cS 44^ THE EDINBURGH NEW PHILOSOPHICAL JOURNAL, EXHIBITING A VIEW OF THE PROGRESSIVE DISCOVERIES AND IMPROVEMENTS IN THE SCIENCES AND THE ARTS. CONDUCTED BY ROBERT JAMESON, OfSSSOn OF NATURAL HISTORY, LECTURER ON MINKRALOGY, AND KEEPER OP THE MUSEUM IN THE UNIVERSITY OF EDINBURGH ; FeDowof the Royal Societies of London and Edinburgh; of the Antiquarian and Weraerian Societies of Edinburgh; Honorary Member of the Royal Irish Academy, and of the Royal Dublin Society ; Fellow of the Linnean and Geological Societies of London ; of the Royal Geological Society of Cornwall, and of the Cambridge Philosophical Society ; of the York, Bristol, Cambrian, Northern, and Cork Institutions; of the Royal Society of Sciences of Denmark; of the Royal Academy of Sciences of Berlin ; of the Royal Academy of Naples ; of the Imperial Natural History Society of Moscow ; of the Imperial Pharmaceutical Society of Petersburgh ; of the Natural History So- ciety of Wetterau ; of the Mineralogical Society of Jena ; of the Royal Mineralogical Society of Dresden ; of the Natural History Society of Paris; of the Philomathic Society of Paris ; of the Natural History Society of Calvados; of the Senkenberg Society of Natural History ; Honorary Member of the Literary and Philosophical Society of New York ; of the New York Historical Society ; of the American Antiquarian Society ; of the Academy of Natural Sciences of Philadel- phia ; of the Lyceum of Natural History of New York, Sfc. ^c. OCTOBER 1826... APRIL 1827. TO BE CONTINUED QUARTERLY, EDINBURGH: PRINTED FOR ADAiyi BLACK, NORTH BRIDGE, EDINBURGH ; AND LONGMAN, REES, ORME, BROWN, & GREEN, LONDON. 1827. p. Neill, Printer, Edinburgh. CONTENTS. Page Art. I. Historical Eloge of the late Sir Joseph Banks^ Ba- ronet, President of the Royal Society. By Baron CuviER, - - - - 1 II. Remarks and Experiments relating to Hygrometers and Evaporation. By Mr Henry Meikle. Com- municated by the Author, - - 22 III. On Coloured Shadows. By Messrs Zchokke and TRESCHELyMmor, - - - - 32 IV. Notice regarding the Little Andaman Island in the Bay of Bengal. Communicated by Cornet J. E. Alexander, H. M. 1 3th Light Dragoons. With a Plate, - - - - . 43 V. Some particulars relative to the Tides in the upper part of the River Thames, and of the obstructions caused by the present London Bridge. By P. Bar- low, F. R. S. Mem. Imp. Acad. Petrop., &c. Com- municated by the Author, - - 49 VI. On the Affinities of the Empetreae, a natural Group of Plants. By Mr David Don, Libr. L. S. &c. Com- municated by the Author, _ - 59 VII. Establishment of Vegetation at the Surface of the Globe, 64 VIII. Observations made during a Visit to Madeira, and a residence in the Canary Islands. By Baron Leo- pold Von Buch. (Continued from former Volume, p. 380.), 73 IX. Observations on the Arctic Sea and Ice, and the in- tended Expedition of Captain Parry to the North Pole. By Thomas Latta, M. D. Communicated by the Author, - - - - 86 ii CONTENTS. Art. X. General Observations on the former and present Geo- logical Condition of the Countries discovered by Captains Parry and Ross. By Professor Jameson, 104< XI. Remarks tending to explain the Geological History of the Earth. By Professor Esm ark, - 107 XII. Observations on the Structure and Functions of the Sponge. By R. E. Grant, M.D. F.R.S.E. F.L.S. M. W. S. Honorary Member of the Northern Insti- tution, &c. Communicated by the Author. Con- cluded from the preceding Volume, p. 351. With a Plate „ - _ . 121 XIII. Enumeration of the Instruments requisite for Me- teorological Observations ; with Remarks on the mode of conducting such Observations. By Pro- fessor Leslie, - - - - 141 XIV. Description of the Eruption of Long Lake and Mud Lake, in Vermont, and of the desolation effected by the rush of the waters through Barton River, and the lower country, towards Lake Memphre- magog, in the summer of 1810, in a Letter to Prof Silliman. By the Rev. S. Edwards Dwight. With a Plan of the Lakes, - - 146 XV. Information regarding the Overland Arctic Expe- dition, _ - - - i6i XVI. On the Luminousness observed in the Eyes of Hu- man Beings, and also in those of Cats, Dogs, Horses, and Sheep. By Dr Charles Ludwig ESSER, - - - - l64 XVII. Account of the Habits of the Turkey Buzzard (Vul- tur aura), particularly with the view of exploding the opinion generally entertained of its extraordi- nary power of Smelling. In a Letter to Professor Jameson, by John J. Audubon, Citizen of the United States, - - - - 172 XVIII. List of Rare Plants which have Flowered in the Royal Botanic Garden, Edinburgh, during the last three months ; with Descriptions of several New Plants. Communicated by Dr Graham, 184 XIX. Celestial Phenomena from January 1. to April 1. 1827, calculated for the Meridian of Edinburgh, Mean Time. By Mr George Innes, Aberdeen, 188 CONTENTS. iii Art. XX. Proceedings of the Royal Society of Edinburgh, I90 XXI. Proceedings of the Wernerian Natural History So- ciety, - - - - - 191 XXIir Scientific Intelligence. METEOROLOGY. 1. Meteors seen in India. 2. Water-spouts in the Irish Chan- nel. 3. Winds in the Polar Regions, - 191-193 CHEMISTRY. 4. The presence of animal and vegetable matter, or emanations from them, not necessary for the formation of Nitre. 5. Phosphorus in Kelp, - - - 193, 194? GEOLOGY. 6. Geognostical Structure of the Country around Darwar. 7. Account of Libellulite found at SolenhofFen. 8. Beds Sea-shells, nearly in a fresh state, 200 feet above the le- vel of the Sea. 9. Green-sand formation in Sweden. 10. Coal of Hoganas. 11. Hill of Magnetic Iron-Ore. 12. Hyaena Cave, - - - 19^-197 MINERALOGY. 13. Crystallizations of Sulphate and Carbonate of Lead ob- served by M. Hartmann. 14. Geognostic Position of Platina in America. 15. Jet discovered in Wigtonshire. 16. Geognostical Distribution of Gold in the Uralian Mountains. 17. Geognostic situation of the Siberian Platina. 18. Cordierite found in Norway. 19- Magni- ficent Crystals of Sulphate of Iron, or Green Vitriol. 20. Iserine and Iron-sand in Cheshire. 21. Bismuth Cobalt-Ore. 22. Selenium in Red Copper-Ore, 197-201 HYDROGRAPHY. 23. Discovery of a New Substance in Sea Water. 24. Iodine and Lithion in the Mineral Springs of Theodoreshall at Kreutznach. 25. Thickness of Salt Water Ice, 201, 202 ZOOLOGY. 26. Sword Fish found in the Frith of Forth. 27. Discovery of the Circulation of the Blood in Insects. 28. Turf* V CONTENTS. Leech, 29. Notice of two new species of British Sponges. SO. South African Museum, (1st Series). 31. Ditto (2d Series). S2. Narcotic Spider. 33. Power of the Sto- mach of Birds. 34. Vulture shot in Somersetshire. 35. Gigantic Orang Outang, - - - 201-207 BOTANY. 56. Irish Furze, Broom, and Yew, - - 207 ARTS. 57. Easy mode of Cutting Glass, - - - ib. Art. XXIII. New Publications. 1. Mathematics practically applied to the Useful and Fine Arts ; by Baron Charles Dupin, Member of the Insti- tute, of the Academy of Sciences, &c, &c. Adapted to the State of the Arts in England; by George BiRKBECK, Esq. M. D. President of the London Me- chanics' Institution, - - - 208 2. ^udubon's great Work on the Birds of the United States of America, _ _ - _ 210 3. The Aberdeen, Leith and London Tide Tables for the year 1827; by George Innes, Astronomical Calcula- tor, Aberdeen, - - - - 211 XXIV. List of Patents granted in England from 18th September to 18th November 1826, - 211 XXV. List of Patents granted in Scotland from 9th September to 8th November 1826, - 212 CONTENTS. Pages Art. I. Biographical Memoirs of Charles Bonnet and Ho- race Benedict de Saussure. Read to the Royal Institute of France by Baron CuviER, - 213 II. A Description of some appearances of remarkable Rainbows. By the Reverend William Scoresby, F. R. S. Lond. & Edin. M. W. S. &c. Communi- cated by the Author. (With a Plate), - 235 III. Tour to the South of France and the Pyrenees, in 1825. By G. A. Walker Arnott, Esq. A.M. F.L.S. & R. S. E. &c. In a letter to Professor Jameson. (Continued from the preceding Volume), - 241 IV. Account of a Visit to the Glaciers of Justedal, and to the Mantle of Lodal. By Mr G. Bohr, of Bergen, 255 V. Observations on Serpentine and Diallage Rocks. By Dr A. Boue'. In a Letter to Professor Jameson. Communicated by the Author, - - 265 VI. Observations on the Natural History of the Alligator. In a Letter to Sir William Jardine, Baronet, and Prideaux John Selby, Esq. By John J. Audu« BON, Esq. Member of the Wernerian Natural His- tory Society, &c. - - - - 270 VII. Observations and Experiments on the different kinds of Coal. By M. Karsten, - - - 280 VIII. Considerations regarding the shining of the Eyes of the Cat, and several other Animals. By M. Bene- dict Prevost, - - * . 297 IX. Remarks on the Rhubarb of Commerce, the Purple- coned Fir of Nepal, and the Mustard Tree. By Mr David Don, Librarian of the Linnean Society, Member of the Imperial Academy Naturae Curio- sorum, of the Wernerian Society, &c. Communi- cated by the Author, - - , SO* ii CONTENTS. Art. X. On the Structure and Characters of the Octopus ven- tricosus, Gr. (Sepia octopodia^ Pent), a rare spe- cies of Octopus from the Firth of Forth. By R. E. Grant, M. D. F. R. S. E. &c. Fellow of the Royal College of Physicians of Edinburgh, Honorary Member of the Northern Institution, &c. Com- municated by the Author, - - 309 XI. Meteorological Observations made in Jamaica by the late John Lindsay, Esq. Surgeon, Jamaica. Com- municated by W. C. Trevelyan, Esq. M. W.S. &c. 317 XII. A Description of the genus Malesherbia of the Flora Peruviana; with Remarks on its Affinities. By Mr David Don, Libr. L. S. ; Member of the Impe- rial Academy Natura? Curiosorum, of the Werne- rian Nat. Hist. Society, &c. - - 320 XIII. Account of a Gelatinous Quartz or Siliceous Sinter, which forms the basis of varieties of Old Red Sand- stone. By M. T. Gutllemin, - - 324 XIV. Experiments to compare the specific Heat of Air un- der a constant volume, with its specific Heat under a constant pressure. By Mr Henry Meikle. Com- municated by the Author, - - 328 XV. On the Detection of Arsenic in cases of Poisoning. By J. L. Berzelius, - - _ $$8 XVI. On a Chemical Composition of Zinkenite and Jame- sonite. By H. Rose, Member of the Royal Aca- demy of Berlin. And Description and Analysis of Pyrochlore, a new Mineral. By F. Wohler, 341 XVII. The Law of the Preservation of Species, illustrated by the Phenomena of the seed of the Stipa pennata. By Mr John Macvicar, Lecturer on Natural His- tory in St Andrew's, (With a Plate.) Communi- cated by the Author, _ - . 343 XVIII. Account of the Observations and Experiments made on the Diurnal Variation and Intensity of the Mag- netic Needle, by Captain Parry, Lieutenant Foster, and Lieutenant Ross, in Captain Parry's Third Voyage ; with Remarks and Illustrations. By Pe- ter Barlow, F. R. S. Mem. of the Imperial Aca- demy of St Petersburgh, &c. (With a Plate.) Communicated by the Author, - - 347 XIX. On the Use of a Simple Syphon as a Hydrometer. By Mr H. Meikle. Communicated by the Author, 366 CONTENTS. iu Art. XX. On the Marine Live Cockles, said to have been found at a great distance from the Sea in York- shire. In a Letter to Professor Jameson. By W. C. Trevelyan, Esq. M. W. S. &c. - 367 XXI. Notice of Fresh Water found in the Sea at a great distance from the Land. By D. Buchanan, Esq. In a Letter to Professor Jameson, - 369 XXII. Description of Anatina villosiuscula, a new Spe- cies, and of Venerupis Nucleus, a Species new to the British Fauna. By Mr William Mac- GiLLivRAY, M.W. S. &c. With Figures. Com- municated by the Author, - - 370 XXIII. Account of the Capture of a colossal Orang-Ou- tang in the Island of Sumatra, and Description of its Appearances. By Dr Clark Abel, 371 XXIV. On the Lead-Mines in the South of Spain, 375 XXV. Letter of Professor Buckland to Professor Jame- son, and of Captain Sykes to Professor Buck- land, on the Interior of the Dens of Living Hyaenas, - - _ - 377 XXVI. On the growth and preparation of Straw used in the Tuscan trade, - . . 380 XXVII. Remarks on Dr Latta's Observations on the Arc- tic Sea and Ice. In a communication from the Rev. Mr Scoresby to Professor Jameson, 382 XXVIII. On the Coniometer. In a Letter from Professor Leslie to Professor Jameson, - - 384 XXIX. List of Rare Plants which have Flowered in the Royal Botanic Garden, Edinburgh, during the last three months; with Description of a new species of Euonymus, Communicated by Dr Graham, - - - _ 336 XXX. Celestial Phenomena from April 1. to July 1. 1827, calculated for the Meridian of Edinburgh, Mean Time. By Mr George Innes, Aberdeen, 387 XXXI. Proceedings of the Wernerian Natural History Society, - - _ . 339 XXXII. Scientific Intelligence. natural philosophy, 1, Repulsion of Heat inversely as the square of the distance. 2. The Beech-tree a Non-conductor of Lightning, 39I, 392 iv CONTENTS. HYDROGRAPHY. 3. Silica in Springs is dissolved by means of Carbonic Acid, SpSf ZOOLOGY. 4. Tit-Lark caught at Sea. 5. Egyptian Antiquities in Liver- pool Museum. 6. Notice regarding the Common Star- fish, Asterias rubens, - - - 393, 394, BOTANY. 7. Conclusions of M. Bureau de la Malle's Inquiries respecting the Ancient History, Origin, and Native Country of the Cereales, and especially Wheat (Triticum hibernum and aestivum), and Barley (Hordeum vulgare and hexastichon). 8. Instructions for Collecting and Preparing Fungi for Herbariums, and for Preserving them from the Attacks of Insects and their Larvae. 9* Effects of certain Manures on the qualities of Plants, - - _ 395^397 ARTS. 10. New mode of applying Graphite, or Black Lead, in Draw- ings. 11. On Etching and Dyeing at once figures on Ivory; by Mr J. Cathery, - - - 398,399 NEW PUBLICATIONS. 1. Essay on the Theory of the Earth. By Baron George Cu- viER ; with Geological Illustrations by Professor Jame- son. Fifth edition. Translated from the last French edition, with numerous additions by the Author and Translator. Eleven Plates. Blackwood, Edinburgh ; Cadell, London. 14s. - - - 400 2. Illustrations of the Geology of Sussex, containing a general view of the Geological relations of the South Eastern part of England ; with Figures and Descriptions of the Fos- sils of Tilgate Forest. By Gideon Mantell, Esq. F. R.S. Fellow of the Royal College of Surgeons, F.L.S. M.G.S. &c. One volume quarto, - - . 402? 3. Mathematical and Astronomical Tables for the use of Stu- dents of Mathematics, Practical Astronomers, Surveyors, Engineers, and Navigators. By William Galbraith, M. A. Oliver & Boyd, Edinburgh. 9s. - 404 Art. XXXIII. List of Patents granted in England, from 8tb December 1826 to l6th January 1827, 407 XXXIV. List of Patents granted in Scotland from 13th December \S26 to 24th February 1827, 409 List of Plates, - - - -r 410 THE EDINBURGH NEW PHILOSOPHICAL JOURNAL. Historical Eloge of the late Sir Joseph Banks, Baronet, Pre- sident of the Royal Society. By Baron Cuvier *. X. HE works which the distinguished individual of whom we have now to speak has left behind him, are confined to a few pages, and these of but little importance ; yet his name will shine with lustre in the history of philosophy. Impelled by an ardent love of science, in his youth, abandoning the pleasures which an independent fortune held out to him, he braved the dangers of the sea, and the rigours of the most opposite climates. During a long series of years, he made use of all the advantages which affluent circumstances, and the friendship of men in power, afforded him, for its benefit; lastly, and it forms his chief claim to our respect, he always regarded those who laboured for its advancement, as having an acquired right to his interest and assistance. During the war of the revolution, which carried its ravages into almost every part of the two continents, the name of Sir Joseph Banks was every where a palladium for those of our countrymen who devoted themselves to useful researches. If their collections were seized, it was only necessary for them to apply to him to have them returned; if their persons were detained, the time • Read to the Royal Academy of Sciences of France on the 2d Aprif 1821. OCTOBER— DECEMBER 1826. At g Baron Cuvier's Historical Eloge of necessary for transmitting them intelligence, was the only de- lay which their restoration to hberty experienced. When the seas were shut up against us, they opened at his voice for our scientific expeditions. Geography and Natural History are indebted to him for the preservation of precious labours ; and, without him, our public collections would still, at the present day, and perhaps for ever, have been deprived of a part of the riches which adorn them. It will, without doubt, be admit- ted, that the benefit accruing to science from services like these, is fully equivalent to that resulting from the authorship of books ; and if, in this discourse, it is principally the acknow- ledgment due to noble actions that we have to express, it is not too much to augur of our hearers, that this feeling will not be less intensely participated by them, than that of admiration for great discoveries would have been. Sir Joseph Banks, Knight Baronet, Counsellor of State to the King of England, Grand Cross of the Order of the Bath, President of the Royal Society of London, and Foreign Asso- ciate of the Academy of Science of the Institute of France, was born in London, in Argyle Street, on the 13th February 1743. His father'*s name was William Banks Hodgenkson, and his mother"*s Marianne Bate. Some trace the origin of his family to one Simon Banks, a Swede, who settled in Yorkshire in the time of Edward HI., and who would have been the eighteenth progenitor of Sir Joseph. Others say that his family came from Sweden only a century before, and had seen but two generations in England. It appears that Sir Joseph's grand- father practised medicine in Lincolnshire, and that the suc- cess which he met with in his profession, afforded him the means of acquiring a pretty large fortune. Having risen to considerable importance in the county, he was invested, in 1736, with the office of Sheriff, and sat in one or two Parhaments as represen- tative of the town of Peterborough. Joseph Banks, like the greater number of young English- men born in easy circumstances, after having been confided for some time to the care of a clergyman, was sent to a public seminary. His parents at first made choice of that of Harrow, near London, from whence they removed him to Christ's Col- Sir Joseph Banks, Bart. 3 lege, in the University of Oxford ; and his father dying in 1761, he entered the world at the age of eighteen, master of himself and his fortune. This might have proved a dangerous shoal for so yoimg a man ; but henceforth Mr Banks was only sensible to the enjoyments attached to the labours of the mind, and the only use he made of his liberty was to devote himself exclusively to them. About this period, Natural History began to raise itself from the low condition in which the more advanced sciences had kept it. The eloquent pictures of BufFon, and the ingenious classi- fications of Linnaeus, afforded numerous attractions to the mind. In the steps of these celebrated men, there were seen to open paths alike new and full of interest ; and it was in ex- ploring these paths that a young man would naturally engage, who devoted himself to science only for the sake of gratifying his inclination. Mr Banks, therefore, at an early period, en- gaged in the examination of the productions of nature, and especially those of the vegetable kingdom. His taste for plants soon changed into a passion, and he made all the sacrifices to their investigation that it required. The first of these, as every ^ody knows, is to travel much on foot ; and this sacrifice is more disagreeable than any other in a country where this mode of travelling is so little in use, that it might of itself render a man hable to be suspected. Our young botanist was in fact more than once taken for a thief ; and one day that he had fal- len asleep from fatigue at a distance from the highway, he was violently seized by officers of police, and carried bound before a Magistrate, who was much amused with the adventure. However, his ardour for study did not make him forget to take care of his affairs. From this time, also, he began to re- flect, that the way in which he could be enabled to serve society with most ease, was to put himself in a condition for serving it, without demanding assistance from it. The most considerable part of his property was situated at Revesby, in Lincolnshire, upon the borders of that vast extent of marshy meadows which surrounds Boston Bay, the nature of which, in its characters, bears so close a resemblance to the province of Holland, that a portion of it has obtained the same name. He spent a part of the a2 4 Baron Cuvier's Historical Eloge of year in this country. Here he perfected the art of digging canals and raising dikes, so important for the improvement of land like this ; he peopled the pools and small lakes of this fenny country, and sometimes amused himself with fishing. It is even said that it was in this exercise that he contracted a friendship with John Montagu, Earl of Sandwich, who afterwards became First Lord of the Admiralty, and who saw his name immorta^ lized by the surprising advances in physical geography that took place during the time of his administration. If this anecdote be true, it presents an additional example of the great eiFects that may result from a trivial cause ; for it can- not be doubted that Mr Banks's influence contributed power- fully to multiply these discoveries. If he did not require to ex- cite the Earl of Sandwich to expeditions which the will of the King sufficiently recommended to him, it is not the less true that he more than once pointed out to him the places to which it would be most advantageous to direct them, and acquainted him with the surest means of rendering them successful. The example of this minister besides, became at length a sort of rule, and the numerous successors which he had in this elevated post, all thought themselves honoured by consulting the man whose advice had proved so beneficial. Mr Banks, however, did not wait until he had acquired this degree of credit, to carry his views into execution. In 1766, one of his friends being captain of the vessel that was destined to protect the Newfoundland Fishery, he profited by the oppor- tunity thus aflbrded of visiting that country. This was not indeed directing his first course toward the most attractive coast, but he soon had an opportunity of compensating for it. The peace of 1763 came to restore tranquillity to Europe, and to open the seas again. The nations sought to repair, by new enterprises, the evils which their dissensions had caused. England especially, victorious in both hemispheres, and seeing unlimited careers present themselves on all sides to her fortune, shewed an energy, which, directed by an ambitious chief, might have proved highly injurious to humanity. Fortunately, at this period, a sceptre which was almost that of the ocean, passed into the hands of a young Monarch, pure in his morals, simple in his tastes, and who had early learned that useful discoveries Sir Joseph Banks, Bart 5 might reflect as much lustre upon a reign as conquests. He was the first among princes who formed the idea of visiting new countries without carrying terror into them, and of making known his power only by his benefits. Whenever the historian records an example like this, it is his duty to shew it in all its beauty. It especially belongs to the historian of science, in ful- filling this duty, to raise himself above the wretched rivalships of nations : and although the nation which has merited this ho- mage has been so often and so long at war with France, it is undoubtedly not before an assembly such as ours that I need apologise for having rendered it. George III. was therefore eager, upon his coming to the throne, to send some vessels to the South Sea, with general in- structions for extending geographical knowledge. Commodore Byron had been sent there in 1764. Two other officers, Cap- tain Wallis and Captain Carteret, were sent out in 1766 ; they had not yet returned, when a fourth expedition was fitted out, under the command of James Cook, who, by this voyage, and the two others which he performed, contributed more to extend the knowledge of the globe, than any navigator who had pre- ceded him for two centuries. His voyage had in viev/ at once the interests of geography and of astronomy ; for Cook's principal commission was to observe the passage of Venus over the Sun's disc, which, having already taken place in 1761, was to occur again in 1769. Mr Banks resolved to make it also contribute to the advan- tage of Natural History, and requested for this purpose to parti- cipate in its dangers, and devote to it a part of his fortune. He spared nothing to ensure its success, in as far as regarded himself; he provided at his own expence a great store of ob- jects that might be useful to the people he was about to visit ; he got all the apparatus necessary for physical observations, and the preservation of natural objects, placed in the vessel ; he engaged a distinguished pupil of Linnagus, lately settled in England, Dr Solander, to prosecute with him the science which was the common object of their love ; he took with him two painters, to make drawings of what could not be preserved ; he engaged the necessary servants ; in short, he provided all that might render his enterprise agreeable and successful. 6 Baron Cuvier's Historical Ehge of We would remark here, that this period must be noted in the history of science, as that at which natural history began to extend its researches upon a large scale, by contracting an al- liance with astronomy and navigation. It was also for the pur- pose of observing the same transit of Venus, that the Empress Catherine II. appointed the great expeditions into Siberia, un- der the direction of Pallas, and during which valuable collec- tions were made by numerous naturalists. At the same time, Bougainville, by order of Louis XV., sailed round the world, taking with him Commerson, a man of boundless activity, and of almost universal knowledge. And it was truly in these three enterprises, which were nearly contemporaneous, that govern- ments learned by what point the sciences are connected, and how the services which they confer are increased by combining their investigations. I may be excused from relating, in detail, to the present au- ditory, the events of this first voyage of Captain Cook. W^ho is there among us that has not, from his childhood, read the ac- count of it with a sort of delight ? Who has not trembled for our travellers, when the cold threatened to chill them into a fatal sleep among the snows of Terra del Fuego ? Who has not wished to live for a short time, like them, in the midst of the primitive people of Otaheite, — amid those beings so beautiful, so mild, happy in their i^nnocence, enjoying, without disquietude, all the pleasures that are to be found under a serene sky, and upon a fertile soil ? Whose heart has not palpitated for the fate of our navigators, when, having struck upon the coral rocks of New Holland, they saw the planks of their vessel come asun- der, one by one ; a leak opening which their pumps were unable to subdue ; and when, after having no other prospect but death before them, for two days, they were suddenly saved by the expedient suggested by a man who was no mariner, of pushing, from without, bundles of wool into the gaps of the vessel ? All the circumstances of this expedition, — the perils and plea- sures of the navigators, the varied manners of the tribes among which they landed, the caresses of the new Circes of Otaheite, the combats with the cannibals of New Zealand, with the general con- flagration of the grass, in which the inhabitants of New South Wales were on the point of enveloping them,— seem to realise Sir Joseph Banks, Bart. ^f those amusing fables of the Odyssey, which have been the de- hght of so many nations and so many ages. Now, it is incontestably to the presence of two men educated with other ideas than those of mere sailors ; it is to their manner of observing and feehng, that this powerful interest is in a great measure due. Nothing was spared by them for enriching their collections, and satisfying their curiosity. Mr Banks especially, always manifested an astonishing activity ; he was neither re- pulsed by fatigue, nor arrested by danger. He is seen at Bra- zil, gliding, like a smuggler, along the shore, in order to pick up some of the productions of that rich country, notwithstand- ing the stupid jealousy of the governor. At Otaheite, he has the patience to let himself be painted black, from head to foot, in order to be admitted to a funeral ceremony, which he could not otherwise have seen. And it is not only for seeing and ob- serving that he displays his character : in every place, although destitute of legal authority, he seems naturally to assume the rank which in Europe would have been given him by the con- ventions of society. He is always foremost. He presides at the markets, and over negotiations. It is to him that both parties address themselves in any dispute. It is he who pursues the thief, and recovers the articles stolen. If he had not thus re- covered the quadrant, which had been adroitly carried off by an islander, the principal object of the enterprise, the observation of the passage of Venus over the sun^s disk, would not have been accomplished. Once only he did not dare to render him- self justice; but it was when the Queen Oberea, having lodged too near him, stole away all his clothes through the night ; and it will be allowed, that, in such a case, it would not have been gallant to have insisted too much on his rights. This sort of magistracy, to which he found himself raised, de- pended upon the circumstances, that, while his figure and coun- tenance were formed to inspire respect, his unremitting goodness laid claim to friendship. He gave to the savages instruments of agriculture, seeds of culinary vegetables, and domestic animals ; he was watchful to prevent their being maltreated, and even to such a degree as to have them treated with indulgence when the fault was upon their side. If there exist a natural pre-eminence, it is that which is the offspring of intellect and beneficence. 8 Baron Cuvier''s Historical Ehge of His collections, during the three years which the voyage last- ed, of objects of all descriptions, were immense, even although a part of them was lost, in consequence of an accident that befel the ship. It was for a long time hoped that Solander and him- self would indulge the public with an account of them ; and it is difficult to imagine what prevented them from doing so. So- lander only died in 1782, and he could have employed ten years of his life in this undertaking. Besides their common journal, their notes, and all the drawings made under their in- spection, still exist in the Banksian Library. The engraving of a splendid series of plates, intended to extend to two thousand, was begun ; but, to the great regret of naturalists, nothing has appeared, at least under the auspices of the authors. Per- haps Mr Banks judged that his treasures would not be the less profitable to science, although he did not publish them himself. One of the most remarkable traits of his character was the gene- rosity with which he communicated his scientific treasures to all who appeared to him worthy of perusing them. Fabricius de- scribed all his insects. He gave specimens of all his fishes to our colleague Broussonnet, for the ichthyology which he had commenced. Botanists who wished to see his plants, had free permission to consult his herbaria. Gaertner constantly profited by this indulgence for his admirable history of fruits and seeds, and Vahl for his Eclogues ; and, in these later times, the excellent work of Mr Robert Brown on the Plants of New Holland, a work composed in Sir Joseph Banks's, and in the midst of his collections, has fulfilled, and more than fulfilled, all that could have been hoped from himself. Besides, he distri- buted, among all the gardens of Europe, the seeds of the South Sea, as in the South Sea he had distributed ours. Lastly, he was satisfied that, in all that could regard immediate utility, the object of his voyage had been as effectually accomplished as it could be. In fact, a multitude of beautiful shrubs, which he first introduced, now ornament our groves and grounds. The Otaheitean cane, which affords more sugar, and ripens more freely, has, in part, repaired the disasters of our colonies ; the bread-fruit tree, carried to the warm countries of America, will repay the services which America formerly rendered to us, when it furnished us with the potato ; the New Zealand flax, the fi- Sir Joseph Banks, Bart. A bres of which are more tenacious than those of any other plant, is cultivated among us, and will infallibly prove, one day, an important acquisition for our marine. Several of our ponds are embellished with the black swan ; the kangaroo and phascolome are kept in some of our parks ; and there is nothing to prevent their becoming animals of game in our woods, as useful as the fallow-deer or the rabbit, which were equally exotic animals. But these are results of ittle importance compared with the ge- neral knowledge which this voyage began to afford us of the Pa- cific Ocean ; of the multitude of islands which nature has spread through it ; and of the creatures, in some measure peculiar, with which they are peopled. New Holland especially, if we except man and the dog, (and these, without doubt, have arrived in it at a comparatively recent period, so miserable is the condition in which they occur there), bears no resemblance, in its organic na- ture, so to speak, to the rest of the world. It possesses other animals, often appearing to unite forms which are contrary to each other ; vegetables which seem destined to subvert all our rules and systems. Within these thirty years, the English have formed an establishment in the middle of this continent, among this creation almost as new to Europe as that of another planet would be. What it has already furnished to science is prodi- gious, and is a source of general advantage to all nations. With regard to the advantages which it gives, and will give, to the mother country, it is not my business to detail them at length ; but every one will perceive what commercial, political, and mili- tary importance a great European colony, in a temperate zone, in a healthy and fertile country, placed between Asia and Ame- rica, and communicating as easily with Peru as with Bengal, must necessarily assume. This much is certain, that, before many years elapse, whether it become independent, or remain subject, it will have multiplied that race of the human species, the most susceptible of civihzation, as extensively as the English colonies of North America have done. Such will be, such already are, in a great measure, the re- sults of the voyage of Cook, Banks, and Solander ; and the rea- son is obvious, because the voyage in question, having men of scientific attainments embarked in it, was directed with more enlightened views, and conducted with more philosophy, than any that had been made for three centuries. 10 Baron Cuvier's Hislorkal Ehge of I need not say with what eagerness these new argonauts were received on tlieir return. All classes of society were anxious to testify what they felt for them ; the King, in particular, shewed them the greatest regard. Friend as he was to botany and agri- culture, he received with great pleasure the seeds and plants which Mr Banks presented to him ; and, from this time, con- ceived an affection for our young traveller, which was never af- terwards interrupted. This description of enterprize, so new and so generous, which originated in England, was so much lauded throughout Europe, that the British government could not but consider itself bound to repeat it. In 1772, Captain Cook was to set out upon his second voyage, of all nautical expeditions the most astonishing for the courage and perseverance of those who embarked in it. Mr Banks was also resolved to accompany him anew ; Solander was again to be taken out ; all the preparations were made : but they demanded, and it was certainly reasonable, to have the conveniency afforded them in the ship, which, without clogging the expedition, might render their exile more comfortable. It is difficult to comprehend how the Captain could resolve to deprive himself of their assistance. Was it jealousy or regret at having his glory divided by men who had so efficiently participated in his labours ? Was it the remembrance of some restraints or in- conveniences which the respect due to persons of their station in society had occasioned him during his former voyage ? We do not pretend to decide. This, however, is certain, that he caused several arrangements which Mr Banks had made in the vessel to be destroyed ; and that the latter, in a moment of irritation, re- nounced all his projects. I shall not here seek to determine between them. If we re- flect that Captain Cook fell out with the two Forsters, who were substituted for Mr Banks and Dr Solander, — that, on the third voyage, he refused to take any naturahst with him, — that there have been none employed since in the nautical expeditions of the English — and that those who have embarked in ours have very seldom been on good terms with their leaders, it will per- haps be found that the freedom of action, to which men of the closet are accustomed, can scarcely be reconciled to the severe discipline so necessary in a ship ; and then we shall neither have Sir Joseph Banks, Bart. 14- to blame our two naturalists, nor the great navigator who could not ageee with them. » Mr Banks, however, as he could not accompany Cook, resolv^ ed to direct his ardour into another path. The northern coun- tries, and especially Iceland, so remarkable for its volcanic phe^ nomena, presented him with sufficient objects of research. In a few weeks a vessel was freighted, laden with every thing that was necessary for naturalists ; and Mr Banks set out on the 12th July 1772, accompanied with his faithful Solander, a Swede, Uno de Troil, afterwards Bishop of Linkoping, and some other persons worthy of taking part in such an enterprise. A fortunate opportunity occurred to them of visiting, in pass- ing, the island of Staffa, so interesting for the immense mass of basaltic columns of which it is formed ; and for the cave of two hundred and fifty feet in depth, entirely surrounded by these columns, the natural regularity of which equals the most surpris- ing efforts of human art. It is singular that this wonder of na- ture, so near a populous country, had been so little known ; but although the island had been named by Buchanan, no person had given any description of its extraordinary structure ; and it may be regarded as a discovery of our voyagers. They soon arrived in Iceland. Here they no longer met with the happy islanders of the South Sea, on whom na- ture had lavished her gifts. A soil, desolated alike by the fire of volcanoes, and by winters of nine months' duration, the low country bristled almost over its whole extent with naked and sharp rocks, mountains of ice floating in the sea, and which often, by their accumulation in the vicinity of the land, caused the winter to recommence ; every thing seems to announce to the Icelanders the malediction of the celestial powers. They bear the impress of the climate ; their gravity, their melancholy aspect, form as great a contrast with the gaiety of the South Sea Islanders, as the countries inhabit- ed by the two nations ; and yet the natives of Iceland have their enjoyments, and these enjoyments of a superior order. Study and reflection soften their lot. Those great natural edi- fices of basalt, and vast fountains of boiling water ; the stony vegetations which this water produces; the northern lights of a thousand forms and hues, illuminating from time to 2 12 Baron Cuvier''s Historical Eloge of time these imposing spectacles, afford them a recompence for their privations, and excite them to meditation. Iceland is per- haps the only colony in the world that has formed a more origi- nal literature than the mother country, or even modern Europe. It is asserted; that one of her navigators discovered America nearly five centuries before Columbus ; and it is only by consult- ing her ancient annals, that documents of any authenticity have been found for the history of Scandinavia. Still at the present day, the meanest peasant is instructed in the history of his country ; and it is in repeating from memory the songs of their ancient poets, that they pass their long winter evenings. Our learned caravan employed a month in traversing the island ; and Mr Von Troil published a very interesting account of what they observed. As to Mr Banks, always little solicitous about himself, he gave to Mr Pennant, for his Journey to Scot- land, the drawings* which he had caused to be made of the island of Staffa and its cave, as well as the description which he had taken of them. In Iceland, as in the South Sea, and as at Newfoundland, it was sufficient for him that his observations were not lost to the public ; and this consideration appears to have satisfied all his wishes. Here, also, he did better than describe ; he became to the Icelanders a not less zealous and a more effective benefactor than to the Otaheiteans. Not only did he draw the attention of the court of Denmark to them, but watching over their welfare himself, he twice, at his own expence, when they were afflicted with famine, sent cargoes of grain to their island. Like the personages which were deified by the ancient mythology, it might be said of him, that he be- came a providence to the places which he had once visited. On his return from two enterprises, in which he had given such splendid proofs of his disinterested love of science, Mr Banks would naturally find his place in the first ranks of those who cultivate it. Having long been a member of the Royal Society, he now took an active part in its administration and labours. His house, open with equal hospitality to men of science of his own and of other nations, became a sort of aca- demy. The welcome of the master, — the pleasure of seeing • These drawings are now preserved in the College Museum of Edinburgh. —Edit. Sir Joseph Banks, Bart. 18 there the meritorious friends whom he had made, — a rich Ubrary, accessible to all, — collections which would in vain have been searched for even in public institutions, drew thither the lovers of science. Nowhere was such a point of union more precious, it might be said more necessary, than in a country where the bar- riers which separate the conditions of society are stronger than in any other, and where men of different ranks meet but rarely, unless some one, for the purpose of bringing them together, puts himself in some measure out of rank, or makes for himself a peculiar and extraordinary rank. Mr Banks was the first who had the good feeling to give him- self this honourable kind of existence, and thus to create a sort of institution, the utility of which was so striking, that it was promptly sanctioned by general opinion. The choice which the Royal Society made of him, some years after, for its president, gave to this sanction all the authenticity which it was capable of receiving. But as is but too common among men, it was at the moment when he obtained this honour, the greatest which he could desire, that the most bitter disputes arose. Here it becomes necessary that we should give some explana- tion to our hearers. The Royal Society of London, the oldest of the scientific academies that subsist at the present day, and, without dispute, one of the first for the discoveries of its members, receives no assistance from government, and is supported solely by the con- tributions of those who compose it. It is therefore necessary for it to be very numerous, and a not less necessary consequence, (as in all the political associations where the participation of the citizens in the government is in the inverse ratio of their num- ber), the men to whom it confides its administration exercise over its labours, and to a certain point over the march and pro- gress of science, a more considerable influence than we can easily fancy to ourselves in our continental academies. The situation of a minister in a representative constitution which obliges him to have guarantees in some measure official for all his acts, contributes still more to this influence, and extends it over the lot of individuals. In reality, a new election is made every year ; but the functions of the president are of so delicate 14 Baron Cuvier's Historical Eloge of a nature that few are capable of executing them ; hence it very seldom happens, that he who has been once invested with them, is not re-elected so long as he consents to be so. A first choice is therefore a great affair in the learned world ; and when it is disputed, it is with great keenness. At the period of which we speak, the discussions that took place had their asperity increased by a singular, I would almost venture to say a ridiculous incident. The natural philosophers of the Royal Society having been consulted about the form that should be given to a lightning-rod that was to be placed upon some public building, had almost unanimously proposed to have it terminated in a point. A single individual among them of the name of Wilson, took it into his head to maintain that it should terminate in a round knob, and he delivered an incom- prehensible harangue in support of this paradox. The thing was so clear, that, in any other country, or at any other time, people would not have listened to him, and the conductor would have been made as all others had hitherto been made. But England was then in the hottest part of her quarrel with her American colonies, and it was Franklin who had discovered the power which points have of drawing off lightning. A ques- tion of natural philosophy therefore became a question of politics. It was carried on not before learned men, but before party men. It was only the friends of the insurgents, it was said, that could be for points, and whoever did not support the knobs, was evi- dently without affection for the mother country. As is usual the multitude, and even the higher classes, were divided, before hav- ing examined the matter, and Wilson found protectors, just as protectors would have been found against the theorem of Py- thagoras, if geometry had ever become an affair of party. It is even asserted that an august personage, on every other occa- sion the generous and enlightened friend of science, had, on (his occasion, the weakness to make himself a solicitor, and the mis- fortune to plead against the points. He spoke to the then pre- sident. Sir John Pringle, a man of sound judgment and of elevated character. Pringle, it is said, respectfully represented, that the prerogatives of the President of the Royal Society did not go so far as to change the laws of nature. He might have added, that, if it be honourable for princes, not only to protect Sir Joseph Banks, Barf. \^. the sciences as they ought, but also to amuse their leisure, by informing themselves of the discussions to which they give rise, it can only be on condition that they do not make their rank interfere in support of the opinions which they adopt. The representations of Pringle were not received with the gracious- ness to which he was accustomed ; and, as this unhappy quarrel had already, for three years, involved him in a thousand bick- erings, he considered it advisable, for his peace, to give in his resignation. It was in his place that Mr Banks was chosen in the month of November 1778. On what side he had placed himself in the war of electrical points and knobs, we do not well know ; but this much every body will comprehend, that, under such circumstances, it was impossible for him to attain the presidency, without encountering many enemies. The circum- stance of Mr Banks enjoying the favour of the august person- age, whom his predecessor had offended, was employed by his enemies against him ; moreover he was rich and young, and al- though he had done more for science than many writers, he had written little. What motives and pretexts for attacking him ! What disgrace (it was said) for England and the mathematics I a mere amateur to fill the seat of Newton ! as if it could have been hoped that another Newton should ever occupy it. A naturalist to be put at the head of the mathematics ! as if it were not just that each science should, in its turn, obtain honours propor- tioned to the fruits which it produced. By degrees these mur- murs degenerated into animosities ; at length, on the occasion of a law that required the secretaries to reside in London, and of which the consequence was the resignation of Dr Hutton, Pro- fessor of Mathematics in the school of Woolwich, these animo- sities burst forth into a violent tempest. Dr Horsley, a learned mathematician and ardent theologian, who was afterwards, suc- cessively. Bishop of St David's and of Rochester, became the principal organ of the opposition. He delivered discourses and published writings remarkable for their asperity ; he predicted all the misfortunes imaginable to the society and to science ; and, supported by some members of more consideration than himself, such as the astronomer Maskelyne, he thought himself at the point of overturning Mr Banks. Fortunately it was perceived that he also had in view to place himself in the chair, a discovery 16 Baron Cuvier's Historical Eloge of that proved a sedative to all the passions which he had eX* cited. Such a chief appeared, even to his own friends, an evil more certain than any of those which he had predicted. He was abandoned, and some meetings after, the society, by a so- lemn deliberation, on the 8th January 1784, declared that it was satisfied with its choice. Horsley, and some violent men like himself, withdrew ; and, since that period, Mr Banks, con- stantly re-elected, filled, in peace, this noble station during forty- one successive years, a duration longer than that of any of his predecessors. Newton himself only occupied the presidency during twenty-four years. ^ Assuredly, if we cast a glance over the history of the Royal Society during these forty-one years, we shall not find that it had cause to repent of its resolution. During this epoch, so memorable in the history of the human mind, the cultivators of science in England, — it is honourable for us to say it, for us whose right to render this testimony cannot be disputed, and who can render it without fear for ourselves, — the cultivators of science in England have occupied as glorious a part as those of any other country in those labours which are common to all civilized nations. They have encountered the ice of both poles ; they have left no region unvisited in either ocean ; they have augmented the catalogue of the productions of nature in a tenfold degree ; the heavens have been peopled by them with planets, satellites, and unheard of phenomena ; they have counted, so to speak, the stars of the Milky Way ; if chemistry has assumed a new aspect, the facts with which they have furnished it have essentially contributed to this metamor- phosis ; inflammable air, pure air, phlogisticated air, we owe to them ; they discovered the decomposition of water ; new and numerous metals are the results of their analyses ; the na- ture of the fixed alkalies was demonstrated by their experiments ; mechanics, at their voice, have brought forth miracles, and placed their country above others in almost every kind of manufac- ture : and if, as no reasonable person can doubt, such successes result from their personal energy and the general spirit of their nation, much more than from the influence of an individual, in whatever situation he may be ; it must yet be always acknow- ledged, that Sir Joseph Banks did not abuse his situation, and Sir Joseph Banks, Bart. W that his influence was not exerted in a prejudicial mannei*. The very collection of the Memoirs of the Society, upon which the president might, without exaggeration, be supposed to pos- sess a more effectual influence than upon the progress of science, has evidently assumed a greater degree of richness ; it has ap- peared more regularly, and under a form more worthy of so beautiful a work. It was also in Sir Joseph's time that the So- ciety itself began to be better treated by the government, and that it occupied, in one of the royal palaces, apartments worthy of a body which does so much honour to the nation. It was impossible for services like these not to be at length acknowledged by impartial men : the public opinion proclaimed them, and the government was obliged to proclaim them also. Raised to the dignity of Baronet in 1781, decorated in 179^ with the Order of the Bath, one of the first among those who were neither peers of the realm, nor provided with great military of- fices, Sir Joseph was, in 1797, named Counsellor of State, which, in England, gives a distinguished rank, and the appellation of Right Honourable, which is not without some importance in a country where etiquette has its sway. To him, however, it was merely a title, but this title was a fa- vour, and it needed not more to awaken envy again. Already, on his return from Otaheite, a wag had addressed to him a he- roic poem in the name of Queen Oberea ; on another occasion, he was made to offer an urgent prayer to God to multiply insects, as at the time of the plagues of Egypt ; and now, pretending that he was admitted to real political counsels, he was repre- sented as running after butterflies, while his colleagues were de- liberating upon the interests of Europe. The only remedy ap- plicable to bites like these was to laugh at them, and it was this he employed. If he did not act ofiicially as a political counsellor, he was not the less a real and a very useful counsellor to the King. He partook in his rural occupations ; he made him acquainted with the interesting productions of distant countries, and thus kept up in him that taste for nature, which had already brought so many acquisitions to science, and which continued to do more for it in proportion as the example of the prince was imitated by the great. It is thus that for thirty years England has^ OCTOBER DECEMBER 1826. M 18 Baron Cuvier's -E/cg*^ o/* been, in some measure, the centre of botany, and the mart of new plants and shrubs. The confidence, arising from this community of occupations, gave Sir Joseph opportunities of still more directly serving his country ; and it is said, that the minister sometimes employed his influence to make the monarch adopt resolutions which po- litical circumstances rendered necessary, but which his natural affections rendered repugnant to him. . Any one who has an idea of the complicated and mysterious progress of the smallest affairs in a government, where intrigues of the heart mingle every moment with the interests of party, must at once conceive the importance that a man might acquire in a situation such as this. It is a thing to be wondered at, that Sir Joseph neither used it for increasing his fortune, nor for gra- tifying his vanity. Whatever favour he possessed, he always made it reflect upon the sciences which had procured it for him. Wherever an as- sociation was formed for a useful enterprise, he hastened to take part in it ; every work that required assistance in money, or patronage from authority, might reckon upon his support. Whenever any important inquiry was to be undertaken, he pointed it out, and made known the most efficacious means for accomplishing it. He was thus a party in forming the plans of all the great voyages undertaken after his own : he contributed much to the establishment of the Board of Agriculture : being one of the first and most active members of the African Asso- ciation, he constantly obtained encouragement for those who have attempted to penetrate into that part of the world. It was in consequence of his repeated recommendations that the discovery of a North-west Passage round America was thought of being tried, and that the enterprise was persevered in, not- withstanding the bad success of a first attempt. All the opera- tions referring to the measurement of the meridian, whether it was EngHsh or French that laboured in them, were favoured by him ; in the time of war, as in peace, passports and hospi- table treatment were assured to them by his exertions. But what we have already stated, and what it is especially our duty to celebrate in this discourse, is the indefatigable generosity with wnich, amidst the most violent national antipathies, he softened Sir Joseph Banks, Bart. 19 the evils of war toward those who were engaged in scientific researches. The virtuous Louis XVI., at the opening of the American war, had, of his own accord, caused orders to be given to his vessels everywhere to respect Captain Cook and his companions. To the honour of our so much calumniated age, this beautiful example has become an article of the law of nations ; but it was chiefly the unremitting zeal of Sir Joseph Banks that procured its being inscribed as such. Not only did he never neglect an opportunity of engaging the English government to conform to it, but also more than once preferred solicitations to foreign go- vernments. At the commencement of the war, he had obtained similar orders to be given in favour of La Peyrouse, if he still existed, and had inquiries made for him in every sea. When discords had put an end to Entrecasteaux"'s expedition, and M. de la Billardiere's collections were transported to England, he suc- ceeded in getting them restored to him ; and he also added the delicacy of sending them without even having looked at them. He v/ould have dreaded, he wrote to M. de Jussieu, to carry off* a single botanical idea, from a man who had gone to obtain them at the peril of his life. Ten different times, collections addressed to the Jardin du Roi, and taken by English vessels, were recovered by him, and delivered up in the same manner. He even sent to the Cape of Good Hope, to release the cases belonging to M. de Humboldt, that had been taken by pirates, and would never receive any reimbursement. He considered himself, as it were, accountable for all the injuries that his countrymen might do to science and its cultivators ; and still more, he thought himself obliged to repair the evil that other nations might cause them. Having learned by the public prints that our colleague Broussonet was obliged to flee from the exe- cutioners of his country, he immediately gave his correspondents in Spain an order to let him want nothing. His assistance reached him at Madrid and Lisbon, and followed him to Mo- rocco. When the celebrated mineralogist Dolomieu, by the greatest violation of the right of nations, and to satisfy the ven- geance of an enraged woman, was cast into the dungeons of Messina, it was the ingenious humanity of Sir Joseph Banks that first penetrated the subterranean abode where he groaned 20 Baron Cuvier's Eloge of concealed from the whole world, and which gave him some re- lief by news of his country and family. If he did not accom- plish his liberty, it was not for want of employing all the means imaginable with the government which detained him with so much injustice. And what he did for our countrymen, he was not less zealous to demand for his own. Every one is aware of that other violation of the right of nations, by which thousands of Englishmen residing, or peaceably travelling, in France, were declared prisoners of war. Sir Joseph hastened to find out all those in favour of whom some scientific occupation or title could be alleged ; it was through the Institute that he was enabled to make the claim, and the Institute was not less eager than him- self in the use of this pretext. Thus were several persons worthy of esteem rescued from a captivity which might perhaps have been fatal to them. Assuredly he who thus uses his influence, has every right to watch that it remain untouched ; it is even his duty to do so ; and in this universal struggle for power, when chance has brought some portion into the hands of a man animated with such sentiments, should he neglect to preserve it, society in general would have a right to complain. This is the only an- swer which Sir Joseph's friends can have to make to what might be said against the jealous care with which he prevented what- ever might weaken the consideration of his place, or excite dis- cord in his Society. Sometimes, we admit, his precautions might have appeared extravagant ; but, attacked so often by exas- perated men, had he not reason to dread, that a moment of re- laxation might grant them success ? The mere fact of having replied with some politeness to the Institute, which in 1802 named him a foreign associate, reawoke all the fury of Dr Horsley, who seemed to have forgotten him for fifteen years, and whose age, and episcopal dignity, ought to have inspired more moderation. He wrote a virulent pamphlet against Sir Joseph Banks, and after his death, left inheritors of his hatred which the death of Sir Joseph himself could not calm. Considering ourselves capable of forming as impartial a judg- ment as posterity, we think it our duty to offer the unreserved tribute of praise to the courage in Sir Joseph Banks, which en- gaged him in so many perilous enterprises ; the whole use which Sir Joseph Banks, Bart. 21 he made of his influence in supporting whatever was useful ; the exemplary assiduity with which he performed the duties of an honourable office ; the amenity which he introduced into the intercourse of the lovers of science ; and the generous solicitude he displayed for those pursued by misfortunes: And when we re- flect how, in reality, and in spite of impotent attacks, he was re- compensed by the esteem of the public, and how happy he must have been in the very exercise of so unremitting a benevolence, and to which he had given so wide a range, we consider it as an urgent duty, to present him as an example to many rich men, who pass in an indolence, fatiguing to themselves and to others, a hfe which their condition in the world might enable them so easily to render useful to mankind. His domestic happiness equalled all his other sources of en- joyment. He did not lose his respectable mother till 1804 ; an accomplished and intelligent sister lived nearly as long as himself; an amiable wife always formed the charm of his so- ciety. Nature herself seemed to have been equally favourable to him as fortune. His person was tall and finely formed ; his constitution vigorous ; and if the gout troubled his latter years, and even deprived him for some time of the use of his hmbs, it could neither alter his intellect nor his disposition. The last moments of a life entirely devoted to the improve- ment of science, were employed in forwarding its interests after he should cease to live. In dying, he bequeathed to the British Museum his rich library of Natural History, a collection formed by fifty years of assiduous research, and which the Catalogue drawn up under the eye of Mr Dryander has rendered celebrated over all Europe, and even useful to those who have not the power of visiting the Library, from the regularity with which not only the works of which it is composed, but even the particular memoirs which enter into these works, are there enumerated and arranged under the diff*erent subjects to which they belong. He made rather a slender provision for the great botanist Mr Brown, who had sacrificed to him hopes greatly superior to all that he could ex- pect from him, but who himself thought that science, and the friendship of a man hke Sir Joseph Banks, merited such a sa- crifice. He also assigned funds for continuing the execution of 22 Mr Henry Meikle's Remarks and Experiments botanical drawings of new plants, that had been commenced in the Royal Gardens at Kew, by the excellent artist Mr Bauer. Sir Joseph Banks died on the 19th May 1820, leaving no issue. The Royal Society elected for their President Sir Hum- phrey Davy, who will equal him in all his good qualities, and who will not give rise to the same objections ; for, young as he still is, his discoveries are among the most admirable of the age. Sir Humphrey Davy was already before this a foreign member of the Institute ; and the Academy of Science has named, in the pla^e of Sir Joseph Banks, M. Gauss, Professor of Gottingen, to whom his excellent labours in the mathematics long gave a title to that honour. Remarks and Experiments relating to Hygrometers and Eva- poration. By Mr Henry Meikle. Communicated by the Author. XT is now pretty generally admitted, that hygrometers, formed of absorbent substances, being necessarily of a changing or pe- rishable nature, are extremely liable to have their sensibility im- paired through length of time ; so that little confidence can be placed in them, however accurately they may have been at first constructed. Nor is there much reason to expect that two such hygrometers will agree, unless the one have been made from the other, or both have been graduated from some less vague instru- ment ; but even admitting that they did agree, what security have we that such accordance shall continue ? Professor Leslie's hygrometer is entirely free from this objection, as like- wise Mr Dani ell's, and some modifications of it proposed by Mr Jones and others. The principle of the latter sort is to cool down an even or polished surface exposed to the air, till a de- position of moisture begin to adhere to it ; and if we could easily and accurately ascertain this reduced temperature, we should be enabled to determine the state of the air with regard to moisture. The cooling principle here employed, as the most convenient, is the evaporation of ether ; and for that purpose, a supply of this costly liquid, of rather a superior quality, must be constantlv carried along with the instrument. relating to Hygrometers and Evaporation. S3 By means of his ingenious researches, and particularly his valuable " Essays," Mr Daniell has contributed greatly to im- prove and extend the science of hygrometry. But without meaning at all to detract from the undoubted merit of these labours, I am not convinced that his hygrometer is either the most convenient and distinct, or even susceptible of being ren- dered so. Whoever has attended to such instruments, must have remarked, that the instant of incipient deposition is not well defined. This defect, to be sure, is not so conspicuous when the instrument is small, and the temperature changing rapidly ; but if a cold liquid be put into a pretty large vessel, along with a sensible thermometer, it will be found, that even then the temperature of deposition cannot be ascertained with much nicety ; and, of course, the uncertainty must be greater with a small fickle instrument moving by starts. Besides, good light and acute eyes are quite indispensable, simultaneously to observe the fleeting temperature, and the corresponding but ill defined commencement of the formation of dew. On the other hand, when we use a thermometer depressed by the evaporation of water, as is the case with Professor Leslie's hygrometer, this may be observed with the greatest nicety and deliberation. A more legible indication is unnecessary ; and its certainty and sensibility are placed beyond a doubt, by the ex- act agreement of several such instruments. Nothing, indeed, is wanting to remove prejudices, and give perfect confidence to this simplest of all hygrometers deserving the name, but a greater number of experiments by different observers. Even supposing that some imperfection did attach to its theory, yet more extensive observations could soon settle or correct this ; but an infinite number of observations could not make the in- stant of deposition well defiiied, whilst in the nature of things it is otherwise. It is much to be wished, that accurate experiments were made by different individuals, to ascertain the quantity of moisture which can exist in the air at low temperatures. Authors of great celebrity differ so widely on this head, that it is doubtful if any of them be quite correct. To attempt to ascertain the force of vapour at low temperatures by means of a column of mer- cury, is out of the question ; because such a method is liable to j84 Mr Henry Meikle's Remarks and Experiments so many errors, that no confidence can be put in it. Mr Dal- ton, to whom this department of science owes so much, has made many experiments in this way to ascertain the force of aqueous vapour at the freezing point ; and these seem to have been very inconsistent, as Mr Dalton only concludes from them, that this force is not greater than three, nor less than two tenths of an inch of mercury.* The latter is Dr lire's estimate ; and Mr Southern makes it 0.16 inch. At lower temperatures, I suspect our tables are little else than a guess. But it is not less remarkable, that as great a diversity of opi- nion should exist regarding the density of steam at the boiling point, or still higher temperatures. Thus M. Gay Lussac makes it to that of air, of the same temperature and pressure, as 5 to 8. Sir Humphrey Davy again alleges, that steam just occupies the same volume as a mixture of its constituent gases does under like circumstances. Its specific gravity would thus be to that of air as 5 to 12, if not rather lower +. I shall now proceed to give an account of some experiments of a different sort from those just mentioned, but connected with this subject ; and which I should be glad to find carefully repeat- ed by others. In order to determine how far the depression of a wet thermometer inclosed with some drying substance, is affect- ed by the capacity of the vessel, I made the following experi- ments. Into a wide mouthed bottle capable of holding an im- perial gallon, I put a quantity of sulphuric acid sufficient to cover its bottom to a small depth ; and from the middle of the cork I suspended two thermometers mounted upon one broad scale. Their balls were about an inch separate, and on the same level ; the one was covered with wet linen, and the other naked. At the time of putting in the acid, the whole interior surface of the bottle had been wetted with it ; and after the moist thermome- ter became considerably depressed, I wetted the interior surface afresh with acid, and then moved the bottle gently, so as to agi- tate the thermometers considerably. This I had also done from the beginning. After fully half an hour, the dry thermo- * Manchester Memoirs, Second Series, iii. 473. f Annales de Chimie, Ixxx. 218; Supp. Encyc. Britan. Art. Steam Engine, p, 535. relating to Hygrometers and Evaporation, Ijl %^ meter indicated 5S°.5 Fahr. and the moist 40°.4, giving a de- pression of 13°.l. The height of the barometer was nearly 30 inches ; but exactness in this, as we shall shortly see, was of no moment. There is, however, reason to think, that a quantity of air, con- fined in a vessel along with a drying substance, such as sulphu- ric acid, can never be rendered perfectly dry, if it, at same time, contain the bulb of a thermometer covered with wet linen ; be- cause this, to a certain extent, will continually supply it with moisture, which must require some time to pass to the acid and be there absorbed, and the more so as the vessel is larger *. To try the effects of a smaller vessel, I put a little sulphuric acid into a small spheroidal flask having about the 27th of the capacity of the former ; and introducing a single thermometer with its ball moistened as before, I fastened Its stem in the neck of the flask. To note the temperature of the included air, I kept the flask and another thermometer immersed in a jar of water, which was frequently stirred. The flask was often turn- ed on its side, rolling it round to keep the interior surface wetted with acid. At the end of about fths of an hour, the full effect seemed to have been attained. The thermometer, in the water, stood, as from the beginning, at 53" Fahr. and that within the flask at 39°.9, giving a depression of 13°.l as before. This and the first experiment were repeated some days after, with the same result -f*. From these experiments I was almost led to the conclusion, that if the interior surface of a bottle be kept wet with acid, its size should be of no consequence. But reflecting, that the balls of the thermometers, in the larger bottle, had been kept in motion, and that within an inch of the acid in the bottom, I was induced to try what effect it would have to fasten the moist ball as near- ly as possible in the centre of the larger bottle. Upon doing so, * Various liquids are known to produce greater cold in the surface from which they evaporate than water does. Yet it is curious, that so volatile a fluid as oil of turpentine should have no effect in this way ; and a covered thermometer, first dipped in oil of turpentine, and then in water, undergoes the same depression as if no turpentine were present. t The like coincidence I find, obtains at 80" Fahr., the depression then amounts to 24.°3. d6 Mr Henry Meikle's Remarks and Experiments the effect was considerably less, especially when the sides of the bottle were dry : as the depression, in that case, was only 53° — 41°.2=rll.°8 ; and by repeatedly wetting the sides with acid, as was done with the small flask, the utmost effect was only 53°. 1 — 40°.4=12°.7. But by suspending the thermometers, and making them vibrate near the bottom as before, the depression reached 53° — 39°.9=:13°.l, as in the former experiments ; though such perfect coincidence may have been a little accidental. In the small flask again, with acid only in its bottom, and its sides dry, the result was 52°.6— 42°.4=10°.2. To do justice to such experiments, a considerable time must be spent on them ; for though, in the open air, the wet thermometer soon attain its utmost depression, yet, in a close vessel, particularly a small one, it proceeds with extreme slowness, and at a retarded rate. Those, who are not aware of this circumstance, are apt to obtain de- ficient results. Motion, in the free air, hastens the depression, but unless it be rapid, it scarcely affects its amount. On the other hand, a dry thermometer rises a little, by being moved swiftly through the air. Wishing to try the effects of different atmosphelic pf^ssures on the depression, I placed the double thermometer over a broad saucer of sulphuric acid on the plate of an air-pump, and covered the whole with a receiver. The following are the results at dif- ferent pressures : Lncnes. 29.7 48.2 36!6 11.6 19.4 47.3 33.2 14.1 17.2 47.2 32.5 14.7 13.3 47.0 31.2 15.8 8.8 46.4 27.2 19.2 The first column is the barometric pressure in inches ; the second the Fahrenheit temperature of the dry thermometer ; the third that of the moist, and the fourth their difference or the de- pression *. • Experiments of this sort take such a length of time, that I only, at first, intended to have tried three different pressures, the 1st, 2d, and 5th, differ- ing about ten inches, but before concluding, I added the other two, to come close upon the freezing point ; though both, as we shall shortly see, should, when corrected, be above 32°. relatitig to Hygrometers and Evaporation. ftl On comparing this with Mr Anderson's results, Edinburgh Encyclopcedia, art. Hygrometry, a remarkable disagreement will be perceived, both as to the quantity of the depression, and the rate at which it is influenced by pressure. The following are the results which Mr Anderson obtained by placing Leslie's hy- grometer under a receiver along with sulphuric acid ; the tem- perature of the air being 48°.5 Fahrenheit. Inches. ^6 m 4.86 23.6 34 6.12 17.6 44 7.92 11.6 m 11.16 5.Q 91 16.38 The first column is the pressure ; the second the depression in degrees of Leslie's hygrometer, which, for the sake of com- parison, I have reduced to degrees of Fahrenheit in the third. The temperature and pressure in Mr Anderson's first case, are nearly the same as mine, but our depressions are very dif- ferent ; his being only 4°.86, whilst mine is 11°. 6, which is more than twice as great. This discordance led me, at first, to suspect, that as, in Mr Anderson's experiments, the wet ball of the hygrometer would, from its construction, be six or eight inches above the surface of the acid, whilst in mine it did not exceed one inch, this might be the reason why his depressions were so small. But on trying this, the result was 49° — 39°=10°, still double of Mr Anderson's numbers ; even though the sur- face of sulphuric acid did not exceed half of that in the former experiments, so that this does not appear to have been the rea- son why Mr A.'s numbers are so small. Indeed I have repeat*, edly obtained greater depressions than 4°. 86, by merely suspend- ing the instrument in a room where no means were used to dry the air, or raise its temperature * ; such as 46°.5 — 40°.5rz6°; 45°8.— 40.°5=5°.3 ; 47°.5— 41°= 6°.5. The barometer was rather higher than Mr Anderson's ; and had the temperature been raised to 48°.5 Fahrenheit, the depression would have been a little increased. The difference surely could not proceed from any defect in > * For, as is well known, very cold air, by being heated, without additional moisture, becomes comparatively dry. 28 Mr Henry Meikle''s Remarks and Experiments Mr Anderson's air-pump, as I understand he has an excellent one, and knows as well how to use it. But it is curious that he seems scarcely to have reached the freezing point, even under greater exhaustions than I have yet employed. My experiments . were made by a very powerful double barrelled air-pump, made by Mr Dunn, optician in Edinburgh, a very ingenious artist, who, to great practical skill in the workmanship, joins a corres- ponding acquaintance with the scientific principles of his profes- sion. The barrels of his pumps are considerably larger than those commonly made in London ; so that a few turns of the handle can freeze the wet thermometer under a receiver perfect- ly white. Most air-pumps are very defective in not having the plate ground truly flat. This, indeed, is reckoned so easily done, that it is too often neglected, to the great detriment of the instrument. The attention of Mr Dunn to this most important part of an air-pump, forms no small recommendation to his in- struments ; though, I believe, he is equally careful in the exe- cution of all his work. Since the foregoing account was written, I have made another ^et of experiments on the effects of pressure at rather liigher temperatures. The following are the results : Inches. 29.9 m-Q 45.5 15.1 20.0 59.5 41.0 18.5 10.0 58.9 34.1 24.8 B,Q 58.5 28.0 30.5 Here, as before, the first column is the pressure ; the second the temperature of the dry thermometer ; the third that of the moist, and the fourth the depression. The greatest exhaustion is here the same as Mr Anderson's, but the temperature of the moist ball is somewhat lower, even though the dry one be 10° higher than his. The depression, in the fourth column, foUows a law very different from the reciprocal of the pressure. The conclusion drawn by Mr Anderson from his experiments is,' that, in air of the same dryness and temperature, the depres- sion is inversely as the barometric pressure. Mr Ivory again, from his investigation, Phil. Mag. Ix. 85, has brought out a very different result, that when the temperature, not of the air, but of the moist bulb, is the same, the depression is inversely as relating to Hygrometers and Evaporation. 29 the pressure. This, no doubt, comes much nearer to my results than to those of Mr Anderson, though it is not -very easy to make the comparison, on account of the different temperatures of the moist ball, at the various pressures in the foregoing tables. I must not omit to mention, that, in these tables, the tempe- ratures themselves still require a small correction ; because the thermometers were, as is usual, sealed or close at top, and would, therefore, stand a little too low when under the reduced pres- sure. For, on placing them in a dry state, under a receiver, and exhausting to the utmost, both stood 1°.5 Fahr. lower when the former temperature was restored. Hence, as the entire ba- rometric pressure is to the reduction of pressure, so is 1°.5 to the correction sought. Other thermometers put in with them did not all undergo the same change. For this, there are no doubt various reasons. It is easily shewn, that, within a moderate range, the error will, caeteris paribus, be nearly as the change of pressure, multiplied by the diameter of the bulb, divided by the thickness of the glass. But the sinking of the dry thermo- meter a little, in these experiments, was partly the influence of the cold wet ball on the still confined air. It has been long known, that thermometers were affected by pressure ; and to avoid this, a very effectual method, when ap- plicable, was adopted by Professor Leslie, who employed ther- mometers open at top, when he had occasion to use them under a variable pressure. Some, however, give themselves no con- cern about the matter. In experiments on the force of steam, the ball of the thermometer is often included in the boiler with the stem projecting outward. The pressure on the ball may then vary from a small fraction of an inch of mercury to many atmospheres ; and, in such cases, the temperatures must be er- roneous enough *. Mr Crichton has already pointed out some serious oversights of a different kind in the Memoir of MM. Dulong and Petit on • Large flasks and receivers, if thin, must have their capacities somewhat altered, by varying the pressure. This alteration in similar shaped vessels, will be, cceteris paribus, nearly as the fourth power of the diameter divided by the thickness. so Mr Henry Meikle'*s Remarks and Eocperiments Expansions * ; and I have some suspicion, that, in their very elaborate experiments on the coolingof large thermometers, they have overlooked the influence of change of pressure ; the effects of which were the more to be feared, on account of the gigantic size of the bulbs, and the great range through which they ope- rated. The glass of large thermometers is usually thinner, es- pecially in proportion to their diameters^ than of small ones ; and if it was so in their case, the errors would be so much the greater ; but these learned authors have given us no data from which the amount of such an effect could be estimated. This, however, they might still do, if the instruments be preserved. Farther experiments are perhaps wanted, regarding the depres- sion of wet thermometers ; but at present, I may mention that the two sets which I have given above, especially the firsts make the depression, through a range which will seldom be exceeded, nearly proportional to ^ , where B is the height of the baro- meter in inches ; and probably a still more exact number might be found, by which the observed depression being divided, will be reduced to what it would have been under the standard pres- sure. As a temperature of 60° rarely occurs at great elevations, the last table is not suited to their case ; and, therefore, its de- viating a little from this formula, when the pressure is small, be- comes a matter of no moment. From these experiments, it ap- pears, that the variations of pressure have much less influence on evaporation than is commonly supposed ; and that, on the same spot, variations of atmospheric pressure may, without much danger of error, be neglected. According to Professor Leslie and Mr Ivory, § the depres- sion of the moistened thermometer, under the same pressure, is proportional to the drying quality of the air after its temperature is so reduced. Or, a given volume at that reduced temperature, can still retain c ^ more grains of moisture than is already con- tained in the like bulk of surrounding air ; c being a constant coefficient to be determined by experiment. Hence, if w =: ac- tual weight of moisture in the given volume, at the existing tem- • Annales de Chim. et de Phys. tome vii. ; Anuals Phil. xiii. ; and for Mr Crichton's remarks, see Annals Phil, xxiii. relating to Hygrometers and Evaporation. I8l perature of the air t, and u the maximum at the temperature m of the moist bulb ; also t — m being = ^, we have w=zu — cj. But if the temperature t, at which w grains would saturate the original volume, be wanted, it may be found from the ther- mometers only, without the aid of any tables, by the following approximate formula, which, however, comes very close to the foregoing, between the temperatures of 25° and 90° Fahrenheit. Put k for the temperature at which the variation in the weight of moisture in the given volume for a change of 1° is c grain, then the temperature sought will be If the volume be a cubic foot, and if, as appears from a mean of various experiments, c= .15, then A; = 53° Fahr., and ,= <_3(£±io«°). If the centigrade thermometer be used, c — ,27, and both k and m must be increased about 18°. Hence The maximum forces of vapour for different temperatures fol- low a law very similar, and nearly related, to the law of the den- sity. So that the actual force of vapour in the air may be re- presented by y=: F — g^\ where F =: maximum force at the temperatures, and^a constant, which will = .0125 or -^^ when c = .15. Hence the temperature at which aqueous vapour ha- ving the force j^ would be in a state of saturation, and which temperature is usually called the dewing point, will be The number substituted for k in this case being 49°.5 Fahr, the temperature at which the variation of force for 1° is .0125. By means of this formula, the point of deposition, or dewing point, may be readily obtained without the aid of tables. With the centigrade thermometer, These formulae are adapted to the ordinary pressure, and are by much the simplest I have ever seen for the purpose. The dewing point, or point of deposition, is the temperature of saturation under the original pressure. The temperature r is 82 On Coloured Shadows. the point of saturation under the original volume. The want of attention to this distinction frequently leads to important errors. My object in the preceding pages, has been rather to state what appeared to be matter of fact, than to throw out a mass of random hypotheses. But this paper, having been drawn up be- fore the article on the air-thermometer in the last Number of this Journal, is more conformable to the common theory of that in- strument. It is only the formulae near the end that could be affected by this circumstance ; and within the limited range of atmospheric temperatures, the difference on these formulae would .not be material. At any rate, till the weight of moisture which can exist in the air at different temperatures be better deter- nfined, it is impossible to construct either rules or formulae which can be depended on with perfect confidence. On Coloured Shadows. By Messrs Zschokke and Treschsel Junior *. X HERE appeared at Aran, at the commencement of the pre- sent year, a memoir upon coloured shadows, read by Mr Zschokke to the Society of Natural Sciences of that city. It was received with the interest which attaches to all the produc- tions of its author, productions so numerous and so varied that one can scarcely believe them to proceed from the same pen. Nor was this the first time that Mr Zschokke, the historian, politician, economist, novelist, &c. bestowed some moments upon the Sciences properly so called ; several scientific memoirs form partof the collection of his works, and bear testimony in favour of the general nature of his acquirements. The opinion entertained by Mr Zschokke on the subject of co- loured shadows, was destined to meet with opposition. Mr Treschsel, son of the learned professor of Berne, to whom we owe the triangulation of a portion of our territory, and several other • Extract of a Memoir of M. Zschokke, entitled, »' Die farbigen Schatten, &c. Arau 1826 ,•" and of a refutation of that memoir, by Mr F. Treschsel ^mw. 4 On Coloured Shadoivs. 33 valuable performances, has charged himself with this task in a memoir which he has latterly communicated to us. The subject is delicate and contestible. We shall give in succession the explanations of the phenomenon in question given by the two authors, announcing at the same time that we do no hesitate to adopt, at least in its fundamental parts, the opinion of Mr Trechsel. M. Zschokke, at the beginning of his memoir, gives an ac- count of the authors who have observed coloured shadows, and attempted to explain them. It will not be uninteresting to go over this ground. Shadows coloured in blue are those which have been most frequently remarked, because in fact nature presents them oftenest to us. Priestley, in his History of Optics, states that this phenomenon was for the first time observed and de- scribed, about the middle of the seventeenth century, by Otto Guerick, the celebrated inventor of the air-pump ; but he is wrong, for Leonardo da Vinci speaks of it in hi^ Treatise on Painting, written in the fifteenth century. This able artist sought to discover, with all the interest excited by a subject of so much importance to his art, to what was owing the colouring of shadows in blue. He only saw in it a reflection of the colour of the sky, or rather of the atmosphere, having recourse for this phenomenon to the same explanation as for the purple tints, which colour rocks and buildings, before the rising and after the setting of the sun, or for the greenish reflection which diffuses itself upon the sides of a vessel, or upon the piles of a bridge above a deep and limpid body of water. Bouguer, in his Optics (1729), Buffon, in his Memoirs of the Academie des Sciences for 1743 ; Begnelin in those of the Berlin Academy for 1767"; Monge in 1789, and other natural philosophers, have more or less adopted the opinion of the celebrated painter. Buffon had the merit of contributing powerfully to direct the attention of observers toward the coloured shadows that form in the solar light. " I observed,'' says he, " during the summer of the year 1743, more than thirty sun risings and as many set- tings. All the shadows that fell upon white, as upon a white wall, were sometimes green, but most commonly blue, and of a blue, as lively as the most beautiful azure, I shewed the phe- nomenon to several persons, who were as much surprised as my- OCTOBER DECEMBER 1826» C 34 On Coloured Shadows, self. Difference of season has no effect upon it, for there are not eight hours (15th November 1743) since I have seen blue shadows ; and whoever will give himself the trouble of looking to the shadow of liis fingers at sun-rise and sun-set, upon a bit of white paper, will see like me this blue shadow," &c. The illustrious naturalist also cites a letter of the Abbe Millot, in which he announces to him that at noon, with a cloudy sky, in which some openings were seen here and there in the clouds, he had observed shadows of a beautiful blue upon white paper ; and further, that, under certain particular circumstances, he had remarked green, violet, or yellowish shadows, or shadows sur- rounded with a coloured margin of these different tints. Buffon, recapitulating these various observations made in 1743, adds in 1773 : " This blue colour of shadows is nothing else than the colour of the air itself *."" M. de Schrank, in the Memoirs of the Academy of Munich for 1812, brought forward again the opinion proposed in 1783 by Opoix, a French naturalist little known, supporting it by new arguments. The blue shadows, according to him, come from the inflection of the rays'* tangent to the edges of the solid, from which the shadow proceeds. As the blue rays are very refran- gible, they are more strongly attracted than the others by bo- dies, and thus come to colour the interior of their shadows. O- poix, as well as M. de Schrank, knew well that the violet rays are more refrangible than the blue rays; and they reply to the objection which arises from this circumstance, the one that, in the shadows of thin bodies, the violet rays are sufficiently de- flected to pass beyond the opposite edge of the shadow, and en- ter into the open light ; the other, that, in the case where the body has a sufficient breadth to prevent the application of such an explanation, the rays fall, it is true, into the interior of the shadow, but that the tint which they carry there is too obscure to be perceived. Rumford observed not only the coloured shadows formed in the pure solar light, but also the various shadows resulting from several sorts of coloured lights combined with each other and with the solar light ; and thinking that he had remarked that, • BufFon, Hist. Nat. d'Min., Memoire viii. , On Coloured Shadozas. B^ when seen through a tube, which excluded all comparison of one shadow with anotherj^ all these shadows appeared black, he con- cluded from thence that all these effects are mere optical decep-' tions*. M' M. de Grotthuss arrived at nearly the same conclusion, but by a different process f. He knew the phenomenon of the blue and yellow shadows, which are produced by the concurrence of the light of a candle and that of the twilight ; he also knew the impression which the long continued observation of coloured plates produces upon the retina; an impression which af- terwards reproduces in the organ spots tinged with colours ex- actly complementary, in the scale of the spectrum, to those on which the eye has been fixed ; and he in like manner considers the phenomenon of coloured shadows as a physiological decep- tion, as the result of the fatigue caused by an effort of the organ in the same direction, and of the disturbance of an equilibrium of sensibility in it. After giving this historical narration, Mr Zschokke remarks, that none of the hypotheses explains all the cases in which sha- dows appear coloured, and he proceeds to the exposition of a new theory. Let us first give an account of the fundamental phenomena, the causes of which form the subject of inquiry. Coloured shadows are produced in the solar light, when it is refracted by the vapours of the lower strata of the atmosphere, or reflected by the clouds. Thus, l^^, the colouring is percep- tible chiefly at sunrise and sunset, when the sun is not higher than from ten to twenty degrees above the horizon, ^d, In winter, the shadows are sometimes coloured at noon, because at that season in our latitude the sun scarcely rises to the height of twenty degrees. In summer, they are only coloured in full day when the sky is overcast, and the clouds reflect a strongly coloured light. Sd, The more deeply the rays penetrate into the lower strata, the more strongly are the shadows coloured, • See Philosophical Transactions 1 794 ; or in the Biblioth. Britann. vol. i. p. 339, an extract of Count Rumford's paper, terminated by a note (p. 372) upon coloured shadows, and the authors who have treated of them. f See in Schweigger's Beytrag. zur Chemie und Pbysik, vol. iii. p. 148. an abridgment of M. de Grotthus's Paper on the Accidental Colours of Shadows, and on Newton's Theory of Colours. 36- On Coloured Shadows and the farther may the opaque body which projects them, the hand, for instance, be removed from the white surface which receives them. The distance, therefore, cannot be assigned at which the opaque body should be from the surface. According lo the greater or less intensity of the light, this distance may vary from five or eight feet to as many lines. At the moment of twilight, or in very dark days, the end of the finger from which the shadow projects, requires to be held at the most two or three lines from the white surface. 4d^ If this bluish shadow be illuminated by the yellowish hght of a burning candle, it assumes, at the very moment, a yellowish tint. 3J, On the other hand, the black or greyish shadow of the light of a candle assumes a blue colour, whenever some rays of the light of day are made to fall upon it. This is Rumford's experiment. 4^/^, If there be placed behind the shadow projected by this day light when it is weak, an object painted red, yellow, or any other colour, the shadow immediately assumes a tint similar to that of the object which sent reflected light to it. 5th, The shadows coming from the interception of the light of a candle, are always of a more or less deep black, provided there has been only one candle burning ; they appear yellowish when two are hghted, of which the one shines upon the shadow produced by the interception of the light of the other. " It is easily seen,*" says Mr Trechsel, " that there can be no question here of the inflection of the light in the shadow, either according to the ordinary explanation of this phenomenon, or according to Mr FresnePs theory of interferences ; for, 1^^, The coloured shadows are homogeneous, and not composed of alter- nate bands; ^dly. They are obtained of any breadth that one pleases ; ^dJy, They preserve, in general, the same colour, al- though they change their intensity at each variation produced in the distances which separate the plane that receives the light, the opaque body and the source of light.'" 40 On Coloured Shadoxvs. Mr Trechsel, in consequence, proposes to distinguish two sorts of coloured shadows, one of which may be termed objective, and the other subjective. Among the former would range them- selves, \st. The shadows, whose bluish colouring is owing to the reflection of the day light ; 9.d, The shadows that are co- loured yellow by the direct light of a candle ; 3t?, Those which are obtained from the reflection of the light by a neighbouring coloured body. To' the subjective shadows would be referred those which are produced in the light coloured either by pris- matic decomposition, or by its transmission through coloured glass. In this latter class would also be placed the remarkable phenomenon of the coloration by day-light in the camera ob- scura, and some other similar phenomena. The shadows, whose colouring is produced by direct or ob- jective means, do not require further explanation ; but the case is different with those whose colouring is only subjective. " With regard to these latter," says Mr Trechsel, " Mr Grot- thuss's hypothesis appears to me the most probable. It accords not only with ordinary observation, but also with the experi- ment of the camera obscura which has -been described above, and which was not known to Mr Grotthuss. According to this author, when our eye receives the impression of any colour whatever, for example, orange light, transmitted in large quan- tity, the sensibility of the organ for this light is diminished, and perhaps the sensibility for the complementary blue light in- creases. If we now make the day light, or any other white light, fall upon a shadow projected in this coloured light, or simply upon a ground tinged with this same light, the orange ray disappears subjectively of the day-light, and we then only perceive the united sensation of the other rays contained in the fasciculus, rays which, by their combination, produce a greenish blue tint, complementary of the orange in the scale of Newton. No doubt can be entertained of the subjectiveness of the phe- nomenon of the camera obscura, which I have already several times mentioned, if it be brought to mind that the day-light sometimes produces the red tint in it, sometimes the green, ac- cording to the colouring of the ground. Another experiment may be added, which, although not new, is yet not the less striking. Let two candles be placed^ so as that two shadows On Coloured Shadows. 41 may be projected from the same opaque body, and the shadow formed in the light of one of the candles be lighted by that of the other. These shadows, as is known, will both be yellowish. Let one of the lights now be coloured red, by making it pass through a plate of glass of that colour ; the shadow coming from the interception of the other light, will immediately assume a red tint, (objective colouring) ; but, at the very instant, the other shadow, which is only shone upon by the pure light of the other candle, will become green, (subjective colouring, pro- duced in the organ of the observer itself, from the defect of the perception of the red ray) ; and vice versa, if one of the sha- dows is objectively and directly coloured green, the other will be subjectively coloured red. Mr Trechsel here remarks, that the phenomenon observed by several members of the Helvetic Society of Natural Science, in a chapel near Soleure, appears to be of an analogous nature to the subjective coloration of shadows, in particular to the pheno- menon last cited, and to that of the colouring of the bottom of the camera obscura by the light of the day. It will not be use- less to recall here the description of this phenomenon, such as we have already given it in our account of the tenth session of the Helvetic Society *. All the panes of the windows of the chapel, without exception, are of pale yellow glass ; the frames of these windows, which are of iron, are perforated here and there with small holes of about a line in diameter ; the light which penetrates by these holes, is of the most beautiful blue, even when through them the view is carried upon perfectly white clouds. The same effect is also produced when one of the windows is opened, and the slit thus formed is blue until the opening attains a certain width. We had explained this phenomenon, as probably arising from the psychological effect of contrast. Now this effect, which in general cannot be contested, may be owing to the momentary paralysation in the organ of the faculty of perceiving one of the partial sensations which compose the total impression. Mr Trechsel concludes his memoir with the following brief review : • See Bibl. Univers. torn. xxix. p. 326. 42 Oil Coloured Shadows. " 1. Coloured shadows may be distinguished into objective and subjective. " 2. The former owe their colouring to the light which ar- rives at them either directly or by reflection ; they are not therefore total shadows, but are rather, to use the scientific term, penumbrcB. " 3. The shadows whose colouring is subjective, are the ef- fect of a particular disposition of our" organ, which, when it is fatigued by the impression of a single colour, no longer per- ceives that ray in a fasciculus of white light ; so that the com- plementary ray predominates and communicates its tint to the shadow projected in the primitive light. " 4. So far as we have been able to observe, the eye follows in this process the scale of Newton. If the corresponding co- lours are not always exactly coniplementary, it must be attri- buted to the difficulty of obtaining artificial tints so pure as those of the solar spectrum. " 5. There follows from this, that the colouring of shadows is impossible, if there be no other light than that by the inter- ception of which the shadow is formed. The presence of a light coming from another part, for example, from the sky, or the clouds, is an indispensable condition to the formation of coloured shadows. " 6. Lastly, the shadow is not necessary to make the comple- mentary colours appear. A small quantity of white light, put in prominent contrast with a large mass of coloured light, as- sumes, in certain circumstances which we cannot well determine, the complementary tint corresponding to the colour of this latter light." Mr TrechsePs explanation appears to us satisfactory ; it intro- duces, it is true, two causes for a phenomenon which has usually been considered as one; but this is not the first case where a careful analysis has obliged us to admit several agents in an effect single in appearance. Without doubt, in the number of the very varied experiments which may be made on the subject of coloured shadows, there will still present themselves many de- tails which will not be immediately explained ; but it is probable that their origin will be found in the peculiar circumstances of PLATE I £din''neu/ Phil.Jour. p. —/3. ) . Skull j/"ihc Andaman Hoy. 2. Jnhabilatil o^lheLiMle AndamanJslani/ . ^A.Hiil y /''rvlilfu; X<'f . ■') ( Pahli^fhed bvA.marh.Edinr.l827. -t'- ->ii/rf(l Bii'^'' Mil, hell *cUf On Coloured Shadows. 43 these experiments, and in the state of the bodies employed by the philosopher in his observations. Bihliotheque Universelle, May 1826. Notice 7rgarding the Little Andaman Island, Bay of Bengal. Communicated by Cornet J. E. Alexande;r, H. M. 13th Light Dragoons. With a Plate. vJn the 12th November 1825, the Honourable Company's transport, Earl Kellie, having on board 4 companies of H. M. 45th regiment, and 100 Madras pioneers, destined for foreign service in the Birman Empire, steering a S.E. course, hove in sight of the Little Andaman Island, in latitude 10° 45' N., and longitude 92° 12' E., bearing from E. to E.S E., and distant 4 leagues. At 10 a. m. bore up, and stood in for the land to get a supply of water, our stock of which was almost exhaust- ed, from the unusual length of the voyage, occasioned by the baffling winds we experienced in the middle of the Bay. At 11 saw a brig, hull down, bearing N. W., steering to the S.E. At 12 sounded on a coral reef 8, 9, 10, 12, and 16 fathoms, patches, the bottom seen plainly under the ship, with numerous sharks following the vessel, one of which we succeeded in kill- ing. Observed a niurwna ophis or sea-serpent ; length about 3 feet ; back brownish, belly white, tail rounded, a row of black spots along the sides, and without the caudal fin. A monstrous fish likewise made its appearance near the vessel, seemingly of the genus Raia or ray ; its length about 20 or 25 feet, very broad, and colour of back reddish. A very heavy swell on the bank ; steering from N.N.E. to N.W. to haul off it, ran a dis- tance of 4 knots, when the water deepened to 20 fathoms. When on the coral shoal, in 8 fathoms water, the extremes of the island from E. j W. to N.N.E., and a small bay in the centre of the island ; — at 11 r. m. saw a light on shore ; brought up off the N.W. point, and anchored in 8 J fathoms, at 2 J miles from shore. VMh November. — At dayjight proceeded in one of the cutters along with the chief mate in search of water. On approaching the shore, observed a woman and child on the beach, who, up- on perceiving the boat, ran into the jungle; they appeared to 44 Mr Alexander'*s Notice regarding the be employed in collecting shell-fish. Found a small sandy bay (which I took the liberty of naming after the ship), with coral reefs running out from both extremes, over which a tremendous surf was breaking ; inside the water was quite smooth. An- chored the boat a few fathoms** length from shore ; and, leaving a couple of hands in her, landed with the remainder of the Las- car crew, six in number, who were armed with muskets. We found the island (which in length is S8 miles, by 15 in breadth), to be of coral formation, entirely flat, and covered with lofty and thick jungle to within a few yards of the water''s edge. Proceeded along-shor^ towards the N. W. point in search of two rills of water mentioned by Horsburgh in his " Directory.'" At an angle of the jungle came suddenly upon a party of the natives lying on their bellies behind the bushes, armed with spears, arrows, and long bows, which they bent at us in a threatening manner. The moment the Lascars saw them they fell back in great consternation, levelling their muskets ; and it was with great difficulty we could prevent them from firing ; on- ly the tyndal or coxswain (a Malay) stood by us. We went within a few paces of the natives, and made signs of drinking. The tyndal salaamed to them according to the different orien- tal modes of salutation. He spoke to them in Malays and other languages. They returned no answer, but continued crouching in their menacing attitude ; and to whichever side we turned, they pointed their weapons towards us. I held out my hand- kerchief towards them, but they would not come from behind the bushes to take it. I placed it upon the ground, and we re- tired, in order to allow them to pick it up. Still they moved not. I counted 16 strong and able bodied men opposite to us, many of them very lusty ; and further on another party i\x or eight in number. Those in front of us were lying in two ranks, with two or three women in the rear ; the whole of them com- pletely naked, with the exception of a stout man, about six feet in height, who was standing up along with the women. He wore on his head a red cloth, with white spots, and probably was their chief. They were the most ferocious^and wild looking beings that I ever saw ; their hair was frizzled, noses flat, and small red eyes ; those parts of their skin which were not besmeared with mud (probably to shield them from the attacks of insects) were a Little Andaman Island, Bay of Bengal. 45 sooty black ; their hideous faces seemed to be painted with red ochre. I may here remark, that the inhabitants of the Anda- man Islands, decidedly a negro race, and differing widely from those of the neighbouring continent, are supposed to be the de- scendants of the survivors from the wreck of an Arab slave ship, said to have been lost here some centuries ago. The Chinese, who occasionally resort to these islands to collect the edible nests of the Hirundo esculenta, affirm that the natives are anthropo- phagi. One thing, however, is certain, that several boats^ crews have fallen into their hands, and have never since been heard of. At the above stage of the rencontre, the other cutter, with two or three of the officers on board, neared the beach, and seeing what we were about, they called to us to retire' a short distance, and allow the tyndal to go up and speak to the savages, for perhaps they were afraid of Europeans. We fell back to the water's edge, and having caused the tyndal to strip to shew them that he was unarmed, he went up to within a few paces of them, and offered them a couple of handkerchiefs, making at the same time signs of drinking ; but* upon his attempting to approach nearer, they drew their bows and threatened him. Seeing this we called him off; and not knowing how to act in this emergency, without advice from the ship, as we had been requested not to use any violence, both cutters returned to the vessel ; and upon report- ing what we had seen relative to the hostile disposition evinced by the natives, a subaltern's party of the 45th, with a couple of buglers, and pioneers to fill the water-casks, were ordered to ac- company us, in order that we might force our way to the water if necessary. We landed at the same spot we had formerly done, and not seeing any thing of the natives, we advanced a- long the beach towards the southward ; and, upon turning a point, saw flocks of sand-larks, curlews, &c. Further on we discovered a hut on the edge of the jungle : we went to it, and found it to be about 20 feet in height, of a conical shape, thatched to within a foot and a-half of the ground with rattan leaves, with just room to crawl in underneath. The floor inside was strewed with leaves, and there were several cots or sleeping places in different parts ; they consisted of four sticks driven in- to the ground, on which was fixed a bamboo grating. Ranged 46 Mr Alexander's Notice regarding the in a row round the walls were the smoked skulls of a diminutive hog; the canine teeth shorter than in the other species of sus in eastern countries, the jaws fastened together by strips of rattan, (Plate 1. fig. 1.) From the roof a piece of red and white chequer- ed cloth was suspended, seemingly of Madras manufacture. In conical baskets pieces of jack-fruit were found, and a nut re- sembling a chesnut, besides several roots. In a corner I found several large mangroves. At a fire the following shells were roasting : The green Murex trihulus, Trochus telescopium, Cy- prcea caurica, and several varieties of mussel. The drinking cups seemed to be the nautilus. The weapons were a bow from 6 to 7 feet in length, which is pulled with the feet, and a hand-bow of 4 feet ; the strings are made of the dark red fibres of a tree. The arrows are 3 and 4 feet in length, the upper part pf a very hard white wood, inserted in a stock of cane. The soldiers shot several of them at a tree ; they penetrated a couple of inches into the solid timber, and it required the joint strength of tw;o men to pull them out, and even then the points were un- injured. Several arrows were found with two, three, and four prongs. No canoes or rafts were seen, and no idols of any de- scription. The hand-nets were formed of the black filaments of a tree. In one of the baskets, carefully wrapped up in a cloth, were the head of a harpoon with two barbs, a Malay chopping knife, and several spike-nails and ring-bolts ; these last were pro- bably from the American ship Dover, Captain Duffin, which was wrecked here several years ago. Naturally concluding that there was water near the hut, we penetrated into the jungle, consisting of Dammer trees, red- wood, the Alexandrian laurel, aloes, rattans, and a very lofty and straight tree, about 15 feet in girth, which, if not too heavy, would answer admirably for masts. Having advanced about 30 or 40 yards from the beach, came to a pool of good water ; but, from its being at an inconvenient distance from the vessel, we retraced our steps, and, on coming opposite the boats, dis- covered a party of 50 or 60 natives waiting our approach in am- bush. We advanced to them, in order to get them to point out a more convenient watering place. So little intention had we of molesting or injuring them, that we had brought with us several looking-glasses, cloth, and baubles to give them. How- Little Andaman Island, Bay of Bengal. 47 ever, we had Ho sooner got within 15 yards of them, than we were assailed with a shower of arrows, which struck several of us. Our files were then extended to skirmishing order, and we returned with a round of musketry, killed and wounded several of them, fixed bayonets and charged them ; but they knowing the intricacies of the jungle, and being extremely nimble, suc- ceeded in not only effecting their own escape, but also in carry- ing off the disabled of their party. We were brought up by a deep pool, and saw them making off on the other side, and heard them calling out Yahun, Yahun. We then continued our march along the beach, and discover- ed another pool of very good and sweet water immediately op- posite the vessel, and just within the skirts of the jungle. The water casks were sent for, a jack was hoisted at the pool (being a preconcerted signal to those on board ; left half of the party there, and proceeded with the remainder along a path into the jungle, expecting that it would lead to a village, where we might get some fresh stock. We advanced aboiit a couple of miles without seeing any more huts or natives, and no quadru- peds of any description. The wood into which we penetrated, and in which the bugle alone kept us together, was one of the most gloomy and dismal that can possibly be conceived. It was indeed, *' Nemus atrum horrenli umbra." The trees were of vast height, and in many places thickly inter- woven with rattans and bushrope. The sun-beams were unable to penetrate the entangled foh'age, the atmosphere in conse- quence bore the Semblance of twilight. The air was loaded with a damp and pestilential odour, occasioned by the rotten twigs, leaves, and fruit, with which the ground was thickly strewed, which, besides, was exceedingly swampy. The death- like stillness was occasionally interrupted by a solitary parmt winging its noisy flight over-head ; but owing to the richness of our vegetable canopy, it was almost impossible to gain even an imperfect view of him. Numerous snakes were observed stealing along amongst the bushes. From several we had narrow escapes. Those that we succeeded in killing were all furnished with the poisonous fangs ; and many of them bore a striking resemblance to the Colubej' pr ester or Viper, but they were all spotted. 3 48 Notice of Little Andaman Island., Bay of' Bengal. Tired with our unprofitable excursion, we returned to the watering pool, and the casks having been rolled up to it, we sat down to dinner before we commenced filling. Whilst engaged with our repast a strong party of the natives came down upon us, and threw in a shower of arrows, which killed one and wounded severely three of the soldiers. We quickly formed, charged them, and killed and wounded several by our fire, and continued skirmishing with them till sunset ; for they seemed to be exceedingly cunning and revengeful, and made some des- perate attempts to cut off the pioneers engaged in filHng. Af- ter they had completed the watering, we pulled off from Kellie Bay for the ship, with the four boats ; but a current at that time setting to the N.E. at the rate of 3 or 4 knots an hour, we found that we could not reach her. The water-boats were anchored in consequence, and the two others went alongside. The ship's anchor was weighed, and dropping down to the long- boat and cutter, brought up in 13 fathoms water, and by mid- night got on board, laden with bows, arrows, specimens of am- bergris, shells, &c. \^th November. — During the night heard the savages shout- ing and yelhng on the beach, seemingly in defiance. At day- light weighed, and stood through Duncan''s Great Passage. At 10. A. M. got on a coral reef, not laid down in any chart ; least water 5 fathoms, with the following bearings : North end of the Little Andaman S.S.E. ; the N.W. point S.W. by S. ; the centre of the South Brother S. E. by E. § E., distant 4 miles ; and the centre of the North Brother E. I N. Both these islands, like the Little Andaman, are flat, and covered with high trees, without a rising ground of any sort on them. Kept away to the northward, and got twelve fathoms all the way between the South Brother and Sisters, and in a few days arrived safely at Rangoon. Prome, Birman Em l&th December 18?5 PIRE, ) 25. j (49 ) Some particulars relative to the Tides in the upper part of the River Thames^ and of the obstructions caused hy the present London Bridge. By P. Barlow, F.R.S., Mem. Imp. Acad. Petrop., &c. (Communicated by the Author). Xjondon Bridge, which has for so many years bestrided the Thames, is now doomed within a very short time to be remo- ved, and a considerable change will be, there can be no doubt, effected in the state of the River from the present site of the Bridge upwards. It may not therefore be uninteresting to re- cord some particulars relative to the present state of the tides, and of the river, in order hereafter the better to compare the change which the removal of the bridge may occasion. When this question was before Parliament, I was summoned to at- tend the Committee to state my opinion relative to some points connected with these probable changes, and it Was on that oc- casion that I collected together the several facts given in the following pages, and which, if they should not be found to fur- nish any present important information, may hereafter be refer- red to as matters of interest by the curious inquirer. Some doubts having been suggested as to the damage which might be sustained by the wharfs. Sec. above bridge, by the rising of the river above its present level at high water, and the exposure of the sewers at low Water, the data here given are such as are connected more particularly with these questions ; they con- sist, 1. Of the sectional area of water-way at the different bridges, at various states of the tide. 2. Of the hourly rise and fall of the tide, and the difference of level at different times of the tide, immediately above and be- low London Bridge. 3. The rise and fall, and interval between the time of high and low water, at Woolwich, and at several other places on the river, ascertained by observations made on the same days. 4. Experiments and observations made on the velocity of the tide at ebb and flood at Woolwich, and other places on the river. OCTOBER— DECEMBER 1826. D 50 Professor Barlow on the Tides 5. The difference of level between the high and low water, at several places on the river, and other miscellaneous particu- lars. 1. Sectional areas of water-way at London Bridge, and at Southward y Blackfriars, Waterloo, and Westminster Bridges, at different periods and states of' the tide. London Southwark Blackfriars Waterloo Westminster Bridge. Bridge. Bridge. Bridge. Bridge. At an extraordinary high tide, 2 feet above the usual average spring tide high water-mark, the water-way through the different bridges is, At the Trinity, high wa- 8130 15,260 15,460 19,822 16,750 ter mark or datum. 7360 13,940 14,117 17,707 15,198 At an average spring tide. high water below Lon- don Bridge, 7122 Do. above Bridge, 6837 13,170 12,975 16,447 14,015 Average neap tide, high water above Bridge, 5293 11,135 10,590 13,116 11,380 Spring and neap tide, low water above Bridge, 1488 5,012 3,724 3,382 3,720 Neap tide low water below Bridge, 1030 Spring tide low water be- low Bridge, 540 The linear water-way at London Bridge between the Piers Ft. itu above the Starlings, - - - _ . 524 2 Linear distance occupied by the Piers, - _ . 406 10 Total distance between the abutments, - . _ 931 0 ' Linear water-way below the Starlings at low water, - 230 11 Linear distance occupied by the Starlings, - - 7OO 1 From this table it appears, that, at low water spring-tide, the sectional area of the water-way at London Bridge is not more than about two-fifths of that at Waterloo Bridge, which has the least water-way at low water of the other four bridges ; this con- traction acts as a dam, and causes the water to accumulate so much above bridge, that the sectional area below bridge is very little more than one-third of that above bridge. And at high water spring-tide, the water-way at London Bridge is, at a medium, about half that at Southwark, which above and hehw London Bridge. 51 has the least section of the other four bridges at high water, and this again causes an accumulation below bridge, but by no means so great as in the former case. The effect of this blockage on the hourly rise and fall of the water at the bridge is shewn in the following table : % TABLE of the Ebbing and Flowing of the tide at Londcm Bridge, taken above and below on the ^9th of July 1821. Low Water 50 minutes past 9 o'clock in the Morning. High Water 35 minutes past 2 o'clock in the Afternoon. Flood Tide. Feet. Inches. Ehh Tide. Feet. Inches. Depth of water when flood commenced, - 6 0 1st Hour, fall - 2 1 1st Hour, rise 2 11 2d Hour, - 2 7 2d Hour, 3 0 3d Hour, - 2 0 3d Hour, 2 10 4th Hour, - 1 9 4th Hour, - 2 8 5th Hour, I 5 45 Minutes, - . - 1 0 6th Hour, - 1 2 7th Hour, . 1 0 4 Hours and 45 Minutes 18 5 55 Minutes - 0 11 Depth at Low Water, 7 Hours and 55 Minute 6 6 s 18 5 Low Water 30 minutes past High Water 18 minutes past 9 o'clock in the Morning. 2 o'clock in the Afternoon. Flood Tide. Feet. Inches. Ebb Tide. Feet. Inches Depth of Water when Flood commenced. 1 3 1st Hour, Fall - _ 2 1 1st Hour, rise 5 9 2d Hour, „ 4 4 2d Hour, 5 4 3d Hour, . 3 1 3d Hour, 2 9 4th Hour, - 2 7 4th Hour, - 2 5 5th Hour, . 2 3 48 Minutes, 1 4 6th Hour, - 1 9 7th Hour, - 1 6 4 Hours and 48 Minutes 18 10 59 Minutes, - 0 11 Depth left, - 0 4 7 Hours and 59 Minutes 18 10 By means of this table we readily find the head of water above and below bridge at each successive hour of the tide, d2 52 Professor Barlow on the Tides viz. by subtracting from the depth of water on one side, the depth on the other. Thus it appears that, on the day in ques- tion, THE FLOOD TIDE. THE EBB TIDE. Feet. Inches, ] Feet. ] [nch( The head at low water above The head below bridge, bridge was 4 9 high water, 0 5 1st hour of flood 1 11 1 st hour do. 0 5 2d hour, head below bridge, 0 5 2d hour above bridge 1 4 3d hour do. 0 4 3d hour do. 2 5 4th hour do. 0 0 4th hour do. 3 3 High water 0 7 5th hour do. 4 1 6th hour do. 4 8 7th hour do. 5 2 Low water do. 5 2 The above deductions are from the observations of a particu- lar day, and are not quite the mean results even for a day, be- cause the high water above and below bridge does not happen exactly at the same time. From a mean, however, of several days, it appears, that the average fall Feet. Inches. Feet. Inche*. High water spring tide is 0 8 greatest 1 1 Average faU low water 1 ^ ^ ^^^^^^^ ^ ^ Do. J High water neap-tides 0 5 Low water do. 2 1 least 1 1 3. Some other particulars relative to the periods of Rise and Fall, and of High and Low Water, above and below Bridge, may be stated as follows : 1. The flood of spring- tides, of October 21st and 23d, pro- duced slack water through the bridge in about 40 minutes after low water below bridge ; from which time a-head gradually in- creased below bridge to 1 foot 10 inches at half flood, and then regularly decreased to about 8 inches at high water. The first flow of these tides, nevertheless, began above bridge about 20 minutes after low water below bridge, although the water was then about 2 feet 6 inches higher above than below bridge; the time of low water below bridge averages 10 minutes earlier than above bridge. above and below London Bridge. 53 The ebb of these tides produced slack water at the bridge about 30 minutes after high water, and then gradually sunk to their greatest fall at low water. The time of high water, October 21 st and 23d, was the same below as above bridge ; but the average time of high water spring tides is 9 minutes earlier below than above bridge. The flood of neap-tide, October 30th, produced slack water through the bridge, in about two hours after low water below bridge, when there was some land-flood in the river ; from which time a head gradually increased below bridge to 1 foot 3 inches at two-thirds flood, and then regularly decreased to 4 inches at high water. The first flow of this tide, nevertheless, began above bridge about 1 hour after low water below bridge, although the water was then 1 foot higher above than below bridge ; but the aver- age time of low water below bridge is 32 minutes earlier than above bridge. The ebb of this tide produced slack water at the bridge about 15 minutes after high water above bridge, and then gradually sunk to its greatest fall at low water. The time of high water, October 30th, was 15 minutes earher below than above bridge ; and the average time of high water neap tides is 15 minutes earlier below than above bridge. 54 Professor Barlow on the Tides I O 1^ r^ ^ o I M o 00 Oi ^^ Oi o M © (M »0 05 <-H (N S © CO ^ -^ 00 CO J © (M CO W » S © OS »X>i g © Tj< OS 5^ -^ © 15 © CO O -^ CO 00 . lO lO lO »o o © g Tf -^ -(f '^l' -<* CO © © ^ W » S © © tJ< (N © i>. W © CO Tf CO CO © j; © t-*co -^ CO © © »0 © Tji t^co g © l>'-H CO (M "* tfl © O »0 CO CO '-^ j; © © (N Summer and winter are the only seasons that occur in Green- land. The former possesses none of those charms so congenial to sense in happier climes ; and the latter is clad in tenfold terrors. At the close of the year the frost, which a summer sol- . stice scarce can soften, sets in with terrible violence, and scatters thick the icy particles on the face of the deep, which counteract the efforts of the rudest tempest, smooth down the billows, and prepare a quiet surface for their coalescence. A continued aug- mentation takes place, scale with scale coheres ; mass becomes glued to mass ; and field to field ; till the dark waters of the ocean are buried under an interminable wilderness, stretching from the dark regions of the north far to the south, till arrested by a latitude which, though almost too cold for the habitation of man, is too mild for the formation of these gelid productions. The line of arrestment extends from the coast of Labrador, . by Cape Farewell and Iceland, and after retiring to form a deep bay, about the 7° or 8° of eastern longitude, it stretches across to NovaZembla, and is much modified by temperature and pre- vailing winds. 90 Observations wi tlie Arctic Sea and Ice, and \ On the approach of spring the seaward limits of this mighty frozen plain are broken up, and the fragments are gradually dissolved, as they are carried by the currents down the Atlantic. Thousands of square leagues disappear in the course of a few weeks, a free course is opened to the fishermen, even to the northern shores of Spitzbergen ; and, as the season advances, the same process evidently goes on to a certain extent, in the un- explored North Eastern Seas. Their fields, too, are destroyed, and the ruins, borne past Nova Zembla, disappear in their drift to the southward. Thus, the reign of winter in these forlorn regions is relaxed by the returning sun, and the slumbering deep roused ^by the storm, rends in fragments the frozen loads, dashes mass on mass, and hurls the whole to ruin. On the shores of Spitzbergen a thawing temperature prevails during the summer, and the flow- erets on the warm bank, disburdened of its snowy cover, flourish for a time, whilst the inland country, buried under the snow of ages, is scarcely visited by a thawing beam. It is by reasoning on the causes of this mighty havoc, and contemplating the effects produced by them, that conjectures on the state of the untraversed seas, north and east from Spitz- bergen, have been conceived. The chief agents in destroying the ice seem to be, the Sun's rays, the tempest, the currents, attrition, and the wind-Upper. Action of the Sun^s Rays. — The sun^s rays exert a double influence ; 1,?^, By expansion : and, 9^dly, By solution. The effects of expansion are of the first magnitude. But for this, the ice of the north, having acquired its usual thickness, might bid defiance to the efforts of every other agent, and re- main almost immoveably the same. The storm may break up the detached fields ; attrition may comminute their fragments, the wind-lipper may wash them out of existence ; or the currents may carry them into other seas ; but until the frozen continent is broken up, and reduced to fields,- all these can make but little impression. Authors have published accounts of the various forms which the ice of Greenland assumes, and have theorized on their mode of formation ; but concerning the detachment of fields, they have ^ been silent, so far as I know. This very important process 4 Captain Parri/s intended Expedition to the North Pole. 91 is accomplished, I apprehend, in the following way. It is a well known fact, that fresh water, at the temperature of 39J°5 is specifically heaviest ; and that it possesses the strange peculiarity of becoming hghter by the farther reduction of temperature ; and at that point where it passes into ice, its expansibihty, if we except its vaporous state, is at its maximum. The same law, a little modified, regulates the freezing of salt water ; the points of greatest density and consolidation being probably a little lower than in fresh water. When water is completely frozen, it, like other bodies, con- tracts by a continued abstraction of caloric. Now, if a body of ice, twenty or thirty feet thick, floats in water at the freezing point, the under surface of that ice will be nearly of the same temperature as the water, and the upper surface may correspond with the temperature of the superjacent atmosphere, which, during winter, in high latitudes, depresses the thermometer to 40° or 50° below zero. Such a difference of temperature must produce a very great difference in specific gravity, and the up- per surface must be much more contracted than the under ; but as the cold increased progressively, it might happen that no evi- dent effect would be produced by this great difference, as the accumulating mass accommodated itself to the gradual change : but as soon as the summer returns, the temperature of the air is speedily raised, communicating its caloric to the surface of the ice, which begins to expand, and ultimately exerts energy suffi- cient to overcome the cohesive force of the frozen particles, and a rent is the consequence ; which, as soon as it has commenced, runs unrestrained in all directions ; and the advancing summer, modifying the winter's sway, prevents reunion, till the attach- ment is set loose by the currents, or drifted off by the winds. The effects originating in the influence of the vicissitudes of temperature in tearing asunder the ice, are awfuUy illustrated by the aspect of the polar glaciers, which are found in the val- leys on shore *. The ice being upwards of 200 feet thick, the hideous chasm yawns horribly to the very bottom, from the brink of which the beholder turns away with indescribable feel- ings of horror. • See Icebergs, Phil. Journ. 1819. 92 Observations on the Arctic Sea and Ice, and The second effect produced on the ice by the solar rays is solution. When the sun has withdrawn his influence, and the long winter night has spread its shades over the regions of the north, all the dark domain is fettered in tenfold frost, — all is silent and dead, — the torpid bear doses in his icy cave, — and the stunted productions of the soil, shrivelled by the cold, shrink into the earth beneath the cover of snow. Ocean is no more ; and, except when the changing moon agitates the keen ether, the forlorn scene is never ruffled by the gale. The thermometer, which, during summer, ranged some ten degrees above the freez- ing point, now sinks to 50° below zero ; and half a moon of such intensity produces enough of ice to replace the whole dissolved by the sun's rays. Indeed, that amounts to little ; as a thawing temperature is felt only at intervals during a month or two in summer, and can scarce effect the solution of the snow covering the ice-field. The feeble action of the sun in thawing the polar ice, is abun- dantly illustrated by the permanency of those ice-shoals which have so long shut up the followers of Eric on the eastern shores of Greenland, — ^by the annual augmentation of the polar gla- ciers, reared in ravines on the shores of Spitzbergen, Beeren- berg, and even the more southern coasts of Iceland and Cape Farewell. The presence of these frigid accumulations in so low a lati- tude, is apt to bias the judgment, leading to an inaccurate esti- mate of the polar climate ; for if, during summer, in a latitude so low as 60°, we find land surrounded by a frozen sea, hills perpetually covered with snow, and valleys filled with solid ice, what picture can our imagination form of those regions 600 leagues farther north ? None other surely, than that they are in all probability ever in a frozen state. If, however, during a summer noon, we visit some sheltered bay in Spitzbergen, whilst, through an unclouded atmosphere, shine the bright beams of a never-setting sun, where the calm ether leaves no impress on the- placid main, gently murmuring along the shore, from which rises the earthy slope covered with verdure, interspersed with flowers, watered by the stream- let from the mountain rock, which echoes the uncouth screams of myriads of the feathered tribes which annually nestle there, Captain Parry's Intended Expedition to the North Pole. 9S — amidst a scene like this (and many such there are), heedless of the frowns of huge adjacent icebergs, which diffuse winter around, and often fill the atmosphere with clouds, despite the conviction that, in inland scenes, valleys are filled, and hills bu- ried, with never-melting snow, we would be disposed to esteem the climate mild, and extend the same character to regions still more remote. The impression formed by such Elysian mild- ness may have divested the ingenious Mr Scoresby of his accus- tomed acuteness, whilst treating of the " Climate of Spitzbergen," in his " Account of the Arctic Regions ;"" for, biassed by the in- dications of the thermometer, he reasons himself into the suppo- sition, that the climate, during summer, is more temperate than even in Scotland, and gives to the circle of perpetual congela- tion, an altitude of 7791 feet, — a statement contradicted by facts. 2. Action of Tempests. — Having noticed the effects of the sun's direct influence on the ice, I shall next make a few remarks on the action of the tempest. Scarce has the sun risen over the polar horizon, and shed his oblique rays on the hoary regions of the north, than the tempest begins to raise up the billows of the ocean, whose heavings rend the detached ice into fragments, and the west setting current carries off the ruins to be dissolved in a lower latitude. This process often exhibits a scene truly awful. The mass of thousands of millions of tons, whose farthest verge rounds off the horizon, floats strong and deep, darkening the abyss, and filling the atmosphere with its effulgence, till the storm heaves up the deep. At first, the waves ineffectually dash along the icy barrier, minghng their spray with the drift, but gathering strength, sea rolls after sea ; the ice-field labours on its undu- lating bed ; and the reiterated thundering crash proclaims its disruption ; and, mixed with the foam, mass reels on mass till the wreck is complete, and the ruins spread along the main. 3. Action of Currents. — The current is a powerful agent in destroying the ice in the North Sea, and is of such importance that, if it did not exert its influence, all the surface of the ocean, within the Frigid Zone, would be crowded with the separated pieces. The currents are rendered very conspicuous in the Greenland Seas, by the drift of the floating substances. They may be divided into two kinds, accidental and permanent. Ac- 94 Observatkytis on the Arctic Sea and Ice, and cidental currents are partial motions in the water, occasioned by the action of the winds, or the movement of the larger bodies of ice. Thus when fields and icebergs are driven from the sea into deep bays, by strong gales, the dammed up water is sometimes forced many feet above its usual level. Such a phenomenon has been noticed by many navigators. I myself saw decided testimony of such, when on shore at Spitzbergen, near Cross Bay, in the vicinity of the Seven Icebergs. All the low land in that neighbourhood, lying behind Fair Fore- land, from its local situation, must be much exposed to inun- dation. The flat on which I landed, was, in general, ten or fourteen feet above the level of the sea, and some leagues in circumference. All this bore testimony of having been re- cently covered by the sea, from the pools of salt water, and the remnants of salt water ice, from the drift timber, and the bones of marine animals, which had been bleaching on the beach. Nearly a mile from the shore, I also found a chest made of rough deals, lying high among the gravel, which appeared to have been lashed by the waves, and considerably chafed. On opening it, I found it to contain a human skeleton, which had, in all probability, been swept from its superficial grave by the same cause which had transported it thither. On the north of Spitzbergen, Captain Phipps found large fir-trees lying at a dis- tance from the shore, 16 or 18 feet above the level of the sea. And Leonin, who was sent to ascertain the nature of this island by the Grand Marshals of Denmark, found a ship's mizen, about a league inland. The tide there does not rise above four feet. The permanent current is that which is of most consequence in opening the sea. This, coming through Behring's Straits, doubles Skelatskoi Noss ; runs along the north of Asia, by No- va Zembla ; and, meeting a feeble remnant of the Gulph Stream, which had crept by the Islands of Scotland, and along the Nor- wegian coast "*, flowP towards Spitzbergen ; and, having passed • Reasoning on the existence of the North-east Passage, some have laid much stress on the nature and condition of the drift timber found in the North Sea, fancying that it cannot reach Greenland but through the Frozen Ocean ; but if we reflect on the direction of the northern branch of the Gulph Stream, we can, without having recourse to unsatisfactory reasoning, account for the mahogany of Honduras being found on the coast of Greenland. In Hke man- ner, the worm-eaten timber may be conveyed thither, although such a condi- Captain Parri/s intended Expedition to the North Pole, 96 that island, sends ofF a branch towards the north. It then trends to the southward, carrying all the detached ice, through- out its course, in that direction. The quantity thus annually disposed of, has been estimated by Mr Scoresby at 20,000 square leagues, which he notices is three-fourths greater than the area of the sea accessible to the whale-fisher. The oppor- tunity of observation afforded this intelligent gentleman, entitles his remarks to every respect. I do not think he has exaggera- ted in this calculation. Nay, some are of opinion that if we were possessed of means to ascertain the precise amount, it would be found considerably to exceed his estimate. But though the area of the drifting ice much exceeds that of the fishing ground, I would not consider all the surplus as the produce of unex- plored regions. Such an assertion might indeed be consistent, if the sea frequented by the whale-hunter was only once frozen during the year, and if this annual coat alone were broken up, and drifted away ; but we must recollect that, by November, the water again begins to freeze, and that the early produce, tion does not testify its being a tropical production ; for, lately examining the bottom of a fishing sloop which had been entirely confined to the banks of Shetland, I found the Teredo navalis rioting in a more fearful extent than I ever observed in the uncoppered planks of vessels which had long traded in the Mediterranean and West Indian Seas. Some specimens of this worm were a foot long, and the largest of their canals were seven-eighths of an inch in (Jiameter. This northern branch is also the cause of the Whale-fishers' Bight, which is a very deep bay in the ice, found during the early part of the season, extend- ing northward towards Spitzbergen, between the meridian of London and 12® or 13* of eastern longitude. There the sea does not freeze so readily, as the temperature of the water is higher than the adjoining sea. It likewise, with the currents coming from the north, accounts for another anomaly, which, even in our day, has been considered unaccountable. M. de Capel Brook wondered why no ice was formed in the harbour of Hammerfest, in Lat. 70* N. though the temperature of the air was 13* below 0. Others have esteemed it an unaccountable circumstance, that the coast of Newfoundland should be strewed with ice, and the sheltered places on the coast frozen up, whilst the shores of Iceland, and even those of Norway, remained free. Now, it is easily to be accounted for, if we bear in mind the course of the currents. The rem- nant of the Gulph Stream is continually passing from Iceland along the coast of Norway, on which the intensity of winter has no influence : and, if the cur- rents from Greenland carry not only a great body of cold water, but much frozen ice over to Newfoundland, the climate and temperature of the sea must be much colder than on similar latitudes on the opposite side of the Atlantic. 96 Observations an the Arctic Sea and Ice, and from its fragility, must be the sport of the waves and the cur- rents ; and, as one portion drifts away, another, [formed on the same spot, succeeds. Similar revolutions take place after the breaking up of the firmer produce of winter, and continue even till late in May : hence masses of ice are met with, of various strength and magnitude, some being only a foot or two thick, which, formed by the spring frosts, are only seen in lov»^er lati- tudes, during the early months ; whilst others are fathoms thick, forming immense fields, which have been the produce of many winters, in more remote regions. Now, if such revolutions take place, much more ice than is sufficient to cover the Greenland Seas must be annually formed on their surface ; and no doubt this is the case, demonstrated by the diff*erence of latitude which exists in the winter limits of the northern ice ; for the current, coming down through the east, carries along its course all the new produce ; and, whilst the sea of Nova Zembla can scarce sup- ply the waste, an accumulation of foreign ice takes place around Jan Mayen Island, and Cape Farewell, where it covers the sea as low as latitude 58° ; whilst, towards Nova Zembla, all remains open as high as 73° or 74°. 4. Action of Attrition. — Attrition has beei^numerated among the ice-destroying agents in the north ; and, although Captain King, who continued Cook's narrative, esteems it as a principal one in Behring'*s Straits, it seems to be an inefficient one in Green- land. No doubt, during the gale, the heaving to and from may wedge each adjacent piece ; and the collision of icebergs may overthrow their frozen battlements ; but change of position alone is effected. 5. Action of the Wind-Upper. — The Upper, too, may act its part, and appears to destroy much ice in lower latitudes ; but, far to the north, where the temperature of the water is low, its effects are trivial. Its little splashings undermine the margin of each piece, giving rise to many a fantastic form. In miniature we of- ten see cities, towers, temples, trees, villages, and many lively re- presentations of animated nature. This destroyer of the ice, in- significant as it may appear, is the source of annoyance to the mariner ; for, as the superjacent portion alone is worked away, that which lies under retains its original extent \ and, stretch- ing horizontally, forms what whalers call tongues, which, from Captain Parry's intended Expedition to the North Pole. 97 their depth, extent, sharpness, and hardness, often injures the bottom of his passing bark. The causes above enumerated are those which annually de- stroy the ice in the Frozen Ocean. The chief of them are wide- ly diffused ; and, if their effects are such as I have noticed, I think we are furnished with matter sufficient to enable us to form reasonable conjectures concerning the state of those seas yet unexplored, which are to become the scene of our adven- turers' investigation during the approaching summer. According to the above sketch, we have the ice broken up by expansion and the tempest, and carried away by the currents, &c. If what has been said concerning the effects of expansion is correct, — if the dilating influence of the warmth of spring rends the ice in pieces, then the whole of it, independent of every other cause, will be traversed with fissures forming, by their circuitous routes, detached fields, which will be floated abroad by the cur- rents and winds, and broken up by the waves, as soon as the sea to the leaward is open. The opening of the sea is a progressive process. Early in spring the devastation commences on the great margin extend- ing from Labrador eastward, and often, in April, reaches the north of Spitzbergen, and clears the western shores of Nova Zembla. At first the process proceeds with rapidity ; for the young ice is easily broken up ; and, during the first months, the storms are most frequent and protracted : then no fields are met with, but sludge^ Jloes, packs, and streams, are scattered over the face of the sea. Whales, about this period, are gene- rally met with in greatest abundance ; for the interior ice, con- tinuing close, forces them to remain where they can reach the surface for respiration. As the season advances, the atmosphere becomes more settled, and the stronger northern ice opposes more resistance to its effects ; and now the current is the most active agent ; hence fields become more numerous, which are seldom met with in groups, except considerably to the eastward, where they are largest. As these large plains are drifted off from the main body, and followed by others, it is probable that, throughout the track of the current, the ice, being divided by fissures, may be more or less in motion ; so that, by August and September, the greatest OCTOBEll DECEMBER 1826. G 98 Observations on the Arctic Sea and Ice, and progress may be made in these seas, though such navigation must be extremely hazardous, as it can be conducted only through lanes and open spaces, where the mariner would be con- stantly exposed to be nipped among the closing fields. To determine how far the Northern Ocean is navigable can be ascertained only by repeated investigation. The course of the currents, and the few facts we possess, seem to indicate that the farther we proceed the sea will be the more crowded, till, around the pole, all remains firm and fast. All the circumja- cent ice is certainly yearly in motion, which, even in the opinion of Parry, may be sometimes navigable. In this he is supported not only by his own observations, but by the evidence of other adventurers. Whilst Heemskerke lay grounded on the ice-piled coast of Nova Zembla, when the season was far advanced, he was shagreened with the view of an open sea extending eastward as far as the eye could reach, whilst he was pushed on shore by the masses which skirted the land. The expedition fitted out by the merchants of Amsterdam, traversed an open sea 100 leagues east from Nova Zembla, in the 80th degree of northern latitude. Baron Wrangel, in a sledge, travelled on the northern ice for forty days, during which he reached a sea free from impedi- ment ; but ere he reached the coast of Siberia the ice had given way ; and, after drifting for some time, he was fortunately driven on shore. Though the expedition conducted by Cook encoun- tered an impassable barrier of ice, uniting Asia with America, preventing all access to the Northern Ocean, through Behring's Straits ; yet the circumstances of this ill managed attempt ren- der the result of less importance. The voyage of Deshnef shews that such is not always the case; for he sailed from the Kovyma ; and, having doubled Skelatskoi Noss, late in October, amidst storms and tempests, was wrecked south of the Anadir in Kamtschatka ; and the whole of the shores of the Arctic Ocean, bounding the north of Europe and Asia, has been explored, ex- cept that portion surrounding Cape Ceverovostochni. If it were necessary, the evidence of other circumstances could be adduced, indicating that the ice is broken up. such as the history of the whale, the presence of drift-timber on islands of the Siberian Sea, &c., but what has been already noticed is suf- ficient for the present purpose. Captain Parry's intended Expedition to the North Pole. 99 From what has been said, it would appear that the breaking up of the ice commences in the Northern Atlantic in February or March, and that all lying to the eastward progressively fol- lows. Much disappears every season, but the season is far advan- ced before the eastern ice joins the train ; and long ere that has reached the Greenland seas, it is arrested by returning winter, so that leaving out the interception of land, and the impediment of adverse winds, the ice generated on the nofth-east of Asia may see many a summer before it is laved by the sea of Spitz- bergen ; indeed the disposition to move reaches the longitude of the Lena in August, and scarcely clears Skelatskoi Noss by October. Now, it is very probable that it may also extend to high northern latitudes, from the ancient fields that are some- times met with. The farther from their source the more scat- tered will these masses be, and consequently the freer the navi- gation ; but remote regions become more and more hampered, till all becomes fixed as terra firma. Much light may be thrown on the nature of this country by the projected expedition, which no doubt will be equipped with all due deliberation, on that plan which past experience sug- gests. It is to consist of two sledges, capable of containing twelve men each, built of light materials, and of such a con- struction, that if water comes in the tract, they may be used as boats. These are to be provisioned for three months, which, with short stages, will allow the party to travel from Spitzber- gen to the Pole, and back. In dragging these vehicles along the ice, dogs or rein- deer are to be used, which may be fed, partly on fish caught by the way, and, in case of scarcity, may serve for provision. This plan is a modification of that proposed some years ago in the Werneriaii Society ^ by Mr William Scoresby Jwmor *, who, during many voyages to the Spitzbergen sea, had ample op- portunities for making observations on the peculiarities of the Greenland ice. He, like every judicious theorist who indul- ges his fancy on the probabilities of executing his project, first conceives the nature of the tract over which he has to pass, • The very interesting details of Mr Scoresby's plan are given in the 2d volume of the Memoirs of the Wernerian Natural History Socety, p. 325. et seq. g2 100 Observations on the Arctic Sea and Ice, and and then accommodates his means to its imagined peculiari- ties, and provides for every anticipated exigency. But as we are entirely ignorant of the real constitution of those parts immediately surrounding the Pole, the plan chalked out by the most sagacious, may, in very many points, prove inapplicable. So the first adventurer must necessarily be exposed to much peril, from unforeseen difficulties, whilst he paves the way for his successors. Though the means adopted by Captain Parry possess many recommendations, yet such might not be impaired by some little modifications. If it is probable that the Pole is perpetually sur- rounded with immoveable ice, the following method seems to possess all the advantages of that which Captain Parry is to put in practice, and may not be entirely worthless, if it is capa- ble of more extensive application. Instead of two, let the party be provided with three sledges , convertible into boats, capable of carrying only Jive men each, suitably provisioned ; let these proceed northward from the place of rendezvous on the north of Spitzbergen. On the meri- dian of which it is probable the boundaries of the stationary ice may not be far distant, for the destructive action of the cur- rent, which, in more eastern seas, makes such ample breaches, is here, as in Behring's Straits, of little consequence, as it flows against the frozen barrier, by which the action of those agents, which would otherwise destroy the ice, is restrained. Having reached the 84th or 85th degree of northern latitude, if the ice seems old, continuous and stationary, they could cal- culate on its being similar all the way northward. Then with safety one sledge might be left in charge of three men, with suit- able orders for their future guidance. In establishing such a position, land would be of much importance, not only in so far as the comfort of these individuals was concerned, but the dan- ger of any movement in the ice changing their longitude would be avoided, — a difference which, if the party were left on ice not stationary, would require to be rectified by daily observa- tion, lest they being drifted out of the way, should be missed by their associates on their return. Provision should be left suffi- cient for these, and to serve the whole party during their return from that latitude to Spitzbergen. The expedition might then Captain Parry's intended Ea^pedition to the North Pole. 101 proceed till they reached the latitude at 8T, where, under simi- lar circumstances, they might leave a second sledge in charge of Jour men, with as much provision as would serve these and the returning party, till they reached the first establishment. The third sledge could be left at the 89th degree, with Jive men, whilst the three remaining with their hand-sledges, blankets, and provisions, disburdened of every other incumbrance, might trudge on to the Pole. In such a journey, the assistance of dogs or rein-deer would be a very sensible advantage. These might be taken even as far as the second establishment, and if land fortunately lies in such a quarter, they might be kept to assist the returning expedition, otherwise the want of provision would render it necessary to de- stroy them, for it is not very probable that many fish can be caught there for food to them. The advantages of such arrangements, if they could be effect- ed, would be very sensibly felt ; for fresh assistance would be de- rived from the lengthened journey. The first sledge, with a load of provision, is left in charge of only three men, consequently not only is the burden of the other two lightened, but two addi- tional hands are added to drag these along. A diminution of burden takes place also at the second establishment, when four men are left in charge. The remaining eight with the last sledge proceed to take up the position just sixty miles from the Pole : three of the company travel the rest, with scarce any cum- brance at all. Thus the burden diminishes whilst the ability to bear it increases ; and, as the party returned, they would more sensibly feel the benefit of such management, as each detach- ment, refreshed and strengthened, would be in good condition to yield their much-needed help to their weary associates. Further, if the unaccustomed toil should unfortunately dis- able any one, rest might be obtained till health was re-establish- ed, and the expedition relieved of any incumbrance which might frustrate all their endeavours. But, perhaps, the idea of a firm continent of ice is chimerical. Mayhap there is not an island, not even a rock, above water, between Spitzbergen and the Pole : well, but most likely there are such things, and if there are none, having such provisions in store, the views of the expedition can be prosec'ated as easily 103 Observations on the Arctic Sea and Ice, and with them as without them. The only untoward circumstance is, that Parry would be confined to the same track in returning, by which means his sphere of observation would be more con- tracted ; but then the chance of encountering difficulties unpre- pared for, on his road homeward, might involve him and his party in ruin. If the Pole is surrounded by ancient ice, may it not, like the polar glaciers, be fissured all over, much to the inconvenience of the expedition ? Far to the north, among these icy realms, the still atmosphere may enjoy perpetual serenity, a matter of the first magnitude in promoting the interests of this undertaking ; for though, in the latitude of Spitzbergen, during June, July, and August, the air is so often obscured by dense raw fogs, yet, in the in- terior ice it is always clear ; if it were otherwise, our adventu- rers would be exposed to the most imminent peril ; for though recent improvements in the compass exclude the influence of such a state of the air on its movements, yet continued obscu- rity would not only cover the sun from their view, but conceal all the circumjacent country, rendering their observations very unsatisfactory. Hitherto the general opinion has been very inimical to under- takings of this nature, and all northern voyages have been con- demned, on account of the impracticability of reaching the ob- ject of pursuit, and the inutility of such, even though it were attained. But the opinions of cui bono philosophers are un- worthy of consideration. We feel convinced that all these ex- peditions have contributed much to our knowledge of the globe ; and we hesitate not a moment in affirming, that every one ha- ving a right feeling of what constitutes the character of a great nation like ours, will agree with us, that the bold and daring en- terprize in which Captain Parry is soon to embark, is worthy the marine of Great Britain, honourable to the science of the country, and a proof, if any were wanted, of the liberal and en- lightened views of our Government. Though the enterprize of Parry may not enable us to solve the grand geographical prob- lein which has for so long a period engaged the attention of man- kind,— though the secrets of the Pole may ever remain unre- vealed, — yet ttie interests of science, and the not less important Captain Parry^s intended Ea:pedition to the North Pole. 103 one of the whale-fishery, now so impoverished, may be much promoted. Many alterations have taken place in the physical distribution of whales, originating probably in the persecution with which they have been so vigorously followed during the last 200 years. Some think that the present scarcity is caused by the numbers captured having over-reached the breeding of that animal ; but the perspicuous view we have in Mr Scoresby's chronological account of the whale-fishery, would rather suggest the idea that captures are now more rare, on account of the scattered haunts to which persecution has driven it. About SOO years ago they were taken in abundance on the shores and in the bays of Jan Mayen Island ; now even a straggler is scarce ever seen in that situation. As soon as they were expelled from thence, they abounded in the bays of Spitzbergen, where they were slain in vast numbers, till, alarmed by their foes, they fled, and are now scattered abroad among the ice ; and their former haunts, which have been relinquished for a hundred years, are now occupied only by the tremendous razor-back and ugly sea-horse. The sea adjoining Spitzbergen is the usual resort of what are called the Greenland fishermen. Their fortune depends on their success during the two early months of the voyage, for whales all disappear by the middle of June. It is, I think, not improbable that this migration may happen as soon as the ice is open in more eastern seas, where a successful fishery might be prosecuted during the late months, if these remote regions can be safely navigated : a point of much importance, the practica- bility of which will be ascertained during the present voyage ; for the Hecla being stationed at Cloven Cliff to wait the return of Captain Parry and his party, the rest of the crew are to be occupied with the boats in surveying the eastern shores of Spitz- bergen, concerning which all our knowledge is derived from the Dutch, whose accounts of other parts in the Frozen Ocean have been found dangerously erroneous. ' Boats, or very small vessels, appear best adapted for examin- ing the sea east from Spitzbergen, being best qualified for navi- gating the narrows among ice-fields ; and, from their portability, are not only less liable to besetment, but may escape the ruin in which they would otherwise be involved, from the approxima- 104 Prof. Jameson mi the Geological Condition of the tion of large masses of ice. In the sea south from Spitzbergen, light boats would be useless ; for it being strewed with the wreck of fields, which, from its various dispositions, acquires the name of 'packs ^ Ur earns ^ or jloes^ the process of boring is requisite, which can be accomplished only with heavy vessels. But, in high eastern latitudes, such a process may be seldom required ; and so far as these little vessels can proceed, they may traverse with tolerable freedom, rendering them the fittest means of seeking the highest northern latitude, or the greatest eastern longitude. General Observations on the former and present Geological Condition of the Countries discovered by Captains Parry and Ross. By Professor Jameson *, X HE observations made during the four Arctic Expeditions, viz. that under Captain Ross, and the three under Captain Parry, afford the following general facts and inferences : 1 . That the regions explored abound in primitive and tran- sition rocks ; that, although the secondary rocks occupy con- siderable tracts, still their extent is more limited than that of the older formations ; that the alluvial deposites are not exten- sive ; that true or modern volcanic rocks were nowhere met with ; and that the only traces of the tertiary strata were found in the sandstones and clays connected with the secondary traps of Baffin's Bay. 2. That the primitive and transition islands were, in all pro- bability, at one time connected together, and formed a continu- ous mass with the continental parts of America ; and that, in the plains and hollows of this land were deposited the secondary limestones, sandstones, gypsum, and coal, and upon these again the tertiary rocks. 3. That, after the deposition of these secondary and tertiary rocks, the land appears to have been broken up, and reduced either suddenly or by degrees, or partly by sudden and violent action, and partly by the long continued agency of the atmo- • From Parry's Third Voyage. Countries discovered hy Captains Parry and Ross. 1 05 sphere and the ocean, into its present insular and peninsular form ; and that, consequently, the secondary and tertiary for- mations were formerly, in those regions, more extensively distri- buted than they are at present. 4. That, previous to the deposition of the coal-formation, as that of Melville Island, the transition and primitive hills and plains supported a rich and luxuriant vegetation, principally of cryptogamous plants, especially the ferns, the prototypes of which are now met with only in the tropical regions of the earth. The fossil corals of the secondary Umestones also inti- mate, that before, during, and after, the deposition of the coal- formation, the waters of the ocean were so constituted as to sup- port polyparia, closely resembling those of the present equa- torial seas. 5. That, previous to, and during, the deposition of the ter- tiary strata, these now frozen regions supported forests of di- cotyledonous plants, as is shewn by the fossil dicotyledonous woods met with in connection with these strata in Baffin's Bay, and by the fossil wood of Melville Island, Cape York, and Byam Martin Island. 6. That the boulders or rolled blocks met with in different quarters, and in tracts distant from their original localities, af- ford evidence of the passage of water across them, and at a pe- riod subsequent to the deposition of the newest solid strata, namely, those of the tertiary class. 7. That nowhere are there any discoverable traces of the agency of modern volcanoes ; and we may add, that, in the Arc- tic Regions, the only appearances of this kind are those in Jan Mayen"'s Island, described by Scoresby. 8. That the only intimations of older volcanic action are those afforded by the presence of secondary trap-rocks, such as basalt, greenstone, trap-tuffa, and amygdaloid. 9. That the black bituminous coal, the coal of the oldest coal- formation, which some speculators maintain to be confined to the more temperate and warmer regions of the earth, is now proved, by its discovery in Melville Island, far to the west, and in Jameson's Land, far to the east, in Old Greenland, to form an interesting and important feature in the geognostical constitution of arctic countries. 106 Prof. Jameson on the Geological Condition, Sfc. 10. That the red sandstone of Possession Bay, &c, renders it probable that rock-salt may occur in that quarter. 11. That, although no new metalliferous compounds have oc- curred to gratify the curiosity of the mineralogist, yet the re- gions explored by Captain Parry have afforded various interest- ing and highly useful ones, such as octahedral or magnetic iron- ore, rhomboidal or red iron-ore, prismatic or brown iron-ore, and prismatic chrome-ore, or chromate of iron ; also the com- mon ore of copper, or copper pyrites ; molybdena glance, or sulphuret of molybdena ; ore of titanium ; and that interesting and valuable mineral, graphite or black lead. 1% That the gems^ the most valued and most beautiful of mi- neral substances, are not wanting in the Arctic Regions visited by the Expeditions, is proved by the great abundance of the preci- ous garnet, which we doubt not will be found, on more particu- lar examination of the primitive rocks, to present all the beauti- ful colours and elegant forms for which it is so much admired. Rock-crystal, another of the gems, was met with, and also beryl and zircon. 1 3. That these newly-discovered lands exhibit the same ge- neral geognostical arrangements as occur in all other extensive tracts of country hitherto examined by the naturalist ; a fact which strengthens that opinion which maintains that the grand features of nature, in the mineral kingdom, are every where si- milar, and, consequently, that the same general agencies must have prevailed generally during the formation of the solid mass of the earth. 14. Lastly, That the apparent irregularities which, at first sight, present themselves to our attention, in the grand arrange- ments in the mineral kingdom, are the offspring of our own feeble powers of observation, and disappear when the phenome- na are examined in all their relations. It is then, indeed, that the mind obtains those enduring and sublime views of the Deity, which, in geology, rewarci the patient observer, raise one of the most beautiful and interesting departments of natural science to its true rank, and prove that its relations connect, as it were, in the scale of magnitude, the phenomena of the earth with those more extensive arrangements presented to our intelligence in the planetary system, and in the grand frame- work of the universe itself. ( 107 ) Remarks tending to explain the Geological History of' the Earth, By Professor Esmark.* xF we carry back our investigations with regard to the structure of the earth to its original formation, we find all involved in thick darkness. There have not been wanting, however, inge- nious men, who have formed theories on this subject ; we find some of these even among the Greek philosophers. Among these, two opposite opinions especially prevailed ; some consider- ed fire as the chief agent in this process ; others water. Anax- archus from Lampascus averred, that in his country the moun- tains had stood under water. Aristotle, Eratosthenes, Strabo, and Plutarch, supported his opinion. In later times, nobody doubts this fact, as we find petrified animals on the highest mountains. In America, such have been found on the Andes, at the height of 12,000 Rhenish feet above the level of the sea -f-. At first it was believed that these petrifactions were remains of the general deluge ; but a more accurate investigation discover- ed, that they could not all be derived from this source ; for, as we find on the highest mountains, and inclosed in the bowels of the earth, petrifactions of animals in every stage of their growth, and arranged in classes such as we still find alive in the sea, it may be readily inferred, that the duration of the flood was not suf- ficient to produce that amazing multitude of organic forms, the remains of which are now to be found in the bosom of the earth, but that these places must have once been the bottom of the sea. In considering these petrifactions with attention, we may ob- serve the following peculiarities among them : — 1. That the greater part of these petrifactions consist of sea animals and sea plants. * It being our intention to lay before our readers, as occasion may offer, statements of the opinions on the formation of the Earth entertained by dis- tinguished writers, we now communicate the ideas on this subject by Es- mark, from the Christiania Journal. + Colonel Gerard found many ammonites at a height of 16,200 feet above the seEj in the Himalya range of mountains. 108 Esmark 07i the Geological History of' the Earth. 9,. That they are not all of the same sort. * 3. That they have not all been deposited at the same time, but at periods far remote from one another. 4. That those which belong to the earliest periods have a less perfect organization, the farther back the less perfect ; that those on the contrary which have been found in mountains of a later formation, have a more perfectly developed organization. 5. That we find a multitude of petrifactions of different ani- mals which are now totally extinct, and that we find others which have some resemblance to animals now existing ; but with differences which prove them to be of another species. 6. That we likewise find a great multitude of plants incorpo- rated with the solid strata, of which some are different from those which now exist, while a great many seem to resemble them. The most remarkable circumstance connected with this fact is, that the climate of those places where these plants are found inclosed in the solid rocks, is not at all like the climate where they are now found growing. We find, for example, a mul- titude of plants in a state of petrifaction in the most northerly re- gions of Europe, which are now found growing in the torrid zone. As they are found with stalks and leaves, and sometimes even with fruit upon them, they must necessarily have grown in the places where they are now found, and could not have been wafted on the surface of the sea from regions lying far distant. 7. That of the human race, we find, with certainty, no re- mains inclosed in the earth, with the exception of a few which have been found partly in tuffaceous limestone, partly in clefts of older mountains which have since been filled up with sand, clay, and rubbish, and which must be considered as remains of the latest revolutionary changes in the earth. We find a variety of theories formed in later times on this sub- ject, by Burnet, Whiston, Woodward, Fontanelle, De Luc, Ray, Hutton, &c. They have each their own peculiar notions ; and though it cannot be said that any one of them is right, this will be a matter of no surprise, when we consider how far be- hind they were in many of the sciences which have made such progress during the last century. Though from this progress in mineralogy, chemistry, physical, mathematical, and astronomi- cal science, we stand on much higher ground than they did, Esmark on the Geological Historic of the Earth. 109 there is still much remaining which we cannot explain, with re- gard to the original formation of the earth, and the successive revolutions it has undergone, especially as we find that all these took place prior to the existence of the human race. For this reason, we are not able to give a perfectly satisfactory account of the history of the creation by Moses, who, without determin- ing the length of this period, merely says, that, " in the begin- ning, God created the heaven and the earth, and that the earth was without form and void." In all probability a very long pe- riod, perhaps several thousands of our present years, intervened between the creation of the world and the time when the earth had advanced £*> far in the arrangement of its parts as to be ca- pable of exhibiting signs of organization. By a day and a night, we now understand the period of the earth's revolution round its axis ; by a year, the revolution of the earth in its orbit round the sun. Moses says, that the light was first formed, and that that was the first day. On the third day after this, the sun and moon were formed. As we have now no light but what comes either immediately from the sun himself, or by re- flection from the moon ; and as there was light, and likewise day and night before the sun and moon were formed, we must infer that the day here mentioned has been of a different charac- ter from our day, and that this light had a different source from an immediate communication from the sun. We may there- fore conclude, that during the period of the incipient forma- tion of the earth, it had possessed a light peculiar to its own constitution, such as we shall afterwards find exhibited in the case of other heavenly bodies in a similar stage of their forma- tion. For this purpose, let us cast a glance over the solar system, stating such phenomena as may assist in explaining this forma- tion of the earth. On viewing this system, besides the earth, which completes its circuit round the sun in a period which we can exactly calculate, there are several other globes, some of them larger than the earth, and some of them smaller, which re- volve round the sun likewise in a determined period, some of them longer than that of the earth, and some of them shorter. Besides these bodies, the planets, with their satellites or moons, there belong also to the solar system a multitude of comets. 110 Esmark on the Geological History of the Earth. There are several phenomena by which these last are distin- guished from the planets. They revolve like them round the sun, but in much more ecGentn<^ orbits. The period of the re- volution of a comet is very different from one century to ano- ther.* Their greatest distance frofia the sun is so immense, that if men could exist upon them, they would not see the sun for thousands of years, and the degree of cold must be such, that if there were sea or water upon them, it must be in a state of ice. When these bodies are advancing to their perihelium, and at different distances approach nearer the earth, we observe that they are not only surrounded by a luminous atmosphere, but that they have likewise a long luminous tail, brth of which be- come the greater the nearer they come to the sun, decreasing in the same manner as they remove from him to a greater dis- tance. With regard to this increase and decrease of light too, we oliserve a difference among them . In the case of some of them, almost the whole mass of the comet is changed into this luminous elastic atmosphere and tail ; in others we perceive a distinct red nucleus, which, on its approach to the sun, has a less expanded atmosphere and tail. These atmospheres, and still more the tails, are so thin and elastic, that, without the least ob- struction, we can see through them the lesser stars. Counsellor Huth has calculated, that the luminous matter in the tail of the great comet of 1811, was a million of times rarer than our at- mosphere at the surface of the sea. The volume of its tail he computed to be 2000 times the bulk of the sun, and the diame- ter of its nucleus to be eighteen times that of the earth. Bessel calculates the period of its revolution to be 3383 years. Her- schel has accurately observed this comet, and, among other things, he concludes, that its light was peculiar to itself. The colour of its nucleus was greenish, or a bluish green, and the nucleus or head was not in the centre of the atmosphere, which was most expanded on that side turned to the sun. The radius of the atmosphere he makes to be about 322,000 English miles, and the length of the tail more than 100 millions. By continued observations on this comet, he found that it underwent actual physical changes in its structure, and that it was globular. On * Their number is considered as exceeding 4000. Esmark on the Geological History of the Earth. Ill its approach to the sun, his light and heat seemed to produce chemical effects upon it ; he believed that it revolved on its axis. By comparing this comet with that of 1807, he concludes, that every time comets approach their perihelium, they come nearer and nearer to the sun ; that, therefore, the comet of 1807 had several times been in its perihelium, it beng 25 million of times nearer the sun than the comet of 1811. Its tail was only 9 mil- lions of miles long, whereas that of 1811 was 91 millions. The effect of the sun on the latter was much greater than on the other, and it had probably seldom or never before been in its perihelium ; whereas, on the contrary, the comet of 1807, in consequence of having been several times in its perihelium, must be more advanced in its growth, and matured. By comparing likewise the constitution of the great comet, with a smaller one in the same year 1811, he found that the smaller one was much more complete, and approached nearer the nature of a planet than the great comet, as the influence of the sun upon its peri- helium, was not much greater than his influence on a planet in the same situation *. I have made these remarks on the nature of comets, and this comparison of some of them, for the sake of introducing certain considerations, drawn from facts, which I consider as a proof that our earth, in its rude and undigested state, has been a co- met. Of this hypothesis, I shall state, in what follows, several strong proofs in phenomena which occur in our own country. Whiston, in his Theory of the Earth, supposes that it has originally been a comet, or the atmosphere of a comet, which, in its course round the sun, has moved in a very eccentric el- hpse; that, of course, in its perihelium, it has been subjected to a very high degree of heat, and in its aphelium, to an ^equally strong degree of cold ; that, in the one of these situations, it was vitrified by the heat, in the other covered with ice ; that, by degrees, its orbit has gradually changed from this long el- lipse, to that almost circular path in which it now moves on the whole, at a much smaller distance from the sun. How far does this agree with the phenomena which we can observe on our • See Phil. Transact. 1811, and Boede*s Astronomisches Jahrbuch fur das Yahr 181G, p. 185. 112 Esmark mi the Geological History of the Earth. globe ? With regard first to the change in the form of its orbit, this must be a matter of very difficult proof; to accomplish such a change, requires a period of incalculable length, and if it has taken place to such a degree, we ought to find the change still going on, approaching nearer and nearer to a circular orbit. By the period of the earth's annual revolution round the sun, we cannot ascertain this point ; for though this continues SQ5\ days without change, every day, every hour, every second, may be shorter, without our being able to discover this. La Place computes, that, since the time of Hipparchus, who lived about 900 years ago, the year has become some few seconds shorter. However inconsiderable this quantity may be, it proves a real change. Probably the change was greater at first, diminishing as the orbit of the earth approaches a circular form. Does the present physical constitution of the earth, and the phenomena which occur on it, countenance the idea of the orbit of the earth having at first been a long ellipse ? From our present knowledge of chemistry and mineralogy, we cannot adopt the idea of Whis- ton, that, in its perihelium, the earth underwent a process of vi- trification, in the sense in which we now understand the word. The solid body of our globe consists of various minerals, com- posed of different kinds of earth, combined together in certain proportions. In former times, these were considered as simple bodies, or, as they were called, elements. But by the discoveries of the illustrious chemists Davy and Berzelius, it has been found, that not only potass and natron, but that all kinds of earths, which we formerly considered as simple, are compound bodies, each species consisting of a peculiar base, with a fixed proportion of oxygen. The form of the earth, a spheroid compressed at the poles, proves, 1^^, That, at its original formation, it was in a state of perfect fluidity. SJ, That to account for this figure, it must have revolved on its axis with more velocity than it does now, as it is higher at the equator, and more compressed at the poles, than it ought to be from the laws of gravity with its present ve- locity. From its original fluidity, all sorts of mineral bodies must have been dissolved in a fluid medium. When we assume that a body undergoes combustion in being combined with oxy- gen, by which it is by no means to be considered as destroyed Esmark on the Geological History of the Earth. US or annihilated, and that a burnt body is a body combined with a certain quantity of oxygen ; then, since all sorts of minerals are composed of particular kinds of earth, combined with a cer- tain proportion of oxygen, our globe must, at certain times, have undergone a state of combustion. This agrees entirely with its present constitution ; and as it appears that comets, during the time of their perihelium, undergo decompositions and combus- tions, we may conclude, that the earth, during one or several perihelia, has passed from its fluid to its present, as we may call it, burnt state. Its original fluidity can scarcely be denied ; but the fluid substance of which it was composed, and in which all other things were dissolved, cannot have been of the same nature with our present water, which is incapable of holding such a multitude of mineral bodies in a state of solution. We are therefore entitled to conclude, that, at the time when the solid masses of the globe were decomposed, the fluid medium which held them in solution was also decomposed and converted into a different character. The peculiar fluids found in cavities, in rocks and minerals, may, when strictly examined, give us some information as to the original fluid in which the matter of the strata was dissolved. During this state of combustion, an immense quantity of light must have been disengaged, as we see takes place with other comets at the time of their perihelium. As we find thus, that both fire and water have acted a part during the period of the earth's first formation, we may, in this manner, without inconsistency, combine the two opinions which have been opposed to one another on this subject. And now, with regard to the other part of Whiston's theory, he assumes, that, during the period of its aphelium, the earth was covered with ice and snow. At first view, it seems not likely that we should be able to exhibit any proof of this. But besides its extreme probability, we shall find actual proofs that the earth has been covered with ice and snow. In our own Norway, so rich in geognostic phenomena, there are to be found unquestionable proofs of this. In reading geognostic and other works, containing descriptions of particular countries, we rarely meet with observations, from which the authors were led to draw this conclusion. Sir James Hall, in his remarks on the changes on the surface of our planet, and on the huge OCTOBER DECEMBER 1826. H 114 Esmark on the Geological History of' the EartJi. masses of rock which are found about Geneva^ and the coast of the Baltic, and the formations of the vast sand-plains which are found in Holland and in the north of Germany, infers that not only strong currents, but ice likewise, must have had a share in producing these effects*. Tl^ere are not wanting many facts to confirm the conclusion that ice has worked prodigious changes on mountain masses, and conveyed from them large rocks into regions, where now no perennial ice is to be found, at a great distance from the mountains, from which they must have come. Men have often had recourse to extraordinary exertions of the powers of nature in explaining these phenomena. Thus has De Luc endeavoured to account for them by the eruption of gaseous fluids from the bowels of the earth, which have burst the mountains, and scattered the loosened fragments to a great distance around. The huge masses of granite which are to be found on the limestone mountains of the Jura range, and which have evidently come from the Alps of Switzerland^ though there lie deep valleys between the Alps and the Jura mountains, have been a riddle to many, especially as they are found very high up on the slope of the hills, and not in the bottom of the valley. Some, as I have mentioned, wish to ex- plain this by a projectile power. Dolomieu imagines that there has been formerly a continued slope from the top of the Alps to the Jura hills, on which these rocky masses have descended from the one to the other, and that the present intervening val- leys have been hollowed out by more recent revolutions. A few suppose that these masses have been brought to their present situation by ice. According to Von Buch this is a very general opinion in Switzerland. It is not only in mountainous regions we find this phenomenon, but also in flat alluvial districts, where these rocky masses lie upon gravel and sand, a circum- stance which cannot be explained in any other way, than by their having been brought thither in combination with masses of ice. It cannot be admitted that they could be brought to such situations by torrents of water, for the same torrents which could have been capable of bringing such masses of rock, must at the same time have carried off* the gravel and sand • Vide Sir James Hall's Memoirs, in the Transactions of the Royal Society of Edinburgh. Esmark on the Geological History of' the Earth. 115 on which they rest. One needs only to travel through the plains of Denmark, to perceive how improbable the supposition is, that such masses could be placed where they are by water. fin short, in every country, whether it be mountainous or flat, we shall find similar traces of the operation of masses of ice. The prominent conglomerations to be found in many districts, may be easily accounted for in the same manner. But it is par- ticularly in Norway I have found many proofs of the operation bf immense masses of ice which have now disappeared. 1. As in other countries we find large loose rocky masses lying spread over pretty level plains ; for example, in travelling from Marstuen, on the Miosen, to Leuten in Hedemark. These must have been brought from a great distance, for there are in the neighbourhood no mountains of the same character as these masses. S. In no other satisfactory way than by the operation of ice can we explain how those prodigiously large loose stones, some- times with sharp corners, have been brought up to the ridges and tops of high mountains, which are found in such numbers in the province of Christiansand. The first time I met with such single loose blocks lying on the ridge of the high moun- tains in Numedal, I thought they must be the remains of strata, or of masses which had covered the mountain, and which had in after-times been decomposed and carried off by water, leaving those traces of their former existence. But, on exa- mining them more closely, I found that this account of the mat- ter would not do, for I found that^ in their internal structure, many of these stones neither corresponded with one another, nor with the mountain mass on which they rested. By the as- sistance of immense masses of ice, on the other hand, it is easy to conceive how they could have been brought from a great distance, and pushed high up on the mountains. 3. In travelling over our mountainous districts, especially in Osterdal, it will be frequently found that the slope^of the moun- tain towards the valley is covered with large loose stones, mixed with a great quantity of loose sand and gravel, and that this covering extends to a considerable height over the bottom of the valley. If we consider attentively this mixture of large loose stones and gravel, we shall find that these could not have been produced and brought hither by any current of water descend- H S ^^ 116 Esmark an the Geological History of the Earth. ing through the valley, and depositing these larger and smaller remains of the ruins of the mountains ; for the current which brought down the large masses, and deposited them there, could not possibly, at the same time, have deposited the finer sand and gravel, but must have carried it down to places where the influence of the current was less powerful. We may indeed suppose that two different currents at different times might produce this mixture ; that the first and largest current deposited the large stones, and that a later and less powerful current deposited the gravel and sand. At first view this sup- position seems not improbable ; but, on a closer examination of this mixture, we shall find that it is not consistent with fact, for if a mighty current had brought down and deposited the large stones in the first instance, they must in that case rest upon one another, without any thing interposed between them, and the gravel, brought down and deposited by the succeeding current, could only have filled up the surrounding cavities ; whereas, on the contrary, we find the large stones lying separated from one another, surrounded by sand and gravel, a circumstance which cannot be explained in another way than by supposing that the whole has formerly been filled up vAi\\ ice, which has pushed the whole mixed mass up the slope of the mountain. The wa- ter of the ice, afterwards thawing, carried off by its rapid streams a part of the stones and gravel, which were then heaped toge- ther, deeper down in the valley : these heaps resemble entirely those which glaciers carry before them. 4. We come now to the fourth and the strongest proof, that immense masses of ice have formerly existed in Norway, in places where now no perennial ice is to be found. When I last summer (1823) undertook a journey to Stavanger, to examine the Union Copper Works, which have been commenced and again given up, I made an excursion from the dwelling-house of Fossan, which Pontoppidan, in his map, calls Fossland, in Holle Annex, in the parish of Strand, to examine a branch of the works at Vasbotten, about a quarter of a mile (more than li English miles) north-east from Fossan. The road went first over some cultivated ground, ascending a little, but after between four and five thousand paces it went over a large level sandy plain. This plain was overspread with a multitude of Esmark on the Geohgical History of the Earth. 117 tumuli, that had been all opened. Urburhill, which reaches out to the sea, lay upon the right hand, and, on advancing far- ther over the plain, you see the dwelling-house of Howkelie, at a little distance to the right, in a valley which stretches up into the hill. At the upper end this sandy plain was bounded by a glacier^dike or rampart, which extended across the whole valley. As this glacier dike is remarkable, and, so far as I know, the only one of its kind lying close to the level of the sea, in a district* where you find only a few heaps of perpetual snow in hollows of the mountains, where it slopes to the north-east, at the height of from two to three thousand Rhenish feet above the sea, I must be a little more particular in describing it. Its length across the valley, from mountain to mountain, is 2250 feet, its perpendicular height above the plain 100. At one of the ends where it approaches to the mountain, it is bro- ken through, so that there the highest part of its brink is not above twelve feet higher than the plain. This opening or breach is not above 200 feet broad. The dike itself consists of coarse gravel and sand, mixed with a great number of immense blocks of gneiss, which is the prevailing kind of rock in the mountain. We find this gravel and sand not only heaped up across'^the valley, but pushed up in great quantity on the oppo- site side of the dike, to the length of 1400 feet towards ihe mountain. The whole bottom of the valley is covered with a lake, which is called Howkelie Water, of the same breadth as the length of the dike, and extending about ten thousand feet up the valley. The people in the neighbourhood say that it is one hundred fa- thoms deep. As the surface of the lake is only ten feet higher than the plain on the other side of the dike, and as this, there- fore, where it is lowest, is two feet higher than the surface of the lake, there can be no run from it on this quarter. The wa- ter has its outgate at the other end, by a fall of a few feet, into a similar lake, and from this again, by a little fall at Vasbotten, it passes into a larger lake, called Ejewater, from which it soon after runs into Lyseford. These three lakes lie in a semi- circle. From this description it will be easy to see that this dike * By observations I made, Stavanger Church lies in Lat. 58' 57' 56". 1 J8 Esmark on the Geological History of' the Earth. could have been formed only by masses of ice, which must have filled up the whole valley, and, by their spreading atid pressure, have hollowed out its bottom. In all probability the water of the melted ice, at a late period, burst through the dike, and for a while had its issue through the opening, and its present outlet either did not then exist, or was filled up with ice and gravel. On the plain below we find not a trace of the gravel carried down from the dike, a thing of course not to be expected, when we think of a torrent 200 feet in breadth rushing out with violence. Not only the dike itself, but the whole horizontal surface, exhibits proofs that there has been a glacier here, for the plain exactly resembles those which I found adjoining to the glaciers presently existing between Londfiord and Lomb, in Guldbrandsdal, where I had likewise occasion to travel last summer. The resemblance is so striking, that every one who has an opportunity of making the comparison, must form the same opinion. As a proof of this I may mention, that Mr O. Tank, a skilful young mineralogist, who visited with me the dike of which I have given the description, and after- wards accompanied me to the glaciers, I have just mentioned, on seeing the latter, without having heard a hint on the subject from me, he immediately exclaimed that the dike we had seen at Stavanger must be a glacier dike,* As I think that what I have stated will be sufficient to prove that the Norwegian mountains have been covered with ice down to the level of the sea, and therefore that the sea itself must have been frozen, we may from this find the reason why the Norwegian mountains in general are so steep, I may say perpendicular, on the sides which hang over the valleys, not only in the valleys which are high above the level of the sea, but in those from the bottom of which the waters run into the Norwegian Fiords (Firths). -[• Ice, or glaciers, by their immense expanding powers, must, beyond doubt, have produced this change in their original form, from this circumstance, that they were continually sliding • The principal glacier in the valley of Boredhus descends from 3000 feet above the sea to 1400, with a moraine or dike, of earth and stones, in front, from 6 to 800 feet broad — Edit. + Our English geographers use Frith from fretuniy instead of the correct word Firth, from the Danish Fwrd. — Edit. Esmark on the Geological History of the Earth. 119 downwards from the higher mountains to the lower districts, and, by this progressive motion, carried with them the masses of stone which they had torn from the mountains. It is easy to explain why no trace of these masses thus separated is to be found immediately below the precipices thus formed. As these mountain precipices are often from three, four, to iive thousand feet high, and the valleys over which they hang are likewise several thousand feet in breadth, it must be a mat- ter of astonishment to think of such valleys being filled with ice to the extent of several miles. This ice in lower districts must have stretched a long way out into the sea, and, on its thawing, large masses must have broke loose, and gone out to sea, as we find takes place now in the polar regions. I have no hesitation in affirming this, when I survey the effects of immense masses of ice, where there is no room to be mistaken. | 1 shall further mention the supposed effects of glacier ice in another part of Norway, at the level of the sea. Last summer I went by sea from Bergen to Sondfiord and Nordfiord, on the outside of the Scars (the rocks which lie along the shore), to examine the petrifactions which Pontoppi- dan talks of in his Natural History of Norway, as to be found in Steensund, in the island of Gule, at the beginning of the 61° of north latitude. I went on shore at different places; and although I carefully examined every place around, I found not a trace of petrifaction.* On the contrary, I found that the part of the continent separated from it by the Sound, and the island of In- ner or Easter Lule, consisted of a solid conglomerate, composed of boulders, from the size of a pea to that of a man's head. These boulders consisted chiefly of gneiss, quartz, and clay- slate, which were involved and bound together in a mass so solid, that it was difficult to find out what the binding medium was, as the interstices between the large stones were com- pletely filled up with small boulders. On closer examination, at particular spots, I found that this binding medium was chlo- rite and hard clay. , ___ . ^ * Professor Rathke, who had formerly been at the same place, and found none, recommended to me to make this examination. 120 Esmark on the Geological Historic qftJie Earth. On this rock there seemed to me proofs of the powerful operation of ice. I found that the precipices on the side of the mountain next the Sound were several feet in height, and perfectly perpendicular ; and though they were composed, as I have mentioned, of boulders cemented together, they were per- fectly even and smooth. If these precipices had been the effect of rents, attended with successive masses tumbling down, then the boulders'adjoining the rent must have been found adhering some- times to the one and sometimes to the other of the separated masses, (those which have fallen into the sea are no more to be seen) ; and, in that case, the boulders left in one mass must have left a mark of itself in the corresponding one. This, however, was by no means the case, as the rock which remained was per- fectly smooth, and had the appearance as if these boulders had been cut across by a sharp knife. I can explain this phenome- non in no other way than by supposing, that large masses of ice pressing through the Sound, have cut these precipices lying pa- rallel to the direction of the Sound. I could give other proofs of the conclusion I have sought here to establish, but, to persons capable of judging of the matter, I consider these as sufficient. The result of what I have said I may state in the following particulars. 1. That, in the beginning, the earth existed in a fluid state. 2. That, during the long period it required to assume its pro- per composition and form, it has alternately been, at one time, at such a distance from the sun, that all the water upon it must have necessarily been converted into ice ; at another so near it, that not only the solid earth and minerals underwent a change, but also the fluid substance which held them in solution was de- compounded and changed. How deep these changes went into the body of the earth we have yet no means of ascertaining. By comparing the phenomena of burning volcanoes with the combus- tion of the metalloids, kalium, natrium, silicium, calcicum, we may conclude, that, deep in the bowels of the earth, there is to be found a multitude of specific metalloids, the combustion of which is the cause of the eruptions of volcanoes. 3. That organisation did not begin till this long period was PLATE n. 3 4 Kt/MrVM. .7om-7'. J^J. OOOOOOOOOOOOOOCC- 12 13 2^ \ Esmark ow the Geological History of the Earth. 121 completed, which the earth required to the full development of its own constitution ; that, after it began, it proceeded by suc- cessive steps from the less to the more perfect formations, end- ing with man as the head of the whole. Observations on the Structure and Functions of the Sponge. By R. E. Grant, M. D., F. R. S. E., V. L. S., M. W. S., Honorary Member of the Northern Institution, &c. Com- municated by the A uthor. Concluded from the preceding Volume, p. 351. (With a Plate.) JL HE silicious and calcareous spicula above described are group- ed into strong fasciculi, which are disposed around the internal canals of the sponge, in the order best calculated to defend these passages from compression, and from the entrance of extraneous bodies, and likewise to form between the canals certain inter- stitial spaces for the development and exit of the ova. Like the hard parts composing the skeleton in other animals, these earthy spicula are maintained in their relative situations by a tough li- gamentous matter, distinct from the other soft parts of the sponge. In the horny species, however, where the axis is com- posed of cylindrical tubular horny fibres, ramified and continu- ous throughout the whole body, this connecting cartilaginous matter appears to be unnecessary, and, from the examination of dried specimens, it appears to be altogether wanting. The exa- mination of the living properties of the axis in the horny species forms a subject of curious and interesting inquiry, which must be left to those who have opportunities of observing them alive in warmer latitudes, as they do not seem to inhabit the British shores. The dried filaments of the S. Jistular'is^ Lam. when viewed through a powerful microscope, appear to consist of one continuous ramified tube, whose central cavity (PI. II. Fig. 19. 6) is entirely filled with a dark opaque granular matter, which does not consist of spicula, while the sides of the tube (a) are trans- parent and amber coloured like common cat gut. In the S. offi- cinalis^ where the filaments are much finer, the sides of the tube (Fig. 20. a) have the same colour and homogeneous appearance, but the central cavity (h) appears empty. Mr Ellis states, 1^2 Dr Grant's Observations on the Structure that, in the branched species, the central cavities of the horny , filaments are filled with a soft white matter, and that they ter- minate by distinct apertures on the surface of the body ; and he considered these cavities as undoubtedly the habitations of ani- mals of a particular kind, (Hist, des Cor. p. 94). The confir- mation of this opinion, by accurate experiments, would establish a very striking distinction between these elastic species and the more friable earthy sponges of our own shores, and would point out a remarkable approximation in these highly organised spe- cies to the polypiferous axis of tubularise, sertulariae, and other keratophytes. In all the calcareous sponges which I have hi- therto examined, we invariably find triradiate spicula, which are completely enveloped in the connecting matter, and are employ- ed in forming the bounding fasciculi of the pores. Besides these complicated spicula, we frequently find a second and simpler form of spiculum, one extremity only of which is immersed in the connecting matter, while the other end, projecting free from the surface, defends the entrance of the pores and orifices. Thus, in the S. compressa (Fig. 23.), the bounding triradiate spicula (Fig. 11.), of various sizes, are found enveloped in the tough connecting matter around the pores, the defending clavate spicula (Fig. 12.) have their straight tapering portion immersed in the connecting matter, while their curved extremity hangs free over the entrance of the pores. In the S. coronata the con- necting matter seems to cover entirely the bounding triradiate spicula (Fig. 17.) ; and only the thick obtuse extremity of the needle-shaped defending spiculum (Fig. 18.) is immersed in it, while the tapering pointed end hangs free over the pores and fecal orifice. I have never observed a combination of calcareous and silicious spicula in the same sponge, nor any kind of spicu- lum in the horny species. Two distinct forms of spicula are very seldom observed in silicious sponges, though they are fre- quent in the calcareous species. In the Spongia ventilabrum, Lin., besides the long waved silicious filament (Fig. 5.), we ob- serve a distinct needle-shaped spiculum obtuse at one end, and tapered to a point at the other, (similar to Fig. 18). In the S. pilosa, Mont., besides the long straight fusiform spiculum, we observe a shorter curved spiculum, of equal thickness through- out, and rather obtusely pointed at both ends, like that of the and Functions of' the Sponge. 123 SpongillafnaUlis (Fig. 1.), but larger. In general, however, the only difference observed among the silicious spicula of the same individual is a great variety in their size. Donati not only observed that the hard spicula of the Tethya sphoerica differed remarkably in size, but likewise, that they were bound together by a peculiar fleshy or tendinous matter, (Mar. Adr., p. 62). In the S. coalita, besides the slender curved fusiform spiculum (Fig. 2.), we observe a long thick spiculum of the same form, which extends along the sides of two or three successive pores, and contributes much to their strength in a species peculiarly liable to have the diameter of these passages disturbed from the flexibility of its branches, and their erect position at the bottom of the sea. At the approach of death, and during putrefaction, the soft gelatinous or cellular matter of the S. panicea escapes plentifully from every opening of the body, and drops down like the ropy transparent colourless matter of an egg, without loosening, in the slightest degree, the connecting matter of the spicula, or alter- ing perceptibly the form of the skeleton. When we extract, by strong pressure, the cellular matter from the S. coalita, S. to- mentosa, &c. we obtain a very tough leathery substance, com- posed of spicula firmly bound together by the cartilaginous mat- ter, and retaining the original colour and form of the sponge. By repeatedly and strongly agitating a thin portion of the recent S. papillaris in fresh water, and then examining it under a pow- erful microscope, we find that the cellular matter has been en- tirely washed away, and the spicula are left imbedded in a trans- parent homogeneous tough matter, which retains its original co- lour and form unaltered. This connecting matter tears like a piece of cartilage, emits a fishy odour when burnt, dissolves with- out effervescence in nitric acid, contracts much, and acquires an amber colour by drying, and becomes very brittle in the dried state, probably alone from the earthy spicula it contains. There seems, therefore, to be a distinct matter in the earthy sponges for connecting, and probably secreting, the spicula of their skeleton. The dried preparations of this animal, preserved in museums, owe their form and stability to this tendinous con- necting substance, and, from its close resemblance in the dried state to the amber coloured filaments of horny species, it is pro- 124 Dr Grant's Observations cm the Structure bable, that, by removing the spicula, we might obtain from the earthy sponges of our own coasts the advantages for economical use derived from the elastic species of tropical seas. The soft gelatinous matter mentioned above, as escaping abundantly from the broken S. panicea, is met with in greater or less quantity in all the other species which have been examined. Cavolini ob- served it to be very abundant and consistent in the S. officinalis and *S'. carnosa. Schweigger observed it to be most abundant in the sponges of the Mediterranean in autumn. Vio and Olivi considered it as a distinct matter from the other soft parts of the sponge; and Schweigger found it to consist almost entirely of minute granules, with a little transparent moisture. It has an unctuous feel, emits a fishy odour when burnt, leaves a thin film or membrane when evaporated, and appears to the naked eye transparent, colourless, and homogeneous, like the colourless part of an egg. But, when a drop of it is examined on a plate of glass under the microscope, it appears entirely composed of very minute, transparent, spherical or ovate granules, Kke monades, with some moisture. These monade-like bodies, nearly all of the same size and form, resemble the pellucid granules or vesicles, which Trembly has represented as composing the whole texture of the hydrae, or the soft granular matter we observe in the stems of living sertulariae, and, indeed, most of the fleshy parts of orga- nised bodies appear to be composed of similar pellucid granular or monade-like bodies in different states of aggregation. This soft substance, which might be termed the parenchymatous mat- ter of the sponge, to distinguish it from the tough connecting matter of the spicula, is found in all parts of the body, but is chiefly contained in the intermediate spaces between the parietes of the internal canals, and it is more abundant at the time when the ova first make their appearance. The tough glistening sub- stance which lines the internal canals, and passes over the sur- face, between the pores, is the most highly organized part of the animal. That of the canals resists repeated strong agitation in fresh water, and appears through the microscope a very con- sistent homogeneous jelly, with a rough granulated internal sur- face. The roughness sometimes assumes a lineal appearance, exhibiting the rudiments of fibres, and the transparent granules which project considerably from its surface, become more rare and Functions of the sponge. -w 125^ near the fecal orifices. There is an apparatus at the entrance of the pores, of a nature very different from any of the parts al- ready described, and which throws much light on the functions of these openings. When we cut a thin layer from the surface of the *S'. papillaris (fig. SI.), and look down through one of its pores with the reflecting microscope, we perceive a very delicate net- work of gelatinous threads (fig. 25, c) thrown over the en- trance of the pore. This piece of structure is so fine as to be perfectly invisible to the naked eye, and is always effaced in dried specimens. It is present in every pore of the living ani- mal, and consists of several broad filaments of a soft transpa- rent, colourless, and perfectly homogeneous substance, which pass directly inwards from the bounding fasciculi, (fig. 25, a b} or gelatinous margins of the pores, to be connected with one or more central meshes, formed of the same threads, and lying in the same plane. This gelatinous net-work, consisting generally of six or seven meshes, lies always beneath the defending fasci- culi (fig. 24. b) in the species^ where these occur. And, while it is admirably protected by the depending spicula of the pores, as in the *S'. panicea, where these spicula spread over it like the rays of a fan, it serves to guard still more completely the inte- rior? of these passages from particles of sand or small floating animalcules. By making deeper sections, we sometimes observe one or more net- works of a simpler structure (fig. 26. c), but of the same nature, lying beneath the first. None of the project- ing granules, which line the whole internal surface of the canals, and compose the parenchymatous matter, are seen on any part of these net- works, and their position, regularity, and constant appearance, sufficiently point out their function, and show, inde- pendently of the surrounding frame-work, and the currents passing constantly in, that the pores are not the open cells of polypi, nor accidental perforations, made by worms or animal- cules in a pulpy substance. When we examine carefully the base of sessile species of sponge, we observe, that the part which forms the connecting medium between their body and the rock on which they spread, is a tough consistent gelatinous substance (fig. 21. h), similar to that which lines the canals, and passes over the surface between the pores ; it insinuates itself into all the inequalities of the surface to which it is attached, and is the rS6 Dr Grant's Observations oti the Structure part we observe to advance first during the spreading of the ovum, (fig. 29. h). It is a very remarkable circumstance, that Aristotle is almost the only writer who has described this part of the anatomy of the sponge. He observes, that they do not ad- here by a continuous surface; that they have some intermediate empty canals ; that they are fixed only at particular parts to the rocks, and have a kind of membrane spread out under their base (Lib. v. cap. 16.) He has accurately distinguished and described the pores'and fecal orifices, and was as well acquaint- ed with their functions as Ellis or Lamarck. He says, we ob- serve on the upper surface of the sponge minute pores (tto^oi) placed close to each other, and almost imperceptible, and a few, about four or five, wide orifices ( tinous network found within the canals, d, Ova hanging by their tapering extremity to the side of the internal canal, and producing currents by the motions of the ciliae covering their free surface. Fig. 27. Highly magnified ovum of the Spongia panicea, viewed from above, when about to fix. a, Central opaque part occu- pied by spicula, and covered with ciliae. h, Zone of vibrating cilise distinctly seen round the margin. c, Zone of accumu- . lated sediment, produced by the ciliae constantly clearing the space next the ovum. Fig. 28. "Highly magnified ovum of the Spongia panicea, viewed laterally, to shew its entire ovate form, a, Ciliae, longest on the vertex of the ovum, and resting on a more translucent part of the ovum, h, White pellucid base by which the ovum fixes a7id Functions of the Spo7ige. 141 and expands. Cj The part where the white base commences, and where the ciliae seem to terminate. Fig. 29. Appearance of the young Spongia panicea, after the ovum has fixed and spread for fourteen days on a watch-glass. a, Central opaque part to which the spicula were at first con- fined, b, Transparent homogeneous margin by which the young sponge spreads, and which likewise produces spicula. Cy Halo of accumulated sediment frequently seen round the margin, at a little distance from the young sponge, and inclos- ing a cleared space, as in Fig. 27. d. The part where the mo- nade-like parenchymatous matter terminates, and where the colourless homogeneous matter commences. Enumeration of the Instruments requisite for Meteorological Observations ; with Remarks on the mode of conducting such Observations. By Professor Leslie. XliVERY meteorological observatory, if it shall register with accuracy, and in a complete and satisfactory manner, the various atmospheric phenomena, ought to be provided with the follow- ino^ instruments. 1. The barometer, which measures the pressure of the atmo- sphere ; 2. The thermometer, which indicates its degree of beat ; 3. The hygrometer, which marks its relative dryness ; 4. The atmometer, which measures the quantity that evaporates in a given time from the surface of the earth • ; 5. The photometer, which indicates the intensity of the light transmitted from the sun, or reflected from the sky ; 6. The cethrioscope, which de- tects the cold showered down from the chill regions of the high- er atmosphere ; 7. The cyanometer, which designates the grada- tion of blue tints in the sky ; 8. The anemometer, which mea- sures the force and velocity of the wind ; 9. The ombrometer or rain-gauge, which marks the daily fall of rain, or baill, or snow ; 10. The electrometer, which indicates the electrical state of the air ; * In a close room or sheltered in external air, the atmometer might supply the place of an hygrometer ; and compared with another one freely exposed, it might serve as a substitute for the anemometer. 142 Professor Leslie's Remarks on the Instruments and, 11. The drosometer, which measures the quantity of dew. These various*instruments are not, however, all of equal impor- tance. The barometer, the thermometer, and the hygrometer, may be considered as quite indispensable. Next to them, de- serves to be ranked the photometer and aethrioscope, which dis- close the more recondite condition of the atmosphere. The atmometer, the ombrometer, and the anemometer, are of great consequence, from the practical results which they furnish. I would strongly recommend, as a most useful auxiliary in meteo- rological observations, Rutherford's maximum and minimum thermometer. In many cases, likewise, it would be convenient for^ the scientific traveller to be provided with a thermometer bearing large divisions, and lodged at the bottom of a walking- stick, protected by a coating of down inclosed within a brass tube. This instrument is peculiai'ly adapted for exploring the temperature of the ground and of springs*. But the value of any meteorological register must depend on the accuracy with which it is kept. The observations should be made in a place rather elevated, sheltered from the direct ac- tion of the sun, but exposed freely on all sides to the aspect of the sky ; and they should be repeated either at equal intervals, during day and night, or at least at those hours which represent most nearly the mean state of the atmosphere. These requisites are seldom attained, and very few registers of the weather, accord- ingly, are entitled to much confidence. It cannot be expected, that registers of the weather will pos- sess much value, so long as they are kept merely as objects of curiosity. Like astronomical observations, as now conducted, they should no longer be left to the chance of individual pur- • It would be particularly desirable, if travellers over land were provided with light barometers and stafF-thermometers. A very portable barometer, sufficiently accurate for general purposes, might be constructed with a conical tube, or two portions of unequal diameters conjoined. But the stafF-thermo- meter might often supply the want of a barometer, by discovering the mean temperature at moderate depths under the surface. Hence the relative alti- tudes of different places above the level of the sea could be estimated with tolerable precision. Had the various travellers who have visited the Interior of Africa made observations of that kind, the question respecting the course of the Niger would have been decided long before now ; at least we should have known, whether the great lakes were, like the Caspian, below the surface of the ocean. requisite for Meteorological Observations ^ ^c. 143 suit. They would require to be unremittingly prosecuted, in all variety of situations, and at the public expence. Proper sets of meteorological instruments should be placed, not only in the regular observatories, but sent to the different forts and light-houses, both at home and at our principal foreign stations. They might also be distributed among the ships employed in discovery, or engaged on distant voyages. The cost of provid- ing those instruments would be comparatively trifling ; and the charge incurred, by conducting registers on a regular and di- gested plan, might shrink almost to nothing in the scale of na- tional expenditure *. The state of the barometer alone is now kept with tolerable accuracy, because that instrument, being little influenced by adventitious circumstances, marks nearly the same impressions over a wide extent of surface. The thermometer, again, is sel- dom observed at the proper hours, or in situations sufficiently detached from buildings and solid walls. It is customary, for the sake of convenience, to note the thermometer in the morning, at the height of the day, and again in the evening. But these three observations must evi- dently give results below the medium temperature of the whole • Government provided our discovery ships, sent to the Arctic seas, with meteorological instruments ; but these, owing either to the ignorance or care- lessness of the makers, were, in some instances, discovered to be very ineffi- cient. Thus the thermometers were found to differ from one another ten de- grees, and the Six's thermometers used for ascertaining the temperature of the sea at different depths, were not trustworthy. In future experiments with Six's thermometer, we would recommend correction to be made for the effect of the compression of the water against the bulb, as had been carefully done in Lord Mulgrave's voyage to those regions. Captain Parry carried out, in his second expedition, two sets of hygrometers, photometers, and sethrio- scopes ; but these instruments, it seems, were entrusted to the charge of the astronomer, who either broke or neglected them. Yet a connected series of observations, performed with such instruments in the Polar Regions, would have furnished most important data for extending meteorological science. In a late philosophical voyage, directed to the Equator, some loose at- tempts have been made to estimate the radiation from the sky. But what- ever may be said of the theory of the sethrioscope, its great delicacy is beyond dispute ; and for an observer to overlook or disregard such an instru- ment, seems about as reasonable as if a navigator should prefer the old cross- staff to the sextant or the repeating circle. 144 Professor Leslie^s Remarks cm the Instruments twenty-four hours, since the accumulated warmth is counted only once, while the freshness, partaking of the night, is re- peated twice. It would come nearer the truth to assume the middle point between the maximum and minimum, though even this cannot be deemed absolutely correct, because the heat neither mounts nor declines in an uniform progression. The hottest time of the day is generally about two oVlock in the after- noon, and the coldest just before sunrise. The hour of extreme descent is consequently, in most latitudes, very variable ; and it would be difficult to fix the times suited for observing, unless they were more multiplied. But even fewer observations could some- times be made to serve the purpose. In this cUmate, the daily average heat may be reckoned from that of eight o''clock of the morning ; and the month of October is found to have nearly the mean temperature of the whole year. The observations usually made with the hygroscopes of Deluc or Saussure, cannot be regarded as affording any definite indication of the dryness of the atmosphere. It would essen- tially contribute to the advancement of meteorological science, if the hygrometer, which I have described, were introduced into general practice. This adoption cannot be very distant *. Some of the monks, in the religious houses dispersed over the Continent, might find agreeable and useful occupation in recording the state of the atmosphere. Many of these establish- ments are seated in lofty and romantic situations ; and several of them, destined by their founders for the charitable accommo- dation of travellers, occupy the summits of the most elevated and inaccessible mountains. Accurate registers kept in such towering spots would be peculiarly interesting. Meteorological registers might be regularly kept by the junior surgeons in all our medical depots which are scattered over vari- ous points of the globe. Lighthouses, too, would, from their usual position, be well fitted for observing the force and direction of the wind, and the swell and relapse of the tide. The elevation of the water could be most accurately noted by extending a leaden-pipe from the shore into the sea, and bending the nearer • We purpose soon to give the results of some interesting observations made with this instrument in the West Indies, and in New South Wales. requisite Jbr Meteorological Observations, ^c. 145 end of it into a low cellar where a vertical glass syphon is at- tached to it. Our navigators who traverse the ocean in every latitude, be- sides keeping meteorological journals and taking soundings, might record the variation of the needle, and examine the inten- sity of magnetic attraction. To promote the science of meteorology, it would be most ex- pedient that the various learned associations, planted in different parts of the globe, should institute inquiries into the state and internal motions of the higher strata of the atmosphere. As the ultimate results would prove advantageous to the public, the several governments, both in Europe and in America, might be expected to defray the moderate expence of carrying this plan into effect. Light small balloons could at times be launched towards the most elevated regions, to detect, by their flight, the existence and direction of currents which now escape our obser- vation. Barometers, thermometers, hygrometers, and perhaps aethrioscopes, in compact forms, and which should register them- selves, might be sent up in the car. Observers, furnished with accurate and complete instruments, could likewise be dispatched occasionally to the intermediate heights in large balloons. By classing the various meteorological journals, and combining those ulterior facts, some new lights could not fail to be struck out, which would gradually reveal that simple harmony, which assuredly pervades all the apparent complication of this Univer- sal Frame. The chief instruments here mentioned, and of the best and most accurate cojistrtiction, may be purchased of Mr John Cary, optician, London, and of Mr Adie in Edinburgh. Prices according to the style of mounting. Hygrometer (branched), Do. (portable), Atmometer, Photometer, (portable), Do. (branched), iEthrioscope, N. B. — Mr Gary manufactures the staff-thermometers, and Mr Adie, Rutherford's thermometers. OCTOBER DECEMBER 1826. K £2 10 0 to £3 0 0 3 0 0 to 3 6 0 1 10 0 to 2 0 0 3 3 0 to 3 10 0 3 5 0 to 3 15 0 4 0 0 to 5 0 0 ( 146 ) Description of the Eruption of Long Ijike and Mud LaJce^ in Vermont^ and ^ the desolation effected hy the rush of the wai- ters through Barton River ^ and the lower country^ towards Lake Memphremagog^ in the summer o/^ 1810, in a Letter to Prof. Silliman *. By the Rev. S. Edwards Dwight. With a Plan of the Lakes. (Plate III.) My Dear Sir, Boston, April 4. 1826. X LEFT Burlington on Monday, August 18. 1823, and proceeded on horseback, in company with Mr , an alumnus of Bur- lington College, to Craftsbury, sixty miles ; where we arrived at 2 p. M. on Tuesday. Through the kindness of my fellow tra- veller, an inhabitant of Craftsbury, I was able to engage a se- lect and very agreeable party of five gentlemen to accompany me, on the succeeding day, to the bed of Long Lake, in the town of Glover, — the lake which was emptied of its waters in the summer of 1810. In the course of the afternoon, I had leisure to examine the local situation of Craftsbury. This vil- lage is built on a table-land, rising abruptly in the centre of a deep valley, which surrounds it on all sides, and separates it, at a moderate distance, from hills generally of the same height with itself, but occasionally aspiring to a greater elevation. This ta- ble-land is about three miles in length, and one and a half in breadth. The valley surrounding it was once probably a lake, and the table-land a large island in its centre. At present it is almost an island ; one river winding more than half round it, in its progress through the valley, and a second nearly completing that part of the circuit which the first had left. Its situation is more than commonly beautiful and picturesque ; and, in con- nection with other more solid advantages, bids fair to render it one of the most pleasant and flourishing villages in the state. The population planted here is of a superior character ; and it gratified me to learn that the village reading-room, or athenceum^ was regularly furnished with the most important reviews and magazines of England and the United States, as well as with * From SiUiman's American Journal of Science and Arts, June 182C. PLATE, in Eduif ne-w PJul Jom: p IJ,^ 6. A. Surface of xong JLalce—H surface ofMudzake.-C wilscn's mUZ. H Keene comer. — E jBlodgets" Mill. — Y snos's mHI. jFossil zihell-uZa.. iig.4. Tablislied bjA.nUuk IdinT., Eruption of Long Lake and Mud Lake, in. Vermont. 147 the gazettes of the latter. The village is well built, and every thing indicated good order and general prosperity. Precisely at 4 a. m. of Wednesday, I sat down with one of my companions, to an excellent breakfast, which was rendered more hearty from the reflection that we might fare worse before the day was over ; and at five we were all on our horses. We rode eastward, through a country chiefly forested, twelve or fifteen miles, to a scattered hamlet in the north part of Glover, called Keene-Corner, and settled by emigrants from Keene, in New Hampshire. As we began to descend from the high grounds towards the hamlet, we first saw the valley of Barton river ; originally resembling the valleys of other streamlets of a similar size, but, at the time of the efflux of the lake, excavated into a broad, deep channel, with perpendicular banks ; in the bottom of which the stream had worked out for itself a some- what deeper bed. This river, which is here too small for a mill- stream, issues from Mud Lake, fbUr miles south from Keene- Corner; and, after running northward from this hamlet about seven miles to the village of Barton, turns somewhat to the north-west, flows about fifteen miles, and is discharged into Lake Mem ph rem agog. I was most agreeably surprized, as I descended the hills which overlook the valley of the river, to find the ravages made by the flood so distinctly visible, after the lapse of thirteen years. Our first view of the desolation presented a gulley, or excavation in the earth, extending up and down the river as far as its course was visible, and varying in breadth from twenty to forty rods, and in depth from twenty to forty feet. This immense channel, except what had been previously worn away by the gradual attrition of the streamlet, had all been hollowed out at once by the violence of the torrent. Its sides were precipices of earth or sand, every where indicating the avulsion of the mass which had been adjacent, and exhibiting in frequent succession, large rocks laid bare, and often jutting out into the guUey ; and, near the top, the uncovered roots of trees, which, having been partially undermined by the water, still nod- ded over the precipice. The bottom of this channel, as far as we could see, was covered with larger and smaller rocks and stones, and in some places with extensive deposits of sand. The sight of this vast excavation only heightened our conceptions of the effects of the flood, and satisfied us that, in our visit to the K 2 148 Eruption of Long Lake a/nd Mud Lake, in Vermont. bed of the lake whose waters had occasioned it, we should not be disappointed. Having engaged a dinner at a sorry substitute for an inn, we turned to the south, and ascended Barton River, about four miles. In order to see the ravages of the flood more perfect- ly, we left the usual path on the left bank of the gulley, and ^ rode all the way in its bed, over ground regularly ascending, until we came upon the northern shore of Mud Lake. This lake was originally the source of Barton River, and lay directly in the path along which the waters of Long Lake flowed, at the time of its evacuation. Here, of necessity, we left the gulley, and rode along the eastern shore of Mud Lake, until we had passed it; when, resuming our route in the bed of the gulley, we found the ground ascending very rapidly, until we entered the bed of the discharged lake. Having rode about half its length, we tied our horses, and pursued our way on foot, through the middle of its bed to the southern end. Here, ascending the bank to the original water-level, we could survey the whole bed of the lake, with its shores and surrounding scenery. From my own personal observation, and from minute inquiries made of several individuals who were concerned in letting off* the water, and of several gentlemen who were present at the le- gal investigation which it occasioned, I possessed myself of the fpllowing facts. Long Lake, before it was drained, was a beautiful sheet of water, about a mile and a half in length from north to south, and, where largest, three-fourths of a mile in breadth. For about ^ve hundred yards from the southern extremity, the lake was very narrow ; and, to this distance, its water was shoal, ha- ving been nowhere more than ten or twelve feet deep. Here there is a sudden and steep descent in its bed, to the depth of 100 feet. Here also the lake opened rapidly to the breadth of half a mile, and then more gradually to three-fourths of a mile. The depth also increased, in the broadest part, to 150 feet, and did not diminish until within a small distance of the northern extremity, where the lake was about half a mile wide. The eastern and western shores were bold, and rose imme- diately from the surface into hills of moderate height. These hills gradually subsided into plains, as they converged near the two ends of the Uke, to form the northern and southern shores. Eruption qfLo7ig Lake and Mud Lake, in Vermont. 149 The lake was supplied with water by a small rivulet, which still continues to flow in on its western side. At the southern ex- tremity, over ground scarcely descending, and through a chan- nel of probably not more than a yard in width, the water of the lake flowed out in a dull streamlet toward the south-west, and between trees, shrubs, and rocks, worked out for itself a slug- gish passage. This was the original outlet of the lake, and the remotest head-water of the river La Moelle, a tributary of Lake Champlain. The northern shore was generally low, rising not more than five or six feet above the surface of the lake, and consisted of a narrow belt of sand, succeeded by a bank of light sandy earth. The country all around the lake, as well as along its outlet at the southern extremity, was one unbroken forest. The distance from the northern end of Long Lake to the south- ern end of Mud Lake, was about 200 rods. There was no original communication between them ; the waters of the former, as we have already seen, having been discharged towards the south, and those of the latter towards the north. The ground between the two was covered with a thick forest, and formed a very ra- pid declivity from Long Lake towards Mud Lake. The low bank of sandy earth which formed the northern boundary of Long Lake, continued of an uniform height for about five rods from the shore, where, becoming more firm and solid, it descend- ed so rapidly towards Mud Lake, that the perpendicular de- scent between the two, in the distance of 200 rods^ was at least 200 feet. The bottom of Long Lake, near the western shore, was rocky ; at the southern extremity, beneath the shoal water, it was a mound of sandy earth, and throughout the great body of the lake was either sand or mud. The mud was black, light and loose ; when wet, flowing like water, and when dry,*of a blue co- lour, and light as a cork. The descent, at the northern shore, was bold and rapid ; and on the bottom, near the shore, was spread out a calcareous petrifaction, or deposit, called by one of the work- men a hard-pan, of the thickness generally of two or three inches, though occasionally of six or eight. I saw numerous fragments of it ; and one, which I brought home, was an inch and a half thick, and had the solidity and hardness of limestone. Its up- per surface was of a light yellowish-brown colour, and had the 150 Erupticyti of Long Lake a7id Mud Lake, in Vermont. smoothness of a stalactite ; while the lower was rough and un- ^ even, embodying pebbles, sand, weeds, and other coarse sub- stances, on which the calcareous deposit, at its first commence- ment, had settled. The fracture, to use the sprightly language of my principal informant, one of the individuals concerned in letting off the water, resemhled frozen gravel This hard-pan reached out from the shore into the lake, for a breadth of five or six rods, resting on the bottom ; and was found along the whole northern extremity. Being rather feebly and doubtfully sustained by the mass of sand underneath, on which it lay as on an inclined plane, it supported the superincumbent water, and formed the only solid barrier which prohibited the contents of Long Lake from descending into Mud Lake. Mud Lake was originally three-fourths of a mile in length from north to south, and half a mile in breadth. -Its shores, both on the western and eastern sides, soon rose into high grounds ; between which, and over the bed of Mud Lake, the waters of Long Lake, if let out northward, must necessarily pass. The bottom of Mud Lake was a mass of thick deep mud, tough and gritty, of a rusty dark blue, many feet in thick- ness ; and, when dry, becoming of a pale blue, and of a hard so- lid texture. This lake was originally deep, though less so than the other. Barton River, its outlet, descended very rapidly through a rough uneven country, over a bed of sand and peb- bles, for about five miles, and then more gradually, and with a margin of meadow on each hand, for six miles, to the village in Barton. All this distance, with the exception of a few .cleared spots at Keene-Corner, and in Barton, the country was, in 1810, a thick forest, on both sides of the stream, to its very banks. At Keene-Corner, four miles from Mud Lake, stood a grist-mill and a saw-mill, both owned by a Mr Wilson ; but the stream was so small that, in the dry season, the supply of water was insufficient for the mills. About seven miles lower down, it unites with a still larger stream from the right, the outlet of Belle Pond, a beautiful lake in Barton. Two miles further down was another grist-mill, owned by a Mr Blodget ; and three miles lower, were the mills of a Mr Enos. The insufficient supply of water at Wilson's mills, was a se- rious inconvenience to the inhabitants of Keene-Corner, as well Eruption of' Long Lake and Mud Lake, in Vermont. 151 as to the proprietor himself. The comparative elevation of the water in the two lakes, and the nature of the ground between them, had long been known at the hamlet, and had frequently provoked discussions of the question, Whether it was not practi- cable to let out a part of the water of Long Lake ijito Mud Lakcy and thus Jurnish an additional supply to the mills on Barton River ? These discussions always ended in an affirmative deci- sion ; and the disposition to test its correctness regularly gaining strength, as the practicability and importance of the measure were more and more developed, it was at length resolved, in mit-qf-door convocation, that the thing should be done ; and the 6th of June 1810, the day of the general election of New Hamp- shire, which, out of respect to their parent state, they had usual- ly observed as a holiday, was selected for the purpose. On the morning of that day, about 100 individuals from Glover, Barton, and several of the adjacent towns, assembled at Keene-Corner, with their shovels and spades, their hoes and axes, their crowbars and pick-axes, and their canteens, and voted that they would march to Long Lake, and there have '' a regu- lar Election Scraped * They arrived at the scene of action about ten o'clock ; and, having selected the spot which seemed most feasible, began to cut down the trees, and to dig a channel for the water across the belt of sandy earth which constituted the northern boundary of the lake. At three o'clock, a trench five feet wide, five or six rods in length, and seven or eight feet deep, was completed. It began within a yard of the water, and reach- ed to the brow of the declivity, towards Mud Lake ; yet gra- dually descended in its line of direction ; so that, when the small remaining mass of sand in the trench should be removed, they might see the" waters of the lake flow out without interruption, to increase the mill-stream of the village. At length, the command being given that all hands should leave the trench, the mass of sand left in it, with a portion of that under the hard-pan, were removed ; and as large a piece of the hard-pan as their pick-axes would reach, was broken off. The water issued at first through the chasm thus made, With a moderate degree of force ; but, to the great surprize of the work- • Scrape^ in this sense, is a colloq[uial Americanism, and denotes a frolic. 152 Eruption of Long Lake and Mud Lake, in Vermont. men, it did not run off into the trench. One fact, having an important bearing on the ultimate success of their enterprize, had escaped their observation. The sand under the hard-pan was a species of quicksand ; and the issuing stream, instead of flowing obhquely towards the dechvity, began to sink perpendi- cularly beneath the hard-pan, and to work down a portion of the quicksand, so that it disappeared with the water. In a few mo- ments a large amount of the sand under the hard-pan was washed from beneath it ; and the portion of the hard-pan, thus under- mined, being unable to sustain the immense pressure, gave way. This occasioned a violent rushing of water to the deeper outlet thus formed ; which, in its turn, sinking under the hard-pan, and washing down a still larger portion of the sand on which it rested, occasioned a still broader and deeper fracture of the hard-pan, and prepared the way for a still more violent gushing of the water, and a still wider and deeper gulf in the sands be- neath, until all traces of the original trench had vanished. This process was repeated a considerable number of times, every frac- ture of the hard-pan being more extensive than the preceding ; imtil, by the undermining force of the water, a deep gulf was worn where the trench had been, several rods in width, and de- scending immediately and rapidly towards Mud Lake. Just as the efflux of the water commenced, four or five of the workmen pushed out into the lake upon a raft ; intending to cross its northern end, and on their way to sound an hurrah be- coming the occasion ; but, the alarm having been given, they put to shore, and had barely left the ground on which they landed, when it disappeared. One of the others, having remained too long at work in the trench, was struck by the torrent ; and the ground being washed from beneath him, he would have been carried away, had he not been caught by the hair of his head. Another, waiting too long to witness the violence of the water, was forced pai'tly under the earth ; and it was owing probably to the momentary resistance presented by the roots of a large tree, against which he was driven, that he, and those who came to his assistance, were saved. These accidents induced the workmen to retreat with rapidity from the sides of the widening gulf In the language of one of them, they felt the ground beneath " quiver, quiver, quiver,"" as they ran away with all possible Eruptio7i of Lang Lake and Mud Lake, in Vermont. 153 speed to save their lives. Having all at length got out of dan- ger, they stood on firm ground near the lake, and on both sides of the widening chasm, and observed the progress of the deso- lation. As the water rushed from the southern towards the northern extremity, it forced up upon the shore a large mass of soft, oozy mud, several rods above the existing water-level, on either side of the outlet. This mud remained stationary for some time, and on its surface a large number of the fish of the lake lay snapping and flouncing. Just as one of the workmen was venturing into the mud to secure some of the fish, the water having chiefly run out ; the two masses of mud, being no longer pressed upward by the force of water, slid down at once into the gulf, and were immediately swept away. This process of undermining and fracturing successive por- tions of the hard-pan having been continued about twenty mi- nutes, a passage was forced through it, down to its lower extre- mity ; and the superincumbent water of the lake, being thus left wholly without support, flowed with such impetuosity towards the northern shore, that it all gave way to the width of more than a quarter of a mile, and the depth of 150 feet. The whole bar- rier being thus removed, the entire mass of waters rushed out with inconceivable force and violence ; and, the northern end be- ing the deepest, it was but a few moments before a volume of water, a mile and a half in length, about three-fourths of a mile in width, and from 100 to 150 feet in depth, had wholly disap- peared. The liberated mass of water made its way down the declivity, to the valley of Mud Lake, tearing up and bearing before it, trees, earth and rocks, and excavating a channel of a quarter of a mile in width, and from 50 to SOJeet in depth. With the immense momentum which it had gained, it flowed into this val- ley, forcing forward, with irresistible impetuosity, the spoils which it had already accumulated ; tore away masses of earth from the high grounds on each side of the lake ; excavated the whole bottom of the valley, including the shores of the lake, to the depth of perhaps SO feet ; and, with the additional mass of water thus acquired, made its way down the channel of Barton River. 154 Eruption of Long Lake and Mud Lake, in Vermont Mud Lake had originally a narrow outlet, and rising grounds of moderate height bounded it at the northern end. The accu- mulated torrent, bearing along the gathered spoils of its own de- solations, broke away this mound in a moment ; and following the course of the river, rushed down the long and rapid descent of five miles towards the flats in Barton. Through all this dis- tance it tore up and carried away the forest trees, and hollowed out to itself a path in the earth, varying from 20 to 40 rods in width, and from 20 feet to 60 in depth, so that every trace of the original bed of Barton River disappeared, and the river was left to choose for itself a new bed, many feet below the old one in the bottom of the gulley. In some instances the excavation was narrower, in consequence of huge rocks on both sides, which the torrent could not move ; but, in such cases, amends were made in its greater depth. Where an immoveable rock was found on one side only, it usually altered the course of the torrent, with- out materially diminishing its breadth. Wherever any such ob- struction made an eddy, by stopping momentarily the torrent's progress, the effect was still observable in deposits of sand, im- mediately above the obstructions, varying in depth and extent with the time during which the water paused, and the surface which it covered at the moment. Some of these are an acre or more in extent, and 20 feet in depth. In these cases there was usually a deposit of the floating forest trees. At Keene-Corner, it not only swept away the grist-mill and saw-mill of Mr Wil- son, with the mill-dams, but the mill-sites, with the ground be- neath them for many feet, as well as the bed of the river by which they had been imperfectly supplied. A man in one of the mills, hearing the noise of the approaching flood, ran to save himself; and had but just escaped from its path as it went by. His horse, tied at a post near the mill, was swept away, and was afterwards found a great distance below, literally torn to pieces. About a mile below the mills the torrent entered a more level country ; where the river had been wont to glide through a broader valley, and was generally bordered with flats or inter- vals of some rods in width, covered with forest trees. Here this moving mass of trees, earth and water, expanded itself as the t!Ountry opened, and with the velocity acquired in its long de- Eruption of Long Lake and Mud Ldke^ in Vermont. J 55 scent, marched onwards in its work of desolation. Not satisfied with tearing up the trees, it removed the earth beneath them to a considerable depth, and bore away masses of earth from the sides of the high grounds, by which the original valley of the river was bounded. These it left precipitous ; exhibiting on the perpendicular face denuded rocks and roots of trees, and in eve- ry place pointing out the exact breadth of the torrent's march. The trees on the brink, which were not destroyed, showed strong proofs of the violence ; proofs which were often discoverable at the end of thirteen years. Wherever the original valley narrow- ed, or suddenly changed its course, and its boundaries were too firm to be pushed away, the torrent, receiving a momentary check, became narrower and higher, and left deposits of sand and of trees in the valley, and frequently on the high grounds. The forests were thus levelled, and the excavation continued some distance below the mill of Mr Blodget, 14 miles from the lake. There, owing to the widening of the hills, and the more cleared state of the country, it gradually spent its force, though many marks of its violence are witnessed all the way to Lake Memphremagog. Through the more level country, the excavation which it left to indicate its path, varied from 30 to 60 rods in width, while its average depth was probably from 10 to 15 feet. An inhabitant of Barton, who was standing at the time on a high ground, told me, that, hearing the noise, he looked up the stream, and saw the flood marching rapidly forward, opening it- self a path through the valley, and bearing a moving forest on its very top ; so that those who were with him gave the alarm that the forest from Glover was coming down upon Barton. The house of a Mr Gould, in Barton, standing 15 feet above high-water mark, was within the track of the torrent, and him- self and his wife were at home. Alarmed by the noise, he caught his wife in his arms, and carried her up the bank ; yet it was with the utmost difficulty that they escaped. The water rose to the eaves of the house^ and removed it from its founda- tion : but bearing it against some stumps of trees, which were very firmly braced in the earth, it remained there when the flood had subsided. The saw-mill of Mr Blodget, with the mill- dam, was entirely swept away, as was every bridge on Barton ri- 156 Eruption of Long Lake and Mud Lake, in Vermont. ver, between Mud Lake and Lake Memphremagog. At Enos's Mills, 5 miles below the village of Barton, and 17 below Long Lake, the torrent retained so much of its impetuosity, that it moved a rock, supposed to be of 100 tons in weight, a number of rods from its bed. Some of the deposits of sand were very extensive ; and the changes effected by the deposition were different in different spe- cies of soil. Extensive tracts of the flats on Barton river were fine meadow land ; while other tracts were sunken swamps. The former, so far as they received the deposits, were left mere fields of barren sand ; while the latter were converted by them in a short time into the richest meadows. One swamp, to the amount of two hundred acres, and several others to the amount of three hundred more, were thus recovered ; while various tracts of meadow, in all about one hundred acres, were perma- nently ruined. Masses of wood were deposited, in greater or less frequency, along the banks of the guUey, as well as in much larger heaps in those places where the progress of the torrent was momen- tarily suspended. Some of the men who witnessed it, told me that tens of thousands of cords, a quantity which could not be calculated, were thus left in Barton, besides a vast number floated further down. Near the church in Barton , a field of twenty acres was covered with deposited timber to the height of twenty feet. In several places, where the torrent was power- fully obstructed and suddenly narrowed, (as I was informed by two of the inhabitants), the timber was piled up by the force of the stream, to the height of 60 or 80 feet. Vast quan- tities of it were sunk under the sand. That which lay upon the surface was burned as fast as it dried, and they had been burning it continually to clear the land ; yet many acres of meadow still remained covered with timber ; and I also saw nu- merous large heaps of it skirting the edge of either bank. The kinds of timber were spruce, cedar, hemlock and hackmontak. The trees were much bruised, the branches generally broken, and the bark peeled off; while the trees left standing near the two edges of the torrent, were principally killed. I was informed that deposits both of wood and sand were made in this manner, on both sides of the torrenf s path, all the Eruption of Long Lake and Mud Lake, in Vermont. 157 way from Barton to Lake Memphremagog ; and that large quantities of forest trees were strewed over the surface of the lake. The hard tough mud in the bottom of Mud Lake, was all forced out and carried away, and was seen scattered in small- er and larger masses — some, of the size of haycocks — for a great distance along the progress of the torrent, and over the adjoining fields. Several of the workmen informed me that when the northern barrier of Long Lake gave way, and while the waters rushed down the declivity into Mud Lake, the convulsion shook the earth like a mighty earthquake ; and that the noise was louder than the loudest thunder, and was heard for many miles around. One of them, whose house was more than five miles from the spot, told me that the noise there was so loud that the cattle came running home, with the most obvious marks of terror and alarm ; and that his family supposed, until his return, that there had been a tremendous earthquake, accompanied with loud thunder. The noise and agitation were also very great, while the torrent made its way downward, from Mud Lake to Keene Corner, and, even during its progress in the more level region, greatly alarmed all the surrounding country. The waters of Long Lake were undoubtedly calcareous. I saw on the bottom many siliceous rocks ; but the fissures of these rocks were frequently filled with deposits of limestone. There were numerous masses or rocks of limestone, of a bluish black colour, occasionally imbedding pebbles of a different co- lour and genus. Some of these masses were exceedingly hard and firm, others were only brittle, while others were friable, and others still were heaps of bluish black limestone dust, — the embryos of rocks which had not yet received the cohesion ne- cessary to bind them into solid masses, when the matrix in which theygwere forming was dissolved. Probably the black sponge mud of Long Lake was chiefly of this character ; as this very substance, when wet, has a similar appearance. In various places on the bottom of the lake, are deposits of a friable white substance, which is almost pure carbonate of lime. This sub- stance, as we shall have reason to see, was much more abundant before the emptying of the lake. Had a skilful mineralogist l58 Erupticyn of Long Lake and Mud Lake, in Vermont. been with me, he might doubtless have made important disco- veries. The bottom of the lake was in some places boggy, but gene- rally so dry that we could walk over it without difficulty. It was extensively grown over with sedge and other weeds, and in many places with shrubs and young trees. The original water- level of the lake was generally discoverable along the shores. The same rivulet still flows in on the west side, which originally supplied its waters ; but it now flows out at the northern end into Mud Lake. It is about a yard over ; and, as no reason can be given why it should have diminished, I conclude that this was the size of the outlet of Long Lake. The flood left obvious traces of its violence within the bed of the lake. At the southern end, the water on the shoal, not more than 10 or 12 feet deep, rushing down the pitch into the deeper part of the lake, swept down a considerable mass of earth and rocks, and near the middle of the pitch, from east to west, formed an excavation, or trench, about one hundred yards in length, nar- rower ^nd shallow at its commencement, but widening and deepening all the way to the bottom, where it is several rods in width. On both shores of the lake, the force of the water tore away large masses of earth, forced rocks out of their original bed, and, in various instances, laid bare the surface of extensive ledges of rock, which had been previously imbedded in earth ; leaving them projecting a considerable distance beyond the line of the shore. These effects were most marked towards the northern end. About twenty rods from that end, an excava- tion, or trench, commences in the bottom of the lake, and con- tinues to widen and deepen, until it coincides with the deep gul- ley at the outlet. The surface of Mud Lake is at least 30 feet lower, in the opinion of the workmen, than before, and has not more than half of its original extent. The soft mud from the bottom of Long Lake, flowed into Mud Lake *, and took the place of the hard, tough mud, which originally formed its bed. So large was the supply, that Mud Lake is now shallow — having been • This lake was without a name, until this event procured for it this less poetical than appropriate designation. Er uption of Long Lake and Mud Lake, in Vermont. 159 fllled up at the bottom, as well as cut off at the top by the abra- sion of the torrent. I saw perhaps twenty of the trees, which had been left in it thirteen years before, standing up from its bottom, in various directions ; and the length of their stems above the water, indicated that the depth was moderate. Be- fore the draining of Long Lake, Mud Lake had no lime ; but large quantities of the white friable carbonate of lime were brought down and deposited within and around it, so as to ren- der the manufacture of quick-lime a regular employment for several of the inhabitants. Mr Blodget, the proprietor of the mill destroyed in Barton, instituted a suit against some of the individuals employed in letting out the waters of Long Lake. In the course of the trial, the whole history of the event was brought to light. He laid his damages at 1000 dollars ; but, pendente lite, compro- mised the matter for 100, on condition that each party should pay his own costs. It was doubtless a favourable circumstance, that Long Lake was drained while the country on Barton River was a wilder- ness. From the singular configuration of the adjacent ground, it is certain that its contents would sooner or later have been emptied into Mud Lake ; and had the discharge been deferred until the country had been well settled, the injury would have been incalculable. At the time when the event occurred no material injury was done, and an essential service rendered the community ; as the bed of the lake furnishes an advantageous site for a road leading to the country eastward of Glover, which the hills had previously rendered impracticable. Such a road had been seriously proposed when I was there ; and my only objection to the measure lay in the fact, that, by effacing the vestiges of desolation, it would violate the rights of philosophi- cal enquiry. This event appears to confirm an opinion, extensively enter- tained in this country, respecting the changes which various parts of its surface have in former periods undergone. Valleys are here and there found, with streams of water passing through them, surrounded on all sides by high grounds, except a very narrow passage for the stream to enter, and another for it to es- cape; and in both, the whole appearance of the ground indi- 160 Eruption of Long Lake and Mud Lake, in Vermont. cates that the high ground actually met, in some former period ; that the valley was originally a lake ; and that its water was discharged by a waterfall. There is so much resemblance be- tween the bed of Long Lake and some of these places which I have examined, that I cannot doubt the correctness of this opi- nion. Had the waters of that lake been discharged two centu- ries earlier, its bed, and the gulley which it formed, would have been filled with a thrifty forest ; and the evidence that it had ever been a lake would have been no more satisfactory than we now possess, that the places to which I have alluded were once filled with water. We now know the fact, however, that lakes may be suddenly and finally emptied, and their beds changed to .» fertile valleys, so as to lose, in no great length of time, all traces of the immediate action of water. Several individuals, well acquainted with the country, in- formed me that the ground at one extremity of Lake Willough- by, which lies a few miles east of Barton, is formed like that at the northern extremity of Long Lake; and that its waters could be discharged with even less labour, than were those of the lat- ter. Lake Willoughby is about seven miles long, about three miles wide in the broadest part, and very deep ; and its waters, if thus discharged, must flow south-eastward, through the val- ley of the Presumpsick, into the Connecticut. Could the dis- charge be achieved without too much hazard, it would be an in- calculable advantage to a large extent of country ; as a long range of towns in the neighbourhood of this lake, are separated from the Connecticut by a chain of pathless mountains, through which no road can be formed, except over the emptied bed of Lake Willoughby, and are thus compelled to find their market down the valley of the Presumpsick ; a fact which has almost entirely prevented their settlement. After we had examined the bed of Long Lake, and the ra- vages which its waters had occasioned, as long and as minutely as our time would permit, we returned down the gulley, and ar- rived at our inn at 3 o'clock, where we sat down to a meal ren- dered welcome by laborious exercise and the fasting of ten hours. Immediately after, bidding four of my companions adieu, I rode down the river in company with the fifth, to the village of Barton. Our course was on the eastern bank of the Overlafid Arctic Expedition. I#l gulley, and every step of the way I could witness the desolation of the torrent. Taking the whole excavation for the twelve miles in which I followed it, it is the highest exhibition of the effects of physical force, instantaneously exerted, which I have yet seen. See Plate III. for a Plan of the Lakes, illustrative of the de- tails above given. Overland Arctic Expedition. XX S any notice, however short, of the scientific doings of this enterprise, cannot fail to prove acceptable, we now add the fol- lowing details to those already communicated. " Fort Frankliit, Great Bear Lake, « February 6. 1826. " Nothing of any importance has occurred since I wrote you last, except that we have received a friendly message from the Esquimaux, through the Sharp Eyes, a neighbouring tribe, who frequent Fort Good Hope, the most northerly of the Com- pany's posts. On the 29th of November last, the S. W. quar- ter of the sky was cloudless, but of a pure emerald-green colour (compared at the moment with Syme's book), soon fading away into mountain-green. The rays of the sun setting to the S.S.E. at the same time tinged some clouds gold-yellow, &c. The au- rora has not been so frequent, and our observations of course upon it are not so interesting, as at Fort Enterprise As far as they go, they confirm the few general remarks then hazarded, although I think not favourable, in general, to Hansteen's theory. With regard to facts. Captain Franklin's observations and Han- steen's seem to agree. The Edinburgh Philosophical Journal for March 1825 reached us last month, and has proved a great treat to us. I am glad to see it go on so vigorously. " We expect, if every thing prospers with us, and at present we have no reason to fear any misadventure, that we shall reach England early in November 1827. This is rather too quick a movement for the purposes of science. Even a cursory view of the geology of the Rocky Mountains §kirt;ng Mackenzie's River OCTOBER — DECEMBER 1826. L 162 Overland Arctic Eocpediticm, might occupy some months very pleasantly ; but the delay of a few days here is the loss of a season, and we cannot reckon on more than two months in the year for such purposes." " Fort Franklin, Great Bear Lake, " March 23. 1826. " My Dear Sib, " In consequence of an imperfect, but very interesting, In- dian report of Captain Parry's wintering on the coast, and which Captain Franklin is desirous of investigating, I have an- other opportunity of writing to you this season. The particu- lars of the report, when ascertained, will be transmitted to Mr Barrow, from whom you may get them. " I mentioned, in a former letter, that a formation of lignite occurs in this quarter. The lignite has a slaty structure, thin- nish, or only moderately thick ; and, when exposed to the atmo- sphere, cracks into forms generally nearly rectangular. Some portions, which are rather thick slaty, with a flat conchoidal fracture in the small, bear a very near resemblance to the slag- gy mineral pitch or bitumen so common in the limestone forma- tion of Slave River (zechstein ?). It is distinguished from it when put in the fire. " In the more common form of the lignite, the surface of the slates is more dull and earthy, of a brownish-black colour, but yielding a shining streak. These slates are entirely composed of fragments, having all the appearance of charred wood united together by a paste of more comminuted woody matter, mixed perhaps with a minute portion of clay. In the paste, there are some minute perfectly transparent crystals, having the form of compressed four sided prisms, and sometimes of tables. The fibrous structure of the woody fragments is fine, and the lustre resembles that of fresh well-made charcoal of brick. The struc- ture is evidently exogenous. The fragments are generally small, but, when several inches in diameter, their layers of structure are waved and curved, as if they had been knots, which of course would not so easily break down as the other portions- One of my specimens shews a small grain, either of resin or of amber; and I have picked out of another a membranous substance, which has all the appearance of a por- tion of Ulva montana (Bot. App. Franklin's Journey) common Overland Arctic Eicpedition. 163 here at the present tiiQe. I inclose this minute specimen, which has already suffered some diminution in the course of my exa- mination of it. Muriatic acid produced no change in it ; but I was afraid to try the nitric acid, lest it should destroy it. " When put into the fire the lignite burns without flame, and emits a very disagreeable stench, unlike that of either peat or of sulphur. The combustion does not cease when the coal is removed from the fire, but goes on slowly, until there is only a brownish-red ash remaining, not one-tenth of the original bulk of the specimen. " The beds of lignite lie on the east side of Bear Lake Ri- ver, where it joins the Mackenzie, are in the aggregate six or seven yards thick, and are covered by a thick bed of loose sand. They were on fire when Sir A. Mackenzie discovered the river (in 1789), and have continued burning ever since. At the dis- tance of a few hundred yards up the Bear Lake River, there are some thick beds of a coarse, bluish-grey, earthy looking sand- stone (very like that on the north side of the Calton Hill), dip- ping at a small angle under the lignite. They were not seen in actual contact. On the opposite side of Bear Lake River, which is 200 yards wide, a craggy hill of (carboniferous ?) limestone rises abruptly to the elevation of 400 feet. About 30 miles far- ther up Bear Lake River, and nearly east from its mouth, the stream cuts the base of another limestone hill, of similar form and height, belonging to a chain of (partly transition ?) hills, which runs N.W. and S. E. through a flat country. At the foot of the nearly vertical limestone, but separated from it by a small rivulet, there are thick horizontal beds of sandstone, re- sembling that at the mouth of Bear Lake River. Upon this sandstone lie a number of thin beds of bituminous shale and sandstone, which weather easily. In the shale there are im- pressions of ferns (polypodiaceae), and in the slaty sandstone lepidodendra ? I have had no opportunity of examining these rocks, excepting very cursorily, as we passed them in the boat, and occasionally snatched a specimen ; but I purpose, if the snow disappeai's long enough before the opening of the naviga- tion, to visit them carefully this spring. The finest sections on the banks of the river will be hid by accumulations of ice till the autumn.*' l2 ( 164 ) 0/i the Luminousness observed in the Eyes of' Human Beings^, and also in those of Cats, Dogs, Horses, and Sheep ^ By Dr Charles Ludwig Esser *. XjLppe A RANGES of light, as is well known, are not uncommon in inferior animals, and the number of luminous animals in the sea is so great, that large tracts of the water's surface have been seen to be illuminated by them. This phenomenon, however, is comparatively seldom observ- ed in fishes, and the more rarely the higher we ascend in the scale of the animal kingdom, if under the denomination of lumi- nousness, we understand the real evolution of light, and do not consider it as the reflection of the incident rays of light ; for in this latter case the luminous appearance does not inhere in the ani- mal body itself, but is in reality merely a reflection, which is totally different from the evolution of light in the inferior animals. A real phosphorescence is sometimes observed in the higher animals, and even in human beings, particularly in their excrementitious fluids. The light of the eggs of the lizard, the luminousness of the perspired matter in man and horses, the irradiation of light in cats and other animals, from the stroking of their hair, and finally the phosphorescent quaHty of human urine, have been frequently observed. On most of these various kinds of light, I have neither per- formed experiments myself, nor have I collected the facts of others ; the present memoir being chiefly devoted to an exami- nation of the light or luminousness of the eyes in human beings and inferior animals. The more perfectly to accomplish this object, I some years ago performed a series of experiments, that led to an important result. Having brought a cat into a room half darkened, I observed that the eyes of the animal when opposite the window, and in a certain direction to myself, sparkled very brilliantly, which phe- . nomenon suddenly vanished, when I, either by the motion of my ' head, changed the direction of my eyes to those of the cat, or the • Karsten's Archiv, b. viii. heft iv. Dr Esser on the Ltiminousness of the Eyes. 165 animal, by moving its eyes to and fro, brought them into a different position. In a situation wherein I could best observe the eyes of my cat, I caused the room to be slowly darkened, by gradually closing the window-shutters. The light of its eyes became weaker, and vanished entirely as soon as the room, on the place where the cat was situated, became absolutely dark. .'Incident rays of light were always necessary to produce the luminousness of the eyes. I wrapped another cat in a cloth, but left the head uncovered, whereby I was able to handle the animal as I had a mind^ and place it in any situation I chose. In this cat what I have just stated was confirmed. I placed it in such a position that its head, at the distance of a few steps, was directed towards the window, by which means I could lighten or darken the room at pleasure. I now permitted a few rays of light to fall through the window into the room, in such a manner, that the place where the cat was present was illuminated; and I placed myself in such a di- rection towards the window, that my eyes were in a straight line with those of the animal, so that I saw the hght of its eyes very distinctly, which light, as in the former experiment, sud- denly vanished when I turned my head, or the cat turned its eyes. At the moment when my eyes were directed in the manr ner just mentioned, I observed a most beautiful green light ; but when they were out of this direction, the caf s eyes had their usual appearance. By the turning of my head, or by any other arrangement I chose, by which I intercepted the inci- dent rays, I could at pleasure cause sometimes the one eye of the cat, sometimes the other, and sometimes both together, to shine. If I intercepted the incident rays of light from the left half of the head, the right eye became luminous, and conversely. In these experiments, I observed quite distinctly that the light of my cat''s eye emanated from the pupil, the eye itself being lightened only in proportion to the dilatation of that part of it. By suddenly admitting a strong glare of light into the room, I produced a contraction of the pupil ; and when I suddenly ren- dered the room somewhat dark, a small round luminous point first appeared in the eye, and that point enlarged according as the pupil was dilated. The pupil of the eye of these animals being thus dilated in imperfect darkness, so that the iris seems to encircle the pupil as a small ring, and the sclerotic in cats 166 Dr Esser on the Luminousness of the Eyes. being scarcely visible, may be the reason why it is believed that the whole eye of the cat is luminous, although its light is, never- theless, only in proportion to the dilatation of the pupil. The dilatation'of the pupil in twilight is, however, not the only cause of the light of the eyes ; but the light surrounding the ani- mal being fainter, also assists us in perceiving with greater dis- tinctness the light as it is more vividly reflected from their eyes ; for, if we suddenly illuminate the chamber in which there is a cat, there remains nothing but a luminous brightness where there was formerly a beautiful yellowish green light. The light of my cat's eyes seemed to be more vivid when she opened them wide from apprehension, or looked around her at- tentively ; whence Treviranus observed, that the eyes of cats sparkled most when the animals were in a lurking position, or in a state of irritation. That author says, " The light of the cat's eyes appears most conspicuous when she is in a lurking position, — when she is attracted by any unusual appearance, — or when irritated. In the first two in- stances, the light is faint and dull : in the last instances, it darts forth in intermittent scintillations, and at those moments when the light is most vivid, there are accompanying movements of the eyes." That the light of the eyes of animals appears bright- er in a state of irritation^ than in a state of quiescence, seems to originate in this, that the eyes of all animals, as well as those of man, appear brighter in violent rage, and sparkle more, than in a quiescent state. This, in man, seems to arise from an in- creased secretion of the lachrymal fluid on the surface of the eye, by which fluid the light of the eye is undoubtedly rendered more brilliant. Treviranus farther observes, " The eyes of the cat shine also where no rays of light penetrate, and the light must in many, if not in all, cases proceed from the eye itself." Before performing the above experiments, I entertained the same opinion with Treviranus, and made many fruitless experiments with cats in the dark, before I abandoned the position. The light must be brighter in proportion to the darkness of the place where the cat is. I soon renounced this . opinion, when, in all the experiments I made on cats, in places absolutely dark, I did not discover the slightest trace of light in the eyes of these animals, let me irritate them as I could. Dr Esser on the Luminousness of the Eyes. 167 Many of my friends, to whom I mentioned my experiments, and the result of them, objected to me, that I could not possi- bly be correct, for they themselves had observed cats' eyes shining in the very darkest places, as, for example, in a cellar. I have had frequent opportunities since of making observations to the same effect ; but every time has, nevertheless, convinced me, that, even in such places, the rays of light having passed through a window or some other aperture, fell upon the eyes of the animals as they turned towards the opening, and were placed in a proper position in regard to the observer. Gruithuisen likewise mentions a case in which he could produce light from ,the eyes of a cat at pleasure ; in places absolutely dark, how- ever, he never observed any light. To ascertain what appearance the eyes of a cat exhibit after death, I cut off the head of one, placed it opposite to the win- dow, at the distance of some yards, so that the rays of light passing through the window might fall on the eyes. I now observed, that the eyes of the dead cat shone far more vividly than those of a living one. By illuminating the apartment, the light was not, as in living cats, weaker but stronger, and was so powerful when I completely illuminated the room, and allowed the sun's rays to fall immediately on the eyes of the cat, that it resembled the most beautiful green fire, which lost its intensity however, and exhibited only a clear greenish brightness, when the rays of the sun, as in the open air, fell on all sides. In places perfectly dark, the light of the eyes, as in all my forma* experiments, completely vanished. All my subsequent experi- ments, in which many a cat lost its life, were uniformly followed by the same result. The light of the. cat's eyes being brighter after death than when in life, may probably be owing to this, — that after death the pupil is so much dilated as almost entirely to hide the iris ; and that the pupil, being now insensible to the rays of light falling on it, is never closed again, and does not obstruct the passage of the penetrating rays of light, as is well known to be the case during hfe. Farther, the light of the eyes of those animals, that after death were subjected to experiment, became gradually weaker as the cornea grew duller. When that part of the eye was 168 Dr Esser on the Luminomness of the Eyes, moistened, the intensity of the light was increased to a certain extent, but faded away with the decomposition of the eye it- self, and eternal darkness reigned in the stead of glorious light. I believe I observed a difference in the degree of light, accord- ing to the colour of the cat ; and it is certain, that black and fox-coloured cats evolve a brighter and more conspicuous light from their eyes, than grey and white ones, though there may undoubtedly be exceptions to this distinction *. Besides cats, many domestic as well as other animals, are furnished with luminous eyes. Under similar circumstances as above, I observed that the light of a dog's eye, as was the case in my experiments on cats, vanished suddenly as soon as I had completely darkened the room where the dog was. I observed the eyes of another dog sparkle when he was irritated, and in the corner of a room that was faintly lighted. The eyes of the animal protruded very much, glittered brilliantly, and the pupils were dilated to an unusual degree. The colour of the light, which was commonly yellow, changed more or less as the rays of light fell on the eyes of the animal, and exhibited the following appearances. When a small body of rays of light fell oh the eye, the light was of a fiery redness, and sometimes so strong, that after I looked a long time attentively at it, my own eyes experienced a disagree- able sensation. When there was a great body of rays, the light was green or yellow, sometimes bluish. In respect to this change in the colour of the hght, I was inclined to think, that it might be owing as much to the motions of the animaPs eyes as to the body of light that fell upon them. This change was different in different dogs, and in some it was not at all observa- ble. Further, the eyes of every dog placed in the same situa- tion, shone, but the intensity of the light varied with the indi- viduals. I have observed luminousness in the eyes of horses, sheep and hares, which was different, however, in colour and strength. Many appearances of light have been observed in the eyes of human beings. Treviranus mentions, that G. T. L. Sachs, and his sister, both belonging to albinoes, had phosphorescent • Bened. PreTOst's Memoir on the Luminousness of the Eyes of animals, will be given in our next number. Dr Esser on the Luminousness of the Eyes. 1G9 eyes. Late in the evening there appeared itv them a lively yel- lowish brightness, which darted forth in fiery coruscations or globules, from the interior of the eyes. The balls rolled hither and thither^ and frequently ejected rays, at least an inch in length. In these two relatives the light was livehest and strongest after their birth, and during infancy : in their more advanced years the light was strongest when they were in deep meditation ; at this time, also, the oscillation, which they had in common with other albinoes, was liveliest. A rather remarkable observation, and similar to the case of the Sachs, is that of Michaelis, who, many years before his death, during the interval between day and night, and during the night itself, observed irradiations of light issuing from his eyes ; sometimes so strong that he could read the smallest print. (Schlichtegroirs Necrolog, des 19. Jahrhunderts, B. 3. s. 837). In a boy, who belonged to the Albino variety, I observed a similar case, though not accompanied with irradiation. In this boy, who suffered so much from the dread of light that he never ventured abroad except in twilight, I frequently observed the same fiery eyes, yet were they very different, both in the strength and colour of their light, from the luminous eyes of animals which I had observed, partly from design and partly from acci- dent ; for this boy's eyes might be called glassy rather than lu- minous. Some years ago I was assured by (Hr" Geheimen- rath W), that his sister had often observed the eyes of her chil- dren, who were also albinoes, to be luminous. These last two cases could be traced to rays of light falling on the eyes. It now remained for me to search out the cause, which, by means of the incident rays of light, gave rise to the shining ap- pearance in the eyes of human beings and inferior animals. The explanation seemed to me no easy matter, yet, from the be- ginning, I expected to be able to search out the cause of this phenomenon, in a reflection of rays of light penetrating into the eye. The colour of the light, however, and particularly its changes in dogs, appeared to me very difficult to explain, and to be rather at variance with my own opinion. To discover the cause of the shining in the eyes of human beings and inferior animals, I came to the resolution of under- taking the extraction of the lens on a cat, from which I antici- pated the best result, in so far as I might, by that means, best 170 Dr Esser on the Luminousness of the Eyes. determine to what extent the remoter parts of the eye contri- buted to its luminousness. I attempted to perform the above operation on a cat, but the utter restlessness of the animal rendered it extremely difficult, indeed almost impossible. Having ascertained that eyes of cats shine after death, I resolved to kill the cat, that I might have it in my power to dissect any part of the eye I thought proper. First, by means of a pair of scissors I cut away the whole of the cornea, and completely destroyed the anterior chamber of the eye. I now observed, that the light of the eye was not in the least diminished, but somewhat weakened in regard to colour, which was changed from a yellow to a pale green. I then took away the iris, that lay exposed before me, without injuring the conformity of the hinder part of the eye, to discover whether the iris, as Treviranus maintained, really contributed to the light. This, however, was not the case ; for the light still continued. The taking away of the lens was followed by a diffisrent result, which considerably weakened the intensity of the light, and the greenness of its colour. It now struck me that the tapetum in the hinder part of the eye must form a spot^ which caused the reflec- tion of the incident rays of light, and thus produced the shining. This was the more probable, as the light of the eye now seemed to emanate from a single spot. After taking away the vitreous humour, I observed, that, in reality, the entire want of the pig- ment in the hinder part of the choroid coat, where the optic nerve enters, formed a greenish silver coloured changeable ob- long spot, which was not symmetrical, but surrounded the optic nerve in such a manner, that the greater part was above, and only a small part below it ; and, therefore, the greater part lay beyond the axis of vision. It is this spot, therefore, that produces the reflection of the incident rays of light, and, beyond all doubt, according to its tint, contributes to the different colouring of the light, to which, nevertheless, the remaining parts of the eye, when conjoined, seem to be no less necessary. The situation of this spot corresponds exactly with the posi- tion in which the shining of the eyes is seen to the greatest ad- vantage. I have before remarked, that the shining is percepti- ble only in a certain position, and, in fact, when the eyes of the observer are almost opposite to the eyes of the animal on which Dr Esser mi the Luminousness of the Eyes. 171 he is performing the experiment. This is easily explained. Only those rays of light are reflected which fall on that part of the choroid where the pigmentum is wanting ; but as this spot occupies rather the upper wall of the concavity of the choroid, the reflection caused by it will not be perceived, if the eye of the observer is not in a nearly straight direction to the eye of the animal, and at some distance ; and hence it is why, in living cats, we observe the light only when their eyes are directed to- wards our own ; in which case, the upper wall of the eye-ball becomes more the hinder and under, and the point of reflection stands in almost a straight line with our own eyes. From these experiments, it is abundantly evident that there is no light or shining in the eyes in places absolutely dark, and that the opinion of many authors is, in this respect, completely erroneous. These experiments, at the same time, prove what has been doubted by some physiologists, the transparency of tlie retina ; for it must naturally be transparent, if reflection takes place from behind it. The transparency of the retina may also be proved from our seeing the image upon the choroid, or ra- ther upon its pigment, while the retina has not the least share in producing the efi^ect ; since it appears when the retina on be- ing taken away, brings the vitreous humour, or the lens, to the coats of the eye. I remarked above, that the light of the eyes of animals was stronger when they were irritated than when they were in a quiescent state ; and I attributed this phenomenon to the great- er projection of the eyes, but particularly to the increased se- cretion of the lachrymal fluids. This was rendered still more probable by my last experiment, when I destroyed the convexi- ty of the eye, by taking away the cornea and the lens. By this it appears, that a shining substance is better fitted for reflection than a dull one, which is proved by the gradual fading away of the light after death, from the cornea becoming duller, and by the gradual increase of light, when the cornea is moistened. I further remarked, that the different colours of animals, parti- cularly of the cat, probably tend to strengthen or weaken the light ; which may be thus explained, that, in beasts, as well as human beings, the greater or smaller size of the pigment may usually be in conformity with the colour of the hair, which is the common covering. 1T2 Mr Audubon cm the Habits of the Turlaey Biizzard. From this examination, it will now be more probable that the luminousness of the eyes of human beings, as well as of beasts, depends on the want of the pigment, and so much the more from being observed only in the albino. With this view of the matter, the two cases already quoted of Sachs and Michaelis are indeed at variance. I must confess that I have read and considered these cases with some degree of interest. Are they really fictions ? When we read of the shape of fiery coruscations, or balls in the eyes, of their rolling round, of their frequently darting forth rays an inch long, our suspicions are surely pardonable. As to the different colours of the light in the eyes of dogs, it is owing to the different colouring of the place where the pig- ment is awanting in the choroid, — a fact of which anatomical experiments on the eye of these animals has convinced me ; and hence the varied colour of the light of one and the same eye may be owing more to the motion of that part where the rays of light are reflected upon different coloured portions of the choroid, than to the quantity of the incident rays of light. Finally, there is no question but the light observed in the eyes of some beasts of prey, as well as in those of birds, has the origin above ascribed to it ; and its nature is neither phosphoric nor electrical, nor has it any psychological relation. Account of the Habits of the TurT^ey Buzzard (Vidtur aura), particularly with the view of exploding the opinion generally entertained of its extraordinary power of Smelling. In a letter to Professor Jameson, by John J. Audubon, a Citizen of the United States *. jc\.S soon as, like me, you shall have seen the Turkey Buzzard follow, with arduous closeness of investigation, the skirts of the forests, the meanders of creeks and rivers, sweeping over the whole of extensive plains, glancing his quick eye in all direc- tions, with as much intentness as ever did the noblest of falcons, to discover where below him lies the suitable prey ; — when, like • This communication was originally intended to be sent to a fiiend un- acquainted with the habits of birds. — J. J. A. Mr Audubon on the Habits of the Turkey Buzzard, 173 me, you have repeatedly seen that bird pass over objects cal- culated to glut his voracious appetite unnoticed, because unseen ; and when you have also observed the greedy vulture propelled by hunger, if not famine, moving like the wind suddenly round his course as the carrion attracts his eye, — then will you abandon the deeply-rooted notion that this bird possesses the faculty of discovering, by his sense of smell, his prey at an immense dis- tance. This power of smelling so acutely I adopted as a fact from tny youth. I had read of this when a child ; and many of the theo- rists to whom I subsequently spoke of it, repeated the same with enthusiasm, the more particularly as they considered it an ex- traordinary gift of nature. But I had already observed, that Nature, although wonderfully bountiful, had not granted more to any one individual than was necessary, and that no one was possessed of any two of the senses in a very high state of perfec- tion ; that if it had a good scent, it needed not so much acuteness of sight, and vice versa. When I visited the Southern States, and had lived, as it were, amongst these vultures for several years, and discovered thousands of times that they did not smell me when I approached them covered by a tree, until within a few feet, and that when so near, or at a greater distance, I shewed myself to them, they instantly flew away much frightened, the idea eva- porated, and I assiduously engaged in a series of experiments to prove, to myself at least, how far this acuteness of smell existed, or if it existed at all. I sit down to communicate to you the results of those ex- periments, and leave for you to conclude how far, and how long, the world has been imposed on by the mere assertions of men who had never seen more than the skins of our vultures, or heard the accounts from men caring little about observing na- ture closely. My first experiment was as follows : I procured a skin of our common deer, entire to the hoofs, and stuffed it carefully with dried grass until filled rather above the natural size, — suffered the whole to become perfectly dry, and as hard as leather, — took it to the middle of a large open field, — laid it down on its back with the legs up and apart, as if the animal 174 Mr Audubon 07i> the Habits of the Turkey Buzzard, was dead and putrid. I then retired about a few hundred yards, and, in the lapse of some minutes, a vulture, coursing round the field, tolerably high, espied the skin, sailed directly towards it, and alighted within a few yards of it. I ran imme- diately, covered by a large tree, until within about forty yards, and from that place could spy the bird with ease. He ap- proached the skin, — looked at it without apparent suspicion, — jumped on it, — ^raised his tail, and voided itself freely (as, you well know, all birds of prey in a wild state generally do before feeding), — then approaching the eyes, that were here solid globes of hard dried and painted clay, attacked first one and then the other, with, however, no further advantage than that of disarranging them. This part was abandoned ; the bird walked to the other extremity of the pretended animal, and there, with much exertion, tore the stitches apart, until much fodder and hay was pulled out, but no flesh could the bird find, or smell ; he was intent on discovering some where none existed, and, after reiterated efforts, all useless, he took flight, coursed about the field, when, suddenly rounding and falling, I saw him kill a small garter snake, and swallow it in an instant. The vulture rose again, sailed about, and passed several times quite low over my stuffed deer skin, as if loath to abandon so good-looking a prey. Judge of my feelings when I plainly saw that the vulture which could not discover, through its extraordinary sense of smell, that no flesh, either fresh or putrid, existed about that skin, could, at a glance, see a snake scarcely as large as a man's fin- ger, ahve and destitute of odour, hundreds of yards distant. I concluded that, at all events, his ocular powers were much bet- ter than his sense of smell. Second Experiment. — I had a large dead hog hauled some distance from the house, and put into a ravine, about^twenty feet deeper than the surface of the earth around it, narrow and wind- ing, much filled with briars and high cane. In this I made the negroes conceal the hog, by binding cane over it, until I thought it would puzzle either buzzards, carrion crows, or any other birds, to see it, and left it for two days. This !was early in the month of July, when in this latitude a dead body Mr Audubon on the Habits of the Turkey Buzzard. 175 becomes putrid and extremely fetid in a short time. I saw, from time to time, many vultures in search of food sail over the field and ravine in all directions, but none discovered the carcass, al- though, during this time, several dogs had visited it, and fed plentifully on it. I tried to go near it, but the smell was so in- sufferable when within thirty yards, that I abandoned it, and the remnants were entirely destroyed at last through natural decay. I then took a young pig, put a knife through its neck, and made it bleed on the earth and grass about the same place, and having covered it closely with leaves, also watched the result. The vultures saw the fresh blood, alighted about it, followed it down into the ravine, discovered by the blood the pig, and de- voured it, when yet quite fresh, within my sight. Not contented with these experiments, which I already thought fully conclusive, having found two young vultures, about the size of pullets, covered yet with down, and looking more like quadrupeds than birds, I had them brought home and put into a large coop in the yard, in the view of every body, and attended to their feeding myself. I gave them a great number of red-headed woodpeckers and parokeets, birds then easy to procure, as they were feeding daily on the mulberry trees in the immediate neighbourhood of my orphans. These the young vultures could tear to pieces by putting both feet on the body, and applying the bill with great force. So ac- customed to my going towards them were they in a few days, that, when I approached the cage with hands filled with game for them, they immediately began hissing and gesticulating very much like young pigeons, and putting their bills towards each other, as if expecting to be fed mutually, as their parent had done. Two weeks elapsed ; black feathers made their appear- ance, and the down diminished. I remarked an extraordinary increase of their legs and bill ; and thinking them fit for trial, I closed three sides of the cage with plank, leaving the front only with bars for them to see through; — had the cage cleaned, washed, and sanded, to remove any filth attached to it from the putrid flesh that had been in it, and turned its front imme- diately from the course I usually took towards it with food for them. 176 Mr Audubon on the Habits of the Tmlcey Buzzard. I approached it often bare-footed, and soon perceived that if I did not accidentally make a noise, the young birds remained in their silent upright attitudes, until I shewed myself to them by turning to the front of their prison. I frequently fastened a dead squirrel or rabbit, cut open, with all the entrails hanging loosely to a long pole, and in this situation would put it to the back part of the cage; but no hissing, no movement was made: when, on the contrary, I presented the end of the pole, thus co- vered, over the cage, no sooner would it appear beyond the edge, than my hungry birds would jump against the bars, hiss furious- ly, and attempt all in their power to reach the food. This was repeatedly done with fresh and putrid substances, all very con- genial to their taste. Satisfied within myself, I dropped these trials, but fed them until full grown, and then turned them out into the yard of the kitchen, for the purpose of picking up whatever substances might be thrown to them. Their voracity, however, soon caused their death : young pigs were not safe if within their reach ; and young ducks, turkeys or chickens, were such a constant tempta- tion, that the cook, iinable to watch them, killed them both, to put an end to their depredations. Whilst I had these two young vultures in confinement, an extraordinary occurrence took place respecting an old bird of the same kind, which I cannot help relating to you. This bird sailing over the yard, whilst I was experimenting with the pole and squirrels, saw the food, and alighted on the roof of one of the outhouses ; then alighted on the ground, walked directly to the cage, and attempted to reach the food within. I approached it carefully, and it hopped oif a short distance ; as I retired, it returned, when always the appearances of the strongest congra- tulations would take place from the young towards this new comer. I directed several young negroes to drive it gently towards the stable, and to try to make it go in there. This would not do; but, after a short time, I helped to drive it into that part of the gin-house where the cotton-seeds are deposited, and there caught it. I easily discovered that the bird was so emaciated, that to this state of poverty only I owed my success. I put it in with the young, who both at once jumped about him, ma- king most extraordinary gestures of welcome; whilst the old 2 Mr Audubon m the Habits of the Turhey Buzzard. 177 bird, quite discomfited at his confinement, lashed both with great violence with his bill. Fearing the death of the young, I took them out, and fed plentifully the old bird ; his appetite had become so great through fasting, that he ate too much, and died of suffocation. I could enumerate many more instances, indicating that the power of smelling in these birds has been grossly exaggerated, and that, if they can smell objects at any distance, they can see the same objects much farther. I would ask any observer of the habits of birds. Why, if vultures could smell at a great dis- tance their prey, they should spend the greater portion of their lives hunting for it, when they are naturally so lazy, that, if fed in one place, they never will leave it, and merely make such a change as is absolutely necessary to enable them to reach it ? But I will now enter on their habits, and you will easily discover how this far-famed power has originated. Vultures are gregarious, and often associate in flocks of twenty, forty, or more ; — hunting thus together, they fly in sight of each other, and thus cover an immense extent of country. A flock of twenty may easily survey an area of two miles, as they go turn- ing in large circles, often intersecting each other in their lines, as if forming a vast chain of rounded links ; — some are high, whilst others are low ;-~-not a spot is passed unseen, and, con- sequently, the moment that a prey is discovered, the favoured bird rounds to, and by the impetuosity of its movements, gives notice to its nearest companion, who immediately follows him^ and is successively attended by all the rest. - Thus, the farthest from the discoverer being at a considerable distance, sails in a direct line toward the spot indicated to him by the flight of the others, who all have gone in a straight course before him, with the appearance of being impelled by this extraordinary power of smelling, so erroneously granted them. If the object discovered is large, lately dead, and covered with a skin too tough to be ate and torn asunder, and afford free scope to their appetite, they remain about it, and in the neighbourhood. Perched on high, dead limbs, in such conspicuous positions, are easily seen by other vultures, who, through habit, know the meaning of such stoppages, and join the first flock, going also directly, OCTOBER I^FXEMBER 1826. M 178 Mr Audubon on the Habits of the Turkey Buzzard. and affording further evidence to those persons who are satisfied with appearances only. In this manner I have seen several hun- dreds of vultures and carrion-crows assembled near a dead ox, at the dusk of evening, that had only two or three in the morn- ing; when some of the latter comers had probably travelled hundreds of miles searching diligently themselves for food, and probably would have had to go much farther, had they not espied this association. Around the spot both species remain ; some of them from time to time examining the dead body, giving it a tug in those parts most accessible, until putridity ensues. The accumula- ted number then fall to work, exhibiting a most disgusting pic- ture of famished cannibals ; the strongest driving the weakest, and this latter harassing the former with all the power that a disappointed hungry stomach can produce. They are seen jump- ing off the carcase, reattacking it, entering it, and wrestling for portions partly swallowed by two or more of them, hissing at a furious rate, and clearing every moment their nostrils from the filth that enters there, and stops their breathing. No doubt re- mains on my mind, that the great outward dimensions of these nostrils were allotted them for that especial and necessary pur- pose. The animal is soon reduced to a mere skeleton, no portion of' it being now too hard not to be torn apart and swallowed, leaving merely the bare bones. Soon all these bloody feeders are seen standing gorged, and scarcely able to take wing. At such times the observer may approach very near the group, whilst engaged in feeding, and see the vultures in contact with the dogs, who really by smelling have found the prey. Whenever this happens, it is with the greatest reluctance that the birds suffer themselves to be driven off, although frequently the sudden scowl or growl of the dogs will causejuearly all the vultures to rise a few yards in the air. I have several times seen the buzzards feeding at one extremity of the carcase, whilst the dogs were tearing the other ; but if a single wolf approached, or a pair of white-headed eagles, driven by extreme hunger, then the place is abandoned to them until their wants are supplied. The repast finished, each bird gradually rises to the highest branches of the nearest trees, and remains there until the full Mr Audubon an the Habits of the Turkey Bvzzard, 1T9 digestion of all the food they have swallowed is completed ; from time to time opening their wings to the breeze or to the sun, ei- ther to cool or warm themselves. The traveller may then pass under them unnoticed, or, if noticed, a mere sham of flying off is made. The bird slowly recloses its wings, looks at the person as he passes, and remains there until hunger again urges him onwards. This takes oftentimes more than a day, when gra- dually, and very often singly, each vulture is seen to depart. They now rise to an immense height, cutting, with great ele- gance and ease many circles through the air ; now and then gently closing their wings, they launch themselves obliquely with great swiftness for several hundred yards, check and re- sume their portly movements, ascending until, like mites in the distance, they are seen all together to leave that neighbourhood, to seek further the needed means of subsistence. Having heard it said, no doubt with the desire to prove that buzzards smell their prey, that these birds usually fly against the breeze, I may state that, in my opinion, this action is sim- ply used, because it is easier for birds to maintain themselves on the wing encountering a moderate portion of wind, than when flying before it ; but I have so often witnessed these birds bear- ing away under the influence of a strong breeze, as if enjoying it, that I consider either case as a mere incident connected with their pleasures or their wants. Here, my dear Sir, let me relate one of those facts, curious in itself, and attributed to mere instinct^ but which I cannot admit under that appellation, and which, in my opinion, so bor- ders on reason, that, were I to call it by that name, I hope you will not look on my judgment as erroneous, without your fur- ther investigating the subjects in a more general point of view. During one of those heavy gusts that so often take place in Louisiana in the early part of summer, I saw a flock of these birds, which had undoubtedly discovered that the current of air that was tearing all over them was a mere sheet, raise themselves obliquely against it with great force, slide through its impetuous current, and reassume above it their elegant movements. The power given to them by nature of discerning the ap- proaching death of a wounded animal, is truly remarkable. They will watch each movement of any individual thus assailed m2 180 Mr Audubon ofi the Habits of the Turkey Buzzard. by misfortune, and follow it with keen perseverance, until the loss of life has rendered it their prey. A poor old emaciated horse or ox, the deer mired on the margin of the lake, where the timid animal has resorted to escape flies and musquitoes so fatiguing in summer, is seen in distress with exultation by the buzzard. He immediately alights, and if the animal does not extricate itself, waits and gorges in peace on as much of the flesh as the nature of the spot will allow. They do more, they often watch the young kid, the lamb, and the pig issuing from the mother's womb, and attack it with direful success ; yet, not- withstanding this, they frequently pass over a healthy horse, hog, or other animal, lying, as if dead, basking in the sunshine, with- out even altering their course in the least. Judge then^ my dear Sir, how well they must see. Opportunities of devouring young living animals are so very frequent around large plantations in this country, that to de- ny them would be ridiculous, although I have heard it attempt- ed by European writers. During the terrifying inundations of the Mississippi, I have very frequently seen many of those birds alight on the dead floating bodies of animals, drowned by the water in the low lands, and washed by the current, gorging themselves at the expence of the Squatter, who often loses the greater portion of his wandering flocks on such occasions. Dastardly with all, and such cowards are they, that our smaller hawks can drive them off any place ; the little king bird proves, indeed, a tyrant whenever he espies the large ma- rauder sailing about the spot where his dearest mate is all in- tent on incubation ; and the eagle, if hungry, will chace him, force him to disgorge his food in a moment, and to leave it at his disposal. Many of those birds accustomed, by the privileges granted them by law, of remaining about the cities and villages in our southern states, seldom leave them, and might almost be called a second set, differing widely in habits from those that reside constantly at a distance from these places. Accustomed to be fed, they are still more lazy ; their appearance exhibits all the non- chalance belonging to the garrisoned half paid soldier. To move is for them a hardship, and nothing but extreme hunger will Mr Audubon on the Habits of the Turkey Buzzard. 181 make them fly down from the roof of the kitchen into the yard, or follow the vehicles employed in clearing the streets from dis- agreeable substances, except where (at Natchez for instance) the number of these expecting parasites is so great, that all the re- fuse of the town, within their reach, is insufficient ; then they are seen following the scavengers^ carts, hopping, flying and alighting all about it, amongst grunting hogs and snarling dogs, until the contents, having reached a place of destination outside the suburbs, are emptied and swallowed by them. Whilst taking a view of that city from her lower ancient fort, I have for several days seen exhibitions of this kind. I do not think that the vultures thus attached to the cities are so much inclined to multiply as those more constantly resident in the forests, perceiving no diminution of number during the breeding season, and having remarked that many individuals, known to me by particular marks made on them, and a special east of countenance^ were positively constantly residents of the town. The Vultur aura is by no means so numerous as the attra- tus. I have seldom seen more than twenty-five or thirty together ; where, on the contrary, the latter are frequently associated to the number of an hundred. The Vultur aura is a more retired bird in habits, and more incKned to feed on dead game, snakes, lizards, frogs, and the dead fish that frequently are found about the sand-flats of rivers and borders of the sea-shore ; is more cleanly in its appearance, and, as you will see by the difference in the drawings of both species, a neater and better formed bird. Its flight is also vastly superior in swiftness and elegance, needing but a few flaps of its large wings to raise itself from the ground ; after which it will sail for miles, by merely turning either on one side or the other, and using his tail so slowly, to alter his course, that a person looking at him, whilst elevated and sailing, would be inclined to compare it to a machine fit to perform just a certain description of evolutions. The noise made by the vultures through the air as they glide obliquely towards the earth, is often as great as that of our largest hawks when falling on their prey ; but they never reach the ground in this manner, always checking when about 100 yards high, and going several rounds^ to excLmine well the spot they are about to aPght on. The Vultur aura 182 Mr Audubon on the Habits of the Turkey Buzzard. cannot bear cold weather well ; the few who, during the heat of the summer, extend their excursions to the middle or northern States, generally all return at the approach of winter ; and I be- lieve also, that very few of these birds breed eastward of the Pine Swamps of West Jersey. They are much attached to par- ticular roosting trees, and I know will come to them every night from a great distance : on alighting on these, each of them, anxious for a choice of place, creates always a general disturb- ance, and often, when quite dark, their hissing noise is heard in token of this inclination for supremacy. These roosting trees of the buzzards are generally in deep swamps, and mostly high dead cypresses ; frequently, however, they roost with the carrion-crows (Vultur atratus), and then it is on the largest dead timber of our fields, not unfrequently close to the houses. Sometimes also this bird will roost close to the body of a thick- leaved tree ; in such position I have killed several, when hunt- ing wild turkeys by moonlight nights, and mistaking them for these latter birds. In Mississippi, Louisiania, Georgia and Carolina, they pre- pare to breed early in the month of February, in common with almost all the genus Falco. The most remarkable habit at- tached to their life is now to be seen ; they assemble in parties of eight or ten, sometimes more, on large fallen logs, males and females exhibiting the strongest desire to please mutually, and forming attachments by the choice of a mate by each male, that, after many caresses, leads her off on the wing from the group, neither to mix or associate with any more, until their offspring are well able to follow them in the air; after that, and until in- cubation takes place (about two weeks), they are seen sailing side by side the whole day. These birds form no nest, yet are very choice respecting the place of deposit for their two eggs. Deep in the swamps, but always above the line of overflowing water mark, a large hol- lowed tree is sought, either standing or fallen, and the eggs are dropped on the mouldy particles inside. Sometimes immediate- ly near the entrance : at other times as much as twenty feet in. Both birds incubate alternately ; and both feed each other whilst sitting, by disgorging the contents of the stomach, or part of them, immediately close before the bird that is sitting. Thirty- Mr Audubon on the Habits qftke Turlcey Buzzard. 18S two days are needed to bring forth the young from the shell, — a thick down covers them completely, — the parents at that early period, and indeed for nearly two weeks, feed them, by gorging food considerably digested in their bill, in the manner of the common pigeons ; — the down acquires length ; becomes thinner, and of a deeper tint as the bird grows older. The young vultures at three weeks are large for their age, weighing then upwards of a pound, but extremely clumsy and inactive ; unable to keep up their wings, then partly covered by large pen feathers, drag them almost to the ground, bearing their whole weight on the full length of their legs and feet. If approached at that time by a stranger or enemy, they hiss with a noise resembling that made by a strangling cat or fox, swell themselves, and hop side-ways as fast as in their power. The parents whilst sitting, and equally disturbed, act in the same manner — fly only a very short distance, waiting there the departure of the offender to reassume their duty. As the young grows larger, the parents throw their food merely before them, and, with all their exertions, seldom bring their offspring fat to the field. Their nests become so fetid before the final depar- ture of the young birds, that a person forced to remain there half an hour must almost be suffocated. I have been frequently told that the same pair will not aban- don their first nests or place of deposit, unless broken up during incubation. This would attach to the vulture a constancy of affection that I cannot believe exists, as I do not beheve that pairing in the manner described is of any longer duration than the necessitous call of nature for the one season ; and^ again, were they so inclined, they would never congregate in the man- ner they do, but would go in single pairs all their lives like eagles. Vultures do not possess in any degree the power of bearing off their prey as falcons do, unless it be slender portions of entrails hanging by the bill. When chased by others from a carcase, it even renders them very awkward in their flight, and forces them to the earth again almost immediately. Many persons in Europe believe that buzzards prefer putrid flesh to any other. This is a mistake. Any flesh that they can at once tear with their very powerful bill in pieces, is swallowed, 184 Dr Graham's List of Rare Plants. no matter how fresh. What I have said of their killing and devouring young animals, are sufficient proofs of this ; but it frequently happens that these birds are forced to wait until the hide of their prey will give way to the bill. I have seen a large dead alligator, surrounded by vultures and carrion crows, of which nearly the whole of the flesh was so completely decom- posed before these birds could perforate the tough skin of the monster, that, when at last it took place, their disappointment was apparent, and the matter, in an almost fluid state, abandon- ed by the vultures. It was my intention to give you further details respecting this bird in the present letter, particularly of the anatomical struc- ture of its head and stomach, wherein I have had the pleasure of meeting corroborating evidence, through the observations made on the same by a learned anatomist of this city, Dr Knox. My time, however, is at present quite limited ; but I will very soon resume the subject with great pleasure, Edinburgh, 1 Bee. 7. 1826. J List of Rare Plants which have Flowered in the Royal Botanic Garden, Edinburgh, during the last three months; with Descriptions of several New Plants. Communicated by Dr Graham. lOth December 1826. Aralia spinosa. This plant has stood on the open wall three winters, protected partially with broom twigs, but never flowered till the beginning of November last, having nearly reached the top of a wall fourteen feet high. Asplenium flabellifolium. Aster pulcherrimus. Banksia integrifolia. Begonia undulata. B. undulata ; fruticosa ; foliis inaequaliter cordatis, undulatis, integerrimis, glabris, nitidis ; capsulse alis rotundatis aequalibus. DESCRiPTiON.-^.^'^em erect, turgid below, tapering upwards, annular ; when young slightly hispid, green, and having numerous small, oblong white spots ; when older smooth, and of a reddish -grey colour ; branch- ed, branches axillary and alternate. Leaves petioled, alternate, distichous, unequally cordate, smooth and shining, undulate, acuminate, full green on the upper surface, paler and minutely dotted below, 3 inches long ; edges occasionally reddish, especially when young, callous, quite entire, but having a dot, like an obsolete tooth, at the termination of each vein ; Dr Graham's List of Rare Plants. 185 petioles hispid, especially on the older branches, one-fourth of an inch long. Siipulce varying in size and shape, pointed, transparent, reddish, and spotted like the stem, caducous. Panicle supported on footstalks about half the length of the leaves, dichotomous, smooth and shining. Bractece unequal, shorter than the pedicel, pellucid, colourless. Flowers white ; corolla of the male of four petals, of which the two outer are large and cordate, that of the female of five petals, the largest about one-third of the length of the wings of the capsule. Capsule., wings rounded, taper- ing towards the pedicel. Stigmata convolute, pubescent, with two promi- nent angles on each, yellow. Stamens numerous, yellow. Seeds very numerous, covering the projecting wings of their green receptacle. We received this plant in 1825 from M. Otto at Berlin, under the specific name here adopted, and were informed that the native country was Bra- zil. It has been kept in the stove. Bignonia candicans. This plant has never perfectly evolved its flowers, but these have repeat- edly decayed, both this year and last, when they were just about to burst. The shrub thrives well in the stove, and is trained to a consider- able length along the glass. Brexia madagascaricnsis. Buddleia brasiliensis. B. brasiliensis ; foliis deltoideis, per petiolos decurrentibus, connatis, irregu- lariter dentato-crenatis, floribus verticillatis, bracteatis, ramis tetragonis, lanatis. Description — Shrub erect. Stem nearly round. Branches opposite, de- cussating, young shoots four-sided, covered with a white wool, which subsequently peels off, exposing the brown and cracked bark. Leaves opposite, decussating, when young oblong, afterwards becoming wider at the base, and more pointed, so as to be nearly deltoid, unequally tooth- crenated, broadly decurrent along the petiole, where quite entire, con- nate, soft, tomentous, especially below where white, green above, reticu- lated. Flowers verticillated, the lower whorl on two short axillary foot- stalks ; verticillus leafy ; bractece small, pointed, green, placed on the out- side of the whorls. Calyx persisting, green, covered with white tomentum, 4-cleft. Corolla orange-yellow, hairy within and without, least so on the upper surface of the limb ; tube more than twice the length of the calyx ; lin^ spreading, 4-cleft, segments rounded. Anthers reddish, sessile in the throat of the corolla, pollen pale yellow. Germen hairy, lodged in the calyx ; style filiform, at length exserted ; stigma rounded, lobular, deep green. Seeds communicated to the Botanic Garden by Mr Hunneman in 1824, and received by him from Russia under the name here adopted. Spren- gel quotes under Buddleia brasiliensis., B. perfoliata of Humboldt ; but this is quite distinct from our plant. Convolvulus candicans. Flowered on the wall outside one of the stoves. Crataegus glabra. This fine plant was covered with flowers on the open wall in November, and will continue so during thi^ month also, unless the weather prove verysevere. It seems probable that it came into flower, and pushed much new wood, at this season, in consequence of the warm rains which succeeded the unusually long continued hot and dry weather of summer and autumn. If it shall prove sufficiently hardy for the open ground, there have been few more desirable additions made to the shrubbery ; and it has alreadv borne, without injury even to its flowers, a cold of 25° Fahr. Crinum anomale. 186 Dr Graham's List of Rare Plants. Crotalaria dichotoma. C dichotoma ; Fruticosa, diffusa ; foliis ternatis, foliolis cuneato-ellipticis, pilosiusculis, mucronatis ; stipulis subulatis, reflexis, persistentibus ; ra- cemis subcapitatis, oppositifoliis. Description — Siem weak, round. Branches long, straggling, pubes- cent, and slightly furrowed towards the top, subdichotomous, one of the limbs being generally a little thicker than the other. Leaves ter- nate, leaflets elliptical, mucronate, wedge-shaped at the base, rather longer than the petiole, and supported on very short, equal, partial footstalks, soft, covered with minute pubescence, very indistinct on the upper surface, bright green, and becoming mottled in fading, middle rib strong, petioles half an inch long, furrowed, spreading at right angles to the branch. Racemes opposite to the leaves, subtriquetrous, occa- sionally one flower in the middle, the rest crowded near the top. Brac- tecB like the stipulae, but less frequently reflected. Calyx bilabiate, hairy, segments pointed, green ; upper lip 2-parted, segments diverging ; lower lip 3-parted, segments parallel, closely applied to the carina. Corolla yellow ; veonllum rounded, reflexed, streaked with brown on the back, claw furrowed and hairy on its lower side ; alee involute, shorter than the vexillum ; carina pointed, equal in length to the alse, split at its base, its lower edge forming nearly a right angle. Stamens monadelpheus ; filaments very slender, five nearly as long as the style, supporting small round (abortive ?) anthers^ five shorter having oblong anthers of deeper yellow colour. German pubescent, flattened ; style turgid at the base, above which it is bent nearly to a right angle, filiform, hairy, persisting ; stigma small and pointed. Legumen covered with small adpressed hairs, inflated, nearly cylindrical, slightly furrowed above. Seeds numerous (about 14), kidney-shaped, and arranged in two rows, at least when young. The seeds of this plant were brought to the Botanic Garden from Mexico in 1824 by Dr Mair, and the plants have flowered in our stove during the last two years. Cypripedium insigne. Dianthus fruticosus. Flowered fireely in the open border. Eucalyptus cordata, and E. perfoliata. These two plants have been covered with buds on the open wall during se- veral weeks, but have not expanded any flowers. They have not, how- ever, been in the least injured by the late severe frosts ; and the last has been out of doors for three years. Lantana hirta. L. hirta ; inerma ; foliis ovato-lanceolatis, acuminatis, rugosis, supra hirtis, subtus nitidis, serrato-crenatis, basi cuneatis integerrimis ; pedunculis axillaribus, foliis brevioribus ; bracteis ovatis, acuminatis. Description Shrub erect ; branches 4-sided, brown, slightly hairy, angles blunt ; hairs most conspicuous and harsh, and suberect on the young shoots. Leaves petioled, opposite and decussating, wrinkled, hispid above, shining, and destitute of all hairs below, excepting on the veins, where there are a few, acuminate, wedge-shaped, and quite entire at the base, the rest serrato-crenate, veins prominent behind ; petioles short. Flowers capitate. BractecB ovate, acuminate, smaller inwards, hairy. Calyx sessile in the axil of the bractea, campanulate, bi- labiate, the Hps placed laterally, hairy, small, greenish-white. Corolla white ; tube equal in length to the bractea, slightly curved upwards, di- lated in the centre, about twice the length of the limb, hairy especially on the outside and in the throat, quite smooth within the calyx, hairs sub- erect ; limb 4-parted, lateral segments blunt and smallest, lower segment subrotund, upper retuse, smooth above, hairy below. Stamens inserted Dr Graham's List of Rare Plants. 187 into the tube of the corolla, at the mouth of the calyx ; filaments short anthers brown, sagittate. Germen ovate, green ; style short, reaching to the mouth of the calyx ; stigma large, rounded, greenish, placed on the anterior part of the style, which projects a little way beyond it. Drupe round, deep purple, juicy ; nut bilocular. The leaves, when bruised, emit a smell considerably resembling the dry root of Valeriana officinalis. This species is a native of Mexico, from whence the seeds were brought by Lord Napier in 1J>25, and obligingly communicated to the Botanic Gar- den. They, and the seeds of many other species, some of them entirely new, were picked by his Lordship from plants in the wild state, among the mountains of Arizaba, or Real del Monte. It is much to be de- sired that others of our countrymen would equally profit by the op- portunities afforded them, of contributing to our knowledge of exotic bo- tany. Metrosideros lanceolata. This plant has stood on the open wall for three winters, partially protected with broom twigs. Monarda punctata. Passiflora capsularis. Patersonia glauca. Pilea mucosa. This curious little plant, so well illustrated in the Collectanea Botanica of Lindley, has for several years flourished in our stove ; but I have not observed it frequently in collections. Ruellia anisophylla. Silene regia. This fine plant was sent, while in flower, from Mr Ferguson's of Raith, whose gardener raised it from seed sent from Montreal. Vanda rostrata. It would be interesting to know, whether any remarkable de- viation from the usual progress of vegetation has been observed, in consequence of the very uncommon degree of heat, and un- interrupted drought, of this season. Nothing easily accounted for by reference to these, has been noticed in the Botanic Gar- den, except the period of flowering in the Crataegus glabra. I have often observed, that, in different seasons, certain plants flower much before, or not till long after, their usual period, when the state of the weather would have led us to expect the very reverse. This season, the hairy-leaved Laurus Tinus will not be in flower till towards the end of January : two years ago, after a very inferior season, it was in full flower during Decem- ber. The Arbutus Andrachne, and laurel-leaved variety of Ar^ butus Unedo, nailed to a wall with a south exposure, are consi- derably later than plants propagated from the same stock, and growing as standards, though the soil where they are placed is equally loose and dry. The tender plants in our borders seem to have suffered less from the frost which we have had lately, than they usually do, probably owing to the dryness of the soil ; for the rains have yet penetrated but a Httle way below the surface. ( 188 ) Celestial Pfienomena from January 1. to April 1. 1827, calcu- lated for the Meridian of Edinburgh, Mean Time. By Mr George Innes, Aberdeen. The times arc inserted according to the Civil rcclconing, the day beginning at midnight. —The Conjunctions of the Moon with the Stars are given in Right Ascension. JANU ARY. D. H. / ,, D. H. , /, 1. 20 42 23 61)6 20. 2 2 15 C5 DaTlje 2. 5 25 51 ^verynearpOph. 20. 3 27 8 dDiTl^ 4. 9 greatest elong. 20. 6 57 52 Im. III. sat. V 5. 0 35 - ]) First Quarter. 20. 16 46 27 ( Last Quarter. 6. 0 51 30 Em. III. sat. -y. 20. 18 8 5 0 enters C55 8. 1 59 44 Im. I. sat. 11 21. 14 47 35 d ])2« — 9. 3 8 34 Im. II. sat. 11 22. 5 46 31 Im. I. sat. 1/ 9. 19 6 43 6 near x «5 22. 12 1 10 6D-^ 10. 2 26 51 dD' « 22. 16 32 30 d Dxnt 10. 18 38 47 dK « 22. 21 9 45 d D M TTL 11. 12 25 4 6DV 22. 21 11 3 n 20. 9 4 5 6 D p opii- 25. 1 45 45 Im. III. sat. % 21. 5 50 41 d D lA' 1 25. 4 29 29 Em. III. sat. 11 21. 6 27 58 dD^f- t 25. 22 15 6 % New Moon. 21. 7 42 0 69^ t 26. 6 23 40 dD^ 21. 9 - - Sup. 6 0^ 28. 2 23 32 Im. IV. sat. y 22. 7 25 9 6D^ t MA] 28. 3 6 7 Em. IV. sat. If. D. **• / // D. H. / // 1. 0 5 20 6D 6 18. 3 50 47 dDx^ 1. 15 10 12 3 near ^ K 18. 4 52 30 ^ near e K 2. 4 10 39 Im. I. sat. 7/ 18. ^ greatest elong. 3. 17 28 - 6 ?¥ 18. 8 30 10 d D 1/3 R. 3. 22 39 2 Im. I. sat. 7/ 18. 8 31 30 d])2i3TTL 4. 8 26 39 Em. III. sat. 11 18. 11 2 40 dDvTTL 5. 1 27 50 6D^ ^ 18. 16 21 34 Em. III. sat. y. 5. 18 25 53 ]) First Quarter. 19. 14 22 29 6 ]) P Oph. 5. $ greatest elong. 19. 20 55 - Im. I. sat. 11 6. 10 22 50 dH « 20. 8 17 27 ( Last Quarter. 6. 23 37 21 Im. II. sat. y. 20. 11 52 55 6))^i- t 7. 0 15 8 6Dh 21. 4 46 46 Im. II. sat. 11 7. 10 37 21 dDvH 21. 8 58 10 0 enters K 10. 0 10 22 d D 1 « 2s 21. 13 10 45 dDd T 10. 10 16 29 d 1) 2a2o 21. 21 12 _ d])¥ 11. 0 32 43 Im. I. sat. 7/ 22. 16 20 17 dD/sn 11. 12 24 21 Em. III. sat. 11 23. 18 39 54 dD? 11. 15 13 55 6D^^ 25. 4 20 22 Im. I. sat. 11 13. 12 6 43 O Full Moon. 25. 20 18 44 Em. III. sat. IJ. 13. 12 59 7 6D^ n. 26. 22 48 53 Im. I. sat. 11 14. 2 11 56 Im. II. sat. 11 27. 11 55 8 % New Moon. 14. 21 13 11 6D H 28. 14 2 35 d])$ 15. 14 15 39 6 1)^W 31. 0 7- c?0V 17. 2 10 40 c5D«- 31. 1 33 50 6))S 17. 23 17 15 d 1)*=^ 31. 23 10 10 Em. II. sat. 11 18. 2 26 30 Im. I. sat. 11 Eclipse of the Sun qf^Qth November 1826. As the Beginning of the Eclipse could not be seen at Aberdeen, owing to clouds, the following is the observed time of the End, as made at the Obser- vatory there : End of the Eclipse, at - ll** 49' 45",0 a. m. Mean Time, after applying the error of the clock, which was obtained by the sun's transit on that day. The time of end is certain to one second. At Edinburgh, neither the beginning nor end of the Eclipse was observed. 190 Celestial Phenomena from January 1. to April 1. 1827* Times of the Planets passing the Meridian. JANUARY. Mercury. Venus. Mars. Jupiter. Saturn. Georgian. D. H. , H. , H. ^ H. , H. , H. , 1 10 27 11 7 15 39 6 10 23 25 13 0 5 10 25 10 44 15 33 5 55 23 6 12 44 10 10 30 10 22 15 30 5 38 22 47 12 27 15 10 38 9 58 15 24 5 19 22 26 12 7 20 10 48 9 44 15 17 4 59 22 6 11 46 25 11 1 9 33 15 13 4 41 21 44 11 25 FEBRUARY. Mercury. Venus. Mars. Jupiter. Saturn. Georgian. D. H. , H. , H. , H. , H. , H. ' 1 11 19 9.19 15 4 4 13 21 14 11 5 5 11 30 9 14 14 59 3 57 20 57 10 51 10 11 45 9 9 14 53 3 38 20 37 10 32 15 11 59 9 7 14 47 3 16 20 17 10 14 20 12 16 9 5 14 41 2 56 19 57 9 65 25 12 29 9 5 14 35 2 34 19 37 9 36 MARCH. 1 D. Mercury. Venus. Mars. Jupiter. Saturn. Georgian. H. , H. f H. , H. , H. , H. , 1 12 38 9 6 14 30 2 18 19 21 9 21 5 12 53 9 6 14 25 2 0 19 6 9 7 10 13 5 9 8 14 19 1 39 18 47 8 48 15 13 12 9 10 14 13 1 17 18 27 8 29 20 13 11 9 12 14 7 0 55 18 8 8 9 25 12 59 9 14 14 1 0 33 17 49 7 51 } Vice-Presidents. Proceedings of the Royal Society of Edinburgh. Nov. 27. 1826.— At a General Meeting held at the Society's new apartments on the Mound, the following Office-bearers were elected for tlie ensuing year : — Sir Walter Scott, President. Right Hon. Lord Chief Baron. Lord Glenlee. Dr T. C Hope. Professor RusseL Dr Brewster, Secretary. Thomas Allan, Esq. Treasurer. James Skene, Esq. Curator of the Museum. PHYSICAL CLASS. Lord Newton, President. John Robinson, Esq. Secretary. Sir William Forbes, Bart. Dr Turner. 1 Counsellws Dr Home. Sir T. M. Brisbane, K. C. B. yforthePhy- Profsssor Wallace. Dr Graham. J sical Class. LITERARY CLASS. Henry Mackenzie, Esq. President. P. F. Tytler, Esq. Secretary. Right Hon. Lord Advocate. Dr Hibbert. Sir Henry Jardine. Sir John Hay. Lord Meadowbank Thomas Kinnear, Esq. esq./ Counsellors for the Literary Class. ( 191 ) Proceedings of the Wernerian Natural History Society. 18^6, Dec. 2. — X3.T this meeting Professor Jameson read Dr Thomas Latta's Observations regarding the Arctic Sea and Ice, and the intended Expedition of Captain Parry to the North Pole. Several sheets of the Great Map of the county of Mayo in Ireland, the work of our ingenious and active countryman Mr William Bald, civil engineer, now engraving in Paris, were laid before the meeting ; and the excellent execution of the work (done at one half of the London charges) met with universal approbation. Specimens of the rare Macartney Pheasant, — a White Spar- row lately shot in Fifeshire, — a specimen of the beautiful Mexi- can bird called the Quezal, — and of the Lama of Peru, were exhibited; and various interesting articles from the Burmese country were shewn and described by Professor Jameson. At ihe same meeting, the following gentlemen were elected Office-bearers of the Society for 1827. Robert Jameson, Esq. President. Vice-Presidents. Professor Graham. David Falconar, Esq. Rev. Dr Alex. Brunton. Major-General Straton. Pat. Neill, Esq. Secretary. James "Wilson, Esq. Librarian. A. G. Ellis, Esq. Treasurer. P. Syme, Esq. Painter. Council. Dr Robert Knox. Dr R. E. Grant. G. A. W. Arnot, Esq. Dr John Boggie. Dr Andrew Coventry. Henry Witham, Esq. John Stark, Esq. Dr John Aitken. SCIENTIFIC INTELLIGENCE. METEOROLOGY. 1 . Meteors seen in India. — Colonel Blacker has given the Asiatic Society an account of a singular meteor, having the ap- pearance of an elongated ball of fire, which he observed at Cal- cutta, a little after sunset, when on the road between the Court- House and the Town-Hall. Its colour was pale, for the day- 192 Scientific Intelligence. — Mcteoi^ology. light was still strong, and its larger diameter appeared greater, and its smaller less, than the semidiamcter of the moon. Its direction was from east to west, its track nearly horizontal, and the altitude about thirty degrees. Colonel Blacker regrets not having heard of any other observation of this phenomenon at a greater distance, whereby he might have estimated its absolute height. As, however, it did not apparently move with the velo- city of ordinary meteors, it was probably at a great distance, and consequently of great size. So long as Colonel Blacker be- held it, which was for live or six seconds, its motion was steady, its light equable, and its size and figure permanent. It latterly, however, left a train of sparks, soon after which it disappeared suddenly, without the attendant circumstance of any report audible in Colonel Blacker's situation. Colonel Blacker con- cludes his paper with some interesting observations on luminous meteors : and considers them of perpetual recurrence, although day-light, clouds, and misty weather, so often exclude them from our view. Of their number no conception can be formed by the unassisted eye ; but some conjecture may be formed of their extent from the fact mentioned by our author, that, in using his astronomical telescope, he has often seen what are cal- led falling stars, shooting through the field of view, when they were not visible to the naked eye ; and when it is considered that the glass only embraced one twenty-five thousandth part of the celestial hemisphere, it will be apparent that these pheno- mena must be infinitely numerous, in order to occur so frequent- ly in so small a space *. 2. Waterspouts in the Irish Channel — Mr James Mackintosh, an accurate and intelligent observer, keeper of the Lower Light- house on the Calf of Man, in his monthly report to Robert Ste- venson, Esq. engineer to the Northern Lighthouses, mentions, that " on the morning of Tuesday the 14th November (1826), at a quarter to ten o'clock, he witnessed a remarkable phenome- non. The morning was clear, the wind from the east, inclining a little to the north, when he observed a column of water rising from the sea, off Kegger Point : this column was about the • On the subject of falling stars seen during the day, see previous Num- bers of this Journal. The work of Brandcs affords much information as to the vast number of luminous meteors always moving through the atmosphere — Edit. Sckntific Intelligence.— Chemistry. 193 height and diameter of the lower lighthouse tower (which is 50 feet high, and 18 in diameter), and there was the appearance of a smoke or fine spray on the top. It seemed be in rapid re- volution, and likewise made great progress out to sea, maintain- ing the same figure till lost in the distance. This first column was immediately followed by a similar appearance from the same point, and which took the same direction. Fahrenheit's thermometer was at 46° ; and the barometer fell to 28.52 on the evening of Monday the 13th, but had risen to 29.46 when the water-spouts were observed on the morning of the 14th. 3. Winds in the Polar Regions. — A decrease of wind inva- riably takes place in passing under the lee, not merely of a close and extensive body of high and heavy ice, but even of a stream of small pieces, — and so immediate is this effect, that the mo- ment a ship comes under the lee of such a stream, if under a press of sail, she rights considerably. Another remarkable fea- ture observable in the Polar Regions, at least in those parts en- cumbered with ice, is the total absence of heavy or dangerous squalls of wind. I cannot call to my recollection, says Captain Parry, in the Polar Regions, of such squalls as, in other cli- mates, oblige the seaman to lower his topsails during their con- tinuance,— Parrifs third Voyage. We verily believe, that, at the Pole itself, neither wind nor tide, rain nor snow, thunder nor lightning, will be found to exist, — or, if any of them exist at all, it will be in the smallest possible degree, — Barrow. CHEMISTRY. 4. The presence of animal and vegetable matter, or emana- tions from them, not necessary Jbr the formation of' Nitre. — M. Longchamp, in a memoir read before the French Academy of Sciences, endeavours to shew, in opposition to experiments considered as correct, 1, That nitrates are formed in places that contain neither animal nor vegetable matter, and which have never been exposed to emanations from animals: 2. That the nitric acid is formed in the open air, in materials which contain not a trace of animal or vegetable matters : 3, That the nitric acid is formed entirely from the elements of the at- mosphere. OCTOBER— DECEMBER 1826. N W^ Scientific Intelligence. — Geology. 5. Phospfiorus in Kelp. — Repeated trials, we are told, by Von Mons, have proved, that the roundish and longish veins found in the varec-soda or kelp, after the removal of the matter soluble in water has been removed, are principally composed of phosphorus. GEOLOGY. 6. Geogfiosdcal Structure of' the Country around Darwar. — " The following geological fact is curious, whether new or not. The eastern part of this country, which we call theDooab, is com- posed of granite, which is succeeded to the westward by an im- mense series of schists, extending the whole way to the sea. But, between the granite and the schists, is a considerable tract of country, consisting of what I would call pseudo-granite, which is the debris of the original granite, again consolidated. It is composed of felspar, quartz, and mica ; the grains of which are not angular, like fresh crystals, but are rounded by attrition ; and I have a specimen with an imbedded mass of felspar about the size of a pigeon's eg^, completely worn into a round ball. From this description, you cannot doubt that this is not original) granite. And now for my curious fact : This consohdated de- bris is almost every where intersected by small veins of quartz, or of quartz and felspar mixed. Nor have these veins origina- ted from subsequent eruption ; for they intersect one another in all directions, and often terminate in two ends, in a small por- tion of rock. Moreover, this rock often displays, in a slight de- gree, a schistose structure, especially when acted on by the weather. There are a number of masses of original granite im- bedded in this consolidated debris ; and, in those places where the latter displays the schistose structure, the imbedded masses have the schistose consolidated debris; or, if you please, the pseudo-granite, surrounding it like concentric lamellae. These facts appear to prove, that a new arrangement of particles may take place in solid bodies, giving rise to crystallization, and to different kinds of structure in rocks. There is a curious fact mentioned by Dr Clarke, in his Travels in Greece, which strong- ly confirms this opinion, viz. that the enormous stalactites in the Grotto of Antiparos, which have been formed by the gradual deposition of lime-water, offer concentric layers only towards their superficies, their interior structure exhibiting a complicated Scientific Intelligence. — Geology. 195 crystallization. You will at once see that this fact, being esta- blished, will prove of importance in enabling us to explain many appearances which have hitherto puzzled geologists in their at-^ tempts to account for the origin and formation of rocks."" — Lei- ter J-rom Alexander Turnhullj Esq. Civil Surgeon, Darwdir^ East Indies. 7. Account of a Lihellulitejbund at Solenhoffen. — Last spring there was found in the famous quarries of lithographic limestone at Solenhoffen, near Pappenheim, in Bavaria, a beautiful petri- faction of an insect of the genus Libellula, represented at Fig. 4. PI. 3. These quarries are already well known, from the nume- rous fossil species of marine and fresh water animals they contain. The body of the fossil libellula is disposed in the direction of the slaty structure of the limestone, and is distinguished from the stone in which it is contained, not by any particular colour, but its greater smoothness. The head is roundish, and not very broad. The neck and the first pair of legs are distinctly visible, but the other feet were not seen. The thorax is the most pro- minent part of the animal, but becomes gradually flatter towards its extremity. The four wings are spread out, and very well preserved, and single veins are observable in some of them. The abdomen is cylindrical, is thinner towards the middle, expands again, and terminates in a notch. The globular head, the hori- zontally expanded wings, the cylindrical abdomen, and the total habitat, shew that it belongs to the genus Aeschna of Fa- bricius, and is distinguished from the Aeschna grandis only by its greater size. The insect just mentioned, measuring from tip of one wing to tip of the other, three inches ; whereas in the fossil species, the length is three and a half inches, and all the other parts are in proportion larger. In the same block of stone with the fossil libellula, was a small asterias, or sea-star,— a fact which confirms the mutual occurrence, in this rock, of land and marine animals. — Vide Leonhardfs Zeitschrift. 8. Beds of Sea-shells, nearly in afresh state, 9X^0 feet above ike level of the Sea. — The following observations, (says Ber- zelius), which I had an opportunity of making on the west side of the Scandinavian peninsula, will serve as an additional proof of the gradual rise of the Scandinavian land above the level of the sea. It is known that, on the sea-coast, and in N 2 196 Scientific Intelligence. — Geology. the islands at Uddevalla, and also on the whole sea-coast of Southern Norway, there are here and there banks of sea- shells, sometimes 200 feet above the present level of the sea. The shells are, in general, well preserved, none are calcined or weathered, and all of them are of species that still live in the neighbouring sea. The horizontal beds in which they lie, shew that they have been quietly formed here, and that they were formerly the bottom of the sea. One of them, the Lepas halanuSy is always attached to the rocks of the coast ; so that, during the motions of the surface of the sea, it is momen- tarily above its surface. Brongniart, with whom I visited these banks at Uddevalla, remarked, that if the sea, at any time, co- vered these places, that we would probably find lepades or bar- nacles adhering, if any of the rocks could be exposed. We searched for exposed portions of rock, and soon found them, with barnacles adhering, which had remained attached from the pe- riod when Uddevalla was 200 feet under the surface of the sea. I consider this as the oldest and most certain of all those marine testimonies which go to prove that the Scandinavian land has risen above the sea ; for a fall or sinking of the sea 200 feet around the whole coast is not to be thought of. What raises the land, and how and when will its elevation be finished ? But who would venture to answer these questions ? 9. Greensand Jorination in Sweden. — Nilson has announced, in the Stockholm Transactions, the discovery of the greensand in Schonen. It contains, besides univalve and bivalve marine shells, different fossil land plants. The green sand of Schonen may be considered as the termination of the great tertiary series of rocks which extends from Germany, under the waters of the Baltic, until it terminates in the higher lying parts of Schonen. 10. Coal of Hogands. — This interesting deposite appears to occupy, in the geognostical series, a place between the old coal formation and that of the brown coal. 11. Hill of Magnetic Iron-ore. — Menge describes a hill of mag- netic iron-ore he met with at Kuschwa, in Siberia, 400 feet high, which rises through primitive greenstone. The iron-ore is asso- ciated with sodalite and augite. On the west side of the moun- tain, he observed a remarkable amygdaloid rock, in which the basis is of garnet. The amygdaloidal masses are calc-spar, and the vesicular cavities are lined with crystals of scapolite. Scientific Intelligence, — Mineralogy. 197 12. Ht/cena Cave. — M. Billaudei, civil-enginer at Bour- deaux, discovered in a quarry on the banks of the Garrone, a cavern, in which he found a quantity of the bones of various animals, among them jaws of the hyaena, of the Hon, or the ti- ger, and of the badger, bones of the fox, &c. MINERALOGY. 13. Crystallizations of Sulphate andCarbonate of Lead observed byM.Hartmann. — The following forms of sulphate of lead (Pris- matic Lead Spar) were observed in a series of beautiful specimens, from a vein in transition clay-slate, near the smelting works of Tanne, five hours from Brunswick, by the translator of Beudanfs Mineralogy, M. Hartmann, and by him communicated to us : — 1 . (P r -f- X )3. P — X . very frequent in crystals half an inch in length, which are often tabular. 2. (Pr -|- x)3. Pr resem- blingfig. 1 . Mollis Treatise^ vol. ii. 3. (Pr -f x )3. Pr. P — x . 4. (Pr + X )3. Pr -f X . 5. P-|-x . P. 6. (Pr + x y, Pr. Pr. 7. (Pr-|-x.)3Pr-|-x. P — x. Twin crystals exhibiting the form represented in PI. III. Fig. 5. M. Hartmann observed, from the same place, the following combinations of carbonate of lead, or white lead spar : — 1. P. % P. (Pr -|- x )3. Fig. 54. PI. 91. Hauy. 3. M. 1. s. (Hauy's Letters) 4. M. 1. f. u. Fig. 36. Hauy, 5. M. 1. s. y. Fig. 57. 6. M. e. 1. f. k. u. Twin, or rather triple crystals, grouped according to the law in Fig. 65, PI. 93. Hauy, ar^d the termination of the planes P. n. i. 14. Geognostic Positiofi of Platina in America. — Hitherto this metal has been found, in the New World, only in the alluvial districts of Choco and of Brazil ; but Mr Boussingault has disco- vered roundish grains of platina, mingled with native gold, in veins in the province of Antioquia. These veins traverse a formation of greenstone, diorite, and syenite. 15. Jet discovered in Wigtonshire. — Beautiful specimens of this mineral have been found between a bed of peat and yellow clay, in the peninsula formed by Loch Ryan and the Irish Chan- nel, by Sir Andrew Agnew. 16. Geognostical Distribution of Gold in the Uralian Moun- tains.— The gold-bearing districts in the Uralian mountains are 198 Scientific Intelligence. — Mineralogy. almost universally composed of magnesian rocks ; of these the most frequent is talc-slate, and less abundant are serpentine and ophite. The gold occurs either disseminated in these rocks, or in quartz veins which traverse them, where it is generally asso- ciated with varieties of iron pyrites, which are usually aurife- rous. Beresowsk is a remarkable point in the Urals : the whole of the district is talc slate, surrounded by serpentine, and tra- versed in all directions with an infinity of auriferous quartz veins. In one place Mr Menge found gold in decayed sye- nite. Erdmann, in his account of the interior of Russia, gives an interesting account of the alluvial gold of that country. The alluvial deposit, on the left bank of the Beresowka, is about thirty feet thick, — the upper layer a loam, underneath which, and forming the great mass of the alluvium, is sand, of which the coarsest kinds are lowest. The gold occurs in the sand, and in largest quantity, in the deepest seated, and coarsest va- rieties. Two opinions as to the mode of formation of this allu- vium have been proposed ; — according to the one, it is believed to be derived from the neighbouring hills, because it is inter- mixed with masses of quartz, and fragments of brown iron ore, both of which occur in the mountains in the vicinity ; — the other opinion, that it has been brought by a flood from a dis- tance, receives additional support from the circumstance of it sometimes containing bones of tropical looking animals, and the gold being different from that of the neighbouring moun- tains. This alluvium, or auriferous sand, occurs chiefly on the east side of the Urals, extending from Bogislowich smelting establishment, to the Polkowischen mine, an extent of 1000 wersts from north to south. It is very rich in the district be- tween Nischni-Tagilskoi and Kuschtymskoi, and the district Lenowka and Lugoowka. There is over the sand a layer of peat and black earth, IJ archines thick. The uppermost bed is richest in gold, the middle less so, and, at the bottom, the gold is scarce. The sizes of the single pieces of gold which have been met with, are worthy of being noticed. The Governor of Perm presented the University of Dorpat a specimen worth 800 rubles. When the Emperor Alexander visited the Mines of Oren burgh, he was presented with twenty-nine different pieces, one of which weighed eight pounds. In the royal Scientific Intelligence.'— Mineralogy, 199 mines of Slatoust, there was raised, in April 1825, within twenty-four hours, a series of beautiful specimens. Several weighed from five to nine pounds, and one sixteen pounds. This bed of sand also affords other metals. Soon after the com- mencement (1819) of washing for the gold of the Urals, many grains were noticed amongst the grains of gold, — these were of magnetic iron-ore, iron-pyrites, lead-glance, brown iron-ore, &c. In the year 1823, Lubarsky detected along with these, also pla- tina, iridium, rhodium, and osmium. 17. Geognostic situatimi of the Siberian Platina. — M. Menge of Lubec, one of the contributors to our Journal, who is at pre- sent travelling in Siberia, gives the following account of the geo- gnostic situation of the Siberian Platina. Being very desirous of examining the locality of that mineral, he proceeded to the spot, on the western side of the Uralian range, with one of the officers of the mine of Nischnin Tagil. There he found primitive clay-slate, much traversed by quartz veins on the banks of the Utka. The ridge of the Urals where he saw it, was composed of Serpentine : at the foot of a hill, named Pugina, which is composed of ser- pentine, resting on talc-slate, he found, under the soil, in decom- posed talc-slate, a quantity of platina associated with gold and native lead. Forty hundred weight of this slate afford half a pound of platina. The slate is a compound of smoke-grey quartz and common talc-slate. Grains of platina were, in all probability, also disseminated through the quartz. The serpentine abound- ed in grains and crystals of magnetic iron-ore; and, in decom- posed varieties of the same rock, grains of platina, but none of gold, were met with. On the east side of Pugina, the serpen- tine appears first in diallage rocks, and in this rock platina also occurs. North-east from Kuschwa, near to Nischnin-Turah, platina occurs in blue limestone, connected with disintegrated ^een porphyry. — The occurrence of gold and platina, in quan- tity, in serpentine and talc-slate, is a fact worthy of the attention of those proprietors in Scotland, where these rocks abound, as in Shetland, and various parts of the mainland of Scotland. 18. Cordierite found in Norzvay. — This mineral has been met with in Norway associated with Wernerite, quartz, garnet, and mica. The pierre de soleil probably belongs to this species. The Norwegian cordierite, when cut and polished, exhibits a stellukr opalescence, resembling that of the stellular sapphire. fHOO Scientific Intelligence.— Mineralogy, 19. Magnificent Crystals of Sulphate of Iron^ or Green Vi- triol.— Although this mineral is not of rare occurrence, it sel- dom appears regularly crystallized. Lately crystals, exceeding in colour, transparency, size, and form, the finest specimens produced by art, were found at Bodenmais in Bavaria, by M. Moldenhauer, and noticed by Leonhardt. 20. /serine and Iron-sand in Cheshire. — " I send you a bag of mixed iserine and iron-sand, which I have, a few days ago, traced quite across the Hundred of Wirral in Cheshire, from the shores of the Mersey to those of the Dee. I found it many years ago at Seacourse in that district, opposite to Liverpool, loose on the beach, and disseminated through a bed of crumb- ling sandstone, which lies below the thick bed of loam which forms the Cheshire soil at that spot. I afterwards traced it a- long the shores of the Mersey for several miles ; and lately, m a short marine excursion to the islet of Kilberry, at the mouth of the river Dee, I was pleased to recognise my old acquain- tance, washed out of the sandstone rock which forms that island, and the greatest part of the ridge of the Hundred of Wirral. I conceive this stone to be the Millstone Grit of the English geologists. Its upper bed is almost a farcilite, from containing many nodules of quartz, and occasionally some of a reddish felspar. It forms the ridge of Bidstone-hill and of Wallesey. At HilbeiTy Isle it lies just under the scanty soil, and rests on a much softer red sandstone, which appears to be identical with that on which Liverpool stands, and which cuts off the coal-measures in the coal-fields at St Helens and Prescot, ten miles east of Liverpool, as well as that of Neston in Wirral, on the shores of the Dee, opposite to Flint, and the portions of that same basin on the Welsh shores of the Dee. Indeed, in Liverpool the hard upper bed has been quarried as millstones, while the under red or yellow sandstone, is much charged with iron, and forms but an indifferent building material, which read- ily corrodes, when exposed to the weather.''' — Letter from Dr Traill^ Liverpool, to the Editor. 21. Bismuth Cobalt Ore. External Characters. — Colour intermediate between lead-grey and steel-grey ; lustre metallic, and gUstening or glimmering; texture radiated, partly stellu- lar, partly parallel It scratches fluor-spar, but this degree of Scientific Intelligence. — Hydrography. 201 hardness is occasioned by intermixed quartz. Streak dull, co- lour not changed, but the powder soils. Specific gravity = 4.5 —4.7. Chemical Characters. — Before the blowpipe on char- coal, gives out white vapours of arsenious acid ; deposits on it a yellow crust, during which the ore becomes of a brown colour. When well roasted before the blowpipe, and then mixed with glass of borax and melted, it communicates to it a smalt blue colour. If some small pieces of the ore are exposed to a low red heat in a glass tube it affords a considerable quantity of arsenious acid. Constiticent Parts. — Arsenic 77.9602; cobalt 9.8866; iron 4.7695; bismuth 3.8866 ; copper 1,3030 ; nickel 1.1063; sulphur 1.0160 = 99.9282. The characteristic ingredients of this ore are arsenic-cobalt and arsenic-bismuth, a combination of these metals hitherto not met with in the mineral kingdom. Geographic^ Situation. — Has hitherto been found only at Shnee- berg in Saxony. — We owe our knowledge of this minei al to Mr Kersten of Gottingen. 22. Selenium in Red Copper Ore. — Kersten of Gottingen, on exposing the capillary red copper ore of Rheinbreitenbach to the blowpipe, perceived a seleniferous smell, which, on farther examination, he found to be owing to the presence of selenium in that ore. The capillary red copper ore of the Bannet he did not find to contain any selenium. HYDROGRAPHY. 23. Discovery of a New Substance in Sea Water. — M. Ballard of Montpellier, has discovered a peculiar substance in sea-water, which he names Brome, and considers it intermediate between iodine and chlorine. It has a disagreeable smell ; hence its name, from /3g2 216 Biographical Memoir of Charles Bonnet. mation of the clouds, penetrate into their interior, or raise him- self above them. But I perceive that, in thus painting the theatre in which the distinguished individuals lived of whom I am about to speak, I have unintentionally presented you with a miniature of their discoveries; and, in fact, their country is in a manner vividly impressed upon their works, even those which are the most comprehensive in their object : nor was it ever left by one of them, — and if the other sometimes separated himself from it, it was always to him the centre and point of comparison to which he referred all that he saw elsewhere ; — powerful influence of first habits,— of which another of their fellow-citizens has given a different kind of example, which the events that have agitated Europe have rendered too memorable. Charles Bonnet was born in 1720, of a rich family, distin- guished for the important offices which it had filled. He was intended for the law, and received the education necessary for preparing him to practise that profession. A facility of concep- tion, and a happy imagination, enabled him to make rapid pro- gress in literature and science ; but they did not at first permit him to devote himself with delight to the more abstract medita- tions of philosophy, and still less to the study of all those forms, all those little particular decisions, with which so many codes are filled. This taste for agreeable ideas, for easy, although ingenious, researches, already indicated a disposition favourable to the study of Natural History ; and accident threw him entirely into that pursuit. He read one day, in the Spectacle de la Nature, the history of the singular industry of the insect called the Lion Spider, Formica Leo. Vividly impressed with facts equally curious and new to him, he was not satisfied until he had pro- cured one of them ; and, in searching for this insect, he found many others which appeared to him not less interesting. He spoke to every body of the new world which had opened itself up to him. Being apprised of the existence of Reaumur's work, he obtained it, after much importunity, from the public libra- rian, who was at first unwilling to trust it to so young a man. He devoured its contents in a few days, and ran about every- where in search of the animals with whose history Reaumur had Biographical Memoir of Charles Bonnet. SI 7 made him acquainted. He discovered a multitude of beings, of which Reaumur had taken no notice ; and now behold him, at the age of sixteen, become a naturahst. He would probably have remained so for life, had not his infirmities constrained him to give another direction to his mind. He entered upon the career of observation with gigantic steps. At the age of eighteen he communicated to Reaumur several in- teresting facts, and at twenty he submitted to him his beautiful discovery of the fecundity of aphides without previous copu- lation. Nine successive generations, independent of sexual in- tercourse, were then an unheard-of wonder ; but the admirable patience exercised by so young a man in determining the fact, all the precautions, and all the sagacity requisite for such an undertaking, were not less wonderful. They announced a mind of which every thing might be expected ; and the Academy of Science thought it could not too speedily but inscribe the name of this young observer in the lists of its correspondents. Soon after, a fellow-countryman of Bonnet's presented a still greater miracle to the astonished world of science ; the history of the polypus, and its indefinite reproduction by cutting, were pub- lished by Abraham Trembley. Bonnet immediately applied the scissors to all the animals commonly called imperfect. He saw the cut parts grow again in land and fresh water worms. He also multiplied the individuals by dividing them, although no comparison could be made between their highly complicated or- ganisation, and the almost perfect simplicity of structure of the polypus. In this manner, a power began to shew itself in animals, which had hitherto been regarded as peculiar to plants. It was by following the views of Bonnet that Spallanzani carried the proofs of this power to their utmost limit, when he caused the head, \yith the tongue, jaws, and eyes, to be reproduced in a ^^"gj — and the feet, with all their bones, muscles, nerves, and vessels, in the salamander. This property, experimented upon in worms, presented Bonnet with several phenomena calculated to excite astonishment. The anterior extremity, on being split, afforded two heads, which, while yet scarcely formed, became enemies to each other. When die animal was cut into three distinct pieces, the middle piece 218 Biographical Memoir of Charles Bonnet. commonly reproduced a head before, and a tail behind. But a sort of error of nature also sometimes manifested itself; the middle piece produced two tails, and being unable to nourish itself, was condemned to quick destruction. It seemed as if it were the destiny of Bonnet, that the half- formed ideas, and uncompleted attempts of others, should fur- nish him with the subjects of great discoveries, and beautiful works; and, in fact, it is less by conceiving ingenious ideas than by unremittingly pursuing their development, that the great geniuses have gained their celebrity. The germ of the differen- tial calculus is to be found in Barrow, and that of the central forces in Huyghens ; yet Newton is not the less entitled to hold the first rank in intellectual pre-eminence. Some experiments, undertaken with the view of making shrubs vegetate without earth, and a conjecture of Calandrini's regarding the design of the difference between the two surfaces of the leaves of trees, led Bonnet to undertake his Traite de TUsage des Feuilles^ one of the most important works on vege- table physiology that the eighteenth century produced. He not only found existing in vegetables, in the highest de- gree, that power of reproduction, by which, from any part of an organised body, the whole may at all times be reproduced ; he also observed and investigated that mutual action of the vege- table and the surrounding elements, so well adjusted by nature, that, in a multitude of circumstances, the plant would seem to act for its preservation with sensibility and discernment. Thus he saw the roots changing their direction, and stretch- ing themselves out in quest of better nourishment ; the leaves twisting themselves, when moisture was presented to them, in a different direction from the ordinary Qne ; the branches straight- ening or bending in various ways in search of purer or more abundant air ; all the parts of the plants moving toward the light, however narrow the apertures by which it was admitted. It seemed as if the vegetable struggled with the observer in sa- gacity and address ; and every time that the latter presented a new allurement, or a new obstacle, he saw the plant bending it- self in a different manner, and always assuming the position most suitable to its welfare. While the leaves formed the prin- cipal object of his reseachcs, Bonnet examined also the functions Biographical Memoir of Charles Bo^met. SI 9 x]^ the other parts of the vegetable. He shewed that there is no circulation, properly so called, in plants. He made observations respecting the internal structure of the vegetable. He proved that pure water and atmospheric air are sufficient for nourishing plants, — a result which might have immediately led to the great discoveries of modern chemistry regarding the composition of water and carbonic acid, had not a knowledge of many other phenomena still been necessary to suggest the want of this solu- tion, and to pave the way for these discoveries. These researches occupied Bonnet for twelve years ; and, from the scrupulous accuracy, and delicate sagacity so conspi- cuous in them, as well as the solidity of their results, they form his best title to distinction. What secrets might not such a mind have unfolded, after so pro- mising a commencement, had nature left him the physical powers necessary for observation ? But his eyes, weakened by the use of the microscope, refused him their assistance ; and his mind, too active to endure a state of absolute repose, threw itself into the field of speculative philosophy. From this period his works as- sumed a new character, and he now only treated of those general •questions that have, in all ages, engaged the meditative faculties of the human mind, and which will probably occupy them as long as the world continues to exist. In the writings of his maturer age, however, we recognise, by the facts which are every where incorporated with them, and the care with which he avoids losing himself in systems founded upon the abuse of abstract terms, the philosopher who has en- tered the region of metaphysics by the path of observation. The choice of Malebranche and Leibnitz for his guides, and the discriminating selection which he made of their views, always recall to his thoughts his first pursuits. But what especially characterised them were those physical hy- potheses which he always added after having exhausted the field of observation, and by which he still seemed anxious to present to the mind objects of external perception, when the senses re- fused to present them to him. This necessity of clear and al- most tangible ideas, which constitutes the true spirit of Cartesia- nism, had been carefully inculcated in the old Acadeiny of Science, and Bonnet had been impressed with it by his correspondence with Reaumur, 220 Biographical Memoir of Charles Bonnet. We shall now give an account of these writings, not in the order in which he published them, but in that in which we may suppose him to have conceived them ; and, on reading them, it is obvious that a single principle must have predominated in the conception of all, and that the author detached its various parts in proportion as he judged them sufficiently perfect to be pub- lished. Although these works are not connected with our ordinary studies, yet they all belong to the individual whose character it is our object to delineate; and we should present but muti- lated portraits of celebrated men, did we not trace, in its de- tails, and even in its aberrations, the progress of their ideas. In Bonnefs youth, a great deal had been written on Genera- tion; and this subject would, therefore, naturally occur among the first to engage his attention. It was impossible for one who had seen nine generations of pucerons succeed each other, with- out males, not to be, like Malebranche, an advocate for the pre- existence of germs, and not to place them in the females. His Cmiside rations sur les Corps organises are almost entirely con- secrated to the defence of this system, and especially to an expla- nation, by partial hypotheses, of the phenomena which were at variance with it, such as those of hybrids and of certain mon- sters. There is much talent in this work, in which all the objections are either solved or evaded with more or less ingenuity. Desti- tute, however, as it was of all proper observations, it would scarcely have prevailed against the directly opposite hypothesis, which the eloquence of Buffon had rendered popular. But the indefatigable Spallanzani brought facts to the support of Bon- net's views, by shewing the young tadpole already existing in the egg of its mother before the male had fecundated it. Haller, who had long supported the idea of the formation of organised beings, by the action of organic powers, returned to the opinion of germs, when he had seen that the chick is attached by innu- merable vessels to parts of the e^g, which undoubtedly existed before impregnation. In another general work, entitled Contemplation de la Nature^ Bonnet supported the proposition of Leibnitz, that every thing is connected in the universe, and that nature makes no leap ; but, instead of confining its application, like the German philoso- Biographkal Memoir of Charles Bonnet. 221 pher, to successive events, having the relation of causes and ef- fects, or at least to the mutual action and reaction of simulta- neous beings, he also extended it to the forms of these beings, and to the gradations of their physical and moral nature. That immense series, commencing with the ruder and more simple substances, rising by infinite degrees to the regular mi- nerals, to plants, to zoophites, to insects, to the higher animals, to man himself, and through him to the celestial intelligences, and terminating in the bosom of the divinity ; that regular gra- dation in the development of beings, unfolded by the talent of Bonnet, formed an enchanting picture, which could not fail to gain many admirers. For a long period naturalists busied themselves in filling up the vacuities which the want of observations, according to their view, still l^ft in this scale ; and the discovery of an additional link, in this immense series, appeared to them an object of the greatest interest. But, however agreeable this idea might appear to be to the imagination, it must be acknowledged, that, taken in this accep- tation, and to this extent, it has no real existence. Without doubt, the beings which constitute certain famihes have more or less resemblance to each other ; and, in some of these families, there are, undoubtedly, beings possessing certain properties in common with members of other families. The bat flies like birds, the swan swiiras like fi«hes ; but it is neither to the last quadruped of the series, nor to the first bird, that the bat has most resemblance. The dolphin would connect quadrupeds and fishes still better than the swan would connect fishes and birds. Thus there are multiplied relations, but no one continued line ; each being is a part which exercises a determinate in- fluence upon the whole, but not a link that would fill a fixed place in it. Bonnet would probably have avoided this illusion, had he ap- plied himself more to the detailed examination of species ; but, with other men of merit in his day, he participated in their un- just contempt for that ingenious art of distinguishing beings by- certain marks, which was then proscribed, under the name of Nomenclature. He was not aware that this art is in Natural His- tory the basis of all further inquiry ; nor did he conceive it to 222 Biographical Memoir of Charles Bonnet. be the path to a much more profound art of determining the in- timate nature of beings, by estabUsliing rational and constant re- lations between them. At the present day, we find it difficult to conceive, how truths so clear could have been misunderstood ; but, we must reflect, that the principles of these truths were then presented in such a defective manner, and in so absurd a style, as could not but dis- gust men of literary attainments, accustomed, in their writings, to please the imagination, in order to penetrate to the under- standing of their readers. Bonnet belonged completely to this last order of writers, and his Contemplation of Nature, in particular, is as remarkable for the pleasing vivacity of its style, as for the accun\plation of facts which he has brought together, and presented under the most interesting relations. It is one of those books that may, with most advantage, be put into the hands of the young, as calcu- , lated at once to inspire them with a taste for study, and reve- rence for divine providence. His Essai de Psychologies and his Essai analytiqne sur les Facultes de FAme, with which he commenced the publication of his speculative researches ; and his Palingenesie Philosophique, with which he terminated them, are but little connected with Natural History, properly so called ; and, for this reason, we shall confine ourselves here to a very summary view of the principal ideas contained in these works. The author investigates the moral and intellectual being in the development of its faculties. He concurred with the Abbe de Condillac, in the idea of determining, by a process of reason- ing, what would happen to an adult and healthy man, who, like a statue animated by degrees (or gradually endowed with the senses and faculties of a rational being), should receive succes- sively all the sensations in the order in which they would be given him ; and thus he developes the history of the mind, lead- ing it, in an ingenious manner, from the acquisition of the sim- plest ideas of all, namely, those derived immediately from the external world, up to |;he creation of those which are the most abstract, and which, from their simplicity also, though of a dif- ferent kind, were so long considered as, in their origin, entirely independent of the senses. This was still following the path of Biographical Memoir of Charles Bonnet. 223 observation ; but he soon diverged, as was his custom, into that of hypothesis. The undeniable facts., that external images arrive at the mind only through the medium of the senses, and that the senses act upon the mind only through the medium of the brain, led him to suppose, that the brain alone is the depository of these images, and that it reproduces them for reminiscence, and consequently also for reflection ; from which he inferred the necessity of a cor- poreal organ to the intelligent being. But, accustomed as he was from his system of germs, to imagine organs so inconceiva- bly small as to belong to the thousandth order in organisation, it was not difficult for him to make this organ survive the visible and terrestrial body. He accounted for the phenomena of asso- ciation in the manner of Hartley, by supposing a mutual excite- ment among the molecules of the brain, analogous to the power which cords, when stretched in unison, possess of making one another vibrate. He admits, on the part of the mind, no action without a motive, as, says he, we see in nature no effect without a cause ; and hberty, according to his view, is only the power of following, without restraint, the motives whose impulse we expe- rience. By this definition he easily defends, as may be imagined, moral liberty against the objections derived from the Divine Prescience. But, would not the term liberty be thus changed from its natural acceptation ? It must be allowed, in fact, that Bonnefs ideas regarding the organs necessary for intelligence, and the motives requisite for action, singularly coincide with those maintained by Priestley, in support of what he, without hesitation or reserve, denomi- nates materialism and necessity ; and yet Bonnet and Priestley were both animated with a very lively feeling of religion ; so true is it, that certain minds may connect opinions apparently the most opposite. Bonnet, in particular, had, in the course of his researches in Natural History, found too many proofs of the agency of an overruling Wisdom, not to be conscious of this idea predominating with him over every other. * His peculiar man- ner of conceiving organic phenomena, the pre-existing germs which he placed everywhere, rendered this agency still more ne- cessary in his eyes, and the tendencies of his mind in this respect were always powerfully seconded by those of his heart. S24 Bwgraphkal Memoir of Charles Bonnet. It is in his Palingenesiey the last of his philosophical works, that he best pourtrays the goodness of his character. The evils that exist in the present world, and the irregularity with which they are distributed, so clearly demonstrate the necessity of a future state of being, for the vindication of the Divine Justice, that he could not admit the one without the other ; and he had too often seen pain the concomitant of sensibility in all beings, to wish any of them deprived of this recompense. He therefore maintains, that the faculties of the inferior animals shall be so perfected as to render them capable of enjoying another life, and that our principal recompense shall be a proportional de- velopment of our powers. Thus, all beings will rise in the scale of intellect, and happiness will consist in knowing. The works of God appeared to Bonnet so excellent, that to know was with him to love. From this brief review will be seen the truth of what we have already stated, namely, that his last meditations were strictly connected with his first ; that all of them, together, form a ge- neral system, embracing the whole of nature, and presenting it under images, if not always correct, at least always clear and easy to comprehend. Those germs, multipHed to infinity, sometimes inclosed thousands of times within each other, some- times disseminated in the organised body, and always ready for repairing the most unforeseen accident ; that original agency of the Divinity ; that scale of perfections, and that ascent of de- velopement ; that necessary, intermediate, subtle organ between the mind and the world, the reservoir of the ideas, and the cause of their association ; that connection of motives and actions in the moral world, similar to that of impulse and motion in the physical, formed a system of highly wrought Cartesianism, a philosophy adapted to the weakness of the human mind, which prefers suppositions tq vacuities in the series of its ideas. It is obvious, that this necessity of the influence of motives would have rendered his moral system defective, had it not led him to infer the necessity of a revelation, as an ultimate and peremptory motive ; and it is with this inference that he con- cludes the series of his philosophical meditations. Having once drawn this inference, it is no longer difficult for him to de- termine what revelation is the true one. Thus, from being a Biographical Memoir of Charles Bonnet. £25 naturalist, he ultimately became a theologian ; and by a singu- lar progress, it was a doctrine closely allied at least to that of ne- cessity, that conducted him to Christianity. In tracing the progress of those meditations in which Bonnet was engaged, I have given you a full portrait of the man. To devote one's-self with such constancy to speculative researches, — to aim at forming out of his own reflections a system of ideas so subtle, — required a mind undisturbed by the concerns of this world, and not less tranquil with regard to those of another ; and, in fact, he preserved, during a pretty long hfe, that composure of mind of which his writings bear the impress. En- joying an easy fortune, in the society of a mild and amiable wife; called to honours in his native country, without being charged with the cares of government ; esteemed by the power- ful and the learned of Europe ; beloved by those who had more intimate connections with him, he tasted, without interruption, all the pleasures of the heart and mind. He had no children, but he bore an affectionate regard for some of his pupils, whom he judged worthy of it ; — a kind of fathership, unattended with the chagrins which are too often attached to the other. It was thus that he passed his life without leaving his native country, doing good to all who surrounded him, and hoping to produce a greater and more general good by his works. Al- though his constitution had never been strong, yet his health remained unbroken during an existence so calm ; and it was not until he had attained the age of seventy-three that he died, after a gradual decline, on the SOth May 1793. The city of Geneva, proud of having had such a citizen, de- creed him public honours. M. de Saussure pronounced his fu- neral oration. Two others of his pupils have published eulo- giums full of the affectionate admiration which animated all who approached him. But, next to his works, the monument which confers most honour upon him, are those very men whom his advice and ex- ample contributed to form ; and we shall add a,poncluding fea- ture to the picture of his life, by tracing immediately after it that of a nephew who was not less illustrious, and who, without having carried his ideas over so wide a field, has made bolder and surer steps in the more narrow career which he traced for himself S26 Biographical Memoir of Horace Be^iediet de Saussure. Horace Benedict de SaussiTre was born at Geneva, on the 17th February 1740, His mother was a sister of the wife of Bonnet, and he soon become one of the favourite pupiis of that philosopher. His father left some writings on agriculture. The happy penetration of his mother prescribed for him laborious exercises at an early age, which so little retarded the progress of his education, that he distinguished himself at college at the age of seven, became a candidate for a mathematical chair at twenty, and at twenty-two was appointed professor of philoso- phy. His pretensions in these tv.^o departments of science suffi- ced of themselves to shew that his studies were at once varied and profound. Of this he gave an additional proof, the same year, by choosing a question in vegetable physiology as the sub- ject of his first essay, entitled Observations siir VEcorce des Feu- illes et des Petales, which he dedicated to Haller, and published in 176S. In this essay he described the cortical net-work which envelopes these parts, the regular pores with which it is perfo- rated, their communication with the internal substance, and their influence upon the nutrition and respiration of the plant. It was a beautiful supplement to his uncle's work on leaves ; and this small performance alone has assigned to Saussure an honourable station among botanists. Occupied afterwards with objects of greater importance, and which required more laborious exertions, he always reposed with pleasure upon those of his first predilections. In the midst of his journeys in the Alps, upon the most precipitous summits, while engaged in those profound meditations which embraced all that nature presents to us of the vast and magnificent upon the globe, he carefully collected the smallest flower, and noted it with pleasure in his book. He seemed to dwell with compla- cency on the view of these living beings in the vicinity of the vast ruins of nature. It was with botany that he terminated his writings, as he had commenced them ; and after having sub- mitted to the Natural History Society of Geneva, in 1790, some observations on the motion of a tremella of the baths of Aix, he also read, in 1796, a few months before his death, conjectures on the cause of the constant direction of the stem and root at the moment of germination. Biographical Memoir of Horace Benedict de Saussurc. S2T But Saussure was destined to other studies ; he was to un- veil deeper secrets. For him it was reserved, first of all, to cast a truly observing eye over those rugged girdles v/hich surround our globe, and in which the substances that compose the nu- cleus of our planet disclose themselves to the naturalist ; to in- vestigate in detail the nature of these substances, their order, or rather the disorder, into which they have been thrown by the catastrophes that have heaped them upon each other ; lastly, to throw some light upon the events that have preceded the pre- sent state of the world, and regarding which there was nothing, before his time, but the vaguest ideas or the most extravagant theories. He had, in some measure, entered upon this study before the age of twenty years ; for, in 1760, following the steps of some Englishmen, he had essayed to mount the glaciers of Chamouny. The ideas which this attempt afforded him were developed during a journey which he performed in France and England in 1768, and during a second, in which he passed through the whole of Italy in 177^. The naturalists with whom he. had intercourse, the collections which he visited, the mountainous countries which he traversed, all recalled to hi& mind how fertile his own country was in facts illustrative of one of the most interesting subjects that could captivate the humanr mind. From this period he formed the project of invariably pursuing this inquiry ; and all his journeys, all his labours, even his most ingenious discoveries, bear a more or less direct refe- rence to this object. To form a more correct estimate of the importance of Saus- sure's labours in this department, it will be necessary to consider the views entertained of the theory of the earth at that time. The naturalists of the sixteenth and seventeenth centuries had described minerals ; they had begun to collect petrifactions, but they looked upon these latter bodies merely as sportive produc- tions of nature, or as remains of the deluge ; and, excepting in the case of metallic veins, they were far from supposing that there was any constancy in the arrangement of mineral substan- ces. Descartes, without attending to what naturalists had pre- viously observed, had formed his globe by incrusting a sun. Burnet, Whiston, and Woodwardt, some by breaking this crust, others by calling a comet into play, had endeavoured to explain 228 Biographical Meynoir of' Horace Benedict- de Saussure. the deluge, and to deduce from it the present state of the globe. Leibnitz was the first who had attempted to distinguish upon the earth parts raised by fire, and others deposited by water. Bourgeret, judging of the high valleys from those of level coun- tries, had them all scooped out by currents. BufFon, lastly, combining the ideas of Whiston, Leibnitz, and Bourguet, made a comet knock oflP from the sun, the melted masses, of which the earth and the other planets were formed, and gave the globe thou- sands of ages to cool, thousands more to receive water from the atmosphere, and become the abode of incipient life, and other thousands still to have its surface elevated into mountains, or scooped into valleys. In his first volumes he made no distinction between the different orders of mountains, and appeared to be- lieve all their strata to be horizontal. It could scarcely be said that the Pallases, the Delucs, and the German and Swedish mi- neralogists, had begun to make regular observations on the struc- ture of the earth, and to draw general conclusions from what they had seen. Their labours were little known in France, and the learned who were in repute treated almost all geology as chimerical. Saussure applied himself to the labour of raising it to the dignity of a real science; and, for this purpose, resolved to carry into it that accuracy of determination which the study of mathematics had given him, together with all the advantages resulting from a profound knowledge of physics. But these aids would still have been inefficient, without the firm resolution of long and patiently observing nature on the spot. Let those who have crossed great mountains only by regular roads, fancy to themselves the courage of the man who destined himself to spend his life among them, to scale all their peaks, to explore all their recesses, and who, for this object, abandoned all the enjoyments of friendship and fortune. To make long excursions in those high valleys which no vehicle ever approach- ed ; to partake with the poor inhabitants of their black and hard bread ; to have only their smoky cabins, open to all the winds of heaven, for a place of repose ; to pursue as the only path the rocky bed of a torrent ; to hook one's way with hands and feet to the sharp ridges of cliffs ; to leap from one point to another above a precipice ; to be at times surprised by winds that blow him over, and at others by fogs that obscure the path or freeze Biographical Memoir of Horace Benedict de Saussure. 229 the breast ; to sound every moment the snow, which perhaps co vers a giilf ready to swallow you up ; to remain days and nights upon those masses of eternal snows, the extreme limits of life, and to which the love of science alone could lead animated be- ings ; — such was the existence to which the historian of the Alps condemned himself, — such was the life which Saussure led du- ring the ten years in which he collected the materials of his first volumes, and which he many times resumed before publishing his last. Without doubt he was not destitute of enjoyment during this period. He describes, with a sort of enthusiasm, in his prelimi- nary discourse, the health which the pure mountain air impart- ed, the admiration inspired by the simple virtues, and the noble character of the inhabitants of those high valleys. He represents himself, from the summit of Etna, viewing empires and men in all their littleness. It is true that a philosopher need not ascend so high to see matters in this light, but it would seem that, at such points of view, every good man, in spitevof himself, would become a philosopher. Had Saussure, however, taken only these vague dispositions with him on his journeys, had he only acquired these general impressions, we should not probably have had his eulogium to make here. He had, on the contrary, as we have already said, prepared himself for these expeditions by the most profound stu- dies, and from these he was enabled to derive the most precise results. Before describing the mountains, it was necessary for him to determine the distinctive characters of the substances of which they are composed ; and, notwithstanding the attempts of Lin- naeus and Wallerius, the science of Mineralogy was at this pe- riod in a very low and confused state. He had, therefore, to commence with increasing its accuracy and extent, and this he effected with a success which Rome de Lisle and Werner have • scarcely surpassed. His experiments on the fusion of minerals, in particular, contributed to the distinction of species that had previously been confounded. He went so far as to invent a ma- chine for comparing the different degrees of hardness of bodies ; and nearly fifteen new kinds have been added to the catalogue of the mineral kingdom in consequence of his observations. It was around Geneva itself that he found at once the specimens JANUARY MARCH 1827. Q ^0 Biographical Memoir of Horace Benedict de Saussure which instructed him in lithology, and the principal documents from which he derived his ideas respecting the history of the earth. The environs of that city were covered with rolled stones, frequently even with great masses of very diversified sub- stances, foreign to the neighbouring mountains, and which are found in situ only in the high Alps. These masses became to Saussure a rich cabinet of mmeralogy, and indicated to him the violent revolutions which had conveyed their materials to such a distance from their original positions. To be perfectly convinced, however, of the existence of these an- cient revolutions, it was necessary to prove that the causes at pre- sent in operation are incapable of producing such effects; and, for this purpose, he required to measure each of these causes, and to appreciate the extent of their influence. He had, therefore, to examine attentively the lake, and the rivers which empty them- selves into it, and which descend from the glaciers ; to determine the velocity and direction of their motions, their temperature, and the quantity and quality of the substances which they carry along with them : he had to employ, and even invent, instru- ments of a delicacy proportionate to the measurements which he had in view to obtain. But these running streams are the pro- ducts of rains, and the melting of the glaciers, which last are themselves incessantly renewed by the snows which the clouds deposite in these high regions. It was therefore necessary to deter- mine the quantity of these various sources, to ascend even to the cause of rain, the most important and difficult to explain of all the meteors ; and as the most probable origin that can be as- signed, is to suppose it to be formed from the vapours of the atmosphere, it was still farther necessary to explore all the means of appreciating the quantity and nature of these vapours in all circumstances. It was by following out this train of ideas, joined to the de- sire of precision which always distinguished him, that Saussure was led to improve the thermometer, for measuring the tempera- ture of water at all depths ; the hygrometer, for indicating the greater or less abundance of watery vapours ; the eudiometer, for determining the purity of the air, and for finding out whe- ther or not there might be any other cause of rain than in the at- mospheric vapours ; the electrometer, for ascertaining the state of electricity, which operates so powerfully on the aqueous me- Biographical Memoir of Horace Benedict de Saussure. 231 teors ; the anemometer, for determining at once the direction, velocity, and strength of the currents of the air ; lastly, it was from these motives that he invented the cyanometer and diapha- nometer, for comparing the degrees of colours and of transparency of the air at different heights. It is unnecessary for us to say that the measurements of heights by the barometer must also have been a continual object of his investigations. Thus, in examining the mountains as a natural philosopher, he explored the atmo- sphere as a geometrician and a chemist ; and it is to him, in fact, that we owe all the positive information which we possess re- garding the composition and motions of the fluid by which we are enveloped. These different applications of physics form so many interest- ing digressions in the narrative of his journeys. We follow him with delight in these delicate investigations ; we find him never neglecting, in the most agreeable as in the most fatiguing situa- tions, to impress upon his observations that scrupulous accuracy which forms the seal and suretiship of correctness. He wrote, however, a separate essay upon Hygrometry, which was the most complicated and the most delicate of these measurements ; and this work is one of the most beautiful with which natural philo- sophy was enriched at the close of the eighteenth century. The question to be solved is, to ascertain how much water in vapour is contained in a given volume of air. In order to solve this problem, it would be necessary to separate the vapour from the air, or, in other words, to dry the air completely. This operation, however, is impossible, and the object can only be at- tained by approximation, and at the expence of much tim&, by employing substances that have a great affinity for moisture. We therefore content ourselves with a body capable of putting itself into a certain equilibrium of humidity with the surround- ing air, and of indicating the moisture which it has taken up by more or less apparent changes of weight or dimensions ; and as the fibres of organized bodies are eminently endowed with the property of being elongated by moisture, and contracted from dryness, it is these substances, especially, that are employ- ed for making hygrometers, or rather hygroscopes ; for, as we have seen, they do not afford an exact measure, but only an approximate indication. It is obvious that there must be great differences of sensibility and exactness between the different a2 232 Biographical Memoir of Horace Benedict de Saii»sure. fibres, and it was for the purpose of ascertaining the best and most effectual means of employing them, that Saussure's experi- ments were made. But to attain this object, it was also neces- sary to examine all the possible combinations of water and air, and the influence which they experience on the application of heat and pressure; to produce, by artificial means, the maximum of humidity and the maximum of dryness ; and to determine the in- fluence which humidity exercises in its turn upon the expansion of the air and the manifestation of heat. From these experiments we therefore see an almost new science springing up, and Me- teorology beginning to possess rational principles. Saussure made choice of hair as the hygroscopic substance, possessing most sensibihty and regularity. This result of his comparisons has been disputed ; but what could neither be ca- villed at,^ nor attacked, were his beautiful observations on the expansion of air in proportion as it is charged with humidity ; on the relations of humidity with pressin-e ; on the nature of the vesicular vapours or fogs which are suspended in the air like so many small balloons ; and on many other points, all more or less new to science, at the period when he published this work. Time does not permit us to lay before you the numerous me- chanical details by which he at length rendered his hygrometer and other instruments capable of convenient use, while, at the same time, he gave them the necessary precision. It is suffi- eient to observe, that, in all these investigations, we discover a mind no less accurate than fertile in resources, and calculated to be the model of natural philosophers as much as that of natu- ralists. Although Saussure had travelled for twenty years among the mountains ; had fourteen times crossed the Alps, by eight diffe- rent routes ; had made sixteen excursions to the centre of that chain ; although he had traversed the Jura range, the Vosges, the mountains of Switzerland, Germany, Italy, Sicily, and the adjacent Isles, and had visited the extinct volcanoes of France ; yet had he never reached the summit of Mont Blanc, which he beheld every day from his window. Ten times he had attacked it, as it were, by all the valleys which terminate on its sides ; he had gone round it, examined it from the sum- mits of the neighbouring mountains, but had always found it inaccessible. On the 18th August 1787, he learned that two Biographical Memoir of' Horace Benedict de Saussure. S33 inhabitants of Chamouny, by following the most direct route, which various prejudices had hitherto made him shua, had re- tiirned the previous day from that summit which mortal foot had never before trodden. His eagerness to follow their steps may be easily imagined, when, on the 19th August, he was at Chamouny ; but the rains and snows prevented him from ascend- ing that year. It was not till the 21st July 1788 that he at kngth accomplished this great object of his wishes. Accompanied by a servant and eighteen guides, whom he encouraged by his promises and example, after having ascend- ed for two days, and lain two nights in the midst of the snows, • — after having viewed horrible chasms under his feet, and heard two tremendous avalanches roll by his side, he arrived at the summit about the middle of the third day. His eyes, he says, were first turned towards Chamouny, where his family were watching his progress with a telescope, and where he had the pleasure to see a flag waving in the air, the appointed signal to assure him that his arrival had been perceived, and that their pain- ful solicitude respecting his fate was at least suspended. He then calmly set about performing his intended experiments, and con- tinued for several hours at this employment, although, at the height he now stood (15,000 French feet), the rarity of the air ac- celerated the pulse like a burning fever, and overwhelmed them with fatigue at the slightest motion, while, in those frozen re- gions, a cruel thirst parched their lips, as if among the sands of Africa ; and the snow, by reflecting the light, dazzled the sight, and scorched the face. The inconveniences of the poles and tropics were alike experienced ; and Saussure, in a journey of a few miles, braved as many hardships and dangers, as if he had gone round the world. His last expedition, and one of the most interesting with re- gard to the theory of the earth, was that to Mount Rosa in the Pennine Alps, which he performed in 1789. Instead of those needles of granite, which commonly pierce their envelopes, to form the ridge of the high Alps, he there observed an enor- mous plateau, where the granite, which every where else ap- peared uncovered, was enveloped under a mass of slate and limestone, disposed, along with the granite, in horizontal strata. From this appearance the views of Saussure, regarding the for- mation of granite in a fluid, and the succession of the other pri^ 234 biographical Memoir of Horace Benedict de Saussure. mitive deposites, which preceding observations had long before established, were now invincibly confirmed. Thus, every step that he advanced among the mountains dis- covered to him some new truth, and either enabled him better to arrange the series of those he already possessed, or to fill up some void in it. It would be interesting to trace all the meta- morphoses which the system of his ideas had undergone ; but time does not permit. Let us content ourselves with drawing a brief sketch of the principal acquisitions to the theory of the earth, which result from a concluding analysis of his works. He destroyed the* idea, which had been very prevalent until his time, of a central fire, a source of heat situated in the interior of' the earth. His experiments even prove that the water of the sea and of lakes is colder in proportion to the depth from which it is taken. He proved that granite was the oldest primitive rock, and that which serves as a basis to all the others ; he shewed that it was disposed in strata, and formed by crystallization in a fluid, and that if its strata are at the present day almost all vertical, this position is owing to a posterior revolution. He proved that the strata of the lateral mountains are always in- clined toward the central chain, namely, the granite chain ; and that they present their precipices to this chain, as if they had been broken upon it. He ascertained that the mountains are the more rugged, and their strata depart the more from their horizontal line, in proportion to the antiquity of their formation. He shewed, that, between the mountains of different orders, there are always heaps of fragments, rolled stones, and all the other indications of violent convulsions. Lastly, he pointed out the admirable contrivance, which supplies and renews among the snows of the high mountains, the reservoirs necessary for the production of large rivers. Had he -only bestowed a little more attention on petrifactions, and their positions, it might have been said, that we owed to him all the foundations on which geology has hitherto been built ; but, incessantly occupied with the great primitive chains, and the terrible catastrophes that must have taken place to have overturned their enormous masses, it would appear that he had formed a somewhat erroneous idea of those lesser mountains or hills whose repose had not been disturbed, and which contain remains of the newest epochs of the history of the globe. Biographical Memoir of' Horace Benedict de Saussure* S35 Possessed o£ materials so numerous and important, it must have required a powerful effort to resist the temptation of form- ing a system. Saussure, however, had this firmness of resolu- tion ; and we shall make it the last and the principal trait in his eulogy. His mind was of too elevated a character not to take a prospective grasp, in some measure, of the whole field of the science, and not to perceive to what extent it was imperfect, notwithstanding all the facts with which he had enriched it ; and it was, therefore, by pointing out what still remained to be investigated that he terminated his labours. So noble an example has not deterred his successors from drawing up, as formerly, the most romantic systems ; but this is only an additional rea- son for paying our tribute to a mind so rare. Saussure still seemed young enough to collect a portion of the observations which were awanting to the science ; but a dis- ease, the germ of which had perhaps originated in the fatigues of his journeys, began, a little after his fiftieth year, to under- mine his constitution. It was increased by some embarrass- ments of fortune, occasioned by the French revolution. Three successive attacks of paralysis reduced him to great weakness, and, on the 22d January 1799, after four years of sufferings, he died, aged only 59 years. Equally beloved and honoured as Bonnet by his fellow citi- zens and by strangers, Saussure had the additional happiness of living again in a son, whom he saw distinguishing himself in science, and whose beautiful discoveries have merited for him a reputation not less honourable than that of his father ; and in a daughter, whose rare virtues and superior mind have rendered her an ornament to her sex. A Description of some appearances of remarkable Rainhozvs. By the Reverend William Scoresby, F. R. S. Lond. and Edin, M. W. S., &c. Communicated by the Author. (With a Plate.)* j^ppEARANCEs of natural phenomena, of rare occurrence, are always worthy of being recorded, both as being interesting to the "•Head before the Wernerian Natural History Society 10th February 1827. 236 Rev. W. Scoresby on some remarJcable Ramhoivs. observer of nature, and as tending to the development of those beautiful principles with which the Almighty has so universally endued the vast range, and every atom of that vast range of the material creation. And they are further interesting, because, when understood, they generally resolve themselves into the ef- fects of some laws, principles, or combinations already known, and afford additional instances of their amazing variety of opera- tions, and of their universality of application. In this view, therefore, even modifications of the more ordinary phenomena, or extreme cases as to beauty, extent, or peculiarity of such, are not undeserving of attention, either to the naturalist or the philosopher. Hence I am induced to offer to the Wernerian Society an ac- count of two appearances of rainbows — though a phenomenon of such ordinary occurrence; because, in one of these cases, there was exhibited perhaps the extreme of beauty of which this brilliant arch is susceptible ; and, in the other case, there was a multipli- cation of the segments beyond any other example of a rainbow I ever before witnessed. The first example that I shall mention, so nearly resembled a remarkable rainbow described in a late number of the Edin- burgh Philosophical Journal (a rainbow that appeared at Lengs- feldt, on the 18th of May last), that I fear the following descrip- tion will seem to be little else than a repetition of what is already before the public. At all events, presuming on the interest which observers of nature always feel in such appearances as are at all of an extraordinary character, I shall not withhold the notes which I made on the occasion. This magnificent phenomenon was seen at Bridlington Quay at 5 p. M. of the 12th of August 1826, during a brilliant sun- shine, and a heavy partial shower that passed across from north to south, to the eastward of the town. Both the primary and secondary bows were complete arches, descending to the ground on the left, and to the surface of the sea on the right hand. The colours were of extraordinary brilliancy throughout. With- in the arch of the primary bow, were no less than three if not four supernumerary bows in close and regular order, but pro- gressively diminishing in intensity, so that the last was scarcely discernible. The primary bow was of course a series consisting PLATE W. Fz§: /. e.ja . , dreadfully dangerous ; it is during spring, during the love sea- son. The waters have again submerged the low countries; fish are difficult of access ; the greater portion of the game has left for the northern latitudes ; the quadrupeds have retired to the high lands ; and the heat of passion, joined to the difficulty of procuring food, render these animals now ferocious and very considerably more active. The males have dreadful fights to- gether, both in the water and on the land. Their strength and weight adding much to their present courage, exhibit them like colossuses wrestling. At this time no man swims or wades among them ; they are usually left alone at this season. About the first days of June the female prepares a nest ; a place is chosen forty or fifty yards from the water, in thick bramble or cane, and she gathers leaves, sticks, and rubbish of all kinds, to form a bed to deposite her eggs ; she carries the materials in her mouth, as a hog does straw. As soon as a pro- per nest is finished, she lays about ten eggs, then covers them Natural History of the Alligator. S79 with more rubbish and mud, and goes on depositing in difFei'ent layers until fifty, or sixty, or more eggs are laid. The whole is then covered up, matted and tangled with long grasses, in such a manner that it is very difficult to break it up. These eggs are the size of that of a goose, more elongated, and, instead of being contained in a shell, are in a bladder, or thin transparent parchment-like substance, yielding to the pressure of the fingers, yet resuming its shape at once, like the eggs of snakes and tor- toises. They are not eaten even by hogs. The female now keeps watch near the spot, and is very wary and ferocious, "go- ing to the water from time to time only for food. Her nest is easily discovered, as she always goes and returns the same way, and forms quite a path by the dragging of her heavy body. The heat of the nest, from its forming a mass of putrescent ma- nure, cause the hatching of the eggs, not that of the sun, as is usually believed. Some European writers say, that at this juncture the vul- tures feed on the eggs, and thereby put a stop to the increase of those animals. In the United States, I assure you, it is not so, nor can it be so, were the vultures ever so anxiously inclin- ed ; for, as I have told you before, the nest is so hard, and mat- ted, antl" plastered together, that a man needs his superior strength, with a strong sharp stick, to demolish it. The little alligators, as soon as hatched (and they all break shell within a few hours from the first to last), force themselves through, and issue forth all beautiful, Hvely, and as brisk as lizards. The female leads them to the lake, but more frequently into small detached bayous for security's sake ; for now the males, if they can get at them, devour them by hundreds, and the wood ibis and the sand-hill cranes also feast on them. I believe that the growth of alligators takes place very slow- ly, and that an alligator of twelve feet long, for instance, will most probably be fifty or more years old. My reasons for be- lieving this to be fact is founded on many experiments, but I shall relate to you one made by rcv^ friend Bourgeat. That gen- tleman, anxious to send some young alligators as a present to an acquaintance in New York, had a bag of young ones, quite small, brought to his house. They were put out on the floor, to shew the ladies how beautiful they were when young. One t2 280 M. Karsten's Observations and accidentally made its way out into a servant's room, and lodged itself snug from notice into an old shoe. The alligator was not missed, but, upwards of twelve months after this, it was disco- vered about the house, full of life, and, apparently, scarcely grown bigger ; one of his brothers, that had been kept in a tub and fed plentifully, had grown only a few inches during the same period. Few animals emit a stronger odour than the alligator ; and, when it has arrived at great size, you may easily discover one in the woods in passing fifty or sixty yards from it. This smell is highly musky, and so strong, that, when near, it becomes in- sufferable ; but this I never experienced when the animal is in the water, although I have, whilst fishing, been so very close to them, as to throw the cork of my fishing line on their heads, to tease them. In those that I have killed, and, I assure you, I have killed a great many, if opened, to see the contents of the stomach, or take fresh fish out of them, I regularly have found round masses of a hard substance, resembling petrified wood. These masses appeared to be useful to the animal in the process of digestion, like those found in the craws of some species of birds. I have broken some of them with a hammer, and found them brittle, and as hard as stones, which they resemble out- wardly also very much. And, as neither our lakes nor rivers, in the portion of the country I have hunted them in, afford even a pebble as large as a common cgg^ I have not been able to con- ceive how they are procured by the animals, if positively stones, or by what power wood can become stone in their stomachs. Observations and Eooperiments on the Different Kinds of Coal, By M. Karsten. X HE celebrated Chief of Mines in Prussia, Karsten, some time ago published, in his " Archivjur Bergbau und Hiittenwesen,^'' a valuable series of observations and experiments on the different kinds of coal met with in the mineral kingdom. This import- ant treatise has been reprinted in a separate form, and sent to us. On reading it carefully, we feel convinced that a condensed view of its most important facts and inferences will be read with Experiments- on the different kinds of Coal. 281 interest by chemists, mineralogists, geologists, and, particular- ly, by all those who are concerned with coal mines. We shall arrange our view of this work under the following heads : 1. Preliminary Researches and General Considerations regard- ing Coal, and other combustibles. % Chemical Examination of Mineral Coal in general. 3. Application of the foregoing principles to the Coal-mines of England, France and Germany. 4. Observations on the Theory of the Formation of Coal. 1. Preliminary Researches and General Considerations regard- ing Coal and other Combustibles. Some naturahsts have asserted, that coal constitutes a true rock formation, or original deposite, and therefore not deriving its origin from vegetables or any other organic matter. A more accurate knowledge of the nature of organic combinations, an advantage which we owe to the progress of chemical sciences, does not permit us any longer to consider coal as a combination of carbon with bitumen. The transition of vegetable wood to the mineral which is called Bituminous Wood, or more properly Fossil Wood^ is so manifest, that, in many cases, one might think he could determine with certainty the species of wood which gave rise to the existence of the mineral ; but the more complete the alteration of the vege- table fibres has become, the less striking do the passages of the one substance into the other appear, and the more difficult to recognise. The fossil wood of Iceland, known under the name of Surturbrand, has scarcely any resemblance to wood, at least in cabinet specimens. This substance appears to be a fibrous brown coal or lignite * ; and frequently brown coal is distin- guishable from true or black coal only, because it is surrounded by brown coal less completely altered. By the denomination pitch- coal or jet, is sometimes designated a true coal, sometimes brown coal ; and the columnar coal (stangenkohle) of Mount Meissner, in Hesse, is introduced .into all the systems of mine- ralogy as a true or black coal, although it is nothing else than a brown coal altered by the action of basalt. Brown coal has no- Vide Jameson's System of Mineralogy, and Manuel of Mineralogy. 282 M. Karsten's Observations and where yet been found in a natural deposit of true or black coal, any more than true or black coal has been found in a deposite of brown coal. The transition of black coal to glance coal or anthracite, is not less insensible than that of brown coal to black coal. True glance coal, as well as graphite, is a formation of rare occur- rence ; and, it would be difficult to point out any instances of their being associated with black coal. Yet this could never be a reason for rejecting^ as improbable, the idea that glance coal and graphite may have arisen from the alteration of vegetable fibres, if there be nothing in the intimate nature of these bodies contrary to such an idea. In unaltered vegetable fibres, the quantity of carbon is less, while the proportion of oxygen and hydrogen is greater, than in vegetable fibres that have undergone alteration. It is from a necessary consequence of this fact that the former, when put in contact with other bodies in a heated furnace, are so differently affected by them from the latter. The greater the alteration the fibres have experienced, the more apparent does the difference become ; in other terms, this difference keeps pace with the in- crease of the relation which the quantity of carbon has to the quantity of the other constituent parts. In glance coal and graphite, this relation appears to have obtained its maximum ; and these two substances, or at least the latter, are regarded as a carbon entirely deprived of oxygen and hydrogen. According to the ideas generally admitted, graphite is a car- bon, and its difference of chemical character from carbon is ex- plained by considering it as a chemical combination of ninety-five parts of carbon with five parts of iron, whence result 100 parts of graphite or percarburet of iron. As to the difference be- tween glance coal and pure carbon, this is less obvious. It ap- pears, in reality^ that it is a difficult problem in chemistry, to explain the difference which exists between diamond, graphite,, glance coal, and pure charcoal. Peat, brown coal, and black coal, submitted to distillation in the dry way, almost always afford more or less distinct traces of ammonia. Such a result is not obtained from the distillation of unaltered vegetable fibre. Thus, azote appears to present itself as a new constituent part of altered vegetable fibre. However, Ea^periments on the different kinds of Coal. ^8S tlie proportion of azote is so small, in all the varieties of l)rowa coal and black coal that have been submitted to examination by Mr Karsten, that this substance does not appear to be an essen- tial constituent part of them. Several brown coals and black coals yield an acid liquor by distillation; but most kindsof black coal furnish none. Peat, in the dry distillation, furnishes so great a quantity of acid water, that it is difficult to recognise clearly in that substance the ammoniacal basis which occurs in it, and this even on saturating the acid with potash. Mr Karsten has carefully investigated and described the very different effects which are produced, whether on wood, and, in general, on unaltered vegetable fibre, or on altered vegetable fi- bres, on peat, brown coal, and black coal, by the different che- mical re-agents, such as water, alcohol, sulphuric ether, caustic ammonia, hydrosulphuret of ammonia, nitric acid, and concen- trated sulphuric acid. In his work we even find detailed ac- counts of the processes followed in these investigations. We shall confine ourselves, however, to the principal results. Those which are obtained on making the acids act upon vegetable fi- bres, whether altered or recent, are perfectly in accordance with the manner in which acids comport themselves, and the circum- stances of the body upon which they act. Nitric acid, which is easily decomposed, and, from this very circumstance, capable of oxidising, produces more promptly, and in a higher degree, the oxidation of vegetable fibres. This acid changes them into a substance analogous to tannin, or even into an acid, while sul- phuric acid can only operate a conversion of the fibres into gum, and finally into sugar. Unaltered fibre undergoes its metamor- phoses more quickly and more completely, because the greater proportion of the quantity of oxygen and hydrogen to the quan- tity of carbon facilitates the action of acids. In proportion as the quantity pf carbon increases, the chemi- cal effect of acids becomes more and more feeble, and perfectly pure charcoal appears no longer susceptible of alteration from acids, excepting in a single case, which happens when this sub- stance occurs, as it does in wood-charcoal, in a loose state of mechanical aggregation. Glance coal, graphite and diamond resist the action of acids ; 284 M. Karstcn's Observations and and this perhaps solely on account of thck great density. Dia- mond, which is the densest kind of charcoal known, only burns at a very high temperature, and by means of pure oxygen. Glance coal and graphite are incomparably more easy to be de- stroyed ; and the charcoal which is obtained on distilling black coal, brown coal, and unaltered vegetable fibres in the dry way, burns the more readily the looser the state of aggregation it assumes during the process of carbonization, or the less the quantity of carbon the body contains which has been employed for producing the charcoal. A coal that is carbonised in a furnace, or still better in a close vessel, affords a charcoal much more compact and more difficult to be burnt, than that which comes from the same coal carbonised in the open air. Elevation of temperature causes a decomposition of the com- bustible, and the formation of new combinations. This process has received the name of carbonization, because in this opera- tion the residuum consists of pure charcoal. If hydrogen, oxy- gen and carbon, on being subjected to different degrees of tem- peratvire, also obey different laws of combination, the quantity of pure charcoal which remains after the carbonization, must depend, not only upon the state of the. body which is to be car- bonised, but also upon the different degrees of temperature which have been employed during this operation. This is actually what takes places. Several resins and fats, which contain much more carbon than vegetable fibres, leave no trace of charcoal in their spontaneous decomposition at a high temperature ; and in the same vegetable fibre, the quantity of charcoal residuum de- pends entirely upon the degree of heat employed during the car- bonization. It is not the quantity of the carbonaceous residuum alone that must vary according to the different degrees of the temperature employed. The same cause must render more variable still the quantity and condition of the other combinations which are formed during distillation in the dry way, that is to say, during carbonization. This is the case precisely, because the quantity of the charcoal residuum is but a consequence oi* the nature and condition of the gaseous combinations and fluids, or vapours, which are formed during the operation. This difference in the manner in which organic combinations are affected under the Experiments on the different Kinds of'Coal. 285 different degrees of a high temperature, is of some importance, even in an economical point of view. From the same oil may be obtained for lighting, either a larger quantity of gas of bad quality, or a smaller quantity of incomparably better gas, ac- cording as the carbonization is effected by means of a weaker or stronger heat. If the principal object of the operation were to obtain char- coal, it would be necessary to employ at first as low a heat as possible, and not to make it rise till near the end, in order to lose only the smallest possible quantity of charcoal in the gase- ous combinations and fluids which are formed. This also shews that the products of dry distillation, with reference to the same organic body, must present differences as well of quantity as of kind, according as the temperatures employed have been diffe- rent. This is a circumstance which, in a great number of cases, would require to be more taken into consideration than it has hitherto been. It is known that the products of the distillation of unaltered and perfectly dry vegetable fibres in the air, are an empyreu ma- tic acid, water, oil, a very small quantity of alcoholic substance, and a gaseous mixture, consisting of carbonic acid gas, carbonic oxide gas, carburetted hydrogen gas, and olefiant gas. The mutual relation of all these combinations, and the quantity of carbonaceous residuum, depend upon the temperature. If shavings of wood be exposed for a long time to a tempera- ture which does not rise above 120° of Reaumur, a period ar- rives when there is no longer observed any change of weight. In this operation, wood dried at the temperature of the air, but not at the temperature of boiling water, loses from QQ to 69 per cent, of its weight. Dried at the latter temperature, the wood would lose at the most from 5Q to 59- Thus the residuum, which perfectly resembles common wood-charcoal, only that it presents a somewhat duller aspect, weighs from 41 to 44 per cent, of the real quantity of wood which has been employed, al- lowance being made for moisture. This carbonaceous substance is what M. de Rumford has named the frame-work, or skeleton, of plants. That philosopher considered it as a pure charcoal, which he imagined to exist in equal quantity in all plants. But M. Karstcn concludes, from his own researches, that the pre-. 286 M. Karsten's Observations and tended skeleton of plants is only an imperfectly decomposed ve- getable fibre, and that it is not at all a pure charcoal. In reality, says M. Karsten, vegetable fibres, after the dis- union of their elements, preserve the external form of undecom- posed fibres, and they experience no other change in their form than a diminution of size ; but it is a consequence of the fact which has been mentioned ; it is because the disvmionof the ele- ments of these vegetable fibres, at a temperature of about 120° of Reaumur, cannot be carried beyond a loss of weight which varies from 66 to 69 per cent. There results from this, that, if the temperature be raised above that point, then a new loss o'f weight commences, which, in its turn, remains constant for the new degree, until, at length, at the temperature of incandes- cence, the disunion of the elements of these fibres is completely effected ; and after this no diminution of weight takes place. The products of this slow decomposition are very different from those which are obtained by a decomposition effected by a rapidly increased heat. Wood of hornbeam (Carpinus hetur- lus), which, under a rapid carbonization, yields the ordinary products of distilled wood, and furnishes 13.3 per cent, of char- coal, developes, under a slow elevation of tlie temperature, much more water, carburetted hydrogen gas, and carbonic acid gas. It then furnishes 26.1 per cent, of charcoal, that is to say, nearly twice as much as in the case of a rapid carbonization. The decomposition of unaltered vegetable fibres commences, therefore, at a pretty low temperature ; and the reason of this is, that, in' wood-fibres, the quantity of oxygen and hydrogen, as is known by the analyses of MM. Gay Lussac and The- nard, occurs pretty nearly in the relation necessary for the for- mation of water. The charcoal obtained from vegetable fibre by means of dry distillation, or by carbonization, appears to vary but little in our common woods. In a synoptical table, the author presents the results of experiments upon twenty-one kinds of unaltered ve- getable fibres, such as oak, beech, hornbeam, birch, pine, lime, straw, fern, reed, and a piece of birch- wood which had served as a prop in a mine for an Imndred years, but was still in good preservation. In all these trials, the matter was employed in the state of shavings, which had been perfectly dried in the open Experiments on the different Kinds of Coal. 287 air, at a temperature of from 12^ to 15° of Reaumur. The same species of matter was, on the one hand, submitted to a very ra- pid carbonization, for which, from the commencement of the distillation, an incandescent heat was employed ; and, on the other hand, to a temperature which was made to rise very slow- ly to this point. The contents in ashes were carefully deter- mined, by means of the incineration of charcoal under the muf- fle of an assay furnace. The weight of the ashes is deducted from that of the charcoal in the following table. Quantities obtained from | Wood «!T1 RMTTTTTJ TO T A TltlOTCT Z AT Tr» V. 100 PARTS OF WOOD. o u JD AfA XX xxjx/ X yj \^^^xvxjv/i.^x.eijlLXXVi.^. By rapid carbo- By sloiv cafbo- 1 nization. nization. 1 Chaxcoal. Ashes, Charcoal. Ashes. Young oak, 16.39- 0.15 25.45 0.15 Old oak, ... - 15.80 0.11 25.60 0.11 Young beech, Fagus sylvatica., 14.50 0.375 25.50 0.375 Old beech, 13.75 0.4 25.75 0.4 Young hornbeam, Carpinus betuius^ 12.80 0.32 24.90 0.32 Old hornbeam, 13.30 0.35 26.10 0.35 Young alder, Old alder, 14.10 0.35 25.30 0.35 14.90 0.40 25.25 0.40 Young birch, ... 12.80 0.25 24.80 0.25 Old birch, - . > - 11.90 0.30 24.40 0.30 Yoimg pine, Pinus picea, 14.10 0.15 25.10 0.15 Old pine, ... 13.90 0.15 24.85 0.15 Young Norwegian pine, Pinus abies. 16.00 0.225 27-50 0.225 Old Norwegian pine, 15.10 0.25 24.50 0.25 Young Scotch fir, Pinus syhestris., 15.40 0.12 25.95 0.12 Old fir, .... 13.60 0.15 25.80 0.15 Lime, .... 12.90 0.40 24.20 0.40 E-je straw, 13.10 0.30 24.30 0.30 Fern, .... 14.25 2.75 25.20 2.75 Reed, ... - 12.95 1.70 24.75 1.70 Old birch*. - - - ' 12.15 25.10 It is sufficient to cast a glance upon this table to observe a general result, which is as follows: — Whatever difference the vegetable fibres of graminea?, ferns, and different species of wood, present to the eye, these matters all afford nearly equal quanti- ties of charcoal by dry distillation. The differences which are observed here and there, may arise from the impossibility of * Instead of Old Birch, say Birch-wood, which, for upwards of 100 years, had been used as a support in a mine, and was still in good preserva- tion. M. Karstcn's Observations and constantly keeping the sand-bath at the same degree of tempera- ture. It was in the rapid carbonization that the results differed most from each other, because, in this case, it is still more diffi- cult to regulate the temperature. The quantity of charcoal ob- tained by means of the rapid carbonization varies, for 100 parts of the matter employed, between 1 1 .90 (the produce of old oak), and 16 39 (that of young oak) ; but, in the slow carbonization, the quantity of charcoal obtained is nearly double, or at the least one-half more. It varies from 24.20 (the produce of lime-wood), to 27.50 (the produce of young Norwegian spruce). In both modes of carbonization, the quantity of ashes remains the same : it varies, in general, from 2.75 (the produce of fern) to 0.11 (the produce of old oak wood) ; but, in most cases, it is below 0.4. Like unaltered vegetable fibre, fossil wood, on being carbo- nised, retains its external form completely, and only undergoes a diminution of size. This preservation of the external form after carbonization, that is to say, after a complete decomposition, is a phenomenon without example in inorganic nature, and one ex- clusively peculiar to unaltered vegetable fibre, fossil wood, brown coal, and some sorts of black coal. Other kinds of coal, i-n the process of decomposition by an ardent heat, lose more or less their form ; and, by the difference which they thus exhibit, they already afford an indication beforehand of what their composition must be. It may be -without rashness asserted, that fossil wood and lig- nite, or brown coal, are still at the present day, so to speak, in a train of developement. This is proved by the frequent oc- currence, in brown coal mines, of pieces of coml-ustible, which present an evident transition from fossil wood to brown coal,— one extremity of the specimen being fossil wood, the other brown coal. With regard to black coal, there is not equal reason for supposing that the formation of that combustible is still going on, or that a change of relation in its elements still continues to be effected, although this is not improbable. From the frequent variations which fossil wood presents in its passages into brown coal or lignite, it might already be expect- ed not to afford, as the residuum of its carbonization, a constant quantity of charcoal, as was seen to be the case with regard to Experiments on the different Kinds of Coal 289 unaltered vegetable fibre. According as fossil wood approaches more or less to the nature of brown coal, it furnishes a greater or less quantity of charcoal ; but, in the carbonization of fossil wood, as well as in that of brown coal, the quantity and kind of the products formed depend upon the degree of the temperature, although, in the species which come nearest to brown coal, the limits are already much more restricted. In general, fossil wood, submitted to distillation in the dry way, affords the same quantities of gas as the fibre of unaltered wood ; but it yields less water, and still less of that oil, of a peculiar and disagreeable smell, by which all the brown coals are instantly recognised. The empyreumatic acid is then only formed in very small quan- tity ; but, on the other hand, the formation of alcohol is much more considerable than in the case of unaltered vegetable fibre. Those lignites or brown coals, which, from their external cha- racters, visibly present a passage into black coal, afford in the dry distillation water, with a very small quantity of fetid oil, and often furnish so much as 70 per cent, of pure charcoal. Thus, therefore, says M. Karsten, those brown coals, the com- mon BraunTcohle of Werner, from which the MoorhoJile of the same mineralogist does not differ, in distillation surpass a great many black coals, as to the quantity of charcoal obtained from them. Add to this, that the specific gravity of these brown coals rises to 1.2881, and is consequently higher than that of several varieties of black coal, which cannot be attributed to the quantity of earthy matter and oxide of iron, since these brown coals fre- quently do not contain one per cent, of them. The quantity of ashes afforded by fossil wood and brown coal is very variable. In the species submitted to examination by M. Karsten, it varies from three-fourths to more than fifty per cent., which latter is the case with earthy brown coal. This produces a serious inconvenience in the employment of these combustibles ; for the ashes, by resting upon the substance which is burning, oppose combustion to such a de- gree, that a stronger current of air must be employed, than the proper nature of the combustible, without this circumstance, would require. Hence the great difficulty of employing this substance advantageously for the purpose in view. The ashes of fossil wood and brown coal contain no traces of fixed alkali. Silica, alumina, oxide of iron, sulphate of lime, a little lime 290 M . Karsteirs Observations and and magnesia, are the substances which are found in the resi- dua of the combustion of fossil wood and brown coal. They present themselves in very different and very variable propor- tions, which depend upon the local circumstances under the in- fluence of which the deposition of matter has been effected in the natural beds of these combustibles. In black coal, the quantity of charcoal which may be obtain- ed, by means of distillation in the dry v^'ay, varies still more than in the different sorts of brown coal, comprising also fossil wood. M. Karsten has not met with any black coal, which, on being distilled, has furnished less than 48 per cent, of charcoal. From this number, the quantity of residuum in charcoal rises to 90 per cent. Between these two limits there is scarcely a number to be found that would not answer for the produce in charcoal, or coke, of some kind of coal. Striking differences, however, are remarked in the external form of the carbonized coals called cokes. In some the form of the coal remains unchanged, the volume only being diminished, as in charcoal from fresh vegetable fibre, fossil wood, and brown coal. Others remain unchanged in form and volume, while some swell and expand more or less. In or- der to observe correctly these different relations, it is necessary to use the coal we intend submitting to dry distillation in the state of powder. Coal of the first kind affords a coke in a dus- ty pulverulent state, without the least cohesion, just as in brown coal. In coal of the second kind, the powder is conglutinated into a cake, often very solid and tough, but without any swel- ling or intumescence. The fine powder, in coal of the third kind, melts, and forms a homogeneous mass, which takes the form of the retort in which it is distilled, and frequently swells so much as to choke up the retort. Here the author divides coals into three classes, which he es- tablishes from the external appearance of the charcoals or cokes which are produced by them. For the object which he proposes to himself, M. Karsten distinguishes, 1*^, The coals with pulverulent coke, (Sand KoJden) ; 9.dly, Those with conglutinated coke, (Sinter Kohlen) ; and, ^dly^ Those with an intumesced coke, (Bade Kohlen). Experiments on the different Kinds of Coal. 291 These three denominations sufficiently indicate the aspect and mode of existence of each of the three sorts of coke, as well as the transition which may take place from one kind to the other. In all these kinds of coal, as in unaltered vegetable fibres, the quantity of charcoal obtained, differs according as a slow or quick heat is employed during distillation. In general, this dif- ference of product is so much the greater, that the coals contain less charcoal. The coals with intumesced coke, however, form an exception. These often, with a greater quantity of charcoal, present greater differences of product in the two modes of car- bonization, than with a less quantity of charcoal the coals with pulverulent coke do, and especially than those with conglutinated' coke. At the most, these differences of product, in all the va- rieties of coal examined by M. Karsten, do not exceed 6 per cent., and even this maximum of difference was only observed in a coal with an intumesced coke, which presented a mean quan- tity of charcoal. The produce in coke of coals of this class, when they possess a greater quantity of charcoal, does not vary more than 4 per cent, in the two modes of carbonization. Another remarkable fact is, that the application of a low heat, raised very slowly to the strongest red heat, diminished in coals the property of furnishing either a conglutinated or an in- tumesced coke. A coal which, on being subjected to a rapid incandescence, announces itself as belonging to the second class (coal with conglutinated coke), may, by means of a heat raised very slowly, present the aspect of a coal of the first class (that with pulverulent coke). It is chiefly in the transitions from the one to the other class, that this fact is observed. In like man- ner, by means of a slow heat, a coal of the third class presents the aspect of the second, and especially if the coal in question possesses only in a feeble degree the property of furnishing an intumesced coke. In every case, if the heat be produced but slowly, the swelling of the coals with vesicular coke is diminish- ed. They then form a less loose, less bulky, and less light mass, than if an ardent heat had been rapidly applied. A distinction between the coals which swell, and those which do not, has long been established in the arts, because these two kinds of combustibles act very differently. Manufacturers have readilv observed the «:reat influence which the manner that dif- 292 M. Karsten's Observations and ferent kinds of coal have in comporting themselves, exercises over their use. They have remarked, that the coals which swell cannot always be substituted by those which do not, and the reverse. But, between the one and the other, common opinion establishes no other difference than the following : — The coals, it is said, which swell, are only distinguished by a greater quan- tity of constituent parts, which are not carbonaceous, parts which have been designated by the name of Bitumen ; in other words, it is the quantity of charcoal which decides Whether a coal possesses the property of swelling or not. This opinion is incorrect ; and, so far from this being the case, it is most commonly observed, that the quantity of charcoal is greater in those coals whichf swell, than in others. There are coals of the first and second classes (with pulverulent and con- glutinated coke), which, on being carbonised, do not yield more than about 50 per cent, of coke, and very few coals of the third class (with intumesced coke) yield so little. On the contrary, a great number of these coals with intumesced coke, furnish up- wards of 80 per cent-^ of a very loose and swollen coke. Such a coal cannot contain so many constituent parts, which are not charcoal, as a coal with pulverulent or conglutinated coke, from which there is only obtained about 50 per cent, of coke. The products of the distillation of coal in the dry way are well known. The greater the quantity of charcoal, the thicker is the consistence of the oil which is formed. All the varieties of coal, without exception, on being subjected to dry distillation, give feeble traces of ammonia. The coals with pulverulent coke, when they have a small proportion of charcoal, present traces of an acid. In all the varieties of coal belonging to this first class, the proportion which the aqueous fluid bears to the oily fluid, is greater than in those of the second class ; and, in these latter, the proportion is greater than in the coals of the third class (those with intumesced coke). The quantity of gaseous substances, and of fluids or vapours which is formed, is in the inverse ratio of the contents in charcoal. A smaller quantity of gas is disengaged by the varieties of black coal, than by most of the brown coals ; but, in the former, the combinations of carburetted hydrogen are more predominant. Sulphuretted hydrogen gas is only formed when the coal is mixed with iron pyrites, which it Experiments on the different Mnds of Coal. 293 very generally is. The more capable the coal is of swelling (the third class), the more does the proportion of oil gas increase in the gaseous mixture. It is only in those coals of the first and second classes in which the quantity of charcoal is small, that a decomposition of the combustible is effected before it has experienced a red heat ; and even in these coals the decomposition does not make a marked progress at a low temperature. The oily substance never begins to be developed until the heat has attained the degree of deep red. To all the coals of the two first classes, as well as those of the third, which contain inuch carbon, a low red heat must be applied to begin the de- composition, and a very strong red heat to terminate it. All the varieties of coal, besides oil and gas, also disengage water, on being distilled in the dry way. In the ordinary trials of coals, the object of which is to deter- mine the quantity and kind of coke or charcoal which they are capable of furnishing by dry distillation, the coals are usually employed in a state of desiccation in the air. This method is sufficient for common purposes ; but it does not answer for che- mical analysis, properly so called . In this latter case, M. Kar- sten found it necessary to dry, at the temperature of boihng water, the various combustibles which he intended to analyse chemically, with the view of comparing the results of the analy- sis, with the effects which the same coals produce on being sub- mitted to dry distillation. The author had at first presumed, that all varieties of coal, taken in their ordinary state of desiccation in the air, and such as they are employed for carbonisation, would not undergo a great loss of weight at any temperature below that of boiling water ; or that, at least, this loss of weight would ,be nearly equal in all. But in order to attain his object, he found him- self obliged to enquire what loss of weight coals experience from desiccation, at the temperature of boiling water. Hence a series of comparative trials which M. Karsten also extended to some other substances. All these matters reduced to powder, were first exposed dur- ing five days, under the same circumstances, to a temperature of from 11 to 12 degrees of Reaumur's thermometer. When they JANUARY MARCH 1827. TJ «sr4 M. Karsten's Observations and were ail thus reduced to the same degree of desiccation, an equal quantity of each of them was weighed, and then dried at the temperature of boiling water ; the matter, while still warm, was afterwards weighed a second time, and the difference of weight ascertained. At this high temperature, no decomposi- tion of the bodies under trial had taken place, as was proved by all these substances resuming their original weight, after being exposed to the air for 36 hours. The following table shews the weight, after desiccation, at the temperature of boiling water, of several substances experiment- ed upon, viz : — Substances submitted to Desiccation at the Tem- perature of Boiling Water, their original Weight being represented by 100. Weight retain- ed after Dessic- cation. Sharings of common hornbeam, Wood charcoal, -- Fossil wood, passing into brown coal, of the country of Aix-la-Chapelle, - - - - - - Columnar coal (stangenkohle) of Mount Meissner in Hesse, - - ■<■ Brown coal of Uttweiler, right bank of the Rhine, - Mineral charcoal (faserkohle)from Ibbenbuhren m Prussia, (Westphalia), ..------ Fibrous brown coal (surterbrand) of Iceland, - - - Compact coal (kennelkohle) of Lancashire, with highly intumesced coke, ._----- The same, with slight intumesced coke, - - - The same, with pulverulent coke, - « - - - Newcastle coal, with intumesced coke, - . - - Mons coal (low countries) with conglutinated coke. Coal of the country of Essen and Werden,.with intumesced coke, ..------- The same, with conglutinated coke, . - - - The same, with pulverulent coke, . . - - Coal of Upper Silesia, with pulverulent coke. The same, with pulverulent coke, . - - . Coal of the Canton of Bardenburg, country of Aix-la-Cha- pelle, with pulverulent coke, Coal of Sulzbach, near Dultweiler, with intumesced coke, Coal of the country of Saarbruck, with conglutinated coke, 90.7 91.6 80.2 97.2 95.05 99.1 86.95 98.4 97.6 94.4 98.7 99.3 98.75 99.05 99.3 91.15 87.3 98.2 98. 94. Experiments on the different kinds of Coal. 295 (Table continued.) Substances submitted to Desiccation at the Tem- perature of Boiling Water, their original Weight being represented by 100. Weight retain, ed after Desic- cation. Coal of Loebejun, in the circle of the Saale in Prussia, with pulverulent coke, .------ Piciform coal of Planitz, kingdom of Saxony, with con- glutinated coke, - - - - - - Coal of Pottschapel, near Dresden, with intumesced coke, Glance coal of the country of Tecklenburg, Lingen, Glance coal (glanzkohle) pretended anthracite of Schonfeld in Saxony, with pulverulent coke, - - . . Glance coal of Lischwitz, near Jena, in Saxony, - Conchoidal anthracite of Rhode Island, United States, - Pretended anthracite of La Motte, department of the Isere, with pulverulent coke, - - . - - Coal of the country of Waldenburg, Lower Silesia, with intumesced coke, ..-.,--- Coal from Westphalia, with pulverulent coke. Coal from Brazil, with pulverulent coke, . - - Coal from Upper Silesia, with pulverulent coke. Another variety of the same, with pulverulent coke. Coal of the country of Waldenburg, passing from coal with vesicular coke, to coal with intumesced coke. Coal of Upper Silesia, with intumesced coke. Coal of the country of Waldenburg, with pulverulent coke, --.---- -- Coal of Upper Silesia, with conglutin^ted coke. Coal of the neighbourhood of Beuthen, Upper Silesia, with pulverulent coke, Coal of the country of Saarbruck, with intumesced coke. Coal of Eschweiler, country of Aix-la-Chapelle, with in- tumesced coke, >-----«- Coal of Eschweiler, another bed, with intumesced coke, - Coal of Wellesweiler, country of Saarbruck, with intu- mesced coke, -.---.-- Coal of the country of Waldenburg, Lower Silesia, with intumesced coke, .-,---- Intumesced coke, -------- Conglutinated coke, Pulverulent coke, ..-.--- Graphite, or plumbago, from Borrowdale, - - - Sugar, --- -- Saltpetre (nitrate of potash) ------ Sulphate of potash, ^ 99. 94.3 94.4 98.3 95.95 94.8 94.9 95.5 97.8 99. 89.4 93.2 97.1 98.5 97.1 96.4 95.9 93.1 95.1 99.1 99.1 97.85 97.8 95.55 95.6 95.5 100. 100. 100. 100. 296 M. Karsten's Observations on Coal The loss of weight indicated by this table, whatever differ- ences it may present, does not appear to have any relation to the properties of the varieties of coal, and in general of the mat- ters subjected to experiment. The greatest loss was experienced by the fossil wood and by the coal with conglutinated coke hav- ing but a small proportion of charcoal. The former substance losses 19.8, and the latter 6 per cent. The more the quantity of charcoal increases, the smaller does the loss of weight be- come. M. Karsten, however, was surprised to see that a coal analogous to anthracite, and anthracite itself, experienced a con- siderable loss (from 5 to 6 per cent.), which would not have been presumed from their hardness and semimetallic lustre. In general, the lightness, that is to say the porous and loose state of a body, does not appear to have any influence upon this loss of weight, or at least it does not always exert an influence upon it ; for if it did so, mineral charcoal, which, of all the substances submitted to trial, is the lightest and loos- est, perhaps, without excepting even wood charcoal, would have experienced the greatest loss. The charcoal of mineral wood, however, does not lose more than 1, while the hard and shining anthracite of Rhode Island loses upwards of 5 per cent. On the other hand, graphite, rendered very loose by bruising and pulverization, preserves its weight unaltered. Are the loss of weight which charcoals experience, and their subsequent in- crease on exposure to the atmosphere, owing to the emission and absorption of atmospheric air and humidity, or of humidi- ty only ? The author has not entered upon this inquiry ; but he thinks, that, with the view of ekicidating the cause of the dif- ferences which are observed in the manner in which mineral combustibles comport themselves, it would be interesting to try them thus at the moment of their being taken from the mine, and particularly those which in the open air increase consider- ably in weight. With regard to such coals as experience a very considerable diminution of weight, on being dried at the tem- perature of boiling water, their produce in coke by carboniza- tion ought to be very small, and not to agree with the results of chemical analysis, if, as is commonly done, coals dried in the air be employed in the carbonization, and in the chemical ana- lysis, coals dried at the temperature of boiling water. (To be contimied.) ( 297 ) Considerations regarding the shining of the Eyes of the Cat, and several other Animals. By M. Benedict Prevost. Hi VERY body knows that the eyes of the cat shine in the dark. Our domestic cats afford us so frequent opportunities of observ- ing this phenomenon, that it seems peculiar to them ; but there are several other animals which equally present it, and I have seen it in the dog, the sheep, the cow, the horse, the polecat, and even in several serpents, and in some insects, among others in the species of sphynx commonly known by the name of the Death's-head Moth. Buffon says that " the eyes of the cat shine in the dark some« what like diamonds, which throw out, during the night, the light with which they were in a manner impregnated during the day."" Valmont de Bomare says, that " the pupil of the cat is during the night still deeply imbued with the light of the day," and some lines lower he adds, " the eyes of the cat are during the night so imbued with light, that they then appear very shin- ing and luminous."*' Spallanzani says that " the eyes of cats, polecats, and several other animals, shine in the dark like two small tapers, and that this light is phosphoric." M. Dessaignes, in his memoir on phosphorescence, which was crowned by the Institute on the 5th April 1809, says that " the eyes of certain animals have the faculty of inflaming, and of appearing like a fire in the dark. Thus the most eminent naturalists and philosophers are of one mind with the vulgar in regard to this fact, that the eyes of cats and some other animals shine in the ^dark with a light which is peculiar to them, or with which they have been impreg- nated during the day. I myself, also, was long in the habit of acquiescing in this opinion, taking the matter partly upon the authority of others, and partly observing the phenomenon for myself in the vague way in which every person sometimes ob- serves things, and men of science as well as others ; which would not, however, be productive of great inconveniences, were not more importance attached to the citing such observations than to the making them. " Every body," says Montaigne, " is sub- ject to say foolish things ; the misfortune is to say them curi- ously." ^8 M. Prevost on the shining of' the Eyes of the Cat, I am quite certain, that neither BufFon, nor Spallanzani, nor M. Dessaignes, ever observed on purpose the shining of the eyes of the cat, and that they never saw this phenomenon otherwise than cursorily, as one sees when he does not attend to a thing, or when one only partially attends to it ; otherwise, they would immediately have perceived that the eyes of cats never shine in intense darkness, and that it is sufficient for them to shine, that too great a light does not prevent the pupil of the animal from dilating much ; that, in reality, the phenomenon is only sensible . to the observer, when his eye receives httle light from surround- ing objects. The case, then, is the same with the eye which shines, as with the light which the pictures of a panorama reflect, and which appears to have all the intensity of that of the objects which they represent, although much inferior to it. The less light the eye of the observer receives, the more is it sen- sible to that which the eye of the cat projects, and the less need has the latter of receiving any ; it must receive more to produce an equal effect, if the former be situated in a lighter place. These are the conditions of the phenomenon. They appear to me to reduce this pretended phosphorescence to light reflected by a shining object. I shall give two examples, which I select Jrom among the best adapted to render me understood. 1st, Ib a long and narrow passage, closed on all sides except- ing the entrance, from which, during a very dark night, there could come but little light, I saw the eyes of a cat shine. They projected strongly upon the dark ground of a sort of deep nich, which made them appear like burning coals. The light which the eyes of the cat then received, and that which they sent back to me, was without doubt very weak ; but to balance this, mine not being affected by any other light, would necessarily be very sensible to it. It was from a similar reason, that I once thought I saw from my bed something which shone like a star of second or third magnitude. It was nothing, however, but the back of a chair not very well smoothed, which reflected some rays of the moon ; but having at the time my head almost entirely enve- loped in my covering, and my eyes receiving no other light, these rays produced so much the more effect upon my retina, that they arrived the more isolated at it. and of several other Animals. 299 ^, In the other example which I have to adduce, the cir- cumstances were in some measure the reverse. It was in a room where the sun shone, but the head of the cat was turned to- ward one of the corners, and I Jook€d at it myself in such a man- ner as not to receive either the direct rays of the sun, or the light directly reflected. Here the eye of the animal received much more light than in the other example, and transmitted more to me, but my eyes receiving more light from another di- rection, and being on this account less sensible to it, the eyes of the cat did not appear so shining. Valmont de Bomare, in the article Chat of his Dictionary, (the edition in 15 vols.), says, after what we have already quoted, " it seems that the lustre, the splendour, which is observed in the day time in the eyes of the cat, comes from the shining part of the retina, at the place where it surrounds the optic nerve." This does not agree very well with what precedes ; for in full day-light the retina of the cat is not visible, and if he means to speak of the lustre that is visible in a weak light, it is certainly of the same nature as that which is observed in darkness, and which Valmont de Bomare attributes to the imbibing of the light of day. Nor does this author speak here from his own observa- tion : what he says of the eyes of the cat is taken almost word for word from Buffon''s works, and from the first edition of the Encyclopedic. We also find in the Geneva edition of 39 vols. 4to, article Chat^ the following words : " It appears that the lustre, the shining, the splendour, which are observed in the eyes of the cat, come from a sort of velvet, which lines the bot- tom of the eye, or from the shining of the retina at the place where it surrounds the optic nerve.'" The phenomenon can be imitated with all its peculiarities, by placing bits of tinsel under suitable circumstances, or by other similar means. It is not therefore necessary to have recourse to phosphorescence for an explanation of it. It is certain enough, that a great number of substances become luminous in the dark, after having been exposed some moments to the light of the sun, or only to the ordinary day-light, or to the light of a lamp, or of the moon. But it is not probable that tlie eyes of the cat are of this class ; for, like those of other animals, they are filled with various humours ; and there results from M. 300 M. Prevost on the shining of the Eyes of the Cat, Dessaigne"*s experiments, that neither the fluids nor the sub- stances which have imbibed them manifest this property. Besides, as I have already insinuated, the eyes of the cat do not shine either in absolute darkness, or even in a very intense although imperfect darkness. A certain degree of light is al- ways requisite, which may indeed be very feeble, but still quite perceptible. I have kept myself several times, thirty or forty minutes together, in dark places with cats, which mewed to each other, or devoured their prey in their usual grumbling manner, yet without their eyes manifesting any luminousness. I have caressed, provoked, tickled, pinched and frightened in the dark a very good natured cat, which has bitten and scratched me in frolic or in anger, but without its eyes having ever shone. Yet some instant before or after, the eyes of all these cats shone as usual, when they were suitably exposed to a certain degree of light. But what convinced me fully that the eyes which shine in the dark, owe this property only to the faculty of reflecting the light more strongly, is, that the eyes of all the animals that are susceptible of presenting this phenomenon, are evidently, and as appears to me exclusively, organized for this purpose. It is known that *' the inner layer of the choroid coat, which appears to be of a firmer texture than the rest of its thickness, and which bears the name of Ruyischian membrane, is lined in man and in several other animals, with a blackish, or even abso- lutely black and dull mucosity, which may be detached or wiped off* with the finger or a pencil, and which serves to prevent the rays reflected by the internal walls of the eye from disturbing the vision. Now, the bottom of the Ruyischian membrane is only covered with a layer of that varnish through which its colour, which varies in a singular degree according to the species, is perceived. In man, and the monkey tribe, it is brown or blackish ; in hares, rabbits, and hogs, of a chocolate brown ; but the carnivora, the ruminantia, the pachy- dermata, the solipeda, and the cetacea, have bright and shining colours in this part. The ox has it of a beautiful gold green, changing into sky blue ; the horse, the goat, the buffklo, the deer, of a silvery blue, changing into violet ; the sheep of a pale gold green, sometimes bluish ; the lion, the cat, the bear, and the dolphin, have it of a pale gold yellow ; the dog, the wolf, and of several other Animals. 301 and the badger, of a pure white, edged with blue. This colour- ed part of the Ruyischian membrane is named the Tapis. Birds have it not *.^ We see from this description, that the eyes of animals which do not shine like those of cats, have no tapis, or have it only of a dark colour. The eye of man does not shine, or only shines in a very slight degree -f-. I have often tried to ascertain whether it does, and in the most favourable circumstances have only at the most perceived an extremely feeble and doubt- ful light. I have never seen the eyes of hogs, rabbits, or hares, which have the tapis of a chocolate brown, emitting light ; while I have very frequently seen the eyes of sheep, oxen, and horses, sparkle with the most lively colours. I have often had nocturnal birds at my disposal, and have often observed them, but without ever seeing their eyes shine like those of cats ; and Spallanzani, who made numerous experiments upon these animals, and who examined them with reference to this subject, by night, by day, and during the twilight, both captive and in a state of liberty, never remarked either that their eyes were susceptible of shining in the dark, with that sort of lustre which he imagined to be phosphoric. It is true, that the tapis of the dog does not agree with the colour of the shining of its eyes ; but this colour may be modified by that of the crystalline hu- mour, or of some of the other humours of the eye. It is astonishing that M. Ciivier, after this description, does not say a word of the phenomenon of which the tapis appears to me to be the cause ; but this celebrated anatomist, whose genius knows to subject itself to the laws of a rigorous accuracy, not having probably observed it himself with sufficient care, has ra- ther chosen to say nothing, than to repeat the opinions of others respecting a subject which, at bottom, belongs much less to ana- tomy than to Natural History. M. Dessaignes not only says that the eyes of certain animals kindle and appear as if on fire in the dark ; but, according to him, they owe this faculty to the expansive effect of the lively passions with which the animal is affected. But he is certainly deceived, * Cuvier's Lejons. d'Anat* Comp. t. ii. p. 397, 402. ^ •f- This luminous property we have remarked in eyes of several individuals, principally females Ed. S02 M. Prevost on the shining of the Eyes of the Cat, or at lea^ this is subject to numerous exceptions. Besides what I have said of the cat in which I certainly excited lively passions, and whose eyes yet gave no sign of luminosity, it is easy to prove directly that the phenomenon may take place independent- ly of the passions ; for the animals whose eyes shine in the dark do not lose this property with life, and are susceptible of it even long after they are dead. I have seen two polecats that had been dead fifteen or twenty hours, whose eyes shone nearly like those of living cats. I have remarked the same thing in serpents and insects. I have also seen the eyes shine in some collared snakes which I extracted from the egg a considerable time before the period when they would naturally have come forth. There was no appearance then of their being susceptible of lively passions. It may be added that the animals whose eyes shine most, are of- ten very tranquil at the moment when the phenomenon is most striking. It was not enough to consider the shining of the eyes as phos- phoric ; it has also been pretended that it serves as a light to the animals which possess it, and that it assists them in seeing and guiding themselves in the dark. But the place which the re- flectors occupy is reasonably a matter of astonishment, for it is not the light which proceeds from the eye to an object that en- ables the eye to perceive that object, but the light which arrives in the eye from it. Spallanzani thought that cats, polecats, and tome other ani- mals, move with promptitude and certainty in a medium totally deprived of light, and this is also a subject of pretty general belief. I cannot help doubting it however. But should this really be the case, it ought not to be attributed to the shining of their eyes, since this aid, as we have seen, fails them when they have most need of it. Animals in the state of nature are never placed in such circumstances. Nor is it even probable that such an occurrence takes place in a state of domesticity. In whatever part they may happen to be, there is always a little light, and in order to see, they only require to have their pupil susceptible of great dilatation, and their retina of an extreme sensibility. It is said that a man shut up for a long time in a very dark dun- geon becomes at length able to read. The nocturnal birds which Spallanzani reared, saw very well in a place in which he and of several other animals. 303 himself could distinguish no object, and he admits that the eyes of these birds do not shine in the dark. Besides sheep, cows, horses, and several other animals which have the eyes shining, would no doubt find themselves much embarrassed in absolute darkness. If some quadrupeds, in fact, move with promptitude and security in complete darkness, it is certainly not to their eyes that they are indebted for it, but to some other sense. The bats in which Spallanzani discovered this faculty, owe it, accord- ing to him, to a sixth sense, of which we have no idea; and, accord- ing to Cuvier,* to the extent of the membrane which their wing presents to the air, and which renders it capable of feeling its resistance, motion and temperature. It is true that the animals whose eyes shine in the dark are all of the number of those whose motions the night rather favours than impedes, when its shades are not too thick, and although several others which feed, take their diversion, or provide for their subsistence, during the night, have not the eyes shining, one is yet tempted to search the cause of the agreement or con- currence of these two circumstances, which we observe so fre- quently to take place. The light does not act upon the retina by impulsion, as some physiologists seem to think ; its action, although its nature is not very well known, appears to be purely chemical ; and the sensi- bility of the eye to the light, being on this account susceptible of a sort of saturation, it was necessary, in order to let it have all the delicacy which it would require to serve the animal in pro- found darkness, either to take care that the eye should receive but very little light during the day, or that this light, at least what was superabundant, should be immediately sent off by some reflector, which would not allow it to enter into combination. If, on the contrary, it were useful for the cat, that its eye should be filled with light in the night-time, nature would take care to pre- vent it from entering the light during the day, or provide that the little which its Ruyischian membrane might receive through a contracted pupil, should be instantly thrown out. To conclude, the preceding observations seem to me sufficient- ly to prove, 1st, That the shining of the eyes of the cat and of other animals, which present the same phenomenon, does not arise from a phosphoric light, but only from a reflected light ; 304 Mr D. Don an the Rhubarb of Commerce* that, consequently, 2d, It is not by an effect of the will of the animal or by that of certain passions, that this light emanates fromgts eyes ; 6d, That this shining does not manifest itself in absolute or too profound darkness ; 4th, That it cannot enable the animal to move with security in the dark. — Biblioth. Britan- nique, T. 45. Remarks on the Rhubarb of Commerce, the Purple-coned Fir of Nepal, and the Mustard Tree. By Mr David Don, Libra- rian of the Linnean Society, Member of the Imperial Aca- demy Naturae Curiosorum, of the Wernerian Society, &c. Communicated by the Author. I 1. On the Rhubarb of Commerce, .T is well known that the plant which yields the rhubarb of commerce has been hitherto involved in much obscurity, and hence there have arisen many discordant opinions, both among botanists and pharmacologists, respecting the species of Rheum which affords this valuable medicinal root. They judged it rightly to be the produce of a species of Rheum, but of what particular species, without authentic materials it was impossible for them to decide. Linnaeus considered it at first as the produce of his Rheum rhabarbarum or undulatum, but he afterwards appears to have altered his opinion in fa- vour of Rheum palmatum ; " while Pallas, who certainly had better opportunities of gaining correct information on the sub- ject, regarded it as composed chiefly of the roots of Rheum un- dulatum and compactum. Mr Sievers, an enterprising assistant of Professor Pallas, and well known by his interesting Letters on Siberia, published in the Nordische Beytrdge, was sent by the Empress Catharine II. purposely to try to obtain the true rhubarb plant from its native country ; and although, after tra- velling for seven years in the countries adjacent to that in which it is found, he was unable to effect the object of his mission, yet he obtained sufficient information to convince him that the plant was then unknown to botanists. But it was reserved for Dr Wallich, the zealous superintendent of the Calcutta Botanic Garden, to set this long agitated question at rest, by the trans- mission of seeds and dried specimens of the true rhubarb plant Mr D. Don on the Rhubarb of Commerce* 305 to Europe. Last spring, Mr Colebrooke received a quantity of the ripe seeds from Dr Wallich, and presented a portion of them to Mr Lambert, who has been so fortunate as to raise a number of plants of this valuable vegetable. The seeds were sown in pots, and, by the aid of artificial heat, soon vegetated. The young seedlings were transplanted into separate pots filled with rich earth, and the pots were gradually changed as the plants increased in size. By this treatment, as might well be imagin- ed, the young plants grew vigorously, and, at the end of autumn, the leaves were from fifteen inches to a foot in breadth, and the footstalks nine inches long, with half an inch of diameter. The pjant, on examination, proved to be identical with my Rheum australe *, from Gosaingsthan in the Himalaya Alps. I find Dr Wallich calls it Rheum Emodi, a name which I should cer- tainly have adopted, had I been aware of it before the publica- tion of my work. The whole plant is thickly beset with nume- rous, small, bristle-shaped, cartilaginous points, which give it a rough feel. The leaves are of a dull green, and the footstalks are red and deeply furrowed. The native samples I have seen appear to be smaller in all their parts, and the leaves, although flowering specimens, frequently not more than three or four inches broad ; the footstalks four inches long, and slender, and the flowering stem not above two feet high. It is curious to ob- serve how well this description accords with what Sievers has given us. The Rheum australe appears to be peculiar to the great table lands of central Asia, between the latitudes of 31° and 40°, where it is found to flourish at an elevation of 11,000 feet above the level of the sea ; and there is little doubt, therefore, of its proving perfectly hardy in our own country. Large quan- tities of the roots are annually collected for exportation in the Chinese provinces within the lofty range of the Himalaya. The best is that which comes by way of Russia, as greater care is taken in the selection ; and on its arrival at Kiachta, within the Russian frontiers, the roots are all carefully examined, and the damaged pieces destroyed. This is the fine rhubarb of the shops, called improperly Turkey Rhubarb. We have yet to * R. australe, foliis subrotundo-cordatis obtusis planis subtus margineque scabris simi baseos dilatatis, petiolis sulcatis teretiusculis cum ramis pedun- culisque-papilloso scabris, perianthii foliolis ovali-ablongis apice crenulatis. — Don, Prod. Fl. Nepal, p. 75. 30() Mr D. Don m the Purpk-Fir of Nepal regret the want of much interesting information respecting the mode of collecting and preparing the roots, and other details in- teresting in a commercial point of view. The unfortunate fate of Mr Moorcroft, whose zeal and multifarious knowledge well fitted him for a scientific traveller, has deprived us of much valuable information on this as well as on many other subjects. 2. On the Purple-coned Fir of Nepal. Mr Lambert has raised two plants of this interesting species from seeds received from Dr Wallich, alongwith those of the rhu- barb plant above described. These are the first that have been raised in Europe ; for, although quantities of the seeds had been received from time to time, from the difficulty of transporting the seeds of coniferous trees, especially through the Tropics, all pre- vious attempts to raise this valuablefirproved unsuccessful. This, which may be regarded as the silver-fir of Nepal, surpasses all others of the fir tribe in beauty. Its lofty and pyramidal form ; its numerous long, erect, cylindrical, purple cones, studded with drops of pellucid resin ; and its flat leaves, silvery underneath, and of a bright shining green above, which thickly adorn its ash-coloured branches, render it a truly picturesque object. The trunk is from 70 to 80 feet high, perfectly straight, covered with a smoothish grey bark, and having a circumference of 7 or 8 cubits. The wood is light, compact, and of a rose-colour, re- sembling in grain and colour the pencil cedar, Juniperus Ber- mudiana. Its cones afford by expression a purple dye. The resin, especially that of the seeds, is highly pungent to the taste ; and its scent is very powerful, not inferior to that of the Deo- dara. The elevation at which it is found, namely, of from 8000 to 10,000 feet above the level of the sea, induces us to hope, that it will be found capable of enduring our severest winters. A magnificent plate of this species, accompanied by a complete description, will be found in the second volume of Mr Lam- bert's monograph of the genus, under the name of Pinus spec- tabilis. 3. On the Mustard Tree. Captains Irby and Mangles, in their interesting Travels *, • Travels in Egypt and Nubia, Syria, and Asia Minor, during the years 1817 and 1818, by the Honourable Charles Leonard Irby and James Mangles, Com- manders in the Royal Navy. — Printed for private distribution^ London^ 1823. 1 vol. 8to. 4. Mr D. Don on the Mitdard Tree. S07 make mention of a tree observed by them in the vicinity of the Dead Sea, which they were led, from certain cir- cumstances, to suppose might be identical with the mustard plant of the Sacred Scriptures. As the passage is instructive, and the work itself in but few hands, I shall here, for the sake of illustration, insert the whole of it. They remark, {Letter v. p. 354«, 355.) on leaving the shores of the Dead Sea, " We now entered into a very prettily wooded country, with high rushes * and marshes ; leaving these, the variety of bushes and wild plants became very great ; some of the latter were rare, and of remarkable appearance.'" And, again, " There was one curious tree, which we observed in great plenty, and which bore a fruit in bunches resembling, in appearance, the currant, with the colour of the plum. It has a pleasant, though strong aromatic taste, exactly resembling mustard ; and, if taken in any quantity, produces a similar irritability in the nose and eyes, to that which is caused by taking mustard. The leaves of this tree have the same pungent flavour as the fruit, though not so strong. We think it probable that this is the tree our Sa- viour alluded to in the parable of the mustard seed, and not the mustard plant which we have in the north ; for, although in our journey from Byson to Adjeloun, mentioned in the Jerusalem Letter, we met with the mustard plant -j- growing wild, as high as our horses' heads, still, being an annual, it did not deserve the appellation of a tree; whereas the other is really such, and birds might easily, and actually do, take shelter under its shadow."" On reading this passage, both Mr Lambert and myself felt inte- rested in ascertaining what the tree might be, and, at first, we were inclined to suppose it was a species of Phytolacca ; with which genus the habit of the plant, as far as could be learnt from the above description, pretty well accords ; but the examination of an authentic sample, in the possession of Mr Bankes, has proved the supposition was unfounded, and that the tree is the Salvadora persica of Linnaeus, the Embelia Grossularia of Ret- zius, and the Cissus arborea of Forskahl. • Scirpus lacustris L, which is abundant in the marshes on the shores of the Dead Sea. •j* Probably Sinapis nigra, which in Spain grows to the height of from ten to fifteen feet, as I am informed by my learned friend Don Mariano LagasCa. 308 Mr D. Don o?i the Mustard Tree. It is figured and described by the late Dr Roxburgh in his splendid work on the plants of the coast of Coromandel — a work which we regret to see discontinued by the Court of Directors. In that work the following interesting remarks on the Salvadora persica are given, which will be found to coin- cide entirely with what Captains Irby and Mangles have ob- served. " This is a middle sized tree, a native of most parts of the Circars, though by no means common ; it seems to grow equally well in every soil : flowers, and bears ripe fruit all the year round. The berries have a strong aromatic smell, and taste much like garden-cresses. The bark of the root is remark- ably acrid ; bruised and applied to the skin it soon raises blisters, for which purpose the natives often use it ; as a stimulant it pro- mises to be a medicine possessed of very considerable powers." The Salvador a persica has an extensive geographical range, being found in Arabia, Syria, Persia, and India, between the parallels of 18° and 31° north latitude. The parallel of 31° appears to be its ultimate limit towards the north. I am far from assuming this tree to be identical with the apocryphal mustard plant of the Sacred Scriptures: indeed, the whole passage in the Gospel by St Mat- thew * appears to militate against such an opinion, and it would seem that some common agricultural herb, of large growth, had been intended by our Saviour in the parable ; but whether the plant belongs to the same family with Sinapis of Linnaeus, and for what purposes it was cultivated, are questions rendered quite problematical at this distant date. We are pretty certain, how- ever, that it cannot be a Phytolacca ; for it does not appear that any real species of that genus has been observed in Palestine. It is true, that, in an academical dissertation of Linnaeus, enti- tled, " Flora Palcestinay'' published in the year 1756, and pro- fessing to embrace all the plants observed by Hasselquist, we find the name of Phytolacca asiatica, by which is probably intend- ed the Salvador a persica, a plant with which Linnaeus does not appear to have ever been well acquainted, and of which he pro- bably derived all his knowledge from Garcin's description, pub- lished in the Philosophical Transactions of the lloyal Society oi' " " A mustard-seed .... which indeed is the least of all seeds ; but when it is grown, it is the greatest among h^bs, and becometh a tree ; ^so that the birds of the air come and lodge in the branches thereof." Mr D. Don on the Mmtard-Tree. 809 London for 1749 ; for, in i\\e first edition of the Species Plan" tarum, published at Stockholm in 1753, we find Phytolacca asia- tica for the first time noticed, with the following specific charac- ter, " Phytolacca folus serratis ;" and a reference made to the Kalagu of Rheede, (Hort. Malah. ii. t. 26.), which has a pin- nate leaf, and is evidently nothing else than Leea sambucina, Linnaeus appears to have been soon aware of his error, as in the subsequent editions of the Species Plantarum^ the name is dis- continued. My only object in this communication was to point out precisely the plant noticed by Captains Irby and Mangles. This object, I trust, I have satisfactorily fulfilled ; but, as to at- tempting to ascertain the precise plant mentioned in the Sacred Scriptures, the difficulties that present themselves appear to me not to be lessened. Addition to the Botanical Notices^ published in No. XXVI. of the Philosophical Journal, October 1825. In my article on the leaves used by the Chinese in lining tea- chests, there is some obscurity in the description of the nerves^ which I think it necessary to remove. It seems as if I denied the existence of a midrib, but this I did not intend .; for I meant to say, that the leaves agreed with the genus Pharus^ and dif- fered from most other GraminecE, in the presence of a midrib, and that their straight parallel nerves, running longitudinally from the base to the apex of the leaf, distinguished them essen- tially from those of Scitaminea^, wherein the nerves arise late- rally from the midrib, traversing the leaf in an obliquely trans- verse direction from the centre to the margin. On the Structuix and Characters of the Octopus ventricosus, Gr. (Sepia octopodia. Pent.), a rare species of Octopus from the Firth of Forth. By R. E. Grant, M. D., F. R. S. E., F. L. S., M. W. S., Fellow of the Royal College of Physi- cians of Edinburgh, Honorary Member of the Northern In- stitution, &c. Communicated by the Author *. X HE species of Octopus, of which I now present two speci* mens from the Firth of Forth, is of rare occurrence on our coasts, * Read before the Wernerian Natural History Society 13th January 1827. JANUARY — MARCH 1887. X ^V^ Dr Grant on the Structure and Characters of and is not to be found among the species of that animal described by Lamarck, nor among those described by Cams, as occurring in the Mediterranean. It possesses the characters of the genus Octopus of Lamarck, but differs from his O. vulgaris and O. gra- mdatus, in having only a single in place of a double row of suckers on each arm. It differs from his O. cirrhosus, in ha- ving the upper margin of the mantle fixed behind, and continu- ous with the back of the head, in place of being free and de- tached all round. And it differs from his only other species^ the O. moschatus, in being entirely free from that remarkable musky odour ascribed to that species by every author, and from which it has received its specific name. Pennant has pretty ac- curately represented our present species under the Linnaean name of Sepia octopodia, (Br. Zool. iv. pi. 28). But, from the description he has given, and from the name he has applied to it, it is obvious, that he was unaware of the existence of any other species of octopus, and mistook this for the O. vulgaris^ which has a double range of suckers, and is much more com- mon. The figure given by Car us of the O. fnoschites (Nova Acta Acad. Caes. vol. xii. tab. 32.) agrees with Pennant's species in its external characters, excepting that the body of the mos- chites is a little more lengthened and cylindrical, the base more tapered, the eyes larger, and the arms more slender. But Ca- ms mentions, that his species smells so strongly of musk as to fill quickly a whole apartment, whether the animal be dead or alive ; and the same remarkable property is ascribed to it by Cuvier, Lamarck, and other writers. Aristotle, Aldrovandus, and some later authors, have divided the Octopoda into two ge- nera, applying the term Eledona (eas^^wvj) Arist.) to those spe- cies, which, like the present^ have only a single row of suckers on each arm ; but this unnecessary subdivision of the well mark- ed genus Octopus is probably not justified by the importance of the character proposed, and the most distinguished naturali&ts,^ as Cuvier, Lamarck, Blainville, and Cams, have not adopted it. As Pennant's species has neither the white skin, the smooth sur- face, the lengthened body, nor the musky odour of the O. mos- chafus, and differs, in more obvious characters, from the other species, we are compelled either to retain its specific name octo^ ^odia given by Pennant, or to devise a new epithet more con- a rare species of Octopus J'rom the Firth of Forth, 811 sist6nt with our present knowledge of these animals. It must be obvious, that the term octopodia, though very appropriate for one of the sepise of Linnaeus and Pennant, cannot be applied to a species of Octopus without a plain tautology, and because ' the specific name, being then synonymous with the generic, would be equally applicable to all the species. Until a more determinate character, founded on structure, be discovered by a careful dissection of the other species, I have called the present species O. ventricosus^ from the rounded appearance of the body in both the specimens I have seen, and in the figure of it represented by Pennant. 'Many excellent details of the structure and habits of the Se- pia, the Loligo, and the Octopus vulgaris have been given by Aristotle, Swammerdam, Monro secundus, Scarpa, Tilesius, and Cuvier ; but, so far as I know, none of the species of octo- pus, with a single row of suckers, have yet been opened by ana- tomists. The O. ventricosus is the fifth species of cephalopo- dous animals I have already procured from the Firth of Forth, the other species being the Octopus vulgaris^ Loligo sagittafa, Loligo vulgaris, and Loligo sepiola; and it is interesting to ob- serve, that these species are nearly all the same as those met with by Carus in the Mediterranean. That naturalist observed in the Gulf of Genoa, specimens of the Oct. vulgaris, Oct. mos- chatus, Loligo sagittata, L. sepiola, L. vulgaris, and Sepia offi- cinalis. The following observations are chiefly taken from a recent a- dult female specimen of the O. ventricosus, lately presented to me by my friend Mr Coldstream, and to abridge the anatomi- cal details, I have compared its organs with those of the O. vul- garis, already fully described by Cuvier in his elaborate me- moir on that animal, (Mem. sur les Moll. p. L) The body of the ventricosus is short, broad, slightly depressed^ rounded, and a little dilated posteriorly, granulated and deeply coloured with small reddish brown spots on the back, smooth and light coloured on the fore-part. The upper margin of the mantle is connected behind, across the whole breadth of the head, and has no lateral expansions to assist in swimming. In the other genera Loligo and Sepia, the mantle is free behind, and in these as well as in the LdMgopsis, it is armed with lateral expansions to assist in swimming. These expansions are supplied in the 0, ventricosus by the muscular web connecting the base of the arms. The funnel is long, narrow, x2 31 S Dr Grant o» the Structure arid Characters of rather soft, and light coloured. The head is broad, short, covered with spots and minute granules on the back part like the body, white on the fore part with few spots. It expands without any pre- vious contraction into eight strong arms, like an inverted cone. Pen- nant has represented a slight contraction of the head between the eyes and the arms. The eyes are very small, almost concealed un- der the folds of the skin forming the longitudinal eyelids, and they are placed rather towards the back than the sides of the head. The iris is white, has a shining silvery lustre, and is almost co- vered with small round spots of a deep reddish brown colour like those of the skin. The eight arms have all the same length, form and structure, but the two interior are much whiter than the others. The arms are about three times the length of the body, much com- pressed throughout their whole length, very strong at their base, and tapering regularly to almost imperceptible filaments at their free ends. They are deeply spotted externally, nearly white on their central aspect, and are armed with a single range of suckers on their inner surface, extending from their base to their extreme points. The bases of the arms are connected to each other, by a strong mus- cular web spotted externally, and white within, like the arms, and extending between the arms to about the twelfth sucker from the mouth. The suckers commence about half an inch from the fringed lip of the mouth ; they are sessile, broad, and very short. The suck- ers next the mouth are nearly a line in breadth, they increase regu- larly in size to the sixth from the base which is the largest on all the arms, and measures nearly three quarters of an inch in diame- ter. From the sixth sucker they again diminish regularly in size, till they become quite invisible to the naked eye near the points of the arms. With a lens they may be counted to within half a line from the points, and about 111 are found on each arm, making SSS on the animal. The first four suckers from the base, are about two lines distant from each other, the rest are placed in close contact. In the 0. vulgaris the first three or four suckers from the mouth are likewise placed in a single row, and a little distant from each other, but from these to the points of the arms there is a double range ; in that species there are about 240 on each arm, making in all 1920. In the 0. granulatus, Cuvier states that there are 1 80 suckers (90 pairs> on each arm, making 1440 suckers on that species. It might be use- ful to observe this external character in all the species. Each suck- er of the ventricosus consists of a central cartilaginous hemispheri- cal cup, surrounded by a very broad flat muscular margin, which is deeply marked like the inner edge of the cup, with from fifteen to seventeen distinct radiating grooves. Cuvier has made no mention of these thick white, firm cartilaginous cups, in describing the suck- ers of the 0. vulgaris. They can be taken out entire with great ease from the centre of the suckers, particularly after immersing them in boiling water. There is no horny circle nor sharp converging teeth within these cups, as we find in the pedunculated suckers of the Sepia and Loligo. The external dimensions of the adult animal are — from the upper margin of the mantle to the lower end of the body 4 J inches; great- est breadth of the body from right to left 3^ inches ; length of the a rare Species of Octopus Jrom the Firth of Forth, 313 arms from the mouth 12 inches; extent of the muscular web between the arms 3 inches ; breadth of the web between each pair of arms 4 inches ; breadth of the head at the eyes 2^ inches ; external aper- ture of the eyelids when expanded into a circle only ^th of an inch. The coloured spots of the skin are of a deep reddish brown colour. In the cirrhosus, Lamarck states that they are of a bluish grey co- lour. In the 0. vulgaris they are brown. Lamarck states that the whole skin of the moschatus is white, but Carus has represented it spotted with red. In the ventricosus they are so minute and crowd- ed together on the back, as to be almost undistinguishable without a lens ; the largest are about the tenth of a line in diameter, and be- tween these are crowded others infinitely smaller. On the fore parts of the body they are few, and placed at greater distances from each other. The colour is of different intensity in different spots, and even in different parts of the same spot. They are confined to a thin layer on the outer surface of the true skin, which may be com- pared to the rete mucosum of the higher animals. When a part of the surface is plunged into boiling water, the coloured superficial film is easily removed. In the living state, the spots appear and disappear in rapid succession, as in other cephalopodous animals. In a young specimen of the ventricosus only about 4 inches in total length (now in the Museum of the University), which I kept alive for some hours in a basin of sea water, I observed, that, when the surface of the body was touched with the finger, the neighbouring parts quickly and rapidly changed colour, clouds of a bright red colour spread rapidly in every direction over the surface, from the part touched. This dif- fused redness, which was like a blush on the human skin, appeared to be produced by some coloured fluid passing repeatedly to and from minute vesicles on the surface of the skin. The animal swam several times hurriedly across the basin, always with its posterior extremity forward, by repeatedly striking forward the whole of its webbed arms at the same instant. Swimming seemed as unnatural to it, as to a pea-crab, which likewise swims hurriedly backward by striking the water with its tail, or to many bivalve mollusca, which swim backward by flapping their shells. It likewise climbed up the sides of the basin, out of the water, by spreading its arms in every direction, fixing its tender suckers to the sides of the vessel, and carrying the posterior part of its body erect. The granules on the back parts of the adult animal are^about the size of a grain of sand, situate in the true skin, and are seen on the mantle, head, arms and webs. The 0. gramilatus is distinguished by these tuber- cles or granules of the skin, but they are not confined to that spe- cies, and Lamarck suspects that it may be only a variety of the vul- garis. There is still a necessity for minuter observations than we at present possess, for the accurate discrimination of these singular and interesting animals. The cartilaginous frame- work of the head is very soft and trans- parent : it forms rather small orbits, very large spherical cavities for the ears, and a small recess between these two shut cavities for lodging the ganglion of the aesophagus, compared to the brain of ver- tebral animals. In place of the osseous or cartilaginous plates extend- iRg down the back of the mantle in the other genera, we find two small cylindrical stiliform cartilages, about the thickness of a crp^v 314 Dr Grant wi the Structure and Characters of quill, extending down the sides of the lower half of the mantle. These bodies are thickest where they commence at the bottom of the branchiae, and become quite filiform as they descend in a curved direction to near the base of the mantle. They are not connected with the muscular fibres of the mantle, as might be expected, but are placed in distinct cavities. On clipping open the cap- sules which contained them, they fell out in loose transparent frag- ments of an amber-colour. The muscular system presents nothing peculiar. The fleshy membranes within the sac immediately en- veloping the viscera, are comparatively strong. Cuvier states that the fringed lip in the O. vulgaris is only a fold of the skin {Mem. p. 25.) On laying open the lip in the veniricosus, a strong sphincter muscle is seen surrounding its upper margin, and very delicate mus- cular bands descend from the sphincter to the sides of the bills. Strong muscular bands are seen passing from arm to arm across the connecting webs ; and within these a thin layer of muscular fibres extends longitudinally to the free margin of the webs. The whole convex outer margin of the cartilaginous cups of the suckers is co- vered with the insertions of oblique muscular bands for the varied motions of these organs ; and a distinct set arises from the margin of the cups, radiating outward to assist the external bands in moving the broad disk of the suckers. The muscular structure of the arms, the mantle, the funnel, the bands connecting these, and the fleshy peritoneal coverings, is the same as described by Cuvier in the O. vulgaris. On laying open these peritoneal coverings, we observe the great length of the glandular-like bodies attached to the supe- rior and inferior trunks of the veins leading to the lateral hearts. When the parts are floating loosely in water, these singular glands extend nearly half an inch from the sides of the veins, and appear as empty white pear-shaped sacs, attached by their tapering ends to the coats of the veins. In place of these long pear-shaped bodies, we find in the Loligo sagittata only a thick soft sponginess of the coats of the veins, which, however, is of the same glandular na- ture, and secretes a thick white -fluid, whose use is entirely unknown. The fluid which escapes by pressing these glands is al«vays more thick and turbid than the blood which we find circulating in the bloodvessels. On cutting open a living L. sagittata, these glandular parts of the veins exhibit a remarkable peristaltic motion, which continues as long as any other motions of the body. The two bran- chial hearts have the same remarkable blackish-grey colour as in the O. vulgaris, which is probably peculiar to this genus. Those of Uie L. sagittata have always a pale-red colour. In the ve?itricosus, these organs are pretty large, destitute of the white appendices we find in the L. sagittata, dark-coloured through their whole texture, and deeply marked internally with columnae carnea3, which form in- numerable small pits in the parietes. The branchiae, about 2i in- ches long, and pretty broad, are immediately connected with a thick fleshy band, which hangs by a thin fibrous membrane to the sides of the mantle ; and along the thick margin of this fleshy band the branchial artery is firmly connected, from the lateral heart to the upper end of the gill on each side. They are ramified in the same manner as in the vulgaris, and they suffered an injection of ti rare species of Octopus Jrom the Firth of Forth. 815 size and vTermilion to pass with great ease both through the vein and the artery. I have often found the vein burst in the L. sagittaia in forcing the same injection through that vessel, in a direction con- trary to the natural course of the blood. The central heart has very thin white firm walls, slightly marked internally with columns car- neae ; and its capacity is more than three times that of each lateral heart. The distribution of the arteries and veins, as might be ex- pected, was similar to that of the vulgaris^ so far as I could trace them. The white fringed lip surrounding the two bills is rather short; the bills, of a deep brown colour, are likewise short and powerful ; the lower one is much expanded at its base. The tongue is cover- ed with an amber-coloured hard, horny, membrane, which has several longitudinal rows of sharp reflected teeth. The upper pair of salivary glands are round, flat, deeply lobed on the margins, of a white colour, bound to the fleshy sides of the mouth, and they send their ducts through these fleshy parietes into th€ mouth. By remaining some weeks in spirits, these glands acquired a purple colour, while the lower pair, equally exposed, were not affected. The lower pair of salivary glands are of a pale-red colour, about an inch long, and three quarters of an inch broad, compressed, smooth, not lobed like those of the vulgaris, firm in texture, some- what triangular'or heart-shaped, and they areloosely suspended behind the upper margin of the liver, by means of their vessels, nerves, and ducts. On cutting open these large compact glands, we find a small cavity, like the pelvis of a kidney, at their upper part, from which the ducts commence. They are about ten times as large as the upper pair. Their two ducts unite into one, which passes up on the fore part of the oesophagus for nearly two inches, to enter the mouth at the root of the tongue. When the oesophagus reaches the upper and back part of the liver, it becomes firmly connected to that organ, and expands into a wide membranous crop, deeply marked internally with longitudinal folds, and covered with a vil- lous appearance. The part of the crop which is most intimately connected with the substance of the liver is drawn upwards in the form of a coecum, and has a glandular texture. The crop tapers as it descends obliquely to the gizzard. This membranous crop is not present in the Loligo sagittata, where the oesophagus passes without dilatation to the stomach, at the bottom of the liver, next to the spinal sac. The muscular sides of the gizzard are of great thick- ness, and as strong in proportion as those of a domestic fowl. Its two fleshy sides are placed nearer the upper than the lower end ; the under end is thin and membranous. The hard cartilaginous lining of the gizzard T found quite detached from the sides ; and, on exa- mining its contents carefully in a watch-glass, I collected some un- digested muscular parts of a pale-red colour, fragments of the crus- taceous covering and joints of young crabs, and some coarse parti- cles of sand. 1 have no doubt, from the appearance of these parts through the microscope, that the particles of sand aided in the commi- nution of the hard shells. In the L, sagittata there is only a thin, wide^ membranous stomach in the place of this thick fleshy gizzard. The upper and left side of the gizzard opens into the spiral stomach, which has nothing peculiar. The large intestine, on leaving the spiral 816 Dr Grant on the Structure and Characters of stomach, makes a long curve downwards behind the Ipft branchial heart, like another coecum, before it mounts upwards on the fore part of the liver, to terminate at the base of the funnel. The liver is short, spherical, of the usual orange-yellow colour, composed of the ramifications of vessels filled with a coloured fluid. In the 0. vulgaris it is cylindrical, from the greater length of the body ; and, for the same reason, it is very long and cylindrical in the L. sagit- tata. Its canals are not surrounded by the pancreatic glands, which I have shewn, in the L. sngittata, to embrace and communicate wjth these ducts during their whole passage from the bver to the spiral stomach, and which were mistaken for the ovarium at a pe- riod when the structure of these animals was very little known, (See Edin. Phil. Journ., vol. xiii. p. 197). The want of these glands in the O. ventricosus is compensated for by the very large inferior pair of salivary glands. The ink-bag is deeply imbed- ded and nearly concealed in the substance of the liver, but it sends out its excretory duct from the lower and fore part of that or- gan, to terminate as usual in the anus. The colour of the ink is quite different from that of the L. sagittata ; and as the colour of this sub- stance is constant in each of the cephalopodous animals, a more in- timate acquaintance with this character might be useful in tracing relations among the different species. The colour of the ink in the L. sagittata is a deep brown, approaching to yellowish-brown, when much diluted, and corresponds remarkably with the coloured spots on the skin of that species. In the 0. ventricosus, the colour of the ink is pure black, and is blackish-grey when diluted on paper. The ink, brought in a solid state from China, has the same pure black colour as in the ventricosus, and differs entirely in its shade, when diluted, from that of the L. sagittata, as may be seen from specimens of these three colours on drawing-paper. Swammerdam suspected the China ink to be made from that of the Sepia, Cuyier found it more like that of the Octopus and Loligo ; but different kinds of that substance are brought from China, probably made from different ge- nera of these animals, where they abound of gigantic size. Ink is at present made from these animals in Italy {Cuv. Mem. p. 4), and from the immense shoals of the L,. sagittata cast ashore every spring in the Firth of Forth, it might likewise be manufactured here. The ink is not contained in a simple cavity attached to the liver, but is diffused through a soft cellular substance which fills the ink-bag, and must render more tedious the preparation pf this substance for the arts. The oesophageal ganglia, compared to the brain and cerebellum of vertebral animals, were-^small, white, soft, without internal cavities, lodged in open recesses of the'cartilaginous ring surrounding the oeso- phagus, and were separated from the oesophagus only by a thin tran- sparent membrane, to which they firmly adhered. The large reniform optic ganglia, the band of nerves proceeding from these to the retina, the white pulpy glandular masses within the back part of the sclerotic, the division of the lens, and the general structure of the eye, are the same as in the vulgaris. At the bottom of the large shut sphe- rical cavities of the ears, which were capable of containing a garden pea, |ay a very delicate membranous sac, containing a little fluid, a rare Species of Octopus Jrom the Firth ofFo^th. 317 and a small red-coloured stone shaped like a limpet, the only earthy matter in this animal. These small bones of the ear are co- nical, solid, of a rose-red colour on the sides, flat and white on the base ; their apex is rounded and curved backward, their length, breadth, and height, are about half a line. When cut, they appear white and translucent within, like the inner layers of an oyster shell j they are very slightly excavated in the centre of their flat base, and they dissolve with effervescence when touched with nitric acid, like other substances composed of carbonate of lime. The great nervous trunk accompanying the small artery in the central tube of the arms, the great ganglion, with about twenty nerves radiating from it, placed within the upper and back part of the mantle, and the other nerves and ganglia, were very conspicuous, and corre- sponded in distribution to those of the vulgaris. The specimen I dissected was ^ female, and the ovarium, consist- ing of beautiful detached ramified trunks, enclosed in a wide mem- branous sac, occupied the lowest part of the general cavity of the body, as in the other cephalopodous animals. The ova, instead of being attached by their peduncles to a single point, as in the vulga- ris (See Cuv. Mem. p. SI. J, were attached to the extreme ramifica- tions of about twenty branched trunks, which hung by separate stalks from the upper end of the membranous sac. The two reni- form glands through which the oviducts pass, and which very pro- bably secret the coverings of the ova, as in the skate and other fishes, and connect them together, were about the size of a pea, of the same dark colour as the lateral hearts, and were placed about half an inch from the lower end of the oviducts. The oviducts opened on each side about half way between the lateral hearts and the anus. Meteorological Observations made in Jamaica hy the late John Lindsay, Esq. Surgeon, Jamaica. Communicated by W. C. Trevelyan, Esq. M. W. S. &c. L HE author of the following Tables is well know'ii to the pub- lic. He published an account of the Epidemic Catarrh of the latter end of the year 1789, as it appeared in Jamaica, in Med. Com, vol. xvii. p. 499, 1792. Also, an account of the Germina- tion and Raising of Ferns from Seed, Trans. Lin. Soc. vol. xi. p. 93, 1792 ; of the Quassia Polygama, or Bitter Wood of Ja- maica ; and, of the Cinchona brachycarpa, a new species of Je- suit's Bark, found in the same island, Trans, Soc. Edin. vol. iii. p. 205, 1794. ( 318 ) A TABLE, shewing the Highest, Lowest and Medium Heat at Sunrise ; between One and Two o'' Clock, p. m. ; and be- tween Eight and Nine o^ Clock at Night, by Fahrenheit s Thermometer, for Five Yeais, viz. 1786, 1787, 1788,1789 and 1790. A. D. 1786. 1 A.D. 1787. j A. D; 1788. 1 A. D. 1789. 1 A. D. 1790. | 1 X 1 S 1 1 ^ S £ 1 s 3 a 1 1 1 bo 1 S . M. 73 66 70 M. 75 69 71 M. 72 68 70 M. 74 69 71 M. 71 67 69 ,i? N 85 83 84 S N. 82 74 81 L^ N. 85 77 81 s N. 85 80 82 N. 82 80 81 ^ N. 79 75 77 ^ N. 78 69 74 ^-5 N. 77 73 75 •-^ N. 80 72 76 ^ N. ~~ m! 72 67 70 M. 72 69 70 M. 72 69 71 « M. 72 67 70 Ji M. 71 68 69 -^ N. 84 77 81 ^ N. 83 80 82 % N. 85 82 83 X N. 84 81 82 t N. 84 82 88 \H N. 78 73 75 ^ N. 76 71 72 \^ N. 78 75 76 \M N. 77 75 76 \m N. 77 73 75 "" M. 75 64 69 ^ 72 69 70 M. 74 71 72 . M. 71 67 68 M. 72 68 70 l5 N. 87 83 85 is N 85 82 83 N. 87 86 84 y N. 84 80 82 1 N. 87 82 83 ^ N. 79 73 76 S N 81 75 78 N. 80 76 75 '^ N. 78 74 75 N. 78 73 75 . M. 79 71 74 _; M. 75 70 74 rA M. 74 70 71 J M. 73 68 70 rA M. 74 68 71 ■R, N. 89 m 87 u N. 85 83 84 o. N. 87 82 85 0-, N. 88 81 84 C ;--i N. 86 77 83 < N. 82 77 79 < N. 80 77 78 < N. 86 77 78 < N. 79 76 78 <3 N. 78 74 76 "~" M. 79 70 75 bl M. 77 70 73 M. 75 72 73 M. 79 71 74 bl M. 80 71 74 ^ N. 92 82 90 i N. 88 83 86 ^ N. 88 85 86 ^^ N. 88 79 85 i N. 88 86 85 s N. 84 75 80 N. 83 80 82 g N. 79 76 77 ^ N. 84 76 81 N. 84 74 80 3J M. 80 73 77 o3 M. 78 74 75 o M. 79 76 77 M. 77 69 73 . M. 75 71 73 > o M. 74 72 73 M. 70 71 73 N. 89 86 87 > o ^. 88 80 84 o N. 8b 82 84 J\. 84 80 82 >• o N. 86 84 85 14 N. 82 77 80 ^ N. 86 75 78 'A N. 81 77 79 A N. 76 74 75 ^. N, 82 73 78 M. 76 71 73 M. 76 68 72 m! 74 67 71 M. 75 66 72 A M. 74 70 71 ,"" N. 86 80 84 % N. 85 73 82 ^ N. 8b 80 82 a; ^. 84 76 81 fl ^. 82 80 81 W X 80 76 77 Q N. 78 70 74 P N. 80 72 76 M N. 77 74 75 N. 80 74 76 92 64 90 68 90 67 90 86 92 67 Mr Lindsay's Meteorological Observations. 319 a 525 o 02 ;> ^ =H ^ :> g frj ^ ^q Sg^^l 1 I M I I I ,^g5§i I M 1 1 ir OD>-«05U)««4*.^Oi© I I I -f 05 O C5 "^ H- ' CS © I to o^S ' _ H-" i-- tt>.g I '-' *>^ tQ^^i 00 CO to W © ^^1 I lO-l t-« «0 H- >-' I— I-- PS rf^ w i» ^ H- oi 5* CO — H-§ ^ §• g. ?5 ^ 1^ ^ ^ 55 Sj bs a • b Is*. CD ;s 1 Ta g5 ^ s 'A. s ^ S <>" % ^ a' ^5, a. ti 5r ^ $e o» 3 ^ Si S ^ ^ ^ ri 5!- 5?- a ^ ^ §3 ^ o s ■^ ^ s Q ;5^ S § k ^ "*j ^ S- ^ g H-« c^ -^ ^ 00 (S>« Ox s The greatest quantity of rain appears to have fallen be- tween the months of May and November. Hail is mentioned in Mr Lindsay's Notes to have fallen on the 27th and 28th of August 1791. A smart shock of an earthquake, which lasted about half a minute, happened on 21st October. Another is mentioned on 1st July 1791. ( 3^0 ) A Descrlptkyn of the genus Malesherhia of the Flora Peruvi- ana ; with RemarTcs on its Affinities. By Mr David Don, Libr. L. S. ; Member of the Imperial Academy Naturae Cu- riosorum, of the Wernerian Nat. Hist. Society, &c. i HE characters and habit of Malesherhia appear to me suffi- ciently important to establish it as the type of a distinct natural group, to which the name of MalesherhiacecB may be given. The necessity of attending minutely to the structure, both of the flower and fruit, is now universally admitted ; and I wish it were as generally allowed, that the object of the botanist should be rather to point out the real structure and affinities of indivi- duals, than to attempt extensive and unnatural combinations, in the present infantine state of botanic science : for it must be ad- mitted, that nothing is more injurious to a system, than the un- natural association, either of genera or species ; and perhaps no- thing has tended more to retard the advancement of systematic botany, than the fear of an unnecessary multiplication of names, thereby inducing the contracted notion of retaining entire many heterogeneous orders and genera. If we but turn our eyes over the pages of works professing to be general Systems of Plants, we will find abundant evidence of the justness of what has been advanced ; and if we but consider how few individuals in any of the extensive genera or orders have been investigated with that care and precision by which the true nature of their parts, and their relative affinities, can alone be ascertained, we should not perhaps be so averse to their separation into smaller groups. The Malesherhiaceoe agree on the one hand with PassiflorecB, and on the other with Turneracece. They differ from the former in their erect ovula ; in the insertion of the styles ; in their ascending incumbent anthers ; in the placentae not extending above the separation of the valves ; in their naked seeds ; in their thick, fleshy, almost hemispherical cotyledons ; and finally, by their great difference in habit, and by the absence of stipules at the base of the leaves. From the loiier (Turner acecB), y/v'ith. which they agree well in habit, and in the structure of their fruit, in their erect ovula, in the structure of the anthers, and in the furrowed nature of their seed-covering ; they are essen^ Mr Don on the genus Malesherhia. 3^1 tially distinguished by the presence of si corona, arid in the per- sistent nature of the inner series of the floral envelope ; by their incumbent anthers ; by the insertion of the styles ; by the pla- centae being confined to the lower half of the capsule ; by their straight embryo, and by the form of the cotyledons ; and, last- ly, by the absence of the fleshy scale (probably the rudiment of an arillus) at the base of the seed. The MalesherhiacecB appeal to be related also in a certain degi^ee to Loasece^ whose charac- ters and affinities are yet but imperfectly understood. M. Au- guste de St. Hilaire, in his valuable memoir on the affinities of the Cucurbitacece, has already pointed out the affinity of Tur- neracecB and LoasecB to Passiflorece. The genus Malesherbia was established by Ruiz and Pavon in their Genera Plantariim FlorcE Peruviana et Chilensis, pub- lished in the year 1794, and dedicated to the memory of the unfortunate M. Lamoignon de Malesherbes, a distinguished philosopher, and a great lover of botany, who fell a victim to his zeal for the cause of justice and humanity, and for the ho- nour and glory of his country, in the early part of the French Revolution. The genus was subsequently published by Cava- nilles, in the fourth volume of his Icones Plantarum^ under the name of Gynopleura ; but what was his object in changing the name does not appear, neither is it a niatter of any importance. I shall now proceed to give a botanical description of the group, which may equally be considered as that of the genus^ MALESHERBIACEife. Passiflorearum genus, Juss. Perianthium monophyllum, tiibulosum, membranaceum, inflatUm, coloratum, nervis dec«m in limbo diffuse ramosissimis, e basi sur- sum peragratum : faux corona continuata brevissima membra- nacea v. acute dentata V. 10-loba, laciniis 2-4-dentatis, ornata: limbus duplici ordine 10-fidus, uterque persistans, patulus, sesti- Vatione imbricata ; interiore petaloideo, aestivatione convoluta. Stamina 5, hypogyna, exserta, apici columnae inserta, laciniis in- terioribus perianthii o^pposita :Jilamenta filiformia, glabra, com- pressiuscula : ardherw lineares, retusae, biloculares, filamentis mediate annexae, incumbenti-erectae : hculis parallelis, margine longitudinaliter dehiscentibus, ab insertione filamenti ad apicem , fere usque confluentibus. Pistillum : ovarium apici columnae adnatum, subglobosum, obscure triangulare, uniloculare : ovulis erectis, biseriatim indefinitisy fu^ 322 Mr Don cm the gentis Malesherbia, nictilo umbilicali stipitatis : stj/li 3, longissimi, capillares, glabri, persistentes, valvis capsulae alternantes, et inter ipsarum bases insert! : stigmata simplicia, clavata, disco concavo pruinoso. Capsula elongata, trigona, 1-locularis, apice tri valvis, dehiscens, polysperma, basi membranacea : valvis crustaceis. Placentce : costa; 3, prominentes, funiculis persistentibus seminiferis stipatae, parieti capsulae infra dehiscentiae locum insertae, axique valvarum perpendiculares. Semina erecta, obovata, ventricosa, duplici serie ordinata, fusces- centia, funiculo umbilicali stipitata, apice strophiola fungosa la- cerata, basi umbilico tuberculiformi aucta, extus sulcis plurimis parallelis aequidistantibus longitudinalibus transverse rugulosis notata : testa duplex ; exteriore Crustacea, crassiuscula ; interiore cartilagine^ membranacea : albumen copiosum, carnosum, aqueo- pallidum. Embryo erectus, teres, axilis, lutescens, albuminis fere longitudine : cotyledones orbiculatae, crassae, hinc convexae, inde planae, pene hemisphaericaB : radicula teres, crassa, obtusissima, recta, cotyle- donibus longior, centrifuga. Plantae (Peruviae v. Chili apricis propriae) erectce, ramosissimoSi pu- bescentes, caule inferne suffruticoso. Folia alterna, simplicia, exsti^ pulata. Flores numerosissimi, axillares v. terminales, solitarii, seS" sileSf lutei. Malbshekbia, Ruiz et Pavon^ Gen. Plant. Fl. Peruv. et Chil. p. 45. Gynopleura, Cav. Icon. iv. p. 52. Obs. Character idem ut in ordine. SPECIES. 1. M. thyrsijlora^ foliis lineari-lanceolatis acutis sinuato-den- tatis tomentosis, perianthii fauce coarctata, corona decemfida : laciniis 2-4-dentatis. Malesherbia thyrsiflora, Ruiz et Pavon, Fl. Peruv. et Chil. iii. p. 30. t, 254 — Syst. Veg. Fl. Peruv. et Chil. p. 79. Gynopleura tubulosa, Cav. Icon. iv. p. 52. t. 375. Hab. In Peruviae apricis argillosis provinciarum Cantae, Huaro- cheri, et Caxatambo (Ruiz et Pavon, Dombey) ; prope oppidum Purruchuco, 18 leucis a Lima frequens, etiamque juxta Obra- gillo et San Buenaventura. — Ludovicus Nee. Vf. Floret Aprili et Maio. Planta sufFruticosa, 2-3-pedalis, foetida, hirsutissima. Folia con- ferta, sessilia, lineari-lanceolata, acuta, obtuse sinuato-dentata, supra leviter canaliculata, basi aliquantulum attenuata, 2-3-un- cialia. Flores flavi. Perianthiuin tubulatum, sesquipollicare. Coronas laciniis altemis exterioribus segmentis perianthii oppositi* angustioribus, plerumque bidentatis. with Remm-ks on its Affinities, 323 2. M, paniculata, foliis oblongis obtusis pinnatifidis cilia- tis, perianthii fauce dilatata, corona siraplici acute dentata. Gynopleura linearifolia, Cav. Icon. iv. p. 52. t. 376. } Hab. In Chili boreali. — Alexander Caldcleiigh, tf. (v. s. in Herb. Lamb.) Planta erecta, pyramidato-ramosissima, leviter canescens, 3-4-pe- dalis. Rami teretes, pube subtili vestiti. Folia alterna, sessi- lia, nunc basi auriculata amplexicaulia, oblonga v. lanceolata, obtusa, pinnatifida, pube sericea pilis plurimis setaceis interraix- ta potissimum ad margines ornata, uninervia^ nervo pinnate ra- moso, patentia, semipollicem v. poUicem longa, et 3 lineas v. semi- unciam lata; ultima lineari-oblonga, saepe Integra: laciniis ohlon-' gis obtusissimis; injimis duahus majoribus, stipulas simulantibus. Flores paniculse modo dispositi, nuraerosissimi, pallide lutei, sic- citate violacei ! pedicello brevissimo crasso sufFulti. Perian- thium copiose villosum, unciale : tubus angustus, cylindraceus, ima basi callosa : faux dilatata, campanulata, tubo duplo triplo- ve longior : corona simplici, tenuissime membranacea, multiden- tata, dentibus brevibus acutis ineequalibus, e nervorum calyci- norum ramis lateralibus arcuatis ortum ducente : limhus duplici ordine 10-partitus, uterque persistens, coloratus; laciniis exte^ rioribus calycinis, lanceolatis, obtusis, aBstivatione imbricatis; interioribus petaloideis, alternantibus, ovato-lanceolatis, mucro- nulatis, lateribus parum inasqualibus, magis coloratis, aestivatione convoluto-imbricatis, basi aliquanto attenuatis. Nerm perianthii adhuc simplices, ad summitatem tubi in ramos tres divisi ; alter- nis ramulo intermedio in laciniis petaloideis ramosissime difFuso^ calychiarum laciniarum raraulis lateralibus brevissime distinctis, arcuatis, caeterum confluentibus. Caetera ut in ordine. For numerous specimens, both in flower and fruit, of this cu- rious species, we are indebted to our highly valued friend Alex- ander Caldcleugh, Esq. F. R. S. & F. L, S. whose zeal in the cause of science is known and appreciated. He discovered it in the neighbourhood of Coquimbo in Chili, together with many other new and equally interesting plants, a complete collection^ of which he has transmitted to Mr Lambert. It may possibly prove to be the same with the plant of Cavanilles above quoted, notwithstanding the discrepancies in the description and figure ;- but, as I have never seen specimens of it to compare, I dare not venture to affirm them to be identical. ( sn ) Account of a Gelatinous Quartz or Siliceous Sinter, which forms the basis of varieties of Old Red Sandstone. By M. T. GUILLEMIN. jflLS this interesting mineral occurs in some of the sandstone of this country, we have drawn up the following account from a memoir of Guillemin, published in the Annales des Mines for 1826. External Characters.^^Th'is mineral is of a pretty pure white colour, which, in some varieties, passes into greyish or yellowish white ; it has a resinous or semiresinous lustre, and passes into dull ; it presents itself in irregular masses ; its fracture is some- times conchoidal, sometimes subconchoidal or even ; it is scarce- ly translucid on the edges ; when dull, it is opaque ; it scratches glass with difficulty, and is scratched by steel ; it is easily fran- gible ; it adheres to the tongue, and is capable of absorbing a large quantity of water ; its specific gravity varies according to the quantity of liquid which it contains. When immersed in distilled water, gaseous bubbles are speed- ily disengaged, which rise after one another ; and, at very short intervals, a whizzing noise is emitted, and from time to time cracks are heard ; a fissure then forms, and gives rise to a new column of bubbles. At the end of twelves hours, there are still bubbles escaping ; after eighteen hours the absorption appear? complete. If boiling water be used, the disengagement is much more rapid, and by means of it bubbles are still made to rise from a fragment that has been immersed in cold water for seve- ral hours, and which appears saturated. "A fragment of about ^ve grammes weight, already containing 11.11 per cent, of wa- ter, according to a trial made at the moment, still absorbed 14.36, in all 25.47 per cent, at the temperature of six degrees of the centigrade thermometer. A hundred parts of this sub- stance, therefore, saturated with water, contain 20.30. Another fragment of about 10 grammes, dried before immersion, absorb- ed 24.51 per cent, of water at zero, or about a fourth of its weight, as in the preceding experiment. These specimens, left to themselves for two or three hours. M. Guillemin's Account of a Gelatinous Quartz, ^c. 825 returned to their original state, that is to say, came to contain only 11 or 12 per cent, of water. The density of a fragment saturated with water was 1.80 at 6i degrees, 1.812 at 6 degrees, 1.797 at 13 degrees; that of a fragment containing 0.111 of water, 1,67 at 2 degrees; and that of a dried fragment 1.53 at 5 degrees. In the two last ex- periments, the absorption of water, and the disengagement of gases were prevented, by covering the surface of the fragments with a thin coat of olive oil. Lastly, the density of this sub- stance, when weighed dry out of the water, and under the wa- ter, after an absorption of eighteen hours, was found to be 2.215 at 13 degrees of the centigrade thermometer. Chemical Characters. — Exposed to the heat of a lamp in a small matrass, this mineral affords water ; gently heated in a platina crucible, it gives out all its water without losing its re- sinous lustre ; it becomes a little more translucent, with a tint of yellow opaline colour; when quickly heated, it decrepitates, splits, whitens, and becomes opaque by the intrusion of the air into the fissures which are formed. It is infusible before the blowpipe. The thinnest splinters, when strongly heated, become transparent, and assume the vi- treous lustre and hardness of hyaline quartz. It is affected, like pure silica, with all the chemical agents. Caustic potash in concentrated solution very readily attacks it at a boiling heat ; it is dissolved almost instantaneously. Muriatic acid precipi- tates it in large white gelatinous flakes, when the liquor is con- centrated ; and, on the contrary, when a sufficient quantity of water is used, a precipitate is not immediately obtained, and by evaporation a transparent jelly is procured. Analysis — The water is not combined in this siliceous sub- stance. I thought, at first, that it was ; having been deceived by the difficulty of chasing the last pordons of this fluid, which is experienced when the heat of boiling water only is employed ; but, I found, that, by a pfrolonged desiccation, the water always diminished, and at length was entirely expelled. The results of its analysis are the following: JANUARY MARCH 1827. Y 386 M. Guillemin on a Gelatinous Quartz or Siliceous Sinter Silica, - 97.70>j^^ Alumina, 97.701 2.30/ It contains no lime, nor have the oxides of iron or of manga- nese been detected in it. I have in vain searched for alkalies by- means of carbonate of lead. Observatioois. — This siliceous substance differs from the quartzes and flints in many of its characters, and especially in the density, which, in these minerals, is about 9..Q5 ; but it has a great resemblance to the siliceous sinter (Quartz concretio^mc ihermogene of Haiiy). Both have the same lustre, the same hardness, the some fracture. The density differs but little ; Klaproth found that of the thermogenous quartz to be 1.807. These two minerals appear to be a siliceous jelly scarcely con- solidated ; they are both equally soluble in potash, and tljey have both the property of retaining water, and the power of ab- sorbing a new dose of it. The difference which exists between these two substances is the manner in which they appear in na- ture. The siliceous sinter or thermogenous quartz is almost al- ways in stalactites or concretions in the neighbourhood of hot springs, particularly those of the Geysers in Iceland. A sub- species occurs in the island of Ischia, upon a decomposed gra- nite, and is considered as a volcanic production *. The position of the gelatinous quartz is different. Geog7iostical and geographical positions. — It occurs in the Commune of Tortezais, in the Department of the Allier, and is very abundantly diffused there, sometimes serving as a cement to sandstones, and sometimes occurring in the midst of these sandstones, in masses often of considerable size. On the route from Noyant to Cosne, between Bussiere and Tortezais, one of these masses is seen intersecting the road for a length of 30 metres, and recurring on each side in the fields in detached pieces over a great extent. It is fissured in various directions, without any appearance of regularity. The surfaces exposed to the air are always more or less altered, and pass into floatstone (nectic quartz) I have not been able to meet with it in the form of concretions. If this • Vide Jameson's System of Mineralogy, and Manual of Mineralogy. Jbrming the basis of' Old Red Sandstone. S^7 substance has been deposited by hot springs, they must have been very large and very numerous, and it would be astonishing should no remains of them be still visible. None of those which I saw were either saline, or warm, or incrusting. The nearest warm spring is that of Bourbon TArchambault, and it does not form siliceous deposits. The sandstones which contain this gelatinous quartz must have been deposited at the same time with itself, for they are in- timately mixed. The gelatinous part always contains rounded grains of quartz, and it is rare that the sandstones have not this jelly, which serves as a cement to it, although it is only in small quantity ; and there is a transition from the one to the other by a change in the proportions of the rounded grains, and of the dis^ solved portion. The variety of sandstone which abounds most in gelatinous silica, is formed of grains of hyaline and milk-white quartz, rounded, and of a small size ; some grains of opal also are seen in it, but there is no felspar or kaolin. When the silica is in the nectic state, it is difficult to determine whether there be kao- lin or not, from the mutual resemblance which these two white and friable substances possess. Another variety of sandstone, is, in a great measure, formed of grains of hyaline quartz ; some scales of mica and spots of red oxides of iron are also perceived in it. The red spots are seen to increase in size and number ; they are formed of a siliceous paste, coloured with tritoxide of iron. The red colour at length predominates, and the mass be- comes entirely of that tint ; a multitude of small grains of quartz and of gelatinous spots are, however, seen in it. These sandstones are supported by conglomerates composed of blocks of quartz, granite and micaslate. These conglome- rates rest immediately upon the primitive formations. Above the red-sandstones there occur strata of sandstone and bitumi- nous slate, with impressions of ferns and junci, containing beds of black coal and iron-ore. They have the same direction and inclination as the coal-sandstones which they support. No rock of volcanic origin is found in all these formations. It is, there- fore, in an intermediate deposit, which might be referred to the old red-sandstone, or the lower beds of a coal-formation, that Y 2 528 Mi- H. Meikle on the Specific Heat this gelatinous silica occurs. This position is very different from that of the thermogenous quartz of the islands of Iceland and Ischia. — Annales des Mines 1826. Experiments to compare the specific Heat of Air, under a con-- stant volume, with its specific Heat under a constant pressure. By Mr Hekry Meikle. (Communicated by the Author.) XT has been long known, that gaseous bodies emit heat when compressed, and absorb it when dilated, — a property, by the by, which is not easily reconcileable with the creed of those who sup- pose heat to be mere motion. Little, however, was ascertained, for a considerable time, regarding the amount of the change of temperature accompanying a given change of density. The earliest experiments to determine this question seem to have been those of Professor Leslie. Mr Dalton and M. Gay Lussac have also engaged in the same inquiry ^. Aa the heat evolved or ab- sorbed by a change of density, depends on the difference between the specific heat under a constant pressure, and that under a constant volume, if we could find the ratio of these quantities, we should be enabled to determine their relation to the heat evolved or absorbed, and from this the change of temperature, and conversely. From certain experiments of MM. Delaroche and Berard, the Marquis de Laplace instituted some calcula- tions -f-, which happened to come nearer the point than could have been expected ; for these experiments were not at all suited to the purpose ; and it is the more remarkable, that they should • According to the experiments of this last anthor, linder or amadou is in- flamed by the sudden compression of air into one-fifth of its bulk. 'Some have even questioned the fact, and others conjecture, that combustion commences at lower temperatures, as the air is denser. But may we not suppose, with more probability, that the pressure on the tinder, being suddenly augmented in an almost nine-fold ratio, should elicit much heat from this compressible substance itself? So that, till something else be known on the subject, we need neither doubt the fact, nor believe that a fivefold compression of air would of itself generate an inflammatory temperature. The melting of fine wires, or thin metallic leaves, would afford a surer test of the temperature irt compressed air, than the kindling of soft spongy bodies. *• Annales de Chimie et de Phys. iii. 238. of Air under Volwne and under Pressure. 329 liave been used as the basis of such calculations, considering that, at as early a period (1812), MM. Desormes and Clement, had, with a very different view, made some better-contrived ex- periments, from which an approach to the true quantity could have been made with more certainty. Their method was very simple, and required no thermometer to shew the variations of temperature, — a contrivance which is said to have been first sug- gested by Lambert. No notice, however, seems to have been taken of these latter experiments, — probably because they were associated with a most fanciful inquiry after the absolute zero, till MM. Gay Lussac and Welter undertook a similar and more extensive series of experiments, giving nearly the same results. Of both of these and the inconsistent conclusions deduced from them by MM. Laplace and Poisson, I have had occasion to speak in the first volume of this Journal, where I have shewn that, whatever be the ratio of the specific heat of air under a constant pressure, to its specific heat under a constant volume ; if that ratio only be constant, the variations of the quantity of heat in a mass of air must be uniform, while those of its volume, under a constant pressure, form a geometrical progression ; and it is remarkable, that our first-rate authorities on the subject, who admit the constancy of this ratio, did not see that it was di- rectly at variance with the commonly received theory of the air- thermometer. But, although the value of the ratio referred to have nothing to do with the true law of temperature, yet its exact determina- tion would be of great moment in various researches. Consi- derable deference is due to the experiments of the illustrious philosophers above mentioned. They were well calculated for shewing that the ratio of the specific heats is constant; because, supposing any inaccuracy to attach to them, it would be com- mon to all the cases. But I had always some doubt whether their apparatus was the most ehgible for determining the exact value of that ratio. The apparatus mostly employed consisted principally of a glass balloon, to the neck of which was fitted a brass cap and stop-cock. From the side of the cap, proceeded a horizontal pipe, communicating with a vertical glass tube, ter- minating in some light liquid to act the part of a very sensible gauge or measure of the variations of pressure. The same ho. 330 Mr H. Meikle m the Specific Heat rizontal tube could be connected with a pump or condenser, for the purpose of rarifying or condensing the included air at plea- sure. Things being thus prepared, a -slight change was effected in the density of the included air ; and, after waiting a little till the former temperature was regained, the stop-cock was opened, and great care taken just to have it shut again by the very nick of time that the liquid within the gauge-tube had acquired the level of the outside, it being supposed that this was a proof that, at that instant, the included air had exactly regained the atmo- spheric pressure. A small interval being again allowed to re- store the former temperature, the column of liquid in the gauge now shewed the change of pressure due to the last variation of temperature. In this mode of operating, there is some ground for suspect- ing two sources of error, but which fortunately would be op- posed to each other. In the first place, the air would take a sensible time to pass through a moderately sized stop-cock ; and, during that interval, a considerable portion of the change of heat due to the change of density, would be lost on the sides of the vessel ; especially considering how quickly heat might be communicated between air in its then agitated state, and a vi- treous surface. On the other hand, the liquid in the gauge-tube might have acquired a force from its motion capable of carrying it to the common level of the cistern, before the spring of the air within had come into equilibrio with the atmosphere. If so, it is evident that, in the above arrangement, the stop-cock has been shut before that equilibrium was attained ; and which shut- ting would, therefore, have been too soon, were it not that it hap- pens nearly to be balanced by the other source of fallacy. To illustrate the second case, let one end of a glass-tube be stopped with the finger, and then let the other be immersed vertically in a jar of water. On removing the finger, the water, which had been depressed by the included air, will start considerably above the common level ; so that, were the finger only partially re- moved, and suddenly re-applied to shut the tube again, at such a nick of time that the water within did not spring higher than the common level, it is clear -that the force of the included air jnust still have exceeded the atmospheric pressure ; and that it of Air wider Volume and under Pressure. 331 was this excess which prevented the liquor from rising to the same height as before. With the view of making similar experiments, which should be in a great measure free from such objections, I had an appa- ratus fitted up on purpose. It consists of a large flask, made of strong tinned iron, and capable of containing 2300 cubic inches of air. The neck is of brass, about two inches wide ; and into this was fitted by grinding a brass stopper, hollow and open in- ward. At equal distances from each other^ four apertures were cut through the sides of the neck and of the stopper. Each is 1.2 inch long and 0.6 broad ; so that these together can form a communication between the atmosphere and included air, equal to 2.88 square inches, or the opening of fourteen half inch stop- cocks, and which communication can be both opened and shut by simply turning the stopper one-fourth round,-^ — an operation which requires but a very small moment of time. Near the neck, a tube branches out, and joins a vertical glass tube, which, terminating in some light liquid, forms the same sort of gauge as in the apparatus first alluded to ; and, on the opposite side^ is an aperture for attaching a pump or condenser to change the density of the included air. The air-vessel is in- closed in another, both for the purpose of keeping the tempera- ture steady, and also for applying a bath to maintain any tem- perature required. But, during tempestuous weather, or when the barometer is very unsteady, no experiments can be made with such apparatus. As a preliminary step in the use of this instrument, it is ne- cessary to ascertain at what rate we should turn the stopper, in order that the included air, when its pressure has been previous- ly changed from that of the atmosphere by about 0.4 inch of mercury, may have a sufficient opportunity of regaining the ex- ternal pressure. To determine this, the following method was employed : Having injected air till the increase of pressure, when the temperature had settled, was indicated by a depressed column of water of about six inches, I turned the stopper one- fourth round, by which it was both opened and shut. During this operation, I noted how far the previously depressed water in the gauge tube started above the common level. The same operation was repeated, with the difference of only turning the 332 Mr H. Meikle on the Specific Heat stopper one-eighth round, so as to leave its apertures complete- ly open ; and, on observing the gauge, it just sprung to the same height as before. Repeated trials satisfied me, that, with such small variations of density, it would require considerable haste to turn the stopper too quickly. In both of the cases just men- tioned, the range through which the stopper turned was limited by a catch. But in the experiments to be afterwards noticed, I generally used a hghter fluid than water. It is evident, that, instead of injecting air, as I usually did, to increase the pressure above that of the atmosphere, it would come to the same thing, if we first close the large vessel at a temperature a few degrees below that at which we wish to oper- ate, and then raise it to the temperature which is to remain con- stant during the experiment. This consideration affords, per- haps, the simplest means of explaining the rationale, or use of this sort of experiments. For, let the pressure of the air when just shut in, be in equilibrio with the atmosphere, but suppose that the temperature of the apparatus is next raised, so as to in- crease the pressure and depress the liquor in the gauge b inches, which we may call b degrees ; then, if, whilst this augmented temperature of the apparatus remains constant, the . stopper be turned one-fourth round, as above described, the equilibrium with the atmosphere will be for a moment restored, the communication with it again cut off, and the included air cool- ed by the dilatation, but it will soon absorb heat, and recover the former temperature, as will be indicated by a second depres- sion of c inches or degrees. This is obviously the change of temperature due to the excess of the quantity of heat, which would raise the temperature b degrees, under a constant pres- sure, above what raises it b degrees under a constant volume. From this it would follow, that the quantity of heat which raises the temperature b degrees under a constant volume, would only raise it b — c degrees under a constant pressure ; or, that the specific heat in the first case is to that in the second as b — c to b. Strictly speaking, neither the volume during the first increase of temperature nor that during the second is constant, because the depression of the liquor in the gauge tube makes a little noore room for the air. This, to be sure, could be obviated by of Air under Volume and under Pressure. using a tall jar, and pouring in more liquor till that in the gauge reached its former level. However, it is easier and more accu- rate in practice, to overlook those increments of volume, because they will be proportional to the depressions themselves, and therefore, the ratio of these depressions, which gives the thing wanted, is not altered by this circumstance. For the same rea- son, it is better to neglect any change in the height of the liquid in the cistern, and only to observe its height when the air-vessel is open. As an error might have been introduced by allowing the li- quid in the tube to spring up and displace a portion of the air it contained, or at least to render the volume uncertain by its undulations, a cork was struck in it, immediately above the com- mon level. It was not so tight as to prevent the passage of air, but it operated as a sufficient check to the rise of the denser fluid. Every other precaution I could think of was attended to, and the mean of many experiments with this apparatus gave the ratio of the specific heat of air under a constant volume, to that under a constant pressure, as 1 to 1.334, which is so near- ly as 3 to 4, that I am inclined to consider this the true value. However, I intend to repeat these experiments, and to prove them by a different process. The ratio of 3 to 4 does not completely bear out the amend- ment proposed on the Newtonian theory of sound, by the Mar- quis La Place. But a complete theory ought to account for the almost absolute control which wind exercises over the intensity/ of sound. I have often thought that both the intensity and the excess in the experimental over the theoretical velocity, are con- nected with the reaction of the earth's surface. As an illustra- tion of this, sound is well known to be rendered more intense, by passing along the face of a wall or precipice ; and very likely it is at same time accelerated. From the experiments of MM. Desormes and Clement, the ratio of the specific heat of air under a constant volume, is to that under a constant pressure, as 1 to 1.354; and from those of MM. Gay Lussac and Welter as 1 to 1.375. The fractional part of both approaches to J, and Mr Ivory has adopted this, and suggested a reason why it should be the true value *. By * Phil. Mag. Ixvi. 9. 334 Mr H. Meikle on the Specific Heat adopting the fraction J, Mr Ivory obtains the following equa- tion, 1 4- ar = ^' ; or. Where t is the initial temperature, a a constant, and i the change of temperature, produced by changing the density from unit to g. That this is the true value of i, considered as proportional to the change in the quantity of heat, Mr Ivory thinks pretty certain ; because he supposes a consequence of it to be, " that, when air contracts or enlarges its dimensions, the heat disen- gaged or absorbed follows the proportion in which the linear distance of the particles is lessened or augmented," — an opinion which he thinks so probable, that it should not be rejected till the contrary be placed beyond all doubt. Now, although my experiments are favourable to Mr Ivory's conjecture regarding the value of this ratio, yet I cannot ac- quiesce in the reason which that able mathematician has given for fixing on that quantity. I shall not enlarge on its incompati- bility with the law of temperature which I formerly laid down ; but that it may not be urged as an argument against that law, I shall, with every deference to Mr Ivory, shew that his view of this part of the subject is otherwise untenable ; because it in- volves a mistake, in that he has inadvertently taken the linear distance of the particles of a mass of air as proportional to the cube root of the density, in place of the cube root of the volume. For it is obvious, that 5^ is not proportional to the linear dis- tance of the particles, but to its reciprocal ; and whilst t is the same, i varies as g^ — l^ that is, as the difference of the re- ciprocals of the linear distances at the beginning and end of the change of density ; so that neither the heat of combination nor the quantity i follows the variation of the linear distance of the particles. For, as we formerly saw, the first follows the va- riation of the logarithm of the volume or cube of the linear dis- tance. The following is a different mode of estimating the ratio of the specific heats, by using great changes of density. Let the density of the external air = e, and suppose the air in a close vessel to be rarified till its mass or density = r ; and that when it has acquired the common temperature, a communi- of Air under Volume and under Pressure, 335 cation with the atmosphere is opened, restoring the external pressure, whereby the density within is increased frooa r to m. The density of the air which has re-entered will thus be dimi- nished from e to 77^5 and its mass will he m — r. Now, from what was formerly shewn of the air-thermometer, the heat evolved by the compression of the rarified mass r, will be to that absorbed by the dilatation of the re-entered mass m — r, as r log — to — {m — r) log — . Their difference or ^^S \ \) \§ \ i^ay therefore represent the change of temperature by the true scale, or the heat evolved by a mass of — J f - y. But the mixed mass is m^ and, therefore, the rise in its temperature on the same scale, is- log -j ("")"'("■) \ = Hence, i the rise of temperature in the mass w, reckoned on the common scale, is equal to what any mass of air at the tem- perature T would undergo by increasing its density from unit to — J - j"» = g. Wherefore, if the specific heat of air under a constant volume, be to that under a constant pressure, in the constant ratio of 1 to 1 + ^, we have i =: i% — • 1 1= -^1 1 I, from the law of Boyle. Hence, p =— , and loff — ° m logg To find the value of r when the surplus heat, or log -j — ( jm I — - log -, is a maximum, -we have 336 Mr H. Meikle m the Specific Heat d\os \ ~ I -^ l"» r = — ' — — = o. Hence, d m = o, ° ( e\r/ } X m p & and, therefore, log- d r — d r = o ; or hyp-log - = 1, and r = ^^,^..^^- I^is value of r is independent of x. When r 2.71828 ^ and X are given, m may in every case be found, from the above formulae, or from , w X r . r m lOff — = m ; — lOff -. ^ e I + X ^ e l^x = |, and r = ^ly^' then m = .903184 e. Every value of m, but its minimum, answers to two different values of r. For instance, r = - e should give the same value to m as rz= - e. If three-fourths of the air be extracted from a close 4 vessel, and, after the temperature has settled, one-fourth be in- stantly restored, no change of temperature should ensue. The law of temperature admits of a somewhat simpler inves- tigation than was formerly given. Let t be the temperature, or rather the indication on the common scale of an air-thermome- ter, p the pressure, and ^ the density of the mass of air ; then a and b being constants, we have, as before, from the law of Boyle, p=z6g(l-fa^). Now, the specific heat under a con- stant pressure being to that under a constant volume, in the in- verse ratio of the variations of temperature produced in these two different cases by equal variations in the quantities of heat, the following expressions respectively contain all the variables which enter into these specific heats, relatively to the ordinary graduation. 1 -__ JL ^g and— -— ^P dt~ d^'l+af df dpi+ut which are obtained from the above equation, by making jo and ^ respectively to vary with t, whilst the other is constant. The variations of the quantities of heat being constant, and, as men- 4 of Air under Volume and under Pressure. ^^7 tioned above, the same in both terms, are omitted, as also the constant linear degree of the common- scale. Let the temperature be reckoned on AB, as on the common ^cale of an air- thermometer commencing at A or — 448° F ; and let CF be a line of such a nature, that every ordinate as BC, EF, &c. may be proportional to the specific heat of air under a constant volume, at the respective temperatures B, E, &c. So that the intercepted areas will denote the corresponding variations in the quantity of heat under a constant volume. But if the spe- cific heat of air under a constant pressure exceed that under a constant volume, in the constant ratio of K to 1, and if these ordinates be every where increased in that ratio, another line GD, passing through their extremities, must be of the same na- ture with CF, and the intercepted areas to the former as K to 1. Again, let the specific heat of a mass of air under a constant pressure be BD x 1° ; and let its temperature be raised from B to E under the same pressure ; then the area BDGE will denote the increase of heat, and EG X 1 the specific heat under a con- stant pressure at the temperature E. Now EG : EF : : K : 1, wherefore EF x 1° is the specific heat of the dilated mass at the temperature E, under a constant volume. But EF x 1° would still have been the specific heat, had the air under its original volume been raised to the temperature E ; and because EF : EG : : 1 : K, its specific heat at the temperature E under a con- stant pressure would have been EG x 1°, as before. Hence, the constant ratio of the specific heats renders them independent of the actual density or pressure, and, therefore -p and ~- are constant quantities. It thus appears, that the above ex- pressions for the specific heats answering to a degree on the com- mon scale, vary inversely as \ -\- a t:, or, that any ordinate BD, or BC is inversely as AB, which is the well known pro- perty of the hyperbola ; and, therefore, CF and DG are both hyperbolas, having A for their centre, and AE for an asymptote. We have, then, without going through the process of integrat- M. Berzelius on the Detection ing a partial differential equation, arrived at the same construc- tion as was used on page 337, vol. i., and which represents the relation between the common and true scales of temperature, viz. that when the variations on the latter are uniform, those on the former follow a geometrical progression. On the Detection of Arsenic in cases of Poisoning. By J. L. Berzelius. XN cases of poisoning with arsenic, the individual may have taken the deadly poison either in the pulverulent form, or in a state of solution. In the first case, we can almost always detect visible particles of arsenic in the contents of the stomach, or on the inner coat of the stomach, where they are distinguished by dark red spots, on which they are to be looked for. The na- ture of these particles, although much under the one-tenth of a grain in weight, may be ascertained with great care and perfect certainty by the process or test of reduction. The following method I employ in the use of this test :—A glass tube, from one-tenth to one-seventh of an inch in diameter, is drawn out, at one extremity, into a fine point, from two to three inches in length, which ought not to be wider internally than the thickness of a coarse knitting needle, and is then hermetically closed at the extremity. (i -r^' ^ -^ The particle of arsenic (even the one-hundredth part of a grain in weight is more than is necessary), is moved upwards to a, and covered with charcoal powder, which has been previously exposed to the flame of the blowpipe, to drive ofl* any moisture it might contain, to 6. The tube is then brought, in a horizontal position, into the flame of a spirit of wine lamp ; and in such a way, that a, where the grain of arsenic lies, remains beyond the flame. As soon as the charcoal at h is heated to redness, a is brought into the flame, by which the arsenious acid is converted into gas ; and, during its passage through the glowing charcoal, is reduced. The metallic arsenic is condensed in the small tube, at th'e line of Arsenic i?i Cases of Poisoning. 389 where it is beyond the flame, in the shape of a shining, dark me- tallic^ing, which, by gentle heating, can be driven farther for- ward ; and thus more is accumulated, by which it acquires a higher lustre. The small diameter of the tube prevents all cir- culation of air, so that no part of the metal is reduced. It only remains to determine the arsenic by its smell. This is effected, if we cut the tube between the charcoal and the metal, then heat it gently in the place where the metal rests, while we hold our nose over it but at a little distance. The second case occurs, when no visible grains of arsenic are present, as in those instances where death has been caused either by solution of arsenic, or by finely pounded arsenious acid. When the poisoning has been caused by the solution of arsenic, it is often impossible to detect the arsenic, because the solution has been carried off before ^ death. If, however, some portion of it still remains, it is discovered by heating the contents of the stomach, at a boiling heat, with caustic potash, and then with muriatic acid. The filtered fluid is reduced, by evaporation, to a smaller volume ; and, if necessary, again filtered, and then a stream of sulphuretted hydrogen passed through it. The fluid is now heated, to cause the precipitate to collect, or evaporated, if it does not subside until it does, and then filtered *. If the quantity of precipitate is so small that it cannot be mechanical- ly removed from the filter, it must be removed from the paper by means of caustic ammonia, and the fluid evaporated in a watch-glass. The sulphuret of arsenic can be oxidized in twa ways : either it is dissolved in a little aqua regia, until all the ar- senic is converted into arsenic acid, the fluid freed from sul- phur, dried by a gentle heat, then the residuum dissolved in a drop of water, and supersaturated with lime-water : Or, bet- ter, we mix the sulphuret of arsenic with saltpetre and defla- grate the mixture at the end of a hermetically sealed glass-tube. We first melt a little saltpetre in the tube, and then gradually • If the quantity of arsenic is very small, the fluid becomes yellow, with- out precipitation ; but if it is then evaporated, the sulphuret of arsenic falls in proportion as the acid concentrates during evaporation. If the fluid be- comes yellow, without any precipitation of sulphuret of arsenic, during the evaporation, it cannot be considered as a sign of the presence of arsenic. This colour almost always occurs when the fluid contains nitric acid, which reduced to the state of nitrous acid, colours the dissolved animal substances yellow. 340 M. Berzelms on the Detection drop into it small portions of the mixture, which burn without deflagrating, when too Httle saltpetre is not used. The mass is dissolved in some drops, or in as small a quantity of water as possible, then lime-water added in excess, and heated to boiling, by which the arseniate of lime is more easily collected and washed. The precipitate is collected, mixed with fresh burned charcoal powder, and put into a glass tube of the following form ; 7. a a so that the mixture comes to lie at a. The tube is first gently heated to drive off any moisture the mixture may have ab- sorbed, and then the under part of a is kept in the flame of the blowpipe until the glass begins to melt. The arsenic is now re- duced and collected in the neck b, where it is spread over so small a surface that the smallest quantity may be detected. One- tenth of a grain of sulphuret of arsenic is sufficient to afford a satisfactory and decisive reduction test. Even the arseniate of lime, which is obtained from one- sixth part of a grain of sul- phuret of arsenic, can, if carefully collected, serve for three dif- ferent reduction tests *. In using these delicate tests, we must be sure that our re- agents contain no arsenic. All the sulphuric acid which is not obtained from volcanic sulphur, but either from the sulphur from iron-pyrites, or immediately from iron-pyrites, contains arsenic, and affords, when it dissolves zinc or iron, an arseniuretted hy- drogen gas. If the same acid is used in the preparation of sul- phuretted hydrogen gas, we have to dread a mixture of arseniu- retted hydrogen gas with the sulphuretted hydrogen gas, by • The following more simple mode of obtaining metallic arsenic from sul- phuret of arsenic has been lately proposed by Berzelius. A very small por- tion of sulphuret of arsenic is introduced into a tube, like that on page 338, and brought up to a. Then a piece of steel piano-forte wire (No. 11.), an inch in length, is inserted into the tube, so far as the surface of the sulphuret. The steel-wire is next to be heated in a spirit of wine lamp, and the heat gradually raised in such a manner that the sulphuret, in the state of vapour, passes along the surface of the glowing iron. In this way, sulphuret of iron, and sublimed metallic arsenic, are obtained. The operation ought to be conducted slowly- Shavings of iron will not answer, because the arsenic combines with them, without any sublimation. of Arsenic in Cases of Poisoning. S41 which the precipitation of an arseniated sulphur may take place, because the hydrogen of both in the test-fluids becomes oxidized by means of the air. The muriatic acid obtained by means of such a sulphuric acid contains also arsenic. We must therefore use, in such experiments, distilled sulphuric acid, but not until we have previously tested it by means of sulphuretted hydrogen for arsenic. The same applies to the muriatic acid used in such experiments. In all cases of this kind we cannot use too much caution. The reduction- test h the only certain one, and it renders all others superfluous. If this does not succeed, the result is al- ways unsatisfactory. Even the garlick arsenical smell so much depended on, is not to be trusted without actual reduction, as such a smell is sometimes evolved from the animal matter from the stomach. We may conclude by remarking, that no chemist or medical man can conscientiously and legally appear in a public court, as an evidence in such a case, without he has actually himself taken the contents from the stomach, or has had them sent to him, under proper seals, by a trust-worthy medical man, who declares on oath that he has taken the same from the sto^ mach *. On a Chemical Composition of ZmJcenite and Jamesonite. By H. Rose, Member of the Royal Academy of Berlin. And Description and Analysis of Pyrochlore^ a new Mineral. By F. WoHLER. I. On the Chernical composition ofZinkenite and Jamesonite, JL he Zinkenite, in its chemical composition, approaches more nearly to Jamesonite and red silver, than to any other minerals. I found it to contain the following constituent parts : Sulphur • From the great delicacy of the reduction-test, it is evident that extremely minute portions of arsenic may be detected. This being the case, the court is entitled to demand of the chemist or medical man, on examination, whether or not he can prove that the articles of food, used by the deceased, did not contain minute portions of arsenic. Bread, for instance, is sometimes adul- terated with alum ; alum is prepared, at times, from aluminous rocks, con- taining iron-pyrites; and iron-pyrites, as mentioned by Berzelius, contains arsenic. This view might be farther illustrated. — Ed. t In the third analysis, the quantity of sulphur could not be determined. JANUARY — MARCH 18^7. % Second. Third. 22.53 38.71 40.35 0.74 0.19 0.21 2.65 2.9G 34.90 ' 34.47t 842 Mr Wohler 07i Pyrochlore^ a new Mineral Species. 5^2.58, lead 31.34, antimony 44.39, copper 0.42 = 99.23. The Jamesonite, like the »inkenite, consists principally of sulphate of antimony and sulphate of lead, but in different proportions. Three analyses of Jamesonite afforded the following results : First. Sulphur, - - 22.15 Lead, - - 40-75 Lead, with traces of iron and zinc, Copper, - - 0.13 Iron, - - 2.30 Antimony, - - 34.40 34.40 parts of antimony in the first analysis, combined with 12.8*7 parts of sulphur, to form the sulphuret of antimony, and 40.75 parts of lead, with 6.33 parts of sulphur, to form sulphu- ret of lead. The excess of sulphur, 2.95 parts, is nearly suffi- cient to form, with the iron, sulphuret of iron. Although the quantity of sulphuret of iron in Jamesonite is considerable, I still consider it as accidental, because neither iron nor lead, in the oxidated or sulphuretted state, combine together ; the crystal- lised Fahlerz, for example, in which sulphuret of iron occurs, never contains sulphuret of lead, even when the tetrahedrons of Fahlerz are imbedded in lead-glance. The true composition of Jamesonite may be expressed by the formula 3P& S" -f 4S& S" ; the sulphuret of antimony in it containing double the quantity of sulphur, as the sulphuret of lead. II. On Pyrochhre, a new mineral species. Pyrochlore occurs in the neighbourhood of Friederich- schwarn in Norway, in zircon-syenite, where it was first found by Dr Tank. Dr Wohler, during his journey with Berzelius and Brongniart, met with this mineral near to Laurvig, in veins in zircon-syenite. Berzelius proposes to name it Pyrochlore^ in order to distinguish it from Polymignite, which, before the blow- pipe, retains its black colour, while the pyrochlore becomes yel- low. Its colour is reddish-brown, like brown titanite, and on the fresh fracture appears almost black : — in thin splinters, is translucent ; in thicker pieces opaque. It crystallises in regular octahedrons. It is generally imbedded in felspar, sometimes in Elaolite. Its specific gravity = 4.206 — 4.216,— i?o*^. It scratches fluor-spar, but is scratched by felspar. Its streak is Mr Macvicar on the Seed of the Stipa Pennata. 343 brown. The fracture is conclioidal, without any trace of clea- vage. The surface of the crystal is shining and smooth, but the fracture surface splendent ; and lustre between vitreous and resinous. Its constituent parts are as follows : Titanic acid 62.75y hme 12.85, oxide of uranium 5.18, oxide of cerium 6.80, oxide of manganese S.75, oxide of iron ^.16, oxide of zinc 0.61, water 4.20, fluoric acid, quantity not determined, magnesia a trace, = 97.30. The Lam of the Preservation of Species, illustrated hy the Phe- nomena of the Seed of the Stipa pennata. By Mr John Mac- vicar, Lecturer on Natural History in St Andrew's. (With a Plate.) Communicated by the Author. XJLLTHOUGH it caunot be said that the primary object of nature, in reference to a species, is to prevent its destruction, yet its ex- istence is an essential condition to that end, whatever it may be, and accordingly, nowhere do we observe a more admirable me- chanism, than in those organs which are most eminently conserva- tive or reproductive. The general law by which their develope- ment and efficiency are regulated, may perhaps be thus stated, that, in proportion as the causes operating to destroy a species increase, so also do the organs or functimis operating to pre- serve it. Thus, as we descend the scale of animated beings, the succes- sive species become more and more restricted in their faculties, their cunning, or swiftness, or force, by which they may meet their enemies, the number of which is also increased, or in those resources by which they may survive the violent action of the elements, which beat upon their more minute and simple structures, as rudely, and as boisterously, as upon the more perfect animals. Their liability to destruction, then, becomes greater as we descend. But to counterbalance this, we find that, in obedience to the law which has been stated, the very degradation of their structures becomes subservient to their existence. For, by a collateral diminution of sympathies, the life of the individual becomes more independent of partial in- z2 S44 Mr Macvicar on the Seed of the Stipa Pcnnata. juries, and a tenacity is imparted to it, which would even be ridiculous in the higher animals. Thus, it is very absurd to think of a man continuing to live after his head had been cut off; yet low in the scale, we find many species which, when deca- pitated, can serve themselves with new heads, as efficient as those of which they had been deprived, and scarcely differing from them, but in their paler complexion. Of this circumstance Mr Dalyel availed himself, in his very interesting investigation of the Planariae. For when he wished to know how many eyes the Planaria nigra possessed, not being able to distinguish them on account of the black colour of the animal, he decapitated seve- ral, and was then able to count the eyes in the pale reproduced heads. As to legs, the amputation of one of which without sur- gical aid, would prove inevitably fatal to a man, there are many animals which seem to part with them without much inconveni- ence ; while there are others (as the crabs), which, according to recent observations, seem to scorn the possession of a leg when in- jured, casting it triumphantly from them. If we descend still farther among animals still more beset by enemies and accidents, we find species which really seem to be *' immortal under the edge of the knife,"" which to cut in pieces, is only to give being to so many individuals as perfect as that which was attacked. The action of the same admirable law is illustrated in the re- production of the race. Thus in the most perfect animals, the species is divided into two groups, only one of which is capable of producing offspring. As we descend, this bisexual character is obliterated, and every individual, often without the presence of another, acquires this power. Still lowerj not only do we find each animal provided with a specific apparatus for this pur- pose, but the same end accomplished in other ways also, as by gems and spontaneous division. In the vegetable economy, which runs parallel to that of ani- mals, we observe the same law to operate. Thus the oak, which cannot easily be destroyed, the individual life of which survives the sweep of many ages, can only be reared from an acorn ; while the tender moss, which springs up among the turf beneath which its roots are spread, or the parasitic lichen on its trunk and branches, the lives of which are subject to a multitude of Mr Macvicar on the Seed of the Stipa Pennata. 345 accidents; may be propagated both by sporules produced in pro- per seedvessels, by germs and otherwise. But besides this beautiful law, the action of which may be distinctly recognised, preserving the species of organised beings in existence, notwithstanding the perpetual destruction which they wage against each other ; we are able to observe the traces of another no less beautiful, that, in proportion as a species is useful in the economy of nature, so are the developement and ef- ficiency of the organs and functions that effect its diffusion. This might be inferred a priori, from what we know of the attributes of the Creator, and the analogy of his works. This^ however, is a mode of reasoning not admitted in Natural History, in which a law must only be framed, as a generalised statement of a number of observed phenomena, tending to a common pur- pose. But that such a law exists we observe many traces of evi- dence. Thus there is no tribe of plants more eminently useful in the economy of nature than the grasses, the foliage and seeds of which supply the first necessaries of life, not only to man but to a multitude of the inferior animals. And, perhaps, in no tribe equally highly organised, do we observe the same tenacity of life, or the same economy and care in the reproductive organs, to avoid the introduction of parts that might be easily injured, and so prevent a successful fructification. In the grasses, the delicate coloured flower that gives so much beauty to most other tribes, is replaced by concave husks, which are not only most hardy, but so situated that the weather can scarcely penetrate to injure the essential organs within. Besides this, the peculiar structure of the embryo, which admits of a number of stems from one seed, might be mentioned, the copious albumen, &c. But I proceed to describe, and a few words will sufiice, the beautiful structure of the awn exhibited in a species of this family, which effects the introduction of the seed into the soil so wonderfully, that I cannot satisfy myself with ad- miration. The Stipa pennata is a most elegant species of grass, which, though not a native of Scotland, thrives luxuriantly in the open border. Its seed is closely invested by the glumaceous perianth, which consists of two husks, a larger and a smaller, the former of which overlaps the edges of the latter, and almost entirely 846 Mr Macvicar on the Seed of the Stipa Pennata. envelopes it. Thus the strong outer covering of the seed is pro- duced below into a very sharp rigid spine ; and terminated above by a long awn, which is articulated to its summit. Originating near the base, and proceeding up certain ridges on this the invest- ing valve chiefly, are lines of stiff hairs pointing upwards. The awn, when fully developed, is about thirty times the length of the seed, or about fourteen inches. It is round, tapering and plumose, with the exception of about three inches at the base, which are compressed, longitudinally sulcated, and without hairs. The seed, therefore, and its appendages, possess a structure such as is imitated in a barbed and feathered arrow, which is so well calculated to find its way into the ground in a vertical di- rection. Many seeds, however, possess a similar structure, and it is not this which gives to the awn of the stipa its most striking peculiarity. It is a change which takes place upon the awn, after it has left the plant that produced it. When it has fallen from the parent plant, it enters the soil vertically, and in a few hours the base and sulcated part of the awn becomes twisted, and the feathered portion becomes horizontal. In consequence of which, it is blown round by the autumn winds like a vane, and every turn screws it farther down into the earth ; for the hollows and ridges which, when it remained upon the plant, were only longitudinal sulci, have now given rise to the hollows and ele- vations, in a word, to the threads of a screw. Thus it is rfioved down, and whatever is gained, is prevented from being undone by a reverse motion of the vane, in consequence of the stiff hairs upon the glume which act as barbs. When it has been thus worked down into the moist soil, into the situation most favourable for germinating, the attachment be- tween the awn and seed is dissolved ; for having drawn up many when they were in this condition, I have invariably procured the awn only, and never, by any chance, the seed. Such appears to be the function of the " spiral articulated deciduous awn '' of this interesting species *. • The seeds of the Stipae often occasion great inconvenience and trouble to travellers, and even to the domestic cattle of the districts where they grow. This fact is well stated in the following notice by Mr Raspail Ed. " On the morbid accidents to which animals are exposed by the seeds of Stipa pen- nata and capiUala.-^lt is known that the husks of the genus Stipa terminate ( 347 ) The accompanying drawing represents the seed and its ap- pendages, more or less magnified. Explanation of the Figures in Plate I. Fig . 6. The two valves of the glumaceous perianth, widi the stiff hairs, the spine and articulated awn. 7. The grain, with part of the skin torn at the base, to shew the albumen, of which nearly the whole is composed, the cotyledon and the embryo. 8. The seed, with a fourth part of the awn, to shew its form when ready to separate from the spike* 9. The same, as it appeals some hours after separation. Account of the Observations and Experiments made on the Diurnal Variation and Intensity of' the Magnetic Needle, by Captain Parry, Lieutenant Foster, and Lieutenant Ross, in Captain Parry'' s Third Voyage, with Remarks and Illustra- tions. By Peter Barlow, F. R. S. Mem. of the Imperial Academy of St Petersburgh, &c. (With a Plate.) Com- municated by the Author. J\.S the experiments referred to in the head of this article were performed under such extraordinary advantages of locality, of at the base in a reversed cone, which is very sharp, and covered with stiff hairs directed upwards, so that when the point penetrates into any substance, the hairs not only prevent it from coming out, but contribute to make it go deeper. M. Desfontaines, in his Flora Atlantica, and M. Lamarck in the Ency- clopedie, have pointed out the inconveniences to which a seed so organised sub- jects travellers passing over the fields of Barbary, Greece, and Portugal, at the time of ripening of the stipas. The seed penetrates into their clothes, and sooner or latter disconveniences them in a high degree, by produc- ing scratches of various depths upon the skin. A great mortality of the cattle, which took place in 1823, in the neighbourhood of the village of Berczel in Hungary, afforded an opportunity to the Professors of the lloyal University of Pesth, of making known a still more singular effect pro- duced by these seeds. It was found that the seeds of the stipas, which abound in the pasture grounds of Berczel, stuck to the wool of the sheep, penetrated into the skin, and even made their way to the internal organs. On dissecting a great number of these sheep, seeds were found in the vicinity of the liver and in the peritonaeum, and the skin, examined between the eye and the light, had the appearance of a sort of riddle. As these grasses occur in all the south- 348 Mr Barlow on the Diurnal Variation instruments, and of observers, they cannot fail to be highly in- teresting to every one who has paid attention to this curious and important branch of natural philosophy. With regard to locality, no place could have been more admirably situated than Port Bowen, in latitude 73° 14' N., longitude 88° 54' W., with a dip of 88° 1', and consequently within a very short distance of the magnetic pole, and yet sufficiently remote to leave to the needles a natural directive power, which they would in all pro- bability have lost, had the approximation to the Pole been much greater. With regard to instruments, every thing that could be effected by the skill of the most distinguished artists in London, was liberally supplied to the expedition by the Government ; and as observers, it is sufficient to mention only the names of Parry and Foster, as they cannot fail to inspire us with every possible confidence, both with respect to the accuracy of the observations, and to the most careful and unbiassed registry of the results. It is but fair, however, to state, that these two distinguished indi- viduals alone, would not have been able, with all the zeal they are known to possess, to have obtained such a series of results as those to which we are now referring. It was necessary for this that they should be seconded by the cordial assistance and co-operation of the other officers of the expedition. This assist- ance was cheerfully given ; and it is acknowledged in the most handsome and liberal terms by the authors of the memoir in which these experiments are recorded, and which has been re- cently pubhshed as a separate part of the Transactions of the Royal Society for 1826. The experiments commenced about the 10th of December 1824, and were continued to the end of May 1825 ; and, when we consider that, for a considerable part of this time, the sun was below the horizon, — that the thermometer was sometimes 40" below zero, — that the place of observation, a snow house, ern parts of Europe, the above fact ought to fix the attention of the agricul- turists of those countries. The stipse do not furnish good fodder, and the meadows would lose nothing by their absence. If they could not be extirpa- ted all at once, the flowers are surmounted by an awn upwards of a foot long, by which they might easily be plucked off, before detaching themselves sponta- neously. Should a seed happen to have buried itself in the substance of the skin, it would require to be extracted by the ordinary means, for accidents of this kind are not to be remedied by a more complicated treatment." and Intensity of the Magnetic Needle. 349 was at a distance from the ships, in order that the needles should be out of the influence of the iron on board ; and that, not- withstanding these obstacles, the needles were carefully watch- ed, the experiments performed, and the results carefully regis- tered every hour, and frequently oftener, during this whole pe- riod ; we shall feel convinced, that more than common exertions were made, and more than usual interest must have been excit- ed, in the pursuit of these curious and valuable experiments ; and, if we add to this, that these energies and these means ^were employed in a situation where Nature has placed her great depot of magnetic powers, and where every phenomenon of this kind is exhibited on the grandest scale, we shall then, and not till then, sufficiently appreciate the value of these interesting and important results. With this feehng, 1 have thought that a brief abstract of these experiments would be acceptable to many of the readers of the Edinburgh Journal, particularly to those who have not the opportunity of consulting the original memoir ; and I have accordingly, in the following pages, endeavoured to convey within the least compass, a general view of the subject, and have ventured also upon one or two illustrations of some of the theo- retical points touched upon by the authors of the papers in question. The first of the magnetic articles is by Lieutenant Foster, from which it appears, that, previous to his leaving England, he had de- termined upon making a series of observations on the daily varia- tion of the magnetic needle, when any opportunity offered of so do- ing J and the first occurred at Whale Fish Islands, during the time of trans-shipping the stores from the transport which had accom- panied the expedition to that place. The time employed in these experiments was only three days, consequently the results are not so certain as we could wish ; but it is satisfactory to find, that the few facts which were obtained agree remarkably well with each other, both as to quantity and to the time of the day when the variation was the greatest westerly, — the least westerly variation, or the maxi- mum of "Easterly variation, occurred during the night, and was not observed. The greatest daily variation westerly was 23', and this occurred at 1*^ 10' p. m., at which time the sun was west by compass, the mean variation being 70° 2' W., and dip 82° 5S' W. The im- portant remark, distinguished above by italics, seems to have been a strong incitement to Lieutenant Foster to prosecute the subject again on a larger scale the next favourable opportunity, which did not occur till the ships were laid up for the winter at Port Bowen. At this place, as we have already stated, the experiments were be- gun on the 10th of December 1824, on one needle only. In the 850 Mr Barlow on the Diurnal Variation course of this month, however, the varied phenomena which this one exhibited, while every thing besides appeared to partake of the stillness and monotony of this dreary region where it was posited, excited that degree of interest amongst the officers of the expedi- tion which we have endeavoured to describe ; and with the new year commenced a much more extended series of experiments on the daily variation, the variation of intensity, and, in fact, of the whole series of which it is intended to give a general outline in the subsequent pages. The detail of the daily variation experiments forms the second of these articles. After describing the needles employed, marked No. 1, and 2., and a third, employed exclusively for determining the changes of intensity ; and also acknowledging the assistance of Lieutenants Sherer, Ross, Messrs Crozier, Richards, and Head, as also that of Mr Hooper for the delineation of a very accurate dia- gram*, offering a graphical exhibition of the several changes ; the au- thors proceed to take a sort of general review of their results, as fol- lows : " Soon after the observations were commenced, it was ascertain- ed that, twice in every four and twenty hours, the needles moved past a certain point, which may be denominated the zero, or mean magnetic meridian ; a fact which was first rendered clearly apparent from the accompanying diagrams, already mentioned, by which it appears, that, in every instance except one, both needles every day passed the line in question. On a single day, February 24., the needle No. 2. did not arrive at it during its eastern motion. " The means of the times of the needle passing this zero, as de- duced from four months* continued observations, is 6 hours 15 mi- nutes A, M., and 4 hours 37 minutes p. m., the mean time in each month being as follows : 1825. A, M. p. M. January, 6 hours 00 min. 4 hours 00 min. February, 6 30 4 00 March, 5 30 ' 5 00 April, 7 00 5 30 6 15 4 37 To avoid the insertion of many useless figures in the tables, the resulting amount of easterly or westerly dejiection on each side of the zero has been computed. The maximum westerly variation at Port Bowen, appears from these observations generally to have occurred between the hours of 10^ A. M. and V^ p. m., the mean result of 120 days' observations being ll'^ 4.9"^ a. m. The minimum westerly variation, or the greatest deflection of the north end of the needle to the eastward, took place between 8^ p. m. and 2^ a. m., the mean time deduced as above being 10^ V^ p. m. * In order to give an idea of this diagram, we have given a sketch of it in Plate v., for six days, viz. from the 20th to the 26th of March, T^cbvnT.Tvetu Fkil. Jou r. p.Si Draum hy W.H.Ba/rlow CToprvvcoAy '^epTexentotvoTv of tfie daily varcatiorh ortne 7ieeme aZ lartBoiveiv 3° Mn.^nk9.n f 1° O 1^ J^Ui6hed hjrA£lacTcEdinl82/. E.MilchtS,: and Intensi of the Magnetic Needle. 351 In a few instances the maximum deflection of the needle to the westward occurred as early as 8^ a. m., and as late as 3^ p. m. ; and, in the like manner, the greatest deflection eastward took place at 2^ and 3^ p. m., on some few occasions. In all these anomalous cases, however, it was remarked, from simultaneous observations on the times of vibration of a suspended horizontal needle, that these irre- gularities were evidently due to an extraordinary alteration in its intensity, which produced a deflection contrary to the regular order of the motion of the needle. The diurnal change of direction appears, by these observations, to have been seldom less than one degree, and sometimes to have amounted to five, six, and even seven degrees j and there can be no doubt, that the changes in this amount were more or less due to the position or influence of the sun, and probably of the moon, on the terrestrial magnetic sphere ; but the particular law of this influence is a question of great delicacy, and of intricate research, and will be best left to the investigations of those who are theoretically conver- sant with these subjects. After these general observations, the tables to which they allude follow ; these, however, occupy forty quarto pages, and, of course, we can only attempt a general explanation of them j they are given under the follow mg title. " Tables, shewing the observed daily variations of the horizontal needle, from 10th December to 31st December 1824 ; and from 1st January to 31st May 1825, at Port Bowen. Lat. 73° 14' N., long. 88° 54' W. Mean dip 88° 1'.4 N., and mean variation 124°''W." After 1st January, when the general series commenced, these ta- bles exhibit the deflection of the two needles No. 1. and No. 2. for every hour, and frequently intermediate observations, to the end of the series, with the registered temperature at the moment of obser- vation ; but, as I have already observed, they are too extensive to al- low us to attempt a regular detail of them. Lieutenant Foster has, however, in a subsequent article, given a general abstract of the five months' observations, and this, by a lit- tle farther abridgment, will reduce them to such a compass, as to allow of their being inserted in the pages of the Journal. Here we have given only the greatest amount of the daily variations for every day, and the hours and minute when the needle had its greatest and least westerly bearing ', or the time of maximum westerly and eas- terly variations ; the temperature at those times ; the state of the winds and weather, with a column, also indicating whether the au- rorae boreales were, or were not, visible. These tables will be suffi- ciently intelligible, with one remark, namely, that, in the column marked A, M., the hours sometimes exceed twelve, and ought, there- fore, to have fallen in a column marked P. M. ; but, to save room, we have preferred the above notation, which will be understood to indicate the hours since midnight. The same occurs in the column of maximum easterly bearings, marked P. M. Here the time indi- cates the hour, &c. past noon. 352 Mr Barlow on the Diurnal Variation ABSTRACT of the Daily Variation Experiments on Magnetic Needle No. 2. from January 1. to May 31. 1825. JANUARY 1825. 1 Times of Maximum. Amount Temp, at Maximum. Westerly Easterly Westerly Easterly Days. daily va- riation. daily va- riation. of daily varia- tion. daily va- riation. daily va- riation. Aurora. Prevailing Winds, and Weather. A. M. P. M. AIR. AIR. H. , H. , • / o 1 13 0 12 0 1 204 — 26 — 26| Not vis. E. ; clear and fine. 2 11 50 19 10 0 53 27 29^ ... do. do. 3 10 0 12 0 0 50 28 34 ., . . . thin cl. with haze. 4 10 10 3 0 0 56^ 26 33 .. ... hazy. 5 11 10 12 0 2 33 324 36 NE. ; a partial haze. 6 9 45 11 5 2 50 294 34 .. E. ; ditto. 7 9 20 12 0 2 3 36 32 ,^ ... fine and clear. 8 ... ... ... ... ... ., ... hazy, with drift. 9 ... ... ... ,, ... ditto. 10 13 0 9* 3 1 23 33 37 .. ... clear. 11 12 0 13 7 2 H 35 38 NE.; ditto. 12 10 10 13 10 0 51 16 384 Visible. ditto. 13 13 0 11 10 1 oi J8 164 Not vis. SE. ; small snow. 14 13 20 11 10 1 22 25 20 ... SSE. ; snow and drift. 15 12 15 14 17 4 13 31 27 Visible. E. ; fine and clear. 16 12 10 11 10 2 25i 264 35 ... ... a thin haze. 17 8 10 10 15 2 29 24 27 ... ... fine and clear. 18 12 10, 6 15 2 56 23 224 ... ... overcast, cloudy. 19 14 10 14 10 1 56 28 23 Not vis. NE. ; very hazy. 20 13 55 5 10 1 8 30 28 Visible. ... clear and fine. 21 13 40 6 5 1 m 27 314 ... N. ; very hazy. 22 12 55 12 5 1 20i 32 29 ... ... cloudy. 23 12 20 8 5 1 16 344 334 Not vis. NNE.; hazy. 24 11 11 13 10 1 34 40 36 Visible. NE. ; clear and fine. 25 15 10 10 5 1 124 29 44 Not vis. E. ; fine and clear. 26 10 7 14 5 2 0 31 264 Visible. ... do. do. 27 13 10 15 5 1 55 254 33 ... NW.; hazy with drift. 28 12 0 6 10 0 44 29 27 ... do. do. 29 11 3 2 2 1 5 27 284 ... NNW.;cl. dense haze. 30 12 0 10 5 1 314 29 31 ... E. ; overcast. 31 8 5 6 10 0 26 324 36 Not vis. ... thick, cloudy. Mean, 11 46 10 50 I 37i 284 30 and mtenMy of the Magnetic Needle. 553 Abstract of Experiments, — continued. EBRUA i RY 1825. Times of Maximum, 1 Amount Temp, at Maximum. Westerly Easterly Westerly Easterly Days. daily va- riation. daily va- riation. ofdaUy varia- tion. daily va- riation. daily va- riation. Aurora. PrevaUing Winds, and Weather. A. M. P. M. AIR. AIR. H. , H. , o / o 1 12 0 11 57 0 39 — 33 — 36° Not vis. E. ; fine and clear. 2 12 3 4 0 0 524 40 414 ... ... do. do. 3 11 4 - 3 4 0 Ilk 32 264 ... ... hazy low down. 4 14 0 13 0 0 54 244 26 ... ... do. do. 5 11 4 2 0 1 14i 25 26 ... NE.; cloudy. 6 12 4 6 0 I 27 16 19 Visible. N. ; hazy, with drift. 7 14 0 10 0 0 46^ 224 29 Not vis. E. ; fine and clear. 8 7 58 13 57 1 104 32 394 ... Calm; do. do. 9 10 58 12 6 0 511 39 394 do. do. 10 6 57 10 58 0 47 38 314 ... ... not a cloud vis. 11 14 10 13 32 3 53 314 20 Visible. NW.; a few light els. 12 13 25 12 0 2 46 114 9 ... ESE.; hazy,withdrift. 13 14 15 13 3 2 25 14 24 ... very hazy. 14 12 33 10 43 5 0 214 33 ... NE. ; thick and hazy. 15 12 28 13 8 4 25 304 33 ... N. ; thick and hazy. 16 13 58 13 0 1 41 34 294 ... NNW.; hazyathoriz. 17 14 12 13 0 2 46 164 25 Not vis. N. ; fine thin clouds. 18 12 0 17 3 0 481 26 32 ... ESE. ; clear, fine. 19 10 58 14 4 1 55 29 37 Visible. NE. ; fine and clear. 20 12 18 10 0 1 41 344 404 ... do. do. 21 7 0 14 10 1 534 42 33 ... N. ; hsizy near horizon. 22 10 56 13 58 2 104 31 29 ... Calm ; fine and clear. 23 10 48 13 8 1 464 25 27 ... ESE. ; hazy. 24 10 4 12 58 0 194 29 29 ... E. ; overcast. 25 10 5 13 6 0 45 314 , 27 ... ... fine and clear. 26 13 5 11 0 1 244 17 84 Not vis. ... fine, with drift. 27 13 9 9 50 0 44 84 13 ... ... thick and hazy. 28 12 2 14 2 0 194 22 224 ... N. ; fine and clear. Mean, 11 46 11 23 1 38 — 26.9 — 28.0 354 Mr Barlow 07i the Diurnal Variation Abstract vf Experiments, — continued. MARCH 1825. 1 Times of Maximum. Amount Temp, at Maximum. Westerly Easterly Westerly Easterly Days. daily va- riation. daily va- riation. of daily varia- tion. daily va- riation. daily va- riation. Aurora. Prevailing Winds, and Weather. A. M. A. M. AIR. AIR. J H. , 11 2 H. , 4 58 1 564 — 33° — 38° Not vis. Var. ; hazy, with drift. 2 10 O 10 50 1 24 45 41 ... E. ; cloudy. [hazy. 3 11 22 11 58 2 29i 26 26 ... ... A.M. fine ; p. m. 4 12 4 9 35 2 0 30 34 ... ... cloudy. [fine. 5 10 33 3 2 1 104 29 30 ... ... A. M. hazy ; p. m. 6 7 3 10 58 1 264 23 39 ... S. ; hazy, with drift. 7 10 25 12 50 1 12 26 31 ... W. ; A. M. hazy ; p. m. 8 11 58 10 40 1 314 26 32 ... E. ; cloudy. [clear. 9 10 0 3 0 I 74 27 26 Visible. ... fine and clear. 10 10 7 7 3 1 174 28 33 ... ... do. do. 11 11 35 11 0 3 394 31 37 Not vis. ... do. do. 12 11 6 12 3 2 13| 31 33 Visible. Calm do. do. l.S 12 23 13 3 3 184 32 35 Not vis. ... do. do. 14 12 33 17 8 3 20 30 33 ... E. ; do. do. 15 16 30 7 10 1 154 24 25 ... ... do. do. 16 14 8 13 33 1 514 25 27 ... NW.; hazy with drift. 17 10 3 9 24 1 44 24 27 ... ... do. do. 18 12 38 13 5 3 7 20 22 ... ... do. do. 19 13 9 10 18 5 26 21 22 ... ... overcast. 20 11 48 16 0 4 11 20 26 ... do. 21 7 55 13 3 2 54 25 35 ... W. ; do. 22 11 46 14 5 1 50 16 34 ... E. ; fine and clear. 23 13 18 13 32 2 40 26 37 ... ... extremely clear. 24 9 28 13 8 1 52 32 39 ... Calm; do. 25 10 4 3 3 1 32 32 30 ... Var. ; fine, horiz. hazy. 26 10 33 15 4 1 6 24 24 ... N. ; do. do. 27 13 0 13 5 1 59 15 25 ... NE.; hazy. 28 13 12 10 30 0 564 18 23 NW. ; overcast. 29 10 3 1 28 2 374 22 19 ... E. ; cloudy. 30 9 58 13 3 2 214 25 35 ... ... fine and clear. 31 12 2 3 38 3 42 26 36 ... ... do. do. Mean, 11 25 10 43 2 14i — 26.2 — 30.7 and intensity of the Magnetic Needle. 355 Abstract of Experiments, — continued. APRIL 1825. 1 Times of Maximum. | Amount Temp, at Maximum. ] Westerly Easterly Westerly Easterly Days. daily va- riation. daily va- riation. of daily varia- daily va- riation. daily va- riation. Aurora. Prevailing Winds, and Weather. A. M. P.M. tion. AIR. AIR. 1 H. , 12 58 H. , 11 5 o / 4 4 — 25° -35° Not vis. E. ; fine and clear. 2 10 55 13 0 2 Oi 25 29 ... ... A.M.fine, P.M. hazy 3 10 0 17 7 2 24^ 23 28 ... ... hazy, small snow. 4 12 3 2 0 2 48i 19 20 ... Calm ; fine and clear. 5 9 35 12 0 2 284 26 25 ... E. do. do. 6 10 0 3 0 2 39i 26 28 do. do. 7 14 2 13 3 3 16i 20 29 ... do. do. 8 13 2 11 12 4 394 17 25 i do. do. 9 13 2 14 57 5 58 14 18- ... do. do. 10 ... ... ... ... ... ... ... do. do. 11 13 0 12 3 4 3 4 + 2 ... NNE. do. do. 12 13 8 18 1 2 9| + 15 — 3 ... ... hazy, with drift. 13 13 30 15 7 2 2i 3 — 16 ... ... cloudy. 14 12 30 11 0 4 34 + 5 -14 ... Calm ; hazy. 15 11 0 3 0 1 2H _ 8 _ 6 ... ... do. 16 2 0 11 7 3 44 + 15 5 ... E. ; fine and clear. 17 12 0 12 4 4 174 26 + 8 ... do. do. 18 6 0 2 32 2 394 — 8 2 ... ... A.M.fine, P.M. hazy 19 13 0 14 2 1 514 + 2 2 ... ... hazy. 20 11 52 9 35 2 134 14 8 ... ... do. 21 12 60 17 0 2 304 17 1 ... ... cloudy. 22 12 42 3 0 3 4 19 15 ... S. do. 23 14 4 13 5 2 434 11 7 ... ... hazy, witji snow. 24 9 30 15 4 1 19 3 1 ... NW.; hazy. 25 12 50 13 5 3 414 15 1 ... cloudy. 26 10 4 10 3 2 6 6 2 ... Var.; do. 27 11 2 12 4 2 15 12 zero ... S. ; hazy, with snow. 28 11 2 11 58 1 524 11 — 4 ... E. ; do. 29 6 3 2 12 2 84 zero + 17 ... ... A.M. fine, P.M. hazy N. ; cloudy. 30 13 28 12 0 2 384 + 24 — 5 ... Mean, 11 13 11 13 2.52.44 — 10.8 — 10.8 S56 Mr Barlow 07i the Diurnal Variation Abstract of Experiments — continued. MAY 1825. Times of Maximum. Temp, at Maximum. Westerly Easterly Westerly Easterly Days. daUy va- riation. daily va- riation. Amount ofyiaily variation. daily va- riation. daily va- riation. Aurora. Prevailing Winds and Weather. A. M. P. M. AIR. AIR. H. / H. , o / 0 1 12 3 10 3 1 55 ■f 11 + 3° Not vis. W.; hazy, small snow. 2 14 4 11 53 1 244 9 3 E. ; squally. 3 9 33 14 10 1 43 9 3 SW. ; much drift. 4 13 10 5 33 5 10 13 12 ... cloudy, with drift. 5 13 3 12 3 4 58 9 1 E- ; fine and clear. 6 13 2 10 30 5 434 20 10 W.; hazy. 7 13 29 14 11 5 25 20 12 E. ; cloudy. 8 13 28 14 0 4 454 21 12 ... hazy. [snow. 9 13 2 14 30 4 23 25 14 W. ; hazy, constant 10 13 2 14 6 2 434 11 4 do. do. 11 9 28 12 2 1 594 9 3 do. do: 12 13 30 13 0 3 184 15 7 do. do. 13 13 33 2 59 4 59 21 21 do. do. 14 6 2 12 2 2 36 9 18 do. do. 15 15 2 13 15 1 344 33 14 do. do. 16 14 20 9 3 3 414 22 16 N. ; do. do. 17 15 4 14 0 3 42 27 18 NE. ; do. do. 18 6 0 3 3 3 33 27 21 N. ; do. do. 19 14 32 14 4 4 524 22 14 E. ; do. do. ' 20 14 0 9 6 4 464 31 17 ... cloudy. 21 15 0 17 0 4 504 29 19 ... do. 22 10 32 2 4 3 584 26 27 ... light clouds. 23 13 35 14 2 4 264 18 10 • N. ; small snow. 24 9 38 18 2 4 104 19 19 . Calm ; very fine and 25 11 3 14 33 3 55 25 21 N. ; overcast, [clear. 26 12 2 14 3 3 594 32 21 ... cloudy. 27 12 0 ... ... ... ... _ Hazy, with drift. 28 12 4 10 0 3 41 33 26 W.; do. do. 29 12 3 1 0 1 11 27 25 SE.; cloudy. 30 13 13 14 33 5 13 38 27 . ESE. ; do. 31 14 2 14 34 3 40 35 25. fine. Me?Ln, 12 25 11 19 3 44 18.2 14.8 It may be well to draw the general monthly mean results from the preceding Table under one head, as follows ; Mean Time of Maximum Westerly Variation. A. M. Mean Time of Minimum Westerly Variation. Mean Daily Variation. Mean Tempe- rature. P. M. January, February, March, April, May, H. f 11 46 11 46 11 25 11 13 12 25 H. , 10 50 11 23 10 43 11 13 11 15 l"37 1 38 2 14 2 52 3 44 — 29I — 271 — 284 — 10| + 164 and intensity of the Magnetic Needle. 857 The above is a general mean view of these curious observations, and the following Table contains the mean results of the experi- ments on intensity. A needle, as we have stated, was kept specifi- cally for the intensity experiments. These were made and regis- tered every hour, by noting the time the needle required to make 60 vibrations ; and the following Table is a general mean for the same hour for all the days in each month. It should be observed, however, that, on the 1st of May, for some reason not stated, the needle was magnetized. The general mean is therefore exclusive of May. Monthly and Genei'al Mean Intensities of the Horizontal Magnetic Needle for every Hour for Four Months. * February. March. April. May. Hour. Mean Time Mean Time Mean Time Mean Time General Mean in perform- in perform- in perform- in perform- independent ing 60 vibra- ing 60 vibra- ing 60 vibra- ing 60 vibra- of May. tions. tions. tions. tions. A.M. 1 1076^8 1079!! 1098^9 916^4 1086'6 2 1073.5 1083.1 1100.7 1089.4 3 1075.7 1082.1 1102.7 930.7 1089.1 4 IO8O.7 1084.8 1102.7 1081.1 5 - 1082.5 1082.8 1101.7 923.2 1090.3 6 1082.1 1082.4 1105.4 1090.6 7 1082.8 1082.9 1108.2 922.6 1092.6 8 1082.9 1083.1 1109.1 1093.4 9 1080.9 1084.7 1108.1 927.5 1094.2 10 1079.5 IO8I.7 1107.1 1091.4 11 1077.9 1081.9 1101.9 923.0 1089.0 Noon 12 1077.1 1077.4 1093.3 1084.6 P.M. 1 1075.1 1074.0 1092.5 914.4 1080.5 2 1072.7 1072.9 1106.6 1084.1 3 1077-9 1076.4 1110.2 905.2 1087.6 4 1077.4 1073.6 1090.9 1080.6 5 1073.6 1073.4 1094.0 905.4 IO8I.7 6 1073.5 1072.1 1090.7 1078.8 7 1074.2 1072.0 1089.2 904.4 1079.1 8 1073.8 1074.0 IO88.7 1079.7 9 1075.1 1074.5 1091.2 906.0 1080.8 10 1073.8 1074.8 1092.1 1081.3 11 1075.1 1075.9 1093.3 911.6 1082.3 Midn. 12 107G.3 1077.1 1096.1 1083.9 We come now to a highly important part of these experiments, and which we owe to a very happy thought of Lieutenant Foster's, while pursuing the two series we have endeavoured to describe ; and which cannot be better illustrated than by using the author's own words. The article here referred to is the seventh in the vo- lume, and is entitled '^ A Comparison of the Diurnal Changes of In- tensity in the Dipping and Horizontal Needles at Port Bowen." These are introduced by the author in the following terms : * In the above Table a few errors have been detected in obtaining the means, and are corrected. JAXUAEY MARCH 1827- A a 55f? Mr Barlow on the Diurnal Variation " These comparative observations on the intensity of the dipping and horizontal needles, were made with a particular object in view, which it will be proper to explain before giving the details. " It was found by observation, that the intensity of the horizon- tal needle was hourly varying. This appeared by the results al- ready given ; but it was doubtful whether this variation of horizon- tal intensity of a needle, proceeded from an actual variation in the intensity of the terrestrial magnetism, or from a variation in the amount of its direction, as indicated by the dip itself. '^ The power of the horizontal needle varying as the cosine of the dip, a change to the amount of a few minutes in the dip, at places where it is very great, would be sufficient to explain all tiie varia- tions of intensity observed in the horizontal needle, without suppo- sing any change to have taken place in the intensity of the terres- trial magnetic force. ** The variation in dip, however, \i! it did occur, was too small to be detected by direct observation ; and I failed also to render it sen- sible by the application of magnets, as stated in a former communi- cation. " My object, therefore, in making the experiments contained in the following table, was to ascertain, by several series of vibrations made with the same needle, mounted alternately as a dipping nee- dle, and as a horizontal one, whether or not a corresponding varia- tion of intensity would manifest itself in these two positions respec- tively, as ought to be the case, if the diurnal changes of intensity in the horizontal needle proceeded from a general change of intensity in the terrestrial magnetic power. But, on the other hand, if the force indicated by the dipping needle should be found to remain constant, then it would be equally clear, that the variations of inten- sity in the horizonta-l needle proceeded from an actual change of dip only. "As this question is of considerable importance in the theory of terrestrial magnetism, I regret that I had not an opportunity of making a more extended series of experiments of this kind ; but, as far as they go, they certainly appea;- to indicate, that the alterations of intensity in the horizontal needle, are due rather to a daily change in the amount of the dip, than to any variation in the general inten- sity of the earth's magnetic force, although some change in this also is observable by vibrations of the dipping needle. This explanation of the cause of the change of horizontal intensity, it may be remark- ed, is consistent with the observations made in Em*ope, which like- wise shew an alteration of intensity in the horizontal needle during the day, but in a much less degree than at Port Bowen. Now, if the variation in question really proceed from a change of dip, to the amount of three, four or five minutes of a degree, the change of in- tensity in the horizontal needle will be less and less obvious, as the dip decreases j but if it proceed from a change in the actual inten- sity of the earth's magnetism, it ought to be constant in all parts of the world, which is contrary to observation. " The following are the results of these experiments. The table is divided into two parts , the first contains the observations on the times of vibration of the needle in its horizontal position j and the second, those on it when used as a dipping needle. In the first co- lumn of each part, is inserted the day of the month ; in the second. and Intensity of the Magnetic Needle. 359 the hour and minute at which the observations were commenced ; the third cohimn of each part contains the mean time in seconds taken by the needle in its different positions, to perform one hun- dred vibrations j and, in the fourth, is inserted the temperature of the needle at the time of observation. First Part, Second Part, Horizontal Needle. HORIZONTAI . Needl] E. Mean time Mean time 1825. Time of com- in seconds Temp. 1825. Time of com- in seconds Temp. mencement. of perform- Fahr. ment. of perform- Fahr. Feb. ing 100 vib. ing 100 vib. H. M. Feb. H. M. // 12. A. M. 6 35 2128'6 —17 12. A. M. 1 1 58 405.4 -174 10 54 2127.6 -17° P. M. 0 30 405.7 -174 P.M. 1 32 2079.9 -17 13. P. M. 3 41 410.0 -174 13. P.M. 1 42 2103.1 —17 14. A. M. 10 34 408.0 -194 2 54. 2152.5 -174 P.M. 0 12 406.5 —20 14. A.M. 11 21 2088.2 —20 8 33 408.4 —22 P.M. 1 14 2067-7 —20 10 00 409.0 -214 9 00 2086.0 22 11 12 408.7 -214 15. A.M. 0 41 2107.0 —22 15. A.M. 1 34 411.1 —22 10 48 2115.5 —21 10 32 410.0 —21 P. M. « 44 2064.2 —23 11 35 409.6 —21 10 29 2071.0 —23 P.M. 8 9 409.2 —23 16. A. M. 11 4 2077.4 -27 9 43 408.7 —23 17. A.M. 10 18 2071.0 —22 11 15 409.2 —22 11 12 2058.2 —21 16. A.M. 10 38 409.9 —28 P. M. 0 29 2079.5 —20 11 46 409.1 —27 19. A. M. 10 18 2092.2 —22 4 17. A. M. 9 42 409.0 —22 11 54 P.M. 1 10 408.5 409.0 —20 —204 19. A. M. 10 00 10 58 408.5 408.1 —23 —22 Mean *, 2092.33 — 20i ' Mean •, 408.65 -214 " The above results show, that the mean of all the observed times which the horizontal needle required to make 100 vibrations, was 2092.33 seconds, but that differences appear in these times amounting to 94.3 seconds, or s^d part of the interval ; whereas, in the dipping needle, in which the mean of the times required to perform 100 vibra- tions was 408.65 seconds, the greatest difference is only 57 seconds, or ygd part of the interval, which is a much less proportional change than the former. " Therefore, as has been stated, the change of intensity in the hori- zontal needle is due, principally, to a daily variation in the amount of the dip, not to a real change of intensity in the terrestrial magnetic force. This, at least, appears to be a legitimate deduction from the preceding observations ; from which circumstance, and that of the daily variation in the direction of the horizontal needle, we are naturally led to the conception of a small variation in position of the magnetic axis^ corresponding to a revolution of the polar point round its mean posi- tion as a centre, produced by the action of the sun, on the magnetism * The dip of the needle resulting from these elements is 87° 48' 8 N. A a ^ 360 Mr Barlow 07i the Diurnal Variation of tlie parts of the earth successively exposed to its influence. And, moreover, it seems by no means improbable that the annual variation of the position of the magnetic pole, may ultimately be traced to the same universal cause. " I have not attempted to enter into any minute calculations on this subject, but I believe it will be found, that, if the radius of the circle, described by the pole of the general magnetic axis of the earth during the day, be supposed to subtend at the centre an angle of 2 or S* mi- nutes, it will reconcile, to a considerable degree of precision, nearly ali the observations on the daily variation of the direction, and daily change of intensity of the horizontal needle, made both in Europe and with- in the Arctic Circle." In order to illustrate the very ingenious hypotheses which Lieute- nant Foster has thus deduced from the experiments last reported, it will be best to refer to Fig. 1. In this, P represents the terrestrial pole, M the magnetic pole of any place L, of which the dip and variation are given ; Join M L, which is the magnetic meridian of the place L, and produce M L to /, m Q L representing the equator ; as also, P I-. be produced to meet the equator in Q, then MLQ will be the me- ridian of the place L ; and from M draw Mm, perpendicular to ML /. Then, confining our illustrations to the time when the sun is in the equator, the arc Q /, converted into time, will give the time when the sun is on the magnetic meridian of the place L ; Q ?w, converted into time, will give the time when the sun is perpendicular to that meridian, and, of course, from these may be readily determined the time when the sun is again on the magnetic meridian, and when again he is per- pendicular to the same ; let us, therefore, go through the necessary cal- culations, and see how nearly the several phenomena which have been recorded, agree with the hypotheses in question. First, let L represent London, Lat. STST, dip 70°34', Long 0°0'. TT • V o ,1 tan 70°34' ^^o^o. Here, since tan dip = 2 tan mag. lat. we have — ^ ^^ 54<°4o' mag. lat. conseq. ML = 35^12' PL = 38°29', and PLM = 24^30' variation. From these we readily find MP = 14t'58' colat. of magnetic pole, and angle LPM = 67"41' =-. long, west of magnetic pole. In the tri- angle LQ/, right angled at Q, we have LQ = 51°31', and the angles QL / = 24°30', whence we find IQ= 19°38', which, converted into time, gives about 10*^ 40"^ a. m. for the time when the sun is on the magnetic meridian of London ; and, in a similar manner, we - find Qm = 55^24' equal to about 3'^ 40™ p. m., the time when the sun is perpendicular to the magnetic meridian of London. These being determined, let us proceed to a comparison of recorded phenomena with the hypotheses in question. Lieutenant Foster con-" ceives, that the sun, by some influence or other, causes the magnetic pole M to describe, in the course of 24 hours, a little circle about the mean point M, whose diameter is about 5' or 6', the pole bein^ con- stantly deflected towards the sun. Now, first, according to this sup- position, at 10*^ 40"^ A. M. M will be deflected towards L, the magne- tic colat. will be diminished, and, consequently, the dip increased ; and this increase of dip will induce a less magnetic intensity on the hori- and Intaia'ity of the Magnetic Needle. 361 zontal needle, and the least that ought to take place in the 24 hours, and this is precisely the time that the minimum intensity is recorded to take place. At 10^ 40"^ p. m. we ought, in like manner, to have the greatest intensity, because then the sun will be again on the meri- dian, but its tendency will be to increase the magnetic colat., and, con- sequently, to diminish the dip. We have no ^stinct account of the intensity at this hour, but at 9^ 30™ v. m.* it is greater than at any other hour recorded ; we may, therefore, I conceive, fairly state this as a con- firmation of the agreement of the hypotheses with observations on these cases of intensity. Again, at about 3^ 40™ p. m.j we have seen that the sun is to the west of the magnetic meridian, the needle ought, therefore, at this hour to have its greatest westerly bearing. This hour agrees very well with a number of recorded observations, but, in the recent observations by Colonel Beaufoy, the maximum is said to happen at 1^ 30™, at least this was the time at which he always recoiilethl^, The slender tube has besides another set of numbers engraved, corresponding to the triplication, as the former does to the duplication, of the vo- lume of included air. By comparing the two results, we are enabled to determine, whether the air contained in the porous substance exists in a condensed state, and to calculate the de- gree of condensation. 5thl2/ and lastly. The coniometer has already indicated some very curious and interesting results, which I regard, however, at present as only approximative. As soon as I have brought the instrument to a more perfect form, I purpose to institute a series of accurate experiments with it. 386 Dr Graham's List vf Rare Plants. In conclusion, I think, a journalist certainly entitled to re- mark, in a tone of right feeling, those coincidences which must at times occur in the history of science, when different persons happen to strike into the same path of inquiry ; but to hunt in- cessantly after obscure, vague and distorted charges of plagi- arism, only betrays the workings of a base and malignant dispo- sition. I ever am, &c. (Signed) John Leslie. Queen Street, \ March % 1827. J List of Rare Plants which have Fhzvered in the Royal Bota^iic Garden, Edinhui'gh, during the last three months ; with Description of a new species of Euonymus. Communicated by Dr Graham. 10^/^ xMarch 1827. Banksia latifolia. serrata. Dichorisandra thyrsiflora. Euonymus scandens. E. scandens ; fruticosa, scandens, radicans ; foliis lanceolato-ovatis, crenato- serratis, venis obliquis ; pedunculis filiformibus, axillaribus bis (terve ?> dichotomis ; germine scabro. Description — Shrub climbing to a great distance. Branches very long, cylindrical, green with brown scars, adhering to every thing in contact with them, by long, flattened, branching, white threads, which at first spring in linear tufts, but afterwards throughout the whole length of the branches, and hanging loose on all sides, conceal these in an entangled mass. Leaves opposite, somewhat decussating, the older ones somewhat coriaceous, the younger shining and membranous, bright green, and paler on the back, ovate or ovato-lanceolate, acuminate, crenato-serrate, the serratures being frequently, especially on the ovate leaves, compound, veins oblique, and, as well as the middle rib, prominent on both sides, reticulations at the edges most distinct on the under. Petioles chan- nelled, approximate on the branches, distichous on the flowering-shoots (^inch long) ; stipules minute, brown, lacerated, one on each side of the petiole ; buds lanceolate, pointed, covered by imbricated blunt scales, some of which are persistent upon the base of the twig. Bractece small, awl- shaped, brown, reflected, slightly fringed, with brown glands at their edges. Peduncles axillary twice (or thrice ?), dichotomous, filiform, an- gular, straight, nearly three times as long as the petiole. Calyx very small, green, tetraphyllous, segments rounded, persisting, at every pe- riod concave, and closely applied behind the bases of the stamens. Co- rolla yellowish-white, 4-petalous, petals rounded, minutely toothed, re- , fleeted, attached by small claws, which are about the length of the calyx, and concealed. Stamens Ai filament»-wh.\\X'ih. and tapering, scarcely longer than the claw of the petals, at first erect, afterwards reflected, inserted into broad, flattened, green bases between the petals; anthers yellow, of two roundish lobes, about as long as the filaments. Germen flattened, yellowish-green, indistinctly warted. Stigma at first deejj green and ses- sile, after the shedding of the pollen paler, blunt, and continuous with a stout, linear, furrowed style equal in length to the filaments. Celestial Phenomena Jrom April 1. to July 1. 1827. 387 This species was received from the Botanic Garden, Calcutta, under the name here adopted, in 1823, its native country uncertain, probably Ne- pal. It approaches nearly to E. echinata and E. vagans of Flora Indica ; but is distinguished from the former by the oblique veins of the leaves, and from the latter by its rooting stem, and probably by its spiny fruit, though, as this has not yet ripened in the Botanic Garden, the appear- ance of the germeji only can be stated. Liparia sphaerica. Mirbelia speciosa. Pensea squamosa. Perdicium brasiliense. Celestial Phenomena from April 1. to July 1. 1827, calculated for the MeriiVian of Edinburgh^ Mean Time. By Mr George Innes, Aberdeen. The times are inserted according to the Civil reckoning, the day beginning at midnights —The Conjunctions of the Moon with the Stars are given in Right Ascension. APRIL. D. H. , ,, D. H / 1. 9 28 38 d D^ « 14. 18 18 42" dDvlTl 1. 21 36 18 Im. III. sat. 7/ 15. 20 50 55 6 D p Oph. 2. 0 15 22 Em. III. sat. 2/ 16. 2 7 - d b" n 2. 18 22 2 6K « 16. 5 33 11 Im. III. sat. 11 3. 2 52 57 Em. I. sat. 7/ 16. 17 50 30 6])2f. t 3. 10 26 12 6 Db 17. 19 32 45 6 ^n 7. 8 41 45 61)-^ 17. 22 42 50 ( Last Quarter. 8. 3 16 - ^ very near /it K 20. 21 43 49 Em. I. sat. 11 8. 6 49 3 61)11 21. 21 32 43 0 enters U 8. 9 7 5 ^ very near 1 x ^ 22. 11 0 34 dD? 8. 9 21 21 $ very near 2 x b 22. 15 14 26 d ?o K 9. 9 56 7 c$ D a Tlje 24. 5 10 24 d])? 10. 1 37 49 Em. It. sat. 2/ 25. 18 23 24 ^ New Moon. 10. 20 43 54 6])2a- 27. 0 24 - 61)$ 11. 8 8 41 O Full Moon. 27. 8 6- 61)^ b 11. 16 49 38 c5 V — 27. 23 38 17 Em. I. sat. 11 11. 21 8 36 d))x=c= 28. 8 31 24 d D V n 12. 1 20 49 Em. I. sat. 7/ 28. 10 11 10 6Dh 12. 1 32 50 6 D lA^ 31. 9 27 31 d ]) 1 a 2S 12. 1 34 5 d])2/2TTi 31. 10 30 48 d ]) 2a So 12. 3 57 2 d D vTTl JUNE. D. H. , ,/ D. H* / // 2. 20 37 29 ]) First Quarter. 12. 16 11 26 c^ ]) 132 « 3. 17 19 34 d D " ^ 12. 21 55 58 Em. I. sat. 7/ 3. 22 47 24 Em. II. sat. y. 15. 17 41 - d? <^ 4. 14 29 39 6D11 16. 8 14 8- ( Last Quarter. 5. 19 11 48 d ^ 132 a 21. 19 21 34 d D9 5. 19 54 46 6DCCW 22. 5 10 11 d D^ d 7. 7 23 51 6D2 — 22. 6 11 3 0 enters ss 8. 3 38 44 d D« — 23. 14 6 11 6D^ t 8. 7 57 24 dD^-^ 396 Scientific Intelligence. — Botany. 1. That the city of Nysa, the native country of wheat and bar- ley, is the same as Scythopolis or Bethsane, and is situated in the valley of the Jordan. 2. That the identity of the wheat and barley, anciently cultivated in Egypt and Palestine, with our Cereales, is certain. 3. That the habitat of all the vegetables, animals, and minerals, indicated by the most ancient monu- ments, as existing in the country of barley and wheat, has been confirmed beyond doubt. 4. That the comparison of the various zodiacs, the migrations of the worship of Ceres, confirm this origin of the Cereales. 5. That the greater number of species of the genera Triticum, Hordeum, and Secale, whose habitat is known, being indigenous in the East, the testimony of history accords sufficiently with the rules of criticism established by science ; and that the valley of the Jordan, the chain of Li- banus, or the part of Palestine and Syria, which borders upon Arabia, may with great probability be assigned to our Cei^eales, as their native country. 8. Instructions for Collecting and Preparing Fungi Jbr Herbariums, and Jbr Preserving them from the JttacJc's of' Insects and their Larv/e. By M. C. H. Persoon, — A few words regarding the proper time for gathering Fungi, and the "locali- ties in which they are found, precede these useful instructions. The following are the principal rules of preservation given by this celebrated mycologist : — 1. To gather the coriaceous and suberose fungi, before they begin to get old, lest they should contain germs of destruction, the most formidable of which are the eggs of insects, and to expose them from time to time to the rays of the sun. 2. To subject to pressure, with- out squeezing too much, the thinner species, to change the pa- per often, and expose them to the open air. 3. To leave in the open air, until perfectly dry, the gelatinous fungi, such as the Tremellfe, Auricularia, &c. When immersed in water, they resume their original form and colours. 4. To model in wax, or immerse in weak spirits, the species whose forms cannot be exactly preserved., 5. To gather the Lycopeixlinece when half mature, and let them dry in the air, that they may bear a sHght degree of compression, without being deformed. 6. To preserve' the Trichiacca. and Isaria, which grow upon chrysa- lids, in small boxes furnished with cotton, in order to retain Scientific Intelligence. —^Botany. 397 their delicate forms, which would be destroyed by the slightest shock. 7. To dry, in the usual manner, by a moderate degree of pressure, in grey paper, the Fiaigoids of a thin and papyra- ceous consistence, as well as the epiphyllous fungosities. 8. Lastly, After complete desiccation, to inclose them in paper bags, to prevent the attacks of insects and worms, and especially to defend them against the contact of foreign bodies. In this man- ner, says the author of the Synopsis Fungorum, these produc- tions may be preserved for a long time, in order to compare them with one another, examine them without fear of losing them, and communicate them to others. 9. Effects of certain Manures on the qualities Xrf Plants, — Among the fertilizers of the soil, high importance is attached, and deservedly, to that mass of matter which results from the process of putrefaction upon organic substances undergoing cor- ruption after death. By reason of its efficacy, it' is assiduously procured to fertihze poor soils, to renovate exhausted ones, and prevent good ones from wearing out. Animal manures have a peculiar rankness. Some of them stimulate, or, it may almost be said, cauterize with vehemence. Hence they require ad- mixture of milder materials to mitigate their force. Yet, after the offal and scrapings of large cities, have been mingled with soil in such proportion as not to destroy the life of plants, but to promote their vegetation, they have been considered as com- municating, in many cases, a disgusting or offensive quality to some of the vegetables they nourish. They have been charged with imparting a biting and acrimonious taste to radishes and turnips. Cabbages are less sapid and delicate. Potatoes have been observed to borrow the foul taint of the ground. It has been traced to the bulb of the onion. Millers observe a strong and disagreeable odour, in the meal of wheat that grew upon land highly charged with rotten recrements of cities. The like deterioration of quality, has even been remarked in tobacco rais- ed in cow-pens. And stable-dung has been accused of impart- ing a disagreeable flavour to asparagus. It seems as if some portion of the foul matter of the manure was absorbed by the vegetable radicles, and, after passing unassimilated through the sap-vessels, was converted by the process of nutrition to living substances. This condition of the vegetable species, seems to 398 Scientific Intelligence. — Botany. receive illustration from analogies in the animal kingdom. Ducks are rendered so ill-tasted from stuffing down garbage at the kit- chen door, as sometimes to be offensive when brought as food to the table. The quality of pork is acknowledged to be modified by the food of the swine. The bitterness of partridges has been ascribed to the buds upon which they live ; and the peculiar flavour of piscivorous wild fowl, is rationally traced to the fish they devour. Thus a portion of nutrimental matter passes into the living bodies of plants and animals, in certain proportion, without haVing been entirely subdued, or assimilated. It be- comes, therefore, a subject of curious and important reflection. The horticulturist mostly calculates on the quantity of his crop. It is, however, a becoming subject of research, that he should likewise, attend to the quality ; or perhaps the consumer, his customer, may inform him that an offended palate and injured health, will induce a careful provider to seek uncontaminated articles for his table. — Dr MitchilVs Discourse at the Anniver- sary of the New Yorh Horticultural Society^ 1826. ARTS. 10. New Mode of applying Graphite^ or Black Lead, in Drawings. — Mr C. Galpin, the inventor of this improvement in the management of graphite, as applied to drawing, having long regretted that a material of so pleasing a neutral colour, should only be capable of producing broad shades, by means of a laborious repetition of hnes or touches, commenced a series of experiments with reference to this subject, which, however, did not at first lead to any useful result, on account of the granular separation of the substance, when applied to paper. At length, having thought of reducing it to an impalpable powder, and using it with a brush, he obtained the most complete success, having found that every possible degree of shade can be produ- ced with the nicest uniformity, and in less than a twentieth part of the time required in the ordinary manner. The process is described as follows : — The instruments required are, a small piece of mushn, filled with black-lead reduced to fine powder, which is called a shader ; a palette, made of thick card board ; and a brush of medium size. The shader is rubbed two or Scientific Intelligence. — Arts. B99 three times on the palette, near one extremity, by which a small portion of the lead is sifted, as it were, through the muslin ; the brush is passed round in the pulverised graphite, and on some other part of the palette, to adjust the shade required ; the brush is then applied to the paper, to produce a sky, or other expanse of shade, with a circulating motion. To produce a darker shade, the graphite may be rubbed in with alder, pith, or any similar substance, brought to a point. — GilPs Technical Repository/, 1827. 11. Oji Etching and Dyeing at once figures on I-oory ; by Mr J. Cathery, — The usual mode of ornamenting ivory in black, is to engrave the pattern or design, and then to fill up the cavi- ties thus produced with hard black varnish. The demand for engraved ivory in ornamented inlaying, and for other purposes, is considerable, although the price paid for it is not such as to encourage artists of much ability to devote themselves to this work, which consequently is trivial in design, and coarse in exe- cution. IVIr Cathery's improvement consists in covering the ivory with engraver's varnish, and drawing the design with an etching needle. He then pours on a menstruum composed of 120 grains of fine silver, dissolved in one ounce measure of ni- tric acid, and then diluted with one quart of pure distilled wa- ter. After half an hour, more or less, according to the required depth of tint, the liquor is to be poured off, and the surface is to be washed with distilled water, and dried with blotting pa- per ; it is then to be exposed to the light for an hour, after which the varnish may be removed by means of oil of turpen- tine. The design will now appear impressed on the ivory, and of a black or blackish-brown colour, which will come to its full tint after exposure for a day or two to the light. The proper- ty which nitrate of silver possesses, of giving a permanent dark stain to ivory, and many other substances, has been long known ; but Mr Cathery has the merit of having advantageously applied it in a department of art in which it is likely to be of considera^- ble service, by improving the quality of the ornament, and at the same time of diminishing the cost. Varieties of colour may also be given, by substituting the salts of gold, platina, copper, &c. for the solution of silver. — GiWs Repository, Feb. 1827. 400 Scientific Intelligence.--^ New Publications. NEW PUBLICATIONS. 1. Essay on the Theory of the Earth. By Baron Geouge Cuvier; with Geological Illustrations by Professor Jame- son. Fifth edition. Translated from the last French edition, with numerous additions by the Author and Translator. Eleven Plates. Blackwood, Edinburgh ; Cadell, London. 14s. On the suggestion of Professor Jameson, the celebrated es- say of Cuvier was translated by the late Robert Kerr, Esq. F. R. S. E., and under the revisal of the present editor, who also added to the original a series of notes and illustrations. The success of the work was great. It was speedily repub- lished in America, and translated, with its notes and illustra- tions, into the German and Italian languages. Another edi- tion was soon required. This, in its turn, was speedily ex- hausted. Although, in the third edition, as in the former, the impression, was great, a fourth and enlarged edition appeared in 1822. The present, which is the Jifth edition, is translated from the last edition of the illustrious author, and may be con- sidered nearly as a new work, from the numerous additional facts and views which it contains. The many thousand copies of this work now circulated throughout the British Empire, and indeed in every country where the English language is known^ is a proof not only of the very general interest excited by geo- logical facts and reasonings, but also of the absurdity of the opi- iiion still entertained by some of the inutility of this branch of natural history. On this subject. Professor Jameson, in the preface to the present edition, has the following remarks : " Geology, now deservedly one of the most popular and attractive of the physical sciences, was, not many years ago, held in little estimation ; and, even at present, there are not wanting some who do not hesitate to maintain, that it is a mere tissue of ill observed phenomena, and of hypotheses of bound- less extravagance. The work of Cuvier now laid before the public, contains, in itself, not only a complete answer to these ignorant imputations, but also demonstrates the accuracy, extent and importance of many of the flicts and reasonings of this delightful branch of Natural History. Can it be maintain- ed of a science, which requires for its successful prosecution an intimate ac- quaintance with Chemistry, Natural Philosophy and Astronomy, — with the details and views of Zoology, Botany and Mineralogy, and Avhich connects these different departments of knowledge in a most interesting and striking manner, — that it is of no value ? Can it be maintained of Geology, which discloses to us the history of the first origin of organic beings, and traces their gradual developem^nt from the monade to man himselfj-~which enu- Scientific Intelligence. — Nezv Publications. 401 merates and describes the changes that plants, animals, and minerals, the at- mosphere, and the waters of the globe, have undergone from theearliest geo- logical periods up to our own time, and which even instructs us in the ear- liest history of the human species, — that it offers no gratification to the phi- losopher ? ' Can even those who estimate the value of science, not by intel- lectual desires, but by practical advantages, deny the importance of Geology, certainly one of the foundations of agriculture, and which enables us to search out materials for numberless important economical purposes? Positive geology or geognosy, as Cuvier, in his life of Wer- ner, remarks, originated with that remarkable man ; and all that has been done towards unravelMng the structure of the crust of the earth since his views were made known, has been in harmony with them. The Editor remarks, " Geology took its rise in the Academy of Freyberg, with the illustrious Werner, to whom we owe its present interesting condition. This being the case, we ought not, (as is at present too much the practice), amidst the nu- merous discoveries in the mineral kingdom which have been made since the "system of investigation of that great interpreter of nature was made known, forget the master, and arrogate all to ourselves. In this island, Geology first took firm root in the north : in Edinburgh, the Wernerian geognostical views and method of investigation, combined with the theory of Hutton; the expe- riments and speculations of Hall; the illustrations oi Playfair ; and the la- bours of the lloyal and Wernerian Natural History Societies, excited a spirit of inquiry which rapidly spread throughout the empire ; and now Great Bri- tain presents to the scientific world a scene of geological acuteness, activity/ and enterprise, not surpassed in any other country." Independent of the numerous additions to the text of the Es- say, the editor has added upwards of two hundred pages of notes and illustrations on the following important topics. On the Subsidence of Strata. Deluge. Formation of Primitive Mountains. The distribution of Boulder-Stones in Scotland, Holland, Germany, Switzer- land and America. The Alluvial Sand of the Danish Islands in the Baltic, and on the coast of Sleswigh. The Sand-Flood — Sand-Flood in Morayshire. Sand-Flood in the Hebrides, &c. Moving Sands of the African Deserts. Action of the Sea upon Coasts. The Growth of Coral Islands. The Level of the Baltic. Fossil Remains of the Human Species. Account of the Displacement of that part of the Coast of the Adriatic which is occupied by the Mouths of the Po. The Universal Deluge. The Action of Running Waters. Connection of Geology with Agriculture and Planting. Account of the Fossil Elk of Ireland. Account of the Living Species of Elephant, and of the Extinct Specits of Elephant or Mammoth. Account of the Caves in which Bones of Carnivorous Animals occur in great quantities. Cave containing Bones at Adelsberg, in Carniola. View of the Genera of Fossil Mammifera, Cetacea, Aves, Reptilia, and In. secta ; with their Geognostical Number and Distribution. View of the Classes, Orders, or Families of Animals, occurring in a Living or Fossil state ; with their Geognostical Distribution. 402 Scientific Intelligence. — New Publications. This work, so rich in well authenticated and well arranged geological facts, and abounding in beautiful views of the mineral and animal kingdoms, cannot be too strongly recommended. It ought to find a place in the library of every one who takes an interest in the natural, and even the civil, history of the planet we inhabit. 2. Illustration of the Geology of Sussex, containing a general view of the Geological relations of the South Eastern part of England; with Figures and Descriptio7is of the Fossils of Tilgate Forest. By Gideon Mantell, Esq. F. R. S. Fel- low of the Royal College of Surgeons, F. L. S. M. G. S. &c. One volume quarto. M. Mantell is already advantageously known to geolo- gists, by his interesting and valuable volume on the geology of Sussex. The present elegant work is a further proof of his skill and activity ; and, therefore, we truly regret to find, from the preface, that this will, in all probability, be the last time we shall have an opportunity of noticing his geological labours, as he intimates his intention of taking leave of this department of Natural History. Sussex, Mr Mantell informs us, is composed of portions of all the v secondary formations of England, from the Purbeck limestone to the tertiary deposits ; outliers of the London and Isle of Wight basin, and accumu- lations of diluvial and alluvial matters. The regular deposits are the plastic clay and London clay., chalk, shanMin sand^ weald clay, and the sands and clays of Hastings. All these different deposits are carefully and luminously described ; the various or- ganic remains with which they abound well described, and many of the more remarkable represented in a series of twenty beau- tiful lithographic plates. The stratification of the Forest of Til- gate, which has excited so much interest on account of its organic remains, is fully described, and evidence adduced of its being older than chalk. The description of the organic remains of Tilgate Forest is concluded with the following striking obser- vations, which also close the work. " In concluding this description of the organic remains of Tilgate Forest, we would repeat, what we have elsewhere remarked, that the vast preponde- Scientific Intelligence. — New Publications. 40^— ranee of the land and fresh-water exuviae over those of marine origin, observ- able in these strata, warrants the conclusion that the Hastings beds were form- ed by a very different agent from that which effected the deposition of the Portland limestone below, and the sands and chalks above them. The seas in the primitive ages of our planet were inhabited by vast tribes of multilo- eular shells, which, however variable in their species, were not only of the same family, but also of the same genera, namely, Belemnites^ Ammonites^ and Nautilites. These shells, if we may draw any conclusions from our knowledge of the habits of the recent species of the only genus that still exists, were in- disputably inhabitants of the ocean ; and the presence of their remains in any considerable quantity in a stratum, affords a fair presumption that such stra- tum is a marine deposit. The converse of this proposition, we conceive, must hold good in a case like the present, where not a vestige of these ancient ma- rine genera can be traced, among innumerable remains of terrestrial vege- tables and animals, and of fresh-water testaceae. The occasional occurrence of marine exuviae affords no grounds for a contrary opinion, since this fact is no more than might be expected under such circumstances, and is in strict accordance with what may be observed in the deltas and estuaries of all great rivers. " We cannot leave this subject, without offering a few general remarks on the probable condition of the country through which the waters flowed that deposited the strata of Tilgate Forest ; and on the nature of its animal and vegetable productions. Whether it were an island or a continent, may not be determined ; but that it was diversified by hill and valley, and enjoyed a climate of a higher temperature than any part of modern Europe, is more than probable. Several kinds of ferns appear to have constituted the imme- diate vegetable clothing of the soil ; the elegant Hymenopteris psilotoides^ which probably never attained a greater height than three or four feet, and the beautiful Pecopteris reticulata, of still lesser growth, being abundant every where. It is easy to conceive what would be the appearance of the valleys and plains covered with these plants, from that presented by modern tracts, where the common ferns so generally prevail. But the loftier vegetables were so entirely distinct from any that are now known to exist in European countries, that we seek in vain for any thing at all analogous without the Tro- pics. The forests of Clathrarice and Endogenitce (the plants of which, like some of the recent arborescent ferns, probably attained a height of thirty or forty feet), must have borne a much greater resemblance to those of tropical regions, than to any that now occur in temperate climates. That the soil was of a sandy nature on the hills and less elevated parts of the country, and ar- gillaceous in the plains and marshes, may be inferred from the vegetable re- mains, and from the nature of the substances in which they are inclosed. Sand and clay every where prevail in the Hastings strata ; nor is it unworthy of remark, that the recent vegetables to which the fossil plants bear the great- est analogy, affect soils of this description. • If we attempt to pourtray the animals of this ancient country, our description will partake more of the cha- racter of romance, than of a legitimate deduction from established facts. Turtles of various kinds must have been seen on the banks of its rivers or lakes, and groups of enormous crocodiles basking in the fens and shallows. " The gigantic Megalosaurus, and yet more gigantic Iguanodon, to whom the groves of palms and arborescent ferns would be mere beds of reeds, must have been of such prodigious magnitude, that the existing animal creation presents us with no fit objects of comparison. Imagine an animal of the liz- ard tribe, three or four times as large as the largest crocodile, having jaws equal in size to the incisors of the rhinoceros, and crested with horns ; such a creature must have been the Iguanodon. Nor were the inhabitants of the waters much, less wonderful ; witness the Plesiosaurus, which only re- quired wings to be a flying dragon ; the fishes resembling Siluri, Balistse,'* &c. 404 Scientific InteUigeiice. — Nexo Publications, 3. ^Alathematical and Astronomical Tables for the nse of Stu- dents of Mathematics, Practical Astronomers, Siirveijo7'Sy Engineers, and Navigators. By William Galbraith, M. A. Oliver & Boyd. Edinburgh. 9s. This portable and cheap volume is well worthy of the attention of the practical men alluded to in the title page, and we have no doubt, that, when its merits come to be sufficiently known, it will supersede the use of every other with which we are acquainted. It is needless to mention, that Mr Galbraith g'rves all the ordinary tables to be found in works with similar objects, such as the lo- garithms of numbers, logarithmic sines and tangents, and others, without which no surveyor, seaman, or astronomer, can advance a step ; and we shall confine ourselves in this notice to an enu- meration of such additions and improvements as Mr Galbraith has made, and which we think claim for his work, as we have said above, the notice of all men who are really at work on such subjects. In the first place, we consider that Mr Galbraith has great merit for giving, in a clear, well ordered, and perfectly scienti- fic style, such a course of demonstrative reasoning on the theory as well as the practice of his subject, as cannot fail to be very useful to students who have a real wish to understand what they are about, and whose better taste and judgment have hereto- fore been offended by these epitomes which, to use their slang, phrase, have been reduced to the lowest capacity. The various methods of obtaining the longitude, are discussed at some length, and with singular clearness. We are not aware that in any other work of this elementary nature, those minute corrections in the lunar method are given ; and, in fact, we suspect few navigators are aware of their importance. We allude to the equations for second differences in the distances, which are correctly given only for every 3 hours in the Nautical Almanac, but which are not found in strictness, for an intermediate period, by simple arithme- tical proportion. This equation, in some cases^ amounts to 6 se- conds of distance, 12 seconds of time, or 3 minutes of longitude. Mr Galbraith has computed two little tables for obtaining the pro- per correction (Introduction, page 102.) Another small correc- tion on account of the oblique semidiameter, is found in two tables by Dr Young, given at page 101. And a table is given by Mr Scienij/lc Intelligence. '^New Publications, 405 Henderson of Edinburgh, for another correction still, nfundy, that arising from the ejfiPect on the horizontal parallax of the moon, caused by the oblate figure of the earth. We recommend Mr Galbraith, in his next edition, to bring all tSiese corrections distinctly under the reader's view at one place. Our author does not eonfine himself, however, to the pro- - blems in ordmary use, &uch as lunar observations, occultations * of the fixed stars, chronometrical observations, and the measure- ment of heights by the barometer, which last is admirably exe- cuted, but enters also with the full spirit of an observer, and all the minute accuracy of a computer, into the elegant disquisi- tions dependent upon the figure of the earth, the velocity of sound, and other topics of high interest. We shall now pixxjeed to point out briefly those improvements and additions which we have been most struck with in the tables. In Table II, of the common logarithms, there are added pro- portional parts, which greatly facilitate its use. Table V. or logarithmic tangents, &c. has two sets of argu- ments, one for time, and one for arc, besides proportional parts for seconds at the bottom. We are decidedly of opinion, however, that, for most practi- cal purposes, it is infinitely better to have separate tables for converting time into arc, and the reverse ; and we have reason to believe, accordingly, that Mr Galbraith stopped the press to give tables LXI. and LXII. at our suggestion. In the next edition we hope he will place these two tables by the side of XXX. and XXXI., for converting solar into siderial time, and the reverse, and near XXXII. for converting mean time into parts of the equator. These are all eminently useful ; and we are glad to observe Mr Galbraith giving them at full length, to single seconds, and not in the usual abbreviated shape, which is very teazing. Tables VI. and VII., for natural sines, tangents, &c. are too contracted, being given to degrees only ; if given at all they should be to minutes. Table IX., for taking out the proportional parts for daily dif- ferences of declination, right ascension, &c. we do not much like; as it requires the use of the proportional logarithms in die next JANUARY MARCH 1827. D ^ 406 Scientific Intelligence. — New Publications^. table. We approve more of the table of proportional logarithms to twenty-four hours by Lax and others, which gives the answer at one inspection. Tables XIII. gives the correction to be added to the sun's al- titude, and combines the dip, refraction, parallax and semi-dia- meter. We confess, however, we prefer that these corrections sliould not be slumped together in this way, and have always made it a rule to teach our young friends to shun such tables, and take out each correction separately. Table XVI. has been re-computed, expressly for this work, from the sun's horizontal parallex taken at S.'^CS. Table XVII. gives Mr Ivory's refractions, but it has been considerably extended, and, as we think, improved, by having the refractions and their logarithms to every KY from the zenith to the horizon. Tlie addition of proportional parts to the three succeeding ta- bles for the corrections due to the thermometer and barometer is very praiseworthy, as it materially facilitates their applica- tion. We observe, that a column has been added to table XXVII. of Equations for second differences, by which they are adapted to the sun's declination ; and although, in ordinary cases, no cor- rection for the irregularity of the sun's motion is necessary, it does become of consequence in very accurate observations for latitude made near the Solstices. Table LIX. gives the logarithms of the numbers in Rossel's well known table for correcting the longitudes determined by chronometer, when the rate has been found to have varied. Everything v/hich contributes to the accuracy of such determi- nations is valuable ; and we think Mr Galbraith, by dwelling so frequently on these minute corrections, does essential service to science, by making observers aware how easily and safely they may be taken into account. Table LXIII. contains, in a compendious shape, many ex- tremely useful numbers, with their logarithms and comple- ments. Tables LXVI. and LXVII , for the third and fourth diffe- rences of the moon's motion, are by Mr Henderson, a very in- genious mathematician in Edinburgh. List of English Patents, 1826-T. 407 The last table, for finding the latitude by the Polar Star, is by Captain Kater, and is sufficiently accurate for sea purposes. We agree, however, with that observer, in thinking the direct method the most satisfactory one. List of Patents granted in England, from Sth December 1826 to \&h January 1827. 1827, Dec. 8. To Thomas Machell of Berners Street, Oxford Street, London, surgeon, for improvements on apparatus applicable to the burning of oil, &c. To Robert Dickinson of New Park Street, Soutliwark, for an in- vention for the formation, coating and covering of vessels or pack- ages for containing, preserving, or conveying goods, whether liquid or solid, &c. 13. To Charles Pearson of Greenwich, Esq. Richard Wilty of . , Hanley, Staffordshire, engineer, and William Gillman of White- chapel, engineer, for a method of applying heat to certain useful purposes. To Charles Harsleben of Great Ormond Street, Esq. for his ma- chinery for facilitating the working of mines, and extraction of diamonds, &c. gold, silver, &c. from the ore, the earth, or the €and ; applicable likewise to other purposes. To John Costigni of CoUon, in the county of Louth, civil engi- neer, for improvements in steam machinery or apparatus. To Peter Mackay of Great Union Street, Borough Road, for im- provements, by which the names of streets and other inscriptions will be rendered more durable and conspicuous. 18. To William Johnston of Droitwich, for improvements in the mode of process and form of apparatus, for the manufacturing of salt, and other purposes. To Maurice de Jough of Warrington, cotton-spinner, for im- provements in machinery or apparatus for preparing rovings, and for spinning and winding fibrous substances. 20. To Charles Harsleben, of Great Ormond Street, Esq. for im- provements in building ships and other vessels, applicable to va- rious purposes for propelling the same. To Thomas Quarrill, of Peter's Hill, London, for improvements in the manufacture of lamps. To William Kingston, master mill-wright, of Portsmouth Dock- yard, and George Stebbin&,j mathematical instrument-maker, of High Street, Portsmouth, for improvements on instruments or apparatus for the more readily or certainly ascertaining the tune and stability of ships or other vessels. 408 Lisi of English Patents^ 18^6^-7. D«c. 28. To Mebvii, WiisoN, of Warnford Court, Tkrogmorton Street, for improvements in machinery for cleaning yice. To Charles Scidler, of No. 1. Crawford Street, Portman Square, for a method of drawing water out of mines, wells, pfts, and other places. To Frederick Andrews, of Stanford Rivers, Essex, for improve- ments in the construction of carriages,, and in the engines or ma- chinery to propel the same, to be operated upon by steam or other suitable power. To Charles Random, Baron de Barenza, ofTarget Cottage, Kentish Town, for improvements in gunpowder-flasks, powder-horns, or other utensils of different shapes, such as are used for carrying gunpow- der, in order to load therefrom guns, pistols, and other fiire-armB; 21'. To Valentine Bartholomew, of Great Marlborough Street, for his improvement in shades for lamps, &c. To John Gregory Hancock, of Birminghwit, plated beading and canister hinge manufacturer, for a new elastic rod for umbrellas and other like purposes. 22. To Thomas, of Vail Grove, Chelsea, Esq. for his process of rendering boots, shoes, and other articles, water-proof. To David Redmund, of Greek Street, Soho, engineer, for improve- ments in the construction and manufecture of hinges. 29. To Elijah Galloway, of the London Road, Surrey, engineer, for 1:827, a rotatory steam-engine. Jan. 9. To John Whiting,, of Ipswich, architect, for ^improvements in win- dow sashes and frames. 11. To James Frazer, of Houndsditch, engineer, for sin improved me- thod of constructing capstans and windlasses. To James Frazer, of Houndsditch, engineer, for an improved me- thod of constructing boilers for steam-engines. 15. To William Wilmot Hall, of Baltimore, America, at present residing in Westminster, for an engine for mooring and propell- ing ships, boats, carriages, mills-, and machinery of every kmd. To William Hobson, of Markfield, Stamford Kill, Middlesex, for an improved method of paving streets, lanes, roads, and carriage- ways in general. To James Neville, of New Walk, Shad-Thames, engineer, for an improved carriage, to be worked or propelled by means- of steam. To William Mason, of Castle Street East, Oxford Market, West- minster, patent axletree-maker, for improvements in the con- struction of those axletrees and boxes for carriages known by the names of mail-axletrees and boxes. 16. To Robert Copeland, of Wilmington SquarBj Middlesex, for im- provements on a patent already obtained by him for combinations of apparatus for gaining power. Feb. 1. To' Robert Barlow of Jubilee Place, Chelsea, for a new combina- tion of machinery, or new motion for superseding the necessity of Lis{ efPatentSy 18^6-7. 409 the ardiaaary crank in st^am-englntts, andfoK otheu^rposes where power is required; Feb. 1. To John Frederick Danii!Ul,. E%. df Gower: S4ireet, Bei^M Square, for improvements in the naanufectare of. gae; To John Oldham of Dublin, for improvements in the construction of wheels for driving machinery impelled by water, oo' wind, also applicable to propelling, boats,. &c. To- Ralph Hind-marsh of Newcastle-upon-Tyne, master-mariner, for. an improvement in the construction of capstans and wind- To Robert StiR£in<3^, Clerk, minister of Galston, in Ayrshire, and? Jjim^s Stirling, engineer, of Glasgow, for improvements ia air-engines for moving of machinery. To John White of Southampton^ engineer and ironifounder, for improvements in the construction of pistons or buckets for pumps. To Samuel. Parker, Airgylfe Place, Argyle Street, Westminster, bronzdst, for improvements in the construction of lamps. To Ant CINE Adolphe Marcellin Marbeot, of No. 38. Norfolk Street,. Strand, for improved machinery for working or cutting wood into all kinds of mouldings, rebates, cormcesy or any sort of fluted work. List of Patents grmvted in Scotland J^rom l^h December 1826 to 9.Uh Fehnmry 1827. Bee. I3i To Jam** Yandei^l of Broad Wall, in the parish^ of Christ Church, Surrey, private person, for " certain improvements in apparatus for cooling and heating fluids." 14. To Henry Charles. Lacy of Manchester, in the county palatine of Lancaster, coach-master, for " a new apparatus on which to sus- pend carriage bodies." To Thomas Machell of Berners Street, Oxford Street, in the county of Middlesex, surgeon, for " certain improvements on ap- paratus applicable to the burning of oil and other inflammable substances." 20. To Dominique Pierre Deurbrouck of Leicester Square, in the county of Middlesex, Esq. for an invention communicated to him by a foreigner residing abroad, " of an apparatus adapted to cool wort or must previous to its being set to undergo the process of fermentation, and also for the purpose of condensing the steam arising from stills during the process of distillation." 29. To Count Adolphe Eugine de Rosen, of Prince's Street, Ca- vendish Square, in the county of Middlesex, for an invention eommunicated to him. by a foreigner residing abroad^ " of anew engine for communicating powei? to answer the purposesofi a steami- engine." 410 List of Patents, 1826-7. To William Bush of Broad Street, In the city of London. Esq. for " certain improvements in propelling boats and ships, and other 1827, vessels or floating bodies." Jan. 15. To Henry Richardsok Fanshawe of Addle Street, in the city of London, silk-embosser, for " an improved winding machine.'* To MosE Poole of the Patent-Office, Lincoln's Inn, in the county of Middlesex, gentleman, for an invention communicated to him by a foreigner residing abroad, " of certain improvements in the machines used for carding, slubbing, slivering, roving, or spinning J wool, cotton, waste silk, short staples, hemp, or flax, or any other fibrous materials, or mixtures thereof." Feb. 2. To John Frederick Daniell of Gower Street, Bedford Square, in the county of Middlesex, ^Esq. for " certain improvements in the manufacture of gas for the purposes of illumination." To Maurice de Jongh of Warrington, cotton-spinner, for " cer- tain improvements in machinery or apparatus for preparing ro- vings, and for spinning, twisting, and twining fibrous substances." 7. To James FRASERof Houndsditch, in the city of London, engineer, for "■ a new method of constructing steam-boilers." 13. To Robert Stirling, minister of Galston, in the county of Ayr, North Britain, and James Stirling, engineer in Glasgow, in the county of Lanark, North Britain, for " certain improvements in air-engines, for the moving of machinery ." 16. To James Fraser of Houndsditch, in the city of London, for " an improved method of constructing capstans and windlasses." 24. To Robert Bush and William King Westley of Leeds, in the county of York, flax-spinners, for " certain improvements in ma- ,;. ,. chinery for heckling or dressing, and for breaking, scutdiing, or cleaning hemp, flax, or fibrous substances." LIST OF PLATES. \ ,|^; :^v^ Plate I. Fig. 1-5. Little Andaman Island, &c. 6-9. Awn of the Seed vessel of Stipa pennata. 10. Anatina villosiuscula. 1 1. Venerupis Nucleus. 11. Illustrations of Dr Grant's Observations on Spongia. III. Fig. 1. Eruption of American Lakes. 2. Libellulite of Solenhoffen. IV. Illustrations of Mr Scoresby's observations on Rainbows. V. Explanatory of Mr Barlow's view of Magnetism. Memorandum. — Want of room has obliged us to delay several Articles and Notices of New Publications, and also to limit more than usual the Scientific Intelligence. ( 411 ) INDEX. Abel, Dr Claik, his account of a colossal orarig outang killed in Su- matra, 371. Air, Mr H. Meikle's experiments with respect to the specific heat of, 328, Alexander, Cornet J. E., his notice regarding the Little Andaman Island, 43. Alligator, Mr Audubon's observations on the natural history of the^ 270, Andaman, Little, Cornet Alexander's notice regarding it, 43. Anatina villosiuscula, description of, 370. Arctic sea and ice, Dr Latta's observations on the, 86. Mr Scoresby's remarks on Dr Latta's observations on the, 382. Arnott, G. A. Walker, Esq. his account of a tour to the south of France and the Pyrenees, 241. Arsenic, J. L. Berzelius's remarks on its detection in cases of poisoning, 338. Arts, notices in the, 207, 398. Asterias rubens, notice regarding, 394. Astronomical calculator, notice respecting Mr Innes's, 2n. Audubon, Mr J. J., his account of the habits of the turkey buzzard, 172. — observations on the natural history of the alligator, 270. — notice regarding his intended work on American ornithology, 210. Banks, Sir Joseph, Baron Cuvier's historical eloge of, 1. Barlow, Mr P., his account of experiments and observations on the mag- netic needle made during Parry's third voyage, with remarks, 347. — his observations on the tides in the upper part of the Thames, 49. Beech-tree, a non-conductor of lightning, 392. Berzelius, J. L., his remarks on the detection of arsenic, 338. Bismuth cobalt-ore, description of, 200. Bohr, Mr G., his account of a visit to the glaciers of Justedal and the Mantle of Lodal, 235. Bonnet, Charles, Baron Cuvier's biographical memoir of, 213. Botany, notices in, 207, 395. Boue, Dr A. his observations on serpentine and diallage rocks, 265. Brome, a new substance discovered in sea water, 201. Buch, Baron Von, his observations made during a visit to Madeira, 73. 412 INDEX. Buchanan, D., Esq. his account of fresh water found in the sea far from land, 369. Celestial phenomena, from Jan. 1. to April 1. 1827, 188. — from April 1. to July 1. 387. €ereales, thear origin and native country, 89d. Chemistry, notices in, 193. C!oG(l> -M. JKiarsfcen s observations and experiments on the different kinds