zero, and temperatures, as mea- sured from it, absolute temperatures. It is shewn from the equations in the preceding section, that ab- solute temperature, as thus defined, is simply proportional to the quantity of heat in one atom, plus a constant, multiplied by a con- stant coefficient. The constants depend on the nature of the sub- stance, and the coefficient especially on its chemical constitution. The reciprocal of this coefficient is, of course, the real specific heat of one atom, which, being divided by the atomic weight, gives the real specific heat of unity of weight. The following laws, which have been to a great extent established experimentally by Dulong, are inferred from the theory— That the specific heats of all simple atoms are either the same, or vary only in certain simple numerical ratios, That the specific heats of atoms of similar chemical constitution are either the same, or vary only in simple numerical ratios. The fourth section relates to the actual coefficients of elasticity and expansion of gases. The coefficient of increase of elasticity with temperature at constant volume, and the coefficient of expansion under constant pressure, are the same, and equal to each other, for every substance in the state of perfect gas, being the reciprocal of the absolute temperature of melting ice, (or 00364166 per centi- 280 grade degree), when the volume and pressure at that tempera- ture are respectively taken as units. The state of perfect gas, how- ever, can be only approximated to in nature ; for in all gases, espe- cially the more dense and composite, the actions of the atomic nuclei or centres on their atmospheres, and of separate atoms upon each other, have more or less influence on the elasticity. M. Regnault has made several elaborate series of experiments, to determine the deviations from uniform expansibility thus produced, in various gases. The author, by applying his theory to data furnished by the ex- periments of M. Regnault, has obtained formulz for the coefficients of expansion of atmospheric air, carbonic acid gas, and hydrogen, the results of which agree closely with those of observation, in every case in which a comparison is possible. The fifth section treats of the elasticity of vapour in contact with the same substance in the liquid or solid state, or what is called the pressure of vapour at saturation. The equilibrium of a substance filling a limited space, partly in the form of vapour, and partly in that of liquid or solid, is shewn to depend on three conditions. The first condition of equilibrium is, that the total elasticity of the substance in the two states must be the same. The second condition of equilibrium is, that the superficial elasti- cities of every two contiguous atoms must be the same at their sur- face of contact, and hence, that the superficial-atomic elasticity must vary continuously ; so that, if, at the bounding surface between the liquid or solid and its vapour, there is an abrupt change of density, (as the reflection of light renders probable) there must there be two densities corresponding to the same superficial atomic elasticity. The third condition of equilibrium is deduced from the mutual at- tractions and repulsions of the atoms of liquid or solid and those of vapour. In a gas in which the atomic centres are equidistant, the actions of the several atoms on cach individual particle at an appre- ciable distance from the bounding surface of the gas, balance each other, and are accordingly treated as merely affecting the total elas- ticity by a quantity which is a function of the density ; but near the bounding surface between a liquid or solid and its vapour, the action of the liquid or solid upon any atom must be greater than that of the vapour, A force is thus produced which acts on each particle in a 281 line perpendicular to that bounding surface, and which is probably attractive towards the liquid or solid, very intense close to the bound- ing surface, but inappreciable at al) perceptible distances from it. Such a force can be balanced only by a gradual increase of superfi- cial-atomic elasticity in a direction towards the liquid or solid. Hence, although at perceptible distances from the liquid or solid, the density of vapour is sensibly uniform, the layers close to that surface are probably in a state of condensation by attraction, analogous to that of the earth’s atmosphere under the influence of gravity. Professor Faraday has expressed an opinion that certain well- known phenomena arise from a state of condensation of this kind, produced in gases by the superficial attraction of various solid sub- stances. This third condition of equilibrium is expressed by a differential equation, the integral of which, taken in conjunction with the first two conditions, would be sufficient to determine the respective densi- ties, and the total elasticity of a liquid or solid and its vapour, when in contact with each other in a limited space at any temperature, provided we had a complete knowledge of the laws of molecular force. In the present imperfect state of that knowledge, the integral in question indicates the form of an approximate equation, expressing the logarithm of the elasticity of vapour at saturation, in terms of the reciprocals of the first and second powers of the absolute tempe- rature, the coefficients of which the author has calculated empiri- cally, for water and mercury, from the experiments of M. Regnault, and for alcohol, ether, turpentine, and petroleum, from those of Dr Ure,—three experimental data being required for each fluid, to calculate three constants. The agreement of the results of the formule thus obtained with those of experiment is as close as the uncertainties of observation render possible, throughout the whole range of pressures and temperatures observed. For steam, in par- ticular, the coincidence is almost perfect. The author gives a table of the constants for the fluids enumerated, and refers to the Edin- burgh New Philosophical Journal for July 1849, for the details of the comparison between calculation and experiment. The section concludes with a speculation as to the probable effects _ of the atmospheres of dense vapours supposed to exist at the sur- faces of solid and liquid bodies. The author conjectures: that the presence of such atmospheres may be the cause which prevents solid 282 bodies from cohering when brought together, and produces that re- sistance to contact which is visible not only in them but in drops of liquid. He conceives it possible that it may also be the cause of the * spheroidal state” of liquids at high temperatures, and may assist in maintaining the vesicular state, if such a state exists. The sixth and last section of the first part relates to mixtures of gases and vapours of different kinds. The principle stated in the second section that the elasticity of the atomic atmosphere is proportional to its density, is here expressed in the form, that the elasticity of any number of portions of atomic atmosphere, compressed into a given space, is equal to the sum of the elasticities which such portions would respectively have if they occu- pred the same space separately. It is shewn, that if this principle be considered true, not only of portions of atomic atmosphere of one kind of substance, but also of portions of atomic atmospheres of sub- stances of different kinds, when mixed, it leads to the well-known laws of the elasticity and diffusion of mixed gases and vapours. He also speculates on the possibility of solid bodies, which have no per- ceptible vapours of their own at ordinary temperatures, acquiring the power of resisting cohesion by means of a superficial atmosphere of foreign substances. The second part of the paper treats of the dynamical relations of the heat and the elasticity of bodies in the gaseous state. The first section contains the general theory of the mutual con- version of heat and expansive power. After recapitulating the mode of expressing quantities of heat in terms of gravity, the author refers to the experiments of Mr’ Joule on the production of heat by electro-magnetic currents, by friction, and by the compression of air, as proving the convertibility of heat and mechanical power. He states reasons, however, for believing that the mechanical value of heat as deduced from those experiments (viz., from 760 feet to 890 feet per degree of Fahrenheit, applied to liquid water) is too large, owing to various causes of loss of power, and gives the preference to experiments in which no machinery is used, such as those on the velocity of sound, as data for such a cal- culation. The laws of the production of heat by compression, and its con- sumption by expansion, are then deduced from the following two principles, the first of which is peculiar to the hypothesis of mole- cular vortices, while the second is a consequence of the law of the conservation of vis viva. First, As every portion of an atomic atmosphere is urged towards the nucleus or atomic centre by a centripetal force equal to the cen- trifugal force arising from the oscillation which constitutes heat, it follows that, when by compression, each portion of such an atmo- sphere is made to approach the centre by a certain distance, the vis viva of its oscillation will be increased by the amount corresponding to that centrifugal force, acting through that distance; and conversely, that, when, by expansion, each portion of the atmosphere is made to retreat from the centre, the vis viva of its motion will be diminished by a similar amount, Secondly, Let a portion of any substance undergo any changes of temperature, volume, and figure, amd at length return to its primi- tive volume, figure, and temperature, Then, the absolute quantity of heat in the substance, the arrangement of the atoms, and the dis- tribution of their atmospheres, being the same as at first, it follows that the algebraical sum of the vires vivee consumed and produced j 283 : : : during the changes, whether in the shape of expansion and compres- sion, or in that of heat, must be equal to zero ; that is to say, if on the whole, a certain amount of mechanical power has appeared, and _been given out from the body in the form of expansion, an equal amount must have been communicated to the body, and must have disappeared in the form of heat; and if a certain amount of mechanical power has appeared and been given out from the body in the form of heat, an equal amount must have been communicated to the body, and must have disappeared in the form of expansion, _ From those principles the author deduces an algebraical expres- sion of three terms. The first term represents the variation of heat arising from mere change of volume; the second, the variation of heat produced by change of the distribution of the density of the atomic atmospheres dependent on change of yolume ; and the third, the variation of heat due to change of the distribution of the density of the atomic atmospheres, dependent on change of temperature. In all those terms there is a common factor, bearing a constant ratio to the absolute quantity of heat in the body. In the first term, that factor is multiplied by the variation of the logarithm of the density of the ody, and in the second and third by certain functions of the density 284 and temperature depending on the law of the influence of molecular attraction and repulsion upon the superficial-atomic elasticity. This section concludes by contrasting the author’s theory with that of Carnét, which has hitherto been followed, either explicitly or virtually, in all calculations respecting the motive power of heat (except in the investigations of Mr Joule, already referred to), and of which a very clear and able account, with copious illustrations, was read before the Royal Society of Edinburgh, in January 1849, by Professor Thomson. Carnét considers heat to be something of a peculiar kind, whether a condition or a substance, the total amount of which, in nature, is incapable of increase or diminution. It is not, therefore, according to his theory, convertible into mechanical power, but is capable, by its transmission through substances under particular circumstances, of causing mechanical power to be deve- loped which did not before exist. According to the author’s theory, on the contrary, as well as to every conceivable theory which regards heat as a modification of motion, the production of expansion by heat, and of heat by compression, consist in the transformation of mechanical power from one shape into another. The second section relates to real and apparent specific heat, espe- cially in the state of perfect gas. The apparent specific heat of a given substance is defined to be the sum of the real specific heat, and of that heat which is employed in producing those changes of volume and of molecular condition which accompany an elevation of one degree in the temperature of the substance. The same sub- stance may therefore have different apparent specific heats, accord- ing to the manner in which the volume is made to vary with the temperature. The general algebraical expression for apparent spe- cific heat is deduced from the equations of the preceding section. That expression being applied to the case of a perfect gas, or of a gas which may be treated in practice as sensibly perfect, it is shewn that the apparent specific heat of such a gas, at constant volume, is sensibly equal to the real specific heat, and that the apparent specific heat at constant pressure exceeds the specific heat at constant volume in a ratio which is sensibly constant for a given gas. Laplace’s method of calculating this ratio from the velocity of sound is referred to, and applied to atmospheric air, oxygen, and hydrogen, using the correct coefficients of dilatation of those gases, as determined by M. Regnault. 285 The following laws, which have already been inferred from experi- ment by Dulong, are then deduced from the theory : ‘The specific heat of wnity of volume, at constant volume, varies for different perfect gases inversely as the fraction by which the ratio of the two specific heats exceeds unity. _ Equal volumes of all substances in the state of perfect gas, at the same pressure, and at equal and constant temperatures, being eenreneed by the same amount, disengage equal quantities of heat. _ The data now obtained being employed to calculate the value of Theat i in terms of the force of gravity, it is found that the real specific heat of atmospheric air is equivalent to a fall of 238-66 feet per centigrade degree, and the apparent specific heat of liquid water at the pemperatare of melting ice (being what, is commonly termed a f et per degree of Fahrenheit. _ The author next investigates the apparent specific heat of vapour saturation. This quantity, according to his theory, is altogether different from the variation of the total heat of evaporation, with which, according to the theory of Carnét, it is identical. It is in general negative ; so that if vapour at saturation is allowed to ex- pand, being cut off from external sources of heat, a portion of it must @ liquefied in order to supply the heat necessary for the expansion of the rest, in addition to the heat set free by the fall of tempera- The third section treats of the latent and total heat of evapora- tion, especially for water. It is in the first place proved, from the principle of vis viva, that he latent heats of evaporation and liquefaction, at a given tempera- ture, are equal, with contrary signs. The total heat of evaporation is defined to be the sum of the tent heat of evaporation, and of the heat required to raise the quid to the temperature at which it is evaporated, from some arbi- ry fixed temperature—(generally that of melting ice). he law of variation of the total heat of evaporation with tempera- e is then deduced from the principle of the conservation of vis va, which, as applied to this subject, takes the following form :— Let a portion of fluid in the liquid state be raised from a cer- in temperature to a higher temperature ; let it be evaporated at ie higher temperature ; let the vapour then be allowed to expand, 286 being maintained always at the temperature of saturation for its density, until it is restored to its original temperature, at which temperature let it be liquefied: then the excess of the heat absorbed by the fluid above the heat given out will be equal to the expansive power generated. From this principle it is deduced that when a vapour is sensibly in the state of perfect gas, and of very small density as compared with its liquid, the total heat of evaporation increases uniformly with the temperature, and the rate of increase is sensibly equal to the ap- parent specific heat of the vapour at constant pressure. This con- clusion is verified by the experiments of M. Regnault upon the eva- poration of water. As an additional verification of the theory, the real specific heat of steam is calculated from the total heat of evapo- ration, and also from the specific heat of atmospheric air; and the results of these two processes are found to agree exactly, being equal to 0°183 of the apparent specific heat of liquid water. The fourth and last section of the second part is an investigation of the mechanical action of steam, treated as a perfect gas, and the power of the steam-engine. The density of steam of saturation at 100° centigrade, is calcu- lated from its chemical composition on the assumption of its being a perfect gas, and found to agree with the result of experiment, being yess of the maximum density of water; and thence it is inferred that, in the absence of more precise data, steam at ordinary pres- sures may be treated in practice as a perfect gas, without material error. The mechanical action of unity of weight of steam while entering a cylinder, and before it has begun to expand, is found by multiply- ing its pressure by its volume. The expansive action is next inves- tigated, taking into account the liquefaction of a portion of the steam in supplying the heat required to expand the rest. The exact ex- pression of this action is extremely complicated; but approximate formule of a more simple kind are given, suitable for calculating its amount with accuracy sufficient for practice, in different portions of — the scale of pressures. From the sum of those two portions of power, deductions are made for the loss of power arising from clearance, and — for the effect of the counter-pressure of the escaping steam. Thus is obtained the complete expression for the gross effect of unity of weight of steam, which, being multiplied by the weight of water effectively — 287 evaporated in unity of time gives the gross effect of the engine in unity of time. The result affords the means of calculating all the circumstances connected with the working of a steam-engine ac- cording to the principle of the conservation of vis viva, or, in other words, of the equality of power and effect, which regulates the action of all machines that move with a uniform or periodical velo- city. This principle was first applied to the steam-engine by the Count de Pambour, and, accordingly, the formule of this paper only differ from those of his work in the expressions for the pressure and expansive action of the steam, which are results peculiar to the au- thor’s theory. As an illustration of the use of the formule, the maximum useful effect of a double-acting Cornish engine is computed, and compared with the result of the calculation of M. de Pambour for the same engine, shewing the latter to be too large by about one- fifteenth. In an Appendix are given two tables; one for calculating the vo- lume of steam from its pressure, and vice versa, and its mechanical action at full pressure, the other for computing the amount of its ac- _ tion in expansive engines. In order to shew the limit of the possible effect from the expen- _ diture of a given quantity of heat in evaporating water under given circumstances, the maximum gross effect of unity of weight of steam, _ evaporated at a higher temperature, and liquefied at a lower, is com- _ puted in two examples, and compared with the heat which disappears during the action of the steam, as caleulated directly. In the first _ example, the water is supposed to be evaporated at the pressure of four atmospheres, and condensed at that of half an atmosphere ; in the second, to be evaporated at eight atmospheres, and condensed at _ one atmosphere. : In both these examples, the direct calculation of the heat rendered - effective, agrees with the calculation from the power developed, ‘thus verifying the methods of computation founded on the author's theory. The heat converted, in those examples, into engine-power amounts io only about one-sixth part of the heat expended in evaporating the water, the remainder being carried off by the steam and liquid water which escape from the cylinder. In practice, the proportion of heat rendered effective is still smaller, and in some unexpansive engines ‘amounts to only one twenty-fourth part, or even less. It is thus ‘a 288 shewn, that there is a waste of heat in the steam-engine, which is a necessary consequence of its nature. It can be reduced only by increasing the initial pressure of steam, and the extent of the expan- sive action; and to both these resources there are practical limits. In conclusion of the present paper, the author states, that, from his equations, many additional formule are deducible, with respect to the specific heat of imperfect gases, to certain questions in meteor- ology, and to the specific heat of liquids; but from the want of suffi- cient experimental data, he conceives that they are not as yet capa- ble of being usefully applied. 2. On Probable Inference. By Bishop Terrot. The paper commenced with a suggestion, that, as the inferences of ordinary logic admitted no premises but such as were absolutely cer- tain, and as the premises with which we have to deal in the business of life were not certain, but only probable, therefore it was highly de- sirable that we should have a logic, or rules for drawing inferences on the case of probable premises. The attention of the Society was then drawn to the 15th section of the article Probabilities, in the Encyclopedia Metropolitana, and especially to the following passage: ‘‘ It is an even chance that A is B, and the same that B is C; and therefore, 1 to 3 from these grounds only that A is C. But other considerations of themselves give an even chance that A is C. What is the resulting degree of evidence that A is ©?’ To which query the answer in the Ency- clopedia is 8. On this passage it was observed, in the first place, that the asserted ratio of 1 to 3, or the probability 4 in the first syllogism, was true only on the hypothesis that A can be C only through the intervention of the middle term B. But that when such is not the case, when other ways are conceivable but totally unknown, the probability is not } but 3; these two fractions representing, the one the probabi- lity of the evidence of a complete proof that A is C, the other the probability that A is C; and it was observed, that, in practical ques- tions, it is the latter probability alone which we have an interest in determining. 289 It was then shewn generally, that, if the probabilities of the premises be P for the first, and Pr for the second ; then the proba- bilities of the dated possible pene are, / 1. AisBand Bis C, witha probability of ail for A is C, 79 Mat and H mot Us hess ..-cck-p--c ese PY ~PP's. & not C. MEE A not Band Bis. ©, ccrrerecrese-nsareass PR 77 | Bet arid, EB mGGO, » secs sane snes sonny nets PP Pd" Pa + 9d 99 If A can be C only through the intervention of B, then the proba- f bility of the proposition A is C is 7 But if A may be C in other unknown ways, we must add together all the probabilities arising from all the combinations, the result of which addition was shewn to ay 4 pp’ +3 97-3 py 6 qq’ -2 p/ 3 q7 —4 pp’ +p7 6 qf —2 py Probability for Probability against = Whence it was inferred, that if g’=2 p’, or if the second premise have a probability of 4, each of these fractions becomes 3, or the probability that A is C becomes }. it was then shewn that a weak argument, that is to say, one af- ording a probability of less than }, diminishes instead of increasing he probability arising from any previous argument or evidence ; and was proved, that even if we take } for the probability arising from e first argument, the probability arising from both conjointly was n0 & but 2. 290 bability, the probability of the conclusion is the product of the pro- babilities of the premises, in those cases only where the presence of the middle term is necessary for the connexion of the major and minor terms. When this is not so, then the probability of the con- clusion is the product of the probabilities of the premises, plus the sum of the probabilities arising from the other conceivable causes of connexion. 2. In asorites of probable premises, any premise with a proba- bility of } brings the force of the argument up to that ‘premise in- clusive to a probability of 3. 3. When various arguments of different validities have been ad- vanced for a proposition, or when evidence has been brought in sup- port of argument, or argument of evidence, the resulting probability is not the sum, but the average of the several probabilities ; so that a weaker argument following upon a stronger, weakens it, or rather weakens the probability produced by it. 291 : PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. VOL. II. 1850. No. 38. Monday, 4th February 1850 (continued). The Hon. LORD MURRAY, V.P., in the Chair. 3. On the Ante-Columbian Discovery of America. By Dr Elton. Communicated by Dr Traill. __ The object proposed by Dr Elton, is a summary of the knowledge we possess on the discovery of the Continent of America, by several adventurous European voyagers, anterior to the time of Columbus. This subject, which has been for almost a century and a half well known to the students of northern history, was first made known to the rest of Europe by the publication of the Vinlandia Antiqua of the celebrated Torfeus in 1705; and most of the facts given by Dr Elton are extracted from that work. Torfeus proved from exist- transmitted to us prove that they landed on what are now New- foundland, Nova Scotia, Massachusetts, and Rhode Island. _ The first adventurer was Leif, the son of Hirik the Red, who, in and which he named Helluland, or Rocky Land. From that he ailed south-westward, till he arrived at a country, which from be- VOl. II. 292 ing covered with wood, he denominated Markland ; and which, from the course and length of his voyage, is believed to be a part of Nova Scotia. Pursuing his course southwards, he reached a portion of Massachusetts, not far from Cape Cod; and coasting along this, he took up his winter quarters in a fertile country, which, from his description, is easily seen to have been about Rhode Island. This region, from the discovery of a species of wild vine found there, he termed Vinland. In the summer, he fitted out his vessel, and sailed to join his father in Greenland. The fame of his discovery induced his brother Thorwald, in a.p. 1002, to sail for Vinland, intending to settle there; but in one of his excursions he encountered and was slain by a people, the Ice- landers, in contempt denominated Skrelings, evidently Esquimaux, who then appear to have possessed the shores far to the south of their present location. The next and most remarkable voyage to Vinland, was that of Thorfinn Karlsefne, which took place in a.p. 1006. He carried with him his wife, and one hundred and thirty-one followers, and domestic animals, with the intention of establishing a colony at the huts built by Leif in Rhode Island. The soil and climate were suitable, and they remained in that country till 1011, when they were attacked by a vast number of Skrelings, whom they repulsed; but the hos- tility of the natives induced him to abandon his design, and he finally settled in Iceland. Thorfinn, however, had a son, Snorro, born in America, from whom some of the most distinguished families in Iceland are lineally descended. After this period, it appears that there were many voyages to Vinland, and that Iceland sent colonies thither for more than a century ; for it is stated in Icelandic MSS., that Hirik, bishop of Greenland, went to Vinland in a.p. 1125, to confirm the colonists in the Christian faith. The work of Torfeus also gives us a singular aceount of Icelandic voyages to a country, either a continent, or a vast island, lying far to the west of the British Islands, and near Vinland. It seems to have been first visited by Are Marson in a.p. 983, who was driven there by a great storm. He named it Huitramannaland, or Land of White Men, from the complexion of the natives, who were also Chris- ‘tians; and Are himself was then converted from the worship of Odin to the religion of Christ. : : | : id R . 293 The same land was visited afterwards by Gudleif Gudlagson, an Icelandic trader with Ireland; who, in a voyage from Dublin to Iceland, was driven by a tempest to a far western land, where he was taken prisoner by the natives, but delivered by their chief, who turned out to be an Icelander. He was dismissed with presents, but forbidden to return. The natives were white, and seemed of European extraction, with a dialect like that of Ireland; and the American archeologists, with considerable reason, have considered that their whereabout was on some part of the new world, between the Chesapeake and Florida. These early voyages seem to us very surprising ; but they do not seem at all foreign to the habits and enterprise of the bold Icelanders of those ages; who not only traded to every part of the west of _ Europe, but to the Mediterranean, and explored Bafin’s Bay, as high as Lancaster Sound. We have now a certain proof, that they were at least as high in it as at 72° 55’; for in 1825, a memorial stone with a Runic inscription, and the date of 1131, was found on the island of Kingiktersoak. _ Several Runic inscriptions are said to have been found in America ; but the most remarkable of these is the mass of greywacke on the shores of the river at Dighton, in the township of Berkley, in Mas- sachusetts, not far from the supposed site of the settlement of Thor- inn Karlsefne. This has been lately carefully figured and engraved in the Antiquitates Americane of the Royal Soicety of Northern Antiquaries of Copenhagen, and repeated in Jacob Aal’s translation of the Chronicles of Snorre Sturleson. Dr Elton, who has examined the original, assures us, that this engraving is a faithful transcript. n this rock, antiquaries read, amid figures supposed to represent Thorfinn, his wife and child, and his companions, the letters—9rjin and exexi, the number of his companions. _ Dr Elton next adverted to the voyage of the Welsh Prince, Madoc, jon of the greatest of the princes of North Wales Owen Gwenedd, about the year 1170. This voyage, though doubted by many, is fully believed in by Dr Elton, and it is noticed by Hakluyt, Purchas, 3roughton, &c. Dr Elton quotes the singular story given by the Rev. Morgan Jones, chaplain to the British commander of the forces of Virginia in 1669. Jones was taken prisoner by the Tusscarora n ans, who intended to torture him in their usual way, when he yan to lament his cruel fate in Welsh, which was understood by 294 the Indians, and he was suffered to depart in peace. These, Dr E. thinks, may have been descendants of Madoe’s followers; and he seems inclined to ascribe to them also those very remarkable mounds, fortifications, and enclosures, which are found in such quantity in the valleys of the Mississippi and the Ohio. He is inclined also to trace to these Welsh adventurers, or at least to some early Europeans, the now almost extinct tribe, the Mandans—a people fairer and hand- somer than the Red men,—that are now found 1800 miles above St Louis, on the Missouri, as described by Lewis and Clarke, and Cat- lin, the American travellers. These, and several other circumstances, which might have been adduced, prove that Columbus cannot be regarded as the original discoverer of the New World. The following Donations to the Library were announced : Philosophical Transactions of the Royal Society of London, 1849. Part II, 4to.—By the Society. Kongl. Vetenskaps. Akademiens Handlingar, for 1847 &1848, 8vo. Arsberattelser om Botaniske Arbeten och Uptiickter for 1843 & 1844, 8yo. “Arsberittelse om Framstegen i Kemi under Ar. 1847. 8vo. ‘Arsberiittelse_ om Technologiens Framsteg. 1842, 1843, 1844, 1846. 8vo. Ofversigt af Kongl. Vetenskaps. Akademiens Forhandlingar. 1848. 8v0.—By the Academy. Monday, 18th February 1850. The Right Rev. BISHOP TERROT, V.P., in the Chair. The following Communications were read :— 1. On the Equilibrium of Elastic Solids. By James Clerk — Maxwell, Esq. Communicated by the Secretary. This paper commenced by pointing out the insufficiency of all theories of elastic solids, in which the equations do not contain two 295 independent constants deduced from experiments. One of these constants is common to liquids and solids, and is called the modulus of cubical elasticity. The other is peculiar to solids, and is here called the modulus of linear elasticity. The equations of Navier, Poisson, and Lamé and Clapeyron, contain only one coefficient ; and Professor G. G. Stokes of Cambridge, seems to have formed the first _ theory of elastic solids which recognised the independence of cubical and linear elasticity, although M. Cauchy seems to have suggested a modification of the old theories, which made the ratio of linear to cubical elasticity the same for all substances. Professor Stokes has deduced the theory of elastic solids from that of the motion of fluids, and his equations are identical with those of this paper, which are deduced from the two following assumptions. In an element of an elastic solid, acted on by three pressures at right angles to one another, as long as the compressions do not pass the limits of perfect elasticity— 1st, The sum of the pressures, in three rectangular axes, is pro- portional to the sum of the compressions in those axes. 7 2d, The difference of the pressures in two axes at right angles to one another, is proportional to the difference of the compressions in those axes. _ Or, in symbols :— being the modulus of cubical, and m that of linear elasticity. These equations are found to be very convenient for the solution of problems, some of which were given in the latter part of the paper. _ These particular cases were— _ That of an elastic hollow cylinder, the exterior surface of which was fixed, while the inferior was turned through a small ig The action of a transparent solid thus twisted on polarized ligt t, was calculated, and the calculation confirmed by experiment. 296 he second case related to the torsion of cylindric rods, and a method was given by which m may be found. The quantity 9mn saan found by elongating, or by bending the rod used to determine m, and yp is found by the equation, lag EL Ai ~ 9m—6E The effect of pressure on the surfaces of a hollow sphere or cylin- der was calculated, and the result applied to the determination of the cubical compressibility of liquids and solids. be An expression was found for the curvature of an elastic plate ex- posed to pressure on one side ; and‘the state of cylinders acted on by centrifugal force and by heat was determined. The principle of the superposition of compressions and pressures was applied to the case of a bent beam, and a formula was given to determine E from the deflection of a beam supported at both ends and loaded at the middle. The paper concluded with a conjecture, that as the quantity w, (which expresses the relation of the inequality of pressure in a solid to the doubly-refracting force produced) is probably a function of m ; the determination of these quantities for different substances might lead to a more complete theory of double refraction, and extend our knowledge of the laws of optics. 2. Two Letters from W. E. Logan, Esq., to Earl Cathcart. These letters were dated in August 1846 and September 1847. Earl Cathcart intended himself to have read them to the Society, but, having been prevented by his official duties from coming to Edinburgh, had sent them, to be communicated in his name. In the first letter, the author, who had been sent to examine the geology of Canada, describes a visit which he made, on his way to Fort-William, Lake Superior, to the silver and copper mines on the south side of the lake, in the territory of the United States. He considers the formation in which the mines occur as being older than the new red. ‘They consist of parallel ranges of trap and conglomerate, apparently interstratified. They are well displayed at and near Copper Harbour. They are sometimes so thick as to 297 form mountain ranges. The conglomerate consists of trap pebbles in trap sandstone; the trap is sometimes compact, at other times amygdaloidal, The strata run ina curvilinear direction. They dip to the north, with a slope of 16° to 30°, the veins are at right angles to the strata, and run nearly north and south. The veinstones are steatite, quartz, calespar, and zeolites. The ores are those of eop- per, silver, iron, and lead, the two former being productive. The two metals are chiefly native, but occur also in other forms. They are least abundant in the conglomerate, more so in the trap, most of all in the amygdaloid, They are found also in amygdules of the rock near the veins. The quantity of native copper is very great. In the Copper Falls Mine, near Eagle Harbour, on sinking a pit to 72 feet, the compact trap and amygdaloid were found to alternate six orseven times. The main vein was 18 to 20 inches thick. In the shaft, about 40 feet down, a mass of native copper was found, of which the dimensions were estimated by the author, in situ, to in- dicate a weight of about 30 tons. It had not yet been found pos- _ sible to remove it. A diagram of its position was given. From other shafts in the vicinity, much copper had been ex- _ tracted, but with prodigious difficulty, from the tough metal binding _ the rock firmly together, and rendering blasting useless. The author saw, on the surface, besides many pieces of 25 lb., seven masses, varying from 75 to 1200 lb., and weighing in all 4000 Ib., or nearly 2 tons. Native silver is found with the copper, and a mass _ of 3} Ib. had been obtained. The author saw one of 1} lb. The author is of opinion that the very richness of this mine in native _ copper may render it unproductive, from the difficulty and expense of working it. ___ In the Cliff Mine, on Eagle River, there is the same abundance of copper, with more silver. Part of the rock was said to yield 7 per “cent. of silver; but subsequently was found hardly to pay for its extraction. The author saw here a mass of silver of 34 1b. Every vein in the trap seen by the author contained native copper. At the Eagle River Mine, silver is found in large masses, one of which weighed 7 lb. 2 oz. ~ On the Canada side, as far as the author had then examined it, 298 shore of the lake. A system of veins occurs at right angles to the dikes, containing barytes, in addition to the veinstones formerly men- tioned. The veins vary from 6 inches to 20 feet. In one of them 14 or 15 feet thick, well seen on Spar Island, gray sulphuret of copper occurs in considerable abundance, especially in a part of the vein, nearly 5 feet thick. Native silver also occurs in small quan- tity. There are also veins parallel to the dikes which contain ores of copper. But the author could not form a decided opinion in 1846 of the value of these mines. In the second letter, he gives some of the results of an examination of the eastern townships of Canada, from Lake Champlain and the Richelieu to the Chaudiere. He observed facts proving the green mountains of Vermont to be more recent than the Loraine shales, or Hudson River group. Of the upper rocks, the most interesting was a band of serpentine, 150 to 400 yards broad, which the author traced continuously for 150 miles, and which probably extends as far again. It has occasionally rich beds of magnetic iron and of chro- mate of iron; of the latter, a boulder was found, weighing 6 cwt. The gravel on the Chaudiere, besides these minerals, contains tita- niferous iron and gold. The author expects to find platinum, as the gravel in all other respects resembles that of the Russian auriferous district. The auriferous sand is found on the tributaries of the Chaudiere. It will probably pay for extraction. 60 bushels washed by Mr Derby, yielded 18 dwt. 8 gr., or about 1s, 6d. worth per bushel. The gold has not yet been found in situ. 3. Notes on Practical Chemical subjects. By Alexander Kemp, Esq. Communicated by Professor Gregory. 1. On the Purification of Sulphuric Acid. The author, after describing the different methods, recommended for purifying sulphuric acid from nitric acid, namely, boiling with a little sugar, and heating with sulphate of ammonia, both of which had proved troublesome and imperfect, stated, that after trying va- rious plans, the only one which he found to answer well, was the action of sulphurous acid on the oil of vitriol, after diluting it to the sp. gr. of 1°715, or lower. He adds one volume of water to three of the oil of vitriol, passes sulphurous acid gas through the hot liquid till it is in excess, and then boils off the excess of sulphurous acid ; or, still better, three volumes of oil of vitriol are added to or diluted with, one of a saturated solution of sulphurous acid in pure water, 299 and boiled. The acid is thus so perfectly purified from nitric acid, that when used for making hydrochloric acid, it yields a product quite colourless, which was not the case with the oil of vitriol puri- fied by any other process. If the oil of vitriol be diluted with one-half its volume of sulphur- ous acid solution (or of water, previously to passing the gas through it), the sulphate of lead is also totally separated, and the clear liquid, decanted from the precipitate, and boiled down to sp. gr. 1°845, is colourless, and almost chemically pure. 2. On the Preparation of Pure Hydrochloric Acid. Professor Gregory, in his process for preparing hydrochloric acid, by heating 1 equivalent of sea-salt with 2 equivalents of sulphuric acid of sp. gr. 1-650, directs the use of patent salt, to avoid the pre- sence of iron in the product. The author observed, that there is always a certain quantity of iron in the residue, even when patent salt is used; but that none passes over with the hydrochloric acid. He then added iron and peroxide of iron in considerable quantity to the materials, Still no iron passed over. It would appear, that when iron had been ob- served by Professor Gregory in minute quantity, in the hydrochloric acid made by his process, from common salt, it had either passed over at the very end of the process, when the temperature rose very high, although the author could not, in his own experiments, ob- serve this, or, more probably, had been present in the test employed. It is probable that, even when much iron is present in the materials, the presence of the excess of sulphuric acid, and also the low tem- perature at which the process goes on, prevent the formation of the chloride of iron. The author’s observations enable us to prepare, from the com- monest and cheapest salt, perfectly pure and colourless hydrochloric acid, and thus still further to reduce the price of this reagent, so essential to the chemist. Professor Gregory also briefly stated some observations by Mr Kemp and himself, on the purification of chloroform, which he was to describe more fully at a subsequent meeting. Dr Srark Was balloted for, and duly and unanimously re-elected a _ Fellow of the Society. 300 Monday, 4th March 1850. General Sir THOMAS MAKDOUGALL BRISBANE, Bart., President, in the Chair. The following Communications were read :— 1, Analysis of the Anthracite of the Calton Hill, Edinburgh. By Dr A. Voelcker. Communicated by Dr George Wilson. Dr Voelcker observed, in the introduction to his paper, that we are in possession of analyses of anthracite from different localities, from which it appears that different specimens vary much in the pro- portion, but very little in the nature, of their ingredients. All samples of anthracite which have been analysed, have been found to contain carbon, oxygen, hydrogen, and nitrogen, as well as more or less inorganic matter. Sulphur also has generally been found, at least when sought for; but it does not appear in many recorded analyses. The anthracite employed in the following analyses was furnished by Dr Fleming, and first carefully dried, after being finely pow- dered, by exposing it for several hours to a current of dry air, at a temperature of 230° F. The carbon and hydrogen were ascertained, by burning from three to four grains of the mineral with a mixture of oxide of copper and oxide of lead, which is much less hygroscopic than the pure oxide of copper. A mixture of this oxide and chlorate of potass was also placed in the shut end of the combustion-tube, from which oxygen was evolved in the usual way towards the close of the process, The nitrogen was determined by Will and Varentrapp’s method, The sulphur was ascertained by projecting into a red-hot platina crucible, in successive small quantities, a mixture of anthracite in powder, with nitrate of potass and carbonate of soda, and afterwards maintaining the product of deflagration at a high temperature for some time. The resulting fused mass which was perfectly white, was dissolved in water, super-saturated with hydrochloric acid, and precipitated by chloride of barium. About ten grains of the mineral were employed in the determina- tion of the amount of ash. It was red, and contained oxide of iron. The following are the results of the analysis :— 301 Carbon, . ; , 91°23 Hydrogen, , ‘ 2°91 Nitrogen, : . 0°59 Oxygen, . ‘ ; 1:26 Sulphur, . ; , 2°96 Ash, F , . 1:05 100-00 The most remarkable peculiarity of the Calton Hill anthracite, as appears from the results given above, is the large proportion of sul- phur it contains, amounting to nearly 3 per cent. Sulphur has been supposed to occur in the different varieties of coal in combina- tion with iron, as pyrites, but the trace of that metal present in the Calton Hill anthracite is so small, that the sulphur must have been combined with the organic constituents of the mineral. Note on the Crystallisation of Carbon, and the possible derivation of the Diamond from Anthracite and Graphite. By Dr George Wilson. The author stated that the object of his communication was, to suggest the possibility of anthracite as well as graphite being sub- stances from which the diamond is developed. After referring to previous theories, as all assuming that carbon must have been fluid or semifluid, before it crystallised, he stated that his hypothesis contemplated the possibility of graphite, as well as amorphous car- bon, and its solid combinations, such as anthracite, undergoing erys- tallisation into the diamond, without losing their solidity during the change. He thought anthracite more likely than most substances to yield the diamond, for the following reasons :— Firstly, As it occurs in nature, in many localities, it is found pass- ing by insensible gradations, on the one hand, into common coal, on the other, into graphite; so that it may be regarded as representing the transition-state from fossilised vegetable matter to pure carbon, and as tending, under the influence of certain agencies, to change ultimately into the latter. Secondly, The chief element of anthracite is carbon, of which it frequently contains 91, and sometimes 95 per cent. Thirdly, Its other ingredients (with the exception of the ash, which is often under one per cent.), namely, hydrogen, oxygen, nitro- gen, and sulphur, form volatile compounds with each other, and-with 302 the oxygen of the air, so that by a slow process of spontaneous de- composition, and gradual oxidation or eremacausis, all the consti- tuents of the anthracite, except the excess of carbon and the ash, may be evolved, and carbon left free. The separation, in this way, of the non-carbonaceous elements of the anthracite would be attended with a disturbance of the molecu- lar equilibrium of the mineral, which would necessitate a new ar- rangement of its particles, and might determine the induction of the crystalline condition characteristic of the diamond. During this pro- cess, the inorganic saline matter, or ash, would either be excluded by the power crystallising bodies are known to possess of expelling hetero- geneous matter, or be included in the crystallising carbon. Either view would consist with observation ; for whilst some diamonds appear to be pure carbon, many leave a slight ash when burned in oxygen. The author further observed, that whether anthracite will crys- tallise into graphite or diamond, will be determined chiefly by the temperature at which crystallisation occurs, and the rapidity with which it proceeds. Graphite represents the condition of most stable equilibrium, which the crystalline molecules of carbon assume, when aggregated rapidly at a high temperature. The diamond, on the other hand, has all the characters of a crystal which has formed very slowly at a lower temperature, and it will not change into graphite, unless it be suddenly exposed to an intense heat. Whenever, there- fore, carbon crystallises very slowly at ordinary temperatures, it may be expected to become the diamond rather than graphite, and the latter must be considered as a substance which, when not main- tained at an elevated temperature, is liable to re-arrange its par- ticles in the condition of more stable equilibrium characteristic of the diamond. The author, at the same time, observed, that he did not seek to affirm that all diamonds had been produced from anthra- cite or graphite, but thought it, on the other hand, probable, that, like other crystallisable substances, carbon might be crystallised in various ways. 2. On the Proportion of Fluoride of Calcium present in the Baltic. By Professor Forchammer of Copenhagen. With some preliminary Remarks on the presence of Fluorine in different ocean waters. By Dr George Wilson. Dr Wilson reminded the Society that he had announced to them in 1846 the occurrence of fluorine in the water of the Frith of 303 Forth, and mentioned, that, in the preceding summer, he had found it in deposits obtained during the evaporation of sea-water from the Frith of Clyde, and the German Ocean. Professor Forchammer had made similar observations on the Baltic, and had furnished Dr Wilson with the account of them which follows. Before reading this, he wished to add, that he had recently examined incrustations from the boiler of a steam-vessel sailing between Liverpool and Dub- lin, and similar deposits from the Canada Transatlantic steamer, and H.M. war-steamer Sidon, which had been three years on the Medi- terranean station. The different crusts were, without preliminary treatment, except reduction to powder, heated with oil of vitriol, and were found to yield an acid vapour which etched glass. Specimens of glass, in illustration, were shewn to the Society. From these ob- servations, Dr Wilson inferred the presence of fluorine in the Friths of Forth and Clyde, in the German Ocean, the Irish Sea, the At- lantic, and the Mediterranean. He then proceeded to read Profes- sor Forchammer’s communication, which follows. It is dated, Copen- hagen, 20th December 1849. Abstract of a Paper by Professor Forchammer, on the rarer Sub- stances which occur in Sea-water. Fluorine and Phosphoric Acid. 100 Ib. of sea-water, as it occurs in the Sound, near Copenhagen, of which the average quantity of salts is between 2 and 23 per cent., was evaporated. When the solution was so concentrated that it began to deposit salt, it was, without filtering it, mixed with an excess of ammonia, and the precipitate collected and washed. The whole precipitate which contains carbonate, sulphate, and phosphate of lime, fluoride of calcium, silica, and magnesia, was redissolved in muriatic acid, which left the greater part of silica undissolved ; the ‘solution was mixed with muriate of ammonia, and a second time precipitated by an excess of ammonia. This precipitate from 100 lb. of sea-water weighed 3-104 grains, and consisted of phosphate of lime and fluoride of calcium. It was divided into two equal parts, of which the one was in a platina crucible, mixed with concentrated sulphuric acid, and allowed to act on a slip of glass, covered with wax, ‘in which some words were scratched with a copper needle. The glass was most decidedly etched, but the words appeared more clear 304 and legible if breathed upon. The second half part was likewise mixed with sulphuric acid, but in a bent tube, and distilled into a small vessel which contained a weak solution of ammonia. The tube was etched, and the vessel contained precipitated silica. It was thus completely proved that sea-water contains fluoride of calcium, but the quantity in 100 lb. sea-water from the Sound at Copenhagen can hardly exceed one-half of a grain, or since the proportion of the different salts varies very little in sea-water, it will be about one grain in 100 lb. of water of the ocean, which contains. between 3°5 and 4 per cent. of salts. All the residuums from the trials to find fluorine were dis- solved in muriatic acid, and thrown down by an excess of ammonia. The precipitate, washed, dried, and heated, was mixed with potassium in a glass tube [and heated], until the excess of potassium was driven off. The lower part of the tube was cut off and thrown into water, where it for hours continued to give out small bubbles, distinguished by the peculiar smell of phosphuretted hydrogen, although they did not inflame by themselves. Thus the existence of phosphoric acid was likewise proved, although I could not try the delicate test for phos- phoric acid which we owe to Mr Svanberg, it not being known at the time when I made my experiments. In all the different species of corals which I analysed, i like- wise found fluorine. In a postseript to the preceding communication, Professor For- chammer states, that the paper, of which it is an abstract, ‘‘ contains experiments on many other substances, contained in minute quantities, in sea-water ; for instance, manganese, ammonia, baryta, or strontia, besides iron and silica, which occur in proportionally large quan- tities."—G. W. 3. On an Application of the Laws of Numerical Harmonic Ratio to Forms generally, and particularly to that of the Human Figure. By D. R. Hay, Esq. The author stated in some prefatory remarks, that a belief in the operation of the laws of numerical harmonic ratio in the constitution of beautiful forms had long existed, although those laws had not been systematised so as to render them applicable in the formative arts. In proof of this, Mr Hay quoted a correspondence upon the subject 305 of harmonic ratio, between Sir John Harrington and Sir Isaac New- ton, in which the latter expresses his belief in such laws in the fol- lowing words: ‘ I am inclined to believe some general laws of the Creator prevailed with respect to the agreeable or unpleasing affec- tions of all our senses; at least the supposition does not derogate from the power or wisdom of God, and seems highly consonant to the simplicity of the macrocosm in general.”” The belief of this great philosopher, the author trusted, would form some apology to men of science for the repeated attempts he has made to establish the fact. These attempts he had hitherto made with reference to architecture, to ornamental design, and latterly to the human head and countenance ; but on the present occasion he intended to shew the operation of these laws in constituting the symmetrical beauty of the entire human figure. He next proceeded to point out the remarkable similarity that exists in the physical constitution of the organs of hearing and see- ing, and the manner in which external nature affects the sensorium through these organs ; shewing the difference between noises and musical sounds in the one case, and irregular and regular forms in the other. He explained that each musical sound was produced by a number of equal and regular impulses made upon the air, the fre- quency of which determining the pitch of the sound, their violence its loudness ; and the nature of the material by which the impulses were made its quality or tone. In like manner, he shewed that the effeet upon the optic nerve produced by external objects is simply that of the action of light, and amenable to the same laws. Variety of form being analogous to variety of pitch ; variety of size to that of intensity or loudness, and variety of colour to that of quality or tone. Mr Hay next explained the nature of the harmonics of sound, which result from the spontaneous division of the string of a mono- _ chord by the formation of nodes during its vibratory motion. He _ then shewed how the harmonies of form could be evolved from the _ quadrant of a circle by the following process :— From a horizontal line MR (figure 1, of the annexed Plate), he produced two parallel vertical lines ML and RS indefinitely, and with a radius MR described, from the centre M, the quadrant OR. From 0 he divided the are of the quadrant into parts of 3, }, 3, 3, 4,4,and 4. From the centre M, and through these divisions, he produced the lines MN, MP, MQ, MT, MU, MV, and MS, until 306 they met RS, forming the right-angled triangles MPR, MQR, MTR, MUR, MVR, and MSR. He then shewed, that as the angles at the vertex of each of these triangles, contained respectively 45°, 30°, 22° 30’, 18°, 15°, 12° 51’ 26”, 11° 15’, they related to the right angle, as the harmonies of sound, expressed by the signs Cx. ByutyaBpoBs bp, and & relate to the fundamental note C, pro- duced by the string of the monochord. These triangles he combined in the following manner upon a line AB (figure 2, of the annexed Plate), which he said might be of any given length according to the size of the figure to be formed. From B at an angle of 11° 15’ with AB he drew the line Bg indefinitely, and from A at an angle of 15° with AB the line Ar, also indefinitely, and cutting Bg in K. Through K he drew KL at right angles with AB, forming the tri- angles ALK and KLB. Through K he drew the line pO parallel to AB. From A at an angle of 12° 51’ 26” with AB he drew AV, cutting pO in M, and drew MN at right angles with AB, forming the triangle AMN. From A at an angle of 18° with AB, he drew Au, cutting pO in H, and drew HI at right angles with AB, form- ing the triangle AHI. From A at an angle of 22° 30’ with AB, he drew At, cutting pO in F, and drew FG at right angles with AB, forming the triangle AFG. From A at an angle of 30° with AB he drew As, cutting pO in C, and drew CD at right angles with AB, forming the triangle ACD. From C at an angle of 45° with AB and CD he drew CE, forming the triangle CDE. Thus, he ob- served, were the triangles arising from the harmonic angles con- structed upon AB in the same relative proportions to each other, that they were when formed upon the line RS, figure 1. Upon the other side of AB he constructed similar triangles forming the equila- teral triangle ACC; the right-angled isosceles triangle ECC, and the acute-angled isosceles triangles AFF, AHH, AKK, AMM, and BKK. Within this diagram he shewed that the human skeleton could be formed in the most perfect proportions, determining, at the same time, the centres of all the various motions of the joints; and also that the symmetrical beauty of the external form, whether in a front or profile view, was governed by these angles; thus en- deavouring to prove that an application of the laws of numerical harmonic ratio in the practice of the sculptor and painter would give these imitative arts a more scientific character than they at present possess, and, so far from retarding the efforts of genius, would rather tend to facilitate and assist them. 307 PROCEEDINGS OF THE _ ROYAL SOCIETY OF EDINBURGH. VOL. Il. 1850. No. 39. Monday, 4th March 1850 (continued). The following Gentlemen were duly elected Ordinary _ Fellows :— ; Lieut. W. Driscort Gosset, Royal Engineers. Dr Witt1aM Sexrar, Pres. R.C.P.E. The following Donations to the Library were announced _ at the Meeting of 18th February :— he London University Calendar. 1850. 12mo.—By the Pub- lishers. ~The American Journal of Science and Arts. Conducted by Pro- ; fessors Silliman and Dana. Vol. IX., No. 25. 8vo.—By the Editors. — ‘Mémoires de Académie Impériale des Sciences de St Pétersbourg.- Sixiéme Série. Sciences Mathématiques, Physiques et Natur- elles. Tome VIII™e, .2me partie. Sciences Naturelles. _ Livraisons 3™°, 5™°, et 6™°. 4to. Mémoires présentés 4 l’Académie Impériale des Sciences de St ___- Pétersbourg, par divers Savants et lus dans ses Assemblées. Tome VI™. Livraisons 24 et 3™°. 4to.—By the Academy. [essungen zur Bestimmung des Héhenunterschiedes zurischen dem _ Schwarzen und Caspischen Meere, von G. Fuss, Sawitsch und Gabler. 4to.—By the Authors. Rapport fait al’ Académie Impériale des Sciences de St Pétersbourg, 2D 308 par W. Struve. Sur une Mission Scientifique dont il fut chargé en 1847, 4to.—By the Author. W. Struve sur la Delatation de la Glace d’aprés les expériences faites en 1845 et 1846 A l’Observatoire Central de Poulkova, par MM. Schumacher, Pohrt, et Moritz. 4to—By the Authors. Uber Prof. Midlers Untersuchungen iiber die Eigenen Beweyungen der Fixsterne, von C. A. F. Peters, Dr. 4to.—By the Author. P. H. Fuss Nachricht iiber eine Sammlung Unedirter Handschriften Leonhard Eulers, und iiber die Begonnene gesammtausgabe seiner Ueineren schriften. 8vo.—By the Author. Uber die Genanig-keit der in Lalandes Catalog, publicirt von der British Association, enthaltenen Sternérter, von Dr Lindhagen, 8vo.—By the Author. Verhandlungen der Schweizerischen Naturforschenden Gesellschaft bei ibrer Versammlung zu Slothurn. 1848. 8vo.—By the Society. Mittheilungen der Naturforschenden Gesellschaft in Bern, aus dem Jahre, 1848-9. Nos. 135-161. 8vo.—By the Society. The following Donations to the Library were announced at the Meeting of 4th March :— Transactions of the Cambridge Philosophical Society. Vol. VIII. 4to.—By the Society. The Astronom. Jour. Vol. I., Nos. 2,3, &4. 4to—By the Editor. Proceedings of the R. Ast. Soc. Vol. X., No. 3. 8v0.— By the Society. Proceedings of the Linnean Society of London. Nos. 30-40. 8vo. Charter and Bye-Laws of the Linnean Society. 1848. 8yo. List of the Linnean Society. 1849. 4to.—By the Society. Journal of Agriculture and Transactions of the Highland and Agri- cultural Soc. of Scotland. No. 28,N. 8. 8v0.—By the Society. Annales des Sciences Physiques et Naturelles, d’Agriculture et d’Industrie, publiées par la Société Nationale d’ Agriculture, &e.,de Lyon. Tom. II. 1848. 8vo.—By the Society. A Collection of Maritime Charts, with corresponding Descriptions. —By the French Government. 309 Monday, 18th March 1850. The Right Rev. BISHOP TERROT, V.P., in the Chair. The following Communications were read :— 1. Note regarding the American Electric-Observing Clocks. By Professor Piazzi Smyth. The object of this communication was chiefly to exhibit a speci- men of the register of the electric chronograph, wherein the second’s beats of two clocks were marked side by side, one going nearly to sidereal time, and the other to solar; and the length of a second’s interval on the paper was so great, and the accuracy of the punctua- tion such, that the minute acceleration of the one clock on the other could be registered almost from second to second. The electric register can be applied with ease to any clock, and at _ any distance from the recording apparatus ; and two or more clocks, or they may be simple pendulums, can be made to register their vibra- tions on the same slip of paper. The author pointed out how this method might be made available for determining the density of the earth, by observations on the shores of the Bay of Fundy, during the rise and fall of the enormous _ tides which occur there. He likewise mentioned several purposes to » which Lieutenant Maury, U.S.N., proposed to apply the electric chronograph ; amongst others, to determining the height of moun- _ tains, as he thought that the accuracy capable of being attained in determining the time of vibration of a pendulum in this manner, was _ so extreme, that the method might be safely applied to such problems. 1849. By Professor J. D. Forbes. _ On the evening of the 19th December 1849, whilst walking near q me - southern part of Edinburgh, about fifteen minutes past five. Greenwich time (as I afterwards estimated), I observed a meteor, brighter than Venus at her average brilliancy, moying from W. towards N., parallel to the horizon, elevated 15° above it, and 4 allowed by a distinct luminous train. This angle was subsequently 310 taken by estimation by daylight, with the aid of a theodolite; and the compass-bearing of the meteor, when first seen, ascertained in the same way, must have been 47° W. of N. When it bore 29° E. of magnetic north, it was observed to have divided into two, the one part following the other at some distance ; and I soon after lost sight of it in the obscurity of the smoke of the town. When it split, its altitude was estimated at 6°. It thus described an arc of no less than 76°, in doing which it occupied, as I roughly estimated, about 15 seconds, or possibly more. “‘ Having sent a short notice of the appearance of the meteor to the Courant newspaper, I received from many quarters accounts of its having been seen under circumstances remarkably similar to those just described. I believe that nearly forty communications on the subject have reached me from places included between Longford, in the centre of Ireland, to near Bervie, in Kincardineshire, a dis- tance of above 300 miles, in a direction nearly NE, and SW., whilst in a perpendicular direction, or from NW. to SE, the range of observation has been comparatively small ; for I have received no information from beyond Renfrew, in the one direction, and Durham in the other ; being about 140 miles distant in a straight line. The meteor was seen at Longford, in Ireland, 74 miles west of Dublin, but not in Dublin itself. It was seen at Belfast, between Carlisle and Gretna at Stewarton in Ayrshire, at Johnstone, at Paisley, - Renfrew, and by many persons in Glasgow and the neighbourhood. It was also generally seen in Edinburgh, in East Lothian, near Melrose, and at Durham, as already mentioned. Further north, I have received accounts from Crail, St Andrews, Dundee, Perth, and Johnshaven to the north of Montrose. “« The greater number of these communications concur in estimating the direction of the motion of the meteor to have been from SW. to NE., although, as might be expected, they vary excessively as to its distance and magnitude; being described by some persons as only 50 or 100 yards off, and as large as the moon; by others, as ‘a ball of 9 inches in diameter, or the size of a large egg. One per- son only professes to have heard a sound. The time during which it was seen was variously estimated. At Longford, by Mr Curtis, 20 sec.; at Glasgow, by Mr Stevenson, at 20 sec.; at Johnstone, by Mr Cunningham, 15 sec. ; at Perth, 15 or 20 sec.; at Durham, by Mr Carrington, 30 sec. ; at St Andrews, 15 seconds according to one 311 ‘observer, and 18 to 21 seconds according to another ; at Johnshayen, 3ths of a minute. The hour of the appearance of the meteor, in most of the descriptions, is stated at between dh, 10m., and 5h. 16m. “ The arc of the horizon which it was seen to traverse depended, of course, on the point where the meteor first caught the observer's eye. At Granton, it was traced by Professor Kelland through 125° of azimuth ; at Perth, 130; at St Andrew's, 74°; at Edin- burgh, 76°; at Durham, 65°; at Glasgow, from 60° to 70°. The _ division of the head or nucleus into several parts, and, first of all (in most cases), into two, has been noticed with remarkably slight varia- tion ; consequently, the explosion of the meteor marks a well-deter- mined point in its path. The separation was specially noticed at Edinburgh, Granton, Glasgow, Renfrew, Melrose, Haddington, Johns- haven, Perth, Durham, St Andrews, “In a majority of cases a luminous train was observed ; and Iam confident, that the existence of this train, which has been estimated at from 2° to 3° long, cannot be questioned. Dr Adamson, however, especially remarked that no train was to be seen at St Andrews. “On revising the whole accounts, it does not appear that any of them can be relied upon, for ascertaining the position of the meteor in space, except the observations of Mr Carrington of the Durham ob- - servatory ; of Professor Kelland, Mr Stirling, and myself, at Edin- burgh ; of Dr Adamson and another observer, communicated by Professor Fischer of St Andrew’s; of a young gentleman at Perth, communicated by Thomas Miller, Esq., Rector of the Perth Aca- _ demy ; and of A. D. Stevenson, Esq., and W. Gourlie, Esq., junior, at Glasgow. My inquiries were chiefly directed to the two follow- ing points: jirst, the angular elevation of the meteor in the NW. quarter of the heavens, where it is admitted by all that its peeth appeared almost horizontal; secondly, to the bearing of the aeteor at the instant of explosion. * “ At Durham, Mr Carrington saw the meteor first when the bear- ‘ing was true NW., the altitude (by theodolite) was then 10°, or not exceeding 11°; when it burst, it was due N, (true), and con- tinued to move 10° or 12° further before it disappear red. Professor mete por appear ed rather to rise as it approached the ety but with a doubt. This supposition, however, appears inadmissable, from the nanimity of the other accounts. 312 “ At Granton, near Edinburgh, Professor Kelland caught sight of the meteor a little to the N. of the moon, and several diameters below it. This corresponds, by after estimation with a theodolite, to 75° W. of magnetic N., and an altitude of 12°. Professor Kelland thinks that it rather rose afterwards. It split into two at 20° E. of magnetic N., having then an altitude of only 5°; it continued for a considerable time bright, then began to fade, as if by the effect of distance, and also to separate into several parts: it was finally lost sight of 50° E. of magnetic N, (this bearing is well ascertained), with an altitude estimated at only half a degree. The position and circumstances of these observations, made at an elevated station above the Frith of Forth, were eminently favourable. “Mr J. Stirling, civil engineer, looking up North Hanover Street, Edinburgh, saw the meteor separate into two parts; the bearing he afterwards estimated at 25° E. of magnetic N. (the probable error not exceeding 1°), and the altitude at 8° 30’, certainly not exceeding 9°. “T think we may conclude, that at Edinburgh the meteor attained a maximum elevation of 15° (that mentioned in the commencement of this paper), since it no doubt rose after Professor Kelland first saw it to the S. of the true W., with an altitude of only 12°. The course of the meteor was evidently such as to be nearest the specta- tor when in the true NW. or WNW. * The place of the meteor when it burst stands thus :— Kelland, N. 20° E. (mag.) Alt. 5°. Stirling, N. 9 or abe Alt. 8° 30’. Forbes, N. 29° E. Alt. 6% “ The average is almost 25° E. of N., or about 1° W. of the true meridian, the variation being nearly 26°. The mean of the three observations of altitude would be 6° 30’; but admitting Mr Stirling’s to be entitled to the greatest confidence, we may suppose it 7°, or possibly a little more. « At St Andrews, the meteor was seen by Dr Adamson, when riding in a northerly direction, on the Largo road, Professor Fischer was so kind as to accompany him afterwards to the spot, and to re- duce his observations with all the accuracy of which they were capable. It was first noticed when bearing 83° W. of magnetic N., and disappeared at 423° E. of N.; the altitude was conjecturally 313 stated as between 14° and 183°, and it appeared to move horizontally, but rather declining towards the N. “ After describing three-fourths of its course, it split into two parts, which went on close together for a little, then broke into four or five, became dull red, and rapidly disappeared ; the separate pieces travel- ling on together until the last. _ “ Another intelligent observer near St Andrews, whose evidence was taken by Mr Fischer, first saw the meteor 292° W. of magnetic N., and estimated the point where the meteor burst at 44° E. of N. ; but this last number coincides so closely with Dr Adamson’s estimate of the point of final disappearance, that it is perhaps allowable to suppose, that this second observer had mixed up these two events in his description. Dr Adamson’s statement, that one-fourth of the are which he saw was described after the meteor had split, would give an azimuth at that moment of almost 30° E. of N. magnetic, or 4° E. of N. true, as Mr Fischer determined the magnetic decli- nation to be about 25° 46’. The altitude of the meteor, as seen by this observer, appears not to have exceeded 15° (the same as at Edin- burgh) ; which number we shall therefore adopt. * At Perth, the passage of the meteor was seen from the North Inch, by a young gentleman of intelligence, whose observations were reduced to numbers by Mr Miller, Rector of the Perth Academy, who was so good as to accompany him to the spot, and take the angles with a theodolite. Its bearing, when first seen, was 46° S. of W. true ; its angular altitude was at that time only 3° 30’. This _ is by far the most southern azimuth which has been observed, Its _ bearing, when it disappeared, was 6° W. of N., but it was then lost inacloud. If I understand right, it had, by this time, separated _ into fragments. Its apparent altitude, in the middle of its course, q was about 17° 30’. These observations, extending over an are of 130°, taken along with Professor Kelland’s, clearly demonstrate that the meteor appeared with a very low altitude in the SW. quarter of the heavens, and disappeared in a similar way in the NNE., attain- _ ing its greatest elevation about WNW. (true.) _ * At Glasgow the meteor was very generally and well seen. Mr "William Gourlie junior saw it move from SW. to NNE., over an are of 60° or 70°, and divide into two, when it bore 40° E. of mag- netic N. He estimates its greatest elevation at 30°, and that it 314 decreased to between 15° and 17°, or even less, at the time of its separation. He adds, that he is not much accustomed to such ob- servations. Mr A. D. Stevenson, living in South Portland Street, Glasgow, saw the meteor moving along, at a height just sufficient to clear the chimney-tops, on the west side of the street, an elevation which he afterwards estimated, as he states, with considerable accu- racy at 28°. I have received farther and more minute accounts of the appearance of the meteor from Mr Stevenson, who has been most kind and intelligent in his communications ; and my friend Mr James Peddie has verified the accuracy of Mr Stevenson’s observations be- yond the possibility of mistake. It appears that the meteor passed quite clear of a stack of chimneys on the opposite side of the street, which would give it a well-defined minimum altitude of 25° 41’; but Mr Stevenson is of opinion that it rose more than 2° higher, or to not less than 28° (perhaps even to 28° 21’); when it was highest, its bearing was 523° W. of N. (magnetic), and it disappeared from his view when it bore 40° 27’ E. of magnetic N. It was then de- cidedly single. Now, this bearing coincides with that at which Mr Gourlie observed it to become double ; and, consequently, the limit towards the N. of this event is severely defined. ** The following Table contains the most definite of these observa- tions, and the azimuths are all reduced to the true meridian :-— True True True _ |Altitude Greatest | Azimuth | Azimuth | Arc ob-| Azimuth at Altitude. | when first | of disap- | served.| of first {first ex- seen. pearance. | explosion. |plosion. Durham, 10° 30 IN. 45° W./N. 12°E.| 57° |. N. [Ecbabores, | 15° \W. 11°S.IN. 24°E.} 125° | | St Andrews, 15° |N.55° WIN. 16°E.| 71° | N. 4° E. 17° 30’ |W. 47° S.|N. 7° W.| 130° 2 | Perth, J (in a cloud) . Glasgow, | 28° 100°? N. 14° a 15° | 315 Remarks on the Observations. ** 1. On the whole, these observations are not consistent, and can- not (I conceive) be cleared up without additional and accurate ones, _ which it may now be too late to procure. The central group of stations, Edinburgh, Perth, and St Andrews, are sufficiently accord- ant, and indicate that the path of the meteor must have been nearly parallel to a line passing through the first and last of those places, or in a direction N. 27° E. (true) ; which accords well with the ob- servations at most of the individual stations, and particularly with the vanishing direction in Professor Kelland’s remarkable observa- tion at Granton. «2. The Durham observation is compatible with the above-men- tioned group within the limits of error. By the combination of _ Durham and Edinburgh (the base line perpendicular to the assumed _ direction of the meteor’s motion being 95 miles), I calculated that _ the meteor passed vertically nearly over the Island of St Kilda, with an absolute elevation of about 88 miles. But this solution seems _ absolutely excluded by observations at Glasgow which admit of no question, and which I have spared no pains in verifying. Had the { position of the meteor been such as I have first assumed, it could not possibly have been seen over even the roofs of the houses from _ the station occupied by Mr Stevenson, much less over the chimney- tops. The bearing, at the moment of explosion at Glasgow, also singularly enough corroborates sufficiently well the comparatively small elevation (about 20 miles above the earth) which the combina- tion of Edinburgh and Glasgow gives; and this bearing we have seen to have been also accurately defined by the physical obstacles 1 bounding the observer's view ; it would have given a parallax of 15°, 3 subtended by the perpendicular on the meteor’s path, referred to asgow and Edinburgh respectively. Now, if this calculation were anything iike correct, the Perth observation is entirely wrong ; and _ the meteor could not have risen about 6° above the horizon of Dur- ham, instead of 10° or 11° as estimated. Iam unable, in any de- _ gree, to explain these conflicting results. ** 3. The observations of Professor Kelland at Granton, and those at Perth, through the great azimuths of 125° and 130°, described by the meteor with such remarkable deliberation of motion, lead, when analyzed, to the very same results which presented themselves to the ws os 316 mind of the spectator intuitively ; namely, that the motion must have been sensibly rectilinear, equable, and parallel to the horizon at Edinburgh. Assuming that the greatest altitude at Edinburgh was 15°, and the bearing then N. 63° W. (true), we may calculate that the altitude should have been on this hypothesis, when first seen by Professor Kelland, 11° 47’,—instead of 12° as observed; at explosion, 6° 59’ (7° observed), and at its final disappearance 0° 47’ (instead of 0° 30’ observed). Again, at Perth the observed altitude, when first seen, was 33°, and the calculated altitude 5° 3’, taking the maximum altitude at 173°. The coincidence is, on the whole, re- markable, though it, would be rash to push it to an extreme, as an error of some degrees may exist in the assumption of the direction of the meteor’s course. Some later observations, received from Mr Curtis at Longford, and a consideration of the effects of perspective at Perth and Edinburgh, incline me to admit that the path might make an angle 3° or 4° greater with the meridian than I have above supposed. These conclusions are independent of the actual distance or parallax of the meteor ; which, as I have said, cannot be deter- mined without further observations, which I should be glad to re- ceive from any quarter, but more particularly from Ireland, and from the centre and NW. of Scotland. If correct, they entitle us to infer that the meteor in question was most probably a body moving in space, in a path little curved, and not revolving round the earth.” 3. Notes on the Purification and Properties of Chloroform. By William Gregory, M.D., Professor of Chemistry in the University.* 1. Chloroform has been prepared both from alcohol and from wood-spirit. The latter has been used for the sake of cheapness ; but as it is a mixture of several liquids, all of which do not yield chloroform, it gives an impure product, in a proportion which varies much, but is always below that obtained from alcohol. There is * Although I am alone responsible for the opinions contained in this paper, it is my duty to state, that all the experiments and observations mentioned in it have been made by me in concert with my able assistant, Mr Alexander Kemp, of whose ingenuity and accuracy I have had constant opportunities of judging. 317 therefore not only no advantage, but the contrary, in using wood- spirit, which is not, after all, much cheaper than alcohol. 2. But the chloroform from these two liquids, when fully purified, is quite identical in all its properties. Its smell, density, boiling point, and action on the system are, in both cases, exactly the same. That from alcohol is, no doubt, more easily purified than the other ; but it also contains volatile oily impurities, which must be removed before it can be safely used. The peculiar oils which adhere to both kinds of chloroform are not identical, or, at least, not all identical ; but they are of analagous constitution and properties. 8. Soubeiran and Mialhe have examined these oils. They con- tain chlorine, have a disagreeable smell, and, when inspired or smelt, eause distressing headache and sickness. In the case of wood-spirit, some of its own impurities distil over unchanged, and are found in the chloroform. 4. It is well known that many persons, after the use of chloro- form, have suffered from headache, nausea, and even vomiting, as I have more than once seen, Headache and nausea I have myself experienced, when I have tried different specimens of chloroform, without taking so much as to produce the full effect. _ 5. Perfectly pure chloroform, such as is now on the table, does not, so far as I have seen or experienced, produce these disagreeable effects. It is, therefore, highly probable that when they occur, as they do with some individuals, from the use of chloroform of more than the average goodness of quality, this depends on the presence of a trace of these poisonous oils. 6. All good manufacturers of chloroform purify it by the action _ of oil of vitriol; which destroys the oils, while, at the same time, a part of the acid is reduced to sulphurous acid. The chloroform, to _ remove this, is then distilled with lime or carbonate of baryta, and __ is tolerably pure, if the process be well conducted. 7. But this is not quite pure, and contains a trace, more or less distinct, of the oils. I have found this to be the case with all the best chloroform made here, up to 1849; and I have several times seen headache and sickness from the use of such chloroform, which, as we all know, was the best anywhere made. I must add, however, - that the quantity of oils was, although variable within certain limits, always, in the Edinburgh-made chloroform, so small, that it was fit for use, and only caused headache, &c., in a few peculiarlysensitive persons. 318 8. It was desirable to have a test for these impurities, as well as an easy and effectual mode of removing the last traces of them ; especially as many sorts of chloroform, not made here, were far in- ferior in quality to that prepared in Edinburgh. One very déli- cate test is, that oil of vitriol, which should be quite colourless and pure (as it may be rendered by Mr Kemp’s process, lately read to the Society), when agitated with the chloroform, becomes yellow or brown, from its action on the oils, which it chars and destroys. Any change of colour is easily seen by the contrast with the colourless chloroform which floats above. Pure chloroform gives no colour to the acid. It is essential that the oil of vitriol be colourless, and also of full density ; for, if coloured, it is not easy to see a slight change in its colour; and if below the proper density, that is, too weak, it is not much coloured by a chloroform which will render brown the acid of proper strength. 9. Another test, still more delicate, I find to be the smell of the oils. When chloroform is poured on the hand or a handkerchief it rapidly evaporates; but the oils, being less volatile, are left behind, and their smell, previously covered by that of the chloroform, is easily recognised. Until very lately, no chloroform was sold, or, indeed, known, which would stand this test, or even the former. 10. Up to 1849, the best commercial chloroform had a specific gravity of 1-480, which was considered a guarantee of its purity. But it had been obtained, by chemists, of specific gravity 1-494 and even 1:497. I have found that chloroform of 1-480, when once more acted on by oil of vitriol, which destroys the oils and becomes brown, may be obtained, after removing the sulphurous acid, of spe- cific gravity 1-500 at 60°. This I take to be the specific gravity of pure chloroform. Our best makers have lately, much to their credit, pushed the purification so far as to furnish chloroform even of this highest density, and also, in other respects, such as it ought to be. 11. There are still, however, many makers, in other places, whose chloroform is not so pure; and I shall now describe the method which, with Mr Kemp, I have employed for purifying, per- fectly and easily, any commercial chloroform (except one remarkable specimen, of which more hereafter), a process which will enable any medical man to purify it for himself with the greatest facility. 12. The chloroform, having been tested as above, and found more 319 or less impure, is to be agitated with oil of vitriol (half its own volume will be sufficient), and allowed to remain in contact with the acid ; of course in a clean, dry, stoppered bottle, and with occasional agitation, till the acid no longer becomes darker in colour. As long as the action is incomplete there will be seen, after rest at the line of contact, a darker ring. When this no longer appears, the chlo- roform may be drawn off, and, for greater security, once more acted on by a quarter of its volume of the acid, which should now remain colourless. It is now to be once more drawn off, and, in a dry -stoppered bottle, mixed with a little powdered peroxide of manganese, with which it is gently agitated and left in contact, until the odour of sulphurous acid is entirely destroyed, and the chloroform has acquired a mild agreeable fruity smell. It has then only to be poured off into a proper phial. It will now leave no disagreeable smell when evaporated on the hand. (If the commercial chloro- form, after having been frequently well shaken, and left for some time in contact with the acid, has given only a moderate tinge of colour to it, it is probable that it may be completely purified by that first process. To ascertain this, test a small portion in a tube with fresh acid, shaking well, and allowing it to stand some time. If it do not colour the acid at all, then the whole chloroform has only to be finally purified by the oxide of manganese. If the acid become coloured in the test tube, it will be as well to act on the whole chlo- ‘roform a second time with fresh acid, till it stands the test. Mr Kemp has observed, in repeating this process for me, the very curious fact that, as soon as the action is complete and the oily im- purities are destroyed, but not sooner, the chloroform tested with the acid in a tube exhibits a strongly convex surface downwards, where it rests on the pure acid, or, what is the same thing, the acid becomes concave at its upper surface. The smallest trace of impurity, not sufficient to affect the density of the chloroform, we have found to _render the line of junction horizontal. It is probable that this may become a valuable test of the perfect purity of chloroform, but we shall not say more on this subject until we have thoroughly examined it.) _ This process requires no apparatus beyond a few stoppered bottles, P and a syphon, or a pipette, if we wish to draw off the whole chloro- e form without loss. The use of the oxide of manganese is due to Mr Kemp; and, on the large scale, the chloroform may be filtered 320 through a cylinder full of it. In this final purification of genuine, although not quite pure chloroform, no distillation is necessary. 13, It may be considered as certain, that the use of chloroform, thus purified, will very rarely, if ever, cause the disagreeable effects above noticed.* As to more serious bad results from the use of chloroform, so often spoken of elsewhere, it is enough to state, that a large proportion of the cases must be attributed to the use of a liquid so impure, as hardly to deserve the name of chloroform at all. Such a product, I rejoice to say, our Edinburgh manufacturers have never sold; and, I may add, that, no doubt chiefly in consequence of this, our practitioners have not yet seen a fatal result from the use of chloroform. But in London, and elsewhere, chloroform has been extensively sold, so bad, that I have examined specimens which did not contain half of their bulk of chloroform ; others with not one third or one fourth ; and I have seen one which hardly contained any at all. But, to make up for this, they were rich in poisonous oils, and * Dr Simpson informs me, that the purest chloroform he has used not unfre- quently causes vomiting. On further inquiry I find that this occurs when itis administered after a full meal. This can easily be avoided, and must not be confounded with the headaches, nausea, and vomiting alluded toin §§ 4 and 5; which symptoms are persistent, and occurred, in my experiments, always with an empty stomach, the experiments being made an hour or two before dinner. Dr Carmichael, assistant to Dr Simpson, has mentioned to me some facts which confirm the view I have taken. At one period, for more than a week, Dr Simpson and Dr Carmichael were kept in a state of continual anxiety by the occurrence, in all the puerperal cases in which chloroform was used, of very unpleasant symptoms, particularly of frequent pulse and other febrile symp- toms, lasting for some days. At last, after much annoyance from this cause, it occurred to Dr Simpson that he was using one particular speci- men of chloroform, supposed to be of good quality. As soon as this idea occurred, he threw away all that remained, and returned to that which he had generally used. The unpleasant symptoms no longer appeared. (I regret much that I had not an opportunity of examining that specimen; but I may add that the maker, not an Edinburgh one, now produces chloroform of much better quality, though not yet absolutely pure.) But the striking fact is this, that Dr Simpson and Dr Carmichael state, that during the period above alluded to, when that one kind of chloroform alone was used by them, their handkerchiefs became quite offensive from the smell left on them, which even adhered to them after washing. There can, I think, be no doubt that here the oily impurities alluded to in $§ 4 and 5 were present in notable quantity. I suspect that a majority of the specimens mentioned in the Table would have a similar effect, more or less marked. (I have since ascertained that this chloroform, which was much above the average in quality, had not been subjected to the action of oil of vitriol in ats preparation, which strongly confirms the view I have taken. W. G.) 321 often in free hydrochloric acid. Very many specimens, although better than this, are yet so impure, that no one could, with comfort or safety, use them, 14. The chloroform now, and for some time past, made here, is of first-rate quality. I have two specimens which are absolutely pure, or nearly so; and a third, which is hardly inferior, all made and sold by Edinburgh manufacturers. 15. On the other hand, I have various specimens, maker un- known, besides some from makers in other places, which are not so pure, although, in general, much purer than those which I examined nearly three years ago. But one specimen deserves a separate notice, It is labelled “pure chloroform.’ It is yellowish, has a strong smell of the oils, and of impure wood-spirit ; and, when treated with its own volume of oil of vitriol, developes much heat, colours the acid dark brown, and disappears almost entirely, any trace of chloroform it may contain being boiled off by the heat disengaged. It contains also so much free acid, that the cork is corroded. It is to be hoped that this product disgraces no longer the market. I do not know the name of its maker. Three of the specimens became milky, when mixed with the acid, One, after contact with the acid, acquired a strong smell of musk. Another lost about a third of its bulk, All __ but two coloured the acid decidedly at once; and all left, more or less, _ adisagreeable smell on the hand. One of the two which did not _ much colour the acid at first was that which acquired the smell of _ musk; the other, evaporated on the hand, left a white stain, depend- ing partly on the matters present in the skin. This was the case also with another; yet these two coloured the acid but little at first, - more strongly after a time: but both left a smell on the hand. _ Only one (Edinburgh made) specimen, of density 1-500, gaye no _ colour, or only a perceptible tinge, to the acid. 16. In conclusion, I would remark, that while the use of chlo- roform in Edinburgh, in many thousand cases, has never yet led to a _ fatal result, I do not intend to maintain that the use of pure chlo- _ roform never can cause fatal effects. On the contrary, I haye no _ doubt that, if rashly, carelessly, or ignorantly administered, so _ powerful an agent may, like any other powerful drug, especially in’ _ individuals of peculiar temperament, and in cases of severe, though latent internal disease, give rise to fatal results. That no such cases have here been met with is due partly to the good quality of the 322 chloroform used, and to the care with which it is prepared ; and partly to the experience and judicious management of those whose duty it is to administer it, at the head of whom stands the introducer of chloroform, my friend and colleague, Dr Simpson. It is much to be regretted that, in London and elsewhere, chloro- form is not by any means so extensively employed as it ought to be, in consequence of the occurrence of some fatal cases, attributed (whether in all cases accurately or not, is a question) to the drug. There can be no doubt that most, if not all, of these cases have resulted from the use of very impure chloroform, such as even at a recent period was largely sold in London; and that, if pure chloro- form alone had been employed, there would, by this time, have been no prejudice against its use. It is not, as I have shewn, necessary that chloroform should be very impure, in order to produce very disagreeable or even dangerous results. It is evident that even a small proportion of the oils above mentioned, if they are deleterious (and this cannot, I think, be doubted), will suffice, when applied in the form of vapour to the internal surface of the lungs, to act powerfully on the system. On the other hand, I am far from blaming those chemists who have manufactured impure chloroform for anything more than a want of due care in the preparation of an agent so energetic. And it is but fair to bear in mind that it was a new manufacture, hardly yet fully understood, and that those who made it were not probably aware, either of the existence of the im- purities, or of the best mode of removing them. I have no doubt they did their best to produce a good article; and my chief object in this paper has been to put it in the power of every one to do so, and to point out strongly the bad effects of even a small amount of impurity. While I acquit the makers of impure chloroform of any desire to adulterate it, I think it right to add that some of them must have been entirely ignorant of what was published concerning its proper- ties. Thus some sold it of specific gravity 1-465, others of 1°347; and in the case of No. 8, which I have no doubt was under 1-000, although I had not enough to take its density accurately, the maker had evidently rejected the chloroform, and preserved the lighter liquid floating over it!—not knowing even that chloroform was a heavy liquid. It is lamentable to think that persons so ignorant are free, by our laws, to set up as makers of the most potent drugs. —a1 323 I may here add, that no rectification at all is required from the — first, if the chloroform be only washed with water till its volume no longer diminishes, and then treated, as above, with concentrated sul- phuric acid. It is possible that some of the fatal cases may have occurred from an injudicious mode of administering the vapour, or from the opera- tor intrusting the administration to persons not qualified to recegnise those signs which tell the experienced practitioner that it is time to stop. There ought always to be two well-qualified persons present, —one to watch, without intermission, the effects of the vapour, which he also administers as required; the other, of course, to ope- rate. He who gives the chloroform must carefully attend to the state of the respiration, as has been often recommended by Dr Simpson. But these are matters beyond the proper province of this paper, and I leave them them to those who are better qualified than I am to discuss them. I have only to add, that this paper was written and read before I heard of a recent article in ‘‘ Chambers’ Journal” on the subject ; and that I had not the remotest knowledge of or concern in that article, which I have not yet seen, although, as I am told, the author of it agrees with some of my conclusions in regard to the em- _ ployment of chloroform in London. A tabular view of the properties of chloroform will be found on _ the following page. VOL. II. oR 324 “poy -jand aq 03 oamnbad os0y9 Jo [[@ yng ‘ose «vad ou uoao 10 ‘savak oM4 OAnd O}INb polled ueeq GAvIL TI® PINOA ‘TT pur *y ‘9 ‘¢ ‘g "SON 8B T[OA Sv ‘SITLL, *S101]}0 [B19A08 wry} 19990q ynq fosn soy oand ATQUOTOWFNS JON “prov OY} UO SuIJsea MOY ‘SpAVAUAMOP oORJANS X9A M00 OY} JIQIYXO Jou pIp sty} UeAe yng “pored -o1d yjosdut OAVY T[ ULAOJoAOTYO ysoand oyy wMo.ly poysinsuysrp oq ATpavy uvo 47 “ApIsuoep TINT ‘oand oj1nb padopued oq ApIsvo 4ySrur 41 yYSnoygye fosn Arvurpas0 Loy 4y ayy ‘eand Ajavou Ar0A pur ‘Aqtsuop [DJ OUT “sno10d -uvp JSOUr 0q pies. osn og, ‘uorsodoad of.xe] ut ‘s[10 snouostod oY} SB T[OA SB “plow OTAOTYIoapAT, 901] TONU pourezUoo pur ‘eouRzsqns FVy} JO [[OULS ay} UOAO JOU PLY FY “MAOJOLOTYO JO YIOLAITy -9U0 UL} etOM UTe}UOD You prIp ATUTeIA09 SIYT, “SIT OF LOTMOJUT SOAOIT -0q J ‘Jou svai ‘zg “d ‘ajou oT} Ul PouorzUEUT WIIO} -O10T9 OY, "9 PUL G*SON ULTA 109}90q LOTTZRY "GON SB ATIVON -oand you ynq ‘Aq17enb e[qex9[03 JO “Loyeur ours oyy ATquqoad { Z*ON Surpquiosey *aind jou qo& gnq *Z 10 [ ‘SON ULTy 19930q YORU si SILT, ‘osn 0} oyesun A1OA 0 PINOM YOY “TON wey} orndurt ssoy yng ‘MOT 00} Ivy Os[V AQIsuE(T ‘ost OF sno -desuep A19A ‘OUNTOA Ss} JO YJANOJ-9Ul0 Oo YIU -9U0 480] JT “prow oy} YATA gowguoo uy “Aqtandunt | 9vea3 oy} seAoad oou0 ye or0y AQISUOP ACT OTL, “SHUVNGY TVYUINIH *[[OUIS FSIS Jaq JoursT *]IOWS JOUTISICT ‘Tews o[qrydooaod ysu *[[9uUs FOUTBSTT *[[ours e1qQe -90.L9eSIp PUB Fu0ajs AOA B WOT *TTows FOUTISIC *]Tours gourqsrp Ao A *[JouLs JouTISIC *L ‘ON SB OWES OUT, *[[ouls gourgsrp Aaoa v JOT ‘TON 8t ommes OY, *[]OWS SUOIJs B JOT ‘UAMOIG Yep ‘Buryeys quonbowy pure ‘ourry OULOs LOY f4say 4v poanojoos APYSIS *G “ON SV ‘PON 88 ‘OULT] B 109jv UAOIG YIUp oureo9g ‘osuvyo FY Sts A190 A *UMOLG, YAlep spavadeqye ‘mozjok oyed AioaA omMBoog *pOSN [OMIA JO [0 OYY UI PEATOSSIp 71 JO afoy AN aya Ajtvayy "yoy A104 pu ‘UMOIG Yep OULD *UMOAG Yep oujuood sqnoy FZ puv suryeys quonbea a0qye f4say 4e podojaaep «nooo o1491T *sanoy Fz 10qjv UAOAG $ aUINTOA UT YOnUET YsturMarp you prp ynq ‘MoT[ed ATIYSI[s oMvIEg *SInOY FZ Lye aoyiep foumpoa ur 447 S17s A[UO poystulwrp ynq ‘UMOIG SpIvALOYe pure ‘Mo[jed AY[IUL oULROOg “uMoIg Yep ATOA ‘sanoy FZ 1oqye ¢ MOTTAA uy pur AY][TUL OULROAg *ysnur jo [19Ws JouNSTp V poambow ose at ‘yarep Ar8eA oy OULOS LOR § ISI YL OANAXTUL UO ‘poqoaye A[OO.TBOg a AdOA ouloveg pry JI ‘sinoy Fz 1093v f Yon os A[Lvou YSt -UTWUTp JOU pIp Ft 3Vyy 9dooxe ‘T ‘ON Sv OWNS OTL, ‘oUIN[OA UT poysIurutp osTe 41 fuAModq yrep Ar9A ‘sanoy Anoj-44u9KN9 109 V ‘uAOIg Of Sulsuvyo ‘MoT]oA pue AY]IOr auTRONg *puvy uo poyerodvae uot Ay ‘ploy o1mnydyng pozvayuoou0g Jo uoloy 006-1 008-1 S6F-L O6F-L CFT CLET C6FL SOFT LET “009 18 Ayawiy oyroads GI “ON TT ‘ON OT ‘ON 8 “ON L ‘ON ON o g ‘ON % ON € ‘ON & “ON Ld “m0JOLO[ YD 30 Ajorie A “msofosopyy Jo saywadoug aya fo mag mynqny 325 The following Donations to the Library were announced : Some Account of the last Yellow Fever Epidemic of British Guiana. By Daniel Blair, M.D. Edited by John Davy, M.D., F.R.S.L. &E. 8vo.— By the Author. Das peripherische Nervensystem der Fische, Anatomisch und Phy- siologisch untersucht von Dr Hermann Stannius. 4to.—By the _ Author. _ Neue Denkschriften der Allg. Schweizerischen Gesellschaft fiir die gesamimten naturwissenschaften. Bd. x., mit. xiii. Tafeln. 4to. —By the Society. On the Diffusion of Liquids. By Thomas Graham, Esq., F.R.S., F.C.P. 4to.— By the Author. ‘ Description of the Instruments and Process used in the Photogra- phic Self-registration of the Magnetical and Meteorological In- struments at the Royal Observatory, Greenwich. 4to.—By the _ Astronomer-Royal. Proceedings of the Royal Astronomical Society. Vol. X., No. 4. 8vo.— By the Society. 4 Description of the Observatory at Cambridge, Massachusetts. By William Cranch Bond. 4to. _ Astronomical Observations made at Cambridge Observatory, Massa- chusetts, 1847-8. 8vo.— By the Observatory. Monday, 1st April, 1850. Gen. Sir T. MAKDOUGALL BRISBANE, Bart., in the Chair. 4. On a Peruvian Musical Instrument, like the ancient 4 Syrinx. By Dr Traill. The author prefaced his description of the instrument, by a few general remarks on the communication, in very remote epochs, be- ween the inhabitants of the old and new worlds, as deducible from ties in their traditions, their cosmogenies, their religious rites and structures, their astronomical cycles, and their determination of the length of the year. 326 The Peruvian instrument was discovered, some years ago, in a huaco, or vast tumulus, that was believed to cover the remains of an Inca of Peru. It is not of unequal reeds, like the Greek syrinx, but is cut out of a piece of potstone, of a trapezoidal form, in which are cut eight tubular holes of unequal depths. These tubes or holes are of equal diameter, and have been carefully made with some sort of drill. The breadth of the instrument, including a short handle, is 6-2 inches ; its greatest depth, 53 inches; and the thickness of the stone varies from 0-7 to 0-5 inch. The instrument in principle and in form is analogous to the Pan’s pipe of antiquity, or to the organetto of modern Italy ; but has one remarkable difference in a small ventilage on each of four of its pipes; when one is uncovered, that pipe is mute, but when covered by the fingers of the player, the full sound is produced. A strolling Italian, who performed well on the organetto, was employed for several evenings to play on the Peruvian instrument ; and, with the assistance of three skilful musical friends, one of whom was an adept on the violoncello, the author of the paper was enabled to ascertain the scale of the instrument. This scale extended from E on the lower line, through I sharp, G, A, D, C sharp, F to A, above the lines. By means of the ventilages, the ordinary notes of the instrument seemed to be divisable into two tetrachords,—one in the key of E minor, the other of F major—the first a perfect te- trachord ; the second, nearly so. The form of the instrument and its use have a striking similarity to the Syrinx of the Greeks, the invention of which was ascribed to the god Pan, or to Egypt; and it is worthy of notice, that the great musical system of the Greeks also consisted of tetrachords. A syrinx of unequal reeds was found by the celebrated Humboldt, in the hands of the natives, on the banks of the Orinoceco. It is in use among the Arabs of the desert, and a similar instrument, composed of twelve unequal reeds, is figured by Kempfer among the instru- ments of the Japanese. 2. Some Remarks on Cometary Physics. By Professor Piazzi Smyth. That theories of the physical appearances of comets have generally failed, appeared to the author to arise from the facts having been mis- understood or misinterpreted in general by the observers themselves. 327 Asa particular instance of this, the wide-spread notion of comets shooting forth their tails, at, or a little before the perihelion passage, and drawing them in again afterwards, so as to be larger at that period of their orbits than at any other, was mentioned; and in place of which, the author shewed that the comets were at the perihelion, of their smallest size; the tails becoming then more visible, not from being actually produced at that time, but from being more dense, and illumined by a stronger solar light, as well as being in general seen from a smaller terrestrial distance. The author then proceeded to collect together the facts which he thought well made out with regard to comets ; to describe the cor- rections which the apparent, required, to give the true phenomena ; and to detail the various practical methods by which better observa- tions might be procured. The so-called established facts mentioned above, were collected in _ aseries of axioms, which are here appended; as they seem to be : worthy of being discussed, and either disproved or assented to, by astronomers. Ist, A comet consists of a nucleus, and one or more gaseous en- velopes, 2d, The nucleus, if solid and material, is infinitely small. _ 3d, The nucleus is excentrically situated in the gaseous body. 4th, Comets of longest period have the largest bodies. __ 5th, Those comets whose orbits have the greatest excentricity, are _ the most excentrically situated in their envelopes, or, vulgarly, have _ the longest tails. 6th, A comet revolves on an axis passing through the nucleus, _ and at right angles to the major axis of the envelope, in the same _ period of time that it takes to revolve about the sun; hence the tail _ being turned away from the sun in the normal position, is turned away from him in all other parts of the orbit also. _ 7th, This axis is not at right angles to the plane of the orbit, but variously inclined in the case of different comets, as with the planets. 4 _ 8th, A quicker rotation round the longer axis of the body also appears to exist. _ 9th, A comet shines by reflected light, and shews a sensible 10¢h, The gaseous envelope is of extreme tenuity, is elastic, and, 328 with regard to light, is slightly reflective and imperfectly transpa- rent ; it decreases in size, but increases in density and light reflee- tive power in approaching the perihelion, and the reverse when re- ceding from it ; and this occurs in a degree proportioned to the ex- centricity of the orbits of the comets. 11¢h, The axis of the tail of a comet is straight at the perihelion, . but at any point between this and the aphelion, is curved; and is concave towards the latter, the radius of curvature being inversely as the excentricity of the orbit. 12th, The molecules composing the envelope of a comet are only held together by their mutual gravitation, each constituting almost a separate independent projectile, and describing its own parabola about the sun. 3. Abstract of Professor Kelland’s Exposition of the Views of D. R. Hay, Esq., on Symmetric Proportion. The fundamental hypothesis of the author was stated to be this :— That the eye is capable of appreciating the exact subdivision of spaces, just as the ear is capable of appreciating the exact subdivi- sions of intervals of time ; so that the division of space into an exact number of equal parts will affect the eye agreeably in the same way that the division of the time of vibration in music, into an exact num- ber of equal parts, agreeably affects the ear. But the question now arises, What spaces does the eye most readily divide? It was stated that the author supposes those spaces to be angles, not lines; believ- ing that the eye is more affected by direction than by distance. The basis of his theory, accordingly, is, that bodies are agreeable to the eye, so far as symmetry is concerned, whenever the principal angles are exact submultiples of some common fundamental angle. Accord- ing to this theory we should expect to find, that spaces, in which the prominent lines are horizontal and vertical lines, will be agreeable to the eye, when all the principal parallelograms fulfil the condition that the diagonals make with the sides, angles which are exact sub- multiples of one or of a few right angles. This application of the theory was exemplified by a sketch of the new Corn Exchange erected in the Grassmarket by David Cousin Esq., whose beautiful design was shewn to have been constructed with a special reference to the fulfil- ment of this condition. The author was stated to proceed to apply his theory to the con- 329 struction of the human figure, in which we should expect @ priori to find the most perfect development of symmetric beauty. Diagrams were exhibited which represent, with remarkable accuracy, the human figure ; and it was explained that not a single lineal measure is employed in their construction. The line which shall represent the height of the figure being once assumed, every other line is deter- mined by means of angles alone. For the female figure, those angles are, one-half, one-third, one-fourth, one-fifth, one-sixth, one-seventh, and one-eighth of a right angle, and no others. It must be evident, therefore, that, admitting the supposition that the eye appreciates and approves of the equal division of the space about a point, this figure is the most perfect which can be conceived. Every line makes with every other line a good angle. The male figure was stated to be constructed upon the female figure by altering most of the angles in the proportion of 9:8; the proportion which the ordinary untem- pered flat seventh bears to the tonic, A drawing was exhibited, which had been designed with great care from the life, by the distinguished academician John A. Houston, Esq. On this drawing the author had constructed his diagrams; and the coincidence of theory with fact was seen to be complete. Professor Kelland concluded by claiming for the author the attention of the Society. He argued, that a principle so simple and comprehensive in its character, and thus far apparently truthful in the conclusions to which it leads, merits, and should receive, the most complete and rigid examination. Whatever might be the ultimate result (and it promised to be satisfactory in the extreme), the ingenuity, energy, and zeal, shewn by the author, entitle him to our warm approba- tion, The following Donations to the Library were announced : _ Magnetical and Meteorological Observations made at the Royal Ob- _ servatory, Greenwich, 1847. 4to.—From the Observatory. Journal of the Statistical Society of London. Vol. XIII., Part 1, 8vo.— By the Society. Deuxiéme Mémoire sur le Daltonisme, ou la Dyschromatopsie, par E. Wartmann. 4to.—By the Author. _ The Accommodation of the Eye to Distances. By William Clay Wallace, M.D. 8vo.—By the Author. 330 Transactions of the Zoological Soc. of Lond. Vol. III., Pts. 5 & 6. 4to. Proceedings of Do. Parts 15 & 16. —8vo. Reports of Council of Do. 1849. 8vo.—By the Society. Monday 15th Aprit. Rev. Dr GORDON in the Chair. The following Communications were read :— 1. On the Constitution of Codeine, and its Products of De- composition. By Thomas Anderson, M.D. The author commenced his paper by referring to the analysis of codeine made by different chemists. On these analyses four different formule had been founded; but two only, those of Regnault and of Gerhardt, required special mention, the others being now known certainly not to represent the constitution of the base. Regnault had deduced from his analysis the formula C,, H,, NO,, while Gerhardt gives C,, H,, NO, as the expression of his results. The author submitted codeine to careful analysis, and obtained the following results :— Calculation. Carbon, 71:91 72°02 72°09 72:09 72°24 Hydrogen, 7°05 7°04 7:14 7:16 7°02 Nitrogen, 4°41 4°60 4°50 eas 4:68 Oxygen, 1663 1634 16:27 ad3 16°06 100700 100°00 100°00 100°00 agreeing closely with the formula C,, H,, NO,, and confirmed by the analysis of its platinum salt, which contains an equivalent of water, and gave, as the mean of seven experiments, 19-25 per cent. of platinum, while the calculated quantity is 19-19 per cent. The author then describes in detail the properties and constitution of its salts. The hydrochlorate crystallizes in groups of short radiated needles, the formula of which is C,, H,, NO, HCl +4 HO. The hydriodate is obtained in long needles, which, dried at 212°, retain two equivalents of water, and have the formula C,, H,, NO, HI+2HO. The sulphate, nitrate, phosphate, oxalate, hy- drosulphocyanate, and platinochloride are also described. ia — os «CO a 331 The author then proceeds to the consideration of the products of decomposition of codeine. When treated with strong sulphuric acid, codeine passes into an amorphous condition, similar to that in which quinine is obtained when treated with an excess of acid, and in which state it forms resinous compounds with acids. With dilute nitric acid it gives a new base, nitrocodeine, the for- mula of which is C,, H,, (NO,) NO,, which is precipitated from its solution by ammonia, in minute silvery crystals, sparingly soluble in water, but dissolving readily in alcohol and ether; and erystallising on cooling in small yellowish needles. It dissolves readily in acids, with the formation of salts, which have a more or less yellow colour; and all crystallize except the hydrochlorate. Of _ these the hydrochlorate, sulphate, oxalate, and platinochloride are described. By the action of bromine, two different bases are obtained—bro- mocodeine and tribromocodeine. The first of these is prepared by adding bromine water to powdered codeine until it is dissolved, and _ then precipitating with ammonia, when the base is thrown down as a crystalline powder, which is obtained in needles by solution in boiling water or alcohol. Its formula in the crystallized state is _C,, H,, Bre NO,+3 HO. Its salts are similar, in most of their _ properties, to those of codeine, and all crystallize in small needles. _ By the further action of bromine, a yellow powder, sparingly soluble _ in water, is obtained, which is the hydrobromate of tribromocodeine, and from which the base is obtained by solution in hydrochloric acid, and the addition of ammonia. Tribromocodeine is a gray powder, “insoluble i in water and ether, but soluble in alcohol; it is an ex- : tremely feeble base, but dissolves in acids and as salts, all of which are sparingly soluble in water and amorphous. Its formula is C,, H,, Br, NO;. _ The author fond that chlorine, by acting upon codeine, gave rise to amorphous compounds, which were not obtained of definite con- stitution ; but by the use of a mixture of chlorate of potash and ny Brochlorio acid he obtained chlorocodeine, C,, H,, Cl NO,, similar in its general properties and constitution to irontosedia. and resembling that substance so closely that it may be easily mis- vken for it. _ By the action of cyanogen another base was obtained. This 332 substance is best prepared by passing cyanogen into codeine dissolved in the smallest possible quantity of alcohol. The gas is rapidly absorbed, and there is deposited from the solution a mass of crystals which, when dissolved in alcohol, are obtained in six-sided plates, with a fine silvery lustre. These crystals gave to analysis the fol- lowing results :— Carbon, 68°22 68°04 Hydrogen, 5°93 6:17 Nitrogen, 11°81 11°50 Oxygen, 14-04 14:27 and the author attributes to them the formula C,, H,, NO, 2C,N, and gives to the substance the name of bicyanocodeine. It is a base ; but owing to its extreme instability, no salts could be obtained. When treated with an acid it is rapidly decomposed, ammonia being formed, and, after a time, hydrocyanic acid evolved. By treating codeine with a mixture of potash and lime, at a tem- perature of 250° Fahr., it undergoes slow decomposition, and a vola- tile base is evolved, which differs according to the circumstances of the experiment. The author found that, under certain cireumstances, the base evolved had the formula C, H, N, and forms the term in the series of bases homologous with ammonia, which corresponds to metacetonic acid, and which may be called metacetamine. Under other circumstances the base evolved had the formula C, H, N, and corresponded, in all its properties, with the methylamine of Wurtz. The following is a tabular view of the constitutions of the sub- stances described in this paper :— Codeine, . : es ape crystallised, . C,,H,, NO, +2 HO. Hydrochlorate, . . C,, H,, NO, HCI+4 HO. Hydriodate, : :, Oy. Hos INO, Wars EnUr Sulphate, . . . C,, H,, NO, HO SO, + 5 HO. Nitrate, . é ; ea H,, NO, HO NO,. Phosphate, : HE Tae HO) 2HO PO, +3 HO. Oxalate, . : . C,H, NO, HOC, 0,+3 HO. Hydrosulphocyanate, C,, H,, NO, HC, NS, + HO. saat salt dried at 2 C,, H,, NO, HCl Pt Cl, + HO. crystallised, . O©,,H,, NO, HCl Pt Cl, +3 HO. Ee ian. 2 ane aie = 333 Amorphous codeine, . C,,H,, NO,. Nitrocodeine, . bt Ose H,, (NO,) NO,. Sulphate, . €,, H,, (NO,) NO, HO SO,. Platinum salt, . O,. 8,5 (NO,) N 0, HCl Pt Cl, +4 HO. Bromocodeine, . 5! ge Hey Be NOe hydrate, . . C,,H,, Br NO, + HO. terhydrate, . C,,H,, Br NO,+3 HO. Hydrobromate, . . C,,H,, Br NO, HBr+2 HO. Platinum salt, . . C,,H,, Br NO, HCl Pt Cl,. Tribromocodeine, 1) Gagittyy Fitg tees Hydrobromate, . . 2(C,,H,, Br, NO,) 3 HBr. Platinum salt, . . C,,H,, Br, NO, HCl Pt Cl,. Chlorocodeine, . «* Cog Hag Gl NO,. terhydrate, . C,,H,, CLNO,+3 Ho. Sulphate, . : . C,, H,, C1NO, HO SO, +4 HO. Platinum salt, . . C,,H,, CLNO, HCl Pt Cl,. Bicyanocodeine, . 1 Cy, Hy, NO,'2-C, N. Metacetamine, . Pug EN 2. On the Physical and Scottish Statutory Limits of Sea and River, as applicable to Salmon Fisheries. By Dr Fleming. Dr Fleming directed the attention of the Society, in the first in- stance, to the characteristic features of sea and river proper; and then proceeded to consider the peculiarities of that common space, alternately sea and river, to which he restricted the term estuary. He then considered the nature of the space between high and low _ water, and pointed out the mean level, or mid-tide mark, as the only constant and universally applicable boundary plane. The influ- ence of the tidal wave in reversing the current, checking the velocity, and increasing the depth of the river, was next brought under notice, and an experiment exhibited, illustrating the conservation of force, _ which causes the waters at the head of an estuary, and the connect- ed river, in certain circumstances, to attain a higher level than the _ high-water mark of the neighbouring sea-shore. He then considered, _ successively, the tests which, on different occasions, had been proposed and employed; viz.—point of stagnation ; presence of sea or river _ water ; the growth of sea-weeds; fauces terra; deltas and bars; and - pointed out their uselessness in determining the physical limit between sea and river. 334 The second part of the paper was occupied with an examination of the Scottish statutory limit of sea and river, as applicable to the salmon fisheries ; in which the author indicated Jow-water mark, as the only limit contemplated, and justified the sagacity of our ancient legislators, by proving that, with this limit, the object of the statutes was secured. He pointed out the inapplicability of the physical test which he had previously established, and of the spurious ones which had been noticed, to the settlement of the fishery question. He concluded, by expressing his regret, that the Legislature had de- clared certain engines, for catching fish, to be legal or illegal, accord- ing as they are used in sea or river, without defining what is sea or what is river; and his expectation that, should any bill be brought into Parliament, in connection with this subject, the present state of the law will not be permitted to remain in culpable obscurity. 3. On the Combined Motions of the Magnetic Needle, and on the Aurora Borealis. By J. A. Broun, Esq. Communi- cated by Sir T. M. Brisbane, Bart. When a steel needle or rod is so constructed that its centre of gravity is in a finely-turned axle at right angles to its length, it will rest in any position when the axle is placed upon polished planes ; when, however, we magnetize the needle, it assumes a position which is that of the direction of the magnetic force at the place: in this way we obtain the ordinary dipping-needle. The dipping-needle can obviously move only in one plane, that to which the axle is at right angles ; were it possible to suspend it freely, so that it could move in every plane with every variation of the direction of the magnetic force, we should then be able, by observing the variations of its posi- tion, to determine at once the laws which a magnet in its true posi- tion obeys; this, however, we have not been able to do; even the small variations in the vertical plane, which we might expect to ob- tain from the ordinary dipping-needle, are nearly or altogether de- stroyed by the friction of the axle upon its supports; and there are many mechanical difficulties in the way of the other methods of sus- pension. It has been found convenient, then, to make use of the simplest methods of suspending magnets in a horizontal plane ; and to endeavour to deduce, from the composition of their motions, the ——————=-- 335 laws both of the variation of the force with which a truly suspended magnet is directed, and of the direction of that force itself. The most convenient of these is that termed the declination magnet, which is suspended horizontally by a fine silken thread; the tendency of the needle to dip being obviated by placing the point of suspension north of the centre of gravity. This instrument is | very convenient, especially in high latitudes, for exhibiting in a mag- nified form that portion of the motion of the freely suspended dip- ping-needle, which is at right angles to the vertical plane of the needle. Two other instruments, one termed the bifilar magneto- meter, from its suspension by two threads; the other named the balance magnetometer, from its resemblance to the beam of a balance, en- able us to observe the variations of the horizontal and vertical com- ponents of the force with which the freely suspended dipping-needle is directed ; whether these variations be due to a change in the total value of the force, or simply to a change in its direction parallel to the vertical plane. In high magnetic latitudes, the bifilar or hori- zontal component magnetometer will be most affected by changes of the direction of the force in the vertical plane, and the balance or vertical component magnetometer will be most affected by variations of the intensity of force : in low latitudes the reverse is the case. In all three instruments the magnets are forced from their natural posi- tion. By means of a well-known formula, however, we can com- pute, from the observed variations of the two components, the variations of the total force, andof its direction in the plane of the magnetic meri- dian. Theoretically this operation is simple enough, but practically there are great difficulties; these difficulties are due to the effect of tem- perature upon the positions of the bifilar and balance magnets, which -require to be eliminated, and to sources of error that I have pointed _ out in the Edinburgh Transactions in the determinations of the change of value of either component of force, which corresponds to a change of, say one minute in the angular positions of the magnets. I conceive that I have, by the employment of new methods, reduced the errors due to these causes to a very small amount ; and it is for this reason that I claim for the results deduced from the Makerstoun Observations, a consideration which they could not otherwise have been entitled to. I refer to the part of the Transactions now in the _ press, for the results relative to the separate magnetic elements, and to the total force; I confine myself at present to those touching the A 336 motions of a magnet supposed freely suspended in the direction of the magnetic force. I may state shortly the process by which the following results have been arrived at. The corrected observations for each of the three magnetometers having been discussed with reference to a particular argument ; such as, the month, the moon’s age, the moon’s position in declination, the sun’s hour angle, and the moon’s hour angle; the motion of the (supposed) freely suspended needle at right angles to the plane of the magnetic meridian, was obtained with reference to the argument in multiplying the corresponding variations of declina- tion by a constant factor (the cosine of the dip); the motion parallel to the same plane was obtained from the variations for the two com- ponents by the formula already referred to ; the value of the former part of the motion for any epoch being taken as the abscissa, and that of the latter for the same epoch as the ordinate, the motion of the north end of the needle is constructed. Annual Motions.—The difficulty of determining the law of an- nual variation of any of the magnetic elements has been so great, that it is doubtful whether that for the magnetic declination has ever been obtained, though the instrument upon which its determination depends is unaffected by variation of temperature. I believe that I have succeeded in the determination of the laws of all the elements, and from these the annual motion has been constructed. The an- nual motion deduced from the observations of the three magnetome- ters for the four years 1848, 1844, 1845, and 1846, is shewn in figure A ; another and rather more symmetrical figure, deduced from a different combination of years, is shewn in figure B, Plate VI., Edin. Trans., Vol. xix., Part 2. From near the vernal till the autumnal equinox the annual mo- tion forms the half of an ellipse whose major axis, passing at the vertex through June, makes an angle of about +11° in figure A and of + 16° in figure B with the projection of the magnetical me- ridian, At the autumnal equinox the north end of the needle again ascends till the winter solstice, after which it descends till the vernal equinox, In its descent, the north end of the needle having crossed its previously ascending path, it forms a loop which, when untwisted and continued downwards from the equinoxes, completes the ellipse ; the portion formed by the loop having almost exactly the same peri- meter as that regularly formed when the sun is north of the equator ; 337 the completed portion is indicated by dotted lines in figures A and B. It does not seem improbable that in southern latitudes the figure will be inverted, and that it will be a simple ellipse near the equator. Monthly Motions.—The motion corresponding to the moon’s vary- ing phase has not been projected, chiefly because of the irregularities still existing in the result of the four years’ observations for the mag- netic declination, the epoch of minimum being ill-determined ; it is conceived that the figure is a simple ellipse with its major axis in the astronomical meridian, the northern extremity being at conjunction, the epoch of minimum dip, and the southern extremity at opposition, the epoch of maximum dip ; this, however, is doubtful. The motion for the moon’s position in declination has been ob- tained in the following manner :—Having first projected the means of magnetic declination for each three days of the moon’s position in declination, as obtained from the Tables for the years 1843-6, the day after tho farthest northerly position being the abscissa, a curve was passed freely among the points; the values of the ordi- nates at the points of intersection by the curve were then taken as the interpolated value of magnetic declinations for the corresponding abscissee: a similar operation was performed for the magnetic dip. In both cases very satisfactory curves, agreeing nearly with the true points, were obtained. These values are projected in figure C, Plate VI., Edin. Trans., Vol. xix., Part 2. From this figure the north end of the dipping-needle commences its ascent about two days after the moon is north of the equator, attains its highest point about two days after the moon is farthest north, and afterwards it descends till the moon is again near the equator; thus forming a figure like a portion of an ellipse with its vertex about one day after the moon is farthest north, the major axis making an angle of about — 30° with the magnetic meridian. It will be remarked that so far this motion is quite similar to that for the sun’s position in declination, with the exception of the axis of the figure being on the opposite ‘side of the magnetic meridian ; when we trace the figure farther, the analogy still subsists ;—as the moon proceeds south of the equator the north end of the needle again ascends till the moon is farthest south, thereafter descending, and, in crossing its previously ascending path, a loop is formed lying partially out of the pectetpal figure, as in the case of the annual motion. 338 The correspondence of the two results gives a great weight to the accuracy of both; this will be more evident when it is remembered, that the whole motion of the dipping-needle for the moon’s varying declination is included by a small circle with a diameter of little more than one-tenth of a minute of space, and, that no observation in the sixty thousand employed for this result has been rejected, however greatly affected by disturbance; although the graphic in- terpolation to remove slight irregularities may be considered as an equivalent operation. Diurnal Motions —The monthly mean diurnal variations for the magnetic declination and magnetic dip, from four years’ observations, still present irregularities, especially from 10" p.m, till 42 a.m., the hourly positions for this time depending on only two years’ observa- tions. For this reason, the values from the Tables having been pro- jected, curves were passed freely among the points, and the interpo- lated ordinates thus formed, were taken for the projections in Plate VII.: the interpolated quantities differ very little from the actual values, and this is especially the case for the summer months. The diurnal motions for the four winter months , November to February, are of the same class, and they differ considerably from those for the other months (see Plate VII.) : in each of these months the motion consists of a figure of two closed loops : the north end of the needle moves eastwards with little change of dip from about 1” p.m. till 95 or 10° p.m., after which it turns westwards, and begins to ascend about 45 a.m., crossing near its position at 6" p.m.; thus forming an eastern loop, which is small gompared with the western loop, excepting in December. After 6 a.m., the north end of the needle having moved a little westwards, again descends, crossing a second time the afternoon track near 5} p.. ; still moving westwards, it ascends about 11” a.m. till it meets the position of 1> p.m., thus completing the western loop. The eastern loop is not formed in March, the north end of the needle not rising sufficiently high to cross the afternoon track. The change in the figure from February to March is very great; in April and May the remains of the east- ern loop are still visible, but in June and July its position is indi- cated by a simple inflection in the figure ; in August and September the germ of the eastern loop becomes more distinct, and in October the loop is actually formed. The transition in form from autumn to winter is quite gradual, unlike that from winter to spring. In the Eee 339 winter months, the principal or western loop is formed by the mo- tion from 8" a.m. till 55 p.w.; in the months from April to August, three-fourths of the whole diurnal motion oceur between 6" a.m. and 6 p.m., the remaining fourth forming a slightly inflected side to each of the figures : it is this side which is gradually twisted up to form the eastern loop of the winter months. It is evident that no proper comparison can be made of the areas of these figures on account of the involved forms in the winter months ; the areas, however, of the figures from April to August, differ very little. Perimeters of the Figures.—The twisting of the sthhibere which renders a comparison of the areas of little value, does not appear to affect the length of the motion, and this therefore seems a fair sub- ject for examination. The following are the values of the angular _ motion, or length of the perimeter, for each month, as obtained ap- proximately from Plate VII. Jan. Feb. March. April. May. June. 5"60 6°16 9”22 1218 12°04 12”:00 July. Aug, Sept. Oct. Noy. Dec. 11°56 1164 1048 9-78 7°22 5°84 December and January shew the least perimeters, April, May, and June, the greatest, though the perimeters for the months from April to August are nearly constant. Hourly Angular Motions —Having obtained the approximate motion from hour to hour for each of the monthly figures, we find that, on the whole, they follow nearly the same law, that indicated in the following numbers, which are the means for each two hours _ of the hourly motions from the 12 separate months. 12h. 14h 16h). 18h 20h 22h ob Qh 4h 6h gh (10h 0°43 0°48 0°46 0°62 1°19 1°60 1°34 1°08 0°99 0°60 057 0%29 These numbers give the following curious result ;—That the velo- q city of motion of the north end of a magnet freely suspended in the direction of the magnetic force is a maximum when the sun makes its superior transit of the magnetic meridian (between 10" and 11" a.m.), and a minimum when it makes its inferior transit of the same meridian tween 10" and 11% p.m.). This result is the more curious that the epoch of the minimum velocity of the diurnal motion is an epoch of maximum disturbance ; and, in as far as the declination is con- - VOL. I. 2F 340 cerned, the epoch of maximum velocity of the diurnal motion is also an epoch of minimum disturbance. When we compare the results for the irregular disturbance, with reference to the separate elements of magnetic declination and mag- netic dip (see Ed. Trans., Vol. xix., Part 2), with the velocities of motion as deduced from these figures, we find, that when the diwrnal motion is most rapid the departures from the direction of that mo- tion are least, and when the diurnal motion is slowest the irregular departures from the hourly mean position are greatest. Thus, if we examine the mean disturbance of magnetic declina- tion for each hour, as deduced from two years’ observations, we find it a maximum during the hours from 8 p.m. till 2 a.m.; this is the period for which the motion of the needle is at once slowest and least as regards the declination ; about 21) (referring to the figure for the year, see Plate VIII., Edin. Trans., Vol. xix., Part 2), the motion is most rapid and nearly altogether in declination, the minimum disturbance in declination occurs immediately before this hour; another and nearly equal minimum occurs under the analogous cir- cumstances about 55 p.m,.; a secondary maximum occurring about 1 or 2° p.m. If we approximate to the hourly mean disturbance of the magnetic dip by means of those deduced for the two components of force, we find the minimum to occur about 65"~7" a.m., when the velocity of motion is considerable, and when almost wholly in the direction of dip ; the disturbance increases from that time till about 2 a.m., shew- ing a secondary minimum about 1 p.m. and about 8" p.m., at both of which times the direction of motion is chiefly that of dip: the maximum disturbance occurs from about 10" p.m. till 8” a.m., during which period the velocity of motion is least. On the whole, then, the magnetic disturbance appears to be chiefly at right angles to the direction of the motion of the needle, and to be inversely as the velocity of motion. It is scarcely possible to connect the previous facts of area, perimeter, or velocity of motion with the laws of variation of tem- perature. In the mean for the whole year, the temperature changes most rapidly between 8" and 9 a.m.; but it changes with nearly equal rapidity between 5? and 6" p.m. There is no corresponding fact in the previous numbers. When we compare the variations of temperature with the variations of position for the suspended mag- j eer ‘ NE he Ri be ' m4 34] net in the summer months, we find the difference between the two classes of facts even more marked: in summer, the temperature changes most rapidly about 7 a.m. and 74 p.m., the change for May, June, and July, from 66-8" a.m., being + 3°80, and from 6%—8" p.M., being — 3°54 ; for the same months, the mean angular motion of the needle from 6"—8" a.m. =1/:00, from 95-11" a.m. =2’12, and from 65-8" p.m. =0''74, ‘There is a diminution in the velo- city of the motion between 1" and 2" p.m.; there is also a slight diminution at the turning point, 64-7) p.m., and between 2 and 3 A.M. These diminutions appear to be connected with the fact, that they occur at turning points in the figures. It may be remarked that the line representing the astrono- mical meridian, and passing through the centre of gravity of the perimeters of the figures, for the months during which the sun is north of the equator, also passes through the position of greatest velo- city, and nearly through that of least velocity, of the diurnal motion. General Form and Turning Points of the Diurnal Motions. —The general forms of the diurnal motion vary between rude el- lipses and circles. In the winter months, the principal portion, or loop of the figures, is elliptical, with the major axis horizontal ; near the equinoxes, the figure becomes somewhat circular, and in the midsummer months it again becomes rudely elliptical, with the major axis inclined about 20° or 30° west of the magnetic meridian. In the usual investigations of the conventional element of declination, it has been remarked, that the turning from the farthest westerly posi- tion occurs near the time of maximum temperature ; a coincidence which has been supposed to indicate a real connection, though there is no similar coincidence between the epoch of minimum tempera- ture, and the eastern turning point. If, however, we examine the figures indicating the diurnal motions of a needle in its true position, such as those for the months of April, August, October, &c., we might find it difficult to say where is a turning point and where not; and it is difficult to see why the turning points at the extremi- _ties of the horizontal diameters of these rude circles, or at the extremi- ties of a horizontal line, in the ruder ellipses, should be chosen, in preference to the turning points at the extremities of other lines _ drawn in the figures, as tests for a theory ; unless, indeed, it be ex- _ plained by the accident that a horizontal suspension of a magnetic needle, is a convenient one for observing a certain portion of the 342 motion of a magnet, which, independently of gravity, would rest in the direction of the magnetic force. It has been customary, however, to give theories of the cause of magnetical variations, with reference solely to the diurnal variations of the magnetic declination (and not unfrequently with a very indif- ferent knowledge of the facts with respect even to that element). I venture to say, that it will only be from a careful comparison of the whole facts relating to the motions of a freely suspended dipping needle, not for one place, but for different and distant portions of the earth’s surface, that a satisfactory theory will be obtained. The attempt to deduce one from a consideration of the declination varia- tions alone, can only be likened to a similar attempt with reference to planetary motions, the apparent position of the planet being stu- died without any relation to the direction or rate of motion of the place of observation. Dr Lloyd, who has done so much for magnetical science, has lately brought forward a discussion of his declination observations, which he considers strongly in favour of the theory that the diurnal variations of magnetic declination are due to the sun’s heating effect upon the earth, in opposition to the atmosphere. I venture also to offer my guess, founded upon a consideration of various meteorologi- cal facts, that it is in the atmosphere, and not the earth, that we shall find seated the secondary causes of magnetic variations. Inthe mean- time, it is facts that are wanted. It may be noticed, chiefly with reference to the months from March to October, that a line passing through the positions of noon and midnight, also passes through, or nearly through, the mean position, or the centre of gravity, each hour having equal weight : also a line passing through the positions, about four hours before, and four hours after noon, passes nearly through the centre of gravity of the perimeters ; the former of these lines lies nearly in the direction of the minor axis, the latter nearly in that of the major axis of the rude ellipses for the midsummer months. The horizontal line pass- ing through the centre of gravity also passes nearly through the positions of 1" a.m. and 1” p.m., which, therefore are the epochs of mean dip. Angular Distances between the Hourly Positions from the Mean of all, and from the Undisturbed Days.—In order to render the following result intelligible, it must be stated that, after a careful 843 examination of each day’s observations in the years 1844 and 1845, a series was selected, in each month, of days nearly unaffected by magnetic irregularity ; the diurnal variation was then obtained for these undisturbed days, and this was compared with the diurnal vari- ation deduced from all the observations ; the assumption being made that the mean for the whole 24 hours was unaffected by disturb- ance, the differences of the hourly values would evidently shew the effect of disturbance on the hourly mean position, This assumption, it was found, must be as nearly as possible true for the magnetic declination, because the monthly means of the selected days differed little or nothing from those of all the days; this, however, is not the case for the element of dip, the disturbance appeared to affect the daily or monthly mean to a small extent. Confining myself here to the result for the year (referring to the volume of the Transac- tions for the partial results which vary with season); the following numbers indicate the displacement of the mean hourly positions by disturbance, upon the assumption that the centre of gravity for each figure is the same :— 4 (igh 145 «16h igh gob 0 ofgh 6h gh [4h gh gh) 10h 12h 0°35 0°25 0°06 0°15 0°27 0°30 0°23 031 0”30 0°17 0°31 039 0735 The diameter of the figure is little greater than 2’-0. ; In the mean figure for the year (see Plate VIII. already referred to), minima occur at 4 a.m. and about 53” p.m., the maximum occurs about 10 p.m., and a maximum occurs between 8 a.m. and 4" p.m. If, making allowance for the effect of disturbance on the position of _ the centre of gravity with reference to dip, we suppose the centre of _ gravity of the dotted figure for the year, raised 0-15 on the line of mean declination, or that of the continuous figures lowered as much, we find the maximum effect of disturbance to occur about 10 p.m. and 10" a.m., and the minimum effect about 4% a.m. and 5" p.m. _ This result was obtained for the magnetic declination in 1844, and _is given in the volume for that year. Motions with reference to the Moon’s Hour-Angle.—These, as obtained from the means of all the lunations in the years 1844 and 1845, and as deduced from winter lunations for 1845 only, are -shewn in Plate VII. The resulting figures, especially that for the winter lunations of 1845, bear some resemblance to the diurnal mo- tion for the month of December. 344 Avrora BorkAtis. A table of 184 aurore seen at Makerstoun in years 18438 to 1849 is given in pages Ixxv,—Ixxviii. of Vol. xix., Part 2; from this table the following results have been obtained :— A very careful outlook for aurore was kept throughout the whole period, but especially during the first five years; an outlook warned by magnetic disturbance in circumstances unfavourable to the visi- bility of the meteor, and assisted by a practical acquaintance with the faintest auroral indications. In several cases, the auroral appear- ances were very faint ; these are entered in the table as “ Traces,” and, in others, there was doubt whether the appearance was truly auroral; these are indicated by “‘Trace?”’ It should be noted that, with the exception of the years 1844 and 1845, auroree were seldom looked for after midnight. Diurnal variation of frequency of the Aurora Borealis —The following are the numbers of times which aurore were seen, at each hour, from 5” p.m. till 5" a.m., for the whole period—referring to the printed tables for the numbers for each season. Hour, 5h 6h 7h gh gh 70h 11) 19h 13h 14h 15h 16h 17h No., 519 4op0¢ a) Fo-. 00 37 27 Lo. tly eee The greatest number of aurore were seen at 9h p.m.; this result is independent of the effect of twilight, since 9" p.m. is also the hour of maximum frequency for the winter months. This hour is nearly the hour of maximum disturbance for the magnetic de- clination and dip; as, however, the maximum disturbance of the total magnetic force and a maximum of the magnetic dip appear to occur about 5° p.m., this also may be an epoch of maximum fre- quency or intensity, though this can only be determined in higher latitudes. It should also be remarked, that, since the epoch of maximum disturbance varies with season, so, therefore, it is probable will that of frequency of the aurora; some traces of this may be de- duced from the previous table. In the winter quarter, November— January, four-fifths of the times at which aurore were seen were for the hours before 10" p.m., whereas in the spring quarter there were only three-fifths seen before 10" p.m. Annual Variation of frequency of the Aurora Borealis—The first line following contains the numbers of aurorz observed in each month during the six complete years 1843-8, and the second line gives the numbers of hours at which the aurorz were seen. . } es eee 345 Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Noy. Dec. 16036... .26, 14 6 0 0 Fs LO. yee, ee 50 62 65 43 8 0 0 10 32 44 58 38 The greatest number of auroree were observed in March for the first six months, and in October for the last six months of the year: none were observed in June and July. When the six months of 1849 are included, the number for February is 26, and for March, 28. The law of visible frequency of the aurora is the same as that deduced already for magnetic disturbance ; namely, maxima near the equinoxes, and minima near the solstices, the minimum at the ‘summer solstice being the principal. As, however, the shortness of night during the summer months must diminish the number of visible aurore, it is by no means certain from these numbers that a minimum occurs at the summer solstice; the fact of the minimum at the winter solstice is involved in no such difficulty. If we could assume that the aurore had the same diurnal law of frequency at all seasons of the year, the existence of the summer minimum could be satisfactorily determined, by comparing the numbers of times which aurorze were seen at the five hours, 10" p.w.—2" a.m., during which (even in the months of August and May) there is little twi- light to extinguish aurore. The numbers are as follow, for these five hours in each month of the years 1843-8 :— Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Nov. Dec. 15 24 38 31 8 OO Gionke Ter 18 es From these it is evident that the numbers in May and August are certainly less than for April and September; but it has been already mentioned as probable that the diurnal law of frequency varies with season, of which, indeed, a proof is to be found in the great excess of the numbers above for the spring months, compared with those for the autumn months, shewing the later epoch of the maximum frequency in the former. An examination, however, of the table for the disturbance of the magnetic declination (Table 18, Vol. xix., Part 2), will shew that, though the maximum disturbance occurs after midnight, in the months of May, June, and July; yet in August and the two following months it occurs about 10" P.m., so that there can ~ be no doubt of the less number for August than for September and October, if there should be a doubt in the case of May compared with April. The difference, however, even in the latter case is too great to be explained by any slight shift of the epoch of maximum 346 frequency in the two months. Upon the whole, it appears certain that a minimum of actual as well as of visible frequency occurs in summer; a result quite in accordance with that for the amount of magnetic disturbance, which accordance is sufficiently close to per- mit us to complete it, by assuming that the number of aurore is a principal minimum in summer. It has been stated in the volume for 1844, p. 401, that this result was long ago obtained by Mairan; this statement, made chiefly on the authority of Keemtz and Hansteen, is not quite accurate. It is true that Mairan’s numbers give a rough indication of the law, as will be seen below; but when it is remembered that his table in- cludes all the observations (229) of which he could find a record for upwards 1000 years, it will be evident, that the conclusion that a greater number of auroree occurred at both equinoxes than at the winter solstice would have been hasty ; this conclusion, however, is not made by Mairan, and, though he has combined the numbers of aurore in a great variety of ways, he has made no combination ex- hibiting this fact. It did not enter into the necessities of his theory (that aurore are the product of the solar atmosphere) to shew that a greater number of aurorze happened in the northern hemisphere at the vernal equinox than at the winter solstice; he shews, indeed, that the number for one equinox is, and, in accordance with his theory, ought to be, greater than for the other. Some other philosopher has the merit of first pointing out this fact. The following are the numbers of auroree by Mairan (Traité Phy- sique et Historique de l’Aurore Boreale, par M. de Mairan, 1733, p- 199); by Keemtz (Complete Course of Meteorology, translation by Walker, p. 458); and by Hansteen (Mem. de I’Acad. Roy. de Belgique, t. xx., p. 117). Jan. | Feb. | Mar.| Apr. May. June. July.| Aug./Sept. | Oct. |Nov. Dec.| Sum. 22) 12) 1) 5) 7), Op 84) 50). 2eieto 2a Kemtz, . 229 | 307 | 440| 812| 184] 65) 87 | 217 | 405 | 497 | 285 | 225 || 3253 Hansteen, . 29| 31} 47|} 34) 2) O| O| 17] 35] 33] 34] 23] 285 J. A. Broun, || 22) 26] 28} 16} 6) O| Oj 7] 16; 29) 23) 11} 184 Sum cm? 280 | 364/515 |362|192| 65| 87 |241| 456 342) 259) | ! Mairan, . 21) 27 three, Mairan’s numbers are probably included by Keemtz ; a few of the aurore, included in M. Hansteen’s list, are identical with those in my own. 347 Variation of Frequency of the Aurora Borealis with the Moon's Age.—This investigation is evidently beset with considerable diffi- culty, since the moonlight existing nearly extinguishes the appear- ances of all the fainter class of aurors, and it renders the faintest wholly invisible ; the careful watch, however, which was kept for auroral appearances at Makerstoun, probably renders the table given in the Transactions better fitted for such a question than any pre- vious series of observations. It should be remarked, that the latitude of Makerstoun, or perhaps even a lower latitude, is better fitted for this investigation, than much higher latitudes ; at least this is the case as long as only frequency of visibility can be considered. The French Commission du Nord, during their stay in Lapland, found aurore existing, or probably ex- isting, almost every night. In such places variation of frequency there is none, and variation of intensity alone remains for investiga- tion. It is obvious, that till some better mode of measuring this in- tensity can be devised for these high latitudes, we are forced to per- form this operation in a rude manner, by moving to lower latitudes, where the fainter aurore become invisible, and where, therefore, fre- quency is a test of intensity beyond a certain limit. Combining the numbers of aurore observed at each day of the moon’s age into six groups of 5 days (the first group, 43 days), we find the average number of aurore for one day of the moon’s age in each group as follows, from the 63 years’ observations :— Moon’s age. 284—2¢ 3474 §d—]24¢ 13d--174 184994 934-974 - Number. 58 5°2 3°6 50 10-2 6°6 Did aurore occur indifferently at all ages of the moon, we should expect to see the greatest number at conjunction, and the least num- ber at opposition ; this, however, is not the case, the greatest num- ber was seen about two days before the end of the third quarter, and the least number about two days after the first quarter, or the visible ‘maximum and minimum occurred at times equidistant from the. epoch of eupeaition. The frequency of aurore, therefore, is a func- tion of the moon’s age. In order to determine the actual law, we may ‘consider the probable effect of moonlight in obliterating the au- roval appearances; remarking, first, that 9" p.m. is the epoch of ‘maximum frequency for the aurora, and that upwards of five-sixths are seen before midnight. When the moon is about three days old, _ in the months from September to March, it begins to set sufficiently VOL. II. 2°46 348 late, and to have sufficient light to render the earlier of the faint aurore invisible; about the end of the first quarter, it does not set till midnight, and thus shines throughout the period of the occurrence of five-sixths of the aurorse; afterwards it increases in brightness, and the maximum effect in extinguishing faint aurorz is evidently attained at opposition, when the moon begins to rise late enough to allow the earlier aurore to be visible; towards the end of the third quarter, when the moon does not rise till midnight, it is also evident that the number of faint aurore rendered invisible must be very small, From the beginning of the fourth quarter, therefore, till conjunction, the numbers seen will obey nearly the true law of fre- quency ; and as the visible maximum occurred before the end of the third quarter, the true maximum must have occurred even nearer to opposition. On the whole, it appears very certain, that the hy- pothesis of an actual maximum of frequency at opposition, and mi- nimum at conjunction, is satisfied by the previous numbers of aurore, seen under the conditions of the varying duration of moonlight for the hours of maximum frequency. This hypothesis is in unison with the law of magnetic disturbance, which is a maximum at oppo- sition, and a minimum at conjunction. Note on the Theory of the Aurora. Although temptations to frame hypotheses have been avoided hitherto, I cannot refrain from repeating here the opinion, that the phenomena of the aurora borealis are chiefly optical. After watching the various phases of the aurora for some years, the hypothesis of self-luminous beams and arches appeared to me unsatisfactory ; and the strongest argument in its favour, that ob- tained from the computed height of the auroral arches, seemed of a very doubtful character. I was quite prepared, therefore, to adopt the idea, first I believe proposed by M. Morlet to the French Aca- demy, in May 1847, that the auroral arch is an optical phenomenon of position. M. Morlet has pointed out that the arch appears gene- rally as a segment of a circle; whereas, in these latitudes, it ought invariably to appear as the segment of an ellipse, if the hypothesis be true of a real luminous ring, with its centre on the continuation of the magnetic pole. He has also, among many other very obvious objections to that hypothesis, shewn that the summit of the arch is generally in the magnetic meridian of the place, the plane of which 349 rarely passes through the magnetic pole, and seldom passes through the same point, for three different places. I have, however, felt even more persuaded that the aurora is, partly at least, an optical phe- nomenon, from a consideration of that phase of the aurora constituting the corona borealis, a persuasion that I stated in the Literary Gazette of the time, in giving an account of the beautiful corona of October 24, 1847. ‘Mairan, and, more lately, Dalton, have explained this phase of the aurora by a hypothesis of polar beams, long fiery rods of solar atmosphere, according to the one, of red-hot ferruginous particles, according to the other, seen in perspective, as they lie in the direc- tion of the magnetic force. A little acquaintance with the pheno- menon—the rushing and tilting of the beams against each other, one beam occasionally rising from the horizon, passing through the centre of the crown and beyond it—would shew the improbability of this hypothesis, I am persuaded, that the phenomena of the corona borealis is produced in a narrow. horizontal stratum of the earth’s atmosphere. Thanks to the discoveries of Dr Faraday, we do not require a ferruginous sea, in order to have polarized particles ; the watery crystals that inhabit the upper regions of the atmosphere can themselves assume a polar state, determined by the passage of elec- tric currents ; and we have only to complete this fact by a hypothesis of luminous electric discharges seen refracted by these crystals, the position of visibility of the refracted rays depending on the angles of the crystals, and the deflections from the direction of the magnetic force which they suffer, by the electric currents. Such a hypothesis, which occurs at once when an optical phenomenon has to be ac- counted for, would explain these remarkable auroral clouds, so often seen in connection with the aurora itself ; it would also serve to explain the appearance of the arch at certain altitudes, lower for lower alti- tudes, determined by the position of the source of light, direction of the magnetic force at the place, and the effect of the electric current in deflecting the crystals. The crystals successively deflected by electric currents would also exhibit the rushing pencils or beams. It need scarcely be remarked, that differently formed crystals might give rise to different phases of the phenomenon ; while reflec- tion might be combined with refraction in certain cases, especially in the case of arches seen south of the anti-dip. Such a hypothesis evidently assumes a source of light, independent of these optical re- 350 sultants, and the pulsations seen in many aurore may be real lu- minosities. It is hazardous, in the present ill-arranged state of auroral obser- vation, to offer so rude a sketch of a new hypothesis, although we may suffer a considerable defeat in very good company. Since the previous note was written, I find that M. Morlet has published a theory of the auroral arch (Ann. de Ch., t. xxvii, 3me Série). The ideas above were stated by me two years ago, to differ- ent persons. : The following Donations to the Library were announced : Transactions of the Royal Scottish Society of Arts. Vol. III., Part 4. 8vo.— By the Society. Journal of the Asiatic Society of Bengal. Edited by the Secretaries. N.S. No. 32. 8yo.—By the Society. Annali di Fisica dell’ Abbate Francesco Car. Zantedeschi. Fasci- colo 4. 8vo.—By the Author. Quarterly Journal of the Chemical Society. Ny 9. 8vo—By the Society. Scheikundige Onderzoekingen gedaan in het Laboratorium der Utrechtsche Hoogeschool. 57° Deel. 6th Stuk. 8vo.—By the University. Bulletin de la Société de Géographie. 3™e Série. Tom. 12™e. 1849. 8vo.— By the Society. ERRATUM, Vol. IL, No. 33, page 205, line 12 from bottom, ‘or “ These data are (1.),” &., read “ These data are (1.), The known expan- sion of water in freezing; (2.), The known quantity of heat which becomes latent in the melting of ice; and (3.), The quantity of work given out,” &e. Bow iS cl SiGe Het ere SSANNAZ Ne At SES atar 5 = PN CCPC Sey ZO Ni Aaszt a ene on eaae <= GMB Rc Beas: SARER SEER GO OLEE. Ree oeae cues rp opohedeelat Ll" 1 balednleodenbcbea | ttt ok 1 tee) POOR CEE CPE Ee a Pere ees a PS ee BD Oe A OY, +} yp Af ae JE Ue SS aE Claas Biot yt Tr A ol TTT tet te Sete i a Tena irra gt Sec E : % ~ wnnungiprven fy g bug sapbiun imoy suooyy ep of amiatafa YM SUOHON mae Hippuric, on the preparation of, 30. Acids. On some new voltaic arrange- ments with chlorous and chromic acids, with an account of a battery Yielding electricity of great inten- sity, in which the negative as well as the positive element is zinc, 223. Action of the dry gases on organic colouring matters, and its relation to the theory of bleaching, 183. _ Aden, on the fluor-spar of, 159. * Adie (John) on the use of metallic __ reflectors for sextants, and on the ‘determination of the errors arising from non-parallelism in the mirrors and sun shades of reflecting instru- _ ments, 22. _——— Note on the refractive and __ dispersive powers of the humours of 4 oe eye, determined by be waa Adjustments of the equatorial instru- ment, 164. Affinity, vital. See Vital Affinity. Air-pump in England, on the early history of the, 207. Alban Hills, near Rome, on the vol- _ canic formations of the, 259. gebraical symbolism, on, 156. Alison (W. P.) M.D., on the prin- : ciple of vital affinity, as illustrated _ by recent observations in organic chemistry, 83, 114, 115, 117. _Alkalies, phosphates of the organic, note on the constitution of the, 148. America, on the ante-Columbian dis- covery of, 291. American Electric-Observing Clocks. See Electric-Observing Clocks, 309. Anders (Thomas) M.D., on the constitution and properties of pico- line, a new organic base from coal 94. Extracts from a letter of Baron Berzelius, 108. .o INDEX. Anderson (Thomas) M.D., on certain products of decomposition of the fixed oils in contact with sulphur, 134. Note on the constitution of the phosphates of the organic alka- lies, 148. on the colouring matter of the Morinda citrifolia, 179. on a new species of manna from New South Wales, 239. on the constitution of codeine and its products of decomposition, 330. Animal economy, on the structural relation of oil and albumen in the, 136. matter, on a fatty substance derived from, 129. substances, on the products of the destructive distillation of, 186. and vegetable matter, experi- ments and investigations as to the influence exerted over some minerals by, 59. Ante-Columbian discovery of America, on the, 291. Anthracite of the Calton Hill, on the, 175. analysis of the, 300. Arsenic in the human stomach, on the presumed long-continued presence of, 110, Arthur’s Seat, remarks on certain grooved surfaces of rock on, 67. on the composition of the bones from, 88. on the existence of fluorine in the bones from, 88. notice of polished and striated rocks recently discovered on, and in some other places near Edin- burgh, 95. verbal notice on the geology of, 98. silicious stalactites on, verbal notice of, 216. 2H 35 Atlantic and German Oceans, waves of the, experiments to measure the direct force of the, 13. Atmosphere, on the extinction of light in the, 271. of rooms in a tropical cli- mate, on a method of cooling the, 235. Attraction, capillary, on some pheno- mena of, observed with chloroform, &e., 176, Aurora borealis, on the combined mo- tions of the magnetic needle, and on the, 334. note on the theory of the, 348. Bain (Alex.) Application of elec- tricity as a moving power to clocks, 33. Barometer, on the mean height of the, in different latitudes, 101. Battery, voltaic. See Voltaic Battery. Beach near Stirling, notice of an an- cient. Bebeerine, on the constitution of, 46. Bennett (J. H.) M.D., on the struc- tural relation of oil and albumen in the animal economy, 136. Berzelius (M.le Baron). Extracts from a letter of, 108. Binary star « centauri. Binary. Black (Alex.) M.D. A few unpub- lished particulars concerning the late, 238. Blood and milk, miscellaneous obser- vations on, 32, on the influence of contraction of muscles on the circulation of the, 91. Bones, on the extraction of pure phos- phoric acid from, 25. See Star, composition of the, 88. on the existence of fluorine in the, 88. Borrowstounness, notice respecting a deposit of shells near, 265. Boulder formation and superficial de- posits of Nova Scotia, on the, 140. Brewster (Sir David) K.H., on a pe- culiar modification of the doubly refracting structure of topaz, 16. on the existence of peculiar erystals in the cavities of the topaz, 21-23. on the decomposition and dis- persion of light within solid bodies, 64. Brisbane (Sir T. M.) Bart. Presenta- tion of the Keith Prize Medal to, 169. from Arthur’s Seat, on the ' y = Broun (John Allan). Account of the Magnetic Observatory at Maker- stoun, and observations made there, 10. on the thermometric correc- tion of magnetic instruments, 46. on the relation of the varia- tions of the earth’s magnetism to the solar and lunar periods, 58. on a method of rendering mag- netical instruments self-registering, 79. on the relation of the varie- ties of the vertical component of the earth’s magnetic intensity to the so- lar and lunar periods, 97. Results of Makerstoun ob- servations, No. III. On the solar and lunar periods of the magnetic declination, 144. Presentation of a silver medal to, 169. on the combined motions of the magetic needle, and on the aurora borealis, 334. Brown (William J.) Notices of a flood at Frastanz, in the Vorarlberg, in the autumn of 1846, 162. Caius Verres. On the personal nomen- clature of the Romans, with an especial reference to the nomen of Caius Verres, 87. Calcium, fluoride of. See Fluoride of Calcium. Caldecott (John). Observations on the temperature of the earth at Tre- vandrum, 29. Observations of terrestrial temperature made at Trevandrum Observatory, from May 1842 to De- cember 1845, 127. Calton Hill, on the anthracite of the, 175. analysis of the anthracite of the, 300. Campbell (W. H.) Account of the late earthquake at Demerara, 1. Cape of Good Hope, on the appearance of the great comet of 1843, at the, 87. Capillary attraction, on some pheno- mena of, observed with chloroform, bisulphuret of carbon, and other li- quids, 176. Carbon, note on the crystallisation of, and the possible ‘derivation of the diamond from anthracite and gra- phite, 301. Carnot’s Theory of the motive power of heat, an account of, &c., 98. Chalmers (Thomas) D.D. Biographi- cal notice of, 226. Chambers (Robert). Geological notes on the valleys of the Rhine, 189. Personal observations on ter- races, and other proofs of changes in the relative levels of sea and land in Seandinavia, 247. Chemical relations of creosote, on the, 45. Chemical, Practical, subjects, notes on, 298. Chevalier’s experiments on the decom- position of certain salts of lead by charcoal, verbal communication in regard to, 15. Chloroform, note respecting the re- fractive and dispersive power of, 187. notes on the purification and properties of, 316. Chlorous and chromic acids, on some hew voltaic arrangements with, 223, Christison (Robert) M.D., on a new variety of gamboge from the Wynaad, 58. on the composition of the bones from Arthur’s Seat, 88. on the gamboge tree of Siam, Circulation of the blood, influence of contractions of muscles on the, 91. Classification of colours, 190, 214. _ Claudia and Pudens. An attempt to show that the Claudia mentioned in St Paul’s Second Epistle to Timothy, was a British princess, 63. _ Clocks, application of electricity as a moving power to, 33. American electric-observing, note regarding the, 309. Coal tar, on the constitution and pro- perties of picoline, a new organic base from, 94. Codeine, and its products of decompo- __ sition, on the constitution of, 330. Colouring matter of the Morinda citri- folia, 179. Colourless ink, on the use of, in writ- J ing, Pe Colours, on the classification of, 190, 214, Column, vertebral, on the, &c., 176. Comet of 1843 at the Cape of Good _ Hope, on the appearance of the great, Mometary physics, some remarks on, «826. Connell (Prof.) on the action of so- luble lead salts on natural waters, 353 Connell (Prof.) Notice of two ores of copper, one of them a new mi- neral, 146. Copper, notice of two ores of, one of them a new mineral, 146. Creosote, on the chemical relations of, 45. Crystals in the cavities of the topaz, on the existence of peculiar, 21-23. Crystallisation of carbon. See Carbon, Cuchullin Hills in Skye, notes on the topography and geology of the, and on the traces of ancient glaciers which they present, 50 and 54. a few remarks suggested by Professor Forbes’ description of the effects of glacial action among the Cuchullin Hills, and Mr Maclaren’s views of the facts observed by him at the Gareloch, 65. Cullen (Major-General), on the tempe- rature of wells and springs at T're- vandrum in India (lat. 8° 31’, long. 5h. 8m.), 128. Curves, oval, on the description of, and those having a plurality of foci, 89. Curves, rolling, on, 222. Dalmahoy (James). Description of a sliding scale for facilitating the use of the moist bulb hygrometer, 13. Dandelion, extraction of mannite from the, 223. Darwin (Charles). Letters on the ana- logy of the structure of some vol- canic rocks with that of glaciers, 17. Davy (John) M.D. Miscellaneous observations on milk and blood, 32. Dawson (J. W.) on the boulder for- mation and superficial deposits of Nova Scotia, 140. on the mode of occurrence of gypsum in Nova Scotia, and on its probable origin, 141. Decomposition and dispersion of light within solid bodies, 64. Demerara, account of the late earth- quake at, 1. Deposit of shells near Borrowstounness, note respecting a, 265. Differentiation, on general, 108. Digits of numbers, on the sums of, 49. Diluvial scratches on the rocks in the neighbourhood of Edinburgh, ad- ditional example of, 159. Dimensions and refracting power of the eye, 251. “ Dirt-bands” of Glaciers, an attempt to explain the, 195. Discovery, ante-Columbian, of Ame- rica, 291. 354 Distillation, destructive, substances, 186. Dochart, Loch, on a black powder which appeared on the surface of, on the morning of 23d Nov. 1846, 129. Donaldson (Rev. J. W.) on the per- sonal nomenclature of the Romans, with an especial reference to the Nomen of Caius Verres, 87. Drainage water, on the solvent action of, on soils, 28. Dunbar (Prof.) Examination of some theories of German writers, and of Mr Grote, on the authorship of the Iliad and Udyssey, 154. of animal Earth’s atmosphere, Wollaston’s argu- ment for the limitation of the, to the finite divisibility of matter, 34. Earth’s magnetic intensity, on the re- lation of the variations of the verti- cal component of the, to the solar and lunar periods, 58. Earth’s magnetism. On the relation of the variations of the earth’s mag- nitism to the solar and lunar periods, 58. Earth, temperature of the, at Trevan- drum, observations on the, 29. Earthquakes, speculation respecting the cause of, 114, 115. Edinburgh, notes on the superficial strata of the neighbourhood of, 110, LLL. Edinburgh Royal Observatory. Observatory. Elastic solids, on an instrument for measuring the extensibility of, 173. on the equilibrium of, See 294, Electric (Locke’s) observing clock, notice of, 226. Electric-observing, American, clock, note regarding the, 309. Electrical apparatus in the Flapper Skate and other Rays, on the exist- ence of an, 1, 8, 9. Electricity, application of, as a moving power to clocks, 33. Elliot (James) on some peculiar im- pressions on the surface of certain strata of greywacké schist, at Goldielands, in Roxburghshire, 217. on the causes of local pecu- liarities of temperature in different parts of Great Britain, 218. Elton (R.) LL.D, on the ante-Colum- bian discovery of America, 291. Equations, differential, on the solution of certain, 257. Equatorial instrument, practical illus- tration of the adjustments of the, 164. Equilibrium of elastic solids, on the, 294. Eruption of Hecla, on the recent, and the volcanic shower in Orkney, 56. Estimates of probability, 228. Eye. On a possible explanation of the adaptation of the eye to distinct vision at different distances, 6. on the gradual production of luminous impressions on the, and other phenomena of vision, 230. note on the refractive and dispersive powers of the humours of the, determined by experiment, 232, note respecting the dimensions and refracting power of the, 251. Fatty substance derived from animal matter, on a, 129. Fixed oils, in contact with sulphur, on certain products of decomposi- tion of the, 134. Fleming (Rev.John) D.D. Remarks on certain grooved surfaces of rock on Arthur’s Seat, 67. on the recent Scottish Madre- pores, with remarks on the climatic character of the extinct races, 82. two verbal notices, (1.) on the geology of Arthur's Seat; (2.) on the dentition of the walrus, 98. notes on the superficial strata of the neighbourhood of Edinburgh, 110, 111. verbal communication on fos- sils of the lias formation, from South Africa, 133. geological notices, (1.) addi- tional examples of diluvial scratches on the rocks in the neighbourhood of Edinburgh; (2.) on the fluor- spar of Aden, 159. on the anthracite of the Cal- ton Hill, 175. verbal notice of silicious stalac- tites on Arthur’s Seat, 216. Verbal notices, (1.) on the shell referred to by Ure in his “ His- tory of Rutherglen and Kilbride,” as a species of “ patella ;” (2.) on the “ fossil echini” of Ure, 219-220. on a simple form of rain- gauge, 234. on the physical and Scottish statutory limits of sea and river, as applicable to salmon fisheries, 333. Ris OO 355 Flood at Frastianz, in the Vorarlberg, notices of a, in the autumn of 1846, 162. Fluoride of calcium, on the solubility of, in water, and the relation of this property to the occurrence of that substance in minerals, and on recent fossil plants and animals, 91. Fluoride of calcium present in the Bal- tic, on the proportion of, 302. Fluorine in the bones from Arthur’s Seat, on the existence of, 88. remarks on the presence of, in different ocean waters, 302. Fluor-spar of Arden, on the, 159. Forbes (Prof.) on a possible expla- nation of the adaptation of the eye to distant vision at different dis- tances, 6. note on the crystalline lens, 9. notes on the topography and geology of the Cuchullin Hills in Skye; and on the traces of ancient glaciers which they present, 50, 54. Biographical notice of the late Sir John Robison, K.H., Sec. R.S.E., 68. New observation on the. gla- ciers of Savoy, 103-107. Account of a geological ex- amination of the voleanoes of the Vivarais, 158. on an instrument for measur- ing the extensibility of elastic solids, 173. Note respecting the refrac- tive and dispersive power of chloro- form, 187. Observations on the commu- nications of Messrs Milward and Strachey on glaciers, and especially on the cause of the annual rings of glaciers, 196. on the classification of co- lours, 190, 214. Note regarding an experi- ment suggested by Professor Robi- son, 244, Note respecting the dimen- sions and refractingspower of the eye, 251. on the intensity of heat re- flected from glass, 256. on the volcanic formations of the Alban Hills, near Rome, 259. Account of a remarkable meteor, seen on 19th December 1849, 309. A few remarks suggested by Professor Forbes’ description of the effects of glacial action among the Cuchullin Hills, and Mr Maclaren’s views of the facts observed by him at the Gareloch, 65. Forchammer (Prof.) on the proportion of fluoride of calcium present in the Baltic, 302. Fossils of the lias formation, from South Africa, verbal communica- tion on, 133. Frastiinz, in the Vorarlberg, notices of a flood at, in the autumn of 1846, 162. Freezing-point of water, the effect of pressure in lowering the, 267. See water, freezing-point of. Gamboge tree of Siam, on the, 263. from the Wynaad, on a new variety of, 58. Gases, dry, on the action of the, on or- ganic colouring matters, and its relation to the theory of bleaching, 183. Glaciers, “ dirt-bands” of. See “ Dirt- Bands” of glaciers. annual rings of, observations on the cause of, 196. analogy of the structure of, with that of volcanic rocks, 17. viscous theory of, 19, Himalayan, on the rate of progression of the, 196. of Savoy, new observations on the, 103-107. Glass, intensity of heat reflected from, 256. Goldielands, in Roxburghshire, im- pressions on the surface of certain strata of greywacké schist at, 217. Goodsir (Prof.) Observations on the electrical organs of the rays, 9. Verbal notices respecting the thyroid, thymus, and supra-renal bodies, 80. Gordon (Prof.) Letter on the viscous theory of glaciers, 19. Gregory (William) M.D., on the ex- traction of pure phosphoric acid from bones, and on a new and ano- malous phosphate of magnesia, 25. on the chemical relations of creosote, 45. on the presumed long-con- tinued presence of arsenic in the human stomach, 110. Chemical notices (1.) on a fatty substance derived from animal matter; (2.) on a black powder which appeared on the surface of Loch Dochart on the morning of 23d November 1846, 129; (3.) on 356 the preparation of hippuric acid, 130. Gregory (William) M.D., on the pre- paration of kreatine, and on the amount of it in the flesh of different animals, 160. Notes on the purification and properties of chloroform, 316. Greywacké schist at Goldielands, in Roxburghshire, on some peculiar impressions on the surface of certain strata of, 217. Grooved and striated rocks, 238. Grote (George). Examination of his theory on the authorship of the Iliad and Odyssey, 154. Gypsum in Nova Scotia, on the mode of occurrence of, and on its probable origin, 141, Hansteen (Prof.) on the mean height of the barometer in different lati- tudes, 101. Harmonic, numerical ratio. merical Harmonic Ratio. Hay (D. R.) on an application of the laws of numerical harmonic ratio to forms generally, and particularly to that of the human figure, 304. Abstract of Professor Kel- land’s exposition of his views on symmetric proportion, 328. Heat, Carnot’s theory of the motive power of, an account of, with nu- merical results deduced from Reg- nault’s experiments on steam, 198. reflected from glass, on the in- tensity of, 256. motive power of, notes to a paper on the, 241. on the hypothesis of molecular vortices, and its application to the mechanical theory of, 275. Hecla, on the recent eruption of, and the volcanic shower in Orkney, 56. Henderson (Prof.) Biographical no- tice of the late, 35. Himalayan glaciers. See Glaciers. Hippuric acid, preparation of, 130. Hope (Thomas) M.D., biographical memoir of the late, 148. Humours of the eye, refractive and dispersive powers of the, 232. Hydra viridis, on the co-existence of ovigerous capsules and spermatozoa in the same individuals of the, 123, Hydrochloric acid, on the preparation of, 299. Hygrometer, moist bulb, description of a sliding scale for facilitating the use of the, 13, See Nu- Iceland spar, experiments on the ordinary refraction of light by, 139. Iliad and Odyssey, examination of some theories of German writers, and of Mr Grote, on the authorship of the, 154. Inference, on probable, 288. Ink, colourless, on the use of, in writ- ing, 21. Jacob (W. 8S.) on the extraction of light in the atmosphere, 271. Keith prize medal, presented to Gen, Sir T. M. Brisbane, Bart., 169. Kelland (Prof.) Biographical notice of the late Professor Henderson, 35. on general differentiation, Part ili., 108. on the solution of certain dif- ferential equations, 257. Kemp (Alex.) Notes on practical che- mical subjects, 298. Kreatine, on the preparation of, and on the amount of it in the flesh of different animals, 160. Laws of numerical harmonic ratio. See Numerical Harmonic Ratio. Lead. Chevalier’s experiments on the decomposition of certain salts of lead by charcoal, 15, Lead salts, on the action of, on na- tural waters, 62. Lens, crystalline, note on the form of the, 9. Lias formation, fossils of the. See Fossils. Light in the atmosphere, on the ex- tinction of, 271. on the decomposition and dis- persion of, within solid bodies, 64. experiments on the ordinary refraction of, by Iceland spar, 139. Zodiacal, contributions to the phenomena of the, 162. Limits of sea and river, as applicable to salmon fisheries, 333. Local peculiarities of temperature in different parts of Great Britain, 218. Lochaber, on the parallel roads of, with remarks on the change of re- lative levels of sea and land in Scotland, and on the detrital de- posits in that country, 124, 132. parallel roads of, on the theory of the, 170. Locke’s electric observing-clock, notice of, 226. 357 Logan (W. E.) Two letters to the Earl Cathcart, 296. Luminous impressions on the eye, on the gradual production of, 230. Macdonald (William) M.D., on the ver- tebral column, and some characters that have been overlooked in the de- scriptions both of the anatomist and zoologist, 166. Mackenzie (Sir George S.) Bart., on the use of colourless ink in writing, 21. A few remarks suggested by Professor Forbes’ description of the effects of glacial action among the Cuchullin Hills, and Mr Mac- laren’s views of the facts observed by him at the Gareloch, 65. Speculations respecting the origin of trap-tuff, the cause of earthquakes, and of partial changes of the bed of the ocean, 114, 115. Remarks on the hypothesis of progressive development in the or- ganic creation, 130. Maclagan (Douglas) M.D., and Tilley (Thomas G.) on the constitution of Bebeerine, 46. Maclaren (Charles). Notice of an an- cient beach near Stirling, 7. on grooved and striated rocks in the middle region of Scotland, 233. Notice respecting a deposit of shells near Borrowstounness, 265. Madrepores, on the recent Scottish, with remarks on the climatic cha- . racter of the extinct races, 82. Magnesia, phosphate of, on a new and anomalous, 25. Magnetic instruments, on the thermo- metric correction of, 46. needle, on the combined mo- tions of the, and on the aurora bore- alis, 334. observatory, Makerstoun, See Makerstoun. Magnetical instruments self-register- ing, on a method of rendering, 79. Makerstoun magnetic observatory, ac- count of the, and observations made there, 10. observations, results of the, No. I. On the relation of the varia- tion of the earth’s magnetism to the solar and lunar periods, 58. No. II. On the relation of the variations of the vertical component _ of the earth’s magnetic intensity to the solar and lunar periods, 97, ¢ + » * Makerstoun observations, results of the, No. III. On the solar and lunar periods of the magnetic declination, 144, Malta, mud-slide at, description of, 195. Manna from New South Wales, ona new species of, 239. Mannite, on the extraction of, from the dandelion, 223. Marshall (Margaret H.) Experiments and investigations as to the influence exerted over some minerals by ani- mal and vegetable matter, under certain conditions, 59. Maxwell (James Clerk), on the deserip- tion of oval curves, and those having a plurality of foci, 89. on the equilibrium of elastic solids, 294. Meteor, account of a remarkable, seen 19th December 1849, 309, Milk and blood, miscellaneous obser- vations on, 32. Milne(David). Notice of polished and striated rocks recently discovered on Arthur’s Seat, and in some other places near Edinburgh, 95. on the parallel roads of Loch- aber, with remarks on the change of relative levels of sea and land in Scot- land, and on the detrital deposits in that country, 124, 132. Milward (A.) An attempt to explain the “ dirt-bands”’ of glaciers, 195. description of a mud-slide at Malta, 195. Minerals. Experiments and investi- gations as to the influence exerted over some minerals by animal and vegetable matter, under certain conditions, 59. Mirrors and sun-shades of reflecting instruments, determination of the errors arising from non-parallelism in the, 22. Moist-bulb hygrometer. meter. Molecular vortices, and its application to the mechanical theory of heat, on the hypothesis of, 275. Monstrosities, an account of some, 267. Morinda citrifolia, on the colouring matter of the, 179. Motions, combined, of the magnetic needle, 334. Motive power of heat, 241. Mud-slide at Malta, description of a, 195. Muscles, on the influence of contrac- tions of, on the circulation of the blood, 91. See Hygro- 358 Muscular substance of the tongue, 258. Navigation in tidal rivers, on the im- provement of, 26, Negative quantities, Warren’s doctrine respecting the square root of, an attempt to elucidate and apply, iN New South Wales, on a new species of manna from, 239. New voltaic battery of intense power, 239. Nomenclature, personal, of the Ro- mans. See Romans. Nova Scotia, on the boulder formation and superficial deposits of, 140. on the mode of occurrence of gypsum in Nova Scotia, and on its probable origin, 141. Numbers, on the sums of the digits of, 49, Numerical harmonic ratio, on an ap- plication of the laws of, to forms generally, and particularly to that of the human figure, 304. Observatory (Royal) of Edinburgh, on the course of observation to be pursued in future at the, 126. on certain anomalous devia- tions of the transit instrument at the, 142. Makerstoun. See Makerstoun Observatory. Trevandrum, observations of terrestrial temperature made at, from May 1842 to December 1845, 127. Ocean, speculation respecting partial changes of the bed of the, 114, 116. Oil and albumen in the animal eco- nomy, on the structural relation of, 136. Oils, fixed. See Fixed Oils. Ores of copper, notice of two, one of them a new mineral, 146. Organic creation, remarks on the hy- pothesis of progressive development in the, 130. colouring matters, on the ac- tion of the dry gases on, 183. Orkney, volcanic shower in, and re- cent eruption of Hecla, 56. Oval curves, description of, 89. Ovigerous capsules and spermatozoa in the same individuals, of the Hydra viridis, on the co-existence of, 123. Parallel roads of Lochaber. See Loch- aber. Paul’s (St) 2d Epistle to Timothy, an attempt to show that the Claudia mentioned in, was a British prin- cess, 63. Peruvian musical instrument like the ancient syrinx, 325. Phosphate of magnesia, on a new, 25. Phosphates of the organic alkalies, note on the constitution of the, 148. Phosphoric acid from bones, on the ex- traction of, 25. Physics, cometary, remarks on, 326. Picoline, a new organic base from coal- tar, on the constitution and proper- ties of, 94. Powder, on a black, which appeared on the surface of Loch Dochart, on the morning of 23d November 1846, 129. Probability, an attempt to compare the exact and popular estimates of, 228. Probable inference, on, 288. Proportion, symmetric, Professor Kel- land's exposition of the views of Mr D. R. Hay on, 328. Purification and properties of chloro- form. See Chloroform. Rain-gauge, on a simple form of, 234, Ramsay (Rey. E. B.) Biographical no- tice of Dr Chalmers, 226. Rankine (W. J. M.) Abstract of a paper on the hypothesis of molecu- lar vortices, and its application to the mechanical theory of heat, 275. Reflectors, metallic, for sextants, on the use of, 22. Refracting power of the eye, 251. Refraction (ordinary) of light by Ice- land spar, 139. Refractive and dispersive powers of the humours of the eye, 232. Refractive and dispersive power of chloroform, 187. Reid (John) M.D. Account of a pecu- liar structure found in the Vag- marus Islandicus, 241. An account of some monstrosi- ties, 267. Rhine and Rhone, geological notes on the valleys of the, 189. Rings, annual, of glaciers, observations on the cause of, 196. Rivers, tidal, improvement of naviga- tion on, 26. Robison (John). Note regarding an experiment suggested by, 244. (Sir John) K.H., Sec. R.S.E. Biographical notice of the late, 68. a ——— OE ‘af 359 Rocks in the neighbourhood of Edin- burgh, additional example of dilu- vial scratches on the, 159. on grooved and striated, in the middle region of Scotland, 233. Notice of polished and striated, recently discovered on Arthur’s Seat, and in some other places near Edinburgh, 95, volcanic, analogy of the struc- ture of, with that of glaciers, 17. Rolling curves, abstract of a commu- nication on, 222. Romans, on the personal nomenclature of the, with an especial reference to the nomen of Caius Verres, 87. Rooms, method of cooling the atmo- sphere of, in a tropical climate. See Atmosphere. Salmon fisheries, on the physical and Scottish statutory limits of sea and river, as applicable to, 333. Salts, soluble lead, on the action of, on natural waters, 62. Savoy, new observations on the gla- ciers of, 103, 107. Scandinavia, personal observations on terraces, and other proofs of changes in the relative level of sea and land in, 247. Scotland, on grooved and striated rocks in the middle region of, 233. Scottish Madrepores. See Madrepores. Sea and river, on the physical and Scottish statutory limits of, as ap- licable to salmon fisheries, 333. Sextants, on the use of metallic re- flectors for, 22. Shells, near Borrowstounness, notice respecting a deposit of, 265. Shooting star, notice of a, 236. Siam, on the gamboge tree of, 263. Skate, flapper, and other rays, on the existence of an electrical apparatus in the, 1, 8, 9. Smith (Messrs) on the extraction of mannite from the dandelion, 223. Smyth (Prof.) on the appearance of the great comet of 1843, at the Cape of Good Hope, 87. on the course of observation to be pursued in future at the Royal Observatory of Edinburgh, 126. on certain anomalous devia- tions of the transit instrument at the Royal Observatory, Edinburgh, 142. en Contributions to the pheno- ‘mena of the zodiacal light, 162. - Practical illustration of the VOL. Il. adjustments of the equatorial in- strument, 104, Smyth (Prof.) Notice of the binary star « centauri, as recently determined by Capt. W. 8. Jacob, Bombay Engineers, 178, An attempt to improve the present methods of determining the strength and direction of the wind at sea, 180. Notice of Locke’s electric ob- serving-clock, 220. on a method of cooling the atmosphere of rooms in a tropical climate, 235. Notice of a shooting star, 236. Note regarding the American electric observing-clocks, 309. Some remarks on cometary physics, 326. Solar and lunar periods of the mag- netic declination, on the, 144. Solids, elastic, on an instrument for measuring the extensibility of, 173. on the equilibrium of, 294. Soluble lead salts. See Salts. Solvent action of drainage water on soils, 28, Stactites, silicious, on Arthur’s Seat, 216. Star, binary, « centauri, notice of the orbit of the, as recently determined by Capt. W. 8. Jacob, 178. Star, shooting, notice of a, 236. Stark (James) M.D., on the existence of an electrical apparatus in the flapper skate, and other rays, 1, 8. Stenhouse (John) M.D. Analysis of the mannite, 223. Stevenson (David) on the improve- ment of navigation in tidal rivers, 26. (Thomas). Account of ex- periments to measure the direct force of the waves of the Atlantic and German oceans, 13. Stirling, notice of an ancient beach near, 7. Strachey (R.) on the rate of pro- ecg of the Himalayan glaciers, 196. Strata of Greywacké schist, impres- sions on the surface of certain. See Greywacké Schist. Strata, superficial, of the neighbour- hood of Edinburgh, notes on the, 110, 111. Strength and direction of the wind at sea, 180. Sulphuric acid, on the purification of, 298. 21 hens f ph aces