Go A Cowes 14 iy bay y 5 * Pe ee. tS praehh \ wy) Nisa tie rig Pe rene : % = * = ¥ aes = Sanne i x Mi ite 4) ni hs i Bf ane : cident aia ih : y Pais ie : iy i Be =: Sees bite? OSE ote oar hee = ‘ 7 t aoe Pp ‘C) | Evinhurgh JOURNAL OF SCIENCE, EXHIBITING A VIEW OF THE PROGRESS OF DISCOVERY CHEMISTRY, MINERALOGY, GEOLOGY, BOTANY, PRACTICAL MECHANICS, GEOGRAPHY, AND USEFUL ARTS* IN NATURAL PHILOSOPHY, COMPARATIVE ANATOMY, ZOOLOGY, ANTIQUITIES, AND THE FINE NAVIGATION, STATISTICS, CONDUCTED BY DAVID BREWSTER, LL.D. ¥.R.S. LOND. SEC. R.S. EDIN. F.S.-5S> A. 4 ACADEMY; MEMBER OF THE ROYAL SWEDISH HONORARY MEMBER OF THE ROYAL IRIS: ACADEMY OF SCIENCES; AND OF THE ROYAL SOCIETY OF SCIENCES OF DENMARK; &c. &c. Vesa Ag, Se Se VOL. IV. NOVEMBER—APRIL. WILLIAM BLACKWOOD, EDINBURGH: | AND T. CADELL, LONDON. ) M.DCCCO.XXVI. | 10 biel UC TRye 4S eee Sin Petes Pay Seen e AXA #0 'tAsNTOD Tory Vane Ff pie CONTENTS EDINBURGH JOURNAL OF SCIENCE. No. VII. Art. I. Biographical Notice of the Abbé Haiiy, - wes II. A Popular Summary of the Experiments of Mens indice; Christie, Babbage, and Herschel, on the Magnetism of lron and other Metals, as exhibited by Rotation. By a Correspondent. - - - bB , IIL Account of an Improvement on the Galvanic Battery. By Mr JoHN Hart, Civil Engineer, Glasgow. In a Letter to the Editor. - 19 IV. An Account of the Frontier between the Southern part of Bengal and the Kingdom of Ava. By Francis Hamr.Ton, M. D. F.R. S.and F. A.S. | Lond. and Edin. Communicated by the Author.—( Concluded from Vol. III. p. 212.) a - * 22 V. Proposal for Improving the Vosthoanmal. By Wii11aM RITCHIE, A. M., Rector of Tain Academy. In a Letter to the Editor, - 37 VIL N olkces of Insects of unusual occurrence which have occasionally appear« ed in great numbers on Trees, &c. By Sir G. S. MACKENZIE, Bart., F.R.S. Lond. and Edin. In a Letter to the Editor, - ~ ib. VII. On the Crystalline Forms and Properties of the-Manganese Ores. By WILLIAM HarpincErR, Esq. F. R. S. E. Communicated by the Author. - With a Plate, - - - - 41 VIII. Account of the Eruption of the Volcano of Jorullo in is Montiel By Ba. } RON ALEXANDER DE HumBoxpt. With a Section of the Mountain, 50 TX. Observations on Humboldt’s Theory of the Volcano of Jorullo. By G. PoULETT ScroreE, Esq. Secretary to the Geological Society, - 55 X. Observations on the apparent Distances and Positions of 389 Double and Triple Stars. By J. F.!W. HERscHEL, Esq. Sec. R. S.-Lond., and F.R.S. Edin. and James Sours. Esq. F. R. 8. Lond. and Edin. — (Concluded from Vol. III. p. 288,) - 66 XI. Notice of an Earthquake felt at Sea, in February 1825. Uoenbiaticat- ed by a Correspondent, - “ “ . - 70 XII. Remarks on the Defoliation of Trees. By the Rev. Roms FLEMING, D. D. F. BR. S. E. &c. Communicated by the Authir, - - 72 XIII. On the Habits and Food of the Stickleback. From:a Correspondent, 76 XIV. On the Improvement of the Pipes of Organs. By M. FELix Savart, . 80 : ii . CONTENTS. XV. CONTRIBUTIONS TO POPULAR SCIENCE, - a No. V. On the Invisibility of certain Colours to Certain Eyes, ~ No. VI. Description of the Thaumatrope, ry - No, VII. Singular Optical Dlusion seen through a Talebeips i No. VIII. Variation 6f the Optical Deteption of Le Cat, - No. IX. Optical Illusion in examining a Dioramic Picture, - - XVI. On the Quartz District in the Neighbourhood of Inverness. (Con- cluded from Vol. III. p. 218.) By GEORGE ANDERSON, Esq. F. R. S. E., F.S. S.A. and Secretary to the Northern Institution for the Promotion | OF Seiehce and Litetatare at Tuvetniess, Ooininunicatéd by the Author; | 91 XVII. Description of the Bituminous Rock which occurs in Ross-shire, and - the neighbourhood of Inverness, &c. By GEORGE ANDERSON, Esq. F. R.S.E., &c. Communicated by the, Adithor, ° S 93 XVIII. Description of an inverting Sextant Telescope with Nautical Eye- Tube, for taking Altitudes at Sea when the Horizon is Invisible, In- vented by Mr MarHew Apam, AM. Rector of the Academy of Inver- esearee ness. Communicated by the Author, | - 5 iz 95 ; TX. On the Optical Illusion of the Conversion of Cataphs into Intaglios, and _ of Intaglios into pomoery with an Account ‘of other yg Pheno- mena, ¥ 99 XX. Ahalysis ‘of Piotostiiine. By eunhives maowvs Bq. of Berlin. Communicated bythe Author, - as 103 ” eXK Oh He Means of ‘Détecting ‘Lithia ‘in Minerals Dy the Blowpipes” "By. Epwarp TURNEH, M. D. F,'R.S. E. &e. Lectirer on Chémistty, and Fellow of ‘the Royal College of 2H reg Comitnitinieated ‘by the Awthor, 113 XX. On'the Apparent Direction of Eyes in a Portiait. By Ww. u. Wor. Laston, M.D.F.R.S: and V. P. With a Plate, . 117 > XXL On the vegeiiete Productions of the Island of Sh eager By Dr i. Kuuz, ‘ - - - at BAO XXIV. (CONTRIBUTIONS TO METEOROLOGY, - 2 124 1. On the Negative Electricity of Showers. By Mr Joun: args ib. 2, ‘Account ‘of an Improved Hygrometer,: G 97 XXV- Account6f the Discoveries and Bikpérigniits of the Swedish Chethists during-the year 1825. Drawn up for this Journal fs a Pi tae at Stockholm, Jie “ % 128 '. ‘Professor Berzelius’s Daiitivery of ‘Lithia in Minéri Waters, ib. 2. Professor Berzelius’s Experiments‘on the Orange Gas + pam , “a mixture of Fluor-Spar and Chromate’of Lead, > - 129 3. Aceoutit of Professor Berzelius’s Method of Deviesg Atsenic id Uh Bodies of Persons Poisoned, '- - - ign? 13] ‘4. Professor Bet zelius’s Researches on ‘Molybdena, ~~ == 133 5. M. Setterberg’s Experiments on the Sulphiurets of Cobalt, = . ) 136 ‘6. M. Mosander on the aie anesaptagocea et Carbonate of Soda, Py as | qs M. Mosander’s Analy of - the Oxidesof tom forined by coniatlied UZ - Heat; % 4.2 it eae 137 XXVEOnsome: Remarkable. edebidteae sndenieedltdana in the Sandstone of Kerridge in ‘Cheshire. . By Samuex Hipert, M.D, FOR. S. BE. and” a i ae CONTENTS: iii M. GS Secretary to the pi of Scottish pa Conimuhieat- ~e ed by the Author, - - » 138 XXVII. Notice regarding the Dhpeeey of Live Cockles in a Peat Mose ata. ‘great distance from the Sea. By Jomn mia. ate M.WS8. Com- municated by the Author, - 142 XXVIII. Notice of Captain Party’s ban Expedition to the Arctic Regions in 1624 and 1825, “| - - - - - 147 . XXIX. HISTORY,OF MECHANICAL INVENTIONS AN D / PRO. _ CESSES IN THE USEFUL ARTS, « alayt 150 1. Description of the Double Weather Sluices invented by Rostnt — THOM, Esq. Rothesay. Communicated by the _e a) ib. ‘2. Description of a Rotatéry Gas-Burner, - : 153 3. Curious Law respecting the Vibration of Pendulums, ‘. 154 4. Reverend Mr Lardnér’s Methiat'of ervey Carriage Wheels on theit Axles, - - - . 2 155 XXX. ANALYSIS OF SCIENTIFIC BOOKS AND MEMOIRS, ib. I. Account of the Earthquakes which occurred in Sicily, in March 1823, By Sig. Anaté Ferrara, Professor of Natural a in the, University of Catania, - Bebiropnnne | V Il. Schow’s Essay on Botanical Baaeply. Fe ae "1833, ‘161 _ITI. Memoir on the Red Snow of the Arctic Regions. By Professor “Adarpa of Lund, - ea ee el it iS 167 XXXI. PROCEEDINGS OF SOCIETIES, A i “173 1. Proceedings of the Royal Sogiety of Edinburgh, ws ib. 2. Proceedings of the Society for Promoting the Useful Artsin Scotland, 174 XXXII. SCIENTIFIC INTELLIGENCE, res ee > 175 I. NATURAL PHILOSOPHY. AsTRONOMY.—l. First Comet of 1825. 2. Second Comet of 1825. 3. Third Comet of 1825. 4. Fourth Comet of 1825, the periodical Comet of Encke. 5. Fifth Comet of 1825. 6. Stars without any proper Motion. 7. Miss Herschel’s Catalogue of Nebula. 8. Mr Pond’s Method of Determining the Direction of the Meridian. 9. Remarkable Effect on the Cambridge Transit Instrument, - - - = 175—177 OptTrics,—10. Committee for the iutieheditbele of Glass for Optical purposes. 11. Traces of Polarized Light in Halos. 12. Telescopes without Irradiation. 13. Optical structure of Edingtonite. 14. Phosphorescence of certain Fluids, . - - - - 177, 178 ELEctTRIcITY.—L5. Electricity produced by Evaporation. 16. Electricity of « the Atmosphere. 17. Electricity of Flame. 18. Subterraneous passage of Lightning, - - - - - - 178, 179 GALVANISM.—19. Analogy between the Phenomena of Galvanism and those of Fermentation. 20. Avogadro’s Multiplying Voltimeter, - 179, 180 METEOROLOGY.—21. Mean Temperature of the Equator. 22. Diminution of the Temperature with the Altitude. 23. Fall of a Meteoric Stone, at Nantgemory, Maryland. 24. Hoar Frost on Iron Rails, 25. Mean Height iv CONTENTS. ! of the Barometer at the level of the Sea. 26, Rain without Clouds. 27, Fall of Meteoric Stones in Italy. 28. Baron. Krusenstern’s opinion of Mr, Adie’s Sympiesometer. 29. Mr Jones’s Improved Hygrometer. 30. Re- markable Waterspout. = - ~ = oe) 180183 Il. CHEMISTRY. 31. Highly calcined Charcoal a conductor of Caloric. 32. Selenium in the Sulphur of the Lipari Islands. 33. Iodine discovered in a Mineral. 34, New Experiments on Flame. 35. Prussian Blue in the Soda of Sicily. ~ 36. Analysis of Benzoin. 37. On Rinmann’s Green. 38. Oxalicacid found in great quantities in lichens, &c. 39. Action of Nitric Acid on Charcoal. _ 40. Temperature of different Animals. 41. Analysis of the Piney Tallow - from Malabar, - - - - ,- : " 183—185 Ill. NATURAL HISTORY: MINERALOGY.—42. New Analysis of Dioptase. 43. Mr Swedenstierna’s Collection of Minerals. 44. Remarkable Law in Mineralogy, — - 186.187 ’ \ ! s IV. GENERAL SCIENCE. . 45. Copley Medals adjudged to Mr Barlow and M. Arago. 46. Figures in Amber. 47. Establishment of two Royal Scientific Prizes, - 188 XXXIII.—List of Patents for New Nop! sealed in Scotland since Au- gust 19, 1825, - ° = z Ps ib. XXXIV. Celestial Phenomena, from Saati 1, 1826, to April 1, 1826, Adapted for the Meridian of Greenwich, 189 XXXV. Register of the Barometer, Thermonieter, ‘and Rain-Gage, kept at Canaan Cottage. By ALEX. ADIE, Esq. F. R.S. E. - 192 pita'Es ofl. ‘to CONTENTS OF THE ag EDINBURGH JOURNAL OF SCIENCE. No. VIII. Page Arr. I. Account of an Orang Outang, of remarkable height, from the Island of Sumatra. By Crarke ABEL, M.D. Communicated in a Letter to Dr BREWSTER. With a Plate, « - - 193 Il. Memoir on the Mechanism of the Human Voice. By M. FELtx Sa- VART, - > - - - - 200 _ FIT. Account of a Voleano i in the Himalayeh Mountains. Communicated to Dr BREWSTER by a Correspondent in India, - 209 IV. Researches on the Refractive Power of Elastic Fluids. By M. Duele, 211 V. Description of the Grotto of Ganges, By M. MarsorxiEr, =" 216 VI. Notice respecting the Eggs of the Boa Constrictor, and of a young Brood . hatched from them in Assam. Communicated to Dr BREWSTER by a Correspondent in India, - heater. - - 221 VII. Analysis of a Lithion-Mica from Zinnwald in Bohemia. By C. G. GMELIN, Professor of Chemistry in the See! of bie vie Ina Letter to Dr BREWSTER, - - = 222 VIII. On the Law of the Compression of Air, and of paver: capable of being ~ Liquefied by Pressure. By H.C. OERSTED, Professor of Natural Philo- sophy in the University of Copenliagen. Communicated by the Author, 224- IX. Route to India, by Egypt and the Red Sea. By Caprarin PRINGLE, ' Royal Engineers. Communicated by the Author, - - 234 X. Observations and Experiments tending to show that the Sense of Taste is not a separate one. By a Correspondent, ne 243 XI. Account of Dr Clark and Captain Sherwill’s Ascent of ‘Mont Bla, i August 1825, . - - - 255 - “MII. Farther observations on the History of Mr Babbage’s Experiments on_ the Production of Magnetism by Rotation. = § - 257 XIII. Description of the Great Stone Bridge of Seventeen sisi envined over the Garonne.at Bourdeaux. In a Letter to the pape from a Corres- pondent, - 260 XIV. Account of the Shock of an Earthquake felt at Sea by the laiaoursble East. India Company’s Ship Winchelsea. Ina Letter to the Matron, ' from CapTaIn LACHLAN, 17th Regiment, - - - 264 s ii’ CONTENTS. } Page XV. Notice of ‘Two Earthquakes felt at Sea, - 267 XVI. Abstract of a Memoir on the Birds in the Environs of Geneva, » £i.A. “ NEcKER. ‘With Observations, by a Correspondent, * 269 » XVII. Account of the Discovery of an Inhabited Island in the Pacific. By Captain Exe of the Pollux Sloop of War, i in the Service of his Majesty the King of the Netherlands. In a Letter to Dr BREwsTER from G. Motu, Professor of Natural Philosophy in the University of Utrecht, 278 “XVIII. Notice respecting the Working and Polishing of Granite in India. In a Letter to the Ep1tror from ALEXANDER KENNEDY, M.D.F.R.S. E. 281 XIX. Observations on the Superiority of Achromatic Pernt with Fluid __ Object-Glasses, as constructed by Dr Barr, - 282 XX. On Epistilbite, a New Mineral Species of the Zeolite Family. By Dr Gustavus Rose, Berlin. Communicated by the Author, - 285 X XI. On the Horary Variations of the Barometer. By Banon ALEXANDER DE HUMBOLDT, - - > - - 290 XXIl. Notice regarding Professor Mitscherlich’s Observations on the Dimor- ‘phism of Hydrous Sulphate of Zinc, and Hydrous Sulphate of Magne- siae By WILLIAM ae a ri -, F. R. 8. E. Communicated by the Author, - - rs i - 801 XXIII. Observations on the Gaiety of the Burrampooter and the Sanpoo Rivers. By Captain R. ee tent 17th Regiment. In a Letter to the Eprror, - - 302 XXIV. On a Property of Light, exhibited in the Baesinaciod of small Lu minous Points by Telescopes) By Proressor Amici of Modena, 306 XXV. Observations on the Relative Performances of Achromatic and Re- flecting Telescopes. By Mr MEROGHR TS Mr saan and PROFESSOR AmMICcT, - - - 309 XXXVI. Farther Observations on ahaa a Non Mineral Species By the EpIToR, - - - 316 XXVII. On the Torpidity of the Tortoise and Dormouse. By Jonn Mur- © RAY, Esq. F. S. A. F. L. S., &e. &e. . - - . 317 -XXVIII. Observations on the Intensity of Magnetism in different parts of “ the Earth’s Surface. By Curist1AN HANSTEEN, Professor of Astro- nomy in the University of Norway. - = - 323 X XIX. On the Magnetising Power of the more refrangible rays of Light. By Mrs Mary SOMERVILLE, - - - - 328 XXX. HISTORY OF MECHANICAL INVENTIONS AND PRO. CESSES IN THE USEFUL ARTS, - . 338 1. Description of a simple Punt-Boat for saving time and labour. By ANDREW hcg: Esq. F. R. S. E. Communicated by the Au- thor, - . - - ib. 2. Method of secibiehion wood lad giving it a closeness of grain for re- sisting moisture, for the construction of furniture and other purposes. ‘ By Mr James FaLcoNER ASTLIE, ° - 333 3. Discovery of a Fine Sand for Flint Glass at Alloa, wipe to that from Lynn Regis. By RoBEKT BaD, Esq. F. R. S. E. Civil Engi- neer. Sect fir Ld = - a? 3 - ib. CONTENTS. ni XXXI. ANALYSIS OF SCIENTIFIC BOOKS AND MEMOIRS, pr I. Considerations on Volcanos,—the Probable Causes of their Pheno- mena,—the Laws which Determine their March,—the Disposition of their Products,—and their Connection with the Present State and past History of the Globe ; leading to the Establishment of a New Theory of the Earth. By G. PouLerT ScRopPE, 7" Dit to the Geological Society, London, 1825. - ib. II. Account of the Earthquakes which occurred in Sicily in March 1823. By Sig. ABATE FERRARA, Professor of Natural Philosophy in the University of Catania, (Concluded from last Number, p. 161.) 362 III. ScHow’s Essay on Botanical Geography. Copenhagen, 1823.— (Concluded from last Number, p. 167.) . - “= - 370 XXXII. SCIENTIFIC INTELLIGENCE, - we.” _376 I, NATURAL PHILOSOPHY. AsTRoNOMY.—l1l. Hansen’s Parabolic Elements of the second Comet of 1825. “ 2. M. Capocci’s new elements of the Comet of 1825. 3. Pons and Capocci’s Ob- servations on the tail of the second Comet of 1825. 4. Hansen’s elliptical elements of the second Comet of 1825. 5. Fifth Comet of 1825. 6. Mr Pond’s Observations on the Double Star 2 Bootis, ote 376—377 Oprics,—7, Luminous Phenomenon observed between Paisley and Glasgow, 378 : Il. CHEMISTRY. 8. On the Sulpho-Naphthalic Acid newly discovered by Mr Faraday, ib. III. NATURAL HISTORY. ZooLocy.—9. Fossil bones near Montpellier. 10. Crocodiles of Egypt. 11. on the Egg and Tadpole of Batracian Reptiles, - 378—380 BotTany.—12. M. Ramond on the Vegetation of the Summit of the Pyrenees, 380 XXXIII. List of Patents granted in Scotland since November 17, 1825, 381 XXXIV. Celestial Phenomena, from April 1, 1826, to July 1, 1826. 382 XXXV. Register of the Barometer, Thermometer, and Rain-Gage kept at Canaan Cottage. By ALEX. ADIE, Esq. F.R. S. E. - . > ‘a wi nt th iat fs ‘ al ee vt SH fan hen wait ree pee be Seb na a sada Mts Ba cot wy er se ite 2 po 4 THE EDINBURGH JOURNAL OF SCIENCE. Art. I.— Biographical Notice of the Abbé Haiiy.* Rene-Just Havy, Honorary Canon. of ‘the metropolitan church of Paris, Member of the Legion of Honour, Professor of Mineralogy in the Royal Garden, and in the Faculty of Sciences of Paris, and Member of the Royal Academies of Paris,| London, Petersburgh, Berlin, Edinburgh, Stockholm, &c.; was born on the 28th of February 1743, at Saint- Just, a little village in the department of the Oise. He was the elder brother of the late Mr Haiiy, so well known as the inventor of a method of instruction for the blind. The father of these two children, who were destined to extend the bounds of science, and enlarge its applications, was a poor weaver, who, according to all appearances, would never have been able to give his sons any other profession than his own, if some generous persons had not come to his assistance. There was then at Saint-Just an Abbey in which the young Haiiy attended with assiduity to the religious ceremonies that were practised, and showed much taste for the sacred music of the church... He drew the attention of the Prior, who sent. for him, interrogated him, and, struck with the extraordinary in- telligence of the child, had him instructed by some of the re- * This biographical sketch is composed of the eloquent eloge upon Haiiy delivered by Baron Cuvier at the public sitting of the Academy of-Seiences on the 2d June 1823, interspersed with copious additions ota ae writings and scientific labours.—Ep. 0 VOL. IV. No. I. JAN, 1826, ) A Q Biographical Notice of the Abbé Haiiy. ligious incumbents of the Abbey. The progress of the scholar was so rapid that his masters engaged his mother to take him to Paris, where he might find the means of continu- ing his studies. » The courageous mother followed this advice, notwithstanding that difficulties of all kinds presented them- selves, and persevered through all the trials which she had to sustain in supporting herself and her son in a great city, where she found herself without resources. ‘The first relief which she obtained, after a long period of expectation, was a place for her son as one of the infant choristers in a church in the Fauxbourg St Antoine. The young Haiiy was able to improve upon the simple instruction which he received in that employment; he became a good musician. At length his pro- tectors obtained for him.a purse in the College of Navarre, and it is from his entrance into this college that we must date the commencement of his regular studies. His conduct secured the esteem and attachment of his professors; and when he ceased to be a scholar, though still very young, his masters judged him to be worthy of sharmg with them in their Ja- bours. At the age of twenty-one he was regent of the fourth, and sone time after, he passed as regent of the second to the college of Cardinal Lemoine. Nothing, until then, had: dis rected his attention to the natural sciences, but he had attend: ed the course of Brisson in the college at Navarre, and ac- quired some taste for experimental physics. Among his new confreres in the college of Lemoine was Lhomond, a man of profound knowledge, and yet more modest and pious than he was learned. This person had limited himself to the instruc: tion of the sixth, and had composed works only for children; but they were remarkable for an uncommon clearness, and a simplicity of tone conformable to the character of the author: The young Haiiy soon became the friend of the respectable Lhomond, entrusted him with the secrets of his conseience; and felt for him the tenderness of a son. He took care of his business, comforted him im his sufferings, and accompanied him in his walks. Lhomond loved to herborize, but Haiiy had yet no idea of botany. The industrious friendship of the young professor enabled him to fill up, in a very short time, this blank in his information, in order that he might be more A t 04 ; Biographical Notice of the Abbé Haiiy. 3 agreeable and useful to his friend. At the first herborization, he could name the plants, and assign them their botanical characters; very soon he was on a level with his companion atid from that time every thing ‘was common between them, even to their amusements. The College of Cardinal Lemoine is near the aide of Plants; and it was natural that Haiiy should often choose it for his promenade. Seeing one day a crowd of auditors press ing in to the attendance of a lecture of Daubenton, on: mi- néralogy, he wished to hear this professor, and was charmed to find, in’ this part of natural history, subjects of theory more analogous té his taste for the physical sciences, than the pursuits of botany. The comparison of these two varieties'of the productions of nature, excited in his mind a train of: re+ flections which led the way to his discoveries in crystallogra- phy. How is it, said he, that the same stones and the same salts should show themselves in cubes, in prisms, in‘ needles, without the change of a single atom in their composition, while the rose has always the same petals, the gland the same flexure, the cedar the same height and devélopement? He was occupied with these ideas, when examining one day some minerals at the house of his friend M. Defrance, he awk ward- ly, though luckily, let fall a beautiful group of prismatic cry- stals of calcareous spar. Some fragments broken from. the group, presented the appearance of a new and regularly form- ed crystal, with smooth surfaces. Haiiy discovered, with sur- prise, that this form was precisely that of rhomboidal crystals of Iceland spar. “* The mystery is explained,” cried he. Yn fact, his’ whole theory of crystallography, a monument as im- perishable as the truths of geometry, is founded on this ob- servation ; but because this discovery was altogether geometri- cal, it was necessary that it should be explained and perfected through the medium of geometry. Haiiy felt on this’ occa- sion also, that his studies had been imperfect. But he was not discouraged. He perceived what he stood in need of in order to continue his researches upon the structure of cry- stals; invented a method of measuring and describing them, and not till then did he venture to speak of his discoveries to his master, to whose lessons he had modestly and silently at- 4 Biographical Notice of the Abbé Haiiy. tended... It may readily be conceived that Daubenton was eager to accept and to make known such: valuable labours.’ M. de Laplace, to whom he communicated them, hastened to. encourage the author to bring them before the Academy of. Sciences. But it was not easy to induce the modest Haiiy to leave his happy obscurity to show himself at the house where the Academy held its sittings, and in the midst of this society of distinguished men. He yielded, however, to the solicita- tion, and went to the house as to an ecclesiastical ceremony, clothed with the costume prescribed by the canons. It was found necessary to have recourse to the authority of a doctor of the Sorbonne, to persuade him that he might, with a safe conscience, wear the same garb as.the other ecclesiastics of that day. It is probable, however, that the Academy would haye received him, whatever dress he might have chosen to appear in, On the 12th of February 1783, he was admitted as. an adjunct in the class of Botany. In the prosecution of the new views which Haiiy had adopted respecting the structure of crystals, he was led to:pay particular attention, to. the physical. properties of ‘minerals, The developement of electricity by heating the tourmaline, which had_ been discovered by Lemery, attracted. his particu- lar notice; and he was led to the discovery of the same pro- perty in the siliceous oxide of zinc, in boracite, in mesotype, prehnite, and sphene. So early as 1785, he published, in, the Memoirs of the Academy of Sciences, his observations on the pyro-electricity of tourmaline, and in the same volume he an- nounced his discovery of the pyro-electricity of the oxide of zinc, which is the more remarkable, as it belongs to the class of metallic substances. His attention having been thus par- ticularly directed to the subject of electricity, he published, in the year 1787, his first separate work, in 1 vol. Syo., en- titled, Exposition Raisonnée de la Theorie de ’Electricité et du Magnetisme, @apres les Principes de M. Apinus. . The work of M. Aipinus, in which this theory, first appeared, was published at St Petersburg in 1760, under the title of Zien- tamen Theorie Electricitatis et Magnetismi, and was the first successful attempt to generalize the phenomena of these two interesting branches of science, _ Although the original work Biographical Notice of the Abbé Haiiy. 5 is written with great perspicuity, yet, from its want of method, Haiiy had an opportunity of presenting the theory under a more systematic aspect, of explaining it by more precise and popular illustrations, and of adding the details and the theory of ‘several interesting phenomena, such as the influence of points, the electrical spark, and the electricity developed in the cooling and evaporation of bodies according to the obser- vations of Lavoisier, Laplace, and Saussure. By employing also the true law of magnetic and electrical action, as deter- mined by Coulomb, he was enabled to give the theory a more precise form, and to rectify several of the calculations of ACpinus. While Haiiy was pursuing these peaceful labours, the Re- volution burst upon the nation. The Bastile was destroyed, and the monarchy soon after shared the same fate; but all this did not disturb the naturalist from the train of his occu- pations, nor induce him to participate in the general move- ments. As he refused to take the oath to the ecclesiastical constitution prescribed at that period, he was deprived of all his perquisites, and found himself as poor as at the period when the place of an infant chorister was the object of his am- bition. This poverty did not shield him from imminent dan- gers. Very ignorant of all that was passing around him, he saw one day his modest retreat invaded by men, who demand- ed of him whether he had any fire-arms. “ TI have no other than this,” said he, drawing a spark from his electrical machine. They seized his papers, which contained nothing but mathe- matical calculations, overturned his collection, which was his. only property ; and, finally, shut him up with other priests in the Seminary of St Firmin, which had been converted into a prison. In thus exchanging one cell for another, he was not very uneasy in his new habitation.. Calm under all circum- stances, and seeing himself in company with many of his friends, he only thought of sending for his drawers, that he might put his crystals inorder. Happily, he had friends without who knew better than he what was preparing for those who had incurred the popular displeasure. One of his pupils, afterwards his colleague, Geoffroy de Saint Hilaire, member of the Academy of Sciences, lodged then in the Col. 6 Biographical. Notice of the Abbé Haiiy: lege of Cardinal Lemoine. As soon as he was informedof the fate of his master, he ran. instantly, to, implore all those who he thought might have some influence, to,endeavour to save hit. An order was at length obtained: for his deliver- ance. M: Geoffroy ran with it to St Firmin;, but, he was late: Haiiy was so tranquil that nothing could induce him to go.out on that day... The next day he was taken out’ almost by force,—and the day after was the 2d of September ! It is very remarkable, that, .after the massacre from which Haiiy had been so providentially rescued, he met with no fur- ther disturbance. One day only he was compelled to appear at the review of his battalion, but he was soon dismissed on account of his bad figure. This was nearly all,that he knew, or at Jeast all that he saw of the Revolution. ,At the time at which the convention was acting with the greatest violence, he . was named one of the commissioners of weights and measures, and keeper of the cabinet of mines... When Lavoisier was ar- rested, when Borda and Delambre were deposed, Haiiy alone’ gould. write in their favour, and he hesitated not to do it: he, an unregistered priest, performing every day, his ecclesiastical functions ! At such an epoch, his. impunity was more aarpsten ing even than his courage. At. the death of Daubenton, the public voice Pe pee Haiiy as his successor. The yotes of the Academy. were, however, in favour of Dolomieu, probably on account of the extreme modesty of Haiiy. . But the former was at that, time under arrest, contrary to the rights, of nations, in the dun- geons of the Neapolitan government ; and: the only evidence of: his being alive was a few lines written upon the margin of a book with a splinter of wood, and the smoke of his lamp, which the ingenuity and humanity of an Englishman, had bribed the jailor to transmit to his friend. -Vhese lines, as well _ as his works, pleaded powerfully in his favour, and the mem~ ber who urged his election with the greatest zeal. was Haiiy himself. It might have been expected that such testimonials of esteem, rendered by such men, would have softened the ri- gour of Dolomieu’s treatment ; but how many persons.are there in power, who, when blinded by a momentary passion, take no pains to inform themselves af the opinion of their fellow-crea- Biographical Notice of the Abbé Haiiy. - q tures, until they discover it in the indignation of posterity’! Dolomieu was released from his dungeon only by virtue of an article in a treaty of peace, and a premature death, occasioned by the treatment he had been subjected to, but too soon re- stored to Haiiy the appointment he had so generously re- nounced. From this time, instruction in mineralogy acquired a new life. Collections were quadrupled, and arranged in an order conformable to the most recent discoveries. The mine- ralogists of Europe assembled to witness so many objects so well arranged, and to hear a professor so clear and elegant, and withal so complaisant. » His native benevolence displayed itself on every occasion to those who wished to be informed. He admitted them to his chambers, opened to them his cabinets, and refused no explanations. ‘The most humble students were received like the most learned and august personages; for he . had pupils of all ranks. - During the unfortunate period when his country was torn by faction, Haiiy was occupied in the more glorious pursuit of completing his mineralogical system, on Saneh his reputa- tion was destined.to depend. He accordingly published, in 1801, under the patronage of the Council of Mines, his Traité de Mineralogie in 5 vols. “Of this work we cannot speak with too much praise. It was the first great step to place mineralogy upon the immutable basis of scientific prin- ciples, and to wrest that noble science from the usurpation of ignorant charlatans. No man could pretend to follow our author through the varied and beautiful details of his system without some share of mathematical learning, without some knowledge of chemical science, and without a pretty general acquaintance with those branches of natural philosophy. which come into such immediate contact with the physiology of mi- neral bodies. In Great Britain, therefore, the labours of Haiiy were for along time completely overlooked. Mineralogi- cal lecturers could not be expected to expound what they did not themselves understand ; and the traders in bulky compila- tions on mineralogy scarcely ventured to notice, and still less to adopt, the vast improvements with which Haiiy had reno- vated and adorned their science. Dr Thomas Thomson, now Regius Professor of Chemistry 8 - Biographical Notice of the Abbé Haity. in the University of Glasgow, was, so far as we know, the first who seems to have studied and appreciated the labours of our author, and in his conversation, his lectures, and his writ- ings, he was, no doubt, the means of making his ee acquainted with the wi pans rise oysicmn wiyi * See the Article CrysTattocraruy drawn up by Dr Thomson for the Edinburgh Encyclopedia, and his, System of Chemistry, 5th Edition, vol. iii. p. 125. Mr Tilloch, so early as 1798, reprinted the sketch which Hatiy had given of his theory in the Annales de Chimie, vol. xvii. In speaking thus highly of the works of Hatiy, we have no design of depreciating the previous labours of Romé de I’Isle, and we think it right to add the following estimate of his merits, drawn up by an eminent Crys- tallographer, as an addition to the life of Romé de I'Isle in the, Edinburgh. Encyclopedia, vol. xvii. Part ii. which is on the eve of publication. The great merits of Romé de I’Isle in mineralogy are less generally ac- knowledged than they deserve ; particularly by the French mineralogists. Modern mineralogists are often astonished at the accuracy of the descrip- tions given by this author, even of such substances as were afterwards con- founded with each other by Haiiy and those who copied him. In almost every page his power of observation is displayed in a remarkable degree, joined with good sense, correct reasoning, and vast mineralogical erudi- tion. His figures of crystals, indeed, are frequently far from affording the pleasing effect of geometrical ,perfection, which captivates the eye in the figures adorning the great work of Haiiy ; yet they betray the hand of the master, who seized the peculiar character of the individual crystals which he represents, and which is often better preserved in these sketches than in better executed drawings. The student will always find a great deal of instruction in perusing the second edition of his Crystallographie, the result of more than twenty years continued and well-directed exertions ; but those who are already proficient in the scieuce will find pleasure in discovering in his writings that they have often been anticipated in their descriptions. It may be said, with perfect propriety, that, however ingenious the views of Hatiy may have been.in regard to the property of cleavage, he could ‘never have’ succeeded in establishing them as a general system, applicable to all erys-) tallized minerals, had he not possessed the observations and drawings of Romé de l’Isle. This great man met with all the opposition commonly incidental to new ideas, or to a degree of accuracy which, in fact, is far beyond what had been customary before ; but the predjudices had worn’ off, when Haiiy’s system appeared, which then earned the rewards both of its own merits and of Romé de I’'Isle’s.._ Haiiy has always veal enough to acknowledge every thing he owed to the latter ; the link which made Romé de I’Isle’s observations useful, by i eee general views in crystallography, founded upon edmetHical Vedleies ai by giving a particular name to every substance determined Reesor trind Biographical Notice of the Abbé Haity. 9 After Haiiy had published this great work, he devoted him- self to the composition of a treatise on natural philosophy for the use of the French National Lyceum, a task which he ex- ecuted with considerable success. This work appeared in 1803 under the title of Traité Elementaire de Physique, in 2 vols. 8vo., and was translated into English in aes by Dr Olinthus Gregory of Woolwich. The impulse which Haiiy had given to aniasraléer was, im a few years, propagated over all Europe. Communications: were made to him from every quarter, and many new min- eral species were discovered. A new edition of his work, therefore, became necessary, and after twenty years labour he was enabled to complete it a short time before his death. In this edition, which appeared in 1822, the Crystallogra- phy was published separately in 2 vols. 8vo., while’ the Treatise on Mineralogy occupied four 8vo volumes, with a volume of plates. Besides these works, Haiiy was the author of the Tableau comparatif des Resultats de la Crystallogra- phie et delAnalyse Chimique, which appeared at Paris in 1809, of the T'raité des Caractéres Physiques des Pierres Precieuses, pour servir a leur determination lorsqwelles été taillés, Paris 1817, and of many valuable memoirs on the theory of crystall- ization, and on the forms and characters of individual minerals which were published in the Memvires de l'Institut, Rozier’s species. Romé de l’Isle was particularly regardless of the two great points, which, according to Linneus, like the thread of Ariadne, lead us through the maze of the variety of nature,—the systematic disposition and deno- mination of the species; although, in his paper Des Caractéres Extéri- eures des Minéraux, he has given principles for the determination of the latter, independent of chemical analysis, which will stand every attack, and remain one of the most valuable disquisitions on the subject ever pro- posed to the public, and which ought to be studied by every one who wishes to inform himself on this important subject. . Romé de Isle was the first to vindicate mineralogy to the province of natural history ; against the pretensions of chemists, who, even at that time, when the chemical. knowledge of minerals. was so imperfect, undervalued every thing that was constant in minerals. This may account, in a great measure, together with the neglect of these parts which have been after- wards so highly improved by Hatiy, why Romé de I’Isle’s works have never had that degree of influence to which their excellence so justly en- titled them.” 10 Biographical Notice of the Abbé Haiiy. Journal de Physique, the Annales du Muséum, the Journal des Mines, and the Annales des Mines: 9) ~The University, at the time of its fécnditionl Ariane it an honour to place Haiiy on the list of one of its faculties. He was not required to deliver lectures, for he was supplied with an adjunct well worthy of him in M. Brongniart, at present member of the Academy of Sciences, and his suc- cessor in the Museum of Natural History. But Haiiy was unwilling to receive .a title without fulfilling the duties whieh it implied. He accordingly invited the pupils of the Normal school to attend him at his rooms, and by amiable and diver- sified conversation, he initiated them» mto his secrets. His college life was thus agreeably renewed, he almost sported with the young people, and never sent them away without an ample collation. ‘Thus passed his days. | Religious duties, profound researches, and acts of benevolence, particularly in relation to young people, occupied his whole time. As to- lerant as he was pious, the opinions of others never imfluenced his conduct towards them: As pious as he was faithful to his studies, the most sublime speculations could not divert him from any of the prescriptions of the ritual, and upon all worldly objects he placed’ just the value which they’ might be expected to hold im the eyes of a man penetrated with such sentiments. From the course of his pursuits, the most beau- tiful gems which nature produces came under his observa- tion; and he published a treatise especially upon them, but without regarding them in any other light than as crystal- line forms. A single degree, more or less, in the angle of a schorl, or a spath, would undoubtedly have interested him more than all the treasures of the two Indies: and if any room can be found for reproaching him with too strong an attachment to any thing, it was to his opinions on this sub- ject. He devoted himself to this theory, and when objec- tions were made to it, a degree of impatience was excited, which troubled his repose. It was the only occasion which could influence him to forget his inherent mildness and be- nevolence ; and it must be acknowledged that this disposi- tion was not without its effect. But at the same time that Biographical Notice.of the Abbé. Hay. VW he was paying) this tribute :to the weakness. of humanity, he was occupied with what he regarded: as the true interests of, science, and | suffered himself to be vexed only by ob- stacles seen in his estimation, were opposed to the triumph of truth. | | Such services deserved.a estas and: he was: at different times pressed to make known what would be most agreeable to himself. All his views were limited to the request. that he might be put into a situation to collect his family around him, in order that they might take care of him during his age and infirmity.. . This desire: was. immediately satisfied by granting to the husband of his niece some little station in the department of finance. Who could believe that a recom- pense so well merited as this, would disappear on the. first political change, and that the friends of Haiiy should be able to obtain no other reply to their solicitations, than that ‘f there was no connection between the: a9 neichtolagaanee and iil tallography.”. ‘This trial was not the only one which this illustrious savant had to support. A short time afterwards, ‘the state of the finances occasioned him to lose a pension which he could bad- ly dispense with. | His brother, who had: been imvited ‘to Russia to spread’ a knowledge of the method of: instructing the blind, returned from that country without a fulfilment of any of the promises that had been made him, and in a state of health so enfeebled as to render him a ‘charge to his family. It was thus that, towards the end of his days, Haiiy found himself reduced to the same necessitous ‘condi- tion that he: had more than once experienced. His religious resignation would have become of indispensable importance to him, if his young relations had not concealed from him, with the greatest care, the embarrassment of his worldly affairs. The less he had it in his power to testify his grati- tude to them, the more earnest were they to bestow upon him every delicate attention. The love of his pupils, and the respect of all Europe contributed also to console him. In- telligent men of all ranks who came to Paris, were anxious to express their regard for him and almost at the close of his 12 Biographical Notice of the Abbé Haiiy. life we have seen the heir of a great kingdom (the Prince Royal of Denmark) take various opportunities of conversing with him at his bed side, and evincing in the most feeling terms, the interest which he took in his welfare. But the best support which he experienced in this period of trial was, that in the midst of his glory and of his fortune, he had never abandoned his college habits, nor those of his native village. His hour of rising, of taking his meals, and of going to bed; had never been changed ; he took every day nearly the same exercise, walked in the same places, and even in his walks, found some occasion for the exercise of his benevo- lence. When he saw a stranger in difficulty with respect to the way, he conducted him himself, or sent him a ticket of admission to the collections ; numerous are the persons who have received these agreeable marks of attention, without doubting the hand from which they have sprung. His an- tique dress, his simple manners, his language, modest in the extreme, were not calculated to emblazon his reputation. When he spent a short time in his native village, none of his old neighbours would have suspected that he had become a considerable personage. One day, in a walk upon the boule- vard, he met two soldiers who were about to settle a dispute by fighting ; he immediately inquired into the cause of their quarrel, and succeeded in reconciling them; and that he might insure the continuance of their tranquillity, he went with them to a beer-house and sealed their reconciliation i in the manner of a soldier. Science and humanity were deprived of this worthy man on the 3d of. June, 1822, at the age of 79.. He left his family but one inheritance—his valuable and magnificent collection of crystals, which the donations of almost all Europe, during twenty years, had placed above all those which have hitherto been formed.* | . * This fine Collection is now in the possession of the Duke of Bucking~ ham. taMs jiaowilic: c Popular summary of Experiments, &c. 13 Ant, TI. Popular Summary of the Eaperiments of Messre Barlow, Christie, Babbage, and Herschel, on the Magne- _tism of Iron and other Metals, as exhibited by Rotation. Turns are few, branches, of modern science: that are likely to excite a greater interest than that which relates to theinfluence of rotation on the phenomena of magnetism. We are proud to think. that this remarkable discovery was first made in out own country, and that, with the exception of a few important experiments made in France, it has been prosecuted solely by the Fellows of the Royal. Society of London. At no period of its history, perhaps, has this distinguished body exhibited such a display of pre-eminent and varied talent. In the high- er mathematics, in the nicest manipulations of chemistry, and in the most recondite branches of physics, it can now boast of names which posterity will pronounce with reverence, and cherish with affection. The Transactions of the Royal Society, for the year which is now about to close, cannot fail to excite such feelings in the minds of those who peruse them, and particularly that part which contains the valuable memoirs, of which we now pro- pose to give a brief and popular summary. It fortunately requires no mathematical knowledge, and no stretch of intellect, to comprehend the principal.results of these investigations, and as the experiments. address themselves in a peculiar manner to the eye, they are likely to be repeated and. extended wherever a magnet and a turning, lathe can he procured. In the year 1818, when Mr Barlow. first proposed the cir- cular plate of iron for. correcting the local attraction of ves- sels, he found that, as the plate was made to turn, upon its centre, different parts of its circumference had different, de- grees of magnetic action on the compass, and, for this reason, he has, from the first, employed a double plate, so as to be enabled to combine the strong part of one plate with the weak part of the other, im order thereby to equalize the pow- er in every part. * _In repeating and extending these experi- * See Essay on Magnetic Attraction, ist ed. p. 90. 14 Popular summary of Ewperiments on the ments, Mr Christie afterwards found, that not only had different points in the cireumference of the same plate differ- ent attracting powers, but the same point had a different in- fluence according ‘as the plate was made to'revolvé to .the right or left hand. Suppose, for example, any point in the circumference of the plate marked (a,) to be brought opposite to the compass, by turning the ‘plate slowly round to the left hand, and that the entire action of the plate at that time de- flected the needle from its true position 12°; then, if the plate be again turned on its axis to the right hand, till the same point (a) occupies the same position as before, the de- flection of the needle will not be the sume, but be altered, per- haps to 18° or 14°. If it be made to revolve a second, or third, or, indeed, any number of times in the same direction, still the deflection will remain as before, (viz. 13° or 14°, ac- cording to our supposition ;) but if after this it be turned one revolution back again to the left, the deflection will become as at first 12°, and this quantity will not be altered by repeating the revolution in this direction. The quantity of deviation stated above is merely assumption, as the actual deviation dif+ fers in amount according to the distance of the plate from the needle, and its position with reference to the same. Mr Christie has, by means of ‘a very ingenious machine, been enabled to place the plate in any positioti, and adopting the views of his friend Mr Barlow, by conceiving an ideal mag- netic sphere to circumscribe the compass, he registers the lati- tude and longitude of the centre of the plate on this sphere with the corresponding deflection in each case, and then’ sub: mits his experimental results to the test of theoretical investi gation. We cannot follow the author in this part of his la- bours, but our readers will readily comprehend the following illustrations of the observed effects, (although we are ‘not quite certain that it is the same view which the author him: self has taken of the subject.) 7978 ~« Liet ws conceive a plate of iron placed in the magnetic me: ridian. This plate will be polarized by induction from the earth,—that is, the magnetic fluid im the plate will réceive a cer- tain polarized direction. If we could’ now conceive this plate to become hard steel, the magnetic fluid would become fixed, hatte —— - = Magnetism of Iron Exhibited by Rotation. 15 and, however the plate might be made to révolve; the partis cles of the fluid would revolve with the plate, and the en- tire action of the plate would be reversed by ‘reversing: its position. On the other hand, if we could find & ‘plate of ‘per- fectly soft iron, then the magnetic particles of the fluid would maintain their direction independently of the rotation of the plate, and the effects obsstvedl by Mr Christie wouldnot take place. But iron cannot be obtained perfectly soft : "There will be certain points in the best manufactured iron, which are harder, or which offer a stronger coercive power to the magnetic fluid than others ; and, therefore, the magnetic particles will not revolve with the plate as in the first case, nor remain constant in position as in the second. ‘The iron in the ¢ase in ques: tion being, however, nearly soft, the greater part of the fluid will maintain its original polarized: direction, but other par- ticles, meeting with the obstructions alluded to during the ro- tation, will be carried to the right or left hand with the plate; and produce all the observed phenomena ; differing in effect, according as the position of the plate is more or less advan- tageously situated on the magnetic sphere, for the develope- ment of its magnetism: This, at least, appears to be the most simple explanation of the phenomena, and it has the ad- vantage of requiring the acknowledgment of no principle of magnetic energy that is not already adiiniveed by most of the philosophers of the present day, and which has been found sufficient to explain all the phenomena. We ought ‘to observe, that these experiments appear to have been ‘made about three or fowr years back. They are very ¢xtensive and varied, but as an abstract of them has already appeared in this Journal, we shall not enter farther lhe gee them in os place. One of the most striking esti itt the preceding ex- periments is, that no increase of effect is produced by multi plying the number of ‘rotations, so that there was nothing to conduct us to the inference that velocity had any essential in- fluence. From some other considérations, however, which he states; Mr Barlow was led to conceive that magnetism which is produced by various processes with iron, might even be ex- 16 _ Popular summary of Experiments on the cited, or disturbed by rapid rotation, and to pursue this inquiry, the following experiments were undertaken.) =) They were begun in December 1824, and completed last January, but the publication of them was delayed till June; in order that Mr Christie’s paper might appear at the same time, the similarity of the inquiries rendering this measure desirable. During this interval, M. Arago discovered the mag- netic effect of copper and other metals while in rotation; a subject which we shall have occasion to resume in our abstract of Messrs Babbage and Herschel’s experiments. | Mr Barlow’s first experiments were made ona thirteen inch shell, attached to one of the lathes in the Royal Arsenal, turned by the steam-engine, the mean speed of which was about 640 revolutions per minute. . With this the effect of velocity was at once rendered obvious,—the deviation of the needle increasing with the speed,—and it remained constant in all cases when the velocity was constant; but the needle always returned correctly to its proper or original direction, the moment the motion of the ball ceased. . This, therefore, is a phenomenon different from that observed by Mr Christie. In the latter, the effect is permanent, and independent. of the number of revolutions; while, in the former, it is tem. porary, and is altogether dependent on the rapidity of rota- tion. Mr Barlow afterwards suspended an eight inch shell after the manner of the cylinder of an. electrical machine, and having the means of placing the axis of rotation in different azimuths, he examined, by neutralizing the needle, the direc. tion of the new force thus impressed upon the shell, which he found in all cases equivalent, to a polarization at right angles to the axis of rotation ; and, the explanation, he has given is nearly the same as we have ventured upon inthe preceding experiments, viz. that, if the iron were ‘perfectly soft, the magnetic fluid would maintain its natural polarized position; but this. not being the case, it is/carried, forward © by the rapid rotation of the ball, thereby giving a certain de- gree of obliquity to the general axis of polarization, which oblique force, being resolved into two forces, one of them,in the natural direction of the needle, the other perpendicular il i a Magnetism of Iron Lahibited by Rotation. 17 to it, and the former being neutralized as above stated, the new force at right angles to the axis exhibits itself to the observer, by the direction which it, impresses, on the needle, and which, in all cases, appears to. be consistent, with this view of the subject. We have already stated, that, prior 1 to the publication of the preceding experiments, M. Arago had discovered the curious fact, that if a copper plate be put in rapid rotation under a horizontal needle freely suspended, the rotation of the copper will first deflect the needle out of its true direction, and if the motion be made sufficiently rapid, and the needle and plate of sufficient dimensions, the former will increase in its deflec- tion, till its passage to the opposite point, after which, it will continue to rotate, and ultimately with such velocity, as to be nearly undistinguishable by the eye. This experiment was repeated in London by, M. Gay Lussac.in March or April, and soon after Messrs Herschel and Babbage undertook the experiments of which we now propose to give a sketch. In order to obtain, more, measurable. effects than, could, be arrived at: by merely putting the needle in rotation, it was found necessary to reverse the experiment, by setting in ro- tation a strong horse-shoe magnet, and suspending over it. thin plates of various metals; and by preserving always the same speed. in the revolving axis, the effect produced was measured by the. number. of revolutions which the different plates made in a given time. ‘The substances in which signs of magnetism were thus developed, were copper, zine, silver, tin, lead, antimony, mercury, gold, bismuth, and carbon, in that peculiar metalloidal state in which it is precipitated from carburetted hydrogen i in gas works. In the case of mercury, the total absence of iron was secured. . The relation in which the different indiale stand, towards pa in their magnetic power, was estimated by having thick circular plates:of the more usual of them cast all in the same mould, about a foot in diameter, and these being made to re- volve at such a distance below a delicate compass as not to produce rotation, but merely a. deviation in. the. needle, the respective powers were estimated by the detlection they pro- VOL. Iv. NO. Ir JAN. 1826. B 18 Popular summary of Experiments, &c. — - duced, their order, as thus obtained, beifig as follows, viz. copper, zine, tin, lead, antimony, and bismuth, which latter is very feeble in its action, compared with the first two. A second method was also employed, viz. by finding the times of rotation of a neutralized system of magnets suspended over them. The two methods gave always the same results, except in the cases of zine and copper ; the former according to three experiments, and the copper in the former, oeupied respectively the first place. Our authors next investigated the fact which M. Arago had stated, viz. that if the disc of copper, or other revolving metal, be cut from the circumference towards the centre like radii, but without taking away the metal, it will produce, upon the needle, a very diminished action. This was verified by Messrs Herschel and Babbage, and the farther ‘curious fact ascertained, namely, that re-establishing the metallic eoritact with other metals, restores, either wholly or very near- ly, the original powers, and that, too, even when the metal used for soldering has in itself a very feeble magnetic power.» The law of increase of force, with a decrease of distance, was next examined, but it was not found to follow any constant ratio; it appeared to vary between the ara and. the cube. The remaining part of the paper is employed in denetab. izing and explaining the facts detailed. The explanation given by Messrs Babbage and Herschel, is nearly the same as that given above relative to the rotation of iron. The different metals, for example, are conceived to contain a cer- tain portion of latent magnetism, which is induced or called into action by the power of the magnets employed ; but; in consequence of. the coercive power of these metals, (although very small,) this developement is not instantaneous, nor is it lost instantaneously when the magnets are removed; the needle is therefore constantly urged forward by the mag- netism which it has itself exerted, till it at length acquires:the rotation above stated. 5 diluone The preceding paper nibly Messis Babbage and Hersehel, is followed by a letter from Mr Christie, stating that he had re- peated and verified all the oa results, and midiny some a4 Mr Hart's Jinprovement on the Galoanie Batlery. 19 experiments relative to the law of the force. Mr Christie found, that, when a thick copper plate was made to revolve under a small magnet, the force tending to deflect the needle, varied inversely as the fourth power of the distance but when the magnets were large, and the copper dises small, the power varied as stated in the preceding paper, according to some power of the distance between the square and the cube, and for plates of different’ weights, the force was very nearly in the ratio of the weights. Ant. 11} —Account of an Improvement on the Galvanic Bat- tery. By Mr Joun Harr, Civil Engineer, Glasgow. In » a Letter'to the Editor. Dear Sir, vi donee me, decrah the medium of your valuable Journal, to deseribe an improvement on the galvanic battery, which I have reeently made, and, the advantages of which have been ascertained. by actual experience. Before I proceed, how- ever, to give a description of it, it may be proper to notice the prominent defects of those which are in common use. The pile of Volta is very troublesome to put in action, and as the moisture is liable to be pressed out of the dises of cloth by the weight of the plates, it frequently runs over the edges and destroys their insulation. A capital improvement was made on this apparatus by shi petit of the trough, by the ingenious Mr Cruikshanks of Woolwich. This trough, though extremely convenient and powerful, is subject to some disadvantages, the principal of which is, that the exciting liquid causes the wood to warp. The cement into which the plates are fixed, is thus cracked, and the liquid, insinuating itself into the fissures, soon de- stroys the insulation. For the purpose of keeping them in order, the cement must therefore be occasionally run over with a hot iron, which is a tedious and very troublesome pro- cess.. In Mr Children’s battery, (which was a combination of Volta’s couronne des tasses and the trough of Cruikshanks,) 20. Mr Hart’s Improvement on the Galvanic Battery.’ porcelain troughs were substituted in place of wooden ones; but, independently of their being expensive, they oceupy ‘a great deal of room, and are easily broken, while the strong’ affinity of the glaze for moisture, soon renders the insulation imperfect, particularly if the acidulous exciting liquid be so’ strong as to cause effervescence. If this occurs, a shower of) minute globules is thrown up from the liquid, which, falling» ‘on the edges of the cells, soon moisten them so completely as to destroy the insulation. ‘To this fault, as well as the diffi. culty of drying the edges of the cells after they have been charged, both this and the preceding troughs are liable. Dr Wollaston’s improvement on Mr Children’s trough, added considerably to its deflagrating power. .His improvement con- sisted in having a counterpart of copper to each side of the gine; but still this did not remove the former objection. The great advantage of his modification of the apparatus, was strikingly exemplified in Mr Children’s magnificent galvanic battery constructed on the above principle. _ + After seeing the improved battery of Dr Wollaston, and knowing from experience that the copper is only partially acted upon by the exciting liquid, it occurred to me, that, — if sides and bottoms were added to the double copper plates, they would form cells of themselves for the acidulous liquid, and thus enable us to dispense with the use of troughs alto- gether. An opportunity of proving this wbciteead to me last sum- mer. In examining the apparatus of Anderson’s Institution for the purpose of causing ‘additions and repairs to’ be made, the galvanic part was found extremely defective ; and, to sup- ply the deficiency, I gave a sketch of the battery I thought most suitable, to Mr John Condie, a most ingenious mecha- nic, well known for his philosophical acquirements, and at present engaged in constructing new apparatus for — a tution. He constructed six batteries of twenty-five triads each awn on the plan I gave him, and upon trial they were found su- perior to a new: battery of Dr Wollaston’s construction, made by that excellent artist, Mr Newman, of Lisle Street, London, with the same number of plates, but the plates of which con- . Mr Hart’s Improvement on the Galvanic Battery. 21 tained double the surface. ‘The comparative energy of these two forms of the apparatus was ascertained in the manner first proposed by M.M. Gay Lussac and Thenard, namely, by the amount of gas evolved from the decomposition of water collected in a graduated glass tube ; a method which, according to these celebrated chemists, is a more correct mode of estimating the power of the battery, than the ignition of different lengths of metallic wire. In this way, two of Dr Wollaston’s batteries, each containing ten triads in porcelain troughs, evolved a certain volume of gas in seventeen mi- nutes, while a battery of the new construction, with the same number of triads, but presenting only one-half the surface of the other, yielded the same volume of gas in fourteen mi- nutes. ; Such a result can be attributed to nothing but the superior - means of insulation possessed by this battery. The cells are formed by cutting the copper in the form represented by Fig. 1. Plate I.; they are then folded up as seen in Fig. 2, and the seams grooved. Mr Ritchie on Improving the Phantasmagoria. 37. Art. V.—Proposal for Improving the Phantasmagoria. By Witr1am Rircuir, A. M., Rector of Tain Academy. In --a Letter to the Editor. Dear Sir, You are well ‘aware, that, in the common Phantasmagoria, the object becomes brighter and brighter as it diminishes, or as it seems to retire, till, at length, it verges into a luminous point. Now, this is so completely contrary to what takes place in na- ture, that the momentary belief of reality, so forcibly impres- sed on the mind, becomes gradually weaker, and at last total- ly vanishes. To supply this defect, I would, therefore, pro- pose the following alteration, which will render the deception much more natural and striking. Let a small portable gasometer be procured, capable of holding a sufficient quantity of condensed oil gas. Let a stop-cock, having a small groove, gradually deepening, be adapted to it, so that the quantity of gas escaping to the burner may be increased or diminished at pleasure. By di- minishing the light according to a certain law, the brilliancy of the object will be gradually impaired as it retires, the linea- ments of the figure will become shadowy and obscure, and the phantom itself will at length vanish into thin air. If you consider this notice worthy of a place in your Journal, by in- serting it, you will oblige, Dear Sir, your most obedient, and humble servant, - Witri1amM RITcHIE. Tain Acapemy, Nov. 15, 1825. Axr. VI.—Notices of Insects of wnusual occurrence which have occasionally appeared in great numbers on Trees, &c. ‘By Sir G. S. Macxenziz, Bart., F. R. S. Lond. and Edin. In a Letter to the Editor. | My Dear Sir, Tue appearance, this season, of an unusual number of aphides, which have done great mischief to almost every tree, as well as _ 38 Sir G. 8S. Mackenzie's Notices of to the more diminutive vegetables, having recalled to my memory some insects altogether new to ‘the inhabitants .of this country, which appeared many years ago, it’ has occurred to me, that some account of them, however slight, may be ac- ceptable to you; as, by recording it, future observers may be enabled to note more precisely the habits of ‘these singular erentures, as well as to describe them. Not being: sufficiently versed in the technicalities of entomology, I must confine my- self to a simple notice, and a very imperfect description. » The facts; however, ate curious, and may interest those who have paid particular attention to that branch of natural history." The first insect which I have ‘observed as of unusual oc- currence, appeared eighteen or twenty years ago, and covered the panicles of the oat crop in this part of Scotland. Ttowas of a globular shape, and of a deep brown, almost black colour: It secined quite inert, and fixed to one spot on the grain. The size Was about thatof No. 3 shot. I-could not find any per- gon who had before observed the same insect, and it has not appeared since.’ The crop did not appear to have —_ may serious injury from it. The next was a caterpillar, which I found sinfesting ith pear-trees of only one garden in this county, that at Geanies House, situate on the eastern promontory of Ross. It appear- ed about the same time, I think, with the insect already noticed. It resembled very much a small black leech, and appearedias if wet with water. I think it was late in the autumn when: it appeared. Ihave’ now to regret that I did not preserve some of these insects. If I mistake not, it was in the year 1815, that a caterpillar, which I did not see, stript the birch trees of their leaves, over a great extent of country. I happened to be in Edinburgh at the ‘time it was committing its ravages, and travelled north- ward’ after it had disappeared. I noticed the birch trees. to the nérth of Dunkeld, and all along the Highland road, to be as naked about the end of July, as they had been in winter ; and I dreaded to find my own extensive birch woods complete- ly destroyed. I found, however, that the'déstroyer had kept within a ‘certain limit to the westward ;. but I, didnot ascer- tain how far its ravages extended eastward. .'The insect was — Insects of unusual Occurrence. 39 described to meas a small, green, caterpillar; and its numbers, must have been immense, to, have extended. over,a tract of, country..more than a hundred miles long... But. no. wing- ed insects. were observed, which might baye been supposed to have laid their eggs on the leaves. . I examined some very old men, two of them near eighty years of age, but they could not recollect any thing similar to the destruction of the foliage . of the birch which they then witnessed. _ Such examples as these might very well be cited as instan- ces of equivocal generation, were it not that a. little considera- tion leads,us.to believe that there is. nothing equivocal in, na- ture.. Some have supposed that the, ova of insects, like the seeds of many vegetables, may, in certain circumstances, be preserved during very loug periods, until some accidental oe- currence place them in a condition to produce a living crea, ture. I.do.not think, however, that the analogy with seeds is good; and it appears to me, that it is not necessary to seek for distant analogies to explain such phenomena, since we may find a better. analogy in the habits and transformations of in. seets themselves.. It is not so much the sudden appearance of insects unknown to the generation which suffers by their de» predations, that.is to be wondered at, but their as sudden and total disappearance,’ It is this latter ¢ireumstance which I think explains the former. It is well known, that many tribes of insects exist.im three states, that of the ovum, the pupa, and the imago, or perfeet insect. It is also known, that. while most insects, remain. but a short time in the first state, the time during which they are in the second varies very much, When ova are deposited, it is on or very near that substance or element which is to afford food.to the larva; and, conse- quently, the time for being in the ovum is limited by the du- ration of the substance on which it is placed, . The. birch- trees already referred to had grown up. in the memory of those persons whom I examined; and, indeed, none of them could exceed the age of forty years. But, during the whole period of their growth, nothing had happened’ similar to the devouring of their leaves, The ova must, therefore, have been deposited onthe leaves the same season in which the caterpil- lars were produced. The disappearance happened: when the 40° ‘Sir Gi S. Mackenzie's \Notiees of Inseéle, gc. caterpillars took the form of pups; and it is probable’ that the nature of this particular insect is such that it continues in that form perhaps longer than a century. "To suppose that this is the case seems to me more natural, as it’ is’ more con-’ formable to analogous facts, than to suppose that the’ova con=' tinues so long. There were no circumstances, such. as’ the stirring of the soil, which could have brought the ova into’ a condition to live; and the simultaneous appearance ‘of the? - insects in different parts of the country, and their ravages’ be- ing limited to a certain breadth, make it probable that the in- sects, after their usual long period, had issued from the earth,’ ascended the trees, deposited their eggs, and died. The-pur’ pe into which the host of caterpillars passed are now proba~’ bly in the earth under the trees, and from them ‘a new host’ will at length arise, more numerous perhaps than the last. If it should happen that the trees shall have been removed before the pupz shall have become perfect insects, no proper food will be found for their progeny, which will perish. tis) probably this circumstance that saves much that we value from destruction ; the proper food of insects being removed from the place where the pupze are concealed. Of course, this does not limit the wanderings of migratory insects, but many even of these must perish, while in search of a “proper place for their ova. This season, there is an amazing number of wphiden There is scarcely a vegetable without its aphis..'There has been a most luxuriant harvest for the bee tribe on the thorn hedges, which are loaded with the honey-dew, the produce of the aphis, which the bees greedily devour, The foliage of the birch has suffered severely from the attacks of an ‘aphis. Even the strawberry has had its variety ; but it was only on some plants which I forced on which I observed it. There is an aphis which we have every year on the spruce-fir, ;which forms a very beautiful nidus on the young shoots, resembling a small seed-cone, for which it has often been mistaken. The» silver and the balm of Gilead firs have been killed in great ., gstumbers by the attacks of a woolly aphis, like that which in- ~ fests the larch, and ‘it attacks wie net in thes nee the apple aphis. 9 hog sow ex! Rit ‘Mr Haidinger on the Momguivese Ores. 41 ~ Larveé, whieh are produced under the surface have been very numerous, ‘and the onion and cauliflower tribe have suffered much. ‘An insect, which I have not been able to de- tect; has’ almost totally destroyed my crop of apples and pears, by eating out the cores of the fruit when just set. Plums. are all destroyed. I do not recollect a richer display of blossom than that which we had in spring, and our disap- pointment has been proportional to the hope excited. The Curculio vastator, which, by committing its depredations in the night, too often escapes the vigilance of the gardener, has not been so numerous as usual ; nor have I seen so many moths and butterflies as usually occur. _ For some years past wasps have been scarce, but this season they are plentiful. I have observed that they are fond of the flower of the Daucus hispidus, which seems to stupify them, as they fall to the ground when the flower is shaken, or they may be picked off by means of pincers. Perhaps the flower of the common carrot may have the same effect. At any rate, I hope that the Daucus hispidus will be found a useful means of destroy- ing this arch enemy of ripe fruit, by being planted i in diffe- rent parts of a garden,—a boy or girl being employed to go round and pick off the wasps that settle on the flowers. Ever yon BR G. S. Mackenzie. Soul 3d agmst 1824. | Ant. VIL—On the Crystalline Forms and Properties of the Manganese Ores. By Wit114mM Harpincer, Esq, F. R.S.E. Communicated by the Author. With a Plate. » Bays B Prismatoidal Manganese Ore. Founpamentat form. Scalene four-sided pyramid. P = 130° 49’, 120° 54’, 80° 29. Plate IT. Fig. 1. | ny a:b: e:=)b: J 8872/24. Character of gS on See with ideebiansil faces. 42 Mr Haidinger on the Crystalline Forms Simple forms contained in the combinations which were ob- a among the crystals of the variety onnalatte roe 19.) (4°PxH QF (g)= 172° 80/, 114° 37’, 66° QB... 4” (Pr 1 (ce) = 115° 17, © 148° wig 16° 56’. 5.. (Pr) (n) = "' 95° '4/, | 182° 50’, 103° 24." 2 P+1(m) = 12°85, 97°35, 118° 45,/ 8. P+oa(M) = 99°40 - ‘i 6. (Pr+@)()) =. 51° 18. 8, (Prt 0) (r) =, 194° 14, Il. Pr (d) = . (1149 19’, « ease y (Pr—1))(h) = 154° 18/, 9 11610, 70°. 2 Ania OOP, Yay Co noakgen gree By, 44 cover eagewn 10. (Pr4+0)°(s)= ‘16° 36. wnt P 1. P(P) =" 130° 49, "120° 54’, 80° 22”, Gira “Combinations. 1. (4 P —> 2)’: My ys, Pp mi i P+o-. (Pr 4.0)% (Pr+ a). a | The 8d figure represents the projection upon P — @, the 4th figure the elevation upon a plane parallel to the shot dia- gonal of the prism P + @. The hemi-prismatic character of the species appears only in the disposition of the faces marked c. . They form horizontal edges of combination with (Pr). The edges between (4 P—2)° and P + 1 are parallel to those between P + 1 and (Pr4o)*. These crystals are from two to three lines in thickness, and some of 0 reat an inch jong, i Q. Pr, (Pr— 1). Pr. P,P +1. P+e: (rs). (Pr + 0 )’. (Pr4+o0)% Fig. 5. Small, but very well pronounced cryStals of this variety were cinengaged from the same specimen which contains the variety 1,, They were found in small drusy cayities, which were discovered when the whole was broken, up for analysis, The faces of Pr; marked ¢ in the figure, have not been de- scribed ; they are rarely observed in the crystals of this species. Cleavage, Pr highly perfect and easily obtained; P--oo also perfect, but less easily obtained ; traces of Pr+oo, and of and Properties of the Manganese Ores. 43 Po. Fracture uneven, surface, of the, vertical prisms streaked parallel to their common edges’ of intersection; Pr streaked parallel to the edges’of combination: with P; P—co parallel to those with Pr. In general, the faces are smooth, and possess pretty high degrees of lustre. ~ Lustre, imperfect metallic. Colour,’ dark brownitubleck, inclining to iron-black. Streak, reddish-brown. Opaque, in larger masses. When broken or cleaved in the direction of Pr 4, and exposed to the light of the sun, minute splinters are often observed, which, by transmitted light, appear of a bright brown colour, so that the mineral cannot be said to be absolutely opaque. Brittle. Hardness = 4.0.+—4.25. Sp. gr. = 4,328, of a number of fragments of crystals; = 4,312, in another experi- ment of a single-crystal of considerable size. ~ Compound Varieties: 'Twin-crystals, formed in two. differ- ent manners. In the first of them the axes of the two indiyi- duals are parallel, dependant on the hemi-prismatic character of the combinations of the species ; in the second, they are in- clined. 1. Face of composition, parallel-to Pr+@ , axisof re. volution perpendicular to it. Fig. 6: If we did not give atten- tion to the compound state of this variety, shown in the present instance by the groove along the place of junction, which is not always visible, we might be induced ‘to believe that. it ssesses a hemi-prismatic character, referred to an axis in- clined upon the base of the fundamental pyramid; which is not the case. One can generally trace the peculiar dis- position of the crystalline faces upon each of the individuals. A repetition of this law produces thick prisms, terminat- ed perpendicularly upon their axis by a rough face, which consists of the apices of numerous individuals, or rather of numerous particles of two individuals, alternating with each other. Such faces are not uncommon in the prismatoidal manganese ore. 2, Axis of revolution perpendicular, face of - composition parallel to a plane of Pr. Fig. Y. ‘The disposi- tion of the faces marked ¢, upon which the hemi-prismatic character ef the species depends, is such,’ that a mere revolution of 180° is not sufficient to bring the two individuals in the position required for joining in a regular twin; though the 44 Mr Haidinger on the Crystalline. Forms general disposition takes place also\in: the present instance, the portions of the two crystals, similarly situated, being 180°. distant from each other, compared to the plane of. composi-_ tion. Irregular composition is very common in this species ; ; Itis either granular, or columnar, . The latter occurs much more frequently. Observations. _ © Few species im mineralogy have been so incorrectly described. as the ores of manganese, and, in particular, the most common one among them, the prismatoidal manganese-ore.. It is not alone that the slight difference in the angles of two of the prisms, and the situation of the perfect cleavage, was not exactly refer- red to constant positions, but also colour, streak, hardness, speci- fic gravity, and other important properties, were either incor- rectly stated, or confounded with those of other species. The insufficiency of Haiiy’s descriptions was felt by many mineral- ogists, and several of them have endeavoured to substitute bet- ter ones in their place. The result; obtained by M. Von Leon- hard,* is by no means more satisfactory than that of Haiiy ; Mr Phillips, with his usual skill in ctystallographic observations, has succeeded much better. The description of the forms given by Mohs ¢ agrees very nearly with the latter, at least much more so than any two other descriptions. There are some. differences, however, in regard to the absolute measure- ment of the angles, and in the statement that, according to Mohs, the cleavage parallel to the short diagonal of the prism P+ = 99°40’ is; more distinct, and more easily obtained than any other cleayage of the species ; whereas, according to Phillips, the crystals “ cleave readily, and with brilliant sur- faces parallel to the lateral planes of a rhombic prism of 100° and, 80°, and both its diagonals.” Though, in many varieties, the cleavage parallel to the long diagonal of that prism may in faet be obtained, it is always less distinct than that pa- rallel to the short, diagonal, and often not at all observable. It . * Handbuch der Oryctognosie, p. 371. 0 WH Siedo + Elem. Introd. to Mineralogy, p. 243: 00) jon OBE he LJ + Treatise. on Mineralogy, vol, ii, p. 419, } DOUU DST a yi tiet cy and Properties of the Manganese Ores. 45 is important to attend to this difference in the, perfection of cleavage; the more so, because the cleavage parallel to the short diagonal of P+ = 99° 40’, is at the same time paral- lel to the long diagonal of another prism, (Pr-+a')° ='76° 36’ (the supplement of which is 103° 24’), which occurs very fre- quently in the same mineral, and might be, or has actually been; mistaken for it, in a more superficial examination of the crystalline forms of the species. Descriptions of single varieties are particularly désitabdo, when the characters of the whole species are yet so imper- fectly ascertained as in the present case. . The variety to which the preceding description refers, was brought by Dr Turner from Ilefeld in the Hartz, and to him I have been indebted for the crystals described above. The most re- markable peculiarity in the series. of crystallization of this _ species, is its hemi-prismatic character, the faces of those forms which assume it being inclined to each other. Those marked c, if sufficiently enlarged, would give rise to a form resembling a tetrahedron, like Fig. 8, the planes of which, are equal and similar scalene triangles. Among the remaining spe- cies, whose forms belong to the prismatic system, only; the sul- phates of zinc, of magnesia, and of nickel, are known to pos- sess an analogous formation.,.This was first placed beyond a doubt by Professor Mitscherlich, who observed the fact, that the faces s and ¢, Fig. 9, appear only contiguous to the alternating faces of 1; although the alternating enlargement of these same faces, represented in Fig. 10, had_ been, previ- ously noticed in the sulphate of magnesia, by mineralogists, so far back,as Romé de L’Isle and Linnzus.., Large crystals of this salt generally show the hemi-prismatic character much more distinctly than small ones. In the description given above, the streak oe ‘the crystals i is stated to be reddish-brown, contrary to most indications in works on mineralogy. It is very often the. case,. however, that we meet with crystals, and still more frequently with compound varieties, consisting of the columnar individuals, which actually afford a black streak. The hardness of these varieties is much inferior to the hardness of the crystals that present a brown streak, being generally between 2.5 ard 3.0, 46 Mr Haidinger on the Crystalline Forms (a little below calcareous spar ;) and sometimes, in fibrous’ va~ rieties, it is so inconsiderable as to soil the fingers, and” write upon paper. On the contrary, their specific gravity is higher, and often approaches to 4.7, It is important to observe, that the exterior strata of large crystals sometimes afford a black streak, and show low degrees of hardness, while the im- ‘terior parts still offer the characters indicatéd in’ the preced- ing description. It should seem, therefore, that the differ- ence in several of these properties is owing toa change or decomposition of the — itself, which does not ater the regular form. ) , t Il.—Pyramidal Manganése Ore. Fundamental form. Isosceles four-sided pyramid. P: te 105° 25/, 117° 54. Fig. 11. a= f 216. Simple forms. $ P—4 (a) = 139° 56, 58° se pat a 114° 5Y’, 99° 11’; P (P). Char. of comb. pyramidal. as Combinations. 1.4 P—4. P. Fig. 12. 3 A 2,4 Pi4. P21. P. 2OKW, gB9i9 Cleavage, P—o rather perfect ; P—1 and: P less distinct, and interrupted. Fracture uneven. Surface, $P—4,’ v smooth and shining, P horizontally streaked and often dull. © Lustre imperfect metallic. Colour brownish-black. Sereee dark-reddish, or chestnut-brown. | Opaque. Hardness = 5.0..:5.5. | Sp. gr. = lp of a crystallin variety. Compoind Varieties.—Twin-crystals : 4ol of Heh Neih ndicular, face of composition parallel to a face of Pt, Fig. 13. ‘The composition is often repeated parallel to all the faces of the pyramid, Fig. 14. Generally small particles’ only of the surrounding individuals are joined to ‘the cefitral, ‘one. Massive : composition granular, firmly connected. a ee Observations. The preceding description is given by Professor Mohs.* " Treatise on Mineralogy, Transl, vol. ne 416, EE and Properties. of the Manganese Ores. 47 It would be superfluous to enlarge here on the propriety of considering this as a species of its own, since, besides Mr Mohs, it has likewise been established as such by Messrs Brooke and Phillips,* and by the Abbé Haity.+ Even in the works of the Wernerian school, the. pyramidal forms had been Jong ago described, in reference to the identical specimen from which the above. description was derived. Its locality: is Ilmenau in Thuringia. Count Bournon{ mentions. an ore of manganese crystallized in regular octahedrons, having their solid angles replaced by low four-sided pyramids 5 a form which might be explained upon the supposition, that the va- riety, Fig. 12, appears in the regular composition represented Fig. 14.; at least it would be interesting to have these varie- ties compared again with each other, IIl.—Uncleavable Manganese Ore. ~ Regular forms and cleavage unknown. ge me not ob- servable. Lustre imperfect metallic. Colour bluish- black and grey- ish-black, passing imto dark ‘steel-grey. Streak brownish- black, shining. Opaque. : Brittle’ Hardness = 5.0:..6.0. Sp. gr. = 4.145, a bo- iryoidal variety. | , , Compound Varieties. Reniform, botryoidal, fruticose -: composition ‘columnar, impalpable ; fracture flat, conchoidal, even ; in a second composition it is curved lamellar, the faces of composition being smooth, rough or granulated. Massive : composition granular, impalpable, Stn. comnected ; frac- ture flat, conchoidal, even. i Observations. The specimen analyzed i is from the neighbourhood. of Schneeberg in Saxony, and < agrees perfectly with the pre- ceding description, extracted from the treatise of Mohs. It consists of alternating layers, having more or less lustre, dis- * Phillips, 3d Edit. p, $81. | + Traité, 2d Edit. t. iv. p- 264. t Catalogue, p. 395. 48 Mr Haidinger on the Crystalline Forms posed in. reniform coats... The specific gravity of those, parts; which possess a rather ‘stronger lustre, and a conchoidal frac- ture, is = 4.004, while the specific gravity of those without lustre, and an uneven fracture, was found to be = 4,079. | IV.—Brachytypous Manganese Ore. : Fundamental form. Isosceles four-sided Maat, Ps = 109° 53’ 108° 39... Fig. 15. : a= J! 94. Simple forms. P—co (0); P(P),. Wunsiedel, Bayreuth ; P+2 (s) = 96° 33’, 140° 30’, Fig. 16., Elgersburg, Thurin- gia; (P+1)* (z) = 144° 4’, 128° 17’, 154 25. Char. of comb. pyramidal. ) Combinations. 1. P—w. P. Fig. 1'7., Wunsiedel. 2. P.P+2. Fig. 18., Elgersburg. 3. P. (P+1)%) Fig..19., St Marcel, Piedmont. 4. P—o, P. P+2. Fig. 20., Wunsiedel. Cleavage, very distinct in the direction of the faces of P ; entire forms of cleavage may be obtained from larger indivi- duals. Fracture uneven. Surface, P,— , possessing less lustre than P, but even, and sometimes. faintly streaked pa: rallel to the edges of. combination with P ; P often a little rounded ; P+ o uneven, rough and _ horizontally streaked ; (P+1)* smooth and even. Lustre, imperfect. metallic. Colour .dark brownish-black, Streak of the same;colour. , Brittle. Hardness — 6.0... 6.5. Sp. Gr. = 4.818, lass cleavable individuals fecan 5 ft ia Compound Varieties. Massive : composition granular, in. dividuals strongly coherent. Observations. The first variety of the species of brachytypous Manga: nese-ore which I had. the good fortune to examine e, was brought by Dr Turner from Germany, thé ticket bearing the t locality of Elgersburg. Being ‘struck with the facility ‘with which this mineral yields to cleavage in the direction of the faces of a four-sided ga and supposing it to belong to of Manganese Ores. 49 the species of the pyramidal manganese-ore of Mohs, I re- quested Dr Turner's permission to extract the form of cleav- age from it, but was much surprised when I could not dis- cover the single cleavage perpendicular to, the axis, which is so very distinct in that mineral, and has been likewise indicat- ed by Messrs Brooke and Phillips. Though the mineral cleaves very readily, yet its great hardness, being superior to that of feldspar, and a strong connection among the particles, render it extremely difficult to obtain the faces smooth and plain enough to reflect a good image even of a single very luminous point. I was, therefore, led to suppose, by several approximate measurements, that the regular octahedron should be considered az the fundamental form of the species, In some of the cavities of the same specimen there were, how- ever, crystals in the form of acute four-sided pyramids, simi- lar to Fig. 16, which did not agree with the symmetry of tes- sular forms. .'They were rough, and possessed of little lustre, so that they afforded only indistinct measurements of about 140° for the base of the pyramid. -Certain varieties from Wunsiedel in Bayreuth, in the cabinet of Mr Allan, engaged in heavy-spar, and associated with prismatoidal manganese- ore in very delicate columnar composition, possess the form of Figs. 15, 17, and 20... The two first of these I also observed in a specimen in the collection of Mr Ferguson of Raith, hay- ing the following ticket by Mr Heuland: ‘“* Hydrous-oxide of manganese, in the form of an octahedron, with a square basis. Thuringia—is extinct.” As Haiiy’s works contain the pyra- midal manganese-ore of Mohs, under the denomination of Manganese oxide hydraté,* this specimen is probably intend- ed for a variety of that species, which, however, is very inac- curately described by Haiiy, who united under one head the physical properties of one species with the physical and the chemical properties of two or three others to form a general description, to which, no object in nature corresponds. | I had long ago observed crystals of the form Fig. 19, engaged in a specimen of the epidote manganésifere of Hatiy, in the cabi- net of Mr Allan, but which I believed likewise to be a variety * Traité, 2de Ed. t. iv. p. 264. — VOL. IV. No. I. JAN. 1826. D 50 M. Humboldt’s Accownt of the of the ‘pyramidal manganese-ore. | Upon; measurements; how evar, for which the small but beautifully formed and bright crystals of this variety are better suited than any. ofthe rest, these also turned out to belong to’a species different from the pyramidal one formerly described. ‘The angles which these © crystals afforded are given above as the dimensions of the spe- cies. The results obtained from the remaining varieties:ate not sufficiently consistent ‘to be considered. different from these, and as, moreover, the colour of: their streak and their hardness coincide, we may safely consider them as belonging to the same species. Some of the octahedral crystals, quoted by Count Bournon,* for which he proposes the denomination of fer oxydulé manganésien, must also very likely be referred to the brachytypous manganese-ore. He supposes their form tobe derived from the regular octahedron, but) does not quote any decisive proofs in favour of this opinion, which is rendered necessary when a species nearly resembling” it:is found to have, for its fandamental form, a four-sided pyramid so little different from the regular octahedron. Those varie- ties which have their solid angles replaced by four faces; may perhaps belong to the pyramidal manganese-ore, as is men tioned in the observations annexed to that species, which was likewise not distinguished as a species of its own at the i of 7 of Count Bournon’s ra Ate t etees At Ant VITT— Account of the Eruption of the Volcano of Jo- rullo in Mexico. + By Baron PIEXABDER 8 DE Hivitsotbr. | With a Section of the Mountain. ~~ mane We. i. To the east. of the: Pie de ‘Lasicnaro, dha Volcan de Jenin (Xorullo,; ‘or Juruyo) was formed in the night of the 29th ‘September 1759. 'M. oe at rigors tg ee: ‘* Catdtogiie, p.'395.°9° 0 828 Boniiay atfo + Dr Turtier is‘oceupied: igeithy the wi Nl of the scone eset in this Paper, and. will give the results ina subsequent) Numbern.—Eip. 1 { We have given the above abridged account of sie remarkable, % cano, in reference to a new theory of its formation b ‘Rik Sc forms the subject of the next ‘Aetiele. "Seo Humbéle dt’s. ary whith sur la Nouvelle Espagne, his Essai Fergnastique, P. 351, and his ae tion Histortque—Ep. — POA WT Mov EL — PSs Soe, Eruption of the Volcano of Jorullo. 51 ter on the 19th September 1803. | The great catastrophe in which this mountain rose from the earth, and by which a con- siderable extent of, ground totally changed. its appearance, is, perhaps, one of the most extraordinary physical. revolutions in the annals of the histoty of our planet. Geology gives us no example of the formation, from the centre of a thousand small burning cones, of a mountain of scoria and ashes.517 metres (1695 feet) in height, comparing it only with the level of the old adjoining plains in the interior of a continent, 36 leagues distant. fromthe coast, and more than 42 leagues from every other active volcano. A vast plain extends from the hills of Aguasarco to near the villages of Teipa and Petatlan, both equally celebrated for their fine plantations of cotton. 'This,plain, between the ~ Picachos del Mortero, the Cerros de las Cuevas, y de Cuiche, is only from 750. to 800 metres (from 2460 to 2624. feet) above the level of the sea. In the middle of a tract of ground in which porphyry, with a base of greenstone predominates, basaltic cones.appear, the summits of which are, crowned with evergreen paks of a laurel and olive foliage, intermingled with small palm trees with flabelliform leaves. This beautiful ve- _ getation forms.a singular contrast with the. acuity of the plain, which was laid waste. by. voleanic-fire: «|.» ‘Till the middle of the 18th cenwry;, fields dultivated. with sugar-cane and. indigo. dccupied the extent of ground between the two. brooks ‘called \Cuitamba and San Pedro. .. They were bounded by. basaltic mountains, of, which the structure seems to indicate that all this country, at a very remote period, had been already. several times conyulsed, by voleanoes.,. These fields, watered by artificial means, belonged to the plantation (hacienda) of San Pedro de Jorullo, ‘one, of the greatest and richest of the country... In. the, month of June 1759, a sub- terraneous noise was heard, ‘ Hollow. noises of a most alarming nature (bramidos,) were accompanied.by frequent earth quakes, which succeeded .one another for from 50 to 60 days, to the great consternation of the inhabitants of the hacienda. Erom the beginning of September every thing seemed to an- nounce the complete re-establishment of tranquillity, when, in the night between the 28th and 29th, the horrible subterrane- 52 M. Humboldt’s Account of'the ous noise recommenced. The affrighted Indians fled to the mountains of Aguasarco. A tract of ground from three to four square miles in extent, which goes by the name of Malpays, rose up in the shape of a bladder. ‘The bounds of this convulsion are still distinguishable in the fractured strata. The Malpays near its edges is only 39 feet above the old level of the plain called the playas de Jorullo ; but the convexity of the ground thus thrown up increases progressively towards the centre to an elevation of 524 feet. See Plate I. Fig. 6. Those who witnessed this great catastrophe from the tp of Aguasarco assert that flames were seen to issue forth for an extent of more than half a square league, that fragments of burning rocks were thrown up to prodigious heights, and that, through a thick cloud of ashes, illumined by the voleanie fire, the softened surface of the earth was seen to swell up like an agitated sea. The rivers of Cuitamba and San Pedro pre- cipitated themselves into the burning chasms. ‘The decomi- position of the water contributed to invigorate the flames, which were ‘distinguishable at the city of Pascuaro, though situated on a very extensive table land 1400 metres (4592 feet) elevated above the plains of Jas playas de Jorullo... Erup- tions of mud, and especially of strata of clay, enveloping balls of decomposed basaltes in concentrical layers, appear to ‘indi- cate, that subterraneous water had no small share in produc- ing this extraordinary revolution. Thousands of small cones, from two to three metres (from 6.5 feet to 9.8 feet) in height, called by the indigenes ovens (hornitos,) issued forth from’ the Malpays. Although within the last fifteen years, according to the testimony of the Indians, the heat of these volcanic ovens has suffered a great diminution, I have seen the ther- mometer rise to 95° (202° of Fahrenheit) on being plunged in- to fissures which exhale an aqueous vapour. | Each small cone is a fwmarola, from which a thick vapour ascends to ‘the height of ten or fifteen metres. In many of them a subter- raneous noise is heard, which appears to announce the proxi- mity of a fluid in ebullition. i oi In the midst of the ovens six large masses, elevated - from 4 to 500 metres (from 312 to 1640 feet) each above the old level of the plains, sprung up from a chasm, of which’ the di- 1 Eruption of the Volcano of Jorullo. 53 rection is from the N.N.E. to the S.S.E. This is the phe nomenon of the Montenovo of Naples, several times repeated in a range of volcanic hills. The most elevated of these enor- mous masses, which bears some resemblance to the pays de lAuvergne, is the great Volcan de Jorullo. It is continually burning, and has thrown up from the north side an immense quantity of scorified and basaltic lavas, containing fragments of primitive rocks. These great eruptions of the central vol- cano continued till the month of 1760. In the following years they became gradually less frequent. The Indians, frightened at the horrible noises of the new volcano, abandon- ed, at first, all the villages situated within seven or eight leagues distance of the playas de Jorullo. They became gradually, however, accustomed to this terrific spectacle ; and, having returned to their cottages, they advanced towards the mountains Aguasarco and Santa Ines, to admire the streams of fire discharged from an infinity of great and small volcanic apertures. The roofs of the houses of Queretaro were then covered with ashes at a distance of more than 48 leagues in a straight line from the scene of the explosion. Although the subterraneous fire now appears far from violent,* and the Malpays, and the great voleano, begin to be covered with vegetables, we, nevertheless, found the ambient air heated to such a degree by the action of the small ovens (hornifos,) that the thermometer, at a great distance from the surface, and in the. shade, rose as high as 48° (109° of Fahrenheit.) This fact appears to prove, that there is no exaggeration in the ac- counts of several old Indians, who affirm that, for many years after the first eruption, the plains of Jorullo, even at a great distance from the scene of the explosion, were uninhabitable, from the excessive heat which prevailed in them. ‘The traveller is still shown, near. the Cerro de Santa Ines, the rivers of Cuitamba and San Pedro, of which the limpid * We found, in the bottom of the crater, the air at 116°, 130°, and 139° of Fahrenheit. We passed over crevices which exhaled a sulphu- reous vapour, in which the thermometer rose to 185° Fahrenheit. The pas- -sage over these crevices and heaps of scoria, which cover considerable hol- _ _Jows, render the descent into the crater very dangerous. 54 -\M. Humboldt’s Account, &c. waters formerly’ watered: the) sugat-cane plantation of Don André Pimentel. These streams disappeared in the night of the 29th September 1759 ;, but, at a distance of 2000 metres (6561 feet) farther west, in the tract which was the theatre of the convulsion, two rivers are now seen bursting through the argillaceous vault of the hornitos, of the appearance of mineral waters, in’ which thé thermometer rises to 52°,7 (126°;8 of Fahrenheit.) The Indians continue to give them the names of San Pedro and Cuitamba, because, in» several parts of the Malpays, great masses of water are heard to'run in the direction from east té west; from the mountains of San+ ta Ines towards 7 Hacienda de la Présentacion.» Near this ha» bitation there is a brook, which disengages itself from the sul- phureous hydrogen: It'is.more:than nine yards in breadth, and is the most abundant A sangeet sya bs I ; have ever seen. 9! The position of the new Volcana the Jorullo: gives rise’ toa - very curious: geological observation. In New Spain there jis a parallel of great elevations;"or “a: viarrow ‘zone contain. ed: between 18°, 59 dnd-19% 12! of latitude; in’ which allthe ‘summits of Anahuae which rise above the region of perpetual snow are situated.’ 'Phese summits are either 'volcanoes’*which still:¢ontinue to° burn, or ‘mountains which; from their form, as well as the nature’ of their rocks, have; in all probability, formerly contained ‘subterraneous' fire: © As we recede from the coast of the Atlantié, we) find, im a direction from east to west; the Pie!d’OQrizaba, the ‘two volcanoes ‘of la Puebla, ' the ‘Nevada de, Toluca, the Pic de'‘Fancitaro, and the Volcan de Colima: ‘These great elevations;“im place of forming the crest of the Cordillera of Anahuac, atid following its diree- tion, which is from the south-east to the north-west, are, on the contrary, placed on a line perpendicular to the axis of the great. chath of mountains. It is: undoubtedly worthy of ob- servation, that, in 1759, the new volcano of Jorullo was forni- ed in the prolongation of that line, on the s same parallel with the ancient Mexican volcanoes!” A single glance bestowed on my plan of the environs of -Jorullo will prove that the six large masses rose out of the earth, in a line which runs through the plain from the’ Cerro 4 ee a ee Sa ee ee eS on Mr Scrope on Humboldt’s Theory, &c. 55 de las Cuevas, to the Picacho del Montero ;,and it is thus also that the boeche nove of Vesuvius are ranged along the pro- longation ofa chasm. Do not these, analogies entitle us to suppose that there exists, in this part of Mexico, at a great depth in the interior of the earth; a chasm. in ‘a direction ‘from. east.to west,| for ja length of 137 leagues, along which the volcanic fire, bursting through the interior crust of the porphyritical rocks, has. made. (its appearance at different epochas from the gulf of Mexico to the South Sea? Does this chasm. extend \to the small group of islands called by M. Collnet the.archipelago of Revillagigedo, around which, in the same parallel with the Mexican voleanoes, pumice-stone has been, seen floating ? Those naturalists who make a dis- tinction. between the facts which’ are offered us by descrip- tive geology and theoretical reveries on the’ primitive state of our planet, will forgive us: these general: observations on the general. map’ of New Spain. Moreover, from the lake. of Cuiseo, which is impregnated with muriate of soda, and which exhales sulphuretted hydrogen; as far as the city of Val- ladolid, for, an extent of 48 sqitare leagues, there are a great quantity of hot. wells, which. generally contain »only. muriatic acid, without any vestiges of terreous sulphates or metallic salts. Such are the mineral. waters of the Chucahdiro, Cuinche; San Sebastian, and. San Juan Tararamco. ‘Ant. TX.Obstrvations on’ Humboldt’s Pheory of the‘ Volca- no of Jorullo. By G. Pourert Scrorx, Esq. Secretary “to the Geological Society. ae sheony of the. volcano. of J orullo,, given we le Hitin. boldt in, the preceding article, has been. very ably examined by Mr Serope in his Considerations on Volcanoes, a new and intense Une work which has just appeared. . From a personal examination of almost. all the ‘eetmets) as well as the/active volcanoes of Europe,’ Mr Scrope was led to the opinion, that. they, display a remarkable uniformity of character, presenting few other variations, than what.depend on the degree of energy they have displayed.. _The phe- nomena of. Jorullo, however,:.as.; explained by Humboldt, 56 -» Mr Scrope’s Observations on: forms an exception ‘to this uniform character, and hence, Mr Scrope was léd to examine them with care, with the view of referring them to the ordinary principles of voleanic action. - In this examination, Mr Scrope has analyzed the opinions of M. de Humboldt with that respect and courtesy which are due to his distinguished talents, and he has never permitted the spirit of controversy to disturb the serenity of philo- sophical discussion. We should have wondered, indeed, how any man could have approached even to the errors of that great traveller with any other feelings but those of affec- tion and respect, had we not perused a recent attempt to blacken and insult his high reputation. Every philoso- pher and naturalist in’ Europe view with indignation this warfare against a man who has contributed so much to the sciences which they cultivate; and every Englishman must feel that the character of our literature has been compromised by such unmeasured abuse and depreciation of foreign talent. *< Previous to 1759,” says Mr Scrope, “it appears that the plain, from which Jorullo now rises, presented traces of former volcanization ; its soil being composed of tufa; and the neighbouring mountains consisting of trachyte and basalt. In September of that year, a violent series of eruptions took place, of which M. de Humboldt distinguishes the results in the following order. 1st, The production of six, volcanic cones, composed of scoriz and fragmentary lava. 2dly, 'That of a promontory of basaltic lava proceeding from the summit of the largest of these cones (Jorullo,) which still emits wreaths of vapour from the interior of its crater: — 3dly, ‘Vhe elevation in a convex form of the plain, (four square miles in superficial extent) upon which the cones were thrown up, and the centre of which is occupied by the largest (Jorullo,) at whose base the plain is higher by 550 feet than without the limits of this space. The plain, which M. de Humboldt calls “ un errain bombé en forme de vessie,” and the convexity of which he attributes to inflation Srom below, is represented as closely sprinkled with thousands of flattish conical hillocks, from six to nine feet high, formed of ‘basaltic EE re tae Humboldt's Theory of the Volcano of Jorullo. 51 balls, separating into concentric leaves, imbedded in a black clay: These hillocks, as well as some large fissures which traverse the intermediate plain, act as so many fwmarole, giv- ing out thick clouds of aqueous vapour combined with. pen. ric acid, and at a very high temperature. The two first mentioned products of this eruption are of ordinary occurrence, and testify that, at least for the greater part, the volcanic action took effect here in the usual mode. ‘The phenomena of the third class are remarkable, and de- serving of the greatest consideration, as appearing at first sight to differ materially from any hitherto observed, and as referred for this reason by M. de Humboldt to a mode of vol- canic action invented by him for the occasion, and of which no other recorded eruption has ever afforded a parallel. And here, with the utmost respect for the great talents of this first’ of scientific travellers, and giving all due weight to the impression which appears to have been made upon him on the spot, I own myself still unable to coincide in his opinion as to the mode of formation of this remarkable plain. And this for the two following reasons : 1st. In the first place, the appearances presented can be without the least difficulty explained by the ordinary mode of operation of volcanoes. In which case we are bound to dis- miss one so extraordinary and unparalleled as that brought forward for the purpose by M. de Humboldt, and which, however brilliant or seducing to the imagination, it would be unwarrantable to persevere in. Qdly. All the supplementary arguments which M. de H. adduces, are completely invalid, and, instead of supporting his theory rather tell against it, as will be proved directly. 1. What are the positive facts with which we are acquainted relative to this eruption, divested of all theoretical assumptions? In the month of September 1759, prodigious volcanic erup- tions took place from six different openings, arranged on a single line’ of very little extent, upon the Mexican plateau. — Their fragmentary projections produced six large volcanic cones; the central one being 1700 feet in height. A massive current of lava projects from the side of this last hill, having evidently flowed out of the crater at its summit. If any lava 58 Vanco (o Mir Serope’s Observations on... éurrents were produced by the apertures, marked by the other cones, they do not show themselves ; but the. plain from which these hills rise exhibits a great imtumescence, or convexity. of surface. Its superficial soil consists of horizontal layers of a black clay, in which augite crystals are thickly disseminated. "The same clay, but enveloping. concentric balls, of basalt; com- the numerous ‘little hollow. conical protuberances, al esi with which the surface of the plain is sprinkled... “Now, on comparing these appearances with those whieh re- suit from ordinary volcanic eruptions, little other difference is perceivable: ‘than that the quantity of lava produced, or. at least remaining visible, bears but’a very small proportion to the violence of the eruptions, and the immense quantity of scoriz thrown out.! It seems extraordinary also, that, bat, one ‘outiof six cones’! should have given rise to a lava’ current. ‘Hence a’ suspicion arises that a greater quantity of lava was 4n fact emitted, but that it is concealed. bythe sprinkling of triturated ‘scorize or voleanic sand, which these large cones must have thrown out during the latter period, of . their erup- tions. ne In this manner, the lava currents, produced by the eruption of Vesuvius in October 1822, lie at this moment, covered to a depth of from two to ten feet by the finer fragmentary. sub- stances ejected by the voleano during the last days of its pa- roxysm. » And what renders the. analogy, still’ more striking, these ashes, which, from the fineness of, their comminution mixed into a retentive paste with the torrents of rain that,im- mediately followed the eruption; present, the appearance of strata of a black clay, precisely liké those described. by, M.:de are as.forming the ‘surface of the plain of Malpais. ;, "The convexity of this plain is therefore.most naturally, ac- saree for by supposing it to form the surface of a great bed of lavas resulting from, the union of different currents, which, owing”to’the previous flatness of the surface on which they were poured forth, their simultaneous emission in great abun- ‘dance from ‘so many neighbouring orifices, and their. ple, degree of Liguishity, *: united i into a, sort of pool or lake of laya, ..* The wary coarse grain of the ne of Sapa (Dolerit. ‘Hum umbollt,) ‘warrants this assumption of its extremely ‘imperfect liquidity, = a Humboldts Theory of the Volcano of Jorullo. 59. which ‘spread itself on all sides’ with ‘great reluctance, and, therefore, would necessarily remain thickest and deepest where the lava was produced in’ greatest abundance} diminishing in bulk from thence towards the limits of the space'it covered’; é. ¢. would assunie precisely the convexity of form peculiar to Malpais. The subsequent projections of loose and’pulveru- lent matter from the’ six craters, and principally from Jorul- lo, ‘will have increased that convexity, covering it with strata of volcanic ashes and augite ¢rystals, which ‘were reduced to the appearance of a black clay by mixture with rain water. “ ~ The fact that the only visible lava current ‘proceeds from the crater of Jorullo, is a strong confirmation of this ‘opinion ; since ‘it is at once obvious why this is’ seen, while those that may have been emitted previous to the formation of the other cones are concealed; and it’ becomes” also probable ‘that ‘this promontory of lava is merely one extremity of the current of Jorullo, which, dipping under the strata of ashes, probably ‘unites witli the streams proceeding’ from the ‘other’ apertures to form the stibstratum of the whole ‘convex plains © 2 ~ Thus there’ is ‘no’ difficulty im accounting for the convexity of ‘the plain of Malpais by the effects of the most ordinary voleanic phenomena ; let us see’ whether this supposition will éxplain the other remarkable appearances it is said to exhibit. “And here a fact, recorded by’ M.' de Humboldt himself, net vonly'tends to’ confirm, ‘but may be almost’ said to prove, the correctness ‘of the view I have’taken of the ‘natiire of the plain. “He says that; in 1'780, the temperature of the ‘fissurés ‘which ‘penetrate ‘the surface of the*plain and its hillocks, was so high, that a cigar: might be lighted by plunging it to the depth of a few inches into them. Now I think it impossible ‘to aceount for this:without allowing the’ whole plain’ to have consisted of lava in a state of incandescence immediately be- neath its outer crust; a circumstance’to be expected, even ‘so much as 20 years after its emission; in a bed ‘of lava more than 500 feet in thickness, since Hamilton observed of one of the smaller currents of Vesuvius, that, three years after its pro- duction, a stick might be indamed by. thrusting it into one of -the crevices of the rock. It remains only to account for the formation of the small 60 ‘ Mr Scrope’s Observations on — hillocks (hornitos) with which the surface of the plain is thick- ly studded. And here I must again have recourse to the ré- sults of the highly instructive eruption which took place — Vesuvius in October 1822. * All lava currents are well known both during their pro: gress, and for a long time, often indeed many years after- wards, to disengage torrents of aqueous and sulphureous va- pour. If these are produced on any point in considerable quantity, while the superficial lava is yet soft, their expansion raises up a portion of this into a small dome or bubble, which sometimes remains entire, at others it is broken through, leav- ing the tattered fragments of lava that separate to give passage to the vapour, in an upright position from their sudden con- gelation.* This process is, in fact, one of the causes of the numerous asperities that bristle the surface of most currents. When, however, a deep coating of ashes has subsequently fallen on this surface, its smaller roughness are effaced, and the larger protuberances alone show themselves in the form of small dome-shaped or sub-conical hillocks, which continue, through various crevices, to give a passage to the vapours by which they. were at first thrown up. Many such hillocks, rising five or six feet above the average level of the surface, existed in the spring of 1823, on the Vesuvian lava currents above-mentioned, and sent forth copious columns of vapour, precisely of the same nature as that of the Hornitos of M. de Humboldt; while other fissures, intersecting the intervening surface of the small plain, formed by the lava on the Peda- mentina, gave out similar vapours, presenting, on a small scale, the identical phenomena for which Malpais has been so _ Jong celebrated.+ Where the quantity of ashes, covering the lava bed, aiid mixed up into a paste with rain water, was great, as appears to have been the case on the Malpais, it is probable that nu- merous hillocks of this kind will have been formed by the in- CF * See Breislak’s Institutions Geologiques, i. p. 251. e + That the eruptions of Jorullo threw up a prodigious quantity of vol- canic ashes, is evident from the fact recorded by M. de Humboldt, that the roofs of the houses at Queretaro, 144 miles distant in 5 sda were thickly covered with them ! PA (ty z es lh ene Humboldt’s Theory of the Volcano Sf Jorullo. 61 tumescence of this semi-liquid substance alone above the fu- marole of the lava ;* and the mobility of parts, occasioned by this process, favouring the action of the concretionary forces, probably gave rise to the agglomeration of the clay into the foliated and concentric balls, of which the hornitos partly con- sist. At Pont du Chateau, in Auvergne, is an example of even a very coarse calcareo-volcanic conglomerate having as- sumed this precise variety of concretionary structure; and I suspect, from. their being imbedded in the black clay, and consisting of a fine-grained rock very different from the Dole- ritic basalt of Jorullo, that the globular concretions of the hornitos are not a true basalt, but merely hardened nodular balls of voleanic ashes. They are, in fact, described by M. de Humboldt as fragile and easily crumbled, and totally dif- ferent from the syenitic lava of the current of Jorullo. — It remains only to notice the supplementary facts produced by M. de Humboldt in support of the explanation he adopts of the appearances of Malpais, which I conceive tend much more strongly to confirm the opinion of its being. merely the surface of a great bed of lava, which, up to the period of M. de Humboldt’s visit, retained much of its internal heat. These confirmatory facts are, 1. The noise made by the steps of a horse upon the plain. 2. The frequent formation of cracks or fissures across the plain, and the occasional occurrence of partial subsidences. 8. That two rivers, the Cuitimba and San Pedro, lose themselves below the eastern extremity of the plain, and re- appear as hot springs (at 52° cent.) at its western limit. 1. With regard to the first mentioned circumstance, viz. the sound produced when the surface of the plain is struck by the hoofs of a horse, or, I presume, in any other mode of percussion, it is evidently the same phenomena of reverbera- tion, to which the mimo-phoneutical term rimbombo is so well applied in Italy, and’ which, by a vulgar error, is often sup- posed to indicate a great cavity below the spot so resounding when struck. It is perfectly true that the roof of every large * 469 33S] 38.5 | nf | 27.066, we 208|Corone Bor. 11 N} 3057 | mp 7.168 ann + 5% 6. in} P ; An 2og}s2 of the 145 59 N] 53.43 | mp | 31517) } 210\2’ Urse Min. 2Ni 643 | nf | 31.102 : 2111. 85 39S] 5517 | mp 6,882 |Changed —9° 8’ in Po- sition, and nearly 3” ‘ :: in Distance. 212|[IL. 103 © 15 48} 356N) 53 4 | mp 10.665 2i3|H. C.343 ~—,_—«|lS 49119 248] 5210 | mp | 19.890 214) V. 126 15 5211754 N} 53.25 | sp | 84.923 Q15|LI. 21 prope ¢ Scor.|l5 54/10 56S] 1057 | of 10.601 idem 1 and 3 78 39 | np | 4 41,533 *216|€ Scorpii 15 54110528] 1137 | nf 6.769 opel s Ma mot.) — 0° Scorpii 15 55/19 18S| 6330 | 13.650 |Unchanged. 313 a. C. 159 15 58/13 49 N| 58 44 : 31.935 ' ‘ 219|x Herculis 16 011732 Ni} 80 25 nf 31.169 |Dist. diminished 8”,711. 220|r Scorpio 16 2858S] 6812 | np | 40.817 |Unchanged bs ; *221|49 Serpentis 16 4|l4 1N| 41 57 {st SE atarlgr ey og» Tommy *920\7 Corone Bor. 16 8/3420 Nj. 18 27 nf 1.455 |Brnary. Mean mot.—| 2°.13, much acceler- ated, and distance di-] Ep. 1822.83] minished. 223|¢ Corone Bor. 1 a 1029 36 N]} 65 33 | nf |) 28.694 —1&3 35 9 | ap | 2 64.20 and T'riple Stars. 67 No Star’s Name. [R. A.} Decl. Apale of Pann Distance. Remarks. h. m. en wy) / ” 0 @ Scorpii 16 10)25 98s 1 ll np 20.595 V. 134 16 10/19 368 64 58 np 47.120 |Unchanged in Distance. V. 124 16 1019 40S] 6929 | nf | 13.280 |Slightly changed. 227|y Herculis 16 141935 N| 2614 | gp 38.325 ci, hiuchi {16 1523 18] 8730 | nf 4.065 8 16 18)3727N| 7621 | mp 10.155 SOLLT. 102 16 2111 IN 71 26 nf, 14.833 231/Herculis 71 16 21/1847 N} 19 12 sf 3.236 s 16 551 Ni $1 7 np 7.649 |Probably changed in Pos, H. @; 228 16 23) 8 42 N 17 29 nf 59.544 234/36 Herculis 16 32} 433 N| 39 37 sp |l 8.839 235} V.1271&2 j16 345657 N) 21 0 np 54.307 eke Le 8 7410 | sp |) 30.275 6|1'7 Draconis 16 32153 17 N 25 26 sf 4.512 |Unchanged. & Herculis 16 35/31 56 N 0.000 |Single. | 238/H. C, 369 16 3524 ON) 21 27 np 6.755 239143 Herculis 16 37) 855 Ni} 39 9 sp |1 20.094 240)Prazzi XVI. 236|16 46/19 15S 42 44 sp 5.641 24)/H. C. 510 16 53/47 36 N 6 3 np |1 55.126 4 ; 8 INARY. Mean t. 242/21 Draconis [17 3/54 43 N|_ 61 39 ud $907 | 95792, 243/36 Ophiuchi 1 & 217 426188} _ 42 41 eA 5.546 didi: 1 tee 19 5 | mp |3 0.735 244/¢ Herculis 17 61436N}) 29 33 sf 5.286 |Unchanged, 245] 39 0 Ophiuchi {17 724 5S| 8547 | np | 12.512 |Unchanged in Pos. *246\d Herculis 17 825 3Nj 82 10 sf |0 28.869 |Altered + 9° 42’ in Pos., and — 5”.34 in Dist. 247|»Serp. Ophiuchi 17 1112 39S 59 13 nf 50.213 248lo Herculis 17 173719 N| 37.53 | np 4.463 |Position ch 7° 327 Dist, + 1”.494. 249|53 Ophiuchi 7 26,943 N| 7841 | sp | 41.662 |Unchanged in Position. | 250), Draconis 17 295519 N] 42 23 {#} 1 2.242 |Unchanged in Position. 251|Ophiuchi 2541 & 2117 30} 2 8N} 58 7 | mp {1 51.213 —I1& j ie 68 37 nf |2 18.090 ; - Oe 27 23 nf |1 54.310 252/61 Ophiuchi 17 36,241 N| 333 | sf | 90.520 |Unchanged. 253)/H. C. 348 17 36/13 148 66 48 sp 15.869 254). Draconis 17. 214NV 7514 | nf 31.777 255|67 Ophiuchi 17°52) 257 N 53 4 sf. 55.228 256/H. C. 168 17 52/30 5 N 8 53 np 20.181 | 257/95 Herculis 17 54/21 36 N 8 8 nf 6.623 ’ }"258/70 p Ophiuchi 17 56,233 Nj 64 48 sf 4.266 |Binary. Mean Annual} ! motion — 6°.811 not Ep. 1822.42) uniform. 259/H. C. 362 17 57 9N 15 27 np 21.093 260){ 11. 56 17 5712 ON 12 21 sp 6.748 |Scarcely changed. 261/73 q Ophiuchi [18 1/357 N)~ 1223 | xg 1.989 | Distance incréased.! | 262/100 Herculis 18 126 5N] 87.35 {x} 14.281 © 263)Anonyma 18 718498 77 52 nf 54,302 264/STRUVE 569 i8 81838S 37 22 uf 16.419 265)1. 86 18 1225 28 N 82 48 np 4.587 266)H. C. 298 , 18 1215 10S| 51-37 {24 14.091 Mr Herschel and Mr South’s Observations on : . F Angle of | Qua- : No Star’s Name. |R. A.| Decl. inition, drant. Distance. Remarks. m. , ” Oo? / “” 267/40 Ceph. or Drac. {18 13/7158 Ni) 34 56 sp 21.362 |Unchanged. *268)59 d Serpentis 18 18} 0 5 48 5 np 4.151 |Binary? Orbit in- plane nearly passin Epoch — |Ep. 1822.95| through the eye. *269|39 Draconis 1 & 2]18 21/58 42 N| 86 5 nf 3599 |BINARY ? Mean ; mabe —0°.205, f [1 & 3 68 5 af |\1 30201 270) H. C. 300 18 30/52 13 N 4 34 np 26.226 27\)H. C. 291 18 30/41 7 N) 70 15::) mp 6.000 "272\a Lyre 18 31/8837 N| 42 7 sf 42,108 |Changed both in An a and‘ Dist. by prop Ep. 1822.87] motions. 273/[V. 94 18 36/34 32 N 5 51 nf 24,630 274|H. C. 296 18 36):0 39 S 66 18 np 5.306 275|5 Aquilae 18 37} 1 958 32 42 sf 14.468 ; ( "2764, ¢ Lyre 18 388927 N) 64 7 nf 4.010 |Brnary ? Mean motion seit ; —0°.19 per ann. 277|Debilissima nter ; rs Lyre, {|'8 3613027 S| 50 + 53+ of 278)5 Lyre 18 3813927 N] 69 56 { oT sateen aaa as | 279|2 Lyre 18.383725 N} 5951 | sf | “a4.240 ) | 280|H. C. 170 18 42)1047 N|. 85 28 Sp 4.794 281/46 Lyre 18 433310 N] 60 1 sf 45.778 + 282)/H..C. 19? 18 48)33 46 N 80 15 np 46.035 283/89 Serpentis 18 48}358 N) 14 96 sf 21.679 284]o Draconis 8 491559 10 N 79 11 np 29.949 285|Piazzi XVIII. 274/18 54) 0 58S 58 49 sf 26.019 2g6|15 Aquila 18 564178] 6316 | sp | 35019 287|Anonyma 18 58} 653 N| 67 46 2p 8.521 288\H. C19? Str. 609 |19 2/34 18 N 10 27 Sp 17.124 289) Prec.» Lyre 19 6)3844N 32 18 nf 40.391 290|Cygni 6 19 74931 Nj. 44 6 | sp 10.576 291) Lyre 19 8/38 51 N 5.58 nf 29.336 ‘ 292\8 Lyre 19 10)37 49 N|. | 17 52 nf |1 41.665 293/H. C.90, Str. 616/19 11) 5 44 N|. 87 46 np 31.420 294/H. C. 111,S7TR. 619)19 18) 9548 35 49 sf 11.314 Changed. + 4° 50’ in ags\I1I. 57 19 1920 46 N|. 63 96 spe auad!| lene auctanaee oog{II. 69 19.2186 10N). 23.16. | *% | 7.499 [Hanged + 5° (66! 297|6Cygni 19 24/27 35 N| 35 15 uf 34.3€3 |Unchanged. Aquile 151 19 34] 8 43S 56 34 sf {1 37.112 16 Cygni 19 8750 GN). 4518 13°C) 37.504 [Probably unchanged. Z00/STRUVE 634 — 19 38/33 14 N| 56 15 eer oa 30])Anon. nova 1 & 2 |19 38/3314. N] 15 56 nf 23.467 1&3 57 35 | sf 302|STRUVE, 635 19 3817752 N} 68-30 | nf 11.936 303/STRU. 336 1 & 2 |19 38/35 39 N| 36 52 sf 15.133 1&3 18 5 | sp {2 19.183 304|¢Cygni 19 39/4442 Ni} —_— ~ly Single. 305|x, Cygni 19 40/3320 N} 16 42 nf | 25.503 |Probably *306|7 Aquile 19 4))11 22 Ni 45 27 a 1.957 |BInaRY. Mean + 0°.314, *307|¢ Sagitte 19 4118 43 N44 32 | mp 8.818 |BrnaRy ? Mean mo-| _ | tion. Double and Triple Stars. 69 No.| Star’s.Name. [R.A] Decl. aisha jad Distance. Remarks. h. m. o 4 ° , 4‘ # . « Aquilw 19 42} 824 Ni 55 48 np. |2 33.375 “Common proper motion. 309/57 Aquilae 19 45) 8428 8l 8 sf 36.158 $10Struve, 647 {jg 45/19 5 N| 58 30 gine 42.427 $11|*Draconis 19 49/169 48 N| 85 21 np 2.590 |Probably unchanged. B12\y Cygni 19 51/51 58 NN} 88 0 | sp 4.321 |Unchanged in Position. 313|I. 96 1 and 2 19 56/35 32 N| 86 52 | sf 2.467 a lly changed in Po- —-land 3 59 29 np 41.335 sition. 314/H.C. 16,Srrv. 658/20 0/3518 N| 30 58 np 10.793 idem 1 and 3 61 48 | nf | 36.523 315|Nova. HH. andl. |20 0/35 17 N 33 26 sp 20.164 316|\Nova. H andl. [20 0/35 7N| 54 3 | np | 1 9.479 317|[I. 96 20 3}019N| 6148 | sp 4.100 |Perh ae slow change| in Position. 318)H.C. 182. Srp. 665/20 6] 4 2S} 3633 | sp 14.491 319) Capricorni 20 813 35 21 26 up |\6 12.999 320). 95 20 14/54 48 N 69 39 np 3.980 B J "321|xCephei 20 157710 N| 38 4 | ¢f 8.138 ay much increased} 322\e Capricorni V1. 29/20 1918 24S| 60 45 sf |3 58.021 323|¢ Capricorni II. 51 |20 20/18 24.$| . 87.17 | sf 4.026 324/o 12 Capricorni 20 20119 10S 30 17 sp 22.060 325/H. C. 109; St R.680/20 23/10 35 N 14 22 sp 15.484 326)Anonyma (Nova) |20 32/88 5.N| 88 43 np 9.478 327|y Delphini 1 & 2 |20 381529 N| 343 | xp | 12317 f 1&3 7835 | nf |2 20857 : 328|¢ Equiulei 20 501/336N} 1039 | xf | 12.374 . *329/61 Cygni 20 59/37 52 N 5 19 nf 15.425 |Brnary. Great proper motion — 5” 38 in R. A. and 3”.30 in declin. Mean angular Ep. 1822.29] motion = + 0°730. 330/84 Cephei 21 26169 46 N} 19 35 sp 13.163 331|3 Pegasi 21 28} 548 Nj 78 58 | mp 39.525 {Perhaps a very slow change of Position. - 332lu Cygni 1 and 2 [21 362756,.N] 23 4 | of 5.744 idem 1 and 3 : 28 43 | nf |3 37.401 333/74 ? of the 145 21 461855 Nj 2015 sf 22.052 334/57 of the 145 21 46/5459 N| 76 11 sp 20.308 335|III. 74 21 4915 GN} 33 29 nf 10.093. !Diminished in Distance. 336| Nova Prope III. 74/21 4915 6N} 44 0 sp |1 45.858 337|£ Cephei 21 45 N| 2315 | mp 5.817 338)Pra. XXII, 11. 12.}22 25 N 45 13 np 22.094 339/56 of the 145 [22 412153S] 3042 | sf 5.170 340/120 of the 145 22 17 N 15 31 sp 14.839 341|1 Lacertee 22 51 N| 7843 | sp | 15.619 342/33 Pegasi 22 56N| 75 45 | np | 56.045 343\/STRUVE 751 22 50 N 2 37 sf 3.723 344)64 of the 145 122 27N 0 5 nf 4.238 Lope py Aquarii 22 39 S 3.7 np 10.032 Bian CURB anneal ii & 4, 8 ve a ¢ Aquarii 22 57S} 89 29 p 989 notin. #n484. 347|d Cephei 22 30 N| 7844 | sp 41.612 34818 Lacerte 1 and 2 |22 42 N|_ 85 39 sp 22.674 idem land3| > 55 15 | sf |1 22.520 349) Aquarii 213 2 118 51 19 np 3.398 350) Aquarii 231 1 & 2/22 9S 24 24 sp 4.349 idem 1& 7233 | sf | 57.38) 7 - Angle of | Qua-| nistance. Remutike, No. Star’s Name /R. A.| Decl. Position. | drant. o 4 ‘ au” 16 Lacerte 44 4] nf \1 4.541 |° . Prazzi XII. 306 |22 59/31 5 58 19 sf 8.716 . 353) H. C. 242; SrR. 773/23 2146 5 17 0 sp 14.709 ; 76 Al np 14.998 a A 0 0 p 1 13.953 | 53 30 | sf 5.056 /857/Androm. 281 1 & 223 } 017 13% 8) 5.00 idem 45 25 sf |3 45.941 7 59 11 mp 41,297 359|o Cassiopeiee, 57 41 |. up 2.924 |Doubt. whether changed} lor not, Andromedx 37 3 51132 43 N 81 38 sp 5.263 Supplementary Stars ; mostly imperfect measures. d 361)\Ceti, 27 4S} 18 45 np 9.00 0)}Distance estimated. | 362] Mira (0) Ceti 48S 1 25 nf _ Chan. both in pos. & dis. 363|7 Tauri 51 N| 33 54 nf 21.005. |Distance estimated. . 364|u Persei 57 Ni 3818 | sp |1 31.659 LIL. 65 43°N| 59 0 | af 12.468 41 Auriga 44N} 8316 | np | 8.809 ie 367|Telescopii 15 40N| 43 0 | of 28.064 a 3 p, Geminorum 49 N 56 16 np . 369|nf. 40 Lyncis 9N}. 5715 |. nf |3 22.287 : 1 Ur. Maj. 1 & 2 47 Nj 39 2 | mp 6.474 . idem 1 & 3 . 74 36 | mp |4 45.000 . 37/23 h Ursee Maj. 17/63 51 N| 033 | xp 27.332 372|L04 of the 145 715 228| 36+ | mp 20 + 373|Camelop. 212 488424 Ni 57.0 | = 22.069 ; - 1 374lo 84 Virginis 13 34) 427 N 40 9 sp 3.918 |Binarny ? Mean annual] — 375/18 Libre 14 49110 245| 54 8 | "f 26.614 | motion —0°.288. 37624 Libre Land2 |15 2119 6S| 2139 | #7 50.629 - land3 2139 | 4? — {1,2 and 3 are precisely} — | ‘ in a line. d s7isrruve 489 —«*|t8 27/2720 N| 3020 | sp 5.941 1 - 378|19 Ophiuchi 16 38) 224N} 10+ | gf 10.615 379/40 of the 145 [17 52122 58S] 61 45 | sp 10.952 380|¢ Capricorn - 1940S! 8627 | sf 53.704 Art. XI.—Notice of an Earthquake felt at Sea, in February 1825. Communicated by a Correspondent. Tess are few observations of greater importance, in refer- ence to the theory of earthquakes, than the determination of. the exact time when they are felt at sea. The place where they have their origin,—the velocity with which they are /pro- pagated,—and their probable depth beneath the surface, md Notice of an Earthquake felt at Sea, in February 1825. 71 be inferred from a series of accurate observation on the effects which they produce, and the time when they are felt at differ- ent points on the earth’s surface. The earthquake which was experienced at Lisbon, on the 2d February 1816, at five minutes past midnight, was felt at sea by the Portuguese vessel, the Marquis de Angeja, bound from Bengal to Lisbon, at the distance of 270 leagues from that city ; and it was also experienced by another vessel, bound from Brazil to Portugal, at the distance of 120 leagues. . On the 4th of April 1812, the vessels on the coast of the Caraccas trembled, during the heavy shock of an earthquake, as if they had been on a reef of rocks. In the earthquake which took place at Chili, on the 19th November 1822, the effect on the ships in the bay was such, as if the chain-cable had run out in an instant. On the 10th February 1823, the East India Company’s ship Winchelsea, in east long. 85° 33’, and north lat. 52°, experienced the effects of an earthquake. When the vessel was some hundred miles from land, and out of soundings, a tremulous motion was felt, as if it were passing over a coral rock, and this was accompanied with a loud rumbling noise, both of which continued for two or three minutes, This effect bears a close resemblance to that which is de- scribed in the following extract of a letter from on board the Recovery of in a voyage from Madeira to Honduras, in February 1825. * In running through among the islands, we were in dread of every schooner-rigged vessel we saw, as these seas swarm with pirates. However, nothing worthy of note occurred till off the island of Ruatan. Between seven and eight o'clock at night, being quite dark, we were all alarmed by a rumbling noise, as if the vessel had been running over a reef of rocks. Every one rushed upon deck, and all cast a wishful look over the side of the vessel, expecting every moment to see her go down. The pumps were sounded, but no water was in the well. It was then concluded, that it must have been a large log of timber which the vessel had come in contact with ; but, on arriving in Belize, we ascertained that it was the effect of a smart shock of an earthquake, which had been experienced there at the very time we felt the concussion.” 72 Dr Fleming's Remarks on the Defoliation of Trees: ' Ant. XII.—Remarks on the Defoliation of Trees. * By the Rev. Jonn Fiemine, D.D. F. R.S. E., &e. | Communicat- ed by the Author. Tur arrangemehts wish prevail in the Sasa Sea ll regarding the “* Duration of Leaves” do not appear to have been studied with so much care as many other subjects connected with the economy of plants. Aristotle knew that some leaves were deciduous, others not. Czesalpinus states, that many trees lose their leaves in autumn when their fruits are perfected, and their buds hardened, while such as retain the fruit long, keep also their leaves, even till a new crop is produced, and longer, as in the fir, the arbutus, and the bay. Linneus distributes leaves, in reference to their duration, inte ~ decidua, caduca, persistentia, perennia, sempervirentia. Sir James Edward Smith simplifies this arrangement of Linnzeus, and considers leaves as to their age as of two kinds. sSemper- virens, evergreen, permanent through one, two; or more win- ters, so that. the branches are never stripped, as the ivy, the fir, the cherry laurel, and the bay. Deciduum, deciduous, falling off at the approach of winter, as in most | Parone trees and shrubs. ‘It is much to be regretted that the learned botanist last mentioned should have passed. over this division of the cha- racter of plants without improving the classification of his master, or expressing himself more consistently with the phe- nomena of nature. A little attention to the subject will con- vince us, that winder is not the proximate cause of the falling of the leaf in many trees; that many leaves fall off long be- fore the approach of winter, and that others, which have with- stood its attacks, perish with the warmth of spring. .The want of attention to these circumstances, so’ conspicuous among our systematical writers, and which I have witnessed among well informed practical botanists, may serve as an apo- logy for the following remarks. Perhaps they possess no no- velty to those who are acquainted with the labours of the more recent physiologists. To others, however, they may ap- pear to have a little interest. * Read before the Royal Society of Edinburgh, December 5th 1825. - Dr Fleming’s Remarks on the Defoliation of Trees, 1% Trees, in reference to the duration of their leaves, appear capable of division into three classes. In the first class may be included those in which the leaves cease to exercise their functions whenever the bud has been perfected. In the se- cond, the leaves continue to exercise their functions ‘until new ones are produced in the following season. In the third class, the leaves continue to exercise their functions for several years, In trees of. the first class the leaf may, with propriety, be termed. ‘‘ Foliwm deciduum.” Its principal function appears to be connected with the ripening of the bud, and, when this object is accomplished, the leaf changes colour and dies. The falling of such leaves takes place, as, indeed, in all other cases, in the order in which they were evolved. Hence by midsummer we witness, in willows, for example, a considerable portion of the lower part of the shoot naked, its leaves having fallen, while towards. the extremity its foliage is fresh and in- creasing in quantity. In those trees in which two evolutions of buds take place in the course of the season, as in the beech, the leaves formed on the spring shoot. change their colour and die sooner than those evolved at a later period on the summer shoot. In.those trees which seem to lose all their leaves suddenly, as the ash, the same order of defoliation actually prevails. The first evolved leaves of spring have perished, by degrees, in the course of the summer. Those with which the tree is clothed at the end of the season, are connected with the termi- nal buds, which, by becoming perfeet about the same time, permit the leaves connected with them to fall off in rain suc- cession, The leaves, in some cases, after they have ceased to exer- cise their functions, continue attached until the following spring, as the beech in hedges.. When this plant, however, is not under the influence of the. shears, the leaves fall off in the usual manner. The cause of this want of resemblance be- tween individuals of the same species, may be found in an ex- amination of the different circumstances in which they are placed. When the beech grows exposed to free air and sunshine, the buds attain their true size, the leaves execute 7 Dr Fleming's Remarks on the Defoliation of T'rees. regularly all, their functions, and drop off when they cease to act their part in the economy of the plant. But when the beech is trained~in a hedge, it is too much shaded, the buds seldom attain their true size, and the leaf is s frequently destroy- ~ ed by cold, previous ‘to the end which it is destined to serve having been accomplished. In some cases, leaves, which naturally would fall off i in autumn, continue, when the plant is subjected to the shears, to outlive the winter,—as the privet. The leaves, under such circumstances, may be said, in the language of farmers, to be “« kept back,” and to be capable of resisting the cold, while use- ful to the economy of the plant. Many analogous examples occur among herbaceous plants. ; In the trees with deciduous leaves, it is probable, that, dur ing the period of their nakedness, the bark may be viewed as the aerating organ, destined to effect the escape of the super. fluous carbon from the system. During this period, they may be viewed as resembling “ plante aphylle.”” ‘The bark, in- deed, of the young shoots of several trees and shrubs, as the common broom, is so very like, in colour and texture, to the leaves, as to render it, in all probability, fit to supply their place for a time. In trees of the second class, the leaf may be termed * foli- wm annuum.” It exercises its functions until a new set of leaves be produced, and is then cast off in the ordinary order _ of seniority. Many of our most ornamental evergreens are of this. description, as the bay, laurel, ivy and holly. These are termed evergreens, because the plant is never left naked, and the leaves of this year exercise their functions, and preserve their colour, until the shoots of the following season have ac- quired their clothing. The leaves of the plants of this class, appear, therefore, to exercise a greater influence, in the eco- nomy of vegetation, than in those connected with the first. Here the plant requires the aid of leaves at all times, no other organs, in ordinary cases, appearing to be capable of exercis- ing their functions, or acting as a substitute. Do these annual leaves exercise a greater variety of functions than the decidu- ous leaves? Or does the bark of a ring with annual _ “se ————— sh elo Dr Fleming’s Remarks on the Defoliation of Trees. 18 exereise fewer futctions, than the same organ in trees with de. ciduous leaves ? “When growing too much in the shade, or when subject to the influence of the shears, annual leaves may have the period of their life prolonged, so as to exercise their functions after the new shoots have evolved their leaves. In trees of the third class, the leaf may be termed “*7élium perenne.” Its duration is not influenced, directly, by the per- fection of the bud, nor the new supply of leaves during the following season. The leaves of two or more seasons, exer- cise, in trees of this class, their functions at the same time, and appear to be requisite for the prosperity of the stem, Our ordinary evergreen firs furnish very obvious examples of this persistent leafing. In trees of this description, the leaves seem to exercise functions even of a higher order, and continue to exercise these longer than in those of the two preceding groups. The tree here requires the leaves, not for a few months, or until new leaves be produced, but leaves of different ages,— two, three, or more years old. In the trees of this class there is less regularity i in the fall- ing of the leaf, as to season, than in the two preceding ones. Few of the old leaves drop off, when the tree produces the shoots, and new leaves in spring. A greater number seem to perish about midsummer, and again on the approach of win- ter. "The succession in the fall of the leaves is, as in the other classes, in the order of their seniority on the same stem and branch. But sometimes only a portion (the first formed ones) of the leaves of one season drop off, the remaining portion continuing to exercise their functions during a longer period. On the same tree may even be observed leaves of three, four, five, six, or even seven years of age ; and while a part of those three years old may be changing colour and dropping off, those seven years old may remain green and fresh. Those leaves which are placed in the shade live longest; yet even in this respect I have witnessed many anomalies. These remarks apply to the duration of the leaves of the trees of this country. The influence of climate on the dura- tion of leaves has often been stated as considerable, and 76 On the Habits and Food of the Stickleback. » capable of converting degishiscld leaved trees into evergreens, or the reverse. In cold climates, vegetation is interrupted by winter. In warm climates, plants experience not such in- terruptions. It may therefore be asked, Will a warm climate alter the character of the leaves of certain trees, so far as to change a deciduous into an annual or perennial leaf? Or is there a source of deception arising from the continued vegeta- tion exhibiting trees as evergreens, though in fact their leaves be deciduous ? An affirmative answer to the latter question, will probably be found an expression of the truth. Manse or Fisk, 4th November 1825. Art. XIIL—On the Habits and Food of the Stickleback. From a Correspondent. Iw Volume III. of the Journal of Science, p. 74, Mr Ra- mage of Aberdeen has given an account of a stickleback, which, was taken alive with a leech “ fully as large as the stickleback’ itself” in its intestines. . The leech, “ in a few minutes,” was protruded by the anal opening, and crawled on Mr Ramage’s hand ; but, “ the stickleback died almost imme- diately after giving birth to this strange offspring, and the leech survived it only about twelve hours.” ‘The appearance and motion of the leech, it is added, “‘ corresponded, in every respect, with those of the common leech, excepting that the colour was entirely white.” The theory offered to account for this fact is, “ that the leech was lodged in the small gut, and most probably had been swallowed by the stickleback for food when of a small size, and had grown to its present dimensions in the stickleback’s belly, after having been swallowed.” The leech and the stickleback were transmitted to the museum of the Royal Society of Edinburgh. Upon this detail, it may be remarked, that the circum- stance of a stickleback swallowing a leech is no uncommon one, for young leeches seem to be the favourite food of the three-spined stickleback, Gasterosteus aculeatus, Lin. My © boys had several sticklebacks alive for some months during 4 \" } ‘ ——— SF? oe On the Habits and Food of the Stickleback. vy the last summer, and fed them at first with earth-worms, maggots, and occasionally the small house-fly, which, how. ever, did not seem to be relished. Afterwards, at my sug- gestion, young leeches were brought from the ditch in which the sticklebacks were caught, as being more likely, with the larvee of aquatic insects, to form part of their natural supply, than the food which was submitted to their choice. 'These were found to be preferred to all other aliment, and for a month at least they had scarcely any other food. ‘The spe- cies of leeches procured were the Hirudo sanguisuga, the H. vulgaris, and the H. complanata. 'To ascertain what size of leech would be swallowed, a male stickleback, of about an inch and three quarters in length was selected and put in a large tumbler on a mantel:piece, where its mode of attacking and devouring its prey formed a source of amusement to the children for weeks. On putting the leeches into the water, the stickleback dart- ed round the tumbler with lively motions, till it found a leech detached, and in a proper situation for being seized. » When the leech was very small, say about half an inch in length, it was often swallowed at once, before it reached the bottom of the vessel ; but when a larger one, about an inch or an inch and a-half in length in its expanded state, was put in, and had fastened itself by its mouth to the glass, the efforts‘ of the stickleback to seize and tear it from its hold were inces- sant, and never failed to succeed. It darted at the loose ex- tremity, or, when both ends were fastened, at the curve in its middle, seized it in its mouth, rose to near the surface, and after a hearty shake (such as a dog would give a rat) let it drop. ‘The leech, who evidently wished to avoid its enemy, upon its release again attached itself by its mouth to the glass; but again and again the attack was repeated, till the poor leech became exhausted, and ceased to attempt holding itself by its disc. The stickleback then seized it by the head in a proper position for swallowing, and after a few gulps the leech disappeared. The H. complanata, being of an ovate form, and having a hard skin, was not attacked, unless when very young, and scarcely two or three lines in 78 On the Habits and Food of the Stickleback length;* and leeches of the’ other species, when pretty wal grown, or longer than himself when expanded, were killed in the manner above mentioned, but not swallowed. In one of his: attempts to seize a leech, the stickleback, having got it by the tail, the animal curled back, and fixed _ its disc upon his snout. The efforts’ of the stickleback to rid himself of. this incumbrance were amusing. He let go his hold of the leech, which then hung over his mouth, and darting to the bottom and sides of the glass with all his strength, endeavoured to rub off this tantalizing morsel. This lasted for nearly a minute, when at last.he got rid of the leech by rubbing his back upon the bottom of the vessel. The leech, perfectly aware of the company he was: in, no sooner loosed his hold, than he attempted to wriggle away from his devour- ex; but before he had reached midway up the tumbler, the stickleback had turned, and ofr the contest by swallow- ing him up. This voracious little fish not ale preys upon the young of the leech, but. sometimes devours the fry of its own species. _ In two or three instances, when leeches had not ‘been procured, a young stickleback, about half an inch long, was dropped in- to the glass, and instantly swallowed. On. other-occasions, when some of a larger size were put in along with him, he contented himself with killing them. Perhaps the spines of these larger fish, which are erected when in danger, and upon , ments of Nature in securing the continuance of species, that the young of the H. complanata, which I have generally found attached to aquatic plants, were, in one instance which fell under my notice, affixed to the un« der surface of the parent leech, This animal which, unlike most of its congeners, never swims, had fastened itself to the side of the glass, and three. young ones, about a line in diameter, were thus exhibited to view in a most interesting light for an animal so low in the scale of existence. Thus protected, there was nothing to fear from the attacks of the stickle= back or other enemies. They moved occasionally on the disc of the mo« ther, and, it is conjectured, might remain in that situation, until they had attained such a size as to render further care on the part of the parent unnecessary. To convince myself that this protection was requisite, I de- tached one with the point of a knife, which was instantly devoured by the stickleback. ‘The young H.complanata, from its transparency; forms 2 beautiful object for the microscope. — - 1 as “ It may be mentioned, as a curious instance of the wonderful arrange- On the Habits and. Koo of the Stickleback. 79 the death of the animal, were too strong for the texture of his throat. Inthe ponds and ditches where sticklebacks occur, the young fry will always be found to seek protection in the shallow- est parts of the water from the attacks of their full-grown ene- mies. Our stickleback, at another time, when two minnows, much larger than himself, had been put in to keep him com- pany, attacked them with fury. They fled from his bite in evident dismay ; and one of them, finding no other means. of escape, fairly leaped out of the vessel. Even a female of his own species was not better treated by this ungallant tyrant, who allowed no stranger to-enter his domain with anpe- nity. % The young of the leech being thal it is conceived, a fre- quent food of the stickleback, it is not marvellous that such a little devourer should occasionally gorge himself by swallowing a leech of large dimensions fér the capacity of his stomach. That this was the case of Mr’ Ramage’s stickleback, seems evident from the situation in which:it was found, near the sur- face of the water, and the facility with which it was caught. Leeches possess the power of contracting and expanding them- selves to a great degree; and it is not in the least surprising, that; when relased from pressure by the death of the stickle- back, and swelled by liquid, Mr Ramage’s leech should ap- pear to be larger than the animal that had swallowed it. That it could have lived in the stomach of the stickleback from the period when it was very young till it attained the size men- tioned by Mr Ramage, is very improbable. From the cir- cumstance of sticklebacks feeding on leeches with avidity, it may be inferred, that nature has provided them with the means of digesting this species of aliment; and the fact of their being fed for weeks on leeches alone, and the usual pro- cesses of digestion and excretion going on, raises this inference to absolute certainty. That an animal so tenacious of life as the leech, should, shortly after bemg swallowed, be found alive in the intestines of the stickleback, does not, therefore, appear wonderful ; and that the stickleback should have died when “ a few minutes” out of the water, and in the hands of a child, is still less so, The wonder would. have been, had it continued to exist in an element so foreign to its nature, in- - 80 M. Savart on the Improvement of the Pipes of Organs. dependent altogether of the ae of leech-birth in the hands of such assistants. rid oye a Ant. XIV.—On the Improvement of the Pipes of Preene' * . By M. Fevix Savarr. As the construction of organs has. been hitherto abandoned to a blind routine, I cannot. conclude: these researches better than by pointing out some of their applications to the improve- ment of organ pipes, whether they are open at both ends, ' or open at one end and shut at the other. It cannot be doubted, that much advantage 1 is derived front employing only pipes of similar forms; for when we have once determined the proper dimensions of a tube for producing the best possible sound, it will be sufficient, to construct the rest according to the law, that the number of vibrations in a co- lumn of air are reciprocally proportional to their linear dimen- sions, provided that every thing being proportional in these pipes, the intensity of the sound andthe other qualities, such as the loudness, the clearness, and the’ timbre, are in the most suitable proportions. It is well known that ordinary or- gans are far from presenting this result, and that the grave sounds in them are too weak in relation to the sharp ones. In addition to this, the common pipes get out of tune with the greatest facility, from variations of temperature, and particu- larly from the derangement of the bottom, which is a moveable piston. Pipes of a similar form are free from this inconye- nience ;, both because their dimensions may be determined with the greatest precision, and because the ratios between the num- bers of vibrations which they produce cannot, be influenced by variations of temperature, every thing going on, in each of them, in an analagous and proportional manner. Since the direction of the port-vent and of the bevel have an effect on the sound yielded by a pipe, the true length of a a column of air in vibration is not always the same as that of the * This paper is a translation and abstract of the practical part of M. Sa- vart’s Nouvelles Recherches sur les Vibrations del Air, in the Ann. et Chim. Aout 1825, Tom. xxix. p. 419. j M., Sawvart on the Improvement of the Pipes of Organs. 81 side which carries the bevel. Nay, it may differ very much from this: If, for example, we take a prismatic square tube in which @ piston moves, the length of the column will be the distance of the piston from the base of the tube, provided this ~ distance is greater than the side of the base of the prism of air ; but if it becomes less, the true length of the column of ait is the small side of the base of the prism. In general, when we cause air to sound in any vessel, the depth of the vessel ought to be taken as the length of the co- lumn of air, when its diameter is smaller than its depth, but when this diameter is greater than its own length, it becomes that of the column of air. If, for example, we place a small thin plate of wood or white-iron, or even the blade of a knife, on the orifice of a vessel with a narrow neck like a bottle, or a caraffe, and if we blow the .air-against the edge of the plate, either with a small port-vent, or with the mouth itself; we shall.hear a sound which is in general very grave; but we must not suppose that the diameter of these vessels should be taken for the length of the column of air, this length being equal to the height of the vessel. With respect to the grave- ness of the sound, it depends on the length of the column of air, on its diameter, and on the small extent of the embouchure. Cubical pipes emit sounds extremely pure, and of a’particu- lar timbre: They speak with a facility and a promptitude quite astonishing, and may be employed in the construction of or- gans. They will also have the advantage of occupying little room, at least for the highest octaves. The sound « is given by a cube oneof whose sides is from 53 to 54 lines, whilst the bowrdon, which gives the same sound, is commonly _ from 10 to 11 inches long, and haying one of its sides from 2 to 21 inches. Hence it may be seen, that the sound of a cube of air, made to vibrate by one of its edges, is much more grave than if it were made to vibrate throughout the whole extent of one of its faces; for a column of air 54 lines long, shut up at one end, and made to vibrate with a full orifice, will give the sound fa, which is an octave and a quarter more acute than the sound wé, which is yielded by a cube of 54 -lines made to vibrate partially. Whence it is easy to con- clude, that we may pass from the sound of a cube of air to that “ VOL. HI. NO. I. JAN. 1826. F 8% M. Savart on the Improvement of the Pipes of Organs. | of avery small pipe of the same length as the side of the cube, by a series of sounds graduated as we desire, and which will be given by pipes of the same length, but whose magnitude gradually decreases. I have verified this result with ten pris- matic square pipes, three inches long, whose sizes were such that they described diatonically an octave and a half, com- mencing with the aoe which gave the sound sol 5, and terminat- ing with the sound si 4, which was emitted by the smallest pipe. We may also save room in organs by taking advantage of the fact, that prismatic square tubes’ may be indefinitely di- minished in thickness, by the approximation of their sides. It does not appear to me that the sound undergoes any sensi- ble alteration by diminishing their thickness one-half, and even two-thirds. There is some reason for thinking that we ai not obtain the best possible result by placing the embouchure at one of the extremities of the pipe, as is usually done. Nay, there might even be some advantage in placing it in the middle of its length. I have constructed several pipes in this way, and they yielded a sound of a very fine quality, whether they _ were open or shut at both ends. I have observed also, that in placing the opening on the side, and at one end, as in flutes, the sound has a very agreeable timbre, which organ pipes seldom possess. We may likewise construct flat pipes (made to vibrate by their tranche) of an infinity of powers, cylindrical, triangular, and elliptical; and I am convinced, by experiment, that we can obtain from them very fine sounds. The simple law of the number of vibrations for pipes of a similar form, allows us to determine, with facility, the dimensions which each pipe requires to give out any sound of the gamut. Very short pipes, in which all the plates of air perpen- dicular to the embouchure are not actuated by the same kind of motion, do not appear to be susceptible of yielding agreeable sounds. Spheres of air, for example, yield sounds very dull, and approaching to a noise, without respect to the impression which they make upon the ear. ‘The same thing takes place with cubes, having their embouchure i in the mid- dle of one of their faces. This, quality of sound “may de- ee ee M. Savart on the Improvement of the Pipes of Organs. 83° pend upon this, that the number of harmonics co-existing with the principal sound are very inconsiderable. It is al- most impossible, indeed, to obtain any of them in cubes. In spheres, Ihave found that, the first sound being called w#,, the second was ut,, the third ‘sol, and the fourth wé,; but, from this: ‘great interval between the first and the second har- monic, it is to be presumed, that I have not employed the proper means for obtaining all the series. I mtay besides re- mark, that the pipes which I employed had their embouchure only a small number of degrees of the circumference of one of their great circles, becatise I had it in view only to determine the law of the numbers of vibrations in spherical masses of air. It might have happened that the series of harmonics would have been different, and more easily obtained, had the embouchure been more extended; and perhaps, also, the sounds would have been stronger and more agreeable. ‘The sound wt, is given by a sphere of air about 43 inches in diameter. In the case of curved tubes, it is important to remark, that the material of which the sides are formed has a notable in- fluence on the qualities of the sound, and on the number of vibrations. .The same is true of the thickness of the sides, and, consequently, we must pay attention to this cireum- stance ; and in organ pipes of similar form, we must make the thickness proportional to the linear dimensions of the masses of air. The laws of the number of vibrations for pipes of similar form, and for plates of air, conjointly with the law of Ber- nouilli * for pipes made to vibrate with a full orifice, a law which is sufficiently exact for columns of air of a small diameter, em- brace very nearly all the cases which can occur in the con- struction of organ pipes, whether closed or open. Notwith standing this, I shall point out a very simple method for de- termining immediately the dimensions of all pipes of similar. form, which are susceptible of giving the same sound, and of which there are an infinity. * Namely, that the numbers of oscillations of columns of air, which sound in pipes open at both ends, or shut at one end and open at the other, are reciprocally proportional to the lengths of those columns, pro- vided that they vibrate with a full orifice. 84, M. Savart on the Improvement of the Pipes of Organs. Suppose, for example, that we have a certain numbet of closed prismatic square pipes which give ‘the same sound. Let us then: take the ordinate length for the OY, in Plate I. Fig. '7, and the sides of the base for the abscissa O X, and refer them to two rectangular axes, It is clear that we may, by this procedure, construct a curve which will give the di- mensions of all the pipes intermediate to those which. experi- ence has determined... The curve represented in the figure is constructed in this way. The ordinate O Y is the piesa of a pipe infinitely small, which would give the sound sol ; and the abscissa O X, of the same length as O Y, teprenlaal the side of a square plate of air infinitely small, made to vibrate in all the extent of this side, which would, consequently, give the’ same sound sol. All the other parts of the curve have been obtairied by experiment. ‘Tt i is unvecessary to remark, that this curve will be the same in all sounds, for which we should undertake to con- struct it; and it: follows from this, that the number of vibra- tions are reciprocally proportional to the linear dimensions, in ~ pipes of similar form. I shall now conclude these observations with a few remarks _ on the German top, an instrument which is at present ‘uhex- plained. This top is a hollow sphere, perforated with a hole, whose edges are sharp; and, when a rapid rotatory motion is given it,'a very pure sound is produced. The cause of this will be obvious, if we remark, that, in blowing against the sharp edge of the orifice of the sphere, either with a small port-vent, or with the mouth, it will yield the same sound as when it is in rotation. In the first case, it is the ~ eurrent of air which is driven against the edges of the orifice ; and, in the other case, it is the sharp edges of the orifices which strike the external air, which comes to the same thing ¢ and the fluid contained in the sphere, though it be carried by the motion of rotation, is not allowed to Mpa as if we hae tion did not exist. We may, therefore, by means of the law of the onal of vibrations being reciprocal to the linear dimensions for pipes ~ of asimilar form, determine, a priori, the sound of one of these instruments, in the case where its cavity is exactly spherical. — On the Invisibility of certain Colours to certain Eyes. 85 — Ant. XV.—CONTRIBUTIONS TO POPULAR SCIENCE. No. V. On the Invisibility of certain Colours to certain Eyes. A vanirry of cases have been recorded, where persons with sound eyes, capable of performing all their ordinary functions, were incapable of distinguishing certain colours, and what is still more remarkable, this imperfection runs in particular fa- milies. Mr Huddart mentions the case of one Harris, a shoe- maker at Maryport in Cumberland, who could only distinguish black and white, and he had two brothers almost equally defec- tive, one of whom always mistook orange for green. Harris observed this defect when he was four years old, and, chief. ly from his inability to distinguish cherries on a tree like his companions. He had two other brothers and sisters, who, as well as their parents, had no such defect. Another case of a Mr Scott is recorded in the Philosophical Transactions, in which full reds and full greens appeared alike, while yellows and dark blues were very easily distinguished. Mr Scott’s fa- ther, his maternal uncle, one of his sisters, and her two sons, had all the same imperfection. Our celebrated chemist, Mr Dal- ton, cannot distinguish blue from pink by daylight ; and in the solar spectrum the red is scarcely visible, the rest of it appear- » ing to consist of two colours, yellow and blue. Dr Butters, in a letter addressed to the editor of this work, has described the case of Mr R. Tucker, son of Dr Tucker of Ashburton, who mistakes orange for green, like one of the Harrises. Like Mr Dalton, he could not distinguish blue from pink ; but he always knew yellow. The colours in the spectrum he describes as follows: 1. Red mistaken for ny li ; brown, - 2. Orange ; green, 8. Yellow, generally wiaele but sometimes tithe for orange, 4. Green mistaken for % : : orange, 5. Blue é ; ‘ agar pink, 6. Indigo : ° : A purple, 7. . Violet ae. es ; ae oe 8&6 On the Invisibility of certain Colours to certain. Byes, Mr Harvey has described, in a paper read before the Roy- al Society of Edinburgh, and which will soon be published, the case of a person now alive, and aged 60, who could dis- tinguish with certainty only white, yellow, and grey., He could, however, distinguish blues when they were light. Dr Nichols has recorded a case where a person who was in the navy purchased a blue uniform coat and waistcoat, with red breeches to match the dlwe, and he has mentioned one case in which the imperfection is derived through the father, and ano- ther in which it descended from the mother. In the case of a young man in the prime of life, with whom the writer of this article is acquainted, only two colours were perceived in Dr Wollaston’s spectrum of five colours, viz. red, green, blue, and violet. The colours which he saw were blue and orange or yellow, as he did not distinguish these two from one another. When all the colours of the spectrum were absorbed by a reddish glass, excepting red and dark green, he saw only one colour, viz. yellow or orange. When the middle of the red space was absorbed by a blue glass, he saw the black line with what he called the yellow on each side ~ of it.. We are acquainted with another gentleman who has a similar imperfection. _In all the preceding cases there is one general fact, that red light, and colours in which it forms an ingredient, are not distinguishable by those who possess the peculiarity in ques- tion. Mr Dalton thinks it probable that the red light is, in these cases, absorbed by the vitreous humour, which he sup- poses may have a blue colour; but as this is a mere conjec- ture, which is not confirmed by the most minute examination of the eye, we cannot hold it as an explanation of the pheno. mena. Dr Young thinks it much more simple to suppose the absence or paralysis of those fibres of the retina which are calculated to perceive red; while Dr Brewster conceives that the eye is, in these cases, insensible to the colours at the one end of the spectrum, just as the ear of certain persons has been proved, by Dr Wollaston, to be insensible to sounds at one extremity of the scale of musical notes, while it wyrertect, ly sensible to all other sounds. If we suppose, what we think will ‘ultimately be demon. Description of the Thaumatrope. 87 strated, that the choroid coat is essential to vision, we may ascribe the loss of red light in certain eyes to the retina itself having a blue tint. If this should be the case, the light which falls upon the choroid coat will be deprived of its red rays, by the absorptive power of the blue retina, and conse- quently the impression conveyed back to the retina, by the choroid coat, will not contain that of red light. No VI. Descsiigtion of the Thaumatrope. The Thaumatrope, (or the ssonildicieaapii from deaype a wonder, and rgero to turn,) a very ingenious philosophical toy, invented, we believe, by Dr Paris, is founded.on the well- known optical ‘principle, that an impression upon the retina continues for about the eighth part of a second after the ob- ject which produced it is withdrawn. The luminous rings formed by the whirling of a burning stick in the dark are . well known, and Homer has availed himself of the same prin- ciple in his description of the lengthened shadow of the flying javelin. The Thaumatrope consists of a number of diieiis pieces of card, about two and ‘a half inches in diameter, which may be twirled round with great velocity by the application of the fingers to pieces of silk string attached to two opposite points of their circumference. On each side of the card is painted a part of a picture, so that if we could see both sides at once, the two parts of the picture would form a whole picture. For example, in Plate I. Fig. 8., we have shown two sides of a card, on one of which is a cage, and on the other a bird. If we now take hold of each of the silk strings A and B, between the fore-finger and thumb of each hand, and put it intoa twirling motion, the bird and the cage will appear to the eye at the same 'momént, in consequence of the impression of each continuing on the retina for a short space.of time. The fol- lowing are some of the other devices on the cards of the thau- ‘Matrope : ; A rose-tree, with a garden pot on the reverse. A horse, with a‘man.on the:reverse. ' ee 88. — Singular Optical Mlusion; &c. - & leafless branch, which becomes vende; on ‘the. swirling of the card. A female in one dress on one side, and anceher dress on’ the other. The body of a Turk, with his. head on the reverse. » The Watchman’s box on one side, and himself on the iter. Harlequin and Columbine on different sido appear toge- ther by the revolution of the card. A comic head on one side, which, on turning round, be- comes invested with a wig. A man sleeping, and awakened by being turned round. The principle of the thaumatrope may be extended to many other devices. Parts of a sentence may be written on one side, and the rest of the sentence on the other; and we may even put halves of the letters or words on one side, and the other halves on the other side. This method of breaking down let- ters or words or sentences may be varied ad infinitum, and will furnish us with a variety of rotatory cyphers. Those who have used the thaumatrope, must have been dissatisfied with the general effect of the two combined pic: tures. There is a hobbling motion arising from the i imiper- fection of the method adopted to produce the rotatory motion, which entirely destroys the effect ; and it is manifest, that the rotatory motion should be produced by quite different means. If strings are adopted, they ought to be attached to the circular pieces of card, so that the axis of rotation should be in the plane of the card; but a solid axis of rotation is decid- edly preferable, and will produce much more oi eee combi- nations. No. VII. Singular Optical Illusion seen through a Telescope. If we direct a telescope to the surface of a distant field on which there are no objects, such as trees, houses, &c. and if the field of the telescope embraces nothing but the surface of the field, the eye will speedily recognize that the field is hori- zontal or slightly inclined to the horizon, from the perspective of the furrows or drills upon its surface, or even from its te a Me Oe Variation of the Optical Deception of Le Cat. — 89 atrial perspective, provided the difference in the distances of the nearer and the remoter end is considerable, and. the air sufficiently hazy. The field, however, may be so siesinld and have ait an in- _elination, that, when seen through the telescope, it appears like a perpendicular or vertical wall of earth. . This phenomenon we have often ‘seen in directing a telescope to a field above Melrose Abbey on the northern acclivity of the north-west Eildon Hill. . This field is capable of being ploughed im the direction of its greatest declivity; but when it is viewed through a telescope, the slope is such that the furrows do not appear to converge; and the eye cannot readily perceive any difference between the breadth of the furrows at the remote end of the field, and their breadth at the near end. The ob- server, therefore, immediately concludes that the field must be. nearly a vertical plain rising in front of him. This deception is a very remarkable one, and produces a singular effect on the mind when the field is covered with a crop, and when crows, &c. light upon it. I have not yet observed the effect _ produced when it is in the act of being ploughed. It is very _ probable that the impossibility of ploughing a vertical plain may remove the deception, upon the MWe tart which we have ce in a, subsequent article. | No. VIII. Variation of the Optical Deception of Le Cat. ° M. Le Cat has described in his T'raité des Sens, p. 298, a curious optical deception, in which an erect object placed near a hole in a card next the eye, will appear to be on-the other side, and also inverted and magnified. Let CD, Plate I, Fig. 9 be acard perforated with a small hole, E a white wall or window, D the eye of the observer, and d the head of a pin held near the eye, and also near the hole in the card. Under these circumstances the pin d will be seen at F invert- ed and magnified. 'The reason of this is, as M. Le Cat has observed, that the eye in this case sees only the shadow of the pin on the retina, and since the light which is stopped by the upper part of the pin or its head comes from the lower part of the white wall or window F, and that which is stopped by 90 Optical Iihusion in Examining a Dioramic Picture. the lower end ‘of the pin comes ‘from the upper part of the’ wall or window E, the shadow must necessarily appear iaivent ed with respect to the object. The following variation of Le Cat’s experiment has been de- scribed by the writer of this article. Take a common pin and hold it in any position near the eye, so that the observer sees re- flected from its head a faint circle of light, then hold a second pin opposite to it exactly as in Fig. 9, and an inverted image of the one pin will be seen in the head of the other. If the head of the first pin is round and well polished, the inverted and magnified image of the other. will be more distinct. In this form of the experiment a diverging pencil of light from the window or a candle replaces the diverging pencil in Fig. 15, which proceeds from the perforation in the card CB, and of course produces the same effect. The little round knob, by- the pressure upon which the case of a watch is often opened, will answer better than the finest pin head. No. IX. Optical Illusion in ewamining a Dioramic Picture. In examining a dioramic representation of the inside of Ro- chester cathedral, which produced the finest effect from the entire exclusion of all extraneous light, and of all objects, exe cepting those on the picture itself, the writer of this article was struck with an appearance of distortion in the perspective, which he ascribed to the canvas not hanging vertically. Upon mentioning this to the gentleman who exhibited the picture, he offered to walk in front of the picture, and strike its surface with the palm of his hand, to show that the canvas was freely sus- pended. Upon doing this a very remarkable deception took place. As his hand passed along, it gradually became larger and larger, till it reached the middle, when it became enor- mously large. It then diminished till it reached the other end of the canvas. As the hand moved towards the middle of the picture, it touched parts of the picture more and more remote from the eye of the observer, and consequently the mind referred the hand and the’ object in contact with it to the same remote dis- ‘tance, and consequently gave it’ an’ apparent’ magnitude such 1 — * Mr Anderson on the Quartz District of Inverness. 9% as a body of its size would have had at the distance of the part of the picture which it covered. We have seen an analogous illusion when viewing the mo- saic pavement of St Paul’s from the inside of the cupola. The lozenges had a certain apparent magnitude when seen alone, which, of course, was small. When a person, however, pass- ed over the pavement, our knowledge of his size furnished us with a scale for measuring the real magnitude of the compart- ments in the pavement, and they accordingly increased in size, diminishing again when the person had passed from our view. Art. XVI.—On the Quartz District in the Neighbourhood of Inverness. (Concluded from Vol. III. page 218.) By ‘Grorck AnprErson, Esq. F. R.S.E., F.S.S. A. & Se- cretary to the Northern Institution for the Promotion of Science and Literature at Inverness. Communicated by the Author. Nor to interfere with the description of the characters of the Quartz-Rock, which was given in the last number of this Journal, I have reserved for this place a sketch of its geo- graphical distribution, together with a few other detached no- tices, which may now be brought forward without i injuring the order of the previous details. If we were to describe on a map the space which the quartz rock occupies, its lines of boundary would appear to almost meet at a point. This is the eastern extremity of the depo- sit ; the quartz-rock lying between the granite and the strati- fied sandstone, and assuming a general form that may be just- ly called wedge-shaped. Towards the west and north the quartz rock is extended far and wide, and is variously blended with strata of gneiss. It cannot be said to observe the general bearing of our Scotch chains of mountains, and, indeed, - its. course seems to be transverse rather than parallel to the north-easterly direction of the great Caledonian Valley. The line of junction between the quartz and the granite, which is 80 precise and conspicuous in the rocks of Dun-Jardil, is lost 92 Mr Anderson on the Quartz District of Inverness, _ to the eastward in the narrow space (covered mostly with peat, and gravel) which intervenes between the hills of Balcharnoch, and the granite knolls of Stratherwick. This space is in some places diversified by a series of dark Alpine lakes, which: - extend close to the bounds of the stratified sandstone, and help to vary this otherwise bleak table-land. ___ To the west of Dun-Jardil, the same line can be traced with more distinctness. It is chiefly to be found in a ridge’ which rises close behind the cottage of Boleskin, and the Inn of Foyers, and in a hollow or gully at the south of this ridge, stretching from what is called the head of the pass of Inver- farakaig, towards the cataract of Foyers. Crossing the deep and winding chasm: through which this celebrated river ‘‘ pours down its mossy floods,” the limits and junctions of the quartz rocks and granite may. be obsery- ed among a series of nameless. mountains towards Su-Cuming, the former keeping always the side next Loch Ness, while the latter stretches away over a rugged plain towards the moun- tains of Badenoch. Near Whitbridge, the blue or grey quartz rock first comes to view, and, in union with gneiss, it characterizes the rest of. the country to Fort Augustus. Here several varieties of rock occur, but proceeding still westwards, we again find the quartz prevailing along the banks of Loch Oich, and aes Lochy. — On the south side of these lakes the quartz rock is associat- ed with mica-slate, from which it seems to have acquired a new modification of colour, and a silvery lustre, owing to the: increased commixture of scales of mica. The high-peaked mountains, however, on the north side of the last mentioned lake, called the mountains of Glengary, are almost entirely composed of the red compact quartz vind identical with that of Loch Ness. The same rock is also visible between Loch Lochy and the sea, and I need scarcely remark, that a variety of quartz’ rock ‘has often been described as extending far up Loch Eil.. | To return again to Loch Ness,—its northern shores are: lined with rocks, in which the red quartz.is the most preva- lent, but which jis, in several places, especially near the en-> 4 / anid on the Bituminous Rock of Ross-shire, &c. 93" trances of the Glens Urquhart and Morison, beautifully and - curiously intermixed with strata of gneiss. Nearer the lower end of the lake, the quartz, as already observed, seems to pass into'a small-grained granite, and, along the whole line, all the different kinds of rock are intersected by numerous beds and veins of crystallized hornblende, and large-sized granite. * In the upper part of Glen-Morison, I have met with a yel- lowish porphyritic granite, containing crystals of felspar up- wards of half an inch square, and forming one of the most beautiful rocks in this country ; while, near Inverness, I have noticed. a chain of hills falling into Loch-Beauly, ata farm called Phopachy, composed of a fine distinct red graphic. gra- nite. The quarts rock is not characterized by any suites of sim- ple minerals; the only included substance which I have no- ticed being limestone, and that chiefly in oe beds, near the house of Foyers. In Glen-Urquhart limestone is rather abiocidsnit but it is there contained in gneiss, and is rendered, in a great measure, unserviceable for agricultural purposes, by the quantity of asbestus, asbestous actynolite, and tremolite, which it con-— tains. Bronzite is pid to occur in the same quarter, but I have not been so fortunate as to fall in with it: I ‘have, howeyer, noticed large detached specimens of this substance on the banks of Loch-Arkeg. _ In Plate 1. Figs. 10 and 11, is given: a sketch of the north and south sides of Lochness. Art. XVII.—Description of the Bituminous Rock which oc- curs in Ross-shire, and the neighbourhood of Inverness, &c. By Grorce Anpexson, Esq. F. R.S. E., &e. Communi- cated by the Author. | Lyi the lase Number of; theEdinburgh Journal of Soiewce, I remarked, that the predominant varieties of the sandstone, * Quartz Fock occurs also i in many other districts of this and the neigh, bouring counties, but it would be out of place to trace all its boundaries in the present paper. , 94 Mr Anderson on the Bituminous Rock of Ross-shire. into which the quartz rock, that formed the subject of my) paper, passes, are the common old red sandstone, and a grey and very micaceous ‘sandstone, soft and extremely fissile. The simple minerals found in the sandstone are pyrites, green earth, or earthy chlorite, heavy spar, occasionally arragonite, and foliated celestine, together with large well-defined crystals of prismatic calcareous spar. . ' But, as I have hinted, (see page 217 of the last Number) the most.interesting association of the sandstone is with strata of a bituminous rock, hitherto but little noticed by geologists. By some it has been regarded and passed over as a subordi- nate variety of graywacke slate ; and it has been occasionally called a transition clay-slate, or a secondary shale. But its analysis, I understand, has not yet been given to the public ; and its relations to rocks, so high in the series as the - older sandstone, have not been thoroughly investigated. In the district now under consideration, the exact geological po- sition of this rock may be described as being immediately _ above the old red sandstone. It appears on the acclivities of the conglomorate range of hills, between the quartz rock and stratified sandstone, and hence another very important dis- tinction is afforded between these two rocks. If again we trace this bituminous rock along the course of the River Beauly, we shall find that it possesses similar rela- tions. In the valley of Strathpeffer, in Ross-shire, it is pro- bable that the mineral waters, so highly impregnated with sul- phuretted hydrogen in that neighbourhood, derive some of their properties from their passage through this interesting bituminous compound. I have lately also seen specimens of a similar bituminous rock, which was found associated with - the sandstone formations of Orkney, The external charae- ters-of the rock may be now described. It resembles the slate-clay, or bituminous shale of seconda- ry districts, in the loose and thin slaty mode of its arrange- ment, and in its tending to decompose into an iron-shot, or ochry clay. When fresh, however, it is heavier than slate- clay, and the structure, which in the large is slaty, is in the cross fracture uneven and conchoidal, with a glimmering lustre, derived from numerous minute scales of mica. Its streak is white or grey, and when smartly struck, (especially — 7 Mr Adam's Description of a Nautical Eye-Piece. 96 before it has been long exposed to the air) it emits a strong disagreeable smell. It also appears to contain particles of iron pyrites. In Ross-shire this is an abundant rock; but I have not found it about Inverness in beds of more than three or ee feet in thickness. These particular remarks are offered, from the considera- tion that the frequency of bitumen in the stony materials of the globe, is becoming more and more an object of interesting speculation. In the enumeration of the general substances containing this ingredient, as detailed by the Right Honourable George Knox, in his excellent paper on this ‘subject, which has been published in the Z'’ransactions of the Royal Society of London, no substance is mentioned which exactly corres- ponds to the rock, the characters of which I have described. The nearest approach to it is the occurrence (mentioned by him) of bitumen in mica-slate, and fetid quartz. . Arr. XVIII.—Description of an inverting Sextant Telescope with Nautical Lye-Tube, Jor taking Altitudes at Sea when the Horizon is Invisible. Invented by Mr Marruew Apam, A.M. Rector of the Academy of Inverness.* Com- municated by the Author. Tuts telescope, represented by AB, Plate I. (Fig. 12.) con- sists of three parts; viz. Ist, The eye-tube AE, to the lower side of which a spirit-level ka is attached by the the screws 0, p, passing through the extremities C, and D, of the frame of the level tube; 2d, The object tube FB, which is attached to the sextant by the screw at y; and, 3d, The middle, or connecting tube EF, represented separately by GH, (Fig. 13.) of which the part EH enters the object tube at F, and the _ part EG is screwed into the eye ttbe at E by means of the screw EK, and thus brings the small glass G into its proper * ™ This eye tube was executed under Mr Adam’s inspection in July 1825, by Mr Robinson, Mathematical Instrument Maker, at 38, Devon- shire Street, Portland Place, London. The dimensions of the telescope and level are reduced one-half in the annexed diagrams. — Sée this Journal, vol i. p. 179. aS i « 96 Mr \Adam on a Nautical Eye-Tube, for taking. place at 4, near the field of the telescope, The reduced vp meter of the part GK permits the upper side Al of the ley tube to enter 1-8th of an inch within the lower side of the eye ~ tube, and thus brings the bubble, seen directly through the eye glass at A, as near as. possible to the field of the tele- scope. In the centre of the field two cross hairs of silk inter- sect each other at right angles, the one horizontal and the other vertical ; and the point of their intersection is adjusted exactly into the line. of vision through the telescope by means of the serew nails,c, d, acting on the diaphragm, the edge of which, seen at ¢, is filed quite thin on the farther side, for the purpose of more easily admitting the direct light of a lamp through the aperture ad, to illuminate the cross hairs at night, hi, gr», and st, are rectangular apertures in the frame of the level tube, and ¢v is a reflector placed below. s¢ to illuminate the spirits, and to show more distinetly the sition of the bubble. The lines,4 and g, are painted. on the level tube at opposite extremities of the bubble, when it is in the middle and, as the level is applied so that the line / is placed at the focal distance of the eye glass, the eye end of the bubble can be distinctly seen at J; and at 1-8d of an inch on either side of it. When, therefore, kl, the upper side of the level tube is adjusted parallel to AB, the line of vision through the tele- ‘scope, if the e ye end of the bubble be observed, and kept at S; the line of vision AB must then be truly horizontal, or pa- rallel to the horizon, In order to take the altitudes at sea by a quadrant or sextant, furnished with. this telescope and level, which may be made capable of distinguishing 10’, the obser- ver should hold the sextant, as usual, in a vertical plane, pass- ing through the celestial object whose altitude is required, the telescope being horizontal, and. then bring the reflected image of the sun, moon, or star, into the field by the motion of the index on the limb of the instrument, which, after some ex; perience, he will generally be able to do upon the first or second ‘trial. When the celestial. object. is thus brought into the field, and the near end of the bubble seen at,f in the level tube, the observer should clamp the index on the limb, and,| by means of the tangent screw, while the near end of the bubble is kept at,f; bring the lower limb of the observed object to touch the horizontal hair passing through the centre of the Altituiles at Sea when the Horixon is invisible. 97% field; the required: altitude ‘of the lower limb of that object, affected only ‘by refraction, | will ‘then be round; ‘as ‘usual, on thé limb of the sextant. ‘Do enable the observer to keep the eye'end of the bubble at f till: the required contact is observed,’ a light mahogany rod, about 2} feet in length, attached ‘to the’ sextant »parallel to the telescope, is pressed against some fixed object on deck, which enables him gently to elevate or depress the telescope till: the bubble is brought into the required position, and kept there as'long as may be necessary. For this purpose, an iren staunchion, ‘about six feet in length, should ‘be made to screw, when required, into different parts of the deck near midship,. with a sliding projection, about’ two or three inches in length, which may be fixed by a finger-screw ‘at any required height,, so as to afford a convenient prop, against which the sextant rod may be pressed by the observer, when taking observa tions. To show the cross hairs, and the position of the bub- ble, when taking night observations, a small lamp, miade for this purpose, is applied to the right side of the eye'tube by means of a brass rod, fixed to the lamp, which ‘slides in a square socket, attached to the cylinder on the right of the holder of the telescope. The quantity of light thrown upon the bubble, and cross hairs, is easily increased or diminished by moving the lamp rod a little forward or backward in the socket. ‘I'he same lamp, when detached, enables the observ- er to read off his observations. The screw om, acting through the near end C_of the level frame, gives it its vertical adjustment ; and the two screws at p, acting horizontally against each other through the farther end D, give it its lateral adjustment. The accuracy of the vertical adjustment may be examined by comparing meridian altitudes of a celestial object, taken by means of the level; with those taken at, or nearly at, the same time, by means of an artificial horizon. « At sea, the accuracy of this adjust- ment may be examined by moving the index backwards, off the limb, as many minutes as are equal to the dip of the ho- rizon, and then observing whether the reflected horizon of the | sea is brought up to the horizontal hair in the centre of the field, when the eye end of the bubble is at fin the level per ? VOL, Iv. No. I. JAN. 1826. G 98 Mr Adam on a Nautical Eye-piece for taking if not, its distance + from it is equal to the error of the ver- tical adjustment, which may either be corrected by the screw, . or allowed for, like an index error of the sextant. To examine the lateral adjustment, screw the object ftibe _FB firmly into the sextant holder of the telescope by means of the screw at y, or fix it steadily, by other means, in a hori- zontal position, which is easily determined by the vertical ad- justment of the level. Move the united eye and middle tube a few degrees round in it to the right and left; and observe whether the bubble, formerly in the middle, now moves to either end of the level tube. If it does not, the lateral ad- justment is already made. If it does, correct the observed motion by means of the adjusting screws at p. If this ad- justment is not made, a slight deviation of the plane of the - sextant from the vertical plane, which the observer cannot de- ~ tect, when shut out from the horizon of the sea, may cause a considerable error in the observed altitude. To prevent this, let a plummet be suspended behind the plane of the sextant, which will readily detect any deviation of the instrument from the vertical plane. If EH, the middle tube of the telescope, be moved forward or backward in the object tube FB, so as to place the object glass a little too near, or too far from the cross hairs in the _ centre of the field, the image of the observed object may thus be brought nearer to or farther from the eye than the intersec- tion of these cross hairs, without causing any apparent indis- tinctness of the image. In this case, when the eye is slightly elevated or depressed, it will cause the contact of the 1 image with the horizontal hair to appear either too close or too open, and may thereby cause an error of one or more minutes in the observation, according to the distance of the image on either side of the cross hairs. . To avoid this source of error, care must be abe to mark on the middle tube EH a line « @, to which the middle tube should be moved, so that the image of a celestial object may be formed exactly at the cross hairs; for then, any elevation or depression of the eye will cause no sensible change of the _ apparent contact of the limb of the image with the horizont- al haw, The proper distance of the object glass is a constant. & ~< 28 Altitudes at Sea when the Horizon is Invisible. 99 quantity for all celestial objects, but it varies with the dis- tance of terrestial objects. As considerable care and applica- _ tion are necessary, in order to acquire correctness and facili- ,, ty in the practice of this method of observation, it will be pro- sper, when practicable, that the observer should accustom - himself to take observations by this method on shore, before he proceeds to sea. ) Matrurw ApAM. Inverness AcapEmy, 19th Nov. 1825. N. B.—The nautical eye tube, formerly tried at sea by Mr Adam, being more complex in its construction, was less easi- ly used, and at the same time less susceptible of accuracy, than the one above described. Yet, upon reference to a list of 199 altitudes of the sun, moon, and stars, taken with it by Mr Adam on board H. M. sloop Clio, in the North Sea, in October 1823, it appears that the mean difference of these al- titudes, taken by the eye tube, from those taken at the same time, in the ordinary way, by the officers of the Clio, was less than one minute and a half. | Several of the eye tubes, above described, are now about to be tried under the direction of the Board of Longitude, and four of them, with four new sextants, have been ordered by the committee of shipping of the Hon. the East India Company, for trial on board the first four of their ships pro- ceeding to the East Indies. . Mr. A. has applied a similar telescope and level to the pocket sextant, for the purpose of taking the vertical angles required in surveying, and of thereby dispensing with the use * of a theodolite for that purpose. Art. XIX.—On the Optical Illusion of the Conversion of Cameos into Intaglios, and of Intaglios into Cameos, with an Account of other Analogous Phenomena. ‘Tue remarkable phenomena to which, we propose at present to direct the, attention of our readers, while they possess all the interest which belongs to them as physical facts, have at- 100°.) On the Optical Illusion of the tached to them another kind of interest, not less deserving of attention. To those who are in the practice of exercising a presumptuous confidence in their own judgments, and who — trust in the indications of their senses as infallible guides, we would recommend the particular study of this class of ‘deceptions. They will here find their judgments deluded, where every thing is favourable to the discovery of the truth ; and even when they are aware. of. the source of the deception, they will find themselves again brought under its dominion, and again released from it, by the opera- tion of the most trivial circumstances which they are not - able’ to discover, and the influence of which, if they do discover them, they are not able to appreciate. Tf all this takes place in matters of simple observation, where the senses of sight and of touch are allowed their undisturbed exercise, how much more liable must they be to error, where their pas- sions, their prejudices, or their feelings, concur in promoting ‘the delusion, or even in any remote degree prepare the mind for its reception. The class of deceptions to which we allude, were, so far as we know, first noticed at one of the early meetings of the Royal Society of London, when a compound microscope, on a new construction, was exhibited. "When the members were looking through i itata guinea, some of them saw the head up- on the.coin depressed, while others considered it to be raised, as it was in reality. This deception was studied by Dr Philip Frederick Gmelin of Wurtemburg, who communicated the following observa- tions upon it to the Royal Society of London in 1744. “‘ Being informed by a friend, says he, that if a common seal was applied to the focus of a compound microscope, or opti- cal tube, which has two or- three convex or plano-convex lenses, that’ part which is cut the deepest in it would ap- pear very convex, and so on the contrary ; and that some- times, but very seldom it would appear in the same state as to the naked eye. I was desirous to make the observation _ myself, and found it constantly to happen as my friend told me. I thought the experiment worthy of being farther pro- _ secuted ; and, accordingly, on the 16th of last April, the Conversion of Cameos into Intaglios, &. 101 morning not being very clear, but in a pretty light cham. ber, I viewed a watch hanging against a plain wall, through the optical tube; the whole of it appeared concave, and fixed into the wall.. I also observed some flies that were running about the wall, and they appeared in like man- ner. I also viewed a small globe of a thermometer filled with red spirit, and this also seemed hollow, and fixed within the frame. I found the same to happen with the round parts of _garments of all colours, and with the brazen protuberances of a small cabinet ; all which appeared concave, and deeply sunk into the cloth and wood. I also viewed a small stag’s head, cut in wood, and hanging horizontally on the wall; this also appeared concave, and fixed into the wall. After this, I observed a ball of one of Fahrenheit’s ther. mometers, full of quicksilver : but it did not change its natural convexity ; nor did the empty glass ball of the mverted ther- mometer hanging against the wall, though the lower ball of the samie, filled with red spirit, and that also of Fahrenheit’s, filled with spirit, lost their convexity. Hence, I presently con- cluded, that white or shining uncoloured bodies, appear under the focus of this tube in the same manner as they appear to the naked eye; at the same time, I must fairly acknowledge, that an assisting friend has sometimes made observations di- rectly opposite to mine in the same circumstances ; nay, in & darker day, I myself have found my observations quite contrary to those I had made the day before. Hence, though the obser- vations with the seal held constantly the same, I imagined there must be some particular circumstances hitherto undis- covered, in which these objects appeared thus perverted. — T _ therefore endeavoured to discover some certain laws, accord- ing to which these perverted objects appeared when ‘exposed to these foci, and some others according to which they con- stantly. appeared as when they were exposed to the naked eye. After various experiments, I partly obtained my end. As often ‘as I viewed any object, rising upon a plane, of what colour soever, provided it was neither white nor shining, with the eye and optical tube directly opposite to it, the ele- vated parts appeared depressed, and the depressed parts ele- vated, as it’happened in the seal, as. often as I held the tube 102 » On the Optical IMlusion of the perpendicularly, and brought it in such a manner, that its whole surface almost covered the last glass of the: tube; and in like manner it happened under the compound microscope. But as often as I viewed any of the other objects depending perpendicularly from a perpendicular plane, in such a manner | that the tube was supported in a horizontal situation directly opposite to it, the same always happened, and the appearance was not altered, when the object hung obliquely or even hori- zontally, 1 was mightily delighted with the observation of a tobacco-pipe, which had a porcelain bowl of a snowy whiteness, and a tube of horn almost black, and hung obliquely from a beam ; the bowl preserved its natural convexity, and the tube _ was deeply sunk, and seemed to be almost immersed in the wall. I also observed, that when I placed the watch horizon- tally upon a horizontal plane, and then looked on it perpendi- cularly, near the window, it no longer appeared so depressed, and surrounded with a shady ring ; whence I began to suspect, that all those fallacies were owing to shade, just as painters can elevate or depress a figure, by making the ground lighter or deeper. ‘Thus, when the raised. object was so placed between the windows, that it must be illwminated on ail sides, it did not change its convexity. But at last I discovered a method of making objects always appear with their natural convexity. If any object hung against a wall, or was contiguous to it in any situation whatsoever, I viewed sideways, in such a man- ner as not to oppose the tube directly against it, but below the eminence near the plain at some distance. By those means, the protuberance of the instrument and other objects always appeared to me of their true natural convexity, With regard to the seal, I held it in such.a manner, that the whole cireum- ference was perpendicular, or rather a little inclined. Then I applied the lower side of the tube exactly to the upper margin of the disc of the seal, so that the tube formed an obtuse an- gle with the seal; then, carefully preserving the same situa- tion, I very gently raised the tube from the rim of the seal: upon its face; and then I always saw the seal with its true na- tural face, But why all these things happen exactly after the same manner, I do not pretend to determine; nor why white, or uncoloured transparent bodies, rising in any manner above Conversion of Cameos into Intaglos, &. 108 any plain, afford an exception from that rule‘of vision, and do not appear depressed when viewed after the method above mentioned.” In the year 1780, this subject occupied the attention of David Rittenhouse, president of the American Philosophical Society, who gave a correct explanation of the illusion, by referring it to the inversion of the shadow by the eye-tube. He employed in his observations an eye-piece, having two lenses placed at a distance greater than the sum of their focal — distances; and by throwing a reflected light on the cavities observed, in a direction opposite to that of the light, which came from his window, he was able to see them raised into elevations, by looking through a tube without any lenses. Mr Rittenhouse also observed, that, by putting his finger into the _ cavity, the illusion ceased to take place. Having thus given a brief detail of the experiments of Gmelin and Rittenhouse, we shall proceed to explain more mi- nutely the principles on which this illusion depends. _ It will afterwards be seen, that inverting telescopes and mi- _ eroscopes are not necessary to the production of this illusion ; but it may be best seen by viewing with the eye-piece of an ach- romatic telescope the engraving upon a seal, when illuminated. either by a candle or the window of an apartment. This eye- piece inverts the objects to which it is applied like the compound microscope, and the excavations or depressions of the seal are immediately raised up into elevations like a cameo, or a bas- relief. The cause of this illusion will be understood from Plate I. Fig. 14, where A represents a spherical cavity illu- minated by a candle C. The shadow of the cavity will of course be on the left side S, and, therefore, if we view it through an inverting eye-piece or microscope, the cavity will be seen as at A, Fig. 15, with its shadow on the right hand S of the cavity. As the candle C remains where it was, the observer instantly concludes, that what was formerly a cavity, must now be a spherical elevation or segment of a sphere, as nothing but a raised body could have its shadow on the right hand 8. If a second candle is now placed on the right hand side of A, so that it is between two candles, and is equally il. 104° Om the ‘Optical [lhusion of the’ — by both, the elevation’ will again sink into a mide asin’ Fi ig. 16. ¢ If the object A, in place of beitiy a cavity, is actually the raised segment of a solid sphere, the same phenomena will be observed, the inverting eye-piece converting it into a cavity. These two experiments may be made most successfully with a seal, and:an impression taken from it. It cannot therefore be doubted, that the optical illusion of the conversion of a cameo into an intaglio, and of an intaglio mto a cameo; by an inverting eye-piece, is the result of an operation of our own minds, whereby we judge of the forms of bodies by the knowledge we have acquired of light and shadow. The greater our knowledge ‘is, of this subject, the more’ readily does the illusion seize upon us; while, if we are but imperfectly acquainted with the effects of light and shadow, the more difficult is it to be deceived. If the hollow is not polished, but ground, and the surface round and of uniform colour and smoothness, almost: every ‘person, whether young or old, will be subject to the illusion; but if ~ the object is the raised impression of a seal: upon wax, we have often found that, when viewed with the eye-piece, it still seemed raised tothe three youngest of six persons, while the three eldest were subject to the deception. By such trifling, and often wnappreciable circumstances, is our judgment. afs fected, that the same person at one moment sees the convexis ty raised, and at ‘another time depressed, though viewed as nearly as: possible under the same circumstances. This res markable effect no doubt arises from the introduction of sonie casual reflected lights, which the slightest change of thn will produce. Having thus seen how our judgment concerning olidigatile and depressions is affected by our degree of knowledge of the effects of light and shade, and by unappreciable causes, we shall proceed to consider how our judgment is again doesnt by the introduction of new circumstances. 7 s5tid Let the’ depression A, illuminated by one candle, as /in Fig. 14, be converted into an elevation as in Fig. 15, by the application of an inverting eye-piece ; then, if another candle C’, Fig. 16, is is introduced ‘so as to illuminate the depression & Conversion of Cameos into, Intaglios, &. 105) A in the same manner, and with nearly the same intensity ag C does, the elevation will fall down into a depression. The cause of this is obvious: the application of the inverting eye- piece produces no effect whatever, for both the sides of the cavity are symmetrically illuminated. In moving round the second candle C’ from its position C’,’so as to stand beside C, it is curious to observe the progress of the deception by which the depression is again changed into an elevation. » If, when the depression A, Fig..17, is conyerted into an elevation, we introduce a small unpolished opaque body M, and place it either beside the hollow or in it, so that the body _ M, and its shadow m, may be distinctly seen by the micro- scope, we shall have the appearance shown in Fig. 18, the elevation having sunk into a depression. This correction of the deception arises ftom the introduction.of a new illusion, namely, that which arises from the shadow m; for it is evi- dent, that, as the body M appears to project its shadow in the direction Mm, the luminous body must be supposed to be on the same side D ; and the evidence that this is the case, is more powerful than our knowledge that the candle is actually at C, because it co-exists along with our perception of the depres- sion A, whereas our knowledge of the situation of the candle is an act of recollection. " This correction of the delusion may be effected in another manner, which is perhaps more complete. _ If, in place of the unpolished body. we use a pin with a highly polished head, as shown at M, Fig. 19, and then apply. the imverting eye, piece, we shall have the effect shown in Fig. 20, the cavity A. appearing depressed. The image s of the candle C being seen by reflection in the polished head of the pin M, is seen by the application of the eye-piece at s, on the right hand side of M: in Fig. 20, so that we immediately’ conceive, in opposition to our previous knowledge, that the candle must be at D; and hence the elevation falls into a depression the moment the pin head is pushed up into the field of view. The shadow Mm has also its influence in the present case. ‘The next case in which this illusion is dispelled, is, when the sense of touch corrects the deduction formed through the medium of sight. Let the cavity A be raised into an eleva- ~ 106 » On the Optical Tusion of the tion by the inverting eye-piece, as in Fig. 15. Then, if the cavity is sufficiently deep, and if we place the point.of our finger in the cavity, the evidence which this gives us of its being a depression, is superior to the evidence of its being a cavity arising from the inversion of the shadow ; the apparent elevation will of course sink into a depression ; but the mo- ment the finger is withdrawn, it will again rise into an eleva- tion. If the cavity is a long groove, the part not touched by the finger will appear elevated, while the part touched by it will appear depressed ! Having thus considered some of the principal phenomena arising from the inversion of the object, we shall now proceed to explain some analogous facts which are owing to the semi- transparency of the body. If MN, Fig. 21, is a plate of _ mother-of-pearl, and A a cavity ground or turned in it ; then if this cavity is illuminated by a candle C, or by a window at C, in place of" there being a shadow at the side s, as there would have been had the body been opaque, there is # quan= tity of refracted light seen along the whole. side s; next the: candle. The consequence of this is, that the cavityrappears: as an elevation when seen only by the naked eye, as it is only» an elevated surface that could have the side s illuminated. The fact which we have now stated, is, we think, @ very im- portant one, in so far as it may affect the labours of the sculptor. In some kinds of marble, the transparency is so great, that the depressions and elevations in the human face cannot be represented by it with any degree of accuracy ; and, ‘consequently, transparent marble ought never to be used for works of any importance. ' ‘Illusions arising from the same cause may be obpiaiigal even when the surface of the object is perfectly plain and smooth. If MN, Fig. 22, is the surface of a mahogany table, M Nm a section of it, and abc a section of a knot in the wood, then it often happens, from the. transparency of the thin edge at a, next the candle, that that side is illuminated while the opposite side at ¢ is dark, the eye being placed in the plane of the section abc. The consequence of this is, that the spot abc appears to be a hollow in the table. Henee arises the appearance in certain plates of agate, ee et Conversion of Cameos into Intaglios, &c. 107 which has obtained for it the name of hammered agate. The surface on which these cavities appears, is a section of small spherical aggregations of siliceous matter like abc in Fig. 22, which present exactly the same phenomenon, aris- ing from the same cause as the knots in mahogany and other woods. ; | The very same phenomenon is often seen in mother-of- pearl. Indeed, it is so common in this substance, that it is almost impossible to find a mother-of-pearl counter which seems to have its surfaces Hat, although they are perfectly so when examined by the touch. Owing to the refraction of the light by the different growths of the shell lying in different planes, the flattest surface seems to be inequal and undulating. ? One of the finest deceptions which we have ever met with, arising from the disposition of light and shadow, presented itself on viewing through a telescope the surface of a grow- ing field of corn, illuminated by the sun when near the hori- zon. This field, on Sir Walter Scott’s estate at Abbotsford, was about two miles distant, and was divided into furrows, which were directed to the eye of the observer, as shown in Fig. 23, where AB, C D, EF, represent the furrows. These furrows are of course depressed, and the growing corn. rises gradually from two adjacent ones towards the middle mn, op, so that the surfaces A mC, CoE were convex. The drills of corn on the highest summits mn, op, caught the rays of the setting sun, which shone upon them very oblique- ly in the direction S s, and illuminated their summits laterally, while the furrows A B, CD, EF, were in shadow. The consequence of this disposition of the light and shade was, that the whole field seemed to be trenched, and the corn to be growing in the trenches as well as upon the clevated beds between them. The half furrow A Bn m being shaded on its edge AB, and illuminated on its edge mn, became the elevated part of the trenched ground, while the other half mnCD appeared the sunk part, in consequence of the side mn being illuminated, and its other side CD in shade. Ata certain period of the day, this deception did not take place, and it was dispelled the moment the sun had set. This very 108 - Mr Magnus’s Analysis of Picrosmine. singular illusion we have seen on several days in J uly. ‘The telescope had no effect. whatever. in n (producing it, as it “ objects erect. An illusion of an analogous nature we once observed whieh looking at the Abbey Church of Paisley, where the clustered columns of a Gothic pillar all sunk into hollow flutings. ‘The cause of this deception was not discovered, but it must have arisen from some mistaken notion respecting the direction in which the object was illuminated. ‘The last species of illusion of this nature, and perhaps the most remarkable of all of them, may be, produced: by a:con-. tinued effort of the mind to deceive itself. If we take one of the intaglio moulds used for making the bas-reliefs) of that able artist Mr Henning, and direct the eye to it steadily with- out noticing surrounding objects, we. may coax ourselves into the belief that the intaglio is actually a bas-relief. It is diffi- cult at first to produce the deception, but a little awe 8 never fails to accomplish it. pects ‘We have succeeded in carrying this decdtiben idar; as to be able, by the eye alone, to raise a complete hollow mask of the human face into a projecting head. In order to-do this, we ‘must exclude the. vision of other objects ; and also the margin or thickness of the cast. This experi- ment cannot fail to produce a very great degree of surprise — in those who succeed in it; and it will no’ doubt be re- garded by the sculptor who can use it as a great auxiliary in his art. ; D. B. Art. XX.—Analysis of Picrosmine. By Gustavus Mac- nus, Esq. of Berlin. Communicated by the Author. A pescrietion of this mineral, which was first ascertained by Mr Haidinger to form a distinct species, is contained in the T'reatise on Mineralogy by Professor Mohs,* and in a former Number of this Jowrnal.t The description was ff si * Grundriss der Mineralogie, Th. ii. English Translation, vol. iii: p.137. : ce ti ; t See vol. ii. ‘p. 376, April 1825. fi Mr Magnus’s Analysis Of Picrosmiine.' 109 taken from the same specimen, part of which I subjected to analysis. | When exposed alone to the heat of the blow-pipe, it is in- fusible, but it assumes a much higher degree of hardness... In the mattrass, its colour first becomes black, then white again, and it gives off water. With solution of cobalt, it gives a rose-red colour, indicative of magnesia. Salt of phosphorus and borax dissolve it ; a skeleton of silica being visible in the former. If the mineral has been previously heated to red- ness, it is almost insoluble. Treated with soda or charcoal, it forms a half-vitrified mass, which is not transparent. In order to ascertain the composition of picrosmine, 2.144 grammes, reduced to an impalpable powder, and carefully washed, were exposed in a platina crucible to the action of fuming dilute fluoric acid. The mineral was decomposed, and so much of caloric disengaged, that the fluid mass began to boil. While it cooled, it was now and then stirred with a small platina spoon, then some distilled sulphuric acid was added, and’ the whole carefully evaporated to dryness, and exposed to a slight red heat, in order to remove the fluo- silicic and the superfluous sulphuric acids. What remained was dissolved in water; a small insoluble residue was left, probably of silica, but it could not be ascer- tained, whether it still contained a portion of the undecom- posed substance, becanse there was too little of it. It might have been supposed that it was sulphate of lime, but some other experiments, afterwards to be mentioned, leave no doubt that the mineral does not contain a trace of lime; and I am+therefore inclined to consider it as produced by the decomposition, at a higher temperature, of some of the sul- phates of alumina or iron. Pure ammonia, added to the clear solution, produced a precipitate of alumina, oxide of iron, and a little manganese. and magnesia. The filtered fluid, which ,still contained the greater part of the magnesia and of the manganese, yielded no precipitate with oxalate of ammonia, and therefore did not _ contain any lime. It was evaporated to dryness, and then ignited, to drive off the remaining sulphate of ammonia, and redissolved in a small quantity of water. 110 Mr Magnus’s Analysis of Picrosmine. ‘The precipitate, produced by ammonia, when dried and ig- nited, weighed 0.096 gr. or 4.477 per cent. It was dissolved in muriatic acid, and then digested with an excess of pure po- tash, in order to separate the soluble alumine from the inso- Atte uses of tein. aail manganese, and the magnesia. The alkaline solution of alumina, was rendered acid by muriatic ~ acid, and the alumina afterwards precipitated by carbonate of ammonia. It weighed 0.017 gr. or 0.792 per cent. | What had been precipitated by the potash, was dissolved in muriatic acid, exactly neutralized with pure ammonia, and the iron precipitated by means of succinate of ammonia, The succinate of iron, after being well washed, was decomposed on the filter with dilute caustic ammonia, in order to remove the greater part of the acid. The oxide of iron, dried and ignited, weighed 0.030 gr., equal to 1.399 per cent. ~“. The liquid, from which the succinate of iron had been se- parated, as it did not contain any other substances but mag- nesia and manganese, was evaporated ; the residue, completely dried and ignited, in order to drive off the volatile salts of am- monia, then dissolved in water, and added to the fluid obtain- ed above, which likewise contained only magnesia and manga- nese. The whole was neutralized with ammonia, and hydro- sulphuret of ammonia was added to it, to precipitate the man- ganese. Ignited, it weighed 0. 010 gr., and as these may be considered as a combination of the peroxide with the protoxide of manganese, the proportion of sulphuret of manganese being very small, there can be no perceptible error in supposing them equal to 0.009 gr. of protoxide of manganese, or 0.420 my cent. From the liquid still left all the hydro-sulphuret of am- monia was evaporated, and the sulphur separated by filtration. The remainder was dried and. ignited, in order to get rid of the sal ammoniac ; then redissolved in a small quantity of water, and a few drops of sulphuric acid added. 'Vhe sulphate of magnesia, thus obtained, after being dried and exposed to a ~ slight red heat, weighed 8.098 gr., corresponding ner gr., or 33.848 per cent. of magnesia. In order to obtain any potash or soda srhich might have been united to the latter substance, it was dissolved in water, Mr Magnus’s Analysis of Picrosmine. il and acetate of baryta added, so long as any precipitate appear- ed. The sulphate of baryta was separated, and the remain. ing acetate of magnesia, along with the superabundant acetate of baryta, evaporated to dryness and ignited. .The acetates _ having thus been transformed into carbonates, those of soda or potash should have been contained in the water with which they were digested ; but this, having been again evaporated, did leave only a slight residue, which proved likewise to be magnesia, since it was soluble in muriatic acid, from which it was precipitated by ammonia. The mineral, therefore, does not contain either soda or potash. The quantity of silica was ascertained by the usual process. A quantity of 0.982 gr. of the mineral, carefully prepared by grinding and washing, and mixed with three or four times its weight of carbonate of soda, was melted in a platina crucible, the mass dissolved in water, and muriatic acid added, as long as there yet appeared any effervescence. ‘The fluid was eva- porated, the residue well dried, and then redissolved in water, with a few drops of muriatic acid. The silica obtained weigh- ed 0.539 gr., which corresponds to 54.886 per cent. of the mineral. The remaining liquid gave, with pure ammonia, a precipitate, which after ignition, weighed 0.047 or 4.786 per cent. Not a trace of lime could be detected by oxalate of am- monia. ‘The quantity of water I ascertained, by exposing the mineral, in the state of powder, to the strongest heat that can be produced by means of the spirit-lamp, with double air cur- rent. Two experiments gave the following results :— 0.740 gr. lost 0.0575 gr. equal to 7.76 per cent. 0.453 gr. lost 0.031 gr. equal to 6.843 per cent. the average of which, 7.301, gives pretty nearly the contents of volatile ingredients. They consist chiefly of water, with a slight alkaline action on litmus paper, owing probably to an inconsiderable portion of ammonia produced by the decompo- sition of that substance, which gives the black colour to the mineral when heated; a phenomenon which has been very generally observed in minerals containing magnesia. I pos- - sessed too small a quantity of the mineral to collect the water 119 My Magtitis's Analysis of Picrosmine, obtained by ignition, and to determine immediately its ratio to. thé other ingredients ; nor could I, for the same reason, deter. mine the loss which the mineral migihh sustain ina higher de- gree of incandescence. % ‘The following table shows the results of the tie a -Silica, - -)+ = = 64,886! containing oxygen 28.389 Magnesia, - + ‘= 33.348 12.909 Alumina, - > - 0.792 - 0.367 Peroxide of iron, - -.. 1.899 _ 0.429 Protoxide of Manganese, 0.420 0.092 Water... 4) + = G0" 6.490 ; 98.146 The oxygen contained in all the bases together, is 13,797, nearly equal to half the quantity of oxygen in the silica ; pi- crosmine, therefore, appears to be a bisilicate of magnesia. I must observe here, however, that I do not consider the speci- men subjected to analysis as entirely pure, since it contained throughout its mass small brown dendritic specks, from which, perhaps, may originate the oxide of iron and the alumina in the analysis, for it is not likely that so small a quantity of a substance not isomorphous with the rest of the bases, should form an essential ingredient in the composition of the mineral. - The brown colour of the intermixed substance induced me’ to consider the iron to be contained in the mineral as peroxide and not as protoxide. But I believe the manganese to be con- tained in it as a protoxide; because it is thus very frequently found along with magnesia, with which it is isomorphous, and with which it also agrees in many of its chemical properties, The mineralogical formula, in the method of Berzelius, in re- ference to the solid ingredients, will be zal S2, or if we ne- glect the small quantity of manganese, it will be A/S”. If we consider all the volatile ingredients as water, their contents of ozygen, equal to 6.49 will form exactly one-half of 12.999, which is the quantity of oxygen in the bases, ex- eluding the oxide of iron and the alumina as accidental ingre- dients. The formula of the whole is then transformed into 2MS? + Aq. 11 Dr Turner on the Means of Detecting Lithia, &c. 118 Ant. XKI—On the Means of Detecting Lithia in Minerals by the Blowpipe.* By Kowanv, Turner, M.D. F.R.S. E. &c. Lecturer on Chemistry, and Fellow of the. Royal Col- J lege of Physicians, Edinburgh. Communicated by the Author. Ax the conclusion of a paper on Mica, published in the last number of the Kdinburgh Journal of Science, 1 have made some obseryations on the colour communicated to the flame of a candle by the three alkalies, potash, soda, and lithia, by means. of which they might be readily distinguished from each other. It seemed probable, from some facts there stated, that a body must be fluid, in order to communicate its cha- racteristic colour to flame; and this idea became more plau- sible from the consideration, that the lithion-micas fuse readily, and then tinge the flame red, while some other mine- rals which do not produce that effect, though they contain lithia in considerable quantity, are very difficult of fusion. Hence it occurred to me, that the last description of minerals might also be made to redden flame, could we by any means increase their fusibility ; and the following observation is in support of this notion. A minute particle of spodumene, previously reduced to fine powder, and made intoa paste with water, was exposed to the flame of the blowpipe. For a time the mineral did not fuse, nor was a trace of redness visible ; but, by urging the heat, fusion did-at length occur, and at » that instant the flame was tinged of a red colour, though in a slight degree. On mixing the same mineral with fluor-spar, its fusibility was considerably increased, and it gave a more distinct red hue to the flame. But though the liquid form is favourable to the communi- cation of colour to flame, it is not always an essential eondi- tion. Thus, the carbonate of copper tinges the flame of a candle green without fusing ;- and if the carbonate of strontia be strongly heated. before, the blowpipe, it phosphoresces re- markably, and yields a red colour to the flame, though the assay remains perfectly solid. Nor does a body cause its pe- -* Read before the Royal Society of Edinburgh on the 5th December 1825- VOL. Iv- NO. I. JAN. 1826. H 114 Dr Turner on the Means of Detecting culiar colour to appear from the mere circumstance of becom- ing fluid. Spodumene, for example, can bé made to fuse ‘by the addition of the carbonate of soda or potash, but rid red- ness occurs. Fusion is rendered still more perfect by the ac- tion of boracic acid, or the phosphate of soda and ammonia, but without a trace of redness being visible. These facts prove that a certain chemical condition of a body is necessary, in order that it should produce its effect on flame, and that this cireumstance has a greater influence than form. From the action of fluor-spar on spodumene, I was de- sitous of trying the effect of free fluoric acid on that mineral. _ It was accordingly mixed with some of the bifluate of potash, and a little of the mixture, made into a paste with a drop of water, was exposed by means of platiitim wire to the flame of the blowpipe: It fused very easily, and emitted a brilliant red flame, far more distinct than that occasioned by the fluate - of lime. To vary the experiment still further, a mixture was made, composed of fluate of lime and bi-sulphate of potash in atomic proportion; that is, one part of the former to about four and a half of the latter. When this flux was mixed with an. equal quantity of powdered spodumene, the effect was, if any thing, still greater than in the previous instance. Both these fluxes appear to act by giving out fluoric acid at a high temperature, which destroys the composition of the mineral by combining with the silica and setting the lithia free. The latter flux is more effectual than the former, becausé it re- quires a stronger heat before yielding fluoric acid, and heti¢e the disengagement takes place under the most favourable éir- cumstances. It should therefore be preferred in practice. - In performing these experiments, it is important to kéep in view the action of the flux itself on flame. Those that have been just recommended communicate a faint lilac colour, ow- ing to the presence of potash, which cannot be mistaken for the.action of lithia by any one who compares both effects to- gether, as I shall immediately demonstrate to thé. society. But in case any doubt should arise, it is easy to avoid the dif- ficulty by employing a flux that contains no potash: | Such a one may be made by mixing one part of the fluate of lime with one and a half of the sulphate of ammonia. This mix- Il Lithia in Minerals by the Blowpipe. 115 ture acts on spodumene in the same way as the preceding, and, doubtless, from the same cause. It communicates a pale-blueish green colour to the flame at the first moment, and before fusion occurs,—a property possessed by several of the salts of ammonia; but there is no appearance that can be mis- taken for the red colour of lithia. When petalite is heated alone before the blowpipe, it yields no trace of redness; but if subjected to the process just recommended, it affords abundant evidence of the presence of lithia. Indeed, from the great affinity of fluoric acid for sili- ca, it is obvious that no ‘siliceous mineral can withstand its action; and there can be almost as little doubt that the pre- sence of lithia may be detected in any such compound by the - process which is so successful with spodumene and petalite. _ The advantage of possessing an easy and expeditious me- thod of ascertaining the presence of lithia in mineral bodies, is twofold. In the first place, the mineralogist and. chemist possesses a test for spodumene and petalite, from the want of which other minerals have sometimes been mistaken for them, and the error only discovered at the close of a tedious chemi- ‘cal process. Secondly, we obtam a method of ascertaining the presence or absence of lithia in other minerals. I have examined a considerable number of substances with this view, but have not hitherto been successful. As several of the salts of strontia and lime possess the pro- perty of communicating a red colour to flame, it is natural to inquire, whether the presence of those earths in a mineral might not give rise to fallacy; and I have, accordingly, studied the subject with care. Though there is little danger of mistaking a native carbonate or sulphate of strontia for a siliceous mineral containing lithia, it may not be superfluous to mention the characters they exhibit before the blowpipe. When a particle of strontianite, powdered and made into a paste as usual, is exposed on platinum wire to the blow- pipe flame, it communicates a yellowish colour to it. By con- tinuing the blast for a little time, phosphorescence commen- ces, and soon afterwards a red colour makes its appearance. This latter effect depends on the expulsion of carbonic acid ; for no redness is visible till the phosphorescence sets in, and 116 =“Dr Turner on the Means of Detecting, &. then the assay gives a strong brown stain to moistened tur- meric paper. ‘The property of strontianite in colouring flame is lessenéd by mixing it with the flux. When celestine is ex- posed in like manner, no redness appears at first; but if a strong heat be kept up for a minute or two, the salt is de- composed, phosphorescence commences, followed by a red hue, and the assay is found to be alkaline. ‘This change is facilitated by mixing the celestine with the flux of ‘bisulphate of potash and fluor-spar. Complete fusion then occurs, though without the least trace of a red colour; but, on con- tinuing the blast, the assay gradually becomes solid, and then the strontia is speedily reduced to the caustic state. I have been thus particular in describing these appearances, because they afford us a useful test to distinguish the native salts of strontia from those of baryta ; while they cannot be confound- ed with the effects produced by lithia. | The carbonate and sulphate of lime give rise to the same phenomena, though their effect is less distinct ; and the colour, as in the case of strontia, does not appear till the lime is re- duced to its caustic condition. I have examined a consider- able number of siliceous minerals containing lune, in some of which, as datolite and apophyllite, that earth is present in a large proportion ; but none of them, whether alone, or with flux, give a red colour to the flame of the blowpipe. It is probable, from this fact, that strontia, did it chance to occur in a’ siliceous mineral, would likewise be inert; or if it did redden the flame, it would be under circumstances which would distinguish it from the action of lithia. For the strontia would be converted into a sulphate by the flux, and could not produce its effect till that salt was decomposed. It is very desirable that the presence of potash and soda in minerals could also be discovered by the blowpipe. | The pale lilac produced by potash, though it enables a salt of that alkali to be readily distinguished from the salts of soda or -lithia, is too faint for affording a test of its presence in mine- rals, unless it exists.in considerable quantity. ‘The property soda possesses of communicating a yellowish colour, and of making the flame larger at the same time, may be turned to ‘some advantage ; for several minerals that contain soda act on the blowpipe flame in the same manner as soda itself, from Dr Wollaston on the Apparent Direction of Eyes, &. 1% which we maybe led to infer the presence of that alkali in them. This has been observed in sodalite, analcime, chabasie, albite, pitchstone, and several others. Unfortunately, how- ever, a yellowish colour may be produced by other substances besides soda, so that it is a test which cannot altogether be relied on with certainty. Thus, a similar effect is occasioned, though in a less degree, by the fluate of lime, and, perhaps, by lime under other circumstances. However this may be, it is cer- tain that many minerals that contain soda give a very distinct yellow colour to flame; it is a circumstance, therefore, which may be useful to the chemist and mineralogist, and as such I mention it. I beg leave to observe, in conclusion, that experiments on the colour communicated to flame should be performed with a tallow candle, the colour of which is better fitted for the pur- pose than that of a spirit-lamp. Arr. XXII.—On the Apparent Direction of Eyes in a Por- trait. By W. H. Wottasron, M. D. F. R. S. and V. P- With a Plate. Tus very curious paper of Dr Wollaston’s, of which we pro- pose to give a brief abstract, appeared in the Philosophical ‘Transactions for 1824. As it is one of those scientific papers which may be easily comprehended by general readers, we could have wished to transfer the whole of it to our pages; but it is partly illustrated with engravings on steel by Mr Perkins, which cannot be copied, and we are, therefore, oblig- ed to confine ourselves to an abstract of the most popular and interesting part of it. In examining the eyes of a person opposite to us, who looks horizontally within.a range of about 20° on either side, we shall find that the white parts of his eyes increase and decrease according as they are turned to or from the nose. When the eyes of the person are looking straight at us, the two portions of white are nearly equal, so that, by the relative magnitudes of the white parts of each eye, we can estimate in what degree the eyes deviate in direction from the face to which they be- long. 118 Dr Wollaston on the deparven Direction of Eyes, ge, In judging, however, of their direction in reference to our- selves, we are not guided by the eyes alone, but by the, con- current position of the entire face: This will be understood from Plate III. Fig. 1.»where the pair of eyes were originally drawn from the life by Sir Thomas Lawrence, actually look- ing at him. The face has been added according to the origi- nal design, so that the person represented in Fig. 1. appears decidedly looking at the spectator. If, however, a set of features oppositely turned, are applied to the same eyes, by laying down Fig. 2. the eyes will be found to look considerably to the right of the person. viewing them. . In “« Fig. 1. the position of the face being at a certain angle to _ our left, the eyes which are turned at an equal angle from that position, seem pointed to’ourselves. In Fig. 2. the deviation of the face from us being toward the same side as the turn of the eyes, gives additional obliquity to their apparent direction, and carries them far to the right of us, proving the influence of the stronger features, even in opposition to that of the mi- nuter parts of the eyes themselves, which are not in correct drawing from this position.” - The same principles apply to instances of moderate inclina- tion of the face upwards or downwards ; but the principle is most strikingly exemplified when the turn of a pair of eyes - partakes of both inclinations, so as to be in a direction lateral- ly upwards, as in Fig. 3. By giving the face a downward cast; as in Fig. 4. the change of effect is very remarkable. ** The effect thus producible,” says Dr W. **is by no means li- mited to the mere extent of deviation, as a total difference of character may be given to the same eyes by due representation of the other features. A lost look of devout abstraction, in an uplifted countenance, may be exchanged for an appearance of inquisitive archness, in the leer of a younger face turned. down- wards, and obliquely towards the opposite ‘side.’ The under eyelid which, in the former position, conceals a portion of the ball of the eye, from an effect apparently of mere perspective, will, in the latter, seem raised with effort, and thus give the ap- pearance of a smile to the same eyes, if supported: by corres- ponding expression of the rest of the countenance.” Dr Wol- laston considers these examples as proving that the opposite direction of the eyes to or from the spectator, depends on the Dr Kuhl on the Vegetable Productions of Madeira. 119 balance of two circumstances combined in the same represen tation, viz..1. The general position of the face presented to the spectator ; and, 2. The turn of the eyes from that position. In the same manner as the general position of the face car- ries the eyes along with it, so a change in the position of the eyes carries the face along with them. This fact, which is not mentioned by Dr Wollaston, is not less surprising than its counterpart, and may be well illustrated by causing a pair of moveable eyes to oscillate in the sockets of the eyes of a picture; Dr Wollaston next proceeds to explain a fact which every person must have observed, that, if the eyes of a portrait look at the spectator when he stands in front of the picture, they fol- low and appear to look at him in every other direction. | His explanation and illustration of this is every way satisfactory ; but not so popular as we think it may be made. The follow- ing illustration appears to us more easily comprehended. If a picture represents three soldiers, each firing a musket in parallel directions, and if the musket of the middle one is pointed accurately to one eye of the spectator, the other being supposed shut, then the muzzle of the musket will be exactly circular, and the spectator will see down the barrel, and no part of the right or left side of the barrel. In like manner, the specta- tor will see the left side of the barrel of the musket opposite his left hand, and the right side of the barrel of the musket oppo- site his right hand. If the spectator now changes his place, and takes ever such an oblique position, either laterally or vertically, he must see the same thing, because nothing else is painted on the canvas: ‘The gun of the middle soldier must always point to the eye of the spectator, the gun of the other to the right of him, and the gun of the third to the left of him. They will, therefore, all three seem to move as he moves, and fol- low him in his motions. The same cage, Rs is applicable to poTevne pene Art. XXIII. —On the Vegetable. Productions of the {stand of Madeira. By Dr H. Kout. ‘Tue following account of the vegetation of the island of Ma- deira is given in the “ Botanische Zeitung,” as the substance 120° Dr ‘Kuhl on the Vegetable Productions’ of Madeira.” of a letter received by. Dr: Nees Von Esenbeck, ‘from’ Dri Kuhl, who undertook a scientific voyage to the East Indies,) at the expence of. the King of the Netherlands. ; + el) Dated on: Hoard the Nordloh, Sept. 2%, 1820, 5° West Longitude from Greenwich, 29° south latitude. We had, for a long time. previous to our arrival at Ma-~ deira, been indulging in the anticipation of traversing every part of the island, which, indeed, is but little known: but a residence of five days seemed too short to make us per- fectly acquainted with it; and had it not been for the:ready advice and active assistance of a gentleman of the highest re- spectability, Mr Veitch, the English consul, we should only have confined ourselves to the coast, and seen nothing of the interior, which can only be visited with the assistance of guides, and they again are not easily procured. The roads are nowhere better than footpaths, and, in many places, there are none at all, save the rocky beds or margins of the rivers, where you are obliged to leap from one stone to another, often among thorns and bushes. In this way we travelled for some distance by night, having devoted too much time during the day to botanizing, and then we could procure no shelter. "We had travelled from four in the morning till ten at night, with- out resting above an hour, and then were obliged to lie down to sleep upon the bare rocks till the moon arose, and lighted us to the country house of the English consul, where we ar- rived richly laden with the spoils of the preceding day, at about’six o’clock in the morning. I could easily give you an account of our excursion into the interior of the island, but, I believe; that some botanical information will be more accep- table to you. We examined every spot with the greatest at- tention, and scarcely suffered a single plant that was in flower to escape us. We collected, in the five days we spent in the country, altogether 224 species, and about 1000 speci- mens. Vegetation, however, is in general poor, and bore the character rather of that of Europe, than of the neigh- bouring Africa. As to the animals, they belong to European species, or are closely allied to them: Still, however, in what ‘ concerned the plants, the entire absence of Oaks, Firs, Birch, 1 Dr Kuhl on the Vegetable Productions of Madeira. 121 Willows, &cs must strike every stranger. All our European fruits sare here cultivated ; but such as are not planted in a soil that is properly manured, are far inferior to ours in point of flavour, at least such as we had the opportunity of eating. The grapes, indeed, must be excepted, which possess much richness, and are mostly red. The wine is a true claret, and the good old Madeira has the exact colour of Rhenish wine. The red, which is not a claret, is rare. All the native trees have coriaceous leaves, and one only bears an esculent fruit, which is an arborescent Vacciniwm; the rest have been intro- duced by the Portuguese. One single species of Fir, it is said, was found on the island. when it was discovered, but that was soon extirpated by the use that was made of it in building, for which purpose the Chesnut is now employed and cultivat- ed. Of the thick stems of the arborescent Heaths (Ericas,) which crown the top of the Pico Ruivo, and whose wood is of a beautiful red colour, they make props for their vines, which are not, as with us, trained upright, but horizontally, just above the ground, forming a green covering, ‘As the climate of the different regions varies according to the relative heights of the mountains, so we meet with very different plants at different elevations ; and the different belts or regions may thus be penance 1. Recion oF THE Cactr, Which, according to our calculations, reaches to an elevation of 630 feet above the level of the sea. Von Buch gives the same extent to this region at Teneriffe. In Madeira, how- ever, the succulent Euphorbiw, and other African plants, which abound in Teneriffe, are wanting. Cactus Ficus Indi-- ca grows alone upon the bare rocks, and Vines, Canes, Figs, Arums and Muse, and other southern fruits, are cultivated in the fields. This district is rich in wild plants. We found of CryPTOGAMIA, one species, and that, indeed, Adiantum capillus Vene- ris. Monocotytepons, seven ; three Panica, Cynodon, Setaria, Andro- pogon and Milium. ‘Dicoryiepons, sixty ; amongst which, besides the genera which 122 =Dr Kuhl on the Vegetable Productions of Madeira. abound with us (such as Rumew, Convolvulus, &e.) were Crotalaria, Phys salis, Asclepias, Helminthia, Atractylis, Ageratum; Sida, Myrtus, Cassia, ba) ' The Pomegranates, Figs, and Bananas, which are planted’ about the houses, together with the bright green of the A4rwms, gave a singular charm to this district. Of these sixty-eight species, seventeen extended as far as the region of the Vine, and only two of them were met with again at a height of 5300 feet. 2. REGION oF THE VINE. The cultivation of the Vine may indeed be said to com- mence at the sea shore; but the Cactus does not accompany it above 630 feet. The Vine ascends to an elevation equal to 2030 feet, but higher than that the fruit will not ripen. Tn this region the Arum, Cane, Mulberry, &c. Potatoes, Corn, and Onions, are cultivated, but not the Bananas and Cacti. The hedges consist of Myrtle and Chesnut. Agriculture is more successfully carried on here than elsewhere, on which account few wild plants are met with but such as we had already found in the lower region, and of those three that grew at a still higher elevation. 3. REcIon oF THE CHESNUT. This commences at a height of 2030 feet, and is eminently distinguished by the tall stout stems of the Chesnut, which tree ascends to about. 2950 feet. Those that are found still higher are smaller, distorted, and bear no fruit. We stayed longest in this region, and. our success in collecting panty was proportionally great. We found of rh Cryrrocami4, twenty-three species, of which twelve were Ferns, one Darea and Woodwardia, five Lichens, i shel Marchantia, ‘Boletus, two Jungermannie, &c. 5 Monocorytepons, twelve, of our common Genera ; only one Carer and a beautiful Cyperus. DicotyLepons, sixty-six. Rumew five, Clethra, Lobelia, peal Chamamelum, an arborescent Euphorbia, two shrubby species ; of Teucrium, Cineraria, Disandra. We found nine of these species in the next region. te. * 4. RecIon OF THE SparTium. “ef E This terminated at a height of 3920 feet, and i is singularly 7 Dr Kuhl on the Vegetable Productions of Madeira, 128 poor in its vegetation. We found only one plant which we had not seen before, or which. we did not, meet with in the following region. The whole ridge is coyered with the single Spartium. x 1 5. Recion or tut Hearn. (Enica.) "This extends to the summit of the Pico Ruivo, the highest point in the whole island; and, according to’our reckoning, is 5300 feet above the level of the sea. It is very rich in in- teresting plants. In the middle of it are trees with coriaceous leaves, Clethra, an arborescent Vacciniwm, and two trees called Till and Vintratico, but which, for want of flowers, we could not determine. Between the fourth and fifth region is a tract which is almost entirely covered with Pteris aquilina, and some other ferns, especially another Pteris. On many ridges they abound to the exclusion of all other plants, which was re- markably the case at a height of from 3920 to 4080 feet, whilst below them the Spartiwm, and above them the Ericas, maintain possession of the soil. But again, not far from the top of the Pico, is a tract where the Ericas are supplanted by the Spartium, only, however, for a short space; for the sum- mit is covered by the thick stems of the Heaths. Besides fifteen species of plants common to the lower regions, we found of AcOTYLEDONS, twelve species. - Peziza and Lichens. MoNnocoTYLEDons, seven, among them, two Scirpi. Two of Cynosu- rus, Aira, and Agrostis. Dicotyiepons, thirty-seven. Among them, a Sideritts, a beautiful shrubby Echium, with a blue spike, Crocodylium, Pyrethrum, Phyllis, two Semperviva, Sedum, Cotyledon, &c. ‘There is no Pine region, It would, under existing circumstances, be too great a task to name all the genera which we have collected. We must reserve it for another opportunity ; and I will here only enu- merate the relative proportion of the species in some of the most striking families. Filices, lin 15. Cichoracee, 1 in23. Leguminose, 1 in 23. Graminee lin il. Corymbifere, 1 in 19. Caryophyllex, 1 in 37. Amentacer, linill. Saxifragee, 1 in 224. Malvacer, 1 in 74, Euphorbiacer, 1 in 111. Labiate, 1 in 19. Rosacez,_ 1 in 25. Umbellifere, lin 56. Crucifere, 1 in 23. 124. "Contributions to Meteorology. ‘Whence it appears that the island is deficient inthe north: ern families of the Sawvifrages, Amentacee, Caryophyllea, in the first of these especially. It is poor likewise in the pre- dominant families of the tropics, the Euphorbiaceae, Malvacee and Corymbifera, which latter are only in the proportion of 1 to 19, but at the Cape 1 to 5, and in other countries of the equator 1 to 6. But the Cichoracew, which belong to the temperate zone, are here numerous. In our walks, we found upon the shore whole banks of Fuci: but it is at the MARE,’ we hope to meet with treasures in this department. Dr H. Kouut, Arr. XXIV.—CONTRIBUTIONS TO METEOROLOGY. : 1. On the Negative Electricity of Showers. By Mr Joun Foggo. Scppen and copious precipitations of moisture from the at- mosphere, whether in form of rain or hail, are generally at- tributed to the agency of electricity. Hail showers appear to be always accompanied by indications of electricity, amount- ing frequently to discharges of lightning with thunder. In every fall of rain, indeed, electrical indications more or less strong may be discovered ; but, in those extensive rains which spread over vast tracts of country, the electrometer is seldom affected to a greater degree than may be easily considered as the spontaneous electricity of a moist atmosphere. But the showers, in which the influence of this element appears more decided, have characters different from general rains, and even from the heavy showers which occur in boisterous weather. -They-are more local, or circumscribed, of short duration, and the precipitation is most violent at the commencement; and when they have been preceded by dry and cold weather, their effects are discernible in the rapidity with which vegeta- tion acquires a renewed freshness and vigour which cannot be imparted by artificial watering, or an ordinary shower of equal amount. They are also distinguished by the regulari- ty with which the variations in the kind of electricity succeed each other. When negative electricity occurs in broken wea- Mr Foggo on the Negative Electricity of Showers. 198 ther, its alternations with the positive are iti general so rapid, that it is difficult to note them down, and the changes fron positive to negative are frequently interrupted by periods in which it becomes nw. If an electrometer be attached to a conducting rod, when an electrical shower or hail cloud is ap- proaching, the phenomena are as follows: While the cloud is still at some distance, the air is generally strongly charged with + E.; when the foremost portion of the cloud is nearly over the conductor, the electrometer collapses, and then ex- pands with — E.; this state lasts a short while, when + E. shows itself, and continues till the cloud has passed over, when — E. makes its appearance, and is again succeeded by the na- tural positive electricity of the atmosphere. Mr Howard of London appears to have first distinctly stat- ed, that the electricity at the circumference of a nimbus is negative, while that of the centre is positive. This ex- perienced meteorologist observes, that it would be very inter- esting to ascertain whether the negative electricity is ascend- ing, and the positive descending. About the end of the year 1828, I became anxious to make the experiment, conceiving that, if these ideas were found to be correct, they might be useful in explaining certain electrical phenomena, the history of which is at present very obscure. For that purpose, I prepared an apparatus, resembling that of Bennet, and connected with it a gold-leaf electrometer. No favourable opportunity occurred till the month of March 1824. On the 12th of that month, we had, at this place, a brisk wind from the N.W., with frequent showers all around. About 3, p. M., large dense clouds passed over the zenith, letting fall heavy ‘showers of hail. The conductor was armed with a smoking match, and erected from a south window. During the intervals of the showers, the electricity was always positive, and made the leaves diverge to their full ex- tent. Indeed, the electrical tension of the air was so great, that a detached electrometer was fully charged by the slight- est friction with a piece of dry silk applied to the brass cap, and even rubbing the outside of the glass with soft leather opened the leaves to more than 40°. ~ During the showers, or when the clouds were over head, 126 “. Contributions to Meteorology. though no precipitation took place, the E. was invariably po- sitive, and of such intensity, that I could at, any time draw, sparks from the conducting-wire, by presenting my finger to it. I likewise ascertained, that, by taking hold of the wire, I could at pleasure intercept the fluid from reaching the instru- ment, so that the charge was, without doubt, received from the atmosphere or cloud. _ On the other hand, when the edge or circumference of the cloud was nearly over the conductor, _ the electricity became —, and appeared to be fully as strong as the positive charge. I found, however, that it could not be intercepted as before, by taking hold of the. wire, nor by touching it with a pointed steel rod. The fluid was, therefore, not proceeding from the cloud as before, but was given off by the earth to the cloud. By presenting the steel point to the instrument itself, the divergence was so much increased as to endanger the gold-leaf, and sparks were heard. to pass rapidly between the point and the electrometer, while, sharp pricks were felt when the finger was approached to the brass cap. In experiments on atmospherical electricity, I sometimes find it most convenient to employ an electrometer of the cons struction represented in Plate I. Fig. 31. . It consists merely of a pith ball suspended by a fine silver-wire from a ring or loop, imbedded in sealing-wax, by which it is attached to the lid of the instrument. The lid is of turned wood, and through it are inserted the two glass tubes A.A. - These tubes are about one-third of an inch in diameter, and are coated with sealing-wax on the internal surface. . Brass knobs or caps are fixed on the lower ends of the tubes. Into one of the tubes, the end of a chain, proceeding from the conducting rod, is fix. ed so as to insure direct contact with the knob or cap, anda similar chain is placed within the other tube, to establish a communication with the earth and knob. The latter chain is about, two yards long, and is covered with oiled silk, except. at the ends; it.is secured in its place by a pledget of silk. ... When the conductor is elevated with this instrument. at- tached, to it, and the end of the covered chain rests, on the earth, the pith ball is attracted by the knob connected with the conductor. It then earries the charge it has received to the other knob, and is thus made to vibrate between them Acvount of an Improved Hygrometer. 127 so long as any electricity is brought down by the conductor. As the instilation of the pith ball is easily insured, this form is tore delicate than electrometers with two pith balls, or even those of gold-leaf. | 2. Account of an Improved Hygrometer. _. It has occurred to several meteorologists, that Mr Daniell’s hygrometer might be simplified, by applying the ether direet- ly to the ball of a simple thermometer. Mr Jones of London employs a thermometer with a ball of black glass,.and bent twice at right angles, in order (so far as we can judge from a very imperfect description of the instrument in Mr Brande’s Journal) to bring the deposition surface more easily on a level with the eye of the observer. When one part of the ball is moistened with ether, the vapour of the atmosphere is condensed upen the other, and the temperature at. which this takes place is noted. A similar method has been used during the last summer by a correspondent who has favoured us with a description. A thermometer; with a. ball of black glass, has adapted to it; by gum arabic, a ring of silver, (as in Plate I. Fig. 32.) the upper part of the ball being covered with mus- lin. By this contrivance, the ether; when dropped on the muslin, is prevented from reaching the lower part of the ball on which the dew is deposited ; and, unless some method of this kind be used, we do not see how it is possible to insure accuracy of observation. It has been suggested. to us by several practical meteorologists, that, m this arrangement, there is a possibility of error from the circumstance of the de- position surface not being in immediate connection with the stem, or that part which indicates the temperature of the in- strument. Should this suggestion be found correct, it will be necessary to employ a thermometer, bent as in Plate I, Fig. 83. If the ether be dropped on the upper part of the ball (a) the vapour is condensed upon the lower portion, which is the part that gives the temperature of deposition, arid every chance of error is avoided. . N. 128 Prof. Berzelius on Lithia m Mi inenal Waters. . nbeart th, 5 Ge Anr. RXV Bt cones of the Discoveries and Experiments of the Swedish Chemists during the year 1825... Drawn up for this Journal by a Correspondent at. Stockholm. uta 1. Professor Berzelius’s Discovery of Lithia in Mineral Waters. Proressor Berzerivs has been occupied with the examina- tion of several mineral waters from Bohemia, viz. those of the Eger, or Franzensbad, and those of Marienbad. These waters were found to contain the same substances which this chemist detected in those of Carlsbad, the analysis of which has been for some time before the public, * but in the new analysis he has found also ééthia. ‘The quantity of the carbo- nate of the alkali is very small, particularly in the waters of Carlsbad, and in that of Eger; but the waters of the ‘spring talled Kreuzbrunn, at Marienbad, contain as much as a cen- tigramme of the carbonate of lithia in every bottle. The following is M. Berzelius’s method of discovering this alkali in any solution. He precipitates the lime by means of oxalate of potash, and afterwards separates the magne- sia by carbonate of soda, but the mixture must be evaporated to dryness, and the residue fused ; for otherwise some of the magnesia would be easily redissolved in the form of a double carbonate of soda and magnesia. 'The mass, taken up by the water and filtered, will not give any farther precipitation even when pure phosphate of soda is added ; but if it contains lithia, it will become turbid during the evaporation, which must be continued till the matter be perfectly dry. It is next redis- solved in a very small quantity of cold water, which leaves undissolved a double phosphate of soda and lithia, equivalent to one-third of its weight of carbonate of lithia. The charac- ters which distinguish this phosphate from the earthy phos- phates with which it may be confounded, are as follows: It is very fusible before the blow-pipe. When melted with carbonate of soda, it enters with the soda into the charcoal. On a leaf of platina the melted mixture is limpid. The * See this Journal, vol. ii. p. 176, January 1825. Prof. Berzelius on the Orange Gas Produced; &c. 129 earthy phosphates remain on the charcoal while the soda pe- netrates it, and do not give a limpid mixture when they are inelted on a leaf of platina. With twice its weight of carbo- nate of lime, it fuses at a red heat, without, however, attacking the platina, as lithia ordinarily does; but if some drops of water are added to it, and afterwards evaporated, the platina becomes yellow all round when the mass is heated anew. 2. Professor Berzelius's Ewperiments on the Orange Gas pro- duced from a mixture of Flior-Spar and Chromate of Lead. As the English and French Journals have already given an account of Professor Berzelius’s experiments on the differ- ent combinations of the fluoric acid which have facilitated the reduction of Silicium, Zirconium, and Tantalum, we shall not at present enter upon the subject. A German chemist, M. Unverdorben, has published some: experiments on the fluoric acid, the most. curious of which. was that in which, after mixing together fluor-spar and chromate of lead, he distilled them in a leaden retort, with fuming or anhydrous sulphuric acid. From this there result- ed a gas, which could not be collected, because it destroyed the glass. This gas gave a very thick yellow or red smoke. It was readily absorbed in water, which was then found to contain a mixture of chromic and fluoric acids. When it came in contact with air, the gas deposited small red “oy tals, which were those of chromic acid. ' Professor Berzelius repeated these experiments of M. Unyer- dorben, and he found that the-experiment succeeded equally well with common concentrated sulphuric acid. He collected the gas in glass flasks covered with melted resin, and filled with mercury. The gas had a red colour. It gradually attacks the resin, deposits chromic acid in its mass, and penetrates even to the glass, which it decomposes without change of volume, the chrome being replaced by silicium. -Ammo- niacal gas introduced into it burns with explosion. Water dis- solves it, and yields an orange-coloured fluid, which, evaporat- ed to dryness in a platina dish, leaves as a residue pure chromic acid. The fluoric acid volatilizes entirely. This VOL. Iv. NO. I. JAN. 1826. I 130 Prof. Berzelius on the Orange Gas Produced, &c. method is at present the only one which gives chromic acid perfectly pure. If the gas is. received in a plats vessel of some depth, whose sides have been slightly wetted, and into the bottom of which the gas has been made to descend, the water begins to absorb the gas, but, by and bye, crystals of a fine red colour are seen to form themselves round the opening of the metal- lic tube which conveys the ‘gas, and, in a short time, the ves- sel is filled with a red snow, consisting of crystals of chromic acid. The fluoric acid dissipates itself in vapour, and ab- .sorbs entirely the water added at the beginning of the ex- ‘periment. These crystals have this curious property, that, when they are heated to redness in a platina dish, they begin at first to melt, and afterwards, by a slight explosion, accompa- nied with a flash of light, they decompose themselves into oxygen gas, and the green protoxide of chrome. ‘The chro- mic acid which has been dissolved in the water does not pre- sent this phenomenon. It fuses during its decomposition, but it does not give a flash of light. This difference does not arise from its containing water, for it is perfectly free from it when it is heated to a little above 100° centigrade. M. Unverdorben had already observed, that crystals of chromic acid, introduced into ammoniacal gas, are decomposed with a flash of light. The ammonia is destroyed, and thejacid . leaves the protoxide as a residue. It is necessary to make ‘these experiments. quickly, as the whe acid is deli- quescent. In distilling chromate of lead with chloride of sodium, we obtain a gas similar to the preceding, and which contains chrome combined with chlorine, in such proportions, that the water, by its decomposition, gives rise to the formation of the hydrochloric and chromic acids. The gas is red, and may be collected. over mercury, but it is very much charged with chlorine, when it it is prepared by means of the common con- centrated sulphuric acid, whose water of combination meer a certain quantity of the gas. 3 Prof. Berzelius’s Method of Paiecing Arsenic, &c. 181 '3, Abcdunt Of Professor Berzelius’s Method of Detecting Ar- ot _senic in the Bodies of Persons Poisoned. Professor Berzelius has lately given some instructions for the discovery of arsenic in persons that have been poisoned with it. He considers the reduction of arsenic to the metallic state as the only incontestible proof of the presence of this poi- son: . Arsenic may occur in two ways, viz...when it is found in substance (in the state of arsenious acid) im the dead body, and when it is not found in this state; though the intestines of the dead body may contain it in the state of a solution. In the first of these cases, it is easy to, determine the pre- sence of arsenic. In order to do this, take a piece about three inches.long of an ordinary barometer tube, and having drawn out one end of it C B, as shown in Plate I. Fig. 34 into a much narrower tube, close the end B. Let some of the arsenic found in the body be now put in at the open end A, ~ so that it may fall down to the end B.. Any quantity of this arsenic of sufficient volume to be taken from the body will suffice for this purpose. The arsenic being at the end B, _ alittle charcoal is let fall upon it, after it has been freed from all moisture by bringing ‘it to a red-heat with the blow-pipe. The charcoal is then heated in the tube at the flame of a spirit-lamp, the point B being held out of the flame. When the charcoal is very red, the point B containing the arsenic is drawn into. the flame, The arsenic is then instantly volati- lized, and passing into vapour by the red charcoal, it is ,re- duced, and reappears on the other side of the flame.in a me- tallic state. The flame is then brought slowly towards the metallic sublimate, which is thus concentrated into a smaller space in the small tube, and then presents a small metallic ring shining like polished steel. *.. We, have now only to verify, by its smell, that the metallic sublimate is arsenic. For this purpose, cut the small tube with a file a little above the sub- imate, and, having heated the place where it lies, put the nose above it at a-small distance, and the particular odour of the metal will be.immediately perceived. * Had the experiment been made in the wide part of the tube, the re~ sult would scarcely have been visible with a small quantity of arsenic. 132 Prof. Berzelius's Method of detecting Arsenic, &c. In the case where the solid arsenic cannot. be found, we must collect as much as possible of the contents of the sto- mach and the intestines, or even cut the stomach in pieces, and mix it with its contents. The whole is then to be di- gested with a solution of hydrate of potash. Hydrochloric acid is then added in excess. The whole is filtered, and, if the liquid is too much diluted, it is concentrated by evaporation. A current of sulphuretted hydrogen is then passed through it, which precipitates the arseftic in the form of the yellow sulphu- ret. Ifthe quantity of arsenic is very small, the liquid will become yellow without giving a precipitate. It must then be evaporated, and, in proportion as the hydrochloric acid be- comes more concentrated, the sulphuret of arsenic will begin to be deposited. It is then filtered. If the sulphuret re- maining on the filter is in too small a quantity to be taken . fromthe paper, add some drops of caustic ammonia, which will dissolve it. ‘Then put the liquid which passes the filter into a watch-glass, and evaporate it. The ammonia will be volatilized, and will leave as a residue the sulphuret of arsenic. If it shall still be difficult to collect the sulphuret, we must put into the watch-glass a litttle pulverized nitrate of potash, and, with the finger, mix the sulphuret with the nitrate of ‘ potash, which detaches it from the glass. At the bottom of a small phial, or a piece of glass tube, shut at one end, melt a little nitrate of potash at the flame of a spirit-lamp, and in- troduce into it, when melted, a little of the mixture which contains the sulphuret of arsenic. It is oxidized with efferves- cence, but without fire, or detonation, and without loss of arsenic. The melted salt is then to be dissolved in water, and lime added in excess, and the liquid boiled. The arseniate of lime will then be deposited, and may be collected. 'When dried, itis mixed with charcoal, and then brought to a red _ heat by the” blow-pipe, and a small quantity of this mixture is allowed to fall to the end B of the above tube. It is now gradually heated to expel all humidity which tends to throw it into the wide tube A C, and when it is very dry, heat at the flame of the blow-pipe, the part of the tube which con- tains the mixture. The arsenic will be disengaged, and be sublimed, at a distance from the heated part. An addition of Prof. Berzelius’s Researches on Molybdena, 133 vitrified boracie acid greatly promotes the decomposition which then takes place at a less elevated temperature ; but this acid frequently contains water, and produces a bubbling of the melted matter which raises it in the tube, and causes the vapours to issue by perforating the softened part of the glass. M. Berzelius maintains, that the siath part of a grain of sulphuret of arsenic is sufficient to make three different trials ; ‘but he adds, that, when we have discovered only very small traces of arsenic, we must take care not to introduce any by means of re-agents, among which, both the sulphuric and the hy- drochloric acid may contain it. The first almost always contains some arsenic when it is not manufactured from volcanic sul- phur, and the second, in consequence of sulphuric acid being used in the preparation of the hydrochloric acid, yields the ar- senic which it contains in separating it from soda. We must, therefore, be certain of the purity of these re-agents. When death has been caused by the arsenic, and not by the arsenious acid, the process must be modified, because the sulphuretted hydrogen gas decomposes the arsenic acid too slowly. In this case, we must add hydrosulphuret of ammonia, Which reduces the arsenic acid to the state of sulphuret, which is afterwards Lip by the hydrochloric acid. * 4. pute Berzelius’s Researches on Molybdena. In studying the properties of molybdena, M. Berzelius has _ found that this metal, of which we knew only the purple ox- ide, produced by drying the blue oxide, and molybdic acid, has two salifiable oxides, whose saline combinations were till * It is obvious that Berzelius has not seen Dr Christison’s paper on the ** Detection of minute quantities of arsenic in mixed fluids.” These gen- tlemen agree in precipitating arsenious acid by sulphuretted hydrogen, so as to obtain the yellow sulphuret; but their subsequent methods differ : Berzelius adopts a process which requires all the dexterity of as expert a chemist as himself for conducting it with success. Dr Christison, on the contrary, scrapes the sulphuret from the filtre with a knife, which may be done though a very minute portion of it is present, and obtains metallic arsenic at once by heating it with black flux. . We refer for particulars to his paper in the Edinburgh Medical and seiailaiued Journal. - 134 Prof. Berzelius’s Researches on Molybdaena. now unknown. ‘The’ deutoxide may be procured 'by digest- ‘ing a mixture of molybdic’ ‘acid, ‘metallic’ molybde&na, and ‘sulphuric or hydrochloric acid, till the colour of the liquid becomes a deep red. Instead of metallic molybdena; we ~ _may substitute metallic copper. . The red liquid gives, with ammonia, a rust-yellow precipitate, which is the hydrate of the deutoxide of molybdeena. This hydrate is very soluble in . water. When it is washed, the water, after having removed the saline substances, which caused its precipitation, begins to dissolve the hydrate, and becomes yellow. Itat last dissolves it entirely, and the saturated solution is red. ‘It reddens turnsol. ‘The hydrate dissolves in acids, and gives salts, whose solutions are red, but which, when evaporated’ to dry- ness, are almost black. The protoxide is produced:‘when we macerate the solution of _.asalt, with a base of the deutoxide, with mercury, and add, from time to time, a liquid amalgam of potassium. The colour of the’liquid becomes deeper, and ends by growing black. Before the introduction of the amalgam, we must’ add to it hydro- chlorie acid, in order to prevent apart of the deutoxide from being precipitated before its entire reduction to the protoxide. The black solution is then! precipitated by ammonia, and te black precipitate is the hydrate of the ' protoxide, which must be well washed, and then dried in vacuo. ‘The hydrate ap- pears then under the form of a jet black. powder. When heated in vacuo, it gives out slowly its water, and afterwards, ‘at a temperature which approaches to that of brown-red, it takes fire, and burns with ‘scintillation. The barometer ‘of the air-pump is'‘not affected by this phenomenon, which, in other respects, is of the same nature as that which’is observ- ed in the hydrate of the peroxide of iron, and the protoxide of chrome, and of zircon. The anhydrous protoxide is in- soluble in acids. When heated in air, it takes fire, and burns feebly, producing the brown oxide of molybdena. The salts . of this oxide are black, and their dilute solutions have a com- pound colour ‘of green, black, and brown, though sometimes they assume a fine purple colour. The fluate of the protox- ide, for example, is a very fine purple, and the double. Bates with potash, soda, and ammonia, are of a rose red colour. __, ’ Prof. Berzelius’s Researches on Molybdena, 135 In order to form ‘the protoxide of molybdwna, we may make use of zinc in place of the amalgam of potassium, but the protoxide then retains the oxide. of zine ina very obstinate manner. What is called molybdous acid, that is to say, the blue ox- ide of molybdena, is not a particular acid. It cannot be ~ combined with alkalis, which, on the contrary, decompose it, by precipitating the hydrate of the yellow oxide, and combin- ing with the molybdic acid. It may be produced most readi- ly in dissolving the bimolybdate of ammonia, and adding to it a solution of a salt with a base of the deutoxide. It pro- duces a precipitate of a fine deep blue, which is very solu- ble in’ water, and is only deposited because the water contains salts. We may wash it with a solution of sal ammoniac, after- wards removing the salt by a little cold water. It gives with warm water a blue solution, highly saturated, which may be easily preserved at the ordinary temperature of the atmo- sphere. In the dry form it resembles indigo, and retains its solubility in water. Professor Berzelius has found, that the deutoxide of molyb- deena is composed of one atom of molybdena, and two atoms of oxygen. The molybdic acid contains three atoms. The blue oxide is a bi-molybdate of the deutoxide of molybdeena, that is ‘ Mo +4 Mo: There is still another combination between the oxide and the acid which is produced when the blue liquid is digested with metallic molybdena. It is green, equally solu- ble in water, and precipitable in sal ammoniac. M. Berzelius supposes its composition to be Mo + 2Mo. Tungstic acid likewise combines with the deutoxide of molybdena, and the combination is very soluble in water, and of a superb pur- ple colour. It is also precipitated by sal ammoniac. The molybdic acid performs the part of a base towards the stronger acids. M. Berzelius has examined them in this point of view, and has described some of the salts which it forms.° M. Berzelius has discovered a new sulphuret of molyb- dzna, proportional to the molybdie acid. It is of a ruby colour, transparent and crystallized. It combines with the metallic protosulphurets, and forms with them particular salts, of which a great number are soluble in water. 136 M. Setterberg’s Experiments on the Sulphurets of Cobalt. Molybdena combines with chlorine in three proportions. The first is red, and a little volatile. ''The second is; black, very fusible, very volatiles and crystallizes in a black mass, of a brilliant colour, like iodine, which it resembles even in the colour of its gas, which, however, is more red than violet. The third is colourless, and crystallizes in scales. . These three chlorides correspond to the muriates of the protoxide, of the deutoxide, and of the peroxide, that is to say, of the acid. _ Todine does not combine in the dry way with molybdeena,, but the hydriodic acid dissolves the protoxide and the deu- toxide. The molybdic acid decomposes it, and separates the iodine from it _ The best method of obtaining molybdena, in some quanti- ty, is to heat the molybdic acid in a porcelain tube. “When this tube is heated to gedness, there is introduced into it a cur- rent of hydrogen gas, which is continued as long as it pro- duces water. 5. M. Setterberg’s Eaperiments on the Sulphurets of Cobalt ~ M. Setterberg has found that the deutoxide of cobalt decom- poses sulphuretted hydrogen gas when cold. The sulphuret thus produced. contains three atoms of sulphur. Hydro- chloric acid dissolves some of the cobalt in it, and leaves an- other sulphuret of cobalt in the form of a black powder, which contains four atoms of sulphur for one atom of metal. 6. M. Mosander on the Precipitation of Magnesia by Carbo- nate of Soda. During the analysis of a new species of noble serpentine, M. Mosander made an observation which merits the atten- tion of chemists who are occupied with the analysis of mine- rals.’ He remarked, that when the carbonate of soda is used, to precipitate magnesia, the precipitate contains a double carbo- nate of soda and magnesia; that the alkali cannot be removed from it by edulcoration with water, and that the washings al.. ways contain magnesia. It is necessary, therefore, to evapo- rate the alkaline liquid to dryness, and melt the salt to render, “My Mosander’s ‘Analysis\of the Oxides of Iron. 137 the magnesia caustic. As carbonate of potash is commonly used for this operation, there isno risk of being exposed to this inconvenience ; but it is evident, that, whenever the liquid con- tains a salt with a base of soda; even though potash is used to precipitate the magnesia, the double carbonate of soda and mag- nesia ought to be precipitated. 7. M. Mosander’s Analysis of the Owides of Iron, formed by continued Heat. It is well known that M. Berthier analyzed the cinder which is formed on pieces of iron intended for being laminat- ed to form iron-plate, and that he considered it as a new de- gree of oxidation of iron, which contained 13 as much oxygen as the protoxide. M. Berzelius kept a piece of iron, intended for iron-plate, forty-eight hours in a furnace. ‘The oxidated crust was two lines thick, and exhibited, what M. Berthier has also observed, two distinct layers. M. Mosander under- took the analysis and examination of it. It was at first evi- dent, that M. Berthier had analyzed together two distinct substances. The interior layer is more black than the other, has a grained fracture of little lustre, and is very slightly magnetic. The exterior layer has a brilliant metallic lustre, a brightand shining fracture, and a grey metallic colour, and, what is very remarkable, has a powerful action on the mag- netic needle. : M. Mosander found that the layers consisted of Inner Layer. Atoms. Outer Layer. Peroxide of Iron, 27 1+ 36 Protoxide of Iron, 73 3 64 The formula for the first is Fe+3Fe. The analysis of the outer layer is the same as M. Berthier had obtained for the two layers mixed together. This approached to Fe+2Fe. But, as on this occasion, the oxidated layer was supplied with oxygen from the outer layer, and with iron from the in- terior layer, it may be supposed that there was an insensible gradation from the most oxidated to the least oxidated side. M. Mosander was thus led to analyze different zones of the two-layers; and he found that at the exterior layer this was 138 Dr Hibbert on some Remarkable Concretions actually the arrangement. The external. surface consisted of the red oxide, quite pure ; below this'was the ordinary mag- netic oxide (owidum ferrosoferricum of Berzelius,) and farther - in the quantity of protoxide gradually increased to the com- mencement of the interior layer, which he found homogeneous throughout. It appears, then, to be determined by these ex- periments, that we have two combinations of the peroxide of iron with the protoxide, that is, the magnetic oxide Fe+ Fe, and the less magnetic one which forms the inner layer of the oxidated crusts produced upon metallic iron by heat, Fe+3Fe. Stocxuotm, November 10th 1825. Art. XXVI.—On: some Remarkable Concretions which are found in the Sandstone of Kerridge.in Cheshire.* By Sa- muet Hissert, M.D. F.R.S. E. and M. G.S§, Secretary to the Society of. Scottish Antiquaries. Communicated by the Author. Tue stony concretions that form the subject of this short pa- per are found under circumstances that it will be previously requisite to describe. ‘They are obtained from a sandstone of the coal formation composing a small ridge of hills named Kerridge, situated about three miles from Macclesfield, in Cheshire. Not far distant is the more recent deposit of the newer red sandstone, or red marle formation. Near the junc- tion of the sandstone, of the coal formation, and of that of the red marle, there is a considerable disturbance of the strata. The’ celebrated “hill of Cheshire, Alderly Edge, which rises abruptly from a level country, has its strata of the newer red sandstone, inclined at about an angle of 20°, while the adjoin- ing strata of the same formation are nearly horizontal ; and in like manner, the strata of Kerridge belonging to the sand- stone of the coal deposit, exhibit numerous faults and disloca- tions, being likewise intersected by small rents, or fissures, such as I have observed to take place in the vicinity of whin dikes; but, in this instance, the disturbing cause has not made its appearance. The seams of coal in the i immed iate vi- * Read at the Royal Society of Edinburgh, 5th December 1825. 4 4 . found in the Sandstone of Kerridge. 139 cinity, from»partaking of the dislocation, are said to have de fied the operations of the miner. In faét, there are no rocks of ‘this kind which I have examined, where the Huttonian could discover more presumptive proof in favour of that theo- ry, which attributes the elevation and dislocation of strata to an expansive power acting from beneath; and this view would find ‘additional. support in the very remarkable induration which prevails throug! all the strata of ‘Kerridge,—a cireum- stance which the ‘same: theorist would refer to the intense influence of subterranean heat, which operated on these se- condary strata at the period:of their consolidation. This un- common induration has long rendered the sandstone of Ker- ridge one of the most valuable quarries of Cheshire, for, being very fissile, it readily splits into laminz of various degrees of thickness, yet so very firm in its consistence, as to render it in great demand for the purpose of roofing slate.’ But hard as is the general structure of this sandstone, it is not unusual for the workmen, while-quarrying it, to meet with considerable patches of the rock, the dimensions of which are often seve- ral yards, acquiring an almost superlative degree of sindura- ‘tion. In this state it is converted to ‘the purposes to°which trap-rocks of unquestionable igneous origin are applied, being used for paving and repairing the roads of the: country. When a patch of this unyielding rock occurs, it is very signi- ficantly named by the labourers burnt stone. ‘This’ mode of accounting for the phenomenon, induces us ‘to suspect, that some Huttonian had given*to the rock» so'Plutonie ‘a name, otherwise the originality of the theory taught: by the illustri. ous founder of ‘this school becomes questionable, having been anticipated by the popular view of the same kind entertained by the illiterate quarry-men of Kerridge.. But who, in this age of theorizing, can boast a system that will long remain unchallenged? 'The peasants'of Cheshire have, from time im~ memorial, speculated ‘upon the highly inclined strata of Al- derly Edge, almost ‘in the same manner as Hutton himself would do were the same phenomena to present themselves to his notice. They have elevated these rocks by an expansive force, alleging that an immense vacant space exists beneath them, which they say may be distinctly recognized by the 140 Dr Hibbert on’ some Remarkable Concrétions hollow sound that is emitted whenever a traveller rides over the hill,—the sound being responsive to the tramp of his horse’s feet. It would, however, have been well if an hypothesis like this had even here stopped short; but as geology and romance are often united, the theorists of Cheshire, on the principle of nature abhorring a vacuum, haye filled this vacant space in the hill of Alderley with valorous knights in armour and the fair objects of their chivalry. Nor have the natural pheno- mena exhibited at Kerridge been less the subject of bold spe- culation, The hillisconsidered as spell-bownd, the indications of which are not only the burnt stone, but certain remarkable concretions found imbedded in the rock, which were first in- troduced to my notice under the name of witch-knots. As- suredly the origin of these concretions is as puzzling as most appearances which the geologist encounters. It may be ques- tioned, therefore, whether it is not more prudent to allow the theory which the popular voice of superstition assigns to their causation to remain undisturbed, than to hazard, on this oc- casion, any conjecture of my own, which may perlinps be not a whit the less chimerical. The stony concretions, named witch-knots, which are found. in the Hill of Kerridge, occur. in some abundance, being de- tected when force is applied to the block of stone in which they lie concealed, for the purpose of splitting it up into thin slabs. When a stone has been thus split in the direction of the plane of its fissility into two parts, one slab shows a round hollow in the form of a basin, while the other slab ex- hibits the segment of a solid sphere of sandstone projecting from its surface, and exactly fitting the basin-shaped hollow of the other slab into which it was received when the two fragments were united in situ. (See Plate I., Figs. 29. and 30.) If we could be assured that the fragment in which the basin- shaped hollow is found was in sitw always the lowest, the parallel and horizontal lines, which, on a reference to Fig. 30, of the Plate, will be found to encircle the projecting segment of the spheroid body, would be easily enough accounted for ;. they would indicate a succession of layers of sandstone, which had filled up the corresponding hollow. of the other slab. But I could not learn that this relative situation iv situ of the, “ait - found in the Sandstone of Rerridge. 141 two fragments had been completely ascertained ; or, granting even that this had been done, there would still remain a ques- tion touching the origin of the basin in which these parallel lay- ers of sandstone were deposited. A theory has been hazard- ed by one of my friends, that the hollow might have been induced by the corroding action of running water, which was afterwards filled up by successive deposits of sand, that be- came indurated during the process of consdlidation which the rock underwent. This view, however, admits of little to be said in its support. The dimensions of the specimen, a drawing of which ac- companies this account, are as follows:* From A to B 13 inches ; from C.to ‘D, 17 inches; from A to C, 134 inches ; from B to D, 143 inches. The diameter of the basin, and of the: corresponding section of the spherical body, is 10 inches. All these concretions differ in no respect, as to the nature of the rock of which they are composed, from that of the solid slab in which they are found imbedded. ‘hey are of various sizes, some being double the magnitude of the specimen which is figured in the Plate. Nor is the form of the basin, and consequently of the concretion which fills it, always the same. One specimen had a form something between oval and triangu- lar, the recipient basin corresponding to it. _ : In the same sandstone where. these concretions are found, I detected the fossil remains of gigantic reeds, such as are usually found in coal-fields. . This is all the description which I have to give of these concretions, and of the circumstances under which they are found ; my object being rather to introduce them to the no- tice of the naturalist, than to offer any hypothesis on their origin; regarding which, I actually feel great lack of inven- tion. Without any further observations, therefore, I shall leave the witch-knots of Kerridge to’ be unravelled by some more successful geological. ree than I would confess my- self. to be. * I am indebted for the specimen to Philip Antrobus, Esq. of Bolling. ton, who was so obliging as to point out to me the site of these concretions, 142 Mr Stark. on the tia of Live Coskles Art. XXVIT.—WNotice ah anise the Discovery of Live Cockles in a Peat Moss at a great distance from the Sea. By Joun Starx, Esq. M.W.S., Communicated by the Author. — the meeting of. the Wernerian Society.on the 19thof No, vember, Henry Witham, Esq, read a very. interesting paper “On the Discovery of Live Cockles.in Peat-moss, at a: great distance from; the Sea, and. much above its present: level.” These shells were discovered in the month of October, last in Yorkshire, about forty miles from the sea-coast, in the course of a mineralogical excursion by Mr Witham. through that county., He was led to the spot by a tradition which prevailed in the country of this anomalous. occurrence, and found the cockles alive in the sandy. bottom of a, drain which -had been formed through the moss... This peat-moss is situate about a mile and a half, or two miles, (we understood. him to say) from Greta Bridge, and about two miles arom, the. river, Tees; That.cockles had existed in that spot for a period of unknown antiquity is ascertained from the name of the. farm, in. which this peat-moss occurs, and, which it has borne, for centuries Cocklesbury. . Specimens of the-cockles were laid.on,the table by Mr. Witham, and of the sand in which they. burrowed ; and live specimens would have been exhibited, but,from the circumstance of the ditch being. frozen over when a friend visited the place forthe purpose of procuring them.. The cockles are found in considerable quantity... Mr W..gathered a number, and even had the curiosity to eat some of them. They differed but little in taste from, the;common cockle, un- less it were that they seemed not quite so salt. . The specimens of the shells exhibited. by Mr Witham, and ‘of which the writer. of this notice, by the kindness of that gen- tleman, is. in possession of one, agree in every. respect with _ those found on most of our sandy shores—the Cardium.edule of Linneus. . They are of. the ordinary size, and nothing in their external appearance would lead any one to suspect they were from a locality so very different. With the exception of one instance, which has been pointed out to us by a scientific friend, nothing similar, as far as has come to our knowledge, _ has been remarked before; though the publication of Mr Witham’s discovery, by directing attention to the subject, may a at a Distance from the Sea. 143 lead to the knowledge of collateral facts. ‘The instance allud- ed to is found in the Description of Zetland by John Brand, published i in 1701 ; ‘and as the statement is interesting, and the book in which. it occurs of considerable rarity, we give the in the words of the author : oe gentleman in the parish of Dunrossness told one of the tninisters ‘in this country, that about five years since 'a plough in this parish did cast up; fresh Cockles, tho’ the place where the plough was going was three-quarters of a mile from the sea; which cockles the:gentleman saw made ready and eaten. How these’shell fishes came there, and’ should be fed at such a distance from their ordinary element, I cannot know, if they have not been cast upon land by a violent storm, much of the ground of this parish, especially what they labour, lying very low, and the sea hath been observed in such storms both to ‘cast out stones and fishes; or if these Cockles have been found in some’ deep furrow, from which to the'sea there hath been a conveyance by some small stream, upon which ‘the sea hath flowed in stream tides, especially when there is also some storm blowing. If only shells were found, such as of oysters and the like, the marvel would not be great, seeing such are found upon the tops of high mountains, at a greater distance from ‘the sea, which, in all probability, have been there since the universal deluge ; but that any shell-fish should be found at ‘some distance from the sea, and fit for use, is somewhat won- derful and astonishing.”* When Dr Hibbert was recently in Shetland, he was led by this curious passage to make inquiry on the spot regarding these cockles, but could procure no information on the subject ; and the surface of the soil being covered to some depth by drifted sand, precluded further investigation. Professor Wallace, it may be mentioned, found oyster shells in Bagshot Heath, too recent in appearance to be character- ized as fossil, of which the origin is not known; and modern experiment has proved that shell-fish may be transferred from salt to fresh water with impunity, though it is difficult to believe that the ‘ingenuity of our+ancestors exerted itself in providing such. articles of luxury in such a way. The * A Brief Description of Orkney, Zetland, Pightland-Firth, and Caith~ ness, &¢, By John Brand. Edinburgh, Printed by George Mosman, 1701: 144 Mr Stark’on the Discovery of Live Cockles fact observed and related by Mr Witham, therefore, of live cockles being found at a distance so considerable from the sea, and at such a height above its level, ean only be accounted for by the retrocession of the ocean—or by supposing some great convulsion to have submerged the land, and left these evidences of its effects. In any view the discovery is inter- esting, and similar occurrences will probably lead to a modifi- ' cation of the prevailing theories. If the shells in question had not been found alive, it might have been conjectured. that they had been deposited there at a very distant period, by one of those catastrophes which are supposed to have changed the bed of the ocean, or floated its astonished inhabitants over the land, and an unknown and mysterious antiquity thus assign. _ ed to shells which might have been alive shortly before. That similar circumstances have, on more occasions than one, misled observers we have little doubt. We have seen specimens of shells from the banks of Lochlomond, which seem, from their appearance, to be in this predicament ; and instead of suppos- ing that these were the remains of animals which had been left. there when Lochlomond joined the eastern and western seas, we should conjecture that they had recently lived and died in the very lake on the banks of which they were found. In the paper, by Mr J. Adamson, which gave an account of the shells thus found, and which is printed in the Wernerian _ Transactions, Vol. iv. p. 334, that gentleman says, that ‘ the shells begin to appear about half way between the highest and . lowest, or the winter and summer surfaces of the water, which ‘ varies in this respect about six feet. After removing a slight covering of coarse gravel, we find a thin bed of clay, of dif- ferent shades of brown, passing into yellow colours, as we de- ~ scend. In the upper, or brown clay, are found shells of the following species: . Those marked with an asterisk are doubt- ful. Buccinum reticulatum*, Nerita glaucina, Tellina tenuis*, Cardium edule, Venus striatula, Venus Islandica, Nucula rostrata, young, Pecten obsoletus, Anomia ephippium, young, -Balanus communis, Balanus rugosus, Echinus esculentus. | ‘«* A skilful conchologist would discover many others, from the numerous traces of them in the clay. Those shells appear to have been deposited generally i in an entire state, and many are found with both valves in their natural position. The Ba- at a Distance from the Sea. 145 lanus is still slightly attached to the Venus or Pecten ; and the spines of the Echinus are found clustered in the clay inclosing its fragments; so that they must have been either covered by water to a considerable depth, or thrown on a beach not much exposed to waves. Few of them, however, can be ex- tracted entire, as several of the species are always in a state of gritty chalk; but many complete and beautiful specimens of the’ Pecten can easily be procured. Few of their fragments ap- pear on the exposed part of the beach, but, during summer, many may be seen a few feet under water.” We lately received several specimens of the Buccinum la- pillus from Shetland, which were found alive on the mar- gin of a lake in the island of Yell, about a mile and a half from the seas The lake has an outlet by a small ri- vulet... The shells» are somewhat thinner in their texture than their congeners on the rocks of the neighbouring coast, and are all of the banded variety of that shell, or crossed with dark-coloured: lines» That these shells had been carried to that locality by water-fowl is not unlikely; and the outer lip of the shells. being somewhat broken, may have occurred in the attempt to extract the animal as food. But the fact of the animals being alive when the specimens were picked up, goes to prove that shell-fish may be brought to live in fresh water; and the experiments undertaken by Mr Arnold of Guernsey at the suggestion of Dr MacCulloch, and the dis- covery of live cockles at a distance from the sea by. Mr Wi- tham, leave little room to doubt that many species of fish may be transported to, and live and ee in, inland fresh water ponds and rivulets. As the result of Dr MacCulloch’s experiments may not be generally known, we give a list of the species of fish naturally belonging to the sea, which have been found to live in fresh water. . Those marked math an asterisk have been finally na- turalized : Conger. Greater Lamprey * Plaice * Basse Torsk Lesser Lamprey Flounder Loach Sprat _ Stickleback Red Do. Red Do. Shad Cottus Quadricornis White Whale * Smelt Alose Mullet - Cod * Atherine vOL. Lv. No. I. JAN. 1826. K 146 =Mr Stark omthe Discovery.of Live Cockles, &c. ™ Rock Fish... Sand Eel Herring, .. » Shrimps,» ppyn ah * Cuckoo Fish —_Rockling _* Horse Mackerel Crabs ae ‘Old ‘Wife Whiting Pout “Pollack * Oysters Sole ~~! Mackerel tit (Prawin TRE 02 a ad “ Turbot fs The pond in which the fish are kept is iit foil decline extent, and close by.the sea, from which it is separated by.an embankment ;. but it must not be concealed, that, ‘ receiving an insufficient supply of fresh water insummer, it varies, so that while it, is perfectly fresh in winter, it is nearly salt in very dry weather, and brackish in various degrees at intermediate periods.” The'result of Dr MacCulloch’s experiment, there- fore, though flattering as to the ultimate success of the plan, is not so decisive as if it had been made in a pond at a ' distance from. the sea, and whose’ waters were invariably fresh. Perhaps a series of ponds in which the water was less and less salt, may be found necessary to assimilate the inhabitants of the deep gradually to living and propagating in inland ponds; and though it may require time, and numerous trials, before the experiment fully succeed, yet it is: an) object too important, even in an ecohomical point of view, tobe lightly given up. How many exotics now flourish in ithe open borders of our. gardens, and in our shrubberies, which, not very many years ago, could only be reared under the pro- tection of the green-house or stove! and how many animals, from regions much more genial, are now permanently domes- ticated in our variable climate! If it be not carrying the ana- logy too far, it may therefore be presumed, that the ova or fry of sea+fish, reared in the series of ponds we have suppos- ed, may at last be brought to live and propagate in lakes and waters at a distance from the sea. The spawn of fresh water fish’ is an article of trade in China; and their methods of hatching the ova of fishes might be adopted with promise of success inthe assimilation of the inhabitants of the deep toa change of element. It would be a new triumph to science, if an additional and inexhaustible supply of wholesome and nu- tritious food were thus provided in places at a distance from the sea, and at present precluded from its use. * Quarterly Journal, No. 38, p. 242. Notice of Captain Parry's last Lapedition. 147 ‘Tt may be further noticed, that not, only did the fish in My Arnold’s pond improve materially in quality, but the few ecls which were formerly almost its only tenants, have, since the introduction of fish from the sea, increased incalculably in numiber, and so as themselves to bring in a considerable re- venue. The pond now produces a large rent, and is resorted ‘to for the supply of the market when the weather prevents the boats from putting to sea. On the subject of Food for the supply of the fishes in such ponds, Dr MacCulloch remarks, that, as far as this experiment goes, it proves that fish may be fed «“ merely by: bringing dif- ferent kinds together, as is the case in nature.” Minute a- quatic animals and larvee abound in every piece of water, who find their nutriment in matters invisible to the eye and impal- pable to the touch. . These again form the food of the smaller fishes, aquatic helices, mytili, leeches, and the multitudinous inhabitants of lakes ; and their fecundity is in general so great, as not only to keep up the species, but afford a considerable overplus for the food of ‘others. Mr Pennant relates, that in the fens.of Lincolnshire, and some of the rivers that creep out of them, the stickleback is produced in such quantity, that once in seven or eight years they are forced to migrate. ‘The quantity is so great,” he adds, in one river, the Welland, ‘ that they’are used to manure the land, and trials have been made to get oil from them. A notion may be had of this vast shoal, by saying, that a man employed by the farmer to take them has got, for a considerable time, four shillings a-day by selling them at a halfpenny per bushel.” * But should the smaller fishes, introduced or natives of the lakes, not afford a sufficient supply, the same ingenuity which can reclaim fish from the deep will be exerted with equal success in procuring them food. Arr. XXVITII.—Notice of Captain Parry’s Last Expedition to the Arctic Regions in 1824 and 1825. Tue return of Captain Parry from his last expedition to the Aretic Regions without having accomplished any of the lead- * British Zoology, vol. iii. p. 353- 148 Notice of Captain Parry's last Expedition ing objects for which it was fitted out, will probably termi- nate for a while those valuable and interesting voyages of dis- covery, by which the British government have wtiied 80 much to our knowledge of the Polar Regions. The expedition set sail from the west coast of Greenland on - the 4th of July 1824; but such was the condition of the ice; that the Fury and Hecla were detained in Dayis’ Straits for’ eight weeks. Having disentangled themselves from the ‘ice about the 9th of September, they entered Lancaster Sound, and, passing through Barrow’s Straits, they arrived at the en- trance of Prince Regent’s Inlet. _Here the weather became very severe, and after experiencing great obstruction from the’ ice, they, with considerable difficulty, reached Port Bowen om the 28th of September in North Lat. '73°, and West Long. 79°. Winter was now rapidly approaching, every exertion was’ - made to'prepare for it, and the ships were safely placed in their’ position for the ‘winter on the Ist of October. The ships’ were completely surrounded with young ice so early as _ “5 6th of October. ‘The monotony of an Arctic winter Captain Parry contrived to relieve by such amusements and occupationsas were within the reach of his party. - Once every fortnight a masquerade was» got up in one of the ships ; and as there was a good collection of books on board, the intellectual part of the ships’ company’ were enabled to add instruction to their amusements. The greatest degree of cold observed during the winter amounted to 481° below zero of Fahrenheit, and the winter was considered as comparatively mild. ‘This circumstance will give a greater degree of value to the meteorological observations made on board the ships, as their combination with those formerly made, will enable us to deduce with very considerable accuracy the mean temperature of the parallel of 73°. When the weather .was favourable the hunting of the white bear, of which twelve were killed, formed an agreeable re 1x- ation ; and in the spring considerable numbers of white grouse were shot, which were considered, bate by. the officers And men, as a great luxury. When the spring brought with it more tbe Pauther, par- to the Arctic Regions in 1824 and 1825. 149 ties of discovery were sent out under Captain Hoppner, Lieu- tenant Sherer, and Lieutenant Ross. The party under Cap- tain Hoppner, penetrated into the interior to the eastward; that under Lieutenant Sherer, went along the coast to the south, and succeeded in reaching Fitzgerald Bay, in lat.»'72° 30’; while Lieutenant Ross advanced to the northward and pro- ceeded beyond Cape York in 73° 30’. The summer was ushered in with a shower, of rain, so early as the 6th of June 1825. The thaw advanced with great rapidity, and the weather became agreeable and mild. » Pre- parations were made for quitting their winter-quarters ; and, on the 20th of July, when the ice was fairly broken up, the Fury and: Hecla quitted Port Bowen, after a residence of ten months. On the 22d, they were driven back again nearly to Prince Leopold’s Islands in Lancaster Sound. On the 23d they reached North Somerset ; and, on the 24th, Cape Sep- pings, on the western entrance of Prince Regent’s Inlet. Here the danger to which the ships were exposed now commenced. They worked down to the southward, along the west shore of the Regent’s Inlet, till the morning of the Ist of August, when unfortunately the Fury was forced on shore by masses of ice. By great exertions she was got off, and she bore down a little farther to the southward, in order to be repair- ed. ‘The severity of the weather, however, increased ; and, notwithstanding that the greatest efforts were made to save her, she was abandoned on the 23d of August. All her crew were removed on board the Hecla, which had herself been in imminent danger. Every hope of prosecuting the objects of the expedition now vanished, and it was the opinion - of all the officers that they should return to England. The Hecla accordingly stood to the northward; and, on the 27th August, she anchored in Niell’s Harbour, a little to the southward of Port Bowen. . After two or three days, which were spent in refitting the vessel, the Hecla quitted Prince Regent’s Inlet on the 1st of September. By the 17th they had got through the ice, and passed the Arctic circle ; and, on the Ist October, they reached ‘the Orkney Islands.. On the 16th October Captain Parry ar- 150 History of Mechanical Inventions and rivedat the Admiralty, having landed at Peterhead in Scot- land; and travelled to London by land. » During this voyage only two men were lost;—one perished py disease, and one was drowned. The rest of the crew of both vessels returned in perfect health and spirits. The plants collected during the expedition, have been put into the hands of Dr Hooker for examination; but we under- stand that, they do not contain any thing very new or im- portant. We look forward with much anxiety to the alleges of the meteorological and magnetical observations taken during this expedition ; particularly as they were made at ‘a place in- termediate, both in longitude and latitude, between Melville Island, and the stations of Winter Island, and Igloolik. Art. XXIX.—HISTORY OF MECHANICAL INVENTIONS AND PROCESSES IN THE USEFUL ARTS. 1. Description of the Double Weather Sluices invented by Rosert THOM; Esq., Rothesay. Communicated by the Author. T' nts apparatus is, to a certain extent, similar to the one last described : but it has a double operation, the sluices first opening, one after another, as the streams increase, until they reach a given height ; and then shutting, one af- ter another, as they continue to rise above that height. Again, when the streams begin to fall, the sluices open, one after another, until they (the streams) fall to a certain point, and then again shut, one after another, as they continue to fall below that point ; the same continuous rise in the streams, first opening, and then shutting all these sluices in succession ; and, in like manner, the same continusts fall first opening and then shat. ting them in succession- This apparatus, in whole or in part, may, by a judicious adaptation, be applied to many useful purposes, as will be readily perceived by such as are conversant in these matters ; but the object chiefly in view in contriv- ing it, was its application to white are termed, * Compensation ‘Reser- voirs.” Suppose, for instance, that it is necessary to form a reservoir in) the site of some rivulet or stream, for the purpose of collecting water for some i portant object, and which water is to be carried away in a direction rent from the natural course of the rivulet, it is evident that the tea tors of land, or works on the rivulet, below where the proposed reservoir is to, be. made, will object, to its formation, tinless some compensation be made them for the water thus to be carried away. There may be many Processes in the Useful Arts. 15Y ways of making such compensations: for the sake of illustration, suppose the following: The proprietors agree that such reservoir may be made, providing that only the surplus water of floods be detained therein, and that all the rest shall be allowed to flow down the rivulet as formerly ; that is, all'the water necessary for such proprietors, shall be allowed to flow down the rivulet whilst it produces that quantity, and when it does not produce that quantity, they are to have all that it does produce, the same as if no such reservoir were there. — The usual way of accomplishing this, is to cut an aqueduct round one side of the reservoir, along which the water of the rivulet is always car« ried past the reservoir, except during floods, when the surplus water is al- lowed ‘to flow over into it. .A little consideration will show that a very great quantity of water is thus lost. In the first place, the proprietors below must have all they require, before any is allowed to flow over into the reservoir: but the rise of water in the rivulet that sends a part over into the reservoir, must also send more down the aqueduct; this addi- tional quantity sent down is thérefore lost. But, in all such situations, there must be other small streams falling into the rivulet, between the re« servoir and works below ; and the same rains that swell the rivulet above the reservoir, will also swell the streams below it; and, consequently, the whole additional water yielded by these streams is*also lost.* As the quantity of water thus wasted, is generally much greater than that detain- ed in the reservoir, and as the apparatus about to be described saves the whole, its importance may be easily conceived. But, besides this, the proprietors on the rivulet below generally stipu- late to haye .a certain supply of water from the reservoir during the dry season, as a horus for‘allowing the ‘reservoir to be made ; and, as the re- gulating of this supply has heretofore been left to watermen, who, inde- pendent of neglect, caprice, or ignorance, are liable to be biassed by vari- ous considerations which are well known to have frequently occasioned vexatious disputes and litigation between the parties concerned, it becomes extremely desirable to be independent of such agents. The apparatus shown in Plate VI, Fig. 10. (given in Last Number) by regulating such _™ To explain this more fully, let ABZ, Plate 1, Fig. 24, represent the course of the rivulet upon which the reservoir CDE is to be formed ; AFB the aqueduct to carry the usual water of the rivulet past the reservoir ; Z the mill or other work on the rivulet be- low the reservoir, which requires the greatest quantity of water ; (and, of course, when it is supplied, all the others must be so,) G, H, I, K, streams that fall into the rivu- let between the reservoir and mill Z; L a part of the bank of the aqueduct, low- er than the rest, over which the surplus water of floods passes into the reservoir, and which is made of such height, that no water can pass over into the reservoir un- til enough passes to supply the mill Z. But, when the water rises above this, and a part flows over into the reservoir, an additional quantity must also pass down, the aqueduct, which is therefore lost, the mill Z having enough before. Again, the same rains that swell the rivulet above the reservoir, will also swell the streams G, H, I, K, below it ; all this additional water sent down by them is therefore also lost, 152 History of Mechanical Inventions and supply of itself, does away all this; and the quantity, once ate rey will continue regular and uniform. 10 ‘AB, is a basin of water immediately behind the tunnel of the veniay . in which basin the water is always kept at the same level, by the ai tts tus formerly described. “BC, one of a number of sluices of the same kind on that basin that turns upon pivots at C. DE, a can, open at top, and having a very small aperture in its bottom. F, a pulley. DFG, a chain, which, passing over pulley F, has one end fixed tevin BC, and the other to can DE, H, a weight that keeps the sluice BC always, shut, when the can DE is empty ; when that can is full of water, it lifts weight H, and ett om sluice. ' IK, a section of the rivulet, immediately before it falls into the reser~ voir. LMN, a pipe which communicates between the rivulet at 1K, and ete can DE. Z, this letter cannot be shown on the drawing, but is the neppoie mill or factory, on the rivulet below the reservoir, that requires the bgp est quantity of water. Now, suppose the weather to be dry, and the water so low in che rivu- let as only to reach the aperture 1, then the water that flows out there passes down pipe L MN, and runs out at N into can DE, which, being ; thus filled with water, opens sluice BC, which passes as much water as the rivulet then brings into the reservoir.* But, when the rivulet swells so as to flow out at aperture 2, then (the opening at N not being able to pass the whole) the water rises in pipe LM, and passes along pipe OP, and, falling into another can, opens a second sluice, which, with the first, pass- es as much water as the rivulet then brings into the reservoir. When the water in the rivulet rises so as to flow out at aperture 3, it rises also in LM, and, passing along pipe QR, flows out at R into a third can, and opens a third sluice, and these three pass as much water as the rivulet then brings, and which is here supposed to be the greatest quantity want- ed at the place Z. Suppose, now, the flood should still continue to in. crease, the streams and surface water between the reservoir and Z will increase the rivulet at Z, as well as the higher streams increase it at IK ; but there was formerly enough of water at Z: when, therefore, the rivu- let rises so as to flow out at aperture 4, the water will rise also in the tubes NS, PT, RU, till it come to float S, which it lifts, and thereby shuts valve N ; the water in can DE then passes out at the small opening in its bottom, and the weight H shuts sluice BC, which stops as much water in the reservoir as the streams below have increased. When the water in ane: so as to flow at aperture 5, it rises also in the tubes tt * By a very simple contrivance any one can tell, by merel y looking at vo a whether the same a te of water is flowing from and into the fais “Processes in the Useful Arts. * 158 lift float ‘I’, which sluts another sluice. When the rivulet rises till the water flows out at aperture 6, it raises float U, and shuts the third or last sluice ; the flood being now supposed so great, that the streams below the reservoir are ‘of themselves sufficient for the supply at Z. When the streams begin to fall, the rivulet at IK will also fall ; and when the water ceases to flow into aperture 6, the water falls so far in the tubes, as to let down float U, and open one sluice ; when it ceases to flow out at aperture 5, the float T falls, and a second sluice opens ; when it ceases to flow out at aperture 4, the third sluice opens, which, with the other two, passes all the water that the rivulet is then bringing into the reservoir Should the rivulet continue to fall,-so as not to flow out at aperture 3, then the water ceases to flow along QR, and one sluice shuts; should it fall below aper- ture 2, the water also ceases to flow along OP, and a second sluice shuts, should the rivulet become quite dry, then the third or last sluice shuts. Any number of sluices may be used that are found necessary ; and in this way the same quantity of water will always run in the rivulet at Z, as if no reservoir had been placed upon the rivulet above, except during floods, when all the water not required at Z would be detained in that reservoir. Besides the immense quantity of water thus gained during floods, the ex- pence of cutting an aqueduct round the reservoir is also saved ; nor is any bye-water necessary,“ as the main sluice on the reservoir, that regulates the height of the water in the basin AB, acts also as a waster. When it is necessary to supply any fixed quantity of water from the reservoir, we have only to make an aperture in the basin of the proper size; and, as the wuter there stands always at the same height, the supply will always be the same. 2. Description of a Rotatory Gas-Burner. Various attempts have been made to construct a gas-burner which should revolve upon the principle of Barker’s mill, by means of the reaction of the gas issuing under the ordinary pressure at which it is burned. If the place round which the motion is performed is an ordinary gas-tight joint, the friction is so great, that a motion of rotation cannot be obtained, un- less the gas has been greatly condensed, so as to issue under the pressure of many atmospheres. A rotatory burner of this description was made last year by Mr Deuchar, but it was nothing more than a philosophical experiment, quite inapplicable to gas, as it is generally used. * It is not necessary that the tunnel of the reservoir should waste the water as fast as it flows into the reservoir during the greatest floods, because the water be- gins to waste several feet below the top of the embankment ; and, although the tun- nel should not pass above one half. of the water that flows into the reservoir during the greatest floods, yet as such floods only last for a short time, the water will scarce- ly ever rise in the reservoir more than a few inches during any one flood; and, be- fore another comes, it is again down to its proper level ; this, of course, depends up- on the greater or less extent of the surface of the reservoir, as well as the size of the rivulet or feeder ; but, in most cases, a bye-water will be found to be quite unneces- sary, if a proper tunnel with a self-acting sluice be adopted. 154 History of Mechanical Inventions, &c. The rotatory gas-burner, which is represented i in Plate I. Fig. 25, is the invention of Mr Nimmo, brass-founder in Edinburgh. It displays. great ingenuity, and revolves by the reaction of gas issuing at the ordinary: pressure. , In the section shown in the figure PQR is the gas tube communi« cating by its lower end PQ, with any gas pipe. This tube, which is conical at its upper end R, terminates in a sharp pivot at R, and has several large holes a made in it near the top, so.as to allow the gas to escape. On the outside of the tube PQR, and fixed to it at PQ, is the water tube ABCDPQ; which is filled with water. These parts of the burner are all stationary. - _ The revolving part consists of two horizontal tubes, crossing one ano- ther at right angles. Only one of these tubes, EF, is seen in the section, These tubes communicate with the vertical tube GHMN,,. the lower end of ‘which, MN, is open, and is immersed in the water tube ABCD, the _ whole resting upon the pivot below R, and revolving upon it as a-centre, This revolution is effected in the following manner: The gas ascending the tube PQR, escapes through the openings in it at a; and being pre- vented by the water within the tube GHMN, from getting out at its open end MN, it fills the tubes EF, and issuing at the holes A.A, at their ex- tremities, its reaction upon the opposite sides of the tube produces a ho« . rizontal rotatory motion, the vertical tube GHMN, revolving freely i in the water, in the tube ABCD. If the contrivance now described, formed merely an elegant addition to our gas-light apparatus, it would even, in this point of view, possess cons siderable interest ; but there is reason to think, that, by’a, proper adjust - ment of the velotity of rotation to the quantity of gas discharged, the flame may be supplied with the requisite quantity of air, more perfectly than can be done in a stationary burner. If this shall turn out to be the case, the rotatory gas-burner may be the most economical contrivance for burning gas. , 3. Curious Law respecting the Vibration of Pendulums. The very curious law, of which we propose to give a brief notice, has been discovered by Davies Gilbert, Esq. M. P. and explained in the Quar- terly Journal. As it appears from a very simple calculation, that every inch of variation in the barometer must change about two-tenths of a second the daily rate of a clock with a brass pendulum, in so far as buoyancy is alone con- cerned, Mr D. Gilbert requested Mr Pond and Dr Brinkley to observe the rates of their clocks, when the barometer was at its maximum and minimum height ; and he learned with great surprise, that no variation could be oly served. Upon reconsidering the subject, however, it occurred to Mr D, Gilbert, | chat the acceleration of the time of vibration produced indirectly by an increased: resistance, in consequence of reducing the are of vibration, and the circular excess, might be a perceptible quantity. This had not escaped Mr Gilbert’s notice, but he had regarded it as comparatively an evanes- cent quantity. When submitting it to ‘calculation, however, he found 1 Analysis of Scientific Books and Memoirs. 156 that it was nearly equal to that of retardation arising from buoyancy, 90 that ina brass pendulum (Spec. Grav. 8.8) with an arc of vibration of 3° 53 10” and in a mercurial pendulum with an are of vibration of 3° 3’ 28”, the retardation from buoyancy is ewactly compensated hy the acteleration arising r from the reduction of the circular excess. ‘Hence, if in every clock, the arc of vibration is so adjusted as to make the retardation from buoyancy equal to the retardation caused by the cir- -etilar excess, and if the density and consequent resistance of the medium be supposed to change, the incremental variations of the times arising, from these two causes will be equal and in ignore: directions. 4. Reverend Mr Lardner’s method of sdaloiig Carriage Whedls on Pest - Acles. This ingenious contrivance is represented in Plate I. Fig. 26, 27, 28, In Fig. 26, AB is the part of the axletree on which the wheel revolves, BC a stop or spud forming part of the axletree, and within which the wheel revolves, and CD a screw having a perforation with a linch pin, as shown in Fig. 28. The nave of the wheel is shown in Fig. 27, where may be seen the groove m which receives the stop or spud BC. When the wheel is about to be placed upon the axle, this groove must be brought opposite the spud BC, Fig. 26,80 as to pass over it. The wheel will then revolve within thespud, and cannot come off the axletree, unless the groove m first pass over the stop BC, during which process the wheel cannot revolve. A slide or wedge EF, made to fit the groove exactly, is inserted when the groove is not opposite the spud, so that the wheel cannot, come off, unless this slide works out. A collar GH, Fig. 28, with an aperture corresponding to the stop BC. Art. XXX.—ANALYSIS OF SCIENTIFIC BOOKS AND MEMOIRS. I. Account of the ‘Earthquakes which occurred in Sicily, in March 1823. By Sig. Asatre Ferrara, Professor of Natural Philosophy in the Uni- versity of Catania. Tuts curious Memoir, of which we intend to give an abstract, may be divided into two parts, the first of which gives an account of the general phenomena and effects of the earthquakes, and the second relates to the physical explanation of the phenomena. On Wednesday, the 5th of March 1823, at 26m. ae 5 Pp. M., Sicily suf- fered a violent shock of an earthquake. ‘The first shock was indistinct, but tending from below upwards ; the second was undulatory, but more vigor- ous, as though a new impulse had been added to the first, doubling its force ; the third was less strong, ‘but of the same nature ; a new exertion of the force rendered the fourth equal on the whole to the second ; the fifth, like the first, had an evident tendency upwards. Their duration was (156. Analysis of Scientific Books and Memoirs, between sixteen and seventeen seconds ; the time was precisely marked by the seconds hand of a watch which I had with me. The direction was from north-east to south-west. Many persons who ‘ran towards me from the south-west, at the time of this terrible phenomenon, were opposed by the resistance of the earth. .The spear of the vane on the top of the new gate connected with the palace, and upon which I fixed my eyes, bowed in that direction, and remained so until the Sabbath, when it fell; it was inclined to the south-west in an angle of 20°. The waters in the great basin of the Botanical Garden, as was told me by an eye witness, were urged up in the same direction by the second shock; and a palm tree, thirty feet high, in the same garden, was seen to bow its long leafless branches alternately to the north-east and south-west, almost to the ground. The clocks. in the observatory, which vibrated from north to south, and from east to west, were stopped, because the direction of the shock cut obliquely the plane of their respective vibrations ; and the weight of one of them broke its crystal. But two small clocks in my chamber kept their motion, as their vibrations were in the direction of the shock. The mer- cury in the sismometer preserved in the observatory was put into violent motion, and at the fifth shock, it seemed as much agitated as if it were boiling. To the west of Palermo, within the mountains, the earthquake retained little of its power; since at Morreale, four miles distant, trifling injury only was sustained by the (Benedictine) Monastery of S. Castrense, the house of the P. P. Conviventi, and the Seminary dei Cherici. At Parco, six miles distant, Mary’s College, the Monastery, the parish Church, and a few peasants’ cottages, were all that suffered. At Piana, the battlements of the tower were thrown down. But more of its power was felt in places on the sea-coast, as appears from its effects at Capaci, four miles distant, where the cathedral and several houses were ruined, and at Torretta, four-~ teen miles, where the cathedral, two storehouses, and some dwelling- houses, were destroyed. Beyond, its power continued to diminish ; and at Castellamare, twenty-four miles, the state-house alone had the cleft, which was made in 1819, enlarged. i, ~ In maritime places east of Palermo, the shock was immense. At Alta- villa, fourteen miles from Palermo, the bridge was shaken. At Trabia, twenty-one miles, the castle, and at Godiano, the cathedral and some houses, were destroyed,—enormous masses from Bisambra, a neighbouring mount, were loosened, and fell. At Termini, twenty-four miles, the shocks were very violent, exceeding all that had happened within the me- mory of its inhabitants. Those of 1818-19 were very strong, but the city received at those times no injury ; now the convent of St Antonio, sie College, and various private houses, felt its effects. The warm waters, as wel] those of the baths as those from the. neigh bouring wells, which proceed. from the same subterranean source in the mountains along the coast of Termini, increased in quantity and warmth, and became turbid ; consequences that.always succeed convulsions of the earth, by which their internal streams are disordered. The clay tinged ii Prof. Ferrara on the Earthquakes in Sicily in 1883. 18% the fluid with its own colour, and equal volumes of the water yielded a greater quantity of the clay than before, when the colour was deeper,* Most of the houses in the little new,town of Sarcari, two miles from the shore, and consisting of less than a hundred houses, were rendered unin-. habitable ; the walls were thrown down, and the more lofty buildings were all damaged. The effects of the earthquake are found to be greater in proportion to its advance eastward. Forty-eight miles. from Palermo, at Cefalu, a large city on the shore of a promontory, the effects were various and injurious. Without the walls, two convents, a storehouse, and some country houses, were injured, but no lives were lost. The sea made a violent and sudden rush to the shore, carrying with it a large ship laden with oil ; and when the wave retired, she was left quite dry ; but a second wave returned with such immense, force, that the ship was dashed to pieces, and the oil lost. Boats, which were approaching the shore, were borne rapidly forward to the land, but at the return of the water, they were carried as rapidly back, far beyond their first situation. The same motion of the sea, but less violent, was observed all along the shore, as far even as Palermo. Pollina, a town with nine hundred inhabitants, occupying an elevated position at a little dis- tance from the sea, was injured in almost every building ; particularly in the church of St Peter and Nunciata, in the castle, the tower, and in other places.. Nor did Finale, a little nearer the shore, suffer less ; five of its houses fell in consequence, on the 11th of March. Beyond :the towns which have been mentioned, towards the interior of the island, the shock was vigorous to a certain extent, but kept decreasing as it proceeded throughout the whole surface. At Ciminna, south of Ter- mini, a statue was shaken from its place on the top of a belfry in front of the great church, and a part of the clock tower falling, killed one person and badly wounded another. In Cerda, the shock affected the great church, and also some houses, and half of one of the three forts, placed near the city to support: the earth on the side of a great declivity. : The only church in Roccapalomba, which is situated at the top of an acclivity, was ruined. _ The parish church, and some private houses in the little town of Scillato, were overthrown. In Gratteri, a large town south of Cephalu, injury was sustained by the church of St James and other houses. Considerable damage was sustained by various churches, and many private houses in Colesano, a town containing two thousand inhabitants, and situated on an inclined plain, on the eastern side of the mountains of Madonie. One of the Colleges de Maria was rendered uninhabitable. The hospital, a grand fabric, was made a heap of ruins. The loss is caleu- lated at about fifteen thousand pounds Sterling. In the vicinity of Pozzillo and St Agata, through a large extent of land, many long fissures and cae verns were made. Similar caverns and fissures in argillaceous chalk, were. * The warm and mineral waters of St Euphemia, in Calabria, which. sprung up after the memorable earthquakes in 1638, presented the same phenomena during: those of 1783.—Grimaldi descr. dei trem. del. 1783. 158 Analysis of Scientific Books aid Memoirs.” >“ opened near the little town of Ogliastro, sixteen miles south-east. of Paler= mo. At Isnello, at the feet of the Madonie mountains, the injuries which. were received in 1819 were increased ; Geraci, among the same mountains, suffered a like fate in the ruin of the cathedral ; Castelbuono and St Mauro, within the same regions, were damaged, both by the former and. by the last convulsions ; by the last, the cathedral, the church of St Mau- ro, and five private houses suffered much. ‘The damage done to Castel- buono is reckoned at eleven thousand pounds Sterling. The northern coast: of Sicily, towards Cape Cefalu, after bending to form the eastern part of the great bay, included on the west by the moun- tains to the left of Palermo, extends into the sea towards Molie, (the Li- pari islands,) and presents, towards them, a hollow front, the western part of which is formed by Cape Orlando, and the eastern by Cape Calava, Places situated about this bay, suffered the most violent convulsions. Na- to, containing four thousand souls, and situated on an elevation, was al- most entirely laid waste, and a great number of private houses destroyed ; the monastery, hospital, the churches of St Peter, Anime del Purgatorio, St Demetrius, and the cathedral, were in a great measure overthrown. The Quartiere del Salvadore suffered less. A transverse cleft was made in the earth, and fears were entertained, lest the whole elevation upon — which the city is built should be overthrown. Only two persons lost their lives ; for the people, warned by a slight'shock which was felt some hours before, had all fled into the country. Directly in front of Voleano, one of the isles of Eolia, Patti, a city built on the declivity of a mountain, and at the distance of half a mile from the eastern extremity of Cape Car lava, had its cathedral, bishop’s palace, convents, and many private houses: injured. With the copious showers of the 5th, fell some roofs ; various houses'in the country were ruined. Pozzodigotto, Meri, and Barcellona, were injured a little. At Barcellona, a wide cleft was-made in the belfry of the church, and threatened its ruin. ‘The shock at Milazzo; on ithe sea, was violent, as also at St Lucia, six miles from it, situated on ai emi- nence, ‘but without any bad consequences. Some damage was doné to the hospital, several churches, and private houses at Messina. In the in- terior of Sicily, the motion was communicated as if it were far from the centre of force; in some places towards the south, some buildings which were old and out of repair, felt the effects, particularly at Caltauturo ; and at Alimena, in the cathedral and convent of the reformed. The sbotks, gradually wasted itself as it advanced ; and at Catania, so slight was the impression made on the people, that they went to the theatre the same evening. It was perceived by a few persons only in Syracuse, and in some of the neighbouring towns. - In the district of Modica, towards Cape Pas~ saro, scarcely one felt it. No bad effects were produced by it in the south- ern parts of the island ; in the western it was felt, but without injury. It was pretty strong at Alcdmo, but slight at Trapani. ‘ The ancient city of Palermo was founded upon a rocky tongue of land, between two large and deep bays. The extremity of this point constitutes at this day the centre of the modern city. Matter, transported thither by Prof. Ferrara on the Earthquakes.in Sicily in 1823, 159 the water from the interior, and thrown up by the sea, together with the labour of men, has gradually filled up the lateral spaces, and extended the with this transported and alluvial earth, and formed the present soil. It is now composed in part of calcareous rock, and in part of mud or alluvial earth ; both are traversed by canals and large conduits for the circulation of water for common use, and by common sewers communicat- ing with the neighbouring shore. The adjacent parts present a surface composed of calcareous tufa, and an earthy aggregate, tender and friable ; but, deeper down, it is more durable, and partly siliceous. In the night of the Ist of September 1726, continues Professor Ferre; an earthquake destroyed, or very much injured, all the buildings situated on the muddy soil; and many, which were out of repair, or badly con~ structed, placed on rock. Earth of the nature of the first, is less capable ofreceiving’ motion from a shock than the last, since it possesses less re- sistance. But facts show that this advantage is more than compensated by want of stability in edifices raised upon it- At Messina, in 1783, all the buildings upon a plain, and-upon earth thrown up by the sea, were destroyed, while those on the neighbouring hills were not moyed. The same happened at Calabria, and, in 1805, in the district of Molise. In this account we should notice the cavities made in the earth. . They were esteemed by the ancients as preservatives against earthquakes, not by af- fording an outlet to the subterranean vapours, as some have thought, but by interrupting or diminishing the course of the shock. . ‘Most of the injury, says our author, was done by the second impulse of the shock, when the spear of the vane on the new gate was bent, and the water in the basin in the Botanical Garden was forced violently up one side. Immediately after the shock, he remarks, the apparent injuries were not very great, but the blow was given ; and the long and abundant showers of rain which succeeded continued to develop and increase the injuries, and now, though not very many buildings are entirely destroyed, yet there is scarcely one which has not received some damage. Here fol- low some notices of the dreadful consequences which befell many of the inhabitants, from the falling of the timbers, and stones, and walls ; of the vases from the piazzas into the streets and many other things which it-is unnecessary to mention more particularly. Nineteen persons werc killed, and twenty-five wounded ; in the earthquake of September 1, 1726, four hundred were killed and very many wounded. Messina, which suffered so much in 1783, although violently moved by this last shock, experienced from it no bad effects ; for this noble city has risen from her ancient ruins, robust and majestic. Catania, in 1818, was convulsed in a terrible manner, but its inhabitants were enabled to con- template without a tear all the little injury sustained by their beautiful fabrics.* * After the fatal earthquake of 1693, in Catania, by which 18,000 persons perished, the people began to build of one story, and always after the plan of bar- racks. But, as the fear passed from their minds, they raised their houses two sto- 160 Analysis of Scientific Books and Memoirs. After the shock of the 5th, the black clouds which covered the heavens on the north and west, formed a dark band, measuring from the: zenith | towards the horizon 60°, and extending from north to south. It wasters - minated at its base by a circular line, passing from north to south, through - the west, and elevated at the southern part about 30° dbove the-horizon; The sky itself was very clear, and its extreme brightness was increased: by the contrast with the dark band above, and by the sun just on the point of setting. A little below the band were two other lines, parallel and perfectly. regular. This mysterious appearance inspired with fear the minds of the people, who are always seeking in the heavens for signs of future events. But it prepared a tempestuous night, which followed, with torrents of rain, with thunder, snow, hail, and wind.® py and sometimes even three, and not with much solidity. Since the middle of the last century, the excellent materials afforded them by tna, the good method and prudent regulation of the stories, have promised long duration to this city. It may possibly be injured, but cannot be easily ruined, although at the foot of the most formidable volcano in the world. After the catastrophe of the 5th of March in Pa. Jermo, the lieutenant, the pretor, senators, and police exerted all their zeal. They obliged proprietors to prop up their houses within twenty-four hours ; or to demo- lish them if they were not susceptible of propping. The senate took upon themselves the charge of repairing the houses of poor proprietors, together with the expences. “In all times, sigas have been mentioned as announcing earthquakes near at hand. People read them in the air and upon the earth; and some philosophers even have given them credence. The frequent eccurrence of these signs, without the expected phenomena, is a sufficient argument against them. But less uncertain are those which accompany the phenomena, as rain and thunder. To that of 1693 such fearful storms succeeded, that, for many hours, at Catania, the groans and voices of the miserable wretches buried under the ruins, were drowned by the roar- ing of the torrents of rain and the tremendous thunders. -The same circumstances took place at Calabria in 1783; and we were witnesses of the same on the night of the 5th of March. An extraordinary quantity of electric fluid is developed, and being conducted from the deep cavities of the earth to the surface, by the force of equilibrium, produces there extraordinary vaporization, when hygrometers have shown extreme dryness. The atmosphere, charged beyond measure with vapours, will give room to their decomposition, which changes them into vesicles, and then into rain. Fiery meteors will be produced by the electric fluid, liberated by the passage of the vapours to water. If hydrogen gas escape from the earth, it may be inflamed by the electric spark, and present the appearance of fires, I should men- tion here, that, in-voleanic regions, signs may sometimes precede earthquakes; but this happens from the proximity of the place of the subterranean operations to the surface of the earth, which circumstance connects the internal phenomena with. those of the adjacent atmosphere. On the morning of the 8th of March 1669, at. Pidara, a town on the side of tna, the air. became obscure, as by a partial eclipse. of the sun; soon after the earth began to shake, and continued so until the 11th, when an immense fissure opened near Nicolosi, a neighbouring town, a sparkling . light appeared over the fissure ; and, on that very day, while the terrible shocks were levelling Nicolosi with the ground, an enormous burning river, amidst herrid rum- blings, roarings, and explosions, was belched out, which flowed fifteen miles, cover- ing a great extent of land, and for four months spreading terror over Sicily.— Bor. de. inc. Hin——Ferr, Descr, dell Alina, Prof, Feratia on he Earthquakes ih Sicily 1893, 161. On the night of the 6th, at forty-five minutes past one, in St Lucia de Millazzé, six miles ftom the shore which looks *towards Vulcano and Strouibolf,; a severe shock was felt, and afterwards, at various intervals, horrible noises were heard, four distinct times, rambling fearfully beneath them; and finally, at half past three o’clock, the shock was repeated. Both were felt at Messina, but without any subterranean noises. Nothing of it was felt at Palermo, or in any places in the west. At fifty-six minutes past ten, during the night of the 7th, another shock was felt at Palermo, sufficiently strong to put in motion the pendulum of a small clock, which I had stopped that I might regulate it in the morning. Its vibration, from north-east to south-west, showed me with certainty the direction of the — shock. Light ones were felt on the 26th. On the 3Ist, at fifty-two mi- nutes past two, P. M., one was felt at Messina, moderately severe, of five or six seconds duration, and undulating. Two others on the ist of April, and one at Castelbuono on the 28th. I should add that they mention a slight one there on the 16th of February, but they are more certain of those of the 5th of March, one at one rp. m- the other at three. These were the shocks which induced the inhabitants of Naso to leave their habi- tations and flee into the country, where they were when their city was laid waste. | (To be concluded in next Number.) -IL—Scuow’s Essay on Botanical Geography. Copenhagen. 1828. As this valuable and elaborate work has not appeared in our language, we propose to lay before our botanical readers one of the most interesting portions of it, which has been translated for this Journal, from the Danish, by that active and intelligent naturalist, W. C. Trevelyan, Esq. F. R. S. E. This portion is entitled, “ On the Phyto-Geographie Division~ of the Globe,” and is divided into various sections, the most important of which we shall lay before our readers. A Science, says M. Schow, is not established at once ; its first fasds e exist, are rejected, are touched upon eursorily, or are treated of without its being foreseen that these ideas, will, in their time, form a self-existent branch of our knowledge. Thus it has happened with regard to the geography of plants. That plants stand in relation to climate; that Species, Genera, and Families are distributed, not fortuitously, but’ according to detérmined natural laws over the earth, was too evident not to fall under the view of every attentive observer ; but observations were too few ; the tendency with most botanists to be content with the mere knowistize of the exter nal forms of plants, and the low rank in which vegetable physiology stood, were the causes why the local relations of plants were not viewed as a connected whole, but the objects connected with ‘it rather consider- ed as curiosities. It is, therefore, in relations of travels, in some Floras, and in physiological works, that the first planto-geographical ideas are to be met with, scattered, and without the least pretension of making a connected whole. VOL, 1v. NO. I. JAN. 1826. L »* 162 uals of Scientific Books and Memoirs. ‘Tournefert, ( sod au Levant, ) remarked, that on Mount Ararat the vegetation changed according to the elevation; that at the foot the plants of Asia Minor ; at the middle, those of France ; and at the summit the plants — of Lapland showed themselves. Linné in his treatine “ide Tellutis Habitabi- lis Incremento,” pursuetl this a little farther. In the “Philvsophia Botanica,” a and in the Essay “ Stationes Plantarum,” he proposed a terminology with A reference to the localities of Plants. In another treatise, Colonia P. Ct a rum,” he speaks especially of the migration of plants ; in * Flora . Pie nica,” he gave, not merely an enumeration of the plants which © - Lapland, but also hints of the variations, which difference of situbeton sid of elevation above the sea, cause in vegetation. Similar,general views ; are found in Haller’s “ Historia Stirpium Helvetia,” and in Forskiils “ Flora Eigyptico-Arabica.” _ ‘The penetrating Adanson necessarily fell upon botanico-geographical _ ideas in his work entitled “‘ Familles des Plantes ;’ and he brought for- ward several observations, which might»direct' attention to the distribu- — _* tion of the families of plants. Saussure, who instituted many inquiries connected with vegetable physiology, was consequently attentive to the in- » j fluence of climate on plants ; he gave notices of the height of plants above the sea, and was probably the first who made use of barometrical measure- j ments with this view. Reynier wrote an essay in the “‘ Journal de Phy- sique,” in which the influence of difference of elevation on plants, in par- ticular, is well treated of. Ramond gave some information concerning the height of plants above the sea in the Pyrenees. Young, in his tour, treats of the limits of the most important cultivated plants ; he determined the most Northern limits of the Olive, the Vine, and Maize. Giraud Soula~ | vie distinguished in the ‘‘/’ Histoire naturelle de la France meridionale,” be- | * tween the regions of the Orange, the Olive, the Vine, the Chesnut, and ; ‘the Alpine region, and thus gave a not unimportant hint towards the di- Wwision of a country in a vegeto-geographic view. In several mamuals, for example Wildenow’s ‘‘ Grundris,” and Senebier’s “ Physiologie vege- tale,” T. 5, may be found a chapter under different titles, for vegeto-geo- graphic materials, but these are mixed with others, and cited in a very desultory manner. / Thus it stood with the geography of plants at the end of the last century. In the present century, on the other hand, it has made great advances, . Stromeyer in 1800 published his dissertation, in which he brings forward a “summary and sketch of what he calls the Geographical History of Plants, . ‘and treats of one branch of it, namely, on the limits of the vegetable king- dom. Treviranus’s “ Biologie,” second volume, contains several planto- geographical ideas; he was doubtless the first, who, with any degree of perfection, paid attention to the distribution of the vegetable families on the globe ; he divided, indeed, its surface into different regions or principal Floras ; but his want of materials caused the results, for the most part, to be uncertain, and some, altogether erroneous. L.'v. Buch, in his travels in None and Lapland, attended to the planto-geographic Sadia IL a , i _ ae ‘ .. Schow’s Essay on Botanical Geography. ” 168 he determined the relations of,plants to their elevation by the help of the _ barometer,’ and inquired into the medium temperature which individual . Decandolle in his “ Flore Francaise,” divided France o regions, according to the difference of vegetation, and treated _of the influence of difference of elevation on vegetation. At last.appear- Humboldt in 1807, with his ‘ Essai sur la geographie des Plantes,” Sand Tableau des regions Equinoetiales.” The first was at the most but.a very loose, sketch, neither was the latter at all a complete comparison be- tween climate and vegetation ; but as he elevated the most interesting of " sciences,—as he, in a striking manner, connected so many physical pheno- mena, which preyiously had been handled separately,—so he excited a ge- neral interest for these inquiries, and this work, therefore, decidedly forms an epoch in the science. His ‘ Tableau de la Nature” co-operated also to produce this effect. Next followed Wahlenberg’ s © Flora Lapponica,” a classical work, which advanced the whole of the geography of' plants. This author was doubtless the first who clearly showed that the an- nual medium temperature is not a sure scale for vegetation, but that attention.must.also be paid to the distribution of heat in the differ- ent parts of the year. He was the first who instituted an ample compa- rison between vegetation in all its relations ; and lastly, he was the first, who, in any perfection, showed the mutual relations of families of plants, and it is ‘only to be lamented, that in this he preferred the Linnean to Jus- _Sieu’s natural families. The same author has since published. two equally important works, on the north of Switzerland, and the Carpathian Moun- tains; he has proceeded in them on the same principles as in the “‘ Flora _ Lapponica ;” corrected several of them, for example, his theory on the temperature of the earth as a scale for vegetation, and given his views greater extension, by comparing Sweden with Switzerland, and beth with the Carpathians. In a treatise in “ Magazin der Gesellschaft natur- Sorschender Freunde,” he has made remarks on the difference between the vegetation of the coast, and the inland, (littoral and continental vegeta- tion.) Engelhardt and Parrot have given in their travels some infor- mation concerning the planto-geographic relations of Caucasus. In 1814, \R. Brown published his ‘‘ General Remarks on the botany of Terra-Austra- _ lis.” In this treatise, the relations of the families of plants are discussed with great acuteness and science ; the author’s deep study of the natural families, and the many opportunities he had for comparing the plants of New Holland, with those of other parts of the globe, ought to give this — work a high degree of perfection. On the other hand, he has not so much as touched upon the influence of climate on vegetation. Hitherto, with the exception of single hints in R. Brown’s work, and Treviranus’s imperfect essay, botanists stopped at’single countries, and did not venture to deduce results for the whole of the globe. This step Hum= holdt made in 1818, in the introduction to the botanical part of his travels ; and although, from the plan of the introduction, the representation of the ‘general laws must be disjointed, it could not but lead to general views, and thus, as well as by its richness in ideas, again make an epoch in the +. 4 164 Analysis of Scientific Books and Memoirs. science. Shortly after, 1817, appeared his essay “ sur les lignes isother=. mes,” which reduced the knowledge of the distribution of heat on the globe into a system, and as it also contains botanico-geographic mate~ rials, it is an invaluable work to the planto-geographer. At the same ' time Decandolle published some interesting information on the planto- geography of France, and on the knowledge of the influence of height on vegegation, in the “* Memoires de la, Societé d’Arcueil ;” and in the - following year, J. Brown, on the Herbarium of Professor Smith, gave a view of the vegetation in the vicinity of the Congo, like that on New Holland, with particular regard to the distribution of the families of plants. There are here also ample inquiries with respect to the species which occur in several far separated countries. With similar views re- garding Denmark and Guinea has Professor Hornemann enriched the science; and. von Buch has made us acquainted with the Flora of the Canary Isles in a planto-geographic point of view. Lastly, Decandolle i in the “ Dictionnaire des Sciences Naturelles,” has published the view of the science already spoken of. To prevent misapprehension, and to obtain a nearly similar degree of difference throughout the Floras in general, I think it most proper to fix certain rules concerning what is requisite to form a Flora, or what I would ~ wather call a Phyto-geographic region, 1 am therefore of opinion, that we should require for this, (1.) That at least half of the species should be peculiar: (2.) That at least a quarter of the genera should be proper to the region, or at least have there so decided a maximum, that their species in other regions might merely be considered as representatives: (3.) That individual families of plants be either peculiar to the region, or else have there their maxima. Nevertheless, where this last property is want- ing, while the difference in genera and spécies is very considerable, we ro _ admit of a region. ‘The regions may, again, according to aminor degree of difference in the vegetation, be divided into provinces, for which, for example, one fourth — of peculiar species, and a few peculiar genera, might be sufficient. In order to have a complete view of the phyto-geographic divisions of the globe, the boundaries and circuit of each, its climatic and other physical relations, should be described ; there should, besides, be mentioned what are the characteristic families and genera which prevail, and that both in regard to species in general, and individuals ; and lastly, a view should be given of the whole habit and character of the vegetation. ‘Towards this, the following is merely a loose sketch. The regions and provinces are best named after the vegetable forms which characterize them, (for the pre= yailing vegetable forms are very often the same in different countries.) I have here attempted this ; at the same time, however, I have added the commonly used geographical terms,* and adopted these last only i in cases when I thought that a certain division of the earth ought to form a tinct region, but knew not the vegetation intimately enough to determine the characteristic forms. ® Wildenow, Decandolle and Treviranus haye used only the latter, re os ‘ i | Schow’s Essay on Botanical Geography. Ae I. (Regnum Saxifragarum et Muscorum, vel Flora Aipido-aretiea,) 9) This region includes, in the first place, all the countries within the polar circle, together with some parts of America and Asia which lie south of it, but have a polar climate; (namely, Lapland, the North of Russia and Siberia, Kamtschatka, Canada, Labrador, Greenland, and Iceland ;) next, part of the Scotch and Scandinavian mountzins, as fat'as thity fall within the Alpine region ; and, lastly; the mountains in the central and Southern parts of Europe, in like manner, as far as they are related to the Alpine region. ‘The Alps, indeed, possess many plants which are wanting in the Northern Polar cowntries ; they may even amount to three-fourths of the whole number of species which grow there ; but, as the Genera, with few exceptions, ere the same as in the Polar Flora, and likewise the characte- tistics of each agree very closely together, these two part® of the earth can scarcely be considered otherwise than as two provinces of the same région. As these two provinces do not immediately join each other, so they might perhaps be treated, the one as a colony, the other as the mother-country, which comparison, however, is merely ideal, for hardly will it be in any person’s power to prove that those Alpine plants of the south of Europe, which also occur in the Polar regions, have migrated from one of these parts of the globe to the other ; indeed, I do not consider this to be in-the smallest degree probable. What distinguishes this region, is the abun= dance of mosses and lichens ; the characteristic families, Saxifragea, Gen- tianew, Alsinee, Caricee, Salicee ; an entire absence of tropical families ; a considerable decrease of the characteristic forms of the Temperate Zone ; forests of fir or birch, or else a total absence of forests, scarcity of annuals, abundance of cespitose plants, proportionally larger blossoms of pure co-< lours- The two Provinces are: (a) The Arctic Flora, Provincia Caricum. - The-great abundance of Caricés and some peculiar genera, as Diapensia, Coptis, are the most important distinguishing marks. As subdivisions, we. might take the following countries, whose Floras, however, might recipro- . cally be distinguished by some peculiar species: Lapland, Iceland, Green land, the northern part of North America, and of Siberia, Kamtschatka. (b) The Alpine flora of the south of Europe, Provincia Primulaceatum, et Phyteumarum. 'The most important marks of distinction are ; a larger number of Primulacee, namely, a great many species of the genera Pri- mula and Androsace, of which the polar lands have only a few species, and the genus Aretia, there entirely wanting ; the tolerably numerous genus Phyteuma, the genera Soldanella, Cherleria, and others, which are likewise wanting in the Polar countries; the greater number of Rhododendra, &c. The subfloras would be ; the Pyrenean, Swiss, Tyrolese, Carpathian, Gre« cian mountains, Aiadsine, and, probably, also the Spanish mountain Flora ; and also the’ Caucasian, in so far as I can determine from Biber siein’s Flora, and from Engelhardt’s and Parrot’s travels. II. (Regnum Umbellatarum et Cruciferarum.) This region compre= hends the whole of the north of Europe, (with the exception of such parts as belong to the preceding,) to the Pyrenees, the mountains of the south . of France, the Alps, the mountains of the north of Greece ; and besides 166 “Analysis of Scientific Books and Memoirs. the greatest part of Siberia, and of the country about Caucasus. Its east~ ern boundaries I dare not fix. Gmelin, indeed in his Flora * says, that _ the vegetation is essentially changed at the river J enisey ; but, as this Flo- ra contains so great a number of European species, and has only 15 genera which are watiting in Europe, so this expression can hardly be understood, literally, and Siberia, or at least the greater part of it, may thus belong to the same region as the north of Europe. The country about Caucasus and Krim, falls only partly within this region, for, according to Biberstein’s Flo- ta the southern parts of those ——r have a greater resemblance to the south of Europe. - It might be doubted whether that part of the globe, included within these limits, forms a particular region, or only a province of the next re- gion, which includes all the countfies which surround the Mediterranean Sea; for, although, indeed, this latter region has a great many species, genera, and even families, which are entirely wanting in the north of Eu- rope and Asia, so, on the other hand, this part of the earth stands in so low a rank, in regard to plants peculiar to it, that not only above half of its species are also found in the south of Europe, but very few peculiar ge- -nera appear, and not one peculiar family. -‘But as, on the other hand, this resemblance is not complete, and however some families are rather more numerous here than in the countries on the Mediterranean, so it may perhaps be answered, that it may be considered as a particular region, ‘though its great want of peculiar forms ought to be attended to.- I have called this the region of the Crucifere and the Umbellate, because these two families in this region, form a larger quotient of the total number than in any other ; and because in this way it may particularly be separ- ated from the vegetation of North America‘on the same parallel. From the next region it is moreover distinguished by Fungi being more com- mon, by Rosacea, Ranunculacee, Amentacee, and Conifere forming a ra- ther larger quotient ; that it approaches nearer to the polar forms, especial- ly in the abundance of Caricea ; that the meadows are more flourishing ; that almost all the trees are deciduous in winter ; and lastly, by a number of negative characters, namely, the absence of tropical forms, which have representatives in the next region, and fewer species of the families which belong to the characteristics of the latter. From the Polar region it is dis- tinguished partly by the want of most of the Polar forms before mention- ed, and partly, also, by its greater agreement with the following region. » This region may easily be divided into two provinces; (a) Provincia Cichoriacearum, province of northern Europe. This sub-group of the Composite appears to be rather more numerous in Europe than’ in Asia, where on the contrary, the Cynarocephalee are more common ; the other distinguishing marks, are merely formed of some few peculiar ge- ~nera. The countries belonging to this province, Great Britain, the north of France, Holland, Germany, Denmark, the Scandinavian Peni as far as it does not be to the Pees region, Poland, kd e great "© Flora Siberica, T. 1, Pref. ed atk cat . ae eS - Prof. Agardh’s Memoir on the Red Snow, &c. 167 er part of European Russia, differ only inconsiderably in regard to their vegetable productions ; (b) Provincia Astragalorum, Halophytorum, et Cy- narotephalarum, province of northern Asia. To this belongs a part of the Caucasian countries, and of the remaining part of Asiatic Russia. The abundance of the three’ groups of plants above mentioned, characterize this province, as well from the preceding province as from the following region. (To be concluded in next Number.) oh - III. Memoir on the Red Snow of the Arctic Regions. By Professor Ac« arpa of Lund. “ Uber den in der Polar-xone gefundenen Rothen Schnee.” Nova Acta Academia Nat. Curios. vol. xii. Sivce we have, in former numbers of this Journal, brought forward the observations of authors upon this singular vegetable production, (as it is now universally acknowledge: to be,) and since we have ourselves enter« ed rather fully upon the subject in the yet unpublished Botanical Ap< pendix to Captain Parry's Second Voyage, we shall here subjoin an analysis ’ of Professor Agardh’s valuable Memoir, which is just published. ** Rain, he says, charged with extraneous substances, is not an unusual phenomenon. The most general appearance of this kind, is what is de~ nominated a shower of sulphur. Upon examining this, no sulphur has ever been found, but the farina of the pine, (Pinus sylvestris.) Some years since, rain of this kind fell at Lund, which I had the opportunity of ex< amining, and found it mixed with this pollen, although the pine forests, that must have produced it, could not have been at a less distance than from five to six Swedish miles. 5‘ Next to this kind of rain, that which has been denominated a shower of blood, is the most frequent; but, with the nature of this, we are as yet but imperfectly acquainted. That which Peiresc observed in the year ~ 1608, near Aix in France, was occasioned by insects, as was probably that which fell at Schonen in 1711, and which was examined by the clergy- man Hildebrand ; notwithstanding that the learned Bishop Swedberg looked upon it us a supernatural phenomenon, and as a portentous sign from the Divinity. In such cases, it is absolutely necessary that we ob- serve whether the red particles fell with the rain, or whether they after~ wards became incorporated with it. For another red fluid deserves to be mentioned, that which is known under the name of “ blood red water,” (blutrothe wasser,) but which the common people aver to be water changed into blood, and of which many authors have written ; but that appears, or rather most certainly is, of two kinds. That which is the most common, occurs in spring or in hot summers, in ponds, and is formed, according to Linneus, of an immense number of animalcules, the Monoculus Pulex, Lin. (Daphinia Pulex, Latr,) ;* but according to my P itis singular that Linneus, who appears to be so well acquainted with this ~ Monoculus Pulex, should have ascribed to it the colouring ef the water. 1 have 168 | Analysis of Scientific Books and Memoirs. observations of Monoculus quadricornis, L. (or Cyclope quadricornis of Ltr.) which literally dye the water with the number of their red bodies, Linneus mentions another blood-red water in his Westgotha Resa, which formed a pulverulent mass in the cavities of the Sere myrtitig a dye extracted from a species ¢ of fucus. * “These observations are brought forward in connection with the red snow, which for some years past has been seen near the North Pole, and which has so much excited the attention of naturalists, that one would conclude the phenomenon to be of very rare occurrence ; and yet the red snow is very common in all the alpine countries of Europe, although De Saussure was the first, if I mistake not, who paid any attention to it. He found it in 1760, on Mont Breven in Switzerland, and afterwards observed it to be so common on the Alps, that he was surprised it had not been noticed by other travellers, especially by the accurate Scheuchzer, Ramond found Red Snow on the Pyrenees, and the botanist Sommerfeldt told me that he had seen it in Norway. The Italian Giornale di Fisica, Nov. and Dec. 1818, gives some very interesting accounts of Red Snow that fell on the Italian Alps and the Apennines, .In March 1808, for instance, the whole country about Cadore, Belluao and Feltri was, in one single - night, covered to the height of twenty centimetres with a rose-coloured snow: .but both before and after it pure white snow fell, so that the red formed a layer between the white. At the same time a similar pheno- menon was witnessed on the mountains of Valtelin, Brescia, Carinthia, and Tyrol, Another is mentioned as occurring between the 5th and 6th of March 1803 at Tolmezzo in the Friaul, and one still more remarkable in the night between the 14th and 15th of March 1813, in Calabria Ab- ruzzo, in Tuscany, and at Bologna, and upon the whole chain of the Ap- ennines., On the dath of Apdl Red Snow fell on the mountain of Toual in Italy. . Hence it appears that this pheadieaner! is of sufficiently frequent oc- _eurrence, and that the cause of the red snow found in the voyage of Cap- tain Ross on the 17th of August 1819 at Baffin’s Bay, in 75° 54’ N. lati- tude, being so much noticed, is attributable to the acuteness of the natu-« ralists and chemists who had the opportunity of examining its origin. Ac- cording to the account of Captain Ross, the mountains that were dyed red with this snow were about eight English miles in length, and about 600 feet high. The red colour reached to the ground, in many places to a depth of ten or twelve feet, and appeared so for a great length of time. This is all that was known respecting red snow in its natural state ; but it was reasonable to expect some elucidation from chemical analysis, Thus De Saussure had found, that the colouring matter of the red snow of the Alps gave out, when burnt, a smell like that of plants, and thence, only found a a Cyclops in such water, and which agreed in every thing with’ ¢, quad- ricornis of Latr. whilst it differed from Linnzus’s Monoculus quadricornis, in be ing red, whereas that is brown. The animal must either undergo a change in co- lour, or there are two ies sta il le Prof. Agerdh's Memoir on the Red Snow; %e. 169 as well as from Aistillation, in alcohol, inferred that it was of vegetable origin, and probably consisted of the farina of somé plant, although he could neither account for its having ascended to such elevated regions, nor mention a plant whose farina was of that colour. ‘The Italian naturalists who examined that snow which fell in Italy, found | that it contained siliceous earth, clay, and an oxide of iron, ‘as well as a considerable portion of some organized substance. This too accords with Sementini’s analysis of some bloody rain that fell in Calabria. Upon examining the colouring substance of the red snow discovered by Captain Ross, Wollaston and Thenard came to similar results, and the first was Jed to conclude that it contained seeds of a moss. _. From the hands of the chemist this substance came into those of the bo- ; tanist. The celebrated Francis Bauer, in the Journal of Science and Arts, No. xvi. gave a full description of it, and from the similarity in form, ‘as well from chemical comparison, was induced to consider the ‘red snow as a fungus of the genus Uredo, which he calls Uredo nivalis, and nearly related to the Ustilago segetum of Dittm. Robert Brown had indeed previously expressed his opinion that this substance had a great affinity to the Zremella cruenta of Engl. Bot., and that it might accordingly rank among the Alyw. Of this Mr Bauer did not seem to be aware. Sprengel’s opinion, that it came nearer to Vaucheria radicata, seems to be farthest removed from the truth. . On my various examinations of this substance, the question has fre- quently struck me, what might be the true nature of this substance? © without being even able to satisfy my mind upon it, as I had not seen any thing with which I could compare it ; nevertheless, Mr Brown’s opi-~ nion always appeared to be the most correct, namely, that it. should be placed with the Alew. At length a treatise was communicated to me, from the Royal Academy of Sciences at Stockholm, of Baron Wrangel, upon a new species of lichen, which he called Lepraria kermesina, but which Linneus had confounded with Byssus jolithus. I found a most striking agreement between this. new species of lichen and the plant called Uredo nivalis, and expressed this opinion, together with that, that the lepraria was also a true alga. Yet I had not then seen the plant. When, however, I was in Stockholm, in the summer of 1823, Professor Berzelius gave me some of the colour- ing matter of the red snow which he had received from Dr Wollaston, and Baron Wrangel showed me his Lepraria kermesina. The Uredo nivalis was preserved with the snow-water in a small well closed and sealed bottle, which had not been opened from the time it was filled ; yet, after a lapse of five years it retained its red colour, and was not altered in form. The water was perfectly fresh and without smell. When the bottle remained stationary, the substance settled at the bottom of a brown- ish-red colour, two or three lines in thickness, leaving the water per- fectly clear. But, with the least motion, it again mingled with it. In order to-examine this remarkable substance with more accuracy, F 170 Analysis of Scientific Books and Memoirs. placed a drop of the water, mixed with the brownish-red colouring mat» . ter, under the microscope, when it was immediately seen to consist of a “number of round globules, sessile, of a blood-red colour, shining but opaque, perfectly agreeing with Mr Bauer's figure. Some, however, of the globules were not coloured, but clear as water and women eu The gize of ours was somewhat different from that stated by Bauer, 739 of a line, and sothe of the globules were scarcely half so large as others. In general, if we may be allowed to make a relative comparison, their dia- meter was ten times greater than those of T’remella cruenta. The mode in which these globules were clustered was very irregular ; sometimes they were seen single, sometimes two or three in a line, at other times in irregular groupes, especially when the sediment is shaken up and the glo~ bules mingled together. Lepraria kermesina is a plant which Baron Wrangel had found i in the province of Nerike, sometimes resembling a thin crust or scurf on white limestone ; sometimes dissolved with the rain-water upon these same stones, of a blood-red colour, and leaving a faint smell of violets, which _ gave oceasion to Baron Wrangel to imagine his plant to be the Byssus Jolithus of many authors. This is the same plant of which Linneus speaks in his Journey to Westgotha. By accurately observing this plant with the microscope, I not only found my supposition respecting the near re- lationship of it with Uredo nivalis to be confirmed, but I fully satisfied myself that both belonged to one and the same species. From this, it appeared to me clear, that, as the Lepraria kermesina did not fall with the rain, it was as little likely to be the case with the Red Snow. Although it has not been clearly proved, yet, as I have shown in ano- ther place,* it is very probable, that, in the production of the lower orders of Alga, as of the Animalia infusoria, (which come so near the one to the -other,) they sometimes not only pass into each other, but that they are different states of one and the same thing. Next to warmth, light has the most important effect in their formation. Further we know, that when plants of a higher formation grow on white limestone it induces a red co- lour in the flowers. It will, therefore, have a similar, or more decided, action on those plants, such as the Algw, where colour is more essential. We find, for example, the Anthyllis vulneraria, var. coccinea, only on chal« ky ground ; so, also, among the Algw the T'rremella cruenta,+ E. Bot, the red coloured Byssus cobaltiginea and the Lepraria kermesina occur only on limestone or calcareous ground. That the light here produces the red colour is proved in the Lepraria kermesina, for the colour, in such places where the light was weakest, (as in the crevices of the limestone, where it - could scarcely gain admittance, or on the under-side of stones, ) passed from * See the author’s very curious work on the Metamorphosis of Plants, published at Lund. t Tremella cruenta is most assuredly, in this country, found in situations far re- moved from limestone, or any thing approaching to a white colour, upon damp black rocks in shady places, and dark brick walls in the shadiest _parts of large towns and CitiessamsH, ~ we Prof. Agardh’s Memoir on the Red Snow, §c. 171 red to gréen. Nor is the colour determined wholly by light ; it is aided by the nature of the body on which it strikes, but in a manner quite un- intelligible to us- M. Agardh then goes on to argue, that as white bodies, very dissimilar in appearance and nature, produce the same effect in the formation of red colouring matter, so we must not be surprised to find, that a plant, such as Uredo nivalis, which is found on the highest Alps in the most northern latitudes, in the cold of winter, and only on the surface of the snow, is . again found in the plains, in summer, and on glittering limestone.” Hence it must be inferred, that the existence of the Alga of the red snow must be accounted for by the gradual melting of the snow from the in- tensity of light ; and not, as some suppose, that it is washed down from the neighbouring rocks, or, as might be inferred from the information given from Italy, that it has fallen from the atmosphere. . In regard to the first supposition, were such the case, De Saussure and the English navigators would have noticed such a red stream running down the sides of the mountains, a fact which Saussure denies, and upon which the English are silent. As to the accounts given by so many men of science, that the Red Snow falls from the air} I need only refer to one circumstance, namely, that all the accounts agree in asserting, that this Red Snow fell in the night, which is as much as to say, that no one has seen it fall. Why, we may ask, should the snow only fall red in the night, when no one can discern it to be red, and not in the light of day, before which white cau become red? ; i! I am, on the other hand, of opinion, that the Leprarta kermesina is called ‘into existence by the vivifying power of the sun’s light, after its warmth has caused the surface of the snow to dissolve, combined with that incomprehensible property in white snow, of producing a colour ; ne- vertheless, that it first attracts the eye when there is a some considerable quantity, in the same way as we do not see the colour of the drops of was ter till they have accumulated in the ocean. This opinion is not only con- firmed by De Saussure’s observation, who expressly says, “ qu’on ne trouve la'neige rouge que dans une certaine période de la fonte des neiges, car lorsqu’il ne s’en est pas beaucoup fondu, la quantité du residu » rouge est trés petite, et s'il en est trop fondu, on n’en trouve rien ;” but also by the recollection, that the time that this coloured snow appeared in Italy, namely*in March and April, is the time when the snow begins to melt. An a8sertion of Captain Ross’s does, indeed, appear to come in opposi- tion to this, namely, that the Red Snow extends very far below the sur- face, in-some places reaching to the ground at a depth of twelve feet ; but then, this is directly contradicted by another traveller of the same expedi- . “ This at-least we guess to be the meaning of the author, but the theory-jself seems to us to be very abstruse; and probably from too imperfect an acquaintance with the German language, we may not entirely have given the passage correctly. ae (4 i: - 172 Analysis of Scientific Books and Memoirs. tion, on board the Alexander, who expressly states, that the Red Snow was néver more than one or two inches below the surface. The remark made in Italy, that the White snow fell as well before as after the Red, may be easily explained, by what has been said before. We shall, too, account for the great extent of country which it covered in one night, bet- ter from supposing a cause to act upon an homogenous surface, than by supposing, that the Red Snow fell in one night over the whole mountain- ous parts of Italy. That this snow was seen after only one night I have in part accounted for, by observing, that its red colour could not be noticed before it was formed into sufficient masses; and its rapid appearance will the less sur- prise those naturalists who are accustomed to examine the Jnfusoria, and who well know how quickly an innumerable multitude of these beings can be produced under favourable circumstances. It now remains for us to determine, as correctly as possible, the nature of these minute bodies, about which opinions are so much divided. The idea of De Saussure, that the colouring substance of the Red Snow is the farina of a plant, deserves but little attention, as there is no plant which has the farina, or pollen, of that colour. De Saussure, indeed, en- -deayours to strengthen his opinion, by saying, that the farina may have changed its colour from the intensity of the light upon the Alps; but al- lowing this to be possible, chemical analysis is in opposition to it. . The opinion of Mr Bauer has greater weight with us, namely, that the Red Snow is'a Fungus. Yet, still, I cannot agree with him. The fungi are the offspring of darkness, and are never formed or kept in water. They ratlier prefer a close and moist air, are produced by putrid substances ; properties the very reverse of what we know of the Red Snow ; which is formed in the purest waters, with the strongest light, in the clearest at- mosphere, and without any previous decay. That which Baron Wrangel has described, and which I have shown to be identical with the Red Snow, he considers to be a Lichen of the genus Lepraria, a conclusion to which he may have been led by the crustaceous covering which. this plant forms upon limestone. ‘This crust, however, I take to be a sediment that is deposited on the evaporation of the water ; and De Saussure’s observation, according to which it is also formed on the melted snow, ‘shows, at the same time, that it is not peculiar to stones. To this it may be added, that the sporules of the genus Lepraria have a different form, and yield a different chemical analysis from the globules " the Red Snow. Hence it follows, that this substance must be either an Alga or an Ani- maleula, between which I know no certain limits. Theré are forms amongst them which may, with equal propriety, be ranked with either or both. There are Algw which become Animalcules, and vice versa. Last= ly, there are Infusoria, which, at one period of their existence, are endow- ed with the power of movement, while, at Ly pare they exist only in the character of a vegetable. 4 eee Oo Proveellings af Soviets ifs To conclude, the colour of the Red Snow is not without analogy among the Algw. In autumn, as is well known, there is produced on shady Walls a green powdery substance, composed of globules, which afterwards, accord~ ing to circumstances, change either into Oscillatoria muralis, or into Ulva erispa. This substance comes nearest to Lepraria kermesina. Farther, it has a great affinity with Z'remella cruenta, E. Bot. (which must not be confounded with Ulva montana of Lightfoot): both are red, and both con- sist of globules ; but Lepraria kermesina differs in this particular, that its globules are free, not sunk in a gelatine. I have accordingly placed Lepra-~ ria kermesina of Wrangel in my Systema Algarum as a peculiar genus, un- der the name of Protococcus kermesinus. If my views of the origin of this substance, which may be called the Blossoms of the Snow, ( Blume des Schnee’s,) be correct, our surprise will not be diminished, though the object of it may be changed. If we ean no longer believe, that the Infusoria or Alg@ drop from the clouds, we must nevertheless allow, that the snow of a whole district of mountains, may, in a few days, be covered by a red vegetation, of a very different appearance from that of its own dazzling whiteness. We cannot, indeed, cease to won- der at the power that is active on every point of the earth’s surface, and fills even the snow of winter with life and vegetation. It is generally known, that the colour of the vegetable kingdom becomes duller and paler the less powerful is the light that shines upon them; and that the fields of the north are ornamented with few attractive colours, while those of the tropics glow with the most splendid. But even the north comes nearer to the source of light by means of its Alps, and as it were, heightens the in- tensity of its beams by its snows ;°so that even the winter can sometimes’ produce the same effect as the warmest summer. Nature, in all the dif- ferent and variable forms which she assumes, is in one thing ik alike ; she is ever new, and ever worthy of admiration. Art, XXXI.—PROCEEDINGS OF SOCIETIES. 1. Proceedings of the Royal Society of Edinburgh. November 14, 1825.—The Royal Society resumed its sittings for the winter. A paper by Dr Yuxx was read, entitled Some Obseritiants on Subter- ranean Plants, with a Specimen and Drawing of a nondescript Rhizomorpha. _ November 28th.—At a General Meeting of the Society, held this day, the following Office-bearers were elected :— Sir Walter Scott, Bart., President. Right Hon. Lord Chief-Baron, Lord Glenlee, ; 4 . Dr T. C. Hope, \ ra Prentns Professor Russell, Dr Brewster, Secretary. Thomas Allan, Esq. Treasurer. * 174 Proceedings of Societies. James Skene, Esq. Curator of the Museum. | Physieal. Class. ‘Cok oe Alexander Irving, Esq. President. jek 4 4 “ John Robison, Esq. Secretary. . Fi Counsellors. Sir William eas Bart. _ Dr Home. James Jardine, Esq. Professor Wallace. Sir William Forbes, Bart. Dr Edward Turner. Literary Class. Henry Mackenzie, Esq- President. — P. F. Tytler, Esq. Secretary. Sir William Hamilton, Bart.. Sir Henry Jardine. , Rey. Dr Lee. * Sir John Hay, Bart. Right Hon. the Lord Advocate. Dr Hibbert. December 5th.—Mr Henry Mackenzie read a Supplement to his former Paper on Dreams. ; _A paper, by the Reverend Dr Fiemine, was read, entitled “ Observa- tions on the Defoliation of Trees.” This Paper is printed in the present number, p. 72. Dr Turner read a paper on a Method of Detecting Lithia in minerals by means of the Blowpipe, and he exhibited to the meeting the experiments on which it was founded. This paper is printed in the present number, p- 113. ' Dr Hrszert read a Notice of certain Remarkable Concretions found i in the Sandstone of Kerridge, in Cheshire. One of the very remarkable spe= cimens from that locality was exhibited to the Society. This Pape is printed in the present number, p. 138. Dr Hispert exhibited a Specimen of the Vertebre and Ribs of the Plesiosaurus, a species of gigantic Crocodile lately found at Whitby, and in his possession. At this meeting the following gentlemen were elected Ordinary Mem- bers of the Society :— John Archibald Stewart, Esq. Younger of Grandtully. James Hall, Esq. Advocate. Sir William Jardine, Bart. - 2. Proceedings of the Society for Promoting the Useful Arts in Scotldnd. March 22, 1825.—There was read a Description of Mr Wartstaw’ 8 New Compensation Pendulam. ~ A letter from Mr Jonn Grp, Civil Engineer, to Joun Ropison, Esq. was read, ‘‘ On the Application of Granite to the Construction of Rail- ways. See this Journal, No. v. p. 152. Models of a Fire Engine and a Fire Escape, by Mr WaLrTer Bat- LS LANTYNE, were exhibited. | April 5ih:—A Description of an Improved Rain- Cage! by Mr THom of Rothesay, was read, and the instrument itself exhibited. A Notice of a Method of Extinguishing Fires, hed yond by Major Aston. Astronomy, 115: A Model, showing the Application of the Lever to work Gbain Pumps &c. by Mr W- Battantyn», was exhibited. Mr Tom's Rain-Guage was also exhibited, and an ft Syphon, by Mr Hontexr of Thurston. April 19th.—The various models and iattinss: described to the Saciety, during the Session, were exhibited at this meeting. The Society adjourn- ed till the 6th of December. December Gth—The Society of Arts resumed its sittings forthe winter, An Account of a Rotatory Gas Burner, invented by Mr Nimmo, brass- . founder in Edinburgh, was read. See this number, p. 152. Professor WaLLace gave a Description of a new Revolving Bookcase. There was read, an Account of Mr WuitrLaw’s New Compensation Pendulum. The following Machines were Exhibited. ! 1. The Rotatory Gas Burner was exhibited to the Society i in operation. * . Professor Wallace’s Revolving Bookcase was exhibited. ' 3. Mr Whitelaw’s New Compensation Pendulum and Clock was exhibited in complete operation. A description it will be given in our next number. December 7th.—At a general meeting held this day, the Right Honoura- ble the Lord Provost in the chair, the Society awarded a Gold Medal to Mr Davip Wuite.aw, watchmaker, 16, Prince’s Street, Edinburgh, for his Clock with Improved Compensation Pendulum. The Society also awarded a Gold Medal to Professor Wattace for his Eidograph, an Instrument for Reducing and Enlarging Drawings. The Society likewise awarded a Silver Medal to Mr Surzxts, for his Triangle for Directing the Jet of Fire Engines, described in this Journal, No- vy. p- 150. ‘4 Ant. XXXIL—SCIENTIFIC INTELLIGENCE. - I. NATURAL PHILOSOPHY. ASTRONOMY. 1. First Comet of 1825.—The following elements of this comet ie been calculated by M. Shumacher, from the observations made by M. Gam- bard :— , D. Passage of perihelion, - 1825, May 31. 473 Ps Long. of perihelion - - - 273° 29’ 30” Long. of node - - 4 . 17 48 10 © Inclination of orbit ‘ r t 57 26 40 Perihelion distance - - - 0 89 96 Motion retrograde. M. Pons saw this comet so late as the 14th J uly 1825- 2. Second Comet of 1825.—This comet was discovered by M. Pons on the 15th July in Taurus, and has been observed by various astronomers. M. Capocei observed it about the 25th of August. He describes it as sur- - ; 176 ~ _—- Scientifie Intélligence. rounded with a very extensive nebulosity, and as having a tail “moré than a & degree in length. The following ate its elements:—~ —- Passage'of perihelion at Naples, nee December 84, 895 Mean dhe Perihelion distance - - -,- 1.20808 Log. of do. - - - es - 0.08209 Long. of perihelion o + - 317° 24’ 40” Long. of descending node - - - 35 19 50 Inclination of orbit - se - 32 44 20 Motion | + - - - Retrograde. “This comet became distinctly visible to. the naked eye in October last. & Third Comet of 1825.—-This comet was discovered by M. Pons on the 9th August, at 2a. m. in the constellation Auriga. The following are Inghirami’s observations at Florence :-— Mean Time. App. R. Ascen, ‘North Decl. August 20. 15h 42’ 25” 89° 25 oO” 22° 51’ , 32” 23.15 9 21 91 36 39 16 29 45 24.15 “6 25 92 22 12 14 16 26 25. 15 34 58 93 O 13 12 56 587 4. Fourth Comet of 1825, the periodical Comet of Encke.~This comet was discovered by M. Plana of Turin, on the 10th August, and by M. Pons'on the 14th. M. Pons states, that it seemed to change its form, ap- pearing sometimes elongated, and sometimes round. M. Valz seems to have observed this comet so early as the 13th July. M. Encke predicted the return of this comet ; and the error. of his cal- culations, when compared with the observations made in August, is not a minute of a degree. | 5. Fifth Comet of 1825.—M. Pons discovered another new comet at Florence, on the 7th November. He observed it in the constellation Eridanus, having 44° of right ascension, and 14° of south declination. It was moving in a south-westerly direction, at the rate of about twenty mi- nutes a day, and it requires a good telescope to see it. ' 6. Stars without any Proper Motion-—From a comparison of some of the double stars observed: by Sir William Herschel, with the present relative position of those stars, Dr Brinkley is of opinion that several stars have no sensible proper motion, and by comparing Dr Bradley’s observations with his own, he concludes, that in the last seventy years there had been no sensible changes of place of Rigel, Orionis, Polaris, and ¢ Urse Majoris, &c. Dr Brinkley has since deduced therefrom the quantity of Luni-solar pre- : cession, and also the displacement of the ecliptic on the equator 5 and it is probable that many other important consequences will arise from a more extended inquiry into the subject. See Dublin Phil. Journal, No. I. p. 263 7. Miss Herschel’s Catalogue of Nebule—The catalogue with which Miss Herschel is now occupied is not of stars in general, as our notice in No. V. p. 178 would lead our readers to suppose, but only of Nebula. 8. Mr Pond's Method of Determining the Direction of the Meridian. This method consists in placing two very distinct and well defined objects nearly at equal distances on each side of the north meridian line, and at a distance from each other nearly equal to twice the greatest elongation of the pole star. These objects are placed by means of a teleseope, fixed like a transit on a horizontal axis, and pointed first to the pole star, at its greatest elongation, and then at its reflected image. In thus ig from the star to its image, the central wire, which must ‘describe a strictly vertical circle, will pass over some terrestrial object, which, if well defined, will serve for the mark ; but if not, a mark must be set up so as to be bisected by the wire. The same being done on the other side of the north meridian, the distances of the marks from the central wire must be accurately measured with a micrometer. The horizontal angles between the marks being measured by a theodolite, a meridian mark is to be erected exactly between them. 9. Remarkable Effect on the Cambridge Transit Instrument. In ad- justing the transit instrument recently put up in the New Observatory at Cambridge, Mr Woodhouse observed, that the line of collimation deviated occasionally to the east or west of the meridian mark without any yisible cause. He at last found that this effect arose from the approach of the assistant’s body to the lateral braces used to steady the instrument in an in- variable position at right angles to its axis. The expansion of the brace nearest him thrust the axis of the telescope aside. Mr Woodhouse prov- ed that this was the cause of the deviation, by producing the same effect with hot cloths wrapped round the alternate braces, and he, therefore, pro- vided a proper apparatus to protect the braces from the solar heat, during the approach of the sun to the meridian. o*3 OPTICS. » 10. Committee for the improvement of Glass for Optical purposes. .We understand that the Royal Society of London, and the Board of Longitude, are taking effectual measures for the improvement of glass for optical pur- poses. A regular Glass-house has been built for this purpose, and a series of experiments will be immediately begun, under the direction of a com- mittee of members of the Royal Society, from whose talents and dili- gence we anticipate the happiest results. 3 11. Fraces of Polarized Light in Halos. M. Arago is said to have remarked unequivocal traces of polarization by refraction: in the light of a halo, seen round the sun towards 11 o’clock in the morning; and he concludes, that halos cannot, therefore, be formed by reflection. 12. Telescopes without Frradiation. M. Arago has announced, that he has construeted telescopes in which there is no irradiation. The diameter of one of the satelJites of Jupiter, and that of its shadow on the planet, VOL. IV. No. I. JAN. 1826. M 178 Scientific Intelligence. were found to be the same. Observations on Venus prove also that we is no irradiation in his telescope. 13. Optical structure of Edingtonite.. Mr Haidinger, the discoverer of this new mineral, which he has described in our last Number, and which -has been analyzed by Dr Edward Turner, was so good as to put into my hands three very minute crystals of it for the purpose of examination. It has one axis of double refraction coincident with the axis of the octohedron, which is its primitive form. The character of its action upon light is ne- gative, like that of calcareous spar. ‘This result affords another proof, if any were wanting, of the infallibility of the optical law of primitive _ forms. D. B. 14. Phosphorescence of certain Fluids. The following fluids have been found by Dr Brewster to be phosphorescent Phen poured into a cup of heated iron. 1. Albumen (white of an egg) diluted in water. 2. Isinglass, solution of. 3. The two preceding solutions mixed. 4. The Saliva. 5. Soap and Water. 6. Solution of Rhubarb. 7. Solution of common Salt. 8. Solution of Nitre. 9. Tallow. The phosphorescence of tallow may be distinctly observed when a candle is put out in a dark room. 10. Alcohol. 11. Ether burns with a blue flame. 12. Oil of Dill seed. 13. Oil of Olives. 14, Solution of Alum, very faint. In making these experiments, Dr Brewster found that alcohol would not inflame when poured upon a red hot iron, while ether burned with great readiness. . ELECTRICITY. 15. Electricity produced by Evaporation.—M. Pouillet conten from various experiments, 1st, That simple evaporation, whether slow or rapid, never gives signs of electricity. 2d, Alkaline solutions of soda, potash, barytes, strontia, &c. give dak tricity; and the alkali remaining after evaporation, is positively electrifi= ed. 3d, Other solutions of salts or acids, give also electricity, and the bo- dy combined with the water then becomes te electrical. Bull. de Soc. Phil. July 1825, p. 101. f¥o ‘arr 4 : aS iat ep , Electricity—Galvanism. 119 In M. [Pouillet’s Memoir, he speaks of the large compound lenses as “ la belle invention de M. Fresnel.” M. Pouillet ought to pas known that pee, were invented long before in Scotland. 4 16. ‘Blectricity’ of the Atmosphere.—M. Pouillet has Min that clectri- city is developed during the vegetation of plants, shewing itself the moment that the germ appears above ground. He, therefore, concludes that this is a fertile source of atmospherical electricity.—Jd. May, p. 69. 17. Electricity of Flame.—M. Pouillet has shown that, in a vertical flame formed by the combination of hydrogen with oxygen, the visible part of the flame, and the part without it, to the distance of a centimetre, is positively electrified, while, in the interior of the flame, resinous elec- tricity alone is found. Id. 18, Subterraneous Passage of Lightning.—On the 28th May 1824, a tree in Vernon, Connecticut, was struck with lightning. After. passing down the tree, and tearing up the earth at its root, the electric fluid pass- ed ‘‘ 50 or 80 feet under the surface of the earth without following any such substances as commonly guides its course there, as roots, stones, &c. The fluid seems not to have been guided at all by any attracting sub- stance, but to have been carried forward nearly in a straight course by a momentum it had received, through a medium opposing the most powerful resistance, a medium in which it is commonly supposed to be dissipated and lost.” The electric fluid left unequivocal traces of its passage through - a distance of nearly 50 feet. ‘Through the distance of other 30 feet there can be no doubt of its having passed, as its effects upon a wall were dis- tinct at that distance ; and it cannot be supposed that it came out of the ground and leaped 30 feet to the wall, This account is given by Professor Kellogg, in Professor Silliman’s Journal, vol. ix. p. 84——-86. GALVANISM. 19. Analogy between the Phenomena of Galvanism and ihose of Fermen- tation.—M. Schweigger has observed this analogy in the following points : 1, Galvanic piles, like fermentable mixtures, exhibit their effects only by the reciprocal action of three different bodies. __ 2. The products ef galvanic action are two, an oxidated body, and a hydrogenated body. The same happens with the products of fermenta- tion, Which are alcohol and carbonic acid. 3. The presence of electro-negative bodies favours the decomposition of water, whilst, according to Dobereiner, electro-positive bodies determine the formation of it. M. Schweigger is of opinion, that: the same results may be obtained with fermentable mixtures, as with electrical batteries ; but several ex- periments, made subsequently by M. Dobereiner, stand in opposition to this hypothesis. Schweigger’s Journal sur Phys. &c. vol. x. cah. 3d, 1824, and vol. xi. cah, 4, p. 457. $ 180 Scientific Intellgence. 20, Avogudro’s Multiplying Voltimeter.—This instrument, which differs little from the galvanometer of Schweigger, consists of a sewing needle fixed in the base of a small triangle of paper, passing through two holes in the plane of the paper. It is suspended by a fibre of silk, and is placed above the conducting wire. M. Avogadro prefers that arrangement, as it facilitates the observation ofthe deviation of the needle, when mea- sured on a graduated semicircle. M. A. has applied the voltimeter to determine the order of the metals, relatively to their electricity, by con- tact. Mem. dell. Acad. Reale di Torino, tom, xxvii. p. 43. METEOROLOGY. 21. Mean Temperature of the Equator. From a comparison of various observations, M. Humboldt made the mean temperature of the equator 81° 5, while Dr Brewster, in his formule, makes the mean temperature of the equator in the old World 82° 8. This curious subject, however, has been ably discussed in a memoir on refraction and temperature, by Mr Atkinson, who, from a careful examination of Humboldt’s observations by the method of minimum squares, has obtained the following results :— ** 1. The whole of Humboldt’s observations, both in North and South America, at or near the level of the sea, indicate that the mean temperature of the equator at the same level is 86° 55 of Fahrenheit. **2, All the observations, nine in number, made within 11° of the equa- tor, where the height does not exceed 3500 feet, indicate that its temperature is 84° 53. But if Caripe be excluded, as it probably ought, the remaining 8 give 85° 273, for the mean temperature under the equator. ‘* 3. If those places only be taken, which are within the same limits, and whose height is less than 2000 feet, they indicate that the mean temper- atureis 84° 93.” . It thus appears, says Mr Atkinson, from data, furnished by himself, that Humboldt has fallen into an error, when he asserted that the mean temperature of the equator cannot be fixed beyond 81° 8’. 22. Diminution of the Temperature with the Altitude.—Mr Atkinson has shown that the depression of the thermometer due to the height of 1666 feet is 6°. 412, deduced from 128 observations. From 29 other places he proves that the depression of temperature for 1468 feet is 5°.682. These results give nearly 200 feet for 1 degree, and it is remarkable, how very closely they approach to proportionality to the altitudes to which they be- Jong, thus confirming Mr Ivory’s law. Mr Atkinson’s formula for the depression of temperature due to any given altitude, h is { 251.5+53(n—1) } n=h, where n is the measure of that depression. P 23. Fall of a Meteoric Stone, at Nantgemory, Maryland.—On Februa- ry 10th 1825, between 12 and J o’clock, an explosion was heard, louder than that of a cannon, then a loud whizzing noise, and in less than 15 minutes, a stone fell, and penetrated about 23 inches into the earth. Meteorology. 181 When taken out if was rough and warm, with a strong sulphureous smell. It weighed 16 lbs. 7 0z. The explosion and the noise were heard over an extent of 50 miles square. At a distance of 25 miles from the place where it fell, it caused a whole plantation to shake. Prof. Silliman’s Journal, vol. ix. p. 351. 24. Hoar frost on Iron rails——Dr MacCulloch has obseryed that hoar— frost exhibits a particular arrangement upon iron railing. The minute crystals were aggregated into pyramidal groups, and each pyramid stood on all the four edges of the iron bar, and was equally inclined to the two adjacent planes, to the common section of which it stood perpendicular. The temperature was a little below freezing, and there was a moderate fog, with a high barometer. Brande’s Journal, No. 39, p. 40. 26. Mean height of the Barometer at the level of the Sea-—In 1799, M. Humboldt found that the mean height of the barometer, at the level of the sea at Cumana, was 758,59 millimetres at 37° of Fahrenheit. M. Boussingault found the height to be 760,17 at La Guayra, and M. Arago found it to be 760,85 at Paris. "26. Rain without Clouds—-On the 5th September 1799, at 3 o'clock P. a, M. Humboldt saw large drops of rain fall at Cumana, when the sky was quite blue, and without the slightest trace of clouds. 27. Fall of Meteoric Stones in Italy.—In January 1824, between 9 and 10° p. M., meteoric stones fell in the commune of Renalzo, twenty-one miles from Cento. Their fall was preceded by a bright light, by three loud explosions like the noise of cannon, which were heard over an extent of several miles, and by a, confused noise, like that of a number of bells. The phenomenon lasted 20 minutes. ‘Three stones were found, one of which weighed 14 Ibs. Bull. des Se. Phys. September 1825, p. 183. 28. Baron Krusenstern’s opinion of Mr Adie’s Sympiesometer.—As we had the good fortune to give the first account of this ingenious instrument, invented by Mr Adie of Edinburgh, we are happy to be able to lay before our readers the opinion of such a competent judge as Baron Admiral Kru- senstern, the celebrated Russian navigator, who thus speaks of it in his new memoirs, p. 47 :—“ Although the marine barometer is generally con- sidered as one of the most important instruments in navigation, yet the commanders of vessels have not always the means of providing themselves with one of them, as its price is so high as 12 guineas. But its place may be supplied by the Sympiesometer, an instrument invented some years ago by Mr Adie, a skilful optician in Edinburgh, which will be found of great utility, even when there is a barometer on board the ship.” After giving an account of the principle of construction of the instrument, Baron Kru- senstern adds : “‘ it is therefore to be presumed, that this intrument which js recommended by its moderate price, by its occupying little space, and by its not being affected by the rolling-of the vessel, will be particularly use- . 182 Scientific Intelligence. ful to small ships, which, deceived by the appearance of fine weather, ‘ven- ture into the ocean, and expose themselves to dangers of which they often become the victim.’ “See Zachs’ Corresp. Astron, vol. xii. ps 137. 29. Mr Jones's Improved Hygrometer. This instrument, an account of which was read at the Royal Society, has for its object to ascertain the temperature at which dew is deposited from the atmosphere. It therefore differs from Mr Daniell’s only in having the frigorific action applied im- mediately to the tube of the thermometer which is used to measure the temperature. The tube is large and cylindrical, slightly flattened, and ex~ tended at the end. This end of the tube is turned upwards, the stem of the thermometer being twice bent at right angles. This end is made of black glass and exposed, but the rest of the tube is covered with muslin, which, being moistened with ether, the mercury is cooled, and dew at length settles on the exposed part, at which instant the -degree indicated in the scale is read off. See p. 127 of this Number. 30. Remarkable Waterspout. This extraordinary phenomenon was seen on the 6th July 1822, in the plain of Arsonval, a village about six leagues W. S. W. of St Omer, and six from Boulogne. About 1» 35’ P. M. clouds coming from different parts collected rapidly, and formed a single oue which covered the whole horizon. From these clouds a thick vapour im- mediately descended in the shape of an inverted cone, and having the bluish colour of burning sulphur. The apex of the cone next the earth revolved with great velocity, and formed an oblong mass, of about thirty feet detached from the cloud. It rose with a noise like the bursting of a large bomb, leaving u hollow in the ground, of from 20 to 2d feet cir- “eumference, and from 3 to 4 feet deep in the middle. It then set off in the direction of W. to E. knocked down a barn, and gave to the neighbouring farm-house a shock like that of an earthquake. It overthrew from 25 to 30 trees, and laid them in such a variety of directions, as to prove that it advanced with a rotatory motion. It next travelled through a distance of two leagues without touching the ground, carrying off huge branches of trees which it threw out with great noise to the right and left. Having reached the highest point of the wood Fauquembergue, it carried off the tops of several oaks, which it took along with it;below the village of Ven- dome, at the foot of the hill on the east of the forest. In that commune it did no other harm than to carry off a very large sycamore tree, root and branch, to a distance of 600 paces. vo Continuing its route like a ball fired en ricochet, it attacked the village of Audinetun, where it demolished the roofs of three houses, and carried away several trees, among which were five ashes of great height... After quitting the valley, at the mouth of which these two villages are situated, it ascended — the mountain de Capelle, and several ploughmen saved themselyes by lying down and holding firmly by their ploughs, one of which. was driven. so _deep into the ground, that three horses were unable to pull it out. Demarquoy,, who has described this phenomenon minutely, observes. ee en Chemistry. 188 its form (the form of its section we presume,) was oval, its length being about 30 feet, and its other diameter about 20. The spout turned, in its progress, each of its faces to all points of the horizon. Globes of fire issued from its centre, and often globes of vapours like sulphureous ones. Its noise was like that of a loaded waggon dragged at a gallop over a paved road. Every globe of fire or vapour that issued from it, was accompanied with an explosion like that of a musket, and the wind, which was violent, added to this a terrible whistling noise. Near Mont Capelle, it penetrat- ed into the vallies of Witernestre and Lambre. The first contains about forty houses, thirty-two of which, with their barns, were overturned, and an enormous quantity of trees beat down, torn up and carried to a great distance. AtLambre, the revolving motion of the meteor was seen, and also its sulphur brown colour, and from its centre, like that of a fire, there issued flashes of bituminous vapour. The trees round the church were broken and up- rooted. The house of the curate was unroofed, and eighteen houses, most of them built of brick, were sapped to their foundations, and exhibited the extraordinary phenomenon of the separation of the walls, which were thrown outwards. After quitting Lambre, the spout divided itself; one part was dissipated, but the other went to Lillers, about three leagues from Lambre, where it broke and uprooted nearly 200 trees on the fine meadows of M. Defoulers, before it vanished. At three o’clock the wea- ther became calm, the sky serene, and the thunder terminated with the waterspout. Bull. des. Sc. Phys. Avril 1824, p. 236—239. II, CHEMISTRY. 31. Highly caleined Charcoal a conductor of Caloric. M. Cheuvreusse has found, that charcoal when highly calcined is a perfect conductor of caloric. When the charcoal is not much calcined and is dry, it does not conduct caloric. M. Cheuvreusse proposes to use the first of these char- coals in place of copper in galvanic piles, and also for the purpose of carry- ing electricity into the ground from conductors.—Ann. de Chim. Tom. xxix. p- 440. 32. Selenium in the Sulphur of the Lipari Islands. M. Stromeyer has dis- covered Selenium in sulphur from the Lipari Islands, alternating in white and brownish orange layers, with sal ammoniac. It is probable that the orange tint of the sulphur arises from the Selenium. _ 33. Iodine Discovered in a Mineral. M. Vauquelin has found 18% per cent. of Iodine in the mineral from Mexico which was labelled virgin silver in serpentine.—Ann. de Chim. xxix. p. 99. 34. New Experiments on Flame.—It appears from a series of experi- ments by Mr Dayies of Manchester, that there is considerable foundation for the opinion of Mr Sym, that the flame of a candle is a conical sur- face, the interior of which is not luminous, a section of the flame being a narrow luminous ring surrounding an obscure disc. Mr Davies found that 164 Scientific Intelligence -* 0s there isno oxygen in the interior space within the red flame, as phosphorus and sulphur, though they readily melted, yet never would inflame when placed within it. These inflammable bodies, however, always burned when the flame was blown upon them with a blowpipe, so as to supply them with oxygen. The moment the supply of oxygem was exhausted, ‘they were again extinguished. Mr Davies explains the great power of the oxy- hydrogen blowpipe, by stating, that in it the flame, instead of being a su- perficial film of inflammation, is a solid mass of fire—Ann. of Phil. re 1825, p. 447. 35. Prussian Blue in the Soda of Sicily. In three parcels of soda from Sicily, M. Brandes has obtained Prussian blue. When he heated the soda with warm water in a white iron vessel, he obtained much more of the Prussian blue than when he dissolved it in a _— dish. Arch. des Apoth. ver. 1822, No. 3. p. 215. 36. Analysis of Benzoin. The following analysis of Benzoin has been given by M. Stoltze in the Berlin Jahrbuch, 1824, p. 55. White Benzoin. Brown Benzoin. Yellow resin soluble in absolute ether 798.25 88. 0 Brown resin insoluble in ether 2.50 697.25 Pure Benzoic acid 198.00 197.00 _ Extractive matter 1.50 — Water and loss 1.25 "LT 1000.00 990.00 37. On Rinmann’s Green., . This colour is an intimate mixture of the protoxide of cobalt and the oxide of zinc, which assumes a very lively green tint, after it has been heated to redness. In order to form this green, suddenly, as if by the eruption of a volcano, mix together two parts of nitrate of zinc, and one part of the subacetate of cobalt, and expose the mixture to a spirit of wine lamp ina glass globe, with a short neck. This mixture soon becomes liquid, and appears at first of a rose-red’co« lour, then purple, then blue. In an instant it inflames, detonates, be- comes dry, and assumes a green colour. The product is scattered upon the vessel in the form of small rolled leaves of tea. Bull. des = Nat., May 1824, p. 292. 38. Ovalic acid found in great quantities in lichens, &c. M. H. Bracon- not has discovered that oxalate of lime forms nearly one-half of the weight of .a great number of lichens, to which it bears the same relation that care bonate of lime does to corallines, and phosphate of lime to bones: ©The oxalate diminishes progressively in the family of lichens, as the species loses their crustaceous granular texture, and acquire a foliated mem- branaceous aspect, but the latter still contain a remarkable quantity. About 17 parts of yellowish white oxalic acid were obtained from 100 parts of the pulverised lichen. Ann. me Chim. xxviii. pe 318, red sat Worts yt Chemistry. 185 39. Action of Nitric Acid on Charcoal. Professor Silliman having an- nounced the formation of hydrocyanic acid, ‘by the action of nitric acid in charcoal, M. Frisiani was led to the same result im the following manner: in treating with nitric acid the residue of the calcination of sul- phate of barytes with charcoal, he smelt bitter almonds, This made him suppose that the prussic acid was formed. He repeated the experiment in a glass bottle, and heating the liquor with sulphate of iron, he obtained prussian blue. The boiled nitrates and that of barytes, decomposed by charcoal, do not produce the same ey Giorn. de Fis. &e. 1824, p- 240. 40. Temperature of different Animals. M. Despretz has obtained the following results on the temperature of different animals, that of the air being 59° Fahrenheit. ~ Two Carps, temperature of water 51°.4 _ 53.°0 Fahr. An adult Guinea Pig , 96. 4 3 male children, aged between | and 2 years, 95. 2 4 young persons aged 18 98. 6 9men aged 30 98.85 4 men aged 68 98.83 A dog 3 months old 103.06 ' Three pigeons 109.37 Respecting the cause of animal heat, M. Despretz has drawn the fol- lowing conclusions: 1. That respiration is the principal ¢ause of animal heat, producing seven-tenths of it in very young animals, and often as much as nineteen- twentieths of the whole effect ; the remaining heat being produced by as- similation, the motion of the blood, and the friction of the different parts. 2. That besides the oxygen employed in the formation of the carbonic acid, another portion of gas, sometimes very considerable in relation to the first, disappears also ; more ae disappearing in general in young than in adult animals. 8. That there is an exhalation of azote in the respiration of mammife- rous, carnivorous and granivorous animals, and in the respiration of birds ; and that the quantity of azote exhaled is greater in granivorous than in carnivorous animals. Bull. des Sc. Nat. &c. Avril 1825, p. 244-246. 41. Analysis of the Piney Tallow from Malabar. This curious sub- stance. is obtained by boiling the fruit of the Vateria Indica or Piney, a tree common on the coast of Malabar. The tallow rises to the surface in a melting state, and forms a solid cake on cooling. In this state it is general- ly white, sometimes yellow, greasy to. the touch, with some degree of waxiness, almost tasteless, and has rather an agreeable odour, somewhat re- sembling common-cerate. It melts at a.temperature of 974° Fahrenheit. It is so tenacious and solid, that 9 lbs. of it cast in a rounded form, could not be cnt asunder by the force of. two strong men with a fine iron wire, and it was very difficult to effect a division of it, even with a saw. Its specific gravity at 974° is .8965 and at 60°.9260. According to the analysis of Mr 186 Scientific Intelligence. Babington, from whose paper on the subject we have taken these pntien- pnd piney tallow consists of Carbon 77.0 ay 10 atoms Hydrogen 12.3 9 Oxygen 10.7 1 100.0 Mr Babington remarks that 500 cwt. of piney tallow, may be obtained in the town of Mangalore, for 50 rupees, which is about 24d per pound. Quarterly Journal, No. 38, p. 177. III. NATURAL HISTORY. MINERALOGY. 42. New Analysis of Dioptase.—The former analyses of Yeuqueliis and Lowitz, differ widely from the following results now obtained by Vauque- lin, Lowitz. Vauquelin, Vauquelin, Ist Analysis. 2d Analysis. Silex, 33 28.57 43.181 Carbonic Acid, 18.67 sad Lime, 24.18 Oxide of Copper, 55 28.58 45.455 * Water, 12 11.364 100 100.00 100.000 Vauquelin’s second analysis was made up by decigrammes. 43. Mr Swedenstierna’s Collection of Minerals. This valuable. collection _ of minerals has been purchased by the Prince Royal of Sweden, who has presented it to the university of Upsal, of which he is the head, 44 Remarkable Law in Mineralogy. M. A. F. Kuffner, of the Univer- sity of Casan, has discovered a very remarkable relation between the weight of the atoms of minerals, the volumes of their primitive forms, and of their specific gravities. This law is represented by the equation ns cine we ,w, w’ being the weights of the atoms of ‘two different sub- v ; stances, s,s’ their specific gravities, and v, v' the volumes of their primitive forms, the semi-axis being supposed equal to unity. In order to compare the specific gravities of minerals deduced from this law, with the sree “prea gravities, we obtain from the re tion the formula s’—=— =X = ° , so that, by haying the values of 5 w and v for one substance, ai as risebldetin spar, and the values of ofan w’ for another substance belonging to the same system of crystallization, such as quartz, we shall obtain s’ as the specific gravity of quartz. In the system of octohedrons with a rhombic base, M. Kupffner chose the one of the three Perpendicular axes which gives a result most conformable with his law. — Mineralogy. 187 In this i he obtained the results in the following table :— RHOMBOIDS. Weight of Specific Gravity. Atom. Volume. Calculated. Observed. Calcareous Spar 1262.7 3.1643 —— 2.696 Oligist Iron 978.4 4.6452 5.108 5.01~5.22 Quartz 596.4 1.4318 2.58 2.63 . Apatite 1470.3 4.280 3.132 3.130 Beryl 27523 6.956 2.721 2.72 Emerald 16986 —- 2.775 2.775 Corundum 321.16 1.245 4.177 4.07 Il. REGULAR OCTOHEDRONS. ; Tron (Oxidulé) 2835.29 1.333 4.946 Sulphuret of Iron 2966.1 1.333 4.728 4.749 Silver 6211.06 2.00 6.808 6.90 Vol. of Rhomb. Dodecahedron Sulphuret of Zinc 5513.6 2.00 4.069 4.061 Alum _ 11870.77 2.00 1.772 1.75 Amphigene -5645.37° 1.333 2484 2.468 Muriate of Ammonia 8915.52 1.333 1.566 1.5-1.6 Copper 1597.26 1.333 8.78 8.78 Silver 1344 1.333 10.44 10.47 III. OCTOHEDRONS WITH SQUARE BASE. Oxide of Tin 1870.58 2.945 6.934 Meconite 5735.76 3.3412 2.648 2.65 Tdocrase (Siberia) 12530.6 9.6157. 3.38 3.39 IV. OCTOHEDRON WITH RHOMBIC BASE. Sulphate of Barytes 291618 1.4259 —— 4,481 Topaz 7971.78 3.1017 3.585 3.55 . Arragonite 1262.7 0.39913 2.8972 ; 29204 Sulphate of Strontian 2296.9 0.99321 3.963 3.958... . Lead 3791.3 2.516 7.082 6.0717. . Carbonate of Lead . 3339.3 2.3533 © 6.45 6.45 Epidote 10198.0 3.915 3.519 3.453 Pediot 14800.13 5.466 —- 3.386 3.441 Cymophane 3670.8 1.5188 3.792 = 3.796 Sphene * 23033.2 8.462 3.520 3.51 Carbon. Copper Blue 8600.7. 3.5830 3.818 3.8 Euclase 8072.9 2.735 3.105 3.063 Copper Pyrites 2274.4 1.077 4.34 9% 4.315 - Feldspar 7235.8. 2.087», 2.580. 2.578 Sulphate of Lime 216412.) eee) jo 2.3117 Magnesia 2643.4 0.5062 1.756 175 of Zinc 31331 0.6758 1.977. 2.0 Carbonate af Soda 7162.2 1.1718 1.477 Ld Fluate of Lime 3948.4 1.333 3.095 3.09 Muriate of Soda 5868.5 1.333 2.082 2.08 Ann. de Chim. ie24 188 Scientific Intelligence. ‘% Iv. GENERAL SCIENCE. 45. Copley Medals adjudged to Mr Barlow and M. Arago.—The Royal Society of London has adjudged the Copley medals to Mr Peter Barlow of Woolwich, and to M. Arago of the Academy of Sciences, for their dis- coveries respecting the effects of rotation on the magnetic forces, of which we have given a full account in this number, p. 13. 46. Figures in Amber.—Artists whose profession leads them to work in amber, are able to produce in its interior certain figures which add great- ly to the value of the specimens which contain them. The process by which these figures are created, consists in boiling the amber in oil. In this way flaws are produced, which represent very curious objects. Mag. der. Pharm. Mai 1824, 47. Establishment of two Royal Scientific Prizes-—At the Anniversary Dinner of the Royal Society of London, on the 30th November last, Mr Peel announced his Majesty’s intention of granting the sum of one hundred gutneas annually, to establish two scientific prizes, to be awarded every year for the most important discoveries and inventions. Arr. XXXIIL—~—LIST OF PATENTS GRANTED IN SCOTLAND SINCE AUGUST 19, 1825. | “46. Sept. 5 For a New Polishing Apparatus for houseliold purposes. To Josrrn ALEXANDER Taytor, London. 47. Sept. 16. For-an Improvement in the Loom for Weaving Tape. To Tuomas Woartuineron junior, and Joan Mutiiner, Manchester. 48. Sept. 17. For an Improved Blowing-machine, ‘To Cuartes Pow- ELL, Monmouthshire, 49. Sept. 21. For Improvements in the construction of Rail-Roads and Carriages. - To Wittram Henry James, Birmingham. , 50. Sept. 30. For Improvements in the making of Buttons. To Bensa- MIN SANDERS, Worcester. 51. Oct. 1. For Improvements in manufacturing Carpets. To Anam Eve, Lincolnshire. 52. Oct. 1. For Improvement upon a Machine for working Fancy Net. To Hucu Martin and Tuomas Lzg, Renfrewshire. 53. Oct. 4 For an Engine for Cutting Nails, Sprigs, and Sparables. To James Witxs and Joun Ecroyp, Rochdale. 3 54. Oct. 10. For an Improvement in the Construction of Riding Saddles. To Georce THomrson, Wolverhampton- 55. Oct. 10. For an Improvement in the Construction of Wheels. To Georcr Hunter, Edinburgh. 56. Oct. 10. For anew method of manufacturing Pipes for the conveyance of Water. To Samvet Bacswaw, Newcastle-under-Lyne. 57. Oct. 13. For a process of converting Iron into Steel. To NATHANIEL Kimzatt, London. © gg et rage ee ene 58. Oct. 13. For Improvements in the manufacture of Steel. To Joun MASSAE AT, the younger, Middlesex, and Henry Wi.t1am Suirn, mei m Celestial Phenomena, January-April, 1826. 189 59, Oct. 18. For Improvements in the manufacture of Buttons. ‘Tro Tumoas Dwyer, Dublin. 60. Oct. 16. For Improvements in Machinery for propelling Vessels. To Joun Reepuran, Devonshire. 61. Oct. 28, For Improvements in the process of Refining Sugar. To Henry ConstanTINE Jenninos, Middlesex. 62. Nov: 5. For Improyements in the construction of Diving Bells, To Tuomas Streetz, Cambridge. 63. Noy. 5. For Improvements in the construction of Hats. To Joun Bow er, Surrey, and Tuomas Gaton, Middlesex. 64. Nov. 15. For a Machine for Impelling Power without the aid of fine, water, air, steam, gas, or weight. To WiLLiam Jerrerizs, Middlesex. 65. Noy. 17, For a Cement for Building, To Joun Puruxirs Beayay, Middlesex, Arr. XXXIV.—CELESTIAL PHENOMENA, From January 1st 1826, to April 1st 1826. Adapted to the Meridian of Greenwich, Apparent Time, excepting the Eclipses of Jupiter’s Satel~ - lite’s, which are given in Mean Time. -«# CT xx Calculations hitherto given in this work were adapted to the Me- ridian of Edinburgh ; but as the longitude and latitude of this place have never been well ascertained, there can be no advantage in suiting the cal- culations to a hypothetical meridian. The practical astronomer must re- peat the calculations for his own use; and the general observer, or ama- teur in astronomy, requires only the approximate time of the Celestial phenomena, and can have no difficulty in determining this, for any part of the kingdom, from the times for Greenwich. The longitude of Edinburgh Royal Observatory, according to the best observations, is 3° 10’ 21” W. and its Latitude 65° $7’ 57” N.] N. B.—The day begins at noon, and the conjunctions of the Moon and Stars are given in Right Ascension. JANUARY. D He M S&S D. HH. M. 8S , 1 © 21 © ( Last Quarter. | 7 14 © 37.Im, II. Sat. 2/ 1 if Stat. 7 21 39 © @ New Moon, 1 Conj. y and © 8 22 10 6 ) Conj. 4 Capric. 1 20-35 26 » itp 8 _ - ) Conj. H 2 Conj. D g 19 18 43 g Im, Sat, / 2 16 49 50 Im. I. Sat. 2/ ho 5° 0 0 © Conj. 3 15 0 © Conj. GOT Pe: ye 3 Stat. 4 11 18 7 fmt. Set. {ll 13 11. 27 Im I. Sat. M1 4 11 41° 23>) Conj. 6 tty |l4 16 85. 14 Im, I, Sat, 2/ 6 D Conj. Ceres, [15 14-0 .0 Q Conj.o f 6 ) Conj. 2 Stld 16 28r 20 ) First Quarter. 6 16 15 49 ) Conj. lw ft 17 14 51 §4 )-Conj.d ~ 6 16 51°26 ) Conj 24 f, 18 15 4. 49 Im F, Sat 6 20 0 O ) Conj. S 19 20-0 0 ) Conj. h 190 Celestial Phenomena, January—April, 1826: Me... Se es FE ‘Tim. FEE roe 4 5b ) Conj.. Il 0. © enters rs 18 4) Con. 0 & ~ 33 11 Im. I Sat. 2/ 4p 7" ) Conj. 4, & ¥ TI ts veces a trv. Sat. 2 % Greatest Elong. 0 0 & Conj. HI 16 0 4 in Quadrature. 2 0 © Full Moon. 55 B ) Conj. La 2 47 ) Conj. 2a 11 8+) Conjeo & 48> SE YConje © SC 58 13 = E. Sat. 7/ 23 47 Im. He eh ails Sat, 2 0 0 ¥ Conj.o f ) Conj. 2/ 26 37 Im. 1. Sat. 2/ 39 14 ) Conj. i my 9 0.) Last Quarter. 4) 44 )A a. 27. 26 ) Eclipses 6 m FEBRUARY. 3. 8 Im. IL Sat. 2 17 Im. III. Sat, 2/ 0 0 8Conj. 58 ) Conj.1™ f ) Conj. Ceres. 20 7 Im. I. Sat. 7/ 0 31 ) Conj.2u ft 16 19 ) Conj.d f ) Conj. § H& 24 55 ) Conj. 8 v9 22 0 @ New Moon, 0 9 Q Conj. 4 WF i ade fu ey ARE 38 ° 36 ih Il. Sat. 2/ =) Conj.% ¥ 13. 41 Im, I. Sat. 2 42 5 Im, I. Sat. 57 24) Conj. dv h Stat. 11 0 ) First Quarter. D. 7 Sa on araanr WwW WN = H. 16 = — Pe aAworen eo S& ESSueSsoosk Ss. $92 17 Im. IL. Sat Yo. 39) Eclipses « & 0% Con vp ot 0 )Conj. h % near App. Cw ; 31 ) Conj.7 56 ) Conj.y 1 22 Im. I. Sat. y 0 ) Conj.Z a 52 ) Eclipses 2-a 6 48 Em. III. Sat. 2/ 53 Im. IL. Sat. 2/ 34 Im. I. Sat, 2/ 5 ) Conj.x nm. ) Conj. ¢ B, 6 ) Conj.A 0 Y Conj. © 0 Em. I. Sat. 2/ 0 ) Last Quarter. MARCH. 21 ) Conj. 2 Oph. 53) Conj. 2u-f ) Conj. Ceres & + f 22 Im. 16 Em. ‘ii. Sat. Y 24 ) Conj. P wp 20 Em. II. Sat. 2 0. } in Quadrature. °. New Moet) Mercury. e ’ 20 22 8 21 0 22. 21 19 36 12 338 Celestial Phenomena, JanuaryeApril, 1826. 19) s. et bg DR H M 8 59 Em. II. Sat. 2/ 23 8 7 36 Em. II. Sat 7 57 ) Conj, d ~ 23 10 22 17 Em.L Sat. 2/ 44 Em. I. Sat. 2/ 23 18 42 © © Full Moon. 45.) Eclipses 1 24 12 0 0 ¥ Conj.C x 0 ) Conj. h 24 17 47 12 ) Conj. i. mp 17 ) Eclipses & 26 23 8 32 ) Conj. x os 13 Em. 1. Sat. 2/ 27 _ ) Conj. 0 ) First Quarter. 27. 3 32 32 ) Conj. Am 16.) Eclipses » 11 28 13 41 50 ) Conj. ¢ Ophiuch. 25 Em. TI. Sat. 2/ 29 10 55 31 ) Conj. lu fF 22 ) Conj. Z 1 29 lL 31 54 ) Conj. 2m f 19 ) Conj. 1 « 29 14 5 18 Im. IV. Sat, 2 35 ) Conj. 2a a 30 & Stat é 0 © enters 7 30. 2. 3 0 ) Last Quarter. 12 ) Conj.o 30 10 44 33 Em. II. Sat. 2/ 56 ) Conj 7 30 12 16 28 Em.- I. Sat. 2/ 47 Em... Sat. 2/ 30 13 53 0 ) Conj.d f OEM 31 18 18 6 ) Conj. B ny Times of the Planets passing the Meridian. JANUARY. Venus. Mars. . Ceres. Jupiter. Saturn. Georgian. Ry h ’ Bou, Bs ie pe the 22 50 +18 37° 21 48 #416 18. 10 15) «(OO 38 23..5.118 .3..21 0° 15 187 9°10 28. 37 FEBRUARY. 23 25 17 22 20 26 13 57-7 56 22 30 23 40 16 48 #19 55 12 56 7 O 21 39 MARCH. ne 23 55 416 12 #+419 18 #411 56 6 «8 «(2 48 0. Fo 16 82.518 57-10-58 5.18 | 19: 58 Declination of the Planets. : JANUARY. | Venus. _ Mars. Ceres. Jupiter. Saturn Georgian. ° , e , ° /, co , . 4 es , 2259S 7 58 1938S 715N 2118N 22 29S 23 7 936 20 36 7 28 2115 22 23 FEBRUARY. 2019S 12138 2126S 8 IN 2114N 22 138 15 47- 1358 21 55 8 40 2116 . 22 6 MARCH. “ 949S 1520S 2218S 922N 2121N 22 OS 30 1615 22 36 10 3 2128 © 21 55 1138 The preceding numbers will enable any person to find the positions of the planets, to lay them down upén} a globe, and determine their risings and settings. ed ae — ‘ 5 — rey . 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Arr. I.—Account of an Orang Outang, of remarkable height, Jrom the Island of Sumatra. By Crarxe Ase, M.D. Communicated in a letter to Dr Brewster. With a Plate. Dear Sir, I wave great pleasure in sending you a notice respecting an Orang Outang, of remarkable height, from the island of Sumatra. The notice is taken from a paper which I had lately the honour of reading to the Asiatic Society, and which will be published in the forthcoming volume of its transactions. I have little to remark, in addition to what the notice contains, except that the youth of the animal was equally proved by the state of its teeth, and by the apophysis of the bones of its hands and feet being in- completely ossified. The general conclusions to which I haye come, from a consideration of all the circumstances I have collected respecting this animal, is,—that it is identical with the Orang Outang, described by Wurmb in the Batavian Transactions ; that Cuvier is right in considering Wurmb’s animal as the adult of the young eastern orangs seen in Europe; but that he is mistaken in supposing that it is also the adult of the African species. ‘These are points, however, which require more time and materials than I at present pos- sess, to establish ; for, as I have great hopes of obtaining an. _ other specimen of the Sumatra animal in a perfect state, I VOL. Iv. NO. II. APRIL 1826. N 194 Dr Abel’s Account of an Orang Outang hope it will soon be in my power to furnish more satisfactory data for forming an opinion respecting the many histories and opinions regarding gigantic man-like apes, which adorn the pages of the older travellers, and still occupy the speculations of philosophers. I am, Dear Sir, Your very obedient humble servant, Carcutta, 10th May 1825. — CLARKE ABEL. My attention was first directed to: this Orang Outang, by the following, notice of the animal in the Hurkara News- paper, which was sent to it, as I have ascertained, from one of the persons personally concerned in his capture. “ A party haying landed on the north coast of Sumatra, from the Mary Anne Sophia, Captain Cornfoot, for the purpose of. watering, fell in with an animal of the monkey species, of a most gigan- tic size. It was upwards of seven feet in height, and after re- ceiving seven shots, was killed. After the fifth shot, it climb- ed a tree, and reclined against its boughs, to all appearance in great pain, and vomited a considerable quantity of blood. Its. lower jaw, and the skin of the back and arms, which are brought round to Calcutta, I have seen. Some of the teeth of the upper jaw have also arrived here, and are about to be deposited in the museum of the Asiatic Society. There are some of them about three inches long: The lower jaw is im- mense ; and the skin to which I before referred is so large, that, although cut off from the wrists, each arm is now con- siderably longer than mine, and I ama man not a quarter of an inch’ under six feet... The back is remarkably bread, and is covered with long, coarse brown hair. When the animal made) its appearance, it seemed as if it had come from some distance; and to all appearance it had been walking through a swamp, its legs, up to the knees, bemg muddy. _ Its. gait was slovenly, and as it went it waddled from side to side.” In addition to the foregoing information, I may mention, that I have conversed with Captain Cornfoot, commander of the Mary Anne Sophia, and received from him a verbal de- scription of the animal, which, in most respects, corresponds with others that haye been published. His statement regard- of remarkable Height. 195 ing the height of the animal is, that it was a full head taller than any man,on board, measuring seven feet in what would be it#0rdinary standing posture, and eight feet when it was suspended for the purpose of being skinned, Captain Corn- foot dwells much upon the human-like expression of its coun- tenance, and especially on the beautiful arrangement of its beard. He also obliged me with some account of its capture, as reported to him by his officers, and feelingly described the piteous action of the animal on being wounded, and of its ap- parent tenacity of life. It seems that, on the spot where this animal was killed, were five or six trees, which occasioned his hunters great trouble in procuring thew prey ; for; in conse- quence of the extreme agility and power of the animal in springing from branch to branch, and bounding from one tree to another, his pursuers could not fix their aim, until they had cut down all the trees but one. When thus limited in his range, the orang outang was shot, but did not die till he had received five balls and the thrust of a spear. One of the first balls probably penetrated his lungs, as he, immediately after the infliction of the wound, slung ‘himself by his feet from a branch, with his head downwards, and: allowed. the blood to flow from his mouth. On receiving a wound, he al- ways put his hand over the injured part, and distressed. his pursuers by the human-like agony of his expression. . When on the ground, after being exhausted by his many wounds, he lay as if dead, with his head resting on his folded arms. It was at this moment that an officer attempted to give the coup de grace by pushing a spear through his body, but he imme- diately jumped on his feet, wrested the weapon from his anta- gonist, and shivered it in pieces. ‘This was his last. wound, and last great exertion; yet he lived some time afterwards, and drank, it is stated, great quantities of water, Captain ~ Cornfoot also observes, that the animal had’ probably travel- led some distance from the place where he was killed, as his legs were covered with mud up to the knees. In the accounts which I have received of the circumstances observed by the persons immediately concerned in the capture of the animal, the only discrepancy of any consequence ‘re- gards its height. The measurement of his skin, however, 196 Dr Abel’s Account of an Orang Outang goes far to determine this point ; and the difference of states ment is capable, perhaps, of being accounted for, by swppos- ing different points to have been taken as the limit of his di- mensions by the different parties, or a greater or less bending posture of the animal. The skin, dried and shrivelled as it is, measures, in a straight line from the top of the shoulder to the point whence ‘the ancle has been removed, 5 feet 10 inches ; add to this the perpendicular length of the neck, as it is in the preparation of the head, 34 inches; length of the face, from the forehead to the chin, 9 inches ; and of the skin now attached to the foot, from the line of its separation from the body to the heel, 8 inches,—measurements which I have made myself, and we have’ feet 6} inches as his approximate height. Agr I now proceed to describe the animal.—In order to assist the Society in forming as correct an opinion as circumstances will allow of the form and appearance of the different parts which have been preserved, I have caused the “drawings in Plate IV. to be made of them, which I now offer to their exami- nation. They have been hastily executed, and imperfectly finished, but are, I believe, correct with regard to the propor- tions. I particularly cautioned the artist to draw nothing but what he saw; and, therefore, the hair of the head looks more lank and matted than it would naturally be. Description of the Remains of the Animal. The face of this animal, with the exception of the beard, is nearly bare, a few straggling short downy hairs being alone scattered over it. It is of dark lead colour, excepting the margins of the lips, which are lighter. The eyes are small in relation to those of man, and are about an inch apart. The -eye-lids are well fringed with lashes.. The ears are 1} inch in length, and barely an inch in breadth, are close to the head, and resemble those of man, with: the exception of want- ing the lower lobe. The nose is scarcely raised above the le- Hg of the face, and is chiefly distinguished by two nostrils, 5 of an inch in breadth, placed obliquely side by side. The muzzle projects in a mammillary form. The opening of the mouth is very large. When closed, the lips appear narrow, Sf remarkable Height. 197 but are in reality half an inch in thickness. ‘The hair of the head is of a reddish brown, grows from behind forwards, and is five inches in length, 'The beard is handsome, and appears to have been curly in the animal’s lifetime. Its colour is lighter than that of the head, approaching to a light chesnut. The beard is about three inches long, springing very grace- fully from the upper lip, near the angles of the mouth, in the form of mustachios, whence descending, it mixes with that of the chin, the whole having at present a very wrk ne The face of the animal is much wrinkled. The palms of the hands are very long, are quite naked from the wrists, and are of the colour of the face. Their backs are covered with hair to the last joint of the fingers, and this inclines backwards towards the wrists, and then turns directly upwards. All the fingers have nails, which are strong, con- vex, and of a black colour, The thumb reaches to the first joint of the fore finger. The soles of the feet are bare, and of the same pias as the hands; they are covered on the back with long brown hair to the last joint of the toes. The great toe is set on nearly at right angles to-the foot, and is relatively very. short. The original colour, however, of the hands and arms, and the soles of the feet, is somewhat uncertain, in consequence of the effect of the spirit in which they have been preserved. Description of the Skin of the Animal. The skin itself is of a dark leaden colour. The hair is of a brownish red, but when observed at some distance, has a dull, and, in some places, an almost black appearance; but, in a strong light, it is of a light red. It is in all parts very long; on the fore arm it is directed upwards. On the upper arm its general direction is downwards, but, from its length, it hangs shaggy below the arm. From the shoulders, it hangs in large and long massy tufts, which, in continuation with the long hair on the back, seems to form a continuous mass to the very centre of the body. About the flanks, the hair is equal- ly long, and, in the living animal, must have descended be- low the thighs and nates. On the limits, however, of the la- teral terntination of the skin which must have covered the 198 Dr Abel’s Account of an Orang Outang chest'and belly, it is scanty, and gives the impression that these parts must have been comparatively bare. Round the upper part of the back, it is also much thinner than else- where, and small tufts at the junction of the skin with the neck, are curled abruptly upwards, corresponding with the direction of the hair at the back of the head. In the dimen- sions which I am about to give of the skin, I have stated that it measures from ‘one extremity of the arm to another, 5 feet S inches; to this is to be added 15 inches on each side for the hands and wrists, which will render the whole span of the animal equal to 8 feet 2 inches. The following are the measurements which I have made of the different parts : | Of the Face. Plate IV. Fig. 1. Feet. Inches. Whole length of the face, ~ - - - 0 9 Length of the forehead from. the commencement of the hair to : a point between the eyes, - - - - 0 (4h - From between the eyes to the end of the nose, © = oO ee From the end of the nose to the mouth, - - - 0 iy ‘rom the mouth to the setting on of the neck, - o 48 Circumference of the mouth, - - - 0 Gali Dimensions of the Skin. Greatest breadth about the centre of the skin, . - Pa Greatest length down the centre of the back, = - - she Length from the extremity of one arm, where it is separated from the wrist, to the other, - - ~ 5 s Breadth of the skin from the situation of the os coccygis to the setting on of the thigh, . - - - 1 4 Across the middle of the thigh, - 1% s <0 Greatest length of the hair on the shoulders and back, ft 4h Coe * Measurement of the Hands and Feet. Front Measurement of Hand. Fig. 2, 3. , Length of hand from the end of the middle finger to the wrist in aright line, - - “di: = - 1 Circumference of hand over the knuckle,. _—- - Ono yal wi Length of palm from the wrist, - - - ,-0..5 «imal Length of middle finger, - - Ks . 3 oO ‘5h. — of fore finger, - - - rh aan A a — of little finger, - - - & (Dt oRee ” oe of ring finger, oF - “ jimi 0 6 of thumb, - ms = ; oF rite) a of remarkable Height. 199 wpitaat Feet. Inches Py Back Measurement of Boat T Length of ring finger, - « e 0,» 63 — of middle finger, - «- © - 0 64 — of little finger, - - - - 0 Bf — of fore finger, - - - 0 6 — of thumb, - - - = 0 4 Front Measurement of Foot. Fig. 4, 5- Length from the end of the heel to the end of the middle toe, 1 2 — of palm of foot, . -. - - Oo "93 — of middle toe, - - - 0 44 — of ring toe, - - - ~ 7 0 a — of little toe, — = - - 0 3h — of fore toe, - 2 ya? ° 0° 3} — . of great toe, - - - - O° ey Circumference over the knuckles of the toes, - - 0. 9% Back Measurement. Length of middle toe, - aod bs S 0 6 — of fore toe, “ - - 0 5 — of ring toe, - - - i) 6 — of little tog, - 2% ~ 0 5 — of great toe, . = - < 0 43 Measurement of the Lower Jaw, Circumference of the jaw round ‘the chin, - - 0 Tn Length of the ramus from the head of the jaw to its base, ey ae — . of the coronoid process to the base of the jaw, --- cy Breadth of the ramus or ascending portin. of the jaw, at a level with the teeth; ~ - -. Gre al : Distance from the head of the bone to the process, - OD. awed Bebe of the jaw at the symplysis menti, == = HASTGORPO! 74 Measurement of the Teeth. Teeth i in each jaw 32, namely 2 canine, 10 grinders, 4 incisive teeth. Canine Teeth. * In oth. Whole length of lower canine teeth, - - 2 7 Greatest length of fang, - - - - 2 0 Smallest do. ~ = . 2 6 Greatest length of a or Larncaad, part of the tooth, 1 i Part exceeding the other in, length, ae - 0 4 Lateral breadth measured on a level with the jaw, - 0. 6 Breadth ftom before inwards, - Bed fae 0 7 ‘Incisive Teeth. Whole length, of the lateral, _midee Diss .jpsesy 1 5 Of enamel exposed , - : . Oe Ti Breadth of cutting surface, = - cs *3 gn Of central teeth, - - - e 0 4 200 M. Savart on the Mechanism of the Human Voice. Inches. 10ths- The front teeth of the upper jaw greatly resemble those of the lower, ‘with the exception of the middle incisive teeth which are twice the width of the lateral ones, and narrow at their inner surface, - - - - - - 0 6 Arr. II.—Memoir on the Mechanism of the Humam Voice. By M. Feuix Savarr. Ir gives us particular satisfaction to have such frequent op- portunities of presenting to our readers an account of the ingenious and yaluable researches of M. Savart, relative to some of the most profound and less cultivated branches of Physical Science. His Memoir on the Human Voice, which is printed in the last number of the Ann. de Chimie et de Phy- sigue, * exhibits, in a striking point of view, the sagacity-of its author, who advances step by step from the theory of the- simple whistle of the hunters, to the explanation of the most complicated organ of the human frame. We could have wished that our limits would permit us to give the whole of this memoir; but, as this is out of the question, we shall en- deavour to-convey the substance of it to our readers, which they will perhaps comprehend more readily than if they were in possession of more minute details. The formation of the human voice has been regarded by some as similar to a stringed instrument, while others have considered it as resembling the mouth-piece of organ-pipes ; but M. Savart has shown that both these explanations are inadmissible, and he thus proceeds to an saab of we: subject. When the length of an organ-pipe is from twelve to fifteen times its diameter, the velocity of the current of air has a slight influence on the number of oscillations, and it is diffi cult to make the sound vary a semitone. In short tubes, on the contrary, the influence of the velocity of the current of air is much greater, and cubical pipes can be made to give out several sounds, and embrace the interval of an entire * For September 1825, p. 64-87. = © 7 M. Savart on the Mechanism of the Human Voice. 201 fifth, although there is always one sound which is given out more easily, and iacmerh is: more pure ‘ands ‘more intense than all the others. The hunters, in ordén to imitate the voices of certain birds, employ a small instrument, in which the current of air exerts an influences till more considerable. This instrument, made of bone, wood, or metal, has commonly the form of a-small cylindrical tube about 8—10ths of an. inch in diameter, and 8-10ths high. At each of its ends it is shut up by a thin and smooth plate perforated at its centre, with a hole about 1} tenths in diameter. Sometimes it has the form shown‘in Plate V. Fig 1, which is the section of a hemispherical vase with two opposite orifices. The hunters place this instru- ment between the teeth and the lips, and by drawing in the air with more or less force through the two orifices, they suc- ceed in obtaining different sounds. This effect may be produced with more certainty, by adding to ita cylindrical portvent, as in Fig. 2. By this means, we may obtain all sounds comprised in an extent of an octave and a half to two octaves, passing, in general, through the in- - terval from ut, to ut,. The gravest sounds are generally dull and feeble, and the most acute are unsupportably piercing. The sounds become more grave by increasing the orifices. The sounds produced in this instrument seem to arise from this,—that the current of air which passes through the two orifices, dragging along with it the small mass of fluid con- tained in the cavity, diminishes its elastic force, and, conse- quently, destroys its equilibrium with the pressure of the ex- ternal air, which, reacting upon it, drives it back, and com- presses it till, by its own elasticity, and under the influence of the continued current, it undergoes a new rarefaction, fol- lowed by a second condensation, and so on continually. These ultimate states of rarefaction and condensation being sufficiently near one another, ought to give rise to waves, which, spreading out in the external air, produces the sensation of a determinate sound. It ought also to be noticed, that the thinner the sides of the whistle are, they vibrate with more energy, and if, in a hemispherical one, we replace the plane 202 M. Savart on the) Mechanism of the Human Voice: side by,a thin leaf of parchment, the sounds are emitted more easily, and are more grave, more full, and more agreeable.) When the sides of the orifice are made as in Fig. 3, the sounds are more grave, and less loud. Here the margin of the orifice seems to act like the bevel in organ-pipes.. When the margin is rounded as in Fig. 4, the same effect takes place. In long organ-pipes, the sublsabee of the pipe has little or no influence on the number of vibrations of the column of _ air; but, in short pipes, the substance exerts a powerful in- fluence. If we construct a cubical pipe, with paper or parch- ment stretched over small square frames joined together, to form a cube, the sound which it yields is as acute when the parchment is stretched, as if the sides had been solid ; butf their tension is diminished by humidity, the sound may be made to descend more than two octaves before it ceases to be heard. In the quiet of night» there seems to be no limit to this lowering of the sound. By strewing sand on the sides of the cube, they exhibit a nodal, elliptical, or circular line, and the upper and under surfaces vibrate most energetically. » If we take a prismatic tube nine inches long, and eighteen ° lines of a side, and form half its length next the embouchure of a membrane, thin, and well stretched, then, though it should give the sound re,, yet it produces much more grave ones, even those between ut, and uwt,, or even some of those of the octave from wt, to ut,. The sounds of balabicerishis pipes padres of the quality: of _ those of a flute, and of free mouth-pieces. They have no analogy with those of any musical instrument, and such pipes are im’ some respects the reverse of stringed-instruments. In the latter, the air in the case is put into vibration by the _ solid»sides which inclose it, while, in membranous pipes, the air is the sad which is put directly into motion, and which If we fix a portvent at the convex surface of the nue whistle, and add a pipe at the other as in Fig. 5, 6, and 7, this combination will give a sound which will be exactly that which corresponds to the column of air contained in the pipe, provided. that, among the sounds which the small whistle may give, 1 M, Savart on the Mechanism of the Human Voice. 208 there is one which is the same as one of those which the column of air may give: | This result, deducible from theory, is confirmed by experiment. ‘The sounds obtained by this method have a ‘particular character, distinct from those of all ordinary organ-pipes. They may become very intense and very loud, especially when the apparatus is made of metal, and the dimensions of the columns of air properly chosen. This instrument, like organ-pipes opén at both ends, can only give the series of sounds wt, ut, sol, ut, mi, sol, lat; ut, &e. It may, nevertheless, happen, that the small vessel which serves as the mouth-piece may sound independently of the column of air; but then the sounds are feeble, and want distinctness. From what has been now said, it may be easy to conceive, that a tube like Fig. 7, composed of elastic mate- rials, may give out all possible sounds comprised within cer- tain. limits, depending on the tension of the sides and the vo- lume of air. .| When the pipe, in which the air sounds is pierced with late- tal holes, if we blow uniformly by the portvent, the sound may be varied when the holes are shut and vice versa, so that it would not be impossible to construct a musical instrument upon this principle. . The fundamental sound of a pipe hut up at one end, and of an uniform diameter, is in general more grave by an oc: tave than the sound which the same pipe gives when it is open at both ends. This, however, is not the case with pipes of unequal diameter, such as conical and pyramidal ones, . when they are made to vibrate at their narrowest part. In these the interval, between their sounds when open and shut, becomes as much greater, for an equal length of tube, as the inclination of its sides increases. A ‘conical pipe 4} inches long, and truncated at its summit, and having its larger end 2 inches in diameter, and its smaller one six lines, gives, when open, the sound wf,, and when shut mé,. By widening its large end, or lessening its small one, the other dimensions re- maining the same, the sound "may be lowered even more a two octaves. In order to determine the exact form of the larynx, P tick’ 204 —~M. Savart on the Mechanism of the Human Voice. avast of it by running into it plaster of Paris, and of this cast Fig. & is an exact representation of the natural size, and Fig. 9 a side view of it. The ventricles AA’ sometimes rise still higher than in the figure, and their summit touches the fat body at the base of the epiglottis. \I have seen two cases, in which they were one Paris inch long from the bottom to the summit. In general they are only half that height, viz. 5 or 6 lines. The intervals BB, Fig. 8 and 10, are filled by the vocal ligamients, and. the thyro-arytenoidian muscles, and the intervals CC’ by the superior muscles. In the side view ‘Fig. 9, there is a better view of the extent of the fold of the mucous membrane, which stretches from the epiglottis to the corresponding arytenoid, This fold occupies the space A/BB’ ‘and terminates superiorly at the line AC. Fig. 10 represents a section of the larynx on the line AL, Fig. 9, dividing it into two parts. This figure gives a dis- tinct idea of the interior form of the larynx, which has a very great resemblance to the apparatus in Fig. 7. These facts being established, it becomes easy to explain the formation of the human voice, by considering the vocal organ as composed of the larynx Fig. 10, of the posterior mouth, and of the mouth as a conical tube in which the air is made to vibrate with a motion analogous to that in ‘the flute-pipes of organs.. The vocal tube possesses all the pro- perties that are necessary, in order that the mass of air which it contains may be susceptible, in spite of its small volume, to yield a sufficiently great number of sounds, and even very grave ones, Its inferior part is formed with elastic sides, which can assume all degrees of tension, while the mouth, by opening more or less, and consequently changing the dimen- sions of the column of air, exerts also a notable influence on the number of ‘vibrations conjointly with the lips, which, by their approach and recession, transform at pleasure the vocal tube into.a conical tube, sometimes open and sometimes iat most shut. eorht Ry It deserves to be remarked, that the sound of a conical tube, slightly truncated at its summit, of the same capacity nearly as the vocal tube of man, and of the same length, Viz. 44 inches, does not require to be much lewered, in order to M, Savart on the Mechanism of the Human Voicer 205 become one-of those which the voice can produce. | A similar tube, open at both ends, gives'the sound wf,, and there are many human voices which are no higher, than /a, which is graver only by a third minor. If we shut a great. part of the base of the tube, the sound will, by this means, easily descend to wt,, and even below it, and it would require to be lowered only about an octave more, in order to equal the gravest sounds of the human voice. But if we consider that the column of air in the vocal tube is inclosed, particularly on the lower part, by extensible sides, and which are themselves capable of vi- brating and influencing the motion of the air by dividing it, we may easily conceive, that the sound may be easily lowered an octave more. If we construct, indeed, a pyramidal tube, such as AB Fig. 11, nearly of the same length as the vocal tube, viz. 4} inches, approaching to the same capacity, and membranous in the lower third CD of its length, we may make it produce all the sounds of an ordinary voice, either by making the tension of the membranous part vary, or by shut- ting more or less its great orifice, an aperture, however, being always left. The only difference between this and the vocal tube con- sists in the kind of embouchure. In the vocal tube. it is an- alogous to that of the instrument Fig. 7. The trachea TT’, Fig. 10, is terminated above by a slit which may be made more or less narrow by the approach or recess of the aryte- noid muscles, and by the contraction of the thyro-arytenoid muscles, represented by RB’, Fig. 10. ‘This aperture obvious- ly performs the same part as the aperture in mouth-pieces, The jet of air which comes out of them, traverses the interval between the ventricles, and strikes against the superior liga- ments CC’, which, though rounded, perform the same part as the bevel in organ-pipes.. The air in the ventricles VV then enters into vibration, and yields a sound which, if it were insu- lated, would be feeble, but it acquires intensity because the un- dulations, which set out from the interval situated between the superior ligaments CC, propagate themselves in the vocal tube placed below, and these produce a kind of motion analogous. to that which exists in short, and partly membranous tubes. In order, however, that the definitive sound thus produ- 206 M. Savart.on the Mechanism of the Human. Voice); ced,may unite all the qualities which it, possesses, it is neces. sary that'the tension of the extensible part of the sides of the vocal tube has a proper relation to that of the sides of the ventricles, and also to that of the superior and inferior liga- ments; and that, the extent of the orifices, across which the | air escapes, may also vary, and ¢o as to produce the best, pos- sible result. It is for these purposes that nature has formed all these parts of elastic or muscular tissue. The thyro-ary- tenoidian muscle forms of itself alone the lower and external sides of the ventricle; and it does not:concur, as has been supposed, in the formation of the superior liagment: Though its form is sufficiently regular, yet it is difficult to deseribe it, and even to dissect it well; and, consequently, the descrip- tions of it hitherto given are very incomplete, and often in- correct. This muscle presents an internal face formed by a plane of fibres almost parallel, and stretched between the su- perior part of the re-entering angles of the thyroide, and the inferior anterior part of the arytenoid. The upper margin ofthis face, the plane of which forms, with the axis of the trachea, an angle of from 20° to 25°, is united to the vocal li. gament. The external face is inclined upon the internal one, so that they leave between them an angle whose summit, is turned downwards. ‘The fibres which form this second face, stretch like a fan, and obliquely from above downwards, and from before backwards; and their upper extremities lose themselves successively in all the extent of the large fold formed by the mucous membrane between the epiglottis and the arytenoid. Sometimes the most anterior stretch even to the base of the epiglottis. . These fibres, consequently, rise much higher than those which form the internal plane, and'they again cover almost all the extent of the external side of the ventricle, excepting in front and above, where they seldom reach, on account of the obliquity of the kind of fan which they form. In short, in the interval which the plane of the parallel and ‘internal fibres leaves between it and the plane of the oblique external fibres, there is found a small el- liptical cavity which forms the bottom of the ventricle, where the fibres ‘seem still to be arranged nearly parallel. The uses of this muscle are easily conceived: When it contracts, it M, Savart on the Mechanism.of the Human Voice. 207 gives to the bottom and. the external side of the ventricle, as well as tothe margin of the orifice by which, the air escapes from the trachea, the degree of tension necessary for the sound which it is wished to produce. By the extremities of its ob- liqne fibres, it acts also. upon the fold of the mucous mem- brane which forms the upper part of the extensible. portion of the vocal tube... Its action upon this part is supported»by that of a small muscle, which ought to be called the superior thyro-arytenoidian, for it stretches obliquely from below up- wards, from behind to before the external and inferior part of the arytenoid, to the upper part of the rounded angle of the thyroid, where it is fixed by very short tendinous fibres. . This is a small conical muscular bundle whose base is behind. It is always more developed on one side of the body than on the other... Several oblique fibres of the thyro-arytenoidian are confounded with that small muscle, into which they are inserted. almost perpendicularly. Others go beyond this into the. mucous fold. It is obvious, that the use of this muscu- Jar bundle is to stretch the,external sides of the ventricle con- jointly with the oblique fibres of the thyro-arytenoidian, to which they serve as a point of support. The superior ligaments CC have no proper muscle, but they are formed of a substance sufficiently rigid, and they are thick enough not to require any foreign support.. Though their free margin is rounded, yet this cannot at all injure the production of sounds, as we have already noticed. | One of the most remarkable arrangements of the vocal. ap- paratus of man is, that the larynx is terminated above by two folds of the mucous membrane, which float in the middle of the air which sounds around them, and of whose motion they necessarily partake. It cannot be doubted that these folds ought to have a great influence on. the faculty of modulating and_ articulating sounds, as well as upon the timbre of the voice ; for the inferior larynx of all birds that have a varied song, or which are capable of learning to, speak, present an analogous arrangement, whilst in birds whose voice is limited, - nothing like this is to be found, even when their larynx is provided with the proper muscles. These floating membranes, being susceptible of a variable tension, ought, to be principal- 208 M. Savart on the Mechanism of the Human Voice. ly used for modifying, sometimes suddenly, and sometimes gradually, the number (of ‘vibrations of the air. When ead are stretched, their height diminishes, and, consequently, the sounds become more acute, at first, because the sides which contain the column of air are then more resisting, and after- wards because the extensible part of these sides has a less extent. At the same time that the effect is: produced, the orifice by which the air escapes from the trachea becomes narrower, and the external side of the ventricles assume also a greater degree of rigidity, for it is the same muscle which produces all these movements. When these folds are un- stretched, the contrary phenomena take yo and the sounds become more grave. From the explanation we have now given of the mechanism of the voice, it is evident that, if we remove the upper parts of the vocal tube, and reduce it to the ventricles alone, we shall not diminish the number of sounds which the voice may yield ; the gravest will only become feeble. ‘This explains why we may make similar incisions in living animals without their ceasing to emit different sounds. The air contained in the ventricles may sound independently of that which is in the vo- cal tube ; and, it is to be presumed, even if that tube under- goes no alteration, that certain sounds may be produced from the ventricles alone, particularly those which are occasioned by grief, and, perhaps, also those which are heard when we sing above our voice. This ought to happen every time that the extensible part of the vocal organ cannot take the degree of tension necessary to produce the required sound. This as- sertion is the more probable, that there are animals, such as frogs, in which the vocal organ is reduced to the ventricles alone. The larynx of these animals resembles a small kettle- drum. » Its convex side is cartilaginous. It is situated inferi- orly, and traversed by an elongated orifice which can open at pleasure: The lower side’is membranous, and has an orifice corresponding to that of the convex side. The air having arrived below this membrane, traverses the two orifices, — and sets in vibration the air contained in the cavity. ‘The me- chanism is the same as in Fig. 1, and as in the human ven- tri¢le. This apparatus, simple as it is, would yet be capable 1 Account of a Volcano in the Himalayah Mountains. 209 of yielding fine sounds, if the animal which possesses it had a more complicated respiratory system. The facts on which we have founded the explanation of the Human Voice, may be equally employed to give an account of the sounds which different species of mammiferous animals may emit, whose organ is analogous to that of man. With respect to those which, like the Alouates, have osseous pouches communicating with the ventricles of the larynx, itis very easy to conceive, from the researches which we have already pub- lished relative to the vibrations of air, how it may happen that the masses of air inclosed in these eavities, may give sounds so grave, and, at the same time, so intense. When these pouches are membranous, as in most species of apes, it is equally easy to understand, from what we have said of mem- branous tubes, that animals which possess these organs, ought to be able to emit sounds very dull, and, at the same time, very grave. As this subject requires to be treated in detail, I have merely mentioned these applications, and I shall only farther remark, that the most singular dispositions of the organs of voice in different animals, appear to be explicable upon the principles laid down in this memoir. Art. I1].—Account ef a Voleano in the Himalayah Moun. tains. Communicated to Dr BrEwstTEeR by a Correspond- - ent in India. T xow send you an interesting account of the volcanic ap- pearance in the Purneah District, that you may have seen alluded to in the Newspapers... The mountain is one of the highest in the whole range, and is visible occasionally from the eastern side of the Burhampooter, south of the Garrow hills, and also, I believe, from Bhougilpore, but too indistinct- ly to admit of our seeing the column of smoke observed by Mr Barnes. Several years ago, when examining this peak from Deenhutta, with a good telescope, I observed a singular- looking fissure in the side of it so remarkable, that I took a sketch of it at the time. I think it is highly probable that VOL. IY. No. II. APRIL 1826. 0 210 Account of a Volcano in the Himalayah Mountains. this is|an extinguished crater ;, and if the smoke actually pro- ceeds from a volcano, it may even be the one in action, as it. is on the east side of the peak, and the peak might prevent this appearance being seen from the southward, In the early part of February 1825, * my, brother and my- self, were on our return from the. hill north of Rungapannee, when, early in the morning, just as the sun rose above the horizon, I observed a thick cloud, apparently smoke, rising perpendicularly from the highest point of the mountain, which, after ascending to a considerable height in a thick dense column, took an easterly direction from the upper part of it, as if it had been carried. away by the wind, detached parts of it being separated like small, white clouds, ..The column of — smoke continued to exhibit the same. aspect.as when it was first. seen, and exactly resembled. the smoke of a fierce fire, after ascending far above the influence of the propelling power. At this time the atmosphere was beautifully clear for many successive days; and the appearance above described continued precisely the same, only at times the column of smoke seemed to be larger and more dense than at others, but always rising straight up as if rushing from a crater, and the top always dispersing in the air on reaching a certain height. From having been long in the habit of observing the snowy mountains whenever they were visible, and accustomed to view them for many years past, I may say that I am perfect- ly familiar with their appearance; and I was so forcibly struck with the different aspects they assumed on the day above mentioned, that I thought it possible that a voleano was in action. This opinion, and the desire which every man would feel to witness so grand and sublime a spectacle, has led me to observe it very closely ever since, whenever I could discern the peak; and although no eruption of flame has been seen from this place, which is three miles due west of Runga- pannee, yet the smoke has continued. in the same form and the same direction as above stated, It was once carried. westerly by the wind, and only once that I remember; but at all other times the head of it was wafted to the east. fete? * The letter, of which this is an extract, is dated | Thoon ke Pups. June 13th 1825. M. Dulong’s Researches, &c. 211 The very same appearance continued to present itself until the warm weather began; but the atmosphere was then so hazy as to obscure the mountain altogether during its con- tinuance, nor have the rains, which are only just setting in, brought them yet within view. I am not in the habit of observing, and still less-of describ- ing, the phenomena of nature, and I fear you may not fully comprehend the impression which I wish to convey; but if you figure to yourself a vast column of smoke rushing violent- ly from the flue of a strong furnace, black at the bottom, and burning clearer as it.ascends, and the wind dispersing the top of the shaft when it rises above the influence of the fire, and you will have its appearance in a few words. The peak on which this phenomenon is seen, is that remark- able rocky one due north of Rungapannee, and the most ele- vated of the whole range seen from thence. But I am of opi- nion that, if it really be a volcano, the crater is situated on the north side of the highest point, because when the smoke ' was seen the peak on our side was distinctly visible, and the smoke seemed to me behind it. It is probable that some lower eminence, concealed from. us by the highest point, may be the seat of it. It is hardly possible to believe that the appearances, now described can arise from a cloud, as it is not usual for clouds to retain the very same form and shape for months together, nor to appear in the same identical spot." The summits of all the other peaks remained clear and bright as usual during the whole time that the smoke was observed. Ant. IV.—Researches on the Refractive Power of Elastic Fluids. * By M. Dutone. Tus object of these researches, was to ascertain if the refrac. tive power of gases followed any law analogous to that which . had been found for their specific heats, and if the act of com- * This paper is a Translation and Abstract of an Account of M. Dulong’s Researches, given in the Nouv. Bull. des Sciences, September 1825. 212 M. Dulong’s Researches 6n the bination altered the force of refraction possessed by the ue asia principles when considered separately. ' This last question had already been the subject of a Me. moir, published in 1806, by MM. Biot and Arago; but at that time we possessed only very uncertain data respecting the proportions of the greater number of compound bodies, and it has since been demonstrated, that, in the passage of elastic fluids to the liquid or solid state, considerable changes ate produced in the refractive powers. We cannot, therefore, expect to discover the relation in question, unless by observing bodies in the gaseous state. The philosophers whom we have quoted, having, besides, exa- mined only a very limited number of different species, it bes came indispensable to have recourse to new determinations. The method of observation employed by M. Dulong, was susceptible both of sufficient precision and of ready applica« tion. It is founded on the law announced by MM. Biot and Arago, and which M. Dulong has himself verified in other gases, that the refractive power of the same gas is proportions al to its density. Hence it follows, that if we determine the density of a gas when it refracts exactly as much as air, at the same temperature, and at a convenient pressure, we can deter- mine, by simple proportion, the ratio of the refractive powers of the two gases under the same pressure. We thus obtain, ‘indeed, only the ratios of the refractive powers ; but that is the only element which is necessary for the question which M. Dulong proposes to resolve. ' The apparatus which he employed, consists of a hollow prism of glass, with an angle of about 145%, into which differ ent gases may be successively introduced. A vertical tube, filled, with mercury, communicating with the interior of the prism, permits us to dilate at pleasure the elastic fluid which it contains. ‘The tension of the gas is ascertained either by the barometer of the air-pump, which forms part of the vr paratus, or, in some cases, where the communication wit the pump ought to be ARR apes by a small vertical t opening at its lower end into the reservoir of mercury Which we have mentioned. An astronomical telescope, furnished with cross wires in the focus of its object-glass, is placed ona . oS —— Refractive Power of Elastic Fluids. 213 stand of masonry before the prism, at such a height that we can perceive across it a distant mark. If the telescope and prism are inyariable, or if the telescope i is pointed to the mark when the prism is filled with air, at 0m 76 of tension, for example, then if another gas is made to replace the air, and such a density given to it as to restore the coincidence of the intersection of the wires at the mark, we are certain that the deviation is the same for the same refracting angle, which can only happen when the refractive powers are equal. In this process the limit of error depends on the magnify- ing power of the telescope; but as M. Dulong has remarked, that we cannot determine to less than the 3}, part the pu- rity of the gas, it would be useless to estimate smaller frac- tions in the measure of their refractive powers. This method i is applicable, with some modifications, to gases such as chlorine, which attack all metals, as well as va- pours which cannot support atmospheric pressure. In order to verify the law that, in the same gas, the Febleat tive powers are proportional to the density, M. Dulong de- termines the refractive power of seven miatures, formed by gases which do not combine ; and as the results of observa~ _ tion always agree with those which are deduced from the re- fractive powers of the ingredients of the mixture, we may con- elude, that each gas preserves a refractive power exactly pro- portional to its density. ‘The refractive power of atmospheric air, for example, M. Dulong has found to be equal to that of azote, oxygen, and earbonic acid united, each of them being calculated for its corresponding density in air. But as this equality is never met with in any combination, we thus obtain direct proof, that the elements of air are not combined together. The following table contains the refractive power of twenty gases, as measured by M. Dulong, in relation to that of air of equal density. Names of Gases, Refractive Powers. Densities. Atmospheric Air, 1 1 Oxygen, - 0.924 1.1026 Hydrogen, = © 5 0.470 0.0685 Azote, r ae 1,020 0,970 214. M. Dulong’s Researches on the / Chlorine. -; iter 2.623 2.47 ’ Oxide of Azote 1.710 1.527 Nitrous Gas, - 1.03 1.039 Hydrochloric Acid, 1.527 1.254 Oxide of Carbon, ~ 1.157 0.972 Carbonic Acid, - 1.526 1.524 Cyanogen, - 2.832 1.818 Olefiant Gas, * 2.302 0.980 Gas of Marshes, . 1.504 0.559 Muriatic Ether, 3.72 2.234 Hydrocyanic Acid, - 1.581 0.944 Ammonia, - 1.309 0.591 Oxi-Chloro-Carbonic Gas. 3.936 3.442 Sulphuretted Hydrogen, 2.187 1.178 Sulphurous Acid, 2.260 — 2.247 - Sulphuric Ether, == 5.280 2.580 Carburetted Sulphur, 5.179 2-644 The refractive power of air at 0°, and at 0" 76, being known either from the astronomical. observations of Delambre, or by the direct measures of M. Biot and Arago, we may de- duce from the preceding numbers the value of the absolute refractive powers of all the above gases, as well-as the indices of refraction for the passage of light from a vacuum into each. of the gases. The refractive powers of simple or comitanid gases do not seem to have any necessary relation to the density. The ole- fiant gas, for example, and the oxide of carbon, have nearly the same density, but the refractive power of the first is near- ly double that of the second. It has been long known, that, in comparing solids or Abs quids of a different nature, the refraction is not proportional to the density, and hence it has been concluded that every body exercises upon light an action depending on its own na- ture. But the different: capacities of bodies for heat related to a unity of mass, had led to an analogous conclusion relative to the attractions which were admitted between bodies and the mat- ter of heat. But since, in calculating the capacities of “each particular molecule, it has been found that they were equal, or in simple relations, it would not be surprising if the same idea, applied to refractive power, would lead to the discovery of very simple relations where none had been discovered. EES OEE — Refractive Power of Elastic Fluids. 215 But if an analogous law really existed, it would show itself in the numbers of the’ preceding table, for the gases having been observed at the same temperature and pressure, the inequalities in the refractive powers could arise only from the inequality of the effects of each of the molecules consi- dered individually. M. Dulong next proceeds to examine if there is any appre- ciable relation between the refractive power of compound gases and that of their elements. The following table con- tains the refractive powers’ as calculated and observed in nine different compounds. | Observed Calculated Refract. Power. Refract. Power. Difference. Ammonia, 1.309 1.216 +0.093 Oxide of azote, 1.710 1.482 + 0.228 Nitrous gas, 1.030 0.972 +0.050 Water, vapour of 1.000 0.933 + 0,067 Oxi-chloro-carb. gas, 3.936 3.784 +0152 Muriatic ether, 3.72 3.829 —0.099 Hydrocyanic acid, 1.521 1.651 —0.130 Carbonic acid, 1.526 1,609 —0.093 Hydrochloric acid, 1.527 © 1.547 —0.020 In five of the preceding gases, the refractive power of the compound is greater than that of its elements, whilst in the other four it is the reverse. The particular kind of condensation which accompanies the combination does not appear to have any connection with this variation ; for, in hydrochloric acid, for example, there is a diminution, and, in nitrous gas, an augmentation, though the proportions of, these two com- pounds are the same, and the condensation is nothing in both. Read The only remark which this kind of approximation leads us to make is, that, in the binary alkaline or neutral combi- nations, the observed refractive power is greater than that deduced from the elements, while in acid compounds it is — weaker. ary J . Muriatic ether,‘ which may be regarded as neutral, and the oxi-chloro-carbonic gas, which -is decidedly acid, are ex- ceptions to the law. But we ought to remark, that those com- binations are formed of three primitive elements, which are 216 M. ‘Marsollier’s Description of the probably reunited in two binary combinations having a‘ com- mon element. But it is these binary combinations, the’: im- mediate elements of the combinations in question, that ought to. be compared with one another. This seems to show very clearly, that the refraction de- pends not on the mass of the molecules, like specific heat, but on the electric state which belongs to them. In reasoning on the hypothesis of emission, the sum of the attractions of the molecules of an elastic fluid: on light ought to’be independent of the form of these molecules, since these are liable, as in crystallized bodies, to present certain faces in a determinate direction. But if the refraction depended on these attractions, we cannot conceive how the action of a bi- nary compound should be sometimes greater and sometimes less than the sum of that of its elementary molecules. We may, therefore, regard this fact as a new difficulty attached to the hypothesis of Newton. SOLLIER. Art. V.—Description of the Grotto of Ganges.* By M. Mar- Whuen we set out to visit the subterraneous grotto, we expe- rienced at first nothing but fatigue. It was necessary to climb for nearly three quarters of an hour. The sun, the _ reflection from the rocks, the footpath traced only by the tread of the goats, the rolling stones, the torches, the cords, the provisions of which each carries his part,—all this adds to the difficulty of the expedition. On the summit of a rock in the middle of the mountain there rises a small wood of green oak, which affords an agree- able shade, and protects, with its mysterious shadow, the - mouth of the cavern. This opening has the form of a cask, the top being about 20 fect in diameter, and its depth about 30 feet. This hollow is finely fringed with trees, plants, and wild vines with their grapes, and excites the regret that we are * Translated from Marsollier, as given in Renaud de via Poses dans le Languedoc, Paris, 1825, 4 Grotto of Ganges. 217° to leave nature in her finest aspect, in, order to descend to her darkest abyss. We descended by grasping firmly a rope stretched, and fixed to a rock, till we reached the place where a rope-ladder has been firmly fastened. This difficulty being got over, we find ourselves at the entrance of the first chamber. This en- trance descends progressively, and is covered with maiden- hair. Towards the right is a kind of cave, which is not con- tinued far ; but, in front, there are seen magnificent columns, having the appearance of a row of pillars, and forming gal- leries. . ‘'hese pillars may be about thirty feet high. It is in this first chamber, divided into two by these co- lumns, that the torches are lighted, and that, after having — breakfasted, we quit for a long time the light of day. From the first we pass to the second chamber by a very narrow pas- sage, where the body is obliged to force itself through oblique- ly. This second chamber is immense. In ascending, there is seen to the left, a curtain of a height which cannot be measured, covered with brilliants, folded with grace, and touching the earth at its front, as if the drapery had been ar- ranged by the most skilful artist. Petrified cascades, as white as enamel—others of a yellow hue, which seem to fall about us in heaps of waves ;—several columns, some truncat- ed, and others in the shape of obelisks ;—the roof loaded with festoons and stars;—-some transparent like glass, and others as white as alabaster—crystals—diamonds—porcelain, a rich and strange assemblage, which seem to realize those pic tures which were the amusement of our earliest years. _ In proceeding to the left, we pass into a third chamber of considerable width, but of great length. Its form is that of a winding gallery, in which, after we have walked for some time, we come to a small rugged arch, where we are obliged * to stoop. This place, which is called the oven, has two open- ings, and the crystallizations, which are white, resemble mus- lins of all patterns. .In adyancing, we leave on the right a second oven of less interest, and enter a large chamber where nothing is to be seen but rocks uprooted, crushed to pieces, and suspended, as if it had been the scene of the most vio- lent conyulsions. Every thing is here gloomy and sad, till 218 M. Marsollier’s Description of the we reached the place where M. Lonjon caused a mine to be sprung. The passage is so narrow that we are obliged to creep, and it conducts to a small room which holds about twelve persons. | . ’ Behind three columns, there is a reservoir, the water of which is salt and muddy, and a prodigious number of bats occupied along with us that small space.. Upon the rocks we observed several crystallizations in the form of plants. They were white and shining, and formed a fine contrast with the dark ground to which they were applied. This'chamber had an opening on the side opposite to that at which we entered. Before us we saw a space, the dimensions of which the eye could not measure, and, in order to reach it, there was no other path but over a precipitous rock fifty feet high. Over this was the first stair by which we could descend. The rope- ladder was brought, and fixed to a stalactite. We encou- rage one another, advancing and drawing back, a fright- ful precipice presenting itself on all sides. A stone thrown down took a considerable time to descend, and ‘we heard it leaping and rolling from rock to rock till it was heard no . more. The slightest giddiness, and the slightest genet might here decide the life of the spectator. A peasant of Ganges, as expert as he was bold, was the first who ventured down. M. Brunet followed: him, and, at the end of three toises, the person who descended ceased to be visible, and the time which they took seemed to be enor- mous. At the depth of twenty feet, the rocks suddenly ceas- ed, and the ladder, without any support, swung and turned upon itself. The profound silence—the glimmering light— which diminished without dissipating the darkness—the dread which this profound solitude excited—the ‘alarming noise of some broken stalactites which fell from the roof and rolled from rock to rock—every thing contributed to give to our expedition a romantic character. We now directed our at- tention to an immense space enriched and covered with stalac- tites and stalagmites of every form, and of the most daz- zling whiteness ; but we had still more’ than fifty feet before we reached the ‘bottom. Steep rocks so smooth that the foot could not support itself, and where the hand could not be fix- 1 Grotto of Ganges. 219 ed, held out the prospect of certain death to the person who should be rash enough: to ‘attempt to descend ; we, therefore, decided, though with» much regret, on p eeeenie b's our ladder. Marsollier describes anche small grotto on the vind to st . Bausile to Ganges, and then the preparations for a new ~ aed dition. The Devil's. Pass now presented itself. This was the lds where we had been stopped, and to which we gave this name, from the dangers which it presents. | Notwithstanding, | in- deed, all the labour which had been bestowed, this passage had only a place for the foot... A projecting rock pressed the knees together ; and, as there was a precipice behind, it was necessary to walk sideways upon this inclined plane, the feet . being wholly without. We have never seen any etary pass here without terror. » This difficulty being surmounted, we sausiea a transparent column twenty-five feet high, as white as alabaster, and all formed like cauliflowers placed: above one another, till they formed a pyramid: Here a new difficulty awaited us, and it was necessary to descend : The plain was inclined—the ladder could be of no use—the ground was slippery—a_ precipice was beneath—and it was necessary either to fall. right down, or to run the risk of being lost in.a deep hole, or dashed against the rocks. We, therefore, pushed down a piece of wood to lengthen the declivity, and, upon that alone, we found it necessary to slide directly down, holding by the left hand a rope, which every one fixed the best way he could... Upon reaching that piece of wood, a broken stalactite, a foot in dia- meter,, was the first place where we considered’ ourselves in safety, having now reached.a sort of solid ground. Here we were first-surprised by an altar as white as the purest porcelain, and:three feet in height, of a form perfectly oval, and having regular steps. The table of that altar was of the most dazzling enamel, consisting of leaves placed one above the other, like the leaves of an artichoke. At a greater distance were seen four twisted columns, of a yellowish hue, and transparent in several places, notwithstanding their size. 220 M. Marsollier’s Description, §c. Four men were not able to grasp them. Their height could not be estimated, but we supposed they touched the roof. ' This chamber is as large as the half of Ganges. Our eyes were able neither to measure the height nor the depth of it. ‘We perceived cavities which human industry could not make us penetrate. Seated upon this altar, we were surrounded with such a prodigious quantity of objects, that we were lost in mute admiration. Among others was an obelisk, as high as a church, terminated with a spire. It was perfectly round, and of a reddish colour, chiseled throughout the whole of its height, and in the most exact proportion. We saw, also, masses as large as churches, sometimes in the form of cas- cades, sometimes resembling clouds. In other places were seen columns broken in all directions, and covered. with rami- fications of enamel; cauliflowers, muslins, and every species of the most singular and varied combinations, One of the wonders of this grotto is, a colossal statue placed upon a pedestal, and representing a woman holding two in- fants. ‘I'his statue would be worthy of the greatest Sovereign of Europe, if it could be removed without losing that form ‘which we have so distinctly observed it to possess, In every part of the grotto are seen fringes, curtains, coats of enamel and crystals, laces and ribbons, so delicately arranged, that it was necessary to prove that man had never penetrat- ed these regions, before one could believe that they were not the work of the most skilful artist. This chamber is round, and may be compared to a Basilica surrounded with chapels more or less elevated. In the mid- dle there rises a dome, which we conjecture to be about 300 feet high. The description of the grotto of Antiparos, which was believed to be fabulous in M. de Tournefort, and which appears from the travels of M. le Comte de Gouffier not to have been exaggerated, is a feeble image of the grotto f Ganges. et ae iT; Fin! Notice respecting the Eggs of the Boa Constrictor, 221 Axt. VI.Notice respecting the Eggs of the Boa Constrictor, and of a young Brood hatched from them in Assam. Com- municated to Dr Brewsten by a Correspondent in India. I nap the good fortune of obtaining yesterday, at Bishnath (18th June 1825,) a Boa Constrictor sixteen feet long, but it has been so much injured, that I fear the skeleton of it will be a very incomplete one. About eighty or ninety of its eggs have also been brought in to us, and I hope to be able to hatch for you a brood of young boas of a proper size for sending homie. One of the young ones, taken from a broken shell, showed symptoms of vitality. It is about eighteen, in- ches long. I had previously seen the same species of snakes upwards of twenty feet in length, in Gorackpore. We were attacked last night, by a flotilla of wild elephants coming from the other side of the river. They broke through my line of boats in spite of all our clamour, and one of them sunk a canoe, and crushed to death a man that was in it. I have now (6th July 1825,) hatched a brood of young boas from the eggs which I have already mentioned to you as having got at Bishnath. There are twenty-eight of ‘them here, (at Gowahutty,) and about twenty more at the snake-catcher’s house. They are about eighteen inches in length, and sufficiently lively ; but I fear it will be very troublesome to bring them up, as they require to be crammed with fish or other food; an operation which no one but a snake-catcher who has got over the vulgar prejudice against being bitten by such snakes as these are, would like to per- form. There are also here some very fine hooded snakes, re- sembling the Cobra de Capello, but larger than any of that species that I have before met with, being ten or twelve feet long. It is here considered to be a very uncommon thing to find the eggs of the boa, as none of the snake-catchers have ever seen them before. They were soft, and indented by pressing against each other. Their size is about that of a goose’s egg, and they resembled in appearance the Fungi called Dead 292 Prof. Gmelin on the Analysis of a men’s——— I forget what in Scotland. At the end there was a sort of tag, as if the egg had been attached to something...» - The .young snakes hatched’ from the eggs are still doing* well, (July 18, 1825,) only one of them having died. out of ' twenty-eight. On the fourteenth day after birth, they cast their first skins. They increase considerably in size, but the - snake-catchers are of opinion, that they will take many ‘years to acquire their full growth. Art. VIT.—Analysis of a Lithion-Mica from: Zinnwald in Bohemia. By C. G. Gmewin, Professor of Chemistry in the University of Tubingen. In a Letter to Dr Brewster. Dear Sir, I. nave the honour to send-you the result of the analysis of a Lithion-Mica, along with a few lamine, with the request that -you may examine their optical structure. _When I had found that the micafrom Chursdorf wasa lithion-mica, I search- ed in vain for others of the same nature in my small collection of minerals. Soon after I met with a beautifully crystallized mica from Zinnwald in Bohemia, which I immediately reckon- ed to be lithion-mica... While I was engaged with its analysis, I received the 5th number of your Journal, where I found that several species of lithion-micas had been already discover- ed by Messrs ‘Turner and Haidinger. The lithion-mica from Zinnwald, which I have analysed, is accompanied by eS gle of lead. _ I have obtained the following result : Silica, - - - 46.233 Alumine, m » , 14.141 Oxide of iron, 5a ry 17.973 Oxide of manganese, o re 4.573 Potash, - - - 4.900 Lithion, sl is gs 4.206 mes Fluoric acid, = { 3.729 ad? Water and loss, - @ M245 fa CLE ee Los ae Jactte 100.000 This mica loses by 1 sation: not more than 0.83 per cent., Fond a ee alt. ee Lithion-Mica from Zinnwald. ' 223 eyen if this loss is taken for pure water without fluoric acid,’ there still remains a loss of 3.4 per cent., which, in fact, is very considerable. I have been convinced, by direct ex- periment, that when this mica is fused in a platina erucible, « by far the greatest part, if not all the fluoric acid, remains behind ; for, when the fused mass is covered by carbonate of soda, and again exposed to heat, there is obtained by analysis a quantity of fluoric acid, which is probably not inferior to that obtained from the mica before it has been previously fused. The con- siderable loss may be, I think, accounted for by the volatiliza- tion of the alkaline matter, which is expelled by barytes during the intense heat required for the decomposition of the mineral. This inconvenience might be, I suppose, prevented by the use of oxide of lead instead of carbonate of barytes. The fluoric acid is evidently to be considered as an essen- tial ingredient of mica, and lithion-micas appear to be con- stantly possessed of a large quantity of this acid; and there seems to exist an insensible passage in that respect from the micas to the tales, which also deserve to be examined with greater accuracy. I should have wished to try the easily fusible micas from St Gothard before the blow-pipe, but those which I have had an opportunity to examine fused with difficulty, and did not possess the characters of lithion-micas. It does not appear to be an easy task, to separate mechani- cally those portions of the lithion-mica from Chursdorf, that prove to be different from the rest in their optical structure ; and I have not at present an apparatus fitted for that purpose. If-E.should find an opportunity, I shall take the liberty of sending to you a sufficient’ quantity, that you may exe- cute this separation, and I should be happy to make a careful analysis of both portions. I am engaged at present with a comparative inquiry into the volcanic products, and those of what was formerly called the floetz trap formation. Itis well known, that muriatic acid has been long since discovered in basalts. This acid seems to be much diffused in these formations. I have, for instance, found it in the prehnite from Dumbarton, and in a great many other minerals of a similar origin. I thought that it might also be an ingredient of Tesselite, but I could not 224 Prof, Oersted on the Law of tha discover a sensible quantity of it. It may also be a consti- tuent part of sore meteorolites, which in many respects have a resemblance to the products of the floetz trap formation; but I have now no opportunity to verify this viet T am, Dear Sir, : With high esteem, yours, &e. | C. G. GMELIN. Tisincen, 31st Dec. 1825. . Art. VIII.—On the Law of the Compression of Air, and of Gases capable of being Liquefied by Pressure. By H.-C. OrrsteD, Professor of Natural Philosophy in the Univer- sity of Copenhagen. Communicated by the Author. Taz law of Mariotte,* according to which the volumes of a mass of air are reciprocal to the pressures which they suffer, has ‘not yet been established by accurate experiments, unless in the case of very weak pressures. With regard to high pressures, it may still be doubted whether or not they follow the same ratio. Several distinguished philosophers have taken for granted the accuracy of this law, for all the pressures to which a mass of air can be subjected, while others, such as James Bernouilli and Euler, suppose that the volumes decrease in a much less progression; whereas, in the small number of experiments that have been made under consider-’ able pressures, the volumes decrease in a much higher ‘pro- gression than the pressure. This result, indeed, has been ob- tained by Sulzer + and by Dr Robison, as will Besa from the following tables : alo Ls * This law was first deduced from the experiments of the celebrated Boyle, by his friend Richard Townley, but as it is so well known under the name of Mariotte, who discovered it nearly at the same time, and by his. own experiments, I have made use of this ‘name, already consecrated by time. + See the Memoits of the Actdetny of Beslin, : me ot isto pete 11 Pe - Compression of Air and other Gases. 226 | { Experiments of Sulzer, ; Experiments of Robison | the most complete Series, with dry air. Densities. | Elasticities. | Densities. | Blasticities. 1,000 1,000 1,000 1,000 1,091 1,076 2,000 1,957 ¢ 1,200 1,183 3,000 2,848 1,333 1,303 4,000 3,737 1,500 1,472 5,500 4,630 1,714 | 1,659 6,000 5,342 2,000 1,900 7,620 6,790 2,400 2,241 3,000 2,793 4,000 3,631 . 6,000 5,297 8,000 6,835 Captain Schwendsen and I having proposed to investigate the theory of the air gun, found it necessary to examine, as a fundamental principle, the extent of the law of Mariotte. The apparatus commonly employed to establish this law, con- sists of a bent tube ABCD, Fig. 13, Plate V. of which DE contains the air, and the other ABCE mercury, which serves to inclose and to compress the air. This apparatus has seve- ral inconveniences. It is difficult to divide accurately the portion DE into parts of equal capacity, and this portion is dilated by the interior pressure so as to expose the apparatus to the risk ‘of being broken when the pressure becomes consi- derable. In order to. guard against that accident, tubes of a small diameter have been used, but they occasion friction sufficiently great to produce a sensible influence on the re- sults. - In order to avoid these inconveniences, we had recourse to an apparatus constructed according to the same principle which T employed in my apparatus for the compression of water. A vertical section of this apparatus is represented in Fig. 14, where ABCD is a strong glass cylinder with a brass cover - AC; EF isa divided glass tube (supported by an iron frame 1m no) the lower part of which is an iron vessel, containing a little mercury, which closes the tube EF before its immersion in the mercury which i is found at the bottom of the cylinder ; ; IK is the superior limit of the mercury; GH represents part VOL. Iv. No. 11. APRIL 1826. P 226 . © ProfUersted on the Lazw of the of a very strong glass tube glued into a hollow piece ¢ 4, which has a screw on its outer surface to screw into the opening in the cover AC. . In this cover there is another hole p, which is shut by a screw p E. TV is a wooden stand, surmounted by a pillar RST, which serves as a support for the tube GH. The two supplementary figures, Fig. 15 and 16, represent the frame 7 mn 0, and the transverse section of the lower part of the apparatus. In order to make the experiment, the lid AC is unscrewed, and the tube EF, containing air ‘well dried, is put into its place. ‘The lid AC is then put on, and well closed up. The tube GH is also put in its place, and, by means of a funnel placed in the aperture p, the cylinder is filled with water. The pressure excited by this water is measured by the height of the mercury in the tube GH. ‘The apparatus is then closed up by the screw, which goes into the aperture p, and when mercury is poured into the tube GH, this fluid rises also in the tube EF, and compresses the air which is con- tained in it. The difference between the levels of the mer- cury in EF, and in GH, gives us the compressing power, and as the tubes have equal divisions, this difference of the levels is found by a simple subtraction. Although the tube EF of our apparatus is everywhere of a calibre nearly equal, yet we have determined exactly the capacities corresponding to the divisions by weighing the portions of mercury in each. The divisions on the tube GH reach only a few inches be- low the cylinder. The other distances were measured by a scale. In order to have the tube GH sufficiently long for great pressures,’ we united, by iron screws, several tubes of glass, each 7 feet in length. The experiment was always made in a stair of the house, which contains the physical ca- binet of the university, no apartment being sufficiently high . to permit the necessary elongation of the tube GH. ie With this apparatus we have made several experiments, the ¥esults of which are conformable to the law of Mariotte; but they have not all been attended with the same success, for it is Very difficult to make all the joints and screws sufficiently impenetrable to mercury acting with high pressures. r™ Compression of Air and other Gases. 227 It is only in’ one of the experiments that we reached to a ‘pressure of eight atmospheres, and we shall'now give the results of it. The air in the tube EF was well dried by muriate of lime.. The capacity of the tube was measured-by mercury, and it contained 1054.8 grammes of it, at the temperature of 20° centigrade. The pressure of the atmosphere on the day of the experiment was 0.7578 metres. The following table shows. the ratio which we found between the compression of the air, andthe pressure of the mercury : z Differences Di- Densities. [CO™PFSME | pifferences. | vided by the ge Pressures. 1,000 1,000 0,0000 0,0000 1,1052 11,1051 +0,0001 +0,0001 1,1676 1,1693 —0,0017 —0,0015 1,2736 1,2706 +0,0030 +0,0024 1,4744 1,4694 +0,0050 +0,0035 1,587 1,581 +0,006 +0,004 1,812 1,806 +0,006 +0,003 2,112 2,079 +0,033 +0,016 » 2,529 2,520 +0,009 +0,004 3,168 3,147 +0,021 +0,007 3,616 3,599 +0,017 +0,005 4,209 4,185 +0,024 +0,006 5,057 5,010 +0,047 +0,009 5,603 5,572 +0,031 +0,005 © 6,288 6,287 +0,001 +0,000 8,175 7,082 +0,093 +0,013 8,030 8,014 +0,016. +0,002 The first column of this table gives the numbers obtained by dividing the primitive volume by the volume reduced by the compressing forces, 7. ¢. the densities. The second column -gives the compressing forces in numbers, of which unity is the pressure of a column of mercury of 0.7578 metres, equal to ‘the pressure of the atmosphere on the day of the experiment. The third shows the differences between the compressions and the compressing forces, and the fourth shows the ratios of these -differences to the compressions. It is very difficult in these experiments to determine exactly ‘the volume of air inclosed, since the inferior limit is a curved ‘surface, whose form is often modified by the friction between -the mercury and the glass. In all these experiments we have 228 Prof. Oersted on the Law of the © endeavoured to divide, by the eye, the concave part into \two parts.of equal. volume, but the results show that we have at- tributed -too ‘little of this volume to the inclosed air. With- out this error the differences would) have been smaller. In other respects, they are as small as could be expected. in ye riments where a vernier could not be used. | © In the last observation, for example, where the wheiaied length of the column of air was 56.4 millimetres, the length which would have entirely agreed with the law of Mariotte, is 56.287, which differs only 0.113 millimetres from observation, an error which is unavoidable in such observations. In the last experiment but one, the observed length of the column of air was 63.17 millimetres, whereas the number which would have satisfied the law of Mariotte, is 63.99. .This difference amounts to.0.82 millimetres, but, being between two other ob- servations whose deviations are very small, it cannot affect the. general law. In order to examine the compression of air by great forces, we made use’ of air-guns.'’ Our sovereign, whose enlightened magnanimity has so often contributed ‘to the progress of — science, putiat our disposal all the appatatus which was ne- cessary for this inquiry. The reservoir uf air in this kind of arm is the culasse, which ought to be very strong; we at first measured the capacities of these by weighing them when emp- ty, and when filled with water. It was then easy to calculate the quantity of air which such a reservoir contained. . That which we most frequently used contained 0.891 grammes of air when the barometer was at 0.76. . We were thus capable of determining, by the balance, the degree of compression which we had attained in our expe- riments. ‘This method was found sufficiently exact, as the balance which we commonly used. was sensible to a centi- gramme. Wesucceeded in introducing into this reservoir as much as 101.2 grammes of air, a quantity equivalent to the pressure of 110.5 atmospheres. . We have also, in these ex- periments, taken into consideration the dilatation: which ‘the interior pressure ought to produce in the reservoir.’ »This dilatation was determined by weighing in water the reservoir when empty, and when filled with air; and in the calcula- Compression of Air and other Gases. 229 tions, it was supposed that the dilatations which it experien- ced were proportional to the quantities of air introduced into it. If te reservoir had not been dilated, when 101.2 grammes of air were forced into it, the density of the air would have been 113.5 times that of the atmosphere ; but, when calculat- ed, by applying the dilatation of the reservoir, it amounted only to 110.5. In Fig. 17 we have shown the method in which, we made the experiments on the expansive force of air compressed in such a reservoir. AB represents the reser- voir, that. is the cudasse of an air-gun, CD is a plate with a pillar CE, FH is a piece of iron, whose upper part receives the axis round which the lever FG turns. ‘This lever is ba- lanced by the mass F.. At I the lever carries a tooth or pin with which it presses upon the valve M. A slide N with the scale L of a balance serves to determine the force ne- cessary to open the valve. As this is kept in its place bya spring, we at first examined what was the force required to open it when the air inclosed had the same density as the at- mospheric air. When this was done, we charged the reser- voir as much as possible, and after having determined the re- sistance which the introduced air gave to the valve, we dis- charged the reservoir by degrees, always determining by the balance the quantity of air which remained, and by the ap- paratus in Fig. 17, its expansive power. This class of experiments, however, is not susceptible of any rigour, because the valve does not always apply itself in the same manner. When the valve is covered with leather, in order to make it»shut better, the inequality is very great, and it is on that account that we have made a series of ex- periments with a valve of steel, which was well. ground into the aperture, but we have not been able by this means to ob- tain sufficiently: great pressures. The first table shows the results obtained by a valve cover- ed with leather, and the other the results obtained by a ground steel valve. i / 2% 230 dP rot Mersiad onthe thoes the Ebperiment made with a Culasse, ih Es Valve was covered with Leather. Weights of air | Densities, that )preccures on the) Pressures divid- inclosed, in | of the atmos- | valve in gram-| ed by the den- grammes. phere being 1. ches. sities. 1 1,122 812 725 2 2,273 y 1809 806 3 3,364 2552 758 4 4,484 3693 823 ; | 5 5,604 4395 784 6 6,723 5750 855 7 7,842 6693 853 8 8,960 6797 758 9 10,077 7711 764 10 11,193 8166. 729 10 11,193 8434 753 10 11,193 8480 757 10 11,193 . |. 8445, 754 10 ~ 41,193 8437 753 Experiments. inde with a Culasse; whose Valve was ) without Leather. Weights of air | Densities that | Pressures on the)Pressures divid- inclosed, in | of the atmos- | valve, it, gram-| ed by the den- | grammes, phere being 1. mes. sities. 1, 1,122 1269 1131 2, 2,243 2368 1055 3, 3,364 %88 1007 4, 4,484 47519 1059 5, 5,604 5750 1026 5, 5,604 5620 1002 5,05 5,657 5790 1023 | 5,05 5,657 5800 1025 a | 5, 5,604 5730 1022 | 6, 6,732 6871 1021 . , | z, 7,842 8113 1034 8, 8,960 9344 1043 9, 10,077 10375 1029 ; 10, 11,193 11440 1022 * 10;2 11,417 11725 1027 - 15, 16,76 - 16766 1000" 15,1 16,87 17243 1022 a 20, 22,326 22988 _| 1029 PAR 25,6 28,543 29253 3025 - te 30, 33,393. . 84197 1024) te by 35,2 39,13 40232 1026 ©. 40,1 44,52 45633 102s °? Agr tae 45, 49,894, 51641 » 1035 50, 55,362. 57467 1038 55, 60,816 63102 1037 60, ~ 66,254 67798 | 1023 — Compression of Air and other, Gases. 231 In these tables, the first column shows the weight of air in troduced into the reservoir; the second shows the condensa- tion; the third the force required to open the valve, diminish- ed by the force required to open it before the charge ; and the fourth gives the pressure of the atmosphere obtained by di- viding this force by the condensation. In the first table, the mean number is 797 ; the deviations from it vary on both sides. In the second table; we have, by) rejecting the first number as, too discrepant, 1027 as the mean, and it is evident that most of the numbers are not far removed from it. These experiments, therefore, imper- fect as they are by their very nature, concur in proving that the compressions produced by very great forces, are regulat- ed by the same law as those which are feeble. But, in or- der to decide if the compressions of any gas whatever follows the same law, we have had recourse to gases capable of being liquefied by. a few atmospheres. The sulphurous acid gas, which, according to M. Faraday, is liquefied by a pressure of two atmospheres, appeared to us very fit for this class of ex- periments. - Two equal tubes, the one filled with sulphurous acid very dry, and the other with atmospheric air, were placed in a small mercurial bath, and introduced into an apparatus, where these aeriform bodies could be exposed to a suitable pres- sure; the result was, that. they suffered a diminution of their volume always equal, till the sulphurous acid gas began . to convert itself into a liquid. The following is the detail of the experiment. In Fig. 18, AAAA is a cylinder of glass very strong, and of the same kind as that which I used to show the compres- sion of water. This cylinder has a brass cover surmounted with a cylinder BBBB, in which moves the piston C, pushed by the screw DD ; EE, EE are two equal and divided tubes, whose lower ends are immersed in an iron dish FF, which is fixed to the end of a strip of glass GGGG, which, at the same time, serves to keep the two tubes in a vertical position. The cylinder AAAA is filled with mercury to HH. The experiment is begun by filling the two tubes with the aeriform materials, placing them in the dish FF, and fixing them on the strip of glass GGGG. When this is done, the apparatus 232 Prof. Oersted on the Law of the is introduced into the cylinder AAAA, where the dish FF is plunged in the mercury, which is below the line HH: 'The eylinder is filled with water, and the body BBBB of the ‘pump is put in and filled with. water. The piston DD is finally put in, and is made to act upon the inclosed water. This water communicates its pressure to the mercury, which, in its turn, transmits it to the two aeriform materials contain- ed in the tube. . The following are the results of the experiments with two tubes, one of which contains atmospherical air, and the other sulphurous acid gas, the temperature being 21}° centigrade. - |Condensation of|Conden’sation of or a en the Sulphurous | the Atmosphe- | Differences. Acid. rical Air. ~“131,2 128,5 i; ; 1, 128, 125,33 1,0261 1,0259 +0,0002 122,4 120 1,0754 1,0768 +0,0014 117,33 115 1,1229 1,1215 +0,0014 _ Tile, 110° 1,1750 1,1729 +0,0021 106,875 | 105 1,2302 1,2297 +0,0005 -101,5 100 ‘1,2937 1,2942 +-0,0005 96,3 95 1,3634 1,3644 -+0,0010 91,25 90 1,4396 1,4403 --0,0007 86, 85 1,5278 1,5257 +0,0021 80,75 80 1,6228 1,6228 0,0000 1555 15 1,7329 1,7311 +0,0018 70,6. 70 1,8542 -1,8539 +0,0003 65,6 65 1,9971 1,9974 --0,0003 64,5 64 2,0310 2,0307 +0,0003 63,4 63 2,0649 2,0638 +0,0011 62,4 62 2,0976 2,0982 +0,0006 61,3 61 2,1342 2,1336 +0,0006 60,3 60 2,1705 2,1702 +0,0003 59,25 59 2,2101 2,2082 +0,0019 58,2 58 2,2475 2,2474 +0,0001 57,16 57 22879.” 2,287 4 +0,0005 ; 56,» 56 2,3356 2,3289 +0,0067 . 54,875 55 2,3835 2,3720 —+0,0115 53,875 54 2,4279 2,4166 +0,0113 52,8 53 | 24798 2,4619 +0,0169 51,75 * 52 2,5317 2,5109 +0,0268 50,6 51 2,5831 2,5610 +0,0221 |} 49,6, 50 2,6488 2,6171 +0,0317 | 48,6 49 2,7008 2,6674 +0,0334 | 47,6 48 2,7595 2,7240 +0,0355 | 46,6 47 2,8207 2,7819 | +0,0388 |- 45,5 46 2,8886 | 2,8423 +0,0463 44,4 45 2,9556 2,9057 +0,0499 43,33 44 -8,0240 2.9717 +0,0523 42,4 43 3,0974 . 3,0407 | +0,0567 41,16 42 3,1733 3,1130 40,0603 39,33 41 3,3186 > 3,1889 +0,1297 ao. ne Compression of Air and other Gases. 233 From this table, it appears that the differences are very in- considerable, and vary on oue side and another, till the pres- sure amounts to 2.3 atmospheres, when they become greater, and go on increasing. At a pressure of 3.2689, a little above that represented in the table, the humidity-becomes visible, and beyond this the contraction takes place rapidly... Before this term, there is, perhaps, a feeble liquefaction at the con- tact of the gases with the sides of the cylinder, and at the surface of the mercury ; for the contact of a heterogeneous body seems to favour the transition of the body from one state of aggregation to another, as I have shown in a memoir on the experiments of Winterl, printed in the Journal of Geh- len for 1806, vol. i. p. 276—289. . In some experiments we have found that the water pene- trated between the mercury and the sides of the tube. We have since corrected this inconvenience by cementing to the open extremity of each tube a brass ring, which amalgamates with the mercury, and thus prevents the water from escaping. We have also compressed Cyanogen by the same means, and we have found that the liquefaction of this gas begins when * ad 1 * the air is compressed to 5, of its volume, the thermometer be- | 1 | ing at 28° centigrade, and the barometer at 0.759 metres. It would be easy to multiply these experiments, but those which we have given are sufficient to prove that the compres- sion of air and of gases is proportional to the compressing force, however great that force may be, provided they pre- serve their gaseous state, and have lost the caloric developed by their compression. These researches, therefore, have only served to confirm the opinions of the most distinguished phi- , losophers of our times upon this subject; but, as there were still others who. entertained an opposite opinion, we have not considered the publication of our experiments as altogether useless. t The compression of fluids.is, as far as we have discovered; ‘subject to the same law of being proportional to the compres- sing forces.. We may, therefore, suppose, that gases, reduced to the state of liquids, begin again to follow the same law which they obeyed in their gaseous state. Itis.also probable, that liquids, after being converted into: solids, are subject to ome 234 _ Captain Pringle’s Route to India this law. If that shall be confirmed by ulterior experiments, we may conclude that it is only in the transition of a body from one state of aggregation to another, that this law is not regulated by the compressions. | CorENHAGEN, 9th ‘September 1825. Anz. IX.—Route to India, by Egypt and the Red Sea. By CartaIn Prince, Royal Engineers. Communicated by the Author. Tue contradictory statements which ‘I received respecting the above route, induced me to note down the inquiries which I made up on the subject ; and. their result will, perhaps, be useful to such officers as may have an intention of proceeding by Egypt and the Red Sea to India. The season in which vessels: sail from the Red Sea to In- dia is confined to the short space of about two months, ex- tending from the first of July to the first week in September ; and this is done, that they may have the benefit of the south- west monsoon in the Indian seas, and of the steady weather which is then prevalent. It will be requisite, therefore, to regulate all the previous proceedings of the journey, in order to suit the above season. It will be necessary, then, to arrive at Mocha éither before _ or within that period. It might be possible, indeed, even after that time, to get round the southern shore of Arabia to Muscat, from which place there are vessels sailing to Bombay at all seasons; but such a voyage would be attended with difficulty and danger. In coming from ports higher up the Red Sea, all vessels, I believe, touch at Mocha; at least all that are proceeding to British India, as the Company have their resident there. The vessels employed in this trade are chiefly Arabs. A few.of them are square rigged, but the greater part are Buglas, similar to the Indian Donie, which is a sloop, or large boat, with an unwieldy sail. oouigel them, however, have airy poop-cabins. . The Buglas are almost the only vessels. usellé in communi- cating betwixt the different: ports of the Red Sea. The by Egypt and the Red Sea. 235 Arab vessels, particularly the Buglas, seldom venture to stand directly across from Kosseir to J idda; but, in making that voyage, they go as far north as the’ Ras Mahomet, or en- trance into the bay of Suez, and never lose sight of land ; indeed, they keep generally in a channel between the coral reefs and the shore, and come every night to,an anchor, or to moorings on the coral banks. For the sake of some trifling traffic, they also make delays at the different small ports on the coast. All this renders the voyage extremely tedious. These vessels, however, pass during the whole year from Suez, or Kosseir, to Jidda, and from Jidda to Hodeida and Mocha. The time required for the voyage 7 . "by Egypt and the Red Sea. 239 ~The kanjas have a cabin in the stern, similar to that of a gondola ; and, though low, it is sufficiently large for two per- sons. ‘The servants cook the victuals in the forepart of the boat. The hire of the boat and crew is from sibpel to thir- ‘ty Spanish dollars a month. The antiquities of Alexandria, the position of our army, ‘the site of the action with the French in 1801, may be seen in ‘three or four days. Mr Lee, our consul resident at Alexan- dria, is extremely hospitable and kind in lending every assist- ance. In Alexandria there is an hotel kept by a Maltese, and a table @héte. It will take a week to sail by the new canal into the Nile and ascend to Cairo; but if Rosetta be visited a “vig of days more will be requited. At Cairo there is avery good hotel kept by a Frenchman, a table @héte, &c. The expence there will be about a dollar aday. At Cairo there is also an excellent Cicerone, a Scots- ‘man named Osman, dragoman to the consulate, who is ex- tremely useful, not only in visiting the antiquities, &c. but in procuring the boats and supplies. ‘Ten days will be well occupied in seeing Cairo, and in making ra oT for the journey. Cairo is the last place where wine can be procured, and here, as the expence of transport-carriage across the desert is very trifling, it is well to take a good supply. The packages should be such as will fit the side of a camel; about four ~dozen. Besides.a sufficient quantity of powder and. shot for use, a few canisters of fine powder should be taken as pre- sents for any Cashif or governor who may be civil. These supplies.may be procured in Egypt, but better and much cheaper in Malta, or at the port where you embark from Eu- rope. The desert betwixt Cairo and Suez is passed in two days. To ascend the Nile.to Ghinneh will require about twenty days, allowing a day or half a day to visit each of the princi- pal antiquities on the route. ‘The temples, &c. are generally »at a short distance in the desert ;. but donkeys can always be procured. ‘To ascend from Ghinneh in order to see Thebes will require about a week more; and to.visit A’ssouan or 240 Captain Pringle’s Route to India Syené, the first cataract, seidhtiee fortnight. It is possible to travel more expeditiously on canals; but in that case, besides the journey being more fatiguing, some of the antiquities would be missed, as they lie on both sides of the river. The best season to travel in Egypt is winter, or the early part of spring. Towards April the weather becomes very hot. At rc Ghinneh, the thermometer had risen in the end of March to 104° of Fahrenheit in the shade ; but as the nights are compa- ratively cool, little inconvenience is felt, and there, is none of that sultry oppression, which is experienced in India at a low- er temperature. ‘A few weeks previous to the above state of the thermometer, it had been as low. as 46°; the dress, there- fore, must be such as can easily be adapted to such changes. In Egypt there is no use in adopting the Turkish dress, the European one being a better protection. But in the Red Sea, it may be as well to make your servant wear the Arab dress, or at least to have one for marketing, &c. There is excellent shooting on the Nile and its banks ; ie game consisting of quails, snipes, wild ducks, geese, crocodiles, Ke. At Ghinneh, there is an Arab merchant, named bin i Omar, who acts as an agent for English travellers, and will make arrangements for camels to pass the desert with. He and Osman, at Cairo, are recompensed by a present, or a few dollars. The desert between Ghinneh and Kosseir, is passed with ease in a few days; and each camel employed on this route costs about a dollar. A field “mattress, laid across the camel’s saddle, forms an easy enough seat, and is convenient- ly ready to lie down upon at any short halt. A tent is not-at vall requisite in an atmosphere where it never rains. There are two wells on the road, but the water is a little brackish. Shrubs and camels’ dung for fuel are found in sufficient quan- tity to cook what is necessary. The traveller should provide himself with live fowls, as in some winds butcher-meat = comes putrid in a few hours. Six weeks may be considered as the shortest period fort tra- velling from Alexandria to Kosseir, if it is meant to take a-cursory view of the antiquities of Egypt; but the whole by Egypt and the Red Sea. 241 journey betwixt these two places, may be performed in a fort- night. 9 © The works which have heen. written on Egypt are so nu. merous, that is difficult, if not presumptuous, to say which should be selected as a guide, For this purpose, Denon or Hamilton are generally recommended ; ‘and, for the ancient history of Egypt, Herodotus and Strabo. Volney treats of it . during the reign of the Mamalukes, and describes the various* sects and nations composing its population. Norden, Neibuhr, Bruce, Burckhardt, have also written upon it ; and the last, from having professed Mahomedanism, learned a great deal of the customs, rites, and other ceremonies of the’ natives. There are several very late travels: Legh, 1812, Light, 1815, Captains Mangle and. Irby, Belzoni, Henniker. The last has given a concise journal of the antiquities, &c. - Travelling in Egypt is safe and easy. At present, there is no occasion for a Janizary, as such a person, so far from being of use, would be a mere annoyance, It is necessary, however, to be armed with pistols and a fowling-piece, &c. and to be prepared for danger, particularly should any part of the coun- try be in a state of msurrection, as such a circumstance ren- ders the protection of the government precarious, and often useless, even ata considerable distance from the scene of tu- mult. The Turks always are completely armed ; consequent- ly, arms are looked upon asa part of dress, and insure respect to every person who is entitled to wear them. . The Turks, in general, not excluding the soldiers, were al- ways most willing and ready to oblige, or to be of service; and, during the insurrection, this friendly disposition of theirs was frequently of Some importance. In return for their civi- lities, they merely asked for a little powder for priming, for which purpose, a couple of charges was sufficient, or request- ed us to look at their wounded, and give medicine. They fancy, indeed, that every Frank has some skill in physic ; and, on this account, a few common medicines and ointments should form a part of the stock laid in. _. It has been in contemplation to establish sectuaecaill on the above route. The red sea seems to be particularly fa- vourable for their employment ; and fuel, consisting of wood VOL. Iv. NO, 11. APRIL 1826. Q 242° Captain Pringle’s Route to India, &c. and charcoal, might very probably be obtained in sufficient: quantity, and at a moderate charge. There are also. pits: of petroleum on the coast between Kosseir and Suez at Gabel Ezand ; and, as the petroleum is said to be in great abun- dance, it would, very probably, when burnt with wood, pro- duce a strong combustion. The length of the red Sea is: about 1200 miles. Mocha or Aden would be thé best parts. to depart. from for India. The distance from these to Bombay is about 2000 miles; but the islands of Socotra, which are about one-third of the way, might be made a depot for fuel. But, in the Indian seas, it would probably still be necessary to attend to the S. W. monsoon, which, in’ June and. July, blows very strong, and carries with it a heavy sea. In Au- gust and September, however, a steam-vessel might make good way, as the wind is then comparatively light, and the water smooth. During the N: E. monsoon, which is preva+ lent from October to May, and which: is said to blow. with considerable violence from December to March, it: would probably be better for steam-vessels not to attempt the passage. One plan proposed was to. cross the desert from Suez to ‘{hineh, on the coast of the Mediterranean ; but, in this way, the Nile and Egypt would be entirely missed. If, on the other hand, the Nile were taken, is is quite favourable for steamn-boats ; only that, from the number of the sand-banks, and their so frequently shifting, the boats must, be construct- ed’so as to draw little water. There appears, then, to be no difficulty of establishing, the: above route, if the land passage, or that through Egypt, re- main open to us, and of this there can. be no doubt, so long as — : Mahomet Ali governs Egypt. Should his successor, however; refuse permission, or should Egypt return‘to its state of for= mer anarchy, it might be a question how far it: would be pro- per for us to take possession of the country; for the, Turks hold it only by force of arms, and area quite distinet race from its native population. ‘The natives are principally Arabs, and are a fine athletic people, capable of rendering the coun* try a very re colony, valuable even ag, yagi of Fa P . a Pd . ¢ Obseraations and Kaperiments on the Sense of Taste. 243 the connection it would establish between our eastern and European possessions. So much for the Trans-European part of the route. The principal ports from which vessels sail for Alexandria, are Malta, Marseilles, Leghorn, Genoa, Naples, and Corfu ; and of these, the best probably is Malta. It gives not only a good opportunity for fitting out, and laying in, a proper assort- ment of supplies, but for obtaining a servant, Maltese being a dialect of Arabic sufficiently near to be understood by Arabs. It would be of great use, however, if, the servant, besides Arabic, also understood Turkish. The hire of a good | ser- vant, will be from twelve to twenty dollars a month... Each traveller may take about one hundred pounds in Spanish dol- lars or German crowns, from Malta, as the exchange is much higher in Egypt, and a part of this sum may be converted in Egypt into Turkish gold, though Spanish or German. sil- ver will do very well for the expences of the Red Sea. Bills on Bombay can be cashed at Mocha, The whole ex, ‘pence from Malta to Bombay will be about one hundred and fifty pounds ; but it is far from being advisable to carry more ‘money than is absolutely wanted, and that which is carried should be concealed and divided as much as possible. CoLuMBo, Ciyuon, May 9, 1825. ‘Ar. X.—Observations and Experiments tending to show that the Sense of Taste is not a pacts one. y a Cor- _respondent.* I THINK there is no such.sense as taste, distinct from the other known senses. It has been always well known, and is gerie- rally admitted, I believe, that we do not taste when we have eur noses stopped, or our breath held, and it is also found, that a particular ‘complaint, or illness, will sometimes take off both the power of smelling and tasting, and yet not hinder the oy ” We shall be glad to hear again from the author of this artiele-—Ep. 244 Observations and Experiments on the Sense of Taste. other senses. It is also often observed, and I have always found it so myself, that there is a likeness between the smell of a thing and the taste of the same, or of another thing, and, vice versa, which there is not between the appearance and sound ofa thing, the sound and feel, the smell and colour, &. And this sort of likeness is also quite of a different nature from _ that which we speak of as existing between the appearance of a four-cornered. figure to the eye and the feel of the same fi- _ gure; to perceptions which resemble one another in conyey- ing, though by different senses, the idea of the number four. And it is still more distinct from that association, produced by experience, which we mean to denote when we say ‘such a thing looks like a soft thing,"—* such a person looks like a good-humoured person,”—“such a thing sounds like a solid,” — or, “like a broken thing,”—by which we mean, not that there is any likeness between the perceptions in themselves, for in- stance, between a certain noise and the appearance or feel of a crack in a glass, &c. but that the noise is like andther noise which we had before found to be usually or always connect- ed with the appearance or feel of a crack in a glass.. The like- ness between the perceptions of smell and taste, on the con- trary, seems to every body, I believe, to be that of perfect identity, as to the perception itself, and distinguishable, if it is distinguishable, only by being perceived by a different or- gan, and under different circumstances, in the one case, from what it is in the other. I have also often found, that when I have been surrounded by a very strong odour in the air, and have had, at the same time, my mouth open, I have seem- ed to taste as well as to smell it; and I have been sometimes led to think, from this circumstance, that tastes in the mouth might be seasoned, as it were, by the smell of something placed near us while eating, just as they are by sauces which we taste in the ordinary way, though in a less degree proba- bly.. It is also worthy of remark, that those who treat of the ‘senses find no difficulty, in the case of the others, in pointing out what are the proper organs of each; but when they come to the taste, they seem puzzled, and often differ from one - another: Sometimes the tongue, sometimes the palate, are Observations and Experiments on the Sense of Taste. 245 stated to be the seat of it; sometimes both, or both with the addition of the lips. ‘This difficulty of ascertaining precisely the seat of this sense seems very remarkable in the case of asense which, as we commonly suppose, operates in actual contact ; unlike the sense of sight, &c. which acts at a distance. Besides, though we commonly consider the sense of tasting as - one exercised by some part of the mouth, and as capable of being exercised only on a substance immediately in contact ‘with the organ of tasting; and, on the other hand, consider ° that of smelling as exercised by the nose, and on a substance _ at a distance; or rather, to speak more accurately, on air, and particles contained in that air, though not discernible by any of the other senses, and brought by that air into contact with the organ of smelling; yet when, after eating, air returns from the stomach, we seem to taste the taste of the thing which had been eaten, (of onions, for instance, or turnips,) as _ completely as we can be said to taste any thing; and people sometimes describe this as an operation of tasting, or, “ hay- ing the taste remain ;” yet it is air only that is presented to the organ in this case. Some things of strong scent, perhaps, are tasted after having been swallowed, even independently of this, merely by their adhesion to the upper and unclosed part of the gullet, as onions. ' These facts, though I had noticed them, I had never ‘put together, or much considered, when I found it observed in an article in the Edinburgh Review, in 1821, I think, that there are some things which we smell, while we are tasting or eat-— “ing them, by means of the internal aperture which leads from the back of the mouth into the nose, and through which also we breathe when our mouth is shut; and that this inter- nal smell constitutes what we mean by the term flavour, when we use it as opposed to taste ; which latter term, in this writ- er’s opinion, relates only to a perception which is confined to the mouth. : It appeared to me that the author of that article was so far right, but should have gone farther; and that not only the quality called by him flavour is a quality perceived by the smell only, but that there is not even any such distinction at 246 Observations and Experiments on the Sense of Taste? all, as lie | supposes, between taste and flavour; for that % every thing which we call taste is in fact this internal smell; or else is merely a feel in the mouth; an operation of the sense of feeling ; ; and that any peculiarity it may have'is. owing only to the peculiar kind or degree of sensibility, which the tongue, * and other adjacent parts have; in respect to the sense of feel- » ing, compared to most other parts; just as the inside of the eyelid, a sore place, the sole of the foot, the inside of the sto- mach, the epiglottis and lungs, the naked nerve of.a tooth, the sides, where tickling is administered, &c. have very pecu- liar degrees and kinds of sensibility in respect of feeling, com- pared to one another, or to other parts ; so that one of those parts feels very acutely certain sensations which another of | _them, or which the ordinary skin of the body, scaree regards “at all: So aching 1 is very different from itching, and the sense of ‘hunger in the stomach from that of cold in the fingers ; and yet those different sensations are not therefore considered as being distinct senses; because the difference between them is far less, and of another kind, than that between one sense and another, as seeing and hearing, hearing and feeling, &e. I mean to say, that, on reading this article, I did not recollect, nor can T since find, any instance of the distinction set up by this reviewer: it struck me, that, having adopted his way of aecounting for flayour, I had nothing left for what he would call taste; no instance of what is commonly called taste, but what would be destroyed by stopping the nose, and thus ex- -tinguishing the smell; or else would be properly referred to _ the sense of feeling only. I then proceeded to try experiments. The unpleasant tastes of eastor ou, and of magnesia, are the principal instances which the reviewer selects of what he would call real tastes, and “not flavours; that is, he thinks, stopping the nose would not relieve the sense of them at all, This I can positively deny : 7 I have taken castor oil, and, by persevering in wea ‘the -.* This peculiar feel of certain esculent substances, gercciniad in the » tongue, is sometimes perceived by the teeth too, as the acid and ‘astrin- »gent property of lemon or Seville orange juice ; but nobody « i a consider- sce the teeth as organs of taste. Observations and Experiments on the Sense of Taste. 247 nose shut for an hour or more, been quite free from the very disgusting taste ordinarily experienced from it. And, as to magnesia, though part of the disagreeableness of it is the clammy feel, yet I have found, in this case also, that, with the nose, stopped, that inconvenience was by no means great; owing to its not being then accompanied by the mawkish sick- ly taste which magnesia has, and which, immediately on remov- ing the pressure on the nose, began to be perceived. TI ob-~ served the same thing as to sugar, which is another instance given by the reviewer: he thinks you can taste it as well with the nose stopped. This is not the fact. All that remains, when you stop the nose, is the sort of languid feel, of dissoly- ing as it were, which it produces in the mouth, and which has some resemblance to the feel which one has in the same parts when rapidly warmed after they have been exposed to hard frost; and also to the feeling of languor in the nerves which is,connected with a liability to toothache, and often felt near the time of the actual pain. . I then considered, that, if my supposition was true, the reason why we do not taste when the nose is stopped, or the breath re- tained, must be, that in that state, though the faculty of smel- ling is not at all diminished by it, there is wanting a current of air, to carry the air which is the vehicle or seat of smell, from the mouth into the nose. . For, though it is true, that where there is.a large space of free air, a smell may diffuse itself, and even strongly, though there is no perceivable current or motion in the air ; yet even there it would always strike the sense much more strongly if borne on a current of air, setting towards the organ of smelling; and, besides, in a large space of air, when undisturbed from without, there is probably more motion than there is in a small one when equally un- disturbed from without. Then, if this supposition be true, it would follow, that we might expect to find that we should taste as little while the breath is drawing in through the nose, as while there is no breath at all, either drawing in or out, since no current, from the place when the substance to be tasted is, would then set towards the organ of smell; and _even less if possible, since the current will rather set the.con- trary way; and accordingly I found that it was so. Put into the 248 Observations and Experiments on the Sense of Taste. mouth, while the nose is stopped, a little lavender water, and move the tongue about to the palate, &c. as you do when tasting any thing; you will have no taste, though you will - feel a heat on the tongue, such as you do in the stomach after swallowing spirits; but if asked whether it might not be brandy, gin, peppermint, noyau, that you had in your mouth, %. you could not tell. Now breathe out through the mouth » "as much as you can, still holding the nose, and at the moment when you have breathed out to the utmost, set the nose free; an inspiration will follow, which, if you pay atten- tion, you may make to continue some time, during which, even though you keep smacking in your mouth as before, you will not taste the lavender water; but the instant the breath turns and begins to pass out, the taste will come upon you. My reason for stopping the nose in this case, before I begin, instead of afterwards, is, because you will the easier re- mark the moment at which the taste first comes ,upon you, if you have not tasted the thing at all before; for it will make greater impression. Besides, by this means you may, by shutting your eyes and letting another person put into your mouth a liquor or substance which you have tasted in your life before, but which they have now chosen without telling you what it is, be quite sure that you did not taste it before the breath began to rush outwards through the nose ; since, as in this case, you will not have had the least know- lege beforehand what it is you have in your mouth, it will be impossible for you to imagine that you tasted it. when in fact you did not; and it is the confusion arising from imagina- tion, or association arising from previous knowledge, that we are most to guard against in this matter. But it should be something whose feel in the mouth is not decidedly different from that of all other things, else you will know it by that ; an ‘aqueous fluid is therefore convenient. I chose lavender. water, because it happened to be at hand, but it is rather a good subject for the experiment, because it has a decided taste, — and also a feel, which it has in common: with many other liquors (spirits) from which it yet decidedly differs in taste. I tried it next with sal volatile; but it answers with every thing I have tried; and I also observed, that, in common, Observations and Ewperiments on the Sense of Taste. 249 eating, I do not ‘taste any thing but while the breath is going out: and I suppose I should have observed that be- fore now, if it was more easy and natural, than it is, to take notice spontaneously, without endeavouring at it, when the breath is coming in and when it is going out; but in fact we are seldom led to remark at what moment the change from inspiration to expiration, or vice versa, is taking place. I next tried the experiment with zinc and silver on the tongue; the process usually referred to in lectures on galva- nism. I considered, that if that sensation should prove to be, while the tongue is between the metals, what one would com- monly call a taste, and not merely a feel, it would destroy my supposition ; because it seems clear, that the tongue alone, and not the nose, could be the organ of this sensation which is produced by the galvanic action transmitted through it: ‘unless, indeed, we could suppose some vapour to be generat- ed: but that it would equally, or even more, destroy another supposition, which, I believe, is generally received among ob- serving persons, upon the common notion of the taste; viz. that no taste can happen without touching the palate or roof of the mouth ; since here the tongue is to be kept confined. T saw in “ Conversations on Chemistry,” and I suppose it is so in other similar books, that the sensation produced by this experiment is called ‘‘a taste accompanied with heat ;” but IT did not mind the name ; because, as we are commonly told that our tongue is the peculiar seat of taste, any pecu- liar sensation, of which the tongue was the exclusive seat, might very naturally come to be called so; and I believe the peculiar sensation produced by these metals in this way, isa sensation exclusively confined to the tongue; in truth, it is not easy to find any other place where this galvanic experiment can be tried ; since the metals must be applied on two sides, and near; unless we were to skin one of our fingers for the purpose ; for the skin prevents the action ; at least, I did not find it succeeded when tried on part of the moist inner sur- face of the lip doubled together, or on the two sides of the gums. When tried on the tongue, with a half-crown piece ind a plate of zinc, I think the sensation while the tongue is be- 250 Observations and Baperiments onthe Sense of Taste. tween the two metals, is not a taste, only a sort of feel. When I tried it with a silver spoon, (which I presume is purer silver than a crown piece) and zine, a strong and nasty. taste took place immediately on removing the metals, and leaving the tongue at liberty to touch the palate. But then there was a smell too, exactly like the taste; it was on the spoon, not on the zine, I think. It was also like the smell of a spoon with which an egg has been eaten, and the spoon was tarnished as it is by that; whether owing to albumen in the saliva, or in the nerve, I do not know. This is so full a proof of my supposition, that I need not, but for curiosity, go fur- ther. When I try it with a crown piece ‘alk zinc, the tingling in the tongue greatly abates, on removing the metals, and no taste, that I can perceive on smacking, succeeds. What is called, a brassy taste, which is referred, I believe, to this same galvanic principle, is certainly connected with a strong smell. Brass, and even copper alone, at least copper money, we know has, when rubbed, a good deal of smell. I still, there- fore, see no reason to doubt the truth of my opinion, that, when we have any thing in the mouth, every perception of it which we should ordinarily call tasting, and not feeling, is, in fact, a smell perceived in the nose only, and conveyed thither by the air when passing through the internal aperture. In the case where the taste is perceived as soon as the breath turns to go out, I considered that what is breathed out had been in those experiments before breathed in, from or through the mouth; so that the air, which went out througly the nose, had come, originally at least, from the forepart of the mouth, if it did not do so immediately. And, if it were not for this consideration, the fact would appear not to be agreeable to the theory which I am maintaining; since merely breath- ing out air through the mouth, or even through the nose, _ does not, in one operation, carry air from: the fore-part of the mouth through the nose; and, therefore, if the substance tasted is, as I supposed it generally to be while it is chew- ing and moved about by the tongue, I say, if it isin that “part of the mouth which is forwarder, than the passage up nto the nose, jt would not, but for the consideration ome Observations and Experiments on the Sense of Taste. 25b mentioned, follow that the substance would be tasted ‘white the breath was) going out. _ I therefore tried this experiment : I tried to place myself in such a condition, as that the air breathed out should not have been before breathed in; that is, I applied the substance to the tongue, during the course of a long expiration, as soon as possible after the beginning of the expiration, but so as to make» quite sure that it was not before the beginning of it. There was no stopping of the nose in any part of this experiment: Now, according to what I have just said, the substance ought not in this case to be tasted at first, even though the breath be going out, but must wait till the second expiration, after an intermediate inspiration, except so far as smell may pass into the nose from without; but even that would not be during the first inspiration, but during the inspiration following, and must, as appears from the former experiments, take place only ina very trifling degree. I now tried it with lavender water; a substance in one respect inconvenient, because it dif- fuses its smell so much, that it is likely that some should be drawn in by the nose from without during the breathing i in, and thus make the trial not quite fair as to what is to happen during the second. expiration. - But itis easy to prevent this sufficiently, by spreading the hand. between the nose and the mouth. I found, that if I smacked it about in the mouth, as you do when you wish.to perceive the taste of a thing fully, I tasted it even during the first expiration; and I conclude, that, during that process, at least with a thin fluid like this, some/of tis passed» down the mouth, farther back than the passage to the nose. When I did it without smacking, only laying it on the tongue, and keeping the mouth wide open, it did not taste during the first expiration, but only felt warm ; in the inspira- tion, a very little scent indeed passed in from without, next to none, but I had no taste in the mouth even then, only a feel of warmth still;,and then, when the breath went outwards the second time, I had the ordinary perception which we call ‘taste. I tried it also with ginger, which does not diffuse its ‘smell.so much, and the result was just the same ; no taste per- ceived, but only the hot feel to the tongue, ill the second 252 Obse rvations and Experiments on the Sense of Taste. breathing out. If it is tried with a solid thing, which -you chew, it is rather difficult to avoid checking the breath, and turning the. current, while you chew: however, I found the same result in this case too. Some people may object, that the most Beiking snes, at least of pleasant ones, viz. the smells of flowers, have little or no corresponding taste belonging to them. And, vice versa, that some excellent tastes are not accompanied by smells. In the’ latter case, I believe it will not be found that they are even powerful tastes, though they may be exquisite ones, .* We must remember, that when we taste a thing in the sande we. warm it, and also melt or dissolve it, if it was solid before, both which processes are known to be, in general, _means of drawing out the scent of bodies. It is not, therefore, inconsistent with my supposition, that salt of lemon, for in- stance, should be tasted when in the mouth, and yet have no smell when dry in the bottle. It is not the same thing which we compare in the two instances; but dry salt in the one, and a warm solution of it in the other. We also, in eating and chewing, triturate, as it is called, that is, reduce to small par- ticles, ‘and also bruise and rub, I mean against the palate, the . substance eaten ; and that process, we know, is a great elicitor -of ‘some sorts of smells, as we find when we bruise rosemary leaves, and such like, in the hands, in order to smell them ~ better ; and, indeed, sometimes a leaf will have a strong smell belonging to it, and yet it will not be at all perceived by smel- ling the leaf, but only by rubbing it in the fingers. “Some smells, on the contrary, are not brought out by rubbing, as the fragrant smell of a rose-flower, but rather are destroyed by it, because it brings out other smells which stifle the fra- grant one ; and so it seems to be no refutation of the opinion which Iam proposing, but merely what might be expected, that if we were to chew a rose-petal, we should not perceive, by the taste, so much of the sweet smell as we had perceived, by the smell, before we put it into the mouth. = Further, 1. We must recollect how large a surface it is that the’ smell, when powerful, comes from, in many cases, compared to the small portion which we can chew at once :— a’whole nosegay of violets; a grove of oranges ; whe of ca- i Observations and Experiments on the Sense of Taste. 253 momile, Sev 2. In some flowers, ‘the scent appears to come from one part only; while in others this circumstance cannot be perceived ; in a honeysuckle, we can squeeze out a sort of boil which tastes of the smell of the flower, as I may say. This makes it likely that it is co, in fact, in the case of. all flowers, and such like things, though we cannot ascertain it in all ; and if so, the chewing the whole, including the inodorous part, will be likely to confound the smell. 3. I am inclined to think, that as some smells, as] have already mentioned, are more given out by means of heat, others, on the contrary, are less so, and that this is the case with flowers: in different sorts of wine, I think we find it to be the case. 4. In the case of those flower-smells, which are powerful “ in the air, where they come and’ go,” as Bacon expresses it, we must recollect that there is a cloud of fragrance, as one may say, hovering and collected near them, which, therefore, must greatly ex- ceed what could be at any one time elicited directly from the flowers ; it is on that account partly, that we smell them more at sunset, because the air then becomes. still, and the scent “* lies,” as they say in hunting, that is, it is not blown away. And in the case of such flowers, as “ the steam of rich distilled -perfume” is more delightful, in degree, than the smell of the flowers when near us, as Bacon remarks, and even a little dif- ferent from it in the quality of the scent, it is no wonder it should be more delightful than their taste, and different from it. In the same manner, we find, that we cannot completely judge of the smell of a dead rose-petal, by the strong smell issuing from a drawerful of.them when opened. 5. Another important difference is, that if you smell with the nose, the whole quantity of odour, contained in that draught of air, strikes straight upon the organ of sense; but if you had taken that quantity into the mouth, it could not (as already observ- ed) have reached the organ of smell, till it had first been drawn into the lungs, and so mixed with a much larger body of air, which it would there have met with ; so that, when the same quantity of air was again returned outwards, through the nose, it would bear with it a much less proportion of odour. Unless, indeed, in some few cases, after many breath- ings, the’ whole air in the lungs might become impregnated 254 Observations and Experiments.on the Sense of Taste. with the odour to the same degree, ¢. ¢. in the same propor- tion to the volume, as the air inhaled had been impregnated with it; as I find, in inhaling with the mouth from the mouth of a lavender water-bottle, and immediately stopping my _ mouth and breathing through the nose, that I have much less sense of the smell, than when I inhale through the nose: but yet, when I have drawn the scented air in through the mouth, and breathed it out through the nose with stopped mouth, I say, when I have done this successively several times, I find the sense of smell, which is perceived in the breathing out, get much stronger. 6. We acquire a faculty, when we:want to perceive an external smell. strongly, of drawing in breath quick through the nose some times, sniffing, as it is called, which presents more of the air, and olfactory particles, inva ‘given time, to the organ, than would otherwise reach it. No- thing of this kind is ever done with regard to the internal smell or taste; I do not know whether we could have acquir- ed the power in the latter case, as well asin the former, but, in fact, we have not.- It would have to be exerted’ in the con- trary direction, as appears from what I have said already; and would, even it were performed, produce less effect, from what I have just observed in (5.) cy 7. Lastly, we must bear in mind the effect of absociation. We are used to receive some sorts of smells more from with- out, and others more from within, 7. e. by what we call taste; and in liking, or disliking, each or both, we are guided in part by the system of associations, belonging to that way of per- ceiving, through which we are at the time perceiving the sen- sation in question. We exercise the internal smell, or the taste, principally while we are feeding on what is our needful food; always (except in the case.of physic, or of betel and tobacco) in the feeding on what is not absolutely. hostile or _ repulsive to our digestive organs. Our scale of likings and dislikings, then, as to their sense or mode of. perception, is tinged throughout with this sort of association, derived from what is agreeable to the digestive organs. It is tinged with _ another, perhaps.even more important, viz. touch, the feel to. _ the mouth; neither of which have any thing to do with per- fumes ; on the contrary, the sense of external smell, applied Ai I Dr Clark and Capt. Sherwill’s Ascent of Mont Blanc. 255 to such things as we do not eat, is associated with the idea of the complete absence of all these circumstances; and where pleasant, its pleasure is increased, where painful, its pain is materially diminished, ‘by this very absence, by its independ- ent and semi-incorporeal nature, as I may say. Now, it hap. pens very often indeed, that when, from association, the plea sure or pain, which we derive from'a particular perception, is materially altered, we no longer recognize the perception as being the same ih itself: so that a smell, which as perfume stood high in our preference, may, when taken in as a taste, be thought less agreeable, and thus not readily recognized to be the same perception, and vice versa. Contrary associations produce more diversities in smells than in any thing, I believe. I have known a person, who was passing one of those scavenger’s heaps, which lie near some of the roads in the outskirts of London, but who had not directed his eyes that way, remark, that there was a great smell of musk. In this case, of course, whether such person was pleased or not with the smell, would depend entirely on whether he was undeceived or not as to what was the real cause of it. I had never before the least idea that the smell of musk was identical with the smell in question, which to me, who perceived whence it came, was quite offensive. That which had hindered me from before remarking that they were alike, must principally have been, that I always had been used to find the one pleasant, and the other disagreeable. Art. XI.—Account of Dr Clark and Captain Sherwill’s Ascent of Mont Blanc, in August 1825. Somx time ago, Dr Edmund Clark had formed a plan of ascending Mont Blanc; but, as he had no other motive for this journey but that of curiosity, he resolved to wait for the most favourable weather, and to rely on the judgment of the most experienced persons at Chamouni. Dr Clark had’ sought’ in vain at Geneva for a companion ; bu on the my proceditig site fixed for the “os Captain ¥ 7 256 Dr Clark and Capt. Sherwill’s Ascent of Mont Blanc. Markham Sherwill of Fontainbleau proposed to peg td _ him in the expedition. - On Monday the 25th of August, about % o'clock in the ea our travellers set out from Chamouni, accompanied by seven guides, viz. Joseph Maria Coutet, who had already been three times at the summit of Mont Blane; Simeon »Devuasson, Pierre Tairraz junior, both of whom had once. been on the summit, and Julian Devuasson; Pierre Joseph Simond ; Simeon Tournier, the youngest of the guides, was twenty-six years old, and the oldest thirty-eight. » Having arrived at Pierre Pointue, they quitted their mules, and as soon as they reached the moraine of the glacier, they spent a short time in breakfasting. Before they set out, Dr Clark counted the pulses of several of the guides, arid. he found that their acceleration varied from four to thirty pulsa- tions in a minute. ‘This acceleration did not appear to have _ any proportion, either direct or inverse, to the muscular strength of the individuals. When they had reached the Grand Plateau, the rays of the sun were so scorching, that Dr Clark was obliged to take off his spencer. He experienced in his face the most painful smarting. He was very thirsty, and he frequently refreshed himself by eating snow and some grains of raisins. His re- ,Spiration was not changed, but it was loaded. Captain Sher- ‘will experienced much nausea and oppression. Having sat down on the ice to take some refreshment, they eat very little. Simeon complained of a pain in his head. When they reach- ed the Petits Mulets, the wind became strong and very cold ; at last, at five minutes past. three o'clock, they Reelort the summit of Mont Blanc. The barometer was at 15 inches 9 lines, and ,°,ths. At St Bernard, at the same time, it stood at 21 inches 1 line, yoths; and at Geneva, at 27 inches, 0 lines, and 43ths. The thermometer exposed to the sun stood at half a eae below zero, whereas, at Chamouni, in the shade, it reached 14°. At two o’clock in the afternoon, the thermometer rose at St Ber- nard to 10° below zero, and, in the Botanic Gartlggne at. 2 a ya, to 19°. Dr Clark experienced a ditiegiey of bréailing, even when e Farther. Observations on Eaperiments, &c. 257 he ceased to move. He experienced in his breast a sensation similar to that which precedes emophtisie, a disease to which he had been subject in his youth. He did not spit blood, however, on the summit of Mont Blanc. One of the guides having acci- dentally received a stroke in the nose, lost a little blood, which appeared of a much blacker colour than usual. Dr Clark, as well as Captain Sherwill, had a severe headache,. and their faces were pale and contracted. The Captain described a singular sensation which he experienced near the. summit. He felt as if his body possessed an extraordinary ~ degree of elasticity and lightness, and as if his feet scarcely touched the ground. The guides were in general very much ~ fatigued, and complained of headaches. Our travellers return- ed to the Grands Mulets, where they slept, and next morning they returned in safety to the valley —Bibl. Univers. No- vember 1825, p. 245. Arr. XII.—Farther Observations on the History of Mr Bab- bage’s oe on the Production of Magnetism by Ro- tation. . Iw the last number of this Journal we laid before our read- ers a popular summary of the remarkable discoveries which have been recently made in this country and in France, on the production of magnetism by rotation. One of the objects of this paper was to assign to each philosopher concerned, the share which he had in these discoveries, and we had the good fortune to receive from a distinguished correspondent an interesting communication on that subject, which formed the ground-work of our popular summary. We regret, how- ever, to find that our information was not so minute as could have been wished, and that the opinions and experiments of Mr Babbage were not so amply detailed as their importance demands. We hasten, therefore, to supply this defect, which neither we nor our correspondent had before the means of avoiding. About the month of November 1824, Mr Barlow's experi- ment, in which he produced a deviation of the magnetic VOL. IV. NO. II. APRIL 1826. R- Ts ’ - 258 _ Farther Observations on Experiments on the ~ needle by the influence of iron balls\in rotation, became the~ subject: of conversation at the Royal Society. Upon hearing this result, Mr Babbage, on the authority of magnetical ex- periments of a totally different kind, stated that he should have expected it, and that the. effect depended essentially on the time that iron and steel took to receive and give up magne- tism. This opinion, was not received at the time as possess- ing much plausibility, but, on the following day, Mr Herschel and himself tried Mr Barlow’s experiment with the wheel of one of Mr Babbage’s turning lathes, and they found the _deviations to accord with Mr Babbage’s expectations, and his explanation to be satisfactory. Itis of course manifest, that any: mass of iron becoming magnetic by induction, will, if moved rapidly round, not immediately lose its axis of polarisation, - but this axis will continue to exist with diminished force for a short time, and thus, during rotation, the virtual axis of mag- ~ netism will be deviated a little from its direction while at rest. At this stage of the inquiry, a report reached London in the spring of 1825, that M. Arago had produced rotation in a needle by making a plate of copper revolve under it, and that other metals, and even glass, wood, and other substan- ces, produced the same effect. It was also reported, that when the plates were cut by slits from the centre, no effects were pro- duced.* It immediately occurred to Mr Babbage, that these effects depended on the influence of time, but the statement re- specting the effect of cutting seemed to present great difficulties. His explanation, however, was, that the substances tried by ' Arago were all slightly susceptible of magnetism (as ‘Coulomb had proved of the metals before,) that they acquired magnetism _ more rapidly than they parted with it when once acquired, and, consequently, that if a plate revolve under a needle, the difference of the attractions on the two sides will cause the neédle to advance in the direction of the plate. At this time Mr Herschel proposed to Mr Babbage to enter upon a course of experiments on this subject ; ; and the results which they obtained have been published in the Philosophi- cal Transactions. . “ The latter part of this report was not quite correct. Production of Magnetism by Rotation. 259 _ Even at this period it was stated by Mr Babbage, that in all probability similar results might be produced by elee- tricity, if an insulated and electrified metallic needle were sus- pended over a revolving plate of any substance. This expe- riment he did not then make; but at the commencement of January 1826, while discussing the subject with some friends, he restated his belief, that electricity must produce the same effect ; and finding that they were not so much convinced of this as he himself was, he went home to make the experiment. The apparatus which he intended to use, was a piece of sheet brass of the form O——O suspended by silver wire from glass, and electrified by contact with excited sealing-wax, and placed above a disc of glass or metal. When glass was used, Mr Babbage mentioned his expectation, that a very slow revolu- tion of the glass would produce one in the eleetric needle ; while, in the case of the metal, he thought that it might re- quire great velocity, or, perhaps, more than he could give it, and that this would vary, partly according to their relative powers of conducting electricity. He performed these experiments, and obtained the results which he had predicted. When the glass disc was very slow- ly turned by the hand, it caused an immediate and very deci- sive revolution in the electrified needle, while copper discs re- quired a much greater velocity. These experiments were re- ~ peated at various times in the presence of several scientific friends, who were satisfied as to the truth of the fact, as well as of its explanation. Mr Babbage has now put up an ap- . . ‘paratus for more careful experiments, and in order to measure the different conducting powers of various substances.. The results of these experiments will soon be communicated to the Royal Society. He suspects that some of the effects ascribed to the magnetism of non-metallic substances may have been produced by electricity ; but he is not yet able to speak with certainty on this point. From the : preceding historical sketch of Mr Babbage’s la- bours, we think it cannot be doubted, that he has the sole and undoubted merit of haying been the first to give that ex- planation of the recent experiments of Messrs Barlow, Christie, and Arago, which is founded on the consideration of the time 260 Description of the Great Bridge . that bodies take to receive or part with magnetism, « or ay other similar quality. Yur: XIIT.—Description of the Great Stone Bridge of Sevi: teen Arches erected over the Garonne at Bourdeaux. In a Letter to the Eprror, from a Correspondent. My Dear Sir, I avail myself of an opportunity of sending you a short ac. , ‘count of the erection of the bridge now nearly completed here. I had the pleasure of going over the whole of the works yesterday with MM. Des Champs, and Billaudel, the engineers in charge of the undertaking. It is truly mag- nificent and displays the resources of able men employed in overcoming what had so long been deemed insurmountable difficulties. ‘The interior of the bridge, i. ¢., the space be- tween the road-way of the inner surface .of the arches, is all open work, and is capable of lodging several regiments of soldiers. This mode of finishing the work cannot have dimi- nished. the expence, but it certainly, in a great degree, lessens the load on the piers, which were originally intended for car- rying a light bridge of iron. M. Des Champs is preparing a work, containing the history and particulars of the’ erection. The plates (which ‘are ready) are so numerous and detailed, that they will form a very useful work for all engineey in si- milar situations. So early as 1772, M. Le Trudaine conceived the project of uniting Bourdeaux and Libourne by two bridges, and by a new road, which should establish a direct communication between the capital of the kingdom and the capital of Guienne. _ This scheme was submitted to the inspector-gene- ral of roads and-bridges; but M. De Voglie, after examining the locality, returned with the persuasion, that there were in- surmountable obstacles to the foundation of a stone-bridge over the Garonne. This scheme, however, was brought for- ward in 1808, but Napoleon thought that a bridge of wood was all that was necessary for the passage of his soldiers.’ This bridge was begun in 1810. Its length was to have’ erected over the Garonne. 261 been 580 metres, or 1640 English feet, and its expence was estimated at 5,000,000 of francs. In the year 1811, upon the report of M. Des Champs, M ‘Mole, director-general of roads and bridges, adopted the pro- posal of modifying the original plan, and of substituting in place of it nineteen centres, or arches of carpentry, supported _by twenty stone piers ; the first pier was founded during the campaign of 1811, and in 1812, the foundation stone of the second pier was laid. The scourges of war, however, pressed heavily upon France, the public treasury was exhausted, and all public works were permitted to languish. Upon the return of Louis XVIII. in 1814, only six piers had been undertaken towards the banks of the river; three of these scarcely reached the height of low water, and the other three were imperfectly founded. His ‘majesty immediately ordered this enterprise to be continued, -and from that moment it advanced with a steady pace. In consequence of the difficulty of procuring all the wood necessary for the original execution of this plan of 1811, and for the periodical renovation of the wooden centres, it was decreed in 1815, that the arches should be constructed of - iron; but this plan was afterwards abandoned, and on the 17th March 1819, it was determined upon by M. Becquey, director-general of roads and bridges, that the whole bridge should be built of masonry ; that it should consist of hewn stone and bricks; and that every pier, previous to the com- mencement of the arches, should be loaded with 4,000,000 of kilogrammes, or about 4000 tons. These changes did not occasion any delay in the works; a loan of 2,000,000 of francs was sanctioned by the law of the 10th April 1818, and a joint stock company was organized for completing it. This was the first project submitted to the chambers for a monument of public utility, and it produced a favourable influence.on the developement of the spirit of as- sociation in every part of France. The bridge of Bourdeaux consists of seventeen arches of masonry, of hewn stone and bricks, resting on sixteen stone- piers, and two stone abutments. The seven arches in the ee Description of the Great Bridge ~ middle are of equal dimensions, and are eighty-seven féét indi. ameter. 'The opening of the first and the last arches is sixty: eight feet, and the rest are of intermediate dimensions. The vaults have the form of ares of a circle, whose rise or height is equal to a third part of their cord. ‘The thickness of the pier is thirteen feet nine inches. 'The tympanum or interval between two arches is adorned with the royal cipher, encir- cled with a crown of oak, and engraven on.a ground of bricks. Above the arches is a fine bold cornice, and two pavilions, adorned with porticoes and columns of the Doric-order, are built at each extremity of the bridge. The parapet is five feet ; the width of each footpath eight feet two inches; the width of the road thirty-two feet four inches, and the whole width of the bridge forty-eight feet eight inches. A Slight declivity, commencing at the fifth arch on each side, and descending towards the banks, facilitates the union of the road-way with quays, ahd allows the rain-water to flow off. The injury, however, produced by rains, will be _ more. certainly prevented by an ingenious arrangement, of which no other building presents an example. The impos- ing mass of contiguous vaults, already mentioned, and in ap- pearance so: heavy, is bound together interiorly by a multitude of galleries, similar to the apartments of cloisters, which com- ~ municate with each other, from one end: of the bridge to the other. By means of these vaults, the engineer. can, at any time, examine the condition of the arches below the road- -way, and it will be easy to keep them up and repair them withoat “interrupting the passage of carriages. There exists even un- der each foot-path of the road-way a continuous gallery, in the form of an aqueduct, by which the springs from the hills, on the right bank of the Garonne, maybe peoneyes and distri- - buted through the city. ‘In order to give an idea of the extent of this bridge, «he following table has been drawn up, showing its magnitude in compa with some of the ign ail in Baa” * Full drawings and descriptions of the bridges of Tours, La Guillotiere, and Dresden, will be found in Mr Telford’s article on Briper in the Edinburgh Encyelopedta. 1 2 ee we a a is ee erected over the Garonne. 268 v Length | Width f } . No. of | Diameter | Thickness Names of Bridges. between | between ; Abutments| Parapets. Archies. | of Arches.| of Piers. Eng. Feet.| Feet In. \ | Feet In. | Feet In. Bourdeaux over Garonne,| 1597 | 48 8] 17 86 11} 13 9 Waterloo over Thames, 1237. | 42 0 9 | 118 0} 20 0 Tours over the Loire, 1424 | 47 10] 15 80 0} 16 0 Guillotiere over Rhone, 1870 |24 11| 18 aad. unequal. Dresden over the Elbe, 1447 |34 3] 18 54 9} 32 10 Great as this bridge is in point of magnitude, yet it is nei- ther by the number nor by the size of its arches that it recom- mends itself to the notice of the professional engineer. . The depth of the river, the rapidity of its currents, and particularly the instability of its bed, were the real difficulties which called forth the talents of the engineer; and in these respects, the bridge of Bourdeaux will not suffer by a compa- rison with any other work of the same kind. ‘The Garonne has a depth of twenty, twenty-five, and in some places of about thirty-five feet, and twice every day the flux and reflux of the sea raise its waters sixteen and even. twenty feet high; and its currents, in both directions, have often a velocity of more than ten feet ina second. ‘This ri- ver flows over a sandy and muddy bottom, which is easily dis- placed, and which collects in banks in different parts of its course. In order to found such a building upon a soil of such con- sistency, 250 piles of fir-wood were driven in as the founda- tion of each,pier. After they had penetrated the ground from twenty-six to thirty-three feet, they were all cut over ona level, about thirteen feet below the low water of the river. A large boat, or floating caissoon, with a flat bottom, and of a pyra- midal form, received the first row of stones of the pier; and when this was, as it were, thrown down in its place, the work- men descended in diving-bells, and made the caissoon rest-on the piles destined to bear it. A general pavement, consisting of loose stones, covered the bed of the river in the direction of the arches. These stones enveloped and agglutinated by the mud which collects between them, form a bed impenetrable 264 Capt. Lachlan’s Account of to the corrosive action of the | waters, and insure the Pert nence of the bridge. BourpDEavx, 149h December 1825. Ant. XIV.—Account of the Shock of an Earthquake Felt at Sea by the Honourable East India Company's. Ship Winchel- sea. In a Letter to the A sey from “ie LaAcHLAN, - 17th Regiment. My Dua Sir, Having observed in the last Edinburgh Journal of Science, an article containing some short notices of earthquakes at sea, and among them a slight reference to one experienced’ on board the Honourable East India Company’s ship Winchel- sea, in 1823, I have thought that some further particulars regarding the latter instance from one who was a passenger in that ship, would not be unacceptable to you ; and I, at the same time, take the opportunity of directing your attention to two errors which have crept into the short notice alluded to, viz. that the earthquake took place on the 9th instead of the 10th. February as there given,: though from its having occurred, post meridiem, it would, nautically speaking, be reckoned the 10th ; and that, instead of being in Lat. 52° N., we-were, little more than 1° N. of the line. At ten’ minutes past one, Pp. ‘M., all on board *» were thrown into considerable alarm and agitation by an earth- quake, the shock of -which lasted for. more than a minute. I happened, with several other officers, to be upon the poop ‘at. the time, and was, I believe, one of the first to observe—and not without alarm—a strong tremulous er quivering motion, shaking the whole frame of the ship, for which, being unable — to account, I naturally referred to others, but they seemed as much. at a loss.as_myself ;. some only thinking: it wih a _ © The fine old ship, Winchelsea, Captain W. Adamson, 1330 tons bar, then, brought . home the 17th regiment of foot, besides two detachments ‘of king’s and company’s soldiers, and had on board at the’ time about 550 souls, an Earthquake fult at Sea: 266 owing to the rolling of a large butt upon the gun-deck ; while to others it seemed as if caused by the veering out of cable ; while others again, more seriously alarmed, said they feared we touched the ground. On the last idea being mentioned, I naturally ran to the ship’s side; but observing no altera- tion in the appearance of the water; I was then, for the first time, persuaded that it was an earthquake; and by this tithe the motion had ceased. I then went below to the captain’s cabin, and begged to be allowed to look at the barometer, but there appeared to have been no particular alteration in the mercury at the time. There had, however, I learned, been a previous unusual rise and subsequent fall of about jth of an inch; and it may be added, that, since noon of yesterday, there had been a fall of about ,4,ths altogether, the height then being 30.5 inches, whereas that noted to-day was only 30.1. In the thermometer there had been no particular change, ranging about’83° as usual, but the air felt very sultry. » On advert- ing to the idea that we had touched upon a bank, Captain Adamson said that this was out of the question ; and ‘that, if such had been the case, he must have seen it, as*he had been looking down attentively at the sea from the stern windows nearly the whole time. And, no doubt, considering the clearness of the water, that would have been the case. - The shock seemed to me’ to come aft ; and such also was the feeling of many of the men who were below in the orlop- deck, where the motion appeared to have beem felt more se- verely, some of the soldiers having been seized with a mo- mentary sickness during its continuance. So unusual a phenomenon, of course, furnished abun- dant conversation during the rest of the day, not a little i in- creased by one or two of our companions stoutly maintaining that the motion’ was caused by our scraping either a sand or coral bank. | According to Captain Adamson’s observations and charts, we’ were in latitude 1° 21’ north, and longitude 85° 35’ east, at the time of the shock, from which point the nearest part of the coast of Ceylon bore N. W. 6° 15’, or 375 miles, and Acheen Head E.N. E., distant 10} degrees, or 630:miles, but Pulo Nias Island lay somewhat nearer due east. = 266 Capt. Lachlan’s Account, &c. It will be extremely interesting hereafter to know what other vessels have felt the same shock, and whether it has been experienced any where on land. Independent of earth- quakes not being common in Ceylon, I am inclined to think, from the direction which the motion seemed to take, combined with the frequent occurrence of such convulsions among the eastern islands, that we shall hereafter hear of something re- markable having empened) in Suniatra, or somewhere in that . direction. To the above, I may add the followmg aan note re- specting the day: Sunday, 9th.—Light changeable airs, but chiefly from the southward during the day, and nearly calm at night, with the ship rolling a good deal. Course various, owing to the head wind obliging us to tack.—Meridian latitude 1° 25/ north, longitude 85° 35’ east. And it may perhaps be as well to state also, that the after part of the 8th was so cloudy and threatening, as to induce us to take in studding-sails and reef top-sails, and that it was probably about this time that the barometer fell from 30.5 to 30.1. Before this the wind had been generally from the north-eastward ; but it then shifted round to, the ‘southward, and continued fluctuating for three or four days between S.W. and S.E., with sultry weather, and thermometer from 83° to 85° at noon ; but the barometer regained a steady average alti- tude of 30.5 on the 11th. ” The above are all the particulars which IT am now enabled to give you respecting the earthquake felt on board the Win- chelsea ; but, as you appear desirous of accumulating further notices respecting similar phenomena, perhaps the annexed accounts of two other earthquakes at sea, strongly corrobora- tive of owr feelings, and showing that the puzzling nature of the sensations thereby produced have not been confined to us alone, will not be uninteresting or unacceptable to you., To me they proved highly interesting, from happening to be met with while at sea, a — a time after our i oo tion. I may add, in conan that though I waded the iyo lic prints pretty closely, for some time after our return to Notice of Tw Earthquakessfelt at Sea. 267 England, in hopes of notieing some accounts of corresponding convulsions in the eastern seas or islands, I was never so for- tunate as to meet with any. One is, therefore, inclined to suppose, that the shocks witnessed by us must have either been altogether submarine, and of confined extent, or of so very slight a nature when felt on shore, as not to have at tracted any attention. I remain, My Dear Sir, Yours very truly, — R. Lacutan. Epinsurcu Casriz, 13th Feb. 1826. Art. XV.—Notice of Two Earthquakes felt at Sea. Iw addition to the preceding interesting account of the shock experienced by the Winchelsea East Indiaman, Captain Lachlan has favoured us with the following notices of similar phenomena. * 1. When off Lisbon (about 1770) we had-a foul int, blowing hard all night and the next forenoon, ' when it .sud- denly dropped to a calm,-leaving a heavy cross popling swell. The people were all at dinner, when a general alarm spread quickly throughout the ship, above and below, occasioned by a violent tremulous motion of the ship, as if like to shake it to pieces. The guns and carriages actually rattled on the decks ; and in our more deliberate thoughts afterwards, we could compare the agitation of the ship to nothing but that of a vessel driven violently by a very strong current or tide oyer a hard gravelly bottom, which she raked all the way. The consternation in every countenance was stronger than language can describe; for no one could divine the cause, though all. expected immediate destruction. A rumbling noise accompanied the agitation, arising gradually but speedi- ly from the bottom upwards. It lasted between two and three minutes, subsided and left us as if nothing had happened. * Extracted from Hariott’s Struggles through Life. 268 Notice of Two Earthquakes felt at Sea. The first thing ordered was to sound the well—all was right there. ‘The next was to try for soundings, but none were found with more than two hundred fathoms of line. During this the gunner was called on the quarter-deck, and examined as to the powder-magazine, and when any one was last there. He declared that no person whatever’ had been there that day. The first lieutenant was ordered to go down with the gunner and examine the magazine, and all_below, and I was ordered to attend them. We found every thing as it should be. In the course of this search, the gunner, who was an old — man, swore that he knew what it was, and affirmed it to be an earthquake. This account, added to his being an Irish- man, made us both heartily laugh, although our errand was not of avery laughable nature. | In making his report to the captain, the Hietenmetold him what the gunner said of its being an earthquake, which created another laugh on deck. However, the old gunner was called aft; and directed’ to explain. himself. He said he was on board a merchant-ship lying at anchor in the port'at the time of the great earthquake at Lisbon in 1755, and from the effect it had on the vessel, he concluded this to have pro- ceeded from a similar cause. There was no denying the justness of this remark. Yet not an officer on board could be persuaded it’ was possible, and, from arguing upon it, we deemed it impossible, from the immense body and weight of water, more than two hundred fathoms deep, that any thing - afloat on the surface could be so violently and strangely af- fected by the concussion of the earth beneath. 2. On the 6th of January, the ship Dispatch * experienced the following effects, evidently resulting from an earthquake, and the account is copied from Captain Brown’s Journal. At five, a. m., having a moderate steady breeze at’ E. S. E. - and cloudy weather, steering at N. N. E., at the rate of five miles and a half per hour, along swell from the S, E., felt a motion, as if the ship was running over the ground, or — some other solid substance; and, at the time, for the’ space of * Extracted from one of the Asiatic Annual Registers. M. Necker on the Birds a Genie 269. from five to seven inlay heard a confused grinding, tremu-; lous noise, affecting the ship in every part. It crazed, and the ship was instantly hoved too, and we sounded with ninety’ fathoms of line up and down, but no ground. By this time it’ was perfectly day-light, the sea not in the least confused, nor could we perceive the smallest appearance of any thing which had occasioned it.. The ship was not felt to strike once. She kept perfectly upright, held her way through the’ water, and answered her helm ; nor does she make any water in consequence of the shock received. These circumstances: make-us at a loss to account for it in any other manner than. attribute it to some violent convulsion of nature. Draught of water forward eight feet, and aft ten feet six inches, Lat., 7°, 58° S. Long., reduced from an observation of the sun and) moon on the Ist instant, 87°, 39 E. Ant. XVI.—Abstract of a Memoir on the Birds in the En-. virons of Geneva, by L. A. NecxEer.. With Observations, by a Correspondent. * Tuts interesting memoir was drawn up with the view of forming an Ornithological Calendar, to show the different. periods of the year when the migratory birds of the canton of. Geneva appeared and disappeared. The facts related are, M. Necker states, the result of his own continued observation. for upwards of twenty years; and to these have been added, others communicated by scientific friends, and information derived from sportsmen, and from fowlers by profession. This: curious subject, though illustrated in a great measure by the incidental notices of travellers, and the relations contained in the works of ornithological writers, wants the continued ob- servations of scientific men fully to explain the economy of nature in this wonderful particular. From swallows being sometimes fomd torpid after the usual period of their migration, it was believed by many naturalists, that, in *See Mémoires de la Société de Physique et d Hist. Nat. de Geneve, Tom. ii. p. 29. 270, M. Necker. on the Birds of Geneva. place of winging their flight to more genial climates, they. re-) | mained torpid in holes, or sunk in clusters to the bottom of lakes—that instances had occurred, where birds thus situated, were revived from their torpid sleep by the application of — gentle heat—and the improbability of the continued flight of birds over such an amazing extent of space, was held as giv- ing weight to the theory which asserted their hyemal torpidi- ty. Other naturalists, from the periodical disappearance of many of the feathered tribes,—the fact of their being frequently met with in flocks in a half-exhausted state at sea—and even observed at times corresponding with their disappearance in Europe on the continent of Africa—with more justice con- cluded,-that our annual visitors, led by unerring instinct, come thither for the great purpose of propagating their species in safety, and return, undirected by compass, across the ocean, by the same instinctive impulse, to more genial climes, when the approach of winter threatens to deprive them of their usual food. What M. Necker he done: in regard to the birds which frequent the neighbourhood of Geneva, has been ably per- formed by Mr William Markwick for those which visit Eng- land. I: a paper read before the Linnean Society of Lon- don on. the 3d of February 1789, and which was published in the first volume of their T'ransactions, Mr Markwick has given the results of his personal observation on the appear- ance and disappearance of birds for a period of sixteen years, viz. from 1768 to 1783, and has embodied these results i ina . tabular form, somewhat similar to the Ornithological Calendar of M. Necker. Mr Markwick was induced to make his ob- servations public, from the idea that many authors who have written on the subject, did so, not from their own observation, but from the vague accounts, and imperfect observation of others. Catfield, the place where these observations were made, is situated rear Battle, in Sussex, about five miles from. the sea, in a country finely diversified. with hill, and dale ; and though there is no lange river near it, yet there is much oozy, springy ground, and many woods in the neighbourhood. Were similar observations made in the different countries of Europe, the islands of the Mediterranean, and on the nearest ] oe TOR: sa iss . M. Necker on the Birds of Geneva. QU. points of the African shores, ‘for simultaneous years, the pe- riodical migrations of birds would be ‘satisfactorily ascertain- ed; many curious facts would be elicited regarding the tem- perature of different regions, with which these migrations-are in some measure connected ; and not only would the route of the birds which come from the Arctic ocean, in the end of autumn, and beginning of winter, to seek shelter in our com- paratively temperate climate, be easily traced, but the flight of those which visit us in spring and autumn for thé purpose of incubation, would be with certainty known. ~ There are few places, M. Necker observes, more favoura- ble to the study of ornithology than Geneva. Besides the great variety of species, proper to the climate, which are found in the plains and valleys, the Lake of Geneva is frequented by a multitude of aquatic birds—its borders by others—and the neighbouring mountains, rising to the height of 2000 toises, give a series of climates, “similar to what is found on the globe between 46° N. Lat. and the pole. Thus, in the space of a few leagues round Geneva, are found most of the ‘spe- cies which are dispersed at immense distances on each other through the rest of Europe. Among the birds found near Geneva, some are stationary ; others migrate in autumn to more southerly climates, and re- turn in the spring for the purpose of incubation ; and there are others, again, which arrive from the Arctic sea in/autumn, and remain till the following spring calls them to their des- tined*habitation in the north. Besides these different species, “which may be said to be indigenous to Switzerland, M. Necker remarks, that there are found, as by chance, some in- dividuals of species which inhabit countries very different, and led thither: by causes which are but imperfectly known. They arrive isolated, meagre, and starving ; and their appear- ance forms one of the most curious facts in natural history. The memoir of M. Necker is divided into five sections, the first of which treats of the stationary birds of the low grounds in the neighbourhood, such as the sparrow,—the yellow ham- mer,—linnets,—the blackbird, &c. These are joined about the end of February, or the beginning of-March, by flocks of ‘woodcocks, (Scolopaa rusticola,) which arrive in the forests at 272 M. Necker on the Birds of Geneva, the foot of the mountains, probably from Italy, Spain, or the: south of France. ‘They stop here but till the snows on the. higher grounds are dissipated, and quit the low grounds i in, April to build their nests in colder and more elevated regions. . During the night they feed in the open and humid meadows, - and return by the dawn of day to the protection of the woods., The fowlers, aware of this, intercept them m the evening. and. morning twilight, and kill them, in numbers. Wild pigeons also arrive at the same period, on their flight to the — north, or to the mountains. Towards the middle of March, flocks of starlings and larks come from the south ; and some days after, about the 25th of March, the house-swallow (Hirundo rustica) appears, at first in. small numbers, but afterwards in large troops, which spread themselves over the neighbouring country. Many remain, while others continue their flight towards the north. The ar- . rival of this bird is hailed with joy by the husbandman, as announcing the commencement of the most interesting of the seasons, and the return of heat. It sometimes happens, how- ever, that, after the arrival of these swallows, unexpected cold kills the insects on which they feed, and then, as wit- nessed in 1812, these unfortunate birds assembled in numbers upon the shores of the lake, the Arve, and the Rhone, in the hope of discovering food... Many fell into the water, or, placed on the shore, allowed themselves to be taken by the hand; others flew about the houses seeking insects on the walls ; and many were found dead from hunger in the streets . and highways. _ It may be noticed here, that this remark of M. Necker, regarding swallows falling into the water, when exhausted, and. in search of food, goes far to explain the circumstance, so often related, of their being found in . - winter at the bottom of lakes and ditches. It is very proba- ble, that those individuals which have not taken flight with the main body in their annual migration, deprived of their usual supply by premature cold, may have been seeking their food on the surface of the water, and have dropped aba into the lakes, or sheltered themselves in crevices of. walls from which they were to depart no more. _ The house-swallow (H. wrbica) arrives about fifteen days M. Necker on the Birds of Geneva. 273 after the first ; and the beginning of, April is marked by the arrival of the limnet, .The cuckoo. (Cuculus. canorus) ap- ; about | the tenth ; and towards the middle of this month a, new detachment of birds arrives, which have passed the por in countries more southerly—the shrike—the hoopoe, and the wryneck. About the 20th of April, the melodious song of the nightingale ( Motacilla Luscinia ) is heard; and, about the same time, a few. nocturnal birds make their appearance, among which, besides, some species of owls, the goatsucker (Caprimulgus Europeus) is found. . The quail (T'etrao co- ‘turnix) and the rail (Rallus crew) arrive from Africa about the end of April, and beginning of- May. The kite (Fulco Milvus )—the fly-catcher, and the golden oriole (Oriolus galbula) finish the catalogue of birds which spend the spring and summer in the plains around Geneva. M. Necker goes on, in this manner, to note the arrival and departure after incubation of all the birds which are found. in the low grounds, 1 mixed, with notices of their habits, de.. scriptions of the rarer species, and accounts of the methods ‘pursued by the fowlers for taking them. We regret that the length of the Memoir prevents us giving more than a slight outline of the different sections. - The Second Section is devoted to those birds whieh are found in the higher grounds and mountains; and here a list of birds is given, varying in their species according to the alti- tude. ‘he crossbill (Loxia curvirostra) imbabits the fir woods,—the T'ctrao lagopus, and Fringilla nivalis, are found ofi the snow at the foot of the glaciers—and the Falco fulous, and Falco albicilla of ‘Temminck are found at still higher eleva- tions. The Third Section treats of birds which frequent marshy grounds, and the shores of lakes and rivers, such as the heron, plover, stork, and bittern. .The lapwing ‘and plover begin to arrive about the 20th of, February—the snipe appears about the beginning of March—the grey heron and the stork about the middle of that- month. About the 20th of March, the Tringa pugnae appears 5 and about the end of the same month the Hirwndo riparia arrives, to take possession.of. the elevated ‘and rocky cliffs on the banks of the Rhone and Arve, VOL, Iv. No, 11, APRIL 1826. s 274 M. Necker on the Birds of Geneva. where it excavates its nest, or takes possession of a hole al- _ ready formed. ‘This is the only species of swallow, accord- ing to Mr Charles Bonaparte, an accomplished ornithologist, which is.common to Europe and to North America. The identity of the European and American specimens he ascer- tained by careful comparison. * Water Birds form the subject of the Fourth Section. 'The lake of Geneva, towards the close of winter, is inhabited by a crowd of ducks of various species, which have passed the cold season on the lake. On the approach of spring, nume- rous tribes of palmipedes hasten to regain the seas and marsh- es of the north, which they had been obliged to quit in au- tumn; and, at the same period, birds of a similar kind, and others of different species, are obseryed, which had passed the winter in lakes or marshes more southerly, or on the shores of the Mediterranean. About the 10th of March, the Anas acuta, fuligula and Jerina prepare to depart. Towards the 25th, the Anas clangu- la, and. A. boschas have almost entirely disappeared. Then two species of teal, (A. guerquedula and ‘crecca, ) the coot, ( Fulica atra,) and the Gallinula chloropus make their appearance, the two last of which shelter themselves among the reeds. About the end of April, or beginning of May, the lake is covered by multitudes of little palmipedes, which, always on the wing, dart upon the smaller fishes, or aquatic insects. These are the Sterna hirundo and nigra. These little birds, far from being alarmed by- the noise of a gun, ‘fly in ‘crowds round the body of their murdered’ companion, as if ‘the wished to carry it away. - Gulls are also abundant on the lake ; and it was at one time believed that they formed a number of different species. But since observers have discriminated the variations of plumage caused by age, sex, and the climate, the number of species which frequent the lake of Ge: neva regularly has been reduced to two—the Larus canus, and ridibundus, the last of which is seen for the ae part of the year. Ba Sue It is chiefly, however, on the am of winter, thatthelake ~* Journal oft the pepe, of Natural Sciences of Philadelphia, Vol 1, p- 258, 4 SE M. Necker on the Birds of Geneva. 275 is covered with palmipedes of different species ; and while the land is deserted by its winged inhabitants, the waters are ani- mated by the arrival of numberless birds from the north, who come to seek their food in a lake which the most severe win- ter never freezes. Ducks of various species form a large proportion of the annual visitors; and the taking’ of these af- ford to the fowler a considerable portion of his employment. While the marshy grounds are not frozen over, these leave the lake in numbers to feed there during night; and the people accustomed to take them, post themselves at break of day by the margin of the lake, or on the borders of the marsh- es, to intercept them on their return. But when the frost is severe, the ducks do not quit the lake. They assemble in crowds, seem jealous of the approach of enemies, and the moment a boat approaches in their direction, take flight to another situation. This excessive caution renders ordinary boats of no use in their capture. The ingenuity of some young men belonging to a village in the neighbourhood of the lake, has, however, overcome this difficulty, by the construction of a canoe, or little boat, with which they can approach. the flocks of wild ducks without alarming them. ‘This boat is from six to seven feet long, and the sides little more than five or six inches in height, with a flat bottom. A hole pierced in the centre of the bottom, and - inclosed by a strong and elevated border, to prevent the water from entering the vessel, permits the passage of a little oar, constructed in the form of a duck’s foot ; and a long-barreled gun is fixed to the prow of the boat. The fowler extends himself on his belly along the bottom, and gives motion by his hand to the duck-foot oar. The little boat, thus im- pelled by an oar which is not seen, is directed towards the birds, who, perceiving nothing but a floating chest, are not alarmed, and the fowler adjusts his aim when within the pro- per distance, This frail bark can only be used in very calm weather. The fifth and last section of M. Necker’s memoir is devot- ed to those birds which are only occasional visitors,—the in- habitants of distant countries, separated by accidental causes from the rest of their species, and driven by similar causes 276 -M. Necker on the Birds of Geneva. from their usual haunts. The Chatterer (Bombycivora gar- yrula, Tem.) is one of these. Two instances of their ap- pearance occurred at Geneva in January 1807, and January 1814. At this last period they were very abundant, and -passed the winter in the neighbourhood. They all disappear- ed in March. In 1807, these birds extended over a great part of western Europe, and were seen around Edinburgh in the be- ginning of that year. The Emberiza calearata, an inhabitant of the northern regions, was taken in a snare with larks in Sep- ‘tember 1816; the Falco lagopus was killed near Copet in Janu- ary 1812; the F. rufipes in May 1816; the Stria bubo in October 1818, and 1822; the Roller (Coracias garrula) in September 1805, and 1819; the Bustard in August 1813; the Egret and the Avocette in May 1821; and the Ibis, (Ibis falcinellus, Tem.) one of the species adored by the Egyptians, and preserved among their mummies, was killed in June 1810 on the border of the lake. Many other rare birds are mentioned as occasionally seen in the neighbour- hood of Geneva; but our limits prevent us from giving even their names. Referring to the Memoir for the complete list, we conclude by noticing that the Phalaropws hyperboreus and the Sterna Caspia were procured by M. Netker ; ‘and the Flamingo, the Bee-eater, the Spoonbill, the stormy Petrel, and the Ortolan (Emberiza hortulana) were taken and Soe served by the late Professor Jurine. Respecting the causes of the occasional appearance of birds in countries remote from their native abodes, M. Necker sug- gests, that a temporary want of subsistence may have led some to seek their food in places beyond their usual range— that storms may have unwillingly driven others far from their accustomed dwellings—or the pursuit of rapacious birds may have terrified others from their native territories. And, lastly, i in some ¢ases, it may be supposed, in accounting for the appear- ance of birds, not otherwise to be accounted for, that they may have escaped from captivity, and been thus thre shores very distant from their own. vi An anomalous occurrence of this nature has lately taken place in our own neighbourhood ; for we learn, that a speci- men of the migratory pigeon of North America, (Columba oa) M. Necker on the Birds of Geneva. 277 migratopidy) the first which has oceurred in this country, was shot,in) Fifeshire in January last, and presented to the Uni- versity Museum bythe Rev. Dr Fleming. The number of species of birds found in the canton of Ge- neva, and neighbouring mountains, amount to 242, of which 185. are, properly speaking, indigenous, and 57 are acciden- tal. Of the 185 indigenous species, 95 belong to. the low grounds, (of which 82 are stationary all the year, and 63 are birds of passage) 31 species belong to the mountains ;—-37 are marsh and shore birds, (of which three are stationary, and 34 birds of ‘passage ;)—and, lastly, 22 inhabit the lake, one species only being stationary, the others birds of passage. Of the 57 species of accidental visitors, 20 belong fo the plain, 16 are marsh and shore birds, and 21 water birds. *. At the conclusion of the Memoir, M. Necker gives his Or- nithological Calendar, in which, like the similar list of Mr Markwick, he gives the dates of the earliest arrival and de- parture of ‘all the migratory birds which he has mentioned as frequenting the neighbourhood of Geneva. ‘These two calen- dars are interesting, as affording the means of comparing the arrival and departure of migratory birds in two portions of Europe at a distance from each other; and had they been for corresponding years, the results would have been more satisfactory. From a slight glance at both, the progress of mi- gration does not seem to be so rapid and continuous asmany con- ceive it; but to proceed by stages, as it were, as the animals from the southward find ‘subsistence on their route. There seems no reason, indeed, for supposing it to be otherwise ; but still it would be interesting to know, from a series of such ob- servations, the time taken by birds of the most rapid flight, to traverse such an extent of surface; and to have the means of investigating the causes which stop some species at deter- mined geographical positions, while others, as the swallow, are found scattered in every country of northern Europe. The ear- liest arvival of the swallow (Hirwndo rustica) is marked in the Genevan Calendar on the 18th of March 1806—the latest pe- riod 10th April 1816; while, in Mr Markwick’s table, the earliest arrival of the same bird is April 7, 1788, and the latest April 27, 1771. ‘The swallow leaves the neigh- 278 _ Captain Eeg’s Discovery of an bourhood of Geneva from the 10th to the 23d of October ; and, in England, they disappear between the 15th of October, and the 18th of November. The earliest appearance of the cuckoo near Geneva is noted on the 29th of March 1809— and its earliest appearance in England, April 22, 1769. One of the most curious particulars connected with the an- nual migrations of birds, is the circumstance of individuals returning for a series of years to the same nestling-places. Spallanzani having tied a thread of red silk round the leg of a swallow, which built its nest in his window, saw for three seasons the same stranger annually appear; and similar in- stances are on record concerning many other species of migra- tory birds. This wonderful direction of instinct, which di- vides the innumerable flocks of birds in their progress north- ward, and leads particular families to seek the protection of the same roof, or the same chimney-top which formerly shel- tered them, affords a subject not the least worthy of contem- plation, among the thousand instances of wisdom and benefi- cence which arrest the student of Nature at every step of his progress. i! S. Arr. XVII.—Account of the Discovery of an Inhabited Island in the Pacific. By Carrain Exe of the Pollux . isha of War, in the Service of his Majesty the King of the Netherlands. In a Letter to Dr Brewster from G. Mort, Professor of Natural Philosophy in the Univer- sity of momepion My Dear Sir, Two vessels in the service of Md Majesty, the King of the Ne- therlands, have lately crossed the Pacific. After leaving Wash- ington’s Island, it was deemed expedient to keep in the seventh parallel of south latitude, sailing to the westward, being the track in which Captain Eeg, commanding the Pol- lux sloop of war, thought some islands might probably be ‘dis- covered. The coral islands in those seas being generally small and low, it was reckoned prudent to proceed at night Inhabited Island in the Pacific. 279 under easy sail, and thus to leave de Peyster’s and Sherson’s Islands one degree to the north and south. On the 14th July 1825, at 5" A.M., after a very hazy and rainy night, it was presumed that land was to be seen a-head, but very indistinct- ly; and shortly after the breakers were distinctly heard. The vessel was brought to, and the signal made for the Maria Reygersberch frigate to do the same. After sunrise, they discovered a very low island, bearing W. by S., two miles distant (miles of 60 to a degree.) The land appeared well stocked with cocoa and other trees. About noon, they had the north point of the island, S. 60°E. The longitude of this island and its latitude being ascertained, with as much accura- - -ey as circumstances would allow, and no other island being found in the same position in any of the charts on board, this was deemed a new discovery. ‘The nearest land was de Peyster’s group, but it was 50/ different in latitude. Though the sky was very clear, no other islands were seen at the same time. The name of Nederlandich Island was given to this new land. Its north point is in lat. 7° 10’ S., and the centre of it in long. 177° 33° 16” E. from Greenwich; the varia- tion of the magnetic needle being 7° to the east. The longi- tude was determined by three chronometers. One of these, made by Thomson, was reckoned the most accurate ; its rate shad been ascertained seventeen days before at Nukahiwa, and its differences from the other two were very regular. A few days before coming in sight with the island, the longitude was ascertained by lunar observations, agreeing remarkably well with the chronometers. This island has a form resembling a horse shoe ; its extent is about eight miles. In the west side is an indentation, closed by low reefs, and terminating in a lagoon. The natives, some of whom were armed with long sticks, were very numerous, sitting or running along the shore, as the vessel sailed along. An armed boat was dispatched to- wards the shore. The island appeared iron-bound ; for, at a boat’s length from shore, the depth was six fathoms, and rough coral ground. A ship’s length from shore there was fifteen fathoms depth. At the N. W. point they found a coral reef, projecting far in the sea, and on which there was a heavy surf. It was supposed that these were the breakers heard 280 Captain Keg’s Discovery ofan Inhabited Island, &c. previous to the discovery ofthe'sland. The land had a pleasing aspect, and appeared fertile. .The number of natives as- sembled on shore was estimated at about 300... ‘They were of a dark copper hue, tall and well-made. Few were less than six feet Rhinland measure, or 6.166 English. ‘The women were also very stout. Some of the people were tatoved, but not so much as at Nukahiwa. They were naked, except some cover- ing made of leaves. A few others had some cloth of cocoa bark wrapped round the waist. The heads of some were adorned with feathers. Their conduct appeared very fierce and wild, and they contrived to steal whatever they thought within their reach. The boat-hooks soon disappeared, and they even attempted to tear the oars from the hands of the boat’s crew. An old man, with a white beard, and of respectable appear- ance, carrying a green bough in his hand, was at their head. He continually kept singing some monotonous song, in a melancholy tune. They bartered some cocoa-nuts, and some of their tools, against some old handkerchiefs and empty bottles ; and it appeated that their language had some re- semblance with that spoken at Nukahiwa. When the boat again put to sea, they tried the effect of firing a few musket shots in the air, but the natives did not show symptoms: of fear, and thus appeared unconscious of the effects of Euro- pean arms. No canoes were seen in the possession of these people, nor did they attempt to approach the ships; although the weather was excellent, and the sea very calm. »'The eom- manders of the two vessels regretted very much that their large complement, and the small quantity of water, obliged them to make every possible dispatch. They accordingly pursued ther journey to Sourabaya in Java, where they found other work at hand than the discovery of new countries. I am, Dear Sir, ‘aod 4 tite With very great esteem, Your humble servant, =} att ie as J ? ’ a ¢ : G. M ; Urrecnr, 9th Feb. 1826. 2Ogqha Bay ‘Dr Kennedy on Polishiny Granite in India. * 281 ibd air 4 BE wit ‘ Awe, XVITTLNotice respecting: the Working and Polishing of Granite in’ India. Tn a Letter to the Ebitor., from esiamae Kennepy, M.D. F. 8S. Ev * * hinbens Sir, You will probably recollect, that when the * Notices Hayat ing the Working and Polishing of Granite, by the Natives of India,” appeared in the Edinburgh Philosophical Journal, No. viil. p. 349, you then inquired whether any colouring material was mixed with the lac and corundum, and which would account for the black colour acquired by the granite in the process of polishing. I could then only say, that though I had frequently seen the process performed, and had also _witnessed the preparation of the ingredients, I had never seen any colouring material mixed with them. I neverthe- less set on foot an inquiry, by writing to a friend, who I knew could. easily ascertain the point from the native work: men. It happened to be a subject with which he was himself well acquainted, and, in his reply, after mentioning that the granite is first brought to a smooth surface by being rubbed in the manner usual with masons, with part of its own sub- stance and water, he adds, that, in the process of polishing; which was the object of my inquiries, ‘¢ no colouring ena is used.” I perfectly recollect, that, when the whole of this process was performed under my own eye, the granite, after having been smoothed with its own substance, retained its own col lour and appearance, having then acquired no part of the black colour which it afterwards got under the lac and corun- dum, and as to the origin of which we are still as much in the dark as formerly. There seems. good reason for believing, that the polish which the stone thus aeqiires endures for ages. It is this material which is so often seen used as black monumental slabs, &c. in the Mussulman burying-grounds in India, and of which also the pilasters, cornices, and other ornaments of the mausolea, erected over their princes and great men, 282 Superiority of Dr Blair’s Achromatic Telescopes - are always formed. It also affords a most suitable material for the toorbut erected over the body under the centre of the dome of these magnificent structures, and. which is seomagey covered with inscriptions from the Koran. I had requested my friend to send me a specimen of the polished granite, which he has only been prevents from doing by want of a suitable opportunity. Epinzuren, 15th February 1826. Art. XIX.—Observations on the Superiority of Achromatic Telescopes with Fluid Object-Glasses, as Constructed by Dr Bian. , , AttHoucnu it cannot be doubted that the Achromatic Tele- scope, from its first invention to its latest modifications, is a British invention, to which no foreigner has made the slight- est addition, yet no attempt of any magnitude, and with any reasonable prospect of success, has been made in Great Bri- tain for perfecting this noble instrument. Contented with supplying the European market with this article of their manufacture, our opticians have blindly followed the ancient routine ; and neither our government, nor our public institu- tions, have originated or encouraged any attempt at improve- ment. The opticians of France and of Germany, on the con- trary, have been busily employed, not only in rivalling the English in their methods of working lenses, but, with the aid of public bodies, and of the government itself, they have devot- ed themselves to the more important object of perfecting the glass of which the lenses are composed. The success which they have obtained in these respects has exceeded even their own expectations ; and the telescopes of M. Fraunhofer of Munich, and of M: Lerebours of Paris, * have been brought to such perfection, as to threaten England with the loss of one of the staple articles of her manufacture. tee * The opinions of Mr Herschel and Mr South on these telescopes will be given in a subsequent article. See page 309. with Fluid Object-Glasses. 283 .| The attention of men of science has at last been roused to this subject; and the Royal Society of London has appointed a committee for making experiments on the best method of manufacturing flint-glass for achromatic telescopes. Govern- ment have released the committee from the restrictions of the Excise laws, and an experimental glass-house has been erected for the purpose, We cannot doubt but that these experi- ments will be attended with success ; but a considerable time must elapse befwre our artists regain that advantageous posi~ tion which they have lost. _ Amid all these exertions to improve the achromatic tele- scope, it has often struck us with surprise, that no attempt has been made to introduce and to improve the achromatic telescopes with fluid object-glasses, invented and actually con- strueted by our countryman Dr Blair. The doctor himself took out a patent for this valuable improvement, but practi- cal difficulties were experienced in the manufacture of them . for sale, which prevented the patentee from ever deriving any pecuniary advantage from his indefatigable and successful la- bours. This, therefore, was, in a peculiar manner, a case where the patronage of government was required, and where it ought to have been given. From the want of such encou- ragement, this invention has entirely fallen into oblivion, and is now in the same state in which it was in the year 1789, when it was first submitted to the public! * The only philosopher, as we have elsewhere remarked, * that we know of who actually looked through the telescopes of Dr Blair, was Dr Robison, who always spoke of them in terms of the highest praise. He informs us, indeed, that Dr Blair had a telescope not exceeding fifteen inches in length, with a compound object-glass, which equalled in all respects, if it did not surpass, the best of Dollond’s, forty-two inches long. The effect of this telescope, when applied to the examination of double stars, was, we understand, particularly fine ; and it is deeply to be regretted that Dr Blair was not encouraged, by some public aid, to carry on the manufacture of such valua~ ble instruments. For ordinary purposes, telescopes of this * Edinburgh Encyclopedia, Art. Ortics, yol. xy. p. 484. 284 Superiority of Dr Blair’s Achromatic Telescopes. kind. may, be considexed as too delicate and complex ; but, ad- mitting in its full’ force the objection to them, drawn from the change which, cither does. or may take place in the fluid media, their use in public observatories, and, particularly, their application to fine graduated instruments, were objects of primary importance to the progress of astronomy, even if. the lens required to be renewed every two or three years.” . Since these observations were printed, we find that, at a meet- ing of the Royal Society of Edinburgh, held on the 7th De- cember 1789, Dr Blair exhibited one of ‘his teleseopes to the mémbers who were present, and showed them its performance when directed to double stars... Professor Playfair was one of those members, and: the following: minute ‘is inserted in his hand- writing.in,the account of the proceedings of that evening: ‘‘ Dr Robert Blair, Professor of Astronomy ‘inthe Univer- sity of Edinburgh, produced before the society an achromatic _ telescope of) 1a: hew construction; im which the: convex lenses’ are of common glass, and the errors which arise from the dif- ferent refrangibility of light, and from the spherical figures of the lenses, are corrected by ‘the interposition of transparent fluids. _The focal distance of the object-glass of this telescope is twelve inches, the aperture is two inches, and the powers belonging to it are two double eye-glasses, with one of which it, maguifies: seventy-five times, and with the other ninety- a. times. ‘¢ There arealso four dentin convex lenses, whose focal dis- tance are, one-fifth, one-tenth, one-twentieth, and one-thirtieth’ of an inch, and whose powers: are’ of: consequence, sixty, one hundred: and twenty, ten hundred and forty, and three hun-’ dred and’ ‘sixty times. The fixed stars appear through this: telescope with routid well defined disks ; sometimes surround-’ ed with-imperfect rings,* but free from radiation and glare:! Some double stars that happened to’ be in sight, were shown’ through the instrument to the members present. The power of two hundred and, forty is found to oe best i in separat- ing the ¢lose double stars.” Be on staat “4! ¢! Bac these ritigs are mentioned by Professor nic, as : plgel by the best achromatic telescopes, and also by reflectors, when directed to luni- - nous points, See page 309 of this Numiber. - 10 ‘Dr Gustavus Rosé on Epistilbite. 285 Withi these evidences sin) favour ofthe vast supériority of Dr Blair’s telescopes to’all othér achroniatic instruments, we earnestly hope that the Royal Society of London, or the Board of Longitudé, will take some’ measures for reviving their manufacture, As night+glasses, they would be invaluable, and, if generally used at sea, they might save to the country many a vessel, and to society many a valuable life. The Society for the Encouragement of the Useful Arts in Scotland, has offered an honorary medal for the best achroma- tic telescope with fluid object-glasses, and we trust their ex- ample will be followed by other public scientific institutions. Epinsurcn, February 21st 1826. P< Di Be Art. XX.—On Epistilbite, a New Mineral Species of the Zeolite Family. By Dr Gusravus Rosr, — shies R. 2 Edin. ‘Communicated by the Author. As the fundamental form of the species, we may consider a rhombic octahedron, the three axes of which, ‘a : be, Fig. 20, Plate V, ate in the ratio of ,/ 2.022 : 11.886: 1: The erystals most generally observed, are’ very obtuse rhombic prisms M, Fig. 21, terminated by two planes s, which are set on the acute edges, and having the more obtuse solid angles of combination replaced by the rhombic planes ¢, From this rhombic form of the planes it appears, that the three prisms M, s, and ¢, may be obtained by laying” planes on the edges of a single scalene four-sided pyramid, the same which has been assumed as the fundamental form of the spe- cies, though its faces have not yet been observed in’ nattire: ‘There are also crystals, i in which the faces ¢ ate large enough to intersect each other, and to produce an ‘edge, which’ then forms another termination of the crystals. In these, the faces s replace the acute solid angles of combination, and likewise possess the figure of rhombs, as in Fig. 22." Sometimes, also, the edges between s and M are replaced ‘by the narrow faces marked «; two of them produce parallel edges of conan. tion with ¢. 286 —»- Dr Gustavus Rose on Epistilbite, The formule of these faces, after the method of Proféssor Weiss, pee the ratio of their axes, are— 4 M =[a:b: @ c}. . r=[o a:b: wc}. 4 t=[a:o@ b:c}. s= [oe a:b: c}, w= fa: 3: c}. The following are the measures of the angles : ) M on M = 135° 10. Mon r = 112° 25’. Mon ¢ = 1229. ¢ on t = 109° 46. t onw = 154° 51)’. t ons = 141° 47. id s Ons = 147° 40/ Simple crystals are rare ; generally the epistilbite is found in twins, resembling, in some respect, those of carbonate of lead, and joined parallel to one of the faces of the prism M, as represented in Fig. 23, of which Fig. 24 is a horizontal pro- jection. The faces of the horizontal prism s, in both the in- dividuals, form an angle, which is salient at the edge a, and re-entering at the edge a. ‘The truncations of the acute lateral edges of the prism M form an angle of 135° 10’, equal to the angle of the prism itself, The crystals are implanted on a mass of the same species, consisting of granular particles, in the cayities of amygdaloi- dal rocks, and are found in Acalanc and the Faroe Islands, along with heulandite. : The cleavage of epistilbite is highly perfect, and easily ob, tained parallel to the face 7, which replaces the acute lateral edge of the prism M. In other directions there is uneyen fracture. .The faces M are shining, but uneven, and do not admit of measurement by means of the reflective goniometer 5 the faces s are dull, ¢ and ry are both smooth and_ shining. The lustre of M and ¢ is vitreous, and that of r is pearly and bright ; the colour of the crystals is white, their transparency sometimes perfect; often they are only translucent on the edges. a New Mineral Species of the Zeolite Family. 287 Its hardness is — 4.5, between fluor and apatite ; the speci- fic gravity I found to be = 2,249 in several small erystals ;= 2.250 in a single larger specimen ; both of them at a tempera- ture of 10° R. Before the blowpipe, the indications given by epistilbite are the same as in stilbite and heulandite. In the mattrass, it intumesces considerably, and gives off water. On char- coal, it froths up, and forms a vesicular enamel, but cannot be melted into a globule. Borax dissolves a great quantity of it, and forms a clear globule. It is likewise soluble in sal of phosphorus, with the exception of a silica skeleton. With solution of cobalt the enamel becomes blue. The epistilbite is soluble in concentrated muriatic acid, with the exception of a fine granular ae of silica. After ignition it is insoluble. The chemical composition, sible by analysis, is as fol- follows -—— | ~ Silica, = mH 58.59 containing oxygen 30.44 - 12° . Alumina, ~ - - 17.52 818i= 38 Lime, ° ra) - 7-56 2.12 Sodan = = = = 1.78 0.45 f ~ Water, - - - 14,48 1287 -. 5 The corresponding mineralogical formula is ea Ls +3 ' AS® + 5 Aq. Observations. Several years ago I observed and measured the crystals of epistilbite in the Royal Collection of Berlin. Even before this period, Professor Weiss had placed by themselves, as a new variety of foliated zeolite, some specimens of it, which, how- ever, were not very distinct. ‘The variety which I first ex- amined, occurs in small but simple crystals, along with larger crystals of heulandite. Afterwards, in 1824, I recognized this species in Paris, where Count Bournon likewise had con- sidered it as something new. He allowed me to institute some measurements with these crystals, which I found to agree exactly with those I had obtained before. I feel par- ticular pleasure, in having this opportunity of public- ly expressing my gratitude to Count Bournon, for the ex- 288 _ Dr Gustavus Rose on Epistilbite, treme liberality with which) he perniitted me not. only, to look over the cabinet. under his direction, but also.to examine and measure more minutely the-erystals which it confains,: ©’ The crystals of epistilbite very much resemble) those of - gtilbite, and of heulandite,' with, which probably they have often been confounded. | In allusion to this resemblance, the name of epistilbite has been formed. Like, the crystals of these two species, they possess a single cleavage, with\a strong pearly lustre, while, on the mostly uneven crystalline faces in other directions, their lustre is vitreous. They diffet from them by a greater specific gravity, which, in heulandite, I found = 2.211 at a temperature of 6° R., in stilbite, and between 2.145 and 2.176 at a temperature of 8° R. — Also their hard- ness'is a little greater, for, in both heulandite and stilbite, it is yet below that of fluor-spar. The most considerable differ- ences, however, are those in their regular forms; the angles of ‘epistilbite and stilbite, though within one system of erystal- lization, are incompatible, while in epistilbite. and heulandite, even the system of crystallization is different. - For the sake of an easier comparison, I have added a figure of heulandite, Fig. 25, and one of stilbite, Fig. 26, a little modified, but agree- ing in position with those of Professor Mohs. The crystals of 'epitilbiee are farther remarkable for the frequency of their occurrence in twin-crystals, which have not, yet been described in either of the other species. Of stilbite, Mr Allan showed me a cruciform twin in’his cabinet, which he had himself brought home from Faroe; but this i is one of the manent spe- cimens ever observed. Also the chemical composition of stilbite and heulandite, according to Hisinger and Walmstedt, are different, the for- mule being respectively CS® + 3 AS? + 6 Aq, and CS® + 4 4S° 4+ 6 Aq. The analyses are— ieee. ! Stilbite. Heulandite,~ Silica, = 4 - BLOW ess PBL eRe aE Siam Alumina, - -3rl” aw (0 GO roa 88 ge.Bpeit« _ Lime, - sasa'ets =~ ,9.20 TAD Water, pink) Tt” ie Bee: hae eh (15.10 — p, ; ne ive gt cruigaig ‘peli The analysis of epistilbite was an easy one. The’ mineral a New Mineral Species of the Zeolite Family. 289 is partly dissolved in muriatic acid, giving as a residue a fine- grained po wder of silica. From the remaining liquid, the alumina was ‘precipitated by caustic ammonia, and the lime by oxalate of ammonia. The alumina, redissolved in muriat- ie acid, gave a small additional quantity of silica. The oxa-_ Jate of lime was ignited, then carbonate of ammonia added to it, and, again dried, to transform it into carbonate of lime, which was weighed. The remaining fluid was evaporated, the residue redissolved in water, by which another small quan- tity of silica was separated, and the solution allowed to erys- tallize, Very distinct cubes formed, which appeared to be erystals of muriate of soda, as they did not deliquesce, nor did they produce a precipitate, either when dissolved in alco- hol, and added to a solution of muriate of platinum in alco- hol, or when dissolved in water, and added to a solution af _ tartaric acid in water. The quantity of water given above is the mean of two ex- i which gave separately 14.72, and 14,25, From another analysis of the epistilbite, I obtained the fol- lowing result :— Silica, - - 60.28 ‘containing oxygen 31.31 Alumina, - - - 17.36 9.32 x. Lime, - ~ - 8.32 2 Ti Qe Loss, calculated as Water, - 12,52 11.34 There is less water, and more silica in it, than the quanti- ty required by the formula. This was caused by the cir- cumstance, that, in order to render the mineral more easily acted upon by muriatic acid, I had ground it down to an im- palpable powder, which was suspended in water, and then al- lowed to subside, by which means only the most minute par- ticles are separated. In drying it on the stove, the heat be- came a little too great, so as to drive off a small quantity of the water, and to render part of the mineral insoluble, which therefore increased the apparent quantity of the silica. But I have mentioned this analysis, because I have conducted it with as much exactness as I could command; and, because, at least the relative quantity of alumina, lime, and soda, is correctly determined. VOL. Iv. NO. 11. APRIL 1826. T 290 - M. Humboldt on the Horary _ I have a gh the soda and the lime under one head in _ 4 the formula 5, xfs +8 AS 45 Ag; though these two substan- ces do not appear to be isomorphous. The form of anhydrite, GaS2, is different from that of anhydrous sulphate of soda, NS? as described by Haidinger. ‘The crystals of meionite also, and those of nepheline, cannot be reduced to the same fun- damental form, though the chemical composition of the for- mer, according to the analyses of Leopold Gmelin. and. Stromeyer may be expressed by the formula CS'+ 34S, ‘and that of the latter, according to the analysis of Arfved- son, by the formula NS +, 348. But it is probable, par- ticularly from the analyses of the mesotypes by Fuchs, that soda, containing a certain quantity. of water, may be isomor- -phous with lime, in the same manner in which ammonia, with two atoms of water, is isomorphous with potash, as has been shown by Mitscherlich. In this case, it would be necessary to add some of the water to the soda, in order to have it iso- morphous With lime, ‘and the number 5, which is not a com- mon one among this kind of formule, would then be likewise modified. In the meantime, it will be prudent to express the formula as above,- because the quantities of oxygen, con- tained in each, soda and lime, taken separately, are .in no simple ratio to the oxygen in the other ingredients, though, particularly in the ‘second analysis, the oxygen of the soda, and that of the lime, are very nearly in the ratio of one to six. Ms C7 t \ 3 <2 Ant. XXI.—On the Horary “Variations of the Barometer By Baron ALEXANDER DE Humsoupr, * In the year 1682, + M. M. Varin des Hayes, and De Glos, remarked, fbats at Goree, the barometer was generally lower x This paper is is a brief abstract of the elaborate dissertation on this sib ject, published in the Relation Historique.—Livrais. 5, Folio, p. 270—31 + We must again repeat here what we have said in No. iv. p. 336, that, in 1666, Dr Beale, an Englishman, observed, ‘‘ that very often, both in winter and summer, the mercury stood higher in the eald. morn- — ings pe evenings than in the warmer mid-day.’ Ep. : ¢ ‘ Variations’ of the Barometer. 291 when the thermometer was highest, and generally higher in the night than the day, by from two to four lines ; and that, this instrument suffered a greater change from the morning till the evening, than from the evening till the morning. It was in 1722 that the phenomenon of the hourly varia- tions was observed, for the first time, and with great exact- ness, by a Dutch philosopher, whose name has not descended to our times. In the Journal Litteraire de la Haye, it is said, in a letter from Surinam, “ The mercury rises in this part of Dutch Guiana every day regularly, from 9" in the morning till half-past 11%, after which it descends till 2 or 3: o'clock in the afternoon, and afterwards it returns to its first height. It suffers nearly the same variations at the same hours of the night. The variation is only one-half or three-fourths of a line, or, at most, a whole line. -It would be desirable that the philosophers of Europe would make their conjectures on this subject.”* The observations which I have made seventy-seven years later on the same coast of Surinam, on the banks of the Orinoco, have confirmed, with the exception of the hour of maximum in the morning, the moaned of the first determina- tion of*the periods. - From 1740 to 1750, Father Boudier observed the peer ter at Chandernagore in India. He found that the greatest elevation of the mercury took place every day about nine or ten o'clock in the morning, and the least elevation towards three or four o’clock in the evening ; and he remarks, that, during the great number of. years that the barometer was marked at Chandernagore, there were only-eight or ten days in which this uniform motion of the mercury was not observed. The academicians’ sent to Quito in 1735, observed also the horary variations of the barometer, and they found that it reached its maximum at nine in the morning, and its minimum three in the afternopn, the mean difference at Quite bein ; i of a line. a 1751, M. Thibault de Theisvelon reduced into tables the * We trust that M. Arago will now have the candour to divest his coun- tryman, M. Godin, of the honour which he had erroneously conferred upon him, of having been the first to observe the horary variations of the baro- meter. —Eb. i 292 M. Humboldt on the Horary horary variations of the barometer, which he had observed’ at the Antilles: In a work published in 1761, he observes, ° “that, a short time after his arrival in Martinique, he per-: ceived that the barometer rose gradually during the whole: morning, and that, after it had been some time in motion, it | began to descend till sunset. After having been some time stationary, it rose at the approach of night, till ten in the evening. The most considerable revolutions in the atmo- sphere do not alter this periodical march of the barometer, which coincides with that of the horary variations of the mag- netic needle. In the middle of the most copious rains, of winds and of storms, the mercury rises and descends, if it is its time to rise or descend, as if all was tranquil in the air. «The same variations take place at Senegal.” Since the year 1761, Doctor Mutis has observed the at- mospherical tides at St* Fe de Bogota during forty years. He determined, with precision, the epoch of the minimwm which precedes sunrise ; but, unfortunately, his observations, which he concealed with too much care during his life, have not been published since his death. M. Mutis in New Granada, Alzate and Gama in Mexico, were the first who examined the hourly variations on the back of the Cordilleras at 1200 and 1400 toises above the level of the sea. Neither the observations of Thibault de Chauvelon in 1751, nor the small number of those published by Alzate in 1769, corresponded to the tropical hours, that is, to the epochs when the barometer arrives at the convex and concave summits of the curve of its daily variations. It was in the voyage of La Perouse, that MM. Lamanen and Mongez made, in 1785, every hour the first continuous observations, during three days: and three nights, when they were in the middle of the Atlantic Ocean, between the parallels of 1° north latitude, and 1° south latitude. The work of Lamanon is anterior, by cake years, to that undertaken at Calcutta by Messrs Trail, Farquhar, Pierce, . and Balfour ; but, as their results were inserted in the fourth volume of the Asiatic Researches, published at Calcutta in 1795, while the voyage of La Perouse did, not appear till 1797, the Indian observations acquired more eelebrity in Europe. They were, indeed, the only ones from which, at Variations of the Barometer. 293 my departure for America, I had obtained a knowledge of the regularity of the horary movements of the barometer. * Doctor Mosely, in his T'reatise on T'ropical Diseases, pub- lished in 1792, observes, that the barometer has two daily movements, one of ascent, and the other of descent, rising when the sun approaches the zenith or nadir, and falling when he recedes from these points. Dr Balfour also observed the barometrical changes for every half hour, during a whole lunation, in the year 1794. I commenced the series of my observations on the yaria- tions of the weight of the atmosphere, along with M. Bon- pland, on the 18th July 1799, two days after dur arrival at Cumana, and I continued them for five years with the greatest care, from 12° of south lat., to 23° of north lat., in the plains and on the table lands, whol height is equal to the peak of Teneriffe: Since the time of my voyage to the Equator, this phenomenon has occupied almost all travellers and natural philosophers, who have been provided with instru- ments fitted for making these observations. . As our limits will not permit us to follow our author through the details of his elaborate dissertation, we shall now present our readers with two of the latest and most accurate sets of observation on the horary changes of the barometer made within the tropics, the first by Captain Freycinet in 1820, and the second*by M. Duperry in 1823. 1. M. Freycinet’s Observations at Rio de Janeiro in 1820 o¢ Height of. Height of Hours of the Barometer Hours of the Baromet Observation, in 100dths of | Observation. in 100dths : a Millimetre.} a Millimetre. mm. mim ll’ p.m. . Max. 766.71 1 a.m.° => = 766.65 12. 6m a 76677) | ABN re + 765.96 ey uae 766.59 Lei Muy: gate 4.0% 26576 3 - -- Min. 765.65 3 a " * (764.28 4 - ~ - - 765.67 4 - ~ 764.49 5 - ~ 765.78 5 ~ - -. 764.43 6 - - ~ 766.00 6 - - - %6533 7 - - - 766.35 7 ~ - - 764.69 8 - ” = 1766.49 8 - = = 766.38 9 - - 766.91 9 - - 766.55 10 - Mex, 766.96 10 = - Max. * See this Journal, No. iv. p. 336. \ 294 M. Humboldt on the Horary “In this table, tHe heights are reduced to 32° Fahr., but, in order to correct them for capillarity, and woah error of aha: we must ne 0.922 of a millimetre. 2. M. Dupaays Observations at the Port of Pay in 5° 5” oe South Lat. in 1823. ’ Baro. Centigrade} » Av ier Cena meter Thermo- F meter. | ; * meter. “ meter. Mar. 12, 6a. M. 762.20... 25.0 11} 762-20 26.1 7 762.40 ‘25.3 % a2. i 762.30 26.0 8 '- 762.40 25.9 Mar. 18, Ta. M. 761.30 25.8 84 762.70 26.7. | 2 761.10 25.5 83 762.80 26,7 23 760.70 25.3, 9 0. 762.70 ' 272 3 760.80 25.3 10 762.50 26.8 4 761.20 25.3 il 762.10 26.9 6 761.50 25.6 | : 12° 761.50 28,2 94, 762.30 27.0 ; QP. Me 759.80 28.7 29 Rae: 762.20 26.8 5.0 759.20 29.1 12 761.20 29.5 4 759.20 28.8 23 e.m. . 759.80 30.9 53 %59.20 27.6 ‘era 759.80 30.5 6 759.30 27.7 =e ¢ 760.00 30.4 9 761.40 . 26.9 ‘ 10 761.60 27.3 109%. 762.30 26.7 jl 762.50 27.4 F 102 762.30 26.3 12 762.80 26.4 | 11 762.40 26.2 Although M. Van Swinden announced, in 1'776, the exist- ence-of horary variations in the north of Europe, and fixed the maximum and minimum at + 14> ;—6>; + 10° ;—228 astronomical time, yet we owe the first sicecteh ohepHlaeietis to M. Ramond. “I have obtained,” says this excellent observ- er, “ results very analogous to those which M. Humboldt has brought from the Equator, but the hours of the variation differ according to the season. For winter, the ¢ropical hours (the hours at which the motion retarns upon itself) are 9" a. M., 3 vp. m., and 9° vp. m. In summer, the fall appears to begin from 8" a. M., and to conn | till an Pp. M., and does not re- ~ commence till 10° pv. wu.” In consequence of the singular regularity of the barameene? cal variations at Bogota, MM. Boussingault and Rivero have detected a monthly variation in the oscillations of the mercu- ry; the mean monthly 5 being i ie in June and July, _ Variations of the Barometer. and smaller in December and: January, In the following ta le, the mean heights nearest the sun. are reduced to the zero of temperature, — ims 4° 55 50. sp! Barometer in [Mean of the Os-| Mean Temp. | singe One lparts of a: Me-lcillationsin Mil. of 9%, and 4 9 “A tre. ' limetres. Centigrade. m January, 0.56045 2.31 15.7 February, 0.56048 2.31 15.9 March, 0.56061 2.39 15.3 April, 0.56113 2.34 16.3% May, 0.56075 245 15.4 June, 0.56124 1.86 15.1 July, 0.56134 1.50 14.2 August, |. _ 0.56111 2.22 16.6 September, | 0.56094 2.59 16.2 : October, 0.56071 2.77 15.3 ~ | {November, 0.56045 2.44 15.1 _ |December, 0.56013 2.40 © 15.0 295 when the earth is “Monthly ows Heights of the Barometer at Bogota, Lat. « * The results containediin this table are confirmed by the obser- vations of M. Caldos in 1807 ; and it appears also from fourteen years observations of Herrenschneider, at Strasburg, that the monthly means are higher in September, and lower in April. The following are Herrenschneider’s observations, reduced to 15° centigrade. Result of 14 Years. January, February, March, April, May, J une; - - July, Te - August, ~ September, October, November, December, From seven years observations made Mean Height of the Barometer in Lines. 333-128 333.452 332.905 - 332.449 332.516 - 333.416 “ 333.168 ~ 333.352 - 333.635 332.98 L 332.866 332.700 at Clermont, M. Ra- 296 M. Humboldt on the Horary morid has ascertained that the barometer is highest in ceeter and June, and lowest in April and November. , The next subject of M. Humboldt’s inquiry, is to ascer- tain if these horary variations have any connection with the Juhar motions. M.Toaldo had long a ago averred, that, in Italy, the barometer was much higher i in. the quadratures than in the syzigies, and in apogee than in the perigee ; but the results of the observations of MM. Boussingault and Rive- ro made at Bogota on the subject, by no means confirm the opinion of Toaldo, They were.made in the last five months | of 1823, and the first seven months of 1824, arid the following are the results: ’-' New Moon First Quarter Full Moon _—_ Second Quarter Mean Height of | Metres. =~ Metres. Metres. Metres. the Barometer. 0.56216 0.56161. 0.56198 0.56222 ‘In aletter from M. Boussingault to Baron Humboldt, dated Bogota, February 9, 1825, he says, “‘ I dare not’ deny that there is any lunar influence on the mean weight of the mer- cury; but I believe that this. influence, if it does exist, is ” scarcely perceptible, because it is lost among the other causes of the horary variations.” We shall now conclude this article with Baron Humboldt’s very interesting summary of the laws, or the general relations of this class of atmospherical phenomena. 1, The horary variations of the barometer are felt in all parts of the earth, in the torrid, as well as in the temperate and frigid zones; at the level of tlie sea, and at heights above 200 toises, The two atmospherical tides are not generally of equal duration. In comparing results of unequal. accuracy, and obtained by thirty different observers, between 25° of S. lat., and 55° of north lat., we find, for the epochs of maxi- mum and minimum detintiobe of two hours. By excluding © five results only, the maximum in the morning falls between be. and 103%, the minimum inthe afternoon between 3° and ; the maximum in the evening between 9» and 11%, and * minimum in the morning between 3° and 5%, As the most correct type, we may adopt for the equatorial zone, 10 Variations of the Barometer. 297 fe 2154 5mm hh, 4. 103; 16, and for the temperate zone, + 205"; — 35 ; + 9}; —— 17", astronomical time reckoned from noon. 2. In the temperate zone, the epochs of the maximum of the morning, and the minimum of the evening, are nearer, by 1* or 2%,.the sun’s passage of the meridian in winter than in summer ; but the type of the summer resembles more the type between the tropics. Observations on the morning minimum are still much wanted. ' 8. In the torrid zone, the times of maxima and minima are the same at the level of the sea, and on the table lands _ 1300 or 1400 toises high. We are assured that this isochro- nism does not show itself in some parts of the temperate zone, . and that, at the summit of the great St Bernard, the baro- meter falls at the hours when it rises at Geneva. 4. The variations everywhere become slower near the con- eave and convex summits of the curve which represents them ; and: in some places the mercury seems to remain stationary, during a time varying from 15’ to 2°. §. In general, under the torrid zone, between the equator and the parallels of 15° north and south, the strongest winds, storms and earthquakes, and the most sudden changes of tem- perature and humidity, neither interrupt nor modify the re- gularity of the horary variations. Whereas, in some parts of equatorial Asia, as in India, where the monsoons blow with violence, the seasoii of the rains masks entirely the type of the horary variations ; and, at the same time, when these varia- tions are insensible in the interiér of the continent, on the coasts, and in straits, they show themselves, without any alte- ration, in the open sea, under the same parallels. 6. Between the tropics, a day and a night are sufficient to determine the times of maxima and minima, and the dura- tion of the small atmospherical tides. In the temperate zone, - in 44° and 48° of lat., the phenomena show themselves in all seasons with much distinctness, in the means of from fifteen to _ twenty days observations, 7. The unequal extent of the diurnal variations produces, in the torrid zone, at the same hours, in different months, differences of barometrical height, more or less considerable. 298 M. Humboldt on the Horary ‘The extent /of the oscillations decreases, iin’ proportion ‘as’ the latitude, and the annual deviations due to accidental pertur- bations, increase. In the maxima of the evening, the ‘mer- - eury is generally a little lower. than in the mawxima of: the morning. If we confine: ourselves to observations that are precise, and sufficiently numerous to give means worthy of confidence, we find, that the extent of the oscillations under the torrid zone, between the equator and the parallel of/10°, in the tide of 9" a. m. to 4" p. M., is, in the plains, from /2.6™™ to 8.38" ; on the plain of Bogota 1365: toises ‘high,’ 2.3™™ ; towards the extremity of the southern torrid zone, in the ‘plains 2 millimetres.. In the whole :year, the diurnal varia- tions vary at Bogota from 0.63™™ to 3.64"™5-and the means of the monthly oscillations vary from 1. 5m, to 2.7™™. ) The extent of the oscillations in the morning tides from 9» to 4%, and in the evening from 4° to 11", are generally, under the tropics, in the ratio of 5: 4 or 5:3. ‘The mean. barometric heights of the,days vary between 0° and/10° of latitude, in the plains, 3. 8"™, and on the plain of Bogota 8 millimetres ; a dif- ference of level,. therefore, of 1600. toises, has a very slight influence on the mean of the daily oscillations, and on the ex: tremes of these oscillations. The mean heights at noon, be- - ‘tween the tropics, are constantly some tenths of a millimetre higher than: the general mean of the day, deduced from the maximum of 9» a.M., andthe minimum of 4° rm. In ad- vancing from the equator to the poles, we find the differences of the barometrical heights at 9° a.m. and 44 ¥, m., between 0° and 20° of lat., from. 2.5™™ to 3.0"; between 28° and 30° of lat. to 1.69". in 43° and 45° of lat. to 1.0™™ ; in as 49° 0.8™™, and in 55° of lat. to 0.2™™. 8. The barometrical means of the months differ fii ‘ik _ other under. the tropics from 1.2™™ to 1.5" ; at Havannah; : Macao, and Rio Janeiro, near the tropics of Cancer and Ca- pricorn, from 7 to 8 millimetres, as in the temperate zone. The extreme deviations of the year are, at the same hours; near the equator, from 4 to 43 millimetres. They rise sometimes at the extremity of the equinoctial zone, near the tropic of Ca- pricorn, to 21™”; and near the tropic of Cancer to 25 and 30. millimetres. In the temperate regions of Europe, the limits ~ Variations of the Barometer. 299 of the extreme “monthly oscillations are, in tae ascending mo- tion, onethalf nearer each other than under the tropic of Can- cer. In the limits of the ascending oscillations, this difference between the two zones is much less sensible. The interrup- tion of the horary oscillations presents, near the tropic of Can- cer (in the Gulf of Mexico) a prognostic of the proximity of tempests, of their force and their duration. The monthly means of the barometric heights diminish regularly, from July to December and January, on the plain of Bogota, and even in the southern hemisphere, on the coast of Rio Janeiro. “At the extremity of the northern equinoctial zone, the return of the north winds raises the means of December and January above those of July and August. . 9. Under the tropics, as in the temperate zone, in compar- ing the extreme deviations of the barometer, month by month, we find the limits of the ascending oscillations two or three ~ times nearer than the limits of the descending oscillations. ; 10. The observations:hitherto collected do not indicate any sensible influence of the moon on the oscillations of the atmo- sphere. ‘These. oscillations appear to be owing to the sun, who acts not by his mass, viz. by attraction, but as a star, ra- diating heat. If, m modifying the temperature, the Solar ~ rays produce periodical changes in the atmosphere, it remains to be explained why the two barometric maxima coincide al-' most with the warmest and the coldest epochs of the day and . the night. _. The following table will afford a general view of all the ‘horary results: EquaTor. Nortu anv Soutn Torrip Zones. Tropic. TremMPERATE ZONE. 300 \M. Humboldt on the Horary Variations of the Barometer. General View of the Horary Variations in different parts of | the Globe, and at Different Heights above the Sea. s.- | Maxi- | ; Maxi- | extent Mini- + | Maxi« Names of Ob- | maaf-| "iio" | ma ba he Puaces or OnsERr- servers. phen, Morn- After- Even- tions in VATION. might | ing, | 20° | ing. | Milli- metres. [Lamafon and Atlantic Equatorial Mongez. j — 4> + 10 — 4% + 10° ser eeseoe Ocean. oe gr omen America, rom 23° N. lat., 2° $ Humboldt and 44 +9 } Ane 4h +T1 2.85 lat., and between } Bonpland. _| "| 0.71600 toises high. 4 , P. ta f . Duperry: — 3 |+9 |— 3h |+.114] 3.40 ie ayn oF Ft } atits L slat. 10°86’. Boussingault and|-~*-+|+ 94 |—34 |+ 10 | 244 ae Adee r on Rivero. —4 |#9 |—4 |+ 10 | 2-29 | height 1366 toises. tt Indian and African seas, Horsburgh. —4 [4+ 84 |—4 [+ 11 feos, N. lat. 10°, S. lat. 25°, Langsdorff and 34.14.99 4. | 108 feeeeess Pacific Equatorial ocean.| Horner. Sierra Leone, N. lat. 8° Sabine. — 5 + 94 = 33 + 10 jes ceeves| 30’, Plain of Mysore N. lat. Kater. —s |+ 10,;— 4 [+ 104|... --o0.| 14°11, height 400 tois- F ‘es, rainy season. _ {Pacific Ocean; from N. Simonoff. — Sh 1+ 94 3h 1+ 92 |sevoeeree < ae 30’, to S. lat: Richelet. HB 1+ 9 1 + 10 Jeeves. Macao, N. lat, 22° 12’, Balfour. — : 4 0) | sh M a Calcutta, i lat. 22° 34/. . Equinoctial Brasil, at} . Dorta. Freycinet Rio Janeiro, §. lat. To a r-3 |+ 9k 4 [+11 | 2.34 | 54’, and the Missions c : of the Coralos Indians, Hamilton. 08 seeesleesaes Peslccecesoeelss sere eeltts +e ee Plain of Kathmandu. Leopold deBuch.|... ..../+ 10-|—4 [+11 | 1.10 |Las Palmos, N, lat 28° Coutelle. —s5 |410 | 5 |+ 104| 1.75 |Cairo, N. lat. 30 3 : Sum. |+ 8} |— 54 Toulouse,N. lat. 43° 34/, Marqué Victor. Win. |4 10 lo |+ {1 | 1.20 | five years. : Ps Sum. |+ 74 [—3 Chamberry, N. lat. 45° Billiet. Win + 10 |~@ secese.| 1-00 34’, 137 toises. : Sum. |48 |~4 |+ 10 Clermont Ferrand, N. Ramond. Win- 49 I~s |4o9 0.94 | lat. 45° 46’, 210 toises. ; Strasburg, N. lat. 45° Herrenschneider|— 5 |+ 84 |~ 34 |+ 93 | 0.80 | 46’, six years. = |. Avago etdoecss es +0, oR Paris, N, lat. 48° 50’, "0.70 | nine years. Nell de BreauttéJ..esol+ 9 [/&S [sce La Chapelle, N. lat. 49° 0.36 | 55’, | Sommer and Bes- bes! Konigsberg, N. lat. 54° © sel. — foeemecess + 83 Qh +4 10 0.20 52, eight years. ; Mr Haidinger on Dimorphism. 301: Art. XXII.—Notice regarding Professor Mitscherlich’s Observations on the Dimorphism of Hydrous Sulphate of Zinc, and Hydrous Sulphate of Magnesia. By Witt1am Harpinerr, Esq. F, R.S. E. Communicated by the Au. thor. Donrxe my stay at Freiberg, I had prepared solutions of sulphate of zinc, and of sulphate of magnesia, to examine and. measure crystals newly obtained of the hydrous salts. "When the solution of the sulphate of zinc was quite concentrated, and the temperature of the stove rather high, on which I had placed the solutions for producing a slow diminution of heat, I likewise obtained crystals. These crystals, however, bore no resemblance to the ordinary ones produced at lower tem- peratures, but their forms belonged to the hemi-prismatic sys- tem, somewhat like borax, and their degrees of transparency were very low. The sulphate of magnesia, which, on ac- count of the isomorphism of maguium and zinc, I examined under the same circumstances, gave the same result. ‘These facts, isolated as they were, I mentioned to Professor Mits- -cherlich while at Edinburgh, in 1824. He found that sul- _ phate of nickel, whose second form, a pyramidal one, had been described before, did not yield a hemi-prismatic species, when exposed in the same manner to a higher temperature, Some time afterwards, when he was examining the changes produ- ced by heat in the double refraction of crystallized bodies, he observed that it remained unaltered in the hydrous sulphate of magnesia, till at once the whole crystal, which was heated in oil, became opaque. On being broken, it showed the struc- ture of a pseudomorphous crystal, consisting of a number of — individuals, beginning at the surface, and meeting in the in- side of the original crystal. Professor Mitscherlich repeated the experiment under various modifications, from which it appeared, that this change always ensued at a temperature of ~ about 42° R. (126° Fahr.) both in the sulphate of magnesia, and the sulphate of zinc. When the crystal is exposed in a glass tube to the heat of the spirit-lamp, its decomposition takes place without the loss of water, except, perhaps, what has been me- \ 302. - Captain Lachlan’s Observations on the dilfsically included between the futnellz' proving ‘that it is essentially the same mixture-which forms both species, whose difference merely depends on the arrangement ‘of their parti- cles: Hence, Mitscherlich infers; that a movement of the particles within a solid body may take place, by which they are otherwise symmetrically arranged, and form a new spe- cies, which, in the above mentioned salts, alone exists above a - temperature of 42° R. (126° Fahr.) Did our temperature never below that, we would not know the ordinary prismatic salts at all, or, at least, they ‘would be as difficultly obtained, as the six-sided low prisms of hydrous ‘chloride of sodium, which but few chemists have had occasion to observe. After the change, no more cleavage 1 is visible, and though the compound mass of crystals is yet coherent, it yields to a gentle pressure, and crumbles into pieces. Changes produced in ‘a somewhat ana- . logous manner, have been observed in several. dimorphous bo- dies. According to Mitscherlich, the sulphur obtained by fusion in hemi-prismatic crystals, is quite transparent, but after a day or two it becomes opaque. It is well known, that Arragonite, ‘when exposed to a higher temperature, ‘will at - once fly into powder, while’ calcareous spar, heated along with it side by side, remains unchanged, and even retains its transparency: It is highly probable, that, in the first im- stance, prismatic sulphur; i in the second, permet rsyecive lime- haloide are formed. é ~ Bern, February 12th 1826. . Arr. X Kei eervations on the Geography of the Bubs rampooter and the Sanpoo Rivers. By Captain R. Lacuvan, | 1th Regiment. Ina Letter to the Epiror. 1 “My Dear Sir, Acczrr of my best thanks for the set of the Sketch Map and printed Extract, descriptive of Lieutenant Burlton’s Re- searches in Assam, regarding the source of the Burrampooter, which I return herewith.* Knowing as you do, that, samen * This Lithographic Map, for Nise I have been indébted to an esteem- ell correspondent. in — is: entitled, FE Sketch’ of the Country partie $ eS ee Geography of the Burrampooter and Sanpoo Rivers. $03 quence of strong doubts raised during a short voyage up the Burrampooter, and confirmed by subsequent diligent inquiries, I had, several years ago, ventured to call jn question the accu- ~ racy of the: generally received geography-of that river, as identified with the Sanpoo of Tibet, and that I had, even the year before last, submitted a Memoir on the subject to the Asiatic Society of London, in which I arrived, by simple reasoning upon all that T had-heard read and seen, at nearly the same conclusion respecting the real source of that river, as ‘Lieutenant Burlton has done from actual. survey and investi- gation near-its fountain head,—you may easily imagine how much gratified I. must feel at) perceiving my hypothesis so generally confirmed ; and I shall of course wait the arrival of further advices from India with much. anxiety and in terest. . . 2 _« As you seem solicitous’ sBioas the fate of’ this great geogta- phical-question, it would have afforded me much pleasure to have had it in my power to give you a perusal of the Memoir alluded to; but, unfortunately, owing to bad health, and be- ing much hurried at the time it was given in, I had not lei- sure to get a second fair copy made of it, and I was even obliged to allow g very rough draft, instead of a fair copy, of a Sketch Map of Assam, &c. constructed to elucidate it, to ‘on the Burrampooter,” and is dated from the Surveyor Geueral’s Officé, Calcutta, June, 1825. It is drawn on a scale of eight British miles to an inch, and represents very distinctly the various anastomosing feed- ers which flow into the Burrampooter near its source. The Booree Dheing river, and several of the streams which fiow into it, and have their origin a little to the south of Brama-khoond, anastomose with one another in a most remarkable manner, so as to flow into the Burrampooter at two ~ places, first near its source about Leddeea, by a branch called New Dheing ~ river, and then, a little above Rungpoor, by the Boree Dheing river. In this way there is formed an island 70 miles long by 30, called Mowama- reeah, in which the.town of Rungagora i is situated. ‘About two years ago, Captain Lachlan explained to me his theory of the origin of the Burrampooter and Sanpoo rivers, in which, contrary to _ the opinions of the best geographers, he maintained that these were two separate rivers. This theory appeared to me so ingenious, and so well- founded, that I had no doubt it would be established by the researches likely to be made during the Burman war. It was, therefore, peculiarly gratifying to me to send to Captain Lachlan’ the above map, which*con- firms the principal point of his. peer —~Epitor. 304 - Capt! Lachlau’s Observations on Wie go in with it, without retaining any copy of that, document - atall. This I regret the more, as a single glance at that “map, and its appended notes, imperfect and conjectural as were most of the materials, and rude as was its construction, would have given you at once # full insight into all the feb: tures of what I call my “ Theory ;” whereas your Sketch, be- ing confined‘ to the upper part of Assam, and, therefore, showing none of the leading feeders of the Burrampooter during its course through that country, can be of little assist- ance, except in nearly exhibiting the real source of the river. I say nearly, because I perceive that neither that map, nor the printed extract, point out expressly the actual ‘situation of the Burrampooter’s sources. This, however, it would ap- pear, had subsequently been established beyond a doubt, as I very lately observed in one of the London néwspapers a pa- ragraph, stating that Lieutenant Burlton had discovered the source of the Burrampooter river to be in a snowy rangé of mountains in lat; 28° N. and Long. 96° 10 E.; 1000) miles distant from [i. e. less remote than] the place tohite it was be- Sore supposed to have had its rise !— ‘As matters have turned out, I cannot help: regretting ‘thes my notes on the subject were not given to the public through the medium of some other channel than the Asiatic Society of London, as, independent of the chance of their never see- ing the light, the delay which has already occurred has alto- gether defeated the principal object I had in view, namely, the hope of their speedily attracting the attention of some of our countrymen on service in Assam, and giving an addition- al spur to their investigations so near the very scene of the disputed geographical question. But, unfortunately, not even the slightest notice of the subject of the Memoir, has ever. found its way into any of the public prints, further than that a Paper connected with the geography of the Burrampoo- ter had been read at the Society’s aerinen This, however, cannot now be helped. ager . That you may have some general idea how far T have | been right in my investigations respecting the Burrampooter’ Wee origin, I have much pleasure in stating, without attempting to go into any of the lengthened details given in the Memoir, ‘ Geography of the Burrampooter and Sanpoo Rivers. 305 that perhaps the whole of my theory may. be described as confined to the four following points. lst, I consider the Burrampooter of Assam and Bengal to be quite distinct froni the river of Tibet, known’ in our maps by the name of Burrampooter and Sanpoo, and to have its rise from Brahmakoond, among the. mountains to the E. N..E. of Assam, nearly in the same situation as laid down by Lieutenant Burlton ;—and that point I have taken the li- berty of marking on your Sketch with a red pencil cross. 2d, I am induced to suppose that Major Rennel was led to mistake for the Sanpoo bending N. towards Tibet, either the northern Assamese branch of the Burrampooter, called the Sebunsirree or Khobunkhirree, or that named the Dhekrung, one or the other of which, or perhaps the Somderree, I am inclined to think, may have -their origin in the great lake Jamdro-palte ; but I consider the Burrampooter to be chiefly indebted for the great magnitude of its channel in Bengal. to the copious supplies it receives from the many consi- derable rivers which pour their waters into it within a very ' short distance of each other on the N. E. frontier of that pro- "vince, assisted by the extraordinary abundance and protract- ed duration of the rains in that quarter ; before being recruit- ed by which the Burrampooter, compared with the Ganges, can be considered little more than a mountain torrent !— 3d, The Sanpoo of. Tibet I consider to be altogether dis- tinct from the Burrampooter, though apparently known to . the Nepalese by the same name, and I suppose it to take a southerly course from Tibet into the Ava territory, some distance to the eastward of the sources of the Burrampooter, and ultimately become the great Burmese river, the Irrawad- dy. While, 4th, I consider the chief source of the Kienduan or minor western arm of the Irrawaddy, to lie among the mountains in the immediate vicinity of Brahmakoond, and to flow from them in a southerly direction under the different appellations of Sanpoo or Shanpoo, Borolooit, Boodalooit, and Burma- looit, until it progressively changes to Kienduan, and falls in- to the Irrawaddy under that name; and that it was this di- versity of name, united with the puzzling mythological ori- * VOL. IV. NO. II, APRIL 1826. a 306 “Prof, Amici on a Property of Light &e. * gins bien saiipinen to rivers by the natives of India, that led _ European geographers to infer the existence of a connection between the Burrampooter and Sanpoo of ‘Tibet, as well as of an anastomosis between the Burrampooter and the Ava river. ' How far all these opinions will stand the test of further ac- tual survey and local investigation, is yet to be determined ; and I cannot reasonably expect a confirmation of the whole ; but enough has already been favourably decided to have proved very gratifying to me, and to have fully repaid ‘me for any little time and trouble devoted to so interesting an in- quiry. I need scarcely add, that I was losis assisted in my in- quiries, while in India, by my worthy and intelligent friend, Mr D. Scott, who has furnished so many interesting and va- . Juable morceaux of research from the N:E. frontier of Bengal. Should you wish for any further details, I shall have great pleasure in furnishing you with them as far as in my power. In the meantime, I trust’ that the readiness with which I make the present communication will be accepted as an ear- nest of the willingness with which I shall attend to’ your fu- ture wishes; being, my Dear Sir, Yours very sincerely, | ; R. Lacuran. Epinzurcu Castie, Feb. 20, 1826. ~ Arr. XXIV.—On a Property of Light, exhibited in the Ea- amination of small Luminous Points by Telescopes. § at PY Prorressor Amici of Modena. Titi property of light, which I propose now to explain, and . which I observed some time ago, enables us to distinguish the dises of the: satellites. of Jupiter, which. have a sensible diame- ter from. those of the fixed stars, whose diameter is mappre- ciable by our eyes. 1a to In observing the stars. with my re cee to whidl, I have ~ * ‘This notice is an abstract of part of Professor Amici’s 1 ee the * Observation of Fupiter’s Satellites in the Diiytime: RE BOP rv Prof, Amici on @ Property of Light, se. 307) adapted a divided object-glass mi¢rometer, I have remarked, when, the magnifying power was sufficient to make the phe. nomenon perceptible, that, if I doubled.the image, by sepa+ rating the semi-lenses, the luminous, dises. became elongated, and assumed an oval form... The small diameter of the ellipse thus formed is equal to the diameter of the. primitive. disc. This elongation always takes place, provided that the tele- scope is well centered in a direction perpendicular. to the section of the lens of the micrometer, and it is for this reason that the distance between two. stars is in uo way diminislied. This elongation takes place only for the fixed stars, whose diameter is inappreciable by the eye, and eyen when the,mag- nifying power is from 100 to 1000 times. With respect to objects of an appreciable diameter, as the planets would be, they are not subject: to this luminous expansion, which alters their form ; or, at least, I have not been able to observe it in them.» I, have noticed several times, that the dises of the satellites of Jupiter, though smaller in appearance than those of the fixed stars, preserve themselves perfectly circular, and have their contours well defined, even when their images are doubled. This furnishes us with an easy criterion for dis- tinguishing between a real disc and an apparent one, and, consequently, for distinguishing, at first sight, a new planet from a fixed star; for, if the planet has not a dise extremely small, if we separate the lenses of the micrometer, this. disc will preserve its form, while the image will lengthen itself, if the star is a fixed one. * In seeking for the cause of this phenomenon, I found that tha; ‘elongation of the images could not arise from any proper- ty of the semi-lenses, because the effect takes placeeven when they are removed, and shows itself with Newtonian telescopes, * Sir William Herschel has published, in the Philosophical Transac- tions for 1805, several experiments, for the purpose of establishing the limits of the visibility of small objects in telescopes. He finds, that the rays reflected by the central portion of the great mirror tend to augment the false discs, while those reflected from the circumference tends to‘dimi- nish them. The different effects, therefore, of the internal and external rays, reflected at the surface of a mirror ten feet in focal length, is a criterion _ for distinguishing a false from a real disc, rere that their aanietes exceeds one-fourth of a second.—Amict. ; 308. Prof. Amici ona Property of Light, &c. when half the aperture is shut up by a semicircle of card, in which case the image resembles that formed by a semi-lens. If ‘the card is turned round, so as always to cover one-half of - the. mirror, the elongation, in the image of the star, will al- ways take place in a direction perpendicular to the line which separates the open from the covered half of the speculum. It is easy to ascertain that this effect does not depend on the aberration of the light in the mirror, since, in this ease, it would take place in the direction of the diameter of the semi- cirele of card, and of the section of the semi-lens. In order to be still farther satisfied that the elongation of the images did not proceed from the aberration of spherici- ty, I placed, at the end of a refracting telescope, a rectan- gular aperture, one of whose sides was quadruple of -the, . other, and I put it symmetrically around the axis of the tube. Had any aberration been sensible, it would have shown it- - self by dilating the discs of the stars in the direction of the greater side of the rectangle ;- but this did not happen. The image of the star was accompanied with two long luminous tails, which, in turning round the card, kept always perpen- dicular to the greatest side of the rectangle. This phenomenon, therefore, appears to me to be caused by the light inflected by the sides of the diaphragm, and this éxplanation is confirmed by another fact, which I have ob- served in using Newtonian telescopes. If, when the telescope is pointed to a star, the eye-glass is brought nearer the mirror than distinct vision requires, we perceive, in the margin of the ‘luminous circle, which has the form of the mirror, a very narrow band of brilliant light, which shows itself even round the shadow of the small mirror, and of the arm which carries it. The same thing takes place, if the eye-glass is drawn out beyond the place of distinct vision. I cannot, therefore, at- tribute this phenomenon to any other cause than the inflec- tion of light by the sides of the small mirror, and its sii and by the mounting of the large mirror. . If we examine attentively the formation of the i image oft a star, while bringing the eye-glass from the point of indistinct to that of distinct vision, we shall see that the false disc of the star proceeds, in a great measure, one, almost entirely, from Observations on Achromatic and Reflecting Telescopes. 309 those luminous bands which I have mentioned. If a method is not found for remedying this defect, it will become an ob-« stacle to the unlimited magnifying power of telescopes, which would be obtained, if we could form mirrors so as to give an ‘image as distinct as the object itself. These telescopes, in- deed, would always err from want of light. Phenomena, analogous to those which I have described, take place also in achromatic telescopes; and the phenome- non of false discs is in this case still more remarkable. The image of a luminous point is now accompanied with a series of concentric rings, * which are easily discovered by bringing the eye-glass alternately within and without the place of dis- tinct vision. The cause of those appearances appears to be the same in the two telescopes, but, in the achromatic ones, there is a certain arrangement which favours the production of these rays. Experience has taught me to form double object- glasses, so that I can make either one ring, or a greater num- ber of rings, appear, by moving the eye-glass on each side of the place of distinct vision. ArT. XXV.—Observations on the Relative Performances of Achromatic and Reflecting Telescopes. By Mr Hexscuet, > Mr Smriru, and Proressor Amici. Havine already had occasion to make our readers acquaint- ed with the improvements which have been made on the con- tinent upon achromatic telescopes, we are glad to have an op- portunity of laying before them an account of the fine achro- matic telescope of M. Lerebours, together with the opinions of three eminent astronomers, respecting the relative per- formances of refracting and reflecting telescopes. ‘The re- marks of Mr South and Mr Herschel were addressed to Pro- fessor Shumacher, and published in his Astronomische Nach- richten, and those of Professor Amici appeared in the Corre= - spondence Astronomique of Baron Zach. The diameter, says Mr South, of the object-glass ‘of the * See page 284 of this Number. | 310: -‘Mr South on thie Relative Performances achromatic telescope, constructed by M. Lerebours, now inthe . Royal Observatory of Paris, is rather better than 9.2 inches English, uncovered by the cell, but of which 8.4 itiches only are/in actual use. Its focal length is eleoen feet. | ‘The magnifying powers with which I used it on the night of — the 15th of March last, are 186, 153, 224, 240, 420, and 560. With all, except 560, (which, by some forgetfulness, was not applied,) Venus was extremely well defined during a dark night ; of course, Jupiter and Saturn were well shown. ‘The two stars of Castor, -of y Leonis, of { Orionis, were exhibited with 240, 420, and 560, as round as possible, # Leonis * pre- serited by its side a light-blue star with 420, which could not. be overlooked by the most careless observer, and with 560 both stars were admirably defined. ( I‘need not inform you, that a telescope, having an object- glass of the diameter above mentioned, which, with these pow- ers, will neatly define the limb of the planet Venus, and will give to the dises of the double stars here named images abso- lutely round, deserves to be well spoken of. Indeed, I have ~ no hesitation in saying, that this telescope is the best achro- matic I ever pointed to the Heavens ; nor will I withhold my regret, or even the mortification I feel in asserting, that Eng- land, when I visited tt in May last, could not produce an achromatic any thing like it. The stand upon which it is mounted is not provided with any means of giving to the tele- _ scope equatorial motion. Whilst, however, I say thus faricks, I am far from enter- taining the sentiments of Mr Fraunhofer, as to the decided stiperiority of refractors over reflectors, nor can T accompany Mr Struve in his idea, that the Dorpat telescope “* may per= haps rank with the most celebrated of all reflecting telescopes, namély, Herschel’s.” It is true, I have not had the enviable — qualification of having seen the former ; still I think the Paris telescope furnishes me with data upon which to form some- - thing like a rational conjecture. _ Its object-glass actually in use ‘is in proportion to- Mr . Struve’s, (ifall of # be effective,) as seventy to ninety-two near- ly, a difference not very hard to be allowed for. - * According to Professor Amici, the two stars. are distant 0”.5.—Ep. of Achromatic and Reflecting Telescopes. $11 I have, see the nebulz in Orion; the planets Jupiter and Saturn, with the Paris telescope; and with their appearances in Mr Herschel’s twenty feet reflector, Lam perfectly fami-~ liar, and the comparison is many times in favour of the latter. _.The power of the twenty feet reflector at Slough is well authenticated; and if the indefatigable astronomer of Dorpat will turn his probably matchless achromatic upon some of the faint nebula in the constellation Virgo, or upon some others, not. easily resolvable into stars, he will soon satisfy himself, that his ideas of its space penetrating power are much over- rated. ‘The star € Bootis was seen “ close double” by Mr Pond at Lisbon, perhaps twenty years ago,* and, as I believe, with a Newtonian reflector of six inches aperture, and the circum-_ stances mentioned in a letter written by him to Dr Wollas- ton, The instrument with which I first observed it, in 1810, « close double,” was a reflector of the worst possible construc- tion, viz., a Gregorian reflector of six inches aperture, and ~ thirty inches focal length, but a very perfect instrument, made for me by Mr Watson in the year 1809, and which i is now in the possession of my friend Mr Perkins.” After speaking of the merits of the telescope of M. Lere- bours, Mr Herschel proceeds as follows: Y My object in writing this, is to obviate an erroneous im- pression, that may arise in the minds of those who read Mr Fraunhofer’s Memoir, as to the great inferiority of reflecting telescopes in point of optical power to achromatics in general, — and more especially to, those constructed with such delicacy as his own doubtless are. Those who have witnessed the performance of .M. Amici’s beautiful Newtonian reflector will not readily admit this inferiority, but will feel disposed to wish that some attempt might be made to accommodate such admirable instruments to the more exact purposes of as- tronomy, an object, which sae to have been too easily lost sight of. “ Mr Fraunhofer’s expressions, when speaking of the loss of light by metallic reflection, are, I think, too strong. He observes, that ‘ the most perfect metallic mirror reflects only * See Scientific Intelligence, Astronomy, § 1—Ep. 312 Mr Herschel on the Relutive Performances a small part of the inoideis light, and that the greater part is absorbed ;’ and that, in consequence, the intensity of the light entering the eye of the observer, is always very small.” _ A metallic mirror, however, reflects 0.673 of the incident light, or more than two-thirds, and absorbs léss than one- third of the whole. M. Fraunhofer appears rather to have in view the Newtonian construction, where ¢zwo metallic mir- rors are used, and where the whole effective quantity of light is only 0.452 of the incident rays. * No one who has been half blinded by the entrance of Sirius, or of « Lyre, mto one of my father’s twenty feet reflectors, will say that the in- tensity of its light is small, nor, to take a less’ extreme case, will any one who uses one of M. Amici’s Newtonian reflee- tors of twelve inches aperture, (a perfectly convenient and manageable size, and of which he has constructed several,) be disposed to complain of its want of light. The ordinary re- flector used by my father in his reviews of the Heavens, was a Newtonian, seven feet focus, and barely six inches in aper- ture; and, consequently, equal, ceteris paribus, to an achro- matic of 4} (4.254) English, or 3.999 Paris mches, and there- fore by no means proper to be put in competition with M. Fraunhofer’s chef @awores of seven and nine inches; yet it will be recollected, that, with this telescope, and with a magnify- ing power of 460, w Leonis was discovered to be double, and distinctly separated, and its angle of position measured. In order to demonstrate the superiority of refracting over reflecting telescopes, M. Fraunhofer has selected the star ¢ Bootis, which my father has described asa double star of the sixth class, (No. 104,) in his second catalogue of double stars, but without mentioning the division of the large star into two, as a double star of the first class. It might, how. ever, be very easily overlooked in a review in indifferent weather. It is, at least, as difficult to resolve-as 7 Corona, more so than ¢, either of which, with any telescope, be its goodness what it may, requires a favourable atmosphere for its separation. From this omission, however, Mr. Fraunhofer concludes, that the power of the telescope was insufficient to ~ * The experiments on which this result is founiled, are detailed in the Article Orrics in the Edinburgh Encyclopedia, yol. xv., p. 625, 626.—Ep. ‘of Achromatic and Reflecting Telescopes. 318 -yesolve it, and must, therefore, have been inferior to that of an achromatic in the hands of Mr Bessel, with which’ it was recognized by that eminent astronomer as double. It will be seen, in reference to the Memoir on double stars by Mr ‘South and myself, that this star had been long since ascer- tained to be double, not only by Mr Bessel, but by Messrs -Struve, Pond, and South, and, what is more to the present ‘purpose, by Sir W. Herschel himself. It was only by over- sight that we omitted to refer, in that work, to his account of it, which is published in his paper “ on the places of 145 new double stars,” in the first Vol. of the T'ransactions of the Astronomical Society, p. 178, and read in June 1821. In large reflectors, in which only one metallic mirror is used, thé disadvantage, in point. of light, under which they labour, in comparison with’ refractors, is, however, much less -formidable... A reflector of eighteen inches aperture would - be equivalent to an achromatic of 15}, and one of 48 ‘inches to an achromatic of 414 in aperture, a size we cannot suppose, (from any thing we have yet seen,) that it is possi- -ble the latter should ever attain. Reflectors of eighteen or twenty inches are perfectly manageable, and, I -apprehend, quite within the power of any good artist to execute, and (if intended only for use, and not at all for show) at no very | ruinous expence.. That which I habitually use, of the for- mer dimension, is my own workmanship, and though inferior in distinctness to the exquisite one used by my father in his sweeps, is by no means an instrument to be despised. In- deed, from the experience I have had of these telescopes, I am satisfied of their applicability, even to the more exact pur- poses of astronomy, and that great improvements in their construction and mechanism remain to be made. Having succeeded in observing the eclipses of Jupiter’s Sa- tellites in the day-time, and in measuring the diameters with one of his Newtonian reflectors, Professor Amici was desi- rous of ascertaining the dimensions of an achromatic telescope, capable of a aeey eens with the same distinct- ness. With this view,” says he, “I took a Newtonian telescope of my own making, having a focal ‘distance of 30 inches, and - 814 Prof, Amici on the Relative Performances an,aperture,of 36 lines, and I compared with it an achroma- tic telescope of the same length, having an English, object- glass of two lenses, 23 inches in diameter. In applying to these instruments two equal eye-glasses, and directing them tothe same object, I saw this object with most brightness ° through the achromatic telescope. In order to be certain of this fact, I constructed a parallelopiped, three inches long, by placing, in opposite directions, two prisms, one of colourless, and the other of obscure glass, such as those which are em- ployed for observing the sun. This apparatus furnished a regular gradation of transparency, by placing it between the - eye of the eye-glass, I could easily find the opacity necessary for intercepting entirely the light of the object which I look- ed at,alternately with each instrument. In order to ayoid all calculation, I diminished by diaphragms the aperture of the brightest telescope, till the light of the object was extinguish- ed in the two apparatuses at the same division of the parallelo- piped. After several trials I found that, in order that the re- Jracior and the reflector should have the ‘same brightness, the first must have an aperture of 27 lines, and the second of 36. | I am’ of opinion, indeed, that this ratio of 3:to 4-ought to be | the same for telescopes of all dimensions, as we cannot take into’ account the slight loss of light arising from the great thickness of the two glasses in these telescopes. “In order, then, to see the satellites as bright as I have seen - them, we require an achromatic telescope of 8} inches in dia- meter, and having a focal distancesuch that ch instrument may magnify 400 times. The great object-glass, therefore, of 7% inches aperture at Naples, will show the satellites less dis- tinctly than mine, while the 9 inch object-glass at Dorpat will show them more distinctly. _ “The result obtained by Sir W. Herschel does not differ from the above. By the method of Bouguer he found that the diameters of a double achromatic, and of a Newtonian reflector, must be as 7 to 10, in order to produce the same brightness with the same magnifying power, or as 5 to 6, if the small Newtonian mirror is not used. Henee, in order ~ that an achromatic telescope may equal his 40 feet reflector, - its object-glass must be 40 English inches in diameter. ¢ of Achromutic and Reflecting Telescopes. “B15 “If reflecting telescopes, for which I have a partiality, have, in general, the advantage over refractors, with respect to the distinctness of the images, magnifying power, and smaller focal distance, they must always yield to the latter on account of the smaller apertures which these require, the facility with which they may be applied to different instruments, and the immutability of the substance of their lenses, which render comparable observations made at distant epochs, and partly for the convenience of using them, arising from this, that the object-glass preserves always the well-centered position which the artist has given it. This last quality is so much valued by some observers, that they do not hesitate to Pryce a mo- derate achromatic telescope to a good Newtonian one.” We shall now present, in a small table, the relative perfor- mances of achromatic telescopes, with double object-glasses, _ and Newtonian reflectors, according to Sir W. Herschel, Mr Herschel, and Professor Asnici. . | Ratio of diameters when the per- formance is equal. Achromatic. — Reflector. i. When the reflectors have a small Sir W mirror, - 7 to 10 Herich al 2. When the small mirror is ee used, 8t to 10 $ 3. When the reflectors have a small eo 36 Mr _mirror, - - 7i's Herschel. 4. When the reflector has a small 34 mirror, ~ - Oe kee 40 } Prof. Amici. The following table shows the diameter of an achromatic object-glass that would perform as well as Sir William Her- schel’s great forty feet telescope, whose mirror was four feet in diameter. Achromatic Telescope. Reflecting Telescope. — Diameter. : Diameter. 40 inches: 48 inches Prof. Amici. 413 te AS Mr Herschel. ‘B16 Farther Observations on Levyne. “Abr, XXVIA Farther Observations on ae a Neti Mi- © neral Species. By the Eprror. M. Brocnrart has lately published, in the Annales de Sciences Naturelles, an extract of a letter from M. Berzelius, dated Stoekholm, March 15th 1825, which contains the fol- — lowing passage: ‘*‘ The Levyne sent me by Dr Brewsteris ab- solutely nothing more than chabasie, in which a portion of the lime is. replaced by soda.” As this passage, from which the general reader would infer that Levyne was not a new miineral species, has appeared in most of the Foreign Journals, itn 4 necessary to correct the mistake upon which it is founded. In June 1824, after I had determined Levyne to be anew mineral, and given it that name in compliment to Mr Levy,* ‘I sent a specimen of it, along with various others minerals, to M. Berzelius. In the list which’I retained of these minerals, T have marked this specimen Levyne and accompanying cha- basie. Mr Haidinger, who happened to be .in Stockholm in August last, wrote me that Berzelius had, by some mistake, applied the name of Levyne to chabasie, which, as he remark- ed, would produce great confusion. This mistake surprised — me very much ; but the origin of it became apparent from the — following passage of a letter which I received from M. Ber- — . zelius himself, of the date of 13th September 1825. “ Among the minerals which you sent me, I found, among others, Brewsterite and Levyne. The first of these has al. ready been analyzed by M. Retzius, who had distinguished it asa particular species, under the name of prehnitiform stilbite, and who had found it sey nies according to the fol- _ lowing formula : . oy} 4+ 44S + 84g. With respect to Lecyne, I have myself analyzed it, and I “_ : found it to be composed according to the formula of chabasie, — with this single difference, that it contains, at the same time, — lime, soda, and potash. But Mr Haidinger, who has seen’ “See this Journal, vol. ii. p. 332, where I have stated, that I sent a Jeet ‘ cimen, containing afew minute crystals, to M. Berzelius. i: Mr Murray on the T'orpidity of the. Tortoise, Sc. B17 the specimen from which I took the part. analyzed, insists that it is not the true Levyne.. It is, however, the specimen which you sent me under that name.” It is quite obvious from this passage, that M. Berzelius has analyzed the chabasie, which accompanied the Levyne, and probably along with it the Levyne itself. The Levyne occur- red only in a small cavity of the specimen, and as this cavity, with the crystals which it contained, could not have existed in the specimen when examined by Mr Haidinger, who was perfectly familiar with the aspect of Levyne, it appears to me quite certain, that M. Berzelius has analyzed a substance containing crystals both of Levyne and chabasie. Had he analyzed the chabasie alone, which was more abundant in the specimen than the Levyne, then the Levyne would have remain- ed. This opinion is confirmed by the fact, that the result of the analysis is different both from that of the ordinary chabasie, and of the chabasie from the Giant’s Causeway, the last of which I have determined optically to be a new mineral species. If M. Berzelius analyzed the chabasie only, then there will ° be a. third chabasie, possessing the properties which he as- cribes to Levyue. ; In another passage of his letter to M. Brogniart, M. Ber-. zelius adds, ‘‘ The Mesole which I analyzed, and named somewhere in Dr Brewster’s Journal, is in the same predica- ment. It is merely a chabasie, rich in soda.” ‘According to our notions of mineralogical chemistry, both the mesole and the substances analyzed for Levyne are entitled to the dignity of separate species; but it would appear from the above quo- tations, that M. Berzelius regards them merely as varieties of chabasie. ’ ; Ant. XXVIL.—On the Torpidity of the Tortoise and Dor- mouse. By Joun Murray, Esq. F.S. A. F.L.S., &c. &e: Iw alittle volume just published, Mr Murray has put together under thetitleof Experimental Researches, a few papers written by him atvarious periods, on interesting subjectsin Natural His- tory. They are sixin number, viz. ‘*Onthe Lightand Luminous 318 Mr Murray on the Torpidity 9) >|. Matter of the Glow-W orm,—on the Luminosity of the Sea,—oni) the Phenomena of the Chameleon;—on the Ascent of the Spi-) der into the Atmosphere,—and on Torpidity; as connected: — with the Testudo Greca, or Common Tortoise,” &c.. From the last of these we extract, with the’ author’s permission, his: _ observations on the Torpidity of the Tortoise and Dormouse;, referring to the book itself for the previous details, and much curious information on the subjects of the different essays.. The tortoise may be occasionally met with in gardens in: this country. The T'estwdo geometrica I have certainly seen’ ‘here; but the occurrence is rare. One of three tortoises (the: common,) laid three eggs in a garden at Montrose—one of — these I forwarded to Professor Jameson, of Edinburgh. The — size to which this creature occasionally attains is quite mon~ strous. I remember, some years ago, to have seen one, then semi-torpid, exhibited near Exeter *Change, London, which weighed, if I recollect aright, several hundred weight. Its shell was proportionally thick, and its other dimensions bore a corresponding ratio. It was stated to be about 800 years old. In the library at Lambeth Palace is the shell of a land — tortoise, brought there about the year 16285 it lived until — 1730, and was killed by the inclemency of the weather'during — a frost, iri consequence of the carelessness of a labourer in the — garden, who, for a trifting wager, dug it up from its winter — retreat, and neglected to replace it. Another tortoise was — placed in the garden of the Episcopal Palace at Fulham, by q Bishop Laud, when Bishop of that See, im 1628: this appears — to have died a natural death in 1753. Tt°is not known what — . were their several ages when placed in the gardens. _ Phat of which I am about to give an account, I saw in the Bishop’s garden at Peterborough, adjoining the Cathedral, in the sum- — mer of 181. It died only four or five years-ago. — Why this — ; Episcopal predilection is a question perhaps not unw - tiquarian research! The Testudo greeca is found in th of Sardinia—generally weighing four pounds, and i nal coLasaitge age is about sixty years.) 99) 10 yi sald ral. » From a document’ belonging to the archives of the Cathet dial, called the Bishop's siiteiah it is well salami that th , of the Tortoise and Dormonse. 319 tortoise at Peterborough must have beén about 200 years old: ~ Bishop Marsh’s prededeitor in the See of Peterborough had remembered it above sixty years, and could recognize no visi- ble change. He was the seventh Bishop who had worn the mitre during its sojourn there. If I mistake not, its susten- ance and abode were provided for im this document. “Its shell was perforated, in order to attach it to a tree, &c. to limit its ravages among the strawberry borders. ~ The anima! had its antipathies and predilections. Tt would eat endive, green pease, and even the leek—while it positively rejected aspatagus, parsley, and spinage. In the early part of the season, its favourite pabulum were the flowers of the dan- delion (Leontodon taraxacum,) of which it would devour twen- ty ata meal ; and lettuce (Lactuca sativa,) of the latter a good sized one at a time, but if placed between lettuce and the flowers of the dandelion, it would forsake the former for the latter. It was also partial to the pulp of an orange, which it sucked greedily. About the latter end of June, (discerning the times and the seasons,) it looked out for fruit, when its former choice was forsaken. It ate currants, raspberries, pears, apples, peaches, nectarines, &c., the riper the better, but would not taste cher- ries. Of fruits, however, the strawberry and gooseberry were the most esteemed; it made great havoc among the straw- berry borders, and would take a pint of gooseberries at inter- vals. The gardener told me it knew him well—the hand that generally fed it—and would watch him attentively at the _ gooseberry bush, where it was sure to cia its station while he plucked the fruit. TI could not get it to take the root of the’ dandelion, nor in- . deed any root I offered it—as that of the carrot, turnip, &c. All animal food was discarded, nor would it take any liquid ; ‘at least neither milk nor water ; and when a leaf was moist, it would shake it to expel the adhering wet. © This animal moved with apparent ease, though pressed by -aweight of 18 stones; itself weighed 131 Ibs. In cloudy weather, it would scoop out a cavity, generally i in a southern exposure, where it reposed, torpid and inactive, until thé ge- nial influence of the sum roused it from its slumber. ~ When 320 Mr Murray on the Torpidity in this state the eyes were closed, and the head and neck a little contracted, though not drawn within the shell. | Its sense of smelling was so acute, that it was roused from its lethargy if any person approached even at a distance of twelve feet. About the beginning of October, (or latter end of Septem- ber,) it began to immure itself, and had for that purpose for many years selected a particular angle of the garden > it en- tered in an inclined plane, excavating the earth in the manner of the mole; the depth to which it penetrated varied with the character of the approaching season, being from one to two feet, according as the winter was mild-or severe. It may be added, that for nearly a month prior to, this entry into its dor- mitory, it refused all sustenance whatever. ©The ‘animal ~ emerged about the end of April, and remained for at least a ‘fortnight before it ventured on taking any species of food. ‘Its skin was not perceptibly cold:* its respiration, entirely effected through the nostrils, was languid. I visited the ani- mal, for the last time, on the 9th June 1813, during a thun- der-storm ; it then lay under the shelter of a cauliflower, and apparently torpid. It is very singular that the lettuce and decane should find such predilections with the tortoise. The lactescent juice of the former, from the opium it contains, is powerfully narcotic, and I have found that the extract. taraxici, applied to the sciatic nerves of a frog, acted in a similar manner to opium, by suspending voltaic excitement. It is also remarkable that’ - these should have been rejected when the fruit season com- menced, and the strawberry and gooseberry take precedence. Its antipathy to cherries is equally curious, and not less so its aversion to fluids; in which last, however, we Hane an ae gy in the alpaca, &c. On the whole, that narcotics or sedatives should take vie: cedence, of all other kinds of food, in the former part of the — season, and those that act a different part, in the animal eco- nomy, toward the autumn, is certainly surprising. vt Se ee * Dr Davy took the temperature of the Testudo geometrica at Cape Town, in May—air 61° ; the animal 62°.5. At Columbo, in Ceylon, on : singly E the temperature of a larger specimen was 87°, while the air was 80°.) 11 oe ; oF the Tortoise and Dormouse. B21 As a) proper sequel to the preceding, I may add my re- mane on Hod ‘ingueti> rob? The Temperature of the Skin of the Dormouse. . Inthe beginning of 1824, I received two dormice from a friend in Derbyshire, and commenced a ceries of experiments on the temperature developed by the skin. One of these I accidentally Jost, it having escaped from confinement; and I was shortly necessitated, from various avocations, to resign the prosecution of my researches ‘with the other. The fol- lowing is a note of the temperatures as recorded : — j Sist January 1824, Chesterfield, Derbyshire, at 25 minutes past 7, P. Ms; air of the room, 48° Fahrenheit ; temperature of the. dormice under the breast, 103° Fahrenheit. I soon after lost one of my prisoners. At Hull, Yorkshire, 14th February, at half-past 8, r. mM. ; air 51° Fah- renheit ; temperature under the breast, 62°.5 Fahrenheit. The animal semi-torpid. ) tit Air. Under breast. Feb. 15, At Lh,l5 min. p.m. 46° 104° — — — 8h. 30min. pew. 47°.5 69° Semi-torpid. — — — $h.30 min. p.m. 52° 102°.5 — 19, — 2h. Bs ii $62 99° — 21, — 10h. 30 min. p.m. 54°.5 102° — 22, — 12h. Sais P.M. 57° 97° On the 14th and 15th of February, the dormouse was rous- ed from its apparent death by heat, cautiously applied. ‘The box which contained the dormice had a partition. One compartment contained fresh moss, well dried, in which the animals reposed during. day, having formed for themselves a somewhat elliptical nidus. Two openings, with: slides, con- ducted. into the outer court, where the dormice had their food . prepared for them, consisting of wheaten bread, (sometimes softened with water,) and a basin of milk. Great attention and care were bestowed on them, and the food daily supplied. The sliding pannels were shut when the compartments were cleaned, it being easy to expel them from the one to the —_ and thus prevent their escape. : _ Though their cage was a caly 3 in darkness pte the day, the night season was the exclusive period in which they VOL. Iv. No. 11, APRIL 1826. x 322 Mr Murray on the Torpidity of the Tortoise, &c. took food. One of them had a singular expedient when the — liquid was too low in the basin. It:dipped its brushy tail (somewhat resembling that of a fox,) into the dish, and car- ried the milk in this manner to its mouth, _When the dor- mice are torpid, they may be tossed up into the air like a ball, (they are rolled up like one,) without discovering any index of motion or change.» By keeping the dormouse in a proper temperature during the winter, its brumal torpidity may be entirely prevented ; but in this case it will not outlive the fol- lowing year. The dormouse is fat and in good condition when it enters into torpidity, and. it issues from this state mi+ serably lean. My dormice were'extremely timid, yet they may be so tamed as to run about the table and lick the hand that feeds them. As to their sense of hearing, I found them pe- culiarly affected by the higher notes, or shrill tones. The eyes were like those of albinos, and injured by strong light and exposure to day. Dr Davy gives us the following details of temperature, which approach that of the dormouse, as stated :-— | Air. _ Animal, Columbo, Ceylon, 19th Oct. Squirrel, 81° 102° 8th Feb. Common Rat, 80° 4022" 16th June. Common Hare, 80° 100° 4th Nov. Ichneumon, 81° 1989; 26th Feb. Jungle Cat, 80° 99° Dr Davy, I think, justly infers that the temperature of the human species increases in passing from acold, or even a tem- perate climate, into one that is-warm ; and I think, too, that I am warranted, from my own immediate observations and ex- periments on myself, to add, that the temperature of man — rises with increase of elevation. On the summit of the Sump-- lon, with the ball of the instrument below the tongue, the temperature was 100°.5 ; on Mount Cenis, 101° ; and’on the Great St Bernard, 102° nearly. The temperature of animals will, no doubt, be modified by, or have some determinate re- lation to peculiarities in physiological character. = : ads, (a0 =e Prof. Hansteen on the Intensity of Magnetism, &c. 323 Ant, XXVIII.—Observations on the Intensity of Magnetism in different parts of the Earth's 8 Surfice. By CuristTIaANn HawsrEen, Professor of Astronomy in the University of Norway. * Proressor Hansteen of Christiana, to whose discoveries and writings we owe so much of our present information respect+ ing the magnetism of the earth, has been so kind as to trans- ~ mit to us the results of his most recent experiments upon this subject, and also a'corrected and more complete copy of his chart of the magnetic lines. In order to determine the intensity of magnetism at differ- ent places, and consequently the direction of what he calls the isodynamical magnetic lines, or the magnetic lines of equal intensity, he had a magnetic needle of a cylindrical form, constructed with great care. This needle he entrusted to various philosophers, who counted the time in which three hundred horizontal oscillations were performed, in various parts of Norway, Sweden, Denmark, Prussia, Holland, France, England, and Scotland. The greater number of these were made by Professor Hansteen himself, many of them by M. Naumann, several by M. Erichsen, and a con- siderable number by Professor Oersted of Copenhagen, when he was travelling in England in 1823. Those which were made by this last philosopher in Edinburgh on the 4th July, » and at which we had the pleasure of assisting, were perform- -ed in the field behind Coates Crescent, and nearly at the i in- tersection of Walker Street and Melville Street. 'Fhese pos- sess considerable interest, as being the most westerly of all that have yet. been made. The following table contains the result of these observa- tions, the first and second columns containing the latitude of the place of observation, and its longitude from Ferroe ; and the third the number of seconds in which 300 oscillations are per- formed by the suspended needle. | 324 Prof. Hansteen on the Intensity of Magnetism | Long. | Time of 4 PLACES. ., Lat. | from |300 Oscile | . | PLACES. . ; Ferro. | lations. Berlin - = » 52° 32'131° 2'| 7607.03 Norstebée. = ~—‘|60° 20’ Paris = - 48 50\20 0} 753.03 Holmekjirn -- |60 _ London - - - (51 31/17 34] 775.34 | Maursiter .- |60 — Edinburgh - - |55 58|l4 29} 820.26 | Hifjord - Liverpool - - |53 22\l4 43] 801.6 Ullensvang. - {60 Oxford -- = |5L 46/16 24] 779.8 Johnnas-'T'angen Christiansand: - 58°. 8/26 43] 820.3 Gjermundshafen {60 “Mandal « 58 1/25 9| 814.3 Kaarevigen . = |59 ‘Tjos = « $16.3 Findaas = 59 = Carlscrona = 156 7/33 18] 785.3 Siggens - Ystad - - |55. 26|31 28) 779.3 ite so) be Szrim ‘152 7/384 48) 748.1 Folgerée - 59 Glogau - 51 43/383 36} 748.8 Kingesund =~ 159 Carolath = 51 46/33 37) 752.7 Bekkervig = 189 Zelgos = = |53_ 11/82. 48] 759.7 Bratholmen + _ |60 Danzig ~~ ~ {54 21|36 18] 770.4 Bergen - Marienburg = |54 2/36 42] 766.0 °* Fort Friedrichs- Goslina - 52 34/34 43) 759.7 | berg ...-, |60 Aiistrin - 52 35|32 40] 762.4 * Friedrichsber Christiana =) |59 | 55/28 25) 814.76 Lunggaards. Friedrichshall, 1819159 8/29 4} 821.7 * Lyderhoru, 1255 1822 830.3 feet - Quistrum 1819/58 27/29 25| 816.1 * Lévstakken,1524 1820 815.4 feet - Hede_ - 57 658/29 48| 810.8 * | Haugs - 60 Gotherniung isi9|57° 42\29 38) 812.2 * | Bolstadéren = {60 , 18207 812.1 Evanger - 60 Quibille te 56 47|30 30} 791.6 * | Vossevangen-- {60 Helsingburg ‘ 1820|56 3/30 23] 791.1 * | Tvinde - 60 1820) 790.0 * | Staleim ~~ (60 Helfingéer © 1820/56 2\80 18} 789-8 * | Leirdalséren - |61 1820 | 784.6 * | Leirdals - 61 Copenhagen. - |55 41/30 15] 788.08 Maristuen - (61 Friedrichsburg _ |55\. 56/29. 58] 785.9 Nyestuenh, -, {61, Sorée | 1820|55 27/29 14) 790-6 Vangs. = 1822) | | 790-4 Slidre - 61 Skieberg. - [59 14/28 51] 826.7 Tumlevold.. | - Kongsberg 1820/59 40|27 20] 845.4 Grans - 1821 f , 839.3 Moe - ‘60 $45.1 Sundvold - 837.8 Johnsrud - 1821 859.5 Hurdal - Bolkesjé: >= 59 43/27 0} 834.9 Trégstad - i Vik. “Ree 836.8 Sunbye - 1822|5: Tindosen / 834.6 Sooner = 5 Oernis, | +5 | ri 829.1 Ingolfsland - |59 53/26 28] 833.4 Boe - A 45 Miland - ~ 59 56/26 36) 833.4 Altorp - Tind «*¢..) 160 50 835.7 pe rote Midbéen = - 836.8 Elleéen =. Régsland _- 838.0 Godtskjir = in different parts of the Earth's Surface. | Long. | ‘Time of PLACES. ~ | Lat. from |300 Oscil- PLACE. Lat. ' Ferro. | lations. Corset - 58° 49'127° 19/1 824”.5 || Vigér - P18" Helgerane - |58 59/27 34) 822.7 || Bergen . = 0 stubberud - |59 4/27 55] 818.9 oy WER - Solerud - 59 21/28 9] 826.5 Fldifjeldet - Konnerud-Kollen Lévstakken = 1823 875.5 Friedrichsberg Auestad - (59 4927 33] 852.1 | Lindos - — |60 ragernas - |59 49/27 53) 848.6 Evenvig - 60 vnsborg - |59 52 17| 820.5 “|| Yttre-Sulen - [61 riedrichsvarn Stensund - (61 1s2dls9 ole7 44] 813.5. || Pollefjeld .- riedrichshavn 57 27/28 13] 808.1 Askevold = 1 alborg - 57° 3/27 36) 806.0 Vilnas - - (61 Sporring = = 799.9 Sougesund - (61 huns - 56 10)27 54] 796.0 Alden - 61 dvedkrug = & 798.3 Bneland - 61 eile = »,/65> 43127, 12] -793.9 Sveen - penrade - |55. 8/97 6] 786.4 Quamshest ~*~ au - ‘| 787.9 Forde - Julij6l chleswig - \|54 31\j@7 15) 783.0 ~ Aug. | 785.5 || Jdlster . - {61 emmels - [54 7/27 18] 783.0 Gloppen - 61 Imshorn - |53 46]27 > 18] 779.1 Indvig - 61 ltona - |53 33\@7 33} 776.1 Horningdal - (61 774.9 Hilsylta - 62 erln ~- 52> 32|31 2} 760.4 Nordal - 62 759.9 - || Veblungsnés - |62 Liibeck - 53 51/28 Q1]| 776.2 Fladmark . Pléen - 54 9/28 — 6} 780.5 Nyestuen’ = = Preetz - 54 13)@7 57) 779.0 Fogstuen - 62 Kolding - 55 27/27. 0} 789.1 Jerkin - 62 Odense - 55 24/27 59) 793.7 Foldal - 62 Buskerud. 845.5 Kongsvold - |62 Johnsknuden - 961.3 Drivstuen - (62 Skrimfjeld - 891.3 Riise - 62 Rolloug - 59 59/27 5} 844.0 Synhovedet = ¢ 846.3 Niiverdal - — |62 Eje - 60 6/26 53| 838.5 || Stda_ - 62 Ejesfjeld ‘ 831.2 Géra - 62 Daglio - . {60 18/26 26) 837.4 Tofte < - 61 Torpe - 60 40/26 47) 841.5 Vauge - 61 Haavi - Junijlél 7/26 42} 851.2 | Vinje - 60 Sept. 850.4 Nyestuen “=~ 161 Urland - 61 0/24 55) 849.2 Skougstad - {61 Voss ~ Junijé0 38/24 10| 856.5 Smedshammer - |60 . Sept. 845.9 Sundvold - |60 Age-Nuten = - 842.7 ; > 326 Prof.,Hlansteenion the Intensity of Magnetism The following aiditonal observations have been sent us ay Professor Hansteen : Carlscrona, - -- - - 735 Breslau, _ . o- - - » TAL Stockholm, < - - -" 815 Hernosand, ae - 850 These various results have been laid down on a map by Professor Hansteen ; but, as they occupy only a small part of Europe, we do not think it necessary to copy his chart: Any - of our readers, however, may easily lay down, upon a map of Europe, the lines of equal magnetic intensity, either from the above tables, or more simply by the following directions: - 1. The line of '750, or the line in which '750 seconds are required for the performance of 300 oscillations, passes one-— fourth of a degree to the south of Paris and Rheims, and one-third of a degree to the south of Gotha and Gaslin. * ‘2. The line of '7'75 passes about one-third of a degree south of London, and through Amsterdam and Lubeck. 3. The line of 800 passes about the fifth of a degree north of York, Sporrmg in Jutland, and Falkenberg in Sweden. 4. The line of 820 passes through Edinburgh, and a little to the south of Christiansand in Norway, and Carlstadt in Sweden. — _ 5. The line of 865 passes through Hirdal in Norway. _ - As the lines are almost equidistant, and nearly cane all the intermediate ones may be readily inserted. Professor Hansteen has added the following very interest- ing table, containing the observed dip of the needle, and the — i 4 computed magnetic intensity in various parts of the world, that of the equator being unity or 1.0000. A siinilar table _ was, printed in Professor Hansteen’s paper, in Poggendorff’s Y * Annalen der Physik, but the column of intensity had been wrong computed for all the places in the north of Europe, and we are happy to be able, through Professor Hansteen’s kindness, to. present our readers.with a corrected copy. * The line of 740, of which ngs one point has been determined, passes - through Breslau: s in different parts of the Earth's Surfiwe. 827 Praces or Onservations. | Dip. rr PLACES or OnsERvATIONS.| Dip. Inten- South. Port du Nord - - |75° 50/|1.5773 || St Gotthardt - - 166° 22/\1.81388 Port du Sud “ = 70 48 }1.6188 sath Cenis - - 66 22 |1.3441 Surrobaya in Java = - 25 40 {0.9348 | Urse - = - 66 42 |1.3069 Ambonma + + = {20 87 |0.9532 Altorf - 66 53 |1.3228 > ohn i lai a 9 59 |1.0773 | Atlantic ) 37° 14’ n. 8° 80'0"l67 30 {1.3155 Magnetic Equator in Pera | 0. 0 {10000} Sea {38 52—3 40 |67 40 |1.9155 ; | ' North, il aX - . |67 41 |1.2938 Tompenda = = - 8 11 {1.0191 | Tiibin - eo: 4 |1.3569 ioxa + “ « | 5 24 {1.0095 } Atlantic ‘Sea38°5e'n.3° 40/0". 11 {1.3155 Cuenca. - - 8 43 |1.0286 | Ferrol - - me 82 |1.2617 Quito - - 18 22 |1.0675 | Paris - - . {69 12 |1.3482 St Antonio - - 14 25 {1.0871 | Gottingen . * - 169 29 |1.3485 St Carlos - - |20. 47 {1.0480 || Berlin - -, 169 53 |1.3703 Popayan = - 20 «53 |1-1170 | Carolath - - = |68. 21 |1.3509 Santa Fede Bogata - |24 16 j1-1473 | Berlin = - - - {68 50 |1.3533 Javita - = 4 19 {1.0675 | Danzig — - = - |69 44 |1.3737 Esmeralda - - 58 |1.0577 || London - - - |69 57 |1.3697 Carichana ‘= - 30 24 {1.1575 | Ystad - = 70 13 |1.3742 St Thomas - - {85 61-1070} Schleswig - - = |70 36 1.3814 Carthagena - - |85 16 |!-2938°} Copenhagen - = {70° 36 |1.3672 Cumana - - |39 47 |1.1779 |) Odense - - - |70 50 |1.3650 Mexico - - 42 10 |1.3155 || Helsinburgh - - |70 52 |1.3782 ’ Atlantic Sea ' |) Kolding = - - |70 53 |1.3846 B. 20°46’ n.L.41°.26'w. F.|41 46 |1-1779 || Sorde - - - |70 57 |1.3842 —11 0-—44 32 — |41 57 |1-2617 || Friedrichsburg - - |70 59 |1.4028 — 1234 -—33 14— |45 8 [1.2300] Aarhous - = = [71 13 |1.3838 — 1420 -—28 3 — |52 55 |1-2830 | Aalborg - - - {71 27 |1.3660 —20 8-— 8 34 — [56 42 |1-2510 | Odensala - - - |71 39 |1.3666 — 2136 -— 5 39 — |47 49 |1-2617 || Friedrichshaven - - |71 48 |1.3842 —2515 -— 0 36 — |60 18 |1-2830 || Gothenburg - -|71, 58 |1.3826° Portici = - il 0 5 |1.2883 | Altorp | - - «= 72 14 |1.3891 Neapel Pa - 61 35 |1.2745 | Korset ~ - |72 24 |1.3735 Rome - - 61 57 |!.2642 |) Quistrum - 72 27 \1.4070 Vesuv. Crater - = 62 0 {1.1933 || Skieberg = - 72 29 |1.3725 St Cruz, Teneriffe ° 62 .25 |1.2723 || Elleden - * - |72 38 |1.3340 Valencia - - 63 38 |1.2405 || Helgeroae - - |72 39 |1.3980 Florence - 3 §1 |1-2782 | Soner = + - - |72 41 |1.3835 Atlantic Sea, 32° ww n. 2° Christiana - - 72 34 (1.4195 b2 we * = - |64 21 |1.2938 Ryenberg - - |72 465 |1.4208 Barcellona = - 64 37 |1.3482 Bogstad - = 72 34 |1.4378 Marseille - i 65 10 }1.2938 Bogstadberg - - |73 13 |1.4195 Nimes - 5 23 }1.2938 Nasoden = - |73 @ [1.4517 Mailand - - |65 40 {1.3121 | Barum - - 72 44 [1.3902 Montpellier = - [65 53 |1-3482 | Bolkesjoe - -. |73 15 |1.4053 Airola - - 65 55 \1.3090 || Ingolfsland - - |73 19 |1.4159 Turin = - - 66 3 {1.3364 | Norstebde - 73 - 33 1.4136 Medina del Cainpo - = |66 9 |1.2938 || Drammen ~ = |73 37 |1.3771 Lans le Bourg Mont Genie 66 9 |1.3227 | Maursiter -* 73° 44 11.4656 Como - 66 12 {1.3104 || Ullensvang - - 173 44 |1.4260 St Michel - c 6 12 |1.3488 || Gran = - -|73 45 |1.4221 Lyon - ~ «= \66 14 {1.33384 |} Kongsberg - =/t3 47 \1.4144 828 Mrs Somerville on the Magnetizing Power PLACEs or OpsEervarrons. |. Dip. 9h PLAcEs oF Osservations.} Dip. Tomlevold - - |73° 50'|1.4246 Davis Straits 68° |73 58 [1.4114 10’ w. 83° 8y/1.6 Vang if) Ga 04)". 8 . |73 9 /1.4808 | Hare Island 70° 26" n. 37° Bergen a aoe es 74° 3 11.4220 12’ w. - 82 49 ‘Moe ~' ~ - |74 8 |1.4254 75° 8 n. 42° 43'wl84 25 Maristuen - - - |74° 4 11.4058 Baffin’ 15 61 —45 26 —|84 44} Leierdal «2s fra 6 [1.4190 | PEEPS \76 45 —58 20 —[86 9 Slidre SAU ae ee a ro ae) | 76 8—60 41—(86 0 Brassa = - - |74 QI |L.4471 J 70 35 —49 15 —184 39 The following table shows the dew of variation from. the Equator to the Pole. M sgiesé Dip. 0° ‘ Magnetic Intensity. 2 1.0 1.1 1.2 1,3. 1.4 1.5 1.6 1.7 Arr, XXIX.—On the Magnetising Power of the more re- Srangible rays of Light. By es Mary SomeErvILe. We are delighted in having this opportunity of making our readers acquainted with the beautiful experiments on the ville. -magnetising property of the violet ray, which have been re- cently made by our accomplished countrywoman, Mrs Somer- vite 'This' subject has been long one of deep interest to the sci- ‘entific world, but it has unfortunately been involved in a de-_ : gree of uncertainty, which is seldom attached to a point of mgt experimental inquiry. Dr Morichini, a respectable epee dP in Rome,-discovered this remarkable property of the violet ray. s His expériments ~ were successfully repeated by Dr Carpi of Rome, and the Marquis Cosimo Ridolfi at Florence ; but as M. Dhombre Firmas, who resides at Alais, and Professor Configliachi of Pa- of the more refrangible rays of Light. $29 via, had both failed in obtaining any magnetic effect from vio- let light, and as M. Berard, a most skilful experimenter, had observed only casual indications of magnetism, the discovery of’ Morichini was brought into considerable pc age both in France and England. Fortunately, however, for the reputation of the Italian physician, his experiments were performed both before Sir Humphry Davy, and Professor Playfair,—before the former in 1814, and before the latter in 1817. Sir Humphry Davy, whom we had the pleasure of meeting at Geneva in 1814, on his return from Italy, mentioned to us that he had paid the most diligent attention to one of Morichini’s experiments, and - that he saw with his own eyes an unmagnetised needle render- ed distinctly magnetic by violet light. When Professor Playfair was at Rome, he saw the experi- ment performed by Dr Carpi, in the absence of Morichini, before a party of English and Italian gentlemen. ‘The fol- lowing account of the experiment was drawn up from a con- versation which the writer of this notice had with that dis- tinguished philosepher, and was afterwards copper to him for his approbation. ** The violet light was’ obtained in the usual manner, by means of a common prism, and was collected into a focus by a lens of a sufficient size. The needle was made of soft wire, and was found, upon trial, to possess neither polarity nor any power of attracting iron filings. It was fixed horizontally upon a support, by means of wax, and in such a direction as to cut the magnetic meridian at right angles.. The focus of violet rays was carried slowly along the needle, proceeding from the centre towards one of the extremities, care being taken never to go back in the same_ direction, and never to touch the other half of the.needle. At the end of half an hour, after the needle was exposed to the action of the violet rays, it was carefully examined, and it had acquired neither polarity, nor any force of attraction ; but after continuing the operation twenty-five minutes longer, when it was taken off and placed on its point, it traversed with great alacrity, and settled i in the direction of the magnetical meridian, with the end over which the rays had passed turned towards the north. > + 830 Mrs Somerville on the Magnetizing Power It also attracted and suspended a fringe of iron filings, The extremity of the needle that was exposed to the action of the © violet rays, repelled the north pole of a compass needle. This effect was so distinctly marked, as to leave no doubt in the minds of any who were present, that the needle had received its magnetism from the action of the violet rays,” Such was the state of this subject when Mrs Somerville di- rected to it her attention; and it is no slight praise to say, that she has set to rest a question on which the scientific world was divided, and that by the sagacity and ingenuity with which she has conducted her experiments, she has rendered visible, even in our northern climate, one of the most delicate of the mag- netic influences, which, it was agreed on all hands, required for its developement the serene sky of an Italian climate, The following is a general outline of these interesting ex- periments. Having obtained the prismatic spectrum by means of an equiangular prism of flint glass placed in a hole in the window- __ shutter, Mrs Somervillé took a sewing needle, about an inch - long, and entirely devoid of magnetism.* Conceiving that no polarity would be superinduced if the whole needle were exposed to its action, she covered one half of it with paper, and exposed the other half to the violet rays of the spectrum cast upon a pannel at the distance of five feet. In about two hours, the needle had acquired magnetism, the exposed end ex- hibiting north polarity. 'This experiment was often repeated, and always with the same result. By a similar process, Mrs Somerville ascertained that the indigo rays had nearly as great an effect as the violet, and ~ that the blue and green rays likewise die the same ef- fect, though in a less degree. Mrs Somerville next tried the yellow, orange, and red rays, but neither in them nor in the calorific rays, was the — effect produced, even when the experiments were ; for three successive days. aa Po * This was ascertained by its attracting indifferently either pole of a sewing needle magnetised inthe usual ways This magnetised needle was pushed through a piece of cork, in which was inserted a glass cap, and it . was in that state made to revolve freely on the point of pris ol pig needle. of the more refrangible rays of Light. 331 Mrs Somerville now applied the same method to pieces of clock and watch springs, about 1} inches long, and from } to ; of am imch broad,* and they were found to receive a strong- er, degree of magnetism from the violet rays, an effect which was attributed to their blue colour, and their greater extent of surface. Bodkins were not affected. When the violet ray was concentrated by a lens, the magnetic influence was impart- ed to the needles in a shorter time. In order to give additional confirmation to these results, Mrs Somerville exposed magnetised needles, half covered as former- ly, to the sun’s rays transmitted through glass coloured blue _ by cobalt, and they were distinctly magnetised as before. Needles exposed under green glass received the same property. Mrs Sonierville now inclosed unmagnetised needles in pieces of blue and green ribband, one half of each being covered with paper, and after they had hung a day im the sun’s rays behind a pane of glass, they had acquired magnetic polarity, the exposed ends being north poles, as in the former experi- ments. When red, orange, or yellow ribband was used, no magnetic influence was imparted. In performing these experiments, Mrs Somerville found that the most favourable time of the day was from ten to one o'clock ; and that, as the season advanced, the magnetism ac- quired was less permanent, as the needle required a longer ex- | posure to acquire the same degree of magnetic virtue. Although Mrs Somerville has thus established a most important fact im science, yet the subject is by no means ex- hausted; and we would recommend to her attention the zeal- __ ous prosecution of it, in reference to the examination of the : other physical properties of the solar spectrum. More than twelve years ago, Dr Brewster communicated to the Royal Society of Edmburgh a paper, in which he endea- voured to show, that there existed visible rays beyond the ee and each homogeneous colour of the spectrum was accompani- Se with reps of ete eae This increased refrangi- ey was soccer, 3 Shanes, pradposl, agen che. ete Be * When these possessed any magnetism, it was removed by heating. 332 . History of Mechanical Inventions and the ‘collision of its particles, both at’ its emission from the sun, and at its refraction or reflection from solid bodies. The: experiments on which these results were founded, were exhi- bited to the Honourable Lord Glenlee, and to Professor Rus-. sel, Vice-Presidents of the Royal Society of Edinburgh; and, in 1814, they were described to some foreign philosophers of: distinguished eminence. The author; however, was desirous of extending his experiments before he gave them to the pub- he, and his memoir is accordingly stil] in MS. Art. XXX-—HISTORY OF MECHANICAL INVENTIONS- -AND PROCESSES IN THE USEFUL ARTS. 1.. Description of a simple Punt-Boat for saving ‘time and labour. By AnpREW WavppEL1, Esq. F.R. S. E. Communicated by the Author. T nis Punt-Boat is ica in Plate V., , Fig 12. It is 60 feet long, 16 feet broad, and 44 feet deep. It carries its lading upon deck, and it is for the purpose of transport- ing stones and other materials for constructing wears or breakwaters, and for removing obstructions in dry and bar harbours. In the interior of the boat below deck, there is a water-tight space built on one. side, occupying about one-third of the breadth of the boat, and the whole of the length, which space has no connection with my other part of the interior. In the bottom of this space there is an opening ‘swith a valve to shut at pleasure, capable of admitting as much water in one minute, as will sink down that side of the boat, and raise the other ; thereby forming an in- clined plane, and admitting of the stones or other material on the deck of the boat sliding easily overboard into the ies after the manner in which a loaded cart is emptied. The boat will then instantly resume a ae its upright position, and the valve being left open, the water that was admitted into the above mention- _ ed space, will run out again to the level of the water without. The valye is then to be shut, and any water that remains in the said space pumped out in a few minutes , by means of a wide-chambered pump, and the aid of one man. ia A boat of this construction will be most useful in forming breakw: by dropping the stones at high water, or at any time in deep water, tly. on the spot wanted ; but the above mentioned valve should be 2 ale open and shut with a screw, so that, should the lading be requi be _ put overboard at different parts, the side of the boat might be sunk no — further than to admit of a man sliding the stones down one after another. This boat, when light, draws about one foot and ten inches, cand when, i be ‘| Processes in the Useful Arts. 333 loaded, about four fect water, which difference of two feet and two inches, when immersed will displace a body of water equal to 36 tons weight or mores | bilge keels attached to the bottom of the boat, are for the purpose dale entinig, in some measure, its flat bottom from coming in too close contact with the mud, when deeply laden, which otherwise might prevent the boat from rising with the flood-tide, when grounded in such. situa- tions ; and these bilge keels being firmly united to the bottom of the boat, serve to strengthen the whole of its frame. 2. Method of condensing wood and giving it a closeness of grain for resist- _ ing moisture, for the construction of furniture and other purposes. By Mr James Fatconer Asrtriz. This useful process, for which the inventor has taken out a patent, con- sists in cutting the timber into planks with parallel surfaces. $These planks are passed between parallel iron or steel rollers¢with highly polished sur- faces, which condense the wood by their pressure. The pressure thus ap- plied must be at first small, and afterwards gradually increased, other- wise the wood will be crushed or split. The best way of applying the principle is to place several pairs of rollers behind each other, the distance between each pair progressively diminishing. The sap or moisture will thus be forced out of the pores of the wood, and the ends and sides of the plank, and it will thus be rendered stronger, heavier, and harder, and less pervious to moisture, than in its natural state. When used in furni- ture, it is less liable to scratch, and does not shrink. Oak and mahogany admit of much more compression than fir or other slight woods, and Hon- duras mahogany may‘be rendered as hard and heavy as the best Spanish. If one of the rollers is sufficiently bright, a finished polish will be left up- on the surface. This plan is particularly useful in ship carpentry, for mele wooden bolts, trenails, and dowels of a compact aaliny 3. Discosiery of a Fine Sand for Flint Glass at Alloa, superior to that from Lynn Regis. By Rozert Baty, Esq. F. R. S.E. Civil Engineer. At a late meeting of the Royal Society of Edinburgh, Mr Bald read an account of a fine sand which he had found at Alloa, and which was superior to the sand of Lynn Regis, so long used both in Scotland and England for the manufacture of flint glass. ‘This material occurs among the lower strata of the coal field of Alloa, in the form of a whitish sendstone, which has been long worked for building, and it can be so easily obtained that it may be delivered at Alloa for a shil- ling a ton, whereas the Lynn Regis sand costs 20 shillings in Scotland _ Upon examining this sandstone, Mr Bald found that it consisted of pure crystals of silex held together with only a slight quantity of matter, from which it could be easily separated by washing, and he immediately recom- “ mended it as a substitute for the Norfolk sand. A specimen of flint glass'was accordingly made with it by Mr Marshall of the Alloa Glass- Works, and we have no hesitation in saying that it is perfectly colourless, $34 Analysis of Scientific Books and Memoirs. and equal to the finest flint-glass we have seen. We have also exa- mined with the microscope the sand itself when washed, and are satisfied that it is entirely free of all foreign matter. This discovery is of great importance to the glass manufacturers of Scot- land, and we trust that this respectable body will evince their gratitude to Mr Bald for the great benefit which he has conferred upon them. “ Arr. XXXL—ANALYSIS OF SCIENTIFIC BOOKS AND MEMOIRS. ft I. Considerations on Volcanos,—the Probable Causes of their Phenomena,— the Laws which Determine their March,—the Disposition of their Pro- ~ ducts,—and their Connection with the present State and past History of ~ the Globe ; Leading to the Establishment of a New Theory of the Earth. By G. Poutert Scrors, Esq. Secretary to the Geological Gecienys ~ London, 1825. Aruovuen geology has of late years been cultivated by men of agiitine talents, and has tiow begun to assume the form of a science, yet it has not been entirély wrested from the dominion of the Charlatans. This numerous and thriving race, after being driven from the domains of natu- ral philosophy, and, more recently, from those of chemistry, found a hos- pitable shelter among the strongholds and obscutities of geological specula- tion. No sooner was the barbarous vocabulary acquired from a few _ Yeetures, than every valley came under the surveillance of a philosophical surveyor. Its strata, both visible and invisible, were speedily pourtrayed_ in all the prismatic tints; the process by which the Almighty made it was soon discovered, and our young geologist’ appeared before the pub- lic with this magna charta of his claims to be enrolled among the sages of his country. The transactions of our scientific bodies, and all the nume- rous records of wisdom, were filled with these precious compositions ; and the republic of letters was threatened with a second deluge from the aqueous vapour which was thus suddenly precipitated upon her territory. From the recollection of such things, it is refreshing to contemplate geology and mineralogy under their new aspect. Men of genius and science have entered upon these delightful studies ; men of fortune have jo into distant lands to explore their mysteries ; 3 and the various attainments of modern research have been called into requisition to illustrate thesia ture and formation of our globe. . The work of which we propose at present to give a copious analysis, son of those excellent productions: which appear at very distant intervals, an 1d gi a new tone to scientific inquiry. Mr Poulett Scrope has not only enj numerous opportunities of studying many of the gtand operatio i he describes, but he has exercised unusual diligence in making himse aequainted with the facts and reasonings of our ‘most eminent. geologic travellers. When we say, that this: ‘work: was written after visiting. Mr Poulett Scrope’s Considerations on Volcanos. $35 active voleanos of Aitna, Vesuvius, and Stromboli, and exploring the ex tinct craters of Auvergne, of Italy, of the Rhine, and of the North of Ger- many, we offer our readers some pledge for the accuracy of its facts, and the soundness of its reasonings. The work coramences with a descriptive aceountof the Volcanic Pheno- mena, in which the author treats of the number and dispersion of volcanic vents on the surface of the globe, a detailed catalogue of which is given in an appendix. The number already known is supposed very much within that which really exists, for many reasons, but particularly be- cause the intervals of rest between eruptions are often of such long du- ration that the former activity of the vent is unrecorded, and again, be- cause it is probable that numerous vents exist under the sea, whose acti- vity, however frequent, cannot be made known to us: till the peak of the volcano rises to within a short distance of the surface. Volcanic pheno» mena are classed into subaerial, or those which take place in the open air, and subaqueous. Of the former class, which is more open to study than the latter, some take place from new, others from habitual vents. The last are most common, and most accessible to observation. The condi- tion of all habitual volcanos, or sources of erupted matter, appears to be« long to one or other of the three following phases : _ 1, In which the eruption is permanent (as in Stromboli, &c.) 2. In which eruptions are frequent, prolonged, and at moderate vio- lence, and the intervals of repose short. 3. In which intense eruptive paroxysms, of brief dae alternate with lengthened intervals of quiescence. These phases are separately considered, and examples given of the phe- nomena of each,. as well as a particular description of all the remarkable. circumstances which accompany and characterize a volcanic paroxysmal eruption, and which appear to the author to present so great an uniformi- ty in all places, and at all times, as to warrant the conclusion that the main phenomena are invariably the same ;. “no farther discrepancies ex- isting, than what are fairly referable to’ the modifications produced by lo- cal accidents, or by differences in the intensity of voleanic force developed, and in the mineral quality of the erupted substances.” In Chap. II. the immediate causes of these phenomena are investigat- ed; and it is observed, that all their circumstances, as well as the direct observations of the author himself, Spallanzani and others, go to prove the existence, between every volcanic vent, of a mass of lava, or crystal- line rock in a state of actual ebullition ; the generation, or expansion, of electric fluids within its interior producing intumescence and elevation, and the explosions which take place from its surface. The nature of this elastic fluid has been ascertained by direct experiment, and it appears to consist almost wholly of aqueous vapour or steam. The uniform dissemi- nation of air-vesicles through many lavas proves ‘the vapour to have been generated throughout every part of their mass. We must then suppose the existence of water in combination with the other elements of the rock. This leads to an examination of the nature of lavas; and the author finds $36 —_Anialysis of Scientific Books and Memoirs. \ -reason to conclude, that the crystalline particles of which they ate com- posed were not formed as the substance: cooled ; that few or no lavas are ever reduced naturally to complete fusion (sone in fact but the glassy la- vas, obsidian, pearlstone, &c.) ; but that they consist’ of’ érystalline par- ‘ticles of various sizes, which, when the rock is solid, contain very minute portions of water mechanically combined with their substance," that is, intervening between the parallel plane surfaces of the crystals. In this ‘case, any continued accession of caloric to a mass of such rock confined beneath the crust of the earth, and already at an intense temperature, must sooner or later so increase the expansive force of the confined’ water, as to reduce more or less of it to vapour, breaking through or heaving up- wards the confining crust, and causing the lava to intumesce and rise out- wardly in a state of imperfect liquefaction through any fractures which this violent expansive effort may create in the overlying beds. The li- quidity of lava consists, under this idea, not in its absolute fusion, but in the mobility afforded to its component crystals by the intervention of more or less: of highly elastic vapour between the opposite facets, and the degree of liquidity will therefore depend on the quantity of vapour gene- rated through the substance, and the size of the component crystals. But at a certain term in the relative proportion of these circumstances, the va- pour will become so abundant as to enable a part of it to unite into bubbles, which, by their inferior specific gravity, are urged to rise up- wards, and escape from the surface of the liquefied mass ip which they are formed. ‘The quantity of vapour discharged in this manner consists therefore at all times of the surplus of that which has been generated in the lava beyond what is necessary to communicate to its component crys- tals the degree of mobility required for the union of this surplus vapour into parcels or bubbles, and the rise of these, when formed, to the surface.” The explosions of all voleanic eruptions are produced by the rapid ascent and escape of such bubbles, collecting as they rise through the lava’ ‘into prodigious volumes of vapour ; and the remainder of these parcels of va- pour, which are prevented: from! thus escaping by the superficial indura-— tion of the exposed masses of lava, occasions the cellular and cavernous structure of such rocks, both on the large and small scale. ‘The consoli- dation of liquefied lava, under these circumstances, takes place, not only by loss of temperature, but also, and oni) -by the Be icy ree ed _ ™ This, at least, is the temporary assumption of the eae who, ina later part of the work, observes, that he inclines to suppose the water itself may be generated, together with other fluids, by the volatilization of a superficial pellicle of se mate crystals, and the combination of the oxygen and hydrogen set free by this process, through the intense temperature pervading the mass. | Such a supposition. if not supported, is perhaps not opposed by the present state of chemical know! od and would explain all the phenomena of lavas, as well as the idea of a meck interposition. In short, the existence and general dissemination of basi 0 Gattier steam, in lavas, is a positive fact, susceptible of direct and i incontrovertible __ and it is indifferent to the purpose of the author how, or at what time, we suppose it to be produced there. © : + ‘ Mr Poulett Scrope’s Considerations on Volcanos. 3377 the vapour (which alone occasions the mobility of the crystals) on their superficial exposure to the outward air; subsequently, by exudation through the pores or interstices of that hardened surface, the process is propagated to the interior of the bed of lava. Consolidation may also take place by increase of pressure on the lava, without any change in its temperature ; the vapour being condensed till the crystals reunite, more less conformably, according, as they have been more or less broken up, & disintegrated, by mutual friction when in motion, and by the disaggre~ gative force of the vapour generated within them. Having developed these original ideas as to the nature of lava, which are supported by facts and arguments, the author goes on to explain all the phenomena of earthquakes and volcanos, and the circumstances of dispo- sition; structure, and mineral character in volcanic rocks, by the assump- tion, which, however, is strongly supported bya large body of evidence, . that the interior of the globe, at no great depth from the surface, consists ofa mass of crystalline rock at an intense temperature ; and, therefore, that a continual supply of caloric passes off from the centre towards the circum- ference, wherever the nature of the superficial rocks allows of its transmis~ sion, or temporary vents are opened for its more free escape. Where the superficial rocks, from their constitution, (as is presumed to be the case with the schistose strata, the limestones and sandstones,—or, when consisting of unstratified crystalline rocks, from the intumescence and refrigeration they have undergone, ) are very inferior conductors of ca= — loric, the heat transmitted from below will be concentrated in the beds of denser crystalline rock beneath these, and continually augment their tem- perature, and with it their expansive force. The overlying rocks will sooner or later necessarily, yield to this force. At this time, the expan- sive force will be greatest in the lower parts of the crystalline bed. The upper will be therefore raised en masse, in a solid state. This forcible elevation must be accompanied by the rupture and dislocation of the overs lying rocks ; and every such fracture in the earth’s crust must create a jar~ ring shock and vibratory motion in them, which will be propagated along the prolongation of each rocky bed, with an: intensity proportionate to its ‘solidity ; the strata which are only in contact with those broken through, sharing in the vibration in an inferior degree. These shocks are earth- quakes, none of which are supposed to take. place without a certain, though often inappreciable elevation of the surface of the globe. The fis- sures formed in this manner will be more or less wedge-shaped ; some opening outwardly, some downwards. The latter allow of the sudden ex- pansion and liquefaction of the intensely heated rock in which they are formed, and by this process the fissure is filled with intumescent lava. Where the fissures are broken through, the upper beds of the heated crys- talline rock, contemporaneous veins, or subordinate masses are produced, where, through overlying strata of other characters, injected veins or dikes. The friction occasioned by the resistance of the sides of the cleft to the rise of the crystalline matter partially disintegrates the crystals, and gives a finer. grain to the substance of the vein than that of the including rock ; VoL. Iv. NO. II. APRIL. 1826. Y 338 Analysis of Scientific Books and Memoirs. and also often oceasions ‘the crystals composing the lateral parts of the vein to be more comminuted than those in the centre. The matter filling | these veins is immediately consolidated both by loss of temperature and — pressure, and the fractured rocks are thus repaired and strengthened, An_ interval of tranquillity will then succeed, until a similar expansion occurs. — It is thus that the overlying rocks which form the surface of the globe must be progressively elevated more and more, by the successive dilata- tions of the inferior lava-bed, unless some avenues are opened within a_ limited distance, for the more tranquil escape of the subterranean ca~ loric. But the formation of such apertures (volcanic spiracles) must sooner or later result from the continuance of this process; for, at every crisis of expansion, those cracks only are repaired by the injection and consolida- tion of lava, which open downwards, Others which increase in width to- wards their upper extremity, will remain open, and effectually weaken that part of the crust of rocks across which they are broken. Subsequent expansions, taking effect most powerfully on these weak points, will widen _and extend these fissures, until some one is sufficiently deep and broad to permit the lava in the lower parts of the fissure to rise by its intumes- cence into communication with the atmosphere on one or more points at the upper extremity, thus producing a volcanic vent or vents. In most instances, the fissure must be narrow, irregular, and intricate, and the distance great from the external surface to the focus of ebul- lition. The intumescence will be proportionately slow, and the repres< _ sive foree, consisting of the weight of the rising column of lava, and the accumulation of fragments broken from the sides of the fissure; may stifle the ebullition before the lava has reached the lips of the orifice. Such may be called an abortive eruption, vapour alone escaping outwardly be- fore the fissure is closed. The author attributes the clouds of smoke or vapour, and projections of fragments that have been discharged during vi- — olent earthquakes-from crevices in the soil to a subterranean effervescence of this nature.* But where the width of the fissure, and other circum- stances permit it, the lava reaches the mouth of the vent, and a regular voleani¢ eruption occurs. The author proceeds to examine the laws which regulate the develope- ment of the eruptive force. ‘This is opposed by the repressive force, con- sisting of, t. The supported column of liquid lava ; . 2. The reaction of the vapour generated from the eae to its expansion; mort _ “ It appears that the eaniegns vapour emitted from fissures in the surface : during earthquakes i is in general very great; since Ferrara mentions that e: ti dinary storms of rain immediately follow the occurrence of these henomena. In the violent earthquake which affected the whole northern coast of icily in a ~ remarkable dense black cloud collected over the district affected, and shortly ‘con- densed into ‘terrific deluges of rain. The same thing happened = great earthquake of Catania in 1693, and that of Calabria in sar Mr Poulett Scrope’s Considerations on Volednos. 389 3. The external pressure on the surface of the intumescent lava, Of these elements, the last is the most subject to variation, particularly from changes, 1. In the dimensions of the vent and, 2d, In the quan- tity and weight of matter pressing on the surface of the lava within the vent.’ 1, The violent rise and explosive escape of the elastic fluids must at first breakup and enlarge the fissure, and consequently, the energy of the eruption will progressively increase from its eormsmiencement ; but, 2d, the weight and consolidation of the lava protruded from the orifice, and above all, the immense accumulation of fragmentary ejec- tions) within and around the vent, must, before long, give the predomi~ nance (unless under extraordinary circumstances) to the force of repres- sion ; the crisis of the eruption is past, its violence diminishes progres- sively, and it is at length wholly checked. Hence, a general law is de- duced, that the developement of volcanic action universally tends to its own extinction by augmenting the opposite forte of repression. The author then considers the condition at this time of the dilated mass of lava below, or the focus. Its temperature has been suddenly lawered below that of the surrounding crystalline mass—it therefore abstracts ca- lorie from thence. If this accession of caloric keeps pace exactly with the inerease of the repressive force, the eruption is permanent. If not, the continual increase of the expansive force in the lower parts of the crystal- line bed, resolidifies the upper parts, and seals up the vent. But the expansive force of the focus continues to increase, and, perhaps at length overcomes the resistances opposed to it.. If it break out repeat~ edly in the same direction, it nen an habitual volcano, and finally a volcanic mountain. ° If the repressive force prevail till the focus is equalized in temperature to the stratum in which it lies, it shares in the general expansive force of that stratum. This is continually increasing, and must at length finda vent, generally on the same spot as before, and hence the frequency of ha- bitual volcanos. If on a fresh point, probably on the continuation of the original fissure, the rocks having been shattered along that line by the earlier shocks; hence the linear trains of volcanic vents 80 often noticed, The distance of the new from the former vent, must depend on local cir= cumstances in thé structure, tenacity, and other elements of resistance in the overlying rocks, In this manner, the draught of caloric, passing from the great reservoir below to the exterior of the globe, is shifted from one vent to another ; the focus of each active volcano abstracting ca- loric from its inclosing walls ; neighbouring vents will also more or less retard the activity of each other; and the extreme energy of one may cause the absolute extinction of the other. Other more tranquil modes of escape for subterranean caloric are found by the author in thermal springs, which result from the condensation of aqueous vapour percolating through minor crevices from the subterranean heated lava-rock. So long as by these, or other modes, the caloric passes off in the ratio in which it is re- ceived from below, the general expansive force remains invariable. If not, this force increases, and must at length prevail over the united forces 340 Analysis of Scientific Books and Memoirs. of repression, and produce elevations of the superficial strata, earthquakes, &e. The author thus distinguishes between the general or primary, and the local or secondary expansive forces, each having their peculiar force : ‘the first residing in the general subterranean bed-of heated rock ; the se- ‘cond in minor and less deeply seated foci. The laws thus determined hold good, whatever the scale of magnitude of the phenomena they give rise to, whether the elevation of a few square yards of rock, or of a whole continent ; a quiescent interval of a few hours, or of centuries, | Every habitual voleano acts, therefore, as a safety-valve to.the globe, the caloric which emanates from its anterior passing off by means of this vent into outer space. But these eruptions are necessarily accompanied by circumstances tending to impede their continuance, and they are thus, in the generality of cases, rendered intermittent. Where the opposing forces of expansion and repression are in equilibrio, the volcano is in the first of the phases noticed above. Where they oscillate frequently about an equi- librium, in the second. Where the oscillations are on a large scale, in _the third. The first case must necessarily be very rare. In the instance of Stromboli, our author attributes the permanence of its eruption solely to _ the peculiar form of the crater ; the aperture of the volcano having a high ‘and sloping ridge only on one side ; on the other a precipitous slope down to the sea, which is there unfathomable. Owing to this remarkable figure; less than one half of the scorie projected from the aperture at each explo- ‘sion fall again into it, and, consequently, there can be no accumulation of fragments on the surface of the lava within the vent, which always re- mains level, or nearly so, with’ the mouth of this aperture, without being discharged otherwise-than in fragments tossed up by the bubbles of va- pour which escape from it. The voleano of Bourbon again, -a similar ex- ample of almost continual eruption, is shown by the author to owe this character to another peculiarity of form. ‘This volcanic mountain is a complete obtuse cone, and there exists at the apex an almost permanent source of a very fluid and glassy lava, which slowly boils over the lips of the circular orifice, and flows rapidly on all sides down the steep slopes of the cone. Thus, in this, as in the former instance, the force of repres- sion remains fixed, and that of expansion being always slightly in excess, the eruption is permanent. Where, however, these forcés are so nearly i in equilibrio, a very slight addition to that of repression may stop the erup- ‘tion for a certain time, and Mr P. S. supposes that even changes in the density of the atmosphere will occasionally produce this effect ; and that a permanently active volcano, whose phenomena are, sicottding to him, occasioned by the ebullition of-water in the focal lava, from constant and ‘uniform additions of caloric to it, will be as sensible as the barometer to variations in the pressure of the atmosphere on the surface of the sup- ported column. of lava; the ebullition ceasing for a few minutes or . . as the density of the atmosphere increases, and increasing in pats is diminished. Observation confirms this opinion. Stromboli is made use of as a weather-glass, and securely relied on by the fishermen of the eH isles ; other volcanos likewise have been observed to — their . a Mr Poulett Scrope’s Considerations on Volcanos. 341. activity in tempestuous weather, and, in general, to be most violent in the stormy season of the year. Earthquakes also have been often observed to coincide in time with hurricanes or violent storms; and the author notices the probability that a diminution of the pressure of the atmosphere, taking place simultaneously on a large extent of the earth’s surface, be-’ , neath which the ever-active force of expansion is continually. pressing up- wards, and often restrained by only the slightest degree of superiority in _ the combined forces of repression, may occasionally give the predominance to the former force, and determine one of those partial elevations of the crust of the globe to which he attributes the phenomena of earthquakes. It is remarked, that an individual volcano may occasionally pass from one of the phases, distinguished above, into another ; or may even exist in two phases at once, having a double system of operations, corresponding ‘ to two different foci, seated one below the other ; the latter perhaps at a considerable elevation in the chimney or main vent.of the volcano, and giving rise to minor and frequent eruptions ; the former at a much great~ er, depth, and productive of rare and violent paroxysmal eruptions. It is obvious that the last system must be in activity wherever the supply of caloric is in a faster ratio than its drain through the activity of the upper focus. The paroxysmal eruptions leave usually a prodigiously wide and deep crater, which is subsequently filled up by degrees by the erup- tions of the minor and upper focus. Such alternations of minor and pa- roxysmal eruptions appear to have. produced the colossal crateral cavities of volcanic countries, most of which have one or more recent cones rising from within their circuit, such as Vesuvius within the crater of Somma ; the Peak of Teneriffe, and the cone of Chahorra, from the circus describ- ed by Von Buch ; that of Bourbon from the successive circuses described by St Vincent ; those of Volcano, Astroni, the lake of Roneiglione, &c. &c. The author now preceeds to examine the laws which determine the dis- position of voleanic products on the surface of the globe. The simple cone is first considered, resulting from the accumulation of fragments pro« jected by a series of explosions from a single aperture. | Its figure is a truncated cone, containing a funnel-shaped cavity called the crater. The line in which the inner and outward slopes meet is the ridge. Its regula- rity is liable to disturbance from many causes, such as the fissure-like form of the vent, which usually gives an oblong figure to the cone; the vicinity of other vents; violent prevailing winds ; and, above all, the sub- sequent emission of a current of lava from the same orifice by which one side of the crater is broken down. Examples of these, and other varieties of figure, are given froin Auvergne, Italy, &c. The composition of the cone is next dwelt on, and the nature of the fragments, which are either, 1. Scorie, or portions of lava torn from the surface of that which has risen within the vent, by the explosive escape of the ascending volumes of steam. ‘Their distinctions of shape, struc- ture, and-size, are accounted for, particularly the difference of the scorie of feldspathose lavas (pumice,) and those of basaltic composition. 2. Frag- ments of other rocks broken from the*sides of the fissure by the force of 342 Analysis of Scientific Books and Menioirs. the ascending fluids, These may consist of primitive, secondary, of any” clasd of rocks... The remarkable fragments found in the conglomerates of Somma, and the Hiffel, are attributed to the alteration of calcareous and granite fragments by the volcanic heat, new minerals being produced from’ . the ‘decomposition of these, and the reaggregation of their elements in other forms. Fragments of either kind are, if the eruption contifiues long enough, eompletely pulverized by repeated projections. The electri- cal phenomena, developed during eruptions, are supposed by the author to be owing to this immense friction. The height to which fragments of a large size are carried, exhibits the prodigious escaping force of the steams bubbles. Vesuvius has been seen to launch scori# 4000 feet above its apex, Catopaxi 6000. The latter projected a mass of rock of 1000 cus bic fect to a distance of three leagues. This explosive force proves the vapour to be propelled from a great depth, and at an intense heat. A volcanic cone is shown to be stratified in planes parallel both to the inner and outer slopes of the hill; and, owing to this peculiarity of structure, the character of such a hill may be recognized even from the smallest rée- maining fragment. A plate gives a view of the Capo de Miseno, which offers»a natural section of such a cone. The author next discusses the laws of the protrusion and disposition of lavas, when expelled, en masse, in a more or less fluid state from the volcano; beginning with a notice on the mineral ature of lavas, and their differences of specific gravity and texture, by which their fluidity is invariably determined. He classes them into the heavier lavas (basalt,) in which the ferruginous minerals, augite, hornblende, mica, or titaniférous iron, are abundant; atid the light lavas (or trachytes,) in which the minerals are rare, and felspar, or some equivalent of low specific gravity, almost the sole ingredient. © The fluidity of a lava, or the facility with which it movesjin obedience to its own gravitating force, is compounded of its liquidity, of the mobility of its parts, and of its specific gravity. But the liquidity of lavas, it has been seen before, varies with the average comminution of their crystalline particles, under the same circumstunce of pressure and temperature. Hence lavas, of the sathe mineral quality, and therefore of equal specific gravity, when pro- ~ duced under similar circumstances of temperature and pressure, will possess a degree of fluidity inversely proportioned to the average size of their crys- ‘talline particles, or grain. And, vice versa, when their grain is of the same degree of fineness, their fluidity will be proportioned to their specific gra- vityy i. e, to the proportion of ferruginous minerals in their composition. _ The author illustrates these propositions, by showing, from observation, that the basaltic lavas have generally flowed farther, and spread over @ larger surface than the trachytic ; and also, that the lavas of either class have spread in a horizontal direction, more or less, in proportion to the abundance of the heavier minerals in their composition, and the fineness of their grain. The fact has been long ago remarked, but the of it is presumed to be novel. The disposition of a body of lava, emitted from ah orifice in the surface of the earth, is, in strictness, determined by, 1. The force of expulsion—2, Its fluidity—3, The external circuthstances ~ Mr Poulett Scrope’s Considerations on Voleanos. S48 that may render this fluidity mote or less permanent—4. Those which favour or impede the lateral extension to which it is urged by its fluidity. On the compound influence of these circumstances depend the direction taken by the lava, the velocity of its progress, the extent of its superfici- al spread; and, consequently, the figure of the rock into which it con- geals. According to these, lavas assuine the form either of sheets, streams, hummocks, or domes. Examples are given, in numbers, of their ‘modifications of form; and it is observed, that the general bulkiness of ' the trachytes is simply accounted for by their imperfect fluidity, (owing to a coarse grain and low specific gravity) without presuming that they have swelled up like a bladder from below, agcording to the vague and anomalous idea of Humboldt and De Buch. The author proves, from his own observations, however, in opposition to the statements of Beudant and other writers, that, under favourable circumstances, the trachytic la- vas have often spread into bulky sheets and streams, (nappes et couleis ) particularly in the Mont Dor; from which he gives a section where beds (slightly inclined away from the centre of the mountain with a quaqua- vérsal dip,) both of trachyte, (of the standard trachyte of the French geo- logists) and of basalt, alternate with each other, and with interposed beds of ashes, or voleanic conglomerate. _The author mentions one vast stream of feldspathose lava (clinkstone) which appears to have flowed from the summit of the Mezen, in Velai, into the bed of the Loire, thirty miles dis- tant, with an average width of six miles, and a thickness of 500 feet ; thus rivalling the colossal trachytes of the Andes. Clinkstone, or the laminar variety of trachyte, is presumed to have possessed. in general a superior flu- idity, owing to the parallelism of its crystals, as a very small proportion of elastic vapour interposed between these would give a great mobility to the mass, in the direction of their longest axes. The crystals of all lavas, in- deed, are supposed by our author, when in motion, rather to slide or slip past one another by means of the intervention of a small quantity of fluid between their flat surfaces, than roll over one another, as is probably the case with the globular particles of perfect fluids. This would natu- rally result from their peculiar kind of fluidity, and also explains the ex- freme difficulty with which lavas in motion are induced to swerve from the direction they have once taken. The smallest obstacle is sufficient to check their progress for sometime, and even to consolidate the lava to some distance back from the obstacle. These solidified parts, when again broken up by the increased impetus of the lava behind, oceasions the brec- ciated character of some lavas, where angular fragments are enveloped in a paste of the same material. The zoned and ribboned structure of pearl- stones is similarly accounted for. This sluggishness of lava currents oc- casions great accumulations of the substance on those points where its motion was checked and diverted, as in the angles of water courses, &c.;_ and examples are given from the Vivarais, where huge patches of colum- nar basalt oceupy the concave elbows of the gorges of the granite moun- tains, the connecting strips being shallow, or having altogether disappear- ‘ed. .The curious procedure of lava, when it meets with a perpendicular 344 Analysis of Scientific Books and Memoirs. obstacle, such as a wall, which it cascades over without touching it; is then noticed and explained; as also the arched gutters and cayerns often formed from its subsidence ; and its effect on grass, trees, and fragments of other rocks ; on marshy ground, and when it enters the sea or any body ' of water. Its progress below the water is shown to be similar to that on dry land, though slower, with the same degree of fluidity. The water is heated and discoloured by it, and fish often killed in numbers. The fos- sils of Monte Bolca are attributed by our author to such a catastrophe, since the beds in which they occur are topped by basalt and volcanic cal- careous conglomerate. ' The consolidation of lavas is next treated of. This is effected equally by the condensation or escape of its fluid vehicle. Its condensation takes place either by increased pressure or diminished temperature. ‘T'his mode of consolidation is supposed peculiarly favourable to the reunion of many of the disintegrated crystals, the gradual diminution of the vapour bring- ing the particles by slow degrees within the sphere of their reciprocal at- tractive forces, while the remaining elasticity leaves a sufficient mobility to permit of the reversion of their poles in obedience to these forces ; and thus a partial recrystallization may be expected to take place. Such erys- tals, it is shown, will have their longest dimensions perpendicular to the pressure upon that part of the lava. But that portion only of the elastic fluids will be condensed, which ‘cannot effect its direct escape. This is completely prevented in some cases, as in dikes, &c.' But where the lava is exposed to contact with air or water, this escape takes place to a greater or less degree, in one or both of two modes; viz. 1. By ascent in bubbles through the liquid lava. The more fine-grained the lava, the more spherical the bubbles, from the equalization of the pressure on allsides. These vesicles are often elongat~ ed as the lava moves onwards ; their size will be proportioned to the speci- fic gravity and liquidity, in other words, to the fluidity of the lava, and the same circumstances determine the proportion. of vapour which escapes in bubbles, to that which remains behind. Of the latter, a part escapes in the 2d mode, viz., by percolation through the pores and crevices of the al- ready solid exterior. This process advances from the surface inwardly, with a rapidity proportioned to the porosity of the resulting rock, which will vary directly with the average size and irregular arrangement of crystalline particles. ; From these considerations, the author deduces the following propositions, as to the conduct of different varieties of lava, when protruded upon the surface of the earth. oF. Cee we 1, If of extremely fine grain, and low specific gravity, the superficial congelation of the mass will be rapid, that of the interior slow ; its fluidi- ty considerable ; air-bubbles spherical, sometimes elongated horizontally. or vertically ; the scorie of such lavas is pumice. Owing to the extreme slowness of the consolidation of the interior, and its great mobility of parts, a more or less perfect recrystallization, or concretionary process, will ta place. Pearlstones, radiated or not, or variolites, will be produced ; and Mr Poulett Scrope’s Considerations on Volcanos. $45 these coneretionary parts, if subsequently drawn out by the renewal of. motion in the lava, will give rise to veined, marbled, and brecciated rocks. Numerous examples are given to show how completely these reece accord with observation, 2. A higher specific gravity, with an equally fine grain, increases the fluidity of the lava and its extent of lateral spread ; the bubbles of vapour will rise with greater force to the surface, which they will rend and break up, leaving it bristling with asperities from the rapidity with which the exposed surfaces congeal. Beneath this surface large cavernous blisters will be frequent ; and the lower part of the current, on the contrary, very compact. The great slowness with which this lower part congeals will afford scope for the play of affinities, modified by the extreme fluidity which it derives from its high specific gravity, the result of which, as is shown in a subsequent. chapter, will be tendency to the prismatic or co- lumnar divisionary structure. The fine-grained basalts are specimens of this variety. ; 3. A coarse grain, coupled with a high specific gravity, by diminishing the fluidity of the lava, increases the bulk or thickness of the beds into which it is disposed, creates a porous texture, and a general dissemination of rude angular cells. Such amass will contract greatly on cooling, and exhibit wide and numerous fissures of retreat; by which the surface of the current, particularly, will be shattered into rude flakes or angular fragments. 4. A lower specific gravity, together with a large crystalline grain, by wholly preventing the vapour from uniting or ascending in bubbles, will render the mass still more generally porous, and more bulky in figure; as is, in fact, the case with the earthy trachytes, lava sperone, piperno, &c. 5. When the component crystals are still larger, that is less disintegrated, nearly the whole of the vapour will be condensed by gradual cooling, with- out much derangement in the position of the crystals, and the rock will, therefore, be more compact and freer from pores. Some of the very large- grained trachytes, dolerites, syenites, and granites may be taken as ex- amples of this structure. If the crystals are non-conformably arranged, the fiuidity of the lava is at its minimum. If conformably, as in the clinkstones, and other laminar crystalline rocks, the fluidity may be con- siderable in the direction of the parallel plane surfaces of the crystals. 6. Some masses of crystalline rock, the author supposes, may be occa sionally elevated in a solid state (by the expansion of lava at a great depth beneath) without suffering any disintegration whatsoever, having either been previously cooled down, or being preserved from ebullition by the pressure of overlying strata, which are elevated together with them. Such a circumstance would be in complete conformity with all the laws of sub terranean effervescence, and in the granitic axes of most mountain chains, we recognize facts which can only he accounted for by such a mode of production. The aqueous vapours that eseape from most lavas, as they are consolidat- ed, are aphemnyaniet by mineral substances, which become more and more 3H6. Anahjeis of Séientyfo Books and Mevioire.: abundant as the lava cools, and the quantity of steam exhaled diminishes. These substances are, by the author, supposed to proéeed from’ the inter. nal decomposition of some of the ingtedierits of the lava by its intense Heat, as the pressure created by the elasticity of the interstitial fluid diminishes, _ éwing to its expansion and partial escape through the pores and fissures of the rock above. Specular iron is evidently a sublimation produced in this manner, as well as the delicate crystals of hornblende, augite, melilite, and other minerals which occur in the cellular cavities and fissures of some lava rocks. Sulphur is similarly sublimed, and the same origin must be allowed to the sulpbates of lime and ammonia, the muriates of soda and ammonia, &c., which are deposited often in great abundance at the sides and edges of the fumarole. Other minerals resulting from this internal decomposition are taken up in solution by the steam, and deposited in crystals or concretions, calcareous, siliceous, &c.; in the vesicular cavities of the rock. ‘The cells of most amygdaloids ‘are, however, supposed to have been filled by subsequent filtration of water, carrying in solution mi- neral particles from overlying rocks, and the author supposes the pressure _ ofa high column of water, (as in lavas of submarine origin,) necessary to effect its penetration through the minute-pores of the lava rock. The sulphuric and muriatic acids are also often met with among the emanations of the fumarole, and their action on the lava composing the sides and borders of these crevices, produces new decompositions and com binations. The sulphate of alumine of the Italian and Hungarian aluin works has this origin. These superficial alterations of lava have acquired _ for the spots where they occur, and which are always within the craters of some voléano, the name of solfatara or souffriére. __ Thermal springs, and the generality of mineral sources, are atiributed by Mr Poulett Scrope to the condensed vapours escaping from a subterranean mass of lava. Someare intermittent like the Geisers, and the cause of this phenomenon is dwelt on, and explained. The permanent gases evolved fromi lavas are next treated of; and an instance related by M. Bory de St Vin- cent, of seven or eight birds being seen to drop suddenly, while flying over the volcano of Bourbon, is supposed to offer some confirmation of the poetic fable respecting the Lake Avernus. The circumstances which determine the time occupied by lavas in cool- ing, will depend on the figure of the mass, external circumstances, and the structure and composition of the lava. Instances are quoted of currents retaining a great heat for a considerable time. That of Jorullo, in Mexi- co, is by no means cool yet, though produced in 1759. The next chapter treats of the divisionary structure assumed by lavas on their consolidation. This process must be accompanied, at all times, by a diminution of volume or contraction. Were it to commence at the e tre of a mass, no séparation of parts need take place ; but if at the different centres of contraction must establish themselves, and fissu retreat be formed between them.- The figures these crue ‘approximate to the hexagon. But since there is no en ae. he con- ‘tractile force, in a direction perpendicular to the: ‘subsides Mr Poulett Serope’s Considerations on Volcanos. 347 freely as the mass below contracts, no fissure, or very few will be formed parallel to that surface ; and by the inward propagation of the retreat, the will be lengthened into hexagonal prisms. The slower the pro- cess of solidification, and the finer the grain of the lava, the more regular will be the-prisms, ceteris paribus; hence the interior, or lowest parts of a current alone, in general, require this structure, which does not become visible till denudation has exposed these parts. This is rarely the case with recent lavas; and hence arises, according to our author, the common error of supposing the columnar division confined to the older basalts. This structure is very frequent in dikes, both in the older and recent vo« canic formations ; the columns being always perpendicular to the sides of the dike. When lava rests on a convex surface, the columns diverge ; when on a concave, converge upwards; being always perpendicular to the surface on which the process first acts. The author remarks, that those of the peaks of basalt, which are so numerous in basaltic districts, will be found to consist of a group of convergent columns ; this disposition afford< ing the maximum of resistance to the action of rain and frost, in separat« ing the columns, and breaking up the bed, of which the remainder has probably been destroyed in this manner. More than one kind of division~ ary structure may occur in the same rock ; smaller prisms are sometimes formed within the large. -The globiform structure is next accounted for, and its occasional subdivision into radiating prisms, or concentric leaves. — The angulo-globular structure accompanies a tendency to the formation of globular concretions. The tabular, lamellar, and slaty, or schistose divi+ sionary structures, are supposed to be confined to lavas in which the crys talline particles are disposed more or less conformably, owing to which their mobility is considerable in the direction of their parallel plane sur- faces, and null in the transverse direction. Hence, retreat fissures will be produced in abundance, parallel to the largest plane surfaces of’ the crys- tals, and few or none will be formed transverse to these. By the fre- quency of such transverse fissures, the cubical’ or rhomboidal structure is produced. _ The author next touches on ‘the question, as to the cause of the differ- ence of mineral composition in lavas. He inclines to attribute this variety to certain alterations undergone by the rock, originally of an uniform (perhaps granitic) composition, during its rise to the surface of the globe ; which was probably attended by repeated alternations of intumescence and reconsolidation, from changes in the relative proportions of the intense heat and pressure to which it was subjected. The principal varieties of lava are found in nature to have been usually produced successively, often alternately, from the same or proximate vents. The opinion of the anta- gonism of trachyte and basalt, put forth by Humboldt and Beudant, is ‘combated by our author, and numerous examples adduced of their suc. ‘cessive emission from the same volcano. He then notices on the error of limiting the production of trachyte or basalt to particular ages of the globe, ‘or making “ formations” of them—both are produced before our eyes by recent and still active volcanos ; the error arises from the terms trachyte 4 becomes enlarged into a volcanic mountain, composed ‘of hardened lava- 348. Analysis of Scientific Books and Memoirs. and. basalt not having been — as of right, toa annals meati« ing. . Having thus far traced the laws which determine the disposition of the t _ substances produced by a single volcanic eruption, whether in a Paget? ry form, or as more or less liquid lava, the author proceeds to examine the © circumstances that result from the accumulation of such products, by re-> peated eruptions from the same vent. The simple cone, by this process, streams, (each of which acts as a solid rib or buttress to the hill,) and in- tervening beds of conglomerate. The sides of this hill are frequently,’ during eruptions, split by the pressure of the column of lava, within the) central aperture or chimney of the volcano. The lava then flows out’ through orifices, formed successively at different levels, one below the other ; examples of such occurrences are given from the phenomena of: Etna, Vesuvius, Iceland, &c. It is a general fact, that, in the eruptions of volcanic mountains, or habitual volcanos, the elastic fluids are chiefly discharged froma the central crater, but the lava is emitted from apertures in the side, or at the base, of the mountain. Minor and local earthquakes’ _ are occasioned by these rendings of the frame-work of the mountain, which is even sometimes split in two. The consolidation of the lava that oocu- pies these fissures, produces numerous vertical dikes, which, cutting across its other component beds, acts as braces or ties to the frame-work, and. increase its general solidity. Somma presents an example of such’ dikes in great numbers. The fissures are in this manner hermetically sealed, as it were, and never open a second time. Thus, with the height and bulk, the strength of the mountain increases, without any conceivable . limit; and the author thinks it an erroneous idea, that such limit exists, and that, at a certain height, eruptions can no longer take place from the summit of the cone, since every lateral eruption adds to the strength of the mountain’s flanks, and to the resistance they oppose to the lateral pressure of the internal column of lava. Parasitic cones are thown up by the gaseous explosions which take place from these lateral vents. ‘They have each their crater, and each marks the source of a current of lava. Z£tna has nearly seventy such cones scattered on its flanks, many of con- siderable size. Vesuvius exhibits but a few, but is itself a parasitic cone; thrown up in the centre of the old crater of Somma. The skirts and base of a voleanic mountain are usually covered with conglomerates of an allu- vial character, deposited by torrents of water, proceeding either from the. violent rains, which usually follow an eruption, or from the melting of snows. ‘These debacles of mud and water, are called by the inhabitants of | Vesuvius, lave d’acqua. In Iceland, they constitute the most destructive part of the voleanic phenomena. Such deposits are often carried to some distance from the foot of the mountain, and are found alternating wit currents of lava which have flowed farthest from the centre of . trees and plants are found buried in them. The surturbrand of Iceland is of this origin. If the sea washes the foot of a volcano, these, and other of its prostates will be me with marine depogits, and often carried by - Mr Poulett Scrope’s Considerations on Volcanos. $49" currents to a distance. This’ was the origin of the stratified tufas of Cam~ pania, and the environs of Rome. In Hungary, pumice conglomerates al- ternate with tertiary limestone, as basaltic peperinos do in Auvergne, the Vicentine, and the Val Demona in Sicily. . The craters of volcanic mountains are subject to a series of changes, by which they are alternately filled up and emptied again. The large crater, left. by any paroxysmal eruption, is gradually filled by the accumulating ‘products of minor eruptions, until it is replaced by a convexity of summit. This form is, as we have seen, the most favourable to the permanence of the eruptive process ; but, at the same time, the quantity of matter accu« mulated above the focus, and, therefore, the obstruction to the escape of the caloric in as quick a ratio as it is received there from below, is at its maximum ; consequently, the probability of the recurrence of a paroxysmal eruption, from this inferior focus, is greatest at this time, and such a phe- nomenon will, therefore, probably soon occur. By this, the mountain is once more gutted. The crater left by these paroxysms,.is usually a deep elliptical chasm, resulting from the enlargement of the original fissure of eruption, by the violent ascent of the elastic fluids: Examples are given, in great numbers, of such craters, and of the changes they have under- ‘gone. Paroxysmal eruptions of' this kind have, in some instances, blown into the air the whole frame of the mountain, and replaced it by a lake. The eruption of Vesuvius in 79 A. D., is supposed to have thus shattered one-half of the: original cone of Somma, burying Pompeia and Hercula- neum under its fragments. Such craters are often occupied afterwards by lakes, particularly where the conglomerates are of a feldspathose nature, since these form, by mixture with water, a mud or clay, which is imper- vious to water. Other lake-basins, in volcanic districts, are formed by ex- plosions from a deep focus, on some fresh point of the earth’s surface, as are some in the Eiffel and Auvergne, which have been drilled in this manner through rocks of greywacke slate and granite, the fragments of which are scattered on all sides. The bursting of lakes in the interior of volcanic craters, gives rise to what the author calls, Eluvial deposits; the trass of the Rhine, the moya of America, and some tufas, are attributed to this origin. These conglomerates sometimes assume a divisionary struc= ture on desiccation, and set very firmly, so as to be used as building-stone ; the tufas, which have not been thus forcibly mixed with water, seldom cohere so compactly. Organic remains occur, of course, also in these con= glomerates, particularly wood. ‘The primary vent of a volcano is some~ times shifted laterally ; the original crater remaining extinct, and usually reduced to the state of a solfatara. Teneriffe net Bourbon are noted ex- amples of this circumstance. The next chapter is upon Subaquesus Pelienab » which are supposed by Mr Scrope to be much more numerous than is generally imagined. Indeed, all insular volcanos (and most of those we are acquainted with are of this character,) have been originally produced by submarine vents. ~ The observed instances of eruptions from the sea are indeed few innum- en Our author mentions those off St Michael, one of the Azores in'1638, "850 Analysis of Scientific Books and Memoirs. .- 1720, and 1811; of Santorini, and the Isola Nuova in the Archipelago ; another off the coast of Iceland in 1782; and one amongst the islands in 1814, But, on reflection, we must conclude, that the. weight of the water above the vent, and«the refrigerating effect. of its contact, must, in all cases, condense the escaping volumes of steam, and prevent their rising to the surface, and rendering the eruption visible there, except when the orifice of the volcano has been raised by the accumulated pro= ducts of repeated eruptions, to within a short distance of that level ; so that numerous eruptions may be continually taking place within the depths of the ocean, without our being aware of their occurrence in any way. There is no reason for concluding such eruptions to proceed in any very different. manner from those which are subaerial. The expansive force © and temperature of the lava must be extreme, and proportioned to the great excess of the repressive force occasioned by the pressure of the supported — column of water. The lavas, when emitted, will, therefore, from the in- tensity of their temperature, and the resistance opposed by this dense me- dium to the exudation of the confined vapour, re¢ain their fluidity much __ longer in the open air, and, consequently, spread laterally to a far greater . distance from the vent, with a similar inclination of surface. . According to this, Java-beds, produced at the bottom of the sea, ought to exhibit a greater lateral extension, compared with their bulk, than. those which have flowed from subaerial volcanos ; and, in fact, the great horizontal dimensions of the floetz-trap formations of Ireland, Germany, Iceland, Faroe, the Hebrides, &c. have long been a subject of remark. Again, since little or no vapour can escape from the surface of the lava, such beds ‘should show very few scorie or scoriform. parts on their upper surface ; and, on the contrary, vesicles, or air-cells, may be expected often toabound through the interior of the rock, the extreme tension of the steam causing its parcels to expand as the lava flows on, while the rapid consolidation of the surface, and the weight of the sea above, must prevent their vising.ge wards. These characters also accord with the appearances of many of the flestze - trap rocks, amygdaloids, &¢c. which seem clearly to be the products of J submarine vents. Of the fragments thrown up by the explosions of sub- marine eruptions, some will accumulate round the orifice in rude beds, others be dispersed by currents, and mixed or interstratified with other marine deposits. In the north of Italy and Sicily, are frequent examples of ealcareo-basaltic conglomerates, (peperino) as well as of beds of basalt, alternating repeatedly with compact limestone ‘strata. ‘The hills of the Phlegrwan fields near Naples, the author supposes to have been thrown up by subaqueous eruptions from a very shallow shore, which has been subsequently elevated above the sea-level, by subterranean éxpansi When the summit of a submarine volcano is raised above the the sea, it conforms to all the laws, already investigated, which 1 the conduct of a.subaerial vent. Its elevation takes place in of two modes, viz. 1: By the:accumulation of matter, protruded by re- peated eruptions. 2. By elevation, en masse, from the expansion of. the AS “ta Mr Poulett Scrope’s Considerations om Volcanos. 36% inferior Java, The latter mode will be often accompanied by the heaving up of more or less extensive masses of the neighbouring strata. Examples are given of volcanic islands, which appear to owe their elevation from the depths of the sea to these different processes. Iceland, Teneriffe, Sicily, and some of the Leeward Isles, are quoted as islands which have,risen by the joint effect of both the above modes of subterranean activity ; the Isle of France, Pulo Nias, some of the Madeiras, and of the Hebrides, as instances of the latter mode acting alone. The author supposes the corale ~ line islands of the Pacific to be mostly based upon volcanic submarine eminences ; their circular or elliptical figure corresponding to the ridge of the central crater of a volcano, Many have been subsequently raised tar above the level of the ocean ; and the earthquakes, to which they are so eften liable, proye their elevation to be owing to subterranean. intume- ‘sence, and to be still in progress, while the continual growth of fresh coral’on their shores, augments at the same time their horizontal extent. Chapter IX treats of Volcanic Systems. The voleanic vents observable on the surface of the globe, are arranged either in detached groups, as those of Iceland, the Azores, Canaries, Cape Verd Isles, &c. ; or, and this is the prevailing case, in linear trains, ata greater or less distance ; often so close, that the products of the neighbour- - ing volcanos are in contact, and produce strings of volcanic mountains, such as occur in France, Germany, the Leeward Isles, Java, Sumatra, Ja« pan, Kamschatka, &c. The most remarkable series of vents of this kind on the globe, is that prodigious train which, beginning in the Andaman and Nicobar Isles, runs’through Sumatra, Java, Sumbawa, Sumba, Timor, and the whole group of the Moluccas, whence, taking a northerly direction, it has produced the Philippines and Loochoo Isles, Japan, Jesso, the Kurile group, and the peninsula of Kamschatka. Thence it diverges to the east, _ forming the chain of the Aleutian Isles, and appears to be continued southy. erly along the western coastof North America into California, Mexico, Gua- timala, Nicaragua, Panama, and the vast volcanic range of the South American Cordilleras, even to Terra del Fuego. If, as appears most pro- bable, such trains of volcanic vents indicate fissures, broken through the superficial strata by subterranean expansion, what a prodigious compound fracture in the crust of our globe does this immense chain, of volcanos disclose to us. In these systems, some few vents reniain occasionally acy tive, others closed, the former acting ‘as safety-valves to the neighbouring districts. In case of their permanent obstruction, some fresh vents must be produced, or some former orifice re-opened ; whilé violent earthquakes, and elevations of the neighbouring strata, will precede, or accompany this change. The author then ‘dwells on the appearances in the con-~ stitution of the known surface of the earth, which indicate numerous and forcible elevations of strata, by subterranean. expansions, more particularly in the elevated or mountainous districts, which, according to — him, are those points or lines that have suffered the. maximum of' eleva+ tion, from the extreme developement of the expansive process beneath them. But since, as has been stated above, and as is shown to: be eon- 352 Analysis of Scientific Books and Memoirs. formable to observation from a variety of instances, the existence of attive volcanos obviates the occurrence of such extensive elevations of the su- perficial strata, by letting off, through fissures in these strata, the super= fluous caloric which would otherwise accumulate and produce succes sive powerful expansions of, in the great bed of lava beneath them, we must expect to find such spiracles to be frequent in the lower levels of _ the globe’s surface, and rare in those higher,—and this is precisely true to the letter ; for we know of very few volcanic vents in the interior of the - continents, or amongst mountain ranges, while they rise in vast numbers ‘from the depths of the ocean. If the Andes are urged as a striking ex- ception, it is replied, that this great range is itself composed almost wholly of volcanic, or, at least, pyrogenous rocks, which, like A®tna, Teneriffe, - &c. have swelled to their immense height by the accumulated eeotinn of very productive vents. ‘ But, notwithstanding the distance usually interposed between the prin cipal trains of volcanic vents, and the elevated continental ranges, Mr __ Scrope thinks he perceives a frequent and remarkable parallelism in their direction. Thus, the yolcanic trains of France, Germany, and Italy, run decidedly parallel to the opposite ranges of the Alps and Apennines ; that immense chain which encircles the Pacific, is almost uniformly pa- rallel to the neighbouring high lands of Asia and America, &c. ; and he is thus led to suppose, that the creation of fissures of elevation, and the protrusion through them, of crystalline rock, chiefly in @ more or less so- lid state, together with the heaving, dislocation, and contortion of the strata on either side the cleft, that process, in short, to which he attri- butes the production of mountain ranges, was the immediate and primary _ result of partial expansions of the subterranean lava-bed at a great depth ; while the fissures of eruption, which give rise to the properly so called volcanic eruptions, on different points of these tracks, were second- ary and incidental results of this process, being- chiefly occasioned by the lateral drag of the superficial strata towards the line of elevation, which the action of powerful force, heaving them upwards on this line, must necessarily produce. The author remarks, that the generalization of this important fact, that the elevation, en masse, of the solid strata, composing | the crust of the earth, has been inversely proportional wo the develope- ment of the volcanic phenomena in the same quarter of the globe, demon- strates, that the subterranean bed of intensely heated crystalline rock, (or lava,) whose local existence was proved in the early part of his essay, must extend generally beneath the whole surface of the globe. The transmission of caloric to this bed, from within, appears also to have been uniform and constant, having produced successive expansions in it, and © proportional elevations of the overlying surfaces in those parts where no facilties existed for the outward escape of the caloric, and continual tions attended with little or no elevation, wherever vents were | for the extravasation of the heated and intumescent matter, = F In the Xth Chapter, ‘on the Developement of Subterranean Expan- sion in the elevation of sth and production of continents above may sur- il Mr Poulett Scrope’s Considerations on Volcanos. 363 face of theocean,” the guthor quits the volcanic phenomena, properly so. called, to apply the knowledge with which the investigation of these phenomena has furnished him, on the nature and mode of action of sub- terranean caloric, to account for the geological features of the continental formations. And herein appears to consist a main distinction between the geological theory brought forward by Mr Poulett Scrope, and those of Hutton, or other writers on the same subject} who may seem to have fore- stalled him in some of his principal conclusions ; yiz. that, while the latter class of theorists directed their efforts to prove that the chiefappearances in * the constitution of the earth’s crust could only, or could most rationally, be explained by the hypothesis of an intense central heat producing ele- vations, &e., the author we are at present reviewing, directly demon- strates the existence of this central heat, and elevating power, from the phenomena of volcanos and earthquakes ; draws from the same source, ‘conclusive evidence of the laws under which it acts ; and goes on to show, that such a power must, in the nature of things, have given rise to those elevations of continents and mountain ranges, with all the minor pheno- mena of inclined and distorted strata, dikes, veins, faults, &c. which it is one of the chief objects of geological inquiry to account for. This chapter commences with the remark, that-the arenaceous and sedi- mental strata, which compose the major part of the surface of our con~« tinents, are found to assume a great degree of inclination, and more ir- regularities of position, as we approach the chains of mountains, or lines of maximum elevation and disturbance. They, however, almost uni- versally lean against masses of crystalline rocks, which form the geologi- cal axis of every mountain. Of these rocks, some are stratified, or rather have a laminar structure,.as gneiss, mica-slate, &c., and show marks of | the action of some violent force upon them, in their repeated flexures, cracks, and highly inclined position; others are unstratified, (granite, syenite, porphyry, serpentine, diallage-rock, and greenstones, &c.,) and usually underlie the others, or cut through them in the manner of im- mense dikes. The latter are supposed by the author to be portions of the subterranean crystalline bed, protruded by inferior expansion, sometimes in a state of partial liquefaction, at others as a solid mass, through a longi- tudinal cleft broken across the superficial strata. ‘The laminated crystal- line rocks, which formed the lower portion of these strata, were forced _likewise through the fissure by the tremendous friction of the rising mass, and, during this process, were folded into repeated doublings, like those produced in a bale of cloth or linen, by a powerful pressure, acting nearly in the direction of its layers. In general, the central axis of unstratified crystalline rock, will appear like a vast dike intruded between the repli- _ eated schists on eithér side; at others, these protruded strata will still __-cover the axis like a mantle. Where the temperature of the exposed parts __ of the crystalline axis was intense, a superficial intumescence may have taken place, the liquefied matter overspreading the edges of some of the over- lying or protruded strata, and thus giving rise to the appearance of second- "ary granites, syenites, porphyries, &c. Portions of lava will also be in- VOL. Iv. No. II. APRIL 1826. Z 854 Analysis of Scientific Books and Memoirs. jected between the folds of the lower schists; and into any crevices or fractures formed in them. At the same time, the upper strata recede, in a lateral direction, from the axis of elevation, slipping down the inclin- ed planes of their stratification, by the influence of gravity, and become also more or less bent and folded together, owing to the resistance opposed to this subsidence, by the inertia of their distant unclevated _ parts... Curvatures and replitations could, however, only take place where the strata were in a semi-solid state, or where the peculiar structure of — the rock was favourable to the partial mobility of its parts ; and this ap-_ pears to have been particularly the case with the laminar and schistose rocks, whose parallel plates of mica are enabled to slip, with more or less facility, over one another ; such rocks appear to have often suffered an ex- traordinary degree of replication. By the subsequent destruction of the extreme flexures of these folded strata, they seem, to a traveller passing across their edges, to alternate repeatedly in a recurring series. Where the induration was more complete, or the structure of the rock unfavour- able to flexibility, as in the compact and massive limestone formations, numerous fractures, fissures of all sizes, often of great width, will have been broken through them, and the intervening masses of strata more or less dislocated and disturbed in their position, sometimes, perhaps, left.in isolated patches on the summit or flanks of the protruded crystal- line rocks. This appears to haye been the origin of the insulated py- ramids of dolomite, which rise from the great porphyry district of the Tyrol. Indeed,,any one acquainted with the aspect of the limestone formations of the whole range of the Alps, will acknowledge, that, in this irregularity ‘of position and inclination, their perpendicular escarp- ments, and chasm-like vallies, these vast masses of strata aecord preci ly with what might be expected from a mode of elevation, such as is here attributed to them. Thus, of the fissures broken through the eleyated strata, thdse which descended sufficiently in depth, and open- ed into the: inferior lava-bed, occasioned extravasations ‘of this substance, producing dikes, &c, others which were too narrow and intricate to al« low of their occupation by the intumescent matter, were yet permeable to the vapours that rose from this subjacent and intensely heated mass, bringing with them both earthy and metallic sublimations, which would be deposited’ on the sides of the fissures, together with fragments bro- ken from these sides, or fallen from. their upper parts, whence the mineral veins. Those fissures which did not communicate with the heats ed lava-bed, were filled i in. part, or altogether, by rubbish alone, and these _ are the faults or slips of miners. The formation of calcareous and other _ breccias, and veined marbles, is accounted for by the smallest/of these frac tures ; the still unconsolidated juices of the rock oozing into its cracks and crevices, and filling them with a deposit of finer matter. The q veins of the arenaceous and micaceous rocks are ettailvated to the process. . 1 GF Bea) The author goes on. to draw a distinction ‘ead the primary range, é or axis of elevation, along which the overlying strata were ones i Mr Poulett Scrope’s Considerations on Volcanos. 355)— elevated, solely by the developement of subterranean expansion beneath, and those secondary ranges, or axes of elevation, which consist in the con- vex flexures produced on either side of, and more or less distant from, the primary axis, by the replication of the elevated strata, as they slipped away from this axis. Whatever expansions took place in the inferior crys- talline mass beneath these secondary convexities, were occasioned by the reduction of pressure on it, not by the absolute increase of its expansive force, as in the primary axis. These secondary ridges are more or less parallel to the primary. The occurrence of proximate ranges of elevation, or any other causes productive of local variations in the resistance to the lateral movement of the strata, would occasion proportionate aber= rations from this parallelism. The intervals between these parallel ranges, that is the coneave flexures, or fractures, produced the longitudinal val- lies of mountain districts. In the north of Scotland, such vallies, sepa- rated by intervening secondary ridges, are numerous and remarkable,, forming the basins of the greater number of her lakes and estuaries, The author supposes even the great valley of Switzerland, on one side of the. Alps, and that of Lombardy on the other, to be examples of longitudinal. vallies having this -origin. ‘The range of Jura on one side, and that of the Apennines on the other, are in this view, the secondary ridges occa- sioned by the replication in the strata, which were driven laterally to- wards the north and south, by the forcible elevation of the primary range of the Alps. In England, the ficetz strata are supposed, by the author, to have slid in a lateral direction towards the German ocean from off the, elevated range of Devon, Wales, Cumberland, and Scotland. But besides the longitudinal fractures of the superficial strata, others will often have been formed ini a direction transverse to the axis of eleva« tion, by local irregularities in the mode or time of elevation. Many of the transverse vallies of mountain chains are referred to this.origin, par- ticularly those deep chasm-like gorges which contain lakes at the foot of the higher Alps, both on the north and south. The waters of the ocean retreating from the surfaces, thus suddenly raised above their level, would ' retire with immense impetuosity through these fissures, and enlarge and. deepen them, leaving vast accumulations of transported fragments at the lower extremity of such gorges, where the velocity of the debacle was first checked. (Diluvium of Switzerland, Piemont, the Italian lakes, . &e.) Other transverse vallies were, perhaps, wholly scooped out by these retreating waters, which would excavate their channels along those lines into which they were directed by the accidents of level, and the greater or less resistance of the rocks over which they rushed. These vallies, according to the author, have been enlarged and modified, and many others, particularly all the smaller ramifications, entirely excavated, _ by causes still in action; more especially the fall of water from the sky, and the erosive force of its descent from higher to lower levels. It is re- marked, that there are good reasons for concluding that the quantity of water circulating oyer the globe's surface in this ‘manner, in given times, has progressively diminished, with its diminution of temperature, from the 356 Analysis of Scientific Books and. Memoirs. - Mi earliest ages of the world ; so that we need not shrink from attrib to its agency effects far exceeding in magnitude those of which i it ian, pears capable at “present. . ‘ One decided proof of the slowness of ¥ process of excavation, wherever it occurs, exists in the sinuosity of water- . channels, and in such a case, and such are met with eyen amongst the , ~ largest river vallies, it aie to talk of transient-deluges or debacles as.. the excavating agent.” P With regard to the periods at which the different continents may haven : been heaved upwards, our author concludes, from the analogy of ‘the volcanic phenomena, that such elevations took place by successive shocks ; the greater number being of minor violence, similar to the earthaiuiees which oceur at present ; but some of prodigious power, (paroxysmal ex~ “pansions, ) and analogous to the paroxysms of habitual volcanos. If it_ is true, that outliers of the plastic clay and ‘chalk have been recognized on the highest summits of the Alps, it would appear that this colossal chain, and perhaps with it the whole continent of Europe, owes its eleva-_ tion from beneath the sea to some catastrophe of this nature, at what we are accustomed to- reckon a comparatively recent geological epoch- _ The traces of diluvian action, the boulders of the Alps and Sweden, and the alluvium of the north of Europe, may have been produced | by the retreat of the ocean from this elevated surface, and the successive oscillatory movements to which it must have been subjected before it regained its level. Other paroxysmal expansions may have oc- curred in earlier ages of the globe’s history, and in the old red sandstone formation, it is observed, we may perhaps trace. the result of such a ca- , tastrophe. The occurrence of repeated elevations.on a large scale, is, in- deed, attested by numerous geological facts: It is also probable, from. _ what we know of the power. by. which they are occasioned, that - they. were far more frequent and violent in the early part of the history. of the earth than they can be at present ; for, unless we suppose the pro-, portion of caloric transmitted from the interior of the.globe towards its, surface to have been always on the increase, (which is directly the re-. verse of the opinion professed by the author,) it is clear, that the con-. _tinual and general increase of the repressive force, by the additions made. to the solid strata of the globe, in the products of volcanos, and incrust-. ing springs, and also to the body of water and atmospheric fluids which press upon that surface, must have proportionately diminished the ratio. of subterranean expansion, from the commencement of the process up to the, _ present day. The author then adverts to the mineral nature of the ge-_ neral subterranean bed of crystalline rock, (or lava.) This he concludes. to be probably granitic ; and supposes that some of ‘the elevated portions. : of it, may, by the effect of repeated intumescences, and reconso under varying circumstances of temperature and pressure, by whi component minerals would be more or less disintegrated, d and. their elements recombined in new proportions, and on ‘ points, have been converted into bare greenstone, porphyry, compact, felspar, serpentine, diallage rock, &. The analogy of, ordinary volcanic, Mr ‘Pouleté Scrope’s Considerations on Volcanos. 3571 rocks, in which such changes, to a certain extent, indisputably take place under similar circumstances, supports this conjecture ; and since all the above varitties of rock are found in nature to graduate into one another, it cannot be unreasonable to. suppose alf may have been elaborated from the same raw material. ‘The work would appear to have terminated naturally here, at least the author is anxious to keep the part of which we have now given a sum= mary, and in which he ‘has endeavoured to confine himself within the bounds of strict logical inference, (deducing from the evidence of the vol« canic phenomena, a certain degree of knowledge as to the nature and mode of operation of subterranean caloric, and applying this knowledge to account as well for the detail of these phenomena, as for the inequali- ties in thé surface of the globe,) separate from the concluding’ chapter, which contains theoretical matter of a more general and less substantial character ; in short, an attempt to sketch the outline of what may be called the History of the Globe. =” To this, indeed, the author was naturally led by the results of his pre« vious investigations ; for having proved the existence of. vast subterranean * reservoir of caloric, the effect of which is still to occasion violent changes in the superficial crust of the globe, and which appears to have formerly produced similar changes of far greater magnitude, it is impossible not to suppose the same cause to have had a large share in the original formation and disposition of that crust. In fact, the elevating process, which, in the foregoing chapter, is shown to have produced the present irregular dis- position of the superficial rocks, presupposes a peculiar arrangement of these beds, previous to their elevation above the sea level. The crust of the globe must then have been composed of concentric coats, consisting of, Ist, The secondary and transition series of strata ; 2dly, The series of laminar and schistose crystalline rocks, viz. pevetin, mica-tale and> chlorite, schists, &c.; S3dly, and- finally, the granitoidal matter, confined at an intense heat by the compression of the overlying strata. The origin of the sediinental and arenaceous deposits of the ocean, com posing the first series, discloses itself by the organic remains contained in them, and their analogy to the actual deposits of our rivers, lakes, and seas. The fragmentary rocks apparently owe the magnitude of the scale on which they have been sometimes produced to the violent oscillatory movements to which, as has been noticed above, the ocean must have been subjected by any paroxysmal elevation of a large portion of its bottom. Even where the elevation took effect: only on strata already raised above the sea-level, the effect on the waters of the globe would be still most powerful ; for the radius of the globe being dilated on that point, a propor= tional body of water must rush immediately towards the opposite, or an« tipodal point, to preserve the equilibrium of the globe, and a series of vio« lent oscillatory movements must take place general to the whole ocean, and ‘producing a permanent alteration in the relative levels of land and water all over the earth ; these effects being proportioned to the mass of mat- ~ 358» Analjsie of Scienlific Books and ‘Memoirs. \) ter raised, and thé amount of its elevation. The coarser fragments trans- ported by such moving waters, will have been deposited in the longitudi- nal yallies of mountain ranges, and wlferever the currents were first con- “siderably checked. The finer detritus will have afterwards subsided, when the ocean had regained its equilibrium, and mixed with the precipi- ~ tations which were taking place contemporaneously from its waters, and with the bituminous and calcareous matter, proceeding from the decomposi- tion of vegetable’ and animal substances, the shells of miollusce, co- ralline bodies, &c. produced the sedimentary formations. As the depth of these beds of’ pulpy matter increased, the consequent pressure upon the lowest. of them, by bringing the similar particles slowly and gradually within the sphere of action of their mutual attractive forces, occasioned the successive formation of separate horizontal concretions, or strata, more or less fully consolidated, which some subsequent expansion elevated above the sea-level, where they lost by drainage all the water they contain- ed, and were by desiccation still farther indurated. The author opposes the Huttonian theory, that these strata were har< . dened by heat from the interior of the globe, which he thinks wholly _ disproved by the occurrence of clays and shales beneath indurated strata. The consolidation of limestones, sandstones, &c- he attributes solely to a concretionary action, accompanied by a more or less imperfect erystalli- zation of the very finest particles which act as a cement to the coarser. The more complete the process of crystallization, the more solid and compact the rock ; and therefore the larger the proportion of precipitat- ed matter, (which, as being much finer than any sediment, is more fa- § vourable to crystallization) the more crystalline and the harder willbe ~ the strata. It is well known that, amongst the stratified rocks, the older “are generally the most crystalline, and hence we should expect the quantity of matter precipitated by the waters of the ocean to have been greater in former times than now. The author attributes this to the high- er temperature of the ocean in those ages, and the greater quantity of mi- neral matter carried into it in a state of solution by the vapours evolved from the interior of the globe. Even. the more completely crystalline rocks, such. as statuary limestone, quartz rock, and rock salt, appear to the author in the light of precipitations from the primitive ocean, where, at this time, the sedimentary matter predominated, mica, tale, and chlo- rite slates were deposited. With regard to gneiss, the lowest of the strati- fied rocks, the author considers it to share in a very slight degree in the character of a sedimental rock, to Haye. been in short a granite | which, after a great degree of intumescence, was- reconsolidated by the pressure it sustained between the expansive force of the granite beneath, and the weight of the solid strata which.had settled above it, as well as of the ocean and atmosphere. ” The author then generalizes these viewsas: to the origin of the rock formations, in a “Sketch of a Theory of the Globe,” of wh ch the following is a brief abstract. The mass of the Blobe, or at least its external zone toa great dept i Mr Poulett Scrope’s Considerations on Volcanos. 359 supposed to have been originally granitic, and that, on reaching its actual orbity perhaps before, a great proportion of the pressure was removed which had previously preserved it in a state of crystallization, notwith« standing its intense temperature, (perhaps as an integrant part of the sun, from which the author isinclined to think it a projected fragment, ) according to the notion of Buffon and Laplace.” Violent superficial expansion was the result of this diminished compression ; the dilatation decreasing towards the interior, from the surface, which would be completely volatilized to that point where the disaggregation of the granite was wholly checked by the pressure of the zone of liquefied matter gravitating towards it. “Where the elastic fluid generated between the crystals of the rock, and which oc« casions its liquefaction, was produced in sufficient abundance, that is, in the outer and highly disintegrated zones, the superior specific. gravity of the crystals forced it to rise upwards, and thus a great quantity of aque- ous vapour was urged towards the surface of the globe: as this vapour rose into outer space, its continued rarefaction must have lowered its tem~ perature till a part was condensed into water, which fell baek in torrents upon the surface of the earth, giving rise to the primeval ocean, which, however intensely heated below, would be retained in a fluid state by the loss of temperature sustained from the vaporization of its surface, and the pressure of the highly condensed atmosphere upon it. This ocean will have contained, both in solution and suspension, the earthy substances which. proceeded from the volatilizationof the superficial granite, or which were carried upwards by the ascending vapour from the disintegrated mass below. The dissolved matters were silex, carbonates and sulphates of lime and magnesia, muriates of soda, and other mineral substances which water at an intense temperature, and under such peculiar circumstances, may be supposed capable of holding in solution. The suspended sub- stances were all the lighter and finer particles of the upper beds where the ebullition had been extreme, but, above all, their mica, which, from the tenuity of its plate-shaped crystals, will have been most readily carried up by the ascending fluid, and will have remained longest in suspension. When the excess of vapour had effected its escape from the disintegrated granite, the crystals of felspar, aud those of quartz, which had remained undissolved by the heated water, subsided. first, together with the smal- lest and least buoyant crystals of mica ; and these crystals would naturally arrange themselves so as to have their longest dimensions parallel to the surface on which they were deposited. This mass, when subsequently consolidated by pressure, formed the gneiss formation, which graduates downwards into granite. Upon this, the larger plates of mica and quartz grains would continue to be deposited, while, at the same time, a large quantity of the silex, held in solution by the ocean, was precipitated as - the water cooled. Thus was produced, by degrees, the mica-schist forma. tion, graduating downwards into gneiss. On some spots, and perhaps at a * The author, in a note, compares the globe at this time to an aerolite, in which the superficial crust of vitrified matter bears some analogy to that which then per- haps formed on the surface of our planet. 7 360 ; Analysis of Scientific Books and Memoirs +i ; fh ~ later epoch, ‘instead -of silex, carbonate of lime was precipitated, together with more or less of micaceous sediment, producing the saccharoidal lime- stones.. Upon this mica-schist, and graduating into it,-were deposited in turn, as the waters of the ocean cooled, and’ its local disturbances ceased, , or recommenced, other stratified rocks, composed sometimes of a mixture, . Sometimes of an alternation, of precipitated, sedimentary, and fragmenta~ ry matter, giving rise to the transition formations. In this manner was formed the first crust or solid envelope of the sflobés But beneath this crust’a new process had now commenced, occasioned by the increase of temperature and of expansive force of the upper granite beds ; which, having been greatly reduced in temperature by the dilatation it had - endured, and the partial vaporization of the water it contained, now-be- gan to receive an accession of caloric from the more intensely heated nu-, cleus. The first effect of such an increase in the expansive force of this zone, opposed as it was by the increasing pressure of the strata, whose pro-_ gressive deposition was going on above, would be to consolidate the inter~ mediate bed of gneiss ; the next, to produce, sooner or later, the disrup- tion of the solid crust, which impeded its actual expansion. This result took place on those parts where accidents of texture or composition in the oceanic deposits led to them to yield most readily ; and in this man- ner were formed, in the primeval crust of the earth, those original and deep fractures, through some of which (fissures of elevation) were protruded portions in a more or less solid state of the inferior granite, together with replications of the foliated rocks, (as described in a former chapter ;) while others (fissures of eruption) gave rise to local extravasations of the heated crystalline matter in the form of lavas, that is, still farther lique- fied by the greater comparative reduction of the pressure they supported. ' By these partial elevations of the superficial strata, violent movements were at times, as has been mentioned before, communicated to the waters — of the ocean which broke up the projecting eminences, and distributed their fragments in conglomerate or sedimentary strata. At first, the sur- face of the globe consisted chiefly of mica-schist ; and henee mica and granular quartz predominate in the earlier conglomerates and sedimentary strata, (grey-wacke, grey-wacke slate, quartz-rock.) Precipitations of silex and carbonate of lime, continued to mix with ‘the sediments of this pe= riod, and Mr _Scrope supposes quartz rock. and transition limestone to owe their dark colours to admixture with the finest particles of mica. Fora long time, it is probable that local developements of subterranean ‘expan= sion, producing partial elevations of the earth’s crust, local extravasations — of crystalline rocks in the form of dikes, beds, &c. and local deposits of. conglomerate beds, alternated with periods of comparative tranquillity, _ during which the finer sedimentary deposits and precipitations took we and hence the alternations of the various sedimentary and. sieve ta which compose the secondary formations. Meantime, as. the tempera= ture of the ocean decreased, it began to be thickly peopled =~ beings, animals, and vegetables of simple structure ;. the latter gi by their carbonization to the coal strata. At length, as the temperature Mr Poulett Serope’s Considerations on Volcanos. 961 - of the ocean and atmosphere diminished further, the quantity of water taken into circulation decreased ; the continents were no longer deluged by: perpetual floods of rain, and’ organized nature took possession of them also ;*the marine deposits contained less of precipitated matter, and be« came more earthy, and less crystalline ; strata of shales, dull limestones, chalk; marl; sands, and clay, succeeded those of clay-slate, marbles, and sandstones, unti] the gradual change wrought by the slow refrigeration of the outer zones of the globe brought about the condition in which it ex« sists at present. - The author remarks that, from the circumstances of their origin, the rock formations of every kind or age must have been-more or less strictly _ local; and that, though the formations of any particular epoch will un questionably have some points of general resemblance all over the globe, it would be absurd to suppose the same series of beds to diate been depo- sited contemporaneously over the whole of its surface. The author sums up, by attributing the production of the mineral mas- ses, as af present observable on the surface of our planet, to three sources, distinct in their nature, but of which the products have been often con- fused and mingled together from circumstances of isochronism or collocation. These are, 1. The precipitation of some minerals, particularly silex and carbonate of lime, from a state of solution in water, as its temperature was diminished, &c. . 2. The subsidence of suspended or fragmentary matter from water; to- gether with the accumulation and decomposition of the shells of mollusce, corals, ‘&e - 3. The elevation of eeyinidiins matter through fissures in the crust of the globe. The author conceives, that all the characteristic differetices ibastvuble in the successive formations of every kind, may be satisfactorily traced to the gradual diminution in frequency and energy of those productive causes, the varying nature of the original materials acted on, and the chemical and mechanical changes they have undergone during the process ; and with due allowance for these circumstances, these three modes of production are perhaps fully equal to account for the origin of all the mineral masses of the earth’s surface. ‘They have also one immense advantage over other hypotheses, and which speaks volumes in their favour, and -“ this is, that they are all still in operation,” and producing results completely analogous to those which are here attributed to them. In fact, (the author says,) the theory of the globe, which I have thus ‘hazarded, consists simply in’ the application of those modes of operation which nature still employs, on a large scale, in the production of fresh mineral masses on the surface of the earth, to explain the origin of those which we find there already. If, after fair discussion, and with all reasonable allowances, it is found adequate to this purpose, its truth will be established on the soundest’ possible basis—the same upon which rests the whole fabric of our know- ledge on every subject whatsoever, the supposition, namely, that the laws $62 Annkgors of Scientific Books and Memoirs... esiiiice do not vary; but that similar i iaars ares have: been, and willbe produced, by similar preceding circumstances. = 5) An appendix.is added to the work, containing a list of known volcanos in recent or habitual activity; and an examination of the anomalous phenomena described by M. de Humboldt, as having accompanied the eruption of Jorullo in Mexico.* The work is illustrated ne engravings, — Whiagraphe, and numerous wood-cuts. II. An Account of the Earthquakes which occurred in Sicily, in March 1823. By Sig. Anate Ferrara, Professor of Natural Philosophy: in the Uni- versity of Catania. He: (Concluded from last Number, p. 164.) hich Wuen the people about AStna perceived their houses beginning to shake, they turned their eyes towards ‘the volcano, and waited in expectation of | an immediate eruption. And while they looked, fearful apprehensions filled their minds, and they prayed that the event, be it what it would } might take place at once. _'The philosopher, who observes the phenomena of nature, for the take of reducing to the same class those of an analogous origin, and thence to deduce them from the same cause, observes the link which connects earth- quakes with volcanic operations, and sees with the ignorant vulgar, those mighty forces preparing in the subterranean furnace which are able to put in motion immense masses of the solid globe, and to agitate them as water is agitated by a violent wind. The eruption of tna in 1811 was inter-— esting from the grandeur of the spectacle which it presented, and no less ' go, from the instruction which it conveyed to the naturalist. A new opening was made on the surface of the mountain. Explosions of tremendous force preceded the emission of immense columns of smoke and. inflamed masses of matter, which were incessantly thrown up= wards, and-whose approach was announced by horrid roarings and ex~ plosions, which filled the air to a great distance. Each explosion was accompanied by shocks: and as the interval between them was of but a few minutes duration, the city and country, to a vast extent, were ina eontinued undulation. For many days at Catania, eighteen miles distant, we were rocked as though we had been upon the sea. Some of the shocks’ were very violent. ‘The door of my chamber, which I left purposely ajar, ~ kept a continued beating against its side posts. The shocks lasted as long as the volcano was in operation, that is, for more than nine months ; and when the external phenomena disappeared, the internal fire not being yet _ extinguished, deep subterranean rumblings and explosions were beets and shocks felt at each report. When the fire invests substances, it rarefies their masses. ioe a gree; the acquisition of new volume produces a proportionate e and under the action of an enormous accumulation of inflamed gg is made for it with sudden and fearful energy. bone. ale of * See our Last Number, p. 50. Prof. Ferrara on the Earthquakes in Sicily in 1823. 363 ‘water, for example, under a medium pressure of the atmosphere, is 1728 times its first volume, and it increases in the ratio of the heat. At 230° of Fahr. the pressure is equal to four atmospheres only. The explosion of a single barrel of powder, shocks and overthrows the whole vicinity. If, ‘then, a subterranean stream of water falls upon places where volcanic fires are burning, it is at once converted into steam, acquires a density proportioned to the resistance of the mass of earth above it, circulates about, and agitates the most solid mountains and great tracts of land, until, Josing its heat in the cavities of the earth, it returns to the state of water, ‘without haying given eny external marks of its existence. It seems that the return of the terrible phenomenon is owing to the flow of water into places on fire—of water, the streams of which are determined only by ac~ cidental causes. The vast furnace in the interior of the earth being infaragd, the fire at- tacks every thing exposed to its influence, some are liquefied, while others are converted to vapour ; these, developing their volumes, form a system of force moving with immeasurable power. The subterranean cavities, little able to contain them, are violently convulsed in all their dimensions ; and this effect is transmitted by the solid earth, to distances proportioned to the quantity of force, to the transmissive power of the body moved, and to various local circumstances favourable, or otherwise, to the propagation of motion. After having combated with the obstacles which oppose them, roaring under the earth, like the winds of A®olus, to find an outlet from the places in which they were produced, they circulate in various canals, until a cold temperature deprives them of the heat which gave them such _ power, and they sink into their former state. Often, however, they drive before them the matter which the heat has liquefied ; and urging it to- wards the ancient mouths of volcanoes, discharge it in flaming. rivers in the midst of the terrible phenomena which they themselves produce. Urged by the passion for observation, I have often descended into the - horrid cavity of the crater, and approached near the blazing brink of the new orifices which have vomited forth streams of fire ih my own time; I have seen immense torrents of aqueous vapour urged from the vast chim- ney, whose base is lost in the deep furnaces below ; I have been bathed in the water, to which-the vapour was reduced by the low temperature of the atmosphere into which it entered; often have I seen it fall in fine showers all around me, Haying penetrated into the recesses of the globe, it is in this manner forced, out again by the heat to which it is exposed. I have observed the hydrogen gas; one time burning with its peculiar colour ; at another, bursting forth with a loud, deep explosion; the sul- phuric and muriatic vapours, whitening the immense clouds of smoke, and filling all the air with their suffocating breath ; or, seizing upon the solid substances around, remaining fixed upon them. Fused substances, forced up by the elastic vapours, are disgorged from the same mouths, spread about in torrents of fire, and consolidated by the contact of the air. Is it not possible that the seat of these products may not be extremely deep, and that yet they may reach the surface? Who knows, but, in 864 Analysis of Scientific Books ‘and Memoirs. _ ‘other’ places, those grand laboratories ‘of nature, iin’ causes which will always elude our investigation, may be so deeply seated, that their pro- ductions never arrive at the surface, and that no other evidences of their existence, no other effects of their action are perceptible, but the shaking ‘of the earth, and the rumblings which the aériform elastic vapours make ‘in the cavities of the earth. | - Three principal furnaces have their outlets on the three sides of Sicily, and each with a force proportioned to the circumstances which supply it with combustible matter. tna on the eastern side, by the immensity of its power, rules the whole island. When in full action, the island trembles to its foundation, and feels the mighty power which has borne rule there from time immemorial. Its roarings are heard from one éx- “tremity to the other ; but the parts most agitated are those in its neigh- bourhood, and those between it ahd Cape esa 3 a space of about a hun- “dred miles. : - ‘The mountain of Sciacca, on the southern shore towards the west, seems to cover a place where the elements have been in ceaseless operation for ages’ From dark caverns, which open in the more elevated parts, tor rents of water, in the form of heated vapour, with sulphurous gases, are ejected. Having’ penetrated into the internal recesses, but unable'to ex tinguish the fermentation, the water becomes invested with fire, is con verted into vapour, and thus exhaled into our atmosphere. The extrica ‘tion of the steam causes, in the internal caverns, a deep roaring, and often _ fearful convulsions, felt at a distance.’ At such times, Sciacca, at the foot of the mountain, experiences the most violent commotions. In 1578, it was reduced to ruins. In 1652, for fifteen days, it suffered the most se~. vere and unremitted shocks. Kor some months, in 1724, the earth’ was ‘0 frequently and violently agitated, that all the inhabitants fled into the country: In September 1726, all the western part of Sicily was shaken with the greatest severity ; and, in Palermo, at that time, many lives were lost, and many edifices destroyed ; in June’ of 1740, Seiacea felt twenty~ ‘two shocks, with injury to buildings, and loss of lives; that of the 25th © was of such immense force, that it extended as far as Palermo. After the middle of December 1816, the inhabitants heard extraordinary rum- blings under the mountain, and in January of the succeeding year, the’ ‘shocks were so frequent, that twelve were sometimes counted in one day, and so violent, that it seemed that the foundations of buildings must be ~ rooted up—the rumblings and. explosions under the mountain became fearfully loud—and the sea dashed in great waves against the shore at its foot- Sambuca, fifteen miles distant, suffered much injury. A strong odour of sulphur pervaded the air all about Sciacca. While nature ‘was in this agitation in the western part of the island, the eastern was enjoyit perfect quiet. Over against Sciacca, at the distance of seventy ma Pentellaria rises from the sea, and presents the same phenomena : an of lava, and other burnt matter, and streams of heated vapour of water, and of sulphur issuing incessantly from its cavities, show a great fermen- ‘tation in the deep caverns under the sea, and fo which little is wanting Prof. Ferrara’ on the Earthquakes in Sicily in 1823. 366% to renew itsancient conflagrations. Off the northern coast of Sicily, is situated a chain of islands, extending from east to west, and terminating, with Ustica at the distance of forty-two miles from the western shore of Palermo. All of these islands, sons of volcanic fire, which has raised. them from under the depths of the sea, bear the impressions of the ter- rible element ; and some are still burning, and serye as outlets to the sub- terranean furnaces. Vulcano, twenty-two miles from Cape Milazzo,. burns, roars, thunders, and. throws out continually immense columns of smoke and flame. . Stromboli ceases not a moment. in vomiting forth smoke, flame, and streams of vapour, which, rushing from the inflamed. mouth, produce a horrible roaring, spreading terror among all the Eolian islands, and the adjacent coasts of Sicily, and Calabria. Lipari still pre- serves in its baths, a part of that heat, which one day fused into glass the matter of which it is formed. The action of these islands has almost al- ways troubled’ Sicily. Early one morning, in February 1444, enormous masses Of heated matter, amidst huge volumes of smoke and flame, were raised. from the summit of Vulcano, hurled about the sea to the distance, of six miles, while strong shocks agitated this island and Sicily. Other flaming masses. were thrown out on the 24th of August, 1631, which, driven by the wind, passed over. Naso in_ Sicily, directly in front of Vul- cano, and, on the next day, this unhappy city, by the violence of the con- vulsions of the earth, was entirely laid in ruins. Many persons were in= jured. A cleft was made in the-soil, from which a very strong odour of sulphur issued.. On the 22d of April 1717, at dawn of day, a deep sub-, terranean murmur was heard, accompanied by a severe earthquake, the shocks of which were felt all along the northern shore, even to Messina.. But the places which suffered most, were those nearly over against Vul- eano, as° Milazao, Pozzodigotto, Castroealo, twenty-six miles distant from it. The last city was entirely ruined. Shocks were renewed in the same places in 1732; and with much greater force in 1736, when the whole northern coast was violently aftected, particularly Palermo, Ciminna, which was much damaged, and Naso, which suffered still more. .On the 4th of ’May 1739, about 5 o'clock, Pp. m., the inhabitants of St Marco, a town, back of Naso, saw thrown from the mouth of Vulcano, immense clouds of smoke and burning matter, which, driven by the wind, came roaring and thundering over. Sicily, letting fall perpendicularly into. the sea, and on the neighbouring shore, flaming matter which gave out on every side bright sparks, and struck with fearful crashes. It passed. over Naso and St Marco, and went on wasting itself in the interior. Such phenomena were unlucky omens to these unhappy towns.. At 12 o’clock, on the 9th, a dreadful howling from Vulcano, was followed by a violent shock, which, after a few. moments, was repeated with many explosions ; more thana hundred were counted within six days, and another on the twenty-first, Great rocks were detached from the mountains-in the vicinity. Another flaming mass on, the 9th of June, darted from Vulcano and. passed oyer Sicily ; shocks were felt till the 22d, accompanied by howlings and ‘nu- merous explosions from the burning mountain. St Marco suffered cx- 366 Analysis of Scientific Books and Memoirs. ceedingly, but Naso was entirely destroyed. . The volcanoes of EKolia con~ tributed much to the earthquakes of Calabria and Messina in 1783, Stromboli was almost always in great commotion. For many days it seemed like a mad bull, which, raised above the waves, by his. roaring filled Calabria and Sicily with terror. Vulcano often accompanied it, - and its deep ramblings, and vast columns. of bones _ flame, were ter- rible. After the violent: caittigualadsor Sciacca in 1816, the enh im dante happened to other parts of the island. On the 15th of April 1817; a se« vere shock terrified the people of Caltagirone in Valdinoto, and of the neighbouring places. One happened at Catania in October, and another - _on the 20th of February of the following year, 1818, which was enormous. All the towns about AStna were ruined, and many lives lost. Catania ' felt its injurious effects. _ It was felt all over the island, since at Palermo it produced three undulations. Others which. followed it, and which continued to agitate Catania and the neighbouring region until April, were felt with greater force. All these shocks were the precursors of the grand eruption of Aitna, which burst out on the 27th of May 1819, and which lasted until August. While Sicily was tretnbling, the voleano was making its preparations in silenee. ‘The effects of the operations of Adtna, are felt in places at a great distance from the mountain. After the troubles of February and April, Catania and its vicinity enjoyed repose until the 8th of September, when all Madonia was convulsed. Other shocks succeeded in October and November. On the 25th of February 1819, a very severe one was felt, which extended to a great distance. At — Palermo, three motions were produced, the last of which was very violent. The shocks in the whole of the vast extent of the mountains, where so much injury was done to the houses of the numerous inhabitants of these regions, were always preceded and followed by subterranean murmurs, and distant explosions. Under. these places, it seems that those substan ces were deposited, which tna inflamed and ejected from its mouth in the following May ; because, after the eruption commenced, Madonia was — left quiet ; while A&tna, which, till this time, and during the agitations of Madonia, had remained perfectly calm, became Meiebi pais with earth- quakes. They accompanied the eruption. La With the extinction of the conflagration in August, all si phoneiian ceased, and the eartlf was no longer agitated. .But in 1822, ZZ tna showed that the fermentation within its furnaces was again at work., On the Sth of April, rumblings and continued explosions were heard, which were fol- — lowed by great clouds of smoke, violently driven from the crater by the impetuous current of elastic vapours. A shower of sulphurous ashes fell # all around. On the 6th, a violent shock convulsed all the towns b Atna and Madonia, Capizzi, Cesara, Sperlinga, Troina, Gangi, but in the midst of these, Nicosia seemed the centre of impulse in shocks which followed throughout the month. Its soil appeared point of being torn up by force, many buildings were destroyed, inhabitants fled in consternation to find an asylum in the country. The a ae Prof, Ferrara on the Earthquakes in Sicily in 1823. 367 immense clouds of smoke, and earthy ashes, which were ejected from June to October ; which covered the more lofty part of the mountain with a gray stratum; which filled the atmosphhere, and gave out through the whole region a strong odour of sulphur, clearly prove that all these com- motions were produced by forces collected in the recesses of Al tna. While Nicosia and the whole space between Madonia and Atna were in such commotion, Sicily to the west, and all the northern coast, enjoyed perfect quiet ; but a sad reverse was preparing. In October, Aftna ceas~ ed throwing out sulphurous ashes and sand, and with it ceased all its noises, and shocks, and all was calm. In February, in the beginning of the next year, smal! motions of the earth were felt along the northern side of the island, which were the preludes to the scene _ cere itself in March. The direction of the motion was from N. E. to S. W. as was proved by ‘all the phenomena mentioned in the beginning. 1 will not be guided by the injuries suffered in different parts, for these spring from a complica-- tion of causes ; from the soil, its greater or less capacity of receiving and - eommuhicating motion ; from the manner in which it presents itself to the progressive motion, and from the state of the edifices. These cir- cumstances may sometimes produce anomalies which easily deceive those who do not bestow in the examination of them the attention which they deserve; but without fear of error, I may say, that in general the shock was much the most forcible on the northern shore, and at a little distance from it; and that it went on gradually, diminishing towards the inte- rior. The moving force, then, must have been in operation somewhere under the sea opposite this part of the island. Naso was almost en- tirely ruined ; Patti, and all the towns about Capes Orlando and Calava, and which are nearer Eolia, were considerably damaged. Some very small, thinly inhabited towns lost little, because they had little to lose ; others were in some measure defended by their situations. Palermo, at the bot- tom of a bay which curves towards these burning islands, and surround= ed by large and high mountains on the other side, was exposed to the .~ “whole force of the motion against it; this it was, together with the de-. graded state of its buildings, which brought such ruin upon this beautiful city. Every thing seemed then to announce to us, that the most expan- sive vapours which proceed from the burning furnaces of Eolia, in de- veloping their immense volumes, urged against the sides of those cavities which once contained the matter of which all these islands are formed, produced the motion that struck obliquely against Sicily, and moving along the shore towafds the west, spread despair throughout Palermo. After the shock of the fifth, their motion was more free ; and they were heard murmuring under the soil near our island, seeking an outlet from | the obscure caverns in which they were generated, but not propagating their motion to any considerable distance. The course of that of the seventh was in the same direction with that of the fifth ; but that of the thirty-first was in a direction directly opposite, since it was felt at Mes- sina. and not at Palermo. The undulations were determined by the ho- ye 868 - Analysis of Scientific Books and. Memoirs. >... _ rizontal direction of the motion ;. the. perpendicular shocks; by a force acting from below upwards, which supposes a much greater depth in the situation of the acting force, than the other, without ever. being i in any case nearer the surface. Every one may easily distinguish the difference which subsists between the superficial motion caused by the rapid passing of a heavy carriage, or by the sudden combustion of a large quantity of con- fined powder, which would cause the darting of a large accumulation of electric fluid to restore the equilibrium between the earth and the atmos- phere, were it possible for it to collect in the midst of so many conducting bodies which seem designed to restore the equilibrium instantly ; between this motion and the deep, heavy earthquake, armed with such terrible power, which agitates so violently a great extent of the globe, which sometimes seems ready to tear it from its very foundation, and which has | all the characters of an effect sprung from most. wonderful degrees: of force, and of force which, placed deep in the earth, moves and conyulses those great masses lying between it and the surface. The idea of forces and effects like these, fills with fear the jot art mortal -who creeps upon the face of the earth, and brings his pride down ‘to the dust. When he sees the earth reel, and. the great fabrics which he has raised with so much confidence rushing to ruin, he despairs of find- ing any where one firm support to his frail existence. *.., The chinks and fissures formed in many places, and to mbich the ok gar attribute much importance, are in consequence of the quaking of the soil, and to which the softness of the earth, and the loss of itsinternal —— support have given rise. The country of Bosco, about Ogliastro, of which I have already spoken, became furrowed with diverse, long,, tortuous, deep clefts, the sides of which, in. some. places, sunk ,down ;, in other places, portions of the surface passed down over inclined planes! below them, and took new positions ; the olive-trees which some of these carried with them, were much injured by the breaking and displacing of: their roots. This land is formed of an immense deposit of argillaceous chalk, more than a hundred feet deep. The. water which penetrated it. (and the winter there was very rainy) loosened the. earth, and, carried,.a great part of it into the internal cavities below ; the surface,’ thus wanting solid support, under the shock of the carthauake, became filled with depressions, caverns, and inequalities. ‘The same may be said of a great aperture made in the vicinity of Colesano, which, dilating itself day after day,’ threatened to render those places inaccessible. Copious showers alone produce such. effects in the chalky land of ,many-parts of Sicily. ‘This want of. firm bases frequently causes the overthrow of great rocks at the time of e: quakes. Well do we remember, that, in the earthquake of the : February 1783, a mountain, a mile to the south of Scilla, and y a mile and a half in length, fell over into the sea of. Calabria, two new promontories. mee If all these facts induce us to ae in. Eolia, the causes of, : 4 events of the past. March, it is necessary to inquire if these i exhi= ‘bited, at that -time, any PAPO: which. wey na opinion. — Prof, Ferrara on the Barthquakes in Sicily in 1823. 369 I will mention, therefore, in this place, many facts, about which there can be no uncertainty, and which will be of the greatest importance, should any one wish toypush the conjecture which I have announced in this me- moi, to*certain evidence. Since September of last year, the daily quantity of smoke from Vulca- no, has been much greater than usual; and flame has often been visible in the evening. MKxplosions have been frequently heard on the neighbour- ing coasts of Sicily. But Stromboli has exhibited the greatest activity for ‘almost fourteen months without intermission. Shocks have been very frequent, and so strong as to fill the islanders, although accustomed to them, with great apprehensions. The island, with the blazing mountain - itself, seemed often on the point of being torn up from its foundation, The volcano opened two new mouths on the side which looks towards the sea, and belched out from them fearful clouds of sand, and burning rocks, which, after darkening the air, fell to the earth. Fortunately their di- rection was not towards any of the little habitations, or cultivated fields of. the island. One forest only on the side of the mountain suffered some injury. The inhabitants often found themselves enveloped in_ thick clouds of black smoke and ashes, which the wind drove among them. But only one man was struck by the burning rocks hurled through the air with immense violence. The scoria and ashes did much damage to the cisterns of the island, and to the terraces which serve as tiles over them. ‘Torrents of black smoke, ashes, and sand, were often ejected and thrown to various distances. The greatest shocks were sometimes fol- lowed by a thick dry cloud, which filled the air of the whole island. The shock of the 5th of March was very strong at Stromboli, at Saline, formerly Didime, and at Lipari. The inhabitants of Lipari did not doubt that their houses would this time be reduced to ruins; and they have not yet ceased giving thanks to Heaven, for defending them from utter destruction. ‘They affirm that a moment after the shock, all their thoughts were turned upon the disasters which might hap- pen to places on the neighbouring coast of Sicily, and at Palermo; towards which the direction of the motion seemed to be. Lipari lies between us and Stromboli. Since April the parts of our island which were before agitated, have been left in repose ; but shocks are still frequent at Stromboli, and keep the poor inhabitants there in continued fear. The subterranean furnace seems to have lost much of its power, as the elastic. vapours generated there shake but a very limited space, and the new aper- tures of the mountains emit now and then but a very small quantity of fine sand, which is always the last product of an expiring conflagra- tion. From what I have laid down, it is just to conclude, that the fires of Folia are those which have, for a long time, been preparing the event of last March ; that it was produced by motions generated in those mighty furnaces, and that those motions were propagated to great distanees. -If Sicily, then, is so often shocked, the powers which agitate it must exist in volcanoes that burn within its own bosom, and in the surrounding sea. VOL. IV. NO. II. APRIL 1826. Aa 370 | Analysis of Scientific Books and Memoirs, Situated in the midst of such grand operations of nature, Sicily must be. exposed to all the effects which such powerful causes are capable of pro- ducing. The chemical subterranean operations require that the, earth should every where be traversed by vast cavities and canals, running in various directions ; and the forces of the operatiens act on the different parts of these cavities. But it is natural to believe, and many facts in this memoir demonstrate the truth of it, that places in the vicinity of the three great volcanic outlets, ordinarily feel the force with the greatest vio- lence. In this respect, the situation of Palermo is very advantageous ; since it is distant from A®tna, and from Eolia, and it is near to Sciacca only, which is the least energetic. And this grand and respectable city would be less exposed to such grievous disasters, than all the other cities of Sicily, did its edifices possess that character, which they might easily be made to possess, which constitutes true solidity and resisting firm- ness. III.—Scuow’s Essay on Botanical Geography. Copenhagen. 1823. (Concluded from last Number, p. 167.) Ill. Regnum Labiatarum, et’ Caryophyllearum, the Midland Flora, (Flora Mediterranea.) This region is bounded on the north by the Py- renees, the mountains Of the south of France, the Alps, and the moun- tains of the north of Greece, and thus includes the three Peninsulas of the south of Europe, the Pyrenean Peninsula, Italy, and Greece ; besides, there | _ belong to it Asia Minor and its Islands, Egypt and the whole! of the north of Africa, as far as to the Deserts; lastly, the Canary. Islands, Madeira, and the Azores. ‘That which especially marks this region, is the great abund~ ance of the two families mentioned above, the Labiate (in a strict sense) and the Caryophyllee which, as well towards the north as towards the south, as also in North America on the same parallel, are proportionally much rarer. To its characteristic forms there belong further, Composite, Stellate, Asperifolie ; although they are also found in a similar propor-. tion in other parts of the earth possessing a similar climate. Many tro- pical families appear here, either with single representatives, or several species, as Palme, Laurinee, Aroidee, Terehinthacee, Panicee, Cyperacee propria ; families, which decrease from the Equator towards the poles, are here more numerous than in the north of Europe, for instance, Solanee, Leguminose, Malvacee, Urticee, Euphorbiacee. The forests consist chiefs ly of Ameniacee and Contfere, the underwood of Myrtinew, Ericacee, ‘Terebinthacea, &c. A number of evergreen trees show themselves ; ve- getation never entirely ceases; green meadows are more rare. The sub- floras belonging to this, are the Spanish, Portuguese, Italian, in which _ may be reckoned the south of France, the Grecian, the Levantine, or that of Asia Minor, the Egyptian, the Atlantic, that of Canary, which -bably might also include that of Madeira and of the Azores. — Floras reciprocally run so into each other, that it is. ‘ilhdale eaeine the provinces. However, it appears most proper to admit the following — > ‘\ m ” Schow's Essay on Botanical Geography. 371 five provinces ; (a) Provincia .Cistorum, which includes Spain and Portus gal. Although the genius Cistus is spread over the whole region, it seems, however, to be most numerous in the Pyrenean Peninsula ; (b) Provincia Salviarum et Scabiosarum, the south of-France, Italy, Sicily ; (¢) Pro- vincia Labiatarum frutescentium, the Levantine Flora, Greece, Asia Mi- nor, and the southern part of the Caucasian countries ; (d) Provincia Atlan- tica, north of Africa, of which I do not “know any characteristic that I can give, and probably it might be included under the second province ; (e) Provincia Sempervivorum, the Canary Isles, perhaps also the Azores, Madeira, and the north-west coast of Africa. Many Semperviva, some succulent Euphorbia: and Cacalie characterize particularly this province. IV. The Fastern Temperate part of, the old Continent, namely span, the north of China and Chinese ‘Tartary, probably form a peculiar region ; but we are too little acquainted with these districts to be able to admit it with certainty, and still less are we able to mention any thing characteris- tic in its Flora. Of Japan’s 358 genera, 270. occur also in Europe and North Africa, and about the same number in North America; so that its Flora seems to occupy a middle. place between those of Europe and North America ; the vegetation approaches nearer to the tropical than in Europe ; for we meet with the families of the Cycadew, Scitaminew, Muse, Palme, Anonacew, Sapindacee ; im particular, the approach to the Flora of India is remarkable. The families Rhamni (Frangulacee, Dl.) and Caprifolia are found in a relatively considerable number, and exhibit several peculiar genera ; thence, perhaps this region might deserve the name (Regnum Rhamnorum et Caprifoliorum:- ) y V. Regnum Asterum et Solidaginum.) The eastern parts of North America, with the exception of those that belong to the first region, with- out doubt comprehends two regions, for amongst 417 genera in Walter’s Flora of Carolina 117 are wanting in Barton’s Flora of Philadelphia. ‘The northern parts of North America have truly but few genera which are absent in the southern ; but this only shows, that there occurs here a simi- lar relation to that which takes place between the north and south of Europe. The southern region will’ include Florida, New Orleans, Geor- gia, and Carolina ; the northern contains the other states of North Ame= - rica. What characterizes this region are, besides the numerous species of genera Aster and Solidago, the great number of species of Oak and Fir, the very few Cruciferae and Umbellate, Cichoriacee, and Cynarocephale, the want of the genus Erica, and a larger number of dete than in Europe. : VI. (Regnum Magnoliarwm.) This, which includes the most south- ern parts of North America, is separated from the preceding region by the number of tropical forms which here appear, and show themselves more frequently ‘than on the similar parallel in the old continent, (Sci- taminee, Cycadee, Anonacee, Sapindacee, Melastomee, Cacti, &e.), from 372 = Analysis of Scientific Books and Memoirs. which it is besides distinguished by a smaller ve of ‘Labiate and Caryophyllee, and by more trees with broad shining leaves, and splendid blossoms (Magnolia, Liriodendron, A@sculus,) or ,with pinnate leaves (Gleditschia, Robinia, Acacia, Schrankia, &c.), 1 have’ adopted the name of Magnolias, although they are also found in the southern part of the preceding region, because I know not any better. Vil. ¢ ‘Regnum Cactorumy Piperacearum, et Melastomearum.) This ree gion I propose should include the lowest districts of Mexico, West In- dies, New Granada, Guinea, and Peru, perhaps also of Brazil. . The three families mentioned appear peculiarly to characterize these countries, for the first belongs exclusively to America, the two others possess but few species out of that!country ; also Palme, Rubiaceae, Solanew, Boraginee, _Passiflorea, Composite, are here more common. We may admit of seve= ral provinces ; (a) Provincia Filicum et Orchidearum, comprehends the West Indies ; (b) Provincia Palmarum, the continent of South America. Brazil ought certainly to forma peculiar province, if, indeed, it does not make a distinct region. Melastomee and Palme appear to belong to the more numerous forms. ve ; VIII. ( Regnum Cinchonarum.) It appears from Humboldt’s works, that the middle districts (with regard to eleVation) of South America, should form a distinct region, as they considerably differ from the low lands ; the proposed name seems proper, at least for Peru and New Gra- nada; but, certainly not for Mexico, where the species of Cinchona be ; wanting. . IX. (Regnum Escalloniarum Vacciniarum et sisters) In. this -are placed (also according to Humboldt’s works) the highest parts of South America ; besides the plants mentioned, there belong also to this region many species of Lobelia, Gentiana, Calceolaria, Sulvia, several Kuropean Genera of Grasses, Bromus, Festucu, Poa, and Cichoracee, Hypocheris, Apargia ; alpine forms also show themselves, (Saxifraga, Draba, Arena~ ria, Cerastium, Carex, and Gentiana.) Perhaps, also, those parts of the high lands of Mexico, where the species of oak and fir flourish, belong to the same region, though, in all probability, they will form a epg La vince, (Provincia Quercuum et Pinorum.) KK. (Regnum Chilense.) It appears that Chili may jas a distinet o region, for, amongst the genera which are known from thence, not one-half are found in the low districts of South America ; it has, perhaps, a stronger resemblance to the high lands in the genera Calceolaria, Escallonia, _ Weinmannia, Bea, Campanula, Budleia, but, however, scarcely sufficient — to reduce it toa province. The Flora ofthis country appears.to be essens tially different from those of New Holland, the Cape, and New _ though there is found an approach to them in Govdewias: maejties teacee, Gunnera, Ancistrum. ay ak i. Sa at? = aes rz * Schow’s Essay on Botanical Geography. 378 XI. (Regnum Compositarum arborescentium.) Includes Buenos Ayres, andj in general, the eastern side of the temperate part of South America. It has been already remarked, that the Flora of this part of the earth, in a considerable degree, agrees with that of Europe ; among 109 genera, 70 are likewise found in Europe, 85 in the North Temperate Zone ; on the other hand, it differs considerably from the Floras of the Cape, and of New Holland, for Proteacew, Epacridew, Ericacew, Iridew, Ficoidea, Geranite, Myrtinee, Mimosec, are either entirely wanting, or occur but sparingly. It is also very different from the Flora which is found on the west coast of America ; for, amongst the 109 genera mentioned, only 35 are found in Chili. The charecteristic of this region appears to be the great number of the arborescent Syngenesie (particularly of the subfamily Boopidee,) which, however, do not exclusively belong to this region, but are also found in Chili, and at the Cape. I have hence taken the name, though a more intimate acquaintance with this Flora, at present so little known, may perhaps oblige us to change it. : XII. (Regnum Antarcticum.) Includes the countries near the Straits of Magelhan. The vegetation here also approaches very near that which is found in the north Temperate Zone ; for, amongst 82 known genera from- thence, 59 have also species in the northern hemisphere; the northern Polar forms even show themselves, such as Caricer, Saxifragea, ' Gentianee, Arbutus, Primula. Some resemblance to the Highlands of South America, and to Chili, is shown in the genera Calceolaria, Ourisia, Bea, Bolax, Wintera, Escallonia ; to the Cape, in the genera, Gladiolus, Witsena, Gunnera, Ancistrum, Oxalis; to New Holland, in Proteacea, Mniarum. The characteristic forms I dare not determine ; but as most of the species known from hence, and some of the genera, are newman it ought certainly to form a distinct Oy can XIII. (Regnum Nove Zeelandie.) Well deinativeak on similar grounds, to be a separate region, although its vegetation is a mixture of that which is found on thé three nearest continents, South America, South Africa, and New Holland. It has, in common with South America, Ancistrum, Weinmannia, Wintera ; with South Africa, Mesembryanthemum, Gnapha~ lium, Xeranthemum, Tetragonia, Oxalis, Passerina ; with New Holland, Epacris, Melaleuca, Myoporum ; with both the latter, the families Pro- teacew and Restiacee ; several species are also in common, both with New Holland and Van Diemen’s Land, for instance, Mniarum biflorum, Samo= Jus littoralis, Gentiana montana ; the first is alse found in the Straits of Magelhan. ; ’ be XIV. (Regnum Epacridearum et Eucalyptorum.) Includes the tem~ perate part of New Holland, together with Van Diemen’s Land. This region is very marked ; the families Stackhousee and Tremendree, are quite peculiar to New Holland ; Epacridee nearly so ; Proteacew, Acacia aphyllz, and the great number of Myrtinee (especially of the genera Eucalyptus, Leptospermum, Melaleuca) Stylidew, Restiaceew, Casuarinee, 374 Analysis of Scienti if Books and Memoirs. Diosmee, separates it from most other deghdenes The Gidpical part of New Holland, according to R. Brown, can hardly be united to this, but must be-éither a particular region, whosé Flora resembles vane of the Indian. Flora, or else a province of this latter region. ity XV. (Regnum Mesembryanthemorum et Stapelianem.) This includes the southern extremity of Africa, the Flora of which is distinguished by a high degree of peculiarity. By the families Proteaceae, Restiacea, Poly- galeew, Diosmee, it distinguishes itself from most others, excepting that of New Holland, and from this it is distinguished by the two numerous genera Mesembryanthemum and Stapelia, and by the family Ericacee, _ which is here more numerous than any where else. ‘There belong, more- _ Over, to the characteristic of this region, the many Iridew, Geraniee, Ozxalidee, and the extraordinary large number of Composite. On the other hand, there grow here, as well as in New Holland, but only very sparingly, these characteristic forms of the. northern ‘Temperate | Zone, Crucifere, Ranunculaceae, Rosaceae, Umbellifere, Caryophyllee. ul ~ XVI. (Regnum Africe occidentalis.) We know only Guinea and Congo, of which the vegetation, as has already been remarked, has a very low degree of peculiarity, and is a mixture of the Floras of Asia and Ame- rica, though it resembles most that of Asia. The American tropical fa- milies, Nopalee, Piperacew, Palme, Passifloree, are either entirely want- ing; or occur sparingly ; Leguminose are more numerous than in America. Above two-thirds of the genera, and some of the species of Guinea, are found also in East India. On the other hand, this region approaches America, in possessing many Rubiacee, also in the genera Schwenkia, Elais, Paullinia, Malpighia, and several more which are wanting in Asia, and in several species which it, has in common with America. A con- siderable number of Gramina ‘and Cyperacee, with the peculiar genus Adansonia, belong, to the characteristics of this country, but I dare not name the region from thence.’ The interior of Africa is “shun to us. XVII. (Regnum Africa orientalis.) Of the east coast of Africa, and _ the islands adjacent, we know tolerably well the islands of Bourbon and France ; Madagascar but little, and the east coast itself, scarcely at all. The Flora of the two first mentioned islands has a considerable resem- blance to.that of India. Amongst 290 known genera, 196 = 3, are found _ also in India, and of the species, not a few are likewise Indian ; many of these may, however, have been introduced by the constant intercourse there is between the two parts of the globe. Numerous in species are the ge-_ nera Eugenia, Ficus, Urtica, Euphorbia, Hedysarum, Panicum, Andropo- ‘gon, Sida, Pandanus, Dracena, Conyza, which, for the greater part, have ‘also many species in India. In Ferns these idands are particularly rich. On ‘the other hand, their Flora differs considerably from the South African ; “it has, however, some resemblance, in single representatives, of the Cape were Erica; Ti Gladiolus, epee Menino ‘Seriphium fares: S anes Schow’s Essay on Botanical Geography. 375 and several arborescent Syngenesiw. Still much less resemblance is there to the extra-tropical parts of New Holland. The likeness is stronger to the tropical part of that country, as its Flora also approaches that of India. Single genera only it seems to have in common with America; for in- stance, Melicocea, Ruizia, Dodonwa, Dichondra. ‘These are probably pe- culiar ; Latania, Hubertia, Poupartia, T'ristemma, Fissilia, Cordyline, Assonia, Fernelia, Lubinia, and others. Madagascar appears to possess a very peculiar Flora ; it agrees most with the last mentioned islands, and several genera are only found on them and Madagascar ; for example, Da- nais, Ambora, Dombeja, Dufourea, Didymeles, Senacea ; several species also are common to both, as Didymeles Madagascariensis, Danais fra. grans, Cichona afro-inda ; but, however, among 161 known genera from ‘Madagascar, 54 only are found in the-islands of France and Bourbon ; so that there might-be good grounds for forming a separate region of the first, unless, perhaps, the east coast of Africa might come under the same. With ‘New Holland and thé Cape, Madagascar has still less resemblance than the two other East African islands. XVIII. Regnum Scitaminearum, (the Indian Flora.) To this belong India, east and west of the Ganges, together with the islands between India and New Holland, perhaps also that part of New Holland which lies witltin the tropics. The Sci/aminee are here far more numerous than. in America, likewise, although in a less degree, Leguminose, Cucurbitacee, Tiliacee ; the before mentioned South American forms are more seldom, _or else wanting. This region should certainly be divided into several pro- vinces, but, as yet, we know too little of it, for us to undertake such a di- vision with any degree of certainty. XIX. The Indian Highlands ought to have one, or probably two re~ gions, with a vegetation different from that.of the Lowlands; in the mid- _ dle region, Melastome, Orchidee, and Filices, appear to prevail ;. in the higher, the vegetation approaches very near the European and North Asiatic, and partly the Japanese ; these districts probably form one region with the whole of central Asia. 1 xX. Of Cochinchina’s and the South of China's Flora, it partly comes near India’s, especially in regard to families ; but, however, Loureiro’s Flora contains a very large number of peculiar Genera. It ‘is true, that many of these genera ought probably to be reduced ; but, after all, the vegetation of this tract will most likely be sufficiently peculiar for’ it to form an individual region. : XXI. The Flota.of Arabia and Persia, seems likewise, with good reason, to deserve to be separated from that of India, as it is already suffi- ciently separated from the Mediterranean region (III.); for, amongst 281 _genera in Forskal, 109 only are found in the south of Europe ; more like- ly does the Flora of Nubia, and -part of central Africa, belong to this re- © + gion. With regard to the numerous species of Cussta, and gummiferous 376 | Peni Intelligence. — Mimose, this region might, perhaps, deserve the name of the wane Cassia and Mimose. - » Abyssinia probably forms a distinct region, as the high Jana has rach different climate. ; XXII. The Islands in the South Sea, which lie within the tropics, form, - perhaps, a separate region, though with but a small degree of peculiarity. Among 214 genera, 173 are found in India ; most of the remainder are in common with America, for instance, Chiococca, Weinmannia, Guajacum. Of species, they have, in common with Asia, Zapania nodiflora, Kyllingia monocephala, Fimbristylis dichotoma, Tournefortia argentea, Plumbago Zelanica, Morinda umbellata, Sophora tomentosa ; with America, Dodon@a viscosa, Sapindus Saponaria; with both, Rhizophora mangle; and also some in common with New Holland, as Daphne Indica. Peculiar fami- lies, or such as have there a decided maximum, can scarcely be given ; though, on the other hand, most of the species are peculiar. The Bread Fruit belongs to their characteristic, though this tree is not altogether peculiar to the South Seas. Arr. XXXII. sr eo bin ag INTELLIGENCE. — Tt. NATURAL PHILOSOPHY. | ASTRONOMY. 1. Hansen’s Parabolic Elements of the second Comet of 1825. The fole lowing elements of this comet heve been computed by M, Hansen of See- berg. Mean time. — - Passage of Perihelion at Naples, 1825, - + Dee. 10th. 4192 Leg, of Perihelion Distance, - - = = = 0.092836 - ~ Long. of Nodes, - - 215° 42! 28” — Long. of Node mean that of. Perihelion, - 256 57 21 Inclination of Orbit, Wo? ote - . 33.27 40. Motion Retrograde. Zach’s Cor. Astron. vol. xiii. p., 376. 2. u. Capocci’s new elements of the Comet of 1825. In our last Num- ber, we gave Capocci’s first elements of this comet. The following are his - corrected ones,— Mean Time. Passage of Perihelion at Naples, gy : Dec. 10th, 601. _ Log. Perihelion Distance, ; Pye il - " 0,0930643 Long. of Perihelion, a - 1g°4g2e TAng, dencemmng tote, ~ neti, te hye Some ot ae Inclination of Ont, 4 an se 2°83 30 29) 6} eal Lee. 8. Pons and Capocet's Observations on the tail of the second ‘Comet of 1825. This comet has been observed by M. Pons every day from om Astronomy. 877 10th till the 18th October.. On the 11th, the tail was very narrow at its setting out from the nucleus, and grew less to a certain distance, when it’ widened in the form of a fan. On the 12th, its body was more rough, and the tail a little curved, being very narrow at its origin, and wide at its termination. On the 13th its tail was very shapeless, being considerably bent towards the middle, and as it were in detached pieces. On the 14th, it had a more uniform aspect. On the 15th, the tail was divided into two very sensibly. On the 16th, the tail was very small and faint, and con« sisted of two parts, one of which was more distinct than the other ; and on the 17th, the tail was a little curved. , M. Capocci has also remarked, that the long tail of this comet is subject to continual and very perceptible changes in a short space of time. He believed that he had almost seen the undulations which Pingré had re« marked in the comet of 1779. On the night of the 7th or 8th of October, the tail was divided into three branches, the chief of which was interrupts ed by a considerable space almost void of light, after which the nebulo- sity reappeared, which extended itself to a great distance, bending itself on the side opposite to the path of the comet. 4. Hansen's elliptical elements of the second Comet of 1825, Having perceived that the parabolic elements of this comet, which he calculated, and which we have given above, differed more than three minutes from ob« servation, M. Hansen computed the following elliptical elements, which -agree very accurately with the observations made at Seeberg, Florence, Turin, Naple, and Vienna. ; . Mean Time. Passage of Perihelion at Seeberg, 1825, Dec. 11, 48915 Long. of node, - - - 215° 37’ 26.” 4 Long. of node minus that of Perihelion, = 257 26 24.4 ~ Inclination of Orbit, i a 33 37 46.8 Eccentricity, - - 0.9 765 025 Log. of Perihelion distance, - - 0.092180 ° Revolution, — - - = 382 Julian Years. Motion _ ~ —‘ Fetrograde. Zach’s Cor. Astron. vol. xiii. p. 495. ay Fifth Comet of 1925. The following are the elements of this comet calculated by M. Capocci : Passage of Perihelion, : 1825, Sept. 164 4866 um. 7. Naples. Perihelion distance, an - 3.1971 Long. of Perihelion, : - 46° 34 15” Long. of node, - - - - 211 58 50 Inclination of Orbit, ——- ~ . 60 5 35 Motion 7" Direct. 6. Mr Pond's Observations on the Double Star ¢ Bootis. The following account of this interesting double star was sent by Mr Pond to Mr South. “ Tfirstobserved ¢ Bootis to bea close double star at Lisbon in the year 1795, witha seven feet reflector, which the late Sir W. Herschel made for me ex- 878° Scientific Intelligence. pressly with the greatest care. I immediately communicated the circum~ stance to him, and he wrote me in answer, that, in,consequence of my in- formation, he had examined the star, and found it as I described, but reckoned it at that -time among the most difficult. I brought the same telescope to England, and used it afterwards in Somersetshire for several years, but could never again see the same star distinctly double, which I attributed to change.of climate. The star is now much more easily seen. Our transit telescope separates it with ease. FE recollect, at Lisbon, that it was only on very favourable nights that I could see it double.” Quart. Journ. No. xl. p. 419. ; OPTics. on, ’ Lagat ttions Phenomenon observed between Paisley and. Glasgow. On ie morning of the 14th instant, about 6” 37’. I was gratified by the sight ofa lu- -minons globe or bolide, while going from Paisley to Glasgow. It was tran- quilly stationary as if equipoised, and of a similar specific gravity with the plane it seemed to float upon. _ Its form was somewhat elliptical and translu- cent in consistency, faintly luminous, After a short while it discharged sparks, and this discharge was subsequently repeated, and by the impulse springing from the re-action of the atmosphere, the Lo/ide moved from north to south, maintaining the horizontal plane, not in any section of the arc ofa parabola. The star-like sparks were bright and silvery, and void of any chromatic tint. 'The meteor was interesting and beautiful, and altogether expressive of having its dependence on an_ electro-magnetic princi- ple. The night had been wet and. tempestuous, and the entire day disco-— __yered a horizontal parallelism of the clouds in the distant sky ; the clouds were chiefly cumulostrati.. At 4° 50' a. m. before leaving Paisley, ther- mometer 43° 5’ Fahr. and the hygrometer of de Saussure, 94°.—J. sila sc Il. CHEMISTRY. 8. On the Sulpho-Napthalic Acid newly discovered by Mr Fahdiday. This name has been given by Mr Faraday to a new acid which he discovered by subjecting napthaline to the action of sulphuric acid. It is a solid ery- stalline substance, deliquescing in the cold air, fusing at 212°, and char- ring and burning with much intense flame by a higher heat. The salts which it forms with bases are all soluble in water, and in alcohol. . By Mr Faraday’s analysis, the elements of the salt approximate closely to 1 Proportional of Barytes, - ; : 7.80 2 Ditto of Sulphuric Acid, eats vig’ 8.00 20 Ditto of Carbor; . $e: b 12 07 8 Ditto of Hydrogen, 8B Abstracting the barytes, the remaining eldmenita indicat the composi- tion of the pure acid, which thus appears to contain aboye three-fifths of ny ae Ann. of Phil. \xiii. 228. . lil. NATURAL HISTORY. Hy pa. 2 ZOOLOGY. pat: 9. Fossil bones near Montpellier. —M. Marcel de Sedge’ thas announced to the Royal Academy of Sciences, the discovery of large quantities of fos- Zoology. 379 sil bones in caverns of calcareous strata, in the neighbourhood of Lunel- Vieil, near Montpellier. The bones found in the Kirkdale caves, have occasioned a good deal of speculation among the English geologists, and the proposition of theories to account for their appearance ; and the pre- sent discovery is likely to add a few more to the number. M. de Ser- res has, besides bones of herbivorous and carnivorous animals, found some not hitherto met with in a fossil state, viz. the bones of the camel. . Among the carnivorous animals he places, in the first rank, lions and tigers, much superior in size and strength to the present living species,— animals whose canine teeth are about 16 centimetres in length, and 39 millimetres in breadth. Along with these enormous bones are found others approaching to the species of lions and tigers now existing ; and with them are mixed bones of hyenas, panthers, wolves, foxes, and bears, (differing but little from the badger,) and of dogs. Mixed with these bones of carnivorous animals, are found great quantities of the bones of herbivorous quadrupeds, among which the discoverer met with several species of hippopotamus, wild boars of large size, peccaris, horses, camels, many species of stag, elk-deer, roebuck, sheep, oxen, and lastly, several apeties of rabbits and rats. What renders this circumstance more remarkable is, that the bones of the animals thus buried, (which are sometimes in such quantities that the caverns of Lunel-vieil resemble cemeteries,) seem to have no connec- tion with the habits of the animals to which they have belonged. By the | side of an entire or broken jaw of a carnivorous animal, is often found the bones of herbivorous races, and all are so mixed, that it is rare to meet with two entire bones which have belonged to the same animal, or rat ‘Teast ‘ to animals of the same genus. These fossil bones are thus disseminated in these caverns seithouis or- der, and never entire; and as they are found in the middle of alluvial land which contains a great quantity of rounded pebbles, it may be sup-« posed that they have been transported thither by water. These bones all contain animal matter, and what is singular enough, the earth where they are found, contains more animal matter than the bones themselves, when it has not been cleaned from the bony fragments which are contain - ed in it. Bull. des Setences, Nat. 1825, No. 9. p. 81. 10. Crocodiles of Egypt.—I the sitting of the Academy of Sciences of the - 6th February, M. Geoffroy-Saint- Hilaire presented from M.Caillaud a mum- my crocodile, 7 feet 1 inch in length, in a state of perfect preservation. He had formerly maintained, in opposition to the opinion of M. Cuvier, that there were two species of Egyptian crocodile—one, a sacred animal— mild, and of smaller size, the other the well-known crocodile of the Nile; while M. Cuvier was rather inclined to suppose that the second species was the crocodile of St Domingo. The inspection of this mummy seems ‘to have decided the question. This second species differs from the other chiefly in the structure of the head, the jaws being more lengthened, and indicating a creature of less strength. It was known-among the ancients by the name of Suchus. A live individual of this species was exhibited at Paris in 1823.—-Le Globe, No. 22, Feb. 1826. - . $80 ~* — — Scientific Intelligence. 11. On the Egg and Tadpole of Batracian Reptiles.-At the ‘sitting of the Academy of Sciences of the 13th February 1826, M. Dutrochet read a memoir on this curious subject. Spallanzani had conjectured that the egg of the Batracians was nothing but the tadpole itself in a spherical form. This opinion was at first doubted by M. Dutrochet ; but future examina- tion discovered to him, that, among this class of reptiles, the foetus exists prior to fecundation, which, as is well kuown, does not occur till the ex- trusion of the egg; and that this foetus is a kind of polypus—a simple globular sac, which, containing the emulsive matter for the nutrition of the tadpole, lengthens gradually into a plicated tabe with numerous con+ volutions. M. Dutrochet had formerly remarked, .in his: examinations of insects, that the larve of the bee and wasp might also be found in the egg before fecundation in a similar state-—Le Globe, No. 24, Fev. 1826. BOTANY. 12. M. Ramond on the Vegetation of the Summit of the Pyrenees. Ina’ memoir on this subject read at the Academy of Sciences on the 16th Janu-. ary 1826, M. Ramond remarks, that, from the base of a high mountain to its summit, the vegetation presents a foreshortened view of the same modifie cations which are observed from the same base to the Poles. In proof of this, M. Ramond describes the Pie du Midi, which rises 1500-toises above the level of the sea. On its summit, the barometer stands between 19 inches and 20 inches 3 lines. The greatest height of the thermometer, in sum- mer, does not exceed 62° or 63° of Fahrenheit, and by supposing that, at that height, the variations will be proportioned to those at the levelof the sea, the minimum will be 35° or 36°. On the same principle it will be found, that the thermometer should descend in winter, in places in- accessible to man, to 14° of Fahrenheit. Hence M- Ramond concludes, that the temperature on the Pic du Midi varies between the same limits” as in regions situated between 65° and 70° of latitude. “¢ T have ascended, says M. Ramond, 35 times into this island, lost in the middle of the vast ocean of air, and ‘I have remarked, that not a flower appears till the summer solstice. The spring consequently does not begin at that height till the summer has commenced at the foot of the mountain.” This peak is accessible only during three months of the year. The month - of September is the most convenient for ascending it. In July and August it is not uncommon to see snow fall, which remains for a long time, M. Ramond, even in that climate, has collected 130 species of crypto- gamic or phanerogamous plants, which preserve themselves under the snow. On a small spot, accidentally laid bare, he observed 7 species of plants which vegetated vigorously. : It is a curious circumstance, that the species observed oe the Pic du Midi are related to the same genera as the species collected by Captain Parry in Melville Island, near the Pole. This island, notwithstanding its extent, presents only 113 species, which is 17 less than M. Ramond has. collected on the Pic. In the island, as on the Pic, there is only one shrub, which is the willow, reduced to the same dimensions: — The climate, 5° Liat of Scottish Patents. 381 however, is not so rigorous on the Pic as on the Polar island, The win- ters are cértainly less severe, but the summers are not more warm. Leaving the summit of the mountain, M. Ramond describes the modifi- cations which vegetation experiences as we descend towards its base, and he s particularly of certain vegetables belonging to warm latitudes, which are found in very limited spaces. If we do not admit that these plants prove the existence of ancient communications with the countries to which their species belong, we must recognize an alarming number of particular creationss M. Ramond endeavours to explain these facts by geological considerations, which, however, he offers only as simple War theses. Jue Globe, Jan. 19, 1826, Tome iii. No. xii. p. 62. Art. XXXIII.—LIST OF PATENTS GRANTED IN SCOTLAND SINCE NOVEMBER 17, 1825. 66. Nov. 23. For Improvements in Machinery for preparing, drawing, roving, and spinning Flax, Hemp, and Waste Silk. To ALEXANDER Lams, London, and Wittiam SurTitt, Middlesex. 67. Dec. 14 For Certain Improvements in Chronometers. To Joun GorTties Utricu, Middlesex. 68. Dec. 15..For Certain Improvements in generating Steam... To sa Maccurpy, Middlesex. . Jan. 4, 1826. For a New Method of manufacturing or preparing an on or Oils, extracted from certain vegetable substances, and the applica- tion thereof to Gas Light and other purposes. To Epmunp Luscomse. 2. Jan. 4. For certain Improvements on Machines tor scribbling and carding Sheep’s Wool, Cotton, &c. To Ezexiet Epmonps of Bradford. 3. Jan. 4. For a method of conducting to and winding upon Spools or Bobbins, rovings of Cotton, Flax, Wool, or other fibrous substances. To JosErH CHESSEBOROUGH Dyer of Manchester. 4. Jan. 18. For the Preparation of substances for making Candles, in- cluding a Wick constructed for that purpose. To Mosrs Poote. 5. Jan. 18. For an Improved Power-Loom for the weaving of Silk, Cot- ton, Linen, &c. To Joun Harvey, Surrey. 6. Jan. 18. For Methods of seasoning Timber. To Joun SrerneN LanerTon, county of Lincoln. - 7. Jan. 30. For Improvements in the Manufacture of Hat bodies, com- municated by a foreigner residing abroad. ‘'o James BLyrH Waynman. 8. Feb. 1. For Improvements in the Construction of Carriages and Harness) To Tuomas Coox, Surrey. 9. Feb. 1. For Improvements in Looms, and implements connected therewith. To T. W. Sransretp, and W. Pritcuarp, Leeds 10. Feb. 1. For an Apparatus for propelling Carriages on common ' roads, or on railways. To Gotpswortuy Gurney, Middlesex. 11, Feb. 2. For a new Method of bleaching the Pulp for making Pa- per. To James Brown, county of Edinburgh. 12. Feb. 10. For an Improvement or Improvements in the process of refining Sugar. To Cuances Freunp, Middlesex. 382 Celestial Phenomena, AprilTuly 1826. “13. Feb. 11. For a Machine for. effecting an lsorowstings sition: ber tween bodies revolving about a common centre. To J. Lean, Bristol. — (14. Feb. 11. For certain Apparatus for the concentrating and cy. ligation of aluminous and other saline and crystallizable solutions, &c.) To Josras CuristorHeR GAMBLE, county of Dublin. | id _ 15. Feb. 16. For a new Preparation of fatty substances, and the ap= - plication thereof to the purposes of affording light. To Nicotas Heee~ ~ sirre Manicier, Surrey. te 4 Any. XX XIV.—CELESTIAL PHENOMENA, From, April 1st 1826, te July 1st 1826. Adapted to the Meridian of Greenwich, Apparent Time, excepting the Eclipses of Jupiter's Satel- lite’s, which are given in Mean Time. N. B.—The day begins at noon, and the conjunctions of the Moon and -... Stars are aren in Right Ascension. Catia D.. Hi Ms. 8 D =H OM. 28 Hi Stationary, eS 2 Conj. & K -/28 1 3. 88 ) Conj. 6 1 Conj. 6 V4 andy ee] 28 13° 3 Last Quarter. 4 Greatest Elong. 29 Conj. » s2 ‘6 13 21 37 Em. IL. Sat. 7/ 6 14 #10 44 Em. I. Sat. 2/ ° MAY. 6 21 26 New Moon. 1 Stationary.» 8 3 Conj. o 1 8 51 18m, I. Sat. 2/ 8 #13 Conj. y 1 10 31, 22 Em, II. Sat. 7/ 9 12 52 49 ) Conj.d Y 2 Conj. a 9 Conj. 9 4 Conj. 0 Bien” we 10 14 21 5B2)A& 4 19 vio tippedaentall 11 0 -9. 20 )/)Conj. 2% 4%. 6.14 16. New Moon, 11 17 48 O)Conj-s & ~ Y Geka ' & Stationary. 5 ia | Conj. Fh 7 20 23 29) Conj. A & 12 9°49 0O)) Eclipses € & 8 Conj. 2 13 Stationary. 8 6 9 10) Conj,2x & 13. 9 27 19 )) Eclipses v I 8 10 45 53 Em, I. Sat. 2/ 14 (0 in Quad. with@®~ | 8 13 8 42 8m. IL Sat. 7/ 15 oO 58 ) First Quarter. : 7 45 21 st 2 & 1 8 6 27 1m. " j- F 15 12 8 oy tem, ¢ TVs Sat. 2 19 15 45 hex h 15 10 23 25 Em. III. Sat 2/. 10 15 28 20) Conj.yvT — 15 10 33 42 Em: I. Sat. 2/ _|13 12 26 3) Eelipses 1 # op 16 5 23 A) Eclipses 1 @ 05 13 J3 38 14) Conj. 2 4 oS 16... 6 33 29 ) Eclipses 2 2 o5 14 12 12 First Quarter. 20 3 43 enters 15 12 40 29 Em. I. Sat. h 21 4 53 56 ) Conj. « NY 18 15 30 36 21 19 26 Full Moon. 4 20 11 #19 22 11 #5 41 Im. 32 14 21 g9km¢ Hl SaeY lor 9 25 4 22 12 28 9 Em. I. Sat. 2/ 21 3 16 23 9 11 40 )-Conj. x= 21 4 8 23: «13 27 ~=+50 ) Conj., = 21 4 55 56 23 18 O I1 ) Conj. 1 4 21 4 57 14 23.18. 1 30) Conj.2 2 Re uit 24 2 16 Inf. Conj. 22 8 59 54 24 22 30 29 ) Conj. p Opx 23. BH: 23) 25 19 1 31) Conjle ft 23 5 35 40 25 19 36 44) Conj. 2u f 23 13 °°) _ 26 21° 9 47) Conj.d f 24 6 24 20 NWDSCAanananes & Wao D. 15 1 1439N 15 21 59 The preceding numbers will enable any person to find the positions of the planets, to lay them down upon a globe, and determine their risings and ~ cag - Celestial Phenomena, April—July 1826. 383 8. De THe Be \. 8. 48 Em. I. Sat. 2/ 13 Stationary. Conj. h 14 23 57 50 ) Conj.i 56 ) Con}. 2 V4 15 20 Conj.s & in Quad. with @) |16 22 ' +) Conj. g Last Quarter. 16 19 45 Conj. © 49 Em. III. Sat. 2/ 17 6 9 26 ) Conj. x = 28 Em. I. Sat. 2/ 17 10 29 8 ) Conj. a = . 17 15 3 58) Conj. 12 JUNE. 17 15 5 17 ) Conj. 22 ie 22 Em. II. Sat. 2/ 18 19 25 58 ) Conj. p Oph. 48 ) Conj. d 19 10 54 Full Moon. 28 ) Conj. Ad & 19 15 26 59 Eclipses lw~ ft 4 Im. III. Sat 2/ 19 16 1 4)Conj.2u ft 33) Conj.2 x & 20 16 34 38) Eclipsesd f Eclipsed Invisible. |21 12 44 enters 05 New Moon. 2} 19 6 Conj. 2 a) Conj. ¢ I - 122 & OS 19 ) Conj.€ & 24 cn Conj. © Con}. -126 25 ea ra 10 ) Eclipses » IT 27 28 ) Conj..1 2 o5 30 58 Con}. é$m 4) Conj. 2 # 05 29 Ceres Opposit. © First Quarter. Times of the Planets passing the Meridian. APRIL. Venus. Mars. Ceres. Jupiter. Saturn. Georgian. h é h h h Ae ¢ h 2 0 22 14 35 =~ «(18 9 50 4 21 18 &9 0 36 13 37 17 24 8 55 37796 (Fae MAY. 0 53 12 18 16 38 7 54 2843. 82 <9 1 10 11 15 34 4.'8 1 55 16 12 JUNE. 1 33.. 9 37. 4.29 56 °O 57 15 5 1 50 8 35 13 16 5° 4 On GC Ad o& _ Declination of the Planets. ’ APRIL. Venus. Mars. Ceres. Jupiter. Saturn Georgian. e ’ e , e 4, ° 4 e 4, s ? 534N 1648S 2257S 1041N 2138N 21 50S 12 15 16 43 23. 22 ll 0 21 47 21 48 MAY. 18 41N 16 0S 23578 11 GN 2158N 21 48S 22 29 15 6 24 47 10/58 22. 7 21 49 - JUNE: 2436N 1421S 25598 1030N 22 16N 21 53585 23 38 14 27 2°27 9 55" ° 22:22 21 5Z Werl’6a|zoL"6z||SL"1b |o°Lb | . 9¢]| 8o°Sb | SE°0F'| Ca°bS ~ TISh “63)| 9S°TE |T aisere|1Les] “se Le'se lec"arles'ce|| 62°8e | SF'LE | 9T'6E | UOT "I|LL"268)ce"4e8}} 69TT 8001|| ZEIT | SFIL | 6EST cg" 1 8b°Sa6)Le 601 | 96TT}S98 |} S9OT | CFOTI] CSOT LLIT | $1ST} OFOT| LETT | O91} .| FIT ‘ung 6z°6z| 00°63], OF | Qh | to | Sb | ob |b jIki-y Ob6z/8b'6S || Lo | Te | oo |S" | t6 Te | 7S 02°62] £6°6a||o°62 | Ob | 6S | sb | OF *| HF “}|S0" “Te | ee. | Le, S66 “jee | o¢ ja 62°6s| 8S°6z||o"LE | Sb | OS |) Ih | oh | OF *S gee | 9¢ | 6a S"ss yoo | 65 [ob 0S°6z|99'6s || FF | Zo | 9e | S'Lb | 9b | &F 186] “L OL'6| 9L°6a)| S62 | FE [Se | CO | 1h | OF 84 *s "6g || Tg | 9¢ | 95 fe Be | | 83 7M , || £9°6c|se6s || Te | 9b | oe || ob FTh 4S jo) "IN 98°62] 18°62) Se | FR 9S | SOb | Ob | TF td €9°6z|9°6s "oe | ce | 9s | Of | 0 16 |b 9" |] £L°6z|18°62 || 1b | Le jee || Te | 1b | Te jos) °s 06°6e| FO'0c]) Le | : Flame, on its electricity, 179.—New Ex- periments on, 183. Foggo, Mr John, on a? electricity of showers, 124. -Fossil bones discovered neat Montpel- lier, 378. Fleming, Rev. Dr, on the defoliation of trees, 72. Freycinet on the hourly variations of the barometer, 293. -Galvanic Battery, improvement on the, 19 Galvanism, analogy between it and fer- mentation, 179. Ganges, on the grotto of, 216. Gas burner, on a rotatory one, 153. Gas, on an orange one from Fluor Spar . and chromate of lead, 129. Gilbert Davies, Esq., on the vibtation of pendulums, 154. Gmelin, Prof., his analysis of a lithion~ mica from Zinnwald, 222. Granite, on working and polishing it in : India, 281, Green, on Rinmann’ 55 184, _Grotto of Ganges described, 216. ‘Haidinger, Mr, on the manganese ores, 41.—On dimorphism, 301.. - Hamilton, Dr F., om the frontier be- tween Bengal and Ava, 22. Hansen’s Elements of the comet of 1825, 376, 377. ' Hansteen, Professor, on the intensity of etism on different parts of the - earth’s surface, 323. = Hart, Mr, his improvement on the gal- vanic battery, 19. Haity, Abbé, Life of the, | Herschel, Mr, on refracting and reflect- ing telescopes, 309—his experiments on the magnetism of rotation, 13, 257 1g double stars, 66—Miss on nebulz, 1 Hibbert, Dr, on concretions in sand. stone, 138, Himalayah Stocinisite, on a volcano in e, Hoar frost on iron rails, 180. Humboldt on the volcano of Jorullo, 50.—On the horary variations of the barometer, 290. Hygrometer, on an icapeowed one, 127— On Jones’s improved one, 182. Illusion optical on'a-singular one seen at Melrose, 88.—On another, in ex- amining a dioramic picture, 90 India on the route to, by Egypt and the Red Sea, 234. Insects, on some of unusual occurrence in Scotland, 37. Intaglios, on their apparent conversion in- to Cameos, 99. Iodine discovered in minerals, 183. Jorullo, on the volcano of, 50, 55 Island, on a new one, in the _Paci- fic, 278. uit ae Kennedy, Dr, on polishing granite in India, 281. Kuffher, M.,. on a remarkable law in mineralogy, 186. Kuhl, on the vegetable productions of Madeira, ‘1 19. Lachlan, Captain R., on the shock of an earthquake felt at sea, 264.-On the geography of the Burrampooter and the Sanpoo rivers, 302. Langeh, account of the tribe of, in Ava, 26. Lardner, Rev. Mr, on securing the Axles of Carriages, 155, Light, on a property of, in i daeapes, 306. Lightning, on its subterrancous pas- sage, 179. Lithia, on the means of coe it in minerals by the. blowpipe, 113. fs Lithia, discovered in mineral water, 128- Luminous phenomenon, be- tween Paisley and Glasgow, 378. Mackenzie, Sir George, on Insects of un- usual occurrence, Madeira,’on its vegetable production lio. Magnesia, on its precipitation by: gube- nate of soda, 136, ; Magnetism, developed by Rotation 13,257 257 —on the intensity of, on of the earth, 323—of the violet 09 328. ; 1a 20h: . - “s of gan rties of the, sale 1— pyramidal, — r mit INDEX. 387 Mechanical Inventions, history of, 150, pes cela Edinburgh, proceedings Meteoric Stones in Italy, 181. Mineralogy, on a remarkable law in, 186, Moll, Professor, on a new island in the Pacific, 278. Molybdena, iresearches concerning, 133, Mont, Blanc, on Dr Clark’s late ascent of; 255. Mosander, M,, on the precipitation of magnesia, by carbonate of soda, 136 —on the oxides of iron, formed by continued heat, 137. Murray, Mr John, on the torpidity of the tortoise and dormouse, 317. Necker, M., on birds near Geneva, 269. On a luminous phenomenon observed be- tween Paisley and Glasgow, 378. Oersted, Professor, on the law of the compression of air, 224. Optical illusions, 88, 89, 90, 94. Orang Outang, on a gigantic ones 193. Organ pipes, on the construction of, 80. Oxalic Acid in Lichens, 189. Parry, Captain, his last expedition to the Arctic Regions, 147. | Patents, list of, granted in Scotland, 188, 381. © ' Pendulums, on a curious law respecting their vibration, 154. Phantasmagoria, improvement on the, 37. Phosphorescence of fluids, 178 Pic du Midi, on its vegetation, Picrosmine, a new mineral, analysis of, 108. ‘y Piney Tallow from Malabar, 185. Pond, Mr, on determining the direction of the meridian, 177—on the double star & Bootis, 376. ? Pons, M. on the comets of 1825, 175, _ 376. _ Pringle, Captain, on the route to India ~ by the Red Sea, 234. Processes in the useful arts, history of, 150, 332. Prussian blue in the soda of Sicily, 184. Quartz district near Inverness described, 91. Rain without clouds, 181. Ramond, M. on the vegetation of the Pic Red snow of the Arctic regions, 167. Refractive power of elastic fluids, 211. = M. his analysis of Brewsterite, Ritchie, Mr, his improvement on the phantasmagoria, 37. Rose, Dr Gustavus, on Epistilbite, a new mineral species, 285. 0 Sand, on the discovery of a very fine kind at Alloa, for flint glass, 333. Savart, M., on the pipes of organs, 8L— on the mechanism of the himan voice, 200. Schow on botanical geography 161. Scrope, Poulett, Mr, on the volcano of Jorullo, 55—his considerations on vol- canos analyzed, 334—his theory of the earth explained, - Selenium in the sulphur of Lipari, 183. Setterberg, M., on the sulphurets of co- balt, 126. Sluices, on double weather ones, 150. Societies, philosophical, proceedings of, 173 , Society of Arts, proceedings of, 174. South, Mr, on double stars, 66—on re- fracting and reflecting telescopes, 309. Stark, Mr, on the discovery of live cockles at a distance from the sea, 148. Stars without any proper motion, 176. Stickleback, on the habits and food of the, 76. Sulpho-napthalic acid, 378. Sympiesometer, Mr Adie’s, recommend- ed, 181. . Taste, on the sense of, 243. Telescopes, on the comparative perform- ance of refracting and reflecting ones, 309. Temperature of the equator, 180—on its diminution with the altitude, 180—of different animals, !85—of the dor- mouse, 317. Thaumatrope, description of the, 87. hee Mr, on double weather sluices, 50. : Hed oo of the tortoise and dormouse, Transit instrument, on a singular effect of heat upon it, 177. Turner, Dr, on detecting lithia in mine- rals, 113. Voice Human; on the mechanism of the, 200. ; Volcano of Jorullo described, 50, 55— volcanos, considerations on, 334—in the Himalayah mountains, 209. Si Mr A. on a new punt-boat, Waterspout, on a remarkable one, 182. Wood, on a process for condensing it, Wollaston, Dr, on the direction of eyes in portraits, 117. DESCRIPTION OF PLATES IN VOL. IV. : PLATE I, Fig. 1.—5.' Mr Hart’s Galvanic Battery. Fi-. 6. Volcano of Jorullo. Fig. 7. Mustrative of Savart’s Paper on Organ Pipes. | “Fig. 8. Thaumatrope, * : fy Fig: 9. Optical Deception of Le Cat... ~. Fig. 10, 11. Geology of the North and South side of Lochness. _ | Fig. 12, 13,. Mr’ Adam’s Naatical Eye-Tube. Be 14—22. Figures illustrative of oe, Tilusion of the Convenriott of Cameos into. Intaglios. . » Fig! 23. Optical Illusion: seen through a ‘Telescope ~ Fig. 24. Reservoir for’ Mills. Fig. 25., Nimmo’s Rotatory Gas-Burner. © 3 Fig. 26—28, Method of. Securing the Axles 0 of Cadtiges Fig. 27—30. Concretions in Sandstone. __ Fig. 31, Mr Foggo’s Electrometer for Atmospherical Electricity. Fig. 32, 33. Improved Hygrometer, ‘ Fig. 34. Berzelius’ sMethod of Detecting ‘Arsenic. - a PLATE II. -Is illustrative of the Crystalline Forms of the Manganese Ores. PLATE III. Illustrates Dr Wollaston’s Paper on the Direction of the Eyes ip? Portraits. -PLATE IV. Represents the Head, Hands, and Feet, of the Gigantic Orang ~ % _. Outang from Sumatra. a “PLATE V. tae’ 1.—11. Ace illustrative of M. Savart’s. Memoir on ge ‘Me. fs ' chanism of the Human Voices > Savi et ner Fig. 12, Mr Waddell’s Punt-Boat. le * Fig. 13-—19. Aré illustrative of Professor Oerstes Paper. on the: * mod ‘Compression of Gases. OE Pinte, ¢ Fig. 20.—26, Illustrate Dr Gustavus Rose’s Paper pf auachor Fig. 27. Represents the Annual Daily Curve of the’ crore Leith Fort, as deduced from Observations made every hour oe mei See our next Number. secduitunalts, pe my og ft a a y eee he ae al Lathe, ih eam f a >. Satta et se e i} eeat er ee ¥ ¢ai7 ont Edin? Journal of Seienee Vol lV. 32 ; . ws - ¢ 1 Rae is) \ 4 Edin? Journal of Setence Val pp, PLATE UL —— = Fig. 1. i PLATE Iv. Kedin® Jouri@t Setenee Val. pd fig. 7. Figd. one fourth the real size.—Figs. 2.5.45. one sixth the real sire. Seas at ; fk Bilin! Journal of Setenee Vall Fig. 20. ‘ ¥ ~~ ‘ rm i lm ow RS i S 1 Be iS ; ee ae Va Oe Ee s PIAL dead eee JUN 11 1971 Q The Edinburch Journal 7 of science B3 v4 Physical & Applied Sai. 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