L . R. 1. JOURNAL OF SCIENCE, EXHIBITING A VIEW OF THE PROGRESS OF DISCOVERY IN NATURAL PHILOSOPHY, CHEMISTRY, MINERALOGY, GEOLOGY, BOTANY, ZOOLOGY, COMPARATIVE ANATOMY, PRACTICAL MECHANICS, GEOGRAPHY, NAVIGATION, STATISTICS, ANTIQUITIES, AND THE FINE AND USEFUL ARTS. CONDUCTED BY DAVID BREWSTER, LL.D. F.R.S. LOND. SEC. R.S. EDIN. F.S.S.A. M.R.I.A. CORRESPONDING MEMBER OF THE INSTITUTE OF FRANCE ; CORRESPONDING MEMBER OF THE ROVAI. PRUSSIAN ACADEMY OF SCIENCES ; MEMBER OF THE ROYAL SWEDISH ACADEMY OF SCIENCES; OF THE ROYAL SOCIETY OF SCIENCES OF DENMARK ; OP THE ROYAL SOCIETY OF GOTTINGEN, &C. &C. VOL. VIII. NOVEMBER— APRIL. JOHN THOMSON, EDINBURGH AND T. CADELL, LONDON. M.DCCCXXVIII. ,iii iU PHINTED BY JOHN STARK. CONTENTS OF THE EDINBURGH JOURNAL OF SCIENCE. No. XV. Page Art. I. Biographical Sketch of Alexander Volta, Professor of Natural Philosophy at Como, - - . - - 1 II. Concerning Coloured Spectra from Flame, Moon, and Starlight, and , , from Electric Light. By the late M. Le Chevalier Fraunhofer, Member of the Royal Bavarian Academy of Sciences at Munich, 7 III. Narrative of the Proceedings and Scientific Observations of the late Mission to Ava, - - - - - - 10 IV. On the Foetus of a Polydactylous Horse having the Toes separated by a Membrane. By M. G. St-Hilaire, Member of the Institute, 25 V. On the principles of Dynamics, particularly as stated by French Writ- ers. By the Rev. W. Whew ell, M. A. Trinity College, Cambiidge. Communicated by the Author, - - - 27 VI. On the probable cause of the North -East Winds which occur in the Spring in most parts of Great Britain. By Mr Samuel Marshall, Communicated by the Author in a Letter to the Editor, - 39 VII. On the Systems of Double Stars which are supposed to be Binary ones, from the observations of Sir W. Herschel and Messrs Herschel and South, - - . . , - 40 VIII. Account of the Indian Penance of Gulwugty, or Churuk Pooja. By R. H. Kennedy, M. D. - - - - 44 IX. Account of the Method of Drawing Birds employed by J.J. Audubon, Esq. F. R. S. E. In a Letter to a Friend, - - 48 X. Account of the Cave of Booban, near Punduah, in the Cossyah Moun- tains, - - - - - - 54 XI. Account of the Fosil Bones discovered on the left bank of the Irawad- dy in Ava, - _ - - - 56 XII. On the Mean Temperature of the Equator, as deduced from Observa- tions made at Prince of Wales's Island, Singapore, and Malacca. By David Brewster, LL. D. F. R. S. Lond. and Sec. R. S. Ed., 60 XIII. A Metallurgic Memoir on the Nature and History of the Argillaceous Carbonate of Iron. By Hugh Colquhoun, M. D. Communicated by the Author. (Continued from vol. vii. (p. 242.) - 67 XIV. Description of the new Fluid Telescope recently constructed by Messrs W. and T. Gilbert on a plan suggested by Peter Barlow, Esq. F. R. S., Mem. Imp. Ac. Petrop. In a Letter to the Editor, 93 XV. Notice respecting the Varnish and Varnish Trees of India, - 96 XVI. Account of the Poisonoua Qualities of the Vegetable Varnishes from India and America, - - - - 100 11 CONTENTS. rage Art. XVII. Observations on the Generation of the Lobularia digitata, Lam. (Alcyonium lobatum, Pall.) By R. K. Grant, M. D., F. R. S. E., F. L. S., Professor of Zoology in the University of London. Com- municated by the Author, - .. - 104 XVI n. Description of an Apparatus for Impregnating Liquids with Gases. By James King, Esq. Commiinicated by the Author, - 110 XIX. Account of the Assamese Method of Blasting Rocks. Communicated by a Correspondent in India, - - - 111 XX.. Memoir on the Horary Oscillations of the Barometer at Rome. Com- municated by the Author, - - _ - 112 XXI. On Footsteps before the Flood, in a Specimen of Red Sandstone. By Mr Grierson, - - - - - 130 XXII. On the Improvements in the Elements of the Moon's Orbit. By M. Le Chevalier Burg, Corresponding Member of the Academy of Sciences, F. R. S. E. &c. &c. In a Letter to Dr Brewster, 134 XXIII. Excursory Remarks on Radiant Heat, with a short examination of Professor Leslie's Theory. By William Ritchie, A. M. Rector of the Royal Academy at Tain. Communicated by the Author, - 136 XXIV. On the Effects of the Poisonous Gases on Vegetables. By^EDWARD Turner, M. D. F. K. S. E. Professor of Chemistry in the University of London ; and Robert Christison, M. D. Professor of Medical Jurisprudence and Police in the University of Edinburgh, &Cw - 140 XXV. ZOOLOGICAL COLLECTIONS, - - - 149 1. On the appearance of Locusts in the Doab. By G. Playfair, Esq, ib. 2. Destructive action of the Teredo navalis on vessels built of Teak Tim- ber. By Mr C. Wilcox, - - - - 151 3. Destniction of the Piles at the Chain Pier by the Limnoria tere- brans, - .----- 152 4. On the means by which Spiders that produce Gossamer effect their aerial excursions. By J. Blackwall, Esq. - • 153 5. On the Fascination of Snakes. By Mr Nash, - - 154 V). Experiments on the reproduction of domestic animals. By Mr Ch. GiRON DE Buzareurgues, Corresponding Member of the Royal Academy of Sciences, . - - _ . 155 7. On the Esquimaux Dog. By J. G. Children, Esq. - ib 8. Elephant, - - - - - 156 XXVI. HISTORY OF MECHANICAL INVENTIONS AND OF PRO- CESSES AND MATERIALS USED IN THE USEFUL ARTS, 157" 1. Mr Farey's Improved Lamp, - , - - - ib. 2. Notice of the New Metallic Compound Artimomantico, resembling gold in colour and weight, - - - ib. 3. Notice of a Metallic Alloy for plating Iron and protecting it from Rust, - - - - - - ib. 4. Composition for washing in Sea Water. By Edward Heard, Che- mist, London. ..... 158 5. Process for giving Statues and Medals the appearance of Bronze, ib. 6. Account of an improvement in the construction of Bedsteads, Sofas, &c. ib. 1 CONTENTS. Ill \ Page 7. Account of new Bricks for building both cylindrical and curred Chimneys. By Mr J. W. HioiiT, Atchitect, - - 158 8- Method of Mooring Ships in Roadsteads. By Lieut-Col. Milleh, F. R. S., . - - - - . 15i> 9. On the adhesion of Screw Nails. By B. Bevan, Esq. Civil Engineer, ib. 10. On the great Power and Duty of some new Steam Engines, 166 11. Process for preparing Indelible Writing-ink, - - ib. 12. Observations on the Explosion of Steam Boilers. By Mr W. J. Henwood, - - - - - ib. 13. Account of the Collection and Preparation of the Fucus saccharinus, a sea-weed, for the Chinese market, and its uses, - 162 XXVII. PROCEEDINGS OF SOCIETIES, - - - 164 Proceedings of the Royal Society of Edinburgh, - - ib. XXVIII. SCIENTIFIC INTELLIGENCE, - - - 166 I. NATURAL PHILOSOPHY. Astronomy. — 1. Solar Eclipse of November 1826 observed at Naples. 2. Opposition of Vesta to the Sun. 3. Opposition of Juno to the Sun in March 1828. 4. New Variable Star in the Serpent, - - 166— 1G7 Optics — 5. On the Luminous Appearance of the Ocean. By J, Henderson, Esq. - - _ . - - 167 Magnetism. — G. Eaton's proposed Improvement on Magnetic Needles. 7« Professor Hansteen's Magnetic Tour to Siberia. 8. On the Magnetic Actions excited in all Bodies by powerful Magnets, - » - 169 Electro-magnetioM.— 9. On the Rotation of a Magnet about its Axis, I70 Meteorology. — 10. Sound of the Aurora Borealis in Iceland, observed by Mr Henderson. 11. Auroras Boreales observed in Roxburghshire in 1827. 12. Great Dryness in the Antilles in 1827. 13. Meteoric Stone at Futteh- pore, - - - - - I76--I73 II. chemistry. 14. M. Despretz on the Heat Developed in Combustion. 15. Karsten's Me- tallurgy of Iron. 16. Iodine in Cadmium. I7. Analysis of the Green Iron-ore. 18. Analysis of the Arseniate of Lead. 19. On the Detection of Antimony in Mixed Fluids. By Edward Turner, M. D. 20. Ulti- mate Analysis of several Vegetable Substances. By M. F. Marcet. 21. On a Chloride of Manganese, remarkable for its Volatility. By M. J. Dumas. 22. On the properties of Sulphur. By M. J. Dumas. 23. On a New Method of Preparing the Deutoxide of Barium. By M. Quesne- ville, Fils, - - - - 173—180 III. natural history. Mineralogy — 24. Brachytypous Lime-Haloide of Mohs. 25. Chrysolite in the Cavities of Obsidian. 26. New Minerals. 27. Mica from New Jer- sey. 28. Dr Thomson's Analysis of Pure Chromate of Iron, - 180 182 Geology. — 29. On the Boulder-stones in the North of Germany. 30. Baron Von'Buch on Volcanoes. 31. Greenstone and Porphyry of the Hartz. 32. Geo%ical Map of Germany in 42 sections, - - 180—183 IV CONTENTS. Page IV. GENERAL SCIENCE. 33. Discovery of a Remarkable Structure in the Knee-joint of the Echidria hystrix of Australasia. By Mr F. J. Knox. 34. Hydrogen Gas from Salt Mines employed for producing Light, and for Fuel. 35. Natural Gas Lights at Fredonia, ... - - 183 XXIX List of Patents granted in Scotland since June 14, 1827, - 184 XXX — Celestial Phenomena from January 1st to April 1st, 1828, - ib. XXXI Summary of Meteorological Observations made at Kendal in Sep- tember, October, and November, 1827. By Mr Samuel Marshall, 18G XXXIL— Register of the Barometer, Thermometer, and Rain-Gage, kept at Canaan Cottage. By Alex. Aidie, Esq. F. R. S. Edinburgh, - 188 NOTICES TO CORRESPONDENTS. J. R. had better send his Reply to Mr Rumball on the " Position of the Focus in the Eye," to the Philosophical Magazine^ that the error and its correction may ap- pear together ; though we think the paper already contains its own refutation. We have received the following Hourly Meteorological Observations on the 17th July 1826 from Germany. 1. Vienna University Garden — 2. General Fallow's Private Observatory — 3. Wies- senau in Lower Carinthia — 4. M. St Leopold near Vienna. — 5. Newstadt, near Vienna 6. Alpine Region of the Schneeberg on the frontiers of Austria and Styria. 7. Lay bach 8. Gorrie — 9. Prague. For the 15th January 1827 from I. Vienna University Garden — 2. Neuthor Bastey — 3. Laybach— 4. Rosalia Capelle near Forchtenau. — Watch-house on the Hohenleuthe 6. Baden. An Amateur in Meteorology will, we trust, excuse us for not publishing the Meteorological Journal which he has sent. If he has no objection we shall willingly print an abstract of it. We could fill twenty consecutive numbers with very valuable Meteorological registers ; but we doubt if the occupation of even a small part of each number with such materials would either promote science or gratify our readers. We agree with a Constant Reader that our Small Type is rather too minute for a winter evening and for eyes turned of fifty, but we cannot alter it at present, though we may diminish the quantity of it. At the end of No. XX. or Vol. X. we shall begin a new series, and shall consider seriously his proposal. A's interesting paper on the Cold Caves of Monte Testaccio at Rome will appear in oiu: next, as the present number was filled before its arrival. He will find the barometrical observations at the Observatory for several years in Blackwood's Ma- gazine, and in the Edinburgh Magazine — He is requested to notice an error in p. 137 of the proof sent to him in the sum divided by 18, which affects his general m» suits We have therefore divided his paper, the remainder of which will appear in next number. In answer to his question we beg to inform him. Kitchener's Pan- cratic eye tube has many advantaged. It was described long ago in Dr Brewster's Treatise on Optical Instruments. CONTENTS OF THE EDINBURGH JOURNAL OF SCIENCE. No. XVI. Page Art. I. On the supposed Influence of the Aurora Borealis upon the Magnetic Needle, in reply to the Observations of M. Arago, as communicated to the Academy of Sciences on the 22d January 1828, '- 189 II. On the Elasticity and Change of Volume of Metallic Strings while in a state of Vibration. By Baron Cagniard de la Tour, - 201 III.* On the singular Effects of two Strokes of Lightning upon the vessel called the New York, while sailing from London to New York. By the Reverend William Scoresby. - - 203 III. On the Cold Caves of the Monte Testaccio at Rome. By a Corres- pondent, - - - . - - 205 IV. Observations on the Formation of Ice in India, in a Letter from David Scott, Esq. to George Swikton, Esq. Calcutta, - - 216 V. Memoir on the Horary Oscillations of the Barometer at Rome. Com- municated by the Author. (Continued from p. 129.) - 218 VI. Account of the Necropolis of Petra, a City in Palestine, excavated from the solid Rock. By the Honourable Charles Leonard Irby and James Mangles, Commanders in the Royal Navy, - 227 VII. Notice of the Principal Meteorological Phenomena in the last eight months of 1826 at Patna and Futtehpore. By Alexander F. Lind, Esq. of the Bengal Civil Service. Communicated by the Author, 246 VIII. On the Assay of the Argillaceous Iron-Ore. By Hugh Colqu- HOUN, M. D. Communicated by the Author, - - 250 IX. On the Natural History and Properties of Tabasheer, the Siliceous concretion in the Bamboo. By David Brewster, LL.D., F. R. S. Lond., and Sec. R. S. Edin., - - - - 28* X. On a new Acid of Selenium. By M. E. Mitscherlich, Professor of Chemistry in the University of Berlin, F. 11. S. Ed. &c. &c., 294 XI . Summ ary for the year 1 827 of the state of the Barometer, Thermometer, &c. in Kendal. By Mr Samuel Marshall. Communicated by the Author, - - - . . - 299 XII. Account of an extraordinary Marine Animal or Sea Serpent. By I. Harwood, M. D. F. R. S. Professor of Natural History in the Royal Institution, - - - - 300 XIII. On the Mean Temperature, &c of various places in the State of New York for 1826, * - - - 303 XIV. Account of the Tracts or Foot-Marks of Animals found impressed in Sandstone in the Quarry of Corncockle Muir, Dumfries-shire. By the Reverend Henry Duncan, D. D. Minister at Ruthwell. Communi- ' cated by the Author, - - - - 305 a 11 CONTENTS. Page XV. On the supposed changes in the Meteorol<^cal Constitution of the different parts of the Earth during the Historical Period. By M. ScHow, Professor of Botany in the University of Copenhagen, - 311 XVI. Experiments on the Absorption of Vapours by Liquids. By Thomas ' Grahau, a. M. Commvmicated by the Author, . - - < 326 XVII. Chemical Examination of Tabasheer. By Edwabd Tuener, M. D. F. IL S. E. Professor of Chemistry in the University of London. Com- mxmicated by the Author, - - -, 335 XVIII. ZOOLOGICAL COLLECTIONS, - ^ - 338 1. Bears of India, - - - - ib. 2. On the Crocodiles of the Ganges. By C. Abel, M. D., F. R. S., 339 3. Account of the White Elephants of Siam. By George Finlay- soN^, Esq., - ... 342 4. Account of a Fight between a Tiger and an Elephant. By George FiNLAYSON, Esq., - - - 342 XIX. HISTORY OF MECHANICAL INVENTIONS AND OF PRO- CESSES AND MATERIALS USED IN THE FINE AND USEFUL ARTS, - - - - 343 1 . Account of the Makleua, a Siamese Black Dye. By Captain Bur- NEY, - - - - ib. 2. Account of a new kind of Cloth fabricated by Insects, - ib. 3. Radii of the surfaces of a Double Achromatic Object-Glass. By M. LiTTRow, - - - - 344 4 Exhibition of the National Industry of France, - - ib, XX. ANALYSIS OF SCIENTIFIC BOOKS AND MEMOIRS, 34C 1. A new System of Chemical Philosophy. Part First of Vol. ii. By John D alt on, F. R. S. &c. - - - ib. 2. A History of British Animals, exhibiting the Descriptive Characters and Systematical arrangement of the genera and species of Quadru- peds, Birds, Reptiles, Fishes, Mollusca, and Radiata, of the United Kingdom ; including the indigenous, extirpated, and extinct kinds, together with periodical and occasional visitants. By John Flem- ing, D. D. F. R. S.E. &c - - - - 355 XXI. PROCEEDINGS OF SOCIETIES, - - 359 1. Royal Society of Edinburgh, - - - ib. 2. Proceedings of the Society for Promoting the Useful Arts in Scot- land, - - - - 360 XXII. SCIENTIFIC INTELLIGENCE, - - 361 I. natural philosophy. Astronomy.— 1. Eclipses of Jupiter's Satellites observed at Wilna. By M. Slawinski. 2. Occultations of Stars observed at Wilna. By M. Sla- wivsKi. 3. Occultation of Saturnobserved at Wilna. By M. Slawinski. 4. Occultation of the small star of tho double star of fi Scorpii, observed by •N CONTENTS. m Page Mr Riddle. 5. Comet of June 1827. 6. Comet of September 1827 simi- lar to that of 1780, - - - 361—362 Optics. — 7« Luminous Appearance of the Sea near Prince of Wales* Island. 8. Magnificent achromatic Telescope executed in Paris, - 361»>362 Meteorology — 9. Red Rain, supposed to arise from Butterflies. 10. Waterspout seen on the Lake of Geneva, Ilth August 1827, - 363 — 364 Electricity. — 1 \. Different effects of an electric discharge in Magnetising different needles. 12. On the variable conducting powers of bodies for Elec- tricity. 13. M. Becquerel on the Pyro-electricity of the Tourmaline, 365 II. chemistry. 14. Analysis of the Gas obtained from the Body of a Cow, inflated in conse- quence of feeding too freely on Green Food. By M. Pluger. 15. Singu- ' lar action of Phosphoric Acid on Albumen. 16. On the Manufacture of Bromine. 17. Researches on the Fermentation of Curd and on the Caseous Oxide and Caseic Acid. By M. Henri Braconnot. 18. Caseous Oxide. 19. Caseic Acid. 20. On the Identity of the acidulous Malate of Althein with Asparagin. 21. Analysis of a newly discovered Mineral Spring at Stan- ley, near Wakefield. By Mr W. West. 22. Test for the presence of Ni- tric Acid. By Dr Liebig. 23. Separation of Arsenic from Nickel or Co- balt. By M. Woehler. 24. Experiments on the Nature of Labar. raque's Disinfecting Soda Liquid. By Mr Faraday. 25. On the means of ascertaining the Purity of Sulphate of Quina. By Mr Phillips. 26. A New Method of Separating Manganese from Lime and Magnesia. By Pro- fessor Stromeyer, - - - 365 — 374 III. natural history. Zoology. — 27. Baron Ferussac's Work on the Cephalopodous Mollusca, 377 IV. general science. 28. Royal Medal adjudged to Sir H. Davy. 29. Medal adjudged to M. Struve. 30. Copley Medal adjudged to Dr Prout. 31. Copley Medal ad- judged to Lieutenant Foster. 32. Medal adjudged to Sir Thomas Brisbane. 33. Keith Medal adjudged to Dr Brewster, - - 374—375 XXIII. Celestial Phenomena, from April 1st to July 1st, 1828, - 375 XXIV. List of Patents granted in Scotland since November 2, 1827, - 377 XXV. Register of the Barometer, Thermometer, and Rain-Gage, kept at Ca- naan Cottage. By Alex. Adie, Esq. F. R. S. Ed. - - 378 NOTICES TO CORRESPONDENTS. Dr Forchhammer's interesting Paper will appear in our next Number, and we hope to hear again from him soon. We shall be glad to receive the rest of Professor Schow^s Communication as soon as possible. A's Meteorological Paper is unavoidably postponed till next number. We have made the addition to it which he requested. Professor Hansteen's paper did not reach us till too late for the Number. It will appear in No. xvii. We beg that he will favour us with the results of the Hoiurly Observations at Chrbtiania and Drontheim for 1827, which he mentions ; and we shall be glad to hear of the success of his labours in Siberia. Mr Marshall's Quarterly Meteorological Journal has not reached us as usual. Mr Haidinger's valuable paper, which has only this moment reached us, will appear in next Number. ERRATA. Page 69, line last, /or 631 read 431. 75, — 5, — discovered read described. 81, — 10, — sheets read streets. 85, — 35, ^; — coal read coals. The reader is pat»^larly requested to correct the following errors in the first part of the Memoir on the Horary Oscillations of the Barometer at Rome, which was printed in our last number. Page 115, tliird line from bottom,/or " now on the tube," read " moved on the tube." 116, at bottom of the small table, /or 26.945 Eng. in. read 29.945 Eng. in. 118, col. 5, 1. 2, (obs. No. 33,) /or 57 read 56. col. 4, (obs. No. 57,) /o*- 016 read 30.016. (obs. 74,) /or 806 read 29.806. 121, col. 2, (obs. 328,) ahove « 7" insert " April." 124, col. 5, last line but one, for 'J'Jb read 755. col. 10, 1. G.for 020 read 30.020. 125, col. 10, L 17,/w 057 read 059. 126, col. 10, 1. 6,/(w 163 read 183. 127, col. 10, L 13 from bottom, /or 30.945 read 30.045. 128, col. 5, 1. 20, (opposite 5a.) /or 077 read 0C3. — — 1. 21, (opposite C>k.)fbr 083 read 098. — _ 1. 22, ( 7a.) /or 098 read 107- — — 1. 23, ( 8a.) /or 107 read 116. — _ 1. 24, ( 9a.)/w 1 16 read 127. .__ 1. 25, ( 10a.) /or 127 read 144. _ — 1. 26, ( llA.)/or 144 read WJ. — . 10. 8th line from bottom, /or 264 read 269. 6th for 254 read 258. THE EDINBURGH JOURNAL OF SCIENCE. Art. I. — Biographical Sketch of Alexander Volt a, Profes- sor of Natural Philosophy at Como. Alexander Volta was born at Como on the 18th February 1745, and was descended from an ancient family of that city. Among the misfortunes of his infancy, his friends have enu- merated that of having a foolish nurse, and to this cause they have ascribed the slow developement of his mental powers. The first exhibition of his talent was a piece of poetry ; but even in his poems, which were composed in Latin and Italian, he already pointed out the subjects which were likely to de- mand the efforts of his genius. He soon published, indeed, a paper in prose on the phenomena of electricity, and on a new apparatus destined to carry on the discoveries in this branch of physics. After having completed the course of studies in the univer- sity of Como, he was appointed regent of it, and subsequent- ly obtained the chair of natural philosophy. From Como he went to the university of Pavia, where he devoted to science the labours of thirty years, and dignified the name of his country with deeds of intellectual renown, which fixed the at- tention of Europe, and formed an era in the history of the human mind. One of the first inventions of Volta was that of the electro- phorus, which he described in June 1775, and of which he published an account in Ro%ier'*s Journal de Physique for September 1776. This ingenious instrument consists of a ine- VOL.^VIII. NO. I. JAN. 1828. A 2 Biographical Sketch of Professor Volta, tallic and a resinous plate, by the successive contact of which electricity may be perpetually developed. M. Wilcke had made some considerable approaches to that invention, and con- sequently the honour of it has been claimed for him by his countr)'mcn ; but there can be no doubt that the electrophorus, as an instrument, is an invention entirely new, and that its eminent author was not even acquainted with the previous ex- periments of the German philosopher. * During his summer vacations, he was in the habit of per- forming journeys of considerable length. In 1777 he travel- led through Switzerland, and, accompanied by his friend the Count J. B. Giovio, he paid a visit to the celebrated Haller at Berne, when that great man was sinking under the accumu- lated infirmities of age and disease. They visited also Voltaire at Ferney. In 1776 and 1777 Volta published some remarkable letters on the inflammability of air disengaged from marshes. They were addressed to Father C. J. Campi, and were afterwards translated into French and German. In the same year he in- vented his hydrogen lamp, and his electrical pistol, instruments which are well known to all who have attended an experimental course of chemistry and physics. The hydrogen lamp now forms an elegant piece of furniture, in which a light can be at all times obtained. A stream of hydrogen gas is made to issue from a small aperture by means of the pressure of a column of water, and the gas is kindled by a spark from an electrophorus placed below. About the same time Volta discovered the eudio- metrical process of determining the relative proportions of the two gases, oxygen and azote, which compose atmospherical air. A given measure of hydrogen gas being put into a glass tube with a quantity of atmospheric air, it was inflamed by the electric shock, and the quantity of oxygen was indicated by the diminution of volume. During his travels in Tuscany in 1780 he studied with par- ticular care the fires which burn among the Apennines, on the road from Bologna to Florence, and which are known by the • See Wilcke, Disjmiatio Physica Experimentalis de Electricitatibus con" irariis. Hosted, 1757 ; and Edinburgh Encyclopcedta, vol. viii. p. 423. Art. Electricity. Biographical Sketch of Professor Volta. 3 name of the Vulcanetto di Pietra Mala. Of these he published a description, in which he first explained how these fires, as well as those which spring from the ground near the ancient city of Velleja, arise from the combustion of atmospheric air disengaged from the ground. In 1782 Volta invented an electrical condenser for rendering sensible small quantities of the electrical fluid ; and in the same year he performed a tour through Germany, along with his celebrated colleague M. Scarpa. After his friend parted with him, he extended his tour to Holland, England, and France. On his return from that journey he introduced into Lombardy the culture of the potato, which he had observed in Savoy ; and the peasants who first cultivated this valuable article of food were rewarded with the prize offered by the Patriotic So- ciety of Milan. The curious experiment of Galvani in 1790 on the electri- city of the muscles of frogs gave a vigorous impulse to phy- sical inquiry throughout Europe. Volta took a deep interest in the new science to which Galvani's experiment has given the name, and he had the good fortune to establish it on a scientific basis, and to extend its boundaries by the most im- portant discoveries and inventions. Valli, Fowler, and our countryman Dr Robison, had preceded Volta in their galvanic inquiries, and the latter had made a slight approach to the invention of the pile, by discovering the sensation of taste which was excited when the tongue was applied to the edges of a number of plates of zinc and silver placed alternately upon each other. The first researches of Volta were transmitted to the Royal Society of London in 1793, in the form of two letters to Mr Tiberius Cavallo, entitled Account of some discoveries made J)y M. Galvani of Bologna, with experiments and observations on them.* These letters contain a perspicuous account of the discoveries of Galvani, with a notice of many curious experi- ments of his own. He overthrows the opinion of Galvani, that the animal body has an analogy to the Leyden phial ; he found that two different metals were necessary to produce the effect ; and he concluded that muscular contracti#is arise from * Phil. Trans. 1793, vol. Ixxxiii. p. \0, 4 Biogra2)hical Sketch of Professor Volta, small portions of electricity liberated by the mutual action of the metals. He found that the nerve was the organ on which the Galvanic influence immediately acted, but that, if a part of a muscle be laid upon two different metals, and a communica- tion established between them, a contraction is produced. He then explains all the phenomena on the principle, that when two metals are brought into contact a destruction of the electrical equilibrium takes place; and the one of them gives to the other a portion of its natural electricity, the one becoming positive and the other negative. He regards this as a new law of elec- tricity, and he lays claim to the merit of its discovery. The great discovery of Volta, and that upon which his re- putation will always rest, is that of the pile, which is now known by the name of the Voltaic pile. This grand invention was made previous to 1800, and having been elected a Fellow of the Royal Society of London in 1791? he communicated an account of it in two letters to Sir Joseph Banks, which ap- peared in the Philosophical Transactions for that year. In consequence of the war, however, which then raged between England and France, one portion of the paper reached Sir Joseph several months before an opportunity occurred of send- ing the remainder. Hence the publication of the invention was delayed ; but the apparatus was constructed in London, and very curious experiments were made with it by different gentlemen in that city before the original paper of Volta was laid before the public. This instrument consisted of two per- fect and one imperfect conductor of electricity, viz. silver and zinc, or copper and zinc, which were the perfect conductors, and a piece of card or leather soaked in salt water and a little smaller than the metal plates, which formed the imperfect con- ductor. When one hand was placed on the uppermost con- ductor, and the other on the lowest, a shock was felt similar to that of the Leyden phial. Its chemical actions were still more important, and are too well known to require any notice in this sketch. In 1821 Volta was invited to Paris. He repeated in the presence of the First Consul, and before the Institute, his ex- periments \|i^h the pile. These experiments were highly suc- cessful ; and in order to mark an epoch so remarkable in the Biographical Sfitich of Professor Volta, 5 history of science, that distinguished body presented him with a gold medal with this inscription, A Volta, la Classe des Scierices Mathematiques et Physiques, In the following year the Institute sent him another, with the inscription, A Volta, associe etranger; and most of the academies of Europe were proud to enrol his name in the list of their members. From Paris Volta repaired to Lyons to assist, in the cha- racter of deputy from the university of Pavia, at the meeting which was convoked in that city to elect a President of the Italian Republic. When the election was over he was seized with a serious illness, which obliged him to remain some months at Lyons, and afterwards at Geneva, where he experienced the most hospitable reception from the learned professors of that city, with whom he had long been on habits of the most inti- mate friendship. The honours which our author thus received in foreign countries were followed by others conferred upon him at home. He was raised to the rank of a count, and thus became a se- nator of the kingdom of Italy. In this capacity he was ob- liged to spend part of the year at Milan, and he repaired every evening to the parties of Paradisi, President of the Academy, at whose house were assembled the most distinguished indivi- duals of the country. In the year 1804 he had obtained leave to retire from his professorship, on the condition of his giving a few lectures every year. On this occasion Napoleon said to him, " Great men die on the field of honour."" Volta never forgot this say- ing, and after the fall of Buonaparte he said, in allusion to it, " He, however, has not kept his word with me." Living in a frontier town, Volta was one of the first Ita- lians who presented himself to Buonaparte when he entered Italy for the first time. His fellow-citizens sent him in 1796, along with Count T. B. Giovio, to request the protection of the conqueror. From that time Buonaparte never lost an op- portunity of honouring Volta. He conferred upon him the orders of the Legion of Honour, and of the Iron Crown, and the titles of Count and Senator of the kingdom of Italy ; and at the formation of the national Institute of SciQpce and Let- ters, when they were deliberating in his presence whether 6 Biographical Sketch of Professor Volta. they should draw up a list of the members in an alphabetical order, Buonaparte wrote at the head of a sheet of paper Volta, and delivering it to the secretary, he said, " Do as you please at present, provided that name is the first.'' Volta married in 1794, and had three children. He took a particular charge of their education, and he felt most bitterly the loss of one of them, who had given great promise of being a mathematician. In returning to spend the remainder of his days in his pater- nal mansion at Como he experienced the greatest comfort from the affectien and tender solicitudes of his family. He had now given up his studies, and having been seized with a fever, he died after two days illness on the 5th March 1827. His death was universally lamented, and at a meeting of his fellow- citizens, called on purpose on the 23d of March, it was re- solved to strike a medal, and erect a monument to his memory. On the modern fa9ade of the public schools of Como, in the middle of the busts of Pliny, Giovio, and other great men who were natives of this place, an empty niche was left as a com- pliment to the genius and modesty of Volta. To all the domestic virtues, Volta added the most sincere piety, and his last moments were marked with expressions of religious feeling. As a citizen he was highly esteemed, and his fellow-countrymen entrusted him with all their public concerns, which lie managed with the utmost intelligence and integrity. In 1816 a complete collection of his works was published by the Chevalier Vincent Antinori at Florence, entitled Colle- zione delle Opere del Cav. Conte Alexandro Volta. It was de- dicated to Ferdinand III. Grand Duke of Tuscany, and is embellished by an excellent likeness of the author by Morg- hen. In order to complete this collection it is necessary to add, 1. The Latin poem which we have already mentioned. It treats of the principal phenomena of physics and chemistry. 2. An Italian poem on Saussure's Voyage to Mont Blanc, and some other pieces in verse. 3. Observations and experiments on vapours : and 4, A number of articles on physics and che- mistry, either unpublished, or scattered through the pages of periodical and other works. M. Fraunhofer on Coloured Spectra. Art. II. — Concerning Coloured Spectra ^om Flame, Mocm, ^ and Starlight, and from Electric Light. * By the late M. Le Chevalier Fraunhofer, Member of the Royal Bava- rian Academy of Sciences at Munich. It is already known that the coloured spectrum which is pro- duced by means of the prism from the light of a lamp does not show the dark fixed lines which are contained in the spec- trum from sunlight; but instead of it there is in the orange a light line, which is more distinct than the rest of the spec- trum. It is double, and is found at the same place where in the spectrum from sunlight the dark double line D stands. The spectrum which arises from the light of a flame, kept up with a blowpipe, contains several distinct light lines. It is of much greater advantage in optical experiments, that, with a proper blowing of the flame, the light of its anterior half'is not further dissected through the prism, and consequently is simple homogeneous light. This light has, as far as I have hitherto investigated it, the same refrangibility as the ray D from sunlight. Simple homogeneous light going out in all directions is from known reasons very difficult to produce, and never to be obtained directly by prisms ; and hence this flame is of great utility in many experiments. By means of the very large electrical machine in the cabinet of natural philosophy of the Royal Academy of Munich, I obtained a spectrum of electric light, in which I recognized a great number of light lines ; and I have determined the relative place of the lightest lines, and the proportions of their inten- sity. The light of the moon has given me a coloured spec- trum, which, in the lighter colours, shows the same fixed lines as the sunlight, and precisely in the same place. The light of the moon being too feeble, I could not very distinctly perceive the fixed lines in the darker colours. For the observation of the spectra from the light of the fixed stars, and for the purpose, at the same time, of determining the re- frangibility of their light, I have lately prepared particular • This article forms a supplement to the paper of M. Fraunhofer, which we published in our last Number, p. 251. 8 M. Fraunhofer on Coloured Spectra from Flame, instruments entirely for this purpose. With a telescope hav- ing an object-glass four inches diameter, I have obtained from it several interesting results, although the experiments are by no means finished. The flint-glass prism of this instrument has an angle of 37° 40', and the same diameter as the object- glass. The angle which the ray falling on the prism forms with that coming out of it is about 26°, so that if the refran- gibility of light of one star were ever so little different from that of another the difference could still be very easily obser- ved. In order to observe and determine with accuracy this difference, if it does exist, I have applied another smaller tele- scope, which is fastened to the other, and crosses it at an angle of about 26°, namely, under the angle formed by the ray fall- ing on the prism, and the ray proceeding from it ; the entrance of the star is observed at the wire of the smaller telescope without a prism by one observer, whilst another notices the entrance of a part of the spectrum of the same star through the larger telescope, which is furnished with a micrometer screw, the moveable edge of which the observer, by means of the screw, places in such a manner that at the moment when the star passes across the wire of the smaller telescope without a prism, one of the fixed lines of the spectrum shall intersect the edge in the larger telescope. The instrument, without altering the micrometer, is then directed to another star, to enable us to discover whether its light has the same refraction. If at the moment when this star intersects the wire of the lesser telescope the same colour of the spectrum, or the same fixed line, is at the edge of the micrometer of the larger telescope, the refraction of these two sorts of light is equal. As these experiments require two ob- servers, Mr Soldner, the astronomer, had the goodness to make them with me. These experiments, however, are, as I have said, only to be considered as commenced, and I must yet make essential alterations in the instrument, in order to ob- tain still greater accuracy, and also to gain more time for ob- servation. We have not hitherto found ajixed star, the light of which, in regard to refraction, differs perceptibly from the light of the planets. Whenever the fixed lines of the spectra are seen 4 Moon, and Starlight, and Electric Light. 9 distinctly, this instrument affords a certainty within ten seconds, and for the orange rays within half a minute. Since the whole refraction through the prism amounts to about 26°, a difference, which in the whole refraction amounts to y^^^, could be per- ceived with this instrument ; and this would not amount to the fourth part of a second in the horizontal refraction of the atmosphere. It is well known that some astronomers have hitherto doubted whether the tables of refractions should not be, different for different stars. By the above mentioned ex- periments this doubt would seem to be resolved. The con- tinuation of them will, I hope, lead us to complete certainty on this subject. In order to observe the Ji^ced lines of the different stars with this large instrument, the atmosphere must be very favour- able, which is rarely the case. The spectra from the light of Mars, and from that of Ve- nus, contain the same fixed lines as the spectrum ' from sun- light, and precisely in the same place, at least as far as relates to the lines D, E, b, and F, * of which the relative situation could be precisely determined. In the spectrum from the light of Sirius, I was not able to perceive fixed lines in the orange and in the yellow colours. In the green, on the con- trary, a very strong streak is perceived, and two others very strong in the blue. They do not appear to resemble any of the lines from planetary light. We have ascertained their place with the micrometer. Cas- tor gives a spectrum which resembles that of Sirius. The streak in the green has, notwithstanding the weak light, so much intensity that I could measure it, and I found it ex- actly in the same place as in the green of the spectrum of Si- rius. The streaks in the blue I could indeed distinguish, but the light was not sufficiently strong to ascertain their place. In the spectrum of Pollux I recognized many weak, but fixed lines, which looked like those of Venus. I saw the line D * The line b lies in the green between E and F. It is properly com- posed of three strong lines, two of which are nearer to each other than the third. — Vide my '' Treatise on the Fower of Befraction and Separation of Colours," S^c. p. 280 and 309. 10 Narrative of the Proceedbigs and Scientific very well, and it is exactly in the same place as in the light of the planets. Capella gives a spectrum, in which, at the places D and b, the same fixed lines appear as in that of sunlight. The spec- trum of Betalgeus contains numerous fixed lines, which, with a good atmosphere, are sharply defined ; and although, at the first view, it does not seem to have any resemblance to the spectrum of Venus, yet similar lines are found as in the spec- trum of this fixed star, precisely in the same places where D and ,b are in sunlight. In the spectrum from Procyon some lines are perceived with difficulty, and not so distinct as to de- termine their place with certainty. But in the orange I think T have seen a line at the place D. Munich, July 14, 1823. Art. III. — Narrative of the Proceedings and Scientific Ob- sei'vations of the late Mission to Ava* The Mission left Rangoon on the 1st September, and reach- ed Henzada on the 8th. Here we were received with much polite attention by the future Viceroy of Pegu, who has the rank of a Wungyi, or councillor, the highest enjoyed by a sub- ject. He was very solicitous, however, to prevent our going further, intimating that he was himself vested with full powers to treat with us upon every possible subject. He had no opportunity, however, of exercising his plenipo- tentiary powers upon the present occasion, for the Mission, disregarding his pretensions, on the afternoon of the 10th* quitted Henzada, and on the afternoon of the 14th, a few miles beyond Myanaong, or Loonzay, entered the hilly re- gion, which is the proper geographical boundary of the Bur- man race — all to the south being the Delta or debouchement of the Irawadi, and the true country of the Peguans or Ta- lains. Pursuing our journey with hills now pressing down to the river on both sides, and which struck us at the time as pecu- * A printed copy of this interesting paper has been kindly forwarded to us by a Correspondent in India. Observations of' the late Mission to Ava. 11 liarly picturesque and beautiful, after passing through the long tiresome champaign of the Delta of the Irawadi, we reach- ed Prome on the evening of the 15th. This is one of the largest towns in the Burman empire, and appeared to be not less populous than Rangoon. The inhabitants since the war had returned to their homes — the place was in a good measure restored, and although it had been long the head-quarters of the British Army, there was now no reaction or persecution. All this bore favourable testimony to the moderation of the Myowun, or governor, whom we found an extremely respecta- ble man. We left Prome on the 17th, and on the 20th reached Pat- nagoh and Melloon, the scene of the conferences in December 1825, which led to the first treaty, which was never ratified or even transmitted for ratification, a breach of engagement for which the Burmese received signal castigation on the spot. On the 21st we left those places, and on the 22d reached Renangyoung, or the '' fetid oil brooks," — in other words, the Petroleum wells. In the afternoon we visited the wells and the remarkable and sterile country which surrounds them, abounding everywhere with fossil remains of one of the last great changes which the globe has undergone. On the 23d we left Renangyoung, and in the course of the forenoon passed Senbegyoung, from which leads the best road from Aracan, and by which Major Ross and a battalion of se- poys proceeded in the month of March last. On the morning of the 24th we reached Pugan, and staid there for that day, and part of the following, examining the curious antiquities of this place, the most remarkable in the Burman dominions, and the extensive ruins of which, if such evidence were not too well known to be delusory, might lead to the supposition, that in former ages the Burmese were a people more powerful and civilized than we now find them. On the 27th we passed the confluence of the Kyen-dwen and the Irawadi. The prospect afforded by their junction is far from imposing. Both rivers are here confined to a nar- row bed, and the tongue of land which divides them is so low, and covered with reeds, that it may easily be mistaken for an 12 Narrative of the Proceedings and Scientific island, and consequently the smaller river to be only a branch of the larger. The prospect hitherto presented in a route of little less than four hundred miles was that of a country imperfectly culti- vated and inhabited, and by far the greatest part of which was covered with a deep forest, or with tall reeds and grass, among which there was scarcely any evidence of culture or occupation.. We were now, however, within fifty- miles of the capital, and the scene began greatly to improve. The country became level, the nearest ranges of hills to the east being at least thirty miles distant, and the Arracan mountains to the west not less than fifty in the nearest part, and sixty or seventy in the dis- tant. The villages and cultivation had increased very con- siderably, but neither here nor anywhere else did we see evi- dence of a dense population or active industry. At two o'clock in the afternoon we passed Yandabu, where the treaty was dictated to the Burmans, and sailed within a stone's throw of the great tree where Sir A. CampbelPs tent was pitched, and the conferences were held. On the afternoon of the 28th we reached Rapatong, a vil- lage on the east bank of the river. This was the spot at which the Burmans contemplated making their last effort, had the British army not been arrested in its progress by the treaty of Yandabu. Here they were encamped under the old chief Kaulen Mengyi, the whole disposable force not exceeding a thousand men, and the greater number of these consisting, not of soldiers, but of the personal retainers and menial servants of the chiefs. Two forced marches would have carried Sir A. Campbell to Ava on a good high road, with nothing to resist him but the dispirited fugitives just mentioned. In the even- ing we reached Kyaoktalon, twelve miles from Ava. A short way before coming to that place, a deputation, headed by a secretary of the Lotoo, met us to compliment us on our ar- rival, and usher us into the capital. On the morning of the 29th we left Kyaoktalon. After we had proceeded a few miles, an order from the court ar- rived, requesting that we might stop where we were, as it was the intention to send down a deputation of persons of superior rank to conduct us. The promised deputation, consisting of Observations of' the late Mission to Ava. IS a Woonduck and three Saredaugyis accordingly came, and on the morning of the 30th we arrived at the capital, anchoring about two miles below the city, opposite to the place appoint- ed for our temporary residence. Thousands flocked down to the bank of the river out of curiosity to see the steam vessel. A similar curiosity was displayed everywhere else on our jour- ney, nearly the whole population of towns and villages turn- ing out to see her. On landing we were received with ceremonious politeness by a Wungyi and Atwenwun, the two highest classes of officer? under the Burmese government. These were the individuals who had negociated and signed the treaty of Yandabu. The politeness which dictated the selection of these two individuals was obvious. Our audience, under various pretexts, was put off from day to day until the 21st of October. In the meanwhile we were treated with attention. The expences of the whole mission were paid, and we were put under no other constraint than that of not being permitted to enter the walls of the town, a liberty which would have been contrary to established eti- quette. Meanwhile the negociation had commenced, and on the ISth, 14th, and 15th, we were present, by special invita- tion, at the annual display of boat races, which take place yearly when the waters of the Irawadi begin to fall. The king and queen, with the princes and nobility, were all pre- sent. The splendour of this pageant far exceeded our expec- tation, and would have made a figure in the Arabian Nights'* Entertainments^ as one of the good things got up by virtue of Aladdin's lamp. The period chosen for our presentation was that of one of the annual festivals, when the tributaries, princes, and nobility offer presents to his majesty, and their wives to the queen. Boats were sent for our accommodation, and about ten o'clock in the forenoon we reached the front of the palace. An elephant was appropriated to each of the English gentle- men, and the procession moved on until arriving at the Ring- dau, or Hall of Justice, which is to the east side of the palace, where we were detained for nearly three hours, to afford us an opportunity of admiring the pomp and magnificence of the 14 Narrative of the Proceedings and Scientijic Burmese Court, but above all, to afford the court an oppor- tunity of displaying it. At that place the whole court, with the exception of his majesty, passed in review before us, beginning with the officers of lowest rank, and ending with the princes of the blood. The courtiers were in their dresses of ceremony, and each chief was accompanied by a numerous retinue, besides elephants and horses. The retainers of Menzagyi, the queen's brother, the most powerful chief about the court, could not have been fewer than three hundred. We were at length summoned into the royal presence. The etiquette insisted upon with Colonel Symes seemed not to have escaped the recollection of the Burman officers, and they would have had us to practice the same ceremonies he had been necessitated to submit to, but times had changed. These ceremonies consisted in making repeated obeisances to the walls of the palace, and in walking bare footed, or at least without shoes, across the court-yard. All this we peremp- torily refused, although the officers who led the procession showed us a very good example in prostrating themselves re- peatedly, by throwing their bodies prone upon the bare ground. Upon reaching the bottom of the stairs leading to the hall of audience we voluntarily took off our shoes, passed through the long hall, and seated ourselves in front of the throne. His majesty did not keep us long waiting. After a hymn had been chaunted by a band of Bramins in white, he made his appearance upon the opening of a folding-door be- hind the throne, and mounted the steps which led to the lat- ter briskly. He was in his richest dress of state — wore a crown, and held in his hand the tail of a Thibet cow, which is one of the Burman regalia, and takes the place of a sceptre. He was no sooner seated than her majesty, who, whether on public or private occasions, is inseparable from him, pre- sented herself in a dress equally rich with his, and more fan- tastic. Both had on a load of rich jewels. She seated her- self on his majesty's right hand. She was immediately fol- lowed by the little princess, their only child, a girl about five years of age. Upon the appearance of the king and queen the courtiers humbly prostrated themselves. The English Observations of the lafe Missia?i to Ava. 15 gentlemen made a bow to each, touching the forehead with the right hand. The first thing done was to read a list of certain offerings made by the king to some temples of cele- brity at the capital. The reason for doing this was assigned. The temples in question were said to contain relics of Gau- tama, to be representatives of his divinity, and therefore fit objects of worship. His majesty having thus discharged his religious obligations, received in his turn the devotions and homage of the princes and chiefs. The king did not address a word in person to the officers of the mission, but an Atwenwoon, or privy-councillor, read a short list of questions, as if coming from the king. These, as far as I can recollect, were as follows : " Are the king and queen of England, tbeir sons and daughters, and all the nobility of the kingdom well .? " Have the seasons been of late years propitious in Eng- land ? " How long have you been on your voyage from India to this place .?" &c. * Betle, tobacco, and pickled tea, were after this presented to the English gentlemen, a mark of attention shown to no one else. They afterwards received each a small ruby, a silk dress, and some lackered boxes. This being over, and a few titles bestowed and proclaimed throughout the hall, the king and queen retired, the courtiers prostrating themselves as when they entered. Their majesties had sat in all about three quarters of an hour. The Burman court, upon the present occasion, appeared in all the pomp and splendour of which it is capable, and the spectacle was certainly not a little imposing. The princes and nobility were in their court dres- ses, of purple velvet, with a profusion of lace and gold. The hall of audience is a gorgeous and elegant apartment support- ed by ninety-six pillars, and the whole is one blaze of rich gilding. In going through the oourt-yard the white elephant, and some other royal curiosities were shown to us, and we stopped for a moment to see an exhibition of tumblers, buffoons, and dancing girls. After the audience the gentlemen of the mission were oc- 16 Narrative of the Proceeding's and Scientific ciipied for several successive days in paying visits to the heir- apparent, the Prince of Sarrawadi, tlie dowager queen, and the queen"'s brother. By all these personages they were re- ceived with marked politeness and attention. The ladies pre- sented themselves on these occasions as well as the men. There was no reserve in respect to the fair sex. The negotiation was then renewed, and on the S3d of No- vember, besides settling some points respecting frontier, a short treaty of commerce of four articles was concluded. The mission continued at the Burman capital in all about two months and a half, and quitted it on the 12th of Decem- ber, after being honoured with tv/o audiences of his Majesty, the one on occasion of catching a wild elephant, and the other on that of weaning a young one, favourite diversions of the king. On the occasions in question his Majesty threw off all reserve, and conversed freely and familiarly with our country- men. On the day of departure presents were sent for the go- vernor general, and each of the English gentlemen received a title of nobility. The Irawadi which, swollen by the periodical rains, was deep and broad in coming up, was found in descending to have fal- len from twenty to thirty feet, and the navigation consequent- ly proved extremely intricate and t-edious. The steam vessel was in all a-ground fifteen days, and frequently ran the risk of being totally lost. The voyage to Rangoon occupied thirty-five days, which, in a small boat suited for the river, ought to have been performed in ten. At Pugan, about eighty miles below Ava, the mission was for the first time informed of the insur- rection of the Talains. At Henzada and Donabew the inha- bitants were seen flying from the seat of insurrection. The insurgents were first seen at Paulang. This place, where the river is not above sixty yards broad, was strongly stockaded in three places, and the Talains were seen standing to their arms. The steam vessel came to for a few moments to request a safe passage for the baggage and boats which were behind, and for the boats of some merchants which accompanied them, amount- ing in all to about twenty-two. Boats put off immediately, and the Talains came on board without the least hesitation. They were full of friendly professions, and requested only our neu- Observations of the late Mission to Ava. 17 trality. Our visitors saluted us in the manner of English se- poys, standing up. This they said was the positive order of his Talain majesty, who declared he would permit no one henceforth to crouch in his presence, or that of any other chief. They also boasted that they treated their prisoners after the English fashion, that is to say, disarmed them and set them at liberty without offering them any personal violence. They claimed the greater merit for this, on account of the conduct observed by the Burmans towards them, who, they alleged, put all their prisoners to death, or, as they expressed it, *' di- vided them into three parts.*" On the morning of the 1 7th the mission reached Rangoon. The Burman flag was seen flying on one side of the river, and the Talain on the other, not 600 yards asunder. The town of Rangoon was invested on all sides by the Talains, and the suburbs had been burnt to the ground. We had hardly been at anchor half an hour, and were engaged in reading our let- ters and newspapers, when the garrison made a sortie, and an action took place, reckoned the most considerable since the commencement of the insurrection. On both sides it was pal- try and contemptible to the last degree. The Talains in one place caught sleeping or cooking fled to their boats, and were soon seen crossing the river in great numbers. At another post between the town and the great Pagoda they were more vigilant, and easily repulsed a feeble and cowardly attack made by the Burmans. On the S3d the mission left Rangoon, and in less than four-and-twenty hours reached the new settlement of Amherst, in the harbour of which we found lying the com- pany's ships Investigator and Ternate, and a large fleet of gun-boats. To these in a few days were added the large mer- chant ships Almorah, Felicitas^ and Bombay Merchant, with two trading brigs and some schooners. This was a curious spectacle in a harbour which was not known to exist ten months ago. The settlement contains from sixteen to seventeen- hun- dred inhabitants. Maulamhyeng, tKe military cantonment, twenty-seven miles further up the river, contains twice this number, chiefly camp followers. Neither of them had a single inhabitant a few months back, but on the contrary were co- vered with a thick forest. This fine country already produces VOL. vin. NO. i. JAN. 1828. b 18 Narrative of the Proceedings and Scientifc some of the necessaries and comforts of European life, in a de- gree which under all circumstances is remarkable. Fowls are to be had in abundance for five rupees per dozen ; a milch buf- falo and calf for fifteen rupees ; fish is in abundance and of excellent quality. The best kinds are the Calcop, the large mullet, and the Mangoe-fish. It is curious that this last is found in plenty both in the rivers of Rangoon and of Martaban, with roes for nine months of the year, or from December to August inclusive, whereas in the Hoogly three months is the utmost limit of their season. On the 26th the mission proceeded to Maulamhyeng, and on the 28th ascended the Ataran river in the steam vessel. This stream, which is deep and free from danger, might be navigated for fifty miles up by vessels of 3 to 400 tons burden. It leads to Teak forests, distant about seventy-five miles, in- exhaustible in quantity, and of the largest scantling. On the 8th of February the ship Bombay Merchant having been taken up for the accommodation of the mission, the mem- bers embarked that evening, and on the following morning sailed for Calcutta. The following is a very brief sketch of what has been ob- served by the mission in the department of science. In the departments of mineralogy and geology it is to be regretted that no scientific observer accompanied the mission. Our par- ty, however, were assiduous collectors, and the collection brought back is so extensive, that it would afford men of science a very tolerable notion of the mineralogical and geological con- stitution of the countries which were visited. From between the latitude of 15° and 16^ to between that of 18° and 19°, is a low alluvial country, forming the debouchement of the Ira- wadi river. Here not a mountain or a stone is to be found, except in a very few places, such as Rangoon and Syriam, where a little cellular clay iron ore presents itself in low hills. In about lat. 1 8° 30' we quit the Delta of the Irawadi, the na- tive country of the Talain race, and enter at once into a hilly region, which extends almost all the way to Ava, or to about the latitude of 21° SO'. The Irawadi in all this course is skirted by hills of from about 3 to 500 feet high. The lowest portion of these is composed of breccia, calcareous sandstone, cellular Observations of the late Mission to Jva. 19 clay iron ore, with beds of sand and clay, and the highest of blue mountain limestone. The lowest portions are alluvial, and highly interesting to the geologist. The gentlemen of the mission discovered in these abundance of sea shells, with fossil wood and bones. Among the latter are the bones of the fossil elephant or mammoth, * fossil rhinoceros, various ruminant animals, alligators, and tortoises. An immense collection of these has been brought round for the government. Some of the bones are of great size, and all completely petrified. There are among them the teeth and such other portions of the ske- leton as will enable the experienced naturalist to determine the genera and species to which they belonged. These were ob- tained close to the celebrated petroleum weils. From their great induration, and having been little rolled, they are gene- rally in a very perfect state. The bones, as well as the fossil wood, are found superficially in gravel, the same situation in which similar diluvian or antediluvian remains have been found in other quarters of the globe. <> The ranges of mountains to the east and north of Ava, as far as twenty miles, and those close to the city on the western bank of the river, are all of marble, and this of many varieties. The white statuary marble, some of which is very beautiful, is brought forty miles down the river from a mountain on its eastern bank. i*^i^ ^>f The great ranges of mountains dividing the Burman domi- nions from Arracan on one side, and Siam on another, are rea- sonably supposed to be primitive. In the last direction the roots of these seemed to extend to the new settlement of Am- herst, where we find granite, quartz, and mica slate. Some continuous low ranges in the Martaban district are composed entirely of quartz rock. Blue mountain limestone is a frequent formation in the same district, from which lime of much purity is manufactured. Detached rocks of this substance are scat- tered over the plains. These rise abruptly and perpendicu- larly to the height of from 3 to 500 feet, and in one place to 1500. They contain some spacious caves, which have been converted into places of worship. One of these rocks is so re- * This is a mistake. They belong to the mastodon, as will be seen from a subsequent account of them in this Number, page 56. — Ed. 20 Narrative of the Proceedings and Scientific markable that it deserves particular mention. Its perpendicu- lar wall confines the Ataran for several hundred yards on its right bank. About its middle it is penetrated by a branch of the river, which flows quite through it by a magnificent arch. This is a highly picturesque object. Neither the proper Burman or Talain country appear to be rich in metallic ores, with the exception of those of iron, tin, and antimony. The principal consumption of the country in iron is supplied from the great mountain of Poupa, on the eastern side of the Irawadi, and near the latitude of 21°. Lao, the country of the Shans, as it is denominated by the Burmans, is, on the contrary, extremely prolific in metals. The singular passion of the Burmans for the study of alchemy has brought collections of the ores of Lao into the market of Ava, and this circumstance enabled the gentlemen to make collections of them. The ores thus obtained consisted of those of iron, sil- ver, lead, copper, and antimony. The Shans possess the art of smelting all these, and bring them in their metallic state into th'e market of Ava. The silver ores in the Burman dominions are, however, wrought to the greatest advantage by the Chinese. The mines exist about twelve days journey to the north-east of Bamoo, towards the Chinese frontier. The celebrated sapphire and ruby mines, which have always afforded, and still continue to afford, the finest gems of this description in the world, are about five days journey from Ava, in a direction E. S. E., and at two places called Mo-gaot and Kyat-pyan. The diff'erent species of sapphire, both in their crystallized and rough state, and the matrix, or rather gravel, in which they are found, were seen, examined, and collections made. In these mines are found the following gems or stones ; the red sapphire or oriental ruby, the oriental sapphire, the spinelle ruby, the white, the yellow, the green, the opalescent, the amethyst and girasol sapphire, blue with a reddish reflec- tion, with the common corundum or adamantine spar in large quantities. The oriental ruby, perfect in regard to water, colour, and freedom from flaws, is scarce and high-priced even at Ava. The blue sapphire is more common and cheaper. One spe- cimen exhibited to us weighed 9-51 carats, but it was not per- Observations of the late Mission to Ava, 9.1 feet. The red sapphire oever approached this magnitude. The other varieties are all rare, and not much esteemed by the Burmans, with the exception of the girasol sapphire, of which we saw two or three very fine specimens, and the green sapphire or oriental emerald, which is very rare. The king makes claim to every ruby or sapphire beyond a hundred ticals value, but the claim is one not easy to enforce. The miners, to avoid this sage law, break the stones when they find them, so that each fragment may not exceed the pre- scribed value. His majesty last year got but one large ruby. This weighed about one hundred and forty grains avoirdupois, and was considered a remarkable stone. Sapphires and rubies form a considerable article of the exports of the Chinese, who ' are the cleverest people in the world in evading the absurd fiscal laws made by themselves and others. The use they put them to is that of decorating the caps of their mandarins or nobility. Precious serpentine is another product of the Burman empire, which the Chinese export to a larger value. The gentlemen of the mission examined carefully the cele- brated petroleum wells, near which they remained for eight days, owing to the accident of the steam vessel taking the ground in their vicinity. Some of the wells are from thirty- seven to fifty-three fathoms in depth, and are said to yield at an average daily from one hundred and thirty to one hundred and eighty-five gallons of the earth oil. The wells are scat- tered over an area of about sixteen square miles. The wells are private property, the owners paying a tax of five per cent, of the produce to the state. This commodity is almost universally used by the Burmans as lamp oil. Its price on the spot does not, on an average, exceed from 5d. to 7|d. per cwt. The other useful mineral or saline productions of the Burman empire are coal, saltpetre, soda, and culinary salt. One of the lakes affording the latter, which is within six or seven miles of the capital, was examined by the gentlemen of the mission. The success of the mission has been the completest in the , department of botany. This will readily occur to our read- ers, when they recollect the talent, zeal, industry, and skill of the gentleman at the head of this branch of inquiry. Dr Wallich has been left behind at Amherst to complete his in- 92 Narrative of the Proceeding.^ and Scientific quiry into the resources of the valuable forests of that and the neighbouring districts. Until this be effected the full extent of his successful researches cannot be known. The number of species collected by him amounted, when the mission left him at Amherst, to about sixteen thousand, of which five hundred and upwards are new and undescribed. Among these last may be mentioned seven species of oak, two species of walnut, a rose, three willows, a raspberry, and a pear ; se- veral plants discovered by him are so remarkable as to consti- tute themselves new genera. Among the latter may be men- tioned one which has been called Amherstia, in compliment to the Lady Amherst. This constitutes probably the most beautiful and noble plant of the Indian Flora. Two trees of it only are known to exist, and these are found in the gardens of a monastery on the banks of the Salwen. The number of specimens brought to Calcutta amount to little less than 18,000, among which are many beautiful live plants for the botanical garden, chiefly of the orchideous, scitamineous, and liliaceous families. Dr Wallich when at Ava obtained per- mission of the Burmese government to prosecute his botanical researches on the mountains about twenty miles from Ava. In these, which are from 3 to 4000 feet high, he spent eight days, and brought from them some of the finest parts of his collection. These mountains contain several plants which are common to them with the Himalaya chain, but the greater part of their Flora is rare and curious. The botany of the new provinces to the south is considered to be highly novel and interesting, combining in a great degree the characters of the Floras of continental India and the Malayan countries. In economical botany a good deal has been effected. The tree producing the celebrated varnish has been discovered and described, and the process of extracting and using the varnish observed. * The different mimosas producing catechu have also been determined, and the processes for extracting the drug observed. The localities of the different teak forests throughout the Burman empire, as well as the quality and price of the timber, have been ascertained. The valuable forests of this tree, discovered in our recent cessions, were • See a subsequent article in this Number. — Ed. , Observations of the late Mission to Ava. 23 upon the point of being minutely explored by Dr Wallich. Lieutenant Scotland, under the instructions of Sir A. Camp- bell, had, just before the arrival of the mission at Amherst, made a journey by land to the Siamese frontier, in the course of which he passed through two teak forests towards the source of the Ataran river. The largest of these was five miles in breadth, and scarcely contained any other tree than teak, many of which measured from eighteen to nineteen feet in circumference. ^o J'»'«'i»»i One of the oaks already mentioned, and which grows to a large size, is found in great abundance close to the new set- tlement of Amherst ; and should it prove a valuable timber, which is most probable, it may be obtained with every facility. A fine durable timber, called by the Burmans thinghan, and which they place next to the teak, or almost on an equality with it, is found every where throughout the new provinces. Dr Wallich has ascertained this to be the Hopea odorata of Roxburgh. Another valuable timber, the uses of which are well known in our Indian arsenals and timber yards, the son- dree, Heritiera robusta, is found largely in the maritime parts of the Martaban district, and of a size much exceeding what is brought from the Sunderbunds of the Ganges. Of these woods, and many others in use amongst the natives, although as yet unknown to us, specimens will be brought to Bengal by Dr Wallich, for the purpose of subjecting their qualities to rigid experiment. In the department of zoology, if we except the fossil bones already described, the inquiries of the gentlemen of the mis- sion have not been so successful. The features of the animal kingdom, indeed, differ much less from those of Hindustan than the vegetable. Still there is no doubt much room for discovery, when the countries are leisurely explored by expe- rienced naturalists. In the Martaban provinces, the forests of which teem with the elephant, the rhinoceros, the wild buf- falo, ox, and deer, a new species of the latter is believed to exist. In the upper provinces a species of mole-rat is very frequent, and thought to be an undescribed animal. Some of the officers of our army imagined that they had ascertained the existence of the jackal and fox in the upper provinces of the 24 Narrative of the Proceedifigs of Mission to Ava, Burman empire, but this seems to be a mistake. It is a singular fact, that neither these animals, nor the wolf, hyena, or any other of the genus canis'is found there, with the exception of one ani- mal, which is yet undescribed, and the howl of which it was that was mistaken for that of the jackal. The feline tribe, espe- cially the larger species, are but rare in the upper provinces of the Burman empire, but too frequent in the lower. The night before we left Maulamhyeng, a tiger was shot in the heart of the cantonment by a party of officers who lay in wait for him. Two or three of the smaller species of this family, found in Martaban and Pegu, are thought to be as yet unknown to naturalists. In Martaban, two new species of pheasant have been found, of which living specimens have been sent to Calcutta. The celebrated elephant must not be forgotten. At Ava there is but one albino elephant. This, a male of about twenty-five years of age, was repeatedly seen and ex- amined by the gentlemen of the mission, and his majesty has made a present to the governor-general of a drawing of the animal in its state caparison, which is no bad specimen of Bur- man art. As connected with this department may be mentioned the existence at Ava of a man covered from head to foot with hair, whose history is not less remarkable than that of the celebrated porcupine man, who excited so much curiosity in England and other parts of Europe near a century ago. The hair on the face of this singular being, the ears included, is shaggy, and about eight inches long. On the breast and shoulders it is from four to five. It is singular that the teeth of this individual are defective in number;, the molars or grinders being entirely wanting. This person is a native of the Shan country, or Lao, and from the banks of the upper portion of the Sal u en or Martaban river. He was presented to the king of Ava as a curiosity by the prince of that country. At Ava he married a pretty Burmese woman, by whom he has two daughters. The eldest resembles her mother, the youngest is covered with hair, like her father, only that it is white or fair, whereas his is now brown or black, having, how. ever, been fair when a child, like that of the infant. With the exceptions mentioned, both the father and his child are M. St-Hilaire on a Polydadylous Horse. 25 perfectly well formed, and indeed for the Burman race ra- ther handsome. The whole family were sent by the King to the residence of the mission, where drawings and descriptions of them were taken. Albinos occur now and then among the Burmese, as among other races of men. We saw two exam- ples. One of these, a young man of twenty, was born of Bur- mese parents.. They were ashamed of him, and considering him little better than a European, they made him over to the Portuguese clergyman. The reverend father, in due course, made him a Christian. Art. IV. — On the Foetus of a Polydactylous Horse having the Toes separated by a Membrane. By M. G. St-Hilaire, Member of the Institute. The extremely brief notice of this rather singular specimen of a peculiar kind of deformity in the horse scarcely furnishes a sufficiently accurate account to be submitted to our readers. It would seem that the distinguished naturalist to whom we owe the publicity of the very singular specimen alluded to, having proceeded to the south of France for the express pur- pose of conducting in safety to Paris the camelopard, of which a notice will be found in another part of this Number, examin- ed on his route whatever museums existed ; and in that belong- ing to the veterinary school at Lyons he met with the foetus, the peculiar mal-conformation of whose feet gave rise to his brief notice. For the benefit of those not sufficiently acquainted with the doctrines of comparative anatomy originally laid down by Aristotle, and likewise in order to render M. St-Hilaire's notice intelligible to the generality of our readers, we shall very briefly state the osteology of the horse's foot, and com- pare it with those of other animals, and with man. The pectoral extremities of the horse, or his fore-legs, ar6 composed essentially of the same elements as the human arms, and the bones of each may be arranged and described in this way : — 26 M. St-Hilaire 07i a Poli/dactt/hus Horse. . Bones of In Man. In Horse. the shoulder, 2 1 The clavicles are wanting. Bo. arm, 1 1 Do. fore-arm, 2 2 Only when the animal is young ; when old the ulna, which at all times in the horse is an imperfect bone, becomes firmly united to the radius. Do, carpus, 8 7 The part of the limb corresponding to these bones is very generally, but very improperly, called the knee. Do. metacarpus, & 3 One complete and two incomplete, im- perfect, or rudimentary. Do. fingers. 14 3 Tlie horse, then, has but a single toe or finger, and not three, as some anatomists have said. The extremely imperfect and ru- dimentary metacarpal bones can never be called imperfect toes in strict language ; nevertheless they really constitute the ele- ments of toes, which have been formed in this imperfect and rudimentary manner, because they were not wanted for the safe progression of the animal, inasmuch as we apply this term to the short toes of the pig, which have a metacarpal and digi- tal bones, are detached and protected by a nail similar to the more perfect or longer ones. On the contrary, all that remains of such toes in the horse are two small perfectly rudimentary metacarpal bones ; there is not the slightest vestige of any digi- tal bones or phalanges. It sometimes happens, as may be seen in museums, that the imperfect toes of certain animals (as in the pig for example) occasionally are found perfect, or, in plain language, grow to the same length as the more perfect ones, and of this we have seen one or two instances in the pig, all four toes being in these specimens of equal length and strength, or nearly so. Now this seems to be the case with the foetus of the horse described by M. St-Hilaire, and if so, as we doubt not, is the only in- stance recorded, unless we consider as such the horse describ- ed by Suetonius, and said to have belonged to Cassar ; but to enable us to decide on this point neither the description of Sue- tonius nor of the French naturalist, will be found sufficiently mi- nute. M. St-Hilaire describes the foetus he examined to have been about eight or nine months old. He states that it is poly- dactylous only in the fore-feet ; and that the left foot has three Rev. W. Whewell on the principles of Df/namics^ 4*c. 27 toes nearly equal, but the right only two. The toes are said to be connected by a membrane, a kind of periosteum insulating the metacarpal bones and toes, and even passing beyond them about six lines. Now M. St-Hilaire imagines that this mem- brane extended to the envelopes of the placenta, but this is merely a conjecture, and one founded on a hypothesis. It is not improbable that the description of the foetus in question may ultimately form the subject of a distinct memoir ; and should this happen we shall not fail to give it an early place in this Journal. R. K. Art. V. — On the principles of Dynamics^ particularly as stated by French Writers. By the Rev. W. Whewell, M. A. Trinity College, Cambridge. Communicated by the Author. During the course of the last century, a question was started, and repeatedly discussed among mathematicians, " whether the principles of Mechanics were necessary or contingent truths ?" that is, whether the science could be established upon axioms, drawn from the nature of things, and the relations of our ideas, or whether it was indispensable for the proof of its doctrines to recur to experiment and observation ? It might, perhaps, have been expected that such a question would have been easily decided, and that for its solution it would only have been requisite to inspect any scientific treatise on mecha- nics which pretended to strict logic in the deduction of its fundamental propositions ; and where, of course, these prin- ciples would be proved in the simplest manner which was pos- sible. If, however, we examine the works of authors of the most undoubted science and ingenuity up to the most modern times, we shall find differences of principle among them which seem to show that this discussion has not even yet led to any opinion which possesses elementary clearness, and has found universal reception. With respect, indeed, to the question above referred to, of the necessary or contingent nature of the proof on which these doctrines must rest, it seems now to be allpwed by the general ^8 Rev. W. W he well on the principles of Dynamics^ voice of those who have treated of such subjects, and is in fact demonstrable, that the evidence of mechanical and of geome- trical science are altogether different in kind. That while the latter depends for its truth on the nature of the human mind alone, and its self-produced stores, the former must necessarily derive some part at least, both of its materials and its rules, from the impressions made on us by the external world. This is more particularly the case with regard to that portion of mechanics which refers to motion. For the propositions which concern bodies at rest, (statics,) whether or not they are to be ranked with the truths of geometry in other respects, agree with these at least in this, that the certainty of them is in- volved in the definitions by which they become intelligible, and that they require us to borrow from experience nothing but the ideas which are the subject of their operations. But in dynamics the case is different, and besides being obliged to derive from observation the phenomena about which we reason, we are also under the necessity of taking from the same source the laws according to which the phenomena suc- ceed and determine each other ; the business of the science being to reduce these laws to the simplest form and smallest number, and then by recombining these, to account for, and calculate all mechanical events. Now, with respect to this analysis of such complex occurrences into their simplest and fewest laws, it appears that writers have arrived at different results. It will therefore appear not to be superfluous or un- profitable to show what is the greatest degree of simplicity to which the fundamental doctrines of mechanics can be reduced ; what are the considerations which make it impossible to carry the simplification further than this point, and unscientific to stop short of it ; and how far the mode in which the principles of the science are stated in works of the most acknowledged reputation can be considered as possessing this philosophical simplicity combined with logical strictness. ';'^^ The leading distinction which may be considered as pre- vailing at present upon this subject is that between the English writers, who, following Newton, make three laws of motion the foundation of dynamics ; and the foreign, and more particularly the French writers, in whose Treatises on Mecha- particularly as given hy French Writers. 29 nics the elementary principles of the science are in various ways simplified and established. The most distinguished among the latter deduce, as will be shown, two independent principles from experience ; and what I wish especially to offer to the consideration of mathematicians is the question how far these systems can be identified, and which is the more true and logical one : — Whether with three laws we have some- thing superfluous, or with two something defective. In stating the three laws of motion for the purpose of this comparison, we must, in order to avoid confusion and false reasoning, reject entirely their application to statics. If we do this, (which has not always been sufficiently attended to,) and express them in the simplest form as they regard the mo- tion of bodies, we shall have them as follows : — Law 1. A body in motion, not acted upon by any force; will move on in a straight line with a uniform velocity. Law % When any force acts upon a body in motion, the change of motion which it produces is in the direction, and proportional to the magnitude, of the force which acts. Law 3. When pressure communicates motion to a body, the moving force is as the pressure. If we carefully look in the best French treatises for the principles which they borrow from experience, we shall find them to be these two : Firsts The law of inertia^ that a body not acted upon by any force would go on for ever with a uniform velocity. Second^ That the velocity communicated is proportional to the force. * The first of these principles coincides with the first law of motion, which the best French, as well as English writers, agree in considering as a result of experience, -f* The se- cond and third laws of motion are both reduced to the second principle of the foreign mechanicians ; and the point to be considered is, whether the steps of this part of the reasoning are allowable and satisfactory. *' ^^^^^^ ^' The principle that the velocity communicated is as the pres- sure, leads immediately to the inference that the accelerating force is as the pressure, and consequently, for the same body, f See Note A, p. 36. t See Note B, p. 37. 30 Rev. W. Whcwell on the principles (>f Dynamics, tlic moving force is as the pressure. And the same inference may be extended to a body twice, three times, &c. as large, by considering it as made up of two, three, &c. such bodies, each acted upon by the same pressure. And thus this prin- ciple leads directly to the third law of motion. The question, therefore, now becomes, whether the second law of motion be included in the third .? and this is what the foreign writers alluded to, assert, and pretend to prove. The proof is of the following kind. Let a body be moving in a direction A B with any velocity B C. At the point B let it be acted upon by any force in the direction B D. It will descnbe an in- a b c termediate line B E % the second law of '^^"X motion. But this intermediate direction is v_:^ also deduced from the principle that the D K velocity is proportional to the force, in this manner. The body being at B, and moving with the velocity B C, is in the same condition as if it were at that instant acted upon by a force which is represented by B C. But in that case it would be acted upon by two forces represented by B C and B D, and hence, by the statical composition of forces, it might be considered as acted upon by a single force B E, the resul- tant of B C and B D. Hence, since the velocity is propor- tional to the force, the body will move in B E with a velocity represented by B E. In this case we consider a velocity as depending upon a force without any respect to the time ; and it is therefore clear that the forces must be instantaneous or impulsive ; and that this is the case will also appear from referring to the demon- strations here pointed at. Thus Laplace, Mec. Cel. Ch. ii. Art. 5, assumes " f la force dont un corps est anime en vertu de sa vitesse^'' and then com- pounds such forces by the law of statics. It appears by the proof that he supposes the force to be impulsive. (His object is to prove by experiment that these forces are proportional to the velocities.) Poisson, Dyn. Ch. ii. Art. 212. Takes, " un point sollicite par deux forces, du genre de celles qui agissent instantanement sur le mobile et qui Tabandonnent ensuite a lui-meme.'* He then compounds these by the law of statical composition. He particularly as given by French Writers. SI proves that the velocities are proportional to the forces, (pres- sures) by observing that it is an liypothesis, (Art. 193,) and that the agreement of its results with experience shows it to be the law of nature. It will appear from a careful consideration of these proofs, that, first, it is taken for granted that any velocity waz/ be produced by an instantaneous force : That 2 J, it is proved from experiment that this force is as the velocity : That 3<7, it is taken for granted that we may, at our choice, at any in- stant, consider the body either as possessing the velocity, or as acted upon by the force which would produce it : And that ^th^ it is also taken for granted that these instantaneous forces acting together may be compounded according to the laws of statics. But I shall endeavour to show that there are steps in these reasonings, (and I believe that the considerations generally employed by French writers in the elementary portions of me- chanics cannot be resolved into any more satisfactory than these,) which are on several accounts liable to objections. I. In the first place, I would object to the supposing all velocities in bodies to be produced by forces acting instanta- neously, that is, acting at a single indivisible and uncontinued moment of time. For the fact really is, that there are no such forces in nature, and that forces of impulse and impact, which appear at first sight to operate in this manner, seem to do so only in consequence of a vague and imperfect mode of conceiving them, and do in reality produce their effects by a continued pressure acting for a short but finite portion of time. And this is the case with all forces which ever come under our observation; insomuch that we cannot in •strictness suppose any such process as a body at rest acquiring at once a finite velocity without going through the intermediate degrees of velocity. And even if we allow that we can conceive such an operation taking place, yet it must, it would seem, also be granted, that the process would be different in kind from any of the real actions of bodies one upon another, and therefore it may deserve serious consideration whether it can, in sound reasoning, be made the foundation of deductions which are to be applied to cases of continual pressure. This is a step in the mode of obtaining the first principles. 32 Kcv. W. Whewell on the principles of Dynamics, whicli, T confess, appears to me entirely fallacious, but which must, I think, at least be allowed to be unscientific and un- philosophical. The idea of instantaneous force is introduced merely to be got rid of. It is not deduced from nature, but it is borrowed from the imagination, and made the foundation of the science ; and must again be dismissed before we can apply our conclusions to any of the phenomena of the universe. It is true that we may conceive physical impact after the manner in which it is generally understood ; that is, as con- tinuing during a small definite time, for instance one-tenth of a second ; and we may then imagine such impact to represent all other forces. By this means the force will be a pressure of the kind which really exists ; but then we shall lay the reason- ing open to the objections which the assumption of instantane- ous force seems intended to avoid, namely, the necessity of introducing the time during which the force is supposed to act. II. Supposing, however, we allow this substitution of im- pulsive for permanent forces, we shall, I think, find ourselves met by new difficulties. It is to be proved or assumed, (Law 3,) that this impulsive force is proportional to the velocity which it produces, and this is proved from experiment, in a demonstration (Laplace, Art. 5,) which assumes that these forces thus producing velocity may be compounded according to the law of composition of forces which is established in sta- tics. Now nothing can be clearer than that the statical com- bination of forces cannot apply to the composition of impacts, without complete alteration of the use of terms, and the meaning of the proposition. The definition of statical force, and every step of the process^ supposes the forces to be em- ployed in producing equilibrium^ which cannot in any manner apply to impulsive or instantaneous forces. And this objec- tion is so obvious, and apparently so insurmountable, that I am at a loss to imagine how reasoners so acute as those whose demonstrations I am considering, can have passed it over ; at the same time, I think no person can examine the proofs to which I have referred, without seeing that they are altogether dependent upon this vicious reasoning. The fact, perhaps, may be, that the authors who have adopted this fallacious train of reasoning have not sufficiently particularly as given hy French Writers. S3 reflected that the meanmgs of our words in science are the crea- tions of our definitions, and that we cannot assume any thing re- specting the things meant, which is not either implied in the de- finition, or deduced from observation. Thus they perhaps con- sidered the wordyorc, acting at an angle 9, pro- duced a velocity proportional not to ^^(as + Z>^ + 2 a Z> cos. fl,) but to tj (a^ + Z>2 + ^b (cos. 6 + sin. 6)). In this case, as well as in the other, when 6=0, the result is a + Z», and when 0 = sr, the result is o — /&. VOL. VIII. NO. I. JAN. 1828. c S-l" Rev. W. Whewell on the principles of Dynamics, AB, BD, act at the same point of time.* We resolve the ve- locity AB, as it were, into the force which may have produced it at a former period. Now, it seems hardly self-evident, that, assuming a pressure of ten pounds, or a blow of a certain mo- mentum, to have produced this velocity, we may at any fu- ture period substitute this pressure for the velocity. It is true, it may be said that it makes no difference at what interval of time we suppose these forces to act, and that therefore we may first suppose the force AB to act, and then BD at an indefinitely short distance of time, which comes to the same thing, supposing them to act simultaneously. But when we are requiring the strictness of demonstration, it may still I think be replied, that there may be an essential difference between the successive and the simultaneous action of forces ; and that it is by no means clear that their action, one after the other, however small the interval may be, is the same thing as their acting together. I would even ask any one whether this is manifestly clear in the case of the real physical impact of two balls upon a third. At any rate, it can hardly be said to be self-evident, and therefore ought not to be assumed in a de- monstration of the nature of that which we are now consider- If these objections to the deduction of the second law of motion from the third are well-founded, it will appear that the proper and philosophical method is to deduce the second independently from observation, as English writers are in the habit of doing. It may here be remarked, that if the second and third laws were connected in the way which some .have supposed, either of them might be made the fundamental one, and the other might be deduced from it. Thus assuming the second law, we might, by the same kind of reasoning as that which we have been discussing, prove the truth of the third. • Poisson, torn. i. p. 309. Le point se mouvra uniformeraent sur la diagonale, &c. En chaque point de cette droits le mobile sera dans le meme etat que si la force R agissait actuellement sur lui et lui imprimait la vitesse mc. If the velocity has been produced by a force which acted during a finite portion of time, however small, the replacement of the velocity by the force i%,a supposition attended with still more embarrassing difficulties. particularly as given by French Writers. 35 Let a body be acted on by a force 2 F. This is equiva- lent to two forces, F and F. The first would produce a ve- locity V, and therefore the second may be considered as acting upon the body already moving with the velocity V. But hence by the second laiv of motion it would add a velocity V, and hence the whole velocity would be 2 V ; and similarly we might prove that a force m F would produce a velocity m V, which is easily seen to be an expression of the third law of motion. The preceding are the principal objections which I wish at present to propose. Perhaps some may be at first disposed to think the question rather one of words and definitions than of principles. It will, however, appear on close consideration to be something more. For two different principles obtained from observation cannot be made one by any mere alteration of phraseology. To those who feel an interest in the strict- ness of scientific logic the question will not appear unimpor- tant. It is in fact the question, whether, after carrying the process of induction and generalization as far as is requisite, in order to obtain the three laws of Newton, we can carry it one step farther, and include one of these laws in the other. It, is the question, whether the third law of motion be capable of being considered as a particular case of the second. The pre- ceding considerations seem to disprove such a dependence. The manner in which the French writers have tried to esta- bhsh such a connection has been by including both in the principle that Jbrce is as velocity. But that this apparent simplification is made at the expence of accuracy of language seems certain. To express the two cases clearly, we might say, 1st, that when force acts on a body already in motion, the velocity compounded with the for- mer velocity is proportional to the force ; and, 2d, that when different forces act on the same body, the velocity generated is proportional to the force. And these two propositions are different, and should be established separately, as appears by considering that each might be true though the other were false. Thus the proof given by Laplace, that velocity is pro- portional to force, depends upon this fact, that a body struck upon the surface of the earth moves in the direction in which 36 Rev. W. Wliewell ow the pri^iciples of Dynamics^ it is struck. And this proves ihe Jbrmer of the two cases just mentioned. For if the body be moving from west to east, and is struck from north to south, it moves exactly southwards ; showing that the velocity compounded with its former motion (arising from the earth's motion) is parallel to the force impress- ed. But this parallelism might have occurred, had the velocity impressed in the south direction been of any magnitude what- ever, and depended in any manner whatever upon the force impressed. And again, though the above rule for compound- ing the velocity impressed with the previous velocity had not been true when a force acts obliquely to the motion of the body, it might still have been true that in forces or pressures acting directly the velocity impressed is as the force. And, on this supposition, a body partaking of the earth's motion, and struck eastwards or westwards, would have the same relative motion communicated to it as if it had been at rest, and had received the same impulse. I shall conclude by stating the difference of the two laws which I have considered briefly thus : Suppose that in a ship in motion a ball were made to impinge directly upon an equal ball, (in a direction different from that of the ship's motion) so that they should move on together. Then, if the second law of motion were false, they would move in a direction different from that of the impact ; and if the third law were false, they would move with a velocity different from half the original ve- locity. These and the foregoing reflections seem to show the pro- priety of keeping distinct the second and third laws of motion. Others may view the subject in a different manner, and be of another opinion ; but at any rate it is desirable to bring the question under the consideration of mathematicians, that it may receive that degree of thought which is requisite for its final decision. Notes. (A.) Laplace, torn i. p. 18. Voila done deua; loix du mouvement, savoir, la loi d'inertie, et celle de la force propor- tionelle a la vitesse, qui sont donnes par I'observation. EUes lont les plus natu relies que Ton puisse imaginer, et sans doute particularlij as given hy French Writers. 37 dies d^rivent de la nature meme de la matiere : mais cette na- ture etant inconnue, elles ne sont pour nous que des faits ob- serves : les seuls, au reste, que la mecanique emprunte de Pex- perience. Poisson, torn i. p. 178- Au reste, cette loi et Tinertie de la matiere sont les deua^ seules hypotheses sur lesquelles toute la dynamique est fonde'e ; mais a cet egard la theorie du mouve- ment est moins etendu que celle de Pequilibre, car celle-ci ne depend absolument d'aucune supposition, (B.) Some attempts have been made to demonstrate the first law of motion independently of experience. It may be in- structive to notice some of these proofs, as remarkable instance? how far men of great talents and acuteness may impose upon themselves, and imagine they are producing arguments when they are in fact only variously combining and transposing a few abstract terms. One of these demonstrations is given by D'Alembert, Dy- namique, art. 6. " Un corps mis une fois en mouvement par une cause quel- conque, doity persister toujours uniformement et en ligne droite, tant qu'une nouvelle cause, difFerente de celle qui Va mis en mouvement n'agira pas sur lui, &c. '* Car, ou Paction indivisible et instantanee de la cause mo- trice au commencement du mouvement suffit pour faire parcou- rir au corps un certain espace, ou le corps a besoin pour se mouvoir de Paction continuee de la cause motrice. " Dans le premier cas il est visible que Pespace parcouru ne pent etre qu'une ligne droite decrite uniformement par le corps mu. Car, passe le premier instant, Paction de la cause motrice n'existe plus, et le mouvement neanmoins subsists encore : il sera done necessairement uniforme, puisque un corps ne pent accelerer ou retarder son mouvement de lui-meme." &c. &c. It is clear that we here have the very principle which is to be proved brought as an argument. " Dans le second cas, puisqu'on suppose qu'aucune cause etrangere et differente de le cause motrice n'agit sur le corps, rien ne determine done la cause motrice a augmenter ni a di- minuer," &c. The whole proof occupies two quarto pages. Mr Playfair has also given a demonstration that a body in 38 Rev. W. Whewell on the Principles of Dyanamics. motion will, if undisturbed, move with a uniform velocity. (Outlines^ sect. ii. art. 60.) " For," says he, " if its velocity xhanges, that change must be according to some function of the time," &c. As V = C + Af" + Bt" + &c. " Now there is no condition involved in the nature of the case by which the coefficients A, B, &c. can be determined to be of any one mag- nitude rather than that of any other," &c. Hence he infers, that A and B, &c. are = 0 and V — C. • It is manifest that the question is not what is the law of the velocity of a body Jrom the nature of the case^ i. e. from our definitions, but what it is intact ? Where would be the con- tradiction if we asserted that the law of velocity was expressed by the equation V = Cs — ^ ? (C.) That moving force is something existing in nature, with properties independent of our definitions, seems to be as- sumed when Janguage is used like the following. Laplace, tom i. p.^ 14. La nature de la force motrice etant incannue, il est impossible de savoir a priori si cette force doit se conserver sans cesse, &c. P. 15. La force n'etant connue que par Pespace qu'elle fait decrire dans un temps determine, il est naturel de prendre cet espace pour sa mesure. Mais cela suppose que plusieurs forces agissantes dans le meme sens, feront parcourir un espace egal a la somme des espaces que chacune d'elles eut fait parcourir separement, ou ce qui revient au meme, que la force est propor- tionnelle a la vitesse. Cest ce que nous ne pouvons pas savoir a priori vu notre ignorance sur la nature de la force motrice : il faut encore sur cet object recourir a Texperience ; car tout ce qui n'est pas une suite necessaire du peu de donnes que nous avons sur la nature des choses, n'est pour nous qu'un resul- tat de Tobservation. o:. Poisson, tom i. p. 278. La vitesse communique a la mobile par une force qui agit sur lui pendant un temps deter- mine est une fonction du nombre qui represente Fintensite de cette force ; le peu de donnes que nous avons sur la nature des forces ne nous permet pas de determiner a priori la forme de cette fonction. It is assumed in what follows that this function is the same for the case of a body at rest and a body already in motion. Mr Marshall on the Ver?ial Winds'. Art. VI. — On the probable came of the North-East Winds which occur in the Spring in most parts of Great Britain. By Mr Samuel Marshall. Communicated by the Au- thor in a Letter to the Editor. Phe winds of the torrid zone mostly blow in the same direc- tion, or in opposite directions in stated periods, but this is not the case in the temperate zones. Here the direction of the wind perpetually varies, and " as fickle as the wind"" is prover- bial in this country. The evident irregularity of the winds has long perplexed philosophers to assign an adequate cause for such variations, and perhaps little more can be advanced to this day than the very general conclusion, that " partial changes of temperature are the chief general causes of all winds.''^ In the torrid zone, whilst the barometer seldom varies but in a trifling degree in the temperate zone, it is not less fickle than the wind. This indication of a loss of weight in the at- mosphere can arise only from a local diminution of elasticity in this fluid. On this general ground, therefore, I conceive may be ex- plained the cause of the only periodical wind which we have in this island, I mean that from the north-east, which prevails generally from about the middle of April to the 7th or 8th of May, and sometimes longer; as for instance in the present year it prevailed- till the 18th, which is later by several days than is generally the case. In Sweden and Norway the face of the country is covered with snow to the middle of May or longer. This frozen co- vering, which has been formed during winter, grows gradually shallower to the 15th or 16th of May, or until the sun has ac- quired 17° or 18° of north declination; while, on the other hand, the valleys and mountains of England have received an accession of temperature of 24° or 25°. On this account, when the temperature of Sweden and Norway is cooled down by snow of 32°, that of Britain is 24° or 25° higher than that of the preceding countries. Because, while tbe ground is co- vered with snow, the rays of the sun are incapable of heating 40 Messrs Herschel and South oil the Double Stars the air above 32° (the freezing point.) For this reason the air of England is ^4° pr 25° more heated than that of the be- fore-mentioned countries. The air of Sweden and Norway will then of course, by the laws of comparative specific gravi- ties, displace that of England, and from the relative situation of those countries with this country will produce a north- east wind. This current is in common stronger by day than by night, because the variation of temperature in the air of Great Britain is at that time the greatest, being frequently from 50° to 60° about noon, and sinking to 32° in the night. I do not submit this hypothesis as capable of determining the exact duration, or the existence of this current of the air during the whole of the period I have mentioned, but think it highly probable that it will account for a north-east wind prevailing at this particular season, as observations prove that it does. Art. VII. — On the Systems of Double Stars which are S7ipposed to be Binary 07ies, from the observations of Sir W. Herschel, and Messrs Herschel aiid South. In a preceding Number we have given an account of sixteen systems of double stars which have been demonstrated to be binary ones, from the observations of Sir W. Herschel, and Messrs Herschel and South. We proceed now to those sys- tems which will probably turn out to be binary, from the ob- servations of the same astronomers. 1. 65 Piscium, R. Asc. 0'' 40'. Decl. N. 26° 43\ This star is a double one, and is a very pretty object, both stars being of the seventh magnitude. The angle of position in 1783.15 was 30°. 95, n p or sf. In 1822.86 it was 25°.80. The rate of decrease, from these and other observations, is 0°.l 17 per annum ; and if we suppose it to revolve uniformly in a circle, its period would be 3077 years. The distance in 1783 was IJ, the diameter of the large star. In 1819 M. Struve made it 5". 77. The distance seems like the angle to be subject to a slow variation. which Jorm Binary Systems. 41 % I. m, R. A. 4^ 49'. Decl. N. 1° 23'. ' >•(>?>''-. This star is double. The two are both of the 10th magni- tude, a star of the 5th magnitude following it to the south. In 1783.06 the position was 84° 54' nf, and in 1825.04 it was by Mr South''s observations at Passy, 83° 49' sf or n p, and the distance 9!'. 5^5. Hence here has been a change of 11° \T in forty-two years, or — 0°.269 yearly. This star is likely to prove a binary system, and should therefore be carefully watched. , 3. 32 Orionis, R. A. B^ 21'. Decl. N. 5° 48'. The two stars are in contact with a power of 303. They are unequal. In 1785 the angle of position was 52° 10' s p. In 1822, (^&^ W sp^ and distance less than 1".3. The measures of this star are of the utmost difficulty. It may be a binary system. 4. I. 70, R. A. 9^ 26/. Decl. N. 2P 53'. - The two stars are of the 9th and 9| magnitude. In 1782.86 the angle of position was 36° 24' s p. In 1825.03 it was 21° 89' s p, and the distance 2". 97. The annual change has there- fore been + 0°,35, a quantity too great to arise from error of ob- servation. 5. I. 84, R. A. Q^ 26'. Decl. N. 41° 43'. This is a very close double star, of the 9th and 10th mag- nitude. A power of 133 shows it double, and a power of 303 distinctly separates the two stars, which are of a light-blue co- lour. It is extremely difficult to measure. In 1783.25 the angle of position was 14° nf. In 1824.58 it was 4° 59^ nf, and the distance 1".664. The annual change is 4-0°.219. 6. I. 69, R. A. 6'^ 51'. Decl. N. 53° 1'. The stars are of the 8| and 8| magnitude. In 1782.87 its position was 77° 24' s f. In 1824.59 the position was QQ" 54' s /i and the distance 3".891 . The annual change is — 0^.252. 7. III. 48, R. A. 7'^ 15'. Decl. N. 20° 48'. The stars are of the 8th and 9| magnitude. In 1783 the 42 Messrs Herschel and South on the Double Stars position was 43° 54' n/, and the distance 6".2.5. In 1824.21 the position was 50° 44' nfi and the distance 6".516. The annual change in the angle is therefore — 0°.l 66. 8. 31 Bode. Can. Min. R. A. 7^ 3r. Decl. N. 5° 43/ The stars are excessively close, and nearly equal, being -/j Coronce in miniature, but smaller and much more difficult to separate. They are of the 10th and lOg magnitude. A power of 133 gives no suspicion of its being double, and 303 just se*- parates their discs. In 1781, Nov. 28, the position was 27** 21' sf. In 1820.79 Struve made it 40° 46' n p, and the dis- tance 1" or li". In 1823, Feb. 19, Mr South made the posi- tion 37°.8, and since 1781 the angle has changed 10° yearly. 9. ? Cancri, R, A. 8^ 2\ Decl. N. iW 11'. The stars are pretty unequal. Although beautifully defin- ed and round, it is not to be seen triple. In 1781.89 its position was 88° 16' s p, and the distance 8". In J802.ll it was 81° 47' sf. In 1820.29 Struve found it 71° 21', and in 1822.14 Messrs Herschel and South made it 68° IT sf, and the distance 6".24. This gives a mean annual change of •— 0°.5813. " The change of position," says Messrs Herschel and South, " has also been accompanied with a consi- derable diminution of distance ; and farther observations must decide whether this is the result of rectilinear or orbitual mo- tion. If the former, the minimum of distance will be obtain- ed in about forty years from the present time, and the change during that period much less rapid than heretofore. On the other hand, an orbitual motion will be indicated by the distance continuing to diminish beyond that limit, and probably too by an acceleration in the angular motion. A certain acceleration, indeed, is already perceptible, 10° having been described in the first twenty years, and 13^° in the last; but no great reliance is to be placed on this, as the earlier measures depend solely on single observations. Meanwhile the change remarked by Sir W. Herschel in his paper of 1804 is fully confirmed, both by M. Struve's observations and our own.""— PAiZ. Trans. 1824, part iii. p. 115. lohkhjbrm Biriary Systems. 43 10. Mu Cancri, R. A. 8^ 16^ Decl. N. 25" T. THe stars are of tlie 7th and 8th magnitude, and seem to have experienced a great change both in angle and in distance. In 1783 the angle was 32*, 9' nf, and the interval only one and a-half the diameter of the large star, which can hardly exceed 4" from centre to centre. In Feb. 14, 1822, the angle was 52° 13' 7iJ] and the distance 6".05. This gives an annual motion of-— 0°.514. M. South found the difference of declina- tions of the two stars 4".85. When this is computed for the angle and distance observed by Messrs Herschel and South it comes out 4". 78. 11. 0 84 Virginis, R. A. 13^ 34'. Decl. N. 4'' 27. The stars are exceedingly unequal, the large one being white, and the small one decidedly blue. In 1782.12 the posi- tion was 29° 5' s p, and the distance 2J diameter. In 1802.31 the position was 30*' 1'. In 1821.33 Struve makes it 35° 54', and in May 3, 1821, Messrs Herschel and South make it 40° 9' s p, and the distance 3".91. " The distance,'"* says Messrs Herschel and South, " has certainly diminished considerably. With regard to the angles one of the three positions must be erroneous; and if one be correct, there is no doubt of a sen- sible, or perhaps even a considerable annual motion." 12. g Scorpiiy R. A. 15^ 54'. Decl. S. 10^52'. The stars are of the 4th and 8th magnitude. In 1722.3b' the position was 1°, 23' w/, and distance 6".38. In 1819.5 Struve made it 2P nj; and the distance 9".31. In 1822.46 Messrs Herschel and South made it 11° 37' nf, and the dis- tance 6".77. " The large star of J has not been seen double by us,"" says Messrs Herschel and South. This is perhaps a binary system, with a mean annual motion of — 0°.256. 13. 59 d Serpentis, R. A. 18i^ 18'. Decl. N. 0° 5'. The stars are of the 7th and 8th magnitude. The large one being white and the small one blue. In 1781.79 the position was 44° 33' np, and the distance 1 or 1 J diameter. In 1802.34 it was 42° 25', and the distance 4 or 5 diameters. In 1819.61 Struve found it 40° &', and the distance 3".76. 1825.54 it was 44 Dr Kennedy on the Indian Penance of Gukvugty. 48^ 34', and the distance 4^46. The increase and subsequent decrease of the distance '' agrees," says Messrs Herschel and South, *' with the idea of a rapid rotation of one star about the other in a plane nearly passing through the eye, the small star being at its greatest elongation about 1802. The inference is an interesting one, as this star seems not unlikely to furnish another example, in addition to those already known, of a side- real occultation, which the difference of colours of the two stars, and the rapidity of their motion, will render a most curi- ous phenomenon. 14. 4. £ Lyrce, R. A. \d^ ^8'. Decl. N. 39° ^T. The stars are unequal, and both white. In 1779.83 the position was 5Q° 5' nf and the distance 3".49- In 1803.83 it was 59° 14'. In 1819.69 Struve made it 60° 42', and in 1821.02, 64° 18', and the distance 3".76. In 1822.12 Messrs Herschel and South made it 64^ 7', and the distance 4".01. The annual change is here only 0°.19. 15. I SagiticB, R. A. 19*^ 41'. Decl. N. 18° 43'. The stars are very unequal. The lai'ge one is white, and the small one blue. In 1781.88 the position was 34° 10' n p, and distance 8".83. In 1802.45 it was 40° 41'. In 1819.74 Struve found it 39° 32'. In 1823.69 Messrs Herschel and South found the position 44° 32' ?i p, and the distance 8".82. ** The discrepancy," says Messrs Herschel and South, " be- tween our measures and that of M. Struve is very extraordi- nary, and is the more to be lamented as these stars form, per- haps, a binary system." Art. VIII. — Account of the Indian Penance of Gulwugty, or Churuk Poqja* By R. H. Kennedy, M. D. I do not recollect to have seen a description by a medical wri- ter of the Indian penance of Gulwugty, or swinging with the whole weight of the body suspended on a pair of hooks per- forating the integuments of the loins. The process itself is so • From the Transactions of the Medical and Physical Society of Calcutta, vol. ii. p. 293-299. JDr Kennedy on the Indian Penance of Gulwugty, 45 appalling to an ordinary spectator^ and the after consequences seem so singularly disproportionate to the apparently serious nature of the injury endured, that it deserves consideration. On the western extremity of the old cantonment of the Bom- bay Dekkan division was the village of Seroor, whence the station was named, and on the south eastern extremity of the camp was the village of Hingny, the distance betwixt the two being about three miles. At each of these villages was a pa- goda of peculiar sanctity ; and at certain periods, as far as I can remember once in nineteen years, it was deemed a neces- sary cererpony that the car of Gulwugty penance should be dragged from Seroor to Hingny, with devotees suspended from the mast during the whole route. The car was dragged by as many volunteer labourers from the spectators as could be yok- ed to it, and proceeded at a rapid rate when a sufferer was un- dergoing the torture ; but it remained still in the interval of unloosing one and fixing another, no progressive motion being lawful unless with a devotee pendant from the hooks. The spectators and officials assured me that such a circumstance had never occurred as the car's being unable to reach its des- tination through the want of mortifiers of their flesh ; the peni- tents or devotees were always sufficiently numerous to keep the hooks occupied from one pagoda to the other. The car was four-wheeled, and about the size of an Eng- lish farmer's waggon, rather broader but not so lofty, of the coarsest possible construction, being built of half beams rather than planks, and exceedingly heavy ; upon this was a platform ample enough to hold about twenty persons. A mast twelve feet high was erected in the centre, across which, fitting on an iron pivot, was balanced transversely a pole about fifteen feet in length, divided however unequally, the iron ring which fix- ed on the pivot being inserted into it about four feet from the heavy end, and of course about eleven from the smaller. To the first was suspended a square scale of wood capable of con- taining four or five persons, and from the latter the hooks hung by a chain. The process of the penance was as follows. A devotee, having the hooks fixed in his back, as shall hereafter be de- scribed, the number of persons that were recjuisite to balance 46 Dr Kennedy oti the Indian Penance of Gulwugty, his weight and the lever, from his greater share of the pole, generally four or five stept into the scale at the short end of the transverse beam, and depressing it by their weight as low as the pivot would allow, to an angle of about 70°, they gave the cross beam a circular motion on the pivot by pulling them- selves round the mast, which they could touch, or were push- ed round by other assistants who crowded on the platform ; whilst the poor penitent, dangling at the fearful height of at least twenty feet from the ground, was swung round with a rapidity scarcely describable, and the car mean while dragged forward by the multitude till the sufferer himself prayed to be released from his painful and perilous situation. The longest period I witnessed any one person endure the torture was seven minutes and a half, the generality were satisfied with two minutes. The bold and heroic went up with " sword in hand, and shield on arm,"" as if accoutred for action ; the meeker characters held their beads in their hands, and continued re- peating the names of their gods. The total number who un- derwent the penance was about fifty, and the time required for the car to travel from one village to the other was more than seven hours, two of which were spent within the limits of the village which closed the procession, the car at that time scarce- ly moving onwards a foot with each individual, in order by such slowness of advance to indulge as many as wished to offer themselves for the ceremony. The hooks were precisely similar in shape, but rather strong- er than the flesh hooks of the London markets, the points by no means particularly sharp, nor the iron polished to any re- markable brightness. No preparatory perforation of the inte- guments was made previously to introducing the hooks ; but they were forced through, one after the other, with as much unconcern as can be imagined, the operator no more interested to be tender in the office than as if he considered the patient as accustomed to the ceremony, and as little affected by it as himself. The only care was to avoid a flesh wound ; and the extent to which the integuments were disengaged from the muscles beneath, even in the youngest and stoutest persons, exceedingly surprised me. To effect this tlie patient was laid on the ground, and his back ^violently rubbed with abundance Dr Kennedy on the Indian Penance of Gulwugty. 47 of oil ; this being dried off with sand, another friction equally violent took place with soap scraped into such thin fragments as powdered and disappeared under the hand. This being; again dried with sand, the operator's principal assistant, sitting on the patient's shoulders, commenced with his heels a process of kneading, jerking, and working the integuments over the loins, so as to loosen or slacken them, with a roughness of ma- nual but completeness of success that, as I have already said, struck me with astonishment. This being done, or rather in the intervals of this process, the operator continued gathering up by little and little a fold of the integuments in his left hand, as would raise up the skin for the introduction of a seton, and when he had mastered as much as he could with his utmost exertion force up, he then shoved his hook slowly and deliber- ately through it, always directing the point outwards. One hook being fixed, the other was speedily introduced on the op- posite side in the same manner, the operation of fixing both taking generally about three or five minutes, depending upon the muscularity of the subject. After the patient had swung to his own content he was taken down by the cross pole being lowered nearly to the ground, from the weights at the opposite end removing from the scale ; then being laid flat on the ground the hooks were drawn forth, but without the least precaution to save pain. I did not observe a single instance of the skin having yielded or being rent. The appearance was invariably four wounds in"a straight line, thus, o o o o^ the two made by one hook being always four and sometimes five inches apart from each other. The curative process was simplicity itself. The principal assistant again seated himself on the patient's shoulders, and applying his heels to the wounded parts labour- ed to squeeze out any blood or lymph that might be extrava- sated. One operator sucked the wounds, and another applied a kind of dry poultice of cow-dung and turmeric, the Hindoo specific for every shock that " flesh is heir to." The sufferer's kumur-bund (girdle) supplied the bandage, which was tightly applied round his loins, and he forthwith joined in the cere- mony of swinging his comrades, as alert and unconcerned to appearance, as if the whole he had undergone were but a jest. I had an opportunity of examining daily, until their perfect 48 Mr Audubon's account of his Method cure, seven of the devotees, who were our battalion sepoys or camp followers. In no one instance was pus formed, or did inflammation of any consequence whatever follow ; nor did one quit his duty, or apply for hospital relief. And further, I had reports to be relied on of nearly twenty others from distant villages, whither I sent hospital servants to make inquiries after the poor people who had swung, not one of whom suffer- ed in any important degree beyond a temporary soreness and stiffness in the loins. None but a medical man who has wit- nessed the process could suppose it possible that so little injury- should result from so apparently serious an operation. The' natives of course think it the miraculous interference of the god Cunda Row, in whose honour the torture is endured, a very natural conclusion, for even among our officers, who in great numbers attended to witness the spectacle, there were not a few whom it was difficult to impress with a satisfactory con- viction that the whole was but a natural result from natural causes ; and that the skill of the operator, and the antiphleg- monous habit of his own constitution, was the safeguard of the patient. Art. IX. — Account of the Method of Drawing Birds emplcyy- ed by J. J. Audubon, Esq. F. R. S. E. In a Letter to a Friend. At a very ^arly period of my life I arrived in the United States of America, where, prompted by an innate desire to acquire a thorough knowledge of the birds of this happy country, I formed the resolution, immediately on my landing, to spend, if not all my time in that study, at least all that portion generally called leisure, and to draw each individual of its natural size and colouring. Having studied drawing for a short while in my youth under good masters, I felt a great desire to make choice of a style more particularly adapted to the imitation of feathers than the drawings in water colours that I had been in the habit of seeing, and, moreover, to complete a collection not only valuable to the scientific class, but pleasing to every per- Method of Drawing Birds, 49 son, by adopting a different course of representation from the mare profil&Jike cut figures, given usually in works of that The first part of my undertaking proved for a long time truly irksome. I saw my attempt flat, and without that life that I have always thought absolutely necessary to render them distinguishable from all those priorly made ; and had I not been impelled by the constant inviting sight of new and beautiful specimens which I longed to possess, I would pro- bably have abandoned the task that I had set myself, very shortly after its commencement. Discoveries, however, succeeded each other sufficiencly ra- pidly to give me transient hopes, and regularity of application at length made me possessor of a style that I have continued to follow to this day. Immediately after the establishment of this style, I destrcnj^ ed and disposed of nearly all the drawings I had accumulated, (upwards of 200,) and with fresh vigour began again, having all my improvements about me. ^{ >^. uo. The woods that I continually trod contained not only birds of richest feathering, but each tree, each shrub, each flower, attracted equally my curiosity and attention, and my anxiety to have all those in my portfolios introduced* the thought of joining as much as possible nature as it existed. I formed a plan of proceeding, with a view never to alter it very materially. I had remarked that few works contained the females or young of the diff*erent species ; that in many cases, indeed, those latter had frequently been represented as different, and that such mistakes must prove extremely injurious to the advancement of science. My plan was then to form sketches in my mind\^ eye, each representing, if possible, each family as if employed in their most constant and natural avocations, and to complete those family pictures as chance might bring perfect specimens. > The knowledge I had already acquired of the habits of most of them enabled me to arrange my individuals in rough outlines, finishing probably at the time only one of the num- ber intended to complete it, and putting the drawing thus be- gun aside, sometimes for months, and sometimes for years. VOL. VIII. NO. I. JAN. 1828. J) - 60 / Mr Audubon's Account of his I knew well that closet naturalists would expect drawings exhibiting, in the old way, all those parts that are called by xhem. necessary characteristics ; and to content these gentlemen I have put in all my representations of groups always either parts or entire specimens, showing fully all that may be de- fined of those particulars. My drawings have all been made after individuals fresh killed, mostly by myself, and put up before me by means of wires, &c. in the precise attitude represented, and copied with a closeness of measurement that I hope will always correspond with nature'^ Yfhen brought into contact. The many foreshortenings unavoidable in groups like these have been rendered attainable by means of squares of equal di- mensions affixed both on my paper and immediately behind the subjects before me. I may thus date the real beginning of my present collection^ and observations of the habits of some of these birds, as far back as 1805, not, however, continued always with the same advantages that attended me during the first ten years that I spent in America, for since then I have often been forced to put aside for a while even the thoughts of birds, or the pleasures I have felt in watching their move- ments, and likewise to their sweet melodies, to attend more closely to the peremptory calls of other necessary business. The long journies that I have performed through different parts of the country have been attended with many difficul- ties and perplexing disappointments, some of which have seve- ral times made my mind waver whether I should or should not abandon them all for ever. Being quite unknown amongst naturalists, I have had to de- pend on my own exertions alone, without either correspondents or friends. I have followed slowly to be sure, but constantly my object. T have often listened to the different observations of men who accidentally had made remarks on different spe- cies of birds, but seldom, except when with the rough hunters and squaters of the frontiers, have I discovered naked facts in such relations. This has dissuaded me from ever taking any account given me for granted, until corroborated either by my own ocular opportunities or accumulated repetitions. The astonishing tendency that men have to improve nature in MetJtod of Drawing Birds, 51 their way^ by embellishing each of their descriptions of habits without any farther object in view than that of entertaining the better their hearers, has frequently deterred me from list- ening at all to such accounts, and has brought my physical system to a solitary state of habits and manners so different from those that usually accompany men, that frequently I feel un- easy, as well as awkward, if more than one or two companions are about me. To the improvement of my observations I have found this no detriment. On the contrary, I am per- suaded that alone in the woods, or at my work, I can make better use of the whole of myself than in any other situation, and that thereby I have lost nothing in exchanging the plea- sure of studying raen for that of admiring the feathered race. Pursuers of natural curiosities are extremely abundant in our age. New, quite unknown subjects are those the most sought for. The dried skin of an exotic specimen, of which the colour has not been described minutely, draws all attention, whilst the habits of that same specimen are scarcely inquired after, and those of individuals more interesting, being nearer and more easily obtained, are abandoned, and the pleasure, as well as the profit that might be derived from a complete study of their manners, and faculties, and worth, are set aside. I must acknowledge to you that that kind of curiosity has not ani- mated me half so much as the desire of first knowing well all those commonly about me, — a task that in itself I discovered to be extremely difficult, but through which I found the means of at least drawing valuable deductions. I have never drawn from a stuffed specimen. My reason for this has been, that I discovered when in museums, where large collections of that kind are to be met with, that the per- sons generally employed for the purpose of mounting them possessed no further talents than that of filling the skins, un- til ylum'ply formed^ and adorning them with eyes and legs ge- nerally from their own fancy. Those persons, on inquiry, knew nothing of the anatomy of the subject before them ; seldom the true length of the whole, or the junction either of the wings and legs with the body ; nothing of their gaits and allurements ; and not once in a hundred times was the bird in a natural position. I would not from this have you conclude that museums and 52 Mr Audubon's Account of his collections of stuffed specimens are entirely useless. On the con- trary, I think them extremely well fitted to enhance (in youths particularly) the desire of examining afterwards the same sub- jects at large in all their beauty, the only means of detecting errors. But in forming works entirely with a view to distin-^ guish the true from the false, nature must be seen first alive, and well studied, before attempts are made at representing it. Take such advantages away from the naturalist, who ought to be artist also, and he fails as completely as Raphael himself must have done, had he not fed his pencil with all belonging to a mind perfectly imbued with a knowledge of real forms, mus- cles, bones, movements, and, lastly, that spiritual expression of feelings that paintings like his exhibit so beautifully. Among the naturalists of the time, several who are distin- guished have said that representations of subjects ought to be entirely devoid of shades in all their parts ; that the colouring of the figure, that must be precisely profile, cannot be under- stood by the student if differently represented. Why then should the best artists of the same age give us pictures with powerful breadth of lights and shades ? and why, still more strange, should every individual who looks on such paintingsfeel not only pleased, but elevated at the grand conception of the painter, and at the nobleness of the subjects being so much like through their effect ? My opinion is, that he who cannot con- ceive and determine the natural colouring of a shaded part, need not study either natural history or. any thing else con- nected with it. ,rr,J[f I have joined to many of my drawings plants, insects, reptiles, or views, it has been with the hope to render them all more attractive to the generality of observers ; and as I can as- isure you that all these were copied with the same exactness with which all the birds are represented, you will no doubt view them with as much pleasure. Do not be surprised at finding that I have trampled upon many deeply-rooted prejudices and opinions attached to the habits of several individuals by men who had only heard and not seen. My wish to impart truths has been my guide in every instance ; — all the observations respecting them are my own. All the authors who have formed works of natural history have Metfiod of Drawing Birds. 53 attached to the representation of each species a minute descrip- tion of all their parts. This was done probably because the sub- jects were never or very seldom offered to view of their natural size ; or perhaps, indeed, because these very authors were well aware of the want of accuracy in those figures, seldom drawn by themselves. In my work I wish to curtail these extremely tiresome descriptions ; more anxious that those who study orni- thology should compare at once my figures with the living spe- cimen, than with a description so easily made to correspond with the drawings by any person who merely knows the tech- nical appellations of each part and feathers, with the name of the colours chosen by authors for that purpose. I shall neither describe the eggs of the species that I have procured nor the number. A glance at the drawings will answer the more readily, as you will see classed under each the date of the season, and the average number deposited by each bird when ready for incubation. Not so with the nests. I would wish to see these so well described en masse, that the young na- turalists, when in the woods, would be able to know the artist by his work. This is often a difficult task, the more with those species who will oftentimes form their nests differently, and of different materials, according to localities and climate, and those that oftentimes take possession of that of quite another species. If the greater number of figures given in a work are received as perfectly correct in all their parts, by comparing them with good specimens, and through such an examination the author is greeted with public confidence, why should the reader be tormented with descriptions? Where is the amateur of paintings who could bear the reading of a description of the structure, muscles, and expression of the face of such a man as Rem- brandt, after gazing at the portrait of that eminent artist by him- self ? The study of ornithology must be a journey of plea- sure. Each step must present to the traveller's view objects that are eminently interesting, varied in their appearance, and at- tracting to such a degree, as to excite in each individual thus happily employed the desire of knowing all respecting all he sees. I would have liked to raise an everlasting monument, com- memorating with a grand effect the history and portraits of the 54 Account of the Cave ofBooban, birds of America, by adding to each drawing of a single spe- cies a vignette exhibiting corresponding parts of the country where the specimen is most plentifully found ; but having no taste for landscape-painting, and unable to employ a competent assistant for such a purpose, I with deep regret have relinquish- ed the idea. I mention this to you, my dear friend, with hopes that at some future period some one better seconded by pecu- niary means or talents may still engage in the undertaking. Sorry, notwithstanding, that as time flies Nature loses its pri- mitiveness, and that pictures drawn in ten, or twenty, or more years, will no longer illustrate our delightful America pure from the hands of its Creator ! Art. ^.^-^Account of the Cave of Boohan, near Punduah, in the Cossyah Mountains. In perusing a number of the Calcutta Jmirnal published some years ago, we were particularly struck with the descrip- tion of a remarkable cavern in the Cossyah Mountains, writ- ten by M. Duvaucel, a Frenchman. We were desirous of transferring to our pages that account of so remarkable an ob- ject ; but we were deterred from doing this by the dread of imposing upon 6ur readers for truth what might turn out to be an entire fiction. We accordingly wrote to a correspon- dent in India, to whom this Journal is under many obliga- tions, to ascertain if there was such a cave, and if possible to obtain a description of it. We have been accordingly favour- ed with the following materials. Captain Fisher, surveyor of Sylhet, accompanied by Major Watson, Captain Wildman, and Mr Sullivan, went to explore the cave. They took with them two miles length of twine, and fastened one end at the mouth of the cave, in order to measure the distance to which they penetrated. The follow- ing description of it was drawn up by the learned editor of the Calcutta Government Gazette, from materials furnished by Captain Fisher. The cavern of 13ooban is situated in one of the lower ranges of the Cossyah Mountains, at the distance of about three near Punduah, m the Cossyah Mountams. 55 hou rs' walk, in a north-east direction from the Bazaar of Pun- duah, and at an elevation, probably of six hundred feet above the adjacent plains. The access to it is by no means difficult, though the passage of three hills, which occur in the last hour's journey towards it is fatiguing, as the ascents, though short, are singularly steep, oue of them actually subtending an angle of 46°. These hills are composed of sandstone, but their bases are strewed with fragments of various rocks, chiefly granite and limestone, apparently the debris from the higher regions of the mountain chain. The mouth of the ca- vern, which is found in the face of a limestone mountain, is not in itself remarkable, neither do any external circumstan- ces indicate the existence of the vast hollows to which it affords access. The aperture is small, its dimensions precluding the intrusion of more than one person at a time, and the entrance is completed by a scrambling descent of about thirty feet over masses of rock to a comparatively level space, which, however, is involved in total darkness. By the aid of lighted torches it may be here seen that the cavern has already expanded considerably, and that its sides are covered with numerous stalactites, crystals, and petrifactions, all, however, of the limestone family, of which rock alone the cavern is entirely formed. The passage here is about twelve to fifteen feet in width, and the height varies from about twenty to forty feet, estimated from the base to the highest part of the natu- rally arched roof. In advancing, this latter dimension of the cavern is found to vary greatly, sometimes increasing to seven- ty or eighty feet, and at others diminishing to ten or twelve. The breadth, however, continues nearly uniform. These re- marks apply solely to the branch which appears to have been always followed by the few Europeans who have visited the cavern, and which has been explored from the entrance to the distance of about a mile, where a steep and wide cavity fills up the whole breadth of the passage, and presents an obstacle to further ingress, which, owing either to want of time or pro- per conveniences, no one has yet surmounted. When the party had run out one mile of the rope they were stopped by this cavity, which resembled the interior of a ca- thedral. About fifty yards from this all farther passage was 56 Account of the Fossil Bones discovered prevented by a chasm about forty feet deep, which it was im- possible to descend without a ladder, so that the party was obliged to return. The general direction of the branch which was now visited is north-east, a course from which may be inferred the proba* ble existence of a debouche in the opposite face of the rnoun^ tain, an inference which is strengthened by the fact, that a cold blast of air is sensibly felt in most parts of the cavern* Perhaps the most remarkable appearances which offer them- selves to notice in an examination, however cursory, of this curious phenomenon, are the numerous fissures or openings, which occur at various altitudes in the sides, and which seem to form the entrances of new branches or ramifications, by which the mountain should appear to be perforated in every direction. A few days after Captain Fisher and his party returned. Mr Ellis, accompanied by Mr Wardlaw and Lieutenant White, visited this cave, and passed two days in it. They slept in it, and examined the different courses, but they could not advance so far in any of them as in the one whicli led to the chasm. Art. XI. — Account of the Fossil Bones discovered on the left bank of the Iraxvadi in Ava. * The tdllebtidri of fossil bones brought from Ava by Mr Craw- ford is vei-y large, and consists of fossil bones, fossil shells, and fossil wood. Of the fossil bones the most numerous and remarkable are those of an animal about the size of a large elephant. In the sketch given in your paper of the late mission to Ava these m'e stated to be the bones of the mammoth. This is a mistake. The mammoth is an extinct species of the elephant, differing from the two living species, the African and Indian. The re- mains of this animal have only been found in Europe, and chiefly in Siberia. The Burman fossil bones are unquestion- ably those of the mastodon, as may be clearly seen by com- * From the Cuhuita Government Geatette, March 21, 1827. See page Ifti ; on the left bank of the Irawadi in Ava. 57 paring, as I have done, the grinders with those of the Indian elephant, as well as the accurate descriptions and representations of both in the work of Cuvier. In the different species of ele- phants the crown of the molares or grinders is marked by su- perficial transverse bands. In the mastodon the form is wide- ly different, the crown being marked by deep transverse fur- rows and ridges, the latter divided into two or more obtuse py- ramidal points or mamillae. It was this singular appearance which made the mastodon a long time be considered erroneous- ly as a carnivorous animal. Five species of the genus masto- don are supposed by Cuvier to have been discovered, and I imagine the bones now under consideration will be found to constitute a sixth species, for the molares, on which he princi- pally rests for his specific distinctions, differ very materially from the representations which he has given of the ascertained species. The mastodon of Ava, if it be a distinct species, will be found equal in size to the great mastodon of Ohio, which is reckoned to be equal in size to the Indian elephant. A grinder which I examined measures in circumference between sixteen and seventeen inches, and the circumference of a humeriis round the condyles is not less than twenty-five inches. Several of the grinders and bones, however, apparently of an animal of the same species, are much smaller than these, but this is probably on account of their belonging to younger individuals. I need hardly observe that our mastodon, like others of the same ge- nus, and all the species of the elephant, had tusks. Several fragments of these, but no entire tusks, are contained in the collection. The next most remarkable remains of the collections after those of the mastodon are those of the fossil rhinoceros. There are several molares of an animal of this genus in the collection, Cuvier describes four species of the fossil rhinoceros to have been ascertained, all differing from the living species. The l)ones now found bear a striking resemblance to one of the spe- cies represented by Cuvier, but the molares are considerably larger than any of those which he has represented. The collection seems to me to afford evidence of the exist- ence of two other animals of the same family with the ele- phant, mastodon, and rhinoceros, at least teeth which I have 58 Account of the Fossil Bones discovered seen in it exactly resemble two species of a genus represented in the work of Cuvier, and to which he gives the name of Atithracotherium. The other teeth of quadrupeds which exist, and which I am able to recognize, are those of an animal of the horse kind, and those of an animal of the ruminant family, apparently of the size of the buffalo. There are of course a great many bones which T have not the skill to determine. Among the remains are numerous specimens of those of a crocodile, which I conjecture to resemble the long-nosed alliga- tor of the Ganges, the native name of which has been corrupt- ed by naturalists into Gavial. It is singular that this descrip- tion of alligator, as far as we know, is not at present found in the rivers of Ava. In the same situation with the bones were found consider- able quantities of fossil shells. Some of these were filled with blue clay, but far the greater number with hard sihceous mat- ter. The shells which I have seen are of the genus Turbo and genus Tellina, and the productions of fresh water, although they do not, at the same time, resemble the present shells of the lakes and rivers of the neighbourhood. The fossil wood is found in the same situation with the bones and shells. This is in vast quantity, the hills and ra- vines being strewed with blocks and fragments of various sizes, some of them five and six feet in circumference. The fossil remains now sketched are found on the left bank of Irawadi, and within four and six miles inland from the river, between the 20th and 21st degrees of north latitude, and close to the celebrated wells of Petroleum. The aspect of the country is very remarkable. It is composed of sand-hills and narrow ravines, very sterile, and for a tropical country very deficient in vegetation. Among the sand there are beds of gravel, with ironstone and calcareous breccia. The whole is evidently a diluvial formation. The few scattered trees which exist in this tract consist of some Acacias, a Celtis, a Rhus, a Barringtonia, a Zizyphus, and some Indian fig-trees. To say whether or not the fossil timber found belong to the same spe- cies as these would be a matter of difficulty ; but, upon the 071 the left banJc of the Irawadi hi Ava. 59 whole, it may be said, that the blocks appear too large to war- rant a belief that it does. f^ii The fossil bones, as well as the shells and wood, are all found superficially, or rather indeed upon the surface, for all of them were more or less exposed. Notwithstanding this ex- posure they have suffered very little decomposition. They are not rolled or suffered from attrition, for their sharp edges and processes are preserved with great distinctness, the infe- rence from which is, that the individuals to whom they belong- ed died, or were destroyed on the spot on which they are now found. In one respect the bones differ essentially from all fossil bones of which I have heard. They are complete petri- factions, and all of them more or less deeply coloured with iron. Their substance is siliceous, and some of them are so hard as to strike fire with steel. This no doubt accounts in a good measure for their perfect state of preservation. The wild quadrupeds of the neighbourhood at present are a leopard, a cat, a deer, and the hog. The bones of these do not seem to exist among the fossil remains, nor is there any evidence of those of the elephant, or of any carnivorous ani- mal. As amongst similar remains in other parts of the world, not a vestige is to be discovered here of the human skeleton. I need hardly attempt the refutation of the idle notion which has been entertained by many, that the fossil remains found on the banks of the Irawadi have been generated by a petri- fying quality in the waters of that river. Abundance of or- ganic matter may be seen on the shores of the Irawadi, both animal and vegetable, undergoing the common process of de- composition as elsewhere. There can, I think, be no doubt that the fossil bones, shells, and wood, are here, as similar re- mains are admitted to be elsewhere, all the result of the last, or one of the last, great catastrophes which changed the face of the present globe. They are in fact the remains of a former state of our world, when the greater number of the present races of animals had no existence, and above all, before man was called into existence. The collection is altogether both extensive and curious, and the more worthy of attention, since it is, as far as I am aware, the first of any moment that has ever been discovered in the 60 Dr Brewster on the Mean Temperature of the Equator. East. I shall be anxious to hear that it falls into the hands of those who are capable of appreciating and examining it. We have been promised a selection from these bones for the museum of the Royal Society of Edinburgh, and we may therefore have an opportunity of resuming this curious sub* ject Art. XII.— 0« the Mean Temperature of t/ie Equator, as deduced Jrom Observations made at Prince of Wales'^s Island, Singapore, and Malacca. By David Brewster, LL. D. F. R. S. Lond. and Sec. R. S.^Ed. I HAVE already had occasion to treat of the subject of tlie temperature of the equator in consequence of Mr Atkinson's attempt to controvert the deductions of Baron Humboldt, , which I had used as the data for my climateric formulae, and to fix the tropical heat at a much higher degree than had been done by any preceding author. From observations made at various places in Ceylon and Batavia, I was led to conclude that the mean temperature of the equator did not exceed 80|°. * Since that time I have taken measures to obtain observations made still nearer the equator, and I have been in expectation of receiving them through the kindness of a correspondent in India, whose zeal for the promotion of science is unbounded. I observe, however, in the last part of the Transactions of the Royal Asiatic Society -f* a series of meteorological obser- • See this Journal, No. xi. p. 117 — 120. In the same Number, p. 136, we liave given an abstract of Baron Humboldt's own able defence of his de- ductions. t We earnestly hope that Mr Colebrooke, the distinguished director of this flourishing institution, will use the influence which he possesses in recommending the establishment of meteorological registers in different parts of India, and in collecting and publishing in the Transactions of the Astatic Society the various meteorological observations which are made throughout our extensive dominions in the East, especially those made near the equator. The council of the Asiatic Society of Calcutta have, we ob- serve, taken up this subject, and we expect much from the enlight- ened zeal of its members. As the subject of climate is so intimately connected with the diseases of the human frame, we take the liberty of Dr Brewster on the Mean Temperature of the Equator-. 61 vations made at Prince of Wales's Island, within 5° of the equator, and at Singapore and Malacca, within 1° and 2° of it, and as these are the very points where observations have beeii most wanted, I have endeavoured to deduce from them the mean temperature of these places, and thus to determine the mean heat of the equator itself. This element is one of the most important in meteorology. It is not only necessary for ascertaining the law of the distribution of heat in different latitudes ; but, by its accurate determination in different meri- dians, we may expect to throw light on that curious specula- tion, in which a connection is supposed to exist between the distribution of heat and the distribution of the magnetic in- fluence over the globe. We shall begin with the observations at Singapore, as being made nearest to the equator. 1. SiNGAPOEE. North latitude P M. East long. 104°. The observations at Singapore were made with instruments kept under a thatched bungaloo by Lieutenant-Colonel Wil- liam Farquhar. They were made at six in the morning, at noon, and at six in the evening. 1822. Mean annual temperature at 6^ and 6^, - 79° 45 . — 12^ noon, - 84 0 In order to deduce the mean daily temperature from these observations we shall make use of the corrections deduced from the hourly observations made at Leith Fort for 1824 and 1825. The mean daily temperature, for example, ex- suggesting to the Medico-Physical Society of Calcutta the propriety of* taking it under their patronage, and of thus adding greatly to the already high interest which their memoirs possess. . It would be of the greatest importance to meteorology if a set of hourly meteorological observatio?is could be instituted at Calcutta, Bombay, Ma- dras, Singapore, Malacca, and some station on the elevated plains of Hin- dostan. What we have been able to accomplish at Leith, and to continue for four years, and what has been accomplished more recently at Christi- ania and Drontheim by Professor Hansteen, may surely be easily executed under the genial sky of the East, and by means of the we^jjji |^(ji leisure which there abound. 62 Dr Brewster on tf*€ Mean Temperature of' the Equator. ceeds that of 6^ a. m., and C^ p. m. h^ 0° 29, and is less than that of noon by 2° 51 . Hence we have Mean daily temperature deduced from that of 6' and 6^ - - 79° 74 12 noon, 81 49 Mean of the two, 80° 47 As the corrections now applied belong to a northern climate, marked with the vicissitudes of summer and winter, they can- not be strictly applicable to tropical regions, where the varia- tions in the monthly temperature are so exceedingly small. We have therefore deduced the corrections from the hourly temperatures of the three summer months, during which the variations of the daily curve must have a greater resemblance to those of the torid zone. These corrections, though differ- ent from those used above, produce, as will be seen presently, very little difference in the mean results. These corrections are — 3.08 and — 3.00, and they give. Mean daily temp, deduced from Q^ and 6'^ . 79° 37 12 noon, 81 80 Mean of both, 80° 18 Hence the mean annual temperature of Singa- pore for 1822 was - - - - 80° 18 1823. Mean annual temperature of 6** and &" - 79° 0 12 noon, 83 7 By applying the same corrections as before, viz. those dedu- ced from the summer months, we have Mean daily temp, deduced from 6*^ and 6^ - 78° 92 . — . 12 - 80 70 Mean of both, 79* 81 Hence the observed mean annual temperature of Singapore for 1823 was - - 79° 81 And the observed mean annual temperature of 1822 and 1823, .... 80 00 Dr Brewster on the Mean Temperature oftJie Eqitatar, 63 Mean annual temp, calculated from my formula • « * ^ ti • t of T = 8P8sin.D+ 1, . - 81° 36 Difference, 1« 36 2. Malacca. North latitude 2° 16'. East longitude 102° 12'. The observations at Malacca were made in 1 809 by Lieu- tenant-Colonel William Farquhar, and the instrument was kept within the Old Government House. Mean annual temperature at 8^^ - * 77° 67 4 - - 82 33 The corrections deduced from the Leith observations are + 1° 24 and — 2° 97, which gives Mean daily temperature deduced from 8^ - 78° 91 4^ - 79 36 Mean of both, 79' 18 But by applying the corrections deduced from the summer months only, viz. + 1° 24' and — 3° 95', we have Mean daily temperature deduced from 8^ - 78° 91 . 78 38 ih Mean of both, 78° 65 Hence the observed mean annual temperature for Malacca for 1809 is - - - 78° 65 Do. calculated from my formula T =r 81° 8 sin. D + 1, - - - - - - 81 02 Difference, 2° 39 3. Prince of Wales's Island. North latitude 5" 25'. East longitude 100° 19^. The observations at Prince of Wales's Island were made for 1815, 1816, 1820, 1821, and for 1823. They were taken in George Town, and those for the two latter years were made in the Library. We have also a set made on Government 64? Dr Brewster on the Mean Temperature of the Equator, Hill, but as we do not know the height of this station w6 cannot use them in the present inquiry. 1815-16. The observations for this year extend from June 1815 to July 1816. They were made at intervals of three hours, viz. at 6\ 12\ 3, and 9^ p. m. Mean temperature at 6^* a. m. - - - 76° 1 12 noon, - . - 79 6 3 p. M. - - - 81 5 9 P. M. - - - 79 1 The corrections for these hours deduced from the observa- tions at Leith are -f 2° 61 ; — 2° 5 ; — 3° 20 ; — 0° 43. Hence we have Mean daily temperature deduced from 6^ 12 3 .. 9 Mean of the four, 78° S But by applying the corrections taken from the summer months, viz. + 3° 5 ; — S° 9 ; — 3° 9 ; + 0° 7, we have Mean daily temperature deduced from 6h - 79° 6 . 12 - 76 7 3 - 77 6 9 - 79 8 78° 7 77 1'- 78 2- 78 7 Mean of these. 78° 4 Hence the mean annual temperature of Prince of Wales's Island for 1815-16 is - - 78° 4 1820-21. The observations for this year were made at 7'^ a. m. 12 noon, and 4 p. m., and the results were, Mean annual temperature at 7*^ - - - 77° 8 12 - - - 81 6 4 - - - 83 1 The corrections for these hours deduced from the observa- Dr Brewster on the Mean Temperature of the Equator ^ 0^ tions at Leith, are -f 1° 98; + S^ 51 ; + :2° 97^. Hence we have Mean daily temperature deduced from 7*^ 1 o - 79° 8 - 79 1 Ai - 80 1 Mean of these, 79° 67 But by applying the corrections taken from the summer months, viz. + 2°.46 ; —3°. 03 — 4.24 we have . Mean daily temperature deduced from 7^ - 80^ 3 12 - 78 6 4 - 78 9 Mean of these, 79° 26 Hence the mean annual temperature for 1820-1 is 79® 26 1823. The observations were made only on the first eleven months of this year, and were recorded at S^, 12'', and 4^. The results are as follows : Mean temperature at 8^ - - 78° 85 ' — 12 - - 82 90 4 - - 83 89 The corrections for these hours deduced from the Leith observations are + l°-24 ; — 2°. 51 ; — 2°.97, and we have, Mean temperature deduced from 8'' - 80° 09 12 - 80 39 __ 4 . 80 92, Mean of these, 80° 47 But by applying the corrections taken from the summer months, viz. + 1°.25 ; —3^03 ; — 4°.24, we have, Mean temperature deduced from 8^ - 80° 10 12 - 79 87 ' . _.. 4 - 79 65 Mean of these, 79° 87 VOL. VIII. mo, I. JAN. 1828. e 66 Dr Brewster 07i the Mean Temperature of the Equator. Hence the mean annual temperature for 1823 is 79°.87 We therefore have Mean annual temperature for 1815-16 IQOA Of 78° 4 79 26 79 87 18^3 Mean of these, 79° 18 Observed mean annual temperature of Prince of Wales's Island from three years observation. Do. calculated by my formula of T = 81°.8 sin. D + 1 - - - 79 93 Difference, 0° 75 From these calculations it appears that the mean tempera- ture of three different points of the Malay Peninsula is lower than that which is deduced from formulae founded upon Humboldt*'s estimate of the equatorial temperature. As we do not know the altitude of the places of observation, a slight in- crease must be made in reducing them to the level of the sea ; but this is too small to alter in any way the general conclusion which the observations authorize. If we now deduce from the same observations the mean tem- perature of the equator by means of the formula. T Equatorial temperature = — . - we shall have Mean temp, of equator from Singapore observations 80° 03 Malacca do. 78 71 Prince of Wales do. 79 53 Mean temperature of the equator, 7^° ^^ Hence it follows that the mean equatorial temperature is considerably less when deduced from the observations made in the Malay Peninsula, than when it is deduced from the obser- vations in Ceylon, Batavia, and Hawai, as the following table shows. Dr CoJquhoun on the Argillaceoiis Ore of Iron. 67 No. of sets of observation. Mean temp. eq. from Ceylon observation 5 80® 66 Batavia do. 4 81 08 Hawai do. 1 79 67 Malay Peninsula do. 3 79 42 The mean of which, taking into account the number of observations in each set, is - 80° 44> We may therefore safely conclude from these results, that in fixing the mean temperature of the equator at 81 1°, Ba- ron Humboldt has exhibited that sagacity which characte- rizes all his researches; and that the climateric formulae in which we have adopted his determination represent better than any other the great mass of observations which have been made in the different parts of the globe. Even if the observations at Pondicherry * were made with care, and at those times of the day which give the mean daily temperature, it would be un- philosophical to regard such a solitary example of high tem- perature as affecting, in the slightest degree, general results de- duced from numerous observations, made at various and distant points of the equinoctial zone. Aet. XIII. — A Metallurgic Memoir on the Nature and History of the Argillaceous Carbonate of Iron. By Hugh CoLauHouN, M. D. Communicated by the Author. (Con- tinued from vol. vii. p. 242.) These are the general mineralogical features which distinguish the ironstone. We shall now proceed to divide the subspecies into its principal varieties. 1. Common Compact Argillaceous Carbonate of Iron. This is the general type of the species, and, as such, the extreme variations of which it is susceptible in colour, fracture, texture, and hardness, have been already noticed. It is sometimes so much impregnated with bituminous matter, that its external • Its mean temperature is stated at 85°.28'. L 68 Dr Colquhoun on the Argillaceous Ore of Iron. appearance assumes the resemblance of bituminous schist, and, occasionally, even of certain coals. 2. Nodular or Reniform Ironstone. The characteristic of this variety is its occurrence in detached, subglobular, or irre- gularly shaped masses. A considerable variation is found to prevail among the different specimens in this class. Thus the structure, which is generally uniform and compact, is some- times changed to concentric lamellae, especially when the ex- ternal surface has undergone decomposition. Sometimes, also, the nodules, instead of being solid throughout, contain a cavity in the centre. This cavity is occasionally empty, at other times it contains some extraneous body. In most cases, this enclosed matter consists of crystallized carbonate of lime. It is sometimes abundant enough to fill the entire hollow, though generally it merely occupies it partially, in the form of a regu- lar geode, shooting out at the same time in thin veins towards the exterior surface of the nodule. A specimen of this de- scription formerly received the name of septarium, or ludus Helmontii. In other instances, which are of much rarer oc- currence, the cavity includes a quantity of the ironstone itself either in the state of a powder or in the form of a detached and solid ball. When the latter case occurs, and the entire nodule is shaken in the hand, a rattling sound is heard to pro- ceed from the interior, and it was on listening to this property of a somewhat rare variety of ironstone, that the ancients con- sidered it to be a quality sufficiently unusual and unaccount- able, to justify the idea that the stone itself possessed some excelling and peculiar virtue. They accordingly held it to be an amulet of great value, and esteemed it a sovereign preser- vative, and remedy against diseases. It received the name of cetites or eaglestone, from a belief that the eagles transported it to their nests. S. Columnar or Concretkniary Ironstone. The occurrence of this variety of the ore is rather uncommon. It consists of columns which are aggregated together, and lie in a direction parallel to each other. These concretions are sometimes con- nected by a thin crust of carbonate of lime, but at other times they appear to be aggregated together without any extraneous Dr Colquhoun on the Argillaceous Ore qflrwi. 69 cement, in the same manner as the columns which compose a mass of starch. 4. Oolitic, Lenticular, or Granular Ironstone. The cha- racteristic of this variety, (which is found chiefly imbedded in schist,) consists in its being formed of an aggregation of round- ed particles of the mineral, generally held together by the in- terposition of some extraneous cement. Several remarkable specimens of this variety have been described by the French chemists, one or two of which deserve to be particularly noti- ced. In the Annales des Mines, vol. iv. p. 355 and 633, M. Berthier has described two sorts of granular ironstone. The first was found at Anzin (departement du Nord,) associated with coal, and was composed of globular grains of the size of small peas, agglutinated together by a bituminous schist. The second was obtained from the vicinity of the village of Pou- rain, in the department of Yonne, and was remarkable for its occurrence in a tertiary formation where it seemed to be con- temporary with potter's clay. This sort was found in round- ish masses of various sizes, some of them very large, irregu- larly distributed through a ferruginous sandy clay, situated in the neighbourhood of a bed of ochre. The globules were weakly cemented together by a thin incrustation of grey co- loured clay, which quickly softened when immersed in water. Another remarkable specimen, in which the grains were found to be strongly bound together by bitumen, is described by MM. Combes and Lorieux. * It was taken from a pretty thick bed, in the immediate vicinity of a stratum of coal at Lasalle (Aveyron.) The grains were of a greyish colour, which strongly contrasted with the dark hue of the cement. The composition of the ore was rather remarkable, and as it differs materially from any of the analyses of the British spe- cimens which have been given in an earlier part of this treatise, we shall take this opportunity of mentioning it here. The principal constituent was carbonate of protoxide of iron (in the proportion of 62 per cent.) mixed with small quantities of the carbonates of lime and magnesia, and with not less than 17 per cent, of bitumen and water, and 11 1 per cent, of sul- • Annates des Mines, viii. 631. 70 Dr Colquhoun on the Argillaceous Ore of Iron. phuret of iron. Massive pyrites occurred abundantly in the neighbouring beds, but that which existed in the mineral was in a state of such extreme division, that it could not be obser- ved even with the aid of a magnifying glass. • 5. The last distinct variety of the ore may be made to in- clude all the minute varieties of external form, which are the result of the contact of some organized body, as a fish, a shell, a vegetable. All these are not uncommonly met with. M. Berthier has given a particular description of a specimen of this kind, which aflPected the form of trunks of trees. It was found in a district (departement du Cantal) belonging to an alluvial formation. * It is worthy of remark that in every specimen of this ore, the partial decomposition of the carbonated protoxide of iron, (a process of frequent occurrence,) has the effect of introdu- cing into the composition of the mineral a mixture of the per- oxide of iron or of the hydrated peroxide, according to cir- cumstances. The hydrate thus formed is occasionally met with, prevailing over a considerable tract of country. It is always found to retain the form of the original carbonate, whether that had existed in the shape of bands, nodules, or otherwise. In general it possesses most of the characters of common iron ochre : but, as the transformation of the carbo- nated protoxide into the hydrated peroxide does not seem to occasion any sensible diminution of the bulk of the ore, it is of lighter specific gravity than the genuine hoematites.-f* The infiltration of water, acting in a slow and imperceptible man- ner, seems to be the cause which produces this decomposed form of the ore. There are many localities, however, where the hydrated peroxide of iron is never observed, but where, on the contrary, it is an extremely frequent occurrence to find a portion of a stratum converted into the simple peroxide. We possess the strongest reason for believing that the decomposition of the ore, on all such occasions, has been effected through the agen- cy of heat. Whenever the stratum of ore is observed to have * Journal des Mines, xxvii. 477. •f- Berthier, Sur les mineratix de fer, aj^les mines douces. Ann. des Mines, ix. 82.5. Dr Colquhoun on the Argillaceous Ore of Iron. 71 undergone this alteration, it is very generally found to Lave come into the vicinity of whinstone. And the individual cha- racters of this rock, as well as its geological relations to the strata in which it occasionally makes its appearance, conspire to prove that it has been forced up from beneath in a state of igneous liquefaction, among the minerals which compose the coal formations at some period subsequent to their consolida- tion, and that it has, of course, induced more or less alteration upon them, in proportion to their comparative liability to suf- fer decomposition from the application of heat. The colour of the ironstone thus altered depends both on the extent to which the decomposition had proceeded, and on the nature of the extraneous ingredients which it happened to contain : it varies from red to purple and reddish black. The five subdivisions above described seem to mark the leading varieties which occur in the ironstone. The next point of view in which we have proposed to regard it is its ge- ological character. In this part of the subject we shall confine ourselves to giving a rapid and general delineation of the most prominent features of its history. One of the most striking geological peculiarities of the ar- gillaceous carbonate of iron, is its almost universal occurrence in the immediate vicinity of a stratum of coal. How import- ant this circumstance is to the manufacture of iron, we shall no- tice afterwards in speaking of the smelting of the ore, but at present we shall only remark that so invariable a connexion appears to subsist between the two minerals, that the discovery of the one in any situation, is the surest proof which can be obtained of the near vicinity of the other. In those immense isolated basins, the independent coal formations, which are found scattered throughout Britain, and many parts of the continent of Europe, the argillaceous carbonate of iron is al- ways found to constitute a component mineral. It belongs therefore to that portion of the crust of the earth which has been distinguished by the appellation of secondary. There are some continental mineralogists, indeed, who state that it has also been found occasionally associated with minerals of the transition series ; but if the fact be so, at least no instance of it appears to have yet been met with in this country. 72 Dr Colquhoun on the Argillaceous Ore of Iron. In many respects the geological habitudes of this ore are very analogous with those of the other minerals of which the coal basins are composed : they are distinguished however by some peculiarities of their own. Thus the ore generally occurs in regular strata, more considerable in point of number than extent. In ordinary cases, the strata dip from the directly horizontal position, with a declination varying from one yard in four, to one in ten. But there is no particular angle of in- clination to which they are limited. They are sometimes found lying quite horizontal, and, on other occasions, where the for- mation has undergone some violent convulsion, they suddenly rise up in a direction which is nearly vertical. Faults or dykes also occasionally make their appearance in the strata of iron- stone, as in the other strata which compose the independent basin, and these, without their occurrence being always refer- able to any adequate apparent cause, have the effect of abrupt- ly breaking the continuity of the bed of ore, and of either ele- vating or depressing the whole succession of strata, however they may be composed, on one side of the break, for several hundred yards out of their natural course. In this manner these dykes completely disjoin what seems formerly to have been connected, and severely perplex the miner whose opera- tions are often thereby brought to a sudden and unexpected pause.* It seldom happens that a single stratum of the ore is disco- vered by itself, and apart from all connexion with other beds of ironstone. On the contrary, the strata which occur toge- ther are often very numerous, varying from about ten to thirty or forty, in the same tract of country, but all of them differing both in the chemical and mechanical constitution of the ores • It may be observed that the manner in which the miners use the term di/ke is not strictly accurate, for they apply it indiscriminately to every dis- turbance which takes place in the equable and progressive extension of strata. In its correct application, however, the term is nearly synonymous with vei7i, and denotes a vertical fissure which is filled up with some fo- reign mineral. An abrupt elevation or depression of strata, unaccompanied by the interposition of any extraneous body, is, properly speaking, a slip. The very common occurrence of faults compounded of the slip and d;yke has probably been the cause of these two terms being so frequently con- founded. Dr Colquhoun on the Argillaceous Ore of Iron, 73 themselves, and also in the nature, extent, and relative position of the beds of other minerals which are contiguous to them. Sometimes the several strata of ore have a considerable num- ber of layers of argillaceous schist, as slate-clay, clay-slate, bi- tuminous schale. Sec, or coal, or limestone interposed in every variety of arrangement between them ; and more rarely there are found to be beds of marie, sandstone, indurated clav? &c., which similarly alternate with these strata of ore, and with each other. But it does not always happen that two strata of the ore are separated by any number of interposed minerals, or that they are situated at any distance whatever from each other in the coal formation. They are often found lying the one superimposed immediately upon the other, and yet each completely distinct in its properties and composition. It is indeed impossible to discover any general principle of arrange- ment as prevailing among the various strata which compose the coal basin. In so far as we have hitherto examined, the general geolo- gical character of the iron-ore is completely analogous to that of the other minerals composing the coal formation. There is, however, one very decided and anomalous peculiarity of occa- sional occurrence, which distinguishes it from all the others. It is not always met with in the shape of a continuous strati- fied mass, as the schist, the coal, the limestone occur in their Respective beds ; but on the contrary, it is very frequently dis- tributed in distinct, independent nodules which are found im- bedded, in very different degrees of abundance, in some other mineral. It sometimes happens that these nodules lie in a horizontal position, and at regular distances from one another, forming, in fact, a regular stratum, which is excavated as eager- ly by the ironsmelter as the ordinary uninterrupted strata. More frequently, however, they are disseminated in the most promiscuous manner throughout the whole extent of the stra- tum in which they exist imbedded, and are found abundantly in some parts of the stratum, while in others not far distant, they are altogether wanting. A regular stratification of no- dules is termed a line of balls by the miners ; when irregularly diffused, they are called flying balls or lunkers. The former seem to occur exclusively in argillaceous schist, the latter, for 74 Dr Colquhoun on the Ar^lUaceous Ore of Iron. the most part also make their appearance in schist, but they are occasionally found imbedded in other minerals, such as indu- rated clay, limestone and coal. * A continuous stratum of the ore is termed a hand of ironstone. The bands of ironstone are found to vary in, thickness from half an inch to sixteen inches, but they most frequently run from six to eight inches thick. The balls or nodules have generally a flattened form, and it is invariably observed that the long diameter lies in a direction strictly parallel to the stratum in which they are imbedded. They present themselves of every size from a few inches to four or five feet in horizontal diameter, and rather less than hali* these dimensions vertically. Their weight varies from a few ounces to upwards of a ton. Those of most general occurrence seldom exceed twelve inches in their long diameter. The ex- ternal surface of the balls is smooth, and its predominant co- lour inclines to red. In structure, they are compact, except in those rare cases where they are found to consist of concen- tric lamellae, and which occurs when the exterior portion of the carbonate of iron has begun to undergo decomposition. Upon being fractured, they exhibit nearly the same appearances as the band ironstone. There is a very singular peculiarity which is occasionally observed in these balls of ironstone, and which belongs in an eminent degree to some individual stratifications of them, al- though it cannot be said to be possessed universally by all the nodules situated in any stratum. A considerable quantity of a black-coloured bituminous substance is found to be inclosed within the nodule. This bitumen is soft and slightly elastic. It is destitute of taste, and is inodorous when cold, but emits a weak bituminous odour upon being slightly heated. It burns without leaving any earthy residue, according to an experiment of Mr Mushet. •(• Many balls have been lately excavated in the coal field around Glasgow which contained on examination • I am not aware that balls of ironstone have been met with in Scotland imbedded in coal ; but an instance of this kind, occurring at Anzin in France, is related by MM. Clere and Tournelle in the Annates des Mines, iv. 345. t Philosophical Magazine, iii. 47* Dr Colquhoun on the Argillaceous Ore of Iron. 75 half a cubic foot of this bitumen. Mr Mushet has remarked that the bitumen is of rarest occurrence in those nodules in which the calcareous spar is most abundant. The Hatchetine, lately discovered by the Reverend Mr Conybeare, appears to be a very pure form of this bituminous substance. It was found " filling small contemporstneoua veins lined with calcareous spar and small rock crystals in the iron- stone of Merthyr Tydvil." The most remarkable feature dis- tinguishing it was its colour, which was yellowish-white. It had the external appearance, and many of the mechanical pro- perties of wax ; being soft, inodorous, inelastic, and melting at a very low heat. * Such are the general geological characteristics of the argil- laceous carbonate of iron. On looking at the share which the carbonate of iron occupies in the crust of the earth, it seems susceptible of division into three leading classes. To the first of these may be assigned all those important ores which occur in primitive or transition formations. They are characterized by a crystalline structure, and must all be ranked as varieties of the sparry iron ore. To the second class may be referred the ores which present themselves in the secondary formations. These belong, for the most part, to the coal basins, but strata of them are also found, though very rarely, in the calcareous beds which lie immediately above these formations. They con- stitute the argillaceous ores, which are the peculiar object of this memoir. To the third class remain the very scanty exam- ples of those ores which are found in alluvial districts. It is probable that the ores found in such situations will fall to be classed sometimes along with the sparry iron-ore, sometimes with the argillaceous carbonate. Having now pointed out the general characters of ironstone viewed as a mineral, and subdivided it into its several minera- logical varieties, and having also given a brief notice of its geo- logical history, we may proceed to consider it, in reference to the chemical nature and affinities of the various ingredients which enter into its composition. This indeed is the most im- portant point of view in which we can regard a mineral which * Annals of Philosophy ^ New Series, i. 136' 76 Br Colquhoun o7i the Argillaceous Ore of Iran. may be truly denominated the basis of the most interesting of all our metals, the material for the most important of all our manufactures, and the most powerful instrument in the hands of civilized man for advancing the arts, and for adding to the comforts of the species. It probably has been by an applica- tion of some of the more elementary processes of chemistry, that simple fusion was first employed to extract the iron from the ore in which it was concealed. The manifold uses of the developed metal could not fail to command the continued and eager attention of men, as soon as its extrication was first dis- covered. And a long and careful experience has at length car- ried forward to a stage of very considerable advancement, the art of mingling in the furnace, along with the ores, such foreign bodies as have been found best fitted by their individual or combined chemical properties, for aiding the action of heat, in extricating the pure metal. And besides this, owing to the same power which different sorts of earthy matter possess of mutually fluxing one another, it has been discovered that when two ores, each of which smelted separately would yield its iron with the greatest reluctance, are taken and fused together, they not unfrequently give up the joint product of both their metals with comparative ease. In viewing the ironstone, then, as a subject of the metallurgic art, and in selecting those varieties to each of which the same fluxes will be available, we shall find that it may be subdivided as follows. 1. The pure carbonate of iron. — Under this head, the smelter will comprehend all those ores in which the extra- neous ingredients are too small in amount to be capable in any sensible degree either of favouring or of resisting the liquefying, operations of the blast-furnace. It is rare to met with ores thus constituted ; for they are generally combined with some earthy ingredient requiring a peculiar flux. Of these extrin- sic bodies the most common are bitumen or coal, sand, clay, lime, and magnesia. But the sand or clay frequently occur not singly, but mixed with large proportions of carbonate of lime ; and all these three substances are often found united with a very considerable amount of bitumen. According to the manner in which the ore presents itself, as combined with Dr Colquhoun on the Argillaceous Ore of Iron. 77 one or other, or with several of these substances, it assumes a different character in the eyes of the ironsmelter, and must be differently treated by him in respect of the preparatory calci- nation and the appKcation of his fluxes. There are still other occasional constituents of the ore which are fortunately of comparatively rare occurrence, but which bear so very decided a character in their effect on the operations of the iron manufac- turer, that it is indispensable to take some notice of them here. These are sulphur and phosphorus. Keeping in view these ingredients, as each of them constituting a distinct class of ironstones, according to its predominance, we shall find that the ore must be divided into the following classes. Besides first, the pure carbonate of iron, the preponderance of bitu- men or coal will form the second class or hituminoits carbonate of iron. When sand is the principal ingredient, as this re- quires to be treated with a pecuUar kind of flux, it will form a third class, the siliceous carbonate of iro7i. If clay be a large constituent of the ironstone, for the same reason, it forms a fourth class, the argillaceous carbonate of iron. This is by far the most abundant variety of the ore; and when the amount of clay Hes within moderate limits, it affords a cast- iron of excellent quality. As the same set of fluxes act, with nearly equal effect upon lime and upon magnesia, and be- sides, as the carbonate of magnesia, when it occurs in the ore, is almost invariably accompanied by carbonate of lime, these two constituents, which are both alkaline earths, may be said to possess but one character, and to form, in re- gard to the metallurgist, but one class of ores, the fifth in the present order, and which may be called the calcareous carbo- nate of iron. When it happens that several of these extra- neous substances enter into the composition of the mineral, a different mode of treatment by the smelter is required, and new classes of the ore are thereby formed. These seem to be fitly described, according to the respective preponderance of the mixed ingredients, and form, sixth, the calcareo-siliceous, if sand be the principal and lime the secondary constituent ; seventh, the calcareo-argillaceous, if clay hold the place of the sand in the previous blass ; eighth, the bitumino-siliceous, if coal or bitumen be the ingredient that is associated in the ore 78 Dr Colquhoun on the Argillaceous Ore of Iron. with the sand; ninth, the bitumino-argillaceous ; and tenth, the bitumino-calcareous, — terms which sufficiently expdain their own meaning, in conformity with the foregoing nomen- clature. To the eleventh and last class, belong the sulphure- ous and phosphorized ores, or those whose constitution, what- ever it may be in other respects, is contaminated by the presence of sulphur or phosphorus. These are the leading classes into which the ore of iron may be divided when it is regarded as a subject of manufacture. And as we have already endeavoured to give a mineralogical and geological account of this ore, we shall not dwell \ong(*r upon the first of the crude materials used in the smelting of iron, but shall proceed to examine the nature of those which remain. These are fuel and limestone. Section 2. — On Fuel and Fluxes. . After examining the nature of the ironstone, which is the sub- ject, and the basis of the iron smelter's manufacture, the class of crude materials still remaining to be considered, consists of those with which he treats the ore, for the purpose of detaching its me- tallic ingredient. This class is composed of fuel and fluxes. By the application of the first of these, the oxide contained by the ore is reduced to the metallic state. But this process of re- duction constitutes only a single stage in the course of the ironsmelter's operations. The iron thereby developed re- mains dispersed, in small particles, throughout the substance of the ore ; and even the intense heat of the blast-furnace would prove inadequate to combine these particles together, and extricate the solid metal in a united state, unless some thing more than mere fuel were employed. It is necessary to bring the earthy matter, with which the metallic particles are intimately intermixed, to a state of thin fusion and liquidity, before they can associate into small masses, and then, by their superior specific gravity, subside together to the bottom of the furnace. But as there is generally one earthy ingredient, the amount of which is greatly predominant over the others in each ore, and as all the simple earths, and even the greater number of their binary mixtures are infusible by the heat of the blast-furnace, it is necessary for the smelter to call in the lud of some other agent for the purpose of reducing them to Dr Colquhoun on the Argillaceous Ore of Irmt. 79 a state of liquidity. Every substance resorted to with this intention is termed in the metallurgic art, ,most severe tests to which this telescope has been at present submitted. Polaris appears a beautiful picture of a sun and planet. The small star in Aldebaran is so bright as to be seen the instant that the eye is applied to the telescope. The small star in a Lyrse is a little less obvious, but still distinctly visible, s Persei is seen very clearly double, as is also w AurigcB and the double star 5 Aquarii is so well-defined, that no question can be entertain- ed as to the inequality in the size of the two stars, although this has been hitherto considered rather doubtful. I hope soon to be able to submit this telescope to more numerous and severe tests. I have omitted to state, that the highest power I have yet used is Jour hundred, — I remain, Dear Sir, your's truly, Peter Barlow. Woolwich, November, 19 1827. Art. XV. — Notice respecting the Varnish and Varnish Trees of India. Having received from George Swinton, Esq. of Calcutta, in India, very considerable quantities of the Indian black varnishes, viz. the varnish of Sylhet, and the varnish from Rangoon in the Burman empire, for the purpose of ascertaining their qualities, and their applicability to the arts of this country, we are desirous of laying before our readers the information respecting these va- luable substances which was sent along with them, and an ac- count of some observations which we have made upon them. In the years 1755, 1756, and 1757, a good deal of interest was excited respecting the varnish trees of the East, in conse- quence of a discussion which took place in the Philosophical On the Varnish and Varnish Trees of India. 97 Transactions between the Abbe Mazeas, Mr Philip Miller, and Mr John Ellis. Mr Miller was of opinion that the Caro- lina toxicodendron was the same plant with that which Ksemp- fer describes as yielding the varnish of Japan, but Mr Ellis seems to have proved very clearly that this was not the case. This shrub is known in Japan by the name of Sitx, or Sitz- dju, and was chiefly cultivated in the provinces of Tsi, * KocTao, and Fijo. According to Kaempfer it is thus obtained. They first slit the bark of the branches of the shrub in different pkces with a knife. From these wounds there flows out a white clammy juice, which soon turns black when ex- posed to the air. The same juice is contained in the leaves and stalks of the plant. This juice has no other tasteable quality but that of heating without turning sour ; but it is dangerous to handle, being of a poisonous nature. When they make these incisions in the branches of the trees, they place wooden vessels under them to receive the juice as it drops from the wounds ; and when these become dry, and will afford no more juice, they make fresh wounds in the stems of the shrubs near the roots, so that all the juice is drawn out of them. They then cut down the shrubs to the ground, and from the stock new stems arise, which in three years are fit to tap again. This native varnish scarcely wants any prepara- tion, but if any dirt should happen to mix with it, it is strain- ed through a coarse gauze to cleanse it. It is then put into wooden vessels, covering it with a little of the oil called toi, and stretching a skin over it to prevent it from evaporating. Kaempfer then goes on to state, that other sorts of varnish are collected in Siam, Corsama, &c. inferior in quahty, and pro- duced by other plants ; but one of the best he says is pro- duced from the Anacardium, or Cashew Nut tree. This lat- ter varnish he says is used without any mixture for staining black. The Sylhet varnish which we have received from India was made to order for Mr Swinton. It consists of two parts of the juice of the Bhela, (the Seme-Carpus anacai^dium, the tree w^hich bears the marking nuts of India,) and one part of * May not the name of Tsi-tzi given to the Rangoon varnish have been originally applied to the varnish from Tsi or Sitz-Tsi ? VOL. VIII. NO. I JAN. 1828. G 98 On the Varnish and Varnish Trees of India. the juice of the Jowar. The articles varnished with it at Sylhet are of the most beautiful glossy black, and it seems equally fitted for varnishing iron^ leather^ paper, wood, or stone. It has a sort of whitish gray colour when first taken out of the bottle ; but in a few minutes it becomes perfectly black by exposure to the air. In the present temperature it is too thick to be laid on alone, but it may be rendered more fluid by heat. In this case, however, it is too clammy, and seems to dry very slowly. When diluted with spirits of tur- pentine it dries more rapidly, but still with less rapidity than is desirable. The Tsi-tsi, or varnish of Rangoon, is less known than the Sylhet varnish. Mr Swinton considers it to be made from the juice of the Bhela, or Seme-Carpus anacardlum alone. It appears to have the same general properties as the Sylhet varnish, but dries more rapidly. The varnish from the Kheeoo, or varnish tree, may be the same as the Rangoon varnish ; but it is at present considered to* be different. The Kheeoo grows particularly in Kubboo, a valley on the banks of the Ningtee, between Munnipore and the Birman empire. It grows to such a large size, that it affords planks upwards of three feet in breadth, and in ap- pearance and grain it is very like mahogany. A British officer who travelled through Kubboo in the beginning of the present year, and an abstract of whose journal is now before us in MS., gives the following account of the method of obtaining the varnish from the Kheeoo. " The Sepoys felled a Kheeoo, or varnish tree, at Mure, of which I took the measurements as follows : Height to first branch, - - - 42 feet. From lowest branch to extreme of top one, - 18 Diameter when hewed, - - 2J Circumference of do. - - 7$ This, comparatively with others of the same species, is a small tree. I measured the circumference of one, which, near the ground, was thirteen feot. I had an opportunity of ascer- taining the process of extracting the varnish from the tree, which is by making incisions in several parts of the trunk, to which choonghas are fastened so as to receive the varnish On the Varnish and Varnish Trees of India. 99 which oozes from them. The incision is only through the bark. The choonghas are allowed to remain two days. One tree affords about a gallon. The varnish is extracted annually from each tree at the commencement of the rains. No after preparation is required to render it fit for use. The tree is at present (Jan. 17th, 18^-7) in blossom. The bark is nearly the same as the bark of the Saul, but somewhat lighter in colour. The leaf resembles that of the horse-chesnut more than any other I can recollect."" The varnish tree of Martaban, which we presume must be the same as the Kheeoo, has been particularly examined by an eminent botanist, Avho gives the following account of it : " The varnish tree is found in great plenty and perfection at Martaban. The tree is very distinct not only in species, but genus, from the varnish tree of Sylhet, and that of the Malay Archipelago, China, and Japan. It has been named Melan- orhea usitatissima, and a very fine object it is, especially when in fruit, the latter being supported by five or six spread- ing red and very large wings. The varnish, when good and fresh, is of a rather pale rust colour, which by exposure to the air becomes jet black." Before concluding this notice, we shall give an account of some observations which we made upon the constitution of the Sylhet and Rangoon varnishes, in order to determine the change which takes place in them when the colour passes from a whitish brown to a deep black. A small quantity being put between two plates of glass, the plates were pres- sed together till the thin film of varnish which they enclosed was translucent. Upon examining this film with a power- ful microscope, it was obvious that the fluid was not a ho- mogeneous one, but was organized, and consisted of an im- mense congeries of small parts, which exhibited the finest ex- ample of mottled or striated colours. These particles dis- persed the sun's rays in all directions like a thin film of un- melted tallow, or like organized fluids, such as the blood and milk. After standing two days exposed to the action of the air, I found that the portions which the air did not reach, viz. that between the glass plates, exhibited the same constitution as 100 On the Poisonous Qualities of the before ; while that which was squeezed out between the glasses, and on which the air freely acted, had become of a fine colour like that of treacle. I now placed this portion between two plates of glass, and found, to my great surprise, that the or- ganized structure of the fluid was entirely gone, that it ^as perfectly homogeneous, and showed the sun of a beautiful red colour, as when it is seen through a thin film of pitch, or through a darkening glass. The action of the air had com- pletely disorganized the vegetable juice, and reduc-ed it to a state of homogeneous fluidity. The application of heat seem- ed to accelerate this organization ; but I have not been able to produce the same eff'ect by the action of heat upon the var- nish when not exposed to the air. We now opened one of the Bhela nuts, the fruit of the Seme-Carpus anacardium, and found that the juice of it when placed between plates of glass, was nearly as homogeneous and transparent as the Rangoon varnish when acted upon by the air. There were, however, small portions of it which ex- hibited an organized structure. Abt. XVI. — Account of the Poisonous Qualities of the Vege- table Varnishes from India and America. Having experienced and witnessed in more than one case the singular effects produced upon the human body, by a poisonous vapour which is exhaled from the Sylhet varnish, we have been induced to collect the information which the ex- perience of others has already made known. This information, however, had ceased to be of any use, for the varnishes in question are supposed, even by our country- men in India, to be devoid of any noxious quality. We are informed by Mr Swinton of Calcutta, that the Munni- poores who were lately in that city, when questioned respect- ing the Kheeoo varnish, described it as of a poisonous nature, causing the hands and face to swell, and producing an intoler- able itching. A British officer then in Munipoore denied the truth of this, and stated that the varnish was perfectly harmless, being always laid on by the hand. Although the Munipoores were not likely to be mistaken in a matter which must have Veoetable Varnishes from India and America, 101 frequently come under their observation, yet it never occurred to me that the poisonous qualities which they ascribed to the Kheeoo varnish were likely to belong to the Sylhet varnish ; and I accordingly made numerous experiments with the latter, without any suspicion of its possessing deleterious properties. Having laid it in its undiluted state upon part of an iron rail- ing, a maid servant accidentally rubbed her arm against it. In one part of the arm touched by the varnish the skin was at the same time slightly ruffled, but on other parts touched by the varnish the skin was perfectly sound. In a few days all these parts were inflamed, and became extremely itchy. A con- geries of angry pimples followed, which were hard at their base and extremely red. These pimples have remained more than three weeks without healing ; and what is very strange, fresh ones have appeared on parts of the arm which the var- nish never touched. One of my sons, who had been the principal operator in put- ting the varnish on the iron, and who from the coldness of the weather was obliged to render it fluid by holding it above the fire, was thus peculiarly exposed to the vapour exhaled from it when hot, and also during the time that he was laying it on. A few days after, his hands, which the varnish had never touched, were covered with red pimples, exactly the same as those already described. The effect gradually extended up his arm, and in two days afterwards his face and eyes were swelled to a most alarming degree, both cheeks being a mass of small red pimples. The itchiness was intolerable, but there was neither fever nor pain, and the swelling disappeared after six or seven days. We at first ascribed these effects to the nettle-rash ; but after reading the account given by Dr Joseph Papa of the effects of the Indian varnish, and Comparing the pustules with those on the arm of the maid-servant, there could not be the least doubt that the varnish was the cause of the disease. The account now referred to was drawn up in 1701 by Dr Joseph del Papa, physician to the Cardinal de Medicis, and was communicated to the Royal Society by the celebrated bo- tanist Dr Sherard. The following is an abstract of it. " The using and handhng of the Indian varnish, while lay- lOS On the Poisonous Qualities of the ing it on objects to be varnished, having produced such extra- ordinary effects on Signior Ignatio, and more remarkably on his maid-servant, viz. great swellings of their heads and eyes, and in their arms, and indeed almost their whole body, with an intolerable itching, inflammation and pimples, is so new and extraordinary as to call forth our wonder and curiosity. There are indeed some juices of roots and herbs, which by touching our flesh either inflame or ulcerate it, or produce swellings, pustules, and itchings ; but all these cause the disorder only where they touch, and do not spread their invisible venom over other parts of the body. In short, I know not an instance of any one thing, which, either touched with the hand, or in-/ sinuating itself by its fumes into our body, is able to produce almost over the whole skin inflammations, swellings, itchiness, and pustules, as if the whole body were stung with an infinite number of wasps, for such are exactly the effects produced by this varnish. ^' This varnish exerts all its malignity against the skin, the viscera and blood being untouched ; besides, I observed that the maid, at the same time that almost her whole skin was hard, inflamed, swelled, and full of pustules, had yet no fever, no pain in the head, nor any inward illness. This varnish, there- fore, is only an enemy to the skin ; and that this mischief should attend it, it is not necessary that the varnish should be heated, for when cold it emits the same steams, which insinuate themselves into the body, especially when touched and hand- led. " I have several times spread a great deal of this varnish hot upon the naked skin of poultry, and they never received any hurt from it either internal or external. I have caused other fowls to swallow crumbs of bread steeped in the varnish, and they seemed to like it very well ; others I have pricked in the heart till the blood came, and then anointed it all over with varnish, which, instead of hurting them, proved a balsam to heal them. Having once, however, spread some of it on the naked breast of some fowls, leaving it sticking there for three days, I afterwards found between the dried varnish and the flesh, the place all festered, and full of a yellowish serum, but with- out any further harm. I have attempted the same thing on Vegetable Varnishes from India and America lOB dogs and cats, but without success, for these animals with their tongues and claws soon take off all the varnish from their bo^ dies, and take no hurt by it." The poisonous qualities of the Japan varnish are mentioned also by Kaempfer, who states that it exhales a poisonous va- pour, which occasions great pains in the head, and causes the lips of those who handle it to swell ; on which account the ar- tificers when they use it are obliged to tie a handkerchief over the nose and mouth to prevent these effects. Although the Poison Wood tree of New England, the Rhus vernioc of Linnaeus, is different from the varnish trees of India, yet it resembles them in its poisonous qualities. The Honourable Paul Dudley informs us that it poisons two ways, " either by the touching or handling of it, and that its scent when cut down in the woods, or on the fire, has poisoned persons to a very great degree. One of my neigh- bours was blind for above a week together with only handling it, and a gentleman in the country, when sitting by his fireside in the winter, was swelled for several days with the smoke or flame of some poisonous wood that was in the fire. It has this effect only on some particular persons and constitutions, for I have seen my own brother not only handle but chew it without any harm at all ; so that by the sAme fire one shall be poisoned, and another not at all affected. But this sort of poison is never mortal, and will go ofi' in a few days by itself like the sting of a bee ; but generally the person applies plantain water, or sal- lad oil and cream. As to its operation within a few hours after the person is poisoned, he feels an itching pain that pro- vokes a scratching, which is followed by an inflammation and swelling ; sometimes a man's legs only have been poisoned and have run with water."" Dr William Sherard, in describing the same tree, states, that the wood is as cold as ice, and that when laid on the fire, out of five or six persons sitting by it, some will swoon, faint, or yawn, continuing so for some days, others but a few hours, and others of the company not at all. I handle, says he, cut, and burn it with impunity, and so it is with several others, I suppose according to their constitutions. It was never known to kill any body, but only to do hurt to some persons.'' 104 Dr Grants Ohservatimis on the , In treating of the different species of Rhus which were sup- posed to resemble the varnish tree, Mr Ellis mentions " that the Rhus Shiense, when first it began to extend its leaves in the small stove, had so remarkably a disagreeable smell, that he frequently complained of getting the headache, and a sickness of his sto- mach, by remaining too long near it ; and after it was removed into the great stove, where, notwithstanding that building was very spacious, and near twenty feet high, yet, as it grew most luxuriantly, we could not without pain continue long near it." Art. XVII. — Observations on the Generation of the Lobii- laria digitata^ Lam. (Alcyonium lobatum, Pall.^ By R. E. Grant, M. D., F. R. S. E., F. L. S., Professor of Zoo- logy in the University of London. Communicated by the Author. In various observations and experiments on the structure and economy of Zoophytes found inhabiting the Frith of Forth, I have already shown that in many silicious, calcareous, and horni/ species, theminute reproductive gemmules by which these animals propagate, are highly organized portions of the gela- tinous substance of the parent, which possess the power of swimming freely to and fro, for a considerable time after their separation, by the rapid vibration of very small ciliae covering their surface. Although I had not an opportunity of observ- ing this singular phenomenon in any zoophyte which discharges its ova through the bodies of polypi, I was induced from analogy to believe that the motions observed by Cavolini in the ova of the Caryophyllia and Gorgonia, which are discharged through po- lypi, were produced by similar organs, and that these organs in the same situation are probably of much more general occurrence in this class of animals than has yet been observed. During the month of October I procured some specimens of the white variety of Lobidaria digitata from the Frith of Forth, with their ova in a state of maturity, which afforded me the means of observing the process of generation, not only in a species whose ova pass through polypi of a very complicated struc- ture, but also in a zoophyte with Sijleshy and contractile axis, Generaticm of the Lohularia digitata. 105 differing much from those I had already examined. Both the red and white varieties of this animal of various shades of in- tensity, are found in every part of the Frith of Forth from this to the opposite shore, adhering in large masses to stones, shells, and fuci. At low water we observe it hanging in nu- merous fleshy lobes from the under and sheltered surface of rocks ; after storms, quantities of it are often left on shore, adhering to marine plants and animals which have been torn from their seat; and by accompanying the dredgers daily em- ployed in the Forth we constantly find it brought up by the dredges from deep water, spreading on all kinds of solid sub- stances lying at the bottom, as broken bottles, glasses, shells, &c, Jussieu examined the structure of this animal with the mi- croscope, on the coast of Normandy, more than eighty years ago, and has given accurate representations of many parts of its structure (Mem, de VAc. 1742. J. Mr Ellis, who mentions it as occurring in great plenty round all the coasts of the Bri- tish islands, has given many excellent figures illustrating its internal structure, the appearance and situation of its ova, and their mode of passing out through the bodies of the polypi (Phil Trans, liii. PL XX.J. He has placed groups of 5 — 8 loose ova in each of the canals below the polypi, and similar groups in the transparent bodies of the polypi below the stomach, which are represented passing up one after another towards the mouth. It is to be regretted that he has not left a full description of the interesting appearances represented in these figures. Dr Spix of Bavaria, without noticing the accurate and elegant plates of Mr Ellis, and with a low esti- mation of the labours of our distinguished countryman, has given several figures to illustrate the mode of generation of the Lobularia (Ann, du Mus, L xiii. PI. XXXI 11.^, which differ as much from nature as they do from the plates of his prede- cessor. He has represented the head of the polypus as con- sisting of a large round vesicle or stomach, to the sides of which are closely applied eight thick cylindrical claviform ten- tacula covered with minute papillae; descending from the stomach he has represented a long narrow tapering tube, and the ova are placed in a single line, inclosed in a small curved canal, like a string of beads. His observations correspond 10ft Dr Gram's Observations on the with his figures. He states that the tentacula appear to be filled with globules of air ; that the polypus can withdraw the tentacula into its mouth ; that the body of the polypus is not thicker than a hair ; and that the polypi die contracted. He mentions also that each of the round red globules which are discharged through the mouth, is an ovarium, containing, within a distinct capsule, a multitude of small eggs hke those of a fly, an appearance which he has represented in the figures, and he is thence led to inquire whether all zoophytes may not in the same manner be oviparous. It is singular that this author commences his observations by stating that Mr Ellis generally mistook the ova of zoophytes for ovaria, an error which he has not shown to belong to the great British zoophy- tist, but which he has himself obviously committed with re- gard to the Lobularia. Lamouroux has corrected some of the errors of Spix, and has given elegant magnified figures to illustrate the anatomy of the polypi of this animal, (Hist, des Pol. PI. XI 11.^ ; but as he examined the Lobularia only in .spring, he could detect no trace of ova or ovaria in its struc- ture, and was therefore unfortunately prevented from throw- ing any light on this interesting part of its economy. On laying open the white Lobularia in the direction of its canals; I found in all these cavities numerous small red-co- loured spheres of a regular form and soft consistence, and about the fifth of a line in diameter. Many of them much smaller, and of a white colour, adhered to longitudinal white lines at the upper end of the canals. There were several of these lon- gitudinal rows of ova at the base of each polypus, and most of them were connected by peduncles or tubes to the white lon- gitudinal folds of the canals. The smallest had the strongest connection, those of a larger size were connected only by a slender filament, and the largest red ova were quite free. The white folds to which the ova adhere, are continuous with the eight longitudinal folds seen within the polypi. There were generally about twenty small white ova in each canal, besides ten or twelve perfectly formed, and of a red colour. Most of the mature ova were collected together near the basis of the polypi, where they were quite loose, of a deep red colour, and of a larger and more equal size than those attached to the Generation of the Lobuluria digitata. > 107 folds of the canals. Their appearance closely resembled the figures of Mr Ellis ; they were quite visible to the naked eye, and when a section of the animal was placed in water the red ova fell out separately, and sunk slowly to the bottom. -The red colour of these ova is mentioned by Dr Spix, the ova of the Gorgonia and Madrepore have a red colour, and the ova of the Medusa aurita, Lin. are described by Dr Rosenthal (Zeitsck. fur Phys. i. B. s. 328.) as round bodies of a red co- lour, and somewhat lengthened form, which " in their mature state move backwards and forwards in a lively manner without altering their form." The ova of the Lobularia exhibited va- rious shades of colour, from white to deep red, according to their size and maturity. By pressing the red ova between the forceps they were found to consist of a distinct transparent membranous capsule, filled with a gelatinous matter, which ap- peared under the microscope to be composed of the same small globules or monade-like bodies which compose the ova of other zoophytes, and almost all the soft parts of animals. They did not produce the slightest effervescence in nitric acid, al- though every part of the fleshy substance of the adult Lo- bularia contains calcareous matter. By remaining a few days in spirits, or in fresh water, the ova entirely lost their red co- lour, and assumed a yellowish- white appearance even in the centre of entire lobes. After a specimen of the animal had remained for some hours suspended in its natural vertical postion in a crystal jar filled with pure sea-water, and its polypi, had fully extended them- selves, I was delighted to find the large red ova beginning to descend from the interior of the canals into the transparent bo- dies of the polypi, where I could easily observe their progress with the aid of a lens, through the sides of the glass vessel. They advanced slowly and only when the polypi were distend- ed. In the space of twenty-four hours ova were seen in the bodies of most of the polypi ; some polypi had only one, several had two or three, and in others groups of four or five ova were observed together placed without any regular order. Many of the polypi had no ova, in others the mouth was seen distended with a single ovum in the act of being discharged, and a few ova were found lying separate at the bottom of the jar. All 108 Dr Grant's Observatio?is on the those which had descended into the bodies of the polypi, and those found loose in the jar, were of the full size and deep-red colour. None of the imperfectly formed white ova were detach- ed from the sides of the canals, or seen in the polypi. I collected carefully the loose ova from the bottom of the jar, and on placing them in a watch-glass with sea-water I could perceive with the naked eye that they continually changed their situations, gliding to and fro with an almost imperceptible mo- tion. Viewed with the aid of a lens, their motions were ob- vious ; they were seen to contract themselves frequently during their progressive motions, and sometimes they appeared revolv- ing round their axis. When placed under the microscope, and viewed by transmitted light, they appeared as opaque spheres surrounded with a thin transparent margin, which increased in thickness when the ova began to grow, and such of the ova as lay in contact united and grew as one ovum. A rapid cur- rent in the water immediately around each ovum, drawing along with it all loose particles and floating animalcules, was distinctly seen flowing with an equal velocity as in other cilia- ted ova, and a zone of very minute vibrating ciliae was per- ceptible, surrounding the transparent margin of all the ova. The progressive motion of the ova, always in a direction con- trary to that of the current created by their ciliae, was very obvious, though less rapid than in any other zoophyte in which I have observed the same remarkable phenomenon. The specimen suspended in the glass jar filled with pure sea- water I now brought so close to the transparent side of the vessel, that I could examine through it, with the assistance of a powerful lens, and without disturbing the animal, the mo- tions and progress of the groups of ova passing through the colourless bodies of the polypi. To the naked eye at first sight all appeared motionless. The deep vermilion hue of the small round ova, and the colourless transparency of the outer covering of the polypi, formed a beautiful contrast with the pure white colour of the delicate longitudinal folds, the central open canal, and the slender filaments which wind down from its sides towards the clusters of white ova at the base ; but the living phenomena discovered within were even more admirable than tlie beautiful contrast of colours, the Generation of' the Lobular ia digitata. 109 elegant forms, and the exquisite structure of all the parts. When observed with a lens the ova were seen to be in con- stant motion, and quite free within the bodies of the po- lypi. They moved themselves backwards and forwards, and frequently contracted their sides, as if irritated or capable of feeling. I could observe none passing upwards between the stomach and the sides of the polypi. They never assumed the appearance of a string of beads inclosed in a narrow shut curved tube, as represented by Spix,Jbut swam freely in the water which distended the polypi, as figured by Ellis. Their motions in the polypi, though circumscribed, were so incessant, that by watching attentively I could observe them with the naked eye, and they became more conspicuous as the ova advanced to the open base of the stomach. From their restlessness, as they approached that last passage which separates them from the sea, they seemed to feel the impulse of a new element, which they were impatient to enjoy, and by following the direction of that impulse they appeared to find their way into the lower open extremity of the stomach, without any organic arrange- ment to lead them into that narrow canal. In their passage through the stomach, which was effected very slowly, the spontaneous motions of the ova were arrested, unless some im- perceptible action of their ciliae, or some contractions of their surface, might tend to irritate the sides of that canal, and thus direct or hasten their escape. The clusters of ova found in autumn at the base of the polypi of the Lobularia, have no relation to the ovaria of higher animals. They are true gemmules or buds which grow from the sides of the internal canals ; they are nourish- ed by umbilical cords ; they fall off and escape when mature ; and, as in other zoophytes, they leave no trace of their exist- ence behind. Their spontaneous motion establishes the exist- ence of this remarkable property in a tribe of zoophytes with a fleshy axis, where it had not before been observed, and opens to our contemplation a new and singular arrangement for aiding and directing the passage of these delicate reproductive globules, through the complicated bodies of animals where irri- tability is nearly extinct. It would be highly interesting to trace how far up in the scale of animals this simple arrange- 110 Mr King'^s apparaUisfor impregnatmg liquids mth gases. ment takes place to facilitate the exit of the embryo from the inert body of the parent. The above remark of Dr Rosen- thal respecting the Medusa, shows that it takes place in the class of Radiated animals ; and I have shown in a former num- ber of this Journal (No. xiii. p. 121.), that in the class of Molluscous animals, the escape of the foetus from highly com- plicated ovaria, as those of the Buccinum, is effected in like manner by the rapid vibration of ciliae placed on the surface of the young. The transformation of the ova above described, from their moving, irritable, and free condition of animalcules, to that of fixed and almost inert zoophytes, exhibits a new metamorphosis in the animal kingdom, not less remarkable than that of many reptiles from their first aquatic condition, or that of insects from their larva state. Ulvae and confervae have been seen to resolve themselvesinto animalcules, (Schweig- ger^s Beobacht. auf N. R, s. 90. J, and Professor Aghard has seen these animalcules reunite to construct the plants. Mosses and Equiseta are found to originate from confervas, (Mem. du Mus. tom. ix. p. 283.^, and all the land confervse with radi- cles appear to pass into the state of more perfect plants. The Oscillatoriae which cover the stones in our fresh water pools with a green and velvety crust, resolve themselves into ani- malcules and lively moving filaments, whose motions have been described by Saussure, Vaucher, and others. The glo- bules of our blood have been seen to arrange themselves in- to fibres, (Phil. Trans. 1818. p. 112.), and the densest fibres have been resolved into their regular component globules. But few known changes in the vegetable or animal kingdom are more singular than that which the ova of zoophytes present in passing from the state of lively, free, and spontaneously moving bodies, to that of fixed horny roots, or equally inert calcareous cells. Art. XVIII. — Description of an Apparatus for ImpregnfiU ing Liquids with Gases. By James King, Esq. Commu- nicated by the Author. In the year 1820 I had the pleasure of suggesting to Dr Hope the construction of an apparatus for impregnating liquids with I On the Assamese Method of Blasting Rocks. Ill * gases. That eminent chemist had one of them made for his own use, and another was executed for Dr Fyfe ; but as no account of it has yet been published, you would oblige me by insert- ing the following brief description of it in The Edinburgh Jour^ nal of Science. The advantages of this apparatus are, that it does away with bent tubes and luted joints of Woolfs, all of which can be ground with ease. The liquid to be impregnated is advantageously exposed to the gas. As there are no lutings, it can be put up and in action in a few minutes, and as quick- ly dismounted ; and not at all liable to derangement. In Fig. 2. Plate III. A is the retort; B the receiver for the condensable part of the product ; C contains the liquid to be impregnated, which is filled up to the dotted line D ; E is a vessel open at the bottom, into which the liquid ascends during the action of the apparatus ; F is to keep up pressure on E, when the stopper is out ; G is a conical stopper to increase the pressure on the whole. A stop cock at H would be very convenient, to ex- amine a little of the liquid as the operation goes on. This can be introduced at G ; and if the safety tube described in the last number of this work were applied at the top, in place of the conical stopper at G, it would render it more complete. Art. XIX. — Account of the Assamese Method of Blasting Jiocks. Communicated by a Correspondent in India. An Assamese stone-cutter has shown me a mode of blasting rocks, which I think superior to any thing practised in Eng- land, and you may perhaps consider it worth communicating to The Edinburgh Journal of Science. The old mode of ram- ming has you know been superseded of late by the use of loose sand poured over the powder ; but whatever may be the case with the softer description of rocks, I have always failed in this way here, except in one instance, probably owing to the ex- cessive strength and hardness of the granite and primitive greenstone, on which the experiment has been tried at least a dozen of times, and in holes nearly a foot deeper than is stated to be necessary in the Supplement to the Encyclopcedia and Philosophical Magazine, where the method with sand is de- scribed. The following is the result of the Assamese plan. 112 On the Horary Oscillations of the Barometer at Rome. A hole was bored about twenty-six inches deep and one and a- half inch diameter in a large block of greenstone. It was tried to blast this rock with powder and loose sand, and the latter was blown out. The same charge of powde)- was then put in, and the mouth of the hole closed with a wooden plug about five inches long, with a touch hole bored through it, and driven into the aperture with a mallet. Between the powder and the lower part of the plug an interval of several inches was left, and the communication was perfected by means of a tin tubule filled with powder, and passed through the centre of the plug. On firing it the rock was rent in every direction to the distance of four feet, and several large pieces were detached, one of them weighing fully a ton. The advantages are, that the plug is as safe and more efficacious than the sand, and that with it the force if it goes out may easily be replaced, whereas with sand it becomes necessary to have recourse to the tedious operation of again scooping out the contents of the hole as far down as the charge of powder. The only time I succeeded with sand was when the hole was bored near the ex- terior edge of the rock, and then a slice was cut off. It may be proper to mention that the sand used was the ordinary kind procurable from the river banks, and rather fine-grained. I think it is probable that the method above explained would be applicable to bursting or rendering cannon unserviceable. The great effect produced is, I conceive, chiefly owing to the interval left between the charge of powder and the plug, as it is well known to sportsmen that a gun will certainly burst as the barrel opens, if a ball or charge of shot be not properly rammed down. Art. 'SJL.'^Memoir on the Horary Oscillations of the Ba- rometer at Rome. Communicated by the Author. Amongst the various branches of the science of meteorology few have been so little investigated as the horary variations of the barometer ; and indeed till lately so little has it been at- tended to, that in few meteorological essays or treatises which I have seen has it been noticed, and in still fewer has it elicit- ed facts or discmsions proportioned to its interest and singu- On the Horary Oscillations of the Barometer at Rome. 113 lavity. The principal hints on the subject which I have seen are contained in Nos. iv. and viii. of The Edinburgh Jour- nal of Science, and in Mr Daniell's admirable essays, particu- larly the last edition. In the course of the hourly observations which I made at Rome on the 15th of January last, and formerly transmitted to this Journal, the horary changes which took place on the mercurial column that day led me to believe these oscillations to be much more regular and better defined than the sequel proved to be the case. Stimulated by this conviction, in the beginning of Febru- ary I commenced a series of observations to be made each day as frequently as convenience would allow, which I continued every subsequent day of my residence in Rome. Those who do not travel with a professedly scientific aim too often find their limited residence in any particular place so much occu- pied by the new scenes daily presented to them, that no time is left, even if they had the inclination, to institute any thing like a series of regular experiments ; and hence, to the detri- ment of science, we find that little or nothing is derived from those who, enjoying the advantages of visiting various cli- mates and latitudes, might make the most important physical investigations. As a traveller, then, I must make this my apology for whatever barrenness may be found in these obser- vations, made during a limited residence in the ancient mis- tress of the world, where so much tends to divide our atten- tion and withdraw it from abstract speculation. At Rome my business was to mahe the observations which lay by for re- duction at a future period. During fifty-four days of residence in February, March, and April, about 470 observations have been made with the data of thermometrical correction for each. When on my return to Scotland, I reduced all these results with the utmost accuracy into the form of tables ; and when I came to determine the value of the several quantities, I regretted to find that the sums were considerably irregular, and did not rise and descend with the same steadiness from hour to hour as any one day's observations within the tropics might have exhibited ; and I was led to believe that the num- ber of data I proceeded on was not sufficiently great or regu- VOL. Viri. NO. 1. JAN. 1828. ' ' .B ' 114 On the Horary Oscillations of the Barometer at Rome. lar to separate the small diurnal changes from the mass of adventitious variations of pressure which we experience in the temperate zone. I afterwards noticed that some additional results, included with the rest by rather a circuitous operation, (with a view of enabling me to include the whole of my obser- vations) appeared to increase these discrepancies ; I shall there- fore give the results obtained both with and without these sup- plementary numbers ; but more of this when we come to the table of final reductions. When I found that my computations did not produce such clear results as I had hoped, I was tempted to relinquish the idea of ever presenting them to the public ; and I may be al- lowed to state, in a few words, why I now hazard them for insertion in this Journal, "[st, then, from the very imperfec- tions of this branch of science, and the discrepancies which evfery where occur in the best journals of barometrical oscilla- tions in the more northern latitudes, I am bold enough to hope that these observations as they stand may add a faint glimmering to the weak light already thrown upon this phe- nomenon. Sc?, No observations have, I believe, been yet made in Italy with a view of elucidating this point, and there are no results from the latitude of Rome, or in any part of Italy in Humboldt''s table. 3g^, Though I cannot pretend to determine to a nicety the hours of maximum and minimum, and to trace the precise progress of oscillation from hour to hour, yet a general idea will easily be obtained on both these points, and the range of variation be the same within a minute fraction of what we should have inferred it to be from independent observations. Lastly^ I am in hopes that this memoir may stimulate to exertion travelling and other meteorologists in this department of their study, than which none requires more continued exertion and minute accura^ cy ; and to such as have time and inclination I trust that my type of calculation and reductions may serve as a guide in treating their observations in that rigorous manner which is so highly desirable * It will now be proper to make a few • I am encouraged to express the latter hope, from observing how deeply Mr Daniell recommends a very studious attention in this parlicu- lar. '' Let tlie meteorologist/' says he, " be assured, that it is only by the same painful care to minutia; that his own favourite science can ever ue 071 the Horary Oscillations of the Barometer at Rome. 1 15 remarks on the construction of the instrument, and the pre- cautions taken in the use of it. The barometer was made by myself, and was on Sir Henry Engelfield's construction. I here give the note of its dimen- sions. Inch. Tube, internal diameter, - - 0.150 external diameter, - - 0. 22 Cistern, area for rise of mercury, - 9216 — 484 = 8732 But, internal area of tube, - 225 Quotient or correction of cistern level, qqIsI The correction of level then being ^^ittj I have always in practice considered it ^^o* The tube was of Roman manu- facture, much thinner than the English ones, and I fear not so perfectly equal. It was boiled over a spirit-lamp with the utmost care, and ever after exhibited the most brilliant flashes of electrical light in vacuo. The cistern was close and of hard wood, but with a piece of cork inserted in the bottom to admit the air ; and although, after being much carried about, for a time it did not perform well, yet hung as it was constants ly during these experiments in the sam^ part of the same room, I have no reason to believe that it was the least slug- gish in its variations. Attached to the case was a small ther- mometer graduated by myself with the Fahrenheit and Centi- grade scales ; the former has always been used. I likewise gra- duated the inches of mercury on a slip of brass fixed to the case, and a vernier, now on the tube, which showed to jj^ of an inch. Though I cannot pretend that my graduation was all to that degree of exactness, yet it certainly read off much raised to that standard of exactness of which there can be no doubt that it is susceptible, but from which it is to be lamented it is at present so for removed." In another place, " Observers will render a much greater service to science by devoting less of their time to the inspection of their instruments, and more to applying the proper corrections." Should that intelligent philosopher ever read these pages, I think I can assure him that few observations have ever received more attention than mine with regard to the boiling of the mercury in the tube, the accuracy of the observations, and the precision of the corrections. 116 On the Horary Oscillations of the Barometer at Rome. more accurately than to hundredths^ which was my principal The positive height of the mercurial column, and con- aim. sequently the neutral point, were not accurately determined during my stay at Rome, as I had no dividing engine or me- thod sufficiently accurate of measuring off a given quantity ; the position of the scale of inches was therefore only approxi- mate. On my way to Florence the instrument was acci- dentally broke, and I had recourse to the published journal of the Collegio Romano at Rome, to reduce it to the standard of the instrument there observed. I selected sixteen corre- sponding observations at 7ioon in February. Feb. Sums, Means, My observ. Bar. Eng. Inch. 30.031 30.250 30.048 30.072 29.886 29.790 29.874 29.886 29.900 30.118 30.020 29.906 29.760 29.624 29.937 30.176 479.258 29.954 Ther. 57 58 57 54 54 55 53 52 51 54 54 5Q 67 5i^ 53 52 873 54.6 Coll ilora. 1 French Inches. In. Lin. 28 1 .4 28 3 .2 28 0 .3 28 1 .0 27 9 .3 27 9 .3 27 11.0 27 10.3 27 11.2 28 1 .3 27 11.3 27 10.3 27 7 .7 27 8 .2 27 11.6 28 2 .8 447 2 .2 27 11.38 =z 5^6.945 Eng. inches. 29.954 DifF. 00.009 By a very unexpected concordance the difference amounts to only f /ijy of an inch, a variation in this case quite to bg On the Horary Oscillations of the Barometer at Rome. 117 neglected, as a very small difference of level would occasion it. The Collegio Romano stood nearly on the same street, and on very flat ground, and the level of both barometers was proba- bly almost exactly the same, viz. about 1 20 feet above the sea. Hence I assume the heights given to be correct, and the neutral point is considered at 30.000 inches, as this agreement took place only -^^q lower. The capillary attraction of the in- strument comes to be by Mr DanieU's estimate in boiled tubes 0.044. The instrument during the whole observations hung in the same spot, except a few days in January, (including the 12th and 15th,) when, though in another house, I consider the difference of level to have been next to nothing. As to the precautions taken to ensure accuracy, I shall simply state, that every one of the observations has been made with great care hy myself personally, excepting only one or two morning ones on the 12th and 15th January ; that the whole corrections and calculations have been performed by myself from the best da- ta; and that in the whole series not a single dubious obser- vation has been made use of. I now give the first table, including the original observations, as transferred to my re- gister. TABLE I. No. Day. Feb- 1 Hour. 10 M. Barom. Ther. i?: Day. Feb. Hour. Barom. Ther. 29.840 3 A. 30.252 59 2 8iM. 892 5Q 4 236 60 10 M. 886 55 5 226 58.5 10^ A. 854 6 222 58 3 IUm. 814 20 8 226 58 4 10 M. 960 57 9 224 58.5- 11 30.018 57 10 224 58.5 1 A. 044 58 11 224 57 9 120 57 6 8 M. 194 57 10 10 164 57 9 150 55 11 174 58 10 118 57 5 8 M. 210 58 11 094 58.5 9 224 56 12 048 57 10 242 56 1 A. 020 57 i 11 12 250 58 30 1 5 2Q.996 57 , 1 250 58 I« 970 57 118 On the Horary Oscillations of the Barometer at Rome. Day. Day. No. Feb. Hour. Barom. Ther. 57 No. Feb. Hour. Barom. Ther. 55 7 29.938 u 29.800 8 908 57 2iA. 756 54 9 870 56 4 750 54 10 850 55 9 778 54 U 832 56 80 10 800 54 7 8 M. 774. 56 U 800 54 9i 740 55 12 796 54 91 65^ 55 13 8 M. 8U0 55 4.0 2 A. 650 56 9 800 55 7 622 56 m 790 55 8 594 55 12 790 55 i/.rl ^ ,<)lr.^ y 91 10 574 574 574 56 56 56 5 A. 8 770 54 768 758 54 54 ' ■ '■; ' 8 8 M. 600 56 90 12 760 54 10 626 54 14 9 M. 800 54 11 650 56 10 856 54 21a. 630 55 11 858 52 .50 5 690 54 12 874 53 8 718 55 1 A. 886 53 9 768 55 2 892 53 10 806 54 4 900 53 11 850 54 5 910 53 9 9 M. 938 55 10 916 53 9f M. l980 55 100 11 918 53 1 A. 016 55 12 918 53 2 036 55 15 8 M. 902 54 H 050 55 9 890 50 60 8 078 54 10 878 51 12 094 5t Uf 866 52 10 8 M. 086 55 2 A. 864 52 10 070 5'^ 7 890 52 12 072 54 8 890 51 5 A. 100 54 9 896 51 \. . 10 100 54 110 10 896 51 '^' ■' <", 'f 1^ 100 54 16 11 896 51 10 074 54 8 M. 896 51 " 11 10| 096 55 9 894 50 2\. 068 55 n 888 49 70 7 050 54 1 A. 892 51 8 042 54 2 892 51 11 016 54 8 904 51 12 006 54 9 906 51 12 9 M. 8C6 55 120 10 907 50 10 790 55 lli 9O8 50 On the Horary Oscillations of the Barometer at Rmie, 119 f Day. Day. J No. Feb. 17 Hour. Barom. Ther. 52 No. Feb. Hour. Barom. Ther. 8 M. 29.900 1| '' 29-808 56 9 900 51 II 9 802 51 lOi 900 51 1 10 790 57 12 900 51 170 11 788 51 1 A. 902 52 12 760 51 7 924 52 2|A. 724 51 8 950 51 8 666 51 9 950 51 11 646 51 10 958 50 12 624 51 130 11 96'0 51 23 10 M. 626 58 18 10 M. 30.018 52 U 624 57 2 A. 056 52 52 12 624 56 5 080 5| 650 55 7 100 52 180 7 700 55 8 108 51 8 726 55 10 118 51 H 748 55 11 120 51 10 786 55 19 8 M. 118 51 11 800 55 1 A. 118 54 24 7|M. 855 55 140 I 120 54 8 874 56 8 124 54 9 892 54 ^i- 132 34 10 916 53 10 110 53 11 930 54 11 106 5S 190 Ua. 946 53 20 9 M. 066 54 4 950 54 10 040 54 5 950 54 12 020 54 10 962 54 1 A 014 54 10| 964 54 2 000 54 25 9 M. 970 53 150 3 29-996 55 10 984 53 5 9QQ 55 1 A. 990 5S 6 962 55 2 990 53 7 962 55 7 996 52 8 958 55 20c 10 30-002 52 11 950 55 11 020 52 12 950 55 26 9 M. 144 53 21 9 M 940 56 91 170 53 10 1 918 56 12 176 52 12 906 56 2iA. 200 52 16( ) 1 A . 896 56 3 200 51 2 872 5Q 6| 238 50 6i 850 56 9 258 51 7 834 56 10 288 50 8 840 56 21( D 11 310 50 12i 816 1 B^ 27 9 M. 350 49 22 1 1. I. 812 56 |10 376 |49 120 On the Horary Oscillations of the Barometer at Rome. Ko. Day. Feb. Hour. Barom. Ther. 51 No. Day, Mar. Hour. lOj Barom. Ther. 60 1 A. 150.404 260 29.962 10 404 50 Hi 974 61 12 408 50 n A. 30.006 59 28 9 M. 41 C 52 12 046 59 5\a. S64 52 6 8 M. 100 59 9 358 51 9 122 58 220 11 358 51 6 150 59 Mar. nj 356 51 8 170 59 1 8 M. 356 52 9 180 59 9 330 50 10 198 60 10 330 50 270 11 202 59 11 334 5-1 7 8 M. 240 59 121 328 53 10 258 58 11 A. 314 53 11 262 58 2 314 53 2 A. 276 59 5 300 5S 6 276 59 2S0 6 300 5S 7 276 59 9 294 52 8 296 59 10 290 53 9 300 59 11 276 53 10 312 58 2 8 M. 274 55 280 Hi 316 58 ' 9 274 53 8 8 M. 320 59 10§ 260 53 10 307 59 11 242 54 11 306 59 12 2b4 55 1 A. 296 59 12| 274 54 2 288 60 240 11 A. 200 53 6 260 59 12 174 53 7 248 58 3 8 M. 176 55 10 A. 30.248 58 10 in 55 11 238 58 11 160 56 29c ) 9 8^M. 196 59 12 M. 30.154 51 H 196 60 1 A. 148 59 10 196 60 9 136 56 10} 174 60 10 124 56 7 A. 110 60 11 124 56 9 102 60 250 4 9 M. 104 58 10 096 60 1 A. 050 60 11 100 60 i 2J 020 62 10 9 M. 070 60 6' 29.950 61 10 058 60 7 950 60 300 11 060 60 9 938 59 1 040 61 10 92s 58 2 018 61 11 936 58 3 008 61 .5 S^M. 94-6 59 4 29.990 60 9 952 59 6 976 59 On the Horary Oscillations of the Barometer at Rome. 121 No. Day. Mar. Hour. Barom. Ther. 60 No. Day. Apr. Hour. 9 Barom. Ther. 61 9 29.99t 30.258 10 ^^^ 58 10 258 62 11 30.002 ^^ lU 250 62.5 11 8 M. 120 60 2 A. 238 Q^ 310 9i 150 59 3 238 63 10 170 58 8i 224 61 IJA. 206 S^ 9 230 61 3 226 59 10 220 60 10? 244 58 360 Hi 220 60 296 58 11 SjM. 218 61 12 314 5^ 9^ 208 61 12 7 M. 340 59 Hi 198 61 9 350 57 2iA. 192 63 0 350 58 3 192 63 320 11 350 58 4 192 63 12 352 8^:^ n 196 61 12 348 61 11 9 A. 200 61 5 320 60 101 204 61 0 290 58 370 11| 204 60 11 274 58 12 8 M. 226 62 13 n^M. 252 59 9 230 62 8 238 61 IJA. 260 ^S 7 9 A. 162 S3 3 275 63 0 144 53 10 296 61 330 11 124 53 11 305 62 8 18 M. 146 60 IS 10 M. 358 64 9 158 61 lOf 378 63 ] I J A. 158 61 1 A. 378 64 c ) 158 61 380 3 580 64 I 4 156 61 H 379 64 i 5J 180 60 n 379 63 i '>\ 198 60 10 378 62 9J 210 60 111- 378 62 0 222 60 14 7iM. 370 Q^ 340 iij 226 60 81 370 64 9 18 M. 240 60.5 11 354 63 0 258 61 1 A. 342 64 11 258 63 2 322 64 12 A. 258 63 390 Sf 302 64 3 258 63 ^i 294 64 6 258 61 7 278 64 8 256 61 91 258 62 9 256 61 11 256 63 u 256 60 15 7iM. 184 63 350 iH 260 60 8 160 63 10 3 M. 256 60 ^\ 146 62 122 On the Horary Oscillations of the Barometer at Rome. Day. Day. No. ^pr. Hour, i iarom. Ther. No. 61 Apr. Hour. 1 9 Barom. rher. 1 A. 30.100 30.020 64 2 080 61 10 020 64 400 3 058 61 11 / 020 63 4 048 61 19 6iA. 020 63 n 010 61 8 018 QS 8J 010 61 440 9 016 62 9 020 61 10 016 62 10 020 61 u\ 018 QS 11 008 61 20 8 010 63 16 8 M. 29.990 62 9i 010 63 9i 990 6S lOi 014 63 10 990 63 11 014 QS 410 l2iM. 990 6S 12 014 62 1 A. 968 64 2iA- 016 QS 2 958 64 2| 016 GS 4 962 62 450 5i 000 63 51 950 62 ni 29.996 63 7 962 62 994 62 8 970 62 21 8 M. 990 64 9 970 62 S\ 990 64 lOi 982 62 10 30.000 65 11 986 62 7JA. 29.986 QQ 420 17 7iM. 982 63 8 972 QQ 8 994 6S 10 964 m 9 996 63 11 960 65 10 996 63 460 22 9 M. 958 65 llj 30.008 63 1 A. 950 66 m 010 63 2 94^8 64 2 A. 014 64 3 948 65 2f 010 64 8 950 64 5 016 63 10 948 65 6'i- 016 62 Hi 942 64 430 10 018 62 23 7 n 950 64 11 018 62 ^ 7| 946 66 Hi 018 62.5 10 948 64 18 7iM. 8 020 016 6S 64 470 11 950 64 N. B. The preceding temperatures are from the attached thermometer. The preceding table being the results of the simple observa- tions, as inserted in my register, the next object was to reduce them, 1*^ By interpolating numbers for such intermediate hours as it was evident could be done with sufficient accuracy, and by reducing the heights which happened to be taken at On the Horary Oscillations of the Barometer at Rome, 123 fractionary parts of hours to the whole hours. 9.d, By apply- ing the correction for level, being -^-q and the neutral point 30.000. 8c?, By making the correction for the temperature of the mercurial column, which was done from the following table, interpolated from that given in Daniell's Meteorological Es^ says. ^ Temperature. Barora. •29.5 30. 30.5 o 4.7 o 4^8 o 49 0 50 0 51 o 52 o 53 o 54 0 55 0 56 0 57 o 58 o 59 0 60 o 61 o 62 0 63 o 64 o Q5 o 66 38 4^1 44 t6 48 50 53 b5 58 61 64 66 Qd 72 74 76 79 81 83 86 38 41 44 46 48 51 53 56 59 62 65 67 70 72 75 77 80 82 85 88 39 42 45 47 49 52 54 57 QO L Q5 Q^ 71 74 76 79 81 84 S6 89 The upper line contains the temperatures, the other three the corrections in lOOOths of an inch. It may at first appear that the following table might have been consolidated with the first, but the number of interpolations and changes in the hours render that impossible. To prevent repetition, the uncorrected heights are not again given, nor the interpolated ones ; but any one may be found by applying the two corrections contrary to their signs to the corrected number in the last column, which number — 044 for capillary action, and -{- .138 for a reduc- tion to the sea-shore (from about 120 feet above it) will give the true height of the barometer at 32®, andat the level of the Mediterranean. 1 TABLE II * Day. Corr. Corr. Barom. IDay. Corr. Corr. Barom. Feb. 2 Hour. 8m. level. + 3 temp. —62 correct. Feb. Hour. 9 level. — 3 temp. —65 correct. 29-829 30.058 9 + 3 —60 827 10 —4 ^■65 103 10 + 3 —59 82 -i 11 —4 — 67 111 4 lOM. 4-1 —65 894 5 8 — 5 -67 148 n +0 —65 953 9 —5 —62 137 12 — 1 —67 966 10 —6 —62 172 1 A. — 1 -67 978 11 -6 —67 177 124 On the Horary Oscillations of the Barometer at Rome. Day. Feb. Hour. 12 COIT. level. — 6 Corr. temp. —67 Biuom. jorrect. Day. Feb- 9 Hour. 9M. Corr. level. + 2 Corr. temp. -59 Barom . correct. 30.177 29.881 3 a. — 6 -70 176 10 +0 —59 9S5 4. — 6 —73 157 lA. — 0 -59 947 5 — 6 -Q9 151 2 — 1 —59 976 6 ~ 6 —61 14-9 3 — 1 —59 987 7 — 6 —67 151 8 —2 —56 020 8 — 6 —67 153 12 2 —56 036 9 — 6 -69 151 10 8 m. 2 —59 025 10 — 6 —69 151 9 —2 —54 022 11 — 6 —65 153 10 —2 —51 017 a 8 m. — 5 —65 124 11 —2 —53 016 \j 9 — 4 —59 087 12 —2 —56 014 10 — 3 —65 050 5 a. —2 —56 042 11 -, 2 -69 023 10 10a. 2 —56 30.042 12 — 1 —65 29.982 11 —2 —56 042 lA. — . 1 —65 954 12 2 —56 042 5 + 0 —65 931 11 10m. —2 —56 016 6 + 1 —65 906 2 a. —2 —59 007 7 + 2 —65 875 7 — 1 —56 29.993 8 + 2 —62 848 8 — 1 —56 985 9 + 3 —62 811 9 — 1 —56 977 10 + 3 —59 794- 10 —1 —56 968 11 + 4 ^62 774 11 0 —56 960 7 8 m. + 6 —62 718 12 —0 —56 950 9 + 6 —58 696 12 9 m. + 5 -59 752 ( ; % 91 10 + 9 —57 606 10 + 5 —59 736 doub tf'ul 11 + 5 —59 746 ?, 2 a. + 9 —60 599 2 a. + 6 —56 709 7 + 9 —60 571 4 + 6 —56 700 8 + 11 —60 545 9 + 6 —56 728 9 + 1^ —60 521 10 + 5 —56 751 10 + 11 —60 525 11 +5 —56 751 11 + 11 —60 525 12 + 5 —56 7*7 12 + 11 —60 525 13 8M. +5 —59 746 8 8m. + 10 —60 550 9 + 5 —59 746 9 + 10 —57 565 10 + 5 —59 738 10 + 9 -54 581 11 +5 —59 736 11 + 9 —60 599 12 + 5 —59 746 2 a. + 9 —57 573 5a. + 6 —59 720 5 + 8 —54 644 6 +6 —59 719 6 + 8 —55 652 7 +6 —56 719 7 + 7 —56 660 8 + 6 —56 718 8 + 7 —57 668 9 +6 —56 715 9 + fi —59 715 10 + 6 —56 712 10 + 5 —56 115 11 +6 —56 709 11 + 4 —56 798 12 +6 -59 707 On the Horary Oscillations of the Barometer at Rome. 125 Day. Jorr. ( :orr. Barom. Day. Corr. Corr. Barora. Feb. 14 Hour. 1 9M. evel. t +5 emp. ^56 correct. Keb. Hour. 10 level. + 1 temp, correct. 29.749 —46 29.913 10 + 4 --56 804 11 + 1 —48 913 11 + 4 —51 811 18 IOm. — 0 —51 967 12m. + 3 —53 824 2 A. — 1 —51 30.0041 1 A. + 3 —58 836 3 —2 —51 012 2 + 3 —53 842 4 —2 —51 020 3 + 3 —53 847 5 2 —51 027 4 + 3 —53 850 6 —2 —51 037 5 + 2 —53 859 7 2 —51 047 10 + 2 —53 865 8 —3 —48 057 11 +2 —53 867 9 —3 —48 062 12 + 2 —53 867 10 — 3 —48 067 15 8m. + 2 —56 847 11 —3 —48 069 9 + 3 —46 847 19 8m. —3 —48 067 10 + 3 —48 833 9 —3 —50 065 11 + 3 —50 823 10 3 —51 063 12 + 3 —51 817 1 A. —3 —56 057 11 A. + 3 —51 817 7 —3 —56 061 2 + 3 —51 816 8 -3 —56 065 7 + 3 —51 842 9 —3 —56 071 8 + 3 —48 845 10 —3 —53 064 9 +3 —48 851 11 —3 —53 054 10 + 3 —48 851 20 9M. —2 —56 008 11 + 3 —48 851 10 — 1 —56 29-987 12 + 3 48 851 11 —1 —56 973 16 8m. + 3 —48 851 12 —1 —56 963 9 + 3 —46 851 1 A. —0 —56 958 10 + 3 —44 845 2 —0 — 56 944 11 + 3 —46 818 3 + 0 —59 937 12 + 3 —46 848 4 +1 —59 913 i A. + 3 -48 847 5 + 1 —59 908 2 + 3 —48 847 6 +1 —59 904 8 + 2 —48 858 7 +1 —59 904 9 + 2 —48 860 8 + 1 —59 900 10 + 2 —46 h63 9 +1 —59 896 11 + 2 —46 863 10 +1 —59 893 12 + 2 —46 864 11 +1 —59 892 17 8m. + 3 —51 842 12 +1 —59 892 9 + 3 —48 845 21 9m. +1 —62 859 10 + 3 —48 845 10 + 2 —62 858 11 + 3 —48 845 11 + 2 —62 852 12 + 3 -48 845 12 + 2 —62 846 1 A +2 —51 853 lA. + 8 —62 837 7 + 2 —51 875 2 + 3 —62 813 8 a . +1 — 4J J 90s 1 6 + 4 1-62 796 9 + 1 —4^ ^ 90s || ■ .;7 + 4 —62 776 126 On tlte Horary Oscillations of the Barometer at Rome, Day. ICorr. Corr. Barom. Day. Corr. Corr. Barom. ~ Feb. Hour. 8 level. + 4 temp* —62 correct. Feb. Hour 10 level. — 4 temp. —53 correct 29-782 30.113 12 + 5 —62 761 12 — 4 —51 121 22 IM. + 5 —62 755 lA. — 5 —51 142| 2 + 5 —62 747 3 — 5 —48 Wt 1 9 -f- 5 -^65 742 6 — 6 —46 163 10 + 5 —65 730 9 — 6 —49 205 11 + 5 —65 728 10 — 7 —47 234 12 + 6 —65 700 11 — 8 —47 255 1 A. + 6 —64 686 27 9M. — 9 —45 296 2 + 7 —64 671 10 — 9 —45 222 8 + 8 —64 610 11 —10 —47 33t 9 + 8 —64 604 12 —10 —47 343 10 + 9 -64 597 lA — 10 49 345 11 + 9 —64 591 10 — 10 —47 347 12 -f 9 —64 569 11 — 10 —47 349 23 10 M. + 9 —66 569 12 — 10 —47 351 11 + 9 64 569 28 9 m. —10 —52 348 12 4- 9 6l 569 5 a. — 9 —52 302 5 a. + 9 —58 594 6 — 9 —52 305 6 + 8 —58 622 9 — 9 —49 300 7 + 8 —58 650 10 — 9 —49 300 8 + 7 —58 675 11 — 9 —49 300 9 + 6 —58 692 Mar. 12 — 9 —49 296 10 + 5 —59 732 1 8m. — 9 —52 295 11 + 5 —59 746 9 — 8 —47 274 24 7M. + 4 —59 787 10 — 8 —47 274 8 + 3 _62 815 11-. — 8 —52 274 9 + 3 —56 839 I 2m. — 8 —54 267 10 + 2 —53 S65 lA. — 8 —54 265 11 + 2 —56 876 2 — 8 —54 242 12 + 1 —57 885 3 — 8 —54 247 1 + 1 -^53 S9'i 4 __ 8 —54 242 4 + 1 —56 895 5 — 8 —54 238 5 A. + 1 —56 895 6 — 8 —54 238 10 + 1 56 907 7 — 7 —53 237 11 4- 1 —56 910 8 — 7 —53 236 25 9m. + 1 -53 918 9 — 7 —52 235 10 + 0 -53 931 10 — 7 —54 229 1 A. + 0 —53 937 11 — 7 —54 215 2 + 0 —53 937 2 8m ~ 7 —54 213 7 + 0 —51 9^5 9 — 7 —54 213 8 ■f 0 —51 946 10 — 7 —54 204 9 + 0 — 5J 948 11 — 6 —5S 180 10 — 0 —51 951 12 — 7 —60 217 11 - — 1 —51 968 lA. — 7 —57 1 206 26 9M. - - 4 —53 30.087 11 A. — 5 - -^53 \ 144 On the Horary Oscillations of the Barometer at Rome. 127 Day. Corr. Corr. Barom. Day. Corr. Corr. Barom. Mar. Hour 12 level. —4 temp. —53 correct. Mar. 8 Hour. 8m. level. —8 temp. —71 correct 30.117 30. 241 3 8m. -«4 —59 113 9 —8 —71 232 9 —4 —59 112 10 —8 —71 228 10 —4 —59 111 11 —8 —71 227 11 —4 —62 094 12 —7 —71 223 12 —4 —65 085 lA. —7 —71 218 1 A. _4 —70 074 2 —7 —74 207 9 —3 —62 071 6 —7 —71 182 10 —3 —62 059 7 —6 -67 175 11 —3 —62 059 10 —6 —67 175 4 9 m. —3 —67 034 11 —6 —67 165 I A. — 1 —72 29.977 9 8 m. —5 -Q^ 122 2 — 1 —77 918 10 —5 —71 120 6 + 1 —75 876 10 —5 —72 119 7 + 1 —72 879 11 —4 —72 091 8 + 1 —71 874 7. A —3 —72 035 9 +2 —70 870 8 —3 —72 031 10 +2 -67 863 9 —3 —72 027 11 +2 —67 871 10a. —2 —72 022 5 8m. + 1 —70 874 11 —2 —72 026 9 + 1 —70 883 10 - 9 m. —2 —72 29.996 10 + 1 —72 888 10 — 1 —72 985 11 + 1 —73 . 896 11 — 1 ^72 987 12m. + 1 —75 907 12 — 1 -73 976 11 A. — 0 —70 936 I A. — 1 —75 964 12 — 1 —70 975 2 — 0 —75 953 6 8m. —2 —70 30.028 3 — 0 —75 933 9 -—3 -67 052 4 + 0 -72 918 6 a. —4 —70 076 5 + 0 —71 912 7 —4 —70 086 6 + 1 -70 907 8 —4 —70 096 9 + 0 —72 922 9 —4 —70 106 10 + 0 —67 929 10 —5 —72 121 U - 0 —70 932 11 —5 —70 127 11 8 m. —3 __7-2 ' 30.945 7 8 m. —6 —70 164 9 —4 —70 07c 9 —6 —68 175 10 —4 —67 09S 10 —6 —68 184 1a. —5 —70 134 11 —7 —68 187 2 —5 —70 142 2 a. —7 —71 198 3 —6 —70 15C 6 —7 —71 198 r. —6 —67 17( 7 —7 —71 198 10 —7 ^6S 21^ 8 —7 —71 218 11 —8 —68 22J 9 -^7 —71 222 12 —8 ^6S 23i 10 —8 —68 236 12 7 m. —8 -71 26 11 —8 —68 242 8 —8 —68 26< 1 12 —8 —68 243 1 9 —9 ^Q5 27< 1 28 On the Horary Oscillations of the Barometer at Rome. Day. Corn Corr. Barom. Day. Co rr. Corr. Barom. Mar. 12 Hour. 10 level. —9 temp. —68 correct Apr. 10 Hour, le^ 2a. — el. 6 temp. —80 correct. 30.153 30.273 11 ~9 —68 273 3 — 6 —80 153 12 —9 —71 272 8 — 6 —75 145 1 A. —9 —73 277 9 — 6 —75 149 2 —9 —76 263 10a. — 6 —72 142 5 — 8 —74 238 11 — 6 —72 142 10 —7 —68 215 11 8m. — 5 —75 140 11 —7 —68 199 9 — 5 —75 132 13 7 m. —6 —68 181 10 — 5 —75 124 Apr. 8 —6 -75 157 11 5 —75 119 7 9 a. —.4. —53 105 2 a. — 5 —80 107 10 —4 —53 087 3 — 5 80 107 11 —3 —53 068 4 — 5 __80 107 8 8 m. —4 —72 070 7 — 5 —75 115 9 —4. —75 079 8 — 5 —75 117 I A. —4 —75 079 9 — 5 —75 120 2 —4 —75 079 10 _ 5 -175 123 3 --4 —75 078 11 — 5 —72 127 4 —4 —75 077 12 8m. — 6 _-77 143 5 —4 —75 077 9 — 6 __77 147 6 —4 —75 083 10 6 —79 152 7 ~5 —72 098 1a. — 7 _85 173 8 —5 —72 107 2 7 —83 180 9 —5 —72 116 3 — 7 —89 187 10 ^6 —72 127 10 — 7 -_74 215 11 ^6 —72 144 11 8 —76 221 12 —6 —72 149 13 10m. — 9 —84 265 9 8m. 6 —74 160 11 _ 10 —81 292 9 —6 —75 168 I A — 9 —84 285 10 —6 —76 176 2 — 9 84 286 11 —6 —81 171 3 9 84 287 2 A. —6 —81 171 4 9 __84 285 3 —6 —81 171 7 — 9 —81 289 4 -^6 —80 173 10 — 9 —79 290 5 ~6 —78 174 u 9 —79 290 6 —6 —76 176 14 7 m. — 9 —71 280 7 —6 —76 175 8 . — 9 —84 277 8 —6 —76 174 9 — 9 _83 274 9 —6 -76 174 10 -- 9 —83 264 10 —6 —75 175 11 9 __81 264 11 —6 —74 176 12 — 9 —81 254 12 —6 —74 184 1a. — 9 —82 251 10 8M. —6 —74 176 2 -- 8 —82 232 9 ' —6 —76 176 3 — 7 —82 221 10 —6 "~79 173 4 __ 7 —82 208 H —6 —79 166 7 — 7 —82 189 On the Horary Oscillations of the Barometer at Rome. 129 Day. Corr. Corr. Barom. 1 Day. Corr. Corr. Barom. Apr. Hour. 9A. level. —7 temp. correct. Apr. 18 Hour. 7m. level. — 0 temp. —80 :orrect. —77 30.178 29.946 10 —6 —79 174 8 — 0 —82 934 11 -6 —80 170 9 ^-0 —82 938 15 7m. —5 —80 111 10 -0 —82 938 8 —4? —84 076 11 — 0 —80 940 9 —3 --77 052 19 6 a. -^0 —80 941 1 A. —2 —75 023 7 — 0 —80 939 2 —2 —75 003 8 —0 —80 938 3 — 1 —75 29.982 9 — 0 —77 939 4. — I —75 972 10 — 0 —77 939 7 — 0 —75 935 11 — 0 —80 938 8 — 0 —75 9S5 20 8 m. _^0 —80 930 9 — 0 —75 945 " 9 0 —80 930 10 —0 —75 94:5 10 _o —80 933 1] — .0 —75 933 11 0 —80 934 16 8 m. 4-0 —77 913 12 — 0 —77 931 9 +0 —80 910 2a. — 0 —80 936 10 ■fo —80 910 3 0 —80 936 11 +0 -80 910 5 0 —80 922 12 + 0 SO 910 10 +<^ —80 916 1 A. + 1 —82 887 11 +0 —77 918 2 + 1 —82- 887 21 8 m. +0 —82 908 4. + 1 —77 886 9 -fo —83 910 5 + 1 -77 875 10 +0 —85 915 6 + 1 --77 880 7 a. +0 —88 902 7 + 1 —77 885 8 +1 —88 885 8 a. + 1 —77 894 9 +1 —88 880 9 + 1 —77 894 10 +1 —88 876 10 +0 —77 903 11 +1 —85 876 11 +0 —77 909 22 9M. +1 —85 874 17 8 m. +0 —80 914 lA. +1 —88 863 9 +0 —80 916 2 4-1 —82 861 10 4-0 —80 916 3 +1 S5 864 11 — 0 —80 924 8 i-1 —82 869 12 —0 —80 929 10 4-1 —85 863 2a. —0 —82 932 11 4-1 —82 863 3 —0 —82 928 23 7m 4-1 —82 869 5 —0 —80 936 8 4-1 —88 858 6 —0 —77 939 9 4-1 —85 863 10 —0 —77 941 10 4-1 —82 867 11 —0 —77 941 11 4-1 —82 869 12 —0 —78 939 (To be concluded in next Number.) VOL. VIII. NO. I. JAN. 1828. 130 Mr Grierson on Footsteps before the Flood. Art. XXI. — On Footsteps before the Floods in a specimen of Red Sandstone, By Mr Grierson. * -It was obtained from the sandstone quarry of Corncockle Muir, about two miles to the north of the town of Lochmaben, iri, the county of Dumfries. The existence of specimens of this kind in that quarry has been known for a considerable time. Having lately spent a few days in that neighbourhood with Dr Duncan of Ruthwell, who is in possession of the finest specimens that have yet been procured, and who was anxious to obtain some others for Professor Buckland of Ox- ford, with whom he had been corresponding on the subject, I went with him to the quarry to see the original deposite, and, if possible, to procure a small slab for myself. The professor having received a cast of the most distinct impressions which Dr Duncan's specimens exhibit, together with a fragment of the sandstone itself, was so fully convinced by them that the rock, while in a soft state, had been traversed by living qua- drupeds, though the fact was at variance with his general opi- nions respecting the geological formation, that he wrote to the doctor, earnestly requesting him to procure, at any expence> any specimens that could then, or that might in future be dis- covered. On entering the quarry we found that the dip of the strata was towards the west, and at an angle of about 35 degrees. On the eastern side, therefore, it was the upper surface of the strata that was presented to us, and of this there was a great lateral extent. The upper edge of the strata, the face of which was there exposed, reached within about 15 feet of the surface of the ground. From this upper boundary down to the line where they disappeared under the rubbish, which, since the working had been carried on chiefly on the opposite side of the quarry, had accumulated at their base, there were fully 15 feet of their surface distinctly exhibited, and this for a range of not less than between 40 and 50 yards. On ex- amining the whole range of this acclivity, we found no less • Read before the general meeting of the Literary and Antiquarian Society of Perth on the 22(1 November last. IMr Grierson on Footsteps before the Flood. 131 than four separate tracks of as many different kinds of ani- mals, and all of them different from two of the specimens at least which were already in Dr Duncan's possession. Three of these tracks were towards the south extremity of the range, on the surface of the same identical layer, and two of them within two or three yards of each other. The fourth one was towards the north extremity, and probably on the same layer as the others, but owing to some bendings in the direction of the strata, and to a quantity of earth, which at one place has rolled down and interrupted the view, this was what we did not fully ascertain. The simple inspection of the tracks themselves, however, made it impossible to doubt in what manner they had been produced. The great number of the impressions in uninterrupted continuity — the regular alterna- tions of the right and left footsteps — the^r equidistance from each other — the outward direction of the toes— the grazing of the foot along the surface before it was firmly planted — the deeper impression made by the toe than by the heel — the forcing forward of the sandy matter of the rock by the down- ward and scarcely slanting direction in which it is remarkable that all the animals have traversed this singular acclivity — and in the largest specimen which Dr Duncan has, and which was found in a different part of the quarry — the sharp, and well-defined marks of the three claws of the animal's foot — are circumstances which immediately arrest the attention of the observer, and force him to acknowledge that they admit of only one explanation. Of the four different tracks here mentioned, the one which was farthest to the south exhibited the deepest and most dis- tinct impressions, and it was from it, therefore, that 1 wished to obtain a specimen. Having selected and marked off six prints of the foot, three on each side, it was found an easy process to detach them, as the layer which contained them did not exceed three quarters of an inch in thickness, while the one on which it rested was not less than a foot and half. The thinness of the slab, which rendered its separation so easy, rendered it at the same time so extremely fragile, that it went to pieces in the hands of the person who was removing it to the bottom of the quarry, and who was forced into a running 13^ Mr Grierson 07i Footsteps before the Flood. motion by the steepness of the path in wliich he had to de- scend. Owing, however, to the comparative hardness of those parts which had been subjected to the pressure of the animal, the footmarks were but little injured by the fracture, and having collected and arranged on the spot as many of the fragments as we could clearly distinguish, they were afterwards put in a flat wooden case, and cemented with stucco, which, besides keeping them in their relative positions, served as a sort of compensation for those that were awanting. Mutilated as it is, the specimen is sufficient to show the size and shape of the footmarks, and the length of the stride or step, which is about 12 or 13 inches, and therefore of course a kind of index to the length of the animal's body. To what species the animal belonged I leave it to more skilful naturalists to determine. The impressions, of which a cast was sent to Dr Buckland, are thought by him to have been produced hy the feet of a tortoise or crocodile. The track next to the one from which this specimen was got, was that of an animal whose foot must have been about seven or eight inches in length, and fully four inches in breadth ; and whose stride measured about twenty inches. The footmarks of this track were not so distinct as those of the preceding ; and in some instances they had been filled up by a subsequent de- position of sandy matter, which was a little more elevated than the lip or edge of the impression — presenting exactly such an appearance as is sometimes exhibited on the sea-beach, where the tide has passed over and filled up the footsteps of a recent traveller. Of these impressions we eagerly set about obtaining a specimen, in order that Dr Duncan might meet the request of Professor Buckland ; but we had the mortification of finding, that in the neighbourhood of this track, the thin superficial layer was, owing as it seemed to the pressure of the large ani- mal which had walked over it, so closely compacted with the stratum beneath, that it was impossible to remove the specimen without quarrying an immense solid block. One or two foot- marks, indeed, we did succeed in flaking or tearing off", but in a very imperfect state ; and we had then an opportunity of ob- serving, that in the centre of the part where the pressure had keen greatest, the matter of the thin layer was less adhering to Mr Griersoii on Footsteps before the Flood. 133 the one below ; while the matter of this under one, escaping as it were from this pressure, had been forced up round the an- terior margin of the foot, and produced a hollow impression on the under side of the incumbent layer. A few yards to the north of the tracks already described, there was a third, in which the footmarks were all filled up and elevated rather than depressed, though the general outline was perfectly distinct. One row of them, indeed, was much more distinct than the rest ; for it seemed as if at this place two or three animals of the same species had descended in succession, at some distance of time from each other. The shape of the footmarks was a blunt oval about 1| inch in length, and those on each side were not more than 3| inches asunder, while the distance of the one side from the other did not much exceed 1| inch. Of these a very good specimen was obtained, the thickness of the containing layer being at this place nearly equal to that of thin pavement. The separate track at the north extremity of the range was that of an animal still smaller than the one last mentioned, and whose foot was more circular. Here too more than one animal had passed along. The impressions were very numerous, and could be traced from the earthy belt on which we stood up to the very outgoing of the stratum ; but besides being probably slight at first, they had all been so completely filled up with a sandy sediment, exactly similar to the rest of the rock, as not to afford any specimen that would have been of much value, when unconnected with others, or with the series to which it belonged. It will be obvious, from the preceding description of the stratum containing these animal impressions, that though now lying bare and superficial as at the time when these impressions were made, it is really the one on which all the other strata of the quarry had been superimposed. It may be proper to state, too, that though the tracks here described are at the upper part- of the acclivity, one of the specimens belonging to Dr Duncan, which contains the deepest and most distinct impressions that have yet been discovered, was found at the base of the stra- tum, in the lower part of the quarry, perhaps 60 or 70 feet beneath the surface of the earth. In what manner the facts 134 M. Le Chev. Burg's Improvements of the Lunar Tables. and phenomena now described may affect some interesting questions in geology, I shall not presume to inquire ; but I think I may be permitted to remark in conclusion, that we have now specimens of the new red sandstone, containing im- pressions of quadrupeds^ impressions which, to say the least, may be denominated, Footsteps before the Flood. Art. XXII. — On the Improvements in the Elements of the Moon's Orbit. By M. Ee Chevalier Burg,* Correspond- ing Member of the Academy of Sciences, F.R.S.E. &c. &c. In a Letter to Dr Brewster. i. AM glad to perceive from your letter that you have been in- terested in the communication which I sent you two years ago respecting my investigations into the elements of the lunar or- bit. I have continued these researches without intermission, and I am resolved to occupy myself with them during the rest of my life. My principal object is to establish several epochs in order to decide the question, whether or not the mean mo- tion of the moon is modified by an equation still unknown. I have, however, no intention of neglecting the correction of the other elements, and the more so as I am convinced that most of the coefficients of the equations of longitude may be dedu- ced with certainty to half a second^ and that the epochs deter- mined will be as much more certain as the tables with which the observations are compared are exact. I have indeed already corrected almost the half of the equations of longitude, and as soon as I have done this with the rest, I shall calculate the se- lect observations of Bradley in order to establish the epoch of 1755. If I live long enough to be able also to determine the epochs of 1802 and 1825, or 1830, we may consider the above mentioned question resolved. It is true that we can only ar- rive at this by employing much time and labour, but as analy- sis has not yet afforded the solution, and is not likely to do it • This distinguished astronomer obtained the prize offered by the Board of Longitude at Paris in 1800 for the best Lunar Tables, and since that time lie has been incessantly occupied in the improvement of that great work. These Tables were published by Dr Vince in the Third Volume of his Asironomv* M. Le Chev. Biirg's Improveme^its of the Lunar Tables. 135 soon, we have no other alternative but by comparison with ob- servations. I have succeeded in finding the first coefficient of the varia- tion independently of the radius of the moon, by determining its value from the meridional passages of both kinds observed by Maskelyne at the full moon from 1765 to 1803. In ge- neral the result was not different from that which I had for- merly found, by comparing the observations made at Green- wich between 1765 and 1794 before full moon, with those made after full moon. The result shows, that the radius of the moon adopted in my tables ought on no account to be di- minished, as Burckhardt believes, but, on the contrary, in- creased by 1"4 from 1765 to the 11th July 1772, and by 0"3 after this period, in order to reduce exactly to the moon's centre the observed right ascensions of her limbs. From the first coefficient of the variation found in this manner we de- duce the sun's parallax 8"62, and it appears to me that this value is not less probable than that found by M. Encke from the two transits of Venus in 1761 and 1769. The result given by the two equations, one of which depends on the longitude of the node, and the other on the true longitude of the moon, is equally satisfactory. The first gives for the flattening of the poles of the earth ^ J55 and the second, which is quite in- dependent of the first, gives ^1^. With respect to the fundamental epochs, I have found for 1779, and for the meridian of Greenwich, Mean longitude of the moon, Mean anomaly. Supplement of the node, These results include the secular equations. I have found also the Annual motion in longitude, 4s 9^ 23' 4".8195 in anomaly, 2 28 43 18 1737 Suppl. of node, 0 19 19 4103 As the observations on which these mean motions are found- ed embrace a period of only twenty-nine years, they will per- haps require ulterior corrections, but I consider them to be 2? 12° 45' 55".73 5 11 50 33 0 9 10 34 50 136 • Mr Ritchie on Radiant Heat. more correct than that which I have hitherto adopted. I have the honour to be, Sir, your most obedient servant, WiESENAU, October 23, 1826. F. T. Bueg. Art. XXIII. — Excursory Remarks an Radiant Heat, Tenth a short examination of' Professor Leslie'^s Theory/. By William Ritchie, A. M. Rector of the Royal Academy at Tain. Communicated by the Author. Professor Leslie, in his ingenious works on heat, endea- vours to account for the various phenomena of radiant heat, by supposing that caloric is carried from a heated body to another at a distance, by certain pulses excited in the ambient air. " By wh^t process the several portions of heat thus delivered to the atmosphere shoot throfigh the fluid mass, it seems more difficult to conceive. They are not transported by the stream- ing of the heated air, for they suffer no derangement from the most violent agitations in that medium. The air must there- fore, without changing its place, disseminate the impressions that it receives by a sort of undulatory commotion, like those by which it transmits the impulse of sound. The portion of air next the hot surface suddenly acquiring heat from its vi- cinity, expands proportionally and begins the chain of pulsa- tions. In again contracting, this aerial shell surrenders its sur- plus of heat to the one immediately before it, and which is now in the act of expansion ; and thus the tide rolls onwards and spreads itself on all sides.'*''* If air be the medium of commu- nication, we may ask how it happens that caloric radiates more rapidly in the most complete Torricellian vacuum than in at- mospheric air of any density whatever ; or why it radiates more copiously in rarified than in condensed air ? Sir Humphry Davy has proved, by a very simple and ingenious experiment, that in air exhausted to the 120th part of the whole, the effect of radiation was three times greater than in air of the common density. An explanation of his method may be seen in Dr Henry's Elements of Chemistry, vol. i. 83. The same fact • lUlations of Air to Heat and Moisture, page 21. Mr Ritchie on Radiant Heat. l37 was observed by the celebrated Lambert, though both he and Cullen seem to me to have given a false explanation of the cause ; Pyrometria, sect. 49^. Saussure notices the same fact, and remarks: " Le grand geometre Lambert rapport cette meme experience dans sa pyrometrie ; et il ajoute, que Texpe- rience reussit plus silrement et donne un difference de chaleur plus grande lorsqu''on pompe Pair avec diligence, et que le recipient n'est pas trop petite."" Essais sur V Hygrometrie, p. 232. Now this fact, which by no means receives a satis- factory explanation from the theory of aerial pulsations, is easily accounted for by the idio-repulsive theory. If the exterior film of caloric be pressed towards the body by the ambient air, this pressure will evidently act as an antago- nist force to the repulsive energy of the molecules of heat. If this process be diminished or removed, the atoms of heat will act on each other with a less restrained force, and a more copious radiation will be the necessary consequence. If this pressure be augmented by condensing the air there will not only be a greater number of aerial molecules, but they will also press with a greater force against the exterior film of heat. The atoms of caloric will therefore be much restrained in their mutual actions, and consequently the current of ra- diant heat will be much diminished. Were the air to be highly condensed, and the temperature of the body proportion- ably low, the two forces might become equal, and radiation completely prevented, as is the case -wdth a heated body not visible in the dark when plunged into water. Dr Wells, in his elegant Essay on the Formation of Dew ^ has given a similar explanation of the process by which water is converted into ice, on the extensive plains of Hindostan, when the tempera- ture of the air is many degrees above the freezing point. Evaporation he proves is insufficient to produce the effect. Radiation is also necessary to reduce the temperature of the water to the freezing point.* In order to account for the striking difference between the radiating powers of different surfaces, Professor Leslie assumes that " air never comes into actual contact with any surface, but * Esmy on Dew% from p. 261 to p. 279. 138 Mr Ritchie on Radiant Heat approaches nearer to glass or paper than to polished metal, from which it is separated by an interval of at least the 500th part of an inch. A vitreous surface, from its closer proximity to the recipient medium, must hence impart its heat more co- piously and energetically than a surface of metal in the same condition.'*' If air never comes into actual contact with any surface, by what power, we may ask, is caloric carried over the space between the surface of the body and the atmospheric boundary ? Surely not by the pulses excited in the ambient air, since there is no air in which such pulses can be excited. Is this power, whatever it may be, so feeble as to lose its in- fluence just at the atmospheric boundary, when it has deliver- ed its charge to the wings of the ambient air ? If a power, different from the ambient air, exist, which is capable of tran- sporting caloric over the 500th part of an inch, why should not the same power carry it over the 100th part of an inch, or even a whole inch ? The supposition which Mr Leslie has very in- geniously made, even if it were well-founded, could not, on the pulsatory system, account for the striking difference between the radiating powers of glass and polished metal. The true cause of this difference we have endeavoured to assign in one of the numbers of the Edinburgh Philosophical Journal, The various contrivances to which the author had recourse in supporting his favourite theory are numerous and truly in- genious, though to us they appear to support with much greater force the opposite theory. *' When a pellicle of gold-beater"'s skin," he observes, " was applied, the metallic surface imme- diately under it repelled partially the atmospheric boundary, and reduced the darting efflux of heat from ten, which would have been thrown by the skin alone, to about seven, or only six more than the efficacy of the naked metal. The repelling in- fluence of the metallic plate was sensible even under four coats, or at the distance of the 750th part of an inch from the exter- nal face."" The metals, as is well known, possess a powerful attraction for the matter of heat. This attraction will there- fore be exerted at some distance from the surface of the metal. The calorific atoms ranged along the surface of the metal, and also in the interior of the pellicle of gold-beater's skin, will there- fore be attracted with considerable force towards the metallic Mr Ritchie on Radiant Heat. 139 surface. This attraction will evidently act as an antagonist force to the tendency which the molecules of heat have to ra- diate from the surface. The flow of caloric will therefore be less than if no such counteracting force existed. By the addi- tion of several coats the exterior film of heat is removed beyond the sphere of attraction of the metal, and hence an increase of radiant heat will be the necessary consequence. There is also another circumstance which must materially aid the rapid dis- persion of heat, by the application of additional coats to the metallic surface. It is obvious that in soft or porous bodies ra- diation goes on not only from the surface, but also from some depth below it. In this observation I am supported by the high authority of M. Biot, who seldom risks, an hypothesis that is not well founded. That accurate and profound philosopher concludes : " Car si, comme tout Findique, le rayonnement n'emane pas seulement de la surface, mais aussi d'une petite pro- fondeur dans Pexterieur des corps, cette profondeur devra aug- menter a mesure que la temperature s'elevera, puisque la ma- tiere qui forme le corps deviendra plus permeable aux rayons calorifiques, et cette double circonstance devra produire un rayonnement plus abondant."* Now, if radiation takes place at a greater depth below the surface than the thickness of a single pellicle of gold-beater's skin, a much greater quantity of caloric will radiate from a metallic body having two or three such coatings than only one. The same thing will obviously take place by using coatings of oil or jelly of different degrees of thickness. But the most formidable objection to the theory of aerial pulsation is derived from my experiments with thin liquid sci*eens, published in the last volume of the Philosophical Transactions. "^ If heat be carried along on the wings of the ambient air, the aerial wave will be as completely stopped by the thinnest film of a viscous fluid as by an opaque screen of considerable thickness. It can only communicate its heat to the liquid film, which in its turn will act as a new source of radiant heat. But the effect on the thermometer was proved to be instantaneous, and such as could not possibly arise from • Traite de Physique, tome iv. 642. t See this Journal, No. xiv. p. 348. 140 Drs Turner and Christison on the effects of the screen acting as a secondary source t)f heat. Mr Leslie has proved, both by experiment and reasoning, that, if an opaque screen be placed between the heated body and the reflec- tor, a striking difference of effect will be observed with every remove of the screen from the heated body. " At each remove," says he, "the impression upon the focal ball will regularly di- minish ; insomuch, that, when the screen has gained a position one foot advanced from the canister, and consequent!} two feet from the reflector, it will not exceed the thirtieth part of the full effect." * Now we have endeavoured to prove by nu- merous experiments, that the effect on the thermometer is nearly the same, whether the thin liquid screen be placed near the heated ball or the differential thermometer. If this ex- periment be correct, the theory of aerial pulsations cannot possibly be the true theory of radiant heat. I have request- ed Professor Leslie to examine the delicate experiments to which I have alluded ; and I am convinced, that, should they be correct, he, from his love of philosophical truth, will be the?^ very first to abandon a theory which, though no longer te- nable, has in his hands been the means of advancing this de- partment of physical science. Aet. XXIV. — On the Effects of the Poisonous Gases on Vege- tables. By Edward Turner, M. D. F. R. S. E. Professor of Chemistry in the University of London ; and Robert Christison, M. D. Professor of Medical Jurisprudence arid Police in the University of Edinburgh, &c.-f- Having been called on last July to give evidence before the Jury Court, in the case of Hart against Taylor, relative to the effects of a black-ash manufactory on the vegetation in its neighbourhood, and having been unable to find any distinct facts recorded respecting the influence on vegetable life of the gases disengaged in the preparation of that article, we were induced to make some experiments on the subject, which were originally intended for our private satisfaction only. But we have since understood, that the case in which we were concern- • Inquiry f p. 30. ^ » \ From the Edin. Med. and Surg. Journal, No. 93. . the Poisonous Gases on Vegetables. 141 ed is no less than the third or fourth instance in Scotland of the same kind of manufactory having subjected the proprie- tors to a prosecution on the ground of its destructiveness to vegetation, while nevertheless no data have hitherto been made public, except those derived from the very equivocal and con- tradictory testimony of unscientific witnesses as to the actual mischief done around the works. We have therefore conceiv,. ed that a succinct account of our observations may be useful to others who may chance to be similarly circumstanced with ourselves.— Since the trial, besides repeating our original ex- periments, we have tried the effects of other gases ; and we have annexed the results, not that we imagine them to be im- portant in themselves, but for the purpose of drawing the at- tention of the botanist to this little tried, but probably valua- ble instrument for investigating the physiology of plants. The interesting experiments of M. Marcet on the effects of solid and liquid poisons on vegetable life,* and those related in the subsequent remarks regarding the effects of the gases will show, that the operation of poisons may furnish the attentive inquirer with as many useful facts in the case of vegetable as in that of animal physiology. It was at first our intention to give an account of the lead- ing facts brought out upon the several jury-trials alluded to. But on inquiry, we have found the evidence, as in most pro- secutions for this description of nuisance, so opposite and irre- concilable, that we must rest contented with an abstract of our personal researches. The black-ash, we may simply observe, has been for many years a most important and extensive arti- cle of manufacture, being one of the substances formed in the course of the process for converting into soda the Glauber''s salt, and more particularly the refuse in the making of bleach- ing powder. In the course of the process for preparing it, some chlorine and a good deal of sulphurous acid are evolved, and in those manufactories in which the black-ash is converted into carbonate of soda, an additional quantity of sulphurous acid is disengaged. It was to these gases, therefore, and more • Ann. de Ckim. et de Phys. xxix. SOU. See this Journal, No. vi. p. 293. 142 Drs Turner and Cliristison on the effects of " especially to the sulphurous acid, that our attention was drawn in the first instance. The Sulphurous acid gas appears to be exceedingly delete- rious to vegetables, even in very minute quantity and propor- tion. We first observed that when four, or even only two cu- bic inches were introduced along with a young mignonette plant, into the air of a glass jar of the capacity of 470 cubic inches, the leaves of the plant became greenish-gray, and drooped much in less than two hours and a half ; and though then taken out and watered, it soon died altogether. We next found that when somewhat less than half a cubic inch was introduced into a jar of the capacity of 509 cubic inches, a mignonette plant introduced along with it began to lose its colour and to droop in three hours ; and although taken out three hours after that it languished, and gradually died in the course of a few days. But the peculiar effects of the gas, and its extraordinary de- structiveness, are better shown when its quantity and propor- tion to the air are still less, — as, for example, in the following experiment. A wide-mouthed bottle, containing a mixture of six cubic inches of air and /o^^thsof acubicinch of sulphurous acid, was fixed, mouth uppermost, on a stand twenty inches high ; — at the bottom stood a young mignonette plant, a young laburnum tree six inches tall, and a young larch, which had been all transplanted at least five days before, and had recent- ly been well watered ; — and over the whole was placed and carefully luted to the table a glass jar two feet high, and of the capacity of 2000 cubic inches, so that the proportion of sulphurous acid was nearly a 9000th part. The jar stood in a situation where it was exposed to a bright diffused light, but not to the sunshine. We had previously found in a simi- lar experiment with a mignonette plant alone, that it became affected in less than twenty-four hours ; and in a subsequent experiment with a laburnum visible effects were caused by the same quantity and proportion in nine hours. In the pre- sent instance, on account of the large surface of moist earth exposed, which would absorb some of the gas, the effect was slower and less complete. In forty-eight hours, however, all I the Poisonous Gases o?i Vegetables, 143 the plants were distinctly acted on. The tips of some of the mignonette leaves and larch leaves were grayish-coloured, shrivelled, and dry-looking, and the three lower leaves of the la- burnum were speckled with irregular grayish-yellow dry-looking . spots. The air was then renewed, together with the same proportion of gas, and it was allowed to act for forty-eight hours longer, during which the effects slowly extended to- "wards the footstalks and over more of the leaves. The plants were then taken out. The earth continued moist. The middle leaves of th'e mignonette, but the lower leaves of both the larch and the laburnum had suffered most. The leaves of the mignonette were withered chiefly at the tips or edges ; — most of those of the larch at the tips, in some, however, at the middle ; — those of the laburnum were affected more uni- formly over their whole disk, they drooped considerably, a gentle touch was sufficient to break the leaflets from the foot- stalks, and the footstalks from the stem, — nay, some of the leaflets had dropped off while the plant was in the jar. The bud-leaves were not injured in any of the plants. * The effect of this poison seemed to resemble considerably the ordinary decay of the leaves in autumn. It was invari- ably produced in several repetitions of the foregoing expe- riment.— The proportion of gas was sometimes a ten-thou- sandth only, the quantity a fifth of a cubic inch, and yet the whole unfolded leaves were nearly destroyed in forty-eight hours. We remarked that the withering and curling of the leaves always rapidly increased for an hour or two after the removal of the plants into the open air, so that some leaves which had been apparently but little affected in the jar died afterwards in the air quickly and completely. The whole plant, however, was never killed by these small proportions. Segments near the footstalks, particularly of the upper leaves, continued green and juicy, and the buds put forth fresh though generally stunted leaves. Even when the proportion of gas was larger, the plants were not killed altogether : the stem was not affected unless the proportion was considerable, and even then it was only the top which suffered. — It will be afterwards seen how different these phenomena are from the effects of deleterious gases not irritants. 144 Drs Turner and Christison on the effects of It is particularly worthy of notice that the proportion of sulphurous acid which thus seems to be so deadly to plants, is hardly or not at all discoverable by the smell. When a ten- thousandth part of sulphurous acid gas was intimately mixed with air, we could not be confident that its odour was percep- tible, although we have reason to think our sense of smell is acute ; and when this proportion was mixed in the same jar, and in the same manner as in the experiments related above, but without either plant or moisture being present, we were certain that in eight hours no part of the air in the jar had the slightest odour of the gas. This fact, though simple, is an important one in regard to what has been stated in evi- dence on some prosecutions against chemical manufactories,— namely, that the emanations were not perceptible to the smell in the neighbourhood of the works, and therefore not likely to be in a state sufficiently concentrated to prove injurious. We do not pretend to infer, as an absolute conclusion from these experiments, that manufactories from which sulphurous acid gas is disengaged even in large quantities must be injuri- ous to surrounding vegetation. It is probable, nay certain, that, small as the proportion was which we have tried, the proportion contained in the air in the vicinity of the largest manufactories is a great deal less. But it seems certainly a fair presumption, that, when such extraordinary effects are produced in so short a time, by so minute a quantity, and notwithstanding so liberal an admixture of air, effects analo- gous, if not quite so fatal, will be produced by the lengthened application of a larger quantity, though inferior proportion of the same poison, in a state of constant renewal. The next gas, whose effects we have particularly examined, is the Hydrochloric, or Muriatic acid gas. Its effects have appeared to us not inferior, nay even supe- rior to those of the su]phar(}us acid. In our first experiments with it we found that four cubic inches and a half mixed with a hundred times their volume of air, and two cubic inches mixed with four hundred volumes, began to turn the leaves of a mignonette plant grayish-yellow in ten minutes, then caused it to. droop, and in five hours killed it altogether and irreco- verably ; and that the leaves were wet and acid. We next the Poismious Gases on Vegetables, 145 remarked that half a cubic inch in a thousand times its vo- lume of air began to affect another mignonette plant in an hour, and killed all the leaves in twenty hours ; that the plant, though then tak^n out with its stem erect, soon died ; but that the leaves were not damp or acid, as in the former in- stances. Various inferior proportions were tried with similar results, till at length the following experiment was made : A fifth part of a cubic inch of hydrochloric acid gas was mixed with three inches of air in a long jar, and placed under a glass receiver of the same size and form, and with the same precautions to secure a gradual and thorough mixture, as in the experiments with the sulphurous acid : The plants chosen were a healthy laburnum tree five inches tall, and a little larch tree. In nine hours the edges of some of the laburnum leaves appeared to be curling inwards ; in twelve hours this eflfect was unequivocal: As the latter examination was made by candle light, we could not say positively whether the colour had faded. In twenty-four hours the leaves had all acquired a dull-gray- ish green colour, and dry appearance, and their edges were crisp- ed and curled. The crisping effect increased during the next twenty-four hours, after which the plants were removed into the open air of the room. The lower leaves were evidently most affected, and some of them even dropped their leaflets when the plant was shaken ; none, however, had escaped, ex- cept a young half unfolded one at the top ; all the rest seemed quite dead. As in the case of the sulphurous acid, so here the crisping and curling of the leaves increased rapidly after the removal of the plant from the jar; an effect which is probably to be ascribed to the more rapid evaporation of their moisture, no longer renewed from the leafstalks. The larch plant, whose changes could not be properly seen in the jar, on account of its colour being nearly the same in its natu- ral, as in its withered state, was found, on close examination, to be wrinkled and dry, particularly on the lower leaves, and on the tips of them. Neither of these plants, however, died ; the unfolded leaves were all destroyed, but the buds gradually expanded themselves, though nipped on the tops. This gas must therefore be very injurious to vegetable life, since so small a quantity as a fifth of an inch, although dilut- VOL. VIII. NO. I JAN. 1828. K 146 Drs Turner and Christison on the effects of ed with 10,000 parts of air, destroyed the whole vegetation of a plant of considerable size in less than two days. Nay, we afterwards found that a tenth part of a cubic inch in 20,000 'volumes of air had nearly the same effects. In twenty-four hours the leaves of a laburnum were all curled in on the edges, dry, and discoloured ; and though it was then removed into the air, they gradually shrivelled and died. Like the sulphu- rous acid, the hydrochloric acid gas acts thus injuriously in a proportion which is not perceptible to the smell. Even a thou- sandth part of hydrochloric acid gas is not distinctly percepti- ble ; a ten thousandth made no impression on the nostrils what- Qver, although great care was taken to dry thoroughly the vessels used in making the mixtures. The other gases whose effects we have examined are chlorine, nitrous acid gas, sulphuretted hydrogen, ammonia, cyanogen, carbonic oxide, olefiant gas, and protoxide of azote. But our examination of these has been cursory. Chlorine may be expected to have the effects of hydrochlo- ric acid gas ; and so indeed it has ; but they appear to be de- veloped more slowly. Two cubic inches in two hundred parts of air did not begin to affect a mignonette plant for three hours ; half a cubic inch in a thousand parts of air did not in- jure another in twenty-four hours ; but when the plants did become affected, the same drooping, bleaching, and desiccation were observed. Nitrous acid gas is probably as deleterious as the sulphurous and hydrochloric acid gases. In the proportion of a hundred and eightieth it attacked the leaves of a mignonette plant in ten minutes ; and half a cubic inch in 700 volumes of air caused a yellowish green discoloration in an hour, and drooping and wi- thering in the course of twenty-four hours. The leaves were not acid on their surface. The effects oi Sulphuretted hydrogen are quite different from those of the acid gases. The latter attacked the leaves at the tips first, and gradually extended their operation towards the leaf-stalks ; when in considerable proportion their effects began in a few minutes, and if the quantity was not great the parts not attacked generally survived if the plants were removed into the the Poisonous Gases on Vegetables. 147 aif. The sulphuretted hydrogen acts differently. Two cubic inches in 230 times their volume of air had no effect in twen- ty-four hours. Four inches and a half in eighty volumes of air caused no injury in twelve hours, but in twenty-four hours several of the leaves, without being injured in colour, were hanging down perpendicularly from the leaf-stalks and quite flaccid ; and though the plant was then removed into the open air the stem itself soon began also to droop and bend, and the whole plant speedily fell over and died. When the effects of a large quantity, such as six inches in sixty times their volume, were carefully watched, it was remarked that the drooping be- gan in ten hours at once from the leaf-stalks, and the leaves themselves, except that they were flaccid, did not look un- healthy. Not one plant recovered, any of whose leaves had drooped before it was removed into the air. The effects of Ammonia were precisely similar to those of sulphuretted hydrogen just related, except that after the leaves drooped they became also somewhat shrivelled. The progres- sive flaccidity of the leaves, — the bending of them at their point of junction with the foot-stalk, and the subsequent bend- ing of the stem, — the creeping, as it were, of the languor and exhaustion from leaf to leaf, and then down the stem, were very striking. Two inches of gas in 230 volumes of air began to operate in ten hours. A larger quantity and proportion seemed to operate more slowly. These phenomena, when compared with what was observed in the instances of sulphurous and hydrochloric acid, would ap- pear to establish, in relation to vegetable life, a distinction among the poisonous gases nearly equivalent to the difference existing between the effects of the Irritant and the Narcotic poisons on animals. The gases which rank as irritants in re- lation to animals seem to act locally on vegetables, destroying first the parts least plentifully supplied with moisture. The narcotic gases — including under that term those which act on the nervous system of animals, destroy vegetable life by attack- ing it throughout the whole plant at once. The former pro- bably act by abstracting the moisture of the leaves, the latter by some unknown influence on their vitality. The former seem to have upon vegetables none of that sympathetic influence 148 On the effects of the Poisonotis Gases on Vegetables. upon general life, which in animals follows so remarkably in- juries inflicted by the purest local irritants.* Cyanogen appears allied to the two last gases in property, but is more energetic. Two cubic inches diluted with 230 times their volume of air affected a mignonette plant in five hours ; half a cubic inch in 700 volumes of air affected another in twelve hours ; and a third of a cubic inch in 1700 volumes of air, affected another in twenty-four hours. The leaves drooped from the stem without losing colour, and removal into the air, after the drooping began, did not save the plants. Carbonic oxide is also probably of the same class, but its power is much inferior. Four cubic inches and a-half diluted with 100 times their volume of air had no effect in twenty-four hours on a mignonette plant. Twenty-three cubic inches, with five times their volume of air, appeared to have as little effect • Other occupations prevent us making the requisite inquiries for exa- mining such practical conclusions as our experiments seem to lead to. One, however, may be briefly mentioned. The differences described above show that the injury sustained by vegetation in the heart and vicinity of a great city must be caused by some irritant gas, if circumstances regarding the soil and exposure do not account for it, which they seldom or never will. The plants are rarely killed altogether ; their vegetation is merely blight- ed for the season. In the spring it recommences with a luxuriance not surpassed in country situations ; but when the leaves attain maturity, and have no longer the superabundant supply of moisture they received while young, they are blighted anew. How exactly do these phenomena concur with what we should expect from the influence of the irritating gases as ascertained in our experiments. Such a gas, it is well known, is disenga- ged in abundance from our coal-fires, — namely the sulphurous acid. There has long been a vulgar and very general notion, that coal smoke diffused and diluted in the atmosphere hurts vegetation ; but we are not aware that it has rested till now on any solid reason. A curious fact, indeed, and the only one we have been able to find, is mentioned in Evelyn's Fumifugiumy — namely, that one year, when Newcastle was besieged during the civil war at the Revolution, and coals were in consequence exceedingly scarce in London, in various gardens of the nobility in the metropolis fruit trees, which never bore fruit either before or after, were loaded with it. But the Fumifugium contains so many monstrous and incredible facts, and shows such an uncompromising determination to call in the aid of coal-smoke to account for everything wrong in London which could not be more easily explained, that the modern inquirer will naturally pause before he gives the lively and ingenious author credit even for what appears probable. Zoological Collections. 149 in the same time ; but the plant began to droop when it was removed from the jar, and could not be revived. Olefiant gas in the quantity of four cubic inches and a-half, and in the proportion of a hundredth part of the air, had no effect whatever in twenty-four hours. The Protoxide of nitrogen^ or intoxicating gas, the last we shall mention, is the least injurious of all those we have tried ; indeed it appears hardly to injure vegetation at all. Seventy- two cubic inches were placed with a mignonette plant in a jar of the capacity of 509 cubic inches for forty-eight hours ; but no perceptible change had taken place at the end of that time. In all of the foregoing experiments, with the exception of those made with minute proportions of the sulphurous and hydrochloric acid gases, the gas was placed at the bottom of the jars, and the plant on a stage raised nearly to the top of them. It is hardly necessary to add, that comparative expe- riments were also made on plants in jars of pure air. It is well know that plants are sometimes affected different- ly by the same agent. Some thrive in situations which are in- jurious to others, and where to all appearance the difference does not depend on the nature of the soil alone. Sir H. Davy found that while some plants grow in an atmosphere of hydro- gen, others are speedily destroyed by that gas. We may hence anticipate that a variety of curious and interesting re- sults would be obtained by experiments directed with this view ; but circumstances have not permitted us to undertake the inquiry. We may observe, however, that of six different species of plants subjected to the action of sulphurous acid, aH of them appeared to be affected by that gas nearly in an equal degree. Art. XXV.— zoological COLLECTIONS. 1. On the appearance of Locusts in the Doab.* By G. Playfair, Esq. About the 20th June 1812, a very large flight of locusts was observed hovering about Etawah, which at length settled in the fields east of the town, where they remained some time, and were seen copulating in vast " From the Transaction* oftlie Medical and Physical Society of Calcutta^ vol, i. p. 103. 160 Zoological Collections. numbers : they then took their departure, biit continued to hover about the place for a month afterwards. On the 18th July, while riding in that direction, I discovered an im- mense swarm of very small dark-coloured insects in the vicinity of a large pool of stagnant water : they were collected in heaps, and covered the ground to a considerable distance. These, on minute inspection, proved to be young locusts, but without wings. In this place they remained, hourly increasing in numbers for some days, when the great body moved off. Taking a direction towards the town of Etawah, they crept and hop- ped along at a slow rate, until they reached the town, where they divided into different bodies, still, however, keeping nearly the same direction, covering and destroying every thing green in their progress, and distribut- ing themselves all over the neighbourhood. The devastation daily com- mitted by them was almost incalculable. The farmers were under the necessity of collecting as many people as they could, in the vain hope that they might preserve the crop by sweeping the swarm backwards ; but as often as they succeeded in repelling them in one quarter they approached in another. Fires were lighted all round the fields with the same view : this had the effect of keeping them off for a short time ; but suflScient fuel could not be supplied, and the moment the fires became extinguished, the insects rushed in like a torrent. Multitudes were destroyed by the birds, and many more by branches of trees, used by the farmers for that pur- pose, as well as by their being swept into large heaps, and consumed by firq; yet their numbers seemed nothing diminished. They so completely covered some mango trees, and the hedges surrounding the gardens, that the colour of the leaves could not be distinguished. They had no wings, and at this time were about the size of small bees, their heads of a dark red colour, their bodies marked with black lines. They continued to creep along the ground, but hopped and leapt about when their progress was interrupted. July 27th. They were increasing in size, and had overspread that part of the country in every direction. From the want of rain, and the over- whelming inroad of these insects, the farmers were nearly ruined. No- thing impeded their progress : they climbed up the highest trees, and scrambled over walls, and notwithstanding the exertions of several people with brooms, the verandah and outer walls of the hospital were complete- ly covered with them. They no longer continued to move in one particu- lar direction, but paraded backwards and forwards, wherever they could find food. On the 28th July the rains set in with considerable violence : the lo- custs took shelter on trees and bushes, devouring every leaf within their reach ; none seemed to suffer from the rain. On the 29th it did not rain, and the young swarm again were on the move continuing their depredations ; they were fast increasing in size, and equally lively as before the rain. It rained on the 30th, and again the locusts took shelter on the trees and fences ; several large flights of locusts passed over the cantonments. Destructive action of the Teredo navalis. 151 and I observed that the wings of the young ones began to appear. The head still retained the dark-red colour, but the black lines on the body had become much fainter. Again, on the 31st, large flights continued to pass, driven by the wind to the southward ; of course very few alighted. They caused little mis* chief within our view. The wings of the young tribe (the whole four being now formed) were about one-eighth of an inch in length. After this time, I made no particular observations on their progress, being otherwise engaged ; but they disappeared in a few days. 2. Destructive action of the Teredo navalis on vessels built of Teak Timber* By Mr C. Wilcox. The following interesting observations on the oeconomy of the Teredo navalis is taken from the Report of the Portsmouth and Portsea Philoso- phical Society. They form the report of a lecture by Mr C. Wilcox. " The habits and economy of the Teredo navalis, the most destructive of the testacea, were described, and the irregular shape of the shell, descrip- tion of the head, and formation of the hinge and valves noticed. A fine specimen was exhibited, and the statement of authors who affirm that it extends the whole length of the tube proved to be erroneous ; since these tubes, which are formed by a peculiar secretion from the body of the ani- mal, are often many feet in length and circuitous in their course. This was shown to be the fact, by a large piece of wood pierced in all directions. The manner in which it effects its passage, and the appearance of the interior of the tubes were described. The assertion that the Teredo does not attack teak timber was shown to be incorrect, and its destructive ra- vages on the bottom of ships exemplified, by a relation of the providential escape of His Majesty's ship Sceptre, which, having lost some copper from off her bows, the timbers were pierced through to such an extent as to ren- der her incapable of pursuing her voyage without repair. The lecturer then exhibited the formation of the tubes (through an extent of several feet) in a plank of African timber. Hence the opinion, that the Teredo is attached to one end of the shelly tube was considered to be erroneous, as in this case it would have exceeded seven feet in length. The opinion that the animal revolved was also presumed to be unfounded, for then only one valve (from the peculiar construction of the head) would be ef- fective ; whereas by a seraivolution both are called into action ; while, from its very tender state, and the contorted direction of the tubes, it must of necessity be twisted up, if such revolutions took place. Mr Wilcox then noticed the habits and economy of the Pholades, exhibiting some specimens both in the living and dead state. Their manner of boring was explained, their phosphorescence shown, and their ravages described. The lecturer next adverted to an insect called the Lepisma, and concluding by stating that these minute depredators were frequently so numerous, that 300 will occasionally be found in the space of two inches Square, and their attack commences the moment the timber is in the water, more particularly in the eastern part of the globe. 162 Zoological Collections, ** An interesting debate followed as to the mode of action of the valves of the Teredo; in the course of which Mr Wilcox observed, that he thought Dr Turton, in his observations relative to Sir E. Home's opinion on the modus operandi of this animal, had mistaken tlie action of the double nosed auger, and had described it as a centre bit ; but that their opinions of the method of boring admitted of being reconciled ; the mode appearing to be, that, by a secretion from its body, the decomposition of the material is effected and reduced to a species of soft mud or pulp, which is mecha- nically removed, and a fine polished surface left. This idea, while it agrees with many of the statements, does not invalidate the experiments made on the charcoal produced by burning the excreraentitious matter, and meets the difficulty which at first appears as to the possibility of such fragile animals piercing materials of so hard a texture- " At the conclusion of this lecture, the curator of the museum drew a comparison between the recent Teredines and the fossil remains of that animal, as exhibited in specimens of wood from the London clay of Sheppy ; showing, that, though the identity of these could not now be ascertained, yet such identity was very probable, as their operation and effects appear to have been the same. He also produced specimens of the Mytilus litho- yhdgus, M. Fholadis, and M. rugosus, the two former penetrating ma- drepores, the latter limestone. " Having pointed out the structure of the animals, and the formation of the valves, he concluded, that, possessing no apparent means of producing their perforations by a mechanical operation, this tribe at least might be considered as producing this effect by a chemical solvent, which, as the substances acted upon were calcareous, was probably an acid ; although he admitted that the action of tests had not made the presence of such se- cretion satisfactorily apparent,— recommending a prosecution of observa- tions and experiments, as the subject had excited much attention." iVo/e.— On the subject of boring marine animals, and their means of perforating wood and rocks, see this Journal, vol. v. p. 98, and vol. vi. p. 270. The assumption of a chemical solvent by Mr Wilcox is, in the present state of our knowledge, entirely gratuitous, as the most delicate tests have failed in detecting any such solvent or acid fluid. In supposing the LepismcB also to burrow in submerged timber, we suspect Mr W. labours under a misiake. It is more probable that the animal he alludes to may be congenerous with the one which has committed similar depre- dations on the piles of the Chain Pier at Trinity near Edinburgh, and of which a notice follows. 3. Destruction of the Piles at the Chain Pier by the Limnoria terebrans. As a sequel to the preceding observations the ravages of the Limnoria terebrans on the piles of the Chain Pier at Trinity may be noticed. These piles were on examination found to be perforated through a great part of their thickness by a marine animal, in a very short time, and thus render- ed unserviceable. The extension of the eastern pier at Leith, which was proposed to be chiefly a wooden erection, induced Mr Day, one of the Dock On the aerial excursions of Spiders. 15§ Commissioners, to turn his attention to the subject, and to make various experiments on different kinds of wood submerged at the same place, with the view of learning their mode of boring, and if possible to discover some ' means by which the contemplated erection might be secured from their depredations. We are not aware that any thing has been discovered, fur- ther than the necessity of covering that part of the piles under water by a casing of metal. Reports on the subject from three learned professors in this University were, it is understood, procured by Mr Day, which there is no doubt will have conveyed all the known information regarding the animal, its habits, ami the best mode of securing submerged wooden work from its depredations ; and it would be desirable that the results of their recommendation were generally known, as the animal seems to be pretty generally diffused. The animal was ascertained by Mr Stark to be the Limnoria terebrans of Dr Leach, and which was first described by that gentleman from spe- cimens sent him by Mr Stevenson in wood from the Bell Rock Light- House. It is a very small crustaceous animal, about three lines long, and makes the perforations which are so destructive to submerged wood-work merely as places of retreat. From the observation of the living animal by Pro- ; fessor Grant it does not appear to feed on the ligneous matter. 4. On the means by which Spiders that produce Gossamer effect their aerial excursions. By J. Blackwall, Esq. The following interesting abstract of a paper on this subject read at the Linnaean Society, is given in the Philosophical Magazine for August. '' After noticing, that, in the absence of accurate observation, the ascent of gossamer spiders through the atmosphere had been conjecturally ascribed to several causes, such as the agency of winds, evaporation, electricity, or some peculiar physical powers of the insect, or from their webs being lighter than the air, Mr Blackwall states that the ascent of gossamers takes place only in serene bright weather, and is invariably preceded by gossa- mers on the ground. He then details the phenomena of a remarkable ascent of gossamers, October 1, 1826, when, a little before noon the ground was every where covered with it, the day being calm and sunny. A vast quantity of the fine shining lines were then seen in the act of ascending, and becoming attached to each other in various ways in their motions, and were evidently not formed in the air but on the earth, and carried up by the ascending current caused by the rarefaction near the heated ground ; and when this had ceased in the afternoon they were perceived to fall. An account is added of two minute spiders that produced gossamer, and of their mode of spinning; and particularly when, impelled by the desire of traversing the air, they climb to the summits of varicus objects, and thence emit the viscous threads in such a manner as that it may be drawn out to a great length and fineness by the ascending current, until, feeling themselves sufficiently acted upon by it, they quit hold of the objects on which they stood, and commence their flight. Some of these insects,, which were taken for the purpose of observation, when exposed to a slight |L54 Zoological Collections. current of air, always turned the thorax to the quarter from whence il came, and emitted a portion of glutinous matter, which was carried out into a line." 5. On the Fascination of Snakes. By Mr Nash. '* I have often heard stories about the power that snakes have to charm birds and animals, which, to say the least, I always treated with the cold- ness of scepticism, nor could I believe them until convinced by ocular de- monstration. A case occurred in Williamsburgh, (Mass.) one mile south of the house of public worship, by the way side, in July last. As I was walking on the road at noon day, my attention was drawn to the fence by the fluttering and hopping of a robin red-breast, and of a cat bird, which upon njy approach flew up and perched on a sapling two or three rods distant. At this instant a large black snake reared his head from the ground near the fence. I immediately stepped back a little, and sat down upon an eminence ; the snake in a few minutes slunk again to the earth with a calm placid appearance, and the birds soon after returned and lighted upon the ground near the snake, first stretching their wings upon the ground and spreading their tails. They commenced fluttering round the snake, drawing nearer at almost every step, until they stepped near or across the snake, which would often move a little or throw himself into a different posture, apparently to seize his prey, which movements I no- , ticed seemed to frighten the birds, and they would veer off" a few feet, but return again as soon as the snake was motionless. All that was wanting for the snake to secure his victims seemed to be, that the birds should pass near his head, which they would probably have soon done, but at this moment a waggon drove up and stopped. This frightened the snake, and it crawled across the fence into the grass ; notwithstanding, the birds flew over the fence into the grass also, and appeared to be bewitched to flutter around their charmer, and it was not until an attempt was made to kill the snake that the birds would avail themselves of their wings and fly to a forest one hundred rods distant. ** The movements of the birds while around the snake appeared to be vo- luntary, and without the least constraint ; nor did they utter any distressing cries, or appear enraged, as when squirrels, hawks, and mischievous boys attempted to rob their nests, or to catch their young ones ; but they seem- ed to be drawn by some allurement or enticement, (and not by any con- straining or provoking power.) Indeed, I thoroughly searched all the fences and trees in the vicinity to find some nest or young birds, but could find none. " What this fascinating power is, whether it be the look, or efliuvium, or the singing by the vibrations of the tail of the snake, or anything else, I will not attempt to determine ; possibly this power may be owing to different causes in different kinds of snakes. But so far as the black snake is concerned, it seems to be nothing more than an enticement or allure- ment, with which the snake is endowed to procure his food." I On the reproduction ofDornestic Animals. 155 Observations by Phofessor Silliman. " In the month of June 1823, in company with a friend, I had just crossed the Hudson River, from the town of CatskJll, and was proceeding in a carriage, by the river along the road, which is here very narrow, with the water on one side, and a steep bank covered with bushes on the other. *' Our attention was at this place arrested by a number of small birds of different species flying across the road, and then back again, and turning and wheeling in manifold gyrations, and with much chirping, yet making no progress from the particular spot over which they fluttered. We were not left long in doubt, when we perceived a black snake of considerable size, partly coiled, and partly erect from the ground, with the appearance of great animation, and his tongue rapidly and incessantly brandished. This reptile we perceived to be the cause and the centre of the wild mo- tions of the birds, which ceased as soon as the snake, alarmed by the ap- proach of the carriage, retired into the bushes. The birds however, alighted upon the neighbouring branches, probably awaiting the reappearance of their tormentor and enemy. Our engagements did not permit us to wait to see the issue of this affair, which seems to have been similar to that ob- served by Mr Nash." — Silliman's Journal, June 1827. 6. — Experiments on the reproduction of domestic^ animals. By Mr Ch. GiRON de Buzareurgues, Corresponding Member of the Royal Academy of Sciences. The experiments alluded to, and of which a brief notice was read to the Academy on the 2d April 1827, had for their object to determine the means by which in sheep the number of male or female lambs could be diminished or increased, according to the wishes of the proprietor of the flock. The experiment is stated by its author in this manner : to divide ajlock of ewes into two equal parts, and to cause to be produced by one half of the flock so divided a greater number of males or of females than in the other, according to the choice of the proprietor. This object seems to have been effected in the present instance by a selection of the ram or male ; for it would appear, that, if the male be very young, there will be produced more females than males ; and vice versa, that is, in order to obtain a greater proportion of male Iambs to the females the ram must be four or five years of age. — AnnaL des. Sc. Nat. 7. — On the Esquimaux Beg. By J. G. Children, Esq. ■ From this brief notice by Mr Children on the Esquimaux dog, accom-' panied by a very beautifully executed engraving, it would appear that the editors of the splendid work on Zoology now publishing in France, under the title of L'Histoire Naturelle des Mammifcres, have inadver- tently committed a very great error. They have caused to be represented, as a real specimen of the Esquimaux dog, a spurious issue, the product of a cross breed between a male Newfoundland dog and the female of the true Esquimaux race, which had been presented to the French naturalists by Dr Leach. The error thus committed is stated to have been first pointed out by 156 Zoolog^ical Collections. Captain Sabine in bis supplement to the appendix of Captain Parry's voy- age in 1819-20. Under these circumstances Mr Children gladly embraced the opportunity afforded him by the kindness of Lieutenant Elliot Morris, R. N. of giving an accurate figure of an unquestionable genuine male Es- quimaux dog, brought from the Polar Seas by Mr Richards, in Captain Parry's first voyage, and by him presented to his friend, Mr Morris, in whose possession the dog still remains. Mr Children, in his notice, has given the dimensions, colouring, &c. of the dog in question ; but as the Es- quimaux dogs are unquestionably domesticated, and must therefore be ex- posed to the powerful influence of this cause, we do not think it necessary to republish details which could be interesting only with reference to a wild or undomesticated species of animal.— Zoo /og-ecaZ Journal, No. ix. January 1827. 8. — Elephant, The dismemberment of the genus Elephas, for the purpose of establish- ing a new one under the name of Loxodonta, has been attempted by IMessrs Geoffroy St Hilaire, and F. Cuvier in the fifty-second and fifty-third Livraisons of the L'Histoire Naturelle des Mammiferes. The following remarks by the editors of the Zoological Journal will put our readers in possession of the principal facts on this subject. " M. G. Cuvier first pointed out to the satisfaction of modern zoologists the specific distinction existing between them, and employed to designate the former the name of E. capensis, while to the latter was assigned that of E. Indicus. M. F. Cuvier has now advanced still farther, and has re- garded them as the types of two genera, differing from each other as much as Canis from Hyaena, or Lagomys from Lepus. For the elephant of Asia he retains the original generic name Elephas. The surfaces of its molar teeth present fasciae of enamel irregularly festooned ; while in those of the African elephant, the type of the new genus Loxodonta, the enamel is dis- posed in lozenges. In addition to this striking distinction derived from the dentary system, M. F. Cuvier also enumerates the other characters which have hitherto been regarded as specific, — the smaller, more elon- gated, and less irregular head of the African aniinal, when compared with the Asiatic ; the rounded forehead of the former strongly contrasted with the deep depression in the middle of that of the latter ; the ear of the for- mer also twice the extent, while the tail is only half the length, &c. ''Since 1681 no African elephant has been seen in Europe, until the young female figured by M. Cuvier, which is now alive in Paris, having been sent as a present by the Pacha of Egypt. Its habits, so far as those of a very young animal can be relied on, exhibit none of the ferocity usually ascribed to it, and are indeed fully as mild, intelligent, and trac- table as those of the elephant of Asia." This novelty in the division of the genus Elephas will probably not be accepted by naturalists. The two species resemble each other far too closely to permit of their dislocation into separate genera. We can affirm from personal observation that the habits of the wild African elephant resem- ble entirely those which have been assigned to the Asiatic, and that the for- mer generally are iully taller and larger than the latter. History of Mechanical Inventions^ ^c. 157 Aet. XXVI.— history of mechanical inventions and OF PROCESSES AND MATERIALS USED IN THE FINE AND USEFUL ARTS. 1 . Mr Farey's Improved Lamp. Our readers are doubtless well acquainted with the various contrivances both of a hydrostatic and a mechanical nature, by which oil is raised to supply the wick of a lamp, when it is required that the reservoir of oil shall not be placed above the flame. The most ingenious of these will be found described in the Article Lamp, in the Edinburgh Encyclopoedia, which was written by Mr Farey, the inventor of the jiresent improvement. In place of raising the oil hydrostatically by the pressure of a column or water as in St Clair's and Keir's lamp, or by a piece of clock-work, which pumps up the oil, as in the beautiful contrivance of M. Carcel, Mr Farey puts the oil in a bladder, or other flexible vessel, which is prevented from collapsing by a helical wire spring. Above this bag is placed a disc with several ring- formed weights, which by their pressure force the oil up to the wick. Mr Farey founds his patent right on the idea of " applying the di- rect action of a descending weight, or the direct pressure of a spring to the raising up of oils, or other inflammable fluids in sufficient quantities, regu- lated by the smallness of the holes through which such oil or fluid has to pass in its ascent to the wick of his improved lamp." A drawing and more accurate description of this lamp will be found in Newton's Journal^ No- vember 1827, p. 128. 2. Notice of the new Metallic Compound Artimomantico, resembling gold in colour and weight. This metallic compound is invented by a gentleman at Leghorn, a friend of T. Appleton, Esq. the American consul there, who has sent an account of it with specimens to Dr Mease of New York, where it has been examined by competent judges. It is of the same weight as gold of 18 carats, and can be made hke that of 24. Mr Appleton's snuff" box is made of it, and is always mistaken for pure gold. At a manufactory of it established at Bologna metal buttons are made of it at 50 cents per dozen ; when new they resemble the most highly gilt buttons. The inventor sells the metal to the manufacturers at Bologna at two dollars and 60 cents per lb. of 12 oz. which makes 9 dozen of coat buttons. The editor of the Franklin Journal states that the Artimomantico is soft and bends, and founds its superiority to other gold-coloured metals on its not tarnishing. -^Franklin Journal. . 3. Notice of a Metallic Alloy for plating Iron and protecting it from Rust. This invention is by the discoverer of the Artimomantico, and is commu- nicated by the same gentleman. It is easily and cheaply applied, forms an amalgam with the iron, penetrates to some depth, and effectually pro- tects it from rust. It derives this property from its refusing to unite with 168 History of Mechanical Inventions, atid oxygen at common temperatures, or even when artificially heated. It is formed out of many metals. It does not increase the hardness of the ar- ticle to which it is applied, nor does it efface the finest lines on the sur- face. It does not injure the temper of knives. Four ounces of this com- position is sufficient to cover an iron bedstead; and twelve ounces are valued at a dollar and 50 cents. A company is already formed at Bologna with a capital of 1 00,000 dollars for coating iron work, and they are now drawing out plates which can be united to one another by heat, without any injury to the coating. — Frank- tin Journal, 4. Composition for washing in Sea Water, By Edward Heard^ Chemist, liOndon. This composition, which is secured by patent, is thus made. Take a high- ly concentrated solution of the alkalis, soda, or potash, with an equal weight of any earthy base, (China-clay or porcelain earth is best.) These mate- rials being mixed together are to be ground in a mill in the same way as white lead is ground, and this will produce a thick paste, one pound of which is sufficient to soften four gallons of sea water.— See Newton's Journal, Nov. 1827, p. 151. 5. Process for giving Statues and! Medals the appearance of Bronze, Take two drachms of sal-ammoniac, half a drachm of salt of sorrel, and dissolve them in half a pint of white vinegar ; after having well-cleaned the metal from verdigrease, moisten a brush by dipping it softly into this solution, then rub it continually on the same place till the colour becomes dry and assumes the tone or depth of shade desired. In order that the drying may be more rapid, this operation is to be performed in the sun- shine, or by the heat of a stove. The oftener it is repeated on the same place the deeper proportionably will be the colour of the bronze. This process is used by M. Jacob of Paris. — Journal des Connaiss. Utiles. 6. Account of an improvement in the construction of Bedsteads, Sofas, ^c. This improvement, communicated to Mr Perkins by a foreigner, is very simple and effective. The object of it is to keep the canvass bottom or sacking of a bed always in a proper state of tension. This is effected by making the two horizontal bars or rails to which the canvass is nailed, turn a little round their axis by means of a lever. They are then held in this position, which of course stretches the canvass, by a click and ratchet wheel, which has also the effect of keeping the joints of the rails and posts firmly together. — See Newton's Journal, July 1827, p. 256. 7. Account of new Bricks for building both cylindrical and curved Chim," nies. By Mr J. W. Hiort, Architect. This contrivance is a very ingenious one, and at the same time highly useful. The patent bricks are of a wedge form, as their upper and lower sur&ces are not parallel, and one of their sides has the curve of a quarter of Processes in the Useful Arts. 159 an inch, so that four of them joined together make a complete circle. If two bricks were placed with their thickest sides exactly opposite, the upper and under surfaces of the two, when combined will be parallel, so that in this way a cylindrical chimney will be formed, but when it is necessary to bend the chimney, then two bricks are placed with their thick ends toge- ther, and when it is required to bend it back again, the thin ends of the bricks are placed on the same side as the thick ends were before. This will be understood from Plate III. Fig. 4. Fig. 5 is a horizontal plan of the flue. — See Newton's Journal, Aug. 1827, p. 325. 8. Method of Mooring Ships in Roadsteads. By Lieut. Col. Miller, F.R. S. The method of mooring ships proposed by Col. Miller, consists in secur- ing a large buoy by means of a block of cast iron, so that it cannot be moved by stress of weather, to which a vessel can make fast without letting go her anchor. Col. Miller proposes to make the buoy of the following di- mensions. Length, 16 feet. Diameter at middle, 9 Do. at ends, 7^ Length of chain, 36 Diameter of cast iron block, 3 Do. at bottom, 5^ Height of do. 24 Weight of do. 7 tons. The buoy must be bound with iron, and coppered, and a strong iron hoop must pass round its centre, to which the chain and ring are attached. --Ann, of Phil Aug. 1827, p. 110. 9. On the adhesion of Screw Nails. By B. Be van, Esq. Civil Engineer. The screws used in these experiments were about two inches long — 15 diameter at the exterior of the threads, — diameter at the bottom, the q t depth of the worm or thread being , and the number of threads in ^ 1000 h one inch 12. They were passed through pieces of wood exactly half an I inch in thickness, and drawn out by the weights given in the following table: Dry beech, 460 lbs. Dry mahogany, 770 lbs. Do. do. 790 Dry elm, 655 Dry sound ash, 790 Dry sycamore, 830 Dry oak, 760 The force required to draw similar screws out of deal and the softer wood is about half the above.— PAi7. Mag. Oct. 1827, p. 291. 160 Hutoi'ij of Mechanical Inventions, and 10. On the great Power and Duty of some new Steam Engines. Our mechanical readers are aware that the power of a steam engine is measured by the number of pounds of water that it will lift one foot high by each bushel of coals consumed. Hitherto the best engines have been able to raise only 40,000,000 lbs. of water one foot high by means of one bushel of coals. An improvement, however, has been made by Captain Samuel Grose, which increases their power without any additional com- plication or expence. The first wiiicli he erected was at Wheal Hope with a sixty inch cylin- der, working single as usual. The following was the work which it per- formed : , April, 42,101,739 lbs. July, 55,012,292 lbs. May, 42,241,650 August, 50,979,084 June, 54,725,716 Another engine subsequently erected at Wheal Towan by Captain Grose, having a cylinder of eighty inches, produced the following re- markable effects ; April, 61,877,545 lbs. July, 62,220,820 lbs. May, 60,632,179 August, 61,764,166 June, 61,762,210 Phil Mag. Oct. 1827. 11. Process for preparing Indelible Writing-ink. Make a saturated solution of indigo and madder in boiling water, and in such proportions as to give a purple tint ; add to it from one-sixth to one-eighth of its weight of sulphuric acid, according to the thickness and strength of the paper to be used. This makes an ink which flows pretty freely from the pen ; — and when writing which has been executed with it is exposed to a considerable but gradual heat from the fire it becomes completely black, the letters being burnt in and charred by the action of the sulphuric acid. If the acid has not been used in sufficient quantity to destroy the texture of the paper and reduce it to the state of tinder, the colour may be discharged by the oxymuriatic and oxalic acids and their compounds, though not without great difficulty. When the full propor- tion of acid has been employed, a little crumpling and rubbing of the pa- per reduces the carbonaceous matter of the letter to powder ; but by put- ting a black ground behind them they may be. preserved, and thus a spe- cies of indelible writing-ink is procured, (for the letters are in a manner shaped out of the paper) which might be useful for some purposes; per- haps for the signatures of bank notes. — Brande's Journal. 12. Observations on the Explosion of Steam Boilers. By Mr W. J. Hen- :> 1 WOOD. In the Annals of Philosophy for June 1827 Mr Henwood has published some interesting observations on Mr Taylor's opinions respecting the cause of the explosion of steam boilers, which were reprinted in our Journal, No. xii. p. 335. I Processes in the Useful Arts. 161 ti ]yjj Taylor," says he, " proposes several questions which I shall en- deavour to answer, *' The Pen-y-frau engine," says Mr Taylor, " had been stopped a few minutes, and the workmen had opened tlie fire-doors of three of the boilers, and closed the dampers of two of them. The engineman observed a gust of flame from the fire-place, which was almost immediately succeeded by an explosion." — " In this case," asks Mr Taylor, ** had the rush of the flame from the fire-place any thing to do with the subsequent explosion ?" I think there can be little doubt that the rush of the flame was in conse- quence of sorne fracture having already taken place in the boiler ; probably the fissure was not at first of very considerable size, as we know that wrought iron does not break at once, as cast iron, but rends. The rent being at first small it would have occasioned the rush ; but as the fissure, once made, weakened the boiler, and the aperture not being sufficiently large to permit the escape of a very considerable quantity of water or steam, a moment between the gust of flame and the explosion would in all proba- bility have elapsed. " And admitting that the steam was so far within the pressure that could, by mere expansive force regularly excited, injure Buch a boiler, might not the rupture be occasioned by the void that a vacuum suddenly created might produce ?" That the expansive force of the steam, 30 lbs. on the inch, was not sufficient to injure the boiler, remains yet to be proved, as we do not know the strength of the boilers. Admitting the pos- sibility of a vacuum, it might perhaps help us towards a real knowledge of the cause ; but I am not aware of any circumstances to which the power of forming a vacuum can be ascribed. " Does not the bursting of one boiler after another as at Polgooth seem to indicate that exterior causes operated ? Is it possible to conceive,— sup- posing the pressure equal in two boilers as at Polgooth, both being con- nected to the same steam pipe, — that the relative strength of the two should be so exactly the same as that which would by mere expansive force burst the one should haVft the same effect upon the other?" Mr Taylor informs us that the plates of which the interior tubes are made are \ an inch thick, and those of the outer f ths. Now, if we sup- pose each boiler to be made of 200 plates, would it not be truly surprising if in 400 plates there were not two of the same strength, the thickness be- ing the same, and (as we suppose both boilers were made at the same manufactory) the quantity similar in each ? Here then we have an ex- pression of two known quantities only ; whilst, if we refer the accident to the agency of an explosion of coal gas with atmospheric air, we must take into consideration the activity of the distillatory action, the facilities of escape afforded to the gas in either boiler, the intensity of combustion in the fire-place, the influx of air, &c. which leads us into a much more com- plicated calculation. The evidence then appears to preponderate in favour of the idea of its explosion originating in the expansive force of the steam, which it would seem w^as permitted to obtain too strong an elasticity. ** At the Pen-y-fras engine we see that the fire-door is thrown open, and then the current of air up the flue is stopped by closing the damper ; VOL. VIII. NO. I. JAN. 1828. L 162 History of Mechanical Inventions^ and the interior is filled with atmospheric air, mixed to a certain extent with coal gas ; the latter is increased by the distillatory action of the fire, until the proportion is attained which is explosive ; it takes fire, producing the rush of flame which would be followed by a sudden vacuum in the tube, ' while the other side pressed by the steam gives way to this sudden im- pulse, and is destroyed by a force very much smaller than would be re- quired if uniformly excited." What Mr Taylor says may be very possible, with the exception of the formation of a vacuum. Motion only obtains when the resistance is infe- rior to the force applied, and ceases, except under particular circumstan-* ces, as soon as the two forces become equal. This then is the case in the phenomenon before us. The explosion may occasion a rush of air out- wards through the fire-door, because the elastic force of the fluids within the tube exceeds that of the atmosphere, but as soon as that within has so expanded as to be reduced in elasticity equal to the pressure of the atmo- sphere, no farther emission of air from within the boiler can possibly ensue. Again, supposing the possibility of a diminution in volume of the gaseous matter Avithin the boiler, the fire-door (say l4 feet wide and 24 feet long) in such boilers would afford an aperture quite sufficient to supply (at the moment of the diminution of volume) the void. Hence then it is evi-' dent, that no force at all varying from the atmospheric pressure, can, un-"- der any circumstances, be exerted on the part of the boiler exposed to the' fire. Mr Kenwood is of opinion that hydrogen is not generated by the decom- position of water from leaks in the boiler. He conceives that the sudden- bursts of flame from the chimneys of steam engines arise from gusts of air carrying the flame farther up the flue at some times than at others. Those who take an Interest in this very important discussion will find another paper in the Phil, Magazine, signed an Engineer, in which the author endeavours to show that the explosion of steam boilers is almost always owing to neglect, or to the originally bad construction of the boil- ers. Another correspondent, Mr J. Moore of Bristol states, that steam engines have often exploded on their being stopped, and he is of opinion that this arises from an additional strain on the boiler from within, occa- sioned by the steam which previously had a free passage being prevented from escaping anywhere but at the safety valve ; the aperture of which, compared with the contents of the cyhnder into which the steam passed before, is very small. Mr Moore suggests the application of a large valve on the tube adjacent to the part where the steam is prevented from passing to the engine. 13. Account of the Collection and Preparation of the Fucua saccharinus, a sea-weed J for the Chinese market, and its uses. This vegetable, by the Malays termed Agar-Agar, and botanically Fuctis saccharinusy abounds on the coral shoals in the vicinity of Singapore, and forms a bulky article of native import and export for the Chinese market, a very small portion only being reserved tor the consumption of the settle- ment. Processes in the Use/id Arisi^, ,, , , • - 1 63 Those reefs and shoals exposed by the very low tides during the height of the north-east monsoon afford the most luxuriant crop of this weed, which appears in its native state very similar to a species of fern, the Hamionitis of Linnaeus. The finest agar-agar known in the Archipelago is found on the coast of Billitoii, where it grows to a great length, and fetches when prepared more than double the price of that which is collected elsewhere. On ac- , count of its superior quality it is called by the Malays mayung agar- agar. The whole produce of our vicinity is gathered by the followers and retainers of the Sultan of Johor, who repair to the banks for this pur- pose in the month of December, and remain till April and May, by which time the business is pretty well got through, and gleaners are allowed after this the pickings, until the departure of the Junks, which generally takes place by July, from which time until the next season the beds or fields are allowed to grow. It is reported that this season presents the appearance of an extraordi- narily abundant crop, and it is stated that the common harvest of 6000 pe- culs may probably be doubled. The inhabitants of the islands of Sugi and Moro are the monopolizers of this commodity, the former of whom are divided into two parties, those living on the banks of Sungei Salet (about 400 persons) occupy the east, and the people of Sungei Sugi (about SOO in number) possess the west side. The population of Moro is about 200 souls, and they collect in the Straits of Dryon or Salat Duri, from Red Island to the southward, along the west side only of Pulo Duri. The weed is here found scanty and poor, when compared to the produce of Sugi- The grand field extending from the Buffaloe.rock to the east side of Pulo Sugi, about fourteen miles in length, by a nearly similar breadth, belongs to the people of Sungei Salet, who, assisted by the Orang Laut from more distant parts, collect on Pulo Trong, and fish the extensive shoals about Pulo Dankan. The Sungei Sugi people are confined to their own shores. During the season, from 1500 to 2000 poor wretches are more or less engaged in the pursuit, subsisting themselves on their means during the whole time. The weed is plucked by the hund very readily, stowed in small boats, and taken ashore, where it is exposed fOr two or three days to the sun, and then brought to Singapore, partly by the natives themselves, and partly by Chinese, who visit the spot, and by taking small investments of rice, &c. &c., by administering to the crying wants of the reapers, and bribing the agents of the Sultan, are enabled to make more advantageous contracts. The whole collection is, however, under the control of the Sultan, whose agents have the power of levying a duty, or allowing the labourers a sum for their trouble as they please, which never exceeds one- third of the value of the weed, when imported into Singapore, fetching generally' in its then half-dry state, and very heavy, from twelve to eighteen Spanish dollars per bahar of twelve peculs. The Chinese sailors belonging to the Junks are the next performers, for i64 Proceedings of the Royal Society of Edinburgh. it falls to their lot to complete the drying, and prepare the article for ex- portation to China. For this purpose the streets, and every vacant spot in the town, are occupied with mats spread out and covered by the agar- agar in various stages of exsiccation. The first process is washing in salt water, and the picking out of all extraneous matter ; after this, exposure merely dries it, and it requires but little attention to pick out parts which occasionally decompose as the process goes on, and to house it in case of rain, which is very prejudicial to its preservation. — Indeed that which, through neglect, has felt the effect of showers of rain seldom keeps to China. The labour attending it is not very great, and is nearly the same as kelp undergoes in England previous to calcination. In its dry state, when packed iJp ready for exportation, it is worth from three to four dollars per pecul, and fetches usually in China double that sum, but it must be remembered that the duty is very high. The article is kHown to the Chinese by the name of Hy-Chy, and is converted by them to various useful purposes, such as glue, paint, &c. The chief con- sumption of it is in the dressing and glazing of their cotton manufactures, and the preparation of sacrifice paper, and paintings for their temples. A small portion of the finest part is sometimes made into a firm jelly, wliich on being cut up, and preserved in syrup, makes a delicious sweet- meat. We may here remark, that where the weed abounds, between Red Island, in the Straits of Dryon and Battam Point, so called in Horsburgh's charts, there is no passage for ships, the islands and shoals are extremely numerous, and called by the natives emphatically Pulo sa Gantang-, mean- ing that there are as many islands and shoals as there are grains of rice in a gantang-, a measure about the size of an English gallon. — Calcutta Go- vernment Gazette, October 26. Akt. XXVII.— proceedings of the royal SOCIETY OF EDINBURGH. November 26th. — At a general meeting of the Royal Society the fol- ing Office-bearers were elected. President. — Sir Walter Scott, Baronet. Vice-Presidents. — Right Hon. Lord Chief- Baron. Lord Glenlee. Dr T. C. Hope. Professor Russell. Secretary — Dr Brewster. Treasurer. — Thomas Allan, Esq. Curator of the Museum. — James Skene, Esq. Physical Class. — Lord Newton, President. John Robison, Esq. Secretary Counsellors. — Sir William Forbes, Bart. Professor Wallace. Dr Home. Dr Turner.. Proceedings of the Royal Society of Edhiburgli. 165 Sir T. Makdougall Brisbane. James Hunter, Esq. Dr Graham. Dr W. P. Alison. Literary Class.— Henry Mackenzie, Esq. President, P. F. Tytler, Esq. Secretary. Counsellors. — Right Hon. the Lord Advocate. Lord Meadowbank. Sir Henry Jardine. Thomas Kinnear, Esq. Sir John Hay, Bart. Dr Brunton. Dr Hibbert. Sir W. Hamilton, Bart. Dec. 3.— Dr Turner read the first part of a Paper, entitled " An Ex- amination of the Ores of Manganese." A letter from Captain Parry to Dr Brewster was read, accompanying two sets of hourly meteorological observations made on the ice and on board the Hecla on the 17th of July last. The first of these sets of observations were made in 824° N. lat., the highest at which a meteorological instrument was ever used. The second set was made in lat. 79° 55' in a harbour on the north-east of Spitzbergen. In this letter Captain Parry mentions the cu- rious fact, that they experienced that season at least twenty times as much rain as in any other summer they passed in the arctic regions. A Paper by Mr Thomas Graham, M. A. was read on the influence of the Air in determining the Crystallization of Saline Solutions. The following, among many objects of natural history and the fine arts, were presented to the Society by George S win ton, Esq. Secretary to the Government, Calcutta, and F. R. S. E. 1. Three fine Marble Statues of Burmese gods. 2. Two Models, as large as life, of a Dwarf now in Calcutta. 3. Head of a Dugong. 4. Numerous Barrels and Bottles, containing Snakes from various parts of India. 5. An Armadillo. 6. Ship Fish from Arracan. 7. Head of a Horned Beetle. 8. Book of Natural History in the Talien language. 9. Two Dresses of Carian Women of Tavoy. 10. Bamboo joints containing Tabasheer. 11. Specimens of the Shola, in its natural state, and formed into sheets like paper. 12. Corals and Shells. 13. Specimens of Oils, Varnishes, Bhela or marking Nuts, Gums, Mi- -^' nerals, &c. ■ 14. Stuffed Birds. 15. Large Sponge, or Neptune's Cup, from Singapore. 16. The Leaf Insect from Sylhet. 17. Skeleton of a Boa Constrictor. 18. Petrified Trunk of a Tree from the Irawaddy. 19. Large Chama gigas from the South Seas. 166 Scientific Intdligence. 20. A pair of Elephant's Tusks. 21. Skeleton of the Iguana, &c. &c. &c. Art. XXVIII.—SCIENTIFIC INTELLIGENCE. I. NATURAL PHILOSOPHY. ASTRONOMY. 1. Solar Eclipse of November 1826 observed at Naples* — 'ITie eclipse of the sun was seen in the most beautiful manner under a true Italian sky on November 29, though the weather preceding and following was bad. As I had no proper instrument for observing it, I contented my- self with throwing the sun's image through a pocket-glass on a sheet of paper, and measured the observation. I had previously by projection obtained the time of the eclipse, and during its continuance made several meteorological observations, not a single cloud appearing on the horizon to disturb their accuracy. The whole may be classed as follows : Naples. App. Time. 11^ 16' Eclipse begins (calculated.) 12 0 Temperature in the sun, 844*. 12 2 Visible conjunction in AR. 12 25 Dig. eclipsed 6' 33' (measured.) 12 25i Middle. Digits calculated, 5"* 42'. 12 27 Visible conjunction in Long. 12 30 Temp, sun 8H°, shade 55°. 12 35 nearly. Digits eclipsed 5" 15. 12 40 Temp, sun 82|* shade 51 i°. 12 46 Digits eclipsed 5° 2'. 12 53 Temp, sun 84° 51^° -h in the shade 1 0 Temp, sun 84|°, do 1 0 Digits eclipsed 4" 12'. 1 10 Temp, sun QT shade 52°— 1 20 89° 52° + 1 2f» Digits eclipsed 0° 55'. 1 35 End calculated — Temp, sun 90°. As I had the means of making accurate observations, I resolved to try to what accuracy the end might be determined by the naked eye, merely screened by a smoked glass. At 1^. 32^, the eclipse was some way from being oflP, and I believe that half a minute after it would not have appear- ed to be gone, for at 1**. 33' I judged it to be just gone to a very few seconds; and, on the whole, I think I may say, that, under such favourable circum- stances, the end of a solar ecHpse may be determined by the naked eye to a quarter of a minute on either side of the truth. Such is the accuracy of the human eye in completing precisely the periphery of an unfinished cir- cle. The space described by the moon from the sun in the sum of the above specified limits did not amount to 15". In the previous experiments on 3 Astronomy-^Optics. 167 the thermometer, the one in the sun had its bulb wrapped in very thick soft black silk, and exposed above a bunch of white paper on a stone bal- cony fronting the south. The result from the one in the shade ought uni- formly to be diminished one degree. The thermometer was not perhaps sufficiently sensible to denote the minute changes which may have taken place during the eclipse in the shade ; but the instrument in the sun, which was both excellent and sensitive, shows the eflPect of the observation in di- minishing, and even counteracting the natural increase of heat at this period of the day, and afterwards of accelerating it to a great degree as the shadow went off. As there were no clouds of any kind, adventitious altera- tions did not interfere. a. 2. Opposition of Vesta to the Sun. — This planet was in opposition to the sun on the 'l5th December, in R. ascension, 5^^ 30' 40" and N. Decli- nation, 19° 15'. The following are the places of this planet. R. Asc Decl. N. 1828, June 1. 5^ 12' 27" 19° 47' 2. 5 11 28 19 49 3. 5 10 30 19 52 3. Opposition of Juno to the Sun in March 1828. — This planet will be in opposition to the sun on the 25th March in R. Asc. 12.^ 27' 52" and Decl. N. 2° 15'. The following are the positions of this planet given by Mr Taylor for March and April. R. Asc. Decl. 1828, March 5. 10. 15. 20. 12 42' 35" 0°38i S. 12 39 18 0 Oi N. 12 35 42 0 454 N. 12 31 49 1 30 N. 25. 30. April 1 5. Opposition. 12 23 55 2 58 N- 12 22 21 3 144 N. 12 19 20 3 47 N. 10. 12 15 46 4 25 N. 13. 12 13 44 4 46 N. Ann. of Phil. ^^ Variable Star in the Serpent. — Professor Harding of Gottin- 4. iV gen has discovered a small variable star in the Serpent. Its position for 1800 is in right ascension 235° 22' 3" and in north declination 15° 44' 48". Its period seems to be about 11 months. When smallest it is entirely invisible. — Phil. Mag. OPTICS. 5. On the Luminous Appearance of the Ocean.* By J. Henderson, Esq. — On the 5th of March 1821, when on board the licensed ship Moffat, in N. latitude 2°, and W. longitude 21° 20', a strange anomaly occurred in the phosphorescent appearance of the sea, and one which, as far as I am From the Transactions of the Medical and Physical Society of Calcutta, vol. i. p. 107. 168 Scientific Intelligence. acquainted, has never hitherto been remarked. During a gentle breeze, the continuation of the north-east Trades, the sea appeared uncommonly luminous, and increased gradually in brightness, from a little after sunset until near midnight. The intensity was particularly great about nine o'clock ; and every one who then kept his eyes fixed upon it but for a short time, was immediately seized with headach, giddiness, pain in the eyeballs, and slight sickness. Some on board certainly felt these symp- toms more violently than others; but there was none who was not more or less affected by them. For my own part, the headach, &c. which im- mediately followed my looking at the water, was particularly severe ; nor did it go off until morning. I cannot give a better idea of my sensations, than that the effects resembled those produced from having smoked an over quantity of tobacco. The brightness gradually decreased long before dawn, nor did it ever afterwards impress us with the same peculiar effects I have just described. The luminous appearance of the sea seems as yet to have excited but little attention among philosophers, who are content with ascribing it to fish spawn, or animalcules. Of the two, I should rather be inclined to adopt the latter opinion, though their actual existence has not yet been ascertained. The following are my reasons for doing so. l.y^. The luminous appearance is greatest where there are evidently few- est fishes. 2d, They are often seen in great masses, many fathoms from the sur- face. Now, as they do not give light without motion or agitations, it fol- lows that these cannot be in the state of rest their position would lead us to suppose. 3d, They are of greater size, and more thinly spread in higher latitudes; whereas near the line they become more and more minute, and are seen in infinitely greater numbers. 4>th, The luminous appearance varies according to the quarter from which the wind blows ; and as fish spawn is, comparatively speaking, in- animate, it is improbable that so slight a cause should produce such a change upon it. The shoals of them we observe below the surface appear to be owing to their attaching themselves to animal or vegetable matter, whose specific gravity being somewhat greater than water, it has sunk till it found an equilibrium. I have often observed them with a tolerably good micro- scope ; but the motion of the vessel, and other circumstances, give me little confidence in the experiments I have made. The most interesting subject, however, is the principle in which their resplendent property re- sides. It is generally denominated phosphorescent ; but phosphorus, in its most concentrated state, affords no effect such as I have described. I have witnessed it burning in oxygen gas, while its light almost rivalled that of noon day : its action then upon the eye was nothing more than would have been produced by looking for a few moments at the sun ; while during the phenomenon I have described the slightest beam of that luminary would have rendered the whole invisible. If, therefore, we Optics-'-^Magnetism* 169 conclude, that the symptoms I have mentioned constitute a natural pro- perty inherent in the insect, and produced when its light and numbers are in a sufficient degree of intensity, we at the same time ascribe to it a power which no luminous animal or other substance possesses but itself. In conclusion, I have only to remark, that having made some experiments on the specific gravity of the sea, I found that it decreased, with slight ex- ceptions, gradually from the line, so that, if these are correct, the ani- malcules are found smaller and more numerous where the specific gravity of the sea is the least, provided at the same time the temperature admits of their existence. MAGNETISM. 6. Eaton's Proposed Improvement on Magnetic JVeedles.-^Viofessor Amos Eaton proposes that the needles of compasses should be tipped with silver, brass, &c. This not only preserves the points from rust, but with- draws the poles from any attractive power in the brass, whether it arises from hammering, or from any particle of steel or iron which may have been accidentally left in the brass. — Dr Silliman's Journal, No. xxv. p. 16. 7. Professor Hansteens Magnetic Tour to Siberia, — -We mentioned in our last Number that this eminent philosopher proposed to set Out to Siberia, to examine the intensity of the earth's magnetism in that vast country. We are happy to inform our readers that the national assembly of Nor- way has voted the necessary funds for this purpose. Dr Erman Junior, the son of the celebrated Professor Erman of Berlin, has offered his ser- vices as the companion and assistant of Professor Hansteen, and from his knowledge of mineralogy and geology, we may expect much important in- formation respecting Siberia. Professor Hansteen sets out in March, from Christiania for Stockholm and St Petersburgh, where he joins his compa- nion from Berlin. We trust that Professor Hansteen will endeavour to ob- tain some information respecting the mean temperature of Siberia, which acquires a great interest from the proximity of the Asiatic Pole of maxi- mum co\d»— -Letter Jrom Professor Hansteen. 8. On the Magnetic Actions excited in all Bodies by powerful Magnets* —In a memoir on this subject read to the Academy of Sciences, on the 17th September, M. Becquerel points out the positions in relation to a powerful magnet, assumed by a small cartouche of paper filled with tritox- ide of iron, or a needle of any substance whatever freely suspended, and the position of whose centre of suspension varies in relation to the nearest pole of the needle. When this centre is very near one of the extremities, and in a line parallel to the line of the poles, the needle will place itself in a direction perpendicular to this line, in place of taking the direction of the line which a magnetical needle would have done. If the centre of suspension is brought nearer the magnet, from 1 to 5 millimetres, the needle then deviates from the perpendicular direction. From numerous ex- periments, M. Becquerel has shown that the essential difference in the phenomena produced in a needle of iron, or steel, and needles of other substances is, that in the first, the distribution of magnetism is constantly 170 Scientific Intelligence in ike direction of their length ; whereas in the lattery it is in the direction of their breadth, particularly when a single bar magnet is used, — Le Globe, September 20th 1827. ELECTRO-MAGNETISM. 9. On the rotation of a magnet about its axis. — M. Pouillet has succeeded in giving a magnet a motion of rotation by means of a metallic ring nearly encircling the magnet, which must be nearly cylindrical, and by placing on the ring a small quantity of mercury in contact with the magnet, and which the capillary force prevents from escaping out of the small inter- val which is left between the magnet and the ring. By this means, the communication being made between one of the ends of the pile and the magnet, as in Ampere's apparatus, by a small cavity full of mercury hollowed in the upper end of the magnet, the communi- cation with the other end of the pile takes place only at the points of the horizontal section of the needle or the point where the ring is placed. By this arrangement we may compare the velocities of rotation which corre- spond to each position of the ring along tlie magnet. M. Pouillet has shown that the velocity is a maximum when the ring is placed at the middle of the magnet ; that it goes on diminishing, but remains always in the same direction whether the ring rises or falls ; and that the magnet remains im- moveable when the ring is placed very near one of its extremities beyond the pole.— ie Globe, Aug. 28, 1827. METEOROLOGY. 10. Sound of the Aurora Borealis in Iceland, observed by Mr Henderson."^ *' The most striking aerial phenomenon exhibited by an Icelandic winter is doubtless the Aurora Borealis or Northern Lights, which are here seen in all their brilliancy and grandeur. I had an opportunity of contemplating them almost every clear night the whole winter, sometimes shoothig across the hemisphere in a straight line, and presenting to the view, for a whole evening, one vast steady stream of light; but more commonly they kept dancing and running about with amazing velocity, and a tremulous motion exhibiting as they advanced some of the most unrivalled appearances. On gaining one point of the hemisphere, they generally collected as if to mus- ter their forces, and then began again to branch out into numerous ranks, which struck off to the greatest distance from each other as they passed the zenith, yet so as always to preserve the whole of the phenomenon in an oval shape ; when they contracted nearly in the same way as they ex- panded, and after uniting in a common point, they either returned in the course of a few minutes, or were lost in a stream of light, which grew fainter and fainter the nearer it approached the opposite side of the heavens. They were mostly of a dimmish yellow, yet often assuming mixtures of red and green. When they are particularly quick and vivid, a crackling noise is heard, resembling that which accompanies the escape of the sparks from the electrical machine. They almost always took their rise from the sum- mit of Mount Esian, which is about due north-east from lieykiavick, and proceeded to a south-west direction. When visible the whole length k Electro-Ma-gnetism-^MeteoTology. 171 of the hemisphere, they were uniformly strongest towards the north and north-east, and were always sure to be seen in that quarter, when they appeared nowhere else. Once or twice I observed them in the south, but they were very faint and stationary. " In the days of superstition, these celestial wonders were received as por- tending certain destruction to nations and armies, and filled the minds even of the most enlightened with terror and dismay. At the present day, the Icelander is entirely free from such silly apprehensions, and only regards their uncommonly vivid appearance as predicting a hurricane or storm ; an observation founded on experience, and which I frequently brought to the test, when it invariably turned out, that in less than twenty- four hours, after the Northern Lights were in a great commotion, we had either sudden squalls, or a heavy gale of wind from the north. " It was scarcely ever possible for me to view this phenomenon without reflecting on Job, xxxvii. chap* 22. * The golden splendour cometh out of the north ;* and it seems extremely probable, that it is to these Elihu here alludes. The idea not only agrees with the light spoken of in the preced- ing verse, but is far more suitable to the latter clause of the same, ' With God is terrible Majesty.' In some parts of Asia, the northern lights are so terrible, that ' they strike the beholders with terror.' Every animal is struck with terror, even the dogs of the hunters are seized with such dread, that they will fall on the ground and remain immoveable, till the cause is over." — Henderson's Iceland, p. 277. Edinburgh, 1819. 11. Auroras Boreales observed in Roxburghshire in 1827. — The follow- ing Aurora? were observed at AUerly, near Melrose, in Roxburghshire. October 6, - Brilliant. November 18, - Brilliant. 19, - Faint. 12. Great Dryness in the Antilles in 1827. — A distressing and singular dryness was this year experienced in the Antilles ; during a period of sixty six days not a drop of rain fell. This dryness was succeeded by abun- dant rains, but the crops had been previously almost wholly destroyed. These rains were immediately preceded by an earthquake, which was felt at Martinique on the 3d of June at 8 o'clock in the morning. As the yellow fever raged this year with great severity in the Antilles, M. Moreau de Jonnes considers this fact as an objection to the hypothesis that this disease is produced and kept up by a moist heat. These facts were communicated by M. Moreau de Jonnes to the Academy of Sciences on the 17th September last.— ie Globe, September 20, 1827. 13. Meteoric Stone at Futtehpore. — A communication was laid before the Medical Society of Calcutta from Dr Tytler, giving an account of a meteoric stone which fell at Futtehpore in the Doab, in November 1822. On the evening of that day^, a short time after sunset, and before daylight had entirely faded, a meteor was distinctly seen, shooting with considerable velocity in a direction nearly north-west. This appear- ance was also observed by Europeans in the lines, and natives in the l^a Scientific Intelligence. city ; and is described to have comprised a blaze of light, surrounding a red globe about the size of the moon, wliich impressed the spectators with the idea of that luminary descending from the skies. The same phenomenon, and at the same moment of time, it appeared from the newspapers, was likewise noticed at Hazareebaug, in Bengal, a distance of upwards of two hundred and fifty miles eastward from Allahabad. But, as the atmosphere was clouded when the ball was seen at the latter station, and the light was sufficiently strong to illuminate the horizon, the meteor appearing between the clouds and earth's surface, it is evident that at that particular moment its elevation could not have been greater than a few thousand feet from the ground. The meteor descended at Rourpoorj a village under the jurisdiction of Futtehpore, situated nearly seventy miles north-west from the station of Allahabad, immediately after it was seen at that place. The descent was accompanied with noises resembling the ex- plosion of distant artillery, and a stone was seen falling, which, in the act of descending, is said to have emitted sparks similar to those proceeding from a blacksmith's forge. A strong sulphurous smell was also perceptible, and when first discovered the stone was hot to the touch. Besides the stone thus actually known to have fallen, several others of a similar de- scription were picked up, at the distance of several coss from each other, whence it appears that a shower of stones in this instance took place, — or that several stones were enclosed in the body of the meteoric globe, which, analogous to balls emitted from a ShrapnelVs shell, were projected in va- rious directions at the moment of explosion. The meteor seen at Hazareebaufr and Allahabad is identified with the shower of stones which fell near Futtehpore. The fragments amount to several pounds in weight. One weighs nearly one pound and six ounces avoirdupoise, and is heavy for its size. The external surface is of a deep black colour, the stone exactly resembling a body coated with black paint or pitch. In some places are also seen smooth black specks, darker than the rest of the covering, that looks as if it were cracking from the action of fire, to which it has evidently been exposed. The coat is likewise indent- ed or rough, as if it originally possessed a softer consistence, which has been compressed by the action of some hard body, and in certain places is also covered with a yellowish-coloured substance. This black coating is not thicker than the finger nail, and encloses a whitish, or ash-coloured mass, which is very friable, contains a number of shining particles, and exhibits small brown specks, and streaks, or veins of the same colour. Upon examination with a magnifying glass of considerable power the shining particles are discovered to be evidently metalHc, and to present an appearance exactly resembling the Tutenague, or white copper, named put by the natives, that is commonly employed in the bazars for the for- mation of domestic utensils. The three substances just mentioned are connected together by a fourth of an earthy consistence, and so soft that all the 9ther substances may be easily separated by the point of a knife or the nail, and the stone itself crumbled to pieces between the fingers. This cement is of a grey colour. Meteorology-^Chemistry. J79 The proportion and size of these different constituents vary considerably in different specimens ; but all of them bear a striking resemblance to each other. The specific gravity varies from 3.352 to 4.281. Dr Tytler then noticed the different theories that have been proposed to account for the appearance of these aerolites, and shows that none of them are free from objections. He then suggests their terrestrial origin, and that they have been emitted from volcanos upon the surface of the earth, for the following reasons : 1^;, The stones in their appearance plainly bespeak a volcanic ori- gin, and it is evident they have been subjected to the action of intense heat. 2' The recent infusion of gall-nuts produces a copious yellowish white pre4 cipitate in a concentrated solution of tartar emetic. The liquid is render- ed turbid, when the proportion is two grains to an ounce ; but it under- goes no change when the tartar emetic is in the ratio of one grain to an ounce of water. Sulphuretted hydrogen acts with far greater delicacy and certainty than any of the others. On transmitting this gas through eight ounces of water containing one grain of tartar emetic, the solution instantly acquired an orange colour ; and after saturating the liquid with the gas, and boiling in order to expel the excess of it, a considerable quantity of the sulphuret of antimony quickly separated. * From these experiments it fully appears, that of all the tests of tartar emetic enumerated by toxicologists, sulphuretted hydrogen is the only one which is sufficiently delicate for being entitled to confidence. It is the only one, also, the indications of which as to the presence of antimony are precise. The orange tint'of the precipitated sulphuret of antimony can scarcely be mistaken for any other metallic sulphuret by a person acquaint- ed with its appearance. Its colour is quite different from that of orpiment * This precipitate is commonly, but I conceive incorrectly, regarded as a hydro- sulphur ct of the oxide of antimony. It appears rather to be a hydrated sulphuret of the metal. 176 Scientific Intelligence. or of the bisulphuret of tin ; and from the sulphuret of cadmium, to which it bears a greater resemblance, it is distinguished by its ready solubility in a solution of pure potash. On the contrary, the other tests, taken sing- ly, supply no proof whatever of the presence of tartar emetic ; though, when they all agree in their indications, their evidence is not likely to be deceptive. In describing sulphuretted hydrogen as a test of tartar emetic, it is al- most unnecessary to state that this gas merely indicates the presence of antimony, without directly showing in what state it existed. But since tartar emetic is the only pharmaceutic preparation of antimony which is soluble in water, the detection of the metal itself, in judicial cases, leaves little doubt of its having been in the form of the double tartrate. This, however, is not a point of much importance, because all soluble antimo- nials are poisonous. In order to ascertain if sulphuretted hydrogen may be relied on for dis- covering the presence of antimony in complex animal and vegetable fluids, tartar emetic, dissolved in water, was mixed with tea, broth, porter, and milk, in such quantity that each solution amounted to four ounces, and contained two grains of the compound. Through these solutions, after being acidulated with tartaric acid, boiled and filtered, a current of sul- phuretted hydrogen gas was transmitted during fifteen or twenty minutes. In the three first liquids an abundant precipitation ensued immediately, and the same took place in the milk after boiling. The precipitate subsid- ed easily from each, and the colour of that from the tea, broth, and milk, was quite characteristic. That procured from the porter was not so satis- factory at first ; but on collecting and drying it upon a filter, the paper presented the distinct orange tint of the precipitated sulphuret of anti- mony. In recommending the use of tartaric acid, I may observe that the em- ployment'of this substance should in no case be omitted. According to my observation, all the precipitates occasioned in tartar emetic by reagents, sulphuretted hydrogen excepted, as well as by animal or vegetable fluids, are readily dissolved by tartaric acid. Thus the precipitates occasioned by lime-water, or muriatic acid, disappear instantly on the addition of tar- taric acid ; and the compound of tannin and the oxide of antimony, whe- ther formed by the infusion of gall-nuts, tea, or cinchona bark, may easily be rendered soluble by the same means. If milk is present, muriatic acid should likewise be employed, by which the coagulation of the caseous mat- ter is more completely ejBfected. In order, therefore, to form a rule appli- cable to every case, the following directions may be given : The fluid sup- posed to contain tartar emetic should be mixed with a drachm or two of muriatic and tartaric acids, boiled for a few minutes to separate any sub- stance coagulable by heat, and then allowed to cool, and filtered. The liquid should next be exposed to the action of sulphuretted hydrogen, and boiled to expel the excess of the gas ; after which the sulphuret will sub- side if tartar emetic had been present. After procuring the sulphuret of antimony by the process above describ- Chemistry. 177 ed, it is important to subject the compound to some operation by which the metal may be obtained in a separate state. Professor Orfila, in his work on Toxicology, (vol. i. p. 465, third edition,) states, that the pre- cipitate in question, '' dried on a filter, and mixed with charcoal and the potash of commerce, gives a button of metallic antimony by the action of heat. This reduction of the oxide of antimony by charcoal may be made in an earthen crucible, and is completed in the space of about ten or tyvelve minutes." It is chiefly to this part of the process for detecting antimony that I have found reason to object. I do not, indeed, deny that the pro- cess will succeed perfectly, when a considerable quantity of the materials is employetl ; but in operating on such quantities as are likely to be met with in medico-legal investigations, my attempts to procure the metal in this way have proved completely fruitless. Thus, four grains of the sul- phuret, precipitated from tartar emetic by sulphuretted hydrogen, and well dried, were mixed with an equal weight of charcoal and dry carbonate of potash. The mixture, protected on all sides by charcoal, was placed in a Hessian crucible, carefully luted, and was then exposed to heat during fifteen minutes. The experiment was twice repeated ; and on one occasion a full red, and on the other a commencing white heat was employed, but in neither case could I perceive any trace of the metal. On examining the residue chemically, I found that some particles of metallic antimony were diffused through the mass, though they could not be discovered by the eye ; while another portion still remained as sulphuret, and was dissolved by the potash on the addition of water.* These experiments were varied by mixing the sulphuret with black flux, and heating the mixture in a glass tube by means of a spirit lamp ; but a metallic globule was not pro- cured, though the heat was augmented by aid of the blowpipe. It is worthy of remark, that in none of these trials was there any appearance of a metallic subli^nate; so that, were colour insufficient for distinguishing orpiment from the sulphuret of antimony, the black flux would afford an easy mode of distinction. Having failed in my attempts to procure the metal by the preceding process, I had recourse to another whicli proved successful. It is founded on the property hydrogen is known to possess, of separating sulphur from antimony at an elevated temperature, — a property, of which advantage has been taken for the purposes of analysis. In performing this operation, the dry sulphuret is placed in the middle of a glass tube about three inches long, and a quarter of an inch in diameter. One end of the tube is con- nected by means of a cork with a vessel, from which hydrogen gas is evolved ; and to its other extremity is adapted a bent tube, which opens under water, so as to conduct away the hydrogen, and at the same time ex- clude atmospheric air. After the air within the apparatus has been expel- led, heat is applied by means of a spirit lamp to the part of the tube on which the sulphuret is placed. The decomposition of the sulphuret commences • This, we apprehend, is owing to the formation of a double sulphuret of anti- mony and potassium — E. T. VOL. VIII. NO. I. JAN. 1828. M 178 Scientific Intelligence. at a temperature by no means elevated ; but in order to render it completo and fuse the antimony, the glass should be made red hot, and kept in that state for five or six minutes. The temperature at the close of the process may with advantage be increased to bright redness by the use of the blowpipe. The appearance of the metal within the tube depends upon the manner of conducting the experiment. If the sulphuret had been placed in a heap, the metal is found partly in a spongy state, and partly in minute globules ; but if it had been diffused over a considerable space, no globules appear, and the metalhc lustre is indistinct. The metallic nature of the spongy mass may, in general, be brought distinctly into view by placing it on a piece of white paper, and pressing it with the nail or the blade of a pen- knife. The result also depends on the velocity with which the hydrogen is transmitted through the tube. If the gas passes rapidly, some of the metal is hurried off at the moment of separation from the sulphur, and is deposited within the tube as a metallic film, which is sometimes very dis- tinct. If, on the contrary, the passage of the gas is slow, this appearance does not take place. By means of this process, I have succeeded in procuring from the tenth of a grain of the sulphuret metallic antimony, the lustre of which could be distinctly seen with the assistance of a lens. From half of the precipitates procured from the mixture of two grains of tartar emetic with broth and milk, I procured distinct metallic globules. Should a considerable quantity of animal or vegetable matter subside with the sulphuret, the metallic antimony will then be so mixed with char- coal that its lustre cannot be seen distinctly. This occurred to me in de- composing the sulphuret obtained from porter. In a case of this kind the mixture should be placed in an open tube, and heated to redness by means of a spirit lamp. The antimony is then oxidized, and the oxide, which attaches itself to the cool parts of the tube in form of a white powder, may be recognized by its appearance and volatility. 20. Ultimate analysis of several vegetable substances. — By M. F. Mar- CET. {An. de Ch. et de Ph. vol. xxxv.) The mode of analysis employed by M. Marcet is that which was introduced by M. Gay-Lussac and The- nard. It consists in mixing the substances to be analyzed with peroxide of copper and heating the mixture to redness. Its composition is calculat- ed from the loss of weight experienced by the oxide of copper, and the quantity of water and gas which are collected, the substance having been previously dried by exposure to the action of sulphuric acid under the ex- hausted receiver of the air-pump. Starch in its common state, and modified by heat, (Amidine of Cavcn- tou) is thus constituted :— Common starch. Torrefied starch. Starch from malt. Carbon, 43.7 35.7 41.6 Oxygen, 40.7 58.1 51.8 x Hydrogen, 6.6 6.2 6.6 Chemistry. 1*79 Torrefied starch contains more oxygen and less carbon and hydrogen than common starch. Though modified starch in some of its properties is analogous to guni, in its chemical constitution it differs more from that substance than common starch. The hordein of Proust is composed, according to M. Marcet of 44.2 parts of carbon, 47.6 of oxygen, 6.4 of hydrogen, and 1.8 of nitrogen. It differs slightly, however, from starch in the proportion of carbon, oxygen, and hydrogen, and in containing nitrogen. It differs also from the fibrous matter of the potato, which consists, according to Marcet, of carbon 55.7, oxygen ^^22, hydrogen 7.8,' and nitrogen 14.5. The zimome of M. Taddei was likewise analyzed, but appears similar in composition to common glu- ten. If this be true, it follows that the elements of gliadine must be in the same proportion as those of zimome. Yeast was found to consist of carbon 30.5, oxygen 57.4, hydrogen 4.5, and nitrogen 7.6. 2J. On a chloride of Manganese, remarkable for its volatility. By M. J. Dumas, {An. de Ch. et de Ph. v. 35.) — This chloride corresponds to the manganesic acid, and is transformed by contact of water into muriatic and manganesic acids. It is readily formed by putting a solution of manga- nesic acid into strong sulphuric acid, and then adding fused sea-salt. The muriatic and manganesic acids mutually decompose each other; water and the chloride of manganese are generated, the former of which is re- tained by the sulphuric acid, and the latter assumes the gaseous form. This chloride, however, does not constitute a permanent gas. When first formed, it appears as an elastic fluid either of a copper or greenish co- lour ; but on traversing a glass tube cooled down to — 15° or — 20° C, it is condensed into a greenish-brown coloured liquid. When generated in a capacious tube, its vapour gradually displaces the air, and soon fills the tube. If the vapour is then poured into a large flask, the sides of which are moist, the colour of the vapour changes sud- denly on coming into contact with the moisture, a dense smoke of a pretty rose tint appears, and the sides of the vessel acquire a deep purple colour, which is occasioned by manganesic acid. In fact, water thus coloured yields a copious precipitate with nitrate of silver ; and when heated with potash undergoes the same change as mineral chameleon. The best mode of preparing this remarkable compound consists in form- ing the common green chameleon, and converting it into red by means of sul- phuric acid. The solution, when evaporated, leaves a residue of sulphate and manganeseate of potash. This mixture, treated by strong sulphuric acid, yields a solution of manganesic acid, into which are added small fragments of sea salt, as long as coloured vapour continues to be evolved. An analogous compound is formed when sea salt is replaced by a fluoride, but M. Dumas has not succeeded in collecting it so as to submit it to exa- mination. From the circumstances under which the new chloride is generated, it must obviously contain as many equivalents of chlorine as the manganesic acid does of oxygen. If, as Forchhammer supposes, this acid consists of one 180 Scientific Intelligence. equivalent of metal, and four of oxygen, the new chloride will be compos- ed of 28, or one equivalent of manganese, and 144, or four equivalents of chlorine, and hence contains four times as much chlorine as the common chloride. 22. On the properties of Sulphur. — By M. J. Dumas, (Ibid.) M. Du- mas, in verifying the well known fact that sulphur liquefied by a certain heat is rendered more tenacious by an increase of temperature, has ascer- tained the degree at which these changes take place. M. Dumas fixes the point effusion of sulphur at 108° C. Between 110° C and 140° it posses- ses the greatest degree of fluidity, and is of an amber colour. It begins to thicken near 160° C and acquires a reddish tint ; and at the tempera- tures between 220° and 250° C. it is so tenacious that the vessel may be inverted without causing it to change its place. From 250° to its boiling point it becomes liquid again, but never to the same extent as when at 120° C. It is also a familiar fact, that sulphur heated to a sufficient degree is ren- dered tenacious and soft if suddenly cooled by being poured into cold wa- ter. M. Dumas finds that the temperature required for this effect is 220° or above it. If the temperature is below 170° C. when the sulphur is put into cold water, it becomes brittle. 23. On a new method of preparing the Deutoxide of Barium. By M. QuESNEViLLE, Fils, (Ibid.) — The method proposed by M. Quesneville, which appears to us a great improvement, is to introduce nitrate of baryta into a luted retort of porcelain, to which a Welter's tube terminating un- der an inverted jar full of water is attached. Heat is then gradually ap- plied to the retort, and a red heat is continued as long as there is any dis- engagement of nitrous gas or nitrogen. When these have ceased, and pure oxygen passes over, which is a proof that all the nitrate is decomposed, the process is discontinued. The peroxide of barium is then found in the retort, the baryta and oxygen having united in their nascent state. III. NATURAL HISTORY. MINERALOGY. 24. Brachytypous Lime-Haloide of Mohs. — Professor Stroraeyer has an- alyzed the brachytypous lime-haloide of Mohs, and has found that the following varieties of this species consist of 1. 2. 3. 4. Magnesia, 41.06 40.19 42.40 43.44 Protoxide of iron. 8.57 10.53 6.47 4.98 Oxide of manganese. 0.43 0.49 0.62 1.52 Carbonic acid. 48.94 48.48 49.67 49.93 Carbon, 0.11 No. 1. is a crystallized wine- yellow variety, from the Zitterthal in Salz- burg. No. 2. a crystallized pale yellowish-brown variety, in chlorite slate, from the Fassathal in Tyrol. No. 3. a granular straw-yellow variety, ac- companied with bitterspar and talc, from St Gotthard mountain in Swit- Mineralogy. 181 zerland: No. 4. a granular black variety, from Hall in Tyrol. As the mineral contains no lime, it cannot be placed under the genus lime-ha- loide. Professor Stromeyer called it Magnesite-spar. — Gottinger gelehrte Anzeigen, No. 158, 1827. 25. Chrysolite in the Cavities of Obsidian. — Professor Gustavus Rose of Berlin has found in the cavities of Obsidian, in the Jacal Rock near Real- del-Monte in Mexico, little crystals, greenish, and reddish-yellow, and transparent, which belong to the species of prismatic Chrysolite. — Pog- gendorff's Annalen, Vol. x. p. 323. 26. N'ew Minerals. — Professor Breithaupt (Schweigger's Journal der Chemie und Physik, N. S. Vol. xx. p. 314, &c. gives a description of the following new mineral species : I. Karphosiderite, Name derived from the straw-yellow colour. Re- niform masses, rarely from granular composition, uneven ; shining and glimmering in the streak, with resinous lustre. Colour and streak pale and high straw-yellow. Hardness = 4.0 ... 4.5. Sp. Gr. = 2.5. Feels greasy. Before the blowpipe upon the coal it becomes black and melts in a strong fire into a globule, which is attractible by the magnet. In glass of borax it is easily soluble, and with salt of phosphorus it melts into a black scoria. It contains oxide of iron, phosphoric acid, water, with small quantities of oxide of manganese and zinc. It has a great similarity to oxalite, yellow iron-ore, or iron-sinter. It occurs in Greenland. II. Mesitine-spar. Name derived from fxiTitmiy that is, what stands in the middle (of brachytypous lime-haloide, and brachytypous parachrose baryte.) Rhombohedral, R — cc. R =. 107° 14' R + oo. Cleavage dis- tinct, parallel to R. Lustre vitreous. Colour dark-greyish, and yellowish- white... yellowish-grey. Streak white. Transparent... translucent. Hard- ness =4. Sp. Gr. = 3.34...3.37. Before the blowpipe the mesitine-spar decrepitates. In muriatic and nitric acid a feeble effervescence takes place, but it is entirely soluble. It contains probably magnesia, lime, pro- toxide of iron, and oxide of manganese. It is found in little crystals, in rhombohedral quartz at Traversella in Piemont. III. Tautolite, Prismatic. Fundamental form, scalene four-sided pyramid. aib'^c —I: 1.9451: 1.3648. Observed combinations : 1, ilf r= CO a : 6 : c = 109^ 46'. ^ = 4 a : Z> : ao c = 51° 52'. A = Gc a: b : c Fig. 9 of Mobs treatise, 2, M; g; h; i=z ^ a: I b : c = 36° 22'. ) ^^^ p, . ttt !?;«. a Cleavage, only in traces and interrupted, parallel to Mand h. Fracture conchoidal... uneven. Lustre vitreous. Colour velvet-black. Streak grey. Opaque. Hardness = 6.5. ..7.0. Sp. Gr. = 3.865. Before the blowpipe, upon charcoal, the tautolite melts to a blackish scoria, which is attracted by the magnet ; with borax it melts to a clear green glass. These and other reactions show that the mineral consists of silica, black protoxide of 182 Scientific Intelligence, iron, magnesia, and alumina. It is found in the volcanic feldspath-rocks, in the neighbourhood of the Lake Laach Sea in Rhein-Prussia. The tau- tolite seems to be related to the chrysolite, as the Ceylanite to the Spinelle. 27. Mica from New Jersey. — It is tetarto-prismatic, and blackish-green. The angles, in reference to Fig. 32 of Moh's Treatise on Mineralogy, are the following. M on T = 73° 40', P on M = 110°, P on T — 118° 0'. Cleavage parallel to P. — {Vide Kobell, in Kastner's Archiv.fur die gesammte Naturlehre, Vol- x. p. 291. 28. Dr Thomgon's analysis of Pure Chromate of Iron, — Hitherto the specimens of chromate of iron were mixed with octaedral iron and other extraneous matters. Dr Thomson however succeeded in finding octaedral grains nearly pure. Green oxide of chrome Peroxide of iron, - - . Alumina, ... Silex, .... Or when free of all mixture. . 515.0 - 31.0 - 13.0 - ii trace Atoms. 2 57.1 1 28.6 1 14.3 Green oxide of chrome. Peroxide of iron, ... Alumina, - . . . . Ann. des. Mines, 1827, p. 280. GEOLOGY. 29. On the Boulder-stones in the North of Germany. — Professor Haus- mann, in a paper read before the Royal Society of Gottingen, at the meeting of the 25th August 1827, has shown that the numerous fragments of rocks and boulder-stones found in the sand-plains of Northern Germany, and in Denmark, originate from the mountain-formations in Sweden and Norway. 30. Baron Von Buck on Volcanoes. — Baron Leopold Von Buch had pre- pared in 1 825 a physical description of the Canary Islands. This important work is not yet published, but a notice of a most interesting part of it, a trea- tise " on the nature of the volcanic phenomena in the Canary Islands, and their connection with other volcanoes of the earth," is given, with many new notices, in vol. x. of Poggendorff's Annalen der Physik und Chemie. " Baron Von Buch, one of the most celebrated observers of volcanic phenomena, di- vides all volcanoes into central ai.nA /«nmr(Reihen)volcanoes; the last appear to follow great fissures in the earth, and these again take the direction of the primitive rocks. Under the central volcanos this celebrated geologist ranks those of the Lipari Islands, Etna, the Phlegraean fields, Iceland, the Azo- res Islands, the Canary Islands, the Islands of Cape Verde, the Gallo- pagos. Sandwich, Marquesas, Society, and Friendly Islands, the Island of Bourbon, and many other volcanoes in the interior of several countries. All others are linear volcanoes. 31. Greenstom and Porphynf qfihe -ffar^*.— Careful observations iu the General Science. 183 mines near Harzgerode, in the south-east part of that mountain, so inte- resting to the geologist, show that the greenstone and porphyry are raised from the interior of the earth. Baron Leopold Von Buch is of the same opinion, with regard to the granite of the Hartz and the porphyry in the neighbourhood of Ilfeld. 32. Geological Map of Germany in 42 sections. — This great map is pub- lished by Simon Shropp and Company in Berlin, under the direction of the Baron Leopold Von Buch. The twelve sections now published con- tain I, the title-page ; 2, the table of colours ; 3, the review of the sections ; 4, -the country of Odensee ; 5, of Copenhagen ; 6. of Lincoln ; 7, of liOn- don; 8, of Boulogne; 9, of Munich; 10, of Salzburgh; 11, of Milan ; 12, of Triest. IV. GENERAL SCIENCE. 33. Discovery of a remarkable structure in the knee-joint of the Echidna hystrix of Australasia. By Mr F. J. Knox. — We confine ourselves, at the request of Mr Knox, to a very brief notice of this remarkable structure which he has discovered to prevail in the knee-joint of the Echidna, and to a certain extent also in that of the Ornithoryn' chus paradoxus, Blumenbach ; but the notice, though short, will be intel- ligible to all anatomists acquainted with the structure of the human knee- joint. That peculiar structure in the human knee-joint, usually known by the name of the ligamentum adiposum, constitutes, in the corresponding joint of the Echidna, a broad double membrane, dividing the joint into two perfectly distinct synovial cavities. In the superior of these cavities, the articular surfaces are the patella and a portion of the condyles of the fe- mur ; in the lower cavity the articular surfaces are the inferior half of the same condyles and the upper surface of the tibia. A full account of this discovery, with explanatory drawings, has been transmitted some months ago to the Royal Society. 34. Hydrogen Gas from Salt Mines employed for producing light, and for fuel. — In the salt mine of Gottesgabe at Rheine, in the county of Teck- lenbourg, there has issued for sixty years from one of the pits, which has on this account been called the Pit of the Wind, a continued current of inflammable gas. The same gas is produced in other parts of the mines. M. Roeders, the inspector of the salt mines, has used this gas for two years not only as a light but as fuel for all the purposes of cookery. He collects it in pits that are no longer worked, and conveys it in tubes to the house. It burns with a white and brilliant flame. Its density is about 0.66. It contains only traces of carbonic acid and sulphuretteel hydrogen, and there- fore should consist of carbonated hydrogen and olefiant gas. 35. Natural Gas Lights at Fredonia.— This village, on the shores of Lake Erie, is lighted every night by inflammable gas from the burning springs, as they are called, in its vicinity. Captain Hall has visited this village and will no doubt give us a good account of it on his return. 184 Celestial Phenomena, January ^^ April 1828. Art. XXIX.— list OF PATENTS GRANTED IN SCOTLAND SINCE JUNE U, 1827. 18. June 14. For certain Improved Machinery for Spinning Cotton. To Philip Jacob Heisch, London. 19. .July 2. For certain Improvements in Machinery for the purpose of Spinning Wool, Cotton, &c. To Lambert Dexter, London. 20. June 30. For Improvements in Machinery for Hackling or Dressing and Cleaning Hemp, Flax, and Tow. To Solomon Robinson, county of York. 2L July 5. For certain Improvements on Locomotive or Steam Carriages To Timothy Burstai.l and John Hill, bothof Leith. 22. July 17. For certain Processes for Rendering Distillery Refuse pro- ductive of Spirits. To Robert More, county of Stirling. 23. August 4. For certain Improvements in the process of preparing and cooling Worts or Wash from Vegetable Substances for the production of Spirits. To Robert More, county of Stirling. 24. August 8. For certain Improvements in apparatus for spinning Fibrous Substances. To William Church, of Birmingham. 25. August 23. For certain Improvements on Capstans. To Charles Phillips, Esq.county of Kent. 26- Sept. 5. For certain Improvements in Sizing, Glazing, or Beautifying the materials employed in the manufacturing of Paper, Pasteboard, &c. To Gabriel de Soras, county of Middlesex. 27. October 3. For an Improvement on Steam Engines. To Peter Burt, County of Middlesex. 28. October 24. For a New and improved method of forming and mak- ing of hollow Cylinders, Guns, Ordnance, Retorts, &c. To Joshua Horton, County of Stafford. Art. XXX.— CELESTIAL PHENOMENA, From January 1st, to April 1st, 1828. Adapted to the Meridian of Greenwich, Apparent Time, excepting the Eclipses of Jupiter's Satellites, which are given in Mean Time. N. B. — The day begins at noon, and the conjunctions of the Moon and Stars are given in Right Ascension. n. H. M. s. -NUAni. I 17 60 O Full Moon. 4 4 ^6%^Sn'^' 7 8 9 13 11 I 30 ?6^n~ 9 16 48 49 Im. II. Sat. IJ. 9 19 15 ({ Last Quarter. 9 22 44 22 D d « TIJ ) 68' N. 10 17 3 32 Im. I. Sat. % 11 11 11 16 y \n . 12 22 29 46 )C5»TTJD64'N. D. H. M. s. 13 15 6 21 ?7 c5 cT A F7 2r S. 15 22 idT-n 16 12 24 A New Moon. 17 7 ?6«^n 17 18 56 58 Im. I. Sat. 9/ 18 19 0 enters CS5 20 11 56 23 8 }) First Quarter. 11 6^*^ 23 18 25 22 ^6^^^ 26 15 18 48 Im. I. Sat. % Celestial Phenomena, Jamuiry 1828 — April 1828. 185 D. 29 31 31 15 17 19 7 14 22 23 5 5 5 19 7 8 14 8 11 8 12 10 16 10 16 11 7 11 13 14 22 16 20 18 9 18 15 19 2 20 6 22 2 25 17 27 19 42 48 d 1 « 2s T) 36' FEBRUARY. 30 12 13 15 54 52 39 53 43 24 57 45 58 11 12 S. 16 26 41 58 33 57 45 6 30 27 25 37 38 20 54 47 20 ^□0 ^^ Im. I. Sat. 11 ^ Sup. c5 0 Em. III. Sat. 11 d " ,0. }) 5' N. d P ^ y n ^n d ^ TIJ D 1' N. d 2 tf :£^ ]) 53' N. ff Last Quarter. Dc54^-])1 Im. I. Sat. If. Im III. Sat. U $6^W , Ira. I. Sat. % A New Moon. ?d^^ D d«K ]) 1 Im. I. Sat. % enters K d

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I. — On the supposed Injiuence of the Aurora Borealis upon the Magnetic Needle, in reply to the Observations of M, Arago, as communicated to the Academy of Sciences^ on the ^^d January 1828. w Nothing is more agreeable, and certainly nothing more use- ful to the progress of science, than the candid and temperate discussion of such scientific questions as admit of difference of opinion. Science is sure to gain by the collision of minds even of unequal strength, — by the scrupulous examination of state^ ments often mutilated and partial, and by the fair and manly array of facts and arguments which either our prejudices or our ignorance have placed in apparent opposition. Compelled, therefore, as we are, to take up the gauntlet, which an eminent member of the Academy of Sciences has thrown down to us, we shall endeavour to discuss the subject with no other feelings but those which the interests of truth and of science demand. At a meeting of the Royal Academy of Sciences, held at I Paris on the 22d January 1828, " M. Arago* made a commu- nication relative to a letter recently written by Mr Dalton, on several magnetic phenomena, and particularly on an observa- tion of the Aurora Borealis. M. Arago prefaced this commu- * This passage is translated from an account of the proceedings of the Academy, published in Le Globe of the 26th January 1828, and an abt stract of it has been printed in almost all the English and Scotch news- papers, i; -^^ VOL. VIII. NO. II. APKIL 18^8. N 190 On the supposed irifluence of' the nication with some illustrations necessary to point out its im- portance. " Since the commencement of the last century, several natural philosophers, among others Celsius and York, (a misprint, we presume, for Hiorter) had remarked that the appearance of the Aurorae Boreales ahvays occasioned in the magnetic needle irregular and very sensible movements, a certain proof that they attj'ibuted to magnetism the phenomena of' these Auroras, At Paris, Father Cotte and Cassini put it beyond a doubt that the Aurorae Boreales exercise a magnetic influence even in our climate, whatever be the distance which separates us from the polar regions. But M. Ar ago has gone much Jarther. He is the first person who has maintained that not only do the Aurora; Boreales impress movements on the needle wherever they are visible, and wherever also they might be seen if the clouds did not conceal them ; but that this influence extends much farther, and that even where they are not visible from their not passing the horizon, they still manifest themselves in the motions of the magnetic needle. " This assertion has been keenly controverted, chiefly in Eng- land, and particularly by Dr Brewster of Edinburgh ; and our celebrated natural philosopher (M. Arago) in order to esta- blish the truth of it, has for some years marked at Paris, where the Aurorae Boreales are no longer seen, the days on which they ought to have been perceived in higher latitudes. Hitherto his predictions have been airways Jbund exact, but a singular ex- ception took place about two years ago. On the 29th March 1826, between eight and ten o'clock p. m. in very clear weather, the magnetic needle in the observatory of Paris exhibited the most distinct movements, in consequence of which M. Arago had anncmnced that an Aurora Borealis had taken place in the north. Hitherto this prediction had not been verified, and the English philosophers saw in this the ground of a grave objection. But Mr Dalton''s letter actually contains the account of an Aurora Borealis which happened on the 29th March 1 826, exactly between eight and ten o'clock in the even- ing. This Aurora, whose height was not very considerable, (three leagues if we rightly understood it), formed a very large Aurora Borealis on the Magnetic Needle. 191 arch (of three leagues extent and about as much in widtli) that is to say, it presented all the conditions necessary to agitate the magnetic needle.'* -j^» .j ■* In the preceding passage it is distinctly asserted as M. Ara-: go's opinion, 1. That the Auroras Boreales, whereiier they are visible, im- press motions on the magnetic needle. 2. That the Aurorae Boreales, wherever they are prevented from being visible by clouds, impress similar motions upon the magnetic needle. 3. That the Aurora Boreales impress the same motions upon the needle, even when the needle is observed at places where the Aurorae Boreales are never seen. 4. That all M. Arago's predictions of Aurorae Boreales from the movements of the magnetic needle at Paris have been ful- filled, with one singular exception, which Mr Dalton's letter has removed. We shall now proceed to examine the truth of these general propositions ; and if we do not entirely overturn them in their imposing generalities, we anticipate at least the thanks of our readers for having shown them the other side of the question, which is so completely concealed in the preceding communica- tion to the Academy of Sciences. There can be no doubt, as stated by M. Arago, that Cel- sius, Hiorter, Father Cotte, and Cassini, to whom we add Wargentin, and our celebrated countryman Canton, observed that the magnetic needle was often agitated during an Aurora Borealis ; but we cannot agree with M. Arago, that such ob- servations are a certain proof that they attributed to magnetism the phenomena of these aurorce. Two events may accompany one another even always^ and yet they may not have to each other the relation of cause and effect. The agitation of the needle; and the Aurora Borealis, may be the concomitant effects of a more general cause ; and this general cause may produce the one effect without producing the other, or it may produce both of them, or it may itself exist without producing either of them. This, indeed, is the opinion of Mr Canton himself, who considers the Aurora as the light arising from the electri- 192 On the supposed injluence of' the city of the heated air, and who attributes the disturbance of the needle, not to the Aurora, but to the effect of the same heat on the great terrestrial magnet, — a result which he has illustrated, by placing a needle under the influence of heated magnets. Mr Canton regards this opinion as strengthened by the fact, that the inhabitants of northern countries observe the Aurora to be remarkably strong when a sudden thaw happens after severe cold weather. This opinion is countenanced by the observa- tion of Mr Winn, recorded in the Phil. Trails, for 1774. " I believe the observation is new that the Aurora Borealis is coiutantly succeeded by hard southerly or south-west winds, (the warmest winds in this climate,) attended with hazy weather and small rain. I think I am warranted from experience to say constantly ; for in twenty-three instances that have occur- red since I first made the observation, it has invariably obtain- ed. The gale generally commences between twenty-four and thirty hours after the first appearance of the Aurora."" The Reverend James Farquharson of Alford, in Aberdeen- shire, who has observed the Aurora for many years, states the same opinion, that it precedes or accompanies westerly or south-easterly * gales. These views will receive a singular confirmation when we examine the observations of Colonel Beaufoy ; and we have adduced them, not as our own opinion, but in order to show that very competent judges have believed, that the Aurora Borealis is the effect of a cause which may also produce agitations in the magnetic needle, and that the two phenomena may co-exist, either occasionally or constantly, with- out the one being the cause of the other. We now come to a period when the variation of the magne- tic needle became the subject of regular observation. Colonel Beaufoy, a name which will ever be venerated in the annals of English science, began at Hackney, near London, a regular series of observations, not only on the magnetical needle, but on the state of the atmosphere. He observed, with a delicate apparatus, the variation of the needle three times a-day. His • We suspect this to be a typographical error for south-westerly, as the author in the very next paragraph describes a fine Aurora during a souths westerly gak. Aurora Borealis mi the Magnetic Needle. 198 observations began in March 181B, and were, with the exception of J 81 6, continued till 1821, and the numerous agitations of the magnetic needle which he observed, were diligently compared with the state of the weather. All these observations have been given to the world, and by their means it is in the power of any philosopher to study the relation between the irregularities of the needle, and the meteorological or electrical phenomena of the atmosphere. He can compare these irregularities with the Aurorae which took place between Hackney, (near London,) and Thurso in the north of Scotland, a distance of seven de- grees of latitude, in which a much greater number of Aurorae must have been observed than in the same distance of seven degrees which intervenes between Paris and Leith. As Aurorae are almost always recorded in the English and Scotch magazines and newspapers, it would be useful to science if M. Arago would enter upon this examination. If he does so, the general result will be this : He will find a certain number of the agitations of the needle accompanied with Aurorae Boreales: He will find a certain number of Aurorae which were not ac- companied with any irregular indications of the needle ; and he will find a great number of agitations of the needle which were not attended with Aurorae, but which, as Colonel Beau- foy has stated, were accompanied or followed by squalls and gales of wind, principally from the southern quarters of the horizon. We come now to M. Arago's own observations. In the Royal Observatory of Paris there is a delicate magnetic needle, the variations of which have, we believe, been carefully ob- served for some years ; but the series of observations which are made with it have never been published ; and though M. Arago is the editor of a monthly journal, and prints regularly all the meteorological observations made in the observatory, yet the Jar more important magnetic observations, upon the authority of which he builds theories and utters prophecies, are withheld from the public eye. At particular times he ob- serves agitations of this needle, and he predicts that an Aurora has happened in the north. At another, time he reads in the EngUsh journals the account of Aurorae, and looking back to 194 On the supposed influence of the his magnetical observations, he finds that the needle was not " true to the pole." All this is very well so far as it goes ; but as M. Arago has established a hypothesis on the authority of these observations, and as he maintains this hypothesis with so much keenness as to identify it with his own reputation, we humbly suggest to him, that it is his duty as a man of science to publish these observations without delay. Some philoso- phers will thus be indulged with the luxury of prediction which he now monopolizes, while others will enter upon the more useful occupation of drawing up a list of all the irregular agitations of the needle, and classing them according to their magnitude or their duration, and of comparing them with the Aurorse Boreales which they have become acquainted with either by reading or by observation, and with the more strik- ing meteorological phenomena of the atmosphere. Until this is done, philosophers are entitled to regard M. Arago"'s deduc- tions as little more than the special pleadings of a party in- terested in the establishment of a favourite hypothesis. In order to illustrate the force of these observations, we shall give an example of M. Arago's mode of reasoning ; 1st, when he has received information respecting an Aurora ob- served in Scotland ; and, 2dly, when he predicts the existence of one from his magnetical observations. 1. Dr Coldstream and Mr Foggo of Leith observed on the 17th August 1825, at 10^ p. m. a display of the Aurora Bo- realis, which was " neither vivid nor long-continued, and pre- sented only the usual appearance of that meteor." Upon examining his magnetical observations, M. Arago finds that there was no agitation whatever in the needle that evening^ and it had then its ordinary position. But he finds that at half past eight o''clock in the morning, 13J hours be- fore the Aurora began, *' the declination of the needle was 5' greater than the mean of the month at the same hour. Here, then, the Aurora takes place at Leith on the 17th August, and it is admitted that during its existence the needle is still. This is no doubt a stubborn fact, but such is the ingenuity of hypothesis, that M. Arago " suspects that this was the termina- tion of an Aurora Borealis of the day." If the suspicion were Aurora Borealis on the Magnetic Needle. 195 correct, why was not the Aurora seen from 7** till lO'^ ? but even admitting that it was the termination of an Aurora of the day, why did the magnetic needle at Paris not feel its influ- ence on the evening of the 17th ? Another case of exactly the same kind occurred on the 4th November. An Aurora of' great beauty^ with numerous and very bright rays, appeared at Leith in the evening ; but the magnetical needle at Paris is then perfectly quiescent. From nine till two p. m. it was much agitated, and M. Arago again supposes that this " was most likely the remains of an Aurora of the day." 2. We next proceed to a prediction which is thus announ- ced : " In this same month of August, on the night of the 2lst, the morning of the 22d, the night of tfie ^6th, and par- ticularly on the night of the 29th, great anomalies were ob- served in the extent of the oscillations of the needle. On all these occasions the sky was I believe clouded at Leith. If not, and the observers there did not see the Aurora, for instance, on the night of the 29th of August, we will be obliged to ad- mit that there exist other causes of which we are still ignorant, which excite considerable influence over the magnetic needle." " In reply to this remark," says Dr Coldstream,* " I may ob- serve, that the notes in our Journal of the state of the sky on the night of the 21st, and morning of the 22d, are not satis- factory ; that the night of the ^6th was particularly clear, with bright moonshine, and that much cloud prevailed on the 29th, and so that had an Aurora existed we could not have seen it." Here, then, we have an agitation of the magnetical needle at Paris on fmr days, the 21st, 22d, 26th, and S9th August 1825, and yet Aurorae, so far as we can find, were seen neither in Scotland or England. The night of the 26th was particularly clear, and though clouds prevailed on the 29th at Leith, yet the predicted Aurora, had it existed, might have been seen elsewhere, and must have been recorded. Before concluding this part of the subject, we may add, that an Au- rora, " which played with considerable brilliancy," was seen at Leith at 10"^ p. m. on the 11th September, and we believe • See this Jovrnal, No. x. p. 90. 196 On the supposed hifluence of the that there was no corresponding agitation of the needle at Paris on that day. We may now ask the candid inquirer after truth to compare these facts with the assertions made by M. Arago in his com- munication to the Academy of Sciences. Do they support the sweeping conclusions which are there deduced ? or do they not rather entirely overturn them ? Before we quit this part of the subject, we must notice a very inexplicable passage in the communication to the Acade- my of Sciences. In speaking of the agitation of the magnetic needle on the ^9th March 1826, between 8 and 10 p. m., ayd of his own prediction that an Aurora Borealis had taken place in the north, M. Arago says: " Hitherto this prediction had not been verified ; and the English philosophers saw in this the ground of a grave objec- tion,'" Now, we do not scruple to characterize this statement as a philosophical dream. The prediction was verified ; and the English philosophers took no cognizance of the matter whatever. The Aurora Borealis of the 29th March was as well known to every philosopher in England, as the battle of Navarino is to every politician. A long and minute account of it was pub- lished in this Journal for April — June 1826, by Messrs Cold- stream and Foggo * ; and as M. Arago uses this Journal in his editorial capacity, it is strange that he should have overlooked a meteorological paper by the two accomplished meteorologists whose labours for 1825 had given him such high satisfaction. After M. Arago had uttered his prediction, might we not have supposed that he would have searched with avidity every English journal for the evidence of its truth ; and might we pot have expected his scrutiny to have been repeated with fresh diligence, when the English philosophers brought grave objec- tions against his hypothesis from the want of an Aurora on the 29th of March. On the contrary, M. Arago remains nearly two years in the belief that his prediction was unverified, and he peacefully submits to the grave objections of the English * See Meteorological Observations made at Leithf in No. ix. p. 190. Aurora Borealis on the Magnetic Needle. 19T' philosophers till 1828, when Mr Dal ton kindly relieves him from his dilemma, by sending him an account of an old, a well known, and now forgotten Aurora. We now approach the period of sound inquiry, when the magnetic needle and the Aurora Borealis are observed at the same time, and on the same horizon, by men who had no hypo- thesis to support, — who possessed the finest instruments, — who lived among the very beams of the Northern Lights, — and whose attention had been especially directed to the subject now un- der discussion. During the different voyages of Captain Parry to the Arc- tic Regions, the phenomena of the Aurora Borealis and of the magnetic needle were carefully observed ; and it is a most singular circumstance, that neither the needle por the electro- meter were in the least degree affected by them, although they were often carefully watched, in order to ascertain this very fact. In Captain Parry's third voyage, in 1824-5, a most splendid Aurora was seen, which actually shot its beams between the observer and the land, which was then distant only 3000 yards ; — yet did this Aurora exercise no disturbing force on the magnetic needle ! " Our variation needles,'" says Captain Parry, " which were extremely light, suspended in the most dehcate manner, and from the weak directive energy, susceptible of being acted up- on by a very slight disturbing force, were never in a single in- stance visibly affected by the Aurorce, which could scarcely fail to have been observed at some time or other, had any such disturbance taken place, the needles being visited every hour for several months, and oftener when any thing occurred to make it desirable.*" The observations themselves upon which Captain Parry founds his conclusions are the most numerous, and we hesitate not to say the most correct, that have ever been published. They occupy nearly J^OO pages in the fourth part of the Philo- sophical Transactions for 1 826. Lieutenant Foster has given an abstract of the daily variations of one of the needles for the months of January, February, March, April, and May 1825. 198 On the supposed infltience of the In one column is the amount of the daily variation, and in ano- ther column are placed all the Auroras which were visible, so that we can compare the mean oscillation of the needles during a period when there were no Aurorse, with the mean oscilla- tion during a period when there were many Aurorae, and thus obtain the united effects of groups of these motions. The following table will put this in a clear light. 1825. Number of Aurcrae vi- sible. Mean Amount of Daily Vari- ations. January, February, March, 14 14 2 P 371 ) 1 38 ) a 14 J April, 0 2 52 W 1 May, 0 3 44 39 J Mean. 3 18 41' These comparisons, which Lieutenant Foster seems to have overlooked, present a very curious result. In place ofexer^ cising a disturbing infltiejice, the Aurorce in the Arctic Regions would seem to exercise a sedative influence upon the needle. The observations from which this conclusion is deduced were made by seven difterent observers, Captain Parry, Lieut. Foster, Lieut. Sherer, Lieut. Ross, and Messrs Crozier, Rich- ards and Head. " The needles were visited every hour during four successive months;" and as Lieut. Foster observes, " when any extraordinary change appeared to be going on, the needles were more closely watched ; and every phenomenon, such as the Aurora Borealis, meteors, clouds, the kind and degree of light, the moon's position, and the temperature within and without, were at all times carefully noted ;" * and he con- tinues, " we have reason to believe, that on no occasion were tlie needles in the slightest degree affected hy the Aurores, meteors, or any other perceptible atmospheric phenomenon." •(- » Phil. Trans, 1826, Part iv. pp. 75, 76. + In speaking of a motion of the needle on the 27th March, Lieutenant Foster states, that there was no appearance of an Aurora ; and he adds in a note, " The Aurora generally appeared about N. by compass, extending in an arch from about N. E. to N. W., at an elevation from 10° to 20°, Aurora Borcalis on the Magnetic Needle. 199 fe' That these observations and these results are deemed of the highest value, and worthy of the highest confidence, by - philosophers of the first order, is proved by the fact, that the Royal Society of London have rewarded them with their Copley medal for 1827, and in those eloquent and admirable addresses which their distinguished President, Mr Davies Gilbert, de- livered along with the medals, he has ranked among the most important contents of Lieutenant Foster's paper, the " Re- jftitatioJb of the supposed connection between tremors of the Needle and Aurora Borealis.'''' * We may now be permitted to ask the philosophers of every country, if they are disposed to set aside, as of no value, the Herculean -f- labours of Lieutenant Foster and Captain Par- ry, and substitute in their place the responses which issue from the Royal Observatory of Paris, from a mysterious re- cord which only one eye is allowed to see, and upon which only one judgment is allowed to be exercised ? Will they prefer the sweeping conclusions presented to the Academy of Sciences on the 22d of January, to the cautious inductions of the English navigators ? — and if they do, will their preference for these conclusions be increased, when they learn that M.* Arago was long before in possession of the results of Captain Parry and Lieutenant Foster's observations ? It may be proper to state, that a very able observer. Pro- fessor KufFner of Kasan, has observed a coincidence between agitations of the needle and Aurorae Boreales which appeared with streamers sometimes shooting towards the zenith. At times when it was brightest, though not very briUiant during any part of the winter, I have frequently watched this needle without ever being able to detect a change that could be ascribed to its influence." — Phil. Trans, 1826, Part iv. p. 175, note. * Addresses to the Royal Society, &;c. by Davies Gilbert, President, &c. Lond. 1828, p. 16. It is distinctly stated that the medal is awarded for the " observations and deductions" of Lieutenant Foster. t The President of the Royal Society justly remarks, " One is utterly astonished at the magnitude of these labours, and at the accuracy and care ivith which they were conducted (as is manifest from internal evidence) in a situation where comfort and ease were unattainable, and where peculiar difficulties presented themselves at every step." — Adresses, P' ^4., ,.,,, :,,,, SOO On the supposed injiuence of the Aurora, ^c. in latitudes more northerly than his own, and this fact has been triumphantly submitted to the Academy of Sciences as a confirmation of the views that we have been controverting. The opinions, however, which we maintain are not in the .slightest degree affected by any such observations, the truth of which we have no hesitation to admit ; but even if a thousand observers on a thousand different meridians were to observe similar coincidences, they could only prove that certain AurorcB are attended with agitations of the magnetic needle, — a propo- sition of very different import from those which were submit- ted to the Academy of Sciences on the 22d of January. In taking a general view of the different facts to which we have had occasion to refer, we may consider them in two points of view. 1. If we regard it as proved, and we thiiik there is no fact in physical science better established, that Aurorae occur which have no influence on the magnetic needle ; that agitations of the needle take place when no Aurorae are seen ; and that these two phenomena sometimes appear simultaneously, — we must then view them as the separate though occasionally co-existent effects of some more general cause. But even if their co- existence were not occasional but constant, this could never prove that the one was the producing cause of the other; and it would still be as probable as before that they were both refer- able to a more general cause. What this cause is we do not pretend to know ; but it has been and is the opinion of many eminent philosophers, that both the luminous meteor and the developement of magnetical action may have their origin in certain disturbances in the electrical equilibrium of the at- mosphere. 2. Although we should have been disposed, previous to the voyage of Captain Parry, to adopt the preceding views, yet the observations of this distinguished navigator and of Lieu- tenant Foster seem to have embarrassed the question with a new difficulty. In the two months during which 2S Aurorae occurred, the mean monthly excursions of the magnetic needle on each side of its mean position was only 1° 37}'; whereas during the two months when there were no Aurorae, it was Baron de la Tour on Metallic Strings^ ^c. 201 almost exactly double, viz. 3° 18^ 41". If this difference, which is far too great to be accidental, shall be confirmed by future observation, it will prove that in the arctic latitudes, and in those periods which abound with Aurora?, the excursions of the magnetic needle are diminished ; while in our own latitudes the causes which produce Aurorse increase the excursions of the magnetic needle. In the present state of our knowledge, it would be idle to speculate respecting these apparently opposite effects. Nume- rous accurate observations, made in different points of the mag- netic meridian, can alone furnish us with the data which such speculations require. On a subject involved in so much difficul- ty, and so far withdrawn from experimental research, it would be presumptuous to pronounce any rash opinion ; and those who would fix us down to any dogmatical explanation, or shackle the freedom of discussion where every hypothesis must present so many vulnerable points, can neither be acquainted with the history nor imbued with the spirit of inductive science. Art. II. — On the Elasticity and Change of Volume of Me- tallic Strings while in a state of Vibration* By Baron Cagniard de la Tour. * It is well known that if we draw out a plate of caoutchouc, it becomes thinner and narrower as its elongation is increased, so that in changing its form it does not seem to change its vo- lume, since it loses in one dimension what it gains in another. The same effect might be expected in metaUic strings ; but M. Cagniard de la Tour has proved, that if we submit a metallic string to a moderate elongating force, the diminution of its dia- meter is less than it ought to be if its decrease of thickness were exactly compensated by its increase of length. Hence it follows, that in drawing a wire, a sensible vacuum is left be- tween its molecules. • This abstract of Baron Cagniard de la Tour's paper is translated from Le Globe, Jan. 5th 1828. jj-j . 202 Baron de la Tour on Metallic Strings^ S^c. M. Cagniard de la Tour is of opinion that the preceding re- sult can only be observed in wires formed of substances suffi- ciently solid to support the weight of the atmosphere, which necessarily tends to fill up the vacuities. In performing this experiment, our author took a metallic wire two metres (6^ feet long) and about one millimetre (l-25th of an inch) in diameter, and he immersed a portion of it, six milli- metres long, in water which held a glass tube of a very small bore. This portion of the wire displaced the water, and rais- ed it five millimetres in the tube. " Having then" says the Ba- ron, " adjusted this little tube as a thermometric column on a large vertical tube of glass, and sufficiently long to contain two metres of the string, I filled with water the whole apparatus. The inferior end was closed by a cork beyond which the lower end of the cord projected. This end was fixed to a bit of wire driven into a piece of wood which supported the whole, and the lower extremity of the wire was rolled round a cylin- der, by turning which the wire could be stretched at pleasure." When the wire was lengthened, so as to be drawn six mil- limetres beyond the small tube, the descent of the column of water, in place of being ^u^ millimetres, as it should have been, had the diminution of its diameter compensated its increase of length, was only from SJ to 2J millimetres. This experiment several times repeated always gave the same result. Wishing however to know what would happen if he went beyond the elastic amplitude of the wire, he drew it out six millimetres beyond its primitive elongation ; but in this case the descent of the water in the tube, which ought to have been a little less than in the first experiment, on account of the diminution of the diameter produced by its first extension, was, on the contrary, greater, and approached very nearly to fimr millimetres, because, says the author, «* the wire having been in some degree forced to draw itself like a substance which is ductile but not elastic, there is in this case a greater compensation between its elongation and the diminution of this diameter. Baron Cagniard de la Tour proposes to submit to similar trials rods of glass and other elastic substances, but by means Rev. Mr Scoresby on the Effects of Lightning. 203 of a process in which the extremities will not project beyond the apparatus. It would doubtless be curious to demonstrate that sonorous bodies of hard substances, like glass, bell-metal, &c. not only change their form in vibrating, but very sensibly increase or diminish their volume, nearly in the same manner as if they were heated and cooled alternately, which would explain how these motions may produce molecular sounds analogous to those which liquid phosphorus emits when placed upon a bass, and in the act of becoming solid ; and it might perhaps fur- nish some new data for explaining why the sonorous effect of solid bodies loses its intensity when the bodies are freed from the pressure of the atmosphere. The same results might perhaps furnish also a new argu- ment in favour of the theory by which our author explains how the sound of vibrating bodies arises principally from the shocks of the molecules propagated in the air like the noise of a musical hammer, rather than from their atmospheric excur- sions. Art. III.* — On the singular Effects of two Strokes of Light- ning upon the vessel called the New York, while saili?ig from London to New York. By the Reverend William Scoresby. * During the passage of the ship called the New York from London to New York, a voyage which she generally perform- ed in twenty-five days, a stroke of lightning overturned all the partitions without exception, but no person was hurt. The vessel was deprived of its conductor. The next day the Captain, dreading another storm, had placed a conductor upon the main-mast. The lightning struck the rod of the conductor, and melted it entirely ; it al- so melted the iron conductor, which fell in drops into the sea. Almost all the passengers had observed the water of the sea sink down in a distinct manner, in a certain space round the • This is an abstract of a paper read to the Academy of Sciences on the 14th January. 204 Rev. Mr Scoresby on the Effects of Lightmng. point where the electrical current had entered the ocean. The rod of the conductor which was melted was four feet long by five inches and a-half in diameter, and the iron conductor was three-tenths of an inch in diameter. It was evidently too small, (in France they always make their conductors thicker.) An excellent chronometer, whose error never exceeded the tenth of a second in twenty-four hours, was so much derang- ed by the stroke of lightning, that it was accelerated thirty- four minutes. The cause of this error was perceived in London, where it was ascertained that all the parts of the instrument had ac- quired a great degree of magnetism, in such a manner that its general motion depended very sensibly upon the position which was given it. The second stroke of lightning, like the first, killed nobody; and it is a singular fact, that it even performed a very remark- able cure. A passenger, very old and overgrown with fat, was so much palsied in his limbs, that for three years he had never been able to walk altogether above half a mile ; since he em- barked, he had never been seen to stand up for a single instant. After the discharge, which took place near the bed where the poor cripple was sleeping, they observed him with asto- nishment rise and walk to the deck, where he continued to pa- rade for a long time, as if he had never been ill. At first he lost his senses, but this mental affection did not last long, and the cure is complete. This person, who was formerly paralytic, having continued to walk with ease all ihe rest of the voyage, had the entire use of his limbs when he arrived, and he tra- velled on foot from the place where he disembarked to his own residence. All the knives and forks of iron which were found melted in the ship had acquired magnetic power. The effects produced upon the magnetic needles were very remarkable. Although they were all in the same room, the lightning produced upon them very different effects. In some the magnetic action was augmented, in others it was diminish- ed, in some it was destroyed, and in others the poles were re- versed. [^m.^ i'l.Air, w Edm!.' Jcatyiat &fs<;cifM.ce I,' f /// v^ 5^n^#Ss %.4 On the Cold Caves of the Monte Testaccio at Rome. 205 Art. III.— 0/i the Cold Caves of the Monte Testaccio at Rome, By a Coreespondent. Happening recently to notice in the tenth volume of the Edinburgh Philosophical Journal^ some remarks on the causes of the remarkable coldness of the cellars in the Monte Testac- cio at Rome, I was surprised to observe that the ingenious author of that paper denies the influence of evaporation in pro- ducing that cold, — an explanation which I have always under- stood to be deemed so generally satisfactory, that, during a late residence in Rome, I did not think of investigating minutely this remarkable phenomenon, which neglect I now extremely regret. Some mistakes in the data and misconceptions of the locali- ties shown by your correspondent, induce me to offer some im- perfect remarks towards defending the theory of evaporation, and to lay before that gentleman a few hints for the correction of his observations, to which no one will be more able to apply the rigid mathematical investigations which he has elsewhere so successfully employed. Indeed, the science of hygrometry has lately received such an accession of accuracy, and such ex- tension of limits, that I found my inquiries more difficult and minute than I at first anticipated ; and I shall state my obser- vations with greater brevity than I at first proposed, as I am not so familiar as I could wish with the modern refinements of this branch of meteorology. Saussure found the temperature of one of the cellars, July 1, 1773, to be 441**, and of another 44°, while the external air was at 78°.l. Now, (says the author of the article in ques- tion,) as a cubic inch of air at 78° can contain .005878 of a grain of water in solution, and at 44° only .00203S, the degree of dryness in the external air must have been ffff, or .346, (saturation being — unity,) = 23° Deluc's hygrometer ; " a degree of dryness," he adds, " which is seldom observed except in high latitudes ;" and a little before remarks, that a state of perfect dryness can rarely occur at Rome. On this I have to observe, l^f. That the present is a very extreme case ; and we may assume the atmosphere to have been in a state which VOL. VIII. NO. II. APRIL 1828. o Reau. Fahr. 12° 59° 13 61i 15 65i 15 65h 11 561 V6 en 10 5^ n 79 206 On the Cold Caves of the Monte Testaccio at Rome. " seldom'" and " rarely'** occurs at Rome. That this was so, the following observations, taken from *' LumsderCs Antiqui- ties of Rome,'*'' which afford an uncommonly parallel instance, will easily show : August 26, 1762. On the ground at the entrance of the cellar, Four feet from the ground. Top of the cellar, _ - - Half way from the door to the farther extremity, seven feet from the ground. On the ground, - - _ Farthest extremity seven feet high. On the ground, - . _ External air in the shade, - . - The reputation of Saussure prevents us from a moment doubting his accuracy ; but the external temperature being al- most exactly the same, and the internal so much higher, proves that his was an extreme case. But, 2^, .346 is given as the required degree of dryness, (though we shall presently see that the author has not stated his argument in the strongest light,) and I by mere accident have the means of proving, that a much greater dryness does sometimes occur at Rome. Whilst examining the meteorological diary kept at the Collegia Ro- mano, for the purpose of comparison, shown in my paper on the Horary Oscillations of the Barometer, I kept a note of se- veral of the maximum and minimum results. For 1826, I found the maximum of the hygrometer, August 8th, 55°, and minimum, November 5th, 0*^. For February 1827, the range 0® — 48®. The head of the column for the hygrometer is en- titled, " Igro. a Cap.," which, without the possibility of doubt, means " Igrometro a Capello,""* or Saussure's Hair Hygrome- ter. It is, however, evident, that the 0** or zero indicated per- fect dampness, not dryness., as is usual ; but that this is some- times done with common hygrometers, we have the testimony of ihe author himself, * after mentioning the common arrange- ment. " Some artists, however, reverse this order, and place the zero at extreme moisture, — a practice which cannot fail to * Edinburgh Encyclopasdia, Art. Hygrometry. On the Cold Caves of' the Monte Teataccio at Rome. 207 lead to mistakes in recording the indication of the instrument/' In this case, therefore, 55° indicates on the common scale ^S* from dryness, and 48°, 52°. Now, 45'' of Saussure is equiva- lent to .^413 parts of saturation, (see the above quoted arti- cle,) a degree of dryness very much greater than .346, which it was thought could not be counted upon. 3J, The influence of the localities, as well as of the latitude, in altering the hy- grometric state of the atmosphere, does not seem to have been sufficiently considered. The writer of the article before us elsewhere observes, * that " the quantity of moisture mechani- cally con^bined with the air over different regions, must de- pend, in the Jirst place, on the mean temperature ; and, se-. condly, on the presence of a sufficient quantity of water at the surface of the earth, to afford an adequate supply of moisture to the atmosphere by evaporation." And though he observes that such dryness as .346 can seldom occur but in northern latitudes, he elsewhere remarks, -f that the distressing effects of the Sirocco and Simoon arise from the power oi iheix extra^ ordinary dryness on the human frame. That this does not hold with regard to the Sirocco in Italy, my remarks, No. xiv. p. 263, sufficiently prove, which is evidently owing to the crossing of so large a portion of the Mediterranean. But an extremely dry cold wind comes from the northern quarters called the " Tramontana," which prevails in winter, and with- out doubt lowered the hygrometer in February to such a de- gree as was stated above. Besides, if we consider the situation of Rome, we shall not be surprised that in summer the wind should be excessively dry. Sterile arid deserts surround it on every side from twelve to at least eighteen miles distance ; and towards the north particularly, whence the dry winds un- doubtedly blow, the plains are extremely extensive, flat, and barren ; abounding in every direction with small volcanic rising grounds, composed of ashes, breccia, tufa, and pozzulana, than which few substances show more avidity for moisture. Shall we then wonder that Rome frequently labours under excessive brought ? The copious streams of delightful water which sup- ply fountains in every street and square of the eternal city * Edinburgh Encydopcedia, Art. Physical Geography, p. 508. + Ubi supra, p. 505. tOS On tfte CM Caves of the Mwite Tesiaccio at Rome. are brought by aqueducts from distances of from fifteen and eighteen to twenty-four miles, all beyond the confines of the Arid Campagna. Let us now turn to the little mountain itself, which has such a situation. It is no figure of speech to say that it is com- posed of broken pottery. It is literally and entirely so, without a particle of earth between the fragments ; and in only a few spots on the outside is there a finger's breadth of soil deep to permit a stunted grass to grow, and a few coarse weeds which extend their roots into the fragments. Some excavations in the sides for mending the roads, permit us to see that its inter- nal structure is exactly as I have described, and so loose, that, if you move a small morsel near the bottom, a whole avalanche of the necks, bottoms, and handles of Amphora; descend upon you. The hill is about 160 feet high, and 590 paces, or nearly a third of a mile in circumference. It is evident that the weather must have complete access through the hill, and hence it follows: 1st, That the pots will imbibe and retain the rain water which falls in enormous torrents in winter ; and, 2d, That the wind must have a pretty free access between the cre- vices of the fragments. With regard to the cellars themselves, the one which I entered extended, I suppose, above fifty feet in- to the hill, nor did I observe that the wind came from any par- ticular funnel or chimney prepared for it, but rather appeared to proceed from the sides of the cavern on all hands, which were so loose and full of crevices as to require to be artificially supported. Saussure expresses himself of the same opinion : " Cet air vient lui-meme des interstices, que laissent entreeux les debris d'urnes, d'amphores et d'autres vases de terre cuite, dont cette petite montagne paroit entierement composee." Now, if we attiibute the effect entirely to evaporation, the case seems to stand thus : The exterior air in a state of great dry- ness enters the mountain laterally, passing through it with per- fect freedom, and at the same time acquiring with avidity the humidity presented to it by innumerable surfaces of baked clay, which have already been thoroughly wetted by the rain to the very centre of the mountain ; hence the air must in all cases reach a state of perfect dampness before it reaches the caves ; therefore, the depression of temperature depends golel^ 4 * On the Cold Caves of the Monte Testaccio at Rome. 209 on the dryness of the air when at the external temperature, and not when it is reduced to the mean temperature of the place in the interior of the hill, because there it will always be saturated. What the mean temperature is, has, by the errors both of the writer and the printer of the article before us, been most erroneously stated. " A quantity of loose materials," it is said, '' whose mean temperature cannot be less than 46°." And in a note : " The mean temperature of Rome is, accord- ing to Humboldt, 45°.9 in winter, and 55^.2 in summer." Puzzled by such a mass of mistakes, I referred to the original passage in the Edinburgh Enc^/clopcedia, Article Physical Geography, where I found the mean temperature still called 46°; but Humboldt's summer average, 75°.2 instead of 55°2, giving the real mean temperature 60^.6, which I know from experiment to be very exact ; this, therefore, is the real mean temperature of the materials. In Saussure's most extreme ex- ample, the case is, that air of a certain degree of dryness, and at the temperature of 78", moistened to humidity with moisture of the temperature of 60°, produced a cold air of 44°. This is a case too complex to be solved by the common hygrometric formulae ; I therefore undertook the following experiments, not with the hope of a complete solution of these delicate inquiries, but to obtain such general facts, as to give to the case in ques- tion an approximate estimation of the truth. The experiments themselves are in some measure similar to those of Saussure, (though I had not them in my eye at the time,) but are con- ducted upon more distinct principles, and by more precise data, I. The room in which my first experiment was made had, at the beginning of my operations, a temperature of 59J, but at the end had risen nearly to 62°, and in both cases the tem- perature of a thermometer with a moistened bulb was 55^. The air was both hotter and drier, therefore, at the conclusion ; but we shall take the temperature at 61 as an average. We then have for the dryness of the apartment, * y ' =ft — T^ZZTrB' in this case, supposing the barometer at 30 inches, as it was nearly ; /61 — ^|^q_3 > we obtain .0021893 grains in a * Ed, JEncy, Art. Hycjkombtry, 585. SIO On the Cold Caves of the Monte Testaccio at Rome. cubic inch, and a degree of moisture (saturation being expressed by 1.000) of S^Q. I then caused the iron-pipe of a pair of bel- lows A, Plate IV. Fig. 1, to pass through an earthenware cylin- der BB, to which it was firmly attached, and the interstice was filled up with sand. The muzzle of the bellows and its case was then heated, till the temperature of the air which issued from the mouth on working the bellows was 80% and it was then placed touching the lower orifice of a large glass jar C, having a wide open neck D ; in the bottom of the jar were placed fragments of pottery, moistened with water, at the temperature of the room. A thermometer E, was suspended among the pots, just at the lower tubulature of the jar, so that the bulb was only about three inches distant from the orifice of the bellows ; these arrangements having taken some time, the heated stream of air was somewhat diminished in temperature. The bellows hav- ing been worked for some time, the thermometer (which had its bulb covered with paper and thoroughly moistened) was stationary at 59-5. When the experiment was finished, the stream of heated air was 74^ ; the air at the top of the jar, shown by the thermometer F, was QGP^ and among the pots 62°, to which the air of the apartment had now risen. II. It then occurred to me that the experiment might be va- ried in a more just manner. The air of the room was 62° A moistened thermometer fell to 55^'^ hence the grains of moisture in a cubic inch were .0022631, and the ratio to saturation .627? or almost the same as before. The stream of heated air pro- duced in the same manner, but very equably, was 81 J°. In- stead of using the jar, it was made to pass through a porcelain tube soaked with water, about eight itiches long and half an inch in diameter, and at the farther end from the bellows was placed the thermometer, moistened with water, at 62°. When the bel- lows were worked, it fell to 60, or about half a degree higher than in the last experiment, the stream of air being at least 4° warmer. III. To take the simplest, and perhaps the truest, view of the case, on an after occasion I caused a stream of air, heated to 80°, to fall directly on the moistened bulb, placed at the distance of only three inches from the muzzle of the bellows; and by a separate contrivance, drops of water at 64°, fell re- On the Cold Caves of the Monte Testaccio at Rome. 211 gularly at intervals upon the thermometer. The temperature of the room was 64% and a moistened thermometer fell to 57°» The grains in cubic inch were .0025635, on the degree of dry- ness .668. The heated air was at first 81°; and, after a con- siderable time, had fallen only two degrees. The thermome- ter became stationary at 59°. By making the proper propor- tions, I find that the dryness of the heated stream of air in these three experiments, using the mean temperature of 77% 8I|°, and 80% was respectively .482, .347, and .411. Now, the results of these experiments go to prove, l^^, the circumstance which I have already insisted on, the small im- portance of the state of the air within the mountain, or at 60°. Although the temperature of the room varied from 59 J to 64, the final results are all within the limits of 59 and 60, because the condition of the surrounding air is always that of satura- tion; and a difference of 5° in the temperature of the humidity applied, (which is the most important agent,) gives no sensible alteration. The differences of result are solely owing to the change in condition of the hot stream of air applied. They can- not be ascribed to the different forms of the experiments ; for it is sufficiently evident, that, whether the thermometer be simply applied to the direct blast of air heated to the high de- gree of 80% and the reduction of temperature left to the simple coating of the moistened bulb ; or whether the air reach the moistened bulb in a state of saturation, and surrounded by pots, which contribute to cool an atmosphere round it, as in the first experiment ; or as in the second, whether the air reaches it already cooled down to the circumambient tempera- ture, and loaded with moisture, the difference of result is wholly unimportant. In the second place, these experiments prove the influence of having the humidity which moistens the surfaces, over which the hot air passes, of a temperature con- siderably lower than that of the air itself, which is the sole effect which I am disposed to attribute to the comparatively low temperature, (that of 60°,) which undoubtedly exists within the mountain. For let us take the case of the third experiment, and find what coolness would have been produced by air of 80° impinging on a surface moistened with water at its own tempe- rature; or rather in this case, what dryness was required in the 212 On the Cold Caves of the Monte Testaccio at Rome. air at 80° to reduce the temperature to 59S as it did in that experiment. This is solved by the formula above quoted, which in this case becomes SOf-^ |-- — — ' whence we have 1.0014 — .6195 = S819, and as 10014 : 6239 : : 3819 : 2379, or .002379 grains in a cubic inch, and §yj = .381, the ratio to saturation or dryness the air would have required to have had, instead of .411, as we found above that it really had, which shows the smaller degree of dryness that was necessary in this case than in the simple one ; and the difference would undoubtedly have been greater had the formulae been appli- cable to both cases. What the value of this reduction of temperature would be, owing to the coolness of the humid medium, when the result- ant temperature is only 44°, as in Saussure's case, I do not feel myself able to pronounce ; but my experiments show that it must have an effect probably of several degrees, suppose of four. In that case, the means of reducing the temperature to 48° would be all that was required by ordinary evaporation. Having attained this point, it is still evident that we can hardly admit quite so great a stretch of evaporating force as this requires ; but nature, I must observe, has extended me- thods of operation, like a great series, of which our experi- mental knowledge reaches only to a few terms. Though we may understand, in the main, the plan of any particular operation, yet all the combining minutiae, the effects alternately augment- ing and augmented, have only their proper scope in her great scale of action. '' Mazes intricate. Eccentric, intervolvecl, yet regular Then most, when most irregular they seem." One circumstance, the temperature of the moistening water is liable to be cooled to a much greater degree than we have yet considered, and in some respects, I may say, to an almost indefinite degree. Let us review the steps of the process. Air highly dried, and at the temperature of 78°, enters an enormous mass of aggregated materials, — a mass so large, that not only is it retained throughout at the mean temperature of the area of soil on which it is placed, 60°, but, being completely On the Cold Caves of the Monte Testaccio at Rome. 21S imbued with moisture, the air of the atmosphere being sup- posed at the dryness to saturation of .238, is instantly reduced to a state of saturation ; and, in the^r6'^ place, to a temperature of 54°, (by formula ;) but also to a point several degrees lower, because the moisture contained in the pottery had a tempera- ture of 60° instead of 78°. As the current forces itself inwards, and constantly reduces to 53° or 54° the tiles and fragmerits in the interior, which by and by assume the same temperature, and about the middle of summer may produce fresh evapo- rative force, as the heat of the sun may have prevented the full acquisition of humidity in passing through the outer stratum ; and as we approach the centre of the mountain, these causes will always increase in rendering the moistening agent of a lower and lower temperature. It is the vast bulk of the hill which must necessarily produce more powerful and extended effects than our petty experiments and minute rea- sonings can enable us to judge of; and in some extreme cases may produce a cold of 44 or 45. Saussure, in his account of the Monte Testaccio, has treated the subject not very philo- sophically, particularly when he considers the evaporative force the same at all seasons, which arises from the obscurity of hy- grometric science at that period ; and I think it may be ques- tioned how far even its present state can admit such extended inathematical formulae as are now applied, and which I have so much employed in this paper. Be it ever remembered, that these Jbrrmdoe are founded merely on experiments on a small scale, which must ever give more partial and incomplete re- sults, (though they may agree well with one another when made under similar circumstances) than in the vast operations of the example before us. Saussure, however, states one impor- tant fact, that he considers the observations of the Abbe Nollet in 1739, and therefore by analogy those of Lumsden in 1762, as strictly comparable with his own. The former found the temperature, Sept. 9th, when th^ air was 72|°, to be 53|°; and the latter, Aug. 26th, with the air at 79°, to be 54J°. To ac- count for this rise of temperature at the end of summer, he has an unsatisfactory theory of capacious, cool, and dry caverns ; but we are able to account for it in an instant, either generally by the setting in of damp weather, or particularly by a simple 214 On the Cold Caves of the Monte Testaccio at Rome. change of wind. For were the wind to wheel from the N. E. to S. W., I have very httle doubt that next day the tempera- ture of the cellars would be found to have increased. If o com- paratively moderate a heat as 78° at Rome, in the middle of summer, may well be supposed to arise from the " Tramon- tana,'" after crossing the extent of the Campagna, which in winter blows such a dry chilling blast. We have already ob- served (p. 206) that in February 1827, Saussure's hygrometer stood at 52°, or in the ratio to saturation of .294-. From my own Meteorological Journal, I find that in 13 days out of the 28, the wind was from the northern points, and on nine more it was variable ; whereas in the 31 days of January it blew only eight days from those points, which may be considered a suf- ficient illustration of the fact. I have only farther to add on this point, that there is another and most legitimate source of coolness we have not yet noticed. Lumsden's observations sufficiently prove that a current of external air enters by the top of the door of the cellars ; is cooled as it proceeds inwards ; joins the cool air of the mountains ; and comes out by the bot- tom of the door.* Now nothing can be more evident than that, as the interior of the caves are saturated with moisture in the coolest state, which all the circumstances we have before con- sidered could reduce it to, that is, from 45° to 50% a new quantity of dry external air comes upon it in that state, and must experience a great reduction by being moistened with such cool humidity. It is this new air which fills the caves, and which creates the currents. It is necessarily it which has its temperature taken ; and it must necessarily be coolest at the bottom of the back of the cellar, as Lumsden found it, (see pao-e 206.) This gives the concluding touch to the reduction of temperature, and is, I have no doubt, sufficient to produce even that cold which Saussure observed ; and all the other cases on record will be easily solved by it. In concluding these remarks, which have swelled so much beyond my original intention, I may be allowed to remark, that if it is thought by any that I have not made good the point I have proposed ; that the certain determination is only what extensive experiments on the spot can give ; and that I • See his work, pp. 172 and 173. On the Cold Caves of the Monte Testaccio at Rome. S15 have endeavoured, as naturally as possible, to combine what hypothetical and even speculative reasoning was necessary, with those facts which a knowledge of the localities, an attentive con- sideration of the subject, and the results of several experiments enabled me to lay down ; and though it may seem like a " re- duetto ad ahsurdum^'' that it seems impossible to explain the phenomenon in any other way, even the gentleman whose sen- timents I have ventured to oppose, after conceiving he has proved, that to evaporation " no part of the effect can be as- cribed," is compelled to come to the conclusion, that " it is dif- ficult to conceive in what other way the temperature could be reduced so low as 44°.'" Allow me farther to add, that that philosopher's theory of ice caves is quite insufficient to explain the coolness observed by Saussure in Ischia and at Terni, * which he supposes to arise from crevices which descend from the higher regions of the mountains. The mean temperature of the latitude of Ischia is about 62° ; and as the height of the very summit of the island is only between 1800 and 2000 feet, the reduction of mean temperature at the top will only be about 6° or 5Q° '^ whereas Saussure found the grotto 45 2°, and was assured that it was still lower in summer, which, from the analogy of the Monte Testaccio, we may naturally suppose. Nearly the same remarks apply to the example at Terni. The theory which ascribes the coolness of the Monte Tes- taccio to certain salts distilled from the pottery, may, I think, be set at rest by the following experiment : — I took 160 grains in powder, taken from a portion of an Amphora brought from the hill itself, and boiled it with three ounces of water for some time; I then threw it on a filter, and took a portion of the pure liquor, adding to it a decoction of litmus ; but no change what- ever on the colour of the litmus was produced. I then added a little sulphuric acid, but not the smallest symptoms of pre- cipitation appeared. I next took another portion of the super- natant liquor, which I found had no taste, except a very slight one of clay, or earthy matter, which, of course, arose from a minute portion of the terra cotta remaining in mechanical mix- ture with the water. I evaporated it to dryness, but no saline residuum appeared. Something, however, being visible in the * Mentioned in the Philosophical Journalt viii. 13. ^16 Mr Scott's Observations on tJie bottom of the small earthenware evaporating dish, I treated it with a small quantity of litmus, which appeared to have its tint extremely slightly reddened. To ascertain the presence of any of the stronger acids, I added a little carbonate of ammo- nia, which produced no action whatever. These rude trials render it probable that none of those saline matters usually employed to produce cold occur in the terra cotta of the Monte Testaccio in any sensible degree. The coolness of the cellars renders the wine preserved in them extremely agreeable in such a hot climate as that of Rome ; and many of the town's people go out to the Monte Testaccio to drink it in full perfection. The Abbate Venuti, in giving an account of the hill, seems as if he spoke con amove of its effect on his favourite beverage. " Ha questo monte una mirabile proprieta," says he, " ed e, che nell' estate esce da questi frammenti nella parte infima quando siano ben dis- posti, un vento freddissimo, e pero vi si sono fatte d'intorno piu sotto stanze e grotte al piano del terreno di fuori con ca- panne e Spartamenti, nelle quali viene il vino notabilmente ririfrescato,'''' ^ Aet. IV. — Observations on the Formation of Ice in India, in a Letter from David Scott, Esq. to George Swinton, Esq. Calcutta. I HAVE received your letter, with Dr Brewster's enclosures, at a time most opportune for giving you what information I possess on the various subjects which he mentions, having been for the last week enjoying the delightful climate and scenery of the Cossyn mountains. This part of the country is much higher than the Jyntah territory, I should think near- ly 4000 feet above the plains ; and the climate is proportion- ally colder. The thermometer is now, (10th November,) at noon, 63° in a small hut, and this morning the grass on the low grounds was covered with hoar frost ; and ice one-third of an inch thick was prodliced in vessels placed upon straw. The subject of artificial congelation is one which seems to be more imperfectly understood by scientific men in Europe than al- Formation of Ice in India, 217 most any other. The old story of evaporation being at the bottom of the process, and porous pans being necessary for its success, is repeated by one author after another, although nothing can be more erroneous. In respect to the first, it seems suffi- cient to observe, that, when ice is produced in temperatures above the freezing point, a plentiful deposition of dew is al- ways going on, which seems to be altogether inconsistent with the idea of the air being in a state capable of receiving fresh accessions of moisture. I have also found, by repeated experi- ments, that ice may be produced, although a thin film of oil be spread over the surface of the water ; the latter being con- tained in glazed plates, which indeed answer much better than the porous pans of the country, the ice in them being inva- riably thicker, and the water, when it does not actually freeze, somewhat colder than the similarcontents of porous pans placed in exactly the same situation. The fact is, that the natives use porous pans from necessity, there being no other descrip- tion of crockery ware manufactured in the country ; but so well are they aware that the porosity of the vessels is of no ad- vantage, that they usually rub them with grease for the purpose, I was informed long ago, of more easily extracting the ice; — but also, I now fancy, because it must tend to facilitate the process, by keeping the straw, upon which they are placed, in a perfectly dry and non-conducting state. The only author that I have read, who has treated this subject properly, is Dr Wells in his Treatise on Dew. I have repeated many of his experiments, and sometimes with singular results. On one occasion, a turban being suspended across the ice pit, three feet above the pans, it, as it always does, prevented the formation of ice in those immediately un- der it ; and in several which it only partially covered, ice was formed on the half of the water out of the perpendicular line, while that immediately under the turban was fluid. Two strings crossing each other, and placed at a less height above a pan, will also divide the ice into four quarters ; but it is ob- vious that these results will not always be obtained ; for if the temperature be rather lower than would be necessary to freeze the water, supposing no impediment to exist, the whole may be frozen although partially covered ; and, on the other band. 218 On the Horary Oscillations of the Barometer at Rome. if just sufficient to freeze the water under the njost favourable circumstances, the contents of a vessel not fully exposed to the influence of the sky may remain fluid throughout. I have never found it practicable to make ice (operating, however, on a small scale) when the temperature exceeded 4P on the level of the pits ; but on such occasions the temperature is much higher at some distance from the ground, and I have found a series of bottles filled with water, suspended from a mast of about seventy feet high, to show an increase of about 1^ for every ten feet in height. Sir H. Davy is therefore right in saying that ice may be made when the thermometer is above 50°, if he allude to the upper regions of the air, or hills of moderate height ; but, as I have already said, it cannot, according to my experience, be made when the thermometer, suspended at the distance of three feet from the ground, on the level plain, stands at above 41°. I wrote a letter on this subject to Mr Colebrooke some years ago, of which, I believe, I can still send you a copy. My experiments extend to the height of 3400 feet, at which elevation, on a detached mountain, the tempera- ture of the air at sunriseas several degrees higher than it is in the plain of Bengal. I should like much to hear of this experi- ment being repeated, or of its having been already tried in some of the colder countries, where I suspect the same result will be obtained in the winter season with a clear sky, and at day-break. NuNGKLow, 1 0th November. Art. V. — Memoir on the Horary Oscillations of the Baro^ meter at Rome. Communicated by the Author. (Continued from p. 129.) The observations being reduced into the above table, it re- mained to be considered how the actual results would be most simply and accurately elicited. Had the observations been complete for every hour of each day the means for each hour in inches would have given the desired products ; but as we find them unequally scattered through different days, they are so strongly affected by what the positive height of the mercury f On the Horary Oscillations of the Barometer at Rome, 219 might be at different times, that the most erroneous results would have been obtained. For instance, suppose the mean of six observations at nine o'clock to be 30.000 on days when no observations at ten o'clock had been made; and again, that after a month I find the mean of six observations at ten to be 30.500, I would note half an inch for the horary variation, be- cause the radical height was less at the former than the latter period. I therefore resolved to take the daily difference from some standard point, which, though liable in some degree to the same objection from the inequable fluctuations of the barome- ter, yet I expected that the combination of a sufficient number of observations would neutralize these irregularities. I resolved to employ 10 m. as the standard, the instrument being most regularly observed at that hour. I have since found that Cap- tain Sabine uses the maximum for that purpose, but I rather prefer my own scheme, as it may often happen that the maxi- mum of the day is not observed. Such is the ground-work of my third table. Part first contains the differences of each hour from 10 M., arranged in columns from 7 M. to 12 a. or eighteen hoursoutof the twenty-four, in which the observations have been most frequently made. As to part second, it is merely to give a wide guess of the state of the barometer during the night, as it only contains three sets of observations, and these not the most favourable. The first supplement contains the most useful ob- servations selected from my ordinary diary in January, to find the difference between 10 m. and 10 a., since the reductions of the second supplement depends in a great degree upon that point, as it contains observations on those days on which 10 m.. has not been observed and 10 a. is therefore substituted. 220 On the Horary Oscillationa of the Barometer at Rome. TABLE III.— Part I. N. B. — The sums in the several columns are the difFerences between the cor- each column ; and these differences are -Day. 10 M. 7 M. 8 9 11 12 1 A. 2 Feb. 2 29.824 +5 + 3 4 894 +59 + 72 + 84 5 30.172 —24 —15 + 5 + 5 rt 6 050 +74 + 27 —27 +68 —96 8 29.581 —31 —16 +18 —8 9 9S5 —54 + 12 +41 10 30.017 + 8 +5 — 1 — S 11 016 —9 12 29-736 + 16 + 10 —27 13 738 + 8 +8 —2 + 8 14 804 —56 +7 +20 + 32 +38 15 833 + 14 + 14 —10 —16 —16 —17 16 845 + 7 +7 + 3 + 3 + 2 +2 17 845 —3 0 0 0 + 8 18 967 + 37 19 30.063 +4 +2 —4 20 29.987 + 21 —14 —24 — :>1 —43 21 858 +1 —6 —12 —21 —45 22 730 + 12 —2 —30 ^U —59 83 5^59 0 0 24 865 —78 —50 —26 + 11 + 20 + 28 25 931 —13 + 6 +6 26 30.113 —26 + 8 + 29 27 222 —26 + 14 + 21 + 23 March 1 274 + 21 0 0 —7 —9 —32 2 204 + 9 +9 —24 + 13 + 2 3 111 +2 +1 —17 —26 —37 5 29.88 b —14 — 5 + 8 + 19 7 30.184 —20 —9 + 3 + 14 8 228 + 13 + 4 — 1 —5 —10 —21 9 119 + 3 + 1 —28 10 29-985 +9 +2 —9 —21 —32 11 30.095 —54 —29 +35 +43 12 273 —12 —4 + 3 C -^1 +* —10 April S 176 —16 —8 —5 —5 ^ IC 173 + 3 + 3 —7 —20 11 124 + 16 4-8 —5 —17 IS 15'. —9 —5 +21 +28 IS \ 26i + 27 +2C +21 1^ 'z6c + 11 + 8 +5 —5 —11 —18 Carriec —37 on On the Horary Oscillations of the Barometer at Rome. 291 Final Reduction of Barometrical Observations, tected height of the Barometer at 10 a. m. and the hour marked at the head of expressed in thousandths of an inch. 3 4 5 6 7 8 9 10 11 12 + 164 + 209 +217 +6 —15 —21 —119 —23 —144 —21 —175 —19 —202 —21 —239 —21 —19 —276 +63 + 71 +79 + 87 + 134 + 176 +217 +52 +25 + 85 + 101 + 25 +25 +25 —23 —3] —39 —48 -^5Q -^66 —36 —8 + 15 + 15 + 11 —16 —17 —17 —18 —21 —24 —27 —29 +43 +46 ■^55 +61 + 6S -{-GS +9 + 12 —7 + 18 + 18 + 18 +18 +19 + 15 + 18 + 18 + 30 + 58 + 58 + 68 +68 +45 +5S +60 +70 + 80 —2 + 90 + 2 + 8 + 100 + 1 + 102 —9 ^50 —74 —79 —83 —62 —83 —82 —87 —76 —91 -94 --9^ —97 — 120 —126 — 133 —139 —161 +25 ■i-5S + 81 + 106 + 123 + 163 + 177 + 30 +30 + 42 +45 + 14 + 15 + 17 f20 +33 +34 + 70 + 92 + 121 + 25 + 142 +27 f29 —27 —32 ^-36 —36 —37 —38 -39 —40 —45 —52 —59 —60 -52 +48 +58 —87 +77 +59 + 14 + U + 34 + 38 + 52 —46 ' -53 —SS —63 —9S —97 —101 —106 —102 —52 -67 -73 78 —63 —56 —56 +51 . . A.C +71 + 119 + 129 + 139 —5 —3 —2 0 —1 —2 —2 ""'^ +8 —20 f —28 —24 —31 -31 —17 — 17 —9 —7 —4 — 1 +4 + 36 +63 +69 +22 +20 + 24 + 25 +25 — i8 —61 —80 —91 .—95 —99 to next pa^ Te. VOL. VIII. NO. II. APRIL 1828. ^22 On the Horary Oscillations of the Barometer at Rome. Day. 10m. 7m. 8 9 H 12 lA. 2 t April 16 17 18 20 21 23 29.910 916 938 933 915 867 + 8 + 2 + 3 —2 —4 —3 —9 0 0 0 —3 —5 —4 0 + 8 + 2 + 1 +2 0 +13 —23 —23 +16 +3 t —2 Jan. 12 15 *914 *906 +98 +6 + 40 —12 + 40 —16 —12 —2 —46 —46 _46 Pos. sums 125 238 199 180 202 306 249 Neg. do. 90 262 ' 316 167 262 376 451 or Truesums 1439.518 435 —24 —117 + 13 -60 —70 1 —202 • (B) Divisors,! 48 7 33 43 37 29 28 28 1st Results, 29.9900 +0050 —0007 —0028 + 0003 —0021 —0025 —0072 i " I (A) 269.742 + 171 + 167 +399 CARR H::D 0 VERF + 157 ROM +175 ki^ (B) 9 1 4 7 4 5 A + A 1709.260 +206 + 143 +282 +13 —60 +87 -72 rt .B + ? 57 8 37 50 37 29 32 SS I'Y ^tl results. 29.9870 +0158 + 0039 + 0056 + 0003 —0021 +0027 —0022 * Reduced to the probable mean temperature of 54° for these days, t These divisors are the member of observations contained in the respective co- lumns. Ujj., e£ TABLE III— -Part II. January 12th I M. 2 3 4 5 6 + 108 + 25 + 120 + 110 + 17 +120 + 104 + 104 +78 +98 +54 +98 +38 15th February 22d Results, +0665 +0823 + 1120 +0910 + 0760 + 0680 .«S8r Jifl^r; On the Horary Oscillations of the Barometer at Rome. ^n 3 4 5 6 7 8 9 10 11 12 +12 + 3 —24 —35 +20 —11 —30 + 23 —25 —13 —16 —30 — 16 -^35 —7 + 25 —17 —39 — 1 +25 —15 —39 +23 —52 —62 —48 —26 —18 +2 +28 —2 + 54 +96 +98 304 149 278 372 331 491 780 1350 1621 672 271 388 480 545 742 778 960 1139 1169 535 +33 —239 —180 +211 + 452 + 137 —212 —173 -^411 — 287 18 14 41 42 19 18 18 24 24 29 +0018 —0170 —0118 —0096 —0171 —0120 —0062 +0051 + 0108 + 0074 THES —is ECON] —30 OSUPI -.-49 >LEME —46 NT. + 9 -4-37 t -4-64 +30 +16 S 2 ^ 5 6 7 8 Xu 9 3 +20 —269 —261 —219 —400 —278 — 143 +275 + 482 +153 21 IC 20 23 30 31 37 55 51 22 J-OOIO —0168 — 130 —0095 — 13S —0090 —0039 + 0050 + 0095 +0070 X This is taken from the first supplement, and deserves confidence. TABLE III.— First Supplement, Containing the ratio of\OA. to IOm. in January- Jan. 410a — 182 5 - -\.5^ Hence we have f | = .0046 in- 6 7 From tab. 3, pt. 1 + 211. div. 41 v. 8 Again, here + 64 14 9 10 Thence for the ratio of 1 1 -t- 10A.to lOM.«|-f == + 0050 iiches. 16 X. ig 22 23 30 " xiv. 31 +26 -flOS i ^ ^c)6 i ^ ' 2 —2 —36 —60 +40 —84 +142 —60 +22 sums +490 — 426= +64 'fo'^24 On the Horary Oscillations of the Barometer at Komi 1 < o tOCOOOi-^O^OiOi cr> o oS o Oi (>{ crt CM CO G< 3^ CO -^ 1 < GO 1 o GO + ov 1 05 rfot^«5oor^oo + +7+-} G^ 1 CO 1 GO + 00 si o GO O 1-^ 'O 00 Qi »— 1 CM r-4 CM O^ 1 1 + +1 1 ' ' CO CO CO CO CO 1 C75 + l>- ri t- CO ^D LO t- O^ O G>1 CO 1— 1 00 C3^ l-H 1 + cc" r^ r-i CO CO + +1 1 Co •o o 7 CD *o -^ ^ + ^ c^ CO ' c:r^ 1 r < CN ^^ '^ ^ 1 + CJ< ^ 1 o GO 1 CM c3 GO ^ 00 1 + + 00 CO § 00 1 00 1 30 <^ <^ t- OO ^ lO ■ + + 1 + 1 co o JO + **o 4 < 1-H CO 00 + 1 + o CO co + 4 ^ ! 0* , { > 4 Oi — OO --^ Ol lO l- t- "* ^ CO CD O +++I 1+ + 00 GO CO CO + Oi Oi 00 + t> 1 00 CO CO T^i -^ G^ O^ t- CO + 1 1 + CO + Tf. < CO CO + + CO CO t-GC'<^vOr-ao*cc?iCN ■s 1 i ui s < s 3 ca t» o 0^ > a 'n Pi o .22 '> Q r3 ** Si" On the Hwary Oscillations of the Barometer at Rome. 225 From a view of the two sets of results at the bottom of it, it is easily evident that those derived from the second supple- ment merely destroy the others, and they have only been in- serted to show the complete execution of the ti/pe, for the num- bers are too few to correct each other, and the difference of — 005 between 10 a. and 10 m. (of the same day) is utterly insufficient for correcting them. The morning observations are therefore quite destroyed, while the evening ones are less af- fected. Let us then notice the Jlrst results. The morning maxi- mum occurs between 10 and 11, probably near the latter hour, as it diiTers from 10 positively ^ merely loloo^h of an inch. Whether the mercury is actually falling at 7 and 8 o**clock it is not so easy to decide. The observations at the former time, from their small number, are not much to be depended on, but they are abundant at the latter hour, and appear to indicate the conclusion of a fall, but it is probably inconsiderable, some fluctuation between the morning minimum and maximum. The mercury sinks regularly from 11 till 3. At that hour a temporary elevation is shown ; but I am inclined to think it erroneous, and arising from an overplus of observations with the sign + , and an accidental deficiency of the others, which an inspection of the column will confirm. At 4 it decidedly attains the afternoon minimum ( — 0170), and fluctuates till about 7, when the height is nearly the same, and then rises constantly for four hours. By 11 it has rapidly risen, and at that hour we have the evening maximum : at 1 2 it is lower. During the night I can give no account. Part second of this table shows all I know concerning it from three sets of obser- vations, but two are so affected by irrelevant causes that I can- not pretend to discover the truth. They tend to indicate a maxi- mum at 3 M., when we ought rather to have a minimum. I Tiere give the mean results in inches of mercury found by ap- plying the means in the columns to the height of 10 m. It only includes part first of the third table. D. 7m. 29.9950 8 9893 — 57 9 9872 — 21 10 9900 + 28 4 a. 5 6 7 29.9730 9782 9804 9729 D. — 188 -f 52 + 22 — 75 226 On the Horary Oscillations of the Barometer at Rome. 11 12 1a 2 9903 9879 9875 9828 9918 + 3 24 — ^4 — 47 4-90 8 9780 + 51 9 9838 + 5a 10 ' 9950 + 112 11 30.0008 + 58 12 29.9974 — 34 269.9018 269.8595 269.9018 18)539.7613 Mean, 29.9867 Such is the precise statement; but we shall have a better idea of the general course of the mercury by taking out a few of the best observations and giving them to lOOOths of an inch, thus; 8 m. 29.989 — 10 and 11 m. 29.990— 12.29.988 —2A.29.983.4.29.973— 7.29.973— 9 — 29.984— 11.30.001 — 12.29.997. Hence we may safely infer, Ist, that the maxima occur very nearly at 11 both morning and evening; 26?, that the minimum is at 4 a., after which it remains for some time nearly stationary ; 3J, that the falls are more gra* dual than the ascents ; and, 4^A, that the ranges between the morning and evening maximum is + 0105, and between the afternoon minimum and evening maximum .0278, which is somewhat less than we should have reckoned by Humboldt's table. But there can be little doubt of its approaching the truth, and possibly, had the morning minimum been properly observed, it might have shown a greater range. It is to be re- membered that in the northern latitudes the hours of variation change in summer and winter. These observations were made towards spring, and therefore probably represent very exactly the mean curve. Indeed they coincide remarkably with tl^^ hours found in the tables ; and, notwithstanding any differences which exist between my observations, and those of Humboldt's table, it will be there observed that different series of observa- tions made for several years together do not coincide in the way that might have been looked for, in a path where certainty had been more attainable, and some allowance will therefore be made for these observations of mine, made during a very li- Captains Irby and Mangles's Account qfPetra. 227 mited period, and under many unfavourable circumstances.* It remains only to be observed, that the mean height of the barometer at Rome appears to have been nearly 29-9867 inches, or when corrected for capillary action and reduced to the level of the sea 30.0807, and that this mean appears to oc- cur about 7 m., between 1 and 2 a., and 9 and 10 a., which would therefore be the proper hours for observation. A'^J' Art. VI. — Account of ' the Necropolis of Petra, a City in Pa- lestine, excavated Jrom the solid Rock. By the Honourable -Charles Leonard iRBvand James Mangles, Comman- ders in the Royal Navy, -j- boME hundred yards below this spring begin the outskirts of the vast Necropolis of Petra. Many door-ways are visible upon different levels cut in the side of the mountain, which to- wards this part begins to assume a more rugged aspect. The most remarkable tombs stand near the road, which follows the course of the brook. The first of these is on the right hand, and is cut in a mass of whitish rock, which is in some measure insulated and detached from the general range. The centre presents the front of a square tower, with pilasters at the cor- ner, and with several bands of frieze and entablature above ; two low wings project from it at right angles, and present each of them a recess in the manner of a portico, which consists of two columns whose capitals have an affinity with the Doric order, between corresponding antae ; there are, however, no tri- glyphs above. Three sides of a square area are thus inclosed ; the fourth has been shut in by a low wall and two colossal lions on either side of the entrance, all much decayed. The interior has been a place of sepulture for several bodies. On * Mr Daniell found the variation not far from a-half more than we should have estimated from Humboldt for London. f The travels of these two able and enterprising officers having been printed only for private distribution ; and the very interesting account which they have given of the famous city of Petra not having appeared in any pe- riodical workj we have been induced to lay it before our readers with some slight abridgement. 228 Captains Irby and Mangles's Account of the Necropolis the front are little niches and hollows, cut as if for the reception of votive offerings. Farther on upon tfie left is a wide fa9ade of rather a low proportion, loaded with ornaments in the Ro- man manner, hut in a bad taste, with an infinity of broken lines and unnecessary angles and projections, and multiplied pediments and half pediments, and pedestals, set upon columns that support nothing. It has more the air of a fantastical scene in a theatre than an architectural work in stone. What is observed of this front is applicable more or less to every spe- cimen of Roman design at Petra. The door-way has triglyphs over the entablature, and flowers in the metopes. The cham- ber within is not so large as the exterior promises. It is a broad raised platform round three sides, on which bodies were pro- bably disposed. Immediately over this front is another of al- most equal extent, but so wholly distinct from it, that even the centres do not correspond. The door-way has the same orna- ments. The rest of the body of the design is no more than a plain front, without any other decoration than a single mould- ing. Upon this -are set in a recess four tall and taper pyra- mids. Their effect is singular and surprising, but combining too little with the rest of the elevation to be good. Our attention was the more attracted by this monument, as it presents per- haps the only existing example of pyramids so applied, though we read of them as placed in a similar manner on the summit of the tomb of the Maccabees and of the Queen of Adiabaene, both in the neighbouring province of Palestine. The interior of the mausoleum is of moderate size, with two sepulchral recesses upon each side, and one in form of an arched alcove at the up- per end ; a flight of steps leads up to the narrow terrace upon which it opens. Fig. 3, Plate III. given in last number, may convey an idea of some of these singular excavations. The sides of the valley were now becoming precipitous and rugged to a high degree, and approaching nearer and nearer to each other, so that it might rather deserve the name of a ra- vine, with high detached masses of rock standing up here and there in the open space. Of these the architects had availed themselves. In some instances the large and lofty towers are represented in relievo on the lower part of the precipice, and the live rock is cut down on all sides, so as to make thcresem- / of Petra, a City excavated from the solid Rock. 229 blance complete. The greater number of them present them- selves to the high road, but there are others which stand back in the wild nooks and recesses of the mountain. All seemed to have been sepulchral ; and it was here that we first observed the features of a sort of architecture that was new to us, and is per- haps not elsewhere to be found. To erect quadrangular towers for sepulchres seems to have been the fashion in several inland districts of the east. They abound at Palmyra, and are seen in the valley of Jehosha- phat near Jerusalem, &c. : but the details and ornaments of these universally betray an imitation of Roman architecture, whilst at Petra they bear all the marks of a peculiar and indi- genous style. Their sides have generally a shght degree of that inclination towards each other, which is one of the characte- ristics of Egyptian edifices, and they are crowned with the Egyptian torus and concave frieze. A very remarkable super- structure rises above as a parapet. Two corresponding flights of steps represented in relievo, ascend in opposite directions from two points near the centre. They are connected to- gether by a horizontal line drawn between the uppermost steps, and these are usually from four to six. At the an- gles are pilasters. In many instances they have a conside- rable diminution upwards. The capital is very peculiar, and appears like the rough draft of an unfinished Ionic capital as it comes from the quarry. It is, however, almost universal on these tombs, and may be called the A7'ahian order of architec- ture. An entablature and frieze, little differing from the Ionic or Corinthian, rests upon these pilasters. Above there is a blank space in the nature of a low attic, which is finished with the Egyptian torus and frieze, bearing the superstructure which I have described. There is one single example near the thea- tre of an upper door- way opening in this attic, to which there is no visible access. There may possibly, however, be some stairs in the interior. The lower door-way is unluckily choaked, so that we could not ascertain. In some instances the pilasters are multiplied to four in the front, and are rounded instead of being angular. What is the least peculiar in the details of these Arabian elevations is the decorations of the door-ways, which have in many instances a pediment not distinguishable 280 Captains Irby and Mangles's Accmint of the Keciopohs from those of the Romans, and in others a plain horizontal ar- chitecture with the same character in the mouldings. It is re- markable that in very many instances the whole frame and ornament of the door has been of separate pieces, and grafted on upon the solid rock. Sometimes there are cavities for pegs or rivets, which would seem to have fastened these decorations in metal or in wood. In others they seem to have been of mar- ble, or some finer sort of stohe set into grooves, which show in the hollow their exact form. We were at a loss to account for the apparent conformity of this single member of the building to the rules of the Greeks and Romans. It seems too strong to be accidental ; and if we suppose the imitation to have taken place so far back as the first Macedonian expedition into this country, it will still make the tombs by many ages more recent than it is probable that many of them really are; since, from the days of Rekem, king of the Midianites, who passes for the founder of Petra, to those of Alexander the Great, there must have been a long suite of kings, and these monarchs probably had tombs. Yet, if the form of the door-ways be judged de- cidedly posterior to that period, it is so general that few if any of the larger sort will remain for that early dynasty. If we bring them still later, and suppose them a Roman innovation, the difficulty is increased ; because we must then believe a much greater lapse of ages to have passed in a flourishing kingdom without any considerable monuments, when architecture was not unknown. It is possible such of the door-frames as were not cut in the solid may have been added afterwards, but this does not appear very probable, nor does it entirely remove the difficulty ; especially, as in some instances in the higher parts of the design, broad bands seem to have been attached in a simi- lar manner, which very probably were charged with inscrip- tions. It is surprising, amongst such a multitude of tombs, to find so few with any inscription to record for whom they were con- structed. We only met with two instances. One was on the tomb which had a door in the attic already mentioned, as being near the theatre. It is much mutilated. The other which we copied is on the left hand side of the track leading towards Dibdebar, on a large front of pure Arabian design, '>'^S^>^i;y^qf Petra, a City excavatedfrom the solid Rock. 231 with four attached columns ; and in this monument the archi- tect, from failure, or a defective vein in the sandstone, has been obliged to carry up the lower half in masonry, so as to meet the upper, which is sculptured on the face of the moun- tain, where also there were flaws, and here pieces have been let in to make up what was defective. These last remain, but the whole substructure has disappeared entirely, and the upper part is left hanging from the rock above without any base whatever. This is not the only proof that is to be found among the remains at Petra, that those who wrought on the live rock, contrary to the necessary practice of builders, began their work at the top. To return to the inscription ; it is upon an oblong tablet without frame or relief, but is easily distinguished from the rest of the surface from, be- ing more delicately wrought. There projects, from each of its ends, those wings is in form of the blade of an axe, which are common both in the Roman and Greek tablets, and which would seem to have been in their origin, for the purpose of receiving screws or fastenings without encroach- ing on the part inscribed. This original purpose seems to have been particularly kept in view in the present instance, since, although the whole is in the solid, there is upon each side a chain of metal, which must be the effect of studs of bronze actually driven in, to give the whole tablet the ap- pearance of a separate piece. The letters are well cut, and in a wonderful state of preservation, owing to the shelter which they receive from the projection of cornices and an eastern aspect. None of our party had ever seen these cha- racters before, excepting Mr Banks, who, upon comparing them, found them to be exactly similar to those which he had seen scratched on the rocks in the Wady Makootub, and about the foot of Mount Sinai. He subsequently found a passage in Diodorus Siculus, wherein he speaks of a letter written by the Nabathaei of Petra to Antigonus, in the Syriac character ; though this, perhaps, is no proof that the Syriac was in use with them, since they may have chosen that lani guage only as more familiar to the court they were addressing. The tablet has five long lines, and immediately underneath a single figure on a larger scale, probably the date. The very 232 Captains Irby and Mangles's Account of the Necropolis same occurs at the bottom of the Hebrew characters on the tomb of Aaron. The interior of the tomb we have been de- scribing has two chambers, with recesses for bodies, but no peculiarity worthy of notice. The front is crowned with a double flight of steps in the usual form. In many instances, in lieu of two flights diverging from each other, they are brought to meet in the form of pyramids, being reduced to a much smaller scale, and repeated in the manner of battle- ments to the number of three or five entire, with the half of one at each extremity. We have preferred collecting into one view the most re- markable features of these tombs before we advance further, without confining ourselves strictly to those which are met with in the approach from Wady Mousa to the city, in order to generalize the description, and avoid interrupting the nar- rative by alluding to them as they present themselves, which is the case not only in every avenue to the city, and upon every precipice that surrounds it, but even intermixed almost promiscuously with its public and domestic edifices. To return to the description of the eastern approach to Pe- tra. As we advanced, the natural features of the defile grew more and more imposing at every step, and the excavation and sculpture more frequent on both sides, till it presented at last a continued street of tombs, beyond which the rocks, gradually approaching each other, seemed all at once to close without any outlet. There is, however, one frightful chasm for the pas- sage of the stream, which furnishes, as it did anciently, the on- ly avenue to Petra on this side. It is impossible to conceive any thing more awful or sublime than such an approach. The width is not more than just sufficient for the passage of two horsemen abreast ; the sides are in all parts perpendicu- lar, varying from 400 to 700 feet in height, and they often overhang to such a degree, that, without their absolutely meeting, the sky is intercepted and completely shut out for 100 yards together, and there is little more light than in a cavern. The screaming of the eagles, hawks, and owls, who were soaring above our heads in considerable numbers, seemingly annoyed at any one approaching their lonely habitations, of Petra, a City excavated from the solid Rock. 233 added much to the singularity of this scene. The tamarisk, the wild-fig, and the oleander, grow luxuriantly about the road, rendering the passages often difficult. In some places they hang down most beautifully from the cliffs and crevices where they had taken root. The caper plant was also in lux- uriant growth, the continued shade furnishing them with* moisture. Very near the first entrance into this romantic pass a bold arch is thrown across at a great height, connecting the oppo- site sides of the cliff. Whether this was part of an upper road upon a summit of the mountain, or whether it be a por- tion of an aqueduct, which seems less probable, we had no opportunity of examining it ; but as the traveller passes under it its appearance is most surprising, hanging thus above his head Jbetwixt two rugged masses apparently inaccessible. Im- mediately under it are sculptured niches in the rock, destined probably for statues : and we suspect, that, by careful inspec- tion, inscriptions might be found there ; but the position in which they are viewed is disadvantageous, and the height so great, that it would require a good glass to distinguish them. Farther down, upon a much lower level, there is an object frequently repeated in sculpture along the road-side, which we were at a loss to explain. An altar is represented in a niche, upon which is set a mass of a lumpish form, sometimes square, and sometimes curved in its outline, or rising in other instances ' to a sharp or obtuse cone. In one instance three of them are coupled together in one niche. It might possibly be a representation of the god Terminus, or perhaps one of the stones which were objects of worship amongst the Arabs down to the time of the coming of Mahomed. The number of these representations on the face of the rock is very consider- able. In some instances there are many almost contiguous with Greek inscriptions on them, all of which are too much defaced to be of use in explaining their object. The ravine, without changing much its general direction, presents so many elbows and windings on its course, to which the track of necessity conforms, that the eye can seldom pene- trate forward beyond a few paces, and is often puzzled to dis- tinguish in what direction the passage will open, so completely 234 Captains Irby and Mangles's Account of the Necropolis does it appear obstructed. The exact spot was not pointed out to us, but it is somewhere amidst these natural horrors that upwards of sixty pilgrims from Barbary were murdered last year by the men of Wady Mousa on their return from Mecca. The wrapping cloak of one of them was afterwards offered to us for sale at Ipseyra, and one of their watches at Zaphoely. Salvator Rosa never conceived so savage and suit^ able a quarter for banditti. The brook has at this season dis- appeared beneath the soil, but the manner in which its occa- sional overflowings have broken up the antique pavement, and the slippery passes which the running of the waters have made by polishing the live rock where it had been cut away to form the road, sufficiently prove the necessity of providing another course for its waters. A trough, carried along near the foot of the precipice upon the left hand side, was destined to con- fine the water, and to convey it upon a higher than the natural level to the city. At a considerable distance down the ravine the water-course crosses over to the opposite side, and towards its extremity may be traced passing along at a great height in earthen pipes, bedded and secured with mortar, in horizontal groves cut in the face of the rock, and even across the archi- tectural points of some of the tombs, which makes it probable that it is posterior to them. We followed this sort of half subterraneous passage for .the space of nearly two miles, the sides increasing in height as the path continually descended, while the tops of the precipices retained their former level. When they are at the highest a beam of stronger light breaks in at the close of the dark perspective, and opens to vkw, half seen at first through the tall narrow opening, co- lumns, statues, and cornices of a light and finished taste, as if fresh from the chisel, without the tints or weather stains of age, and executed in a stone of a pale rose colour, which was warmed at the moment we came in sight of them with the full light of the morning sun. The dark green of the shrubs that grow in this perpetual shade, and the sombre appearance of the passage from whence we were about to issue, formed a fine contrast with the glowing colour of the edifice. We know not with what to compare this scene. Perhaps there is nothing in of Petra^ a City excavated from the solid Rock. 235 the world that resembles it. Only a portion of a very extend sive architectural elevation is seen at first, but it has been so contrived that a statue with expanded wings, perhaps of vic- tory, just fills the centre of the aperture in front, which, being closed below by the sides of the rock folding over each other, gives to the figure the appearance of being suspended in the air at a considerable height, the ruggedness of the cliffs below set- ting off the sculpture to the highest advantage. The rest of the design opened gradually at every pace as we advanced, till the narrow defile, which had continued thus far without any increase of breadth, spreads on both sides into an open area of a moderate size, whose sides are by nature inaccessible, and present the same awful and romantic features as the avenues which lead to it. This opening gives admission to a great body of light from the eastward. The position is one of the most beautiful that could be imagined for the front of a great temple, the richnesss and exquisite finish of whose decorations offers a most remarkable contrast to the savage scenery which surrounds it. It is of a very lofty proportion, the elevation comprising two stories. The taste is not exactly to be commended, but many of the details and ornaments, and the size and propor- tions of the great door-way especially, to which there are five steps of ascent from the portico, are very noble. No part is built, the whole being purely a work of excavation, and its minutest embellishments, wherever the hand of man has not purposely effaced and obliterated them, are so perfect that it may be doubted whether any work of the ancients, excepting perhaps some on the banks of the Nile, have come down to our time so little injured by the lapse of ages. There is, in fact, scarcely a building of forty years' standing in England so well preserved in the greater part of its architectural decorations. Of the larger members of the architecture nothing is deficient excepting a single column of the portico. The statues are nu- merous and colossal. Those on each side of the portico re- present in groups, each of them, a centaur and a young man. This part of the work only is imperfect, having been mutilat- ed probably by the fanaticism of early Christians or Mussel- men, directed against idolatry, and particularly the human 236 Captains Irby and Mangles's Jccounf of the Necropolis form. In the upper tier the figures are females, two are wing- ed, and two appear to have been dancing or much in action, witli some instruments lifted above their heads, of which that on the left hand seems to be the Amazonian bipennis. Unfor- tunately the centre figure, which was doubtless the principal one, is too much defaced for her attributes to be determined ; nor is there any thing in the ornaments that could enable us to discover to what divinity the temple has been dedicated. i The principal chamber of the interior is large and remark- ably lofty, but quite plain, with the exception of the door- frames and architraves, of which there are three, one at the further end, and one at each side, all opening into small and plain cells. There is also a lateral chamber on each side, opening from the portico, of a rude form. The centre of the superstructure, which comprises the second storey, is a circular elevation surrounded by columns, with a dome surmounted by an urn. This latter has not escaped or failed to excite the covetousness of the natives. We heard of it as the deposit of a vast treasure, " Hasnah-el-Faraoun,'' (treasure of Pharoah,) as far as Jerusalem ; and that it has been repeatedly aimed at by musket shot there are evident proofs in the marks of bul- lets in the stone. None, however, seems to have succeeded in aiming at it by climbing, which would indeed be a difficult task. The green stains on either side would lead to the sup- position that the handles had been of bronze. It is doubtful whether one of the perforations by a musket ball does not show that the urn is hollow. Above the monument the face of the rock is left overhanging, and it is to this that the excellent preservation of its details is to be ascribed. The half pedi- ments, which terminate the wings of the building, are finish- ed at the top with eagles, which, combined with the style of architecture differing little from the Roman, can leave no doubt that this great effort of art is posterior to the time of Trajan"*s conquest. Some of the heights whose steep sides in- close the area in front of the temple, are rendered accessible, though with great difficulty, by flights of steps cut in them. We found the ascent, in some instances, so steep and slippery that we were obliged to take off our shoes, and also to use our hands nearly as much as we did our feet. of Petra^ a City excavated from the solid Rock. 2S7 Some small pyramids hewn out of the rock are on tlie summit of these heights, and we discovered a much higher conical point of mountain, to whose summit there is a regular spiral staircase of ascent, cut with great care and neatness, the same point possibly on which we could distinguish from another quarter a single pillar or obelisk. We first observed, also from the heights above the temple, the vase which crowned another monument to the N.W. The wide space which con- stitutes the area before the temple is about fifty yards in width, and about three times as long. It terminates to the south in a wild precipitous cliff, rendered accessible by the steps above- mentioned to the N. N. W. The defile assumes, for about three hundred yards, the same features which characterize the east- ern approach, with an infinite variety of tombs, both Arabian and Roman, on each side. This pass conducts to the theatre, and here the ruins of the city burst on the view in their full grandeur, shut in on the opposite side by barren craggy pre- cipices, from which numerous ravines and valleys, like those we had passed, branch out in all directions. The sides of the mountains, covered with an endless variety of excavated tombs and private dwellings, presented altogether the most singular scene we ever beheld ; and we must despair to give the reader an idea of the singular eff^ect of rocks, tinted with most extra- ordinary hues, whose summits present us with nature in her most savage and romantic form, whilst their bases are worked out in all the symmetry and regularity of art with colonnades and pediments, and ranges of corridors adhering to the per- pendicular surface. The short notice of Petra by Pliny is as follows : " The Nabataei inhabit a city called Petra, in a hollow somewhat less than two miles in circumference, sur- rounded by inaccessible mountains, with a stream running through it. It is distant from the town of Gaga on the coast six hundred miles, and from the Persian Gulf one hundred and twenty-two." — 6th Book, c. 28. Strabo says, " The capi- tal of the Nabataei is called Petra. It lies in a spot which is in itself level and plain, but fortified all round with a barrier of rocks and precipices ; within furnished with springs of ex- cellent quality for the supply of water and the irrigation of gardens ; without the circuit the country is in a great measure VOL. VIII. NO. II. APRIL 1828. Q 238 Captains Irby and Mangles''s Account of the Neci'opolis desert, and especially towards Judea. Jericho is at the dis- tance of three or four days/"* He adds, that one of the royal lineage always resided at Petra, and had a sort of counsellor attached to him, who was entitled his brother. He premise* their laws and customs. It will be seen that these two ancient geographers, in cha- racterizing the position of the city, not only agree with one another, but will be found sufficiently conformable to the re- ality, though strictly speaking the situation can neither be called a valley with Pliny, nor a plain with Strabo ; yet it is certainly both low in position and level in surface, when com- pared with the crags and precipices that surround it. It is an area in the bosom of a mountain, swelling into mounds and intersected with gullies ; but the whole ground is of such a nature as may be conveniently built upon, and has neither as- cent lior descent inconveniently steep. Within the actual circuit of the city there are two mounds, which seem to have been entirely covered with buildings, being still strewed over with a prodigious quantity of loose stones, tiles, and frag- ments of ancient ware, of a very light and delicate fabric. The bed of the river, taking its course to the N.W., flows be- tween these two spots. The water has now sunk beneath the surface, and perhaps creeps through the rubbish which ages have accumulated in its bed. Great part of it seems to have been arched over in the same manner as the stream at Phila- delphia. In the low grounds on the left bank of the stream seem to have been some of the principal edifices ; the first to the N.W. from the theatre, was an archway of a florid ar- chitecture, with pilasters having pannels enriched with foliage in the manner of Palmyra : the whole is much ruined. The arch was the introduction to a great pile of building standing nearly at right angles to it. This building had a door on one side ; on the three others it was decorated with a frieze of triglyphs and large flowers in the metopes. Beams of wood are let in at intervals between the courses of masonry, and continue to this day a strong proof of the dryness of the cli- mate. The front had a portico of four columns ; this part is much fallen into ruins. The interior of the edifice was divid- ed into three parallel qjjambers, and there seem to have been of Petra, a City excavated from the solid Rock: 239 several stories. This interior economy made us suspect that it was not a temple, but rather a palace or private edifice. Whatever may have been its nature, it seems to have been destined to the same purpose as the ruined building at " Bait- el-Carm," which we afterwards saw from our camp above Dib- debar, and which is the only considerable work of masonry existing at Petra. Upon the summit of the other mound there is a mass of ruins of some solidity, but no very definite shape. The Nubian geographer, climate three, says that the houses of Petra were excavated in the rock. Now, that this was not uni- versally true, is evident from the great quantity of stones em- ployed in the lesser kinds of edifices which are scattered over the i whole site. But it is also true that there are grottos in great numbers, which are certainly not sepulchral, especially near the palace. There is one in particular which presents a front of four windows with a large and lofty door-way in the cen- tre. In the interior, one chamber of about sixty feet in length, and of a breadth proportioned, occupies three of the windows and the door ; at the lower end, the fourth window seems al- lotted to a very small sleeping-chamber, which is not brought down to the level of the floor of the great apartment, but has a chamber below it of the same size, giving no light but from the entrance. This, which seems the best of all the excavated residences, has no ornament whatever on the exterior ; and the same applies to all the other excavations of this nature. The access to this house is by a shelf gained out of the side of the mountain ; other inferior habitations open upon it, and more particularly an oven and some cisterns. These antique dwellings are close to an angle of the mountain, where the bed of the stream, after having traversed the city, passes again into a narrow defile, along whose steep sides a sort of excavated suburb is continued, of very small and mean cham- bers, set one above the other, without much regularity, like so many pigeon-holes in the rock, with flights of steps, or narrow inclined planes leading up ta them. The main wall and ceil- ing only of some were in the solid ; the fronts and partitions being built of very indifferent masonry with cement. Following this defile farther down, the river reappears flow- ing with considerable rapidity ; though the water is plentifql* 240 Captains Irby and Mangles"'s Acvomit of the Necropolis it is with difficulty that its course can be followed, from the luxuriance of the shrubs that surround it, and obstruct every track. Besides the oleander, which is common to all the water- courses in thrs country, one may recognize among the plants which choke this valley, some which are probably the descen- dants of those that adorned the gardens and supplied the mar- ket of the capital of Arabia ; the carob, fig, mulberry, vine, and pomegranate, line the river side ; a very beautiful spe- cies of aloe also grows in this valley, bearing a flower of an orange hue, shaded to scarlet ; in some instances it had up- wards of 100 blossoms in a bunch. Amongst the niches for votive offerings in the mountain's side, some of which are cut to the height of thirty feet, are pyramids and obelisks ; and in one instance, there is an altar between two palm-trees. The position of the theatre has been mentioned. It is the first object which presents itself to the traveller on entering Petra from the eastward. It is entirely hewn out of the live rock. The diameter of the podium is 120 fieet, the number of seats thirty-three, and of the cunii three. There was no break, and consequently no vomitories. The scene, unfortunately, was built, and not excavated ; the whole is fallen, and the bases of four columns only remain on its in- terior face. The theatre is surrounded by sepulchres ; every avenue leading to it is full of them ; and one may safely say, that a hundred of the largest dimensions are visible from it. Indeed, throughout almost every quarter of this metropolis^ the depositories of the dead must have presented themselves constantly to the eye of the inhabitants, and have almost out- numbered the habitations of the living. There is a long line of them not far from the theatre, at such an angle as not to be comprehended in the view from it, but which must have formed a principal object for the city itself. The largest of the sepulchres had originally three stories, of which the lowest presented four portals with large columns set between them, and the second and third a row of eighteen Ionic columns each attached to the facade; the live rock being insufficient for the total elevation, a part of the story was grafted on in masonry, and is for the most part fallen away. The four portals of the basement open into as many chambers, very dissimilar both in distribution x>fFeifa^ a City edcavatedjrom the solid Rock, Ml ^nd arrangements, but all sepulchral, and without any com* munication between them. In one were three recesses, which seem to have been ornamented with marble or some other ex- traneous material. Almost contiguous to this extensive front is another somewhat smaller, but equally rich, whose design has a great analogy, especially in the circumstance of the half pediment, and the circular lantern in the centre, to the beau- tiful temple of the eastern approach. Though a general vsym- metry pervades this species of architecture, yet there are ir- regularities observable in its doors and windows, which may be explained by the circumstance of their opening into apart- ments no way connected with each other, and intended appa- rently for different families. A little farther to the south-east, an area is gained upon the slope of the mountain by excavat- ing it, so as to form three sides of a square. Two of these have been formed into Doric porticos ; the third, which is the loftiest, as being that which abuts against the body of the mountain, is occupied by a lofty front, decorated with four engaged columns of the same order, but without triglyphs. A pediment surmounts the frieze, supporting an urn, in all re- spects similar to that on the temple of the eastern approach. A door-way with a window over it fills the centre, and there are three windows in the attic, the centre one of which exhi- bits two half-length figures in basso-relievo. In the approach to this tomb, there were arched substructions of great extent now fallen into ruins. It is surprising to reflect, that monu- ments of so vast a scale should be executed subsequent to the Roman conquest, since after that period we can look upon them as no more than the tombs of private individuals. Whence should come so much wealth, and with a taste for magnificence, after the country had lost its independence, it is difficult to conceive. It is possible, however, that a trade by the Red Sea with India, or even the caravan trade with the spice country, may have imported such riches into the place, as to give the inhabitants the same fondness for ostentation and ornament observable at Palmyra, which owed its wealth to the same source. Yet to consider a mausoleum of upwards of seventy or eighty feet high, with lateral porticos and flights of terraces upon arched work leading up to it, as the effeet ^f 242 Captains Irby and Mahgles''s Account of the Necropolis the vanity of some obscure individual in a remote comer of the Roman empire, has something in it surprising and al- most unaccountable. The interior was disposed of in one large and lofty chamber, having six recesses, with grooves in them at the further end. On the establishment of Christianity, these six recesses have been converted into three for the reception of the altars, and the whole apartment has been made to serve as a church ; the fastenings of the tapestry and pictures are still visible on all the walls, and near an angle is an inscription in red paint, re- cording the date of consecration.' These were the only vestiges of a Christian establishment that we were enabled to discover throughout the remains of Petra, though it was a metropoli- tan see. Diodorus Siculus has a long account of the expedition sent by Antigonus against the Nabataei. He mentions that their riches were very great in gold and spices, and that such of them as were feeble and infirm, were left s-^r/ rmg Usr§ag, which he calls afterwards a place of prodigious natural strength, but without any walls ; and distant two days"* journey from any inhabited place. In the second expedition, it is said there was but one way of access to it, which was artificial. The loftiness of the post is afterwards mentioned. It is difficult to apply this description to Wady-Mousa. Upon some of the high points of rocks that rise about the skirts of the city, and tower above them, the remains of walled forts are visible from below ; and as it is probable there was an acropolis, it must be looked for in some of these. Two days were spent in these ruins from day break until dusk, and yet it will be seen by what has been said, that this time was very insufficient to complete an examination of them. It was impossible to remain any longer ; for although Abou , Raschid attended personally with us the whole time, yet hav- ing forced us to decline visiting Abou Zetoun in so abrupt a manner, and having but few attendants, he was never at his ease, and constantly urged us to depart. On the first after- noon, we undertook the ascent to the little edifice, which is visible to all the country round, upon the very highest and most rugged pinnacle of this range of mountains, and is called xyfTetra^ a City excavated from the sdid Mock. 243 *^ the tomb of Aaron." The tomb of Moses has been so grossly misplaced by the Musselmen, who show it half a day's journey beyond Jordan to the westward, that we might look with some suspicion to one assigned to his brother, were it not that Jose- phus expressly says of the place of his decease, that it was near Petra. Compare also Mozera with Mousa, and it seems that the monument and the ruins mutually authenticate each other. We had no doubt, therefore, that the height which we were going to ascend, is the Mount Hor of Scripture. The base of the highest pinnacle of the mountain is a little removed from the skirts of the city to the westward ; v/e rode to its foot over a rugged broken tract, passing in the way many se- pulchres, similar to those which have been described. A sin- gular monument presents itself upon the left hand ; an obtuse cone, produced by the coils of a spiral, is represented as stand- ing upon a vast square pedestal or altar, the whole being ob- tained out of one of the peaked summits of the rock. Not far from thence, close to the way side, is the same representation in relievo, within a niche, which we have remarked upon in the eastern approach^ the form of the recess which surrounds the altar rising into the figure of a sugar loaf. Nowhere is the extraordinary colouring of these mountains more striking than in the tomb of Aaron which we followed, where the rocks some- times presented a deep, sometimes a paler blue, and some- times was occasionally streaked with red, and shaded off to lilac or purple ; sometimes a salmon colour was veined in waved lines and circles, with crimson and crest scarlet, so as to re- semble exactly the colour of raw meat ; in other places there are livid stripes of yellow or bright orange, and in some parts all the different colours were ranged side by side in parallel strata. There are portions also with paler tints, and some quite white, but these last se6m to be soft, and not good for pre- serving the sculpture. It is this wonderful variety of colours, observable throughout the whole range of mountains, that gives to Petra one of its most characteristic beauties. The fa9ade of the tombs, tastefully as they are sculptured, owe much of their imposing appearance to this infinite diversity of hues in the stone. We engaged an Arab shepherd as our guide ; and leaving 244 Captains Irby and Mangles's Account of the Necropolis Abou Raschid with our servants and horses where the steep- ness of the ascent commences, we began to mount the tract, which is extremely steep and toilsome, and affords but an in- different footing. In most parts the pilgrim must pick his way as he can, and frequently on his hands and knees. Where by nature it would have been impassable, there are flights of rude steps or inclined planes, constructed of stones laid toge- ther, and here and there are niches to receive the footsteps cut in the live rock ; the impression of pilgrims'* feet are scratched in the rock in many places, but without inscriptions. Much juniper grows on the mountain, almost to the very summit^ and many flowering plants which we had not observed else- where ; some of these are very beautiful ; most of them are thorny. On the top there is an overhanging shelf in the rock, which forms a sort of cavern. Here we found a skin of ex- tremely bad water suspended for drinking, and a pallet of straw, with the pitcher and the other poor utensils of the shiekh who resides here. He is a decrepid old man, who has lived here during the space of forty years, and occasionally endured the fatigue of descending and reascending the moun- tain. The tomb itself is inclosed in a small building, differing not at all in external form and appearance from those of Ma- homedan saints, common throughout every province of Tur- key. It has probably been rebuilt at no remote period. Some small columns are bedded in the walls, and some fragments of granite and slabs of white marble are lying about. The door is near the south-west angle, within which a constructed tomb, with a pall thrown over it, presents itself immediately upon entering ; it is patched together out of fragments of stone and marble that have made part of other fabrics. Upon one of these are 'several short lines in the Hebrew character, cut in a slovenly manner. We had them interpreted at Acre, and they proved to be merely the names of a Jew and his fa- mily who had scratched this record. It is not probable that any professed Jew has visited this spot for ages past, perhaps not since the period of the Mahomedan conquest ; it may lay claim, therefore, to some antiquity, and in any case it is a curious appendage to the testimony of Joseph us on this sub- ject. There are rags and shreds of yarn, with glass beads qfPetra^ a City excavated from the solid Rock. 245 and paras, left as votive offerings by the Arabs. Not far from the north-west angle is a passage, descending by steps to a vault or grotto beneath, for we were uncertain which of the two to call it, being covered with so thick a coat of white- wash, that it is difficult to distinguish whether it is built or hollowed out. It appeared, in great part at least, a grotto. The roof is covered, but the whole is rude, ill-fashioned, and quite dark. The sheikh, who was not informed that we were Christians, a circumstance which our guide was not aware of, furnished us with a lump of butter. Towards the farther end of this dark vault lie the two corresponding leaves of an iron grating, which formerly prevented all nearer approach to the tomb of the prophet ; they have, however, been thrown down, and we advanced so as to touch it ; it was covered by a ragged pall. We were obliged to descend bare-footed, and were not without some apprehension of treading on scorpions or other reptiles in such a place. The view from the summit of the edifice is extremely ex- tensive in every direction, and the eye rests upon few objects which it can clearly distinguish and give a name to, though an excellent idea is obtained of the general face and features of the country. The chain of Idumean mountains which form the western shore of the Dead Sea, seem to run on to the south- ward, though losing considerably in their height ; they appear in this point of view barren and desolate. Below them is spread out a white sandy plain, seamed with the beds of occa- sional torrents, and presenting much the same features as the most desert parts of the Ghor. Where this desert expanse ap- proaches the foot of Mount Hor there arise out of it like islands, several lower peaks and ridges of a purple colour, probably composed of the same kind of sandstone as that of Mount Hor itself, which, variegated as it is in its hues, presents in the distance one uniform mass of dark purple. Towards the Egyptian side there is an expanse of country without fea- tures or limit, and lost in the distance. The lofty district which we had quitted in our descent to Wady Mousa shuts up the prospect on the S. E. side ; but there is no part of the landscape which the eye wanders over with more curiosity and delight than the crags of Mount Hor itself, which stand up on 246 Mr Llnd on Meteorological Phenomena every side in the most rugged and fantastic forms ; sometimes strangely piled one on the other, and sometimes as strangely yawning in clefts of a frightful depth. In the midst of this chaos there rises into sight one finished work, distinguished by profuseness of ornament and richness of detail. It is the same which has been described as visible from other elevated points, but which we were never able to arrive at ; it bears N.E. half N. from this spot ; but the number and intricacy of the vallies and ravines which we supposed might have led us to it, baffled all our attempts. No guide was to be found. With the assistance of the glass we made out the fa9ade to be larger to all appearance than that of the temple at the eastern approach, and nowise inferior to it in richness and beauty. It is hewn out of the rock, and seemed to be com- posed of two tiers of columns, of which the upper range is Ionic. The centre of the monument is crowned with a vase of gigantic proportion ; the whole appeared to be in a high state of preservation. It may perhaps be an ornament to the northern approach to the city, similarly situated to that on the eastern side from Mount Hor. Petra is intercepted and concealed by the prominences of the mountains. An artist who would study rock scenery in all its wildest and most extravagant forms, and in colours which to one who has not seen them would scarcely appear to be in nature, would find himself re- warded should he resort to Mount Hor for that sole purpose. Aet. VII. — Notice of' the Principal Meteorological Pheno- mena in the last eight months of 1 826 at Patna and Fut- tehpore. By Alexander F. Lind, Esq. of the Bengal Civil Service. Communicated by the Author. ABSTRACT of a Meteorological Diary kept from the 1st May to the 24th July at Patna, Lat. 25° ST N. Long. 85° 15' East ; and from the 6th September to the Slst Decem- ber at Futtehpore, Lat. 25° 56^ N. Long. 80° 45^ East ; and during the intermediate period on the River Ganges, be- tween Patna and Bitora, (Futtehpore.) at Patna and Futtehpore. 2il 1826 Mon. Mean of Far. Thermometer, in the shade, out of doors. Far. Thermometer in the] shade, out of doors. 03 .2 S eg S5 g i loon 103°5 t § Ten p. M. Daily , Range. ll. 0 Lowest Tempera- 1 ture. 1. 110° 1045 May 83°! 95°5 97°1 91°5 86 6 20 10 7 10°5 3 27° 79° June 84 2 90 5 93 3 93 9 90 2 89 6 90 4 86 6 17 81 July 83 4 86 2 85 5 83 8 69 3 13 79 99 98 98 Aug. Sept 834 86 6 88 7 86 8 75 1 14 80 83 88 90 90 7 87 3 83 3 17 80 Oct. 72 6 87 923 79 ^ 93 S 801 87 7 20 6 14 27 66 99 92 Nov .606 74 7 75 8 20 4 3 27 49 Dec .48 4 Q5 9, 701 73 c )66 3 209 Q5 26 46 80 1826 Prevailing Winds. 1 Mon. ' Direction. Force. East. North. •5 0 1/3 3 ^ 0 SS Very Strong. 2 CO s 0 a 3^ May June 101 14-i 19 1| 1 5 31 5 3 18 5 31 151 1 1 30 5 3 3 16 3 30 July 5 25 1 i 31 12 10 9 31 Aug 22| 7 n 31 17 12 2 31 Sept 16 13| 1 30 1 22 7 30 Oct. 25 6 31 2 8 17 4 31 Nov 22^ n 30 1 7 22 30 Dec. 16J m 3i 1 31 1 6 24 31 248 Mr Lind on Meteorolo^rlcai Observations I82G Weather. Atmospheric Phenomena. Rain Gage Mon. < 2' 1 >% 1 •1 S « 1 t4 .MS May ^18J 9J 2J I 31 9 4 2 6 1.244 June 3i 13^ 8i 4| 30 31 18 12 2 6 3.232 July Aug. 16| 81 5| U 10 6 3 8.201 2J 12i 10| 5i 31 15 13 3 2 12.865 Sept. ni 13i 1| 3| 30 31 13 10 4 2 4.471 Oct. Nov. Dec. 22 71 n 4 2 2 0.388 22J 3i H 3 4 30 1 2 0.976 17 lOJ H h 31 2 1 1 10 0.485 May. — The first half of this month was distinguished by cloudless skies and excessive heat. The sun usually rose and set of a pale white colour. On the 21.st May a total eclipse of the moon took place. It began about seven hours sixteen minutes p. m., and ended about ten hours forty-two minutes, and was distinctly visible throughout. At its com- mencement Fahrenheit''s thermometer stood at 93°55 and to- wards the beginning of total darkness, the moon was appa- rently placed between the stars /3 and d Scorpio. The whole disc was visible of a dusky red colour, but here and there darkened with bkck clouds, and stars of the fifth magnitude became visible. When the total darkness ended, and the enlightened portion of the moon's disc was as large as the moon eight or nine days old, the entire disc was to be seen ; but in a moment afterwards, the darkened portion disappeared, and a troubled corona environed the moon with a broken ring ; and as the light increased, the corona often vanished and again formed. There were frequent flashes of lightning during at Pntna and Futtehporg. 249 the continuance of the eclipse, and a few cirri were observed floating through the sky after its termination. At two a. m. next morning, the weather began to blow, thunder, and hght- ning, and 1.003 inch of rain fell. On the ^9th May, after sunset, a singular semicircular band coloured with a deeper blue than the surrounding sky was observed ; its bases rest- ing about as many degrees north of the real east and west as corresponded with the sun's amplitude. The breadth of this baud was about 4°. Next morning, before sunrise, the Hi- malaya mountains were distinctly visible. The distance of some of these hills is as great as 160 miles in a direct line ; of others somewhat less. When the sun rises they vanish. June. — On the 7th, at seven hours ten minutes p. m. a fire- ball fell from the zenith in a south easterly direction. The ball was as large as Venus, and left a broken trail of light behind it. Next evening a beautiful fire-ball moved slowly from west to east over a distance of nearly S'i*', leaving at intervals a trail of fire. On the nights of the 12th and 13th, the moon was surrounded with a discoid halo, tinged with a reddish brown colour. On the 20th the increase of water in the Ganges was very marked, and portions of the bed of the river left dry since the past year began to be covered with water, although since the ist May only 2.24j6 inches of rain had fallen at Patna. July. — At sunset of the 3d a large corona formed round the sun. The sky at sunset of the 6th presented a beautiful appearance, clouds of bright green (portending rain,) being surrounded with others coloured scarlet. At night, coronae formed round the planets and large stars, and on the 8th, 2.249 inches of rain fell. From the 1st to the 14th rain fell daily. August 30th.— While in a boat on the Ganges I observed a curious optical deception. A very violent shower of rain, attended with strong wind, swept from the opposite bank of the river, and the sky and the river became of one colour and indistinguishable the one from the, other. The distant bank, with its trees, &c. appeared exactly like a picture depicted on the clouds. The appearance did not last long. November 14th. — A total eclipse of the moon took place. 250 Dr Colquhoun on the Assay but the clouded state of the sky prevented its being visible. The same cloudiness extended all along the Ganges as far as Calcutta, a distance of 3° 22' of latitude, and perhaps farther. Art. VIII. — On the Assay of the Argillaceous Iron-Ore. By Hugh Colquhoun, M. D, Communicated by the Author. The assay of an ore of iron is the process of subjecting a small portion of it, as an average specimen of the mass, to the test of chemical analysis, in order to discover the amount and value of metal which it may contain, together with the nature and relative proportions of those earthy ingredients with which the metal is associated. If this analysis be conducted by so- lution in acids, and then obtaining each ingredient in a sepa- rate form, so as to ascertain the constitution of the ore with scientific precision, it is styled the humid assay. But if the analysis be made by merely reducing the ore in a crucible, either per se or associated with a flux, and then examining the metallic and scoriaceous mass that results from this reduction, it is termed the dry assay. Each of these processes has for its object the important pur- pose of estimating the metallic richness of any given mass of ore, and the expense in fuel and flux which it will cost to ex- tricate the iron. Each method possesses certain advantages that are peculiar to itself, and each is also marked by its own inconveniences. For although the humid assay, or chemical analysis, affords the only sure method of ascertaining with precision the nature and relative proportions of the ingredients in any ore, yet it requires more delay, and perhaps more care than the smelter is willing to bestow ; and it may also some- times demand a greater acquaintance with the science of che- mistry than he possesses. On the other hand, the dry assay, conducted by a man of practical experience, will seldom fail to give a tolerably accurate view of the amount of metal in an ore, and of the general character of its earthy ingredients. It is a process requiring no great exertion of patience or at- tention, and as being perhaps more congenial with his general habits, it is almost invariably preferred by the metallurgist. of the Argillaceous Iron-Ore. 251 We shall consider the two processes separately : and shall commence with the dry assay. § 1. On the Dry Assay of Ironstones. In performing this assay, the leading object to be kept in view is to effect it accurately, in the most rapid manner, and on the smallest scale. It ought to be in all respects a minia- ture model of the process which is afterwards to be employed in smelting the ore in the blast furnace, and it is only when this point is pretty nearly attained that much reliance can be placed upon the conclusions deduced from the assay. In ex- plaining therefore what is essential to the successful manage- ment of the dry assay, it seems of importance to keep in view, at the outset, the history of the smelting process. After a brief glance at this, the details which more exclusively belong to the assay will be better appreciated. Metallic iron nowhere exists in a native state to any con- siderable extent, ^hat metal must always be extracted from its combinations with oxygen and the admixture of certain earthy bodies, by fusing the earths, and by deoxidating the metal through the agency of carbonaceous matter. When the earthy constituents of the ore are brought into this state, the particles of metal which they include will subside through the fluid by their superior specific gravity, and unite at the bottom of the furnace in which the smelting takes place ; so that when the whole is allowed to cool, the metal will be found collected in a solid lump at the bottom, while the earthy in- gredients are lying above in the shape of a vitrified and homo- geneous mass. In all cases of assay, the metal which is thus found below is called the metallic button, and the superincum- bent vitrified earth is named the scoria. There is no single earth of those which are usually found in ironstones, that can be brought into a state of fusion by the application of any heat of a furnace, however intense. But in some binary compounds of these bodies, and in many ter- nary compounds, the ingredients are found to act mutually on each other so as to yield to the heat of a furnace, and will soften into a porcelain, or melt into an enamel, or flow into a liquid glass, as the case may be. But as it rarely happens Dr Colquhoun on the Jssat/ that these earths are associated with one another in iron ores, so adjusted in their nature and relative proportions as to form easily fusible compounds, it is necessary for the smelter to con- sider what are the earthy ingredients in any given ore, so that he may adapt thereto such a flux as will cause the whole mixed mass readily to melt in the furnace upon a due appli- cation of heat. Thus it appears that it is of primary importance to attend both to the nature and to the proportions of the various earths which are brought together in the furnace. Now, as there is a considerable variety in the kinds of those earths with which iron is associated by nature, and as there is an endless chang- ing in their relative proportions, it is essential that the smelter should possess some knowledge of the composition of any given ore which is to be assayed, in order that he may be enabled to prepare the most appropriate flux for it, — that flux which shall fuse it most perfectly, and produce as the result of the assay, the true amount of metal which the ore contains. In selecting and adjusting his flux, the assayer ought always to have in view the following circumstances. First, the use of a substance which, while it is unexceptionable in other respects, is of such a nature as is best adapted to liquefy the ore at the lowest temperature. Second, the exhibition of this flux in suf- ficient quantity to fuse the whole of the ore ; and third, the limiting of its amount within such bounds, that the whole of it may be engrossed in absorbing and liquefying the whole of the earthy ingredients of the ore. For if an excess of flux be employed, it has often the strongest tendency to form a new ore within the crucible, owing to the disposition of oxide of iron to unite, at a high temperature, with an earthy mixture and to vitrify it. So much indeed is this the case, that the most accurately adjusted fluxes always retain a certain portion ^ of the metal unreduced ; and the amount of this very rapidly augments when an excess of earthy matter is exhibited. Nothing therefore can be more important to the successful operation of smelting, whether on the greatest or the smallest scale, than an accurate knowledge of the nature and relative proportions of the earthy constituents of an ore. This is the only sure means that the ironsmelter can possess for directing oftlie Argillaceous Iron- Ore. 253 hiin in the compounding of his flux, so that he shall select sub- stances of that kind, and in that quantity which are respec- tively the fittest to produce the fusion of the whole mass in the furnace. Nor is it possible to devise any formula for a flux of universal application, oi|e which can be considered as, in all cases, a sure test of the quantity of metal contained in any ore. Our ores are, generally speaking, either siliceous, or calcareous, or argillaceous. Now a siliceous or sandy ore requires a flux in which pure lime is a predominating ingredient. A calca- reous ore, on the contrary, naturally containing a considerable amount of the carbonate of lime, requires a highly siliceous flux. And an argillaceous ore, in order to solve its clay, will need either lime or a mixture of lime and silica. Indeed, some mixtures of silica and lime in an iron-ore may make it neces- sary to add a quantity of pure clay to the flux, before they will liquefy in the furnace. But since all these various kinds of ore often occur in the same coal-field, unless the composition of the flux be made to follow their alterations with corresponding changes on itself, it is plain that the smelting or assaying fur- nace will seldom or never make a fair return of metal. The only certain method, therefore, of trying the real value in metal of any given ore, is to obtain some information respecting its con- stitution, and then to compound a flux expressly adapted to it. It is true, however, that there do exist various powerful sol- vents which will hardly fail to fuse any iron-ore in the furnace, and which, if judiciously compounded, may often be useful, especially when the smelter is left very much in the dark as to the constitution of any particular ore. This indeed is the only situation in which it becomes desirable to possess some uni- form vitrifying material, which may be employed in assaying all kinds of ores, however different from one another in consti- tution. We would recommend for this purpose a mixture of from 15 to 20 parts of silica and 25 parts of quicklime (un- slacked,) to every 100 parts of the (uncalcined) ironstone. This will be found upon trial to be of very general application, and will seldom fail to separate the ore into a metallic button and a scoria : and although the results of the assay will not possess the accuracy of those obtained with a flux selected ac- cording to more systematic principles, it will still afford a to- lerable approximation. When the ore is unusually refractory, VOL. VIII. NO. II. APRIL 1828. R S54 Dr Colqiihoun on the Assay from poverty in metal or the predominance of one of its earthy ingredients over the others, it will be proper to increase the ac- tivity of the above mixture, by the addition of about 10 parts of fluor spar or calcined borax. * Having thus stated the general nature of the operation which it is the object of the assayist to perform, we may next proceed to the details of this branch of the metallurgic art, in examining which we shall adopt the following order. We shall first consider what general rules have been established regarding the fusibility of the several earths which nature or art has associated with the oxide of iron in the smelting fur- nace. After determining what mixtures form the most fusi- ble compounds, we shall next advert to the means of procur- ing in a state of purity any of those substances which the as- sayist's exigencies may require. We shall then consider the mode of subjecting the adjusted compound of ore and flux to • Many different recipes for compounding a general mixture for assaying iron-ores may be met with in chemical and metallurgic works ; but we have seen few that are deserving of commendation. Bergman, for instance, mentions the following heterogeneous mixture for assaying iron-ores as having been long in use among the Swedish metallurgists, and as being held in high estimation. To 100 parts of ore, 100 parts of sal ammoniac. < 100 tartar. 100 glassgall. 50 borax. 50 charcoal dUst. 200 black flux. All these ingredients, after being well intermixed, to be put into an un- prepared crucible, and covered with common salt. Chaptal's general flux for assaying iron-ores consists of. To 200 grains of ore, 400 borax. 40 slacked hme. 200 nitre. The whole mixture to be heated intensely for half an hour in a crucible lined inside with charcoal powder. There can be little doubt that in most assays performed with either of these fluxes, a considerable portion of oxide of iron would be retained in a state of permanent combination by the scoria. But independently of this circumstance, the violent commotion into which the whole materials of the assay would be thrown in consequence of the copious extrication of elastic matter from the sal ammoniac, tartar, nitre, &c. would of itself seem sufficient to render every assay made with these fluxes unsatisfactory. 3 of the Argillaceous Iron-^Ore. 255 the action 6F the assay furnace, and shall conclude this part of the memoir by an examination of the metallic button and scoria, with a view not merely to determine the actual results of any assay which has been made, but also to discover how far it has been successfully conducted, or in what respects it may on a subsequent trial be amended^ In following out the method which has now been laid down, the first point is to state those principles which have been fixed by experience, regarding the fusible or fusifying nature of the ingredients which are usually found associated in the smelting furnace. Upon this subject the three following ge- neral rules will be found of universal application. 1. The earths which usually occur in the ores of iron are silica, alumina, lime, and magnesia. Each of these is infusible when exposed j5^r se to the most elevated temperature of a furnace. The oxides of iron are fusible under the same cir- cumstances. 2. Very few binary mixtures of these bodies afford com- pounds fusible at the temperature of the blast-furnace. The cases in which such compounds are produced are the follow- ing. Silica mixed with its own weight of lime melts under a strong heat, into a sort of enamel : it is fusible also with ra- ther more than its own weight of oxide of iron or of oxide of manganese. Compounds possessed of considerable fusibility in very high temperatures are likewise afforded by oxide of iron, when mixed with less than its own weight of lime or of alumina ; or with a quarter of its weight of magnesia. 3. A large proportion of the ternary mixtures of the earths and the oxides, and a still larger number of their quaternary mixtures, are fusible in the furnace. In these mixtures, if any one of the ingredients, excepting magnesia, predominates con- siderably over the others, the fusibility of the compound may be considered as almost certain. But magnesia, whenever its quantity exceeds that of the other ingi-edients of the mixture, has a remarkable effect in rendering it refractory. It will be observed that in each of these complex mixtures, there is no single ingredient more conducive to fusibility than the oxide of iron or of manganese, and none more adverse to it than magnesia. ^ 256 Dr Colquhoun on the Assay From these general rules regarding the fusibility of mix- tures of silica, lime, magnesia, and alumina, it is plain that no compound of them, more simple than the ternary, is at pre- sent of any practical use in metallurgy. Upon these com- pounds, Mr Kirwan has instituted a series of valuable expe- riments, which lead to the following conclusions. 1. When lime, magnesia, and alumina are the component parts of the mixture. If lime preponderate, and the proportions be 3 lime, 2 mag- nesia, and 1 alumina, the compound may be vitrified in the furnace. Whenever the whole mass is thus melted and run into a glass, the highest state of liquefaction is attained which the smelter can desire. If the proportions only approximate to those just mentioned, the mass may be softened under ex- treme heat, so as to form a porcelain or an enamel, but it will not vitrify. If magnesia preponderate, the compound will be infusible in every degree of heat below 1 Q&^ Wedgwood. If alumina preponderate, and be equal to the larger of the two other ingredients, and at the same time is thrice as abun- dant as the smaller, the mixture may form a porcelain at 1^0° Wedgwood. >moii.;> 'ir^« In a mixture of lime, magnesia, and silica. Mft If the lime preponderate, there are various proportions in which a fusible compound may be composed. n* If the magnesia preponderate, the mixture is infusible, jnl If silica preponderate, few fusible compounds can be pr6»j pared. 3. In a mixture of alumina, magnesia, and silica. If the alumina predominate, only a porcelain can be produ- ced. If the magnesia predominate, not even an imperfect fusion can be effected. If the silica be the most abundant ingredient, there are va- rious mixtures which will yield a porcelain, and one that will even vitrify. This occurs when the mass consists of 3 silica, 2 magnesia, and 1 alumina. 4. In a mixture of alumina, lime, and silica. rl- If the lime preponderate, the product will be a glass, a por- of the Argillaceous Iron-Ore. 257 celain, or an infusible mass^ according to the proportions of the mixture. ^ ys^ If the alumina predominate, many mixtures will yield a porcelain, but none will afford a glass. If silica exceed, a porcelain or an enamel is frequently pro- cured, and it is probable that even a glass may be attaiBt, able.* From a due consideration of these experiments of Mr Kir- wan, and of the preceding general rules, it will not be diffi- cult for the assayist, with a little perseverance, to succeed in adapting an appropriate flux to his ore. In doing this, he will find that the earthy ingredients which are most frequently present to excess in the common argilla- ceous ironstone, are clay and silica. Both of these substances will easily vitrify in the furnace with the addition of lime. Lime is therefore the principal flux which is employed for • Elements of Mineralogy, vol. i. p. 72* The fusibility of mixtures of the earths and metallic oxides has been made the subject of an elabo- rate course of investigation, by several other eminent chemists besides Mr Kirwan. Among these may be mentioned Achard, (Memoirs of the Academy of Berlin, 1779, 1780. Journal de Physique, xxii. 179, 300. xxiv. 280, xxv. 137. J, Gerhard, (Versuche epier Geschichte der Mineral- reich, vol. ii. Journal de Physique, xxviii. 34. J, Klaproth, (Beitrage %ur chem. Kennt, der Miner alkorper, i. l.J, and Lampadius, ( Handhuch der Allgemeine Hilttenkunde, i. 127. Journal des Mines, xviii. 171. J It would be a highly interesting inquiry to examine in elevated temperatures the habitudes of similar mixtures of earths and metallic oxides, made in conformity with the prime equivalent proportions of these substances. Hitherto the only system of investigation pursued on this subject has been by subjecting to the action of heat an endless variety of binary, ternary, and quaternary mixtures. But when we consider the number of distinct substances and the infinity of their possible combinations whose reciprocal action in high temperatures it is of importance to know, it is almost a hopeless task to endeavour to subject each of these successively to the test of experiment. Now, however, that the combining proportions of bodies have been ascertained, the metallurgist is in possession of an infallible rule for his guidance in compounding earthy mixtures ; and in every future prosecution of such an inquiry, he would, of course, systematically mix the substances to be experimented upon, in conformity with their prime equivalent weights. The number of the experiments which he would find it necessary to make, would be thus most materially abridged, while, at the same time, the attainment of important and decisive results would be rendered far more certain. 2^. Dr Colquhoun 07i the Aasaij these ores. The amount of lime thus used will vary accord- ing to circumstances between 5 and 20 or even 30 per cent, of the ore, being increased or diminished according to the amount and the nature of the earthy matter which the ore contains. In assaying ores which are overcharged with silica, and des- titute of clay, it will often be found advantageous to employ, in conjunction with the lime, a portion of pure clay, varying in amount from 5 to 10 per cent, of the ironstone, according to the abundance of the silica. In the same manner, in order to promote fusibility in any argillaceous ore which is more than usually destitute of silica, it will be proper to add a certain amount of that substance, varying from 8 to 12 per cent, of the ore, in order to form a flux along with the lime. But before leaving this topic it is material to observe, that of all the ingredients which are associated with iron in the ore, clay is the most frequent and abundant, and that which re- quires the greatest delicacy in adjusting to it the due propor- tion of its counteracting flux. If the lime be exhibited in ex- cess, the resulting scoria is difficultly fusible and viscous ; and of course, obstructs the coalescence of the particles of reduced metal into a single mass ; but if too small a portion of lime be employed, the consequence will be, either that vitrifaction will take place defectively in the furnace, or that the portion .of the siliceous ingredient of the clay which is left unsaturat- ed, will dissolve and unite with a portion of the oxide of iron, so as to shield it from reduction. It is therefore an object of primary importance to the assayist to determine the exact pro- portion of argillaceous matter contained in any ore, before he commences its assay ; and as this may be easily done, even by those who have very little experience in chemical manipulations, it ought in all cases to be made the subject of a separate and preliminary experiment. This analysis may be conducted in the following manner. Take 100 grains of the pulverized ore ; put it into a wide- mouthed flask, and pour over it an ounce measure of muriatic acid, which has been previously diluted with two ounce mea- sures of water. An effervescence will instantly take place oc- of the Argillaceous Iron-Ore. 259 casioned by the muriatic acid attacking and dissolving the carbo- nate of iron, and any other carbonate, as of lime, magnesia or oxide of manganese, which may exist in the ore. When the whole muriatic acid has been added, expose the mixture to a mo- derately warm temperature, that of a sand-bath, for example, and agitate it frequently, so as to expose every particle of the ore to the direct action of the acid, and to prevent the undissolved por- tion from concreting into a mass. At the termination of about an hour, the whole of the oxide of iron, lime, magnesia, and oxide of manganese, will have been taken up by the acid ; and the portion left undissolved will consist of clay, together with silica, if the ore has been of a siliceous nature, and of carbo- naceous or coally matter. Let the whole be now transferred upon a small paper filter, and the insoluble residue washed, so long as the liquid which passes through has a perceptible taste of acidity. Then dry the filter, first between folds of blotting paper, and afterwards before a fire or upon a sand- bath : it should now be put together with its contents, into a platinum crucible, and calcined, either over the flame of a large spirit lamp or upon pieces of red hot wood charcoal, until the carbonaceous matter produced by the ignition of the paper and the coally matter originally contained by the ore, is en- tirely .consumed. The residue will consist of the clay and si- lica of the ore in a state of separation from all the other in- gredients ; and its weight will of course indicate the propor- tion which the ore contains of argillaceous or siliceous matter. After having thus ascertained the proportion of clay which is present in any ore that is to be assayed, the amount of lime which is to be employed as a flux will be carefully adjusted to it. In most cases a quantity amounting to three-eighths of the clay will be found the most efficacious adaptation. But if ac- tual experiment should prove that a larger supply of lime is requisite, it may be inferred that the clay is unusually abun- dant in silica ; and if, on the contrary, a smaller quantity of lime suffices, it is probable that the ore naturally contains a certain portion of the carbonate of lime. We have now briefly considered the ores in which clay or silica is a preponderating ingredient. Those which are usual- ly styled calcareous seldom contain a sufficient quantity of f60 Dr Colquhoun on the Aasaij lime to flux their natural silica and clay, and it is necessary therefore in assaying them to add a certain amount of lime, ranging from 2 or 3 to 10 per cent, according to circumstan- ces. If, however, the lime be superabundant, the flux to be chosen is silica, which should be exhibited in a proportion not under 6 and not exceeding 15 per cent., and varied with- in these limits according to the excess of the lime, and also according to the quantity of silica already present in the ore. Should the ore contain little natural clay, the flux will be im- proved by the addition of from 6 to 10 per cent, of pure clay. It may be remarked upon the whole of the cases just consi- dered, that, in whatever state the siliceous, calcareous, or ar- gillaceous ore may occur naturally, it should be the aim of the smelter to prepare a mass for his furnace, the general propor- tions of which should be somewhat approximating to 1 part by weight of lime, 1 of clay, and 2 of silica. This is the mix- ture which will most easily run into a glass, and which will yield the most perfect and unreserved return of metal after fusion. Magnesian ores generally prove the most refractory. If the excess of magnesia be considerable, the ore must be fluxed with a mixture of nearly equal parts of silica and lime, (from 6 to 12 per cent, of each,) together with a small amount of clay. If an ore is extremely poor in metal, it may be inadviseable to supply its deficient earth as a flux for those other earthly ingredients which are already present in excess, on account of the inconveniences which arise from having the earthy scoria very abundant in proportion to the metallic product. In such a case as this, recourse should be had to a more powerful solvent, which, although used in small quantity on- ly, may nevertheless flux the ore in the ordinary furnace heat. Fluor spar and calcined borax are the safest and the most efficacious substances for this purpose. If either be taken singly, an amount varying according to circumstances from 12 to 25 per cent, will form the flux ; if they be taken jointly, each may be in the proportion of about 10 per cent, of the quantity of ironstone. Indeed it may be considered as a rule of general application, that whenever an ore is found to be of the Argillcmous Iroi%-Or&. . ^^ more than ordinarily refractory, the flux may be very benefi- cially strengthened by the addition of a small quantity of either of these two substances. They both flux, with nearly equal vigour, either silica or lime, and as they have compara- tively httle tendency to retain the oxide of iron in a state of permanent combination, they are most valuable resources for the assayist in the case of a refractory or a barren ore. We cannot take leave of this subject, however, without clear- ly stating this caution, that neither these nor any saline fluxes whatever should be had recourse to by the assayist, except in those extreme cases where their use can scarcely be dis- pensed with. It is of the utmost importance to the practical metallurgist to maintain a strict analogy between the assay process and mar,ch of the blast furnace : but this analogy is evidently destroyed in the most essential point, when he in- troduces into the assay crucible substances which are never employed in the smelting of the iron-ore on the large scale. * Having now considered in what manner a flux should be adapted to each particular class of the argillaceous, the sili- ceous, and other most abundant of our ores, the next object which we have proposed is to point out in what manner the several ingredients which may be required to compose a flux may be obtained by the assayist in sufficient purity. In do- ing this, he will not encounter any difficulty, the substances in question being hme, silica, clay, borax, and fluor spar. We shall subjoin a simple mode of preparing each of them. To prepare the lime, let a crucible be filled with pieces of pure white-coloured marble, and then exposed to the intense heat of a furnace for about an hour. Immediately after cool- ing, it should be pulverized, the powder should then be sift- ed with a fine sieve, and secured in a well-stoppered bottle. The reason why it is necessary to pulverize this, and all the other ingredients in an assay, is because it is essential to the success of the operation that all the materials should be ex- hibited in such a form as admits of their being thoroughly in- corporated with each other. The uncalcined carbonate of lime, as marble, or any pure common limestone, may be substituted in the assay with little inconvenience for quicklime. But in this latter case. 262 -Dr Colquhoun 07i the Asmy the quantity of flux which is taken will of course require to be increased, as 100 parts of the carbonate are equivalent to only 5Q parts of pure lime. In preparing silica, it is only necessary to reduce colour- less transparent quartz, or calcined flint, to an impalpable powder. The pulverization of the flint is materially facilita- ted by the previous calcination. Pure white coloured pipe-clay, which is composed of little else than alumina and silica, the silica being almost always the preponderating ingredient, will be found a very useful material in any case where the presence of a small quantity of alumina is likely to promote vitrification in the furnace. It will be observed that all clays, however similar in appearance, if obtained from different localities, are liable to variation in the proportion of their constituents, and it is therefore proper, in the prosecution of a series of assays, to preserve a stock of the same clay in the laboratory, so as to make sure of always employing a reagent of the same description in each experi- ment. Without this precaution it is not always safe to com- pare the results of different assays with each other. Fluor spar may be obtained by reducing to powder a tran- sparent fragment of fluor or Derbyshire spar. This spar should be carefully selected, so as to be free from pyrites, a matter which requires the greater attention, as specimens often occur, through which minute crystals of pyrites are dissemi- nated to a considerable amount. Borax, before being used, should always be well calcined, to get rid of its water. Let it be first exposed to the moderate temperature of a sand-bath, until it ceases to swell up, and then let it be acted on by a dull-red heat. While yet hot, it should be pounded, sifted, and transferred into a stoppered bottle. Unless this be done before the borax has been allowed to be- come cold, or if the stopper do not accurately fit the neck of the bottle, the salt will speedily regain its water by absorbing the atmospheric humidity. These seem to be all the substances which can be required to compose any flux in the assay of ironstones. We shall next consider in what manner the ore itself may be fitted for the crucible. of the Argillaceous Iron Ore. 263 Upon this subject we cannot refrain from making one ob- servation, which is of a nature so obvious, that were it not in many cases overlooked, we should hardly have considered it necessary to state it. The remark now referred to is this, that the first step to be taken in procuring any ore for an assay, is to select with care what is a fair average specimen of the qua- lity of the ore. To do this with propriety, as it is only choos- ing a small sample from a large mass, requires a considerable share of discrimination and attention : and yet, to do it with accuracy is a matter of the very last importance, for if a mis- take be committed here, no matter how carefully the other steps of the process may be performed, there still remains the greatest hazard that the result may either leave a mass of rich material undervalued, or perhaps the more fatal error, of causing too high an estimation to be placed on an ore of indifferent qua- lity. In most cases the ore may, without any material inconve- nience, be subjected to the assay furnace, without having been previously calcined. This previous calcination, however, al- ways has a sensible effect in facilitating the accurate performance of the assay. For if it have been omitted, an effervescence ne- cessarily occurs at the commencement of the ignition, through the disengagement of carbonic acid from the carbonates of iron, lime, &c. and also through the escape of gas arising from the decomposition of the carbonaceous ingredient : the mix- ture, in consequence, is apt to be derauged, and a portion of it may even be thrown upwards out of the sphere of the flux al- together, so that though this may also be reduced, it is not ab- sorbed by the scoria, and transmitted to the metallic button. Calcination becomes particularly important when the ore hap- pens to contain an unusually large proportion of carbonaceous or coally matter, as is generally the case with the black-colour- ed varieties ; for if the carbonaceous particles were allowed to remain diffused throughout the mixed mass, they would not fail to exercise a powerful influence in rendering it refractory, and in preventing the particles of reduced metal from meeting in a imited mass. The ore may be calcined in the following manner. Reduce from one to two hundred grains of it to a fine powder, and in- i!^ Dr Colquhoun ofi the Assay troduce this into a large platinum crucible, after which let it be ignited in a low red heat during the first five minutes, and then in a pretty strong red heat, in which it should be kept till the operation is finished. If the ore happens to be overcharged with carbonaceous matter, the calcination will be more com- plete if it be conducted in a shallower vessel than a common crucible ; and it will be necessary to stir the powder frequent- ly, so as to expose the whole of it during the course of the ig- nition, as much as possible, to the free and direct access of the atmospheric air. After complete calcination, the loss of weight sustained during the process will be found to indicate, with considerable accuracy, the proportion of carbonic acid and other Yolatilizable matter which had been contained by the ore. The intermixture of charcoal powder with the flux has been frequently recommended as a useful auxiliary to it for the pur- pose of reducing the oxide of iron. But this practice is not only quite unnecessary, but it may often prove extremely pre- judicial to the accuracy of the assay. A perfect reduction of the oxide may be always insured by simply keeping the whole materials of the assay surrounded externally with carbonaceous matter, as for example, by coating the inside of the assay cru- cible with a lining of charcoal powder. The presence of the carbonaceous particles necessarily adds also to the refractori- ness of the mixture, and constitutes a strong mechanical bar- rier obstructing the aggregation of the globules of reduced iron. Besides this, it is well known to every one at all versant in the assaying of iron-ores, that iron, if imbedded in a state of minute division among charcoal powder and exposed to an intense heat, is liable to be converted into plumbago. This is a substance unattractible by the magnet ; and as the assayist is always in the habit of searching his scoria with a magnet for the purpose of gathering up any small particles of iron which may not have made their way, during fusion, to the metallic button, he is deprived of all benefit from this resource in so far as such iron may have been formed into plumbago, and a proportionate disappearance of the metallic product is of course inevitably produced. The practice of incorporating the ore and flux into a paste with oil is worthy of censure for a similar reason : the oil^ when of the Argillaceous Iron-Ore. 266 it is decomposed by the heat, leaving a quantity of an impal- pable carbonaceous powder intimately diffused throughout the mixture. The best state in which the assay mixture can be introduced into the crucible is that of a fine, dry, and tho- roughly blended powder, and the aid of any adventitious ce- menting matter is altogether unnecessary. The crucibles that are to be employed in the assay obvious- ly require to be highly refractory, and not easily susceptible of cracking, through exposure to any sudden change of tempera- ture. The best are certainly those which are formed either of Stourbridge clay, or of a similarly constituted material. But the common Hessian crucibles, if they be genuine, will be found very suitable in all cases where the temperature of the assay furnace is not raised to an extreme degree of intensity. In the course of numerous experiments on the assaying of iron-ores, during which these Hessian crucibles were almost invariably employed, there did not occur a single failure in consequence of their either cracking or melting. Before introducing the assay-mixture into the crucible, it is necessary to line it interiorly with a coating of charcoal, which in the high temperature of the furnace, deoxidates the oxide of iron and reduces it to the metallic state. This coating may be applied in the following manner. Take a quantity of pulverized wood charcoal, and sift it pretty fine with a wire-cloth sieve. Then form a gum water, composed of 2 parts of gum arabic and 1 part of gum traga- canth, with 100 parts of water, and with this liquor make the charcoal powder into a thick dryish paste. Fill the crucibles with this paste, observing the precaution of introducing it in- to them in small successive quantities, so as to admit of its be- ing more firmly rammed together into a solid, compact mass. Then reduce the crucibles and their contents to a state of thorough dryness, by keeping them in a warm situation for six or eight days. It is not uncommon to diffuse a portion of clay through the gum water, with a view to increase the adhesion of the char* coal powder to the sides of the crucible. This practice ought not, however, to be imitated ; for it is unnecessary, and will evidently cause a portion of clay to intermingle with the ma* ^66 Dr Colquhoiin on the Assay terials of the assay, so as to derange its composition and mo- dify its results. When the moisture is completely evaporated, a cavity for the reception of the assay-mixture is to be hollowed out in the centre of the carbonaceous mass, and of such a size that it shall be considerably larger than is strictly necessary for containing the mixture. A quantity of charcoal should be left to coat the sides of the crucible, not less than one-fourth of an inch in thickness, and as nearly as may be, of equal depth all around. Upon the bottom of the crucible, the char- coal should not be less than an inch in thickness. The cavity for receiving the assay should contain no angles or corners, and be well rounded off at the bottom ; its interior should be smooth ; and all the loosened charcoal must be carefully blown out before the assay is introduced. When the crucible has been thus prepared, take 150 or 200 grains of the natural ore, or a proportionally smaller quantity of ore that has been previously calcined : let the ore and the flux be completely pulverized and thoroughly incor- porated with each other ; of course the weight of the flux which is employed in the assay must be ascertained with the same accuracy as the weight of the ore. Place the mixture in the cavity of the crucible, taking care to leave no detached por- tion of it sticking to any of the upper parts of the sides ; be- cause in that situation it would be left beyond the sphere of the scoria, and consequently, even although reduced, its me- tal would not be transmitted to the metallic button. Fill up the cavity to the top with charcoal powder, and then cover up the crucible with a well-adjusted lid ; or, a similar crucible, somewhat smaller in size, may be inverted within it, instead of an ordinary flat lid. Then let all the joinings be accurately luted with fire-clay, leaving only a single small opening, for the purpose of furnishing a vent to the elastic fluids which are generated during the ignition. The crucible, with its enclosed assay, is now ready for the furnace. It will be found advantageous to strew a little pounded glass over the seat on which the crucible rests within the furnace, in order that it may remain the more securely, at- tached. It may be observed that, in most cases, for the sake of the Argillaceous Iroii-Ore^ S67 of convenience, the assay furnace is made large enough to contain two or three crucibles at the same time. The fuel which is best fitted for the use of the assay furnace is coke^ because it affords both the most equable and the most intense heat, and the crucibles should be kept completely buried in it during the whole process. It is proper to apply the fire at first in a very gradual manner, during the developement of the gaseous matter arising out of the decomposition of the gum, and the deoxidation of the ore, and therefore it should not be allowed to advance beyond a dull redness during the first half hour. By that time, the evolution of gaseous matter will have terminated, and the temperature may then be raised to its highest pitch, at which it should be permanently sustained for upwards of half an hour. The reduction will then be com- plete, so that the crucible may be withdrawn from the fur- nace. It should immediately be tapped, for several times, smartly against the floor, care being taken to preserve its per- pendicular position, and this will have the effect of bringing down any globules of reduced iron which may not previously have descended to the metallic button. When this has been done, the crucible may be set aside till it cools. When the flux is properly adjusted, the ordinary tempera- ture of a good air furnace will be found sufficient for the re- duction of the ore and the complete extrication of the reduced metal. In a pretty extensive series of assays conducted in a small portable furnace, in which no other fuel was employed than common pit-coal, a failure from deficiency of heat was rarely experienced, and in no instance where the flux had been adjusted to the ore with even very moderate accuracy, ii tiami If the assay has been successful, the original mixture of ore and flux will be found resolved into two separate bodies, the one consisting of metal, lying at the bottom of the crucible in the form of a flattened globule, and the other composed of all the unvolatilizable part of the earthy ingredients resting in a superincumbent mass above the metal, and termed the scoria. These bodies should be carefully separated from each other, and preserved for examination. The first step to be taken in this examination is an accurate determination of their respec- tive weights. The upper surface of the scoria will frequently $68 Dr Colquhoun on the Assay be observed to be studded with small globules or particles of iron. In order to separate these, let the whole be pulverized, then draw a small magnet repeatedly through the powder, which will gather up all the minute fragments of iron. The weight of these must of course be deducted from the total weight of the scoria, and added to that of the metallic button. The assayist is now in a condition to fix some of the gene- ral results of his experiments. In the first place, the weight of the metallic button is in each case a direct measure of the amount of metal contained in the ore. In the second place, the weight of the flux, as originally introduced into the cruci- ble deducted from the weight of the scoria, gives the amount of earthy matter contained in the portion of ore submitted to assay ; aijd, in the third place, the sum of the weights of the metallic button and the scoria, deducted from the weight of the original mixture of ore and flux, will leave a quantity which measures the amount of volatilizable matter which has escaped during the operation of assaying. If the ore has been submitted to assay in its calcined state, this loss of weight in volatilizable matter will consist entirely of oxygen, which has been disengaged from the oxide of iron in the process of its reduction. But if the ore was not calcined previously to the assaying, this volatilized matter will, of course, consist of a mixture of oxygen and carbonic acid. It is obvious, however, that even in this instance the amount of oxygen which the ox- ide of iron loses during its reduction may be easily determin- ed, by calcining a quantity of the crude ore per se, and de- ducting the loss of weight which it sustains in the calcination, from the gross weight of volatilizable matter which is separat- ed from the ore in the process of assaying. An examination of the scoria may now be made with much advantage, as its appearances will often be found to indicate in a pretty accurate manney both the nature and the relative proportions of the earthy substances contained by the ore. If the scoria be found uncommonly transparent, and posses- sing most of the characters of a glass, such as brittleness, breaking into sharp-edged fragments and with a vitreous, con- choidal fracture, &c., it is certain that the assay has contained a superabundance of silica. Scoriae thus constituted are al- of the Argillaceous Iron-Ore. 269 ways more or less deeply coloured, in consequence of the ox- ide of iron which the excess of silica holds in a state of combi- nation. If the scoria present the appearance of being completely melted, and has a vitreous and somewhat enamelly aspect ; and if it is at the same time unusually free from colour, this is a proof that the lime has been adjusted in its due propor- tion to the other earthy ingredients of the assay. The colour by which such scoriag are generally distinguished is a light shade of grey. If the scoria be marked by a green colour, this indicates the presence of manganese. It is necessary to observe, however, that it would be unsafe to estimate the quantity of manganese solely from the degree of intensity of the green colour; for when the ignition in the assay furnace is violent and protrac- ted, the oxide which the slag had originally held in solution undergoes reduction, and, coalescing with the iron, forms part of the metallic button. But if, instead of obtaining the scoria fully and distinctly separated from the metallic product, the whole assay, on open- ing the crucible, be found to exhibit a scoriaceous mass, usual- ly of a greyish or blackish colour, attractible strongly by the magnet, and containing particles of iron diffused throughout its entire substance, this result indicates, that although the ox- ide has been reduced in the furnace, yet some of the earths have been present to excess during the assay, and that the flux, either from its amount or its composition, has wanted the re- quisite degree of energy to liquefy the mass, and to unite the metallic particles into a button. Sometimes this product will present the appearance of having undergone a mere incipient fusion, and will be in the state of an incoherent and easily friable mass ; or it may even have undergone a viscous semi- fusion, so as to be left in the shape of a solid opaque mass, very difficultly frangible, and breaking with a compact stony fracture. Unfortunately, a scrutiny of the external characters of the metallic button cannot lead to any conclusions regarding the value of the metal to be obtained by smelting the ore, with the same degree of precision with which a similar investiga- VOL. VIII. NO. II. APRIL 1828. s 9f!© Dr Colquhouti on the Assay tion of the scoria indicates the nature of the earthy ingredients. The appearance and properties of the metalHc product may be so much modified by a variety of circumstances, which may not only be extrinsic to the composition of the ore, but which cannot themselves be subjected to any certain rule, that it is always difficult to deduce from an examination of it any cer- tain inference regarding the quality of the iron. Thus, the intensity and duration of the ignition, some apparently trivial modification of the nature of the fluxing material, or a change in the mode of cooling the crucible, will often produce re- markable differences in the nature and qualities of the metal- lic product. Indeed, in as far as the metallic ingredient of any ore is concerned, the amount of it seems almost the only property which can be certainly gathered from even the most careful assay. We may notice, however, a few of the most striking variations in the quality of the metallic button which will encounter the assayist in his experiments, and also, so far as possible, state the causes which produce them. If the temperature of the assay furnace has been low, the jmetallic product never can present the appearance of black cast-iron, which is never produced without the application of fan intense heat. Again, if the crucible be rapidly cooled, no matter from what intensity of heat, black cast-iron will not be formed ; for even the most perfect specimen of this variety of carburetted iron may at once be converted into a body pos- sessing all the external and physical characters of white cast- iron, by merely melting it, and cooling it suddenly. It is a 'Singular fact, that by this simple variation in the mode of cooling, the same piece of metal, although it must obviously contain in either case the same quantity of carbon, will never- theless have the most opposite properties comtnunicated to it in colour, texture, and hardness. The white cast-iron is of 9- white colour, with a silvery aspect ; it is excessively hard, find is composed of large crystalline laminae irregularly su- perimposed upon each other. On the contrary, the black cast- iron is of a dark grey colour ; it is soft, and exhibits a small crystalline or granular texture. The flux may also exercise an equally remarkable influence over the properties of the metalHc product of the assay. of the Argillaceous IrojuO re. 271 Thus, if it happen to form along with the other ingredients of the ore a highly refractory compound, this will envelope the reduced particles of iron, and prevent them from becoming saturated with carbon. The metallic product, in such a case, has more resemblance to steel or malleable iron, than to cast- iron. In the same way, if the flux contain any compound from which carbon, at a high temperature precipitates a body that is capable of forming an alloy with iron, this circumstance will materially modify the metallic product of the assay. Among the most dangerous of these substances, are sulphur and the saline combinations in which it forms an ingredient, such as sulphate of soda, and sulphate of lime or gypsum, &c. ; or phosphoric acid and its saline combinations, such as phosphate of soda, or phosphate of lime, which occurs in the earth of bones, in ivory black, or in animal charcoal. All of these ought to be most carefully excluded from the composition of the flux. The presence of any of them, even in a very minute degree, would infallibly contaminate the iron with sulphur or phosphorus, either of which is productive of the most injurious effects to the best properties of the metal. Indeed the use of borax in a flux is not altogether harmless in this respect, for it must cause the metal to be alloyed, to a certain extent, with boruret of iron. Both sulphur and phosphorus possess in a remarkable de- gree, the power of augmenting the fusibility of iron. Both of them also are hostile to the formation of that state of the metal which is called black cast-iron. In this respect sulphur is a much more energetic agent than phosphorus. It not only seems to dispose the metal so strongly for fusion as to prevent it from remaining long enough in the higher and hotter part of the blast furnace, but also appears to destroy, to a certain extent, that peculiar state of combination between iron and carbon which constitutes black cast-iron. This latter fact seems to be established from the circumstance, that it is both extremely difficult to produce good black cast-iron from ores contaminated by pyrites, and that any piece of black cast-iron is readily converted into white by being fused along with a little sulphur. When metal that has been melted along with some sulphur is poured from the crucible, it consolidates almoiit 272 Dr Col(|uIioun cm the Assay instantaneously, in consequence of the lowness of the tempc*- rature which sufficed to produce Hquefaction, and its colour also passes with more than the usual quickness to a dull red. Every metallic oxide which is reducible in the temperature of the assay furnace, should be carefully rejected from the composition of the flux, as the reduced metal would inevitably form an alloy with the metallic button. The oxides against which it is chiefly necessary to be guarded, are those of man- ganese, copper, lead, and arsenic. In the assaying of iron- ores it is no uncommon practice to substitute pounded glass for silica ; but, whenever this is done, it is necessary to avoid every species of glass whose composition is tainted with the oxides of manganese, arsenic, or lead. With these precautions we are not aware that it is necessary to add any thing farther on the subject of the dry assay. § % On the Humid Assay of Ironstones, We have now considered at some length the details of what seem to be the most advantageous methods of conducting the examination of an iron-ore by the dry assay. It has already been remarked that it is to this process that the metallurgist has by far the most frequent recourse when he wishes to prove an unknown ore. In convenience and dispatch it is so emi- nently preferable to the humid assay, that, although its results never can be relied on with the same degree of confidence, yet, as they are generally possessed of tolerable accuracy, it is very widely adopted in practice. By the dry method, if it has been judiciously followed out, a single operation enables the smelter to separate his ore into its two grand classes of constituent bodies, the earths on the one hand, and the metals on the other. He thereby obtains in miniature a pretty correct representa- tion of the relative proportions in which the amount of metal and the amount of earth exist in the stratum of ore, and also of the general properties which the ore will be found to possess when treated in the smelting furnace. In many cases, therefore, the dry assay is found to serve all the purposes of the practical metallurgist : but there are also many in which the humid assay or chemical analysis of the ore will be found highly useful, and some in which it is indispen- xiftke Argillaceous Iron-Ore. S73 sable. The constitution of an ore can seldom be thoroughly explored by the dry assay. On the contrary, the conclusions at which the assayist arrives are of the most general nature. The number of the individual ingredients in the ore, the cha- racteristic nature, and still more, the relative amount of each must always remain the subject of more or less doubtful con- jecture. By the dry assay, the smelter possesses no test, to enable him to appreciate the true composition of a scoria, ex- cepting its fusibility, and its external and physical characters. But as there are many earthy mixtures which, although very dissimilar in reality, are yet converted in the furnace into scoriae which do not distinguishably differ from each otlier in any of the characters just mentioned, the assayist by fire, after all his resources are exhausted, may still be left in perplexity respect- ing the individual earthy constituents of his ore. For these reasons the assay, via humida, is frequently indis- pensable, and, whenever sufficient time can be spared, it should be always resorted to, as affording, in every case, the most accurate and satisfactory exposition of the whole constitution of an ore. We shall therefore proceed to state in detail a ge- neral formula of analysis, via humida, by means of which the true nature and amount of the constituents of the mineral that is examined may be ascertained, even without employing any uncommon degree of caution, to within xJo^^ P^^^^ of the whole mineral. Take 100 grains * of the ore, either in powder or in small pieces not larger than a grain of wheat, and put it into a ves- sel of glass or platinum, containing a mixture of one ounce measure of concentrated muriatic acid, with two ounce mea- sures of water. The mineral will immediately begin to pass into solution with effervescence. When the action in the cold appears to have terminated, digest the mixture upon a sand- bath, in a temperature scarcely exceeding 100°, for about four hours. It will now be found that, by this treatment, the whole of the metallic oxides and earths which existed in the * When it is the principal object of the analysis to determine the precise quantity of metal contained in the ore, and when the nature and amount of each of its extraneous ingredients are of minor importance, the assayist may obtain accurate results by operating with fifty or even with only twenty grains- , -- I^W Dt Colquhoun on the Assail/ mineral in union with carbonic acid, have been dissolved, Biit the clay ingredient is scarcely changed in any respect, and re- mains mixed with the carbonaceous matter, in the form of a black-coloured powder. Let this insoluble portion be sepa- rated by a common paper filter, and then let it be thoroughly washed by repeated affusions of water. * The liquid which passes through the filter contains all the oxide of iron which existed in the ore in a state of combina^ tion with carbonic acid ; it may contain also lime, magnesia, * As some of my readers may probably have had very little practice in chemical manipulations, I trust that a few observations on the management oijilters will Hot be deemed superfluous. After a precipitate has been collected upon a filter and dried, it cannot be again completely separated, because a certain quantity of it adheres so obstinately to the fibre of the paper, that it cannot be removed without bringing away with it a portion of the filter. H^nce it would be impossible iii this manner to determine the exact amount of a precipitate. The expedient usually resorted to for obviating this difficulty, is to weigh the filter beforehand : the increase of weight which it acquires in the process is held to indicate the weight of precipitate. But this method is liable to objection; for the weight of the filter is apt to be altered by the liquids filtrated through it. Besides this, unsized paper has a strong attraction for moisture, and the quantity of hy-^ grometric water which it contains is constantly changing, according to the degree of humidity of the atmosphere : it is necessary, therefore, to take some peculiar precautions, in order to have the filter in exactly the same state of dryness both at the commencement and at the termination of the experiment. A much more accurate mode of filtering is to employ two fil- ters. They ought to be in all particulars, such as thickness, fineness, size, &c. as nearly ahke as possible ; and they must be carefully counterpoised against one another on a balance, small portions being cut off from the Jieavier of the two, until they both possess exactly the same weight. One of these is then to be inserted within the other ; and the precipitate is to be poured on this double filter, and washed in the tisual manner. It is ob- vious, that whatever alteration one of these sustains in the course of the pro- cess, will in all probability be sustained by the other; and also, that, at .the termination of the desiccation, the two filters will be in precisely the same state in r^ard to hygrometric humidity. The difference of weight between the inner and the outer filter will tlierefore indicate very accu- rately the weight of the precipitate. A very high degree of precision may be attained by this mode of manipulating. When the precipitate requires to be heated to redness, its weight in the filter ought to be ascertained in the first instance ; a determinate quantity of it is then to be ignited, and from the loss of weight which this sustains, it is easy to calculate the loss which would have been sustained had the whole been ignited. # ' of the Argillaceous Iron-Ore. 2!T5 and oxide of manganese, when these ingredients happen to be present in the ore in the form of carbonates. The solution has always more or less of a greenish tint, in consequence of the oxide of iron being chiefly in the state of black oxide. In the farther progress of the analysis, the first step to be taken is to convert the whole of this oxide into peroxide ; without which, it would not be possible to make an accurate determination of its quantity, because the black oxide of iron cannot be col- lected in the form of a precipitate without its being partially converted, in the course of the operation, into the red oxide. This peroxidation may be conveniently effected by heating the solution nearly to a temperature of ebullition, and then gradu- ally adding nitric acid, in small quantities, until the deep brown colour produced by the first portions of acid has disap» peared, and is replaced by a clear reddish yellow. This \stiA proof that the metal is now entirely peroxidated. Let this solution be diluted with water, and mixed with li- quid caustic ammonia as long as a red-coloured precipitate continues to fall ; and in doing this, some care should be taken to avoid adding an excess of ammonia. The precipitate thus produced consists solely of the peroxide of iron ; for caustic ammonia does not precipitate lime from its solutions under any circumstances, nor does it readily precipitate magnesia or oxide of manganese, when their solutions contain a considerable ex- cess of acid, even although it be added until the mixture ac- quires an alkaline reaction. The precipitate ought to be col- lected upon a filter, and thoroughly edulcorated; then h should be carefully dried, first in the open air between folds of common blotting paper, and afterwards in a moderate tem- perature, so as not to char the filter, between 200° and 250° ; in fine, to complete the expulsion of the whole moisture, let the precipitate be exposed to a low red heat in a platinum cru- cible for about fifteen minutes. 1 00 parts of it, when thus freed from its water by ignition, represent 90 parts of protoxide of iron, and 145 parts of carbonate of protoxide of iron.* This * The ammonia is apt to attract carbonic acid from the atmosphere, and thus to acquire the property of decomposing solutions of hme. In consequence of this, it may be proper in all those cases in which it is of importance to determine the precise quantity of oxide of iron with extreme 276 Dr Colquhoun on the Assay oxide of iron generally contains a very small quantity of silica, but seldom or never any notable trace of alumina. Muriatic acid, assisted by heat, dissolves out the oxide of iron, and leaves behind the silica in the state of insoluble gelatinous flocks. Should the presence of alumina be suspected, the oxide, previously to its desiccation, ought to be digested with some caustic potash or soda ; and the earth may be subsequently precipitated by supersaturating the alkaline solution with an acid, and then decomposing it, in a boiling temperature, with an excess of carbonate of soda. After having thus obtained the oxide of iron contained by the ore, the next step is to separate the lime which may also exist in it. It is necessary, for this purpose, that the alkaline liquid separated from the oxide of iron should be rendered exactly neutral : which may be done, either by adding to it dilute muriatic acid until it ceases to affect vegetable colours, or by supersaturating it slightly with the acid, evaporating to dryness, and redissolving the sahne residue in water. Into this neutralized liquid pour a solution of oxalate of ammonia drop by drop so long as a precipitate continues to fall, and when this is done, set the mixture aside for six or eight hours, in a situation where it will be maintained at a temperature of about 100°. The whole of the lime will by that time be pre- cipitated in the state of an oxalate. Let this be transferred upon a filter, washed and dried in a very gentle heat. 100 parts of it, dried in this manner, are equivalent to 38.36 parts of lime or to 68.49 parts of carbonate of lime. If this oxalate be cautiously calcined in a very low red heat, in a platinum crucible, it will be converted into pure carbonate of lime, 100 parts of which represent 56 parts of lime. accuracy, to make the precipitation in a stoppered bottle, and to draw off the clear liquid with a syphon, after the oxide has had time to subside. The bottle should then be filled up with water, agitated, and set aside un- til the oxide has again subsided to the bottom, after which the liquid should be drawn off as before. In this manner the oxide should be washed seve- ral times, while it is kept from all access of the atmospheric air, until the greater portion of the soluble matter is separated. It may then, with suf- ficient safety, be collected upon a filter, and subjected to the treatment de- scribed above. oj the Argillaceous Iron-Ore. 277 . It is necessary to provide for that case, of very frequent oc- currence, in which the liquid fihered from the oxalate of lime may contain magnesia and oxide of manganese. When this happens, let it be evaporated to dryness, then put the saline residue into a platinum crucible and calcine it in a tempera- ture below a visible red heat, until the whole of the ammonia- cal salts are expelled. It is necessary to do this, for unless these salts were previously got rid of, it" would be impossible to effect a complete precipitation of the magnesia. Let the residue from the calcination be next dissolved in muriatic acid, and having neutralized the solution, either by evaporation or by the addition of an alkali, pour into it a few drops of hydro- sulphuret of ammonia, in order to throw down the manganese. Calcination, under free access of the external air, converts this precipitate into an oxide of manganese, 100 parts of which are equivalent to 90 parts of protoxide, or to 145 parts of carbo- nate of protoxide of manganese. If it be inconvenient, from any cause, to calcine the precipitate, it may be dissolved in muriatic acid, and thrown down, at a boiling temperature, by carbonate of potash. This last precipitate will consist of car- bonate of protoxide of manganese ; 100 parts of which contain 62.07 parts of protoxide. It now only remains to separate the magnesia. This will be effected most accurately by concentrating the solution from which the manganese had been precipitated by hydrosulphuret of ammonia, and then adding to it, while still nearly boiling, a slight excess of carbonate of potash, after which the mixture should be rapidly evaporated to dryness. On digesting the re- sidue with water, the carbonate of magnesia will be obtained in a light pulverulent form. It may be collected upon a filter, washed, and dried ; then let it be ignited strongly in a platinum crucible. The residue will consist of pure magnesia, 100 parts of which represent 210 parts of carbonate of magnesia. It frequently happens that some of the magnesia either re- mains in the solution unprecipitated, or is redissolved from the filter by the edulcorating water. It will be necessary, there- fore, to search for this portion also, when it is desired to deter- mine the entire quantity of the earth with exactness. In this view, the liquid filtered from the carbonate of magnesia should 978 Ik Colquhoun oH tJie Assay be saturated with muriatic acid, then mixed with a httle phos- phate of soda and an excess of carbonate of ammonia, and next evaporated to dryness by the appHcation of a very gentle heat. The whole of the magnesia combines, in this process, with phosphoric acid and ammonia, and forms with them a double subsalt ; which, being insoluble or very nearly so, may be se- parated by treating the saline residue with water. By calcina- tion in a low red heat, it is converted into neutral phosphate of magnesia, 100 parts of which contain about 35.7 parts of mag- nesia. When the quantity of oxide of manganese contained by the ore is inconsiderable, it is a preferable system of manipulation to precipitate it along with the magnesia by carbonate of pot- ash. Let the total weight of this mixed precipitate of magne- sia and the oxide, after calcination, be determined : then re- dissolve it in muriatic acid, and precipitate the manganese in the usual manner by hydrosulphuret of ammonia. The weight of the oxide, deducted from that of the original precipitate, in- dicates accurately the quantity of the magnesia. The portion of the ore which remains undissolved after di- gestion in muriatic acid is next to be examined : in general, it will be found to consist of a mixture of carbonaceous and earthy matter. To ascertain the quantity of the carbonaceous ingre- dient, the residue should be dried in a strong sand-bath heat, in a platinum crucible ; then, after being weighed, it should be calcined under free access of the atmospheric air, until the whole of the combustible matter is burnt off. Its amount will of course be indicated by the loss of weight sustained in the calcination. The residue is to be analyzed by the methods which are cus- tomarily employed in the examination of an earthy mineral. Thus, it may be decomposed by fusion in the furnace in a pla- tinum crucible along with thrice its weight of dry carbonate of soda, the fused mass may then be dissolved in very dilute mu- riatic or nitric acid, the solution evaporated to dryness, and the residue digested in acidulated water, which will take up the earths in the state of saline combinations, while the silica will be left undissolved. Separate the solution from the silica by rne^ns of a filter, and mix it with a rather smaller quantity of of the Argillaceous Irori'Ore. 279 carbonate of soda than would be necessary to precipitate the whole of its earthy contents ; immediately afterwards digest it with a considerable excess of caustic potash or soda. The al- kali will dissolve the alumina ; but the lime and the magnesia, in the state of carbonates, and the iron and manganese, in that of oxides, will remain unacted upon. This mixture may be examined according to the rules which have been already laid down. If the presence of any of those obnoxious ingredients, sul- phur and phosphorus, be suspected in the ore, it will require a separate analysis to ascertain their respective quantities. Fortunately, however, the phosphorus, which is the most in- jurious constituent, is of rare occurrence ; but it is otherwise 'with sulphur. This substance, whenever it is present in the ores, appears to exist in them in combination with iron, con- stituting iron pyrites. Its amount may be ascertained in the following manner. Into a small glass retort put 100 grains of the pulverized ore, and pour over it, in small quantities at a time, half an ounce measure of concentrated nitric acid. A receiver containing a small quantity of water should be at- tached to the beak of the retort, for the purpose of condensing any sulphuric acid which may be carried over with the evolv- ed gases. A very violent effervescence will be produced by the first addition of acid, and there will be given off abun- dance both of carbonic acid gas and nitrous gas. When the whole acid has been gradually poured on, set the mixture aside for five or six hours, and agitate it occasionally : then add half an ounce measure of water, and 10 grains of nitre, in order to prevent any sulphuric acid from being volatilized, and digest this upon a sand-bath for a few hours. Through- out the whole process, the receiver, containing a little water, ought to be kept attached to the beak of the retort. The whole of the sulphur will now have beccwne oxidized, and con- verted into sulphuric acid. Return the liquid contained by the receiver into the retort, then filter the clear solution from the insoluble portion, and by a very gradual addition of caus- tic ammonia, neutralize the excess of acid, as far as can be done without causing precipitation. A solution of nitrate of barytes, now poured into it will throw down the sulphuric 280 Dr Colquhoun on the Assay acid in union with barytes. This precipitate is to be washed, dried, and ignited. 100 parts of it will prove equivalent to 13.56 parts of sulphur. Phosphorus, on those rare occasions in which it exists in the ore, appears to be in the state of phosphoric acid, combined, probably, either with lime or with oxide of iron. In order to ascertain its amount, dissolve from 50 to TOO grains of the ore in nitric or muriatic acid, taking the necessary precautions to peroxidize the whole of the iron. Filter the clear liquid from the insoluble matter, and add a slight excess of ammonia to it. The oxide of iron which will, by this means, be precipitated, will carry down in combination with it the whole of the phos- phoric acid. After this precipitate has been washed, mix it in a silver crucible, with a concentrated aqueous solution of twice or thrice its weight of caustic potash or soda, evaporate the mixture rapidly to dryness, and stir it constantly during the whole process to prevent any portion of it from being thrown out, after which, let the dry residue be ignited in a pretty strong red heat for half an hour. Digest the fused mass in water : the oxide of iron will remain untouched, but the phosphoric acid, now in combination with the alkali, will pass into solution. Neutralize the liquid with nitric acid, heat it, in order to expel all traces of carbonic acid, then render it alkaline by the addition of an excess of caustic ammonia, and lastly, pour in a solution of muriate or nitrate of lime. Phos- phate of lime will fall down, in the form of a gelatinous pre- cipitate : it may be collected upon a filter, washed, dried, and ignited. 1 00 parts of the phosphate, obtained in this manner, contain, according to Berzelius's analysis, about 48.4 parts of phosphoric acid. The proportion of carbonic acid contained by any ore may be ascertained in an approximative manner by putting a deter- minate weight of it, (as, for example, 50 or 100 grains) pre- viously broken down into fragments into a platinum crucible, and exposing it to a brisk red heat for fifteen minutes. The whole of the carbonic acid will be expelled by this treatment, and its amount will be represented by the loss of weight which the mineral sustains. When an ironstone is subjected to ig- nition, however, it is liable to undergo several other alterations of the Argillaceous Iron- Ore. 281 in its composition besides the expulsion of carbonic acid. Thus if it contains any bituminous or coally matter, or iron pyrites, the volatilizable portion of these will be driven off by the heat. The small portion of water which the ore generally contains will also be expelled. AH these circumstances tend to make the quantity of carbonic acid appear greater than it is in reality. On the other hand, it is necessary to remark, that these irregularities are counterbalanced to a certain extent by another decomposition which always takes place during the ignition of an ironstone, and whose tendency is to make the quantity of carbonic acid appear less than it is in reality. When the carbonate of protoxide of iron is ignited, a reaction always ensues between its constituents, the protoxide of iron, in consequence of its disposition to unite with an additional dose of oxygen, attracts that principle from a portion of the carbonic acid, reducing it to the state of carbonic oxide gas, and becoming itself converted partially into peroxide. This decomposition evidently introduces a double error into the re- sults ; for the ponderable matter that is abstracted from the carbonic acid is superadded to the oxide of iron. The decom- position of the carbonic acid, and the consequent peroxidation of the protoxide of iron take place to a much smaller extent in those cases where the ore is suddenly exposed to a pretty strong red heat, than in those where the ignition is brought on very gradually. If it be desirable to ascertain by the most exact method, the amount of carbonic acid contained in any one ore, this is done by dissolving it in an acid. The process may be conducted in the following manner. Procure a globular-shaped glass bot- tle, having a cylindrical neck about an inch in length, * and adapt to it a stopper made by rolling up very loosely a bit of open textured woollen cloth, (flannel for example.) Fill the bottle half full with a dilute muriatic acid, prepared by mix-, ing one part of the concentrated acid with one part and a half of water. The acid should be introduced by means of a small funnel, as it is of some consequence that the inside of the neck of the bottle should be kept quite dry. Then replace tlie * Any person accustomed to the management of a table- blowpipe, may easily form a bottle of this kind with a piece of barometer tube. 282 Dr Colquhoun on the Assaij stopper, and counterpoise the bottle with its contents upon a balance. A determinate quantity of the ore (as from 50 to 100 grains) is next to be weighed oiit ; it ought to be previously reduced to the form of small grains like coarse gunpowder, but none of it should be finely pulverized. Put a small portion of it into the bottle, then replace the stopper, and agitate the mixture occasionally. An effervescence will take place, occa- sioned by the disengagement of carbonic acid gas. The stop- per will readily permit the escape of the gas, but will retain any particles of liquid which the gas may carry up with it me- chanically. When solution is nearly accomplished, introduce an additional quantity of the ore into the bottle, and let this process of adding the ore in small successive portions be re- peated, until the whole is used. When the solvent power of the acid begins to be weakened, towards the conclusion of the process, it may be assisted by heating the bottle very gently ; the temperature must not exceed 90% otherwise a portion of muriatic acid would be expelled along with the carbonic acid gas. When the action of the acid on the ore is completed, set the bottle aside for two hours, in order that it may recover the temperature of the atmosphere. Then remove the stopper,' and having introduced into the bottle a narrow tube, draw out the carbonic acid gas that it contains, which will thus be re- placed by atmospheric air. Nothing now remains except to place the bottle once more upon the balance, and ascertain the addition of weight which it has acquired. This increase indi- 284 Dr Colqulioun on Argillaceous Iro7i-Ore. eight grains of this into a small shallow platinum capsule, and ignite them over the flame of a spirit lamp. As long as any smoke continues to be evolved, the heat must be applied with extreme caution, and the powder must be incessantly stirred. When all the bituminous portion of the coal has been volati- lized, the temperature ought to be raised as high as possible ; and in order to maintain it at this pitch, the lid of a platinum crucible may be placed over the capsule, so as to reflect the heat back upon the powder. At the end of about ten minutes, the whole of the carbonaceous matter will be consumed : an addition of six or eight new grains of the powdered coal is now therefore to be put into the capsule, and after having been mixed up with the earthy matter already formed, it is to be burnt with the same precautions as in the first calcination. Let this process be repeated several times in succession, until it ap- pears that a sufficient quantity of the earthy residue has been obtained ; after which, the weight of this residue deducted from the total weight of the original coal, will give the relative pro- portions of combustible and incombustible matter in the coal. We have directed that the heat should always be applied very gradually at the commencement of the ignition. If the opposite course be followed, the smoke which is given ofi^ will speedily catch fire, and the pounded coal will be converted at the same time into a hard, spongy mass, with a semifused as- pect, resembling coke. In this state, it is excessively incom- bustible ; and indeed it would be found almost impossible to bum it over a spirit lamp, without pulverizing it anew. The intermixture of earthy matter with the pounded coal, which, of course, always takes place after the calcination of the first por- tion, has the beneficial effect of diminishing this tendency to concretion, and it also accelerates the combustion. Upon examining the incombustible residue, which consists of the earthy ingredients of the coal, as there is frequently some sulphate of lime in it, this substance, which possesses a slight degree of solubility, may be dissolved out by boiling the ashes in distilled water; the clear liquid must then be separat- ed and evaporated to dryness, and the weight of the residue ascertained. To determine the constituents of the portion which remains insoluble in water, the same method of analysis Dr Brewster on the Natural History of Tahasheer. 285 should be followed, which has been already recommended for examining the clay portion of the iron-ores. The presence of sulphur in any coal, and its amount may be investigated according to the same process which is resorted to for determining the amount of that substance when it occurs in an ironstone. We have now considered in detail both the processes of the dry and the humid assay. But we cannot conclude without again repeating that the humid assay is the only one which can be relied on with safety for the accuracy of its results. The mode by which this assay may be conducted, as stated on page 272, requires so little scientific skill, and so little nicety of ma- nipulation, at the same time that it affords a very excellent analysis of the mineral, that we have no hesitation in strenu- ously recommending its adoption in every case where the smel- ter can afford the necessary delay. It is hardly ^ necessary to add, that when we reflect upon the very large proportion of the charge in every smelting furnace, which is composed of limestone and of coal, it is of little less importance to examine the constitution of these minerals, than it is to analyze the ore itself. Art. IX. — On the Natural History and Properties of Taha- sheer, the Siliceous concretion in the Bamboo. By David Brewster, LL.D., F. R. S. Lond., and Sec. R. S. Edin. 1 HERE is certainly no substan,ce either in the vegetable or the mineral world so remarkable as Tabasheer. Its locality in the joints of the bamboo ; — its derivation from the juices of that reed ; — its occurrence only in particular situations and particular plants ; — its chemical composition ; — ^and its opti- cal and physical properties, render it an object of very pecu- liar interest to the botanical as well as to the natural philoso- pher. In the Philosophical Transactions for 1819, I have given an account of the optical and general physical properties of tabasheer, as determined from specimens which my late and respected friend Dr Kennedy procured for me from India. Since that time, I have the good fortune to obtain the finest VOL. VIII. NO. II. APRIL 1828. ' T 286 Dr Brewster on the Natural History collection of specimens that has ever been transmitted to Europe. I have received large portions of all the varieties that have yet been found, from the fine opalescent and trans- parent pieces, to the most opaque and coarse masses ; and I have had the satisfaction of taking the specimens with my own hands from joints of the bamboo, that were sent unopened. This collection I owe to George Swinton, Esq., Secretary to the Government at Calcutta, whose liberality and unwearied ardour in the cause of science and the arts is well known to all the public institutions of his native country. Along with these specimens, Mr Swinton has sent me also the following observations on Tabasheer, collected from the Sanscrit works on Medicine, by Dr Wilson, the learned secre- tary of the Asiatic Society of Calcutta. " Bamboo-manna" (says Dr Wilson) " is known in the Ma- teria Medica of the Hindus by a variety of appellations, imply- ing simply its being the produce of the bamboo, or denomi- nating it from some of its sensible properties, the milk^ sugar, or camphor of bamboos. The name in ordinary use is Ban- sa-rochunu. The ornament of the bamboo, corrupted in the vernacular dialect to Bunslcchan. The name in use amongst the Mahommedans of India is Tabasheer^ an Arabic word, explained by Meninski, liquor^ specie sacchari concretus in arundine Indica majore, et quasi petrefdctus ; in India^ sac- car Bamhu (sugar of the Bamboo,) dicitur, pro quo cineres no- dorum aut radicum vulgo distrahi solent. " According to the Sanscrit works on medicine, such as the Bhava Prakas and Raja Nighant, the bunslochun is slightly austere, astringent, and sweetish to the taste. It possesses cooling and demulcent properties, allays thirst and fever, and relieves cough and difficult breathing. It sweetens the hu- mours, and is serviceable in jaundice and leprosy. Its chief virtues, however, and those for which it is mostly esteemed, are supposed to be of a restorative nature, and it is highly ap- prized as an aphrodisiac. ** In the markets of Calcutta it is found in three states. The best is termed Patnai, being brought from Patna, and is in small compact pieces of a milky-white colour, having the lus- tre of enamel, and being seraitransparent. It is termed NiU and properties of' Tabasheer} '■ 287 hunthi^ from its bluish tinge, and Paharilca, from its being brought from the Pahar^ or hills to the westward of Behar. The second sort is of a dead white colour, without lustre or transparency, and much more friable than the preceding. It is termed Chheliita, the Bengali corruption of Sylhet appa- rently, whence it is well known that this substance is pro- cured. The third and worst kind is termed Desi or country ; it is white, with a yellowish tinge, less friable than the second sort, but without lustre or transparency. The last is said to be soluble in water ; the two first are not. An artificial bun- slochun is also manufactured from chalk. " The following information respecting the Puharia or hill tabasheer, has been received from Captain Playfair, residing at Hazareebagh. " Bunslochun is found at Zelda, Boondoo, sixty miles from Huzareebagh, at Luka Kole, 100 miles from thence, at Pa- lamow and at Nagpore. " It is found in the small hill bamboo. In a clump of fifty or sixty, only five or six contain the substance. " From each bamboo one or two rutties (four or five grains) are usually obtainable. It very rarely happens that four anas (from forty to fifty grains,) are procured. " It is found in the same bamboo of different qualities. The best sort is of a bluish white colour and glossy surface. An inferior kind is of a chalky white without lustre, and the worst sort is brown and even black. *' The raw material is sold at ten rupees a seer ; but it is pre- pared for use, and in that state sells from forty to fifty rupees per seer. " The only preparation, however, is its imperfect calcination. " A quantity is placed in an open vessel of baked clay upon a fire of charcoal, which is urged with bellows till the vessel and its contents become of a red heat. The manna first becomes black, but when raised to a red heat, emits a fine diffusible aroma. " It is kept red hot for some time, occasionally stirred with an iron spoon, and sometimes another vessel is inverted over that in which it is contained. The fire is then allowed to subside, and as it cools the bunslochun resumes its white colour. 288 Dr Brewster on ihe Natural Histori o "An ounce and a half, treated in this manner, was reduced to an ounce. The process lasted three quarters of an hour. " The substance is sent to market in this state, and is taken in powder as a tonic, or chewed with betel, with a view to re- novate the constitution.*" From these observations of Dr Wilson, I shall now proceed to give an account of those which I have made upon Tabasheer, including in a very brief form such as I have already published. As tabasheer is found only in a small number of bamboos, we cannot regard it as a secretion from the plant in a healthy state. An inteUigent native of Vizagapatam, who had in- spected several hundred bamboos, observed, that in every joint which contained the tabasheer there was a small perforation evidently made by an insect ; and he conceives that the ex- terior juices of the plant find their way through this opening, and drying up form tabasheer. This observation, however, is by no means correct. I have found tabasheer in many joints where there was no perforation ; and as the perforations are never lined with the siliceous matter, and have no accumula- tion of tabasheer at either end, they can have performed no part either in secreting or conveying the juices of the reed. An examination of the joint or internode of the bamboo will probably lead us to a more satisfactory explanation. The culm or stalk of the bamboo represented in Plate IV. Fig. 2, by MN, consists of a number of concentric rings. The outer rings, AC, BH, shown in section, are continued through the length of the reed, notwithstanding the little annular protuberance which marks externally the place of the internode AB. The inner rings, DE, GF, however, the innermost of which is a delicate membrane, do not pass onwards, but are interrupted by the internode, and turning round at EF, they form the roof of the cavity DEFG, joining the similar membrane on the side FG. Between AE and FB, where the concentric rings diverge, the space left between them is filled up with a soft spongy mass, which forms the substance of the internode AB. As the sap ascends between AC and ED, it must be stopped partially at the internode between A and E, part of it passing A, and part gf it being either absorbed by the spongy mass between AE, and Properties of' Tahasheer^ ',f| 289 and remaining there, or passing through it to the opposite side of the stem. But, however this may be, the juices of the plant are col- lected at the internode, and could not possibly penetrate into the inner tube while the inner ring and membrane are sound, as in the healthy plant. When this membrane, however, is destroyed or rent by disease, or when the whole internode is in a state of malconformation, as I have found it, the juice or milk at the joints is immediately extravasated, lines the roof EF, or the bottom DG of the inner tube, and forms tabasheer by its subsequent induration. The quantity of tabasheer, therefore, does not depend on the size of the reed, but upon the diseased state of its joints ; and it will be seen from those upon the table, that the greatest quantity is in one where the internode is completely disorga- nized. Captain Playfair has mentioned four or five grains as the usual quantity. In the bamboo now alluded to the quan^ tity is fully twenty grains. By the cutting down and transporting of the bamboo, the tabasheer encrusted upon the roof or bottom of the cavity is detached, and is always found in separate pieces of different sizes. Its existence in any individual bamboo may therefore be known by the rattling noise which takes place by shaking the reed. A portion of it, however, often adheres to the place of its formation, and we may sometimes detect it in the pores of the spongy mass from which it has exuded. The largest pieces of tabasheer are generally impressed with the inner membrane of the reed upon which it has been formed. In opening different bamboos, the included tabasheer pre- g^ents various appearances. When the tube has been perforat- ed with holes, it has a brown and dirty aspect, arising no doubt from the admission of dust ; and the perforating insects are often found among the fragments. When there are no per- forations, the tabasheer is clean and pure, presenting a great variety of aspects, depending no doubt on the nature of the juices, on the manner in which they have been extravasated, and on the time in which their induration has been effected. The different varieties of tabasheer may be thus enumerated. 1. The finest variety, which is also the rarest, is of a deli- cate azure blue colour by reflected light, and of a faint yellow- 290 Dr Brewster on the Natural History ish hue by transmitted light. It is easily crushed between the fingers, and it has an aerial and unsubstantial texture which we look for in vain in any other solid. It has its counterpart in the mineral kingdom in some of the finer semiopals, which approach to the precious varieties. 2. Another variety of tabasheer reflects a yellow tint like that of molybdate of lead, and transmits a light of a reddish • yellow tinge. It resembles greatly some of the yellow semio- pals. 3. A third variety is nearly white, with a slight tinge of blue, and is translucent at the edge like cacholong. 4. A fourth variety resembles chalk, and is perfectly opaque. Although these are the forms in which tabasheer generally occurs, yet several peculiarities of structure present themselves in the examination of numerous specimens. In some I have observed a layer exactly like jasper, and in one specimen the surface is covered with a brilliant enamel possessing all the lustre of pure quartz. The chemical composition of tabasheer is still involved in some uncertainty. That which Dr Russell brought from In- dia in 1790, and which is similar to what is now on the table, consisted, according to Mr Smithson, of pure silex ; but Fourcroy and Vauquelin, having examined a portion of what Baron Humboldt brought from South America in 1804, found it to consist of seventy parts of silex and thirty of potash.* When we plunge any of the varieties of tabasheer in water, an effervescence takes place, owing to the rapid escape of air from its pores ; and when this has ceased, the transparent and translucent varieties have their transparency and translucency greatly increased, but the chalky kind retains its opacity The quantity of water imbibed by the tabasheer exceeds in weight the tabasheer itself, and the space occupied by the pores ife to that occupied by the solid particles nearly as 2 J to 1. The chalky tabasheer which does not become transparent by the absorption either of oil of cassia or water, readily im- bibes the fat oils, and with oil of beech-nut it becomes as transparent as glass, but it requires a considerable time to dis- • An analysis of Tabasheer by Dr Turner will be found in a subsequent article of this Number. ' and Properties of TabasJieer. iSigll place the air from its pores. These results are perfectly ana- logous to those which we obtain with hydrophanous opal, and I have also succeeded in giving transparency to the chalky silex from the Gianfs Causeway, by long immersion in oil of beech-nut. If, instead of immersing the tabasheer in water, we place a small drop upon the most transparent variety, the drop is in- stantly absorbed, but the spot which it occupies becomes as white and opaque as if it had been covered with white lead. This extraordinary property, which is not possessed by any of the siliceous minerals, will be explained when we have treated of the optical properties of this substance. The opaque tabasheer which has become transparent by absorbing oil exhibits a very curious phenomenon by change of temperature. If it is laid upon a piece of cold lead, it be- comes suddenly opaque, and if it is restored to a warmer si- tuation, its transparency as suddenly returns. These effects obviously arise from the great expansion and contraction of oil by heat. When the oil retreats from the surface of the speci- men, the mutual attraction of its own particles accumulates them in one place, instead of permitting them to remain in a state of contraction in separate pores, as might have been ex- pected. When the greater part of the oil has been expelled from these specimens by heat, the tabasheer exhibits a beauti- ful veined structure, the veins being sometimes parallel, as in the onyx, and sometimes curved, as in the agate. This effect arises from the different degrees of porosity in the different veins, in virtue of which some of them absorb more oil than others. The limits of each vein are thus rendered visible in the very same manner as the veins of burned chalcedony, which has absorbed oil from the lapidary's wheel, may be displayed in all their beautiful inflexions, although in its natural and transparent state it did not exhibit the slightest trace of such a structure. It is from the same property of some of the amorphous siliceous minerals that the lapidary is able to de- velope, and to colour, the veins of particular agates, and that the artist can execute the finest drawings, which actually lie beneath the surface of certain porous specimens of chalce* dony. Dr Brewster on the Natural History ' fXhe absorptive power of tabasheer is not confined to fluids. It draws into its pores solid bodies in a minute state of subdi- vision. If we wrap a piece of it in a bit of paper, and burn the paper, the tabasheer will come out of it of a glossy black colour, transmitting only red light like a piece of smoked glass. By repeating this operation twice or thrice it becomes so deeply black as not to admit a ray of the meridian sun. By exposing the specimen to a white heat the black matter is discharged, and the tabasheer is restored to its former appear- ances and properties. When the blackened tabasheer is plunged in water it disengages the included air, but with less rapidity than before, because there is less air to disengage ; and when it is broken and pounded its fracture and its powder are black. If the black matter has not insinuated itself copious- ly into the heart of the specimen, this portion is of a bluish slate- colour. When slightly wetted in this place it becomes wfiiie, and when saturated with water it becomes jet black. This, however, is an illusion ; for though it does appear absolutely black, yet it is in reality made translucent by the absorption of the water. This translucency allows the white light which the nucleus formerly reflected to pass on to the black coating, where it is absorbed, — an effect analogous to what takes place in a black inkstand, in which it is impossible to distinguish ink from water by looking at the surface of the fluid.* One of the most remarkable properties of tabasheer is its low refractive power, which is lower than that of any other body, "whether solid or fluid, as will be seen from the following table : • It is on the same principle that the false gems called Doublets form such admirable imitations of the precious stones. No light is allowed to reach the eye except that which is reflected from, or transmitted through an interposed coloured film ; and hence we think that we are viewing the finest gem when we are only looking through a piece of glass. Having had occasion to examine a number of emeralds, which a skilfUl jeweller put into my hands, he pointed out one superior to all the rest; but upon exposing it to polarized light I found it to be a doublet. It is owing to the same cause that octohedriie appears almost black when lying upon its matrix. Its refractive power, which is equal to that of diamond, bends the incident light so much that it cannot escape from the opposite face of the prism : But when the light falls upon a parallel plate of the mineral, its transparency immediately appears. and Properties of Tahasheer. 293 Air, 1.000 Flint glass, 1.600 Tabasheer, 1.111 Oil of cassia, 1.641 Water, 1.336 Diamond, 2.470 Hence it appears that the refractive power of tabasheer is ac- tually nearer that of air than that of water. The index of re- fraction given above is the lowest that I have obtained ; but specimens of greater specific gravity have higher refractive powers, as will be seen from the following measures : Tabasheer, 1.1114 Tabasheer, 1.1503 do. 1.1145 do. 1.1535 do. 1.1292 ' do. 1.1825 do. 1.1454 The specimen of tabasheer which I have described as cover- ed with a brilliant enamel, possesses great hardness ; and from the measure which I have taken of its angle of maximum po- larization, I have no doubt that its refractive power approach- es to that of the semiopals. Th^ determination of the low refractive power of tabasheer enables us to give a satisfactory explanation of the curious fact already mentioned, that a small drop of water produces white opacity, while a greater quantity renders it perfectly transparent. If ABC, Plate IV. Fig. 3, is a prism or piece of tabasheer, we may suppose one of its pores, highly magnified, to be represented hj abed. This space is filled with air, and when a ray of light MN, enters the separating surface AB at e, and quits it at A, it suffers so little refraction, that the tabasheer allows us to see objects distinctly through it. Let us now suppose that a small quantity of water is introduced into the pore abed, so as not to fill it, but merely to line its circumference with a film which terminates at cc 8 y d. Then the light which passes from wa- ter into air at^j and again from air into water at g, will suf- fer a comparatively great refraction, and will be considerably scattered in all directions. Hence the tabasheer must appear opaque. If we now saturate it with water, so as to fill the pore abed, the refractions aty and g are removed, and the ray ef will pass on to h unobstructed, so as to experience no change of direction, except the small one which takes place at e and h, where it enters and quits the fluid. 294 M. Mitscheriich on a tvew Jcid of Selenium. Before concluding these observations, it may be expected that I should attempt to answer a question which every per- son must have put to himself. Whence comes the silex which circulates so abundantly in the juices of the bamboo ? If we consult on this subject our best systematic writers on chemis- try and botany, we shall find it ranked as a " foreign ingre- dient,'" an intruding element which the plant had derived from the pecuhar soil in which it vegetated. Those who examined the drawings and descriptions of the distribution of silex in the Equisetum hiemale, which I submitted to the Society some years ago, will concur with me in the opposite opinion, that the silex is an integral portion of the plant itself, and pro- bably performs some important function in the processes of ve- getable life. Art. X. — Oil a new Acid of Selenium.* By M. E. Mit- scHERLTCH, Profcssor of Chemistry in the University of Ber- lin, F. R. S. Ed. &c. &c. I The existence of this very interesting compound, which we noticed briefly in a former number of this Journal, was origi- nally observed by M. Nitzsch, who has long assisted M. Mit- scheriich both in preparing for his lectures and in conducting his researches. M. Nitzsch, in order to prepare a seleniate of potash, decomposed the seleniuret of lead by fusion with nitre, dissolved the resulting seleniate of potash in water, evaporated the solution to dryness, and heated the residue with sal-ammo- niac. As it was necessary to employ an excess of nitre, he en- deavoured to separate that salt from the seleniate of potash by crystallization. After the separation of the greater part of the nitre, he obtained crystals which had the following characters. They had the form of sulphate of potash, and were analogous to that salt in relation to polarized light. They formed a neutral solution with water, were free from water of crystal- lization, deflagrated like nitre with red-hot charcoal, yielded an insoluble precipitate with the salts of baryta, gave rise to an evolution of chlorine when boiled with muriatic acid, and underwent no change by the action of sulphurous acid. After * Abstract from the Annates de Chimie ei de Physique, xxxv. 100. M, Mitscherlich on a New Acid of Selenium, 295 being heated with muriatic acid, the solution yielded a preci- pitate of selenium with sulphurous acid, and likewise retained its transparency when mixed with a salt of baryta. From these characters it results, that the crystals were a compound of potash and a new acid of selenium, isomorphous with sul- phuric acid. As the new acid contains more oxygen than that discovered by Berzelius, it must be called selenic acid, while to the latter the term selenious acid is appropriate. Preparation of the new Acid. — This acid is easily formed by fusing the nitrate of potash or soda with selenium, seleni- ous acid, a metallic seleniuret, or a selenite. The seleniuret of lead, as the most common ore of selenium, is preferred ; bjut it is very difficult to obtain pure selenic acid by means of this mineral, because it is generally associated with metallic sulphu- rets. The ore is first treated with muriatic acid to remove the carbonates ; and the residue, which is about a third of the mass, is mixed with its own weight of the nitrate of soda, and thrown by successive portions into a red-hot crucible. The lead is thus oxidized, and the selenium converted into selenic acid, which unites with the soda. The fused mass is then treated with boiling water, which dissolves only the seleniate of soda, and the nitrate and nitrite of soda ; while the insolu- ble matter, when well washed, is quite free from selenium. The solution is quickly made to boil. During the ebullition, anhydrous seleniate of soda is deposited, while, as the liquid cools, nitrate of soda crystallizes. On renewing the boiling and subsequent cooling, fresh portions of the seleniate and nitrate of soda are procured ; and these successive operations are re- peated until the seleniate of soda is entirely separated. This process is founded on the fact, that the seleniate of soda, like the sulphate of that base, is more soluble in water of about 91° Fahr. than at higher or lower temperatures. The nitrite of soda, formed during the fusion, is converted into the nitrate by means of nitric acid. > The seleniate of soda thus procured always contains a lit- tle sulphuric acid, derived from the metallic sulphurets of the ore ; and it is not possible to separate this acid by crystalliza- tion. All the attempts to separate it by means of baryta were likewise fruitless ; and the only method of effecting this object is by reducing the selenic acid into selenium. This 296 M. Mitscherlich on a New Acid of' Selenium. is done by heating a mixture of the seleniate of soda and sal- ammoniac, when mutual decomposition ensues, and selenium, nitrogen, and water are evolved. The selenium thus obtained is quite free from sulphur. It is then dissolved in an excess of nitric acid, and any trace of sulphuric acid may be detect- ed and removed by muriate of baryta, which, however, does not render it turbid. The acid solution is then neutralized by carbonate of soda, the selenite of soda converted into the seleniate by fusion with nitre in a crucible of porcelain, and the nitrate of soda removed by crystallization in the man- ner above described. The pure seleniate is dissolved in water, and obtained in crystals by spontaneous evaporation. To procure the acid in a free state, the seleniate of soda is decomposed by the nitrate of lead. The seleniate of lead, which is as insoluble as the sulphate, after being well washed, is treated by a current of sulphuretted hydrogen gas, which does not decompose selenic acid. The excess of sulphuretted hydrogen is driven off by heat, and pure selenic acid remains diluted with water. The absence of fixed substances may be proved by its being volatilized by heat without residue ; and if free from sulphuric acid, it gives no precipitate with the mu- riate of baryta after being boiled with muriatic acid. Any nitric acid which may be present is expelled by concentrating the solution. Composition of Selenic Acid and the Seleniates.^-Since the neutral salts of selenic acid are isomorphous with the sulphates, the composition of selenic acid and seleniates may be expected to obey the laws of isomorphism. Consequently, selenic acid should contain one-half more oxygen than selenious acid for the same quantity of selenium ; and the oxygen contained in the base of the seleniates ought to be a third of the oxygen of the acid. Experiment fully confirms this supposition. Of fused seleniate of potash, 2.6545 yielded 1.7655 of the chloride of potassium, equivalent to 1.117 of potash, and 3.34J35 of the seleniate of baryta, indicating 1.5315 of selenic acid ; because 1.812 of baryta is equivalent to 1.117 of potash. Accordingly, 100 parts of the seleniate of potash consist of Potash, 42.16 of which the oxygen is = 7.15 Selenic acid, 57.84 do. = 21.79 M. Mitsclierlich 07i a new Acid of Selenium. S97 The composition of selenic acid was ascertained by means of the seleniate of soda. The fused salt was boiled so long with muriatic acid, that on adding muriate of baryta no cloudiness ensued,, a circumstance which proved both the ab- sence of sulphuric acid, and the decomposition of all the sele- nic acid. After separating the baryta by sulphuric acid, the selenious acid was decomposed by means of the sulphite of soda; and 4.880 of the seleniate of soda thus yielded 2.020 of pure se- lenium. But since, according to the foregoing analysis, 100 parts of selenic acid, saturate 72.89 of potash, or 48.30 of so- da, it follows that 4.880 of seleniate of soda must contain 3.29 of selenic acid. This acid must therefore be composed of 61.40 parts of selenium, and 38.60 of oxygen. According to Berzelius, selenious acid is formed of 100 parts of selenium, and 40.33 of oxygen. Consequently, if the oxygen in selenic and selenious acids is in the ratio of 3 to 2, the former should be composed of 100 parts of selenium, and 60.495 of oxygen, or should contain 37.68 per cent, of oxygen. It appears from the numbers procured by this cal- culation, that the quantity of selenium, as obtained by ana- lysis, is somewhat too small. This is owing to the loss of a simi- lar quantity of that principle. To eifect the entire decomposition of the seleniate of soda, it is necessary to boil it several times with muriatic acid, and during this operation a little sele- nious acid is volatilized. The precise composition of the se- lenic acid is best ascertained by the analysis of the seleniates, in which case the quantity of oxygen in the acid is inferred from that of the base. According to the analysis of the seleniate of potash, the se- leniates are so constituted that 100 parts of the acid saturate a quantity of base which contains 12.56 of oxygen. i Properties of the Selenic Acid.- — This acid is a colourless liquid, which may be heated to 280° C. without appreciable decomposition ; but above that point the decomposition com- mences, and it becomes rapid at 290° C. giving rise to oxygen and selenious acid. Heated to 165° C. its density is 2.524 ; at 267^^ it is 2.60, and at 285° it is 2.625, but a little selenious acid is then present. Obtained by the process above-mention- ed, selenic acid always contains water, but it is very difficult 298 M. Mitscherlich on a 7iew Acid of Selenium. to ascertain its precise proportion. Some acid which had been heated higher than 280° C, subtracting the quantity of selenious acid present, contained 84.21 of selenic acid, and 15.75 of water. If the oxygen in the water was to that in the acid as 1 to 3, the solution should contain 12.38 per cent, of water. It is certain that selenic acid is decomposed by heat before parting with all the water which it contained ; and the composition of the solution at 280 C. is analogous to that of sulphuric acid which has been heated to 326." Selenic acid has a powerful affinity for water, and emits as much heat in uniting with it as sulphuric acid does. Like sul- phuric acid it is not decomposed by sulphuretted hydrogen, and therefore this gas may be employed for decomposing the seleniate of lead or copper. With muriatic acid the change is peculiar ; for on boiling the mixture chlorine is disengaged, and selenious acid is generated, so that the solution is capable of dissolving gold or platinum hke aqua regia. Selenic acid dissolves zinc and iron with disengagement of hydrogen, and copper with formation of selenious acid. It dissolves gold also, but not platinum. Sulphurous acid has no action on selenic acid, whereas selenious acid is easily reduced by it. Conse- quently, when it is wished to precipitate selenium from selenic acid, it must be boiled with muriatic acid before sulphurous acid is added. Selenic acid, in its affinity for alkaline bases, is little infe- rior to sulphuric acid ; so much so, indeed, that the seleniate of baryta cannot be completely decomposed by sulphuric acid. It is therefore a very powerful acid. As its compounds are isomorphous with those of sulphuric acid, and possess both the same crystalline forms, and similar chemical properties, the history of the sulphates, with a few slight but very interesting modifications, is the same as that of the sulphates. The great number of crystallized compounds which this acid produces, the different forms which they assume at different temperatures, the beauty of the crystals admitting of precise measurement, and the isomorphism of the seleniates with the sul- phates, which with some chromates have supplied the most im- portant facts towards that theory, induce M. Mitscherlich to collect in an essay, that will be published in a few months, the crystalline forms of the sulphates, seleniates, and chromates. Mr MarshaWs Meteorological Summary for 1827. 299 Art. XI. — Summary for tJie year 1827 of the state of the Barometer, Thermometer, ^c. in Kendal. By Mr Samuel Marshall. Communicated by the Author. In comparing the following summary with that for 1826, it appears that the barometer has not reached the altitude which it then attained, 30.78 ; and the mean height for the year is one- tenth of an inch less. The heat of the summer months has not equalled that of 1826, the greatest being 74°, and the mean 48.°03, whilst in 1826 the maximum was 85°, and the mean 47.°81. The superior mean temperature for 1827 may be ac- counted for by the weather's being more uniformly mild. From 26th of April to 21st of November (or a period of nearly seven months) the thermometer was never so low as the freezing point, and from the former date to the end of the year, there have been but eleven days of frost. We have had thirty- two wet days more in this year than in 1826, and the quantity of rain is greater by 14.926 inches. The writer of these remarks has carefully registered observations on the weather in this town for upwards of five years. He subjoins a summary from 1823 to 1827, both years included. From observations made by the late John Gough, and by John Dalton of Manchester, he inferred the mean annual quantity of rain for Kendal to be 51.8 inches. The average for the five years alluded to will be found to be 57.310 inches. The difference may arise from two causes ; one, the difference of altitude in the places where the observations were made above the level of the sea ; but though that does not exceed many yards, yet even so small a difference will affect the amount of the mean in a series of years. The observations from which the former mean was calculated were taken from twenty different years, though not twenty successive years. Assuming all the observations to be equally correct, the mean deduced from the twenty years is most likely to be the correct one. There are few places where rain-gages are kept that have so great a quantity of rain as at Kendal, though it it is probable that in many places there are more rainy days within the same period. From a number of observations now in my possession, the annual mean quantity of rain which falls in England may be stated at 35.2 inches. 300 Dr Har wood's Account of an Years. Mean of Barometer. Mean of Thermometer. Inches of Rain. No of Rainy Days. Prevalent Wind. 1822, 1823, 1824, 1825, 1826, 1827, 29.56 29.76 29.64 29.73 29.63 45.^00 46. 88 47. 49 47.81 48. 03 62.726 198 187 169 147 179 S.W. s.w. s.w, s.w. 62.749 62.762 59.973 43.060 58.006 Means, 29.66 47. 04 57.310 176 s.w. Summary for the year 1827 of the State of the Barometer^ ^c. in Kendal. Quantity Number 1827. Barometer. Thermometer. of Rain in Inches. of Rainy Days. Prevalent Winds. Max. Min. 28.89 Mean. 29.61 Max. Min. Mean. Jan. 30.08 49^ 9° 34.°59 8.630 14 S.W Feb. 30.40 28.89 29.51 53 14 33. 92 2.698 5 N. March, 30.03 28.40 29.36 5Q 23 42. 93 8.676 22 S.W. April, 30.13 29.42 29.77 70 30 47.23 2.553 14 s.w. May, 29.94 29.10 29.56 69 32 52.87 3.483 15 w. June, 30.14 29.27 29.69 74 45 56. 98 4.264 17 w.&s.w. July, 30.15 29.39 29.79 74 42 59.01 3.170 15 w. Aug. 30.18 29.10 29.81 68 46 56. 61 5.214 12 N. W. Sept. 30.20 29.14 29.78 68 41 55. 55 3.329 16 S.W. Oct. 30.18 28.92 29.54 63 34 51. 95 3.009 17 s.w. Nov. 30.05 29.09 29.78 55 21 42.30 2.615 9 w. Dec. 30.46 28.57 29.47 29.63 54 24 42. 53 10.365 23 s. w. 48.°03 58.006 179 Art. '^W.-^ Account of an extraordinary Marine Animal or Sea Serpent. By I. Harwood, M. D. F. R. S. Professor of Natural History in the Royal Institution. * In the autumn of 1826, whilst Captain Sawyer of the ship Harmony of Hull was in pursuit of the Bottle-nosed Porpoise in Davis's Straits, north latititude 62, and west longitude 57, • This paper is a popular abridgement of Dr Har wood's paper in the Phil Trans. 1827, p. 49, e^iraordinary Marine Animal or Sea Serpent. 301 he observed a body floating on the surface of the water, which was at first mistaken by himself and his seamen for an inflated seal's skin, such as the Esquimaux employ in the destruction of large aquatic animals, by attaching it to the harpoon by which they are speared, and thus tiring them out by its float- ing property. On a nearer approach, however, the object which had excited attention proved to be a living marine animal. The creature is still in the possession of Captain Sawyer, who preserved it in rum soon after being taken. Its capture was occasioned by its being, when first observed, al- most worn out by unavailing efforts to gorge a species of perch of about seven inches in circumference, with which it appeared to have been long contending, as it exhibited very feeble signs of life. The organs of motion being extremely small, and its body greatly elongated, this creature would on a cursory view be by all considered as an extraordinary kind of sea serpent,, and this idea is supported by a more close examination. ; Its body is one uniform purplish black, except the filamen- tous extremity of the tail, which is much lighter. The total length is four feet six inches. The enlarged, and extremely elastic pharynx, communicates with an enormous sac or air- vessel, extending in length from the extremity of the snout about twenty inches. When partially filled with air, this sac measured about nine inches in circumference below its union with the tail, and its greatest diameter, including the slender body to which it pertained, was four inches. The use of this enormous pouch Dr Harwood is not able to discover. The skin all over the body of the Ophiognathus is particu- larly soft and slimy, yet it has a slight granular appearance. The spiracles, which are five and a-half inches from the snout, are large and of an irregular oval form. All the fins are ex- tremely small, the pectorals being composed of an adipose disc, which is terminated and nearly surrounded by a narrow radiated membrane. The dorsal fin, which like the rest is very narrow and provided with simple rays, commences at about eighteen inches from the snout, and terminates insensibly upon that slender tape-like filament into which the tail becomes con- verted, and which is continued twenty and a-half inches in length beyond the posterior extremity of the dorsal fin. About this VOL. Vlir. NO. II. APRIL 1828. u 302 Dr Harwood's Account of a Sea Serpent. part of the dorsal fin, a few other minute filaments take their growth from it. The anal fin commences at the posterior union of the sac with the body, and ends at about fourteen inches from the extremity of the caudal filament. The body exhibits no apparent lateral line ; but perhaps the most curious struc- tures which the creature presents to our notice are connected with the head and jaws. The almost entire absence of a tongue might perhaps prove one of its most characteristic dis- tinctions, were we as yet sufficiently acquainted with the con- dition of this organ in those nearest allied to it. The teeth are disposed in a single row above and below ; above they exist only along the margins of the intermaxillary bones ; below they extend almost the whole length of the maxilla ; but the ossa palati are entirely destitute of teeth. Lastly, the jaw-bones are so long, and their articulation is such, that their capabihty of expansion exceeds what I have seen in any other animal, the rattlesnake not excepted ; and as in snakes, when fully distend- ed, the edges of the jaws describe a large circle, and then ap- pear but as the hemming of an ample sac, the pharynx which usually occupies so small a space being an equal participant in this extensile property. When the jaws were gently open- ed, they measured two and a-half inches across, and three and a-half from the front teeth to those below ; but while they pos* sess this power of extension, their contractile power is no less remarkable. A drawing of this singular animal is given in Plate IV. Fig. 4. As this animal forms a new genus of serpentiform fishes, Dr Harwood has given it the name of Ophiognathus ampuU Ulceus, with the following characters. Corpus nudum, lubricum, colubriforme, compressum sacco amplo abdominali. Caput antice depressum, maxillo superiore (paulo) longiore, Dentes in maxilla inferiore, et ossibus intermaxillaribus, su- bulati, retroflexi. Maxilla? elongatae, patulae dilatabiles (serpentium instar.) Lingua vix conspicua. Spiracula ante et sub pinnas pectorales magna. Pinnae pectorales, dorsales, analesque radiis mollibus ; ven- trales nullae. ' 'Mean Temperature of various places in New Yor^, 303 ^^ Oculi minimi, prope extremitatem maxillae superioris positi. Cauda elongata, in filamentum apterum producta, ~ . ' jj (M). Art. Xlli. — On the Meaji Temperature Sfc. of various places f^ in the State of New Yorhjbr 1826. '\\\ m eo The Legislature of the State of New York, with a laudable i; desire of promoting the progress of meteorological knowledge, 5'' has enjoined the Regents of the different universities within their bounds, to make annual returns of the state of the ther- mometer, rain-gage, and weather. The first annual report, which was made to the senate on the 13th April 1827, has been transmitted to us by af-rie»d, and from it we are enabled to lay before our readers the following very valuable obser- vations. It is entitled An Abstract of the Retujrns of Meteorological Observations made to the Regents of the University hy sundry Academics in this ^tc^ie, ifi pbedience to instructions dated March 1,1825. mcTgl-^ The report unfortuhately does not state the latitude and longitude of the places of observation, nor their height above the level of the sea. Of Pompey Academy^ however, it is stated that it is " elevated 1000 feet above the long level of the Erie Canal, from which it is distant in a direct line about nine miles. Many estimate the elevation of this place to be from 1200 to 1500 feet. - At many of the aeademies observations have been made on- ly during some months of the year : These, of course, we have omitted as of little value. The number of these imperfect reports is tzvelve. We trust, however, that in subsequent years the patriotic wishes of the Legislature will be more punctual- ly executed ; and that the longitude, latitude, altitude and peculiarities of situation of the different places of observation will be distinctly stated, even if approximate values only can be given. ? -t u fJ^ ^i- •> '"i The observarions Ihave beeii reducecl fey T^. W^ Joseph Henry, but they have omitted to state the hours at! which the observations were made. ^*^''^-/^'. 304 Mean Temperature of' various Places in New York. TABLE I. Albany Eras. Hall Hartwick Ur. Hall Utica Middleb. Greenv. L.ausing. Onondaga Pompey Jan. Feb. .Viar. April May June July Aug. Sep 28°.25 34«7() Ib.'MJ 31 .61 26.15 25 .45 30.27 26 .29 25 .75 40.81 Mean Temperature ot each Month in lti2<>. 38°.60 40.97 35 .36 40.22 34.32 36.41 i3 .77 36 .00 43 . 36 .58 31 .91 67°.01 71 .19 61 .30 64 .62 65 .78 61 .12 62.52 68.00 65 .55 60.79 73 75 'J6 71 72 68 G8 72. 7371 16 67 72°.38 71 .99 66.75 71.78 70.52 64 .54 68 .T2 m .00 75 m 65 .02 64 67 61 66 «3 60 61 63 70. 57. Oct. 52°.49 54 .06 48.27 •)4 .08 50.80 71 51 .26 2.00 58 .40 45 .48 NoY. Dec. 39°. 88 44.61 36.42 44 .19 37 .77 .38 .35 36 .96 40 .00 40.14 32.75 Ann. Mean. 5r.07 53.96 46.60 52.19 48.73 46.87 48.05 49.68 50.71 45 .97 TABLE II. Highest Lowest Annual Total Fall of 1 1826. Temp. Temp. Range. Rain and Snow. Albany, 93^ — 12° 105° 33.12 inch. Erasmus Hall, 92 + 3 89 44.91 Hartwick, 96 — 5^4 120 42.35 Union Hall, 93 — 5 98 5BM Middlebury, 100 — IS 108 23.96 Greenville, 91 — 17 118 30.69 Lausingburgh, 100 — 18 118 33.00 Onondaga, 99 ^22 121 36.69 Utica, 93 — 18 111 26.67 Pompey, 90 — 13 103 The coldest day in the year at all the above places, except- ing Pompey, was on the 1st of February. At Pompey it was on the 31st January. The hottest day was on the 15th and 16th of May at Albany, Erasmus Hall, Union Hall, and Greenville; and on the 10th, 11th, and 12th of July in all the- other places. The following are the only places whose position is given in the report. West Long. Lat North. Albany, - 73°4r 42°.39' Erasmus Hall, 73 .58 40 .37 Middlebury, 78.10 42.49 According to Dr Brewster's general formula, applicable to the whole globe, the mean temperature of the middle of the State of New York is nearly - - - 49° 8 The mean temperature of all the ten places in the table is 49°.4 Dr Duncan on Foot-marks of Animals, Sfc, 305 But as most of the places are elevated high above the sea, their mean temperature must be all increased ; so that the for- mula will err in defect. Art. XIV. — Account of the Tracts of Foot-Marks of Ani- mals found impressed in Sandstone in the Quarry of Corn- cockle Muir, Dumfries-shire.* By the Reverend Henry Duncan, D. D. Minister at Ruth well. Communicated by the Author. The sandstone quarry of Corncockle Muir is situated be- tween the rivers Annan and the Kinnell, about a mile and a half above their confluence, and not quite three miles from Lochmaben. It is near the top of a low round-backed hill, which stretches about half a mile in a westerly direction, almost in the line of the rivers. The sandstone of which the quarry is composed is, like most other sandstone in the county, of a reddish brown co- lour, and is believed to be what is called in Britain the new red sandstone. Its texture is friable, and its strata of very une- qual thickness. It lies in the direction of the greater part of the sandstone of the district, which is from west north-west to east south-east, with its dip southerly, inclining at an angle of 38°. The remarkable phenomenon I am about to describe, as ex- isting in this quarry, is that of numerous impressions, fre- quently distinct and well-defined, of the foot-prints of qua- drupeds, which have been found by the workmen on the sur- face of certain strata, when the superincumbent layers have been removed in the process of quarrying. This fact, so ex- traordinary, and I believe unique, has not hitherto been no- ticed in any scientific work, though it is fifteen or sixteen years since the discovery was first made. It is not easy to convey an accurate idea of the nature of these impressions in words ; but out of a considerable variety which have been observed, • The Editor has been indebted to Dr Duncan for this abridgement of his very interesting and valuable paper, which was read at the Koyal So- ciety of Edinburgh on the 8th of January last, and which will appear in vol. xi. part i. of their Transactions, now in the press. ^306 Dr Duncan mt the Foot-marks of Animals diifering in magnitude from the size of a hare's paw to that of the hoof of a pony, I shall give some account of one re- markable tract impressed on a slab, formerly in the possession of Mr Carruthers of Dormont, (who procured it from the quarry some years ago,) and now forming part of the wall of a summer-house in the garden belonging to the manSe of Ruthwell. On this slab, which is five feet two inches in length, there are twenty-four impressions, which make twelve of the right feet, and as many of the left, being of course six repetitions of the mark of each foot. The marks of the fore- feet are a little moi'e than two inches in diameter, both from .claw to heel and across, and those made by the hind feet are of much the same size, but somewhat differently shaped. The appearance of five claws is discernible in each fore paw, the three in front being particularly distinct. The three front claws of the hind paws may also be plainly traced, and are placed nearer to each other than those of the fore feet. There Jias obviously been no division in the sole of the foot, as is the rcase in the canine and feline species ; but a gentle concavity ^of surface may be observed, especially in the foi'e paws, occa- sioned partly perhaps by the act of sinking in the wet sand. , The depth of the strongest impression is about half an inch ; and it is observable that the fore feet have made somewhat deeper marks than those behind, — a fact which may either in- dicate a considerable length in the animaPs neck, or the more _than ordinary weight of its head and shoulders ; for, had it ppt been for one or other of these circumstanoesi the chief pressure would have been tlirown on its hinder paws, as is the case in some other specimens, because the surface up which it ^a^ .movingj was of cotisiderable steepness. The distance JFrom tbe claw of the hind-foot, to the heel of the nearest im- pression of the fore foot on the same side, varies, from an inch to an inch and half. This, however, merely marks the posi- .tion of the two feet when the hinder one was brought forward in moving ; and if we would ascertain the animal's step — or rather the distance between the hind and fore paw, when the former was thrown back and the latter advanced — we must measure from the hind foot forward, to the second impression of the fore foot on the same side. Now, this gives a distance found in Corncockle Mnir, Dumfries-shire. 307 of between thirteen apd fourteen inches, which is considerably more, however, than would have been the case if the animal had not been moving. If we compare this with the distance jbetween the line of the right and left feet, (which is, as to the fore-paws, nearly 6| incites*, and as to the hind paws somcr |.hing more than 7| inches,) we shall see that an extraordinary tiiickness of the animal's body, in proportion to its length, is clearly indicated. This description may be considered as applying, in its gene- ral features, to a considerable number of the impressions — I mean those of animals in the act of ascending. Not many tracts, however, have been found, of which the prints are so well defined, and several of them belong evidently to animals of different species. I am myself acquainted with five or six varieties Avhich are clearly distinguishable — the largest of them indicating a quadruped of such considerable magnitude, that the distance between the impression of the hind foot and that of the corresponding fore foot, is more, if I am not greatly mis- taken, than a yard and a half. But there is another class of impressions which must be re- ferred to the tracts of animals in the act of descending the steep face of the stratum. These are not less numerous than the other, but, for an obvious reason, they are not so easily recog- nized to be the prints of feet. The steep face of the stratum has caused the animals to slide in their descent, so that in most instances nothing is observable but the rut made by the heels of their fore paws, and sometimes also a slight mark of their hind paws, which must have rested lightly on the surface, while the animals were sliding their fore paws alternately down- ward, and sinking them in the sand to secure their footing. Of both of those kinds of impressions, traces may at this moment be observed in the uncovered strata of the quarry, though there are none of a very striking character which have not been removed. The best specimens I have seen are in thp summer-house at Ruthwell. With regard to the species of animajs whose tracts have been so wonderfully preserved, I am happy that as to three of them I can give the conjectures of a much more competent judge than myself, one of the first geologists of the age, Pro- 308 Dr Duncan 07i Foot-marks of Animals fessor Buckland, with whom I have been in correspondence, having favoured me with his opinion on the subject. That eminent individual, supposing the sandstone to have been de- posited at an era when, according to the received opinion, no animals existed on our earth of a higher order than reptiles, was induced to look to our present crocodiles or tortoises as the species most nearly resembling those of whose footsteps I sent him casts; and on making experiments with some live tortoises which he has in his possession, he has come to the conclusion, that to animals of this species the tracts belong. With regard to the sliding impressions in particular, he says that he fully adopts my theory of their origin, his tortoises, in going down a declivity over wet sand, having made " almost exactly the same impressions." There are some curious facts connected with this phenomenon which have not yet been mentioned, and which the limits I must prescribe to myself will not allow me to do more than enumerate:-^ 1^^, In most instances the counter impressions are distinctly marked in relief on the under surface of the layer covering the foot-prints, these projections corresponding to the cavities be- low as exactly as a cast to its mould. 2c?, The impressions never occur but on what the workmen call a clay face, by which is meant a stratum, the outer coat of which has a slight admixture of clay, rendering it harder than the rest of the rock, accompanied sometimes with a thin layer of soft clay in the seam between the under and upper stratum. 3(i, All the tracks are constantly in a direction either up or down, sometimes inclining a very little either to the right or left, but never running across the slope in any great degree. 4i7i, In most of the impressions there are marks of the mat- ter being displaced by the foot-marks, and wherever such an appearance occurs, the matter is found to have been carried directly downwards, with reference to the present inclination of the quarry. These two last circumstances, as well as that of the sliding tracts, prove that the strata must have been very much in- clined, while in a soft state, and while in the act of forming. found m Corncockle Midr, DumfT^Hi-ihite. 309 diough this is contrary to the received opinion as to the for- mation of sandstone. 5thy The sand must have possessed, very considerable tena- city, and have even been sometimes skinned over with a stiff coat, for in one of the specimens preserved at Ruthwell, the claws of the animal had evidently broken through the outer coat at every step, and in two others, where the hind paws have rested on the matter just displaced by the fore paws, their pressure, instead of obliterating the appearance of super- added matter, has merely caused an indentation of the part rested on. 6M, There are continuous strata of sandstone resting on those in which the impressions are found, for the distance of not less than a quarter of a mile, all of which must have been deposited subsequently to the period in which the tracks were left on the surface of the sand. ^th. As far down as the quarry has yet been worked, which is not less than forty-five feet perpendicularly from the top of the rock, similar impressions have been found, and these equally distinct and well-defined with such as are nearer the surface. 8^^, The impressions are not confined to a single stratum, but have been found on many successive strata. Since the foot-marks were first discovered, about forty yards of sand- stone have been removed in a direction perpendicular to the line of the strata, and throughout the whole of that extent, impressions have, at frequently recurring intervals, been un- covered, particularly in one part of the quarry, and still con- tinue to be uncovered. Hence it must be inferred that the process, whatever it may have been, by which the impressions were buried in the sand, that of drifting by storms for instance, has not been oc- casioned by any sudden or isolated convulsion of nature, but has been carried on through many successive years or rather ages. Nor has it been the result of tides on the shore of the sea, which can scarcely be supposed to have flowed to the height of between forty and fifty feet ; and even if they had done so, would certainly have swept away or filled up any im- 310 Dr Duncan 07i Foot-7narks of Animals, t^-e, pressions which animals might have made at low water, by moving over the surface of the sands they were depositing. In the midst of so much difficulty, it is not easy to form ■even a plausible conjecture as to the manner in which the sand composing ihe rock was originally accumulated. It might, however, be perhaps worth while to inquire whether or not this successive accumulation could be the effect of the drifting occasioned by violent winds from the south-west. Supposing a sand-hill to be thus formed, a period of r^iiny weather following the stormy season would soften and diffuse the particles of clay, which may easily be believed to have mingled with the sand-drift, and would not only prevent the sand from being again moved by the wind, but would form it into a substance of some tenacity, resembling mortar, well fitted for preserving any impression which it might receive. If, during or immediately after the rainy season, animals were to traverse a hill thus formed, their tracks would be either al- together obliterated, or partially filled up, of which latter state many traces are to be found in the quarry ; but when the surface had begun to dry, the foot-marks impressed on it would remain a considerable time quite distinct and well de- fined. Now, supposing the stormy monsoon again to com- mence, the neighbouring sands, which had not yet been fixed by any mixture of clay, and which happened, from their situ- ation, to be easily dried by a few days of favourable weather, would be suddenly drifted on the hill in question, forming a layer which may easily have covered over the half-indurated surface, without being incorporated with it, and without ii^ any way injuring the form of the footsteps imprinted on it. Let the monsoon be now supposed to continue during the whole course of a dry summer : Fresh layers of sand would be drifted, pure at first, but mingled again towards the close of the season with the clayey dust swept from an arid soil, which mixture would form the materials of what the quarry- men know in its present state by the name of a day-face, and would once more, when subjected to the operation of the re- turning period of rain, both fix the sand, and prepare it for the reception of permanent impressions of the tracks of wan- dering animals. Thus from year to year the same round < Prof. Schow 071 the supposed Changes, experience, having found them very useful assistants in various instances. Mr Dalton's System of Chemical Philosophy. 347 The last method by nitrous gas, has indeed been proposed before, and la- bour bestowed on it both by others and myself, but without reducing the results to any certainty, till lately ; the principal cause of this want of success has arisen from misunderstanding the nature and constitution of nitric acid." (Page 4.) " It sometimes? happens that the nitrous gas is partly or wholly retained by the residue of nitric acid ; but in this case the oxymuriate of lime may be applied to convert the nitrous gas into nitric acid." (Page 5.) Accordingly this method of ascertaining the proportion of oxygen which enters into combination with a metal is the one adopted by Mr Dalton. The metho{l, we should apprehend, is one not likely to be approved by practical chemists ; for though assuredly it must be possible in some in- stances to ascertain the combining oxygen by this method ; yet there is hardly an instance where other methods equally easy and more susceptible of accuracy could not be adopted. Besides, the method rests on a some- what remote deduction from an assumption that the sole product is a ni- trate. Now we know that ammonia results in some cases from the action of nitric acid ; and its production ought perhaps to be suspected in other eases where it has not yet been ascertained. Accordingly we find Mr Dal- ton stating (page 31) that his experiments on the nitric oxide evolved by iron and nitric acid did not afford " satisfactory" data for deducing the oxygen which combines with iron. Part of the nitric oxide was retained by the iron solution ; and when in order to convert this into nitric acid he added a solution of bleaching powder, a pungent gas was evolved, which he supposes to be a compound containing more oxygen than nitric acid. We have no doubt that this " pungent gas" is the same again mentioned by Mr Dalton (Appendix, page 336,) as an accompaniment to the azote evolved when an ammoniacal salt is mixed with a solution of bleaching powder—" exciting sneezing, and inducing catarrh." The offensive va- pour which produces these effects is chloride of azote derived probably in the case of the iron solution from the action of dissolved bleaching pow- der or nitrate of ammonia. Since we are upon the subject, we may ob- serve that it is by no means easy to obtain azote quite free from all smell of chloride of azote, by decomposing ammonia by means of chlorine ; and if we should attempt to free the azote of chloride by washing, we run equal risk of contaminating the azote with other gases separated from the Vater. Messrs Berzelius and Dulong {Annates de Chimie et de Physiqucy vol. XV. page 390) procured the azote of which they took the specific gravity by decomposing ammonia by chlorine ; and the reason that they obtained the specific gravity .976 which Messrs Biot and Arago before then got .968 probably was that their azote retained a trace of chloride of azote. At least we are certain that either their specific gravity of oxygen or of azote must be too much or that of air too little ; for, taking tlie air to con- sist of .21 of oxygen by bulk and .79 of azote, 1. of air by bulk, yields by computation a specific gravity of 1.0026 instead of 1. Admitting the spe- cific gravity of oxygen to be as they state it, we would have to reduce that of azote to .9727, in order to make that of air 1. Besides oxygen and azote, Messrs Berzelius and Dulong took the specific gravity of hydrogen and of 348 Analysis of Scientific Books and Memoirs. carbonic acid ; and from their specific gravities of these four gases, conti- nental chemists have deduced their atomic weights, and have been content to calculate the specific gravities of other gases consisting of oxygen, azote, carbon or hydrogen. This is a deference to which we humbly apprehend the experiments are not entitled. The atomic weight of hydrogen, car- bon, azote, and oxygen are light compared with those of other undecom- pounded substances; and we need hardly remind our chemical readers that the lighter the atomic weight of an undecompounded substance is, the more likely is it to be found afterwards the constituent of another heavier undecompounded substance now assumed to be simple ; and con- versely the heavier the atom of an undecompounded substance, the more likely is it to prove compound. Thus, according to Dr Thomson, the ato- mic weight of fluorine is 2.25, that of chlorine 4.5, and that of iodine 15.5. Iodine being the heaviest atom is most likely to be compound. So far as weight is concerned, iodine viay contain chlorine, and chlorine maif contain fluorine. If the question is put, may iodine be a compound of one atom of fluorine (2.25) and three atoms of chlorine (4.5 X 3 = 13.5 ;) we answer it by adding them together (2.25 + 13. 5) and we get the sum 15.75 instead of 15.5. We can therefore be certain that iodine does not consist of one atom of fluorine and three atoms of chlorine ; provided al- ways that we are sure the atomic weights of fluorine, chlorine, and iodine are, as we have stated, 2.25, 4.5, and 13.5. The day is coming when the art of analysis being exhausted in attempts to resolve into others, substan- ces which resist decomposition, aid will be derived from the indirect light afforded by such considerations as these. We attach, therefore, much im- portance to the accurate determination of the atomic weights of such sub- stances as hydrogen, carbon, azote, and oxygen ; and probably, on the whole, the atomic weights of these substances may be best determined by ascertaining their specific gravities. But we shall be loth to admit the specific gravities of hydrogen, carbon, azote, and oxygen, as determined by any experiments which are not confirmed by similar ones on carbonic oxide (as well as carbonic acid,) on cyanogen, on nitrous and nitric oxides, and on ammonia. If the experiments of Messrs Berzelius and Dulong had ex- tended to these compounds, we would have had proofs which they them- selves have not, of the accuracy of their results ; and the want of such proof must ever in our eyes depreciate the value of their experiments con- sidered as fundamental. Mr Dalton gives experiments on most of the metals, calculating gene- rally from the nitric oxide evolved during their solution in nitric acid. These experiments may be regarded in two points of view ; first, as they afford new quantitive determinations ; second, as they add to our know- ledge of chemical combinations. Viewed as quantitive determinations, we can hardly regard them as of much interest. Most of the oxides he exa- mines had been examined by other chemists before him, or at least have been examined since his experiments were made ; and though doubtlessly repetitions of quantitive experiments are of value in as far as they enable us to approximate to accuracy, we cannot regard Mr Dalton's methods of experimenting to be of that character which would warrant us in employ- Mr Daltotfs System of Chemical Philosophy. 349 ing them for this purpose. Indeed we cannot help regretting that the author of the most important discovery which has ever enriched chemistry should not have partaken of the feeling of the illustrious author of the Novum Organon, who complained that " he, who deserveth to be an archi* tect in this building, should be forced to be a workman and a labourer, and to dig the clay and burn the brick ; and to gather the straw and the stubble all over the fields to burn the bricks withal." Mr Dalton could not indeed, like Bacon, complain that there were no workmen, and that, *' unless he do it, nothing will be done;" for all in all the labourers are not few ; and we cannot but feel, that, if he had employed himself (which obviously he has not) in overlooking their labours, he would have stood more in his place ; and he, who ranks low among workmen, might, as an architect, have continued to add beauty and stability to the edifice of which he was the projector. With regard to new facts, Mr Dalton's work does not furnish many ; yet various statements scattered up and down will repay an attentive perusal. We shall take notice of one or two of these, which, however, are not absolutely new. In dissolving mercury in aquafortis, Mr Dalton says that no gas is evolv- ed in the cold. Without having experimented on the subject personally, we may remark that it is quite possible that by this means a mixture or compound of one atom nitrate and of one atom hyponitrite of mercury may be produced. Thus two atoms nitric acid 13.5 (= 3.5 of axote + 10 oxy- gen, according to Dr Thomson) may resolve themselves into 6.75 (one atom) of nitric acid + 1. (one atom) of oxygen = 7.75, and into 4.75 (one atom) of hyponitrous acid + 1. (one atom) of oxygen = 5.75 which, added to 7.75 gives 13.5, the two atoms of nitric acid. From Mr Dalton's highly valu- able paper on the action of nitric oxide on oxygen over mercury,* it is easy to gather that two volumes of nitric oxide form with one volume of oxygen one volume of nitrous acid ; which volume of nitrous acid is absorbed by the mercury producing hyponitrite of mercury. The effect of heat on the solution of mercury formed in the cold was singular. To simplify the explanation, we shall suppose that exactly fifty grains had been used, which, according to Dr Thomson, should take up two grains of oxygen to form the black oxide and four grains to form the red oxide. Now a boiling heat being employed, nitric oxide was evolved and collected, equivalent to two grains of oxygen. " This would have led me to suppose I had obtained the black oxide in solution ; it was, however, en- tirely the red, as it gave no precipitate by common salt and exhibited the red oxide by lime water; but it required as much oxymuriate of lime as contained two of oxygen to saturate the nitrous gas in the solution before any oxymuriatic acid was liberated." It surely is more probable that the ** oxymuriate of lime" acted on hyponitrous acid than on nitrous gas, since Mr Dalton says he employed a boiling heat, and that only one-tenth excess of acid remained in solution (p. 22.) The nitrate containing the red oxide of mercury consists of 12.5 metal + 1 oxygen + 6.75 of acid = 20.25. Now we conceive that out of the 50 of mercury, twenty-five produced • Annals of Philosophy, x. p. 43. VOL. VIII. NO. II. APRIL 1828. Z 360 Analysis of Scientific Books and Memoirs. twice this quantity of nitrate of red oxide, that is 40. .5 ; in doing which, it is evident, that nitrous gas would be evolved equivalent to two of oxy- gen as Mr Dalton found ; and the remaining 25 of mercury may have divided into two parts, forming with two atoms of nitric acid (13.5) /fV^/, nitrate of red oxide (12.5 metal + 1 oxygen + 6.75 acid = 20.25) and second, hyponitrite of red oxide (12.5 metal + 1 oxygen + 4.75 acid = 18.25,) and this 18.25 of hyponitrite would evidently decompose oxymu- riate of lime equivalent to two of oxygen, as Mr Dalton also found. One-» fourth of the mercury would thus produce hyponitrite of red oxide, and three-fourths nitrate of red oxide. This is a result which may have eluded any other mode of investigation than that employed by Mr Dalton ; for we learn from his paper alluded to, that the hyponitrite of mercury readily ab- sorbs oxygen from the air, becoming a nitrate. Red oxide of lead seems to us a compound, the nature of which requires further investigation. Doctors Berzelius and Thomson agree in the state- ment, that after being treated with vinegar, 27 parts dissolved in nitric acid leave nearly 14 of brown oxide. But before being treated with vine- gar, Mr Dalton (p. 46) says that nitric acid leaves only one part of brown oxide out of five of red lead. M. Longchamp found only one left out of six ; and M. Houton-Labillardiere found one left out of four of a crystal- lized specimen, {Ann. de Chim. et Phys. vol. xxxiv and xxxvi.) Even al- lowing for the accidental presence of litharge (though 50 or 60 in the 100 appear excessive) there is reason to suspect that an oxide of lead may exist consisting of three atoms of metal and four atoms of oxygen. The red oxide of iron is considered by IMr Dalton as a compound of one atom of oxygen with two atoms of black oxide of iron. In the present state of chemistry this view is probably the simplest and the most plausible that has been proposed. Other statements respecting the oxides occur not devoid of interest ; but having dwelt thus long on this part of the work, we must beg to refer our chemical readers to the volume itself. The next section treats of the sulphurets. We do not dwell upon this subject, be- cause the interest of Mr Dalton's statements is now susperseded by the sub- sequent discoveries of Berzelius and Berthier. The next section treats of phosphurets. The most interesting part of this section consists of some corrected statements respecting phosphuretted hydrogen. This is the most unfortunate of all compounds. It has been successively investigated by Davy, Dalton, Thomson, Dumas, and Rose ; and all disagree. Much as has been done, new experiments are still re- quired. Probably the paper of Dumas would be the best starting point. That of Rose proceeds too much on deduction, and includes too many as- sumptions to inspire us with confidence. Under the section of the carburets, Mr Dalton's opinion of the nature of steel merits grave consideration. " From the above account of steel, it is evident there is an essential differ- ence between it and pure iron. That difference consists, according to the common opinion, in steel being a carburet of iron, or carbon and iron united. The fact of the union of carbon and iron in the formation of steel does not seem to me satisfactorily proved^ Mr Collier asserts that iron Mr Dalton's System of Chemical Philosophy. 351 gains about l-180th of its weight by being converted into steel.* But Mr Mushet found that though steel gains weight upon the iron when copi- ously imbedded in charcoal, yet it loses weight if the charcoal is only 1-90 or 1-100 of the weight of the iron, f The same ingenious gentleman seems to estimate the carbon in cast steel, from synthetic experiments, to be 1-lOOth of its weight. " From analytic experiments, however, there does not appear reason to be- lieve that steel contains so much, if any charcoal. Pure steel dissolved in dilute sulphuric acid gives hydrogen gas containing no carbonic acid nor oxide, neither is there any appreciable residuum of any kind in general. *' On considering all the circumstances, I am inclined to believe, that the properties which distinguish steel from iron are rather owing to a peculiar crystallization or arrangement of the ultimate particles of iron, than to their combination with carbon or any other substance. In all cases where steel is formed, the^ mass is brought into a liquid form, or nearly approach- ing to it, — a circumstance which allows the particles to be subject to the law of crystallization. We see that great change is made in steel by the mere tempering of it, which cannot be ascribed to the loss or gain of any sub- stance, but to some modification of the internal arrangement of its parti- cles. Why then may not its differences from iron be ascribed to the same cause?" Pp. 216,-218. In the addenda to the volume Mr Dalton says : '^ Since writing the ar- ticle at page 214', I have had an opportunity of analyzing the crystalline steel, formed by Mr Macintosh's process of cementation by means of coal, gas. I dissolved twenty-one grains of this steel in sulphuric acid, with only a very slight excess of acid. The whole was dissolved except about one- tenth of a grain of silvery-like particles. The gas obtained amounted to 29.6 cubic inches. It yielded no trace of carbonic acid. When fired' with oxygen it yielded 3 per cent, upon the volume of hydrogen of carbo- nic acid ,* and this arose, as I ascertained, from the hydrogen containing 3' per cent, of carburetted hydrogen gas : it contained no carbonic oxide. Supposing the carbon to have been combined with the iron, it would amount only to about 5-8ths of a grain, to 100 grains of iron. Whether such a quantity can be deemed an essential or an accidental ingredient of steel, may be a subject of consideration." P. 354. To us it appears, that whether carbon should or should not turn out to be essential to the manufacture of steel, the iron can never be said to be in combination with carbon, in the same sense that it is said to be in combi- nation with sulphur in its sulphurets. A difference in the structure of iron and steel exists ; but such a difference does not imply necessarily a chemical change ; as we know water to be chemically the same as ice, and* as steam ; and as we know common sulphur, which is very brittle, to be chemically the same as that of flexible sulphur, which is obtained by melting common sulphur, raising it to a high temperature, and dropping it into cold water. With regard to steel, the question is, whether carbon is essential to its change in structure? or whether heat alone is adequate to this change ? * Manchester Mentoirs^ vol. v. p» 120* f Philos. Mag, vol. xiii. 352 Analysis of Scientific Books and Memoirs. The next section treats of alloys. These Mr Dalton considers to be chemical compounds. One striking instance of a true chemical compound occurs in the alloy called • speculum metal. This alloy is formed out of tin and copper. The smallest deviation from the true proportions, it is well known, will spoil the alloy as a reflector. These proportions were, by laborious experiment, ascertained by Mudge to be 32 of copper to 14^ of tin. Now, dividing each of these quantities by 2, we get 16 of copper = 4 atoms according to Dr Thomson, and 7.25 of tin = 1 atom. This, be it observed, is the result of experiments made forty years ago, when atomic weights had as yet been unheard of. To show that chemical investigations on the alloys are likely to afford light on some points long known in practice, we shall quote, with a com- ment of our own, Mr Dalton's table of the alloys of tin with lead. Atoms. Tin , Lead. 1 + 2 + 3 + 4 + 5 + 6 + Weights. Tin. Lead. .58 + 1 L16 + 1 1.73 + 1 2. 3 + 1 2. 9 + 1 3.47 + 1 Sp. Gr. by Sp. Gr. by calculation. Experim. 9.32 9.17 8.64 8.79 8.25 8.49 8.00 8.10 7.93 8.00 7.81 7.90 Fusing I'oint. 430° 350 340 345 350 360 The most fusible alloy, our readers will perceive, is that of 1 atom of lead and 3 atoms of tin. Excluding the alloy of 1 atom of each metal, it will be perceived, that the remaining five alloys taken successively, differ in their smelting points only 10° or 5°. But the alloy of 1 atom of lead with 1 atom of tin, differs in its melting point no less than 80° from that of the alloy of 1 atom of lead with 2 atoms of tin. What, then, would be the consequence, if a pot containing a mixture of these two alloys, both perfectly liquid, should be cooled down to 400° .'' 430° being the melting point of the alloy, 1 atom tin + 1 atom lead, we should expect that the whole of this alloy in the pot should become solid ; and 350° being the melting point of the alloy, 1 atom lead + 2 atoms tin, we should expect that this alloy would remain liquid. Part would be solid, part liquid ; and the mass should be in a sort of intermediate state, resembling that of moist clay. Now the solder used by plumbers consists of a mixture of the two alloys we are considering ; and it is well known that this solder preserves a pasty-form long before it perfectly solidifies, so as to admit of being moulded and pressed about a joint, somewhat like a lute. But though we agree with Mr Dalton in considering many alloys as chemical compounds, we by no means would take for granted, that all al- loys are compounds. Thus an alloy of silver and steel was formed by Messrs Stodart and Faraday, by melting these two metals together. When this alloy was forged into a bar, and then dissected by means of dilute sul- phuric acid, the silver was discovered, not in combination with the steel, but disseminated in threads throughout the mass. These threads of silver may give toughness to the mass, just as hair imparts strength to common mortar; but the silver is as distinctly in a state of mechanical mix- Mr Daltoxi's System of Chemical Philosophy. 353 ture as hair is in common mortar. In like manner small quanti- ties of other metals or alloys are often added, for the purpose, as it strikes us, of imparting mechanical properties, by mixture rather than by combi- nation. But besides combined and mixed alloys, we should regard it quite possible, that some alloys in the solid state, are in fact frozen solu- iions. Mercury, there is no doubt, is capable of holding some amal- gams in solution ; and till experiment shall contradict the supposition, we shall regard it as conceivable and probable, that some melted masses of metal will prove to be solutions of one metal or alloy in another metal or alloy ; and that the solid masses derived from such liquids are congealed solutions. In their present state of ignorance, chemists will regard Mr Dalton's contributions to our knowledge of alloys as an acquisition. But it appears to us, that Mr Dalton has been too scantily furnished with information by practical persons, to render his views available in the arts. Under the last section, Mr Dalton gives some useful experiments on the triple allojjs of lead, tin, and bismuth. The appendix contains a number of remarks which will interest the stu- dious chemist. We were very well pleased with the following judicious strictures on a table of the specific heat of thirteen metals published by Messrs Dulong and Petit. We need not quote this table ; because it has already obtained a place in almost every elementary chemical book ; and we need hardly remind the reader that they profess to have discovered that the atomic weight of a substance multiplied by its specific heat should give a constant product. " The Essay of MM. Dulong and Petit, in the tenth volume of the .4fi. de Chimie (see An. of Philosophy, vol. 14th, 1819) manifests great inge- nuity. It does not appear, however, so fortunate either in theory or expe- riment as the former one. It would be diflicult to convince any one, either by reasoning or by experience, that a number of particles of mercury at the temperature of — 40°, whether in the solid, liquid, or elastic state, have all the same capacity for heat. Indeed the experiments of De la Roche and Berard, if they are to be credited, demonstrate the inferior capacity of con- densed air to rarefied air ; and if the same body changes its capacity in the elastic form, it may well be concluded that all the three forms have not the same capacity. MM. Dulong and Petit have themselves shown, in their former essay, (see page 276) that solid bodies vary in their capacities for heat, and that scarcely any two bodies vary alike ; hence it is impossible that the product of the weight of the atom and specific heat of the body should be a constant quantity. Their specific heat of certain metals differ greatly from what is found by others. For instance, they make the specific heat of lead .0293 ; the lowest authority I have seen is Crawford, .0352, and the highest Kirwan .050 ; from repeated trials I have lately found it, upon an average, .032. The weights of some of the atoms in their table differ ma- terially from what are commonly received ; for instance, bismuth is 13.3 instead of 9 ; also copper, silver, and cobalt, are only half the weights of some authors. The gases too arc unfortunate examples. Oxygen gas gives a product of .236 instead of .375 ; azotic gas gives a product .1967, if oxy- 364 Analysis of Scientific Books and Memoir!t^ gen be to azote as 7 to 6, but a product of .393 if oxygen be to azote as 7 to 10 : by Dr Thomson's ratio of oxygen to azote, 4 to 7, the product will be .482, very different from .375. Hydrogen will give a product of .47 or .41 instead of .375. All these diflPerences, it may be said, are occasioned by errors in the specific heats of the gases ; but if errors of this magnitude can still subsist after all the care that has been taken, we shall scarcely know what to trust in experimental philosophy." Pp. 293, 294. Independent of these inconsistencies, we have grave reason for not ad- mitting the accuracy of Messrs Dulong and Petit's table ; and our reason is simply, that this table consists merely of results (sufficiently different from former ones) without the authors having given any details of their experi- ments even yet nine years after their publication ; so that, forsooth, we are left to pin our faith not merely to the honour but to the immaculate accu- racy of Messrs Dulong and Petit ; for they have taken effectual measures of preventing the repetition of their experiments by others to confirm or to disprove them. Do we doubt their experiments ? We are without evi- dence ; and therefore we do not doubt them : We are without evidence ; and therefore we do not believe them. But we protest against regarding the experiments as ever made, till the authors enable others to repeat them. We cannot help wondering at Dr Berzelius having allowed himself recent- ly to be carried away by this flimsy table, so far as to assign three times the atomic weight to bismuth that he otherwise would, especially when he admits the atomic weight of cobalt to be a-half more than that assigned by Messrs Dulong ajid Petit ; and the atomic weight of silver to be twice as much. Having thus endeavoured to give some idea of the nature and merits of the volume before us, we take leave of it, recommending it to the attention of our chemical readers. The work is one which will not be read as an in- troduction to chemistry ; but it will be perused with interest by all who have made some progress in the science, and who make its doctrines a sub- ject of habitual reflection. Of almost any other chemist than Mr Dalton, we would have complained of the ignorance in which, it is evident, he has kept himself of the researches of other chemists. But we cannot speak in the language of complaint of Mr Dalton, known to the world as a very apostle of science — leaving all worldly advantage behind to follow it, and proceeding on cheerfully, without scrip, or purse, or staff. We know not how to express the feelings with which we glance over the last three pages of this volume, containing a list of the scientific papers which Mr Dalton has published during a period of thirty-five years. One discovery of his gives a glory to the scientific character of the nation ; independent of other discoveries which alone would rank him high as a philosopher. And for whose good ? We cannot look to this list without believing that Mr Dal- ton is tnore likely to have lost money than to have gained by all his publi- cations. In other countries, less happily constituted governments than our own would not have hesitated to put into the hands of such a man the means of prosecuting with independence those discoveries which in all after agos were to render his native land illustrious among civihzed nations. Almost the only means of profit held out to scientific men in this country Dr Fleming's History qf British Animaik. 355 is lecturing, — an occupation not always adapted to individuals who are yet well qualified for the prosecution of scientific research. Assuredly it does become the scientific journalist to complain loudly that even this precarious encouragement to science is about to be taken away ; for a system has be- gun of publishing lectures taken for this purpose by professional reporters, who, by attending the same course twice, may copy a lecturer's manuscript, as accurately as if it were before them ; and the law has in due solemnity pronounced that this description of robbers, who prey upon the vitals of science, are not to be molested in their lawful calling in this free country. We have no fears for the progress of science ; but, looking to the shameful ne- glect of their rights in this country, and to the munificent patronage which is extended to scientific men in other countries, we have fears for the share of glory that will fall to Britain. Amidst these complaints, however, it would be unjust in us to forget that in the case of Mr Dalton, the neglect upon which we animadvert was alleviated by his being presented, through the hands of Sir Humphry Davy, with a royal medal, when his own ge- nius had established a fame, which envy could no longer tarnish, and to which royalty could add no lustre. II. — A History qf British Animals, exhibiting the Descriptive Characters and Systematical Arrangement of the genera and species of Quadrupeds , , Birds, Reptiles, Fishes, Mollusca, and Radiata, of the United King- dom ; including the indigenous, extirpated, and extinct kinds, together with periodical and occasional visitants^ By John Fleming, D. D. F. R. S E. &c. 8vo. Edinburgh, 1828. VV E are happy to announce a work on British Zoology by a naturalist so learned and acute as Dr Fleming ; and are so much more pleased with its appearance, that it affords a practical proof of the progress of the study of Natural History in this quarter of the island. Till lately, notwith- standing the Zoological, Botanical, and Mineralogical riches of Scotland, it is rather a singular circumstance that the published works connected with these subjects have been chiefly written by temporary visitors or tourists, whose means of investigation must have been limited in point of time, and their attention distracted by a multiplicity of other objects. With the exception of Sir Robert Sibbald and the first superintendent of the Edinburgh Botanic Garden, James Sutherland, upwards of a century ago, and afterwards the Reverend George Low, a clergyman in a remote district, we scarcely recollect a name belonging to Scotland which is worthy of record as having contributed to the investigation of indigenous Natural History. The first Flora of Scotland was by an ingenious Englishman, the fellow traveller of Pennant ; and the second, much later in point of time, by a Scottish professor, though from the sister kingdom — Dr Hooker, a most able and zealous botanist. In Zoology, Pennant's British Zoology, however incomplete as a scientific catalogue, long stood without & rival. This was followed by the useful Synopsis of Dr Berkenhout, of which two editions were printed ; and in 1807 by the British Fauna of Dr Tiirton. The systems of British Zoology prior to Dr Fleming's work have been S5^ Analysis of Scientific Books and Memoirs, chiefly arranged on the Linnsean model. In the present work, however, the author classes the British animals according to a niethotl of his own. This method, which seems to have heen suggested to hhn by the tables of Ray, he terms the DichoiomouSy or binary arrangement, the principles of which are detailed in a former work, the Philosophy of Zoology. The quinary and circular arrangement proposed by Mr Macleay, and illustrated by Mr Vigors in the class of birds, Dr Fleming conceives " to have origi- nated in metaphysical prejudices," without suspecting that the same ob- jection may be made to his own binary or any other numerical combination. With regard to both, to use the Doctor's own words, " in the various organs and their numerous modifications, belonging to each species, there are characters which enable the physiologist to trace resemblances in struc- ture and function with the organs of many other species ; so that the same animal may occupy a place in many different physiological groups." We observe, besides, that Dr Fleming docs not give, as is. the usual custom, in addition to his generic terms, the names of the authors who first instituted or used them. Different writers have applied the same generic name so variously, according to their peculiar views, that without this indication it is impossible, amidst their conflicting arrangements, to ascertain the identity of an individual species; and in Dr Fleming's work, which has added not a few to the number, even the divisions instituted by himself are left to be discovered by the previous knowledge or sagacity of the reader. But, waiving altogether these considerations, Dr Fleming, from the ta- lent and industry he has brought to the task, leaves far behind all his pre- decessors in the walk of British Zoology. We have received his work too late to be able to state, by comparison with former writers, the new species he has added to the British Fauna, and the corrections he has made on the statements of his predecessors. " He has long (as he states in his preface) been a practical observer of British Animals, or what a friend of the Honourable Daines Barrington used to term an out-door naturalist. This circumstance has enabled him to correct the specific characters of se- veral animals, and to point out with greater accuracy their habits and dis- tribution, to suppress several spurious species, and to give to the syno- nymes, in many cases, a greater degree of precision." Besides this, and which no previous writer on British Animals has attempted in the same degree, the extirpated and extinct species have been enumerated with a precision of detail, which leaves little to be desired in this most important part of the work. The following are the heads under which the species are classed. " The resident animals are such as can accommodate themselves to all the changes of this variable climate. They are the only species which strictly merit the epithet indigenous. " The periodical visitants chiefly belong to the class of Birds. Some of these come from more southern latitudes, to spend the summer and bring forth their young ; while others arrive from more northern latitudes, to escape the rigours of an arctic winter. The vernal shifting, the author has denominated Equatorial Migration, the autumnal shifting the Polar Dr Fleming's History of British Animals. 357 Migration. AW the species of these groups, though intimately connected with the country by the regularity of their visits, enjoy a right of citizen- ship less perfect than the resident animals. " Stragglers, or irregular visitants, have hitherto occupied a higher rank in every British Fauna, than they seem entitled to possess. Driven from their native haunts to this country by some temporary calamity, the per- secution of foes, or the fury of a storm, they have been recorded inconsi- derately as indigenous species. Their occurrence, as serving to illustrate the distribution of species, should be recorded ; but not in such a manner as to assimilate them with the resident kinds, and periodical visitants. Act- ing upon this principle, the author has been compelled to degrade to the rank of stragglers several birds and fishes which have long occupied a more distinguished place. ' " The extirpated animals are such species as still maintain their ground in other regions, but have been destroyed in this country by the long-con- tinued persecutions of man. " The extinct animals are such as once dwelt in this country, but which have disappeared, and, from various causes, seem to have perished from tfff the earth." (P. xiv.) - " In the enumeration of British Animals contained in this volume, the author has referred to the extinct or fossil species so frequently, as pro- bably to have excited surprise in those accustomed to consult the more modern of the British Faunas. He was led to adopt this course, not for the purpose of filling up the chasms in the fancied laws of continuity, but that the attention of zoologists may be directed to an examination of the extinct races, and that the geologist may connect with his studies a knowledge of the character and distribution of existing species." (P. xix.) Such is the plan upon which the work of Dr Fleming is constructed. The number of existing Mammalia described is 60 ; of Birds 237 ; of Rep- tiles 12; of Fishes 170: of Mollusca 597; of Radiata 67; and of Zoophyta 209. The other tribes of invertebrated animals, such as the Crustacea, In- sects, &c. are to form a future volume. A work of this nature forbids any attempt at conveying a knowledge of its contents by analysis. Of the appropriate and useful remarks distribut- ed throughout the book, the following extract, regarding a most important class of animals, may serve as an example. " The migrations of fishes, in compliance with the arrangements of their reproductive system, exhibit the most singular movements, often complex, but always useful toman. Those which inhabit the inaccessible depths of the sea, in ordinary cases, approach the shores, towards the season of spawning ; and, after depositing their eggs in suitable situations, again retire to their inaccessible haunts. The fry occupy for a time their litto- ral birth-place, and then follow the course of the older individuals, though' in several cases the young seem to execute movements different from the full grown fish. Not a few species, as the salmon, which have their ordi- nary residence in the sea, approach, towards the spawning season, the shores, enter estuaries and ascend rivers, where, having selected a suitable place, they deposite their eggs, and again return to the sea. The fry, after 956 Analysis of Scientific Books and Memoirs. a certain period, likewise leave the fresh waters and betake themselves to the sea. Similar movements are executetl by the fish which inhabits lakes. As the spawning season approaches, several species, as the Gwiniad, leave the deep water, and approach the margin ; while others, as the Roach, not only approach the margin of the lake, but ascend the neighbouring streams. — With a few other species, as the Eel, for example, these move*- ments are reversed; the spawning fish leave the fresh- water lakes and rivers, and retire to the sea to give birth to their progeny. " But there are other movements executed by fishes of a more anomalous character, the necessary conditions of which remain to be investigated. The Herring, Pilchard, and Haddock, for example, after frequenting cer- tain parts of the coast for many years, at stated intervals, suddenly with- draw themselves to other stations, to which they had not been accustom- ed to resort. It is probable that these shiftings of fish may depend on the movements of those animals on which they subsist, or on the changes in the quantity of food occasioned by excessive consumption. " The fisheries of this kingdom are objects of vast importance, yet though they have frequently occupied the attention of Parliament, a great deal remains to be done before they be placed in that state of improvement of which they are susceptible. In point of importance, our fisheries pro- bably rank in the following order: 1. Gadusidce, or fisheries having for their object the capture of Cod, Coal-fish, Haddock, Ling, Hake, Tusk. 2. Salmonidoe, including Salmon, Trout, Char, and Smelts. 3. Clupeadce, including Herring, Pilchard, Shad. 4. PleurunectidcBy including Turbot, HoHbut, Flounder, and Sole. 5. Scomberoidoe, or Mackerel. 6. Raiadce, including Rays and Skates. 7. Cyprinidoe, including Carp, Bream, Tench, &c 8. Anguillidw, including the Eel and Conger. " To those interested in the improvement of these fisheries, the fol- lowing remarks may not be deemed out of place. 1. The fisheries sustain much injury in consequence of the capture of fish ready to spawn. No one can witness the exhibition of the large roes of the Cod, Ling, or Had- dock, on the stalls of our fish-markets, without being convinced of the propriety of some legislative enactment (capable of application) to prevent this prodigal waste of our stores, by prohibiting the fishery of each species for a certain time, at the ordinary spawning season. 2. The fisheries are injured by the destruction which takes place in the fry, in consequence of the operations being carried on at improper seasons, or with improper en- ' gines. The injury done to the salmon fishery by the destruction of the fry has been frequently stated to the public, but few seem to be aware of the vast extent of injury to the fry of many kinds of fish, from the use of improper nets, by the trawlers of the Channel Fisheries. On this sub- ject the reader will find some important remarks in Mr Cornish's View of the present State of the Salmon and Channel Fisheries, Lond. 1824. 3. The fisheries might be extended and rendered more valuable by enlarging the system of bounties, or rather, perhaps, by directing them to new objects. The Turbot and Eel fisheries are neglected in many places where they might be prosecuted to advantage ; and hundreds of our fresh- water lakes, which at present are useless and waste, might be rendered productive of Proceedings of the Royal Society of Edinburgh. 359 much wholesome food. It becomes a question of great national import- ance, whether these, and other obvious improvements in our fisherieg, might be most eflfectually promoted, by pubhc statutes, or by Boards fur- nished with suitable powers." Pp. 221, 222. >. Art. XXI.— proceedings OF SOCIETIES- 1. Royal Society of Edinburgh. December 17th. — Conclusion of a Chemical Examination of the Oxides of Manganese. By Dr E. Turner. " A Notice on the formation of Alcoates, definite compounds of Alcohol and Salts, analogous to the Hydrates. By T. Graham, M. A. Jan. 7, 1828. — Francis Walker Drummond, Esq. and Sir W. G. Gordon Cumming, Bart, were elected Ordinary Members. The Vice-President announced to the meeting that the Council had ad- judged the biennial Keith prize to Dr Brewster, for his communica- tions regarding his discovery of two new immiscible fluids in the cavities of certain minerals. The following papers were read : — 1. Account of a remarkable peculiarity in the Structure of Gflauberite, By Dr Brewster. 2. On the Chloro-ferro-cyanic Acid and its Compounds. By J. John- stone, A. M. 3. An Account of the Tracks and Foot-marks found impressed on Sand- stone in a Quarry in Dumfries-shire. By the Rev. Dr Duncan. See this Number, p. 305. Specimens were exhibited. 4. Demonstrations of propositions published by Dr M. Stewart in 1746, at the end of his general theorems. By A. Gallowat. 5. A letter from the Right Honourable the Countess of Morton, to Sir Walter Scott, accompanying a donation of models and plans, &c. connected with the erection of the Eddystone Light House, and which had belonged to the late Mr Smeaton, Civil Engineer. 6. Experimental inquiries concerning the Laws of Magnetic Forces. By W. S. Harris, Esq. of Plymouth. January 21 — 1. Determination of the Longitude of the Observatory of Edinburgh, from observations of the moon and moon-culminating stars. By Professor Wallace. 2. On the Earliest Maritime Regulations of Modern Europe. By John Reddie., LL. D. February 4. — Erskine D- Sandford, Esq. Dr D. Maclagan, James Craw- ford Gregory, M. D-, Sir Alexander Keith, Knight Marischal, and John Frost, Esq. were elected Ordinary Members. 1. A Notice regarding a Mass of Metallic Iron (supposed to be meteor- ic) firom South America. By T. Allan, Esq. 2. On the Natural History and properties of Tabasheer, the siliceous con- cretion found in the joints of the Bamboo* By Dr Brewster. February 18.— -1. Notice regarding a compendious and easy method of 36(X Proceedings of the Society of Arts. performing the operation of Multiplication in Arithmetic. By Professor Wallace. 2. Part 1st of a Memoir on the Geographical position of Ecbatana the ancient capital of Media. By the Reverend J. Williams. March 3 — Captain Maxwell, K. D. G- was admitted an Ordinary Member. 1. A Notice of some experiments on the Absorption of Vapours by Li- quids. By T. Graham, A.M. Printed in this Number, p. 326. 2. Chemical examination of Tabasheer. By Dr E. Turner. Printed in this Number, p. 335. 2. — Proceedings of the Society for Promoting the Useful Arts in Scotland, December 4, 1827. — A Notice by Dr Brewster on the Varnishes from the Varnish Trees of India was read, and specimens of articles varnished with them, and sent home by George Swinton, Esq. of Calcutta, were exhibited. See Number xv. p. 96. An Account of the poisonous qualities of the Indian Varnishes, by Dr Brewster, was also read. See Number xv. p. 100. An Account of the method of blasting rocks in Assam, communicated by George Swinton, Esq. of Calcutta. See Number xv. p. 111. There was also read an Account of the Black Dye of Siam, by Captain Burney. Communicated by George Swinton, Esq. See this No. p. 343. December 19. — There was read a Description of a New Latch Lock, by the Reverend Mr Brodie. The model of the Lock was exhibited. A Pendulum Chronometer belonging to Andrew Waddell, Esq. exe- cuted by Mr David Whitelaw, Edinburgh, was described and exhibited. Specimens of Screws made by Mr Clark were exhibited. There were read Observations on the Low Temperature of Steam escaping from under High Pressure. Communicated by Thomas GrahAm, A. M. An improved Air Pump was described and exhibited, by Mr Dunn. The following gentlemen were elected Honorary Members : Captain Parry, R.N. John Oldham, Esq. of the Bank of Ireland. Mr John P. Bertram, Clyde Street, was elected an Ordinary Member. Dr Hugh Colquhoun, Glasgow, and Mr Thomas Clark, Glasgow, were elected Associate Members. January 9, 1828. — There was read a Notice of a method of manufac- turing the Nepaul Paper, Communicated by George Swinton Esq, Mr J. W. Johnston of Durham was elected an Associate Member. January 23. — An Account of a New process for obtaining Absolute Al- cohol, by Thomas Graham, A. M. was read. A Farther account, by Dr Wallich, of the manufacture of the Nepaul Paper was read. Specimens of this paper in its natural state and as rc- manufactured at Calcutta were exhibited. There were exhibited to the Society impressions of Drawings executed on Talc. Communicated by George Swinton, Esq. An account of an Engine for cutting the tools for grinding Lenses, by the Right Honourable Lord Oxmantown, was read. The Right Honourable Lord Oxmantown was elected an Honorary Member ; — and Thomas Graham, A. M., and Mr Dunn, Optician, were elected Ordinary Membew. Astronomy. 361 Feb- 6. — The following gentlemen were elected Honorary Members:— S. P. RiGAUD, Esq. A. M. F. R. S. Savilian Professor of Astronomy, Oxford. — G. B. Airy, Esq. Lucasian Professor of Mathematics, Cambridge. — Rev. W. Whewell, M.A.Trinity College, Cambridge. The following papers were read. Observations on the formation of Ice in India. By David Scott, Esq. See this Number, p. 216. Notice respecting a powerful Aromatic Oil obtained from Malwa in India, from a particular species of grass. Mr LizARS exhibited impressions of Engraving on different kinds of paper, including the Nepaul Paper exhibited at last meeting of the Society. Mr L. reported that the coarser kind of Nepaul Paper is well adapted for the purposes of Engraving. Feb. 20. — Observations on Street Railways. By Mr Alexander Scott, Ormiston, were read. A Description of a Method of cutting leading Screws, exhibited at a for- mer meeting, was read. Drawings of the Apparatus employed were ex- hibited. By Mr J. Clark- The Working Model of a Hydraulic Engine by Mr Ruth yen was ex- hibited. A Notice regarding the proper forms of Taps and Dies for cutting me- tal Screws. By John Robison, Esq. F. R. S. was read. Sir John Seppings was elected an Honorary Member. Robert Aytoun, Esq. and James Tod, Esq. were elected joint Secreta- ries of the Society, in room of Dr Turner and Professor Wallace, who retired- March 5. — There was read a Notice of the qualities and adaptation of a species of Stone brought from Caithness. Communicated by Sir John Sinclair, Bart. Specimens of the Stone were exhibited. The masses of stuff from Nepaul for making paper having now arrived, were exhibited. Mr Edward Sacy, Teacher of Mathematics, was elected an Ordinary Member. Art. XXII.— SCIENTIFIC INTELLIGENCE. I. NATURAL PHILOSOPHY. astronomy. 1. Eclipses of Jupiter s Satellites observed at Wilna. By M. Slawinski -The longitude of Wilna is 1^ 41' J 2" east of Greenwich. Sidereal time. 1825, Jan. 17, Im. I. 4^ 0' 23".7 good observation. March 22, Era. II. 8 51 51 .9 very good. April 23, Em. I. 10 44 23 good enough. May 5, Em. I. 12 29 38 .7 very good. 1826, May 8, Em. J. 15 31 56 .1 middling. June 2, Em. II. 16 46 0 .1 middling. 1827, March 18, Im. I. 16 1 14 .9 a little doubtful. April 18, Im. I. 16 46 15 .2 passable. 36£ Scientific Intelligence. 2. Occultaitoiu of Stars observed at Wilna. By M. Slawinski. .00* A -1 t T • f^"*- ^^^ 8' 55".2 very precise. 1825, April 1, e Leonis, 1 1?_ 1 1 i^r ,.. « vii 1 , «, ' *^ ' (Era. 11 15 14 .2 a little doubtful. 23, Star (Mag. 8, 9,) Ira. 11 22 29 exact. 1826, Feb. 15, 208 Tauri, Im. 6 && 58.8 good. 1827, March 18,A Librffi, Im. 17 4 55.9 good enough. 3. Occultatton of Saturn observed at Wilna. By M. Slavtinski. 1»2C, Feb. 16, Saturn, 1st Ansa, ^3^ 11' 58".8\ 1st Limb, lm.\ 3 12 8 .8 > Sidereal time, Ob- f 3" 11 5 3 12 C3 U 2d Ansa, CS U 48 .3 J servation good. 4. Occultatton of the small star of the double star of0 Scorpii, observed by Mr Riddle. — At Greenwich Hospital, in longitude 8" west of Greenwich Observatory, and in latitude 51° 28' 53"north, the small star of /S Scorpii was eclipsed by the southern dark limb of the moon, on the 25th September 1827, at 6^ p. M., but the larger star was not eclipsed at all. — Ann. of Phil. June 1828, p. 26. 5. Comet of June 1827. — The elements of this comet computed by M. Benj. Walz of Nismes are, Passageof Perihelion 1827, - - June 8. 336 Mean time for Midnight at Paris, Perihelion Distance, - - ^ - » 0.808 Long, of Perihelion, - - - 297° 34' 18" Long, of Node, 31814 48 Inclination of Orbit, - - - - 43 37 48 Motion, retrograde. 6. Comet of September 1827 similar to that of 1780.— M. Walz has given the following elements of this comet. Passage of Perihelion, Mean time from Midnight at Paris, Perihelion Distance^ Long, of Perihelion, Long, of Node, Fnclination of Orbit, Motion, retrograde. OPTICS. 7. Luminxms Appearance of the Sea near Prince of Wales* Island.-^ Nothing is more singular in these seas than their phosphorescent appear- ance by night, the ocean showing, like a vast lake of liquid fire, melted sul- phur or phosphorus. In many bays, such as the harbour at Prince of Wales' Island, the bodies which emit this singular light exist in such vast quantity that a boat may readily be distinguished at the distance of several miles by the brilliant light, resembling that of a torch, proceeding from the water, agitated by her bow and oars* We have seen the sea rendered of a Sept. 1827. Sept. 1780. D. D. 11.565 30.2589 0.157 0.099256 254 => 15' 52" 246° 21' 18" [50 26 25 124 9 19 54 53 30 53 18 15 Optics-^Meteorology. 3^ green colour and slimy appearance by day, so that it might have beeii mistaken for the green vegetable matter common on stagnant pools. We have taken up a quantity of this green- coloured water, and by keeping it till night, have ascertained that the green colour by day, and the phosphores- cent appearance by night, were occasioned by the same substance. ' The causes of this luminous appearance in the sea are doubtless various in different parts of the ocean. We know that fish, when dead, afford si- milar light, and experiments have shown that dead fish immersed in sea water, after a time, afford it also. The spawn of fishes is said to afibrd it, and putrefaction is considered as a very common cause of this appearance. In the present instance it appeared unequivocally to proceed from innumer- able granular gelatinous bodies, about the size of a pin's head. These, when taken upon the hand, moved about with great agility for a second or two, when they ceased to be luminous and remained immoveable. — Finlaysons Account of Siam, 8. Magnificent achromatic Telescope executed in Paris.-— "SVe have late- ly been informed by one of our scientific countrymen now in Paris, that M. Lerebours, an eminent French optician, has executed an achromatic tele*' scope with an aperture of twenty -four inches, and a focal length of twenty-' five feet. The object glass is made of M. Guinand's glass. The telescope cost 4-0,000 francs (about L. 1670,) and the stand about 10,000 francs (L. 415) making in all about L. 2080. It has been now above three months in the Observatory, but no good opportunities for observing with it have occurred. Whether this grand instrument turn out well or ill, its execution does honour to the spirit and genius of the French nation, and to the monarch in whose reign it has been made. METEOROLOGY. 9i Red Main, supposed to arise from Butterflies. — The following nar- rative seems curious and important in connection with the various accounts of red rain. It is extracted from Gassendi's Life of Peiresc, p. 110-113. *' Through the whole of this year (1608) nothing gave M. Peiresc great- * er pleasure than his observations upon the bloody rain, said to have fallen about the beginning of July. Large drops were seen both in Paris itself upon the walls of the cemetery of the greater church, which is near the walls of the city, upon the walls of the city, and likewise upon the walls of villas, hamlets, and towns for some miles round the city. In the first place, M. Peiresc went to examine the drops themselves, with which the stones were reddened, and spared no pains to obtain the means of convers- ing with some husbandmen beyond Lambesc, who were reported to have been so astonished at the shower, as to leave their labour and fly for safety into the neighbouring houses. This story he ascertained to be without foundation. To the explanation offered by the philosophers, who said that the rain might have come from vapours, which had been raised out of red! earth, he objected that evaporated fluids do not retain their former hues, as is plainly exemplified in the colourless water distilled from red roses. Nor was he bett* satisfied with the opinion of the vulgar, counte- nanced by some of the theologians, who maintained that the appearance 364 Scientific hitelligence. was produced by demons, or witches, shedding the blood of innocent babes. This he thought was a mere conjecture, scarcely reconcileable with the goodness and providence of God. In the meantime an accident happened, which discovered to him, as he thought, the true cause of the phenome- non. He had found some months before a chrysalis of a remarkable size and form, which he enclosed in a box. He thought no more of it, until, hearing a buzz within the box, he opened it, and perceived that the chry- salis had been changed into a most beautiful butterfly, which immediate- ly flew away, leaving at the bottom of the box a red drop of the size of a shilling. As this happened about the time when the shower was supposed to have fallen, and when a vast multitude of those insects was observed fluttering through the air in every direction, he concluded that the drops in. question were some kind of excrementitious matter emitted by them, when they alighted upon the walls. He therefore examined the drops again, and remarked, that they were not upon the upper surfaces of stones and buildings, as they would have been, if a shower of blood had fallen from the sky, but rather in cavities and holes, where insects might nestle. Besides this, he took notice that they were to be seen upon the walls of those houses only, which were near the fields, and not upon the more ele- vated parts of them, but only up to the same moderate height at which the butterflies were accustomed to flutter. In this way he explained the story, told by Gregory of Tours, of a bloody shower seen at Paris in the time of Childebert, at different places, and upon a house in the vicinity of Senlis ; and another said to have fallen in the time of King Robert about the end of June, the drops of which could not be washed out by means of water, when they had fallen upon flesh, garments, or stones, but might be washed out from wood ; for the time here stated was the season for the butterflies ; and he showed that no water could wash out these red marks from stones. After discussing these and similar arguments in the presence of much company at the house of his friend Varius, they deter- mined to inspect the appearance together, and, as they wandered through the fields, they saw many drops upon stones and rocks, but only in hollows or upon sloping surfaces, and not upon those which were presented to the sky." The butterfly observed by Peiresc was probably the Papilio C. al- bum, or common butterfly. It has been observed to deposit the same red fluid in England. . 10. Waterspout seen on the Lake of Geneva, lith August 1827. — This meteor was seen by Professor Mercanton at 6^ 52'. A portion of a dark cloud suspended below the summit of the Savoy mountains, suddenly took a vertical direction, and being gilded with the deep orange tint of the set- ting sun, it attracted universal att'cntion, and enabled the spectators to trace all its movements. Its form was that of an inverted cone, the sum- mit of which was about 200 feet from the surface of the lake, to which it precipitated itself in less than two minutes. This elongation of the cone took place by an oscillatory motion. This part of the spout appeared cylindrical, and its diameter was about ten or twelve feet. The moment it reached the lake a great mass of the water was briskly agitated as if it had been boiling, the boiling foam rising to a height of more than fifty feet. , Electricity-^Chemistry. 365 1'his large column of water was inflected like a riband exposed to the wind. In eight minutes it reached the mouth of the Rhone, and as long as it was above the river, the boiling continued and the column was un- broken. When it quitted the river the boiUng ceased, and the whole soon disappeared, the base of the cone continuing longest visible.— ^zZ*/. Univers. October 1827, p. 142. ELECTRICITY. 11. Different effects of an electric discharge in Magnetising different needles. — M. Savary, whose electrical discoveries we have already noticed in No. X. p. 369, has recently foun^, that when a number of needles are electrified by a single discharge, some of them are rendered slightly magne- tic, some highly so, and others not at all. For any discharge of determi- nate strength, the distance performs the principal part. The magnetic vir- tue goes on decreasing to a certain distance, then it disappears at a given distance ; — it then increases progressively, is again extinguished, and again increases. The distance requisite to produce the maximum and minimum degree of magnetism depends on the strength of the discharge. M. Savary has likewise determined the effects produced by the interposition of screens. —Le Globe, 26th January 1828. 12. On the variable conducting powers of bodies for Electricity. — Profes- sor Delarive of Geneva has found that the degree of conductibility of bodies for electricity depends on the quantity of electricity which traverses them, so that of two conducting bodies, that which is the best for one electric current may be the worst for either a stronger or a weaker current. 13. M. Becquerel on the Pyro-electricity of the Tourmaline. >— On the 22d January 1828, M. Arago communicated to the Academy of Sciences the following fact respecting the Tourmaline discovered by M. Becquerel. " While the tourmaline is of a certain length it is electrical by heating and cooling ; in a greater length it ceases to be so by heating. In taking cry- stals of different lengths, the phenomena diminish in intensity, and those crystals which are eight centimetres (three inches and l-9th) are neither electrical by heating nor cooling. If this law is inversely true, that is for very small lengths, the atoms of the tourmaline ought to acquire a considerable electrical polarity by the smaU lest changes of temperature." The powerful pyro-electricity of Tourmaline in the state of i\ie finest dust has been long ago described by Dr Brewster, who has pointed out the 'singular contrast between this unexpected property and those of magne- tical and doubly refracting structures. — See this Journal, No. ii. p. 212. II. CHEMISTRY. 14. Analysis of the Gas obtained from the Body of a Cow, inflated in consequence of feeding too freely on Green Food. By M. Plugkr.-^Ac- cording to the observations of M. Pluger, the gas derived from this source had the following properties : — Kit was colourless, and of a very disagreeable odour. 2. It burned slowly with a feeble bluish flame. On plunging a lighted VOL. VIII. NO. II. APRIL 18^. A a 366 Scientific Intelligence. taper into ajar of the gas, the light was extinguished ; but the gas itself was set on fire, and the taper might be rekindled by passing through the flame of the burning gas. , 3. On agitation with lime water, the solution became turbid, and the gas lost three-fifths of its original volume. By the action of ammonia it underwent the same diminution. 4. The gas remaining after the action of lime water or ammonia burn- ed slowly with a blue jflame, and extinguished a lighted taper as before. 5. With atmospheric air it formed a mixture, which was not explosive, but burned tranquilly with a blue flame. Mixed with oxygen gas, it is said to have afforded a similar result, and that the product of the combustion rendered lime water very turbid. 6. A mixture of 100 measures of the gas and fifty of oxygen, fired by the electric spark, yielded 100 measures of carbonic acid gas. From these experiments it is inferred by M. Pluger, that the gas extract- ed from the cow consisted of three-fifths of carbonic acid, and two-fifths of carbonic oxide gas. The air procured from another cow similarly affect- ed, was found to contain four-fifths of carbonic oxide, and one-fifth of car- bonic acid gas. The Editors of the Annals from which this note is taken remark, that the results of M. Pluger differ entirely from those obtained by MM. Fre- my and Lameyran, and published in the Bulletin de Pkarmacie, (t. i. p. 358.) According to their experiments, the gas procured from a simi- lar source is composed of Sulphuretted hydrogen gas, 80 Carburetted hydrogen, 15 Carbonic acid, 5 100 We agree with the editors that this subject requires further elucidation. A mixture of carbonic acid and carbonic oxide gases could not occasion the very disagreeable odour ascribed to the gas by M. Pluger, nor does that gentleman appear to have tested for the presence of sulphuretted hy- drogen.— Annales des Sciences Naiurelles for June 1827. 15. Singular action of Phosphoric acid on Albumen.-^Iti his essays on the animal fluids Berzelius stated, that a solution of albumen is not precipi- tated by phosphoric acid ; whereas Engelhart, in his interesting researches on the colouring matter of the blood, found that albumen is coagulated even in a dilute solution by phosphoric acid. As Engelhart was at Stock- holm last winter, he and Berzelius inquired into the cause of difference in their statements, and discovered that they were both right. A solution of phosphoric acid, which had been kept some time in the laboratory, did not precipitate a solution of albumen ; but phosphoric acid, recently pre- pared either by the action of nitric acid on phosphorus or by direct combus- tion, caused an abundant precipitate. On further examination, it was found that phosphoric acid, recently ignited, always throws down albumen ; but that after being kept in solution for a few days, it loses that property. The coagulating power is restored by heating the acid to redness, but dis- appears again after the interval of a day. 3 Chemistry. S67 The cause of these phenomena is by no means apparent. It does not de- pend on a higher degree of oxidation, for the change ensues in close ves- sels equally as by exposure to the air. Perhaps, says Berzelius, there may be some peculiar compound of water and the acid, which is not formed at the moment of solution, and which has not the property of precipitating albumen. — Annates de Chimie et de Physique^ xxxv. 110. Remark on the preceding notice by Dr Turner. — On comparing the facts observed by Berzelius and Dr Engelhart, with the formation of the pyrophosphate of soda, described by Mr Clark in the 14th number of this Journal, it appeared probable that phosphoric acid heated to redness may be converted into pyrophesphoric acid, or undergo that change which en- ables it to form a white salt with silver. To put this supposition to the test of experiment, some fragments of phosphorus were treated in a plati- num crucible by nitric acid, and the product heated to redness. The so- lution of the resulting pure phosphoric acid precipitated a dilute solu- tion of albumen ; but when carefully neutralized by carbonate of soda, and then mixed with a solution of the nitrate of silver, the common yellow phosphate subsided. Consequently, it was not in the state of pyrophos- phoric acid. 16. On the MdHhJhchh df BrbMne. — M. Balard, to whom we are in- debted for the disfcovery of bromine, and for the knowledge of its most re- markable properties, has established a manufacture of that substance for sale. In consequence of the improvements which he has introduced into his pro- cess, he is able to sell bromine at the following prices : 4 francs the drachm, 14 francs the half ounce, 23 francs an ounce. — An. de Ch. et de Ph. xxxv. 111. 17. Researches on the Fermentation of Curd and on the Caseous Oxide and Caseic Acid. By M. Henri Braconnot. — Of the curd of skim-milk, spontaneously coagulated, 750 grammes were mixed with about two pints of water, and exposed in an open vessel for the space of a month to a tem- perature varying from 20° to 25°C. The putrefaction having fully attained its height at the end of that time, the process was discontinued ; and M. Braconnot states, that all the products of spontaneous decomposition are obtained in this manner as completely as by waiting for a much longer pe- riod. The whole products were put into a filter of linen, through which passed a liquid very slightly coloured, which reddened litmus paper, gave no indication of the presence of sulphuretted hydrogen or carbonate of am- monia, but contained an appreciable quantity of acetate of ammonia. This liquid, on being concentrated by evaporation, yielded a product of a very fetid odour, owing apparently to the presence of an oily substance. To- wards the close of the evaporation vapours of acetic acid passed over, and a liquid of the consistence of syrup remained, which concreted on cooling into a granulated reddish mass like honey, and of a saline bitter taste. Treated by alcohol of 37°, it was separated into parts, the one soluble and the other insoluble. The former was erroneously regarded by Proust as the caseate of ammonia, and to the latter he has, with equal impropriety, applied the name of caseous oxide. 36& Scientific Intelligence. ■ 18. Caseous Oxide. — To obtain this substance quite pure, it is necessary, after washing it well with alcohol, to treat it with animal charcoal, and dissolve it several times in boiling water, from which it is separated by eva- poration. In this state it is a beautiful white powder, inodorous, and of a slight bitter taste. It is heavier than water, and is soluble in fourteen parts of water at 22° C. On allowing the solution to evaporate spontaneously, the caseous oxide crystallizes either in the form of elegant dendritic rami- fications, or in rings composed of delicate acicular crystals of a silky lustre. The aqueous solution of caseous oxide exposed to a moderately warm temperature runs easily into putrefaction. The liquid becomes turbid, de- posits whitish flakes, and emits an exceedingly offensive odour, like that evolved during the decomposition of the most highly azotized animal prin- ciples. The product of the fermentation does not act as a ferment to sugar. ^ The aqueous solution of pure caseous oxide yields with infusion of gall- nuts a white flaky precipitate, soluble in excess of the precipitant. The persulphate of iron, and muriate of lime, and baryta, occasion no change. The muriate of platinum and sulphate of alumina act in a similar way, proving the absence of an ammoniacal salt. The sub-acetate of lead gives a white precipitate. Caseous oxide is more soluble in muriatic acid than in water. Boiling alcohol, as Proust observed, takes up very little ; and of that which is dissolved a part is deposited on cooling in the form of a light white powder. The caseous oxide takes fire when strongly heated, and burns with flame without leaving any residue. Heated in a glass retort, it fuses and swells up at a temperature higher than 212°F. On raising the heat gradually, the caseous oxide was not sublimed, but a large quantity of the carbonate and hydrosulphate of ammonia was generated. At a still higher temperature, a quantity of fatty matter was distilled of the consistence of suet. If, in- stead of distilling the caseous oxide, a small fragment of it is placed in a tube open at both ends, and suddenly heated by the blowpipe flame, it is al- most entirely sublimed without change, but is easily decomposed by a re- newal of the heat. The presence of sulphur in caseous oxide is demonstrated by the forma- tion of sulphuretted hydrogen ; and it is further proved by rubbing a piece of silver with it while heated, when the sulphui'et of silver is formed. When decomposed by nitric acid it does not yield any oxahc acid, as Proust states. M. Braconnot obtained a yellow fluid oil, and a yellowish liquid of a bitter styptic taste, in which he detected ammonia and sulphuric acid, but no oxalic acid. M. Braconnot has not made the ultimate analysis of caseous oxide ; but from the facts above enumerated, it obviously possesses the characters of an animal substance. He states with Proust that it contains very little oxygen, and is of opinion that caseous oxide is a very improper name for it. M. Braconnot considers it to be formed during the putrefaction of all ani- mal matters, and proposes to call it aposepedine, from «»-o and such as sulphate of magnesia or sulphate of lime, burn a portion of it in a silver or platina crucible, or even in a clean tobacco-pipe. Any earthy salt, or any matter indestructible by heat, will of course remain in the lOikly, To ascertain that the sulphate of quina contains the proper quantity of sulphuric acid and quina, dissolve a little in pure muriatic or nitric acid, and add a solution of muriate or nitrate of barytes ; 60 parts should give about 17.3 to 17.4 of sulphate of barytes; or the method may be varied without the trouble of drying the precipitate. Dissolve 60 grains of sulphate of quina in water slightly acidulated with muriatic or nitric acid ; add a solution of 18 grains of nitrate of barytes, and separate the precipitated sulphate of barytes by filtering. If nitrate of barytes be 4XM Scientific Intelligence. now added to the clear solution^ it should still occasion slight precipitation, for 60 of sulphate of quina contain 5.8 gr. of sulphuric acid, equivalent to 19.1 of nitrate of barytes. This test is only to determine that there is no crystallized vegetable patter uncombined with sulphuric acid in the sulphate of quina ; the de- tection of earthy or alkaline sulphates has already been provided for. llthly. Sulphate of quina should lose not more than from 8 to 10 per cent, of water by being heated till deprived of its water of crystallization. Mr Barry informs me that he once examined a sample which contained more than 40 per cent, of water in excess diffused through it. 26. A New Method of Separating Manganese from Lime and Mag' nesta* By Professor Stromeyer. — We are informed in a letter from Professor Stromeyer, that he has found the following method successful in procuring the complete separation of manganese from magnesia and lime. To an acid liquid containing the peroxide of iron together with manga- nese, lime, and magnesia, the carbonate of soda is added in the usual man- ner, so as to precipitate the first, while the three latter oxides are held in solution by an excess of carbonic acid ; and in order to prevent any man- ganese from falling, the actual precipitation of the iron is effected by the bicarbonate instead of the carbonate of soda. After acidulating the filter- ed solution and concentrating it by evaporation, a current of chlorine gas is transmitted through it. On neutralizing the free acid by the gradual addition of bicarbonate of soda, the manganese subsides in the form of the red oxide, being thus completely separated from the magnesia and lime. III. NATURAL HISTORY. ZOOLOGY. 27. Baron Ferussacs Work on the Cephalopodous Mollusca. — A complete Monograph on the Natural History of Cephalopodous Animals, is now pre- paring for publication at Paris, by Baron Ferussac. The work is in folio, and is illustrated by numerous drawings, taken chiefly from a very exten- sive series of specimens in the possession of that distinguished naturalist. Much confusion still prevails in the Natural History of this highly inter- esting and remarkable tribe of molluscous animals, both in regard to the characters of the species, and the synonyms employed by authors, which we have no doubt will be removed by the labours of Baron Ferussac, who has described an immense number of species, and has been at great pains to examine the objects described. IV. GENERAL SCIENCE. 28. Royal Medal adjudged to Sir H. Davy. — The Royal Society of Lon- don has adjudged one of the royal medals to Sir H. Davy, for his method of protecting the copper of ships' bottoms. 29. Medal adjudged to M. Struve.-^The Royal Society has adjudged a gold medal to M. Struve of Borpat, for his observations on double and multiple stars. Celestial Phenornena^ April-^tfuly 1828. 375 30. Copley Medal adjudged to Br Prow^— The Royal Society has adjudg- ed a Copley medal to Dr Prout, for his mode of analysis of animal and vege- table substances. 31. Copley Medal adjudged to Lieutenant Foster. — The Royal Society has adjudged a Copley medal to Lieutenant Foster, fpr h|s observations pn the magnetical needle and the pendulum at Port Bowen. 32. Medal adjudged to Sir Thomas Brisbane. — The Astronomical So- ciety has adjudged one of their medals to Sir Thomas Brisbane, for his valuable astronomical observations made in New South Wales. 33. Keith Medal adjudged to Dr Brewster. — The Royal Society of Edin- burgh has adjudged the Keith medal to Dr Brewster, for his discovery of two new fluids in the cavities of certain minerals. Art. XXIII.— celestial PHENOMENA, From April \st, to Juy Ist, 1828. Adapted to the Meridian of Green- wichj Apparent Time, excepting the Eclipses of Jupiter's Satellites, which are given in Mean Time. N. B. — The day begins at noon, and the conjunctions of the Moon and Stars are given in Right Ascension. APRIL. D. H. M. 1 17 30 2 8 2 33 4 4 15 45 5 20 6 10 14 7 0 6 7 12 41 7 23 57 8 33 13 12 13 21 18 13 21 17 14 14 15 15 16 23 25 16 23 56 19 15 14 20 14 2 21 17 18 21 22 22 10 35 22 11 53 27 15 56 29 10 25 29 10 44 29 11 29 10 I 29 14 25 29 15 36 8 56 17' N. in Quad. 0 58 Ira. I Sat. y. 28 Im. T. Sat. 1/. (( Last Quarter. 30 Im. II. Sat. y. 26 ]) (5 /3 nje ]) 39' N. ? d A « 23 Im. I. Sat. 7/ 0 New Moon. I Sun Eclipsed Invisible $ Greatest Elong. 26 Im. II. Sat. 7/ 1 1) c5 1'^ « 57 P d 2 cT b ^ 0 enters b 25 Im. I. Sat. 7/ ^ First Quarter jp: Quad. 0 37 ^ d 1 « 2S 20 p ci 2 rt 25 31 Im. I. Sat. 11 1 Im. I. Sat. 7/ O FuU Moon. 38 Em. III. Sat. y. 61 ]) d 2 «t 25 ]) 69' N MAY. 4 Em. II. Sat. 7/ ^6oK 41' N. 49' N. 23' N. 2"N. 9 14 43 10 17 8 12 9 12 15 13 9 50 14 7 44 15 10 49 19 D. H. M. S. 6 H Stationary. 6 5 32 ^Last Quarter. 6 14 26 54 Em. J. Sat. 1/. 8 8 55 38 Em. I. Sat. $ 9 14 b d«^n 48 Em. II. Sat. TJ. 51 J) d ^ K ]) 59' N. |d? 0 New Moon. 53 ]) d «^ « D 44' N. 48 Em. I. Sat. y. 9 Greatest Elong. 20 15 34 0 enters n 21 11 n ]) First Quarter. 22 12 44 12 Em. L Sat. y 22 12 § d A b Sup. c5 0 d2* i^ d« n 58 Em. II. Sat. y 28 20 17 QJ'ullMoon. 30 ^ Jitationary. 31 Near 4 f 31 9 7 16 Em. I. Sat. y JUNE. 11 57 10 ]) d ^ TIJ }) 29' N. 20 § d 132 « 11 47 39 Em. II. Sat. y . 10 18 21 Em. III. Sat. y 112 (( Last Quarter. 11 1 50 Em. I. Sat. 7/ 23 24 17 26 15 27 4 27 9 376 Celestial Plienomena, April— ^July 1828. D. H. M. s. D. H. M. s. 9 10 ^d*n 20 2 52 }) First Quarter. 11 12 10 22 Im. III. Sat. l^ 21 0 n C^ enters Qs 11 23 12 0 New Moon. 22 21 Vdv 16 1 30 40 ]) c5 1 « SQ 1) 40' N. 42 1 c5 2 a SS B IC N. 27 5 Greatest Elong. 16 2 48 27 3 48 O Full Moon. 17 12 ^6h 30 11 14 32 Em. I. Sat. V 18 17 6 6- t 30 15 6 se Times of the Planets passing the Meridian. APRIL. Mercury. Venus. Mars. Jupiter. Saturn. Georgian. D. h. / h ' h ' h / h ' h 1 22 36 2 34 17 9 13 58 6 15 19 31 7 22 25 2 40 16 59 13 33 5 54 19 9 13 22 22 2 47 16 48 13 9 5 33 18 48 19 22 25 2 53 16 36 12 44 5 13 18 33 25 22 32 3 0 16 22 MAY. 12 19 4 52 18 5 1 22 43 3 5 16 8 11 53 4 31 17 42 7 22 58 3 10 15 52 11 27 4 10 17 18 13 23 18 3 14 15 39 11 1 3 49 16 55 19 23 44 3 17 15 15 10 34 3 28 16 31 25 0 9 3 17 14 53 JUNE 10 8 3 7 16 7 1 0 45 3 15 14 26 9 37 2 42 15 38 7 1 12 3 10 13 59 9 10 2 20 15 13 13 33 3 3 13 31 8 44 1 58 14 48 19 1 46 2 52 13 1 8 18 1 37 14 21 25 1 05 2 37 12 29 7 63 1 15 13 57 Declination of the Planets. (VPRIL Mercury. Venus. Mars. Jupit sr. Saturn. Georgian. 1 7 13 19 25 1 7 13 19 25 1 7 13 19 25 4 US. 4 31 3 32 1 27 1 SON. 5 ION. 9 22 13 54 18 21 22 9 24 62 N. 25 28 24 43 23 3 20 51 19 43N. 21 42 23 23 24 42 25 40 26 14N. 26 26 26 16 26 45 24 55 23 38 N. 22 17 20 48 19 19 17 40 23 31 S. 23 41 23 50 23 57 24 4 14 23 S. 14 12 13 59 13 46 13 32 MAY. 24 12 S. 24 21 24 33 24 48 25 8 13 18 S. 13 4 12 50 12 37 12 26 JUNE. 25 35 S. 26 3 26 35 27 7 27 38 12 15 S. 12 7 12 0 11 56 11 55 22 40 N. 22 39 22 38 22 36 22 36 22 32N. 22 29 22 26 22 22 22 18 22 12N. 22 7 22 2 21 56 21 49 20 19 20 17 20 16 20 15 20 19 20 13 S. 20 13 20 14 20 15 20 16 20 17 S. 20 19 20 22 20 24 20 26 The preceding numbers will enable any person to find the positions of the planets, to lay them down upon a globe, and to determine their timeja of risings and settings. List of Scottish Patents. 377 Art. XXIV.— list OF PATENTS GRANTED IN SCOTLAND SINCE NOVEMBERS, 1827. 29. Novembers. For certain Improvements in Bedsteads, Beds, Couches, and other articles of furniture principally designed to be used on ship- board. To Samuel Pratt, county of Middlesex. 30. November 2. For certain Improvements on Bedsteads, and in the making, manufacturing, or forming articles to be applied to or used in various ways with Bedsteads, from a material or materials hitherto un- used for such purpose. To Thomas Breidenback, county of Warwick. 31. November 22. For an Improved apparatus for the better manufac- ture of Sugar from the Canes. To William Fawcett, county of Lan- caster. 32. November 28. For certain processes and apparatus for printing and preparing for manufacture Yarns of Linen, Cotton, Silk, Woollen, or any other Fibrous Material. To Bennet Woodcroft, county of Lan- caster. 33. November 27. For certain Improvements in the Combination and Arrangement of Mechanical Powers applicable to the purposes of driving Machinery, and Lifting and Moving Heavy Bodies. To Lemuel Well- man Wright, county of Surrey. ^ 34. November 29. For certain Improvements in the Combination and Arrangement of Machinery for Making Metal Screws- To Lemuel Well- man Wright, county of Surrey. 35. December 6. For a Cartridge or Case, and method of more advanta- geously enclosing therein shot or other missiles, for the purpose of load- ing Fire- Arms and Guns of different descriptions. To Joshua Jenour Jun. county of Middlesex. 1. January 4, 1828. For an Improvement or Improvements on or in Re- frigerators for cooling Fluids. To Robert Wheeler, county of Bucks. 2. January 4. For Improvements in Safety Lamps. To Thomas Bouner, county of Durham. 3. January 10. For an Improved method of constructing and work- ing an Engine for producing Power and Motion. To William Parkin- son, county of Lincoln. 4. January 17. For a New or Improved method or methods of pro- delling Vessels through or on the water by the aid of Steam or other Me- chanical Force. To William Nairn, county of Mid- Lothian. 5. January 22. For an Improvement or Improvements in making Paper by Machinery. To George Dickinson, county of Kent. 6. January 29. For a New and Improved Method of Ballasting Ships or Vessels. To Ralph Rewcastle, of Newcastle-upon-Tyne. 7. February 13. For an Improvement in applying Heat to the purpose of Distillation. To Robert Stein, county of Middlesex. 8. February 13. For Certain Improvements in that part of the Process of Paper Making which relates to the Cutting. To Thomas Bousor Cromi-ton, county of Lancaster. 9. February 23. For Certain Improvements in Machinery for Propel- ling Boats and other Vessels, which Improvements are also applicable to water wheels and other purposes. To George Jackson, city of DubUn: cr" c . «« «j o ^ o w .S -^ ft CO 3 "*> J" •*- •" ea 3 *ai o ^ o ■ '-' ^ jg g, g Jw s.s w ^ a ° c as fl § « c8 Eh " "= • S «i (u a> B C3 H S o o ^ "5b-s ^ £ o « 2 -2 H P< (< CO W ,S SB'S K ■"* .tS -T3 hi H 5 w ^ ej 2 .S •'' ^ ^ 5 if.- •.a a; o ■5S o S a ^ Ills 2 ^ *-* eo a5t--»o ca i» so O lO !N(£) O 00 JO oi-ioapoiWr 0 "O «0 10 kS K5 »0 »0 K5 ^' ^ i i i 33 o •<*" ti d rt f r~co e5i-ids^ Or-noKi''^ t^t>05 0 dTf" cos<5 t^oooi ir<5K5»K3KiK5HltOK3K5K5,j.K5V>}<^,^>0>Ot<' •uoRjo^ci I l3^tO'»ltfi;Ot— OOOarHrHrH -H , ?ia3AiJo-Q ) cJc«cffaH^h&:cccflgH^Hb:cffcffgh^hb:cncflgH^'Hfa: •urea ^gocjoiojoiajoiajcJioiajaiaiciioiCT) S^ S-) -"i 5^ S-l ?■! 5-1 g4 5-) CM S^ G^ -^1 S^ 3^1 S-l •S^ CM 3-) S^ 3^ &J ffl CN G^ 3-1 to S-l 3^ ?-l 5^ Ig3 iC "O ^O "C lO >c >o t^ d t^ 06 -o Tj! ic »o _ T»K5K3tOG^lOK3K3K5®OlCTt<-0>0'0«5 "OiC lO a Tti'^ '^1 iTriTt"-^Tfo >o>o >.o I l>''*t->C>C>0»0'Oi-lCO»-lCOlOi-IOOOS^r-lr-l050>000. .. !tO'^tCtOlCtOlOtOtO®0>0-«<>0-Ji I to W5 CO 00 00 to UOIM .|0 -Q I i-H S^HO tr "O to r-OC OjO^SvltO'VOCD t—OO Cl ©1-1 G^ to a^SMGJI S)xSH^hb:r/;r^SH^Hfc:--/c/;^H^'" •area >o -o c» — 110 Ot— O0t0l0i-i5003 icpdopdddobdddddddddddco wj '— ' '— ^ '-^ oj ^Aj s^ to to to S^ G^ Q0CT)dO5O535CiO5 O ^» ft— iC OCCOIOCOOOIOCX! t— OlCOr-i 05 lO Cf< t— rt G« * 02 t-^-; rH t-OJ OiqiOt-^OJOJ-HiCOOOOJO-^G^Orl iCUSiCO >o»o ICO 1/5 >C lOiC "C W5 ' Sf 2 :f 5? 2 £? -'S? 5? !!? i2 2 '5^' '-' t^ ^5 "? «■• °o 1^ «» = « ^*^tOf^C'^tOG^tOtO iTj<'Vio-c«to^^^>C'vtoTr"^->t"9"<}<'<#*<-*i-iK5«ioorH05oioooo— II TICtOVV'3'»0'*'Tff33MJO 'Q I wcflSH^H&:cflcngH^h&^cflCft5h'^H&:cr>y;gH^'Hfa:cfi7^'g' INDEX TO VOL. VIII. Abel, Dr, on the crocodiles of the Gan- ges, 338 Absorption of vapours by liquids, 326 Achromatic object-glasses, (double) on the best radii for. 344 — telescope, mag- nificent one made at Paris, 362 Acid of selenium, a new one described, 294 Adie, Mr, his meteorological registers, 188, 378, Albumen, singular action of phosphoric acid on, 366 Alloy, on a new metallic ore, 157 Althein, malate of, on its identity with asparagin, 369 Animals, British, Dr Fleming's History of, 355 Antimony, on its detection in mixed flu- ids, 179 Arago, M. on the Aurora Borealis, and the changes in the magnetic needle, 189 Arseniate of lead, analysis of, 174 Arsenic, on its separation from nickel or cobalt, 370 Artiraomantic(^ a new metallic compound like gold, 157 Audubon, Mr J. J. on. his method of drawing birds, 48 Aurora Borealis, on its sound in Iceland, 170 Auroras, observed in Roxburghshire in 1827, 171 — on their supposed influ- ence on the magnetic needle, 189 Ava, account of the late mission to, 10 Barlow, Professor, on a new fluid tele- scope, 93 Barometer, on the horary oscillations of the, at Rome, 112, 218 Barium, deutoxide of, how to prepare it, 180 Bears of India, 388 Becquerel, M . on the magnetism excited in all bodies, I60--on the electric dis- charge, different effects, 362 — pyro- electricity of tourmaline, 365 Bedsteads, on improved ones, 158 Berzelius, M. on the action of phosphoric acid on albumen, 366 Birds, Mr Audubon's method of drawing them, 48 Blackwall, J. Esq. on the way in which spiders effect their aerial excursions, 153 Blasting rocks, on the Assamese method of. Ill VOL. VIII, Boulder-stones in the north of Germany, 182 Braconnot, Henri, M. on ^he fermenta- tions of curd, 367 — on the caseous ox- ide, 368 — on the caseous acid, 369 Brewster, Dr, on the mean temperature of the equator, 60 — on the properties of Tabasheer, 285 Bricks, on new ones for chimneys, 158 Bromine, on the manufacture of, 367 Bronzing of statues and medals, 158 Burg, the Chevalier, his improvements on the lunar tables, 134 Burney, Captain, on the black dye of Siam, 343 Cagniard de la Tour, Baron, on the changes in vibrating wires, 201 Carbonate of iron, on the argillaceous, 67 — on the assay of the, 250 Caseous oxide, 368— acid, 369 Caves of Monte Testaccio, on their tem- perature, 205 Celestial Phenomena, 184, 375 Chemical Philosophy, Mr Dalton's, re- viewed, 346 Children, J. G. Esq. on the Esquimaux dog, 155 Christison, Dr. on the effects of poisonous gases on vegetables, 140 Chromate of iron, analysis of, 182 Chrysolite in the cavities of obsidian, 181 Colquhoun, Dr H. on the argillaceous carbonate of iron, 67 — on the assay of it, 250 Comets of 1827, 361, 362 Cow, analysis of gas from the body of one, 365 Crawford, J. Esq., account of his mission to Ava, 10 — his collection of fossil bones, 56 Crocodiles of the Ganges, 338 Curd, on the fermentation of, 367 Dalton, Mr, his system of Chemical Phi- losophy reviewed, 346 Despretz, M. on the heat developed in combustion, 173 Disinfecting «oda liquid, experiments on it, 371 Dog, on the Esquimaux, J 55 Double star, on the occultation of one, 36 Drawing birds, Mr Audubon's method of, 48 Dryness, a great one in the Antilles, 171 Dumas on a volatile chloride of manga- nese, 179— on sulphur, 180 Bb 380 INDEX. Duncan, Rev. Dr, on tlie foot-marks of animals in sandstone, 130, 305 Dynamics, on the principles of, as given by French writers, 27 Karth, on the changes in its meteorologi- cal constitution, 311 Eclipse, solar, of Nov. 29, observed at Naples, lfJ6 Electricity, on the variable conducting powers of bodies for, 365 Elephants, Albino ones, 32, 341 — new species of, 156 Equator, on its mean temperature, 60 Exhibition of national industry at Paris, 344 Faraday, Mr, on the disinfecting soda liquid, 371 Farey, Mr, his improved lamp, 157 Ferussac, Baron, his work on the Cepha- lopodous Mollusca, 374 Fleming, Dr, his History of British Ani- mals reviewed, 355 Fossil bones on the Irawaddi, 1 8, 56 Foster, Lieut, on the variations of the needle, 197 Foot-marks of animals in sandstone^ 305 Footsteps before the flood, 130, 305 Fraunhofer, M., on coloured spectra from different lights, 7 Fucus saccharinus, on its collection for the Chinese market, 1 62 Gas lights, natural ones at Fredonia, 1 83 Gases on an apparatus for impregnating liquids with them, 110 Germany, geological map of, 183 Giron, M., on the reproduction of domes- tic animals, 1 55 Graham, Mr Thomas, on the absorption of vapours by liquids, 326 Grant, Dr R. E. on the generation of the Lobularia digitata, 104 Green iron ore, analysis of, 174 Grierson, Mr, on footsteps before the flood, in a specimen of sandstone, 130 Greenstone of the Hattz, 182 Gulwugty, on the Indian pennance of, 44 Habenstreet, M. on a cloth made by in- sects, 343 Hansteen, Professor, his magnetic tour in Siberia, 169 Harwood on a remarkable marine ani- mal, 300 Hpat developed in combustion, 173 Henderson, Rev. Mr, on the sound of ihe Aurora Borealis, 170 Henderson, J. Esq., on the luminosity of the sea, 167 Herschel, .J. F. Esq., on binary systems of stars, 40 Horse, on a polydactylous one, 25 Hydrogen gas from salt mines, 183 Ice, on its formation in India, 216 Ink, indelible, how to make it, 160 Insects, a new kind of cloth fabricated by them, 343 Irawaddi, on the fossil bones on the banks of the, 18, 56, Itby, Hon. C. L. on the city of Petra, 227 Juno, its opposition to the sun, 167 Jupiter's satellites, eclipses of observed at Wilna, 361 Karphosiderite, a new mineral, 181 Kendal, meteorological observations at, 186 Kennedy, Dr R. H. on the Indian pen- nance of Gulwugty, 44 King, Mr James, his apparatus for im- pregnating liquids with gases, 110 Knee-joint of the Echidna hystrix, on a remarkable structure in the, 183 Lamp, on Mr Farey's improved one, 157 Liebig, M. his test for the presence ot nitric acid, 370 Limnoria terebrans, account of its effects, 152 Lightning, on the effects of it on a ship, 203 Lind, Alexander F. Esq; on the meteo- rological phenomena at Patna and Futtehpore in 1826, 244 Littrow, M. on the best radii for double achromatic object-glasses, 344 Lobularia digitata, on the generation of the, 104 Locusts, on their appearance in the Doab, 149 Luminositv of the ocean, 167— near Prince of Wales .Island, 362 Lunar tables, the Chevalier Burg's im- provements on the, 134 Magnet, on the rotation of one about its axis, 170 Magnetism excited in all bodies, 169 Magnetic needles improved, 169 tour in Siberia, 169 needles supposed to be influ- enced by the Aurora Borealis, 189 Malacca, on its mean temperature, 63 Manganese chloride of, on a remarkably volatile one, 179 how to separate it from lime and magnesia, 374 Mangles, Captain James, on the city ot Petra, 227 Marcet, M. F., on the ultimate analysis of vegetables, 178 Marshall, Mr S.^ on the cause of tlie ver- nal winds, 39 — his summary of meteo- rological observations at Kendal for 1827, 299. Medals adjudged, 374 Metallurgy of Iron, Karsteu's, 174 Meteoric stone at Futtehpore 171 Meteorological phenomena at Patna and INDEX. Sd\ Futtehporc, 24G — in the State of New York for 1826, 299 Meteorological register at Kendal, 186 — at Canaan Cottage, 188 Mica from New Jersey, 182 Mineral spring near Wakefield, analysis of a new one, 370 Mitscherlich, Professor, on a new acid of selenium, 299 MoUusca, Cephalopodous, new work on, 374 Mooring ships, new method of, 159 Nash, Mr, on the fascination of snakes, 159 New York, results of meteorological re- gisters in the State of, 299 Nitric acid, test for the presence of, 370 Occultation of stars observed at Wilna, 361— .of Saturn, 361— of the double star of y6 scorpio, 361 Parry, Captain, on the variation of the needle, 197 Patents, list of Scotch ones, 184, 377 Petra, account of the excavated city of, 227 Phillips, Mr R., his method of ascertain- ing the purity of the sulphate of quina, 373 Playfair, Dr G., on locusts in the Doab, 149 Plisson, M. on the identity of the malate of althein with asparagin, 369 Pluger, M. his analysis of gas from the body of a cow, 365 Pouillet, M., on the rotation of a magnet about its axis, 170 Prince of Wales's island, on its mean temperature, 63 — luminosity of the sea near it, 362 Pyro-electricity of the tourmaline, 365 Quina, sulphate of, how to ascertain its purity, 372 Radiant heat, Mr Ritchie on, 136 Rain, red, from butterflies, 363 Reproduction of domestic animals, 155 Ritchie, Mr W., on radiant heat, 136 Royal Society of Edinburgh, proceedings of, 164, 359 Schow, Professor, on the changes in the meteorological constitution of the earth, 311 Scoresby, Rev. W., on the effects of lightning on a ship, 203 Scott, D. Esq., on the formation of ice in India, ,2 16 Screw nails, on the adhesion of, 159 Sea water, how to wash with it, 158 Selenium, on a new acid of, 2^4 Serpent, on a remarkable marine one, 383 Shawls fabricated by insects, 343 Singapore, on its mean temperature, 61 Slawinski, M., his astronomical obser- vations at Wilna, 361 Snakes, on the fascination of, 154 Society of Arts for Scotland, proceedings of the, 360 South, James, Esq. on binary systems of stars, 40 Spectra, on those from star-light, 7 Spiders gossamer, how they effect their aetial excursions, 153 Steam-Boilers, on the explosion of, 160 Steam- Engines, on the great power of some, 160 Stromeyer, Professor, on the separation of manganese from lime and magnesia, 374 St-Hilaire, M. on a polydactylous horse, 25 Sulphur, on the properties of, 180 Swinton, Geo. Esq. his donations to the Mu.seum of the Royal Society of Edin- burgh, 165 Tabasheer, on the natural history and properties of, 285 — Dr Turner's ana- lysis of, 335 Tautolite, a new mineral, 181 Telescope, on a new fluid one, by Profes- sor Barlow, 93 — magnificent achro- matic one made in Paris, 362 Temperature of the Equator, 60 Teredo navalis, on its destructive action on vessels of teak timber, 15 J Testaccio Monte, on the cold caves of, 205 Thomson Dr, his analysis of the pure chromate of iron, 182 Tourmaline, on the laws of its pyro-elec- tricity, 365 Turner, Dr, on the effects of poisonous gases on vegetables, 140— -on the detec- tion of antimony in mixed fluids, I74 — his analysis of tabasheer, 335 Vapours, on their absorption by liquids, 326 Variable Star, on a new one, 167 Varnish of India, 96 — Varnish Trees of ditto, 97 — On the poisonous qualities of these varnishes, 100 Vegetable substances, on the ultimate analysis of, 178 Vegetables, on the effects of poisonous gases on, 1 40 Vernal Winds from the N. E. on the cause of, 39 Vesta, its opposition to the sun, 167 Volcanoes, Baron Von Buch on, 182 Volta, Alexander, life of, I Wallich, Dr, his botanical researches in Ava, 22 Walz, M. on the comets of 1827, 361, 362 382 INDEX. Waterspout seen on the Lake of Geneva, 364 West, Mr W., his analysis of a new mi- neral spring, 370 Whewell, Rev. W. on the principles of dynamics, 27 Wilcox, Mr, on the Teredo navalis, 152 Wires, on the change in their volume while vibrating, 201 Woehler, M. on the separation of arse- nic from nickel or cobalt, 3^0 Zoological Collections, 149, 338 DESCRIPTION OF PLATES IN VOL. VIII. « PLATE III. Fig. I. Professor Barlow's New Achromatic Telescopes, p. 93. Fig. 2. Mr King's Apparatus for impregnating Liquids with Gases, p. 110. Fig. 3. Appearance of the Excavated Houses of Petra, p. 227. Fig. 4, 5. Mr Hiort's Bricks for Chimneys, p. 158. Fig. G. Crystals of Tautolite. PLATE IV. Fig. 1. Diagram illustrating the theory of the Cold Caves of Monte Testaccio, p. 205. Fig. 2. Represents the Joints of the Bamboo, p. 285 Fig. 3. Diagram illustrating a property of Tabasheer, p. 285. Fig. 4. Represents a New and Remarkable Marine Animal,, p. 300. EDINBURGH : PRINTED BY JOHN' STAUK-