U , R. , 1 . ANNALS OF PHILOSOPHY; OR, MAGAZINE OF CHEMISTRY, MINERALOGY, MECHANICS, NATURAL HISTORY, AGRICULTURE, AND THE ARTS. BY THOMAS THOMSON, M.D, F.R.S. L. & E. F.L.S. &c. MEMBER OF TBE GEOLOGICAL SOCIETY, OF THE WERNERIAN SOCIETV, AND OP THE IMPERIAL MEDICO-CHIRURGICAL ACADEMY OF PETRKSBDRGH. VOL. X. JULY TO DECEMBER, 1817. EoiiDon : Printed by C. Baldwin, New Bridge-street ; FOR BALDWIN, CRADOCK, AND JOY, 47, PATEBNOSTEll-ROW. 1817. TABLE OF CONTENTS. NUMBER LV.— JULY, I817. Page Biographical Account of Df. Jean de Carro 1 Suggestions and Remarks on Naval Subjects, on Rigging, on Steering, on the Form of the Rudder, on Anchors : with Observations on the Height of Masts and upper Sails, on the Dry Rot, and on the Felling and Preservation of Timber. By Col. Beaufoy 6 Register of the Weather for Six Months at Malone House and Dublin. By Anthony Semple, Esq 11 On the Cells and Combs of Bees. By Dr. Barclay 14 Account of different Currents of Wind observed at the same Time. By T.L.Dick, Esq IG OnVision. By J. Campbell, Esq 17 Method of preserving Volatile and Deliquescent Substances. By Dr. Dewar ^9 Report made by M. Poisson of a Memoir by M. Hachelte respecting the Running of Liquids through small Orifices, and with Pipes applied to these Orifices 31 Determination of the primitive Form of Bitartrate of Potash. By Dr. Wollaston 3? Appendix to the Essay on the Chemical Compounds of Azote and Oxy- gen. By Mr. J. Dahon 38 Description of an Absence Thermometer. By A. Semple, Esq 47 Critical and Analytical Account of the Transactions of the Royal Society of Edinburgh, Vol. VIH. Part I. I8I7 49 Proceedings of the Royal Society, May 22, June 5, 12, and 19 54 Linnsean Society, May £'4, Junes, and 17 56 Royal Society of Edinburgh, May IQ 3? . Geological Society, April 6, and May 2 58 Royal Geological Society of Cornwall 59 Notice of a Lecture 6I Further Improvements in Professor Leslie's Method of producing Ice ibid. Philosophical Society of London 62 Prize Question by the Royal Medical Society of Edinburgh 63 Query respecting the Diseases of the West Indies ibid. On sailing to the North Pole ibid. Description of a Machine for raising heavy Weights, called a Jack. By Mr. Moyle 65 Query respecting the Mode of freeing Wine from common Salt 66 Proposed Improvement in Brooke's Blow-pipe. By Mr. Barchard ibid. Another Improvement. By Mr. Booth 67 Arithmetical Query 68 Singular Formation found within an Egg. By Mr. Strutt 69 Eff'ect of difl'erent Rocks in Scotland on the Magnetic Needle. By Mr. Webster ibid. IV CONTENTS. Page Fusion of Wood Tin 70 Turkey Oil-stone 71 Black Powder remaining after the Solution of Tin in Muriatic Acid .. . .ibid. Holmite ibid. Account of a very remarkable Mineral Water. By Mr. Garden 72 New Patents 73 Scientific Books in the Press 75 Col. Beaufov's Magnetical and Meteorological Observations for May 76 Mr. Howard's Meteorological Journal, May 8 to June 5 79 NUMBER LVI. —AUGUST. Biographical Account of M. Rochon 81 Appendix to the Essay on the Chemical Compounds of Azote and Oxy- gen. By Mr. J. Dalton, concluded 83 A general Formula for the Analysis of Mineral Waters. By Dr. Murray 93 On the Salts composed of Sulphuric Acid and Peroxide of Iron. By Dr. Thomson 98 Mode of exploring the Interior of Africa. By H. Edmonston, Esq 103 On the Spur of the Ornithorhinchus Paradoxus. By M. H. de Blainville. . 112 Table showing the Quantity of Soda contained in Barilla, &c. By C. Tennant, Esq 114 Table of Differential Equations. By Mr. J. Adams 1 16 Experiments on the Composition and Properties of the Naphtha of Amiano. By M. Theodore de Saussurc 118 Critical and Analytical Account of Cuvier, La Rbgne Animal 127 Mr. Donovan's Essay on Galvanism. . 12g Experiments with the Gas Blow-pipe. By Dr. Clarke 133 Proceedings of the Royal Society, June 26 139 Geological Society, May 16, June 6, and 20 ibid. Royal Academy of Sciences 141 A Descending Spout on Land. By L. Howard, Esq 146 Gum from the Congo 147 Disappearance of Sat\irn's Ring 148 Deuto-sulphuret of Copper ibid. Hydrates of Tin 1 49 Butter of Antimony ibid. Emetin 150 Insects living in a Vacuum 151 New Method of detecting Arsenious Acid, or Corrosive Sublimate, when in Solution ibid. Arragonite ibid. New Analysis of the Meteoric Iron of Siberia 152 Serpent found in Devonshire ibid. Translator of Euler's Algebra ibid. Death of Mr. Gregor 153 Morphium ibid. New Patents, 154 CONTENTS. V Page Scientific Books in the Press 155 Col. Beaufoy's Astronomical, Magnetical, and Meteorological Observa- tions, for June 166 Mr. Howard's Meteorological Journal, June 6 to July 5 169 NUMBER LVII.— SEPTEMBER. Biographical Account of Dr. Ingenhousz. By the late Dr. Garthshore.. l6l Chemical Analysis of Cornish Tin. By Dr. Thomson l66 A general Formula for the Analysis of Mineral Waters. By Dr. Murray, concluded 169 On the Vessels of Plants. By Dr. Wahlenberg 177 Analysis of Rice. By M. Henri Braconnot 186 Memoir on the Sodalite of Vesuvius. By M. Le Comte Borkowski ig2 Chemical Examination of a Quantity of Sugar supposed to have been intentionally poisoned. By Dr. Gorham 197 Experiftiental Researches on the Ammoniacal Salts. By Dr. Ure 30* Report on Hachette's second Memoir on the running of Fluids through various Orifices 21 4 Proceedings of the Royal Academy of Sciences 22 1 Notices of Lectures 227 Ores of Cobalt 228 Register of the Weather at New Malton, in Yorkshire 230 Explosion in a Durham Coal-pit 231 ■ on Board a Coal Vessel 233 Coal in Russia ibid. Query respecting the Matter concreted at the Bottom of Coppers ibid. Experiment of Lampadius ibid. Note respecting the Sugar of the Acer Pseudoplatanus. By Mr. Cadell.. £34 Mineralogy and Geology ibid. Correction of a Mistake in the Epitome of Mr. Solly's Paper given in the Account of the Meetings of the Geological Society. By S. Solly, Esq. 235 Col. Beaufoy's Astronomical, Magnetical, and Meteorological Observa- tions, for July 236 Mr. Howard's Meteorological Journal, July 6 to Aug. 4 239 NUMBER LVII I.— OCTOBER. Description of the Laurus Cinnamomum. By H. Marshall, Esq 241 Suggestions for building experimental Vessels for the Improvement of the Navy, with Remarks on the present Mode of Construction : and some Experiments on the comparative Resistance of Water on differently shaped Solids. By Col. Beanfoy 2.'.6 Elementary Ideas on the First Principles of Integration, by Finite Differences. By Mr. G. Harvey 264 On the Quantity of real Acid in liquid Hydrochloric, and on the Com- position of some of the Chlorides ; with the Description of a new Instrument for the Analysis of the Carbonates. By Dr. Ure 268 5 ti CONTENTS. Page Mode of exploring the Interior of Africa. By H. Eclmonslon, Esp. con- cluded 278 Extraordinary Case of a Blind Young Woman who can read by the Points of her Fingers. By the Rev. T. Glover 286 Proceedings of the Royal Academy of Sciences 290 Curious Effect of Paste on Iron 302 Further Improvements in the Oxygen and Hydrogen Blow-pipe 303 On a Lactometer. By Mr. Johnson 304 On a Rain-gauge. By the Same 305 On preparing Extracts, &c. By the Same 306 Observations on the Nomenclature of Clouds ibid. On the Hedgehog 307 Prizes of the Royal Academy of Sciences and Belles Lettres of Brussels for the Year 1 8 1 8 , .... 308 Translator of Euler's Algebra — Heat generated by the Rupture of Iron Bars 311 External Application of Sulphurous Acid as a Remedy 3 1 a Expanding Rigger 313 Mill-stones ^...ibid. Inverted Rainbow 314 Chemical Equivalents ibid. On impregnating Water with Carbonic Acid by the Syringe of Mr. Brooke's Blow-pipe ibid. Notices of Lectures 315 Col. Beaufoy's Magnetical and Meteorological Observations, for August. . 3l6 Mr. Howard's Meteorological Journal, Aug. 5 to Sept. 2 319 NUMBER LIX.— NOVEMBER. Biographical Account of Dr. Brownrigg. By Dr. Dixon 321 Explanation of the Characteristics d and ?. By Mr. Adams 338 Solution of the Equation 4" x = .r. By Mr. Horner 34 1 Of Cinnamon as an Article of Commerce. By H. Marshall, Esq 346 Description of Mr. Wynn's Timekeeper and Pendulum 365 Improvement in the Oxygen and Hydrogen Blow-pipe. By Mr. Osbrey. . 366 A General Table of the Proportions of dry Muriatic Acid corresponding to progressive Specific Gravities of the liquid Acid ; with Observations on the Law of Progression. By Dr. Ure 369 Improvement in the Gas Blow-pipe ; with some additional Remarks upon the Revival of Metals from their Oxides, and of the Fusion of refractory Bodies, by Means of the same Instrument. By Dr. Clarke 373 Proceedings of the Royal Academy of Sciences 377 Arragonite 387 Barley 388 Malt ibid. Brewing 389 Effect of Lightning on a Tree ibid. CONTENTS. V» Page Register of the Weather at New Malton, in Yorkshire 39O Kidney Bean and Common Bean Perennials 3gi Royal Geological Society of Cornwall S92 Remarkable Action of Paste on Cast-Iron 394 New Scientific Books in the Press 395 Col. Beaufoy's Magnetical and Meteorological Observations, for Sept. . . 396 Mr. Howard's Meteorological Journal, Sept, 3 to Oct. 2 399 NUMBER LX.— DECEMBER. BiographicalAccountof Dr. Brownrigg. By Dr. Dixon, concluded.... 401 Application of Fluxions to Lines of the Second Order or Degree. By Alex. Christison, Esq 417 On the North-West Passage; and the Insular form of Greenland. By Col. Beaufoy 424 On the Cells of Bees. By Mr. Barchard 4^8 Demonstration of a Mathematical Theorem. By Mr. J. Adams 430 On some Points relating to Vision 432 Register of the Weather in Plymouth for the last six Months of I816. By J. Fox, jun. Esq 434 Biographical Sketch of Ventenat 440 Account of the Ballston Waters 442 Critical and Analytical Account of Dr. Marcet's Essay on the Chemical History and Medical Treatment of Calculous Disorders 443 Analytical Account of the Philosophical Transactions of the Royal Society of London for the Year 1317, Part 1 44g Proceedings of the Royal Academy of Sciences 452 Titanium and Tellurium in Sulphuric Acid 464 Service of Plate presented to Sir H. Davy ibid. Case of Miss M'Avoy 455 Mineral Water of Schooley's Mountain ibid. Patent Malt ibid. Atmospherical Phenomeon 467 Aerolite at Paris , ibid. List of Patents 468 Col. Beaufoy's Magnetical and Meteorological Observations, for Oct 47O Mr. Howard's Meteorological Journal, Oct. 3 to Nov. 1 473 Index , 47s PLATES IN VOL. X. Plate Page LXVITI. Table of the Barometer and Thermometer at Belfast and in Dublin, Sept. 1816, to March, 1817 11 LXIX. Currents of Wind l6 LXX. An Absence Barometer, &c 48 LXXI. The Cinnamon Tree 266 LXXII. On the Construction of Ships, &c 258 LXXIII. Dr. Clarke's Gas Blow-pipe, &c 373 LXXIV. On Vision, &c 433 LXXV. The Barometer and Thermometer at Plymouth 434 ERRATUM IN VOL. X. No. LIX. page 258, line 9, for stopped, read stepped. ANNALS OF PHILOSOPHY. JULY, 1817 Article I. Biographical Account of Jean de Carro, M.D. Jean de carro, a physician practising at Vienna, was born at Geneva, Aug. 8, 1770. He is descended from one of the most ancient families of tliat little independent state. Already in the beginning of the IStJi century, members of tiiis family had there filled the highest posts of trust ; had served as distinguished officers in the armies of different ])6wers, .particularly in Russia; and had united themselves by marriage with the other ancient and noble families of Geneva. In the year 17J^0, de Carro, having completed his general studies, went to Edinburgh, a University for which his countrymen had always a great predilection, in order to pursue his medical studies. On June 24, \79S, he obtained the degree of Doctor, after having publicly defended An Inaugural Dissertation de Hydrocephalo Acuto, which was also printed. On returning to his native country, he found it in a state of agi- tation which must have rendered it a most unfit residence for a young man of inquiring mind, desirous of information. He deter- mined, therefore, to pursue his studies at the University of Vienna, at which he entered in the year 179 1. His intention was during a year to profit by all tiie opportunities which the hospital, and the other institutions of this capital, would afford ; and then, prepared with fresh stores of knowledge, to return to his native town. The French revolution, tlie influence of which extended even to Geneva, the change which took place in the government, and the barbarous way in which this change was brought about, induced De Carro to remain in Vienna, to await another order of things, and in the mean time to enrol himself in the medical body of that city. Vol. X. N° I. A 2 Biographical Account of [July, Successful practice, and, above all, his marriage with theTraulein von Kurzbeck, in 1 795, induced him to take up his residence per- manently in Vienna, where, after the customary examinations, he was formally admitted, in I'J^G, as a Member of the Faculty of Medicine. De Carro's scientific connexion with England had scarcely made him acquainted with Jenner's important discovery of the cow-pox, and put him in |)ossession of his work, which appeared in 1798, when he, relying implicitly on the accuracy and skill of Jenner, endea- voured to obtain matter, and resolved to make the first trial upon his own sons, Carl and Peter. These children, then, on May 10, 1799, became the first sulijects of the cow-pox inoculation upon the continent of Europe, and of course in the Austrian monarchy. Two months afterwards he subjected them both, under the obser- vation of physicians who had obtained the public confidence, to the inoculation of the small-pox, which, as was to be expected, was found deprived of all its injurious influence upon the protected children. Moravia was the first province of the Austrian monarchy in which the Graf Hugo Salm, under the direction of De Carro, and by his disinterested assistance, introduced in a short time the general use of the cow-pox inoculation. De Carro was required by the Archduke Charles to draw out a statement and instructions how the vaccine might be best introduced into all the establishments for the children of the military, and par- ticularly those of the frontier regiments. When he had completed this, in a manner suited to the objects in view, the Commander, in a private audience, thanked him, in the name of the state and of the army, in the most flattering terms. On March 10, 1S03, the Imperial Council of War issued an order that the German edition of De Carro's first work upon the vaccine (Observations et Expe- riences sur la Vaccine) should be distributed to all the medical officers of the army, that it might serve them as an instruction and rule. In tliis order the work is styled " the best which has made its appearance upon the subject." After he had propagated the vaccine inoculation, not only through the whole of the Austrian monarchy, but introduced it into many other countries of Europe, and to this end maintained an epistolary correspondence with other countries, in which the Government took upon themselves to promote the beneficial discovery, and commu- nicated his letters to committees named for the purpose; after he had instructed young men gratis, rendered the modes of conveying the matter more simple, and improved them by the adoption of ivory needles ; De Carro determined to introduce the vaccine matter over land into the rich country of Indiii, where the small-pox was feared as the wicked deity presiding over the cradle of infant man — no one having yet succeeded, what care soever had been adopted, in introducing it uninjured, and possessed of its power, when carried by sea. J 81 7] Jean de Cairo. 3 Tlie skilful manner in which he contrived to convey the matter in its fluid state from Vienna to Constantinople, to Bagdad. Bassora, Bushire upon the Persian Gulf, Bombay, Goa, Ceylon, Sumatra, and the chief islands of Asia, is fully described in the work which he wrote, entitled, " Histoire de la Vaccination enTurquie,enGrece, et aux Indes Orientales," The pains which he thus unsolicitedly took, and induced merely by an ardent wish for the good of man- kind, to extend the blessing of the vaccine to the British possessions in the East, obtained for him flattering expressions of thanks from the British Government in that country. In the year 1814 the East India Company voted the sum of 200/. for the purchase of a piece of plate, as a mark of their acknowledgment. The same year the Hon. Jonathan Duncan, Governor of Bombay, sent to De Carro's lady a valuable present of articles of Eastern manufacture. The Hospodar of Moldavia, Alexander Moroust, and that of Wallachia Constantine Pysilandi, into whose states he had introduced the vac- cine, likewise sent him valuable presents. Of all the compliments which foreign countries paid to De Carro, nothing gratified him so much as the present of a simple silver snuff-box which he received from Jenner as his " most deserving follower," on which the name of this benefactor of mankind was associated with that of De Carro in this simple inscription — *' Edward Jenner to Jean de Carro." Jenner gave this mark of his respect and his esteem only to two of his disciples — to the Austrian physician De Carro, as the first propagator of the vaccine on the European continent and in Asia; and to Dr. Benjamin Waterhouse, an American physician of the University of New Cambridge, in North America, who in that quarter of the world did what De Carro had done for the greater part of Europe. In the third part of Jenner's work he speaks of De Carro as the first who out of England had trodden in his footsteps. While De Carro, besides cultivating the knowledge of his pro- fession, kept pace with the other branches of literature, and parti- cularly busied himself in the study of travels, in order that he might learn the peculiar advantages enjoyed by other countries, and devise the means hy which they might be transferred to his own, the name of the dry or mountain rice became known to him, the pecu- liar nature of which is shown by its growing in the cool, dry, and high regions of Asia, instead of the marshy grounds in which rice is usually cultivated. The idea of bringing this plant into Europe, of making it usurp the place of the ordinary rice, and thus putting a stop to all those diseases which afflict the countries where the latter kind is cultivated, inspired his mind, and, with his accus- tomed eagerness, he applied himself to the object. He wrote to the numerous supporters and friends whom he hadabtained in those countries by his correspondence respecting the vaccine, and re- quested not only rice seed, but all those seeds which he could with anv good ground suppose might be beneficial in Europe. All his A 2 4 Biographical Account of tJuLY, attempts were vain to obtain these seeds by the way of Bombay, Bagdad, or Bassora ; but he addressed himself with a more fortu- nate result to Dr. Rehmann, who accompanied, as physician, the great Russian expedition to China. In Kiachta, a small town of Siberia on the borders of the Chinese empire, Rehmann received his friend's request, and fulfilled his wishes with exactness and speed. A more particular account of this plant, and of its culture, is to be found in the Bibliotheque Britannique published at Geneva, to which De Carro has furnished many valuable articles. Great, and scarcely to be anticipated, are the benefits which must arise from the introduction of this Asiatic plant into Europe, as was the case with many of the plants introduced into Europe by the crusades. The older botanists have named this plant Oryza Mutica ; more modern writers, in thankful remembrance of the person who intro- duced it into Europe, the Oryza De Carro. This rice appears only to have answered in the warmer parts of Hungary and of Lombardy. Graf Herbustein, the Vice President of the Council, caused seeds to be procured from De Carro, and several experiments to be made in the Bannat. De Carro, whose mind was ever actively employed in some useful pursuit, was struck with the spirit of patriotism which breathed from every line of a German biographical work recently published under the title of the Austrian Plutarch ; and in order to extend the sphere of its utility, spent some of the tranquil hours which his profession afforded him in translating it into French. This excellent translation, which may boast of the life and energy of an original, was dedicated to the present Archduchess of Parma, at that time the Empress Maria Louisa, who complimented the translator with a handsome snuff-box, as a testimony of the satisfaction with which she had perused the work. The excellent observations of Frederick Schlegel upn this laborious, and in every respect most successful translation by De Carro, in ^he first volume of the TEstereichischen Beobacter for 1810, are very worthy of perusal. Amongst the various services which De Carro has rendered to the Austrian people, it may be worthy of mention that he was the means at different times of procuring large importations of merino sheep from Lancy, which were particularly fit for improving the breed of sheep, and by this means the national wealth. His con- nexion with Carl Pictet de Rochement, a State Counsellor of Geneva, and well known both as a learned man and an improver of the breed of sheep, enabled De Carro to do this. During the Congress of Vienna, Lord Castlereagh requested De Carro, to whom the English language is as familiar as the French, to translate an English work against the slave-trade, in which all the horrors of this trade, so digraceful to humanity, are disclosed. De Carro produced, in a very short time, a translation of this work, to the full satisfaction of the author, as will appear from the follow- ing letter : — 1817.] Jean De Carro. 5 " My dear Sir, Vienna, Nov. 14, 1814. " The Viscount Castlereagh has directed me to convey to you his thanks for the translation which you have made of the abstract of the evidence concerning the slave-trade, and to express to you his entire satisfaction at the able manner in which you liave executed it. " The conviction which this transaction has already created in the minds of the different powers of Europe here assembled in Congress, not only of the cruelty and inhumanity, but of tiie im- policy of this traffic, will, it cannot be doubted, tend very consi- derably to reconcile these powers, who until now have persisted in this barbarous trade, to a more speedy abandonment of it than could have been otherwise expected ; and your name, which is already associated with one of the greatest benefits that mankind has received (from the propagation of the vaccination), will be re- corded amongst those of the persons who have exerted themselves in bringing about the abolition of practices so barbarous and in- famous, that posterity will with difficulty be induced to believe that they could have been sanctioned by any civilized nations of Europe in the nineteenth century. " I have the honour to assure you of the esteem with which " I am, my dear Sir, your very obedient servant, " Francis Petkr Werry, Attached to the mission of Viscount Castlereagh during Congress." The readers of the Bibliotheque Britannique have often observed with pleasure and instruction the zeal with which De Carre em- braces every thing which can enrich science, increase prosperity, or diminish suffering ; and how frequently he has that great, though unfortunately often unacknowledged merit, to be the organ by which unknown truths have been uttered and made known, and thus become useful and effective. It is only necessary to consult for this purpose his letters to the Editor on the subjects of vaccina- tion, the plague, the plica polonica, the science of medicine amongst the Hindoos, on the Guinea worm, on hydrophobia, on meteoric stones, on the thermolampe, on mountain rice, and other foreign plants, and, lastly, his translation of some remarkable his- torical details respecting the castle of Duirenstein, and the confine- ment of Richard Coeur de Lion by Baron Hormays. 6 Remarks on Naual Subjects, [JuLT, Article II. Suggestions and Remarks on Naval Subjects, on Rigging, on Steer- ing, on the Form of the Rudder, on Anchors ; with Observations on the Height of Masts and upper Sails, on the Dry Rot, and on the Felling and Preservation of Timber. By Col. Beaufor, F.R.S. The usual mode of supporting the masts of large ships by cordage is attended with the disadvantage of an enormous pressure on the bottom of the vessel, and in some instances in line of battle ships, that part of the keel immediately under the lower extremity of the mast has been bent downwards several inches, a circumstance not only injurious to the strength, but also detrimental to the sailing of the ship. It is evident the use of ropes will always be productive of this inconvenience, because a sufficient power must be applied in setting up the rigging to stretch the cordage prior to the vessel's going to sea, otherwise the shrouds would become slack, and en- danger the safety of the masts. An 80 gun ship has nine shroads on each side of the main-mast cable laid, and which, if of Captain Huddart's manufactory (whose superiority admits of no competi- tion), and lOi inches in circumference, will bear about 82 tons weight. The power usually employed in setting up each of the shrouds cannot be less than half this weight ; consequently the stress is equal to the total weight all the shrouds on one side would sustain. By measuring the distance of each shroud from the mast, and also the length of the shroud when set up, the angle each shroud makes with the horizon will be as follows : — Shrouds. Angles. Tpns. 1 6S<> 4G' 29-825 2 68 40 29-807 3 68 16 29*725 4 66 58 29-449 5 65 46 ... ; i.". ;; 29- 1 80 6 65 09 29-037 7 62 57 28-500 8 62 01 28-259 9 60 10 27-760 Total 261-545 The first column contains the number of shrouds, 1 being the foremost, and 9 the aftermost. In the second column the angles each shroud makes with the deck are set down : and the third column contains the weight, 32 tons, reduced in the proportion of radius to the sine of the angles 68° 46", 68° 40', and so on. In 1817.] Remarks on Naval SuhjeUs. 7 this calculation the pressure caused by the topmast and topgallant shrouds, backstays, &c. is not included, nor the weight of the masts, yards, sails, rigging, &c. Could any method be devised to reduce this enormous pressure, with equal security to ilie tuast, it would be very advantageous to the vessel. In small ships, iron shrouds have been adopted with success. Constructed of solid links, and made as light as by experiment is found to be of sufficient strength, would still be an improvement, because iron chains con- structed in the usual manner elongate when a heavy strain is applied to their extremities.* It is evident no more power would be requi- site to set up the iron shrouds than is necessary to form a straight line from the mast head to the channels; and when once properly arranged, they would be unaffected by dryness or moisture, two in- conveniences cordage must suffer from inevitably, in spite of tar or any other substance which can be introduced among the yarns. Iron, it is true, will be affected by heat and cold ; but the elasticity of the lanyards would compensate for the expansion and contraction of the iron. Instead of having all the shrouds go over the mast head, the two foremost should be secured to the mast somewhat below the wake of the lower yards. This alteration would be attended with two ad- vantages : first, that in case the mast head was either shot or carried away, two pair of shrouds would be left to support the remainder of the mast : and, secondly, by having these two pair of foremost shrouds below the yards, the yard would brace up sharper. These shrouds also might be placed before the centre of the mast, which would be an additional security to the masts when the sails are braced aback. If the shrouds placed before the mast interfere with the lee leech of the sail when upon a wind, or are found inconve- nient when hoisting things in and out of the ship, they may be set up by runners and tackles. It would be advantageous if the two aftermost pair of shrouds were set up prior to the mast being stayed forward, they would resist a purchase applied to the stay of 15-1- tons, and consequently prevent the mast being crippled by that quantity. A tiller f is preferable to a j'oke or cog wheels to steer with, be- cause it brings less strain on the pintles and gudgeons of the rudder. The tiller may be compared to weighing a heavy body with a steel- yard, and the yoke or cog wheels to weighing it in a pair of scales : it is evident there is more stress on the pivot of a pair of scales than on the pivot of a steelyard with the same weight. The present form of rudders has an advantage which appears not * A circular iron bar one inch in diameter, and six feet long, weighs 15-88 lb. Avoir., and will sustain, when in a vertical position, 24"13 tons hung to its ex- tremity. A fathom of cordage weighs 2G'3 lb. Avoir. If the weight of the rope be called 1000, the weight of the iron will be 6038 ; and if the residual strength of the shroud when sot up be called 1000, tlie strength of the iron shroud will ba i:)08. + The best angle for the rudder to make with the ship's keel is 30', not as de- termined by theory 540 44'. (See .^nnaZs for August, 1816.) S Remarks on Naval Suhjects. [July, to have struck those who propose to get rid of that part which, they have thought, has no power to steer the vessel when making head way ; for one-third of the rudder, counting from the bottom, is probably then the only part which has any effect to govern the vessel; and in full- built vessels, such as Dutch, not more than one- fourth, or even less. When the vessel makes a stern board, the length of rudder immersed in the water should equal the vessel's draft of water, and as much rudder should be above the water as is equal to the heaping up of the water by the ship's stern way. It has often excited my surprise that round headed rudders are not intro- duced in the navy, as tiiey are found to answer in East India ships of 1600 tons, and which at times have been laden with 2000 tons. There appears no reason why men of war should not find them equally serviceable ; for can any thing be more unmechanical than to have a large hole in the counter for the rudder head, which is afterwards closed up with a piece of tared canvass to prevent the water getting in ? It is probable that vessels with low counters by getting stern way in bad weather by losing this piece of canvass have foundered. When large ships lose their rudders at anchor, the accident is attributed to the vessel's striking; but, more possibly, it is caused by the centrifugal force (if the expression may be used) of the ship's suddenly rising after pitching heavily, combined with the resistance of the water to the flat under side of the rudder. If the under side of the rudder were a semicircle, it would offer one-third less resist- ance to the water ; for the resistance of a semicircle as found by experiment is to the resistance of its diameter nearly as 30 to 91. The rudder would be more endangered, hung in the present manner, if it were constructed of lighter materials, or made hollow like a box to increase its buoyancy.* The mode of making large anchors is imperfect, from the impos- sibility of welding the internal bars without burning the outer ones. Cast-iron anchors would be of advantage to the service, as they are lighter, and probably stronger, if their brittleness were not an ob- jection ; but might it not be obviated by covering the crown of the anchor with rope, or some other elastic or soft substance ? The strong prejudice which first existed against iron cables is so much diminished, that they are daily introduced into use. The objections to cast-iron anchors might be equally unfounded: and if every ship ♦ The late Earl Stanhope (whom every lover of science must lament) contrived an equipoise rudder, which was fixed to a schooner rigged vessel, built according to his Lordship's plan, and under his direclion. This rudder, instead of being hung in the usual manner to the sternpost, turned on pivots, fixed (in the first in- stance) to the centre of the rudder, under the idea that the water acting on each side of the rudder would balance it, and thereby take away all strain on the tiller; but on trial it uas found necessary, to produce the equilibrium, that the pivots should be placed one-third of the rudder's length from the sternpost. This proves that an accumulation fakes place on that part of the opposing surface first impinged ; a circumstance, I believe, unnoticed by any writer on the resistance of lluids. 18170 Remarks on Naval Siiljecis. 9 in the navy, and in the East India Company's service, was furnished with an additional anchor of cast-iron, tlie advantages or the con- trary would be fairly ascertained. Some professional men are of opinion that lofty masts have a greater power than short masts to impel ships with a progressive velocity, independently of their setting more sail. But the subse- quent experiment proves the fallacy of this idea. To the head and stern of the model of a cutter, and at equal heights above the sur- face of the water, two strings were attached, each of which passed over very accurate pulleys fixed on the outside of the tub in which the model floated. To the end of each line was hung 8oz. ; and to the weight at the head was added as much more as enabled it to draw the model and raise the stern weight. The line was afterwards taken from the head, and fastened to the mast head ; and the pulley being also raised, the result was the same, except that the stem was immersed three-tenths of an inch more in the latter than in the former case.* Vessels designed like cutters to carry large aftersails and small head ones must be built to draw much more water abaft than for- ward ; for it is the lateral resistance of the water abaft against the thin and extended surface of the vessel which counterbalances, without much use of the helm, the power of the mainsail to turn the vessel's head to wind. Therefore Euler, and other theoretical writers on ship-building, are mistaken in supposing the difference of the draft of water of the head and stern counteracts the impulse of the sails to depress the head or bow. In some of the ships of the navy built of British oak, the dry rot has commenced in the treenails made of American wood ; a cir- cumstance that deserves attention, to ascertain by experiment if all foreign woods used for treenails produce the same mischievous con- sequences, which should especially be guarded against, considering the price and scarcity of English oak. With the view of determining this point, it is proposed to perforate a large and sound piece of Eng- lish oak with several holes, and drive into them 11 treenails of each different kind of wood fit for ship-building, and number them one, two, three, &c. Annually let one treenail of each sort of wood be driven out and examined, and a memorandum made of the state and appearance, &c. of everyone, beginning with No. 1, and so on in succession. This plan should be inverted, and logs of foreign timber undergo the same trial. The reason for naming the number eleven is because that is the average period a ship in the navy lasts ; but when that is said, it must not be supposed at the end of that time the ship is decayed or worth nothing, but only during eleven years as much money has been expended on the ship in repairs as would have rebiiilt it. The short duration of a vessel in the navy naturally leads to the • Probably an additional quantity of canvass, by having sqiiarer yards in the topgallant and royal sails, would answer better than having loftier saili. 10 Remarks on Naval Subjects. [July, inquiry to what extraordinary circumstance is the durability of the Royal William of 80 guns to be attributed. It was launched in i7iy, had no repairs till 1757. and was broken up in 1813, a period of 94 years ; and even then many of the original timbers were found undecayed, and which were made into snuff-boxes and other trinkets, highly prized by the curious as an uncommon in- stance of durability. It did not appear when the vessel was taken to pieces that any unusual mode was adopted to preserve the timber; and the enigma must be solved by referring to documents for the means taken in seasoning timber employed in ship-building at that time. About the latter end of the reign of James II. it appears three different modes were adopted in felling of timber : — 1. In the spring of the year, when the sap was risen, and the trees began to bud, they were cut down and barked ; consequently the sap was left in the trunk. 2. The tree was barked first, and then left standing until the winter, when it was felled. 3. The tree was cut down in the winter time. It appears an order was issued in 1687 or 1688 for 150 trees in Bushey Park to be stripped of their bark in the month of April, and left standing until December. The result, however, does not appear to be known. If, therefore, these experiments were repeated by any gentleman resident in the country who is felling trees for building or repairing, he would essentially serve his country; and by communicating the result in the different durabi- lity of the timbers to the public, merit the gratitude of our sailors and the naval world at large. In our naval arsenals the usual manner of keeping timber is by piling the trees horizontally one over another, which prevents a free circulation of air, and the under trees are frequently injured by the exuding moisture and the dripping of the rain from the upper ones. Notwithstanding the labour, it would finally be more economical if the timber were placed in a vertical position with proper supports to rest against, and pieces of plank nailed on the top of each tree, which would prevent it splitting, by securing it from the action of the sun and frost ; and if the bottom were protected by standing the trees on a sloping pavement of flag stones. Formerly ship planks had the requisite degree of curvature ,^iven them by the action of fire, which to a certain degree charrer* the wood. The modern system of bending the planks by steam is cer- tainly more expeditious ; but the former method has been practised from time immemorial to preserve timber exposed to air and mois- ture, and on that account should be preferred. The durability of the ship would compensate for the trouble and expense, if the surface of the component parts of the frame, &c. were charred be- fore they were put together. These hints, and those in the third volume of tlie AnJials of Phi- losophy, p. 470, the writer trusts may induce others to improve on them for practical advantages to our navy and merchantmen, Stale of theB.VROMETEK a.,i| THERMOM ETER ,at >L\LONE HOIT S^ iieai-BELFAS'C.^"i Hi 1) ITBLIN; fr.un S,-ptemb.r Z^. "'^ 181G, t „ AWcli 2(J 'h 1817. J""-/'-!!. I MJI. ^^'*'"' Navenibep. BakomiJtek. Decdmber. 'FeVinaaiy. Majvh.. 18170 Register of the Weather at Malone House andDulUn. 11 Article III. Register of the JVeather for Six Months, at Malone Home and DuhUn. With a Plate (LXVIII.) exhibiting the Variations of the Barometer and Thermometer at each place. By A. Semple, Esq. (To Dr. Thomson.) MY DEAR SIR, Malone House, May 2, 1817. My nephew, Mr. Moore, of Dublin, and I, have for some time kept a comparative register of the barometer, tliermometer, and weather; the scale of which, from the autumnal equinox of ISIS to the vernal one of this year, I now send you, in hopes that it may be thought worthy of a place in the Annals of Philosophy. This station is situated about three English miles WSW of Bel- fast, in the county of Antrim; 98 English miles (by the road) NE of the city of Dublin ; and is about 143 feet above the level of the sea, the other station being about 30 feet above the same level. The column of mercury in both barometers has been (through- out) reduced, to what it would have been at 32° Fahr. Believe me, dear Sir, yours very sincerely, ANTHONy Skmpi,e. Seplemler, 1S16. 23. 24. 25. 26. 27. 28. 29. MALONE HOUSK. Cirrus aud Cirrostratus. Eve clear. N. Cirrus. 9 P.M. a luminous arch, E to W. S. Fine day. Cumulus. SE. Rain and hail. Eve fine. NW. Hazy, with frequent showers. NW. Hazy and showery. SSE. Constant rain in forenoon. WSW. DUBLIN. 30. Showery, with hail. WSW. Very fine morning. Very fine day. Very fine day. Hazy morn. Rain, nooq. Fine morning. A fine day. Violent rain in first part. Showery. October. 1. Nimbus, with showers. WSW. 2. Rainy morn. Fair eve. W. 3. Fair. Beautiful Cirrocumuli. ESE. 4. Incessant rain. WSW. 5. Fair. Showers at night. WSW. 6. Fair. Showers at night. SE. T. Hazy morn. Clear eve. E. 8. Rain, morn. Hazy eve, E. 9. Hazy, with frequent showers. E, 10. Hazy morn, with showers. W. 11. Hazy morn. Fair eve. Nearly calm. W. 12. Hazy, with light air. SW, 13. Fine morn. Evening, showers. SW. 14. Fair. Beautiful Cirrocumulus. SW. 15. Hazy, but no rain. WSW. 16. Fair morn. Eve, heavy rain. WSW. n. Hazy, with showers. WSW. W. Hazy morn. Little raiu. Dark day. W. Cloudy morn. SE. Dark damp day. Fine morn. Wet afternoon. S. Cloudy, and very wet. E by S. Wet morn and eve. Fair noon. Eby S. Wet morn, after light showers. ESE. Wet morn, after light showers. Es£. Damp cloudy morning. E. Fine day. Cloudy eve. W. Very fine day, W. Very fine day. W. Very tine day. W. Very fine day. Very bright. Sby W. Hazy morn. Wet eve. NW. Bright morn, and fine day, SW 12 Register of the Weather for Six Months [Jutv, October. MALONE HOUSE. DUBLIN. IS. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20, 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. Fine day. Cumulus. NW. Cirrocumulu.'!. Blowing hard. WNW. Cumulus. Blowing very hard. NW. Cirrncumnlus. Showers. NW. Blowing fresh, with showers. WNW. Squally, with showers. SSW. Hazy, with frequent showers. SSR. Hazy, with frequent showers. SSE. Morn, heavy rain. Eve, showers. SE. Hazy, with some showers. ESE. Cumulus and Cirrocumulus. £. Hazy and showery. E. Hazy. Blowins; hard. ENE, Fair. Blowing fresh. ENE, Bright morn, and fine day. W. Fine day, not bright. SW. Fine day. Rain at night. SW. Briglit morn, and fine day. SW. Fine day. Brisk wind. SW. Bright morn. Wet eve, SW. Bright morn. Wet night. SW. Showery. Night fair. SW, Very wet day. SE. Dark hazy d.ny. E. Fine morn, after showers. E. Cloudy morn: rain after. E. Cloudy morn. Wet eve. E. Shower, morn. Eve cloudy, E, November. Fine day. A slight shower. E. Cumulu?, with slight showers. WSW. Hazy, with showers. ENE. Cumulus and Cumulostratus. ENE. Dark weather. No rain. ENE. Fine morn. Eve, heavy showers. Var, Morn, snow lies three inches. NNW. Bright morn. Snow showers. WSW. Showery. Blowing very hard. N by W. Showers of snow, lies 4 in. NNE. Blowing very hard, with rain. Var. Blowing hard, with rain. NW. Blowing hard, with rain. NW. Blowing very hard, with snow. WNW. Blowing very hard, with rain. NNW. Blowing fresh. Cumulus. NW. Morn, rain. Eve fair, WSW. Morn, showers. Eve fair. WNW. Morn, showers. Eve fair. WSW. Fair. Clouds various, SW, Fair. Clouds various. SSW, Fair. Clouds various. SSE, Fine day. Clouds various. ESE. A dark day. ESE. Morn, showers. Eve fine. W. Eve, showers, and blowing fresh. SW. Eve, crimson Cirri. Var. Dark weather. Little wind. NNW. Fine day. Cumulus, NNW. Dark weather, W. NW, W. Bright morn. Fine day. W. Bright morn. Fine day. W. Wet morn. Fine afternoon. W, Fine day. Rain at night. NE. Very hazy day. E. l''ine morn. Showery eve. Fine day. W. Fair day. SW. Showery and windy. NW. Bright day. N. Showery day. Storm at night. Var. Hazy day, SW. Bright morn. Wet eve. Dark, with sleet. W, Dark, with rain, W. Fine. Continued rain. W by S, Bright morn, and fine day. Hazy morn. Fair day. SW. Fine day. Stormy night. S. A fine day. S. Bright morn, and fine day, SE, Fine day. SE. Fine day, S. Fine day. SVi. Day fine. Night stormy and wet.SW. Day fine. Night windy. SW. Very fine. SW. Fine day. Hazy at sea. W. Fine day. W. W. December. 1. Dark weather, with hare. W. 2. Hazy, with some rain. NW by N, 3. Hazy, with alight breeze. NNW. 4. Hazy, with a light breeze, SW by S. 5. Blowing hard, and constant rain. SSE. 6. Dark, with haze. W by N. 7. Bright morn. Dark eve. W. 8. J'ine day. Cloudless. ENE. 9. Morn, constant rain. Var. )0, Bright morn. Eve wet. SW. Weather fair. W. Weather fair. W. Weather fair. W. Cloudy. Storm at night. E. Very wet and stormy. E. Some rain and blowing. W, Blowing, bright morn. SW. Day fine and bright. W. Day very wet. Night fair. W. Stonn, with heavy shQwcrs, S. 18170 at Malone House and Dublin. 13 December. MALONE HOUSE. DUBLIN. 11. 12. 13. 14. 15, 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. SO. 31. Lightning. Snow showers, WSW. Fine day. Snow lies 1^ in, WNW. Rain and snow, Var. Frequent showers of sleef, Var. Fine day. Cloudless. WNW. Dark, with snow showers. \V. Hazy, with some rain. SW. Hazy. Aurora Boreal is. Var. Cloudless sky, NE. A fine day. WNW. Dark, with rain in evening, SW. Bright morn. Rain in evening. NW, Dark, with frequent showers. SW. Dark, with frequent showers. SW. A fine day. WSW. Fine morn. Eve, snow, WSW. Cumulus. Some snow. AV. Morn, consiant rain. Eve fair, SW. Fine day. Cumulus. WSW. Dark, with sleet. Var. Dark, with rain. SE. A little snow, morn. S by W. Fine morn. Wet eve. E by S. Little snow. Cloudy. W to S by W. Morn frosty. Heavy rain. Fair. Fair, with frost. Fine day. W. A few slight showers. SW. Fine day. W by N, Thick fog. Dark day. W by N. Fine day. W by N. Fine day. Night, storm. SW by W. Rain and mist. SW by W. Slight rain, SW. Bright morn, aud fine day. S. Wet day. S, Showers of sleet. Var, Rain and great storm. SW. Bright morn, and fine day, Var, Showery. E. A fine day. E. January^ 181 J I. 2. 3, 4, 5, 6. 7, 8. 9. 10. 11. \i. 13. 14. 15, 16. 17. 18. 19. 20. 21. 22. 23. 24, 25. 26, 27. 28. 29. 30. 31. Cumulus and Cirrocumulus. SW. A fine day. Cumulus. W. A fine day. Cumulus. W. Morn, incessant rain. WSW. Dark, with showers. W by S. Fine day. Clouds various. W by S. Fine day. Cumulus. WNW. Fine day. Cumulus. WSW. Fine. Cumulus, Cirrocumulus. WSW. Hazy, with a little rain. SW by W. Cumulus and Cirrocumulus. W. Cumulus and Cirrocumulus. W. Morn, rain. Eve dark. WNW. Morn fine. Eve, snow. W. Fine day. Cumulus. NE. Morn, sleet. Eve fair. W. Dark, with frequent showers. WSW. A fine day. Cumulus. SW. A fine day. Cumulus, SW, Nearly incessant rain, W, Fair morn. Eve, showers, Var, Hazy, with a few showers. W. Hazy, with a few showers. SW. Hazy, with a few showers. SW. A fine day. Clouds various. SW. Ddrk, with constant rain. SW. Fine. Cloudless day. SW. Dark, with showers in morn. SW. Fine. Cirrostratus. W, Fine. Cirrostratus. W. Dark. WSW. Some showers. SW. Some showers. SW. Some showers, SW. . Fine. Sand Var. after W. F'ine. Changed from SSW to W by S . Fine. W by N. iMne. WSW. Fine. S by E. Fine. S by E. Fine. S by W. Fine, Var. Fine. W by S, A little rain. W by S, Fine. W by S. Some snow. NE, N, NW. Snow : afterwards rain. W. Fine, after light rain. S, Var. Fine, after light rain. SW, Wet day, SE. A little rain. W. Fine day. Night stormy, SW. Day fine. Eve, rain. S by W. Day fine. Eve, rain. Day fine. Eve, rain. Day fine, live, rain. Little rain. Cloudy. F'ine. S by E. Very hazy, W. Very fine. W by S. Very fine. W. Very fine. W. SW. SW. SW. February. Rather dark. Cumulus. WNW, Dark, with fog. WSW, Ilazy, with slight showers. WSW. Fine bright day. W. Fine, but cloudy. W. Fiuc, and bright. Night stormy. 14 Register oftJie Weatlier at Malone House arid Dublin. [JoLr, 4. 5. 6. 7. 8. 9. 10. II. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 1. 3. 4. 5. 6. 7. 8. 9. 10. II. 12. 13. 14. 15. 16. 17. 18. 19. 20. MALONE HOUSE. Felruary. DUBLIN. Blowing hard, with snow. WSW. Cirrostratus. Rain in evening. NW. Hazy, with squalb and snow. WSW. Squally, with showers. WSW, Squally, with showers. WSW. Gloomy weather. WSW. Constant rain. NE. Blowing hard, with rain. W by N. Fine. Blowing fresh. NW by N. Showers. Blowing hard. SW by W. Snow, rain, sleet. Blowing hard. Var. Showers. Blowing very hard. SW. Blowing fresh, with lightning, SW. Blowing fresh, with lightning. WSW. Blowing fresh, with lightning. WSW. Showery, with lightning. Var. Showers of snow, and lightning. Var. Constant snow and sleet. WIS W. A shower at noon. NW by N. Blowing hard, with showers. NW by N. Fine morn. Eve, showers. NW. Fine morn. Eve, showers. WSW. Blowing fresh, with showers. WNW. Storm. Thunder, lightning, rain. NW, Dark, with showers, WNW, Showery, Night fair. S. Morn fair. Eve, rain. WSW. A very little rain. WSW. Fine day. Blowing night. WSW. Day fair. Eve and night wet. WSW. Very fine, WSW. Morn fair. Eve, heavy rain. WSW. Showery, Stormy night. WNW. Day fine. Eve wet. WNW, Wet morn and eve. SW. Morn bright. Night wet. W by N. Strong wind and showers. SW. Fair. WSW. Fair. S. Fair day. Wet night, S by W. Fair day. Wet night. S by W. Showers. W by S. Showers of hail and rain. SW. A fine day. W by N. Morn cloudy. Eve, rain. W by N. Fair. W by N. Rain at night. SW. Storm, with thunder. W by N, Cloudy. W by N, Fair. W by N. March. Squally, with hail and rain, W, Snow, rain. Blowing very hard. SSE. Heavy showers. Blowing a rank storm. SW. Showers of snow, lying 2i in. Fine morn. Showers in eve. Fine morn. Showers in eve. Dark, with showers of snow. Severe showers of snow and hail. NW. Blow ina; fresh, with snow. NW, A fine day. WNW. A fine day. Cumulus. A fine day. Cumulus, A fine day. Cumulus, A fiue day. Cumulus. Fine, with a few drops of rain. SSW. Fiue. Eve, a little rain, SSW. A fine day. Cumulus. NNW. Dark. Eve, blowing fresh. SW. Squally, with hail and snow, NW, Squally, with bail and snow. N. WNW. WNW, W. WNW, WNW. NW by W. NW by W. SW. Fine. S. Cloudy. Showers and wind. S. Cloudy. Showers and wind. S. Bright, with showers. W. Bright, with showers. SW, Cloudy. Showers and hail, W. Bright. Cirrus. A shower. W. Bright. Some sliowers. W. Bright. Some sliowers. NW. Bright. A shower. W. Cloudy morn. Stormy night. SSW. Hazy morn. W. Hazy morn. Fair day. W by S. Grey morn. Fair day. SSE. Very fine day. SW. Cloudy, but fair. SW. Fair day. SE. Morn, Stratus. Day fine. E. Cirrocumulus. Hail, snow. WSW. Day fiue. Snow at night, WSW. Article IV, On the Cells and Comls of Bees. By Dr. Barclay. (To Dr. Thomson.) MY DEAR SIR, In your April number of the Annals of Philosophy letters of Mr. R I see two VV. Barchard on the cells and combs of bees and 1817.] On the Cells and Comls of Bees. IS wasps. In the first of these letters Mr. Barchard observes, that he has been for some length of time in the habit of keeping bees, to which he has paid great attention, and considers it very much against the general economy of the bee to suppose they should be- ?to\v the time and pains in making separate, i. e. double partitions, when single ones would suffice, particularly as bees appear to enjoy every thing in common. From this mode of reasoning, were the matter to be settled merely by hypothesis or verbal discussion, would not his opponent be entitled to argue that as bees are so sparing of their time and pains, it must also be very much against their general economy to construct a separate cell for each ovum or egg, as one large cell might suffice, particularly as they appear to enjoy every thing in common. Birds, quadrupeds, and by far the greatest number of insects, find one apartment perfectly sufficient for all the members of their young families ; why should not bees, if so very sparing of their time and pains, be equally economical ? If not, perhaps their industry and passion for labour, which induce them to construct a separate cell for each ovum, may also incline them to construct a double partition between each cell. In my notice concerning the combs of bees and of wasps, pub- lished in the first part of the second volume of the Wernerian Transactions, a notice to which Mr. Barchard alludes, I merely stated what appeared to be the fact, and what, on repeatedly break- ing several pieces of bee and of wasp comb before the Society, ap- peared to be the fact to every gentleman who happened to be present. As the combs, however, appeared to be old, had seem- ingly contained a young brood, and had even been for some time exposed to the weather, Mr. Barchard infers that what we took for a part of the partition was a thin web which the young brood had leit in the cell, and which was afterwards stuck to its sides. Had this been the case, the partition, instead of appearing double, should have appeared triple at least ; and if each cell had twice con- tained brood, the partition should then have been five fold. And indeed Mr. Barchard says that they may sometimes be divided into several leaves, one of the conclusions that necessarily follows from his hypothesis. Yet he made an experiment to support his conclusion, though he happened to forget it when he wrote his first letter. Now, from making the experiment, I should infer that he entertained some doubts about the foundation on which his conclusion rested ; and from his forgetting to mention this experiment in his first letter, that he had still less confidence in his experiment than in his hypo- thesis. Nor is it to be wondered at. His experiment was this. He melted a quantity of virgin comb in hot water, below the boiling point, and it left no residuum. And afterwards a quantity of old comb, which once had brood in it, and it left a residuum. Of the cause of these diflerent results, he finds an explanation in his hypo- thesi?, that the original partitions between the cells are single, and liG Different Currents of JVind at the same Time. [July, appear double only from the webs attached to their sides. It is not impossible that this may be the fact ; but certainly neither his reasonings nor experiment are in the least calculated to prove it. As for the experiment, who would ever think of melting down the materials of a watch to ascertain what had been its structure. If Mr. Barchard should ever be inclined to resume his inquiries, I should wish him to proceed, without any hypothesis, to direct ob- servation and to varied experiment, and to try, among other things, what particular effects a shorter or longer exposure to the weather would produce upon virgin or young comb. I am hapj)y to think that the subject has already engaged his attention ; and if he prosecute it by minute and patient investigation, he may be assured that I shall readily and willingly adopt any conclusion that comes warranted upon the genuine principles of induction. And am, my dear Sir, yours truly, Edinburgh, Jpril 28, 1817. JoUN BARCLAY, Article V. Account of different Currents of Wind observed at the same Time. By Thomas Lauder Dick, Esq. F.R.S. Edin. (To Dr. Thomson.) SIR, Reliigas, May 21, 18\1. In the couse of my ride the other day, I was very much struck with a beautiful, and very singular manifestation, of the existence of opposite currents of wind at different altitudes, which I have endeavoured to represent accurately in the subjoined sketch. (Plate LXIX.) Some furze on an eminence, at several miles distance, had been set on fire, and the smoke, after curling up- wards, was caught by the under stream of wind, and carried sea- ward, in a direction from east to west. After having been driven for several miles towards this quarter of the sky, by gently and gra- dually rising in its progress, it came at last within the influence of a counter current, at a higher elevation, blowing directly from west to east, wliich drove it hack at an angle so very acute as to resemble the sharpened point of an arrow, and presenting the i'ormal and mechanical appearance I have represented ; defining almost mathe- matically the line which separated the two opposite, or upper and under streams, from one another, and which is marked in the sketch by the dotted line, a, h. This upper current was evidently blowing stronger than that beneath it; for in defiance of the natural buoj'ancy of the smoke, it was compelled to proceed in its new direction, with much less deviation from the horizontal line than it had done in the former. It was, therefore, retained longer under the dominion of the new power to which it was subjected. But, . ( 1817.] On different Currents of Wind at the same Time, 17 rising gradually at last beyond this, and above the dotted line c cf, it was assailed by a new current proceeding from the south-east, which carried it, though apparently with less violence, an immense way towards the north-west, until it was at last entirely dissipated. The sky was every where clear at the time, and there was a perfect calm near the surface of the earth. Many facts illustrative of the theory of contrary currents of air might perhaps be collected by kindling daily fires, on some gentle eminence, in the middle ol a vast plain, whilst several observers should be stationed at dirteront points and elevations, to record their various observations on the a[)pearance of the snioke, at stated and simultaneous periods, and afterwards to compare these carefully together. But the obvious difficulties attendiiig the arrangement of such a series of experiments would at once seem to destroy any hope of realizing them. It may happen, however, that what I have here accidentally remarked, may induce some of your readers who may happen to live in the vicinity of a smoke, proceeding from a fire continually kept up for the purposes of some manufacture, in a situation favourable for such investigation, to establish and record a set of curious observations, which may afterwards prove of no mean importance in the science of atmospherology. I am. Sir, your obedient humble servant, Thomas Lauder Dick. Article VI. On Vision. By John Campbell, Esq. of Carbrook, F.R.S Edin. After the abortive labours of so many of our most acute philo- sophers, and the desponding conclusion to which they in general have come, an attempt to explain the phenomenon of vision as connected with the mode of affecting the nerve may probably ex- pose the person who makes it to the imputation of something more than temerity. Were we to judge, indeed, from the hopeless tone of acquiescence with which Dr. Reid, and, still more lately, Dr. Paley, state the hypothesis that the information received hy the eye is communicated by means of pictures formed on the retina, whilst they acknowledge that the mode in which these pictures operate oa the organ is altogether inexplicable, we would infer that the inves- tigation of the subject ought in prudence to be abandoned. In this respect, accordingly, it seems really to have been abandoned, for the theory of the pictures is almost universally received as the established law of vision. Unappalled by these circumstances, but not insensible to the warning they suggest, or the diffidence with which it becomes me to dissent from such opinions, I venture to submit to you a view of Vol. X. N° I. B Ig On Vision. [July, the nature of sight, as far as the mode of afTecting the nerve is con- cerned, which appears to me to explain, in a simple and satisfactory manner, the various phenomena connected with it j and which has this recommendation also, that it developes a unity of principle among all the senses. It can scarcely be necessary to premise that it is not my intention to enter into any discussion of the question, how the information received by the eye is communicated to the mind. That, indeed, would be a hopeless investigation. Although we know, perhaps, as much of mind as we know of matter, yet as we cannot comprehend modes of action which are not analogous to those which have fallen under the observation of our senses, we can form no conception of its structure or operating principle. We have not, therefore, any one datum on which to found even an hypothesis concerning the mode in which mind reciprocally acts and is acted upon by matter. Every thing we observe, in contemplating the human frame, leads to the conclusion that the nerves are the immediate agents wiiich convey information to the mind, and transfuse or excite the living energies throughout the body. Beyond this conclusion, applied to some portion of matter (if the nerves be not that portion), we cannot go; and, therefore, all that we can expect from the most successful physiological research is to obtain an intelligible explana- tion of the problem how the different organs by which sensations are excited are adapted to produce on the nerves which are ramified upon tliem an aftection somewhat c6rresponding to the information to be communicated. In the senses of smell and taste, for example, the knowledge to be attained by them is quite unconnected with the appearance or dimensions of the body submitted to examination. What is wanted is to determine the nature of the ingredients of which a body is composed, in order that, if fit for the purpose of nourishment, it may be consigned to the appropriate vessels for con- verting it to use ; and if discovered to be unfit for that purpose, that it may be rejected at the threshold. The arrangement of the organs of smell and taste, accordingly, are palpably adapted to the attain- ment of that end. The olfactory and gustatory nerves by which they are lined receive into contact minute particles of the substances to be examined, and the "aried excitements produced by the imme- diate action of these particles on the respective nerves communi- cate at once to the mind all the information relative to the substances themselves which these organs were formed to obtain. Few objec- tions have been oftered to the common explanation of the mode in which the sensations are excited by these two organs; unless, in- deed, we turn aside to consider those wild speculations which, assi- mulating all the impressions on the mind to the impressions we see and feel to be made on matter, would dethrone the soul, and de- grade man to a level with the brutes that perish. In consequence of these dreams, many difficulties have been started regarding the sensations produced by these, as well as the other organs of sense ; but these difficulties all relate to the nature of the sensations them- 1817.!I On Vision. 19 selves, not to the manner in which they are excited. When we • have been endowed with new faculties, faculties capable of dissect- ing and of analyzing the mind, of understanding the constitution and the fabric of spirit, then, and then only, will it cease to be a waste of time and of talent to engage in the pursuit of such sub- tihies. It must be much more useful and satisfactory to confine our inquiries to those operations which can be made the subject of ob- servation, and intelligibly explain the mode in which matter acts on matter, in order to produce those effects, the existence of which we know, but for the connexion of which with their cause we can look alone to the fiat of creative wisdom. As we proceed to those organs formed for more extensive and more complicated application, greater difficulties are supposed to present themselves; and when arrived at the seat of vision, at that delicate instrument which enables man to traverse the heavens, and to distinguish and appreciate the minute and countless varieties which fill up the ample space over which it expatiates, the philo- sophers seem to imagine that something vastly more complicated must be found in its constitution ; and, equally unable to find any marks of such intricate machinery in the eye, or to believe that the wondrous effects produced by its action can be produced by causes simple as those which produce sensation in the more limited organs, the inquiry has been given up as hopeless. A discovery interesting in itself, and highly esteemed by all late writers on the subject, and which indeed is referred to as of itself affording a demonstration of the theory of sight, has in my opinion been one of the chief causes of our general ignorance. " The sagacious Kepler," says Dr. Reid, " first made the noble discovery that distinct but inverted pictures of visible objects are formed upon the retina by the rays of light coming from the object," the rays, after being refracted by the cornea and crystalline, meeting in one point of the retina, and there " painting the colour of that point of the object from which they come." Having thus assumed the fact of the existence of a picture on the retina, it was concluded that this picture must be instrumental in communicating the information received. An insuperable diffi- culty, however, immediately occurred, for no one could even con- jecture how these pictures could in any degree produce the effect. Our celebrated philosopher already quoted. Dr. Reid, after noticing some of the conjectures upon the subject, and their unsoundness, expresses himself in several passages as follows : " Nor is there any probability," says he, " that the mind perceives the pictures on the retina. These pictures are no more objects of our perception than the brain is, or the optic nerve." * Since the picture upon the retina, therefore, is neither itself seen by the mind, nor produces any impression upon the brain or sensorium which is seen by the • Inquiry into the Human Mind, 4tb edit. p. 25G. B 2 26 On Vision. [July, mind, nor makes any impression upon the mind that resembles the object, it may be still asked, how this picture upon the retina causes vision.* " In answer," Dr. Reid observes, " we must resolve this solely into a law of our constitution. We may form sucli pictures, }jy means of optical glasses, upon tlie band, or upon any other part of the body, but they are not felt, nor do they produce any thing like vision. A picture on the retina is as little felt as one upon the hand, but it produces vision, for no other reason, that we know, but because it is destined by the wisdom of nature to this purpose." f This is rather a sovereign mode of disposing of the difficulty, and applicable only to first principles ; but as there could be found no trace, either in the structure of the parts, or in the analogy of their functions, to explain the province of these pictures, there remained no alternative. " It is evident," says the Doctor, " that the pic- tures upon the retina are by the laws of nature a mean of vision, but in what way they accomplish their end we are totally igno- rant."! § » Inquiry into «he Human Mind, 4(h edif. p. 257. f P. 262. f P, 254. ^ 1 should have thought it hardly possible that, to any one who had listened t» these quotations, it could have remained doubtful whether Dr. Reid meant, by the pictures which he considered lo be a mean of vision, the assemblage of rays of light as they pass through the retina, or reflected pictures, according to the or- dinary meaning of the term, not passing through, but painted on, that portion of the r.erve. As, however, some members of the Royal Society of Edinburgh did, when (he paper was read, express a dccidod opinion that Dr. Reid had given pre- cisely the same view of the subject that 1 have done, it seems necessary, in de- fence against such respectable opponents, to prove somewhat more at large what really was Dr. Reid's opinion. In doing this, it is unnecessary to enter into any disputation about the application of the terra picture to a determinate assemblage of rays, not reflected, but passing through a transparent bodj'. I am of opinion that such application of the term is improper; but that is of little moment ; for as to the theory of pictures, as explained by Dr. Reid, there can be no doubt that the pictures they refer to are reflected pictures, and therefore with theirs at least my views can have no accordance. In one of the quotations inserted in this paper Dr. Reid says we may form such pictures by means of optical glasses on the hand. Can any one doubt that the Doctor here means a common reflected picture, not passing through the hand, but painted on its surface. The uniform expression of a picture painted on the retina affords proof equally conclusive. Had he referred to the assemblage of rays passing through the retina, he never would have called these a picture on the retina, but a picture in it, or passing through it. In what other sense than that of a reflected pictare can we understand the following lan- guage: " Of all the organs of sense, the eye only, as far as we can discover, forms any kind of image of its object, and the images formed by the eye are not in the brain, but only in the bottom of the eye." (P. 256.) " By what law of nature is a picture upon the retina the means or occasion of my seeing an external object of the tame figure and colour in a contrary position, and in a certain direc- tion from the eye." (P. 260.) " Perhaps some readers will imagine that it i« easier to conceive a law of nature by which we shall always see objects in the place in w hich they are, and in their true position, without having recourse to images on the retina. To this I answer, that nothing can be a law of nature which is contrary lo fact." Not to multiply quotations too much, I only add one more* " We conclude that our seeing an object in that particular direction in which we do see it is not ow ing t»> any taw of nature by which we are made to see it in the direction of the rajs, either before their refraction in the eye, or after, but to a law of our n.aturc by which we see the object in the direction of the right line that passetb from the piclwt of the object upon the retina to the centre of the e^re." 1817,] On Vision. 21 It certainly requires some" hardihood to attack these formidable pictures ; but I feel bold enough to denounce them as mere phan- toms. I deny that any picture is painted on the human retina ; and even in those animals whose nocturnal pursuits, requiring peculiar organization, have ohtained for them a structure which will produce a picture (not on the retina, however, but on the choroides): it will, I trust, be made evident that the picture in these cases is but a passive accompaniment, not an active instrument in the production of sight. Nothing is to me more surprising than the universal and unhesitating credence that has been given to a supposition, which has never, and never could be, verified ; but which, on the con- trary, is in direct opposition to facts demonstrated, and inroUed amongst the fundamental principles of science. Dr. Reid, who seems to have felt doublings upon the subject, states, with truth, " No man ever saw the pictures in his own eye, nor indeed the pic- tures in the eye of another, until it was taken out of the head and duly prepared." It was this passage which excited my scepticism ; and I hesitated not to reject the hypothetical fact altogether, when I found that the Doctor ought not to have made any exception in his statement, no man liaving ever seen, or being able to see these pictures in the eye of another, more than in his own ; for the pre- paration alluded to, and which does produce the capability of show- ing a picture, changes the subject of it from an eye to something else, to an instrument as different from an eye as a window is from a reflecting mirror. What then is the evidence of the existence of these pictures ? It is this : that if an eye be taken, and the sclerotic and choroid coats being removed, a piece of white paper, or any white substance, fitted to reflect the rays of light, be substituted for the retina, or placed behind it, then the picture of any object held opposite to the pupil will be seen distinctly painted on the paper. This is the de- monstration on which the whole hypothesis is founded; and on examination it will appear palpably deficient in every quality of evi- dence to prove the conclusions drawn from it. Wliat is a picture ? It is the reflection of the rays of light under (P. 269.) I trust it is now manifest (for in the last passage the picture and (he assemblage of rajs are conlrasled) that Ur. Reid's theory does introduce real re- flected pictures painted on the retina. Indeed, so completely did Dr. Paley adopt this idea, that he corajiares the eye to a reflecting telescope, the images of the ob- jecls being painted in the same manner on both. I have to make one remark more. Even >vere it still maintained that Dr. Reid means pictures passing throiigli the retina; and were that point yielded, little would be gained ; for certainly Dr. Reid acknowledges that he isalcogether unac- quainted with the mode by which these pictures become a mean of vision. He has not ventured a conjecture on the subject, but resolves it, as the only resource, into a law of nature. It therefore remains to be shown how a theory which deniei the existence of any pictures painted on the retina, and which oflfers an e.vplana- tion (be it good or bad) of the mode in which the rays affect the optic nerve so as to afford the varied perceptions of dimension, figure, and colour, can be so iden- titled with Dr. Reid's opiaion, for he liasi no theory, as to dilTer only by a change of tcrmj. 22 On Vision. [July, such an arrangement ns to correspond exactly with the different parts of the body which the picture is intended to represent. The essential properties, therefore, of an instrument for reflecting pic- tures must be, first, that the rays emanating from the original shall be collected, so that they may impinge on the reflector in accurate, distinct, and corresponding figures and colours; and, secondly, that when they thus reach the focus where the image is to be painted, there be there a proper reflector to send all the rays back again, to produce in the spectator the perceptions of a picture. The first of these qualifications, that for refracting and concentrating the rays, the natural and the prepared eye both possess. These are tlie func- tions of the aqueous and the crystalline humours ; and about the nature or extent of these functions there is no dispute. With regard to the second qualification, however, there is a most material differ- ence between the natural eye and the eye prepared for this demon- stration. In the natural eye there is no reflector. The retina itself is nearly, if not quite, transparent. In proof of this we have only to remember that the black appearance which distinguishes the pupil proceeds from the choroides which lies behind the retina ; and that the retina is so transparent as not even to raise a cloud on the intensity of the black mantle behind it.* But if the retina be really so transparent, it can be no reflector. There is the same difference between the retina and the white paper that distinguishes a piece of common glass from a steel speculum. What is demonstrated by the one can afford no conclusion as to the other. They are, in fact, in opposition to each other, A speculum in a telescope will show the picture of an object within the field of the instrument; but sub- stitute for it a piece of transparent glass, and the picture vanishes; the rays, instead of being reflected, are transmitted. Let it not be said that, even in this case, the picture would be formed in the glass, though it would not be visible; for a picture does not exist by the mere assemblage of those rays, which, if reflected, would exhibit a picture. It is the reflection, and not the assemblage, which calls the picture into being; for if the rays be not reflected, but they pass on to the eye, then we see, not a picture, but the body itself. It is evident, then, that the retina of the natural eye ■» It may perhaps he objected th.it, although thevetinabe sufficiently trans- parent fully to bear out the argument against the pictures, it is not so transparent as here represented. Even when the eye is taken warm from the head of an animal, the transparency is fonnd to be imperfect. In this case I beg to refer the decision to the eye in the living body, where unques'innahly the transparency of the retina is so great as to render it invisible. Even in cases of hydrocephalus, ■when the pupil is so distended as to admit a considerable portion of light, and the i-etina remains invisible; and, according to my judgment, a more perfect trans- parency can scarcely be conceived than that which prevents us from perceiving, notwitlistanding all the different membranes and liquors which intervene, that the blacic coating of the choroides is not sitoated on the external surface of the eye. I apprehend that the transparency of tlie eye diminishes much on the exiinction of the vital energy ; and, therefore, that the removal of it even from a living body would not att'ord a fair testimony, or such as could weigh at sUl against the evi- dence attorded by the living eye itself. 5 18170 0« Vision. 23 does not reflect a picture in the manner in which it is reflected by the paper in the prepared state ; and if there be demonstration in the case, it is a demonstration that the retina cannot possibly reflect a picture at all. But it has been said by Dr. Priestley and others that, though no picture is formed on the retina, it is formed on the coat beliind it — the choroides. A dilemma immediately occurred on this assump- tion sufficient to have startled the most hardy philosoplu?rs. By thus transferring the picture from the retina to the choroides, the optic nerve was discarded as an instrument of vision ; for the retina is in fact the optic nerve. The transparency of that membrane, however, afforded too palpable an obstacle to its being considered capable of reflecting ; and therefore these philosophers conceived that, as a picture must be found somewhere, and it could not be formed on the retina, it might be formed behind it. The difficulty, liowever, was equally insurmountable ; for, to wave the manifest ai)surdity of excluding the optic nerve from the theory of vision, it is evident that the choroides is as incapable as the retina of reflect- ing objects so as to form a picture. The choroides at this part in many animals, as in man, is black — a pure black. Now why is it black ? Is it not because it does 7iot reflect the rays of light ? Although it is black, or rather dark, before it absorbs any rays, it is not because it is dark that it does absorb them, but it is because it does absorb them that we perceive that it is black. Whatever, therefore, may be thought of the reflecting powers of the cat, the owl, and other animals which seek their prey in comparative dark- ness, clear it is that, with regard to the human eye, no picture can be formed either on the retina or choroides. By the one all the rays of light are transmitted ; by the other, they are all absorbed. Liberated from the trammels of this paralizing phantom, let us compare the perceptions which the eye is fitted to produce with the perceptions produced by the action of the kindred organs. With regard to the anatomy of these parts, it is unnecessary for me to say much. The structure of the eye is generally known, and can scarcely be mistaken. Suffice it to observe that, after passing through the ball of the eye, and being collected, and concentrated in their passage, the rays of light impinge on the retina, which is the extremity of the optic nerve, reticulated on a thin membrane, and which forms a transparent screen, through which these rays are transmitted to the choroides, where they are all immediately ab- sorbed. Our present inquiry is limited to the operation of the rays on the retina ; for, as they afford no perception of vision previously to reaching that point, and are all absorbed by the choroides imme- diately on passing through it, the single question is, how can these rays affect the retina so as to produce vision? Vision is composed of two things : the perception of figure or dimension, and the perception of colour. These are so distinct and unconnected with each other, that they ought to be reckoned diffe- rent senses. There is certainly much less distinctive difference be- 24 On Vision. [July, tween smell and taste than between figure and colour. They have been united merely because they are produced by the same organ, and combine together to procure correct information from visible figure. In considering the origin of these perceptions, however, we must separate them. The perception of figure and dimension by the eye is evidently analogous to the perception of these qualities of matter by the organ of touch : the discrimination of colour, again, is more analogous to the discrimination of smell. It will be useful to premise some observations on the mode in which perceptions are generated by the organ of touch. If we admit the nerves to be the media of communication, and observe the close texture of their ramifications over the whole surface of the body immediately under the skin, and particularly the profusion of their minute branches extended over the hands and feet, we can have little difficulty in conceiving how the idea of dimension may be communicated by this organ. The extremities of these nerves are most minutely divided ; no one, it is believed, having yet been able to trace them to their terminations ; but each of them, even the minutest branch, must be considered as a separate nerve, capable by itself of communicating an intimation of its own excite- ment. Hence if any point of the body be forcibly touched, the locality of that point is immediately perceived. It were vain to stop to prove that we at once distinguish the neck from the heel, or the hand from the shoulder. No one ever heard of a person mis- taking the gout for the tooth-ache, or a box on the ear for a kick on the shin bone. How the nerves give that information to the mind is not the question ; that we cannot comprehend : but holding it to be a law of our constitution that the nerves do in some way or other communicate to the mind the sensations excited in the different organs, we may with some hope of success inquire, how the objects of the different senses act upon the organs, and excite the nerves ; and finding, on inspection, that the nerves of the organ of touch extend tiieir fibres in distinct branches over the surface of the body, we perceive that the individual sensation excited by the action of any of these branches exhibits a capability and fitness for com- municating to the mind certain notices of all such bodies as are applied to them, and thus we easily comprehend how they indicate locality. But if they indicate locality as to one point, they must equally do so as to all the points which may be touched ; and, there- fore, if a considerable portion or area be compressed by touch, the extent of nerves thus alfected must be equally perceived. Alongside of each other there must somewhere be two branches — one com- pressed, and the other free ; and the communication of this differ- ence, and of its locality, must be immediately and distinctly made. The information, indeed, that one or more branches of nerves are affected, and that others adjoining are not affected, must be simul- taneously communicated. But the perception of this difference, and its locality, is the perception of dimension and figure. For our idea of dimension is, the extending over two or more points instead 18170 ^" Vision. 25 of one ; and our idea of figure is, that one area of the compressed nerve differs from another area. When the body examined is too large to have its whole figure contained in one impression, a blind man first ascertains the extremities, and then passes his hand over the space which lies between them.* Experience, however, enables the blind to shorten this process ; f and, by putting iheir elbows close to their sides, they calculate pretty accurately from the posi- tion of the fore arms and hands what is the size of a body placed between them. In this case the information is obtained by intro- ducing the knowledge of the distance between the arms and hands previously acquired. But originally it is evident that to acquire a knowledge of the dimensions of a body larger than the hand, it would be necessary to apply the hand repeatedly, so as to obtain by these repeated applications a compression of an area of nerves equal to the surface of the object of examination. By this operation, however, we can easily apprehend how the ideas of dimension and figure are produced by touch. We no doubt often experience sen- sations, the localities of which we cannot precisely distinguish. After the amputation of a limb, a man sometimes complains of pain in that part which is severed from the body, and lies buried ia the earth ; but these are the effects of a diseased state of the nerves, and of fixed associations of ideas, and can militate nothing against the general position, that the nerves intimate the locaUty of those affections they communicate. I conclude, then, that if I take a body two inches long, and press it with my fingers, I shall perceive the extent of the pressure, because I shall perceive where the pressure ends. And if one half of that body be cut away, 1 shall also perceive this diminution of extent. Dr. Reid seems to question this, and to state his opinion that the connexion between the sensation of touch and the idea of extension is inexplicable. :|: Were this scepticism confined to the • There is a beautiful provision made for preserving the continuity of feeling. The digital branches of the medial nervf send each two smuller branches — not to the same finger, but one to each of two adjoining fingers; so that a channel of communication is thus opened, the importance of which may be at once appre- ciated by crossing the fingers, and applying a small body to them in that position. The communication being destroyed, the perception is of two bodies instead of one. + Any one may see this practically illustrated by visiting the Asylum for the blind, and observing the movements of the workmen. 1 was struck w ith the use the blind men made of the little finger. When they wished to obtain precise in- formation of the nature of a surface, they applied to it the little finger. An at- tention to the structure of the hand explains this. The little finger and one half of the ring finger are supplied with nervous energy by the ulnar nervej the re- mainder of the fingers, and the thumb, by the medial nerve. By their hard fingering and thumbing in the execution of their basket work, they blunted the sensibility of the nerves ramified on the thumb and three fingers ; but the little finger being exempted from such Influence, and being supplied by a separate nerve, its sensibility remains, and becomes the most delicate instrument in their hands for obtaining information by touch. J " The notion of extension," says the Doctor, " is so familiar to us from in- fancy, and 80 constantly obtruded by every thing we see and feel, that *c are apt (o think it obvious how it comes into the mind; but upon a narrower examina- tion, we shall find it utterly inexplicable," ^P. 121.)— '• Suppose," io tb« ens? 96 On Visim. [July, nature and mode of the communication between mind and matter, we should, as before explained^ readily agree with Dr. Reid ; for there can be few in the present day, and in the face of his triumph- ant argument on that point, who will still ce.uf,,J tor any resem- blance between the sensation and the idea produced by it. But in as far as he maintains that we cannot in any view understand how the organ of touch should communicate information of dimension, 1 cannot but dissent. It is sufficiently clear that no idea of relative dimension could be communicated in any case, without having some standard to determine the relation ; but I think it is equally impos- sible to deny that this blind man, when he touched a circular body, would necessarily perceive a difference between the sensation then produced from that produced by touching a body which was square or triangular. This would arise from the compressed area of the nerve being in the one case circular, and the other square. In like manner he must necessarily perceive the difference between a larger and a lesser body, between a whole and a half. It is true he might not, as in the case supposed, be al)le to compare any of these bodies or the areas of the nerves affected by them, witii the area of his own body, or with that part of the body generally alluded to in stating dimensions — the foot ; but he would compare them with, each other, and would know that one was larger or smaller thai*; another, or that they were nearly equal ; and what, as to dimen- sion, can the most acute and learned philosopher know, but that one body is larger or smaller, or equal, to another body ? The correspondence, then, between the dimensions of a body which is touched and the dimensions of the area of the nerve which is com- pressed being complete, although we may admit without hesitation that the idea of a circle is no more like a circle than it is like justice or courage, yet we easily apprehend how the nerve receiving the exact impress of these qualities of bodies should in that way, by which the nerves do communicate information to the mind, com- municate the various impressions which it has thus received. But what is all this to the eye ? As to dimension and figure it is every thing; for I apprehend that the very same principles govern both organs ; and that the sensation which gives the idea of dimen- sion and figure is produced in the eye in consequence of similar excitements of the retina ; not, indeed, by the body itself, as in the sense of touch, but by the particles of light reflected by it, and which pass through an area of the retina exactly corresponding to the visible figure of the body. It is here the picture forms a useful ally. It demonstrates that the rays pass through the retina in the determinate form, and with the same distribution of colours, which characterise the object from vvhich they proceeded. The optic nerve, therefore, must be excited in different portions, greater or of a blind raan with no previous knowledge of extension, " that a body applied to him touches a larger or a lesser part of his body. Can this give him any notion of its extension or dimensions ? To rae it seems impossible it should, unless he had some previous notions of the dimensions and figure of his owu body." (P. 121.) 1817.] 0« Vision. 27 less, round or square, or angular, exactly as the figure of the object surveyed by the eye is greater or less, or round or square, or angular. As soon, therefore, as we believe that a nerve is an instrument which, by some means or other, inexplicable to us, does commu- nicate to the mind the impressions made upon it, we cannot surely be in much difficulty to conceive that it should distinctly communi- cate the fact, that only one portion of it has been excited, or that a larger or smaller portion has been excited, or that a portion pecu- liarly excited in one part of the area differs in extent from another portion differently excited, and in another part of the area. It is impossible to conceive any distinct idea arising from sensation, unless it shall extend to these particulars; and if it be granted that the sensations are thus fitted to convey information as to the areas excited, then we ask no more to explain the mode in which a sen- sation indicative of dimension is produced on the optic nerve. An area of that nerve spread out to form the retina is excited exactly corresponding to the visible figure of every body which forms an object of sight. But this explanation reaches only to one of the qualifications of the eye. There remains to be considered the discrimination of colour. A few observations will suffice on this point, because some- what of the same reasoning leads us to what is at least a plausible solution of that problem also. The idea of colour is in some respects analogous to that of smell and taste. We cannot understand why the peculiar affection pro- duced by a particle of matter should produce an idea of sourness, or sweetness, or sharpness, or poignancy. These are particular ideas which arise in consequence of information being conveyed to the mind that the nerves have been affected in several particular ways; and they are ideas connected with these particular aftections by the original laws of our constitution. The ideas of colour, of scarlet, blue, or yellow, are of the same nature. They are perceived whea the optic nerve communicates information to the mind that it has been excited in the various ways by which the red, and blue, and yellow rays of light do actually affect it. These rays are in their nature different from each other, and therefore each of them must produce an affection peculiar to itself. When we recollect, then, that each of these coloured particles, passing through the retina in the precise relative arrangement in which they proceed from the body under examination, must produce the affection peculiar to itself, and that on the point of the area which corresponds to its situation in the object seen, we may understand how we not only perceive the extension and figure of that object, but also its various colours and shades ; and thus, as far as such theories can go, we obtain an intelligible theory of vision. I have mentioned that in the eyes of some animals pictures may really be formed, the coating of the choroides behind the retina being white and resplendent. This provision is suited to the habits of those animals which seek their prey in the dark, and the object 28 On Vision. [July, of it seems to be to aid the weak impressions made by the luminous rays which are but scantily emitted or reflected during the night. To man, to the hawk, and to all those animals whose activity is chiefly exercised in the light of day, and to whom it is of most importance to have distinct vision amidst a flood of light, tlie cover- ing behind the retina is lined with a substance which absorbs the r^iys after they have passed through that membrane, so that none of them can return to confuse the original impression by a second ex- citement. On the other hand, the nocturnal prowlers are not con- cerned so much about distinct vision as to obtain by it a knowledge of the locality of their prey, at a time when it supposes itself in safety. The rays being then in small numbers, the excitement of the nerve must be less acute; but by placing behind it a reflecting instead of an absorbing coat, the rays may be sent back, and by an arrangement of the parts for that purpose, may be returned in the same direction, and thus double the intensity of the excitement. From this view of the final cause, why the colour of the choroides in such animals is white I would conjecture that their eyes, and particularly the parts at the retina and choroides, which are opposite the pupil, are shaped differently from the corresponding parts of the human eye ; and that in their structure there is a provision for re- flecting the particles of light in the same direction in which they originally passed through the retina. The solution which I have now ventured to propose does indeed banish from the problem of vision much of its complexity ; but it increases rather than impairs its peculiar fitness for that which is the most legitimate and satisfactory object of scientific research — the illustration of the attributes uf him who hath conjoined in the mechanism of the eye so much simplicity and such ample power. Unlike the feeble efforts of man, where the causes must be many, though the effects be few, the works of God show multiplied and varied effects produced by a few simple causes. The excitements produced by the rays of light passing through this diminutive screen communicate to the human mind by much the greatest portion of all that varied, extensive, and interesting knowledge, which man can acquire of the material creation. It is true we learn by the sense of touch to appreciate the effects of light and shade, so as to under- stand from the visible what is the real figure of an object ; and we learn still more from experience to draw inferences from circum- stances which at first convey no precise idea to the mind. But that does not at all affect the proposition that it is by the eye chiefly we connect ourselves with the world without us, or that its organization is adapted to the acquisition of all these different kinds of knowledge. A man often employs a valuable machine long before he discovers or applies all its capabilities ; but whether these can be employed with or without a combination with other machinery, or whether they can be all brought into action at the outset, or require repeated practice to enable the possessor to draw from them all the advan- tages they afford, still the construction of a machine which in such 6 1 81 7-] Preservalion of Volatile and Deliquescent S2ilsiances. 29 circumstances can ultin:)ately be so extensively employed carries evidence that power, and wisdom, and design, adequate to all thesa varied ultimate effects, were exerted in that construction. Such is the view in wliich we ought to contemplate the eye ; and when we so contemplate its structure, and its powers ; the simplicity of the arrangement of its parts, and the analogy between it and the other organs of sensation; its adaptation to near as well as distant objects;* tlie rich and varied treasures of information, for usefulness, and for enjoyment, which it explores and appreciates; and the indicatioa of mind, of intelligence, and attection, which it so expressively reciprocates ; we cannot fall to perceive that, were this organ alone submitted to our observation, it would itself demonstrate that it must have been formed by an intelligent Being, and that the Being who formed it must be possessed of infinite power, and wisdom, and goodness. It would demonstrate more, and what is of more imme- diate importance to us, for it follows as a corollary that God has put forth into active exertion all these attributes to promote the happi- ness of his creature man. Article VII. Method of preserving Volatile and Deliquescent Substances. By Dr. Dewar, F.R.S. Edin. (To Dr. Thomson.) SIR, Edinburgh, MayU, 1817. Every person concerned in chemical operations must have ex- perienced inconvenience from the difficulty of retaining volatile, deliquescent, and efflorescent substances in a state of perfect preser- vation. Lagrange directs that no volatile acid should stand in that department of a laboratory which is appropriated to the more deli- cate experiments. Though the stopper of a phial be ever so well ground, it yields to the expansion of the contained substance, occa- sioned by slight elevations of temperature. In hot climates ether is generally kept in stopped bottles immersed in water in an inverted state ; and I believe it will seldom be found that water long thus employed is entirely free from an impregnation of the ether. For obviating these inconveniences, I beg leave to propose the following expedient : — Let every bottle intended for such substances have a circular rim round its shoulder, not rising quite so high as the rnouth of the bottle. In tiie cavity formed by this rim let a quantity of mercury be contained, and let an inverted glass cup, • The grey drone fly is said lo have 14,000 eyes, and the dragon fly a great many more; but how imperfect is the information obtained by these vast aggre- (ales of visual orbs compared lo the information Gommuoicated by tbe pair be- stowed oil Biao, 30 Preservation of Volatile and Deliquescent Suhtances. [JuLf , the mouth of which is adapted to the cavity, be immersed in the mercury covering the stopper and neck of the bottle. The cup, from its lightness compared to the mercury, and from the resistance opposed by the air contained in it, is prevented from sinking to a sufficient depth. The bottom of it, therefore, may be loaded with a flat piece of metal cemented to it. When put on, it should be pressed down, and held a little on one side, for the expulsion of a small part of the air. This pure object may be obtained to any requisite degree by gently warming the cup. It is scarcely necessary to enumerate the advantages which will arise from the adoption of this plan. Volatile acids may stand in any room without in the least endangering the polish of fine metallic surfaces, or affecting the progress of delicate experiments. Those who wish to preserve deliquescent substances in a dry state, ias, for example, muriate of lime, or soil which powerfully attracts humidity (substances which, from their cleanliness, are preferable to sulphuric acid for the formation of ice by the process invented by Professor Leslie), may keep them in bottles of this kind. They may also be employed for the preservation of certain mine- rals, such as extraneous fossils of pyrites, and the lomonite, or mealy zeolite, the preservation of which has occasioned so much unsatisfactory trouble to mineralogists. - A similar apparatus may be used for retaining anatomical prepa- rations in spirits, both for preventing more effectually the evapora- tion of the spirits, and affording greater facility in taking out the preparations at pleasure. The apparatus will be more perfectly understood by an inspection of the annexed figure : A represents the body of the phial : B, B, compartment for mercury : C, C, C, cup inverted in mercury, to keep the phial air-tight ; within this are represented the neck and stopper. When the contents of the bottle are wanted, we take off the cup, and, holding the stopper with the finger, begin with pouring out the mercury into the cup, now standing upright on a table. It might be rendered more carriageable by means of a circle of cork passing between the inverted cup and the containing rim ; and still more so by a piece of leather or of bladder tied over the whole, a circular groove being made on the outside of the rim for retaining the string, and the interior surface of the bladder might be smeared with a tena- cious substance for confining the mercuiy. This would contribute to the perfection of the apparatus, if used at sea. But for standing in a room, it will require no such addition, and will then be of itself much more convenient, cleanly, and secure, than the usual expedient of ground stoppers covered with lute. 1817.] On the Runyung of Liquids through small Orifices. SI Before concluding, I shall observe that the same principle may be advantageously employed in the construction of domestic imple- ments for preventing the escape of the offensive effluvia of excre- mentitious substances in the bedchambers of the sick. Pieces of furniture have indeed been made for accomplishing this purpose by means of water used exactly in the same way. But the relative properties of water to the effluvia alluded to are such that these have been justly complained of as ineffectual, 1 am, Sir, your most obedient servant, Hknry Dkwar. Article VIII. Report made ly M. Poisson of a Memoir hj M. Hachelle respecting the Runnbig of Liquids through small Orifices^ and with Pipes applied to these Orifices.* The experiments of M. Hachette may be divided into three parts. The object of the first is to measure the contraction of the fluid vein proceeding from a narrow aperture. The second exa- mines the cause of the singular phenomena which take place when small cylindrical or conical pipes are added. In the third part the author describes the figure of the fluid vein, and the variations oc- casioned by different forms of the orifice. We shall not attempt to explam all the importance of these different questions, either in practice, or as they relate to the theory of the motion of liquids • but, without further preface, we shall give an analysis of the three parts of the memoir subjected to our examination by the Class. Part L— Contraction of the Fluid Fein. The author examines, in the first place, if the figure of the small orifice has any influence on the quantity of liquid that flows out in a given time. It is generally admitted that, supposing the pressure the same, and the orifice unaltered, the quantity of liquid which fiows out IS not changed. M. Hachette determines the correctness ot this principle when the orifice is circular, triangular, elliptical, or formed of an arch of a circle and two straighT fines. But he bnds the products very different, either in excess or defect, when the contour of the surface presents re-entering angles, which occa< Mons an important modification in the principle which we have thrfl!n-l! „•- r '^ P'^"^ ^" '"^'''^ '' '' P'^'-^«^ be not horizontal, hnnS t ■■"?' ? ""''"' ^^•''^'^ ''"ght to be a parabola corres- ponding to a certain initial velocity which the author has determined trLf nn "?'"^".'■'=;"«"^ Setting out from the place of greatest con- iraction, the thickness becomes constant for a considerable extent; * This raemoir was read to the Royal Academy of Sciences, Dec. 18, 1816. 32 On the Running of Liquids through small Orifices. [July, namely, till the jet, by mixing with the air, loses its shape. In this extent all the fluid molecules describe the same curve, and the vein resembles perfectly pure crystal, supposed immoveable. It was, therefore, easy to measure the abscissas and the ordinates of different points of the same jet ; and by a comparison of these measures the author has recognized that the fluid curve does not deviate senbihly from a parabola. He has concluded, likewise, from the known formulas of parabolic motion, the velocity of the fluid in a given point, for example, at the place of greatest contraction. He has found in this manner thnt the common velocity at all the points of the contracted section is very nearly that derived from the height of the surface above the orifice. Thus the theory of Torricelli is accu- rate when applied to the velocity that takes place at this section of the vein ; but it cannot be true, at the same time, with respect to the mean velocity of the molecules which traverse the section of the orifice on account of the difference between the areas of these two sections. The velocity at the contracted section being known, the observa- tion of the expanse of fluid in a given time will make us acquainted with the ratio of this section to that of the orifice, or with what is called the quantity of contraction, more exactly than can be done by direct measurement. The time is to be reckoned, and the quan- tity of liquid that flows out from a small orifice under a constant pressure is to be measured. At the same time, the quantity of liquid that ought to be discharged by the orifice is to be calculated by the rule of Torricelli. The ratio between the observed and cal- culated discharge will be a fraction which will express the quantity of contraction. This method, pointed out by D. Bernoulli, has been followed by M. Hachette. He neglected none of the precau- tions necessary to diminish the errors of experiment. He measured the time l)y means of a second watch of M. Breguet. The orifices which he employed were constructed and measured by M. Lenoir. Bv inspeeting a communicating tube, he was always sure that the level of the fluirl did not *ary during the experiment ; and, finally, his observations were made on a very large scnle botli with respect to the size of the vessel and the volume of water that flowed out, and likewise with respect to the time during which the liquid was flow- ing out, which sometimes amounted to more than an hour. A table placed at the end of his memoir gives the result of 28 expe- riments made in this manner on heights of water between 135 and 88- millimetres (5-315 and 34-96 inches), and with orifices varying from 1 to 43 3 millimetres (0-03937 to 1-626 inch). The smallest contraction observed by the author corresponds to the smallest diameter. It is 0*78. For diameters above 10 millimetres (03937 inch) the contraction becomes almost constant. It lies between 0-60" nd 0-w,JuhlISV7 ■ the public, it is obvious that an additional scale and vernier may be placed below the present, so as to show the actual state of the 1817.] ylnuhjses of Books. 49 Hierrury, in its passage, from one vernier to tlie other. Those who dii^iike the inverted scale n)ay suspend the verniers, at the other end of the silk, letting them rise and fall on a common scale. I fiar that the accuracy of a floating gauge, to keep the mercury in the reservoir at the same height, is impracticable in this in- strument; but by properly proportioning the diameter of the small tube to that of the reservoir, the correction (however small) may be easily made. Yours very truly, MalcHC Houu, April 11, 1817. AnTHONY SemPI^E. Article XII. Analyses ok Books. Transactions of the Royal Society of Edinhurgh, Vol. Fill. Part I. 181 7. This part contains the following articles : — 1. On the Action of' Transparent Bodies upon the diffcretttly coloured Roys of Light. By David Brewster, LL.D. F.R.S. Lond. and Edin. and F.A.S. Ed. It is well known tliat the spectrum of solar light obtained by passing a ray of light through prisms composed of different mate- rials varies in its length. In some the green rays occupy a compara- tively greater space, and in otliers the violet and blue rays the greater. Hence, when two such prisms are combined acting ia opposite ways upon light, if we look to the bars of a window through them, we ot)serve fringes of coloured liglu. These fringes consti- tute what is called the secondary specinun. The property itself is called the dispersive poiver of the prism. These uncorrected colours constitute the great obstacle to the perfection of the achromatic telescope. In this paper Dr. Brewster gives an account of experiments to determine the dispersive power of 89 different bodies, both liquid and solid, wiiich he arranges according to their action on green light, those that have the least action being placed first, and those that have the greatest action last. Sulphuric acid was found to have t!ie greatest action, and oil of cassia the least. I should conceive the results of these trials upon most of the liquid bodies liable to some uncertainty, because their nature varies so much at different times, that we might expect different specimens of the same body to possess different dispersive powers. The acids are given without any specification of their density or purity, so that We are left very much in the dark al,out them. 'J'hus tiie nitrous acid of the author is proltaljly the fuming acid of the shops, which is very different from real nitrous acid. Prussic acid, when pure, is speedily decomposed; probably, thereJbre, the pru^^ic acid of the Vol. X. N<^ I. D 50 Analyses of Books. [JCLV, author is merely water impregnated with a small quantity of that acid. The phosphorous acid is probably a mixture of phosphoric and phosphorous acids and water. The oils are liable to an equal degree of uncertainty. This ambiguity and uncertainty render it doubtful whether achromatic telescopes can ever be effectually improved by means of liquids. The natural crystals afford a much more probable means. 2. Dsscr'iplion of a ?ieiv Darkening Glass for Solar Observations, which has also the Property of polarizing the whole of the trans- mitted Light. By Dr. Brewster. This contrivance consists in a plate of glass of some thickness, having slips of metal placed upon its opposite faces. An oblique solar ray enters the glass plate, and is prevented from reaching the eye by the slip of metal on the eye side of the glass. It is reflected back through the plate to the slip of metal on the other side, and being again reflected back, passes to the eye much attenuated. 3. Observations on the Fire-damp of Coal-mines ; with a Plan for lighting Mines, so as to guard against its Explosion. By John Murray, IVI.D. F.R.S. E. Published in the ylnnals of Philosophy, vol. viii. p. 40G. 4. On the Lines that divide each semidiurnal Arc into six equal Parts. By W. A. Cadell, Esq. F.R.S. Lond. and Edin. On the ancient sun-dials the day, from sun-rise to sun-set, was divided into ] 2 hours, which of course varied in length according to the season of the year. The object of this paper is to explain the nature of the lines by which this division was accomplished. An account of this paper has been given already in the Annals, vol. viii. p. 63, and it would be difficult to add to that account without having recourse to figures. 5. On the Origin of Cremation, or the Burning of the Dead. By John Jamieson, D.D. F.R.S. and F.A.S. E. The earliest mode of disposing of the dead seems to have been inhumation. Burning them was a subsequent practice. The object of this curious paper is to endeavour to account for the origin of cremation. Much learning and acuteness is displayed ; but the ingenious author, as is too often the case in antiquarian researches, has left matters pretty much as he found them. 6. Additional Commnnications respecting the blind aiid deaf Boy, James Mitchell. By John Gordon, M.D. F.R.S. Edin. This paper contains an account of an attempt to teach the boy by means of tangible letters, suggested by Mr. Parker ; but it com- pletely failed, from want of application on the part of Mitchell himself. 7. On the Education of James Mitchell, the yomig Man horn blind and deaf By Henry Dewar, M.D. F.R.S. Edin. The author of this paper proposes to have words cut in relief in the written character, and to make Mitchell comprehend them by associating them with the things of which they are the names. After he has acquired a good stock of words, he mav proceed to the letters, 1 18170 Edinburgh Philosophical Transactions, 18 1/. 51 if it be found that he has an inclination for the task. It is to be hoped that the ingenious plan sketched out in this paper will be attempted to be put in practice. There can be no doubt that much valuable knowledge may be conveyed in this way, provided the first reluctance of Mitchell can be overcome. 8. On the Optical Properties of Muriate of Soda, Pluate of Lime, and the Diamond, as exhibited in their Action on polarized Light, By Dr. Brewster. Crystallized bodies are of two kinds — those that refract doubly, and those that want that property. Those bodies which crystallize in cubes or octahedrons do not refract doubly. Laplace and Biot have shown that doubly refracting crystals are divisible into two classes : those, such as calcareous spar, in which the extraordinary ray is repelled from the axis ; and those, as quartz, in which the extraordinary ray is attracted towards the axis. Hence it has been concluded that common salt, fluor spar, diamond, spinell, and other bodies which do not refract doubly, neither attract nor repel the extraordinary ray. Dr. Brewster, on examining large crystals of these bodies, found that they acted on light 5 in some parts as the first class of doubly refracting crystals, in others as the second class, and that in some parts there was no action. He considers these effects as occasioned by slight deviations from the cubic or tetrahedral structure. When they deviate a little on one way, they affect light as the first class of doubly refracting crystals ; when they deviate a little the other way, they act as the second class. 9. On a ?iew Optical and Mineralugical Property of Calcareous Spar. By Dr. Brewster. Many specimens of calcareous spar form a multiplicity of images affected with the most brilliant colours. Dr. Brewster shows in this paper that these specimens contain within them a vein of calcareous spar, the axes of which are inclined at an angle of 45° to those of the external crystal. 10. On the Ancient Geography of Central and Eastern Asia, with Illustrations derived from recent Discoveries in the Noj'th of India. By Hugh Murray, Esq. F.R.S. Edin. The object of this valuable paper is to show that the Serica of the ancients was China ; and that Ptolemy's description of Asia is in its great outlines more correct than that of modern geographers. 11. An Analysis of Sea IVater, with Observations on the Ana- lysis of Salt Brines. By John Murray, M.D. F.R.S. Edin. There is a great want of uniformity in the analyses of sea water hitherto published. Lavoisier obtained from a French pound — Common salt 126 gr. Muriate of magnesia 14|- Muriate of lime 23 Sulphate of soda and sulphate of magnesia .... 7 Sulphate and carbonate of lime S D 2 S/2 Analyses of Booh. [Jutlr, b^i-g'tn&n got frotti &h English pint of sea wattr—- Common salt >*.».... 241 gt. Muriate of magnesia w G5'5 Sulphate of lime , . 8 Vogel and Lagrange obtainied from 1000 parts of sea water- Common salt i ....... i. ... . 25'1 Muriate of magnesia 3'5 Sulphate of magnesia 5'78 Carbonates of lime and magnesia » . 0*20 Sulphate of lime 0*15 Lavoisier evaporated the sea water to dryness. The dry mass was digested in alcohol. The undissolved residue was digested in a milsture of two parts alcohol and one part water. In all the other analyses the portion insoluble in alcohol was digested in pure water. Dr. Murray conceiving that the peculiar results obtained by Lavoi- sier were owing to his peculiar mode of analysis, thought it proper to repeat the analysis according to tlie mode practised by that chemist. Four pints of water from the Frith of Forth were evaporated till a pellicle formed on the surface. The precipitate that fell was a mixture of sulphate of lime and of carbonates of lime and mag- nesia. The liquid was now evaporated to dryness, and the saline rtiass thoroughly dried at the temperature of 150°. It weighed 1025 grains. It was digested in four ounces of alcohol of the specific gravity 0*840. The portion dissolved consisted chiefly of earthy muriates. The undissolved portion was digested in a weak spirit, composed of two parts of alcohol and one part water. The greater part was dissolved. The undissolved portion was again digested in still weaker spirit. Lastly it was digested in warm water. A light, soft, tastleless powder, now remained. These different liquids being examined, the saline ingredients found were the following (sup- posing only a pint of water to have been employed) : — Common salt 182*1 Muriate of magnesia 25*9 Sulphate of soda 7'5 Sulphate of magnesia 5*9 Sulphate of lime 7*1 228-5 He now performed the analysis of sea water in the common mode, as practised by Vogel and Lagrange. From a pint of water he obtained the following saline ingredients : — Common salt 184 Muriate of magnesia 21*5 Sulphate of soda 2 Sulphate of magnesia 1 2*8 Sulphate of lime 7*3 227*6 I317'J Edinburgh Philosophical Transactions^ J817. 5^ From these results it is obvious that the sah"ne substances obtained depend in sooie measure upon the mode of analysis employed. Dr. Murray has offered a very ingenious explanation of this apparent inconsistency. It has been shown by Berthollet that cohesion hss such an influence on the action of salts on each other, that whei^ different salts are mixed in solution, and the liquid evaporated, we can always predict what the salts are which will be obtained. The salts formed will always be those which are on the whole least soluble in water. Dr. Murray conceives that when the liquid i^ which salts exist is in a very diluted state, the contrary influence exerts itself, in consequence of which those salts exist in the liquid which are upon the whole most soluble. From this principle, which is very plausible, it follows that in sea water the constituents must be common salt, muriate of lime, mu- riate of magnesia, and sulphate of soda. When the liquid is eva- porated to a certain extent, sulphate of lime and sulphate of ma""- nesia are formed by the decomposition of the sulphate of soda, which is converted into common salt. By examining sea water by means of precipitants, Dr. Murray shows that the saline elements in a pint of sea water are as follows': Lime 2*9 gr. Magnesia 14*S Soda 96*3 Sulphuric acid 14"4 Muriatic acid 97*7 226,- 1 If we adopt the explanation of the action of salts on each other according to the state of the liquid in which they exist, the true saline constituents of a pint of sea water must be as follows : — Common salt 159'3 Miiriate of magnesia 35*5 Muriate of lime 5*7 Sulphate of soda 25*6 226-1 12. Elementary Demomtration of the Composition of Pressures. By Thomas Jackson, LL.D, F.R.S. Edin. and Professor of Natural Philosophy in the University of St. Andrew's. It would be impossible, without figures, to render this ingenious p^per intelligible to our readers. 13. Account of the remmkahle Case of Margaret Lyall, who caiUinued in a Slate of Sleep nearly six Weeks. By the Rev. James Brewster, Minister of Craig. This is a very curious account. Margaret Lyall had repeated oc- curninces of her lethargy. The first time it came on with a bleeding n thp npse, and her sleep lasted three days. The next sleep lasted 54 Proceedings of Philosophical Societies. [July, six weeks ; though she swallowed food, and had occasional alvine evacuations during the time. She had two subsequent lethargic fits, neither of which lasted above a few days. Her end was melancholy. She hanged herself at Dunninald, where she acted as a servant to the family. 14. A general Formula for the Analysis of Mineral IVaters. By Dr. Murray. This paper being of considerable practical importance, we shall publish it in a future number of the Annals of Philosophy. Article XIII. Proceedings of Philosophical Societies. ROYAL SOCIETy. On Thursday, May 22, the remainder of Dr. Davy's paper on the Temperature of the Air and the Ocean, and the Specific Gra- vity of the Sea in Tropical Climates, was read. The temperature of the ocean differs as much at different times of the day as the temperature of the air. In general it is hottest about three o'clock in the afternoon, and coldest at sun-rise. Its temperature is much affected by shallows and by currents. It is now well known that the sea over shallows is colder than when deep. This Dr. Davy verified both at the Cape of Good Hope and at Ceylon. They were two days in approaching the Cape at the rate of two miles an hour. The temperature sunk from ()0° to 58° before they were in sight of land, and indicated their approach to it. The same diminution of tem- perature took place as they approached Ceylon. Currents affect the temperature of the sea very much. Those that flow from a cold quarter are colder than tlie temperature of the sea through which they flow ; while those from a warm quarter are hotter. One of the greatest is that which flows on the south-east side of Africa, and which has been accurately described by Major Rennel. It is about 130 miles in breadth, and runs most rapidly at the western edge, where its temperature is 10° higher than that of the surrounding sea. This current is employed by Dr, Davy to explain a pheno- menon not yet accounted for, namely, the clouds which settle on the summit of the Table Mountain when a south-east wind blows. These clouds are known by the name of the Table-cloth. They are occasioned by this cold wind condensing the warm vapour as it passes over this current. Dr. Davy, during his residence at the Cape, had an opportunity of seeing the passage of the clouds along the sea to the mountain. It was very rapid. At the same meeting a paper by Mr. Sewell, Assistant at the Veteriiwry College, was read, describing a new mode of curing a 1817.] Royal Society. 55 chronic lameness in the feet of a horse. The most valuable horses in this country are apt to be lamed in the fore feet, usually in con- sequence of forced exercise. They are often sold in tliis state for very inferior employments, or even altogether destroyed. A charger having got a chronic lameness in the fore foot, and having been treated in vain by different practitioners, was given by the owner to the Veterinary College for experiment. It occurred to Mr. Sewell that, by cutting the nerves that enter the foot, the sensibility might be destroyed, and the lameness removed. He accordingly cut out about two inches of the nerves that entered the pastern, sewed up the place, and healed it. The consequence was the removal of the lameness, and the restoration of the horse to the owner perfectly sound. On Thursday, June 5, a paper by Dr. Leach was read, on the genus ocythose of Rafanesque. The animal of which Rafanesque has made a new genus under the above name is often found in the shell of the paper nautilus ; and on that account many naturalists have considered it as the original inhabitant of that shell. Others are of a different opinion. Dr. Leach considers the observations made by the gentlemen of the late Congo expedition as deciding the question. Various paper nautili were caught containing these animals in them. When put into water, the animal moved about like a common polypus, left the shell, attached itself to the sides of the vessel, and showed no inclination to return to it again. These and similar observations induce Dr. Leach to conclude that the true inhabitant of the paper nautilus shell is still unknown, and that the animal in question does not belong to it, though it occasionally takes up its residence in it. At the same meeting, a paper by Sir E. Home, Bart, was read, explaining the differences between the sepia and shell vermes. When the young is in the egg, the blood is aerated through its coats. On tbat account the shell of shell vermes is not formed till after they are hatched. To secure the egg from injury, it is put into an annular bag. The author gives a description of the auri- culata, and shows that the animal found in it is a sepia, and not the original animal of the shell, from the way in which the young are produced. On Thursday, June 12, part of a paper by Sir Wm. Herschell, LL.D. &c. was read, on the way in which tlie stars are distributed in space. Astronomers have divided stars into seven classes, accord- ing to their brightness. This difference of brightness must be owing to the difference of distance. The author proposes a new distribu- tion into four sets. On Thusday, June 19, Sir William Herschell's paper was con- cluded. He conceived it probable that the light emitted by each star is inversely as the square of its distance. He therefore con- trived a method of comparing the light given out by tl»e different stars, which he described in the paper. From this method it follows that tlifi distance of the smallest star visible to the naked eye is 12 56 Proceedings of Philosophical Societies. [July, times as great as that of a star of the first magnitude. He gave an account of the shape and distribution of the milky way. He found tliat many of the stars of which it is composed are 900 times further off than stars of the first magnitude. He concluded from his observations that the sun and all the visible stars constitute a portion of the milky way. LINNiEAN SOCIETY. On Saturday, May 24, the Society met for the election of office- bearers for the ensuing year. The following members were cliosen : President. — Sir James Edward Smith. Treasurer. — Edward Forster, Esq. Secretary. — Alexander Macleay, Esq. Under Secretary. — Mr. Kichard Taylor. There remained of the old council : — Sir James Edward Smith ; Samuel, Lord Bishop of Carlisle ; Edward Foster, Esq. ; George Bellas Greenough, Esq,; Aylmer Bouike Lambert, Esq. ; William Horton Lloyd, Esq. ; Alexander Macleay, Esq. ; William George Maton, M.D. ; Joseph Sabine, Esq. ; Lord Stanley. There were elected into the council : — Michael Bland, Esq. ; George, Earl of Mountnorris ; Sir Christopher Pegge ; William Pilkington, Esq. ; Charles Stokes, Esq. On Tuesday, June 3, a paper by Mr, Salisbury was read, con- taining a description of the seeds of the lycopodium denticulatum. He found the description of Brotcro in most particulars correct. He exhibited drawings of the seeds from the earliest periods in which they have been perceived to their ripe state. At the same meeting a description of a new species of malaxis by Dr. W. Barton was read. Dr. Barton found the species near Philadelphia, and called it longifoUa, because its leaves are twice the length of those of the two species previously known. At the same meeting a description of (he lycoperdon solidum, by Dr. Macbride, of Charleston, Carolina was read. The substance so called is an immense tuber, sometimes 40 lb. in weight, found in the southern parts of the United States. It may be used as food. Soon after it is dug up it becomes very hard. It exhibits no regular structure, and seems to have the property of uniting with the roots of those trees near which it grows. It vegetates under the earth, and is usually found in fields that have been cleared of wood only about three years. On Tuesday, June 17, a paper by Sir James Edward Smith was read, giving a description of a rhizimorpha found in a well at Derby. At the same meeting, a paper by Mr. Seaton was read, on the red and white varieties of the lychnis dioica. Some botanists are of opinion that these two plants constitute two distinct species, while others think that they are only varieties. To decide the point, Mr. Seaton placed them near each other. The produce was a hybride plant with pink flowers, which was capable of producing seeds like 18170 Royal Sociely of Edinburgh. 57 any otiier plant. Hence he conceives it to follow that they are only varieties. At the same meeting, Dr. Leach announced that he had exa- mined the specimen sent from Hull under the name of the many- headed serpent, and found it to be the penis of a sow. ROYAL SOCIETY OF EDINBURGH. On the 19th of May a paper by Mr. Stevenson, civil engineer, was read, regarding the operation of the waters of the Ocean and of the River Dee, in the basin or harbour of Aberdeen ; from which it appears that Mr. Stevenson, in the month of April, 1812, witii the use of an instrument (of which he exhibited a drawing), has been able to lift salt water from the bottom, while it was quite fresh at the surface, and has satisfactorily ascertained that the tidal or salt waters keep in a distinct stratum or layer under the fresh water of the River Dee. This anomaly, with regard to the salt and fresh waters, appears in a very striking manner at Aberdeen, where the fall of the Dee is such as to cause river water to run down with a velocity which seems to increase as the tide rises in the harbour and smooths the bed of the river. These observations show that the salt water insinuates itself under the fresh water, and that the river is lifted bodily upwards ; thus producing the regular effect of flood and ebb tide in the basin, while the river flows downward all the while with a current which for a time seems to increase as the tide rises. These facts, with regard to the continual course of the River Dee downward, is such a contrast to the operation of the waters of the Thames, as seen by a spectator from London Bridge, that Mr. Stevenson was induced to extend his experiments to that river in tiie years 1815 and 1816", by a train of experiments and observa- tions from about opposite to Billingsgate all tlie way to Gravesend. Tlie waters of the Thames opposite the London Docks' gates were found to be perfectly fresh throughout; at Blackwall, even in spring tides, the water was found to be only slightly saline ; at ■VVooivvich the proportion of salt water increases, and so on to Gravesend. But the strata of salt and fresh water is less distinctly marked in the Thames than in any of tliose rivers on which he has hitherto had an opportunity of making his observations. But these inquiries are meant to be extended to most of the principal rivers in the kingdom, when an account of the whole will be given. From tiie series of observations made at and below London Bridge, compared with the river as far up as Kew and Oxford, Mr. Stevenson is of opinion that the waters of the Thames seldom change, but are probably carried up and down with tiie turn of the alternate tides for an indefinite period, which he is of opinion may be one, if not tlie principal, cause of what is termed the extreme, softness of the waters of the Thames. Mr. Stevenson has made similar experiments on the Rivers Forth and Tay, and at Loch Eil, where the Caledonian Canal joins the 58 Proceedings of Philosophical Societies. [July, Western Sea. The aperture at Curran Ferry for the tidal waters of thai loch being small compared to the surface of Loch Eil, which forms the drainage of a great extent of country. It therefore oc- curred to Mr. Stevenson that the waters of the surface must have less of the saline particles than the waters of the bottom. He accordingly lifted water from the surface at the anchorage off Fort William, and found it to be 1008*2; at the depth of nine fathoms, 3025-5 ; at the depth of 30 fathoms, in the central parts of the loch, it WHS 1027-2; indicating the greater specific gravity, and conse- quently more of the saline parts as the depth of the water is in- creased. GEOLOGICAL SOCIETY. j^pr'il 6. — A letter from Dr. Meade to Mr. Vaughan was read, relating to the slab of serpentine from North America. The quarry whence the slab was obtained is situated near the town of Milford, in Connecticut. It is a serpentine rock. The whole country in the neighbourhood is of primitive formation, con- sisting principally of gneiss and granite alternating with primitive lime-stone. A stratum of the serpentine several yards wide runs between the lime-stone. It extends for several miles, accompanied with asbestos, amianthus, and diallage. The quarry is extensively worked. This serpentine has considerable resemblance to verd antique; the green parts, which are the most abundant, are of serpentine. Veins of white calcareous spar run through it, and also black pieces of chromate of iron. From this latter circumstance. Dr. Meade is induced to think that all the noble or green serpentines are coloured by the green oxide of chrome. A paper by the Rev. W. Buckland, M.G.S. Prof. Min. Oxford, entitled, Additional Observations on the Beds of the Plastic Clay Formation, was read. Since the author's former communication to the Society he has traced beds similar to those observed near Reading and Woolwich, in various other parts of the London basin, as well as in several parts of the Isle of Wight basin. These observations establish the identity of the deposits, and show a formation next in order of succession above the chalk. This formation is analogous to the series of beds which in France have received the name of plastic clay, and it consists of an idefinite number of beds of sand, clay, and pebbles, irregularly alternating. Of these, in England, the sand forms the most extensive deposi- tion, in which the clays and pebbles are interposed subordinately, and at irregular intervals. The occurrence of organic remains in this formation is, like the alternation of the strata composing it, exceedingly irregular ; sometimes they occupy the clay, at other times the sand or pebbles, and very frequently are wanting in them all. These organic remains consist principally of shells of the genera ostrea, cerithiuro, and cytherea, Sections of these beds as J817.] Geological Society. 59 seen at Lewisham, New Cross, and Newhaven, are given in detail, and agree with those of Reading and Woolwich, as well as with a section of Dieppe communicated to the author by Mr. Brongniart. In several places near the metropolis tlie London clay is seen in de- tached portions resting on these beds. The author supposes that these portions of the London clay are the remaining parts of a con- tinuous stratum that once covered the whole of the intervening country, and connected the deposits of Sydenham, Shooter's Hill, and Highgate, May 2.— A paper by S. Giovanni Massa, Eleve of the Council of Mines of iVIilan, entitled, Observations on the Mineralogy of the Ligurian Mountains and the hills of Montferrat, was read. The mountains which form this range are a branch of the Alp that separate the plains of Piedmont from the sea. That part which extends along the northern side of the states of Genoa is called the Ligurian Appenines. The rock most abundant here is green ser- pentine, of various shades of colour, frequently interspersed with greenish-brown diallage. The serpentine passes into chiorite-siate, which, on tlie other hand, at a place north of the Giovi, passes into gneiss. Beds of lime-stone, both primitive and secondary ; of green- stone containing epidote, and of a conglomerate of which the frag- ments are chiefly of serpentine, are enumerated among the rocks of this district. The author also mentions the occurrence of several minerals, among which is idocrase, much resembling that of Pied- mont. On the northern side of these mountains, towards Montferrat, are high hills formed of an alluvium resulting from the fragments of all the rocks of this district, the parts diminishing in size as the distance from the mountain increases. Beyond these hills are those of Mont- ferrat, of a less elevation, composed of alternating beds of sand- stone and tufa, and containing numerous organic remains, such as cncrinites, ostracites, nummulites, &c. The nature of the substances that compose this large deposit, as well that of the alluvial hills as of the hills of Montferrat, com- bined with the circumstance of the size of the parts of which it is formed, diminishing as the distance from the mountains increases, are, in the author's opinion, proofs that it has been formed by the action of some violent current coming from the Mediterranean, which has worn the mountains in its passage. Thus the fragments of the serpentine rocks, being the largest in size, have been the first deposited ; and the calcareous cement is in such small quantity, that it hardly holds them together. The hills of Montferrat are formed of much finer particles ; and their composition, containing all the materials that compose the gneiss, the author attributes their origin to that rock, which occurs in sufficient abundance in the westera mountains of Liguria to justify this supposition. ROYAL GEOLOGICAL SOCIETY OF CORNWALL. At the quarterly meeting of this Society a paper was read, on the €0 Proceedings of Philosophical Societies. [Jui,y, ditferent Tests for the Discovery of the Presence of Arsenic, by Dr. Paris. The author stated that, since the extraordinary and notorious trial at the late Assizes, his opinion had been so repeatedly solicited upon the subject of arsenical tests, that he felt it his duty to offer the present paper as an answer to them. It afforded him also an opportunity of communicating to the Society a simple method of so modifying the ordinary experiments as entirely to avoid those fallacies which had been attributed to them. The test of nitrate of silver was well known to furnish its indication by the colour of the precipitate which it induced with the suspected liquid. It had, however, been observed by a pupil of Dr. Marcet that the phosphoric salts had the property of throwing down with nitrate of silver a precipitate perfectly analogous in colour to that from arsenic; and as these salts were known to have existence in the animal fluids, a source of perplexity and error was thus connected with any expe- riment, with nitrate of silver, on the contents of the stomach. This difficulty, however, the author stated might be overcome by modify- ing the experiment as follows : — Instead of conducting the trial in glasses, drop the suspected liquor upon writing paper, making a broad line with it. Along this line a stick of limar caustic is to be slowly drawn, when a streak is produced of a colour resembling that known by the name of the Indian yellow, and this is alike ob- tained by the presence of arsenic and of phosphoric salts ; but the one from arsenic is rough and curdy, as if effected by a crayon ; the other, quite smooth and even in its appearance, such as would be produced by a water colour. A more important, and still more unequivocal mark of distinction, soon succeeds : in less than two minutes the phosphoric yellow fades into a '^ sad green," becoming gradually darker until it becomes black ; the arsenical yellow, on the other hand, remains permanent for some time, when it becomes brown. In performing these experiments, the sun-shine should be avoided, or the transition of the colour is too rapid. This experi- ment, however, is not related vvith a view to supersede the more important one of the reduction of the metal : indeed, in a matter x>{ such serious importance, observed the author, a combination of unequivocal proofs was required. Mr. Gregor had suggested to him the application of a nitrate of titanium as a new test. In this case the suspected powder should be treated with nitric acid. The cir- cumstance, however, of the phosphoric acid precipitating the titanium in a manner similar to arsenic, offered an objection which he was not prepared to surmount. It was, however, well worthy the attention of chemists. Sir Rose Price, Bart. V.P. communicated to the Society a Re- solution of the Grand Jury at the late Lent Assizes for the county, framed in consequence of a recommendation from Mr. Justice Abbot, conveyed in his charge to them; the object of which was to impress upon the mining interests the great importance of imme- diately introducing the " Safety Instruments " for the prevention of the accidental explosion of gunpowder, described in a pamphlet lately published by John Ayrton Paris, M.D. 1817.1 Scimtific Intelligence. 61 Mr. Gregor announced, tlirough Dr. Paris, a new species of coal which accompanies the culm, imported from Wales for the purposes of smelting. This substance is characterized by a property of de- tonating most violently with nitrate of harytes ; the result of which is tlie most copious evolution of prussic acid, and the formation of a prussiate, together with a carbonate of barytes. A paper was also read, by John Henry Vivian, Esq. entitled, A Sketch of the Plan of the Mining Academies of Freyburg and Schenmitz. The object of this paper was to point out to the Society the useful and objectionable parts in the detail of these schools, in order to assist the Council in their intended arrangement of a mining academy in Cornwall, and of the establishment of a Pro- fessor's chair; and he informed the Society that when such an arrangement was completed he should present to it his mineralogical collection, formed at Freyburg, immediately under the eyes of VVeriier. Dr. Paris reported that he had been desired to state to the Society, by a letter addressed to him in the county newspaper, the evils and accidents which arose from the use of what is termed the standard iarrow, for carrying copper ore, the weight of which can be little less than four hundred weight. This enormous burthen is borne by all descriptions of persons who are employed in dressing and weigh- ing. It has been asserted that this pernicious practice has given rises to diseases of the most fatal kind. It was resolved that this notice should he entered upon the minutes. Article XIV. SCIENTIFIC intelligence; and notices of subjects CONNECTED WITH SCIENCE. I. Lectures. Mr. Gray, of No. 27, Cross-street, Hatton Garden, began his summer course of botanical excursions into the environs of London, with practical demonstrations of the plants collected in them, on Tuesday, June 3, and continues them twice a week. Mr. Gray has been induced to adopt this plan of teaching in preference to the more formal method of lectures, as better adapted to the improve- ment of the pupils. J I. Further Improvements in Prnfessor Leslie's Method ofproducina Ice. (To Dr. Thomson.) DEAR SIR, Edinburgh, May '20, 1817. I think it worth wliile to mention, in this stage of my experi- ments, that parched oatmeal has a stronger and more extensive 2 62 Scientific IiiteUigence. [JuLV, power of absorbing humidity than even the decayed trap rock. With about three quarters of a pound of meal, occupying a surface of seven inches in diameter, I froze nearly a quarter of a pound of water, and kept it for the space of 20 hours in the form of ice till one half of the congealed mass was again melted. Tlie temperature of the room being nearly 50°, the meal had then absorbed the ISth part of its weight, though it had not yet lost more than one-third of its desiccating power. With a body of dried oatmeal a foot in diameter, and rather more than one inch deep, I have since frozen a pound and a quarter of water contained in a hemispherical porous cup, and, though the room is warmer than before, the energy of absorption seems to be capable of maintaining the state of congela- tion for a considerable time. It is curious to observe that when the experiment was reversed, and the surface of the water about double that of the rteal, this substance acquired, after the air under th« receiver had been ratified, a heat exceeding 50° of Fahrenheit, so as to feel, indeed, sensibly hot on applying the hand. lam, dear Sir, sincerely yours, John Lkslie. 111. Philosophical Society of London. The Anniversary Meeting of the Philosophical Society of London was held at the Society's rooms, adjoining Scots' Corporation Hall, Crane-court, Fleet-street, on Thursday, June 12. The following Noblemen and Gentlemen were chosen officers and Council for the ensuing year : — President. — Right Hon. the Earl of Carysfort, K.P. F.R.S. F.A.S. D.C.L. Vice-Presidents. — Right Hon. Lord Henniker, F.R.S. F.A.S. ; Sir J. C. Hippisley, Bart. M.P. LL.D. F.R.S. F.A.S.; Isaac Hawkins Browne, F.R.S.; Rev. W. B. Collyer, D.D. F.A S. ; Olinthus Gregory, LL.D.; Rev. A. Rees, D.D. F.R.S. F.L.S. ; James Sowerby, F.L.S. G.S.W.S. ; J. F. Vandercom, F.G.S. Treasurer and Honm-ary Secretary. — Thomas Joseph Pettigrew, F.L.S. Registrar. — John Miers. Assistant Ditto. — T. K. Cromwell. Curators. — W. C. Pettigrew ; T. J. Armiger. Orator for 1818. — John Mason Good, F.R.S. Council. — Thomas Adams; James Andrewes ; Jonathan Barber; Rev. George Bathie, D.D. ; Thomas Bedder; Benjamin Bensley; Clarke Burton; Jonathan Thomas Cooper; George Dudley; Thomas Fisher; Charles F. Forbes, M.D. ; H. C. Hodge; Samuel Meadows ; B. H. Smart ; Peter Thomas ; Richard Thompson ; Thomas Tucker ; Rev. T. M. Young, LL.B. The Anniversary Oration was delivered by Dr. Gregory, and will shortly be published. It was very numerously attended ; as was also the dinner; and many excellent addresses were made by H. R. H. the Duke of Sussex, who was in the chair, by Lords 1817.] Scientific Intelligence. 63 Erskine, Kenniker, &c. ; Drs. Gregory, Mason, Collyer ; Messrs. Coleridge, Pettigrew, &c. &c. &c. A volume of Transactions of the Society is now in the Press, and will appear about the close of the present year. IV. Prize Queslion ly the Royal Medical Society of Edinburgh. The Royal Medical Society of Edinburgh propose, as the subject of a prize essay for the year 1818, the following question : — ** What changes are produced on atmospherical air by the action of the skin of the living human body." The members only are invited as candidates. The dissertations are to be vvritten in English, French, or Latin, and to be delivered to the Secretary on or before Dec. 1. To each dissertation shall be prefixed a motto; and this motto is to be written on the outside of a sealed packet containtng the name and address of the author. V. Query respecting the Diseases of the IVest Indies. (To Dr. Thomson.) SIR, I shall feel extremely obliged if you will inform me, through the medium of your Annuls, whether there are any treatises extant on the diseases of the West Indies ; and, if there be any such, which would be the most useful to a person about to embark. With great respect I remain, your obliged humble servant, May 20, 1817. Z. The works of Dr. Grainger and Dr. Moseley on the diseases of the West Indies are well known. In the year 1801 Mr. Clark pub- lished observations on the nature and cure of fevers and of diseases of the West and East Indies and of America, with an account of dissections performed in these climates, and general remarks on the diseases of the army. From any of these works my Correspondent will obtain, in all probability, the information which he wants, — ^T. VI. On Sailing to the North Pole. (To Dr. Tlioinson.) SIR, Glasgow, May 17, 1817. It was with the most lively pleasure I perused the questions and answers sent from Col. Beaufoy, in the last number of the Annals, respecting the practicability of reaching the North Pole. In since discussing the subject at a Society here, one of the members sug- gested that in very high latitudes the centrifugal power likely operates, which may account for all the masses of ice there making their way southward. This idea was combated by all present, ex- cepting that gentleman and myself; they allcdgiug that the effects of that power could not be seen tlierc more than at the equator, and 64 Scientific Intelligence. [Juw, that the cause of the southerly motion of the ice is the great tide making its way round the north capes of the Asiatic Continent, and from thence passing in a southerly direction. I would fain cherish the hope that the above enterprise, if at- tempted, will be crowned with success, and that a northern terra incognita will yet be discovered, with perhaps human inhabitants, and probably the mammoth will be there seen alive. It is not many years since the remains of what was supposed one were found in these regions, with part of its flesh and skin fresh on the bones. This could not have been hundreds or thousands of years preserved there, amongst the snow, as was then asserted by naturalists, but must have come from some, perhaps that, terra incognita. In one of the above answers quoted by Colonel Beaufoy it is said that certain people who have been on the high lands of Nordaster Island saw to the northward Jie whole sea clear of ice, and that large flocks of aquatic birds in the spring take a route in that direc- tion even past Nordaster. 1 would ask, if there be no land, or if the sea there were " as a molten looking-glass," would their in- stincts lead them to perish in a quarter where nothing liquid was to be found ? I should be very glad of the opinion of yourself, or any of your intelligent readers, as to the centrifugal principle acting in the manner above mentioned. We all know that if it were not gravity counteracting, every substance, especially at the equator, would fly off in a tangent : but in the above case I see no law of nature to prevent the ice from obeying the centrifugal impulse; gravity can- not, as a floating body gets neither heavier nor lighter (properly speaking) by approaching to, or receding from, the pole. If it got heavier, all bodies would tend to the pole; and if lighter, ihen all would recede from it, and approach the equator. But, on the other hand, it may be alle;j;ed that, suppose a vessel fitted out for the expedition could be got into the clear sea beyond Nordaster, it would be subjected to the same centrifugal impulse as the ice. This I grant ; but then it would acquire by sails or steam, or both, an impelling power superior io the centrifugal ; and the nearer the vessel approached the pole, unless the poles be very oblate, like those of an orange, the latter power would become weaker, as the velocity of the globf tiiere would decrease. I do not recollect in what direction navigators say the southern ices move ; but no approaches to the south pole have ever been made so near as to the other. Upon the whole, this is a subject that still wants much investigation ; and as new ideas may be elicited by discussion, I hope you will invite your correspondents to turn tlieir attention to it. Much light on natural history may be the result of a successful attempt to explore the " eternal pivots on which this world Tevolves." I am your obedient, B. Z. 1-8 170 Scientific Intelligence, 65 VII. Description of a Machine for raising heavy Weights, called a Jack. By Mr. Moyle. (To Dr. Thomson.) SIR, Being obliged some few months since to raise the roof of an old house that had sunk and fallen much into decay, I was under the necessity of having recourse to an instrument generally denomi- nated the Jack, a machine worked by a handle communicating to a single tooth and pinion (sometimes they are multiplied) that raise a perpendicuhu' lever, the power of which certainly is very great, but often not adequate to have the desired effect; and where they can be used, the immense weight causes so great a friction on the teeth of the lever, and owing to the lever being raised perpendicularly, its teeth become in a short time so much worn that before the second tooth of the pinion can act on the second tooth of the lever, the first is disengaged, and consequently the lever falls back, and no ground is gained. This was the case with one I was obliged at first to use, which of course not answering the purpose led me to think how to improve its construction. I have, therefore, had one made upon the following principle, which is equal to any weight ; and, although the friction is very great, it is more generally diffused, so that the wear of any particular part is not so much but that it will continue useful for a great space of time beyond the one in common use, and by no means liable to the same defect. It may be made more or less powerful, according to the nature of the screws. In the one I have the handles are turned 23 times while the head makes one revolution. DESCRIPTION OF THE PLATfe. Let A (PI. LXX. Fig. 4) be a firm cylinder of wood fixed to the bottom, B, and headed with a collar of steel, C, the upper surface of which is well polished, and on which revolves the head, D, wholly made of brass, the flanches of which, E, E, (Fig. 5) bear the friction, which, being made of these two metals, tlie wear is not so great. This head is revolved by a male iron screw axle, F F, work- ing in a hollow female screw, G G, of the brass head, D. The small stop-wheel, L L, works against the bra^s collar, C. M, M, are the catches. The cylinder is made hollow to allow the perpendicular lever, I, to rise and fall through the brass head, D, which has also a female screw, K, through which the male screw lever works. N, a knob or projection at the foot of the lever, to prevent its turning round, which of course it would in preference to the head, if not prevented. O is a forked head-piece, which may be taken off: its use is to fix firmly on any thing oblique which is to be raised. 1 am. Sir, your most obedient, nelslon, May 1, 1817. M. P. MoVtB, Vol. X. N» I. E 66 Scientific Intelligence. [Jul VIII. Query respecting the Mode of Freeing Wine from Common Salt. (To Dr. Tliomson.) SIR, I should feel extremely obliged if you, or any of your corres- pondents, would inform me if there is any method of ridding some of the salt which may be mixed with it from the sea water, and that without injuring the wine, more particularly Port Wine ; at the same time communicating the process, if any. I am, Sir, yours, &c. _ M. P. M. I am not aware of any practicable method of freeing wine from common salt. Freezing would succeed if it could be employed without injuring the wine. — T. IX. Proposed Improvement in Brooke's Blow-pipe. By Mr. Barchard. (To Dr. Thomson.) MY DEAR SIR, As inventions in general admit of improvement, and gain it frequently from the ideas suggested by different individuals, it will not, I hope, be considered presumptuous in offering some further alteration at least, and I hope improvement, in Newman's blow- pipe, an instrument now so necessary to every chemical laboratory, from its portability, easy application, and extensive use, that every person having once had occasion to use it must be happy in being able to communicate any alteration that may lead to its further application, particularly as it has in its present state so far exceeded the ideas of its original maker, which was that of a common air blow-pipe only. Its present application is, I believe, pretty generally known, viz. its condensed gaseous explodible mixture, which, notwithstanding the various improvements by Professor Cummings, Clarke, VVollas- ton, &c. is still too liable to explode to risk the use of a much larger reservoir than the one at present in use ; though indeed, could \vc adopt ever so large a one, the same objection would still continue, namely, that of its decreasing in power as the pressure is taken off by the escape of a portion of the air ; an objection of material consequence in the reduction of some of the refractory earths, when we frequently find the reservoir empty at the moment the most intense heat is required. It will perhaps be said that my proposed alteration will render it complicated, and of course more expensive ; but surely we are not to give up the use of it in its more extended views because the cost is a few more shillings, particularly so when it is the only way in which we can at present attain the intense heat it produces. \ 1817.] Scientific Intelligence. 6J The annexed sketch (Plate LXX. Fig. 2) will represent the means proposed for introducing a constant supply of gas by means of a double barrel condensing syringe, worked by a rack and sector; in which let A B represent two small condensing syringes, joined too-ether at bottom with two plungers working in them, moved by the handle, D, and sector, C. There is also another tube, G, for the supply of gas from the bag, F, to the barrels. It will appear evident that by moving the handle the plungers will be ultimately raised and depressed, thus forcing a constant stream through the alternate valves, A A and B, to the reservoir, E. It will be ad- visable to place a small safety valve in the top of the leservoir, as represented at H, for the purpose of allowing a portion of the gas to escape, should it be supplied too fast by the syringes. The jet will be thus regularly maintained, and for any length of time. It might be conveniently attached to the treadle of a turning lathe, and thus filled by the foot, by substhuting a crank for the sector. I remain. Sir, respectfully yours, R. VV. Barchabd. X. Another Improvement. By Mr. Booth. (To Dr. Thomson.) DEAR SIR, Barnet, April 15, 1817. Having noticed several improvements proposed, in order to render the use of the gaseous blow-pipe more safe, 1 have been induced to make a further alteration in the construction of that useful instru- ment, which, by possessing several advantages of make, as well as extreme cheapness and simplicity, you may consider worthy a place in your Annals, The apparatus consists of a large bladder to contain the mixed gases, mounted with a stop-cock, by means of which it may be filled from a transferring receiver without the least trouble. It is then placed between two boards, the uppermost of which moves in a frame, and contains the weights requisite for condensing the gases. The stop-cock screws into the top of one of Professor Cumming's syfety cylinders, to which is added a jet of capillary tubes (as pro- posed by Dr. Clarke). [See Plate LXX. Fig. 6] . The advantages of this plan of construction are the following: — 1. Extreme readiness of construction. 2. The advantage of in- creasing or diminishing the force of the jet by means of the weights. 3. Great safety : for, as the last portion of mixed gases is forced out with the same degree of force as the first (which is not the case in the condensing one), there is not that chance of an explosion from the retrograde motion of the flame (supposing it able to over- come the other precautions, which is not likely) as there is in others. And sliould such an accident happen, it would be attended with comparatively little danger. On this account the number of tubes in the fagot, and the diameter of the jet, may be increased with safety. I am. Sir, yours truly, Thomas S. Booth. £ 2 68 Scientific Intelligence. [July, P.S. Since writing the above (which 1 intended to have sent you, last month), I have been informed that a similar mode of construc- tion has been adopted by the Marquis Ripolti) if I am correct in the name). He uses two bladders ; the one containing the hydrogen being furnished with a jet tube twice the size of that containing the oxygen, and the condension formed by means of an iron bar, as the plan of using the gases separately does not appear to possess so good an effect as when combined in the same vessel. You may still con- sider my plan of sufficient safety and utility to lay before your readers. XL Arithmetical Query. (To Dr. Thomson.) SIR, In the fourth number of the Literary Gazette, p. 57 (Feb. 15, 1817)j the following intelligence is given : — " M. Von Synghel, of Ghent, has employed nine years of in- tense study for the purpose of finding out some method of simplify- ing arithmetical calculations, and has succeeded, in the most com- plicated rules, in decomposing, producing, and reducing in one minute, and by means of a dozen figures, operations which required hours, and whole columns of almost unintelligible fractions. His method is applicable to money of all kinds." I dare say many of your readers, as well as myself, would be very glad to find this true. Will you, therefore, take the trouble to say if you know any thing respecting it ; and if so, what means are to be taken to get possession of his method ? Perhaps some of your correspondents may be acquainted with it, if you should not be. Will you also be so kind as to inform me what method is gene- rally thought best to adopt for a person to teach himself mathe- matics, what books are preferred, and what order the different branches should be studied in ? If you will indulge me with this information, I shall ever consider myself to be Your very obliged servant, May 21, 1817. B. P. I am sorry that it is not in my power to communicate any infor- mation respecting Von Synghel s alleged discovery, never having heard either of the discovery or its author till I received my corres- pondent's letter. The usual mode of studying mathematics in this country has been to read the first four books of Euclid ; then to learn algebra, as far as the solution of quadratic equations ; after this, the fifth, sixth, eleventh, and twelfth books of Euclid may be studied ; trigonometry naturally follows ; then conic sections ; then Auctions, The best book on algebra that I have seen, as far as it goes, is Euler's, of which we have an English translation, I believe by Mr. Horner, of Bath; though I state this upon rather hearsay evidence. For the higher branches of mathematics, Euler's books 1817.] Scientific hitelligence. 69 are still the best ; nor is it likely that they will soon be excelled : they possess a clearness not to be found in any other writer on the higher branches of mathematics that I have ever looked into. — T. XII. Singular Formal ion found within an Egg. By Mr. Strutt. (To Dr. Thomson.) SIR, Having accidentally met with a curious formation in the inside of a common hen's egg, I have taken the liberty of sending an account of it for insertion in your Antials of next month. This formation was discovered floating in the white part of a common egg. 1 he outside consists of a shell exactly similar to that of the egg itself, but not so thick, and of a darker colour. It is about one inch and three quarters in length. Its greatest diameter, which is near the upper end, is about three quarters of an inch, and it tapers down to a point at the other end of an eighth of an inch in diameter. By piercing it at the top, and at the bottom, I was enabled, by applying my mouth to one end, to force out the con- tents, which I found exactly similar to the white of an egg, but there was no yolk. The shell gradually becomes thinner as it ap- proaches the narrower end. In the centre of it, on the surface, there is an indentation, or ring, which extends a little more than half round the egg ; and about a quarter of an inch from the nar- rower end there is another indentation, which extends almost the whole of the way round. The egg in which this singular curiosity was found was good in every other respect, and had in it a perfect yolk. I am, Sir^ your obedient servant, Derby, May 21, 1817, J- D. StRUTT. XIII. Effect of different Rocks in Scotlarid on the Magnetic Needle. By Mr. Webster. (To Dr. Thomson.) SIR, Edinburgh, June 10, 181T. The curious fact some years since noticed by my friend Professor Jameson, and lately by Dr. MaccuUoch, that the magnetic needle was sensibly affected when in contact with the granite of certain districts, led me to pay particular attention to the circumstance in a late tour through the highlands of Scotland. The instrument I used was the common miner's compass, and a comparison was often made with another of the same size and construction, placed in a distant situation. Throughout the great formation of mica-slate between Tarbet and Tummel Bridge, the needle was often rendered stationary when the instrument was in contact with the strata. In other instances it varied from 3 to 8, and 15° from the point indicated by the other instrument, and it was more than once much agitated when brought near the subordinate beds of hornblende rock and felspar, ^n the 70 Scientific Intelligence. [July, gneiss district of Garviemore I remarked but two instances, in which the motions of the needle^Xvere unusual ; but at the well- known veins of granite at the Bridge of Grey it was rendered nearly useless, both when in contact with the veins, and when at some distance from them. At the Fall of Fyers, when endeavouring to ascertain the position of the sienitic granite and the conglomerate, the motions of the needle were so irregular and varying, that little or no dependance could be placed upon it. This was the case both with regard to the granite and conglomerate. I was somewhat surprised to observe no effect whatever upon the motion of the needle when presented to the granite of Portsoy, but a very decided and powerful effect from the serpentine, whenever the instrument was brought within a few feet of it. The granite of Aberdeen produced in some instances an effect, in others not the slightest, and this in different parts of the same vein. The only instance in which I have seen the action of the needle disturbed by the rocks of the trap formation was at Stonehaven, where an extensive bed and alternations of trap tuff with the other rocks occur. Here the needle was often, indeed almost constantly, affected. This may perhaps be in some degree attributed to the presence of red and brown haematite, which occur in innumerable small veins in the tuff. I have lately made some comparative ex- periments with the trap tuff of Salisbury Craig and Arthur's Seat, but have ever found the needle perfectly free in its motions. The green-stone of Salisbury Craig, however, frequently affects the needle, even in hand specimens; but in these the glass discovers numerous specks of the hydrate of iron, and often of the sulphuret, to the presence of which we must attribute this circumstance. In no instance have I found a piece of pure green-stone produce any effect. I expected to have found some of the sand-stones, especially the old red sand-stone, affect the instrument ; but in no instance were my expectations realised. It may not be improper here to remark that I found sulphuret of iron in considerable quantity in the granite veins of Garviemore, and brown haematite in one instance at Aberdeen. 1 am, Sir, yours, &c. J. W. Webster. XIV. Fusion of Wood Tin. Dr. Clarke, of Cambridge, has made a curious addition to our knowledge respecting wood tin. When exposed to the action of his powerful oxygen and hydrogen blow-pipe, it fuses completely, acquires a colour nearly similar to that of plumbago, with a very strong metallic lustre. Dr. Clarke was so obliging as to give me some specimens of wood tin thus fused. It was very hard ; as far as I could judge, nearly as much so as common tin-stone. It was brittle, and easily reducible to a fine powder. I found it not in the 17.] Scientific Intelligence. 71 least acted on by nitric acid, muriatic acid, and nitro-muriatic acid, even when assisted by heat. Hence it must still continue in the state of an oxide. The circumstance that wood tin (and probably tin-stone also) acquires a metallic lustre when fused, seems to decide a subject which has been agitated in this country with much keenness. It was asserted by Dr. Hutton, and is still maintained by his followers, that all granite has been in a state of igneous fusion. From Dr, Clarke's experiment, it may be inferred, with considerable confi- dence, that the granite in which the ores of tin occur has never been in a state of fusion. XV. Turkey Oil-stone. This stone, which comes from Iconium, in Asia Minor, and is used as a whet-stone, was lately analyzed by Mr. Holme, from a specimen given to Dr. Clarke by Mr. Knight, of Foster-lane. Its constituents were as follows : — Silica (in very fine powder) 72 Lime 1344 1 O Carbonic acid lO-fC- Alumina 3-f4 100 XVI. Black Foivder remaining after the Solution of Tin in Mu- riatic Acid. Mr. Holme has lately analysed this black powder, which has been long known, and generally supposed to contain arsenic. He finds it a pure protoxide of copper. I think it but fair to mention that I had beeen informed by Dr. VVollaston, several months before 1 heard of Mr. Holme's experiments, that the black powder was copper. Dr. WoUaston had determined its nature by experiment. XVII. Holmite. Dr. Clarke has given this name to a singular lime-stone found in tlie pavement of Cambridge, and analysed by Mr. Holme. The following is his account of it : — " It was found in the pavement of our streets, and brought to me as a mass of emery, its effervescence in warm acids betrayed its real nature ; but its remarkable specific gravity, vvhicii equals 3"597, being equal to, if not greater than Jameson's compact brown iron-stone (vol. iii. p. 258), induced me to pay more atten- tion to it. When acted upon by the blow-pipe, minute particles exhibiting a pseudo-metallic lustre are manifested, and these of course are mica ; but they are not visible until the stone has been thus heated. When this mineral was first brought to me it had the form of an oblique, rhomhoidal, four-sided prism. It was of very considerable magnitude. We know not whence it came j therefore, 3 72 Scientific Intelligence. [July^ if you see no objection, I shall call it Holmiie. The following is Holme's analysis of this mineral :-<^ Lime 27 gr. Carbonic acid 21 Alumina 6-9- Silica G^ Iron oxide ~^\t, Water 10 100 XVIII. Account of a very remarkable Mineral Water. By Mr, Garden. (To Dr. Thomson.) SIR, Some time ago I was requested to examine a sample of an acidu- lous water (which had lately been imported into this country) with a view to ascertain whether it could be applied to any useful purpose. The extraordinary physical properties which it seemed to possess excited in no small degree my attention ; and I found, upon in- quiry, that the gentleman from whom I received it, and who brought it to England, iiad discovered it upon an island in the South Sea. The island, he informed me, is laid down on some of our maps. It is called White Island, and is situated on the coast of New Zealand. It is believed to be of a very volcanic nature, as a considerable portion of its surface exhibited the phenomenon of combustion. The water in question issues from a lake of considerable magni- tude, and constitutes a small rivulet, which flows into the ocean. Its temperature, when taken up, was considerably above that of the, atmosphere. The physical characters of the water as I received it are as follows : — It is of a pale yellowish-green colour ; it has an odour resembling that of a mixture of muriatic and sulphurous acids, and possesses a strong acid taste, in which the styptic taste of a weaU solution of iron is discernible. Specific Gravity, 1'073. With regard to the chemical constitution of this fluid I have not as yet had sufficient leisure to determine it with that precision which, its peculiar nature appears to demand : as I propose to do this at €i future opportunity, 1 shall content myself for the present with stating its composition, in so far as the experiments which 1 have hitherto made enable me to do. A solution of carbonate of soda, when dropped into a portion of the water, produced a brisk effervescence ; and when added to satu- ration, a liglit brown floculent precipitate fell down. Muriate of barytes occasioned a decided precipitate insoluble in nitric acid. IS 1 7.] Scientific Intelligence. 73 Nitrate of silver produced a dense white coagulum, which became coloured by exposure to the solarQrays. A thousand grains of the water was introduced into a glass retort, and distilled to dryness. The distilled fluid (in which a few minute particles of sulphur ■were observed to float) was but slightly affected by the addition of nitrate of barytes ; but when treated with nitrate of silver, an abundant and dense precipitation of muriate of silver instantly ensued. The precipitate, when washed and desiccated, weighed 250 gr., thereby indicating the presence of about 624^ gr. of mu- riatic acid. The mass which remained in the retort was digested in distilled water; the whole was dissolved, to the exception of a small quan- tity of a very insoluble salt, which upon examination appeared to be sulphate of lime. The fluid, after being concentrated by evapo- ration, was set aside for some days, at the end of which a group of octohedral crystals of alum were observed to have been formed. The remaining liquid, vviien decanted from the crystals, and de- composed by a solution of carbonate of soda, gave a precipitate, which, when treated by caustic potash, yielded pure alumine and oxide of iron. From the preceding cursory analysis, to which it will be ob- served I have submitted this curious mineral product, it would appear to consist chiefly of muriatic acid, a slight trace of sulphur, small proportions of alum, muriate of iron, (probably sulphate of iron), and sulphate of lime. As 1 am not aware that any similar mineral water is known, or ever has been described, in which uncombined muriatic acid* forms tiie leading constituent part, it may in this respect justly be considered as a curious production of the mineral kingdom. 1 am. Sir, your obedient servant, 3T2, Oxford-street, London. A. GARDEN. Article XV. A^eiv Patents. John Barton, of Silver-street, London, civil engineer; for certain improvements in pistols. Aug. 31, 181(>. John Kirkman, of Bioad-street, St. James's, Westminster ; for a method of applying an octave stop to piano-fortes. Oct, 14, 1816. • Vaiiquclin is said to have found it in a free state in a volcanic rock situated in tlic Puy-dc-Dome ; and there is, I believe, in the 18th volume of the Annalos du Mus.e, an interesting paprr by Leshenault on a sulphuric aoid lake at the bottom of Wont Iilienne, on the south-east coast of Java; but this, as tite name anaouiices, is almost wholly cuinpusud of sulphuric acid. 7^ New Patents. [July, Louis Fauche Borel, of Frith-street, Soho, Esq. ; for a method of making boots and shoealwithout sewing, so as entirely to keep out the wet ; which invention may be applied to other useful purposes in leather. Oct. 25, 1816. Lewis Granholm, Foster-lane, London, a Captain in the Navy ; for a method or methods, process or processes, or means, for rendering or making articles made or manufactured of hemp or flax, or of hemp and flax mixed, more durable than any such articles are as now made or manufactured. Oct. 25, 1816". William Barley, of Hunslet, parish of Leeds, wire-worker; and Robert Hopwood Furness, of Birdlington, Yorkshire, soap-boiler; for a method of obtaining or producing saccharine matter or substance from wheat, rye, oats, and barley, bear or big. Nov. 1, 1816. Joseph Gregson, of Charles-street, Grosvenor-square, sur- veyor; for a new method of constructing chimneys, and of supply- ing fires with fuel. Nov. 1, 1S16. Benjamin Smythe, of Liverpool, schoolmaster; for a machine or apparatus, or a new method or methods of propelling vessels, boats, barges, and rafts of all kinds ; and also other machinery, as mill-wheels, and other revolving powers, Nov. 1, 1816. William Day', of the Strand, trunk-maker ; for various im- provements in or on trunks ; and also in the application of certain machinery, by means of which machinery they will contract or expand at pleasure. Nov. 1, 1816. William Snowden, of Doncaster, clerk; for an apparatus or machine to be attached or applied to carriages, to prevent them from being overturned. Nov. 1, 1816. Simon Hoskins, of St. Phillack, Cornwall, cabinet-maker ; for a steam-engine upon a new construction, for drawing water from mines for working different kinds of machinery, and for other pur- poses for which steam-engines are in gL-neral applied. Nov. 1, 1816. George Washington Dickinson, of Great Queen-street, Lincoln's Inn Fields, gentleman ; for a method, means, or con- trivance, for preventing leakage from vessels employed to contain liquids ; and for preventing the admission of moisture into packages or vessels intended to be kept dry within. Nov. 1, 1816. John Hbathcoat, of Loughborongh, lace-manufacturer; for improvements upon machines or machinery, invented and in use for the purpose of making that kind of lace commonly known by the name or distinguished by the names of bobbin net, or Bucking- hamshire lace net. Nov. 1, 1816. William Piercy, Birmingham, tortoise-shell-maker; for a method of making thimbles. Nov. 1, 1816. John Day, of Brompton, near London, Lieutenant on half pay of the eleventh regiment of foot; for improvements and addi- tions in the construction of piano-fortes, and other keyed musical instruments. Nov. 1, 1816. Robert Stirling, of Edinburgh, clerk ; for diminishing the Igiy 1 New Scientific Books. 75 consumption of fuel, and in particular an engine capable of being applied to the moving machinery,'»on a principle quite new. Nov. 1, ISIG. , ^ , Robert Raines Raines, of Myton, m the county of the town of Kingston-upon-Hull, glue manufacturer; for a perpetual log or sea perambulator. Nov. 16, 1816. William Russell, of Avery Farm-row, Chelsea, engineer; for an improvement upon cocks and vents for general purposes, parti- cularly useful to brewers, distillers, private families, &c. Nov. 19, 1816.' John Barker, of Cottage Green, Camberwell, artist; for an improvement or improvements in the method or means of acting upon machinery. Nov. 19, 1816. Robert Ford, late of Barbican, but now of Crouch End. near London, chemist ; for a medicine for the cure of coughs, colds, asthmas, and consumptions, which he names " Ford's Balsam of Horehound." Nov. 21, 1816. Walter Hall, of Serjeant's Inn, merchant ; for a method or methods of making soft lead out of hard lead, or slag lead. Com- municated to him by certain foreigners residing abroad. Nov. 21, 1816. . James Kewley, of Aldersgate-street, gentleman ; for improve- ments in and on thermometers. Nov. 21, 1816. Richard Wright, of Bishopsgate-street Within, London ; for improvements in the construction and propelling ships and other vessels. Dec. 10, 1816. William Dean, of Manchester, calico-glazier ; for machinery for waxing calico, or any other cloth or fabric, previous to the process of glazing. Dec. 14, 1816. Article XVI. Scientific Books in hand, or in the Press. Dr. Scudamore is printing an enlarged edition of his Treatise on the Nature of Gout and Rheumatism. Mr. C. C. Bomptis is about to publish an Essay on Light, Heat, and Electricity. A Translation of Orfilas Treatise on Chemistry is about to be published. Dr. Marshall Hall will shortly publish the Principles of Diagnosis, founded entirely on the external Appearances of the Disease. A Sketch of the History and Cure of Febrile Diseases, particularly those of the West Indies, by Dr. Robert Jackson. 76 Colonel Beaufoy's Magnetical [JULT, Article XVII. Magnetical and Meteorological Observations. By Col. Beaufoy, F.R.S. Bushey Heath, near Sianmore. tatitude 51° 37' 42" North. Longitude west in time 1' 20'T". Magnetical Observations, 181 7. — Variation West. Morning Observ. Noon Observ. Evenii ig Obsery. Month. Hour. Variati on. Hour. Variation. Hour. Variation. May 1 Sh 45' 24° 33' 54" Ih 45' 240 44' 58" 6K 50' 24° 35' 48" 2 8 45 24 36 48 45 24 46 47 _ _ 3 8 40 24 30 29 45 24 40 58 6 45 24 35 17 4 8 45 24 30 55 45 24 42 10 6 45 24 31 35 5 8 45 24 32 08 45 24 42 28 6 45 24 33 45 6 8 40 24 31 00 45 24 40 30 6 45 24 34 46 7 8 40 24 31 28 ' 45 24 40 09 6 45 24 32 68 8 8 45 24 34 10 45 24 39 08 6 55 24 35 40 9 8 45 24 33 11 45 24 38 41 6 45 24 30 17 10 8 35 24 32 00 45 24 44 36 _— — — II 8 45 24 32 54 45 24 44 02 6 45 24 35 11 12 8 45 24 30 33 1 45 24 42 24 — — — 13 8 45 24 32 25 55 24 40 02 6 45 24 35 06 14 8 45 24 33 09 45 24 42 36 6 45 24 34 25 15 8 45 24 33 28 45 24 41 23 6 45 24 35 24 16 8 40 24 33 54 40 24 42 08 6 45 24 34 53 17 8 35 24 31 31 40 24 44 00 6 45 24 34 4a 18 8 40 24 31 20 45 24 45 26 6 45 24 36 36 19 8 40 24 32 03 40 24 44 22 — — , — — — 20 — — _- — 50 24 42 53 — — 21 — — — — — — — <-~^ .— 6 40 24 34 18 22 8 40 24 31 51 45 24 S9 43 6 45 24 34 17 23 8 35 24 31 53 45 24 44 09 6 45 24 35 12 24 8 40 24 32 41 55 24 42 18 6 55 24 33 28 25 8 40 24 32 02 55 24 45 46 6 55 24 35 35 26 8 25 24 32 33 45 24 42 01 6 50 24 35 32 27 8 40 24 31 58 35 24 40 06 6 50 24 35 07 28 8 40 24 ■S2. 19 45 24 41 00 6 50 24 35 m 29 8 40 24 33 56 40 24 40 16 6 45 24 33 34 30 8 40 24 28 46 40 24 47 16 6 50 24 34 58 31 8 40 24 31 07 40 24 45 16 6 50 24 34 03 Mean for Month. \^ 41 24 32 20 1 45 24 42 35 6 47 24 34 45 On the 12th, in the evening, the needles were too unsteady for an observation. 1817] and Meteorological Tables. Meteorological Table. 77 Month. Time. Barom. Ther. Hyg. Wind. Velocity. Weather. 3ix'5. Inches. Feet. f Morn .... 29'440 410 66" N Cloudy May 1 ) Voon. . . . 29-457 44 39 NNE 16-166 Cloudy 460 ( Kven .... 29-505 42 58 NNE Cloudy |39 r Morn. . . . 29-544 43 56 N Fine A Noon 29-540 50 47 NE 16-244 Fine 56 \ Even .... _. — — — — ■43 ( Morn i 29-485 50 49 W by N Fine A Noon.... 29-423 54 43 Wby N 15-545 Cloudy 58 I Even 29-375 48 45 W Cloudy }45 c Morn. . . . 29 390 53 53 NVV by W Fine A Noon. . . . 29-440 57 41 WNW 16-949 Fine 39 I Even 29-541 51 42 NW Fine •41 r Morn. . . . 29-643 53 46 ssw Clear A Noon. . . . 29-638 62 37 ssw 16-987 Clear 64 I Even , , . . 29-620 35 42 SW by S Clear 41 f Morn... . 29-705 57 50 NW Fine 61 Noon.... 29 760 60 43 N 8-239 Fine 65 I Even 29-788 53 42 NNE Clear J39 r Morn .... 29-845 52 40 E Clear A Noon.... 29-758 60 35 E by S 21-646 Clear 61 I Even 29-670 55 42 E Clear }„ ( Morn 29-430 56 52 NNE Fine »i Noon... . 29-390 68 54 NK 9-634 Fine 70 I Even . . . . 29-304 54 56 E Fine }« s Morn . , . . 29 -563 49 54 NE by E Fine ^\ Noon. . . . 29-325 55 51 NE by E 17-233 Fine 56 I Even 29-285 50 54 NE Cloudy }« ] Morn . . . . 29-107 49 64 SSW Cloudy \q\ Noon... . 29-043 57 50 ssw 19-368 Cloudy 5S I Even — — Rain }3» 1 Morn. . . . 29-075 48 54 NW hv W Fine 'M Noon... . 20-090 56 38 WSW 18-633 Fine 5S L Even 29090 49 52 SW Cloudy }« X M»rn 28-900 50 62 WbyS Showery n< Noon. . . . 28-935 55 45 WbyS 30-414 Fine 56 Even 29010 45 58 W by N Showery }- f Morn. . . . 29-252 48 30 W Fine Xi< Noon 29-300 51 50 W by N 19-832 Fine 55 L Even . . . . 29-300 47 63 SW bj S Drizzle }« f Morn 29-208 46 69 SE Drizzle 14^ Noon 29-212 55 52 SW by S 21-082 Fine 56 L Even . . . . 29-238 46 60 WSW Showery 41 r Morn 29 347 51 54 W Fine 15^ Noon.. . . 29-392 58 44 W 7-184 iFine 61 I Even ... 29 447 51 56 WNW JFine ^40 1 Morn 29-546 55 53 WSW Clear '^) Noon . . . 29-515 62 37 Var. 5-026 Fine 63 L Even 29-480 54 44 E Fine 66 1 Morn . . . 29-435 55 51 SSW Cloudy \l\ Noon. .. 29-425 64 43 ssw 8-582 Cloudy I Even . . . 29-362 37 44 SW Fine ^49 ( Murn. . . 29-215 59 54 E Cloudy 18 -J Noon.. . 29-100 65 48 ENE 9-196 Cloudy 68 Even .. . 29-0.55 38 70 WNW Cloudy fs Col. Beaufoy's Meteorological Talle. [July, Meteoroloaical Talle continued. Month. Time. Barotn. Ther. Hyg. Wind. Velocity Weather Six's. Inches. Feet Morn 29-078 490 62° NNE Cloudy Rain 45* May 19 J Noon 29-080 54 53 NE liy E 15-898 55 Even . . . . 29-065 54 73 NE Rain 40 Morn 29-060 44 96 NE Rain 2oi Noon . . . . 29-050 49 80 NEby N 16-200 Cloudy Even 29-050 46 84 NE by N Itain 49 Morn . . . . 28-982 44 94 NNE Rain 21 i Noon. .. . — — — — _ Rain Even . . . . 29-000 43 75 W Drizzle |40 50 Morn 29-013 44 68 wsw Cloudy Cloudy Showery Cloudy Fine 22^ Noon. . . . 29-025 49 5S Why S 7-512 Even .... 29-023 45 65 Wby N 59 Morn .... 29-050 48 60 Why N 23-| Noon 29-045 67 47 W 4-945 Even .... 29-045 49 63 WSW Fine |.40 57 Morn 29-085 43 59 sw Fine 24-! Noon 29-080 52 55 w 9-T41 Showery Even .... 29 070 50 54 ssw Fine 53 Morn... . 28-900 50 73 E Showery Showery 25"| Noon 28-847 50 75 ESE 12-673 Even .... 28-806 50 70 ENE Fine }« Morn. . . . 28-763 53 68 SEby E Cloudy 26 -j Noon. . . . 28-818 58 49 SE 12-894 Cloudy Fine 58 Even . . . 28-880 51 59 ESE }4S Morn 29-000 55 65 E Fine 27-J Noon. . . . 29-056 59 52 SE 9 HI Fine 59 Even .... 29-105 53 54 S Fine }44 Morn .... 29-225 56 52 Var. Fine •28-| Noon. .. . 29-243 55 61 NNE 7-991 Cloudy 61 Even .... 29-260 53 63 WNW Showery |47 Morn. .. . 29-185 48 86 N Showery 29 -j Noon. . . . 29-225 47 83 NNE 17-970 Showery 48 Even 29 -'295 45 76 N Drizzle |42 Morn. . . . 29424 46 54 N Fine 30< Noon. .. . 29-443 50 54 N 10-915 Fine 54 Even .... 29-460 46 53 NNE Cloudy ;« Morn... . 29-485 46 54 NW Fine 31 \ Voon. . . . 29-432 50 48 NNW 9-327 Cloudy 55 Even .... 29-382 49 49 W Fine Column Six's contains opposite Noon the greatest degree of heat between the morning and evening observation ; and then follows the least degree of heat between the evening and morning observation, and so on. On the 23d, at four o'clock, P. M. thunder was heard in the south-east. 1817.] Metewologkal Table. 79 Article XVIII. METEOROLOGICAL TABLE. Barometer. Thermometer. | Hygr. at isn. Wind. Max. Min. Med. Max. Min. Med. 9 a. m. Rain. 5th Mo. May 8 Var. 2972 2968 29-700 72 42 57-0 49 8 c 9 N E 29-68 09.49 29-585 54 37 45-5 59 10 S W 29'43 29-3529-390 60 38 49-0 45 — 11 Var. 29-35 29-2329-290 43 48 -15 12 W 29-63 29-2329-430 45 _ 13 s w 29-63 29-5929-610 59 34 46-5 58 •13 14 w 29-74 29-59 29-665 41 •45 15 s w 29-90 29-74 29-820 62 33 47-5 49 16 Var. 29-90 29-80 29-850 65 33 49-0 50 9 17 s w 29-80 29-55 29-675 67 39 53-0 42 1 18 S E 29*43 29-36 29-395 72 44 58-0 53 •11 19 N E 29-46 29-43 29-445 53 38 45-5 67 — 20 N E 29-42 29-34 29-380 52 43 47-5 80 — 21 N E 29-42 29-40 29-410 48 38 43-0 59 — 22 S W 29-42 29-40 29-410 57 40 48-5 50 1-44 23 w — — — — w 24 N E|29-4.0 29-27 29-335 62 35 48-5 65 •IS D 25 S E 29-19 29-16 29-175 57 45 51-0 58 -29 26 E 29-37 29-17 29-270 63 41 52-0 44 27 N E 29-59 29-35'29-470 69 38 53-5 53 28 N E 29-59 29-5(i\2B-S7b 59 47 530 77 29 29-80 51 — 30 29-90 •23 0 31 29-75 29-68I29-715 59 33 46-0 50 6th Mo. June 1 S W 63 42 52-5 41 2 w 29-64 29-58 29-610 64 46 55-0 3 w 29-59 29-45 29-520 64 52 58-0 4 w 29-99 29-45 29-720 65 5 s w 29-91 29-99 29-89 29-16 29-900 65 47 56-0 54 •11 29-533 72 33 50-70 54 3-18 The observations in each line of the table apply to a period of twenty-four hours, beginning at 9 A. M. on the day indicated in the tirst rolumn. A dash denotes, that the result is included in the next following observation. *0 Meteorological Journal. [July, 181}^. REMARKS. "Fifth Month. — 8. Cirrocumulus, mixed with Nimbi, a.m. after which, the cloudiness becoming general, a thunder-storm ensued, soon after four, p.m. : it came from the SVV, with the wind at SE. 9. Cold wind, a.m. with a general cloudiness, 10. Overcast, a.m. \v\i\\ Cumulostratus : a few drops of rain. 11. Cumulus, Cumvlo- stratus, and Nimlnts: the wind NW and SW: rain with wind at night from the southward. 12, a.m. A westerly gale. 13. Showery, with hail twice. 14. Showery: hail, pretty large, at noon from the southward. 15, 16. Fair. I7. A shower, p.m. — Travelling in the interval from the 13th to the 17th inclusive as far as Leeds, in Yorkshire, and home again, I found cloudiness from large Cumulif &c. general, but met with very little rain. On the 15th, passing between Leeds and Pontefract, there was a fine display of Nimhiy one of which let fall a heavy shower on the latter place and its environs. On the 17th, after a deep orange tint in the morning twilight, the sun rose red behind a Cirroslratus ; in emerging from which the brilliant part of the disc was divided by a well-defined line from the lower and coloured portion. — 18. Cloudy, a.m.: gentle rain, p.m. 19. Windy, cloudy, a.m.: wet, p.m. 20, 21. Rainy. 22. Cloudy. 23,24. Some showers: a Straiiis at nine, p.m. the latter day. 25. Thunder at a distance : showers, a. m. 2], A thick fog at niglit, undoubtedly from a Stratus, RESULTS. Winds variable, but for the most part westerly. Barometer: Greatest height 29'99 inches Least 29-16 Mean of the period 29-533 Thermometer: Greatest height 7^" Least 33 Mean of the period .... 50*70 Mean of the hygrometer, 54°. Rain, 3-18 in. I bad anticipated a third dry period, similar to the two we had experiencedy and expected that the rains would return after the summer solstice : in this 1 have been happily mistaken. In the beginning of the present period the weather took a new type with us, the westerly current coming in again, with sortie discharges of electricity, bringing rain, which gradually became more plentiful, and proved exceedingly seasonable. Vegetation has passed, in consequence, from .a starved and backward state, to one of considerable luxuriance and promise. It is ob- servable that the barometer during this period has scarcely passed the boundary of 30 in. in elevation, and has certainly not descended below '29 in. The mean tem- perature, though 6" higher than that of the period immediately preceding, is low for the season. Tottenham, L, HOWARD. Sixth Month, 17, 1817, 5 ANNALS OF PHILOSOPHY. AUGUST, 1817. Article I. Biographical Account of M. Rochon. On April 7, 1817, was buried M. Rochon (Alexis-Marie), Member of the Royal Academy of Sciences. After the funeral service, M, Girard, Member of the Academy, delivered the fol- lowing discourse : — " Gentlemen, " Till a more worthy honour be paid to the memory of our fellow-associate, whom we deposite this day in the tomb, I hope I may be permitted to raise my voice for a few moments to call to your recollection his labours and his services. May the expression of our regret bring some consolation to the melancholy duty which we have just discharged ! " M. Rochon was born at Brest on Feb. 21, 1741. This harbour, and the vessels with which it was filled, were the first objects that struck his attention. Surrounded from his youth with sailors and voyagers, their conversation decided his taste, and the progress of naval science became the special obiect of the whole labours of his life. " He was named Correspondent of the Academy of Sciences in 17^5, To this title he soon added that of Astronomer to the Navy, and in this quality he made a voyage to Morocco in 1767- Imme- diately after his return he set out for the East Indies in a vessel commanded by M. de Tromelin, his relation and friend. He de- termined in 1 769 the position of the islands and rocks situated be- VoL. X. N° II. F 82 Biographical Account of M. Rochon. [A.VG. tween the coasts of India and the Isle of France. He returned from that colony in 177- with M. Poivre, that administrator whose wisdom and talents have left in his jurisdiction so high a reputation. " M. Rochon brought from that expedition the most beautiful crystals of quartz from Madagascar that had been at that time seen. He got some pieces of tliem cut, ascertained the double refraction which it possesses, and conceived the happy idea of applying it to the measurement of angles. Such is the origin of the ingenious micrometer, for the invention of which we are indebted to him. " Nobody knew better than our associate the wants of the province in which he had been born, and what was necessary to increase its prosperity; but the harbour of Brest fixed his constant predilection. Government approved of the plan which he proposed of cutting across Britanny a navigable canal between Brest and Nantes, which would in time of war serve to convey provisions without any risk to the first of our naval arsenals. The memoirs of M. Rochon on this important subject have the rare merit of pointing out at once the advantages, the difficulties to be overcome, and the means of sur- mounting them. ** M. Rochon fully enjoyed during the whole of his life that re- putation which his labours had justly acquired for him. He knew equally well how to make science useful in the society of men of the world with whom he was associated, and to render its applica- tion easy in the workshops of most of those arts with the processes of which he was familiar. It was by the utility of discoveries that he estimated their importance ; and when a few days ago we heard him for the last time, at one of our meetings, it was to oft'er to the Academy the tribute of a useful investigation. •' He was then in his 77th year. His strong constitution, though he had become a good deal weaker for some months past, left us the hope of preserving him, even when we heard that he was at- tacked by the disease under which he sunk. " After he had reached a mature age, M. Rochon had united himself with a widow lady, a relation of his own, and mother of two children. This union was during 25 years the source of mutual happiness, which was destroyed for ever by the fatal event which has collected us together — an event aggravated for his family by a deplorable circumstance. His respectable widow was obliged to divide her attention between her husband and her daughter, who were bolh seized at the same time with a fatal disease. Her care of both was useless, her vows were unavailing. The same instant deprived her of two objects, both most dear to her affections, and left her plunged in the deepest sorrow which virtue is capable of supporting." 18170 On ike Co77ipounds of Azote and Oxygen. 83 Article II. Appendix to the Essay on the Chemical Compounds of Azote and Oxygen. By John Dalton. {^Concluded from p. 47.) Class III.— Experiments over Mercury with Caustic Alkalies. Gay-Lussac liaving recently stated that mixtures of nitrous and oxygen gases over mercury to which caustic alkali was admitted exhibited always the same proportions of oxygen and nitrous gas; namely, one measure of oxygen uniting to four of nitrous gas; I was desirous to try if I could succeed in producing the union in like circumstances ; for which purpose I made the following expe- riments : — 1. To 133 measures of nitrous gas of 97 percent. = 121) real, 4 azote, jait 32 measures caustic soda of 1-11 sp.gr. No diminution in two hours. Put IG of 72 per cent. o.xygen =11-5 real, 45 azote. U9 102 in a few minutes, and remaining so for more than one hour. Put 16 more oxygen of same kind. 118 7^ in a few minutes. 78 in 8 or 10 hours. 76 in 1 day. 75 in 1^ 75 in 2 75 transferred, 63 nitrous by sulphate of iron. This gives 1 oxygen to 2-ai nitrous gas. 2. To 240 of 97 nitrous gas put 32 caustic potash of 1-45 sp. gr. It stood 12 hours without any change. Put 60 of 78 oxygen = 47 real, 13 azote. 300 155 in a few minutes. 1 52 soon after. 141 in 12 hours. 133 in 24 133 in 48 130 transferred over water, 109 nitrous. This gives 1 oxygen to 2-55 nitrous. The loss of 3 nitrous was occasioned chiefly by passing through the water as usual. It is obvious that these experiments are far from according witli F 2 8-1 Appendix to the Essay on the [Aug. those of Gay-Lussac ; and as he has not given us the detail of his, I cannot suggest the cause of the difference. My reason for sub- jecting the nitrous gas in the first place to the action of the alkalies was to show that these do not act on nitrous gas alone ; and I had some ground for this; for in my first trials 1 had obtained a mudi greater reduction of the nitrous gas ; but upon examination I found my potash contained a little sulphureted hydrogen, and this con- verted a part of the nitrous gas into nitrous oxide, and in this way reduced is volume. This was ])roved by admitting nitrous gas alone to the potash, when it was gradually reduced in volume, as if oxygen had been present; but when the residue was examined, it diminished rapidly, by passing a few times through water, and then left a residue of nitrous gas. Class IV. — Experhnevts on the Analyses of Nitrous Gas, Nitrous Oxide, and Ammonia, by exploding their Mixtures aver Mercury. Proust, I believe, was the first person who pointed out the analysis of ammonia, by exploding it with oxygen in Volta's eudiometer. (Jour, de Phys. 1199, vol. xlix.) A. B. Berthollet used the process in 180S, and Dr. Henry in 1809. On these modes of analysis I have already animadverted (Chemistry', p. 434), and have seen no reason since for changing my opinions. Dr. Henry at the same time discovered that the analysis of ammonia was capable of being effected by nitrous oxide and nitrous gas severally as well as by oxygen. This was scarcely to have been expected, especially by nitrous gas, which is not decomposed by hydrogen alone ; but it should seem that the azote of the ammonia, repelling that of the nitrous gas, contributes to the separation of the elements as much perhaps as the attraction of the oxygen for the hydrogen. What- ever may be the true explanation, the fact is a curious and important one ; namely, that two compounds, in each of which azote is an element, mutually decompose each other, the oxygen of the one uniting to the hydrogen of the other, and the azote of both being liberated. It mav enable us to investigate the proportions of the constituents in both compounds. If chemists were agreed respecting the composition of one of the two compounds in such mixtures (namely, nitrous gas and ammonia), it would be an easier task to ascertain that of the other; but unfor- tunately the proportions in both are yet subject to dispute. Gay- Lussac, and I apprehend some others, hold that 100 measures of ammoniacal gas are constituted of 50 azote and 150 hydrogen; whereas, according to my experiments, as well as those of Davy and Henry (see my Chemisty, p. 429, 430, 432), 100 ammonia pro- duce only 186", or from that to 190, of mixed gases by electricity; of which I find 28 or 29 per cent, azote, and the re^t hydrogen. For the sake of those who may not be much conversant in this subject, it may be proper further to state that, supposing (for in- stance) nitrous gas and an)moniaca! gas to be mixed in such pro- portions as, when fired, they may be mutually saturated, by which 18 17-] Chemical Compounds of Azote and Oxygen. S5 we mean the oxygen of the one may saturate the hydrogen of the other, and the azote of both be liberated, then, according to Gay-Lussac, 20 ammonia = 10 azote + 30 hydrogen, and they require 30 nit. gas =15 azote + 15 oxygen for their saturation ; but, according to my view, 20 ammoniacal gas = 10-i- azote + 26 hydrogen, and require nearly 2i nitrous gas = lOi azote + 13 oxygen for their saturation ; all the numbers being understood to denote measures. That is, it a given volume of azote be united to oxygen so as to form nitrous gas, and the same volume of azote be united to hydrogen to form ammonia; then the oxygen of the one will just equal tlie hydrogen of the other to form water. But it is other- wise in Gay-Lussac's view; for he insists that one-third of the hydrogen will remain in excess. In mixtures of nitrous oxide and ammonia the disproportion be- tween us is still greater; for, according to Gay-Lussac, 20 ammoniacal gas = 10 azote + 30 hydrogen, and they require 30 nitrous oxide = 30. azote + 15 oxygen for saturation ; but my view is, that ''" 20 ammoniacal gas = JO^ azote + 2G hydrogen, and that they require 21 ± nitrous oxide = 21 azote + 13 oxygen for saturation ; that is, the azote of the nitrous oxide is double that of the ammonia, whereas Gay-Lussac says it is triple. No detail of experiments on the mutual decomposition of the nitrous compounds and ammonia has been published that I know of, besides that of Dr. Henry soon after the discovery ; and it is pro- fessedly too limited for a complete exposition of the facts. Dr. Henry has only selected one experiment on the decomposi- tion of nitrous oxide and ammonia, the result of which he has ex- plained according to the facts previously discovered by Davy and himself, as the above two theoretic vievvs were not then pubUshed. We shall now see whether it supports either of them. 41 measures ammoniacal gas. 38 pure nitrous oxide. togetlier 79 73 when fired; and then found to consist of 16 hydrogen + 57 azote. 86 Appendix to the Essay on the [Aug. According to the theory of volumes, 41 ammoniacal gas = 204. azote + 6 1 J- hydrogen and 38 nitrous oxide = 38 azote + 19 oxygen. There should then be found 58^ azote + 2'i^ hydrogen, instead of 57 azote and 16 hydrogen. But, according to my view, 41 ammoniacal gas = 21 azote + 53 hydrogen and 38 nitrous oxide = 38 azote + 23^ oxygen. There should then be found 59 azote + 6 hydrogen, instead of 57 azote and 16 hydrogen. Here both theories appear at variance with experiment, and mine rather more of the two ; but the accuracy of the experiment cannot fairly be doubted. We must, therefore, see which theory can be most easily bent to accommodate it. According to Dr. Henry, when the nitrous oxide is in excess, there is evidence of nitrous or nitric acid being formed ; and I have reason to suppose, further, that in every explosion, whatever may be the proportions, less or more of the acid is formed j because I always find a small diminution of the residuary gas on passing it through water. This being admitted, we are to see how the sup- position will influence the preceding calculations. It will evidently decrease the residuary azote, and increase the hydrogen. Let us suppose that two measures azote unite to five oxygen, forming the coloured or mixed acid ; then will the residuary gas on my hypo- thesis be found to be 57 azote + 16 hydrogen, exactly agreeing with the experiment ; but the residuary gas, according to Gay- Lussac, would be 56-1^ azote + 33-i- hydrogen, differing from the experiment by 17^ measures of hydrogen. The error increases as the quantity of acid increases j and I cannot conceive any pro- bable cause to be assigned for the differences observed upon this hypothesis. Two experiments on the mixture of nitrous gas and ammonia are related by Dr. Henry in the paper above referred to : — 1. Ammonia..., 48 measures. Nitrous gas . , 53 101 fired, left 54 azote + 9 hydrogen. 2. Ammonia .... GO measures. Nitrous gas . . 36 96 fired, left 48i azote + 30i hydrogen and 10 ammonia. Before adverting to these experiments, I may observe that the quantity of ammonia present in any experiment, even if measured in the detonating tube, is very uncertain. Such is the effect of the smallest unperceived moisture in the tube or mercury, that I have known 30 measures of ammonia decomposed when there were pnly SI 70 Chemical Compounds of Azote and Oxygen. 87 20 present apparently. The real quantity of ammonia may be equal to or greater than the apparent, but cannot be less. The quantity decomposed must, therefore, often be inferred from tlie results; and the azote is the best guide, because it is that article about which the two theories differ least, my view requiring more azote in the ammonia, and less in the nitrous gas, such as usually to produce nearly a compensation. Assuming, then, in the first experiment, that 54 measures of ammonia were decomposed, instead of 48, the explanation on the two hypotheses will run thus : — Volume theory 54 ammoniacal gas = 27 azote + 81 hydrogen 53 nitrous gas = 26"i + 26-i. oxygen. There should then be found 53^^ azote + 28 hydrogen, instead of 9 hydrogen, as observed ; and the azote account is still rather too little, notwithstanding the assumption. Atomic theory 54 ammoniacal gas = 28-1- azote + 69 hydrogen 53 nitrous gas =24 + 30 oxygen, and there will be found 52-|- azote + 9 hydrogen. This agrees with the observation in regard to hydrogen, but is rather below in azote ; if we may suppose one azote in the ammo- niacal gas (a very probable supposition), it will then bring the azote up to within ^ measure of the observed quantity, and will not be detrimental to the other theory. In the second experiment, assuming 58 ammoniacal gas decom- posed, instead of 40, we have Volume theory 58 ammoniacal gas = 29 azote + 87 hydrogen 36 nitrous gas =18 +18 oxygen, and there will be found 47 azote + 51 hydrogen. Here the azote being 1-i- too little, we cannot have assumed too much ammonia for this theory, and yet the hydrogen is 20-1 measures in excess. Atomic theory 58 ammoniacal gas = 30^ azole + 74 hydrogen 36 nitrous gas =164- + 20-i- oxygen, and there will be found 47 azote + 33 hydrogen, instead of 484- azote and 30^ hydrogen. If we may suppose 1^ azote in the am- moniacal gas, both the hypotheses will accord with observation in the azote, but the former will have an excess of 20-i^ in the hydro- gen, and the latter an excess of 2-i- measures. Hence we may see how far Dr. Henry's experiments support the two systems as far as regards the compounds, nitrous oxide, nitrous gas, and ammonia. I shall now advert to my own experiments on the same subjects. Nitrous Oxide and Ammonia, &c. 1 have lately made about 30 experiments on the deflagration of ammonia, hydrogen, sulphureted hydrogen, and carbureted hydro- 85 Appendix to the Essay on the [Aug. gen, severally with nitrous oxide over mercury. My nitrous oxide was usually procured from nitrous gas by sulphuret of potash or of lime. Nitrous gas of a known degree of purity was put into a graduated two-ounce bottle over water, so as to fill it. This was transferred to the mercurial trough, where about 10 gr. of dry sulphuret of pot- ash were admitted to the gas ; an absorption of oxygen and diminu- tion of gas soon commenced ; in a little time 20 or 30 gr. of water were admitted, so as to dissolve the sulphuret, and then by mode- rate agitation the process was finished in 10 or 15 minutes, as was shown by the cessation of absorption. Sometimes 100 gr. of liquid sulphuret of lime was substituted for that of potash. The gas was then I ran.-ferred, and dried by blotting paper, and found to contain DO nitrous gas, but only nitrous oxide, and the residue of azote in the nitrous gas. In one or two instances the azote seemed rather increased ; but whether from a decomposition of the nitrous oxide, or from a little atmospheric air acquired in the manipulation, I could not ascertain. J was careful to mark the diminution of the nitrous gas when converted into nitrous oxide this way. It was always more than half of the original volume of nitrous gas, allow- ing for the azote. The average reduction of the pure nitrous gas was Irom 100 to 45, the same as Davy determined long ago. This fai t opposes Gay-Lussac's theory of volumes, as the reduction ac- cording to it should be 50 per cent.; but it accords with the high spetitic gravity of nitrous oxide (l'6l) as determined by Davy, and with its constitution such as 1 have above maintained. Nitrous Uaide and Hydrogen. — Davy, in his Researches, has given us some good experiments on this head. He found that nitrous oxide explodes with hydrogen when mixed in a great variety of proportions. When the hydrogen exceeds, little or no nitrous acid is formed ; but if the nitrous oxide exceeds, then not only water, l)ut nitrous acid, and much free oxygen, are found after the explosion. 1 have made more than 12 experiments on this mixture, and hnd that when the hydrogen a little exceeds the oxide in volume the consun)ption of hydrogen is very nearly equal in volume to the nitrous oxide ; but there is always found a trace of nitrous acid, manifested by a loss of one or two measures on transferring the re- siduum over water. If tlie hydrogen is considerably in excess, then more hydrogen is generally spent than is equal to the volume of nitrous oxide. If the nitrous oxide is in great excess, all the hydrogen disappears, oxygen sometimes to the amount of 10 or 12 per C( nt. is found in the residuum, and nitrous or nitric acid is manifest by a variety of means, and consequently a considerable loss of azote. N/lrous Oxide and Sulphureted Hydrogen. — I find that 20 sul- phurtted hydrogen recently made from muriatic acid and sulphuret of antimony require nearly 30 oxygen for their combustion; that is, 10 for the hydrogen and 20 for the sulphur. It would seem 18170 Chemical Compounds of Azote and Oxygen. 89 from the following experiment that 20 sulphureted hydrogen re- quired nearly 48 nitrous oxide. J 9 + sulphureted hydrogen = 18 + pure. 58 nitrous oxide = 46 real + 1 oxygen +11 azote. "77 6G fired. 54 washed. No oxygen nor hydrogen. Here \vc find 54 azote, instead of 57 or 58. This deficiency most probably was occasioned by a residuum of nitrous oxide which the water abstracted. According to Gay-Lussac's theory, 20 sul- phureted hydrogen would require 60 nitrous oxide. Nitrous Oxide and Carbureted Hydrogen. — 1 made two experi- ments on this mixture. Eleven parts pure carbureted hydrogen were exploded with 39 pure nitrous oxide; in all 50; when fired, 50 residue washed in lime-water left 41, of which one or two were hydrogen. Ten pure carbureted hydrogen fired with 45 nitrous oxide gave 5!); washed in lime-water, left 43, of which li were oxygen. In this last experiment theie was evidently an excess of nitrous oxide, besides the redundant oxygen; but these experiments are too few to decide a theoretic question. Nitrous Oxide and Ammonia. — Mixtures of nitrous oxide and ammonia will explode if the ammonia does not exceed the oxide. The results are azote, water, hydrogen, and a little trace of nitious acid, if the ammonia be in excess; but if the other gas be in excess, then we ol)tain azote, water, oxygen, and considerable nitrous acid. The three following experiments exhibit the chief varieties : — 1. 50 nitrous oxide of 84 per cent, = 42 real + 8 azote made 86" by ammonia of 99 percent, pure; tube rather moist; stood 15 minutes to be well mixed. 73 fired. 75^ washed, 3 hydrogen, 'J21 azote. Here if we suppose 50 nitrous oxide to produce 50, or nearly 50 azote (a point upon which we are atjreed), there will remain 2.'^ azote to be accounted for from the decomposition of iimmotna = 45 ammonia by Ghiy-Lussac = 67-^ hydrogen; from wiiich taking three, there remain 64|^ to be converted into water by the oxygen of die nitrous oxide = 21 ; but this would leave 22^- hydrogen un- supplied, and hence sufficiently shows the inadequaiy ol the livpo- thesis. On my view 224^ azote come from 41 ammonia, and these give 57 hydrogen, from which taking three, there remain 54 to be supplied with oxygen. Now 42 nitrous oxide at the rate of G2 per cent, oxygen yield 26 oxygen, being only one less than the cxpL-ri- ment requires. yo Appejidix to the Essay on the [Au«. 2. 69 i nitrous oxide = 53 real + 2 oxygen + 14^ azote. 45 ammonia 99 per cent. 114 96 fired. 94 washed. No hydrogen nor oxygen. Here the nitrous oxide must have introduced 67^ azote. Hence about 2fi azote must have come from the ammonia, which, there- fore, would not be less than 51 = 66 hydrogen = 33 oxygen. It should have been 34 by tlie atomic theory. Probably a minute portion of nitric acid was the cause of the error. But if we adopt the volume theory, there would have been a redundancy of 19 hydrogen. 3. 25 ammoniacal gas, 99 per cent. 53 nitrous oxide, 84 = 44^^ real + 8i azote. 76 when mixed. 7 li fired. 70 washed, 4|- or 5 oxygen, 65 azote. Here supposing 25 to have been the real ammonia, they would produce, according to my views, 13 azote and -32 hydrogen =16 oxygen, to which, adding 5, we have 21; but the nitrous oxide would give 27 oxygen ; hence a redundance of six oxygen ; the azote should have been 66 or (iT, instead of 65 ; but I presume that two azote and six oxygen united to form nitric or nitrous acid. According to the other view, in 25 ammonia there would be 37^ hydrogen = 19 oxygen, and there would be only three oxygen left in the residue instead of five, not allowing any for nitrous acid, though there are marks of it in every instance^ at least when oxygen is in the residue. Of eight experiments on nitrous oxide and ammonia, four, on the accuracy of which I could most rely, accorded with the atomic system, and were inimical to the others : the other four were of a more ambiguous nature, and might be explained upon either prin- ciple. One chief cause of their results differing from the general tenor was, I believe, in the explosions being made before the mix- tures had stood the due time to become uniform. In a long small tube the mixture should stand at least five minutes previously to the explosion. Nitrous Gas and Ammonia. — I made upwards of 20 experiments on mixtures of nitrous gas and ammoniacal gas in various propor- tions, from 10 nitrous to 3*8 ammonia, to 10 nitrous with 14 am- monia, which are very nearly the limits to the explosion of this kind of mixture. The results are by no means so decisive with regard to the two theories as those with nitrous oxide ; because any result that could fairly arise from either theory may very readily be 1817-] Chemical Compounds of Azote and Oxygen. 91 adapted to the other, without any assumption that can be shown as improbable, in two cases out of three, namely, when the residue contains oxygen, and when it contains neither oxygen nor hydrogen. For instance, Suppose 20 ammoniacal gas, measured in the exploding tube. 30 nitrous gas. 50 measures apparently in the tube. 25 azote left, after firing and washing. The volumists would explain it thus : — 20 ammoniacal gas = 10 azote + 30 hydrogen. 30 nitrous gas = 15 azote +15 oxygen. Therefore 25 azote produced. But an atomist might with equal plausibility reconcile the facts to his system. Thus 20 am. gas (23 real) = 12 azote + 30 hyd. (allowing 180 per cent.) 30 nitrous gas = IH +16^ oxygen. 25i Subtract i azote + li oxygen = nitric acid. Therefore 25 azote produced. The 30 hydrogen take 15 oxygen, and the 4- azote takes 1^- oxygen; so that there ought to be just 25 pure azote left when the acid is engaged by water or mercury. After these observations it may suffice to give the particulars of three experiments, exhibiting nearly the extreme cases and the inean : — 1. 41 nitrous gas, 94 per cent. = 38|- real + 24- azote. 53 ammonia containing 3-i- air = 7 oxy. + 2'8 azote. .94 5 f 85 fired. 75 washed, 26 hydrogen, 49 azote. Here 7 oxygen would take 1-^ nitrous to form nitrous acid before the explosion, and we must count on 37 nitrous only. The expla- nation I should give would be this : — 37 nit. gas = 17 azote + 20 oxygen. 52 am. gas = 27 azote + 66 hyd. = 40 (for oxy.) + 26 residue. 44 azote + 5 extra = 49 residue. This result does not seem to adroit of any explanation on the other system, 92 Chemical Compounds of Azote and Oxygen. [Aug. 2. 72 nitrous gas, 924- per cent. = 664. real + 54- azote. 53 ammunia, 99 per cent. = 52^ + i- azote. 125 67-5 fired. 63 washed, 1 or 2 hydrogen, found by adding a little hydrogen, and exploding with oxygen. Here we have 2 hydrogen and 6 azote to subtract, and there will remain 55 azote generated from the nitrous gns and the ammonia. Estimating the effective nitrous gas at 66, the following explanation many be given : — 66 nit. gas = 30 azote + 36 oxygen. 51 am. gas = 264- + 66 hyd. {=64 [= 32 oxy.] + 2). 564- 1-i- +4 oxygen = nitrous acid. The other hypothesis would also afford an easy solution ; but we must admit that no nitrous acid is formed, and that part of the ammonia escapes combustion. Thus 66 nitrous gas = 33 azote + 33 oxygen. 45 am. gas = 22^ + 67^ hydrogen. 55-i- azote, and I4- surplus hydrogen. 3, 78 nitrous gas, 92 per cent. = 72 real + 6 azote. 28 ammoniacal gas, 99 per cent. 106 eO-i- fired, muddy. 60i washed, 8-i- oxygen. Here we find 46 azote generated from the nitrous gas and am- monia, which may be explained thus : — 72 nitrous gas = 33 azote + 39 oxygen. 8i ammo, gas =164. +40 hydrogen. 49i 3^ azote + 10 oxygen = nitric acid. 46 An explanation on the other system might be as under : — 72 nit. gas = 26 azote 4- 36 oxygen (= 19x + 8 + 8-|-). 26 am. gas =13 + 39 hydrogen (19^ oxygen). 49 3 +8 oxygen = nitric acid. 46 azote. 18 17-] Analysis of Mineral Waters. 93 It is clear, therefore, that experiments with mixtures of nitrous gas and ammonia should be made with an excess of ammonia, if they are intended to decide between tlie two theories. Article III. A General Formula for the Analysis of Mineral IVaters. By John xMurray, M.D. F.R.S.E.* Thk analysis of mineral waters has always been considered as a difficult operation. Numerous methods are employed to discover their ingredients, and estimate their quantities, many of which are liable to errors. This diversity of method itself is a source of dis- cordant results; and to those not familiar with such researches, it presents the difficulty often of determining what process is best adapted to discover a particular composition. Hence the advantage of a general formula, if this could be given, applicable to the ana- lysis of all waters. The views which have been stated in the papers connected with this subject, which 1 have had the honour of sub- mitting to the Society, have suggested a method which appears to me to admit of very general application, and to be simple, not diffi- cult of execution, nor liable to any sources of error but what may be easily obviated. The principles on which this method is founded, and the' details of the process itself, form the subject of the follow- ing obseivations. Two methods of analysis have been employed for discovermg the composition of mineral waters— what may be called the direct method, in which, by evaporation, aided by the subsequent appli- cation of solvents, or sometimes by precipitants, certain compoutid salts are obtained ; and what may be called the indirect method, in which, by the use of re-agents, the principles of these salts, that is, the acids and bases of which they are formed, are discovered, and their quantities estimated, whence the particular salts, and their proportions, may be inferred. Chemists have always considered tlie former of these methods as affording the most certain and essential information ; they have not neglected the latter ; but they have usually employed it as subordi- nate to the other. The salts procured by evajwration have been uniformly considered as the real ingredients and nothing more was required, therefore, it was imagined, for the accuracy ot the ana- lysis, than the obtaining them pure, and estimating their quantities with precision. On the contrary, in obtaining the elements merely, no information, it was believed, was gained with regard to the real composition ; for it still remained to be determined in what mode they were combined ; and this, it was supposed, could be interred • From the Transactions of the Royal Society of Edinburgh, vol. Tiii. p. 550. 94 A General Formula for the [Aug. only from the compounds actually obtained. This method, there- fore, when employed with a view to estimate quantises, has been had recourse to only to obviate particular difficulties attending the execution of the other, or to give greater accuracy to the propor- tions, or, at farthest, when the composition is very simple, consist- ing chiefly of one genus of salts. Another circumstance contributed to lead to a preference of the direct mode of analysis — the uncertainty attending the determina- tion of the proportions of the elements of compound salts. This uncertainty was such, that, even from the most exact determination of the absolute quantities of the acids and bases existing in a mineral water, it would have been difficult, or nearly impracticable, to assign the precise composition and the real proportions of the com- pound salts; and hence the necessity of employing the direct method of obtaining them. The present state of the science leads to other views. ^ If the conclusion were just, that the salts obtained by evapora- tion, or any analogous process from a mineral water, are its real ingredients, no doubt could remain of the superiority of the direct method of analysis, and even of the absolute necessity of employ- ing it. But no illustrations, I believe, are required to prove that this conclusion is not necessarily true. The concentration by the evaporation must in many cases change the state of combination, and the salts obtained are hence frequently products of the opera- tion, not original ingredients. Whether they are so or not, and what the real composition is, are to be determined on other grounds than on their being actually obtained ; and no more information is gained, therefore, with regard to that composition, by their being procured, than by their elements being discovered ; for when these are known, and their quantities are determined, we can, according to the principle from which the actual modes of combination are inferred, whatever this may be, assign with equal facility the quan- tities of the binary compounds they form. _ The accuracy with which the proportions of the constituent prin- ciples of the greater number of the compound salts are now deter- mined enables us also to do this with as much precision as by ob- taining the compounds themselves; and if any error should exist in the estimation of these proportions, the prosecution of these re- searches could not fail soon to discover it. The mode of determining the composition of a mineral water, by discovering the acids and bases which it contains, admits, in general, of greater facility of execution, and more accuracy, than the mode of determining it by obtaining insulated the compound salts. Nothing is more difficult than to effect the entire separation of salts by crystallization, aided even by the usual methods of the action of alcohol, either as a solvent or a precipitant, or by the action of water as a solvent at different temperatures ; in many cases^ it cannot be completely attained, and the analysis must be deficient in accuracy. No such difficulty is attached to the other 1817.] Analysis of Mineral IVdters. 95 method. The principles being discovered, and their quantities estimated in general from their precipitation in insoluble compounds, their entire separation is easily effected. Nothing is easier, for example, than to estimate the total quantity of sulphuric acid by precipitation by barytes, or of lime by precipitation by oxalic acid. And this method has one peculiar advantage vvith regard to accuracy, that if any error is committed in the estimation of any of the prin- ciples, it is discovered in the subsequent step of inferring the binary combinations, since, if all the elements do not bear that due pro- portion to each other which is necessary to produce the state of neutralization, the excess or deficiency becomes apparent, and of course the error is detected. The indirect method, then, has every advantage over the other, both in accuracy and facility of execution. Another advantage is derived from these views, if they are just, that of precluding the discussion of questions which otherwise fall to be considered, and which must often be of difficult determina- tion, if they are even capable of being determined. From the state of combination being liable to be influenced by evaporation, or any other analytic operation by which the salts existing in a mineral water are attempted to be procured, discordant results will often be obtained, according to the methods employed; the propor- tions at least will be different, and sometimes even products will be found by one method which are not by another. In a water which is of complicated composition, this will more peculiarly be the case. The Cheltenham waters, for example, have, in different analyses, afforded results considerably different; and, on the suppo- sition of the salts procured being the real ingredients, this diversity must be ascribed to inaccuracy, and ample room for discussion with regard to this is introduced. In like manner, it has often been a subject of controversy whether sea-water contains sulphate of soda with sulphate of magnesia. All such discussions, however, are superfluous. The salts procured are not necessarily the real ingre- dients, but in part, at least, are products of the operation, liable, therefore, to be obtained or not, or to be obtained in different pro- portions, according to the method employed. And all that can be done with precision is to estimate the elements, and then to exhibit their binary combinations according to whatever may be the most probable view of the real composition. The process I have to state, conformable to these views, is essen- tially the same as that which I employed in the analysis of sea-water in a preceding memoir ; and it was the consideration of the advan- tages belonging to it that has led me to propose it, with the neces- sary modifications, as one of general application. Mineral waters have been arranged under the four classes of car- bonated, sulphureous, chalybeate, and saline. But all of them are either saline, or may be reduced under this division. From waters of the first class, the carbonic acid which is in excess is expelled by heat, and its quantity is estimated. Sulphureied hydrogen is in 06 A General Formula for the [Aue» like manner expelled or decomposed ; and iron may be detected by its particular tests, and removed by appropriate metiiods. In all these cases the water remains, with any saline impregnation which it has, and of course is essentially the same in the subsequent steps of its analy^^s as a water purely saline ; the precaution only being observed of these principles being removed, and of no new ingre- dient being introduced by the methods employed. The salts usually contained in mineral waters are carbonates, sul- phates, and muriates, of lime, of magnesia, and of soda. In proceeding to the analysis,^ a general knowledge is of course first to be gained of the proi)able composition by the application of the usual tests; the presence of sulphuric and carbonic acids being de- tected by nitrate of barytes, of muriatic acid by nitrate of silver, of lime by oxalic acid, of magnesia by lime-water or ammonia, and of any alkaline neutral salt by evitporation. It will also be of advantage to obtain the products of evaporation, and ascertain their quantities, without any minute attention to precision, the object being merely, by these previous steps, to facilitate the more accurate analysis. Supposing this to be done, and supposing the composition of the water to be of the most complicated kind, that is, that by the indi- cations from tests, or by evaporation, it has afforded carbonates, sulphates, and muriates of lime, magnesia, and soda, the following is the general process to be followed to ascertain the ingredients, and their proportions. Reduce the water by evaporation, as far as can be done without occasioning any sensible precipitation or crystallization ; this, by the concentration, rendering the operation of the re-agents to be employed more certain and complete. It also removes any free carbonic acid. Add to the water thus concentrated a saturated solution of mu- riate of barytes, as long as any precipitation is produced, taking care to avoid adding an excess. By a previous experiment, let it be ascertained whether this precipitate effervesces or not with diluted muriatic acid, and whether it is entirely dissolved. If it is, the precipitate is of course carbonate of baryles, the weight of which, when it is dried, gives the quantity of carbonic acid ; 100 grains containing 22 of acid. If it do not effervesce, it is sulphate of barytes, the weight of which, in like manner, gives the quantity of sulphuric acid ; 100 grains, dried at a low red heat, containing .84 of acid. If it effervesce, and is partially dissolved, it consists both of carbonate and sulphate. To ascertain the proportions of these, let the precipitate be dried at a heat a little inferior to red- ness, and weighed ; then submit it to the action of dilute muriatic acid ; after this wash it with water, and dry it by a similar heat, its weight will give the quantity of sulphate, and the loss of weight that of carbonate of barytes. By this operation the carbonic and sulphuric acids are entirely removed, and the whole salts in the water are converted into niu- ^^^/•] Analysis f)f Mineral IVaters. 97 riates. ^ It remains, therefore, first to discover and estimate the quantities of the bases present, and then, to complete the analysis, to find the quantity of muriatic acid originally contained. Add to the clear liquor a saturated solution of oxalate of ammonia as long as any turbid appearance is produced. The lime will be thrown down in the state of oxalate. The precipitate being washed, may be dried ; buc as it cannot be exposed to a red heat without decomposition, it can scarcely be brought to any uniform state of dryness with sufficient accuracy to admit of the quantity of lime bomg estimated from its weight. It is, therefore, to be calcined with a low red heat, by which it is converted into carbonate of lime, 100 grains of which are equivalent to 56 of lime. But as a portion of carbonic acid may be expelled if the heat is raised too high, or a little water retained if it is not high enough ; it is proper to con- vert it into sulphate, by adding sulphuric acid to a slight excess, and then exposing to a full red heat. The dry sulphate of lime will remam, 100 grains of which contain 41-5 of lime.* The next step is to precipitate the magnesia. With regard to this there IS some difficulty, particularly as connected with the design of the present formula. The principle on which it is founded is, first to remove all the acids but the muriatic ; and, secondly, to remove the bases, or otherwise estimate their quantities. The lime and the magnesia may be removed by precipitation ; the soda cannot. The process, therefore, must be so conducted as to leave it at the end in the state of muriate of soda. Hence it is necessary either to remove any new product introduced in the previous steps of the analysis, or if any such remain, to be able to estimate its quantity with precision. In decomposing the muriate of lime by oxalate of ammonia, muriate of ammonia is substituted, which can be after- wards dissipated by heat. The object, therefore, is to decompose the muriate of magnesia, and remove the magnesia, either by some similar method, or, if not, by some other in which the muriate substituted can be accurately estimated ; and to attain one or other of these conditions, gives rise to the difficulty to which I have alluded. Tlie decomposition of the magnesian salt by ammonia would have the former advantage, as the muriate of ammonia would he expelled at the end of the process by heat ; but this decomposition. It IS well known, is only partial. Subcarbonate of ammonia causes a more abundant precipitation of magnesia, but still its action is whirh'l*!!?'^"*"'"/^ "^ ^'"'■°'' '° "''''^'' ""'= ='^l» °f <'•« analysis is liable, is that r«.«.«r ""* .'""'■* ''^'■^""^ ''*« *>"" "sed in the first operation than was in .?.. 7, 'J'^'^'P"^'^ "'e sulphuric and carbonic acids. It will be thrown down InH ,h • ° °*^'*'^ of barjtes, and be converted into carbonate and sulphate, c,;„r h^"V- ^PP^""^"* proportion of lime too large. This is obviated, of tion f ,1 1^ ^^^^ '" ^''°'^^ ""'"S ^" e««ss of barjtes. To render the opera- • -!... I, I f^r^*^ "' ammonia as perfect .is possible in precipitating the lime, the !lnnr.r °„ /"' """"r ''^"•'•'''y reduced by evaporation, taking care to avoid any •eparat.on of any of its ingredientj. r » * J Vol. X. N° II. a 98 On Stdphalcs of Iron. [Aue. likewise partial, a ternary soluble salt being formed after a certain quantity has been added. It seemed probable that this might be obviattd by adding the subcarbonate of ammonia as long as it oeca- sioned any precipitation, then evaporating the clear liquor to dry- ness, expelling the muriate of ammonia, and any excess of am- monia, by heat, redissolving, and again adding the subcarbonate of ammonia to decompose the remaining magnesian salt. Proceeding in this way, I found that a copious precipitation took place on the second addition, and even at the fourth a small quantity of precipi- tate was throvvn down. But the decomposition, after all, was not perfect, for the quantity of magnesia obtained was not equal to what was procured by other methods. Subcarbonate of soda or potash has been usually employed to precipitate magnesia from its saline combinations. The precipita- tion, however, is only partial, unless an excess of the precipitant be employed (and even then, perhaps, is not altogether complete); and as this excess cannot easily be estimated, it introduces a source of error in estimating the quantity of muriate of soda at the end of the operation, against which it is not easy to guard. {To be continued.) Article IV. On the Salts composed of Sulphuric Acid a?id Peroxide of Iron,, By Thomas Thomson, M.D. F.R.S. The atomic theory has occupied the attention of chemists for so short a time, that we need not be surprised that several difficulties occur in it which it has not been possible hitherto to remove. One of these, which does not seem the least important, is the determi- nation of the weight of an atom of those metals vvhich combine with two doses of oxygen, having to each other the ratio of two to three. This is the case with sodium, iron, nickel, cobalt, and several others. At first sight the determination appears easy. The oxides of sodium are composed as follows : — 1 protoxide or soda of 6 sodium + 2 oxygen 2 peroxide 6 +3 It is natural to conclude that the weight of an atom of sodium is G, and that soda is a compound of I atom sodium -|- 2 atoms oxygen ; and the peroxide of 1 atom sodium + 3 atoms oxygen. This ac- cordingly is the opinion of Dalton and Berzelius. It was the opinion which I myself adopted in the tables that I gave of the weights of the atoms of bodies in the second and third volumes of the Atmah of Philosophy. But sulphate of soda (abstracting the water of crystallization) is 6 18 1;-.] On Sulphates of Iron. 99 composed of 5 sulphuric acid + 4 soda, or of 10 sulphuric acid + 8 soda. Now the weight of an atom of sulphuric acid being 5, it is obvious that if we consider 8 as the weight of an atom of soda, sulphate of soda must be a compound of 2 atoms sulphuric acid + ] atom soda. In like manner, in all the neutral salts of soda one atom of the alkali will be united with two atoms of acid. The salts of potash, ammonia, lime, barytes, strontian, and magnesia, when neutral, are all compounds of 1 atom acid + 1 atom base. It would, therefore, be singular if the salis of soda should constitute an exception to what appears to he a general law, namely, that neutral salts are compounds of one atom acid and one atom base. When we apply Richter's law to the double decomposition of salts of soda by other neutral salts ; namely, that the new salts formed are as neutral as the original salts, and consequently that there is no unsaturated residue either of acid or base, we immediately find that an atom of soda cannot be represented by 8, but that its true weight must be 4. To give an example : Nitrate of barytes, when mixed with sulphate of soda in the requisite proportion, occasions a total decomposition of both salts : sulphate of barytes and nitrate of soda are formed both neutral, and there is no surplus either of barytes or soda, or of either of the acids. Now nitrate of barytes is com- posed of Nitric acid G''Jb or 1 atom Barytes 9*75 1 Sulphate of barytes of Sulphuric acid 5'00 or 1 atom Barytes 9*75 1 Hence it is obvious that, in order to decompose 16*5 by weight of nitrate of barytes, we must employ a quantity of sulphate of soda containing only 5 or one atom of sulphuric acid ; so that its con- stituents must be — Sulphuric acid , 5 Soda 4 It is plain that if we mix together 9 parts by weight of sulphate of soda (supposing the water removed) and 16*5 parts of nitrate of barytes, we shall form two neutral salts, sulphate of barytes, and nitrate of soda. The weight of the first will be — Sulphuric acid 5 Barytes 9*75 14-75 and the weight of the second — Nitric acid 6*75 Soda 4 1075 « 2 100 On Sulphates of Iron. [Aug, In this decomposition there was present an atom of sulphuric acid, of nitric acid, and of barytes. It is plain that there must have been present, likewise, an atom of soda. But if so, an atom of soda must weigh 4 ; consequently an atom of sodium must weigh 3, and soda must be a compound of 1 atom sodium + 1 atom oxygen. This removes the anomaly respecting the salts of soda ; because, if the weight of an atom of soda be 4, then all the neutral salts are composed of 1 atom acid + 1 atom soda. But as the oxygen in soda is to the oxygen in the peroxide of sodium as 2 to 3, it is obvious that if soda be a compound of 1 atom sodium + 1 atom oxygen, then the peroxide of sodium must be a compound of 1 atom sodium + I4- atom oxygen. Now tliis is as great a difficulty as the one which we have got rid of; for from the very nature of an atom it is impossible to admit its divisibility. On considering the subject with attention, it occurred to me that the difficulty would disappear if we considered the peroxide of sodium as a compound of two atoms sodium and 3 atoms oxygen. On that supposition its weight would be represented by the number 9. As it is difficult to obtain the peroxide of sodium pure in any quantity, and as we are not acquainted witli any compounds of which it constitutes a part, it was not possible to put this supposi- tion, as far as sodium is concerned, to the test of experiment ; but iron, as far as its combinations with oxygen are concerned, is pre- cisely in the same circumstances as sodium. It unites with two proportions of oxygen ; and the oxygen in the protoxide is to that in the peroxide as 2 to 3. If we decompose proto-sulphate of iron by nitrate of barytes, we shall find that the weight of an atom of protoxide of iron must be represented by the number 4'5, and that the weight of an atom of iron is 3 "5. If we suppose peroxide of iron a compound of two atoms iron and three atoms oxygen, to get rid of the anomaly of the half atom, it is plain that the weight of an atom of peroxide of iron must be 10, Now as peroxide of iron is capable of uniting with acids, and forming salts, we can put the supposition that its weight is 10 to the test of experiment. I prepared a quantity of very pure crystals of proto-sulphate of iron, reduced them to powder, and left them in that state upon blotting paper in a dry room till they were quite dry. 100 grains of the powder were then dissolved in distilled water acidulated with nitric acid, and the solution evaporated to dryness, and the dry mass was mixed with water, and evaporated to dryness two or three times, in order to get rid of the whole of the nitric acid which re- mained undecomposed ; but care was taken not to raise the heat so high as to endanger the dissipation of any of the sulphuric acid. The dry mass had a red colour, and an intensely astringent taste. It obviously contained the whole of the sulphuric acid combined with the protoxide of iron, now converted into peroxide by the ag'ency of the nitric acid. I poured a quantity of water on it. A 1^17«3 On Sulphates of Iron. 101 considerable portion dissolved, constituting a red liquid, having an intensely astringent taste. There remained at the same time undis- solved a tasteless powder, having an orange colour, and not altered hy exposure to the atmosphere. The red liquid, being evaporated to dryness, and the residue left in the open air, speedily deliquesced into a red astringent liquid. Now 100 grains of crystallized proto-sulphate of iron are com- posed of Anhydrous salt 55 Water 45 100 The 55 grains of anhydrous salt are composed of Sulphuric acid 28-9473 Protoxide of iron 26'0527 55-0000 The protoxide of iron being converted into peroxide, its weight would become equal to that of the sulphuric acid j so that the con- stituents of the two compounds obtained, taken together, must have been Sulphuric acid 28*9473 Peroxide of iron 28*9473 57*8946 For the sake of greater perspicuity, let us suppose the weight of these two constituents to be 100, or 50 sulphuric acid + 50 per- oxide. "^ I found the weight of the insoluble powder exactly one-third of tl)at Qf the soluble salt ; so that the weight of The insoluble powder was 25 The soluble salt 75 100 I dissolved the insoluble powder in muriatic acid, precipitated the sulphuric acid by means of muriate of barytes, and the peroxide of iron by means of ammonia. The v/eight of these constituents was as follows : — Sulphuric acid 5 Peroxide of iron 20 25 The soluble salt, being treated in the same way, yielded the fol- lowm^ constituents:— Sulphuric ^cid 45 or 15 Peroxide of iron 30 10 75 2£» 102 ^^ Sulphates of Iron. [Aug. We perceive at once that the insoluble sale contained twice the weight of iron, and only one-third the weight of sulphuric acid, that existed in tlie soluble salt. If the weight of an atom of per- oxide of iron be 10, then the insoluble powder will be a compound of 1 atom acid + 2 atoms peroxide, and the soluble salt a com- pound of .S atoms acid + 1 atom peroxide. These analyses, I conceive, demonstrate that the weight of an atom of peroxide of iron is 10. Hence I tliink we may conclude that all those oxides ■which are to the oxides immediately below them in the proportion of their oxygen as 3 to 2 are compounds of 2 atoms base 4- 3 atoms oxygen. This supposition will remove a very considerable difficuhy, hitherto perplexing the atomic theory. The metals to which this law applies are, 1. Sodium, 4. Cobalt, 2. Nickel, 5. Cerium. 3. Iron, The weight of an atom of each, according to the most accurate experiments hitherto made, is as follows: — Sodium 3 Nickel 3-375 Iron 3 5 Cobalt 3-62 Cerium 5*75 The protoxides of these metals, being compounds of 1 atom metal + 1 atom oxygen, must be of the following weights : — Soda 4 Protoxide of nickel 4*375 ■ iron 4*5 cobalt 4-625 cerium G-75 The peroxides, being compounds of 2 atoms metal + 3 atoms oxygen, must weigh as follows : — Peroxide of sodium 9 nickel 9*75 iron 10 ■ cobalt 10-25 cerium 14'5 Besides the two persulpliates of iron analyzed in (his paper, there is a third persulphate, which may be formed by digesting peroxide of iron in concentrated sulphuric acid. A white paste is formed, which I consider as a hydrated persulphate. But there is no means of subjecting it to analysis, because, when water is poured upon it, two salts are formed, one of which dissolves in the water, and the other remains in the state of an insoluble powder, I think it not improbable that two other compounds of sulphuric acid and per- oxide of iron exist ^ namely, one consisting of 1 atom acid + 1 181/.] Mode of exploring the Interm- of Africa, 103 atom peroxide united tofrether, and one consisting of 2 atoms acid + I atom peroxide. Tiie second of these I think I have made ; but I have not been able to obtain satisfactory evidence of the exist- ence of the other. The persulphates of iron, then, are probably four in number : — 1. Subblpersulphate, composed of 1 atom acid + 2 atoms peroxide. 2. Persuljjhate I +1 3. Bipersuipiiate 2 +1 4. Tripersulphate 3 +1 In converting proto-sulphate of iron into persulphate by means of nitric acid, a poition of the sulphuric acid is apt to make its escape. Considerable attention, therefore, is necessary in order to obtain the at)ove results. 1 have, however, repeated the experi- ment several times, and have no doubt of the accuracy of the pro- portions which I have given. Article V. Memoir on the Mode of explorivg the Interior of Africa. By H, Edmonston, Esq. Surgeon, Newcastle-upon-Tyne.* The different expeditions set on foot of late years for exploring the interior of Africa are such as do honour to this age and country, and leave us room only for regret that the success has been so little commensurate to the exertions so repeatedly made. Yet if the causes of failure be carefully and candidly examined, there will be reason to suspect that some of them are not fairly ascribable to the nature of the enterprize in itself; and at all events there are others which, with attention, might have been prevented or avoided. These and similar reflections have often occurred to my mind, more especially since I have read in the periodical journals and newspapers of the outfit and sailing of the two expeditions destined to penetrate into Africa by the rivers Gambia and Congo. And, Sir, as you were among the first to give to the world the journal of Isaaco respecting the probable fate of Mango Park, and as you appear to take a lively interest in the subject, I hope you will not consider the following observations altogether misplaced in the Annals of Philosophy. Some may think that little loss would have been sustained had I kept these remarks to myself; and in all probability I should have * This meoioir w.as originally written not very long after the ivo expeditions ■ nder Major Pcdilic and Captain Tuckey sailed for Africa. But as the specula* tions which it coatainii have not hecii materially affected by the result of those ex- peditions, it is inserted herealinobt T^itbout alteration. 104 Mode of exploring the Interior of Africa. [Aug. done so, seeing that the voyagers have already gone on their desti- nation, and consequently that nothing in my power to advance as mere matter of opinion can have any eHect in counteracting what, I fear, we shall one day have reason to pronounce an illrjudged and most imprudent measure. But I observe in the last number of the Quarterly Review an intimation that tiie son of Mungo Park, ani- mated by the filial enthusiasm of Teiemachus, waits but for " the coming on of time," to go in quest of his father, whom his hopes represent to him as still alive. The idea of this, 1 own, affects me powerfully; and it is chiefly in the view that they may operate as cautions to him that I have determined on submitting my thoughts to the public. I doubt not that those who are, or shall be, his advisers, are thoroughly aware of all the perils of such an exploit. Still the suggestions of even a common observer are sometimes worth attending to. Perhaps some apology is required of me for expressing myself with such freedom as I shall have occasion to do, on account of the appearance which it may have of unnecessarily wounding the feel- ings of those left behind. But I cannot persuade myself to believe any thing else, than that the relatives and friends of the intrepid voyagers have made up their minds to the worst that can happen. It is impossible to meditate for a moment on the character of the enterprize, or to peruse attentively the last journal of Park, without being fearfully impressed with the dangers to which all are exposed who attempt to follow his footsteps. For the sake of perspicuity, I shall divide my remarks into three parts. The frst will comprehend those objections which are more parti- cularly applicable to the manner in which Park's last expedition was conducted. The second, those objections which apply with force to all mili- tary expeditions whatever. The third will contain some suggestions respecting what aptpears to be the most practicable and feasible method of exploring the continent of Africa. First, then, as to the management of Park's last expedition. Where there is so much to call forth our sympathy, sorrow, and admiration, it is an ungracious duty to point out any grounds of censure. But truth, and the safety of future adventurers, require that, if they must, like Park, fall victims to their zeal and spirit, they may at least avoid participating in some of his errors. The very first, and perhaps the most material circumstance, that strikes us is the complete miscalculation with respect to the difficul- ties to be met with, and the means by which they were to be obviated. Park seems to have laboured under the unlucky miscon- ception that a coffle composed of 50 armed persons, their guides, baggage, beasts of burthen, and provender, could move as rapidly through the country as he had done on a former occasion with only 18170 Mode of exploring the Inteiior of Africa. 105 his guide and a negro boy. In consequence of unexpected difficul- ties, many of them such as his utmost endeavours were inadequate to surmount, the unhealthy season came upon hitn when he had but half finished his land journey previous to his embarkation on the Niger. Rather than wait at Pisania till the unfavourable season was completely over, when he might have set out with the earliest return of dry weather, he resolved to attempt what was barely possible, even supposing every thing to have gone on prosperonsly. To this unfortunate resolution, by which at the very outset the whole result was put to the utmost hazard, are perhaps to be attributed all, or many of the disasters which befel the expedition previous to his arrival at Bambakoo, on the Niger. This is the more to be re- gretted, that it could not be said to be necessary. Government and the country placed such entire reliance on his judgment and ardour, that a few weeks or months would have made no difference. He might have taken his own time. How precious that time was, and how usefully it might have been spent in making prudential ar- rangements, it is now as vain as it is painful to contemplate. But, unhappily, he appeared to have been hurried away by an enthusiasm little short of infatuation, and to be buoyed up with expectations which his own experience should have told him were altogether visionary, and which no circumstances could at that time justify. So fully was he under the influence of this impression, that we find him, previous to his setting off, writing to his wife and friends in a strain of certainty, as if the term of the journey could be antici- pated with all the exactness of an East India voyage. One very bad effect which the unseasonable period of com- mencing his travels produced was, that it compelled him, after he began to perceive the time passing off, to post through the country with a degree of speed which must of itself have been sufficient to kindle suspicion in the minds of the Moors, and prevented him from paying that attention to his sick which their situation required. We find Isaaco, on the contrary, who had on every account less occasion to halt, tarrying some days with a chief, on purpose to convince him that he had no sinister object in view, by which means he at once secured his confidence. P^rk had likewise too lofty notions of the superiority of his fire- arms over the numbers and weapons of the natives. Though inex- pert marksmen, the inhabitants of the interior are far from being ignorant of the use of gunpowder. One very glaring mistake into which he allowed himself to fall was not conforming to the manner of the country in the article of '' ' sin. x { 1 - / sec. x} 27. ^ (sec. x"""^' ) = dx (sec. x)'"«' ' (sec. x)^ {^sec. x + (sin. x)*} 28. d (sec. x)"'-' = c?x (sec. x)"" {1 — (cosec. x)^ Isec.x} 29. d (sec. x'"'' ) = d x (sec. x)"''' tang, x sec. x {/ sec. x + 1} 30. d (sec. x'"'"") = dx (sec. x)"'"-" cot. x cosec. x { (tang. x)« — / sec. x} 31. J (cosec. x""') = d X (cosec. xy'-'^cos. x{l cosec. x — 1} 32. c? (cosec. x'°'- ") = — d x (cosec. x)'" '^ sin. x {/ cosec. x + (cot. x)^ } 33. d (cosec. x"°*- ') = dx (cosec. x)''"'^ ' { (sec. x)« / cosec. x— 1 } 34. d (cosec. x""') — — d x (cosec. x)""'-'' (cosec. x)* {I cosec. x + (cos. x)* } 35. d (cosec. x'"' ') = d x (cosec. x)'"'' '^ cosec. x { (tang, x)* I cosec. X — 1} 36. d (cosec. x"'" "^ ) = — d x (cosec. x)"""-' cot. x cosec. x {I cosec. X + 1 } 37. dilog.x^"-") = {Ixy- yj^i^ ^ dj^^ 38. diz-)^z-{dmlz + ^l =z-{o + ^)^mz-'' dz. lis Experiments on the Composilhn and Properties [Auo. Article IX. Experiments on the Composition and Properties of the Naphtha of Amiano, By M. Theodore de Saussure. Read to the Society of Katural Philosophy and Natural History of Geneva.* After ascertaining that alcohol and ether may be represented by defiant gas and a certain quantity of water, which predominates in the alcohol, I was led to examine whether several other inflammable bodies, of which 1 shall hereafter give the analysis, might not be subjected to the same law. One of the first substances which I examined with this object in view is the naphthaf found at Amiano, in the states of Parma, which differs in several remarkable properties from the essential oils. If it were more common, it might advantageously supply the place of oil of turpentine for a variety of purposes. It is more volatile, is at least as good a solvent, has a less tenaceous odour, is not liable to become coloured and thick, to be decomposed by the action of j air and light, and is scarcely altered by the action of the most I powerful chemical agents, such as the mineral acids and the fixed alkalies. As the properties of this bitumen have not been correctly determined, T make it the subject of the present paper. The know. edge of naphtha is very ancient. Dioscorides and Pliny distinguish by this name a volatile combustible liquid, either white or black, which sometimes issues from the earth, and some- times collects on the surface of water. They observe that it catches fire at a little distance from an inflamed body; they describe it as found in the same parts of Sicily, Syria, and the Archipelago, where it occurs at present. We do not know the causes that lead to the formation of naphtha in the bosom of the earth. We know only that when asphaltum is decomposed in close vessels by heat, it yields petroleum and naph- tha: and that petroleum, which is a heavier and less volatile oil than naphtha, yields it also when thus treated. The asphaltum found in the Val-de-Travers, in Switzerland, appears to have an animal origin. The rock which furnishes it, or which is penetrated with it, is almost entirely composed of shells, and exhibits no trace of vegetables. There is no coal in that country; but we meet with a great deal of sulphate of lime. The mines of asphaltum in the department of the Ain are without any coal in their neighbourhood; but we find animal petrifactions and metalline sulphates. It is pro- bable from this that this kind of bitumen may sometimes owe its origin to the action of sulphuric acid on animal substances. » Translated from the Bibliotheque Universelle, iv. 116, for Feb. IS17. + The petroleum of Amiano, which yields abundance of this naphtha when distilled, costs at Genoa only eight centimes the pound, and it employed to light the streets of the city. (Ann. de Chim. torn, xlv.) 18170 of the Naphtha of Amiano. 119 Rectified naphtha is quite volatile at the ordinary temperature of tlie atraospliere ; but there is reason to suspect that it does not occur naturally in that state. It is usually contaminated with petroleum, which may be separated by repeated distillations, and with which it has been often confounded. The natural naphtha of Amiano appears at its source in its state of impurity as a transparent yellow liquid, with a great degree of fluidity, and having a specific gravity of 0'836. When I drew off by a very slow distillation about a fourth of this substance, I obtained a transparent, colourless liquid, as fluid as alcohol, and having the specific gravity of 0*769 at the temperature of 59°. On distilling this liquid twice more, and retaining only the portions that came over first, it differed very little in its appearance from what 1 first obtained, and its specific gravity was 0*758 at the temperature of 66°. This density was not diminished by subsequent distillations, even wlien they were made off a great quantity of muriate of lime. It is to this liquor thus rectified that all the pro- perties which I shall assign to naphtha belong. It was interesting to compare them with the properties of naphthas obtained from a different source ; but the naphtha of Amiano is the only one which I could procure in sufficient abundance for a rigid examination. The naphthas which I procured in small quantities by the distillation of the petroleum of Gabian, and of the asphaltum of the department of the Ain, appeared to me to possess, after repeated distillations, the specific gravity of the naphtha of Amiano, the same fluidity, and nearly the same volatility. They had the same action on alcohol, on the mineral acids, and on the alkalies. They did not differ from pure naphtha, except by having a slight shade of yellow. I de- prived them of it by distilling them from sulphuric acid ; but they became again yellow by exposure to the light ; which is not the case with rectified naphtha of Amiano. Notwithstanding this difference, I think that all these naphthas should be considered as identical in their essential principles. Impure naphtha has usually a strong, penetrating, and very last- ing odour. That of pure naphtha is weak and fugitive. It is almost without taste. It catches fire at a small distance from an inflamed body, and burns with a white flame mixed with much soot. On paper it forms a stain, which disappears in a few minutes, even in the lowest temperatures. According to most authors, naphtha becomes yellow when ex- posed to the air and to light ; it thickens at the same time, and is converted into petroleum. But such marked results have probably been observed only in naphtha already contaminated with petroleum. In my experiments air and light have had no very sensible action on pure naphtha. I exposed to the sun for 15 days naphtha in contact with 20 times its bulk of air, without observing any change. The experiment was continued for 18 months in a diffuse light, and the volume of the air diminished only one hundredth part. The altera- tion which it had undergone was scarcely sensible to the eudiometer. 120 Experiments on the Composition and "Proper lies [Auo. The whiteness and specific gravity of the naphtha were not percep- tibly ahered. The impure naphtha of Amiano deepens in colour when exposed to the light, absorbing oxygen very sensibly. The colourless naphtha obtained by a distillation continued too long, and which has a greater specific gravity than I have indicated for the most complete rectification of this bitumen, becomes yellow in the same manner ; but pure naphtha (of the specific gravity 0758) which I left exposed to the light in phials only half full, has un- dergone no evident alteration in three years. It is possible, how- ever, that some change may take place hereafter, in consequence of the small absorption of air which 1 have noticed above. Naphtha may be totally distilled over several times in a moderate heat without undergoing any decomposition. Of the Vapour of Naphtha, — The elasticity of the vapour of naphtha (of the specific gravity 0*758 1) is equal to 0'0453 metre (1-7S inch) of mercury at the temperature of 7-"5°. Hence it boils at tlie temperature of 18(i°. The elasticity of that vapour is deduced from the dilatation which air underwent over mercury when naphtha was let up into it. This air dilated in the ratio of 100 : 106*67atthe same temperature. This tension, ascertained at the same time in the vacuum of a barometer, was found to amount to 0-0465 metre (1-83 inch). But this last method may be less exact, because naphtha absorbs very quickly a considerable quantity of atmospheric air, which is disengaged in a vacuum, and which cannot be got rid of without putting the liquor again in con- tact with the external air. The vapour of naphtha has an elastic force four times as grt at as that of oil of turpentine, which has the greatest elasticity of all the essential oils properly so called. The density of the vapour of naphtha is 2*833, supposing that of common air to be 1. It will be 2*567 if we suppose that of oxygen gas 1, This density was obtained by taking the weight of air saturated with naphtha at the common atmospheric tempera- ture, and following the process for determining the weight of gases. For this operation the air was impregnated with naphtha over mer- cury in a receiver without lute, and shut by a glass stop-cock, to which vvas attached a globular vessel exhausted of air, which was to be filled with the air impregnated with naptha, I found that at the tein!)erature of 72 5°, and when the barometer stood at 0*72525 metre (28*55 inches), the weight of common air is to that of air impregnated with naphtha as 1 : 1*1145. The density and the tension of the vapour of naphtha appear a little less when this liquor swims upon water, and when we employ fhat liquid instead of mer- cury to shut the receiver. Air impregnated with the vapour of naphtha has several remark- able properties. This vapour is scarcely absorbed by water. It may be passed a great number of times through that liquid, and even kept over water, without losing its principal characters. The presence of this vapour in some carbureted hydrogen gases may occasion a mistake respecting their composition. Thus by dis- l 1S17.] of the Naphtha of Amiano. 121 tilling over the naked fire different specimens of petroleum, I ob- tained over water towards the beginning of the process a carbureted hydrogen gas, which, after being w;ished by a solution of potash, had a specific gravity greater than that of any carbureted hydrogen known. It was rir29, supposing that of air to be 1. 100 parts in volume of this gas required for complete combustion 355 of oxygen gas, and formed 220 of carbonic acid gas. It broke in pieces eudiometers of glass which had remained entire under the same circumstances when olefiant gas was detonated in them. I thought at first that I had obtained a new gas; but on observing that naphtha was produced by the distillation of petroleum, and that on the supposition that the new gas was olefiant gas saturated with naphtha, it would have almost the same specific gravity that I found it to have, I concluded that my supposition was well founded.* Common air saturated with the vapour of naphtha (which I shall call Jiaphthated air) burns like carbureted hydrogengas when placed in contact with a burning body, but cannot be kindled by electricity. This is the case also with naphthated oxygen gas. When a measure of naphthated air is mixed with a measure of hydrogen gas, the mixture cannot be fired by electricity; so that if this test were alone attended to, we might conclude that no oxygen gas was present. It is necessary to add a greater dose of oxygen before combustion will take place. A very small quantity (a 20th, for example) of hydrogen gas, when added to naphthated oxygen, enables the vapour to be kindled by electricity, and the strongest glass eudiometers are broken by the violence of the detonation. If at the common temperature of the air vve put a stick of phos- phorus into naphthated air standing over water, the oxygen of the air is not absorbed. We must apply a heat sufficient to melt the phosphorus before a diminution of volume takes place. Nitrous gas and the alkaline hydro-sulphurets absorb the whole of the oxygen from naphthated air. We may, therefore, by the differ- ence in the result of the eudiometrical processes with phosphorus at the common temperature and the hydro-sulphurets, judge of the presence of certain emanations in air. I put some peas with water under mercury into a receiver filled with naphthated air. They germinated as readily as in the same quantity of pure atmospherical air: but they vegetated a longer time in this last, and their action on the air was different. In common air the grains replace the oxygen which they absorb by the same volume of carbonic acid gas, and of course do not alter the bulk of their atmosphere. But as soon as they have absorbed all the ♦ The analysis does not agree exactly with that supposition. But the olefiant pxs ought to be somewhat modified by the strong heat necessary to distil petroleum. Besides, the analysis can be made only on a small quantity of the gas which I examine, because we are obliged to mix it with six times its volume of oxygen to oable the eudiometer to resist the detonation. 122 Experiments on the Composition and Properties [Ace, oxygen, tliey dilate it by an emission of carbonic acid gas. These results are the same with dead and dying grains ; but in naphthated air ihe grains form more carbonic acid gas than they absorb of oxygen gas ; or, in other words, they dilate their atmosphere by an emission of caihonic acid gas before they have absorbed all the oxygen. This is not because the grains suffer more in naphthated air than in common air; for in this last the dead and dying grains replace all the oxygen by an equal emission of carbonic acid gas. But the cause of the difference is the influence of the oxygen of naphthated air is partly neutralized by the vapour of naphtha; just as the iiifluence of the oxygen on phosphorus while cold is destroyed by the presence of that vapour, which renders the oxygen in certain respects analogous to azotic gas. It is probable from this that the hurtful action of certain odours on the animal economy depends in some cases on a similar cause, and not always on the direct influence of these odours on our nerves. fVater. — Naphtha is insoluble in water; but that liquid becomes impregnated with the odour peculiar to that bitumen. When a drop of naphtha is let fall on the surface of water, it spreads, and assumes the appearance of a thin pellicle, at first colourless, but speedily becoming thinner, and assuming the finest tints of the rainbow, and speedily disappearing by evaporation. This play of colours has been long observed with water and petroleum. With them it is perma- nent, on account of the fixity of the petroleum. I kept for some years pure naphtha in contact with water and air in a close phial, and these liquors have not been sensibly modified. Alcohol. — Naphtha is considered as insoluble in alcohol ; but I have found that absolute alcohol dissolves it in every proportion. Alcohol at 41° of Beaume's areometer dissolves a fifth of its weight of napththa, and an eighth when it is at 36° of that areometer. This liquid dissolves so much less naphtha the more it is mixed with petroleum. The solubility of naphtha in alcohol more or less diluted with water is nearly the same as that of oil of turpentine. Sulphuric ether, petroleum, fat oils, pitch, essential oils, com- bine cold with naphtha in every proportion. Camphor. — Naphtha dissolves cold the three-fourths of its weight of camphor. When hot, it dissolves a still greater proportion, which precipitates as the liquid cools in a spongy state. Amber does not dissolve in naphtha. Shell lac and copal are almost insoluble in it. The decoction of them, made in an open vessel, does not contain one hundredth part of its vi^eight of these bodies in solution. White wax may be mixed cold with naphtha. A milky liquid is produced, which deposites wax in a state of great division, and which exhibits at its surface a transparent solution, containing but little wax. By the assistance of heat the wax dissolves in every proportion in this bitumen. The hot solution, on cooling, coagu- lates into an opake paste, if the naphtha is in small quantity. But 181 7-] of tlie Naphtha of Amlano. 12S if it is very superabundant, we obtain an opake, pasty deposit in a transparent liquid holding the eleventh part of its weight of wax in solution. When caoutchouc is macerated in naphtha, it swells in a noost extraordinary manner. It becomes at least 30 times more bulky than in its primitive state, without changing its shape in the liquid. The naphtha, after a maceration continued for 48 hours, contains ia solution only the seven thousandth part of its weight of caoutchouc. By boiling, and partially evaporating the liquid, we obtain more con- centrated solutions. They form a varnisli, which dries readily, and which presents the elastic substance almost colourless, but possessed of all its properties; but the caoutchouc never dissolves completely in these processes. The insoluble residue has the appearance of a gelatinous matter, impregnated with naphtha, which, when dried, is reduced to a very small volume, exhibiting an elastic substance like caoutchouc. It appears from this that naphtha divides caout- chouc into two elastic substances, the one more, the other less soluble in this menstruum. The last retains the colouring matter. Sulphur is not sensibly attacked in the cold by naphtha. By boiling, a portion of it is dissolved, which does not exceed the 12th part of the weight of the liquid. The solution is yellow and trans- parent. It becomes colourless on cooling, depositing the sulphur crystallized in tine needles, which are long, and very brilliant, but which afterwards break of themselves, and become tarnished. The naphtha retains in solution, after cooling, a small quantity of sul- phur, which is partly carried out of the vessel by ihe spontaneous evaporation of the liquid, and which is deposited in powder on the surrounding bodies. This solution leaves for residue some micro- scopic crystals of sulphur. Phosphorus. — A hundred parts of naphtha, at the heat of ebulli- tion, dissolve six or seven parts of phosphorus. The phosphorus partly precipitates in drops and in powder as the liquid cools. After this precipitation, the decanted liquor deposites in a few days pris- matic crystals of phosphorus. Chlorine. — I caused a rapid current of chlorine in the state of gas to pass for an hour and a half through eight grammes (123-|- grains) of naphtha. The liquor became hot, and the chlorine separated in the state of muriatic acid. After this operation the naphtha smoked, in consequence of the presence of the acid, vi'ith which it was im- pregnated. It gradually lost this property, and then exhibited a fluid oil, which was volatile and inflammable, but a little less vola- tile than naphtha. By that operation it acquired the sp gr. 0-884j or somewhat more than it was before. It was become more soluble in aqueous alcohol, and was more easily altered by the mineral acids. Its smell was analogous to that of thyme. It became brown by the action of air. In other respects, the changes which the naphtha underwent by this experiment were not very remarkable. Iodine does not dissolve cold in naphtha, except in a very small proportion ; about one-eighth of the weight of the liquid. This 124 Exper'nnents on the Composllion and Properties [Aug. solution, which has a deep purple colour, carries off it, when it evaporates, all the iodine which it contains. Mineral yicids. — The acids have little action on naphtha. Con- centrated sulphuric acid has no action in the cold. When a mixture of one part naphtha and two parts of sulphuric acid are distilled, traces of sulphurous acid are disengaged vvithout effervescence. The alteration which the naphtha might have received was not observed. White and fuming nitric acid exhibits no other mark of acting on naphtha in the cold than a very slight yellow shade which it acquires. This result may serve to distinguish naphtha from the essential oils and from petroleum, or to ascertain whether the naphtha is not mixed witii one of these fluids, especially with oil of turpentine, which is often employed to sophisticate it. Nitric acid added to such a mixture becomes brown in a few minutes. Naphtha introduced over mercury into a receiver full of muriatic acid gas ouly absorbs 2-^ times its bulk of it. The liquid is found unchanged after it has given out in the air the gas which it had ab- sorbed. The essential oils act very differently. The rectified oil of lavender absorbed '1 10 times its volume of muriatic acid gas without being saturated, and changed at the same time from pale yellow to blackish red. Oil of turpentine was saturated by absorbing 163 times its volume of this gas. It formed the camphorated matter which is one of the remarkable products of this absorption. Fixed Alkalies. — The hydrates of potash and soda in fragments are scarcely attacked by naphtha. 1 have kept them for several months in this bitumen without their undergoing any other change than a slight brown cloud upon some parts of their surface. When the mixture is boiled, the liquid scarcely becomes muddy. Brown flocks are formed, but in too small quantity to be subjected to any examination. Naphtiia underwent no change when boiled with a concentrated solution of potash in water. It is known that Sir H. Davy, while employing this bitumen to preserve potassium and sodium, first perceived that they did not undergo any alteration in it when it had not been in contact with the air; but that in that case an alkali was formed, which, by uniting with the oily liquid, pro- duced a brown soap. Since the alkalies in the state of hydrate do not form a sensible quantity of this soap, we must conclude that it is not formed except when the oxide of potassium and sodium are not in the state of hydrate. Naphtha is very easily impregnated with atmospheric air ; and we ought to ascribe to this prompt ab- sorption the alteration which potassium and sodium undergo in that liquid when exposed to the air. Aminonia. — Naphtha is capable of absorbing only 2-|- times its volume of ammoniacal gas at the mean temperature of the atmos- phere. The liquid does not become muddy by this penetration. Oil of turpentine exhibits the same results. But the essential oil of lavender absorbs 47 times its volume of this gas, and becomes muddy by this absorption. Naphtha forms with ammonia dissolved in water a white pellicle, which is insoluble. This product, which 18170 9f f'^^ Naphtha of Amiano. 125 is always very scanty, does not liquify at the temperature of boiling water. It is destroyed by long exposure to the air. Sugar, gums, and starch, do not dissolve in naphtha. Decoinposltion of Naphtha in a red-hot Porcelain Tube. — I dis- tilled slowly 22*43 grammes of naphtha through a red-liot porcelain tube, connected with a long glass tube surrounded wiiii cold water, with a small globular vessel, and with the pneumatic trough. The distillation lasted seven hours, and furnished, 1. In the porcelain tube A'~ grammes of very dense charcoal, having the metallic lustre, and similar to that obtained by decom- posing the essential oils in the same way. 2. 4-13 grammes of a brown empyreumatic oil mixed with naphtha and charcoal in a very divided state. This oil, by sublima- tion at the temperature of ^5°, yielded about a gramme of colour- less crystals in rhomboidal plates, thin, transparent, shining, and often truncated on their acute angles. This substance, which is volatile, inflammable, insoluble in water, inalterable by exposure to the air, and having a strong empyreumatic odour mixed with that of benzoin, appears to me to be the same as that which is produced in the decomposition of ether, alcohol, and the essential oils, by the same process. The residue of this sublimation, being treated with ether, was dissolved by that liquid, excepting a pasty matter like pitch, which weighed 0-71 gramme. This solution, when sufficiently concentrated, appeared yellow by transmitted, and green by reflected, light. Petroleum alone, when rectified and concen- trated, has the same property. 3. 9'697 grammes of carbureted hydrogen gas; the first third of which had a specific gravity of 0-3736S, abstracting -^ of azote which was mixed with it, and which might have been furnished by the water of the trough. 100 parts in volume of this gas consumed 135-5 of oxygen, forming Go'iG of carbonic acid gas. Hence it follows that ibo of this gas contain by weight 72'7^ carbon and 27*5 hydrogen. The specific gravity of the last third was 0-4413. 100 parts in volume of this gas consumed 153-25 of oxygen gas, forming 77*17 of carbonic acid. The absence of oxygen in this gas is a strong proof that it does not exist in naphtha. In this analysis there was a loss of 3-9 grammes. It was owing to a brown oily smoke which was carried into the water of the trough. j^nalysis of Naphtha hj the Detonation of its Vapour in Oxygen Gas. — 1 introduced over mercury 9 1'5 milligrammes of naphtha into 1078 cubic centimetres of oxygen gas contaminated with ^-s-^- oi azote at the temperature of 65°, and wlien the barometer stood at 28-23 inches, when reduced to the temperature of 32°. After some hours, all the naphtha disappeared ; for that there might not be naphtha in excess, besides that which was in the state of vapour, I had taken care that the quantity of this bitumen was much less than was requisite to saturate the gas. The mixture occupied under the circumstances above stated 1104-5 cubic centimetres. I added 12G Experiments on the Composition and Properties [Aug, to it -yL of hydrogen gas ; and, after detonating the mixture by electricity, 1 found that, supposing the gas reduced to the volume which it would occupy under a pressure of 0-76' metre (29'92 in.) and at the temperature of 32°, the naphtha alone had consumed 217'7- cubic centimetres of oxygen gas in order to produce water, and 1 53*93 cubic centimetres of carbonic acid gas. A solution of neutral nitrate of mercury added to the water, formed by the slow combustion of naphtha, mixed with sand in a close tube, heated by a lamp, and which contained 250 cubic cen- timetres of oxytren gas, indicated the presence of a little ammonia. The quantity of this alkali, estimated by a process which 1 have described in the Biblioiheque Britannique (Ivi. 347), indicated a portion of azote which amounts at the most to one hundredth part of the weight of the naphtha. When I detonated in a eudiometer the vapour of naphtha with oxygen gas mixed with azote, this last gas rather diminished than augmented by the combustion. These results show that the quantity of azote contained in naphtha must be very small. According to these data, 100 parts of naphtha contain in weight, abstracting the azote, Carl)on 87'6 Hydrogen 1278 100-38 I did not obtain from the combustion of naphtha In the open air, and at the orifice of a serpentine, a quantity of water sufficient to subject it to a rigid examination ; and 1 do not conceal that the composition of this bitumen, deduced (as I have done in some analogous analyses) from the consideration only of the quantity of oxygen consumed, and of carbonic acid produced, by the combus- tion, is liable to some uncertainty. But I have employed the only process which the present state of the science appeared to offer for analyzing a substance so volatile, and so difficult to decompose, as naphtha. To find the ratio of the volume of the vapour of naphtha, and that of its elements, we may admit, taking oxygen gas for unity, that the density of the vapour of carbon is 0'754, and that of hydrogen gas 0*0663. The application of these values to the ana- lysis of naphtha shows that its vapour (whose density we determined by experiment at 2*667) contains five volumes of hydrogen gas and three vohimes of the vapour of carbon, and that the re-union of these elements into a single volume gives the number 2'59'J, which approaches sufficiently to the density of the vapour of naphtha to induce us to consider the two results as the same. If we make this comparison, assuming 2"S33 for the density of the vapour of naphtha, atmospheric air being considered as 1, and admitting, with Gay-Lussac, that the density of the vapour of carbon is 0*416, and that of hydrogen 0*0732, we shall find that 18170 of the Naphtha of Amiano. 127 naphtha is composed of six volumes of the vapour of carbon and of five volumes of hydrogen gas condensed into one ; for this will give the density 2-86"i, very near 2'833, the density of the vapour of naphtha found by experiment. When we set out from the consideration of volumes to rectify the analysis, 100 of naphtha contain in weight Carbon 87'21 Hydrogen 1279 100-00 In the combustion of naphtha thus constituted, the oxygen gas consumed is to tlie carbonic acid gas produced as 100 : 70"59. We conclude from this analysis that naphtha is a carbureted hydrogen containing more carbon than defiant gas, which consists by weight of 85-03 parts of carbon and 14-97 of hydrogen. Article X. Analyses of Books. Le Regne Animal disirilu^ d'apres son Organisation, &c. Par Le Chevalier G. Cuvier, 4 tom. 8vo. Paris, I8I7. In the preface the author professes to give a short account of all the genera of animals that have been established by authors ; and for the purpose of rendering them intelligible to students, for whom the work is intended, he proposes to throw them under great generic heads, and to denominate them sul-genera, suffering them to retain their names, in order to assist the memory.* He rejects the use of technical language, as far as possible; and mentions the authors to whom he is indebted for peculiar views. The introduction is highly interesting: In it he speaks of the systems of natural history in general, and discusses the differences between animals and vegetables ; f but although we have not time to enter into this part of the subject, which is foreign to our pur- pose, yet we cannot but express our surprise at his maintaining the exploded opinion that vegetables absorb the carbonic acid emitted by the respiration of animals ! He treats too of organic elements, of their functions and application, in a manner that does him but little credit. He next treats of the general distribution of animals, which he divides, as in his paper in the Annales du Museum, into four types {embrunchements) . • Fiillowing the L'mnsean method of dividing papilio, plialsena, grjilus, &c. t AoiinaUand veijetables respire, and change the absorbed nutriment inlofluidyi necessary (qj^ their support, increase, &c. : but the line of distinction is as obscure as ever. 3 128 Analyses of Books. [Aug. Type 1. Vertelrata. — Brain and principal nervous cord enve- loped in a bony case, composed of the skull and vertebrae. Muscles attached to the bones. Type 2. Mollusca. — Brain or principal part of the nervous system placed near the oesophagus. Muscles attached to the skin. Type 3. Articulata. — Nervous system composed of two longi- tudinal knotted cords placed in the belly. Muscles attached to the external covering, which is generally hard, and is always articu- lated. Type 4. Radiata. — No distinct nervous system. Body radiated. M. Cuvier has given the characters of each type at full length, and has then divided each into classes. * Tvpe I. — Vertebrata. Class 1. Mamtnalia. 2. Aves. 3. Reptilia. 4. Pisces. Type II. — Mollusca. Class 5. Cephalopoda. 6. Pteropoda. 7. Gasteropoda. 8. Acephula. 9. Brachiopoda. Genera : Lingula and Terebratula. 10. Cirrhopoda. Type III. — Articulata. Class 11. Annelides. Worms with red blood. 12. Crustacea. 13. Arachnidcs. 14. Insecta. \ Type IV.— Radiata. Class 15. Echinodermata. 16". Iidestina. 17. Acalephce. Medusa, actinia, &c. 18. Polypoda. 19. Infusoria. In the detail M. Cuvier has shown a degree of carelessness and inconsistence that we should not have expected from the author of the following passage : — " La determination precise des especes et * Where the classes are different from those mentioned in our preceding numbers, we shall give au example of one or more genera. + The third volame, which is by far the best, contains the classes Crustacea, arachnides, and insecta, and was written by Latreille, who, from his friendship for Cuvier, has sacrificed all his principles, in order to render this part a piece with the rest of the work. J817.] Cuvier, La Regne Animal. 129 de leur cliaracteres distinctifs fait la premiere base sur laquelle toutes Ics recherclies de rhistoire naturelle doivent ttre fondees; les observations les plus curieuses, les vues les plus nouvelles perdent presque tout leur nidrite quand elles sout depourvues de cet appui ; et malgre I'aridite de ce genre de travail c'est part la que doivent comiuencer tous ceux qui se proposcnt d'arriver a des resultats solides." He has even referred to a figure of a mermaid for his diigona ! ! (Vol. i. p. 275) and has placed the argnnauta, nautilus (tmmoiiiles, &c., whose animals are unknown, anWngst the cepha- lopoda : and although he has placed tniio and ariodanta, whose animals are exactly similar, as two disiinct genera ; yet he has considered mytilus and modiola, whose animals are different, as sub-genera ! We might fill a number of our Annals with an enumeration of the inaccuracies and inconsistencies of the author. Those given, however, will suffice to show that the work must be used by students with a great deal of caution. We wish, however, fully to be understood to admit, that it contains more information thin any other introductory work, and a quantity of very valuable matter, which is generally put together with haste and carelessness. The plates are very bad, and in some instances incorrect. It is the worst of Cuvier's productions. II. Essay on the Origin, Progress, and present State of Galvanism : containing Investigations, experimental and speculative, of the principal Doctrines offered for the Explanation of its Pheno- inena, arid a Statement of a new Hypothesis. Honoured by the Royal Irish Academy with the Prize. By M. Donovan. — Dublin, lvSl6. 8vo. This is a work of no ordinary merit, and does great credit to tlie author, both for the extensive knowledge of the subject which it displays, the acuteness with which the different theories are exa- mined, and the ingenuity displayed in the contrivance of the nevir hypothesis, by which he endeavours to account for the different phenomena. The scientific world lie under considerable obligation to the Royal Irish Academy for having occasioned the composition of so ingenious a performance ; and Mr. Donovan promises fair, if lie persevere in the career which he has so happily begun, to do credit to his country, and to contribute materially to the improvement of those sciences to which he has devoted his attention. Chemistry is already indebted to his sagacity for the discovery of the sorLdc acid, which had even escaped the indefatigable Scheele. The present essay does still greater credit to his abilities. If we cannot always subscribe to the soundness of hi-s opinions, we never fail to be struck with the ingenuity which he displays ; and he seldom loses sight of that urbanity of manner with which the opinions of men of science, even when erroneous, ought always to be treated. The essay is divided into three parts. In the first he gives « Vol. X. N° II. 1 130 Analyses of Books. [Aug, sketch of the history of galvanism ; in the second he explains and discusses the different hypotheses by which the galvanic phenomena have been accounted for ; and in the third he gives his own new hypothesis of galvanism. The history of galvanism he divides into four periods: 1. The phenomena observed before the era of galvanism properly so called. These were the shocks given by the fish called the torpedo. An observation of Du Verney, nearly the same with the fact afterwards detected by Galvani, that when the nerves going to the thighs and legs of a newly killed frog are touched with a scalpel, the parts below them are thrown into convulsions.* Sultzer, in 1"C7, ob- served that when a piece of silver in contact with lead is applied to the tongue, a peculiar taste is perceived, though neither metal by itself gives any taste. In 17^7 Mr. Beunet discovered that certain metals, after contact with each other, became feebly, but distinctly, electric. 2. The second period begins in 1791» when Galvani discovered muscular contractions effected by simple metallic associations, and continues till the discovery of the voltaic pile by Volta in 1799. The experimenters during this period were numerous, and the facts discovered curious. Mr. Donovan attaches a greater value to Hum- boldt's experiments made at this time than has generally been done by those who have turned their attention to this brancli of the subject. 3. The third period contains the gradual developement of the physical and chemical powers of combined galvanic arrangements. This period goes only to the commencement of 1804. The prin- cipal experimenters were Nicholson and Carlisle, Cruikshanks, Davy, Wollaston, and Ritter. 4. The fourth period contains the generalization of the chemical effects of galvanism ; and the discoveries that have resulted from the application of a general principle. Here the principal experi- menters were Berzelius, Ritter, and, above all, Davy. Berzelius and Hisinger first generalized the lawaccordingto which bodies are decomposed by the galvanic energy ; and Davy happily applied this law to the decomposition of the alkalies and earths. In this part of his history Mr. Donovan quotes the experiments of Mr. Peele. He does not appear to be aware that Mr. Peele's pretended experiments were merely a ])hilosophical hoax on the public, no such experi- ments in fact having been ever made. He omits, too, all mention of the facts determined by Gay-Lussac and Thenard, and described by them in their Recherches Physico-chimiques, a book of unques- tionable merit, which contains a great number of most valuable facts. I know not whether it be worth while to mention an inad- vertency which pervades the whole of Mr. Donovan's book, and, • Mr. Donovan quotes for this fact Mem. Par. 1700, p. 52. In mj' copy of the Memoires of ths Freocb Academy, wbich is the second edition, the fact occurs ia p. 40. 1817.] J^^*'- Dojiovan's Essay 0}i Galvanism. 131 which, tliough slight, ought however to be corrected : the name of Theodor Fun Groithus is uniformly spelled Grotthius. The second part of Mr. Donovan's essay is divided into five chapters. In the first he eKamines the hypothesis of Volta, wlio considers all the phenomena of galvanism to l)e produced by the agency of electricity alone. Jn tlie second he examines the hypo- thesis of Fabroni, who considers the phenomena of galvanism to be produced by chemical affinity alone. In the third he examines the opinion of the British philosophers, particularly Dr. Wollaston and Dr. Bostock, who united the hypotheses of Volta and Fabroni. According to them, the phenomena are produced by electricity ; but the electricity is evolved by the chemical action of the constituents of the galvanic battery on each other. In the fourth chapter the hypothesis of Davy and Berzelius is examined. It is well known that they consider electricity and chemical affinity to be one and the same power. Bodies, according to them, unite when tiiey are in opposite electrical states, and they separate when brought into the same electrical state. The object of the fifth chapter of this part is to prove that electricity is not the real agent in galvanic phenomena. Part tlie third is occupied with the author's new hypothesis of galvanism. It is divided into two chapters. The fi^st is employed in explaining the hypothesis ; and the second in applying it to the principal phenomena of galvanism. Affinity, in our author's opinion, is a property belonging to all bodies, though they cannot always unite in consequence of it, being prevented by some other circumstances. If a piece of zinc be plunged into diluted nitric acid, it immediately begins to dissolve, in consequence of the affinity between it and the acid. The same solution takes place when copper is put into diluted nitric acid. From these experiments, it is obvious that both zinc and copper have an affinity for nitric acid. If the two metals lie placed in ron- tact, and then plunged into diluted nitric acid, the zinc dissolves more rapidly than before, but the copper does not dissolve at all : therefore tlie copper has Ircunferred its affinity for oxygen to the zinc. The zinc has acquired a stronger affinity for oxygen than before, and the copper has lost that affinity. The copper, how- ever, effervesces, and gives out hydrogen gas. It has acquired a greater affinity for hydrogen than formerly, while the copper has lost its affinity for that principle. The zinc has transfened its affinity for hydrogen to the copper. The affinities of bodies may be divided into two sets. The first set consists of oxygen and acids; the second set, of hydrogen, alkalies, earths, and metals. When- ever two metals are placed in contact, one of them transfers its affinity for oxygen and acids to the otlier ; while that other transfers its affinity for hydrogen, alkalies, earths, and metals, to the first. This transfer of affinity is the principle which, in Mr. Donovan's 9pinion, explains the nature and energy of the galvanic battery. In short, it constitutes the foundation of galvanism, which, in his opinion, has no connexion with electricity whatever. He illustrates 1 2 132 Analyses of Booh. [Aug. his principle with great ingenuity, and brings many valuable expe- riments and observations in support of his opinions ; so that they appear much more plausible in tbe essay itself than they can do here when stripped of all these illustrations and experiments. The galvanic phenomena, to the explanation of which Mr. Donovan applies his hypothesis, are the following: — 1. Metallic Arhurizalions. — It is generally known that if a plate of copper be immersed in a solution of silver in nitric acid, the silver is precipitated in the metallic state, while the copper is dis- solved. In the same way, when zinc is immersed in acetate of lead, the zinc dissolves, while the lead is precipitated in the metallic state. The precipitated metal in these cases usually appears in the form of long threads or crystals, arranged like the branches of trees. Hence the phenomenon is called arborization. Zinc and iron throw down copper and lead in the metallic state ; lead throws down copper, copper throws down bismuth, bismuth mercury, and mer- cury silver. Mr. Donovan shows that his hypothesis explains these precipitations in a satisfactory manner. When zinc and copper are placed in contact, the copper transfers its affinity for oxygen and acids to the zinc, while the zinc transfers its affinity for hydrogen and bases to the copper. Hence when a plate of zinc is plunged into a solution of copper, the copper losing its affinity for oxygen and the acid appears in the metallic state ; while the zinc, having acquired a stronger affinity for oxygen and acids, dissolves in its place. The knowledge of the order in which these tranfers take place, when two metals are placed in contact, enables us to deter- mine when arborizations will make their appearance. Mr. Donovan shows that his explanation will even apply to those cases in which the usual order of the precipitation of metals is reversed in conse- quence of galvanic action. 2. General Chemical Effects of Galvanism. — These effects are the decompositions of water, acids, oxides, &c. the hydrogen or metallic base being evolved at the negative side of the galvanic battery, and the oxygen or acid at the positive side. These decom- positions are ascribed to the increased affinity of the zinc for oxygen and acids, and of the copper for hydrogen and bases. These in- crements of affinity he conceives to be sufficient to account for the decompositions which take place. 3. Electrical Phenomena manifested by Galvanic Arrangements, — He considers affinity and electricity as antagonist forces. Hence he conceives that when affinity acts with energy electricity must be evolved. This is the part of his hypothesis which Mr. Donovan seems to me to have made out in the least satisfactory manner. 4. The Light and Heat manfested by Galvanic Arrangements.—' Heat and affinity being of opposite principles, he conceives that a sudden transfer of the one will disengage the other. And light and heat are so closely connected that we may expect them to accom- pany each other, 5. The Contractions and Shock produced in Animals ly Galvanic 6 o 13] 7 '2 Experiments ivith the Gas Blow-pipe. 13 Arrangements. — He is of opinion tliat these are produced, not by electricity, but by the chemical action of the substances applied on the muscles and nerves. Such is a short sketch of Mr. Donovan's very curious and inte- resting performance. I have perused the work with considerable pleasure, and received from it not a little information. His opinions, I think, deserve a full examination. I must acknowledge, however, that his reasoning has failed to produce in my mind a conviction of the accuracy of his hypothesis. He has been at pains to inform us that by transfer of affinity he means merely tliat the affinity of one body for oxygen has increased while the same affinity in the accompanying body has undergone a proportional diminution. Now I can form no conception of the possibility of such a transfer, unless the two kinds of affinity brought into view by galvanic expe- riments were inherent in two fluids residing in matter, and capable of being transferred according to certain laws. Were we to suppose the existence of two such fluids in copper and zinc, it would be easy to suppose that the fluid producing the affinity for oxygen might accumulate in the zinc, while the fluid producing the affinity for hydrogen might accumulate in the copper. With such an hypothesis for a foundation, it would not be difficult to construct a galvanic theory that would explain all the phenomena, and Mr. Donovan's treatise would greatly facilitate such an attempt. But if affinity be merely an attraction belonging to copper and zinc as matter, and this seems to be Mr. Donovan's opinion, I do not see how any such transfer as he has supposed can take place, and could not therefore admit it as the foundation of a theory of galvanism. Article XI. Account of some Experiments made with the Gas Blow-pipe; leing a Continuation of former Observations upon the same Svhjtct. In a Letter to the Editor by Edward Daniel Clarke, LL.D. Professor of Mineralogy in the University of Cambridge, and Member of the Royal Academy of Sciences at Berlin, &c. (To Dr. Thomson.) SIR, At the conclusion of my letter inserted in the fifty-first number of your Annals, published last March, I promised to renew my communications, respecting the gas blow-pipe, whenever any thing should occur worthy of your notice. Since that letter was written many things have happened likely to interest tho?e who con- sidered my former observations of any importance. In the first place it may concern them to know that this blow-pipe is com- pletely divested of all the danger with which it menaced the ope- 134 Experiments with the Gas Blow-pipe. [Aug. rator. Observing the precautions before described, I have been able to continue the use of it, not only for my private exjieriments, but aUo during an entire course of public lectures, delivered to the Members of this University, without a single accident or interrup- tion of any kind : and the consequence of this public use of it is, that I may nov/ appeal to the testimony of all those, in whose pre- sence the experiments were performed, for the truth of the state- ment already published, touching the results which this blow-pipe has enabled nie to obtain. 1 shall mention only two things which I consider as being essentially requisite in all experiments where the same results may be desired. First, that, as a precaution for his safety, the operator, before igniting the gas, should apply his ear to the apparatus (gently turning the stop-cock of ihe jet at the same time), and listen to determine, by the bubbling noise of the oilj whether it be actually within the safety cylinder.* If there have been a partial detonation in the safety cylinder, as sometimes happens, when the gas is nearly expended, this precaution is doubly necessary ; to ascertain whether the oil have not been driven into the reservoir; when an explosion of the whole apparatus would be extremely probable. Using this precaution, the diameter of the jet may be so enlarged as to equal ^ of an inch. Secondly : If, with this diameter, the heat of the flame be not sufficient to melt a platinum wire whose diameter equals ^ of an inch, the operator may be assured his experiments will not be attended with the results I have described; and for reasons which will presently be explained. The melting of the platinum wire of the thickness now mentioned ought to be considered as a necessary trial of the intensity of the heat; which should be such that this wire not only fuses and falls in drops before the flame, but also exhibits a lively scintillation re- sembling the combustion of iron wire, exposed to the same tempe- rature. To return, therefore, now, to the point at which my former ob- servations were terminated. I mentioned the probable fusion of charcoal ; as the only result wanted for the complete annihilation of the character of infusibilily; every other substance having yielded to the poweiful heat of the ignited gas. This result, as it is well ]8 37 24 31 09 1 37 24 42 14 6 54 24 34 05 Month. ) June 13, in the evening, the needle at intervals vibrated 25' SO". During the night it blew hard from the west. — June 21, at eight 1817.] <^"^ Meteorological Talks, 157 o'clock in the morning, the variation was 24" 2S' : 35 minutes after it increased to 24'^ 35' 31" : in the course of the day several loud claps of thunder were heard in the north-west. Meteoroloslcal Talle. Month. Time. Barom. Ther. Hyg. Wind. Velocity. Weather. Six's. Inches. Feet. Morn... 29 '335 51° 53<' NWbyN Very fine 41 Jiiue 1 ^ Noon. . . , 29-3.30 60 43 NNW 7-263 Cloudy 60 Kveu .... 29-330 51 54 W Showery :|44 Morn 29-333 54 56 sw Fine sJ Noou. . . . 29-305 58 52 sw 16-107 Fine 59 Even .... 29-254 51 52 sw Cloudy |46 Morn — — — — — s) Noon. . . . — — — — . — 68 Even 29-273 53 51 ssw Cloudy ^44 Morn 29-058 55 67 sw by W Cloudy *\ Noou. . . . 29-263 61 48 wsw 38-475 Fine 61 Even .... 29-420 53 50 w Fine I 44 Morn. . . . 29-635 55 59 w Cloudy 6< Noon. . . . 29-655 60 50 sw n-771 Cloudy 60 Even ... . 29-6:^3 54 50 SW bv W Fine |50 Morn... . 29574 55 78 WSW Drizzle *i Noon... , 29-574 55 53 wsw 13-082 Fine -^61 Even .... 29-570 60 68 WbvS Fine |56 Morn.... 29-505 63 63 ssw Fine ') Noon. .. . 29-450 69 52 SW by S 12-911 Fine 78 Even .... 29-335 61 49 SW Fine }« Morn. . , . 29-287 60 59 Why S Fine S-j Noon. . . . 29-295 64 43 WSW 18-907 Showery 64 Even .... 29-363 53 62 AV by S Hard do. Us , 1 Morn.... 29-413 55 77 SW Sra. rain 955 68 52 E Fine }e, Morn. . . . 29-292 71 49 AVSW Very finf 19 j Noon .... 29-300 81 42 SE 6-870 Fine 82 Even .... 29-3 J 6 71 46 Calm Clear |63 Morn .... 29-375 75 43 NE hv E Very fine 20<| Noon 29-380 82 37 SE 8-283 Very fine 824 Even .... 29-380 75 41 E Clear }m Morn .... 29-432 75i 54 NNE Very fine 21 -j Noon. . . . 29-500 84 43 NNE 6-200 Very fine 844 Even .... 29-550 75 54 SE Fine }e, Morn... . 29-615 70 63 N Fine 22 < Noon.. . . 29-643 S2i 49 NNW- 5-512 Fine 83 Even..., 29-630 73 54 NbyE Fine |56 Morn. . . . 29-545 60 60 NNE Fine 23 ^''^ expe- 18 J 7-] -D?'. Ingenhousz. 168 riments on vegetables, demonstrating their power of emitting vital air in sunshine, and azote in the night. I'hese experiments he often repeated, improved, multiplied, and republished, on the con^- tinent, with various other philosophical essays, in French, German, and Latin editions. Of the Experiences sur les Vegetaux, he pub- lished at Paris, in 1787j the first volume, as a much augmented and corrected translation of the English publication of 177^5 a"d, on his second journey to Paris, in 17^9? a second volume of the same work, with much more extended views. On his return to Vienna, he married a sister of Professor Jacquin, by whom he had no children, and with whom he did not live many years : his fondness for travelling, and his extreme attach- ment to England, engrossed the whole of his remaining life ; and that will be best understood by attending to the chronology and analysis of his publications, which, being numerous, can be noticed in a life of this kind only in a summary way. The order of his publications, separate from those already men- tioned in our Transactions, are, first, his Experiments on Vege- tables, published in London in 177!^? before his first return to Vienna ; a translation of which into Dutch was soon after published at the Hague, by Van Breda^ and a German translation at Leipsic, by Molitor, in 1 780 ; each of which was more enlarged than the original : and, what is remarkable, there were four different edi^ tions, published in four diflferent languages, of this work, and all of them in the course of a few months. The first French transla- tion being published soon after he passed through Paris to Vienna, in the year 17^0, a second and much enlarged German edition of this work was published at Vienna, in three volumes, in 1786 : and a second French edition of the first volume of the same work was published at Paris in 17^7; and the second, with many additional improvements, in 1789. His Nouvelles Experiences sur divers Objets de Physique was published in German by M. Molitor, Professor at Mayeince ; and a second part of the same in 1782 : and a second edition of this work was printed in 178'1, containing a number of papers already pub- lished in our Transactions : and all this happened before the publi- cation of the original French edition, which, although it had been finished and sent to Paris in 1781, was very unreasonably delayed by the French publisher till 1785. This volume begins with a very correct and precise account of the system of electricity by Dr. Franklin : and the second memoir is a very ingenious explanation of all the phenomena of the electrophorus invented by Volta on his theory of positive and negative electricity, the greatest part of which he had already published as a Bakerian Lecture in the Philosophical Transactions for the year 1778. In the third memoir he discusses at great length the much disputed question whether points or balls are the best contrivance to preserve buildings from the eflTects of light- ning. He enters into an examination of Mr. Wilson's experiments performed at the Pantheon, and endeavours to establish the supe- L 2 164 Biographical Account of [Sep-?. riority of pointed conductors in opposition to that gentleman, who asserted that they ought to terminate in lialls ; whicli last, he says, will rather attract a strong shock ; whereas the other, by acting at a much greater distance, will silently and gradually attract and convey to the earth the electrical fire, and so prevent its ever occa- sioning a severe stroke. The following memoirs are chiefly employed in experiments on inflammable and dephlogisticated air; in describing air pistols, and lamps; a method of procuring inflammable air from marshes, and in other ways; how to produce the most dazzling light; and how to light a candle at pleasure with an electrical spark ; several of which are to be found in our Philosophical Transactions. In the 13th memoir we have a long account of the nature and best means of obtaining dephlogisticated air from various substances, and especially from nitre. He next republished his paper upon the salubrity of common air at sea compared with the air of the sea coast and of inland countries, which we have in the Transactions for 17SO. We next have a memoir on magnetism and artificial magnets : next a republication of his theory of gunpowder, and of pulvis fulminans. The 18th memoir is on the passage of heat through, and inflammability of, metals ; with an attempt to deter- mine the quantity of phlogiston which different metallic and other bodies contain. Previous to his publication on vegetables, in 1779} he had in the year 1775 published in our Philosophical Transactions, vol. Ixv. hia experiments on the torpedo, which at that time, from the previous experiments of Mr. Walsh, was exciting much attention ; and that subject was further cultivated by experiments on the gymnotus, and by the very accurate anatomical observations of the late eminent Mr. John Hunter. In the year 1776 he published, in vol. Ixvi., an easy method of measuring the diminution of bulk taking place in the mixture of common and nitrous air, according to the disco- very of Dr. Priestley; and he there describes an instrument he had contrived, whereby this nice experiment might be performed with much more facility and accuracy. In the same paper he published his experiments on platina, which, then a new metal, he had taken much pains to investigate and render fusible. He valued highly a set of buttons of this metal, with which he had a coat mounted. He found platina to be as completely, though not so strongly, magnetic as iron ; and that this power was increased by fusion in electrical fire, which he first effected, whilst common fire was found to diminish it ; and this magnetic virtue he constitutes as a specific property of platina, by which it may be always distinguished from gold, which cannot be rendered magnetic. Id the year 177^ we find a ]>aper in the Phil. Trans, vol. Ixviii. describing a ready way to light a candle by a very moderate elec- trical spark excited positively by a piece of glass, and a match made of cotton powdered with resin. In the 48th paper of the same volume we find electrical experiments to explain how far the phe- 1817.] -O''' Ifigenhoiisz. 165 nomena of the electrophorus may be accounted for on Dr. Frank- lin's theory of positive and negative electricity, which he proves to agree pcfectly witli those exhibited by tiie late Mr. Canton with elder pith balls hanging by linen threads from a wooden box ; which balls are excited either negatively or positively by a piece of excited glass. In vol. Ixix., for the year 1779» ^^ gives an account of a new kind of inflammable air, or gas, which can be made in a moment without apparatus, and is as fit for explosion as other inflammable gases in use for that purpose ; together with a new theory of gun- powder. In October of the same year (177^) he published the first edition of Experiments on Vegetables, before mentioned. To this he pre- fixes a most grateful dedication to Sir John Pringle, explaining at length the whole series of obligations he was under to him for his early patronage on his first arrival in this country, and for his very extraordinary mark of confidence and respect in recommending him to the Imperial Family of Germany, leaving this as a public testi- mony of his gratitude, being then about to return to Vienna. In the end of vol, Ixix., for 177^5 we find a memoir on improve- «ients in electriciry, delivered as a Bakerian lecture, which were performed by the use of flat glasses, instead of globes or cylinders, which it now appears he had made use of for 15 years. In vol. Ixx. for the year 17H0, we find a paper on the degree of salubrity of the common air at sea in the Channel compared with that on the shore, and in various parts of Holland. In a letter written from Paris in January, 1780, and in vol. Ixxii., for the year 1782, we find some further considerations on the influence of the vegetable kingdom on the animal creation. In the year 1784 there were two volumes, in octavo, of his various philosophical papers published in German at Vienna. In 1785 we find Nouvelles Experiences et Observations sur divers Objets de Physique, which wholly consist of subjects of electricity, and the different kinds of air, being chiefly what had been before published in our Transactions. This he dedicates to Dr. Franklin, then residing at Paris, as Minister Plenipotentiary from the United States of America. In the year 17*9 he published a second volume with the same title, dedicated to Baron Dimsdale, and printed under his own eye at Paris. The second volume contains chiefly experiments and observations relating to vegetables, and especially to that green matter produced in water, on which so much had been said by Dr. Priestley. These two volumes are pretty much the same with those that have been published in German, in which there were also some medical as well a? physical papers, which, by a mistake of the editors, were omitted in the French edition. His last publication, in the year 1798, preceding his death, is an essay on the food of plants and the renovation of soils, written ■at the desire of Sir John Sinclair, and published by the Board of Agriculture, of which he was President, and of which our philoso- 166 Chemical Analysis of Cornish Tin. [Sept. pher had been made a Foreign Honorary Member. In this paper we have an abridged recapitulation and very ingenious application of his experiments and opinions, so fully illustrated in his Expe- riences sur les Vegetaux, published at Paris in two volumes, 8vo. in the year 1787 and 1789, to which he continually refers. He surely was the first who demonstrated clearly the singular facts of pure oxygen being continually emitted by vegetables when under the influence of light, by which the air was continually ameliorated, and that of their constantly emitting azote in the dark, by which it is corrupted. It is very true that Dr. Priestley had before him dis- covered that living plants always ameliorated the atmospheric air, by absorbing phlogiston, a theory in direct opposition to that of our philosopher, who thought this purification was occasioned by their perspiration instead of absorption, which continual absorption of atmospheric air he also allows ; and proves, by some most ingenious experiments, that plants derive great part of their nourishment by their leaves ; and that respirable air and heat are absolutely neces- sary to vegetation, though light is not, as they can grow very luxu- riantly in the dark, but will emit no oxygen, acquire no green colour, and rather taint than ameliorate the air. As far as concerns the economy of vegetables, he certainly has thrown more light than any other philosopher since the time of Hales, whose ingenuity and success must render him immortal. Though it require too much of the reader's time to enumerate the variety of ingenious inventions and discoveries which he has published, yet I cannot omit making mention of that very brilliant experiment — the defla- gration of solid iron in vital air ; of which he was so very fond that he always carried a phial of it in his pocket, in which he used fre- quently to burn a piece of iron wire, to the great entertainment of his female friends. Article II. Chemical Analysis of Tin from the diffh-ent Smellins; Houses in Cornwall. By l^homas Thomson, M.D. F.R.S. It would appear that there exists on the Continent a prejudice against Cornish tin, or an opinion that it is not pure, but artificially alloyed with some other metal. Some of the gentlemen connected with the tin trade in Cornwall conceived it possible that there might be some particular smelting-house which sent impure tin into the world, adulterating it artificially, for the sake of profit. To verify this suspicion, specimens of tin from every smehing-house in Corn- wall were put into my hands, for the purpose of determining, by a careful analysis, the foreign metals with which they might be con- taminated. I shall state in this paper the results which I obtained. 1817.3 Chemical Aimhjsis of Cornish Tin. 167 The specimens subjected to experiment were 14 in number, col- lected from as many different smelting-houses, without the smelters being aware beforehand of the ooject in view wheij the speciinens were collected. The following table exhibits the specific gravity of these speci- mens, numbered as they were when I received theni : — No. 1 Specific gravity 7-2960 at 60° 2 7*2930 4 7-2943 6 7-2890 7 7-2933 8 7-2881 9 7*3209 10 7-3046 11 7-2853 12 13 7-2974 14 7-2934 15 7-2975 16 7-3082 My mode of analysing these specimens was the following : — 1 poured nitric acid diluted with twice its weight of water upon a determinate quantity of each specimen, and continued the digestion till the whole of the tin was converted into a white powder, adding fresh acid when it became necessary. It was then exposed to heat, in order that all the tin might be peroxidated, and that none of it might remain in solution in the acid. The whole was now thrown upon a filter ; ai;d the white hydrate of tin which remained was edulcorated with water till that liquid came off" tasteless. The hydrate of tin was then dried upon the filter, exposed to a red heat, and weighed. The peroxide of tin thus obtained was a yellow powder, which was considered as a compound of 7'375 tin and 2 oxygen. Knowing the weight of this peroxide, it vvas easy to de- termine the proportion of pure tin contained in the specimen under examination. The liquor which had passed through the filter was concentrated by evaporation. A drop of it was let fall into a solution of sulphate of soda, but no cloudiness whatever could be perceived. Hence I concluded that none of the tins contained lead. VVIien a drop from each of them was let fall into a solution of nitrate of lead, no cloudiness whatever appeared. Hence I coq- cluded that no arsenic acid was present in the solution, and that therefore none of the tins had contained arsenic as an ingredient. All of the specimens, except the solution from No. 9, became slightly blue when treated with prussiate of potash. They therefore contained iron. By comparative experiments with liquids contain- ing known weights of iron in solution, I endeavoured to ascertain the quantity of iron which had been dissolved from eacU spjccimen 5 168 Chemical Analysis of Cornish Tin. [Sept. of tin. The quantity varied from ToWtl» of the weight of the tin, which was the greatest portion, to t« woth» which was the smallest that I could pretend to determine. Nos. 4, 7, 8, and 14, contained ^bout -i-^-5. of their weight of iron. No. 9 contained no sensible portion. In none of the others could the proportion of iron exceed 10000th of the weight of the tin. Ammonia, being poured into the solution, detected copper in all the solutions, except that from No. 1 ; or at least the quantity in No. I was so small, that it was obviously impossible to separate it and weigh it. From all the other solutions I threw down the copper by immersing a plate of zinc into the liquid. The following table exhibits the weight of copper which 1 sepa- rated from 1000 grains of each of the tins examined : — No. 1 yielded only a trace of copper 2 1-0 grain 4 10 6 0-4 7 ...••• 1*5 8 l-O 9 2-0 10 0-5 11 0-1 12 0-2 13 1-0 14 1-0 15 15 16 2-0 Thus we see that Nos. 9 and 16 were the most impure, each of them containing -j^th of its weight of copper. Nos. 1, 11, and \2, were the purest. No. 11 contains rwh-ois. No. 12 ^i^^, of its weight of copper; and No. 1, a quantity of copper which pro- bably did not exceed ^-^'^^^th of its weight. The average quan- tity of copper contained in Cornish tin, provided these specimens constitute a fair criterion, as it is probable they do, is about -rro-oth part of the weight of the tin. When the tin is dissolved in muriatic acid, as it is for the purposes of the dyer, this copper remains un- dissolved, and constitutes the well-known black powder which is obtained when tin is dissolved in that acid. The cupreous portion, therefore, cannot be in the least injurious to the tin when it is to be employed as a mordant. It is evident that this small portion of copper is derived from the copper ore which still remains mixed wirfi the tin ore after it is dressed, and made as free from impurities as possible for the use of the smelters. The copper ore in Cornwall is chiefly copper pyrites, and it is separated from the tin ore by washing ; for the difference between the specific gravity of tin ore and copper pyrites is so great, that they may be separated from each other by means of exposure to a current of water. It would be curious to know whether the tins of Nos. 9 and 16, which contain 1817.] Chemical Analysis of Cornish Tin. 1G9 the most copper, may not be obtained by smelting tin ore which is mixed in the mine with some copper ore of a greater specific gra- vity than copper pyrites. The small quantity of iron contained in these tins may possibly be derived from the tin-stone itself, which probably always contains a small portion of iron. If this be the origin, it would be hopeless to look tor tin totally free from iron. The presence of iron in tin was rather unexpected by me, as the affinity between iron and tin is so feeble that it was supposed, till Bergman demonstrated the contrary, that the two metals could not be united. I reduced the specimens of tin, which I analyzed, by fixing each into a vice, and pulling off the requisite pieces by means of a pair of pliers. It occurred to me as possible that the small traces of iron which I dis- covered in each solution might have been abraded from the vice or the pliers ; but, on dissolving a portion of tin not thus treated, the iron was still perceptible in the solution. I think myself warranted, therefore, in concluding that the iron existed in the specimens. I tried various other modes of analysis besides the foregoing ; for example, I endeavoured to separate the copper from the iron by a current of sulphureted hydrogen gas, I tried likewise to throw down the iron by means of caustic ammonia, which retained the copper in solution ; but in the 100 grains of each specimen which I subjected to analysis, the quantity of iron was so exceedingly small that, when I attempted to collect and weigh it, my results were much more inaccurate than those deduced by estimation from the intensity of the colour produced by prussiate of potash. I think the preceding analysis does great credit to the Cornish tin smelters. It shows that there is no foundation for the opinion that any of them adulterate their tin by the addition of any foreign metal. The presence of — ,', oth of alloy, which characterizes Nos. 9 and IQ, the most impure specimens, I consider as a very small quantity ; nor is it likely that it can be injurious to the metal for any of the purposes to wiiicli it is usually applied. The opinion entertained on the continent of the impurity of Cornish tin is owing probably to pewter having been frequently mistaken for that metal. The same French word, etaln, signifies both tin and pewtur. Pewter, as is well known in this country, is tin alloyed with another metal, usually antimony or lead. Article III. A General Formula for the Analysis of Mineral JVaters. By John Murray, M.D. F.R.S.E. {Continued from p. 98.) The method proposed by Dr. Wollastou, of i)recipitating mag- nesia from its solution, by first adding carbonate of ammonia, and 170 A General Formula for the [Sept. then phospliate of soda, so as to form the insoluble phosphate qf ammonia and magnesia, is one much more perfect ; the whole of the magnesia appears to be precipitated ; and as a method, there- fore, of determining the quantity of this base, it is probably unex- ceptionable. It does not, however, altogether accord with the ob- ject of the present formula. The soda of the phosphate of soda serves to neutralize the muriatic acid of the muriate of magnesia ; a quantity of muriate of soda is of course formed, which remains with the muriate of soda of the water, and the amount of which, therefore, it is necessary to determine with accuracy. This may be done from the quantity of phosphate of magnesia obtained giving the equivalent portion of muriate of soda, either by means of the equivalents of the acids, or of the bases. But still this renders the method somewhat complicated ; and it may be liable to some error, if any excess of phosphate of soda be added, which, in order to precipitate the magnesia entirely, it may be difficult to avoid ; this excess remaining with the muriate of soda, and rendering the esti- mate of it incorrect. And independent of these circumstances, it would be preferable to give uniformity to the operation, by em- ploying some method by which the product in this, as well as iji the previous steps, is removed, at the end of the analysis, leaving only the muriate of soda. It seemed probable that this might be attained by employing phosphoric acid with the carbonate of ammonia to form the triple phosphate of ammonia and magnesia, such an excess of ammonia being used as should both be sufficient for the constitution of this compound, and for the neutralization of the muriatic acid of the muriate of magnesia ; muriate of ammonia would thus be substi- tuted, the same as in the preceding step of precipitating the lime, which at the end would be expelled by heat, leaving muriate of soda alone. I accordingly found that when this variation of the process was employed, the clear liquor, after the precipitation, was not affected by the addition either of phosphate of soda with ammonia, or of subcarbonate of soda, — a proof that the separation of the magnesia had been complete. To establish its accuracy with more certainty, the following experiments were also made. Twenty grains of muriate of soda (pure rock salt), which had been exposed to a red heat, and 10 grains of crystallized muriate of magnesia, were dissolved in an ounce of water, at the tempera- ture of 100''. The phosphate of soda and carbonate of ammonia were then employed to precipitate the magnesia in the mode pro- posed by Dr. Wollaston ; that is, a solution of the amraoniacal car- bonate was first added, and afterwards a solution of phosphate of soda, as long as any precipitation was produced, taking care to pre- serve in the liquor a slight excess of the ammonia. The precipitate, being washed and dried, afforded, after exposure to a red heat for an hour, .5*4 grains of phosphate of magnesia, equivalent to 2* 15 of magnesia. The clear liquor being evaporated, muriate of soda was obtained, which, after exposure to a red beat, weighed 25*7 18170 A7iahjsis of Mineral IVaiers. l/l grains. Phosphate of magnesia being coniposed of 39*7 of mag- nesia, with 60*3 of phosphoric acid, 5-4 grains of it are equivalent to 6-4 grains of muriate of soda, and this deducted from the quan- tity obtained 25 7) leaves 19'3 as the quantity originally dissolved. A solution perfectly the same was prepared, and a solution of carbonate of ammonia was added to it as before. A strong solution of phosphoric acid was then dropped in, as long as any precipitation was produced, observing the precaution of having always an excess of ammoniacal carbonate in the liquor. The precipitate, being washed and dried, attbrded, after exposure to a red heat, 5'5 grains of phosphate of magnesia, equivalent to 2*19 of magnesia. The clear liquor being evaporated, and the dry matter being exposed to a heat gradually raised to redness, weighed, when cold, exactly 20 grains. In both experiments the quantity of muriate of soda is accurately obtained, or as nearly so as can be expected. They correspond, too, as nearly as can be looked for, even in a repetition of the same experiment, in the quantity of magnesia which they indicate. To ascertain how far this corresponded with the real quantity, I con- verted 10 grains of the crystallized muriate of magnesia into sul- phate by the addition of sulphuric acid, and exposed it to a low red heat; the product weighed 6'4 grains, equivalent to 2*13 of mag- nesia. This may be regarded as a perfect coincidence, and as esta- blishing the accuracy of the other results.* It thus appears that phosphoric acid with an excess of ammonia may be employed to precipitate magnesia from its saline combina- tions ; and in a process such as the present, it has the advantage that the muriate of ammonia formed can be afterwards volatilized by heat, and the quantity of any residual ingredient can of course be easily ascertained. Neutral phosphate of ammonia would also have this advantage ; but it does not succeed, phosphate of mag- nesia not being sufficiently insoluble. On adding a solution of phosphate of ammonia to a solution of sulphate of magnesia, the mixture became turbid in a minute or two, and in a short time a precipitate in crystalline grains formed at the bottom and sides; but it was not considerable, and did not increase. Phosphate of am- monia, however, with an excess of ammonia, or with the previous addition of carbonate of ammonia, may be employed with the same effect as phosphoric acid. In applying the phosphoric acid to this purpose under any of these forms, it is necessary to be careful that it be entirely free from any impregnation of lime. There is one other advantage which this method has, that if even a slight excess of phosphoric acid be added, the error it can intro- • According to the result of tliis last experiment, 100 grains of civstallized nniriate of magnesia would give CI of real sulphate of magne.-.ia, composed of yi-S of inagne>ia, .ind 42-7 of sulphuric acid. This quantity of iulphmic acid U equivalent to 294 of muriatic acid. H<-iici' 100 grains of this salt crystallized (in M-bich state its composition, I believe, has not been detcrminedj cu«tii!)t of i.'lS wagneiia, 29 4 muriatic acid, and 49 3 of water. 172 A General Formula for the [Sept. duce must be extremely trivial ; for the effect of it will be only to decompose a small portion of the original muriate of soda; and as the difference is very inconsiderable in the proportion in which phosphoric and muriatic acids combine with soda, any difference of weight which may arise from this substitution, to any extent to which it can be supposed to happen, may be neglected as of no importance.* To apply this method, then, to the present formula : add to the clear liquor poured off after the precipitation of the oxalate of lime, heated to 100°, and, if necessary, reduced by evaporation, a solu- tion of carbonate of ammonia; and immediately drop in a strong solation of phosphoric acid, or phosphate of ammonia, continuing this addition with fresh portions, if necessary, of carbonate of am- monia, so as to preserve an excess of ammonia in the liquor as long as any precipitation is produced. Let the precipitate be washed ; when dried by a heat not exceeding 100°, it is the phosphate of ammonia and magnesia containing -Olf) of this earth; but it is better, for the sake of accuracy, to convert it into phosphate of magnesia by calcination for an hour at a red heat: 100 grains, then, contain 40 of magnesia. Evaporate the liquor remaining after the preceding operations to dryness, and expose the dry mass to heat as long as any vapours exhale, raising it towards the end to redness. The residual matter is inuriate of soda, 100 grains of which are equivalent to 53*3 of soda and 4(j"7 of muriatic acid. It is not, however, to be consi- dered necessarily as the quantity of muriate of soda contained in the water : for a portion of soda may have been present above that combined with muriatic acid, united, for example, with portions of sulphuric or carbonic acid ; and from the nature of the analysis, this, in tlie progress of it, or rather in the first step, that of the removal of these acids by the muriate of barytes, would be com- * For the sake of comparison, and to asrortain the accuracy of different methods, I submitted a similar solution of muriate of magnesia and muriate of sada to analysis b\ subcarbonate of ammonia. To the saline liquor, healed to 100°, a solution prepared by dissolving carbonate of ammonia in water of puie ammonia ■was added until it was in excess. A precipitation rather copious took place ; the precipitate being collected om a filter, the clear liquor was evaporated to dryness, and the saline matter was exposed to heat, while any vapours exhaled. Being re- dissolved, a small portion remained undissolved; and on again adding subcarbonate of ammonia to the clear liquor, precipitation took place, rather less abundant than at first. This was repeated for a third, and even for a fourth time, after which the liquor was not rendered turbid. Being evaporated, the muriate of soda obtained, after exposure to a red heat, weighed 205 grains. The whole precipi- tate washed, being heated with sulphuric acid, afforded of dry sulphate of mag- nesia 4*8 grains, a quantity inferior to that obtained by the other methods, evi- dently owing to the less perfect action of the ammoniacal carbonate as a precipi- tant. A similar deficiency in the proportion of magnesia was found in the analysis of sea water by subcarbonate of ammonia, as has been already stated : while, on the other hand, in its analysis by phosphate of soda and carbonate of ammonia, a larger quantity of miniate of soda was obtained than by the other methods, pro- bably from the difficulty of avoiding an excess of phosphate of soda in precipi- tating the magoe&ia. 1817.] Analysis of Mineral JVaiers. 17' blned with muriatic acid. It does not, tlierefore, give the original quantity of that acid ; but it gives the quantity of soda, since no portion of this base has been abstracted, and none introduced. The quantity of muriatic acid may have been either greater or less than that in the muriate of soda obtained. If the quantity of soda existing in the water exceeded what the proportion of muriatic acid could neutralize, this excess of soda being combined with sul- phuric or carbonic acid, then, in the removal of these acids by muriate of barytes, muriatic acid woutd be substituted, which would remain in the state of muriate of soda; and if the quantity considered as an original ingredient were estimated from the quan- tity of this salt obtained, it would be stated too high. Or if, on the other hand, more muriatic acid existed in the water than what the soda present could neutralize, the excess being combined with the other bases, lime or magnesia, then, as in the process by which these earths are precipitated, this portion of the acid would be combined with ammonia, and afterwards dissipated in the state of muriate of ammonia, if the original quantity were inferred from the weight of the muriate of soda obtained, it would be stated too low. To find the real quantity, therefore, another step is necessary. The quantities of bases and of acids procured (taking the quantity of muriatic acid existing in the muriate of soda obtained) being combined according to the known proportions of their binary com- binations, if any portion of muriatic acid has been abstracted, the bases will be in excess, and the quantity of this acid necessary to produce neutralization will be the quantity lost ; or, on the other hand, if any portion of muriatic acid has been introduced, and re- mains beyond that originally contained in the water, this quantity will be in excess above what is necessary to produce neutralization. The simple rule, therefore, is to combine the elements obtained by the analj'sis, in binary combinations, according to the known pro- portions in wliich they unite ; the excess or deficiency of muriatic acid will then appear ; and the amount of the excess being sub- tracted from the quantity of muriatic acid contained in the muriate of soda obtained, or the amount of the deficit being added to that quantity, the real quantity of muriatic acid will be obtained.* There is one deficiency, however, in this method. If any error has been introduced in any previous step of the analysis, either in the estimation of the bases or of the acids, this error will be con- cealed by the kind of compensation that is made for it, by thus adapting the proportion of muriatic acid to the results such as they are obtained ; and at the same time an incorrect estimate will be made of the quantity of muriatic acid itself. When any error, therefore, can be supposed to exist, or, independent of this, to ensure perfect accuracy, it may be proper to estimate directly tlie » See the notice of an analysis of sea water in illustration of this. (Annals of Philosophy, toI. ii. p. 50.) ' 17'* ^ General Formula for the [Sept. quantity of muriatic acid in a given portion of the water, by ab- stracting any sulpliuric or carbonic acid by nitrate of barytes, and then precipitating the muriatic acid by nitrate of silver or nitrate of lead. The real quantity will thus be determined with perfect pre- cision, and the resuh will form a check on the other steps of the analysis, as it will lead to the detection of any error in the estimate of the other ingredients ; for when the quantity is thus found, the quantities of these must hear that proportion to it which will cor- lespond with the state of neutralization. Thus by these methods the different acids and the different bases are discovered, and their quantities determined. To complete the analysis, it remains to infer tlie state of combination in which they exist. It will probably be admitted that this must be done on a difterent principle from that on which the composition of mineral waters has hitherto been inferred. The compounds which may be obtained by direct analysis cannot be considered as being necessarily the real ingredients, and to state them as such would often convey a wrong idea of the real composition. There are two views accord- ing to which the state of combination in a saline solution may be inferred, and in conformity to which, therefore, the composition of a mineral water may be assigned. It may be supposed that the acids and bases are in simultaneous combinations. Or if they be in binary combinations, the most probable conclusion with regard to this, as I have already endeavoured to show, * is, that the combinations are those which form the most soluble compounds, their separation in less soluble compounds, on evaporation, arising from the influence of the force of cohesion. In either of these cases the propriety of first stating as the results of analysis the quantities of acids and bases obtained is obvious. On the one supposition, that of their existing in simultaneous combination, it is all that is to be done. On the other supposition, the statement affords the grounds on which the proportions of the binary compounds are inferred : and there can be no impropriety in adding the composition conformable to the products of evaporation. The results of the analj'sis of a mineral water may always be stated, then, in these three modes : 1. The quantities of the acids and bases. 2. The quantities of the binary compounds, as inferred from the principle that the most soluble compounds are the ingredients ; which will have at the same time the advantage of exhibiting the most active composition which can be assigned, and hence of best accounting for any medicinal powers the water may possess. 3. The quantities of the binary compounds, such as they are obtained by evaporation, or any other direct analytic operation. The results will thus be presented under every point of view. It is obvious that the process I have described, adapted to the most complicated composition which usually occurs, is to be modi- fied according to the ingredients. If no lime, for example, is ♦ An.-»!ysis of the IMiiieial Waters of Dunblane and Pitcailhly, &c. Jnnals of Philosop/i)/, vol, vi, y. i:56. 1817.] Analysis of Mineral IValers. 175 present, then the oxalate of ammonia is not employed ; and in like manner with regard to the others. I have also supposed the usual and obvious precautions to he observed, such as not adding an excess of any of the precipitants, bringing the products to a uniform state of dryness, &c. having mentioned only any source of error less obvious, or peculiar to the process itself. With regard to other ingredients, eitiier not saline, or more rarely present, it will in general be preferable, when their presence has been indicated by the employment of tests, or by results occur- ring in the analysis itself, not to combine the investigation to dis- cover them with the general process above described, but to operate on sej)arate portions of the water, and to make the necessary allow- ance for their quantities in estimating the other ingredients. The quantity of iron, for example, in a given portion of the water, may be found by the most appropriate method. Silica will be discovered by the gelatinous consistence it gives on evaporation, and forming a residue insoluble in acids, but dissolved by a solution of potash. Alumina may be discovered in the preliminary application of tests, by the water giving a precipitate with carbonate of ammonia, which is not soluble, or is only partially soluble in weak distilled vinegar, but is dissolved by boiling in a solution of potash, or by its precipi- tation from the water sufficiently evaporated by succinate of soda ; or in conducting the process itself, it will remain in solution after the precipitation of the lime by the oxalic acid, and be detected by the turbid appearance produced on the addition of the carbonate of ammonia previous to the addition of the phosphoric acid to discover the magnesia. Its quantity may then be estimated from its precipi- tation by carbonate of ammonia, or by other methods usually em- ployed. Silica will also be precipitated in the same stage of the process ; its separation from the alumina may be effected by sub- mitting the precipitates, thoroughly dried, to the action of diluted sulphuric acid. Potash, when present, which is very seldom to be looked for, will remain at the end, in the state of muriate of potash. Muriate of platina will detect its presence, and the muriate of pot- ash may be separated by crystallization from the muriate of soda. There is another mode in which part of the analysis may be con- ducted, which, although perhaps a little less accurate than that which forms the preceding formula, is simple and easy of execution, and which may hence occasionally be admitted as a variation of the process ; the outline of which, therefore, I may briefly state. The water being partially evaporated, and the sulphuric and car- bonic acids, if they are present, being removed by the addition of muriate of liarytes, and the conversion of the whole salts into mu- riates effected in the manner already described ; the liquor may be evaporated to dryness, avoiding an excess of heat, by which the muriate of magnesia, if present, might be decomposed ; then add to the dry mass six times its weight of rectified alcohol (of the spe- 1;^ ^ General Formula for the [Sept* cific gravity at least of '835), and agitate them occasionally during 24 hours, without applying heat. The muriates of lime and mag- nesia will thus be dissolved, while any muriate of soda will remaiu undissolved. To remove the former more completely, when the solution is poured off, add to the residue about twice its weight of the same alcohol, and allow them to stand for some hours, agitating frequently. And when tliis liquor is poured off, wash the undis- solved matter with a small portion of alcohol, which add to the former liquors, Aithoagli muriate of soda by itself is insoluble, or nearly so, in alcohol of this strength, yet when submitted to its action along with muriate of lime or of magnesia, a little of it is dissolved. To guard against error from this, therefore, evaporate or distil the alcoholic solution to dryness, and submit the dry mass again to the action of alcohol in smaller quantity than before ; any muriate of soda which had been dissolved will now remain undissolved, and may be added to the other portion ; or at least any quantity of it dissolved must be extremely minute. A slight trace of muriate of lime or of mag- nesia may adhere to the muriate of soda ; but when a sufficient quantity of alcohol has been employed, the quantity is scarcely appreciable ; and the trivial errors from these two circumstances counteract each other, and so far serve to give the result more nearly accurate. Evaporate the alcohol of the solution, or draw it off by distilla- tion. To the solid matter add sulphuric acid, so as to expel the whole muriatic acid ; and expose the residue to a heat approaching to redness, to remove any excess of sulphuric acid. By lixiviation with a small portion of water, the sulphate of magnesia will be dis- solved, the sulphate of lime remaining undissolved, and the quan- tities of each, after exposure to a low red heat, will give the pro- portions of lime and n)agnesia. The quantity of soda will be found from the weight of tlie muriate of soda heated to redness ; and the quantities of the acids will be determined in the same manner as in the general formula. This method is equally proper to discover other ingredients which are more rarely present in mineral waters. Thus alumina will re- main in the state of sulphate of alumina along with the sulphate of magnesia, and may be detected by precipitation by bicarbonate of ammonia. Silica will remain with the muriate of soda after the actioai of the alcohol, and will be obtained on dissolving that salt in water : and iron will lie discovered by the colour it will give to the concentrated liquors, or the drv residues, in one or other of the steps of the operation. The general process I have described may be applied to the ana- lysis of earthy minerals. When they are of such a composition as to be dissolved entirely, or nearly so, by an acid, that is, where they consist chiefly of lime, magnesia, and alumina, its direct ap- 1817.] On the Vessels of Plants. 177 plication is sufficiently obvious; where they require the previous action of an alkali from the predominance of siliceous earth, on this being separated, the excess of alkali may be neutralized by muriatic acid ; and the remaining steps of the analysis may be pro- secuted, with any modification which the peculiar composition will require. As the quantities of the ingredients are capable of being estimated with so much precision, it may be employed with more peculiar advantage where a small quantity only of the mineral can be submitted to analysis; and when it is employed, such a quantity only, 10 grains, for example, ought to be made the subject of experiment. Article IV. On the Vessels of Plants. By G. Wahlenberg, M.D. of Upsala, Member of the Royal Academy of Sciences of Stockholm.* A DIFFERENT view of tlie same observations often leads to a very different result, although no mistake exists in the observations them- selves. It is difficult to get out of the trammels of former opinions and conclusions ; and nowhere more so than in the anatomy and physiology of plants. If we depend upon pure anatomical observa- tions, our conclusions will be very difterent from what they will be if we call in the aid of physiology. Even the name organs of plants throws us into some difficulty, as they possess little of tliat constancy which is universally expected in organs, and even considered as belonging to them by the long use of the phrase. The organs of animals and their functions are uni- versally known ; and it would be impossible to alter their names, on account of any different view respecting their uses. Were the same thing the case in the anatomy of plants, and could the same confi- dence be put in the generally received opinions, as may be in the anatomy of animals, the progress of the science would not be so vacillating. In my treatise on the Situation of the immediate Pro- ducts of Plants, t it was my object to steer as clear as possiljle of the vulgar opinions and notions relative to this intricate subject, in which respect I have deviated very much from the conduct of late writers. I cannot desist from speaking of vessels, because I found vessels through which the sap flowed with velocity. It appears to me more correct to say that the sap flows in the wood of the oak, through wooden vessels [vasa lignea), than that it flows through the cellular texture of the wood : and 1 cannot avoid believing that the • Translated from Gilbert's Annalen der Physik, xlv. 49, Sept. 1813. The present paper is drawn up by Gilbi-rtfrom on» published by Wahlenberg in 1612. + De sedibus Matoriaruin immedialarum in Planlis Trartatio. Up^ala, 1806 and 1807. A German translation of it is in Gehlen'i Journal f. Chemie, Phys. uud Miner, viii. 93. Vol. X. N<' III. M 178 On the Vessels of Plants. [Sept; fibres of tlie bark of the lime-tree are of a different kind from the fibres of the wood of the same tree, and the spongy cellular fabric of cork. All that by the late vegetable-anatomists is called cellular suhstance {tela cellulosa) is by the chemists called luood [lignum). In consequence of this mode of speaking, we have ajibrous cellular substance (a mode of speaking which, though common, seems hardly admissible), which is obviously nothing else than the vascular cellular substance {vascularis cellulosa). It is not improbable that I have formed opinions different from those of others, in consequence of having examined a greater variety of trees and shrubs than other vegetable-anatomists. Bly object was to find in the old portions of them the immediate pro- ducts deposited, which can scarcely be found in a substantial form in the tender parts of herbs. For several successive summers I traversed the woods of Wermeland, with a hatchet in my hand, and cut down a great number of trees, in order to examine the wood. I have examined likewise whole chests full of different spe- cies of trees which Afzelius brought from the part of Africa that lies between the tropics. I have likewise examined the different officinal woods, and the various species collected by Swartz in the West Indies. By Messrs. Rudolphi and Link, on the other hand, the different species of wood were considered as of little import- ance. Neither of them, for example, examined tlie wood of the Guaiacum ; and the first of them has overlooked most of the Swe- dish woods, which are domesticated in Germany, as the rhamnus fragula and catharticus, in which the existence of cortical vessels is extremely doubtful, the Sorbus aucuparia, Betula alba, Populus, Ulmus, &c. It is not surprising, therefore, that I have come to results different from theirs ; nor can these differences on my part be ascribed to any want of observations. In order to separate the more solid parts of old wood from the wood itself, I have been accustomed to macerate slips of the wood in different solutions, and to treat them with re-agents. By this method I have ascertained several facts which are very strongly in favour of the existence of wooden vessels {vasa Ugriea) and cortical vessels {vasa corticalia). When a cross slip of a hard wood, quercus robur, for example, is macerated alternately in potash ley and nitric acid, we perceive in every canal of the tubular contexture {con- textus tubulosi) a transparent, complete and round tube, which has a peculiar wall not communicating with the walls of the other tubes. These have every appearance of true tubes extending a great way in length, and I cannot give them any other name than that of wooden vessels {vasa lignea). In the elm are found harder rings, which contain peculiar wooden vessels in their tubular contexture, and at the same time extend further than the peculiar rings, in which no such vessels can be observed. I have particularly stated all this in the second and third sections of my dissertation ; and I think it will be allowed me that no stronger anatomical proofs of the existence of wooden vessels caa well be brought ; but when I speak I 181 7-] 071 the Vessels of Plants. 179 of the woody vessels of the softer kinds of plants, as the ilirca palmtris, where the contexture is entirely cellular, I admit that it is not always possible to distinguish the harder wail from the softer tubular contexture. Hence, wheneier the matter is doubt- ful, I have always referred the cordexlus tiihidosiis or vascularis to the vessels. The term vasa radianlia is not perhaps so easily defended; yet I conceive that the retaining of this old name is excusable, and very convenient. These vessels act a very great part in all woods. As soon as towards harvest the leaves cease to grow, they draw the whole sap from without, over the whole wood, cambium, and the space between the wood and bark, into the bark itself. Through their activity, the bark is more firmly united to the wood, and filled with coloured sap, or at least sap which becomes coloured on exposure to the air. It appears as if the liler were at that time changed into wood ; but tliis is not in reality the case ; only at that season of the year the new bark assumes very distinctly the appear- ance of bark. With what energy the sap can make its way through these vasa radiantia, I have observed with astonishment, when plants from warmer climates freeze with us in harvest. (See my treatise, p. 17). Suppose, for example, the upper part of the stem of the lupleurum rotundifolium to be frozen, and the roots still to retain their full activity, in that case the sap makes its way every night through the vasa radiantia, and freezes in handsome icicles, flowing diiectly out of the wood, and having the size and shape of these vessels. I re- moved these icicles every morning, and found them renewed every night in the same plant. The vasa radiantia have likewise a very peculiar appearance. They run isolated and distinct from the inner part of the wood to the bark, often for a whole foot, without mixing with the woody vessels ; and are so conspicuous, that, when we cleave beech wood, they display a splendent lustre, which the workmen have distin- guished by the name of silver grain {s pie self aser)i). They have strongly the appearance of hundles of vessels. In a foreign wood I can perceive circular holes lying near each other without the least trace of a true cellular texture. If we consider this appearance witliout any regard to other plants, it is anatomically proper to call these holes vessels : at least they give me no idea whatever of a stretched cell ; and I consider the expression slrelched cellular tex- ture which runs ypiuards, as well as siretched cellular texture which runs horizontally, as inconvenient and inaccurate. How do we know that these canals are composed of stretched cells ? When, on splitting a wood, we perceive how regularly the woody tubes run, and how they cross the vasa radiantia, how small is the re- semblance which they present to a cellular texture ! When 1 call the vasa radiantia a peculiar set of vessels, I may be wrong. In fact, I would prefer calling them vasa lignea radiantia ; but I consider it as inconvenient to employ three words M 2 180 On the Vessels of Plants. [Sept. for a name. Besides, their peculiarity is sufficiently well marked to bear some ambiguity in their name; and I do not see why we should be so frugal of names in the anatomy of plants, when such freedom is made with them in botany, that even the most insignifi- cant varieties are often dignified with names : and have not the different varieties of vessels as good a right to be distinguished by peculiar names as the different varieties of plants ? Even supposing the vasa radiantia in vegetables to pass into a cellular texture, can any one be of opinion that in trees, where they are of a very diffe- rent nature, they ought not to have a peculiar name ? Nearly the same considerations have induced me to give the name of cortical vessels {vasa corticalia) to s(»me peculiar ones. They make their appearance in the bark of trees as tubes, or at least as a tubular contexture {contextus tubulosus). In their physical properties they are very different from the woody vessels. How flexible and tough are they not in the bark of the linden, the juniper, and the daphne mezereum, compared with the stiff and rough wooden vessels of the same plants? They are often still better distitiguished from the tela cellulosa than from the woody vessels. For example, in the bark of the lime-tree they form very distinct pillars, the cross fracture of which appears wedge-shaped, with its basis turned towards the wood. By maceration in caustic potash, these tubes assume a yellow colour, become thicker, and may be very readily distinguished from the tela cellulosa and the woody vessels. They then form frequently distinct canals, whose round openings without any angles are very distinct, and may with strict anatomical propriety be considered as tubes. The cortical vessels are very distinct in the rhamnus catharticus, in the bark of which, by pulling it separate, we perceive long stiff hairs, consisting entirely of cortical vessels, with some separate cells. The peculiar disposition of these tubes shows how much the wood differs from the bark, and that no layer of liber is capable of forming the new wood. According to my observations, the wood is not formed from the cortical layers. Indeed, in all bicotyledonous trees the wood and bark form two distinct circulations, which merely communicate to a certain extent in harvest. In spring, when the leaves have acquired a certain size, it appears very clearly that the new layer of wood is already formed. It is still very thin ; ■but by degrees increases in thickness, through new vessels or tubes extending themselves outwards : and, towards harvest, before the bark beconies fastened to the wood, we find in young twigs the new wood often thicker than the whole bark. How then is it possible that it should have been formed from the bark, as is commonly be- lieved ? Either the cortical layers must the whole summer long be perpetually passing into wood, or the formation of the wood from these layers is quite impossible. According to my observations, the cortical vessels are formed quite in the same way as the woody vessels ; they every now and then deposit new lamellae on the inner side of the bark. Hence the interval between the bark and wood 18170 On the Vessels of Plants. 181 is by no means the principal place where the sap flows. In the be- ginning of spring, when the sap flows with force in trees, the bark still adheres to the woud. The separation takes place when the new wood is deposited 3 and when the bark allows itself to be peeled off", the epidermis (as, for example, of the birch,) is not loose ; it be- comes so at a later period. These circumstances point very different periods in the vegetation of trees. The sap in the first place flows into the wood through the woody vessels ; then the new layer of wood is deposited ; and, lastly, towards harvest, the bark swells considerably. During the gruwth of the wood, the union between the bark and the interior part of the tree is quite interrupted, so that only traces of the vasa radiantia can be perceived. But when in harvest the growth of the leaves and young twigs ceases, the ascending sap proceeds outwards, and fills the vasu radiantia, which then pass into the bark very dis- tinctly.* By this means the bark is anew fixed to the wood : not in consequence of a gummy liquid, but from the formation of lae vasa radiantia. The sap, which then first passes through them to the bark, fills the tela cellulosa; new cells are formed between the cortical vessels, so that the bark increases in extent in the same proportion as the wood increases in diameter. Hence the tela cel- lulosa comes further outwards, along with the cortical vessels; and in all probability it is this tela which forms the epidermis so con- spicuous in the birch, and which is divisible into layers, though not so early as the liber. So many and peculiar modifications, which are all performed by peculiar organs, are brought into view during the growth of dicoty- ledonous plants; and yet shall it not be proper to distinguish these organs by peculiar names ; and where so many operations are per- formed, shall we dare to ascribe the whole to nothing else than a long stretched tela cellulosa ? And shall philoso|)hers present us with tiiis limitation of language as a new light thrown upon science ? t It appears to me to be better, for the regular advance- ment of human knowledge, to allow the old names to remain, as they are in some measure known even to the common people, and are besides exceedingly useful and convenient. That observers have often supposed they saw stretched out cells where vessels really existed, is exceedingly likely, as the partition walls of the vessels may approach very near in appearance to • Most writers are of opinion that tlie septa radiantia come from the pith ; but we do not see them standing closer in the stem near the pith than in the neighbour- hood of the bark ; and from recent obseiVations it is evident tha' wherever a new septum appears, the two preceding one^, by diverging separate as far from it as they were before from each other. The septa radiantia exist in the wood, and are doubtless formed of the woody tubes. + " We have to thanii Sprengel and Mirbel that they first banished these vessels (yata lignea, corticalia, radiantia,) from pliysiology, and thereby threw a new liRbt on the subject."— -(Link's Additions to the Anatomy and Physiology ef Plant?, p. n.) 182 On the Vessels of Plants. [Sept, stretched out cells : for, in the first place, it is very difficult to make a section completely parallel with the vessels, without cutting through a vertical wall ; but where the tubes are cut through, they commonly assume tlie appearance of a transverse wall. In the second place, we may be easily deceived by air bubbles, the sides of which may assume the appearance of organic cross walls. In the third place, we cannot always conclude that there exists a perfect partition wall, where we believe we see it ; for it may be only the two sides of the tube approaching each other, where a fold in the canal swells out the vessel itself. That, in fact, the cross walls are not always coniplete where they seem to be so appears to me to be proved by the confervas, in which we think we perceive true parti- tion walls, and yet we see the green matter make its way from one articulation to another. All these considerations have induced me to believe in the existence of continued vessels wherever the sap clearly flows, even though anatomy should seem to decide to the contrary. That the sap, which flows with such impetuosity in the stem of a birch or maple, when it is punctured in the spring, should not proceed from open vessels, but from the so called small vasa spiralin, is quite incredible.* The absorption of coloured liquid by plants seems to establish my opinion : for the coloured liquor is confined to what modern physiologists have been pleased to call stretched out cells, and is not to be found in the tela cellulosa, though supposed a part of it. Who can in such a case believe that there are no vessels or continued canals ? These views and observations allow me to speak of the vessels of luosses, algae, &c. Indeed, it appears to me a very partial proceed- ing to refuse vessels to these fine plants, which vegetate with such rapidity and vigour. In the cmferva elongata very distinct canals or tubes may be observed below the bark. In the ribs of the leaves of leafy mosses we often speak of diictuli, and we mean by this word real vessels. In the Jungermanniae, which grow so rapidly, and assume such beauty, vessels may be observed with the greatest facility : on that account I shall pass them over. The causes why observers have been unwilling to recognise vessels in these plants, and likewise in the perfect plants, are the follow- ing : — They paid so much attention to the spiral vessels, that they conceived they must meet with something similar before they were at liberty to speak of vessels at all. It has an appearance of accu- racy and precision not to speak of vessels unless they be as dis- tinctly marked as the spiral vessels. But in a physiological point of view, the subject becomes darkened and imperfect. According to every analogy, we must give the name of vessels to those organs in which the sap flows, which nourishes the whole body ; and those * Dr. Afzelins has informed me that when the stem of the tetracera potatoria is cut, people can satisfy their thirst with the pure water contained in it. I have examined this wood microscopically, and find therein very large woody vessels, from which this water jiroceeds, and certainly no stretched out cells, 18170 ^'^ '^^^ Vessels of Plants. 1S5 tubes, which carry a more local and less remarkable liquid, and whicli in the anatomy of animals are called dricts, as the salivary ducts, the seminal ducts, &c. In the anatomy of plants philoso- ])hers, without observing it, have nearly fallen into an abuse of language. That the spiral vessels nourish plants, is not very pro- bable. They are exceedingly few, and often altogether wanting. In Guaiac wood we see very distinctly that ihefolse tracliece contain resin, which is not a substance that nourishes plants, but an excre- tion; but the true spiral vessels are only modifications of ihe false irachece, and other similar vessels situated in the wood. To attempt to draw a distinct line between them would be the same thing as in the human body not to admit the veins without valves to be real veins, but to constitute them a distinct class of vessels. The smallest stripe is sufficient to constitute a spiral vessel, and a false trachea members of quite a distinct system ; and the diict lying hard by, where the cross stripe is distinct, is called a lacuna, as if it were altogether fortuitous. Here, where no difierent functions can be discovered, we abound in distinctions and names ; yet we do not choose to distinguish the uoody, cortical, and radiating vessels, in which distinct functions are very evident, from the general tela ceUulosa. On these grounds I call the fine canals containing nourishing sap, namely, the woody and cortical vessels, true vessels : and, on the contrary, name the larger canals, containing materials already brought to a state of perfection, diicts. So that in my language the spiral vessels become spiral ducts. However, I call Hedwig's duc- tuli in the leaves of mosses, &c. vessels, an expression by no means inconsistent with the old and more generally received names, but contrary to the new ones. I shall now give a sketch of the different kinds of ducts, or rather point out the way in which these canals may be arranged. The finer canals, namely, the woody vessels, carry thin, liquid, nourishing sap, to the cellular texture, as we have already seen. The more consistent and viscid sap, which approaches gum and resin in its nature, could not flow in so fine tubes. Therefore larger ducts have been constructed for them, which constitute a vascular •ystem quite different from the system employed in nourishing the plant. But in order that this viscid sap may move freely, the walls of the vessels containing it could not be composed of a single thin membrane, but must be strong, and not liable to be torn. On this account they arc wound round with spiral fibres, by the contraction of which the resinous sap is driven on, or at least prevented from accumulating. These spiral fibres, in young twigs and in herbs, in which no thick sap exists, are usually isolated, and run at a distance from each other. In the finest filaments, and other parts of the blossom, we find spiral vessels of the most delicate and beautiful structure, and no other larger ducts. In older parts of plants these spiral vessels grow together, and nothing more remains of their fine ^wral structure than some cross stripes. They are then Cd\\t^ false la* Oh the Vessels of Plants. [Sept. trachea:. We can still perceive the cross stripes very distinctly in these ducts; for example, in guaiacum wood, in which pretty con- sistent resin is coniained. In red sanders wood the cross stripes themselves in the false tracheae are contracted, so that the red ex- tractive is collected in grains. Their analogy with the spiral ducts in structure and functions cannot in this case be perceived. In older parts of plants the cross stripes are accumulated on the walls of the ducts ; so that the whole assumes the appearance of a thick, confused web : and this is peculiarly the case in those places where greater strength is necessary, or where the thickest resin is to be coveyed along. In the tribe of pines observers have in vain searched for spiral ducts, and yet they constitute the trees richest in resia that we are acquainted with. A fine spiral duct would be speedily torn by the viscid liquid that moves in it ; but nature always takes care to produce a stronger structure where uncommon resistance is necessary. It appears to me very probable that the fine spiral ducts commu- nicate at first with the woody vessels, and that when they proceed further they change intofalse Irachece, from which new spiral ducts proceed, constituting a bundle ; and that at last in the oldest parts of the plant the false IrachecE are changed into those large ducts called cylindric lacunar. These three ducts are usually found near each other lying in a bundle, and commonly so that the spiral ducts are nearest to the woody vessels. It is quite impossible, indeed, to demonstrate all tiiis anatomically, as we cannot follow a single spiral vessel through a complete plant, or even a complete branch. I consider it as probable (and in the present case it is allowable to offer a bare probal)ility) that in these vessels there is a kind of retro- grade motion of the materials of plants: that the most recently formed resinous sap is contained in the uppermost and smallest twigs, where we find separate spiral ducts ; and that it flows down slowly and gradually till we come to the thick resin in the roots. We see at least that the roots abound most in large ducts filled with resin. From all this it appears very probable that the spiral ducts, false tracheae, and cylindrical lacunae, are gradations of the same series. On that account it would be proper to distinguish them by a general name. 1 have given to them all the common name of ductus ligni, or ducts situated in the wood ; 1 call each of them separately ductus spirales, suhspirales, &c. as subspecies. The name ductus ligni is simple, and I do not see why we should give complicated names to so very simple organs. The part which the spiral ducts and their varieties perform in the wood is performed in the bark by other ducts of an equally simple nature. We find quite in the neighbourhood of the bundles of cortical vessels small ducts which contain a milky juice, and which I call ductus guttiferi. In other plants the same ducts seem to pass towards the exterior parts into larger canals, which clearly lie in the tela cellulosa. In 1817.] On the Vessels of Plants. 185 our pimts sylvatica it is very evident that the smaller internal ductus corticis contain a thin resinous sap, which in the larger ducts ac- quires a thicker coT^isteney. In the trees which contain a milky juice {nrbores ouitijerce), as, for example, the mammLu Ainericuna^ we perceive distinctly the tine ducts, as vasa guttif'era, but the larger resiniterous ducts do not present themselves. In like manner the lactescent plants seem to have only finer di/cls, which appear scarcely to differ from the cortical vessels themselves. On that ac- count I have spoken of them distinctly from the ductus gntliferi, as a variety of the cortical ducts. But that the milky juice, especially in the bark, comes from such ducts, is to me very evident. Whether all the ducts of the bark, even though they may contain the same materials with the ducts of the wood, are yet always destitute of every trace of spiral fibres, is a point that cannot be determined with precision. They certainly always lie on the outside of the bundle of cortical vessels; (and not in that bundle itself as the ducts of the toood do). Perhaps there weie not materials there for such spiral filires, which in the ducts of the wood may have some analogy with the vessels or fibres of the wood itself. The cortical ducts lie always in the tela cellulosa, and probably their walls are composed of that matter, and not of fibres. These considerations induced me to give them the name of celtular ducts {ductus cellulosi), especially as some similar canals present them- selves in the pith. Perhaps it would have been better to have called them ductus corticis. Their different layers, and their peculiar structure probably proceeding from that circumstance, show us that the system of the bark in dicotyledonous plants is always dis- tinct from the system of the wood, although both show a strong analogy to each other. The reason why nature has placed the cor- tical ducts on the outside of the bundles of vessels is probal)ly that in such a position it is less injurious to the plant if they happen to be ruptured, and that they can stretch with more facility to admit an increase of matter. Yet to affirm with certainty that all tliese things are so, is quite impossible. When we have a great object before our eyes, we must not be stopped by small difficulties, otherwise we shall be exhausted before the object is attained.* * Dr. Wahlenberg, at the reading of this paper, exhibited to the Society various preparations of slips of wood and baik, in whicb the different vessels could be distinctly seen with a glass, and still better by means of a compound microscope. (Note of the society entitled Friends of Natural History in Berlin.) ISS Analysis of Rice. [Sept. Article V. Anahjsis of Rice. By M. Henri Braconnot, Professor of Natural Histoiyj Director of the Garden of Plants at Nancy, &c.* As rice has not hitherto been anal)'zed, and as it is one of the most important grains, since it serves for food to a groat part of the human species, I thought it worth while to subject it to some expe- riments. Parrnentier appears to me the only person vvho has made some experiments on rice, f His results induced him to consider it as a peculiar substance, which he placed I)etvveen starch and gum, doubtless on account of its horny translucency, and the difbculty of reducing it into a powder, which has neither the fineness, the creaking sound, nor the feel of starch, and which falls quickly to the bottom when diffused in water. But we shall find that this species of grain is more complex than had been supposed. Ac/ion of Water on Rice. A hundred grammes of Carolina rice, unground, lost by drying five grammes of humidity. They were then macerated with water at the temperature of 122°. The grains absorbed the water with avidity, and almost at the same time split by several transverse sections, which did not happen nearly so quickly if the rice had not been previously well dried. These grains, thus split, were easily squeezed between the fingers into a very fine powder. They were pounded in a glass mortar, adding to them in successive portions the liquid in which they had been macerated. Thus a inilky liquid was obtained, which was thrown upon a filter. The greatest part of the substance of the rice remained upon the filter. Being well washed in water, in order to take up every thing soluble, and then dried, it weighed 93*G7 grammes. The water in which it was washed was set aside for examination. These .93*G7 grammes, when diffused through water, passed completely through a silk seirce ; but the milky liquid contained at least two distinct substances : the one, very white, constituting about two-thirds of the total weight, re- mained for some time suspended in the liquid ; the other, less white, was specifically heavier. It was easily separated from the first substance by the affusion of a great quantity of water, and by repeatedly decanting off the emulsive liquid. This liquid in a few days let fall a very white deposite, which had acquired a kind of density by the approach of its particles to each other. When dried, it was of a brilliant white, light, and was easily reduced to an im- palpable powder, which adhered readily to the fingers, and emitted a particular sound when pressed. * Translated from the Ann. de Cliiin. tt Phjs. iv. 370, April, 1817. + Ann. de Cliiin. il. 33. 1S17.] Analysis of Rice. 187 This powder, being triturated with water and a little iodine, pro- duced a colour of a beautiful dark blue, as would have been the case with starch. It dissolved in boiling water; and, when cooled, formed a tremulous and semitransparent jelly, exactly similar to starch. If we boil one part of this same powder with 4000 parts of water, and filter the liquid after cooling, it passes as limpid as water. When lime-water or barytes-water is added to it, a white flocky precipitate is gradually formed. Infusion of galls likewise occasions a slight precipitate. Common starch, treated in the same way, gave a similar result. This shows that, when boiled, it is to a certain extent soluble in cold water, and that the above-mentioned re-agents are capable of detecting minute quantities of it. This constituent of rice, then, was obviously starch. As for the other heavier substance, which was first deposited, it was composed of a great proportion of starch united to a vegeto- animal matter and to a parenchyma. We shall examine it imme- diately. Examination of the soluble Mailers which Water separates from Rice. The water employed to deprive the 100 grammes of rice of every thing soluble was acid, and reddened paper stained with litmus. Suspecting that this uncombined acid might be of the nature of vinegar, the water was distilled in a glass retort. The produce, being mixed with a small quantity of barytes-water, and then eva- porated to dryness, left only a slight residue ; but from which weak sulphuric acid disengaged the odour of acetic acid. During the distillation the liquid in the retort became muddy, especially towards the end, and there was collected a fine white powder, which did not seem to be albumen. The liquid, with its sediment, was evaporated to dryness in a small porcelain capsule. There remained a tolerably dry residue, of a pale yellow colour, slightly attracting humidity, and weighing 1*28 gramme. It was treated with a small quantity of warm water, to give it the consist- ence of a syrup. Then alcohol was poured into it. A copious de- posite was obtained, which, assisted by a gentle heat, was collected into a mass, having a gummy appearance, which could be readily kneaded between the fingers, and which was easily dried. It weighed 0'<)9 gramme. The alcohol which had precipitated this matter, being evaporated by a gentle heat, left 0-29 gramme of a syrupy residue, having but little colour, very difficult to dry, with a sweet taste, and the smell of honey, attracting humidity, like uncrystaliizable sugar, but little soluble in alcohol, and burning vividly, with the odour of caramel. I had presumed that this saccharine matter contained acetate of potash, which contributed to render it deliquescent. But it appears to retain only traces of muriate of potash ; for, having poured sul- phate of silver into the solution, a slight precipitate of chloride of 188 Analysis of Rice. [Sept. silver fell. The liquid, being evaporated, and then treated with phosphoric acid, did not give out the odour of acetic acid. 'J he apparently gummy mass precipitated by alcohol, and weigh- ing 0"99 gramme, being digested in cold water, dissolved entirely, with the exception of a white flocky matter, which was separated by the filter, and which, when well dried on the filler, was found to weigh 0*13 gramme, and to preserve its white colour. A small quantity of this matter being put into a glass tube shut at one end, was exposed to a heat sufficient to occasion a commencement of de- composition. Litmus paper reddened by an acid, being plunged into the air of the tube, recovered its blue colour. The charcoal of this matter, being incinerated, left a notable quantity of phosphate of lime. It did not dissolve in boiling distilled vinegar, nor in diluted muriatic acid. A weak solution of potash, heated slightly with this substance in a silver capsule, did not seem to dissolve it. Black dots were formed, owing obviously to the presence of sulphur. This substance possesses the characters of a vegeto-animal matter. I shall return to its properties when I examine the action of diluted sulphuric acid on rice. The gummy solution, after being separated from the matter just described, appeared still to retain some traces of it; for it was not perfectly transparent, and had an opalescent aspect. It contained phosphate of lime, which ammonia precipitated, and which was pro- bably kept in solution in consequence of the presence of a little acetic acid. It appeared likewise to retain traces of phosphate of potash ; for if, after having precipitated the phosphate of lime, we add to the liquid saturated with ammonia a little muriate of lime or sulphate of iron, a new precipitate of phosphate gradually falls. To separate these substances from the matter apparently gummy, acetate of lead was poured into its solution. The resulting preci- pitate, being decomposed by sulphuric acid, furnished an uncrys- tallizable acid mixed with vegeto-animal matter. A portion of this acid, being heated, left a charcoal which, when exposed to the action of the blow-pipe, left a pretty large globule of glassy, limpid phosphoric acid. Another portion of the same acid, saturated with potash, and exposed to heat, left an alkaline residue, which indi- cates slight traces of a combustible acid. Into the liquid separated from the precipitate produced by the acetate of lead, carbonate of ammonia was poured. The liquid was then filtered, and evaporated to dryness. There remained 0-71 gramme of a matter very little coloured. It was transparent, shining, had a vitreous fracture, and all the appearance of gum, though not quite the insipid taste of that substance. When put upon a red-hot coal, it swells, and emits the smell of burned bread. When distilled, it yields an oil, and a considerable acid product, which did not appear to me to contain ammonia. However, the infusion of nutgalls precipitated the solution of this gummy matter in water. It was precipitated also by lime-water in large flocks, soluble in distilled vinegar. Barytes-water iikeyvise ISlj.^j Analysis of Rice. 189 throws down a flocky precipitate from it. Acetate of lead occasions no change in it ; but the subacetate of lead and the protonitrate of mercury occasioned slight precipitates. Although this matter has quite the external appearance of gum, its chemical properties appear to me to show it to be more nearly related to starch. It is true that it is easily soluble in cold water, and that starch is not so, at least in its ordinary state; but vve know that it becomes soluble when it has undergone a slight modification ; and I have ascertained that the gummy matter, soluble in water, obtained from starch slightly roasted, has much analogy with the gummy matter of rice. Like this last, it was precipitated from its solution by tannin, lime-water, and barytes-water, but not by ace- tate of lead ; and besides, when distilled, it furnished a product which contained no ammonia. This gummy matter approaching to starch exists probably in the greater number of grains which contain this latter substance. Action of diluted Sulplmric Acid on Rice : Separation of the Starch, of the Parenchyma, and of the Vegeto-animal Matter. From what we have said above, it appears that rice, when well dried, and plunged into warm water, becomes so soft that it may be easily crushed to pulp, and that, when triturated with water, it forms a milky liquid, which yields two deposites ; one of which, and the most considerable, is starch ; the other heavier, and having another tint, contains likewise a great deal of starch, besides a vegeto-animal matter attached to the parenchyma, from which it was difficult to separate them, on account of its great subdivision. To accomplish this object, and to determine the respective quanti- ties of these matters, 100 grammes of Carolina rice, unbroken, were macerated in water of the temperature 122°, after having been dried. They were then boiled for about half an hour in water acidulated with sulphuric acid. The amylacious matter was dis- solved, and the parenchyma remained in membranes or flocks float- ing in the liquid, and were separated from it by passing it boiling hot through a fine linen cloth. On cooling, it allowed a matter to fall having the aspect of a semitransparent jelly, and which was separated by passing the liquid through a filter. This acid liquid, which contained the starch, being boiled for some hours, and treated in the proper manner, furnished a syrup, which gradually consolidated into a mass of sugar. The gelatinous matter remaining on the filter was bulky. Being washed with a considerable quantity of water, and then dried, it weighed 3-6 grammes, and had the semitransparence of horn. When boiled with water, it swelled, but did not dissolve, at least in a perceptible manner. However, the liquid was slightly preci- pitated in white flocks by the infusion of galls. When gently heated in a silver capsule, with a solution of potash, the vessel became quite black, as if a sulphuret had been poured into it. Diluted ammonia, being macerated at a gentle heat on this sub- 190 Anniysis of Rice. [Sept. stance^ dissolved it readily without decomposing it. When an acid is poured into the solution, the substance is again thrown down abundantly, but no odour of sulphureted hydrogen is disengaged. Diluted muriatic acid, being boiled with the same matter, dis- solved a very small portion of it, which was precipitated by am- monia. The insoluble matter separated from the acid liquor, and well washed with hot water, then boiled in that liquid, dissolved entirely, forming, it would appear, a neutral muriatic compound, very permanent. It was not affected by ammonia; but an excess of muriatic acid occasioned a considerable white deposite. The supernatant liquor was limpid, like water. When distilled, it furnished a great quantity of yellow concrete oil, a slightly alkaline liquid, which restored the blue colour to litmus paper reddened by an acid, and which contained hydro-sul- phuret of ammonia; for acetate of lead formed in it a brown preci- pitate ; but no carbonate of ammonia sublimed from it. From the properties of this vegeto-animal matter, we see that it is the same which was obtained, though in small quantity, from the water in which rice had been vvashed. It dillers only from this last in containing no sensible quantity of phosphate of lime. It contains less azote than gluten and albumen. I return to the parenchyma of the rice which remained upon the linen cloth. It was of a dull white, like cheese, and could be kneaded between the fingers without adhering to them. When dried, it weighed 4*8 grammes, and had preserved its white colour. It was indeed somewhat semitransparent, owing to the presence of an oily matter, which penetrated it. This was particularly the case with the parenchyma of Piedmont rice. When this matter is set on fire, it burns with a pretty regular flame, in consequence of the oily matter which it contains. It emits the odour of burning bread, and leaves a charcoal, irreducible even at a great heat, which preserves the same dimensions as the substance employed. When distilled, it gives a great deal of oil, an acid product which contains ammonia, and sulphureted hydrogen ; for a paper impreg- nated with acetate of lead, when plunged into the air of the re- ceiver, becomes black. When boiled in a solution of potash, it is dissolved. The liquid, when agitated, exhibited undulations, occasioned by a very fine pearly-looking matter which floated in it, as is the case with a solu- tion of soap. A plate of silver, when plunged into this liquid, be- came brown. Acids formed in it a white curdy precipitate, and occasioned the formation or' the odour of sulphureted hydrogen gas. This matter appeared then to contain sulphur. It is possible, how- ever, that the sulphur might have been produced, in part at least, by the vegeto-animal matter retained by the parenchyma ; for if we macerate this last in iimmonia, a small quantity of the animalized matter is dissolved, which may be precipitated by an acid. Concentrated sulphuric acid has little action on this substance 1817.] Analysis of Rice. 191 cold. When heated, it chars it, with a slight disengagement of sulphurous acid. Nitric acid dissolves it entirely, when assisted by heat. The products are oxalic acid, malic acid, yellow bitter principle, and a slight yellow sediment. When iodine is triturated with this substance moist, it communi- cates a yellowish-green colour. When macerated in the infusion of nutgalls, it unites with tannin, and assumes a fawn colour. When steeped in water, and left to itself, it becomes covered with mucors. From the properties of this parenchyma of rice, it appears to be different from the woody fibre. It seems to be less oxygenated than starch ; and it is probable that it partakes with starch the nutritive properties which are known to exist in rice. Action of Alcohol on Rice. K hundred grammes of Carolina rice macerated in water were triturated, and well diffused through that liquid. The milky liquor was then filtered. What remained upon the filter, after being washed and dried, was macerated in alcohol for 24 hours. It was then heated and filtered. After being repeatedly washed in alcohol, these liquids were mixed together, and distilled. To obtain the greatest part of the alcohol, the evaporation was conducted at a low- heat. A substance remained, which, being redissolved in alcohol, furnished 0'13 gramme of a fixed oil, almost colourless, having a rancid odour and taste, and the consistence of olive oil half con- gealed ) but, when exposed to cold, concreting into a crystalline substance, which separated from it, and which dissolved readily in cold alcohol and in alkalies.* Distillation of Rice. A hundred grammes of rice subjected to distillation furnished a brown, thick oil, in small quantity ; an empyreumatic liquid, strongly reddening paper stained with litmus, containing acetic acid, and doubtless a little ammonia, but which could not be rendered sensible to the smell when the acid liquor was triturated with quick- lime. The gaseous produce was neglected. It contained sulphu- reted hydrogen ; for paper dipped in acetate of lead, being plunged into the air of the receiver, was covered with a coat of sulphuret of lead. The charcoal remaining in the retort weighed 22 grammes. It had a metallic aspect, was liglit, porous, and in a single mass. It was Ixarder than common charcoal, and formed, with difficulty, * It is the general opinion that expressed oils are fimnd only in a small number of grains, rallid, on that account, oily; but it appears that they exist esscniially in all, and the list of plants from whose seeds oils may be pres>ed"is very extensive. Numerous trials have satisfied me that the seeds of most dicotyledonous plants are inihis predicament. I may cite al) those of the family of boriagiiix, dipsacece, lolanpx, labiae, chicoracea?, cynarocephalea;, corymbiferie, pnpnveracear, cruei- form, the greatest part of the ranunculacesE, uiticea;, cucurbitaccae, oiiagiaj, Mlicariac, 192 Memoir on the Sodalite of Vesuvius. [Sjbpt, traces on paper. When well washed in boiling water, it only com- municated to that liquid imperceptible traces of alkali. When exposed to a strong heat, it could not be incinerated. When treated in a crucible with potash, it gave some indications of the presence of a cyanide. This charcoal was almost completely burned by means of nitre. The alkaline mass was dissolved in water, and an excess of muriatic acid poured into it. Ammonia was then added to the filtered liquid, which produced a precipitate weighing 0*4 gramme. It was phosphate of lime ; for when dis- solved in a little nitric acid, the sul)acetate of lead occasioned a precipitate, which, when well washed, was fused before the blow- pipe into a crystallized bead of phosphate of lead. Subcarbonate of soda being added to the liquor from which the phosphate of lime had been precipitated by ammonia, precipitated, when assisted by heat, about three centigrammes of carbonate of lime. The ashes of rice, then, consist almost entirely of phosphate of lime. On appreciating as exactly as poi-sible the results of the comparative analyses of Carolina and Piedmont rice, I consider the approximate constituents of each to be as follows: — Carolina Rice. Piedmont Rice. Water 5-00 7-00 Starch 85-07 83-80 Parenchyma 4-80 4-80 Vegeto-animal matter 3-60 3-()0 Uncrystallizable sugar 0-29 0-05 Gum approaching to starch O-71 0-10 Oil 0-13 0-25 Phosphate of lime 0-40 0-40 Muriate of potash Phosphate of potash Acetic acid Vegetable salt with base of lime l)itto with base of potash Sulphur Traces Traces 100-00 100-00 Article VI. Memoir on the Sodalite of Vesuvius. By M. Le Corate Stanislas Dunin Borkowski. (Presented to the Academy of Sciences, Oct. 28, 1816.) M. Ekeberg was the first who analysed a mineral from Green- land which contains 25 per cent, of soda. Dr. Thomson repeated this analysis, gave a mineralogical description of the mineral, and 5 1817.] Memoir on the Sodaltte of Vesuvhis. 193 made it known in his excellent memoir as a new species, under the name of sodaiite.* No other locality of sodulite has hillicito been observed ; but 1 have been lucky enough to find it on the slope of Vesuvius, called Foiso Grande, which may be fairly considered as the great repertory of the volcanic riches of Vesuvius. Sodalite appears due to the ancient eruptions, which have furnished mine- ralogy with nepheline, nieyonite, and idocrase; but it is very far from being so common as these species. This is no doubt the reaso-ii why it had not been observed by the skilful observers who have examined that celel)rated country. Notwithstanding consider- able search, I could meet with only a single specimen on the spot. Another was afterwards given me by the guide Salvatore. The fol- lowing observations were made uj)on these two specimens :— External Characters, The sodalite of Vesuvius is greyish-white. It occurs in round grains, and crystallized in the form of six-sided prisms, terminated in a point by three faces placed alternately on the lateral edges. T'he crystals vary in size, and 1 possess one which is an inth long. The surface of the crystals is smooth, and rather irridescent. External lustre shining, resinous. Internal lustre vitreous. Cross fracture perfectly conchoidal ; principal fracture foliated; but it is difficult to determine the cleavage. Translucent. Fragments indeterminate ; sharp edged. It is semihard, yielding readily to the file; easily frangible. Specific gravity, 2-89. Chemical Characters, The fragments of the sodalite of Vesuvius, when put into nitric acid, do not lose their lustre while in the acid ; but after they are taken out, they soon become covered with a whitish crust. When put in powder into muriatic acid, they form a jelly. Before the blow-pipe, it melts, without addition, but with difficulty. Position, The sodalite is found in calcareo-talcose quangue, accompanied by pyroxene, green pumice, and a substance crystallized in small six-sided tables, called by Werner icespar. The mineralogical characters which I have just given presented' an unknown substance ; but they were far from ascertaining its real nature. Nor could crystallography serve to determine the species ; for t be form of the crystals, being a six-sided prism, terminated by three-sided pyramids, with angles of 120", gave for a primitive form the rhomboidal dodecahedron ; but this primitive form, being' • Tl(i8 statemrnt woutd require some correction. When I made my analyses, I ivasnot ;i»;irc ilint tlie mineral had been examined by Ekeberg. Etteberg, I be- lieve, nevei pul)lished any thing on ihe .subject. He merely sent Ihe numerical account of his analyses to Mr. Allan, io whose possession 1 saw it. — T. Vol. X. N^HL N 194 Memoir on the Sodalite of Vesuvius. [Sept.- common to several different species, ceases on that account to be distinctive. It was necessary, therefore, to have recourse to che- mistry ,• and the result of my analysis completely answered my in- tention. Chemical Analysis. A. — 25 decigrammes of sodalite in fragments were kept at a cherry-red heat in a platinum crucible for half an hour, without losing any weight. They became milky in their aspect. The angles which touched the sides of the crucible had undergone a com- mencement of fusion r B. — 1. 4 grammes of sodalite reduced to a fine powder were miaed with 10 grammes of muriatic acid diluted with five parts of distilled water. The stone was attacked in the cold. On a gentle ebullition, the solution assumed the form of a stiff yellow jelly, which I collected with much care upon a porcelain capsule, and evaporated the whole to dryness. Towards the end of the evapora- tion,, care was taken to stir the jelly, that the drying might be gentle and equal. When the whole was reduced to powder, it wzs diluted with water, and the residue washed till the liquid ceased to affect nitrate of silver. This residue, being heated to redness,- weighed 17*25 decigrammes. The filter had increased in weight 0*25 decigrammes, which makes the total weight of the residue 17*5 decigrammes. To convince myself that this residue was silica, I heated it for half- an hour, with five grammes of caustic potash, in a silver cru- cible. The mixture fused; and, being taken from the fire, I poured- distilled water on it while still hot. When well diffused through the water, I poured muriatic acid on it, which dissolved it completely. This solution was evaporated to dryness. The silica obtained, after being washed and heated to redness, weighed 1? decigrammes.. The loss of 0*5 decigramme was owing to not having weighed the filter ; for the liquid employed to wash it was neither precipitated- by caustic ammonia nor by carbonate of ammonia, 2. The acid liquid from which the silica had been separated was precipitated by pure ammonia. A very white, bulky matter was obtained, which was separated by the filter. After being washed, it was boiled, while still moist, in caustic potash. The whole was dissolved, except a little brown matter, which was separated by the: filter. The alkaline liquor being neutralized by muriate of am- monia, a copious precipitate fell, which, after being washed and heated to redness, weighed 6^7» decigrammes. It possessed all the properties of alumina. 3. I poured carbonate of ammonia into the liquid from which' the alumina had been separated. Next day I found a precipitatCj- which, having been washed and heated to redness, weighed 2-']b decigrammes. The residue dissolved in sulphuric acid was evapo- rated to dryness, and treated with cold water, which dissolved the- whole. This solution was concentrated by evaporation, and set aside' 1 SI 7-1 Memoir on the Sodalite of Fesuvivs. 195 for spontaneous crystallization. As it refused to crystallize, and had not the taste of sulphate of magnesia, sulj)hate of potash was added to it, on which crystals of alum were formed. The precipi- tate obtained by the carbonate of ammonia was, therefore, alumina, which must be added to the sum obtained by the preceding experi- ment. 4. As there was a matter attached to the rod from which the 275 decigrammes of alumina were obtained, I poured muriatic acid on it, in order to obtain this matter. Brilliant scales were detached, which, when collected on the filter, and dried, had so strong a re- semblance to boracicacid, that I thought at first that I had obtained that acid ; but I soon satisfied myself that it was silica. It weighed 0*25 decigrammes. 5. The brown deposite of the second experiment, which weighed 0*25, was treated with sulphuric acid, which dissolved the iron without touching the silica. The iron, being precipitated from the solution by ammonia, weighed 0-05 decigramme. This metal exists in such a minute proportion, that I think it belongs rather to the green pumice than to the sodalite. The 0*2 decigramme not attacked by the sulphuric acid possessed the characters of silica. 6. The silica, alumina, and iron obtained, not amounting to the weight of the stone analyzed, it was necessary to seek for the other constituents in the liquid from which the earths had been separated by the carbonate of ammonia. The liquid, in consequence, was concentrated; sulphuric acid was added, to drive off the muriatic acid, and convert the same into sulphate. It was then evaporated to dryness, and exposed to a red heat, to drive off the sulpiiate of ammonia and the excess of sulphuric acid. The matter obtained weighed 22*5 decigrammes. It was dissolved in water; the solution was concentrated, and set aside. Some needle-form crystals of sulphate of lime were deposited ; but the quantity was so small that they cannot be estimated. The liquid had crystallized confusedly in small crystals ; and as it precipitated the solution of platinum, I thought at first tliat it was sulphate of potash. But when the crys- tals were redissolved, the liquid furnished, by spontaneous evapora- tion, six-sided prisms, which effloresced in the air, had a cooling taste, and did not precipitate platinum. They had, therefore, all the characters of sulphate of soda ; and as the sulphate of soda ob- tained by calcination weighed 22-5 decigrammes, it contained 1 1 decigrammes of pure soda. The precipitate obtained by the pla- tinum solution is owing to the presence of a small quantity of pot- ash which is mixed with the soda. The mineral analyzed, then, consists, supposing it to be 40 parts, of the following ingredients : — N 196 Memoir on the SodaUte of Vesuvius. (Sept. I Silica 17-95 ■ Alumina 9-50 Iron 0'05 j Soda with a little potash .... 11 -00 i Loss 1-50 I 40-00 ^ Or, supposing 100 parts, of Silica 41-87 Alumina 23-75 Soda with a little potash .... 27'50 ' Iron 0-12 ' Loss 3-7G j 100-00 I The great quantity of soda which I obtained made me imme- diately suspect that the substance analysed was a sodalite. This I suspicion was confirmed when I compared my analysis with those of 1 Ekeberg and Thomson. The following table exhibits their results :— - | Ekeberg, ( Silica 36 ! Alumina 32 j Soda 25 Muriatic acid « . 6-75 Oxide of iron 0-25 i 100-00 Thomson. i Silica 38-52 Alumina 27'48 Soda 23-50 ■ Muriatic acid ^ \ Oxide of iron 1 \ Lime 2*70 | Volatile matter 2*10 1 Loss 1-70 ; 100-00 \ I These analyses differ from mine merely in my having found a little potash mixed with the soda. The loss of 3*76 which I had in i my analysis corresponds with the three parts of muriatic acid ob- i tained by Dr. Thomson, which it was impossible for me to perceive, as I had employed that acid in my analysis. The external charac- j ters of the sodalite of Greenland do not differ essentially from those which I observed in tlie sodalite of Vesuvius; for the six-sided 18170 ^femoir on the Sodalite of Vesuvius. 19/ prism terminated by three-sided pyramids, with angles of 120°, is merely an elongated form of the rhomboidaj dodecahedron, whieli the Count Bournon ascertained to be the primitive form of sodalite. As to the property of forming a jelly with acids, though it was not remarked by Dr, Thomson, it was recognized by M. Haiiy. Now that the existence of sodalite on Vesuvius is known, it will be easy to distinguish it by its mineralogical characters from the other species which occur on the same mountain. The substance with which the sodalite may be most easily con- founded, when it occurs in grains, or massive, is amphigene ; but it may be distinguished by its property of forming a jelly with acids, by its being;^ fusible, and softer than amphigene. Geological Views. The discovery of sodalite on Vesuvius is interesting likewise to geology. After the numerous discoveries that have been made there, it appears to me evident that the substances thus found are the produce of fire ; for it is impossible for me to conceive that species so different as nepheline, meyonite, idocrase, amphigene, pyroxene, garnet, amphibole, spineil, and others, should occur together ready formed at the bottom of the crater, as in a magazine, to be thrown out of the volcano. The sodalite of Vesuvius has very much the character of fusion; for in the specimen which 1 possess it is surrounded with pumice, which is known to be the produce of fire. The sodalite of Greenland, on the contrary, occurs in pri- mary formations, accompanied by felspar rocks, and leaves no doubt respecting its neptunian origin. Thus we have two substances found at the two extremities of Europe formed by two different ways, which yet by their composition and mineralogical character are identic, and constitute the same species. From this it follows that it is impossible in geolosry to prove the volcanic or neptunian formation of a species by simply examining the external characters; for these are common to the two ways of formation. To arrive at satisfactory results respecting the formation of rocks, we must study their geological relations. It is thus that nature herself seems to have traced the grand limits which separate geology from mine- ralogy. Article VII. Chemical Examination of a Quantihj of Sugar supposed to have been intfmttonally poisoned. By John Gorbam, M.D. Member of the American Academy, and Professor of Chemistiy in Haward University, Massachusetts. In February, 1817, I received from Dr. Nichols, of Kingston, in this state, about two drachms of common brown sugar, together 198 Chemical Examination of a Quantify of [Sept. with a letter, in whicli he remarked, " I was called to-day to visit it) a family, of vvliich every member, except one,* was suddenly taken sick, puking every thing swallowed ; and they considered it to arise, and circumstances favoured the supposition, from eating the sugar, of which I send you a sample."' On inspecting the sugar, small white grains or particles could be observed disseminated through the mass ; and, upon tasting a little of it, a peculiar acrid impression was left for some time on the tongue. In order to separate this substance, tlie mass was put into a com- mon jelly glas<, vvbicli was afterwards nearly filled with distilled water, and the liquid was agitated with a glass rod until the whole of the sugar was dissolved. On allowing the solution to remain at rest for a few minutes, a white ponderous powder was first depo- sited, after which there followed a lighter precipitate of a grey colour. When nearly the whole of the insoluble part had been separated, the liquid was poured on a filter, the remaining solid was washed with repeated portions of distilled water, which were preserved, and the solid matter was collected and dried. Its colour was a dirty white, and weighed l^i- grain : but perfectly white par- ticles could be perceived in it, and the shade of colour was owing to the impurities of the sugar. These might amount to one-fourth of a grain ; so that the white substance obtained may be estimated at one grain. It was divided into eight parts ; and, for the sake of greater precision and convenience, these parts were respectively marked No. 1, 2, 3, &c. My first object was to ascertain wliether tliis powder consisted of, or contained, arsenic. ExPER. I. — No. 1 was put intoa watch-glass, with one-third of a grain of pure solid potash ; 20 drops of distilled water were added, and the whole was boiled to dryness. Upon the solid mass were poured about 20 drops of distilled water; by agitation, the greatest part was dissolved, but the solution was turbid. On allowing it lo stand fpr a time, a greyish })owder subsided, and the clear liquid was decanted. One drop of this solution added to a solution of sulphate of copper in water produced a distinct precipitate of a grais-gretn colour. When added to the amount of six drops, the precipitate was abundant. The solution of sulphate of copper, although not saturated, was of considerable strength. ExPBR. II. — One-eighth of a grain of powdered arsenic of com- merce was mixed with one-third of a grain of solid potash, and treated in the same way, viz. by mixture with water, boiling to dry- ness, and subsequent solution in 20 drops of distilled water. One drop of this solution added to another portion of the same solution of sulphate of copper, immediately occasioned a grass-green precipi- tate ; six drops afforded a copious deposition ; and the colour and * This individual eat no sugar. 5 ^Sl7.] Sugar supposed to have been poisoned. 1.09 appearances of this precipitate so closely resembled those of Ex- per. I., that the eye could distinguish no difference between them. ExPBR. III. — ^About a drachm of solution of nitrate of silver was poured into a glass ; one end of a clean glass rod was dipped into a solution of pure ammonia recently prepared, and the drop adheiing to it was brought into contact with the nitric solution ; the other end of the rod was then immersed in the liquid prepared as in Expcr. I., and afterwards made to touch the surface of the solution of silver, a dense yellow-coloured precipitate was immediately formed. Wlien three or four drops of the above-mentioned liquid were added to the solution of nitrate of silver, the precipitate was considerable.* ExPER. IV. — The same quantity of solution of nitrate of silver being poured into another glass, a drop of liquid ammonia was added, and afterwards a drop of a solution known to contain arsenic and potash, or arsenite of potash. A dense yellow-coloured precir pitate instantly took place, precisely similar in every respect to that produced in Exper. III. ExPER. V. — The yellow-coloured precipitate, Exper. HI., was collected on a filter, repeatedly washed with distilled water, dried, mixed with thrice its volume of charcoal, and put into a small and thin glass tube closed at one end, the mouth being obstructed with a roll of paper. The part of the tube containing the materials was held in the flame of a spirit lamp ; it soon became red-hot, and was kept in that state for the space of 10 minutes. When cooled, no metallic film could be perceived ; but the internal surface of the tube, about an inch from the extremity, which had been heated, was found to be coated with a white crystalline, and apparently granular sublimate. Exper. VI. — The yellow-coloured precipitate, Exper. IV., being increased in quantity by the addition of a few drops each of am- monia and of the arsenical solution to the solution of nitrate of silver, was managed precisely as stated in Exper. V. When the tube was taken from the lamp and <:ooled, there was no appearance of a metallic film ; but the internal surface exhibited a ivhite, crys- tailine, and apparently granular sublimate. Exper. VII. — No. 2 of the white powder was mixed with about three times its weight of charcoal powder ; the mixture was put into a thin glass tube about a line in diameter, and hermetically sealed at one end. Its mouth was closed with a roll of paper. The extremity containing the mixture \yas immersed in the flame of a spirit lamp; it soon became red-hot, and was continued in that situation about 10 minutes. After being cooled, its internal sur- face, half an inch from the sealed end, was found to exhibit a dis- tinct metallic ^Im of a lluisk colour. • An alkali bping present in the liquid prepared from No. I, tlie addition of scimonia uas pcrhapii uuperfluous, but tbis cjrcumttaDce did oot occur to tac until after the experiment. 200 Chemical Examinat'vm of a Quantify of [Sept. ExPER. VIII. — One-eighth of a grain of arsenic ©f commerce was mixed with thrice its weight of powdered charcoal, ai^d put into a glass tube, similar to the one above-mentioned ; it was ex- posed in the same way, and for the same length of time, to the lieat of a spirit lamp. After the experiment, its internal surface exhibited a metallic flm of a lli/isli colour; and if any difterence were perceptible between this and that of Exper. VII., the latter was rather more distinct. Exper. IX. — No. 3 was put into a watch-glass, 20 drops of pure muriatic acid were added, and they were exposed to heat until the greatest part of the powder was dissolved. A greyish powder re- mained, which appeared to consist of the impurities of the sugar. The quantity was too minute to admit of a satisfactory examination, and I did not think it essential. A watery solution of sulphureted hydrogen was then made; and a few drops of this solution being added to the muriatic solution, a straw-coloured precipitate was im- mediately formed. When this substance was collected, dried, and exposed on a small spatula of platina, to the heat of a lamp, it first turned red, appeared to undergo fusion, exhaled a sulphureous odour, and was entirely dissipated in vapour. Exper. X. — The eighth of a grain of powdered arsenic of com- merce was dissolved in muriatic acid ; solution of sulphureted hydrogen being then added, a straw-coloured precipitate was in- stantly produced, which, when dried, and exposed to heat, turned red, melted, exhaled a sulphureous odour, and passed off in vapour, leaving no residuum. A fragment of native orpiment, or the yellowr sulphuret of arsenic, was heated on a blade of platina : it assumed a red colour, melted, gave out a sulphureous odour, and was completely vapo- rized. Exper. XI. — No. 4 was taken on the point of a penknife, and held over the flame of a lamp ; a white vapour was soon perceived to rise, having the peculiar alliaceous odour which has been supposed to characterize arsenic and its oxide in the elastic form. No. 5 was unfortunately lost in an attempt to form arsenic acid. It was immersed in nitric acid contained in a glass capsule ; but on exposure to heat in a sand-bath, the glass broke, and the materials were K st in the sand. The object in obtaining arsenic acid was to form arsenlate of silver, by adding it to an ammoniacal solution of nitrate of silver. ExPFR. XI!. — No. V, was mixed with twice its weight of powdered charcoal ; the mixture was put between two polished plates of copper, which were secured by iron wire, and exposed to a dull red heat for a few minutes. When cold, the plates were separated, and a white tnaik, or, in other words, a white alloy, was visible oa each plate, on the surface which had been in contact with the mixi re. ExPER. XIII.— An eighth of a grain of white oxide of arsenia 181 7-] Siigar supposed to have been poisoned. 201 was mixed with twice its weight of charcoal powder; the mixture was put between two similar plates of copper, and exposed to a dull red heat. The results were found to be the same as in Exper. XII. Nos. 7 f'nd 8 were expended in repeating the first, third, and fifth experiments. The phenomena resulting from them were pre- cisely the same as are there detailed, and the conclusions which may be drawn from them were amply confirmed. Ohservations, The results of the experiments above stated are unequivocal. The white matter mixed with the sugar exhibited all the characters of the arsenic of commerce, the white oxide, or arsenious acid of chemists. This fact is demonstrated by the first, third, fifth, and seventh experiments ; hut having a sufficient quantity of the powder to go through with an extensive series, I also performed those which may be considered as of more doubtful character, such, for ex- ample, as the whitening of copper, the odour exhaled i)y exposing the substance to heat, and the formation of orpiment, or the yellow sulphuret of arsenic, by sulphureted hydrogen and the muriatic solution. The action of arsenious acid on the salts of copper has been known from the time of Scheele, and his name has often been given to the green precipitate or pigment produced in this experi- ment. It appears to be a delicate test of the presence of arsenic, and is not, 1 believe, liable to any material objection. The test of Dr. Marcet is equally delicate ; but any alkaline phosphate, and even phosphoric acid alone when ammonia is present, will produce a yellow-coloured precipitate in solution of nitrate of silver ; and it is, therefore, necessary to investigate the properties of this inso- luble substance, in order to ascertain whether it be phosphate or arsenite of silver. This circumstance may sometimes render the use of this test inconvenient ; and where the quantity obtained is very small, even doubtful, from the impossibility of arrivintj at accunite results in examining minute jiortions of matter. Still if the same substance should not only occasion this precipitation in solution of nitrate of silver, but also the formation of Scheele's green in solution of sulphate of copper, no doubt can be entertained respecting its nature. According to Dr. Marcet, the j)hf)sphate of silver yields no smoke, nor crystalline sublimate, when heated in a tube; and when urged before the tilow-pipe on charcoal, it forms a grei-nish-coloured and difficultly fusii)k' globule.* Tl'.e arsenite of silver, with the exception of colour, is charac- terized by very different properties. It grows brown on exposure to light; it is solul)le in nitric acid, and in excess of ammonia; it is decomposed tiy heat ; and, when the procei«s is conducted in a tube, a white vapour ascends, which condensci on the colder part in the * Medico-Chir. Trans. v»l. vi. p. 663. 202 Chemical Examination of poisoned Sugar. [Sept. form of minute octohedral crystals.* It is this decomposition which Dr. Marcet has considered as the erperimentum crt/cis in detecting the presence ot" arsenic. Hence I was lead to perform this experi- ment with great care; and the resuU exhibited in the most unequi- vocal manner that the yellow precipitate, Exper. III., was not phosphate, but arsenite of silver. The crystalline sublimate is there said to be apparently granular, because their real forms, in consequence of their minuteness, could not be distinguished without the aid of a microscope ; and it was my wish to preserve the tube in the state it then was. There can be no doubt, however, that the sublimate was arsenious acid. The formation and decomposition of the yellow-coloured preci- pitate, and the appearances in the tube, as described in Exper. VII., may, independently of the action of sulphate of copper, be regarded as infallible, and as sufficient to establish the fact of the presence of arsenic, without further trials. Water was employed to separate the sugar from the white powder, because, from the comparative slowness with which tlie metallic salts in oxides are dissolved, I presumed that the whole of the former would be liquified before the weight of the latter would be ecHsibly diminished. This was the fact. The solution of sugar, when examined, exhibited no trace of arsenic, nor was any sensible quantity dissolved by the water witli which the powder was washed. Indeed, the proportion of arsenic which water at common tempe- ratures is capable of dissolving is very small; for Mr. Klaproth found that 1000 parts of water at 60° Fahr. took up only 2-1- parts of arsenious acid, even although they were in contact 24 hours. f Some persons perhaps may object to the conclusion drawn from the experiments just stated, in consequence of tlie smallness of the quantity operated upon. Those among them which may lie consi- dered as decisive, an-d which are amply sufficient to justify an un- qualified opinion on the nature of the substance, viz. the formation of Scheele's green, of the yellow precipitate, Exper. III., and its decomposition, Exper. V., were made with ^ of a grain ; but their results were so obvious, that they inspired the same confidence as if they had been performed with -L of an ounce. That it is not neces- sary to operate on large quantities in order to be assured of the accuracy of the ex|)eriments; and the correctness of the inferences has been shown, among others, by Dr. Marcet, who proved that a child had been poisoned by arsenic, by examining the liquids ejected from the stomach, in which he infers that no more than -^ of a grain could have been dissolved. :J: Boston, Mayii, 1817. * Nicholson's Journal, vol. xxxiv. p. 174. + Annals of Philosophy, vol. iv. p. 133. J Medico-Chir. Trans vol. vi. p. 664. .181 /.J On the Ammoniacal Sails. 203 Article VIII. Experimental Researches on the yimmomacal Salts. By Dr. A. Ure, of Glasgow. (To Dr. Thomson.) DEAR SIR, In a series of experiments which I executed some time ago, with the view of ascertaining the best method of separating from each other the common primitive earths, it became requisite to examine very minutely the constitution of the triple phosphate of ammonia and magnesia. On comparing my results with some of those cur- rently received among chemists, I observed unaccountable discre- pancies. These still continued to jjresent themselves, though I repeated and varied the experiments, employing great care, and very accurate instruments of research. I was hence led to institute a somewhat general train of investigations on the saline coml)inations of ammonia. As these are closely connected with the profound dis- cussions on the atomic theory with which you and your correspon- dents have enriched the Annuls uf Philosophy, I shall be happy to submit their results to public inspection in the same work. Aware of tlie intricacy of the subject, I do not offer them as a clue to guide our steps through this chemical labyrinth, but to lead back public inquiry to a department of the science which, after having been for some time a scene of keen and instructive controversy, has been lately neglected as neutral, or avoided as insidious, ground. A quantity of water of ammonia, recently prepared from quick- lime and sal-ammoniac, in a Wolfe's apparatus, was divided into three equal portions of 500 grains each. The first portion was. saturated by 15*77 grains of distilled sulphuric acid, which, from multiplied experiments, I knew to contain 80*9 per cent, of dry acid, such as exists in ignited sulphate of potash. For the conve- nience of experimenting, the acid was so diluted that a single drop of it weighed about -pLj of a grain. The evaporation of the neutral salt was conducted in a platina capsule, such as I use in all my experiments, and was carried to dryness on a regulated sand-bath, with extreme circumspection. Towards the end, the salt was care- fully stirred with a slip of platina, to prevent the sudden exfoliation of minute particles, which is apt to happen with a saline crust closely attached to the heated vessel. 21*6 grains of dry and per- fectly neutral sulphate were procured. As 15*77 grains of the above qil of vitriol contain 1277 of dry acid, 8*83 grains of the salt are Ijase. Ilence in 100 parts we have 60 sulphuric acid and 40 am- moniacal base. 2. The second portion of 500 grains took for saturation 322*7 grains of a dilute nitric acid, which, by a prior synthesis of nitrate of potash, Yi'ere knovvn to contain exactly 1<»*8 grains of dry acid. 204 On the Ammoniacal Salts. [Sbpt. 25*79 grains of dry compact nitrate of ammonia were obtained. Of these 8-99 were base and 16*8 acid. This weight of ammoniacal base accords well with the 8*83 obtained in the preceding exjjeri- ment, from the same quantity of water of ammonia. This nitrate is composed in 100 parts of 65 acid + 35 base. ^ 3, The third 500 grains were neutralized by 303"5 grains of a dilute muriatic acid, equal to 30*35 of that whose specific gravity is \'\\)2, and equivalent to 8*58 grains of such dry acid, as is sup- posed on the old hypotiiesis to exist in dry muriate of potash : 1719 grains of dry sal-ammoniac were obtained. Here we have 861 of base, agreeing very well with the preceding results. In 100 parts of the salt we have 50 acid -f 50 base. The mean quantity of base in the three cases is 8*75, which unites with 12*77 sulphuric acid, 16*8 nitric, and 8*58 muriatic; numbers as near the saturating ratios of the acids as, with easily volatilized and decomposed salts, we can reasonably expect. Is this base dry ammonia, or is it a hydrate of ammonia ? I hope to be able presently to demonstrate that sal-ammoniac is not a chloride of ammonium, as you regard it in the fourth volume of the Annals, but a muriate of ammonia. In this case, since the muriate in the above experiment seems to retain the whole ponderable base that ' enters into the other two salts, if I can prove that their base retains water, may we not infer that the muriate also retains it ? Or are we to suppose that such liquid muriatic acid as contains on the old hypothesis 28*3 per cent, of dry acid, consists really of 36*5 chlo- rine + 1*1 hydrogen = 376 hydro-chloric acid. Hence the above 8*58 parts of dry muriatic acid will then correspond to 11*4 of hydro-chloric, which unite with 6-79 of dry ammoniacal base to constitute the 17*19 of sal-ammoniac obtained. Thus we have three salts of the same apparent dryness, and containing apparently the same weight of base ; but the acid of the last has the faculty of disniissing the whole water, while those of the first two, susceptible in other cases of forming dry salts, here alone retain it in every temperature. The hydro-chloric view of the combination, which we owe to the original genius of Sir H. Davy, is indeed supported by such evi- dence in the direct condensation of equal volumes of dry muriatic acid gas and dry ammoniacal gas into sal-ammoniac, that it is diffi- cult to refuse our assent to its legitimacy. Yet we have precisely the same evidence for the composition of subcarbonate of ammonia. M. Gay-Lussac has demonstrated that it results from two volumes of ammoniacal gas and one volume of carbonic acid gas condensed into a solid salt. 200 cubic inches of ammoniacal gas, weighing 36*3 grains, and 100 grains of carbonic acid gas, weighing 4C*34 grains, form 82'*;4 grains of solid subcarbonate. Hence 100 parts consist of 56 acid -}- 44 ammonia. My analysis of the dense, semitransparent subcarbonate, agrees very well with this synthesis, giving 55 per cent, of carbonic acid. But from this same subcarbonate a very notable quantity of water 6' J SI".] O71 the Ammoniacal Salts. 205 may be extracted in what I conceive you will think an unexception- able manner. Dry sal-ammoniac subjected to the very same treat- ment yields a still larger quantity of water, corresponding to its greater proportion of ammoniacal base. But here the aml)iguity relative to chlorine and muriatic acid intervenes, to unsettle our faith in the obvious deduction of water being one of its pre-existing constituents. I shall commence with the analysis of the sulphate. Having prepared a perfectly neutral and dry sulphate, composition as above stated, .'JO grains of it were intimately mixed by trituration in a mortar with 50 grains of recently ignited pulverulent lime from Carrara marble. The mixture was immediately put into a glass tube hermetically sealed at one end ; and the tube having beea weighed before and after, it was found that no appreciable loss was sustained in the trituration and transfer. To the open end of that glass tube, another, about 20 inches long, bent into a swan-neck at either end (which was open), but straight, and kept horizontal in the middle, was luted. This horizontal tube was surrounded with blotting-paper moistened with ether. The bottom of the sealed tube, where the dry mixture lay, was slowly heated over a charcoal furnace till it was ignited, in which state it was kept for a consider- able time. Water was copiously condensed in the inside of the long tube, while ammoniacal gas exhaled invisibly from its open extremity. When 1 imagined the process finished, the unluted tube was weighed, and found heavier than before by nine grains. The contents were poured out, and found to be water strongly im- pregnated with ammonia. The sealed tube was lighter by 1})*4 grains, of which 10*4 were the ammoniacal gas which was allowed to escape. 1 next endeavoured to find what portion of sulphate of lime was formed, from which I could infer how much sulphate of ammonia remained undecomposed after the operation. By the cautious addi- tion of test muriatic acid, I learned that of the 50 grains of quick- lime employed, 19*55 grains had been saturated with sulphuric acid, corresponding to 28 of dry sulphuric acid, and equivalent to 46 of the above sulphate of ammonia. Therefore four of the 50 grains were left unchanged. Of the above nine grains of liquid ammonia, I ascertained by subsequent experiments that three were gas and six water. Hence if 46 yield six of water, 100 will afford 13-04, = the quantity of water in 100 grains of dry sulphate of ammonia. And as 100 of dry sulphate contain 40, or more exactly 39, of base, this base is a hydrate consisting of 25-9(> ammonia and 13'04 water, being nearly in the proportion of two parts to one. Hence the above nitrate, being constituted of the same base, will consist of 65 acid, 23-1- ammonia, and 1 If water. Dr. Wollaston's scale of chemical equivalents, which, when ex- tended and perfected, will render the same services to chemistry that Ne])cr's general invention of logarithms has done to astronomy and navigation, gives in the last example 65 acid, 10-9 water, and iJ06 On the Ammoniacal Salts. [SKPf* 20*7 ammonia; and in the first (>! sulphuric acid, 26|. ammonia, and 13f water. The ammoniacal combinations seem to form the only vulnerable part of his admirable table of proportions. My experiments were several times repeated, with a satisfactory uniformity of results. Analysis of the Suhcarbonale of Ammonia. — 50 grains of dense semitransparent subcarbonate ot ammonia, containing from 54 to 55 per cent, of carbonic acid, were hastily pulverized, and mixed with 50 grains of dry quick-lime. The mixture, being introduced into a tube as above described, was found to have suffered no loss of weight in the manipulations. The former arrangement of con- densing tube was adopted. It was found necessary to heat the ma- terials very cautiously, otherwise a great part of the subcarbonate escapes without decomposition. Nine grains of liquid were poured out of the refrigeratory tube, after the experiment, and much moist salt in slender needles lined its interior. The constitution of this salt 1 tried to determine by comparing its power of neutralizing sul- phuric acid, with the carbonic acid gas expelled, and it seemed to be a semicarbonate of ammonia, if the expression be allowable in opposition to bicarbonate. The carbonic acid appeared to be united with double the quantity of base in the subcarbonate. But perhaps the result proceeded from the adhering water of ammonia. It is very difficult to get rid of the complication which these needles in- troduce into the estimate of water. I repeated the process, using a retort and receiver, into which the moisture and saline needles condensed. These being again mixed w^th dry lime, and heated, afforded water tolerably free from subcarbonate. The composition which, after many trials, I was finally led to assign to the subcar- bonate, was 54*5 carbonic acid, 30*5 ammonia, and 15 water; or 54*5 carbonic acid and 45*5 hydrate of ammonia. Now does the whole of this compound base pass into the dry sulphate, and also into the muriate, on the common hypothesis? The following ex- periments will show this to be the case. 21' I grains of dense sub- carbonate were introduced into a pear-shaped vessel with a long neck, and were neutralized with dilute sulphuric acid, containing 17'5 grains of distilled acid, and 14*157 (^ry acid. There were obtained of dry sulphate 23'6 grains. In 21* 1 subcarbonate there are 11*5 carbonic acid and 9*6 hydrate of ammonia, to which add 14*157 acid; the sum is 23-757. Now the sulphate actually ob- tained was 23'6, being an exact accordance. The composition of this in 100 parts is G0'\ sulphuric acid and 39*6 base. In numerous other experiments on the quantity of oil of vitriol requisite to neutralize a given weight of subcarbonate of ammonia, I found that a somewhat greater proportion of acid was expended. The average may he reckoned S8 concentrated oil of vitriol to 100 subcarbonate; and the sulphate was composed of 61 acid and 39 base. To dry the sulphate thoroughly without decomposing it, is a very nice operation. The bicarbonate of aaimonia obtained by exposing to the air the 1817.} On the Avimoniacal Salts. '20J subcarbonate in powder till it becomes scentless, is a salt cantaining^ tUe same weight per cent, of carbonic acid ; but its power of neu- tralizing sulphuric acid is to that of the subcarbonate as three to four. Hence it consists of 54*5 carbonic acid, 22*8 ammonia, and 2275 water, being evidently equal quantities of the two latter. 100 grains saturate 66 grains of concentrated oil of vitriol. If we compare these members with those given on the scale of equiva- lents, we shall find a considerable difterence between them. There 100 grains of subcarbonate correspond to fully 125 of oil of vitriol, and 100 of the bicarbonate to somewhat more than SO. Having repeated my experiments on specimens of subcarbonate obtained from different quarters, I have found the resuks sufficiently uniform. Dense subcarbonate in its transition into bicarbonate by exposure to the air, will continually decrease in its power of neu- tralizing the acids ; to which cause many of those anomalies, with regard to this salt, noticed in chemical works may be ascribed. Hence if more or less of the white pulverulent matter encrusting the masses of subcarbonate be taken, we shall find the deviation from Dr. WoUaston's numbers to be still greater. Aware of thi» source of fallacy, I was careful to avoid it, by selecting fresh compact salt which had not been exposed to the air. Muriate of Ammonia from Suhcarlonate. — 50 grains of dense subcarbonate are neutralized by 87'4 grains of liquid muriatic acid, specific gravity 1*192, equivalent to 24-7 of dry acid. There were obtained of dry sal-ammoniac 47316, falls short of the actual product by 0*4684, which in this view must be the water of its composition. In the other mode of considering sal-ammoniac we have 0'C916 ammonia -f- l-G chlorine + 0*4 hydrogen = 2*3316 of hydro- chlorate of ammonia. Here one part by weight of ammonia yields more than three times its weight of sal-ammoniac ; while the base 208 On' the Ammoniacal Salts, [Sept. existing in the subcarbonate yields little more than twice its weight of the same salt. 100 parts of ammoniacal gas should give by the theory of volumes 310 of sal-ammoniac; 100 of the base in the subcarbonate give 209, the deficiency being due to the water in the latter. Hence if 310 of sal-ammoniac indicate 100 of dry am- monia, 209 will indicate G7*42 present in 100 of the subcarbonate base. Hence 100 parts of subcarbonate consist of 54*5 carbonic acid, 3067 ammonia, and 14-83 water, affording a confirmation of the preceding analysis. It probably ought to be stated in even numbers 55, .-^O, 15. On Dr. Wollasfon's scale, the numbers are 56 carbonic acid + 44 ammonia = 100 subcarbonate. Jmilysis of Sal-ammoniac by dry Lime. — Let us now see what quantity of vvater can be obtained from sal-ammoniac ignited with quick-lime. The experiments executed with this view have been carried on for a considerable time past, and have been mentioned to several chemical gentlemen. Dr. Gmelin, an ingenious German chemist, the pupil and friend of the celebrated Berzelius, assisted at the repetition of some of them nearly two months ago. As it was necessary to subject the materials to a full red heat, 1 employed to receive them tubes of green glass, sealed at one end, and con- verted into Reaumur's porcelain.* A mixture of 100 grains of recently heated muriate of ammonia and 100 grains of lime wa3 put into the tube, and over all an additional 100 grains of lime. The tube being weighed before and after, the weight corresponded to the sum of the materials. The refrigeratory horizontal tul)e was attached as before ; but its other end had a narrow glass tube luted to it, which descended into the water of a Woolfe's apparatus. The porcelain tube was now heated, at first gently, and afterwards powerfully, for nearly half an hour, till, notwithstanding the high temperature, the water of the Woolfe's apparatus rose in the small glass tube. The whole being unluted, 19 grains of water of am- monia were condensed in the refrigeratory tube, and one grain of sal-ammoniac was found sticking to the end, which had been in- serted into the porcelain tube. The porcelain tube had no ammo- niacal smell ; and, being weighed while hot, was lighter by 44-9 grains. The water of ammonia in the Woolfe's bottles was exactly neutralized by 115-95 grains of muriatic acid, sp. gr. 1'192, = 32-81 dry acid. After cautious evaporation, 65*05 grains of sal- ammoniac are obtained. The porcelain tube was broken into small pieces, as it was found impossible to extract the fused residutjmi and the whole being put into a glass retort with water, and a little more lime, heat was applied, and the volatile matter was condensed in a Woolfe's apparatus containing water. The contents of the retort being boiled to dryness, and long after all ammoniacal smell had ceased, the water of ammonia obtained was saturated with muriatic • This substance has been called crystallite; but the kind of glass called crystal is not convertible into Reaumur's porcelain. Crystallite may signify any crystal- lized stone or mineral. Yitrite seems unexceptiuuable. 1817.1 On the Ammoniacal Salts. 209 acid, and evaporated, 5'2 grains of sal-ammoniac are procured. If to these 7025 grains of regenerated salt we add the single grain sublimed, we have 71'25 grains. Of the strong ammoniacal water in the tube, nine grains were poured at first into the Woolfe's bottle ; but 1 0 grains adhered to the sides of the tube, which, being washed out, yielded, after saturation, 10 grains of sal-ammoniac. The whole product of salt is, therefore, 81*25 grains, instead of 100. From these 81*25 grains, 13 of water were obtained. Hence 100 would yield 16 grains. The loss of weight in the porcelaia tube consisted of the 20 grains found in the condenser, and 24*9 grains which had passed into the Woolfe's apparatus. Now the ammoniacal gas found condensed in the Woolfe's bottles, exclusive of what was in the long tube, certainly did not amount to more than 20 grains, for it did not yield 60 grains of sal-ammoniac. What are these 4*9 grains ? I cannot conjecture, unless they be supposed to be water, derived from some mysterious decomposition of' the six or seven parts of ammonia, corresponding to the 20 or 21 parts of sal-ammoniac, which constantly disappear in every repeti- tion of this experiment which I have made. Of the tightness of the apparatus I am well assured. Indeed, I have performed the «;ame experiment with a continuous glass tube, sealed and bent do'A'n at one end like a retort, while tlie other end was drawn into a small tube wiiich passed under a jar on the mercurial pneumatic shelf. The middle part was kept horizontal, and artificially cooled. The sealed end contained the mixture of lime and sal-ammoniac. A brush flame of a large alcohol blow-pipe was made to play very gently on the end of the tube at first, but afterwards so powerfully as to keep it ignited for some time. The sal-ammoniac recovered did not exceed three-fourths of that originally employed. Perplexed by this perpetual disappearance of ammonia, I ima- gined that perhaps a portion of nitric acid was formed at the expense of the alkali by the action on its azote of the oxygen, which by some chemists it is supposed to contain. In this case nitric acid might be found in combination with ammonia in the Woolfe's bottles, or with lime in the porcelain tube. A portion of regene- rated sal-ammoniac and residuary muriate, derived from an experi- ment made on purpose, was separately put into two retorts. Dilute sulphuric acid was added, and, heat being applied, the volatilized acid was condensed into cooled receivers. In the acids thus procured slips of clear silver were digested for some time with a gentle heat, but not a trace of muriate of silver was to be perceived. The metallic surface was not in the least affected. In whatever way the lost ammonia is to be accounted for, there is no incondensible product, no evolution of azote or hydrogen ; for after the first discharge of the air of the apparatus, not a bubble of gas is to be seen. And since the above experiments prove that no nitric acid is formed, our only inference must be that water is the product instead of ammonia. Vol.. X. N° III. O 210 On the Ammonlacal Salts. [Sept. That the loss is not owing to the mode of manipulation which I adopt, the following experiment will prove. Into a glass retort I put a mixture of 50 grains of sal-ammoniac and 75 grains of lime, with a little water. A Woolfe's apparatus being connected, the distillation in the retort was carried to dryness. The water of am- monia in the bottles was neutralized with 94 grains of muriatic acid, sp. gr, 1-192, containing 26 grains of dry acid. After cau- tious evaporation, 49 grains of muriate of ammonia were recovered. The residuum in the retort being dissolved in water, filtered, freed from lime by blowing the air of the lungs through it for some time, again filtered, evaporated, and ignited, yielded of muriate of lime 52 grains, which is the quantity equivalent nearly to 50 grains of sal-ammoniac. Though the most eminent chemists of the present day consider subcarbonate of ammonia as a compound of two gases, neither of which contains water, yet we have proved that subcarbonate which sublimes like sal-ammoniac without decomposition to contain about 15 parts of water in the 100. Nor is there any difficulty of assign- ing the origin of that water. The subcarbonate is usually produced by sublimation from a mixture of carbonate of lime and muriate of ammonia. The water either proceeds directly from the muriate, or is generated from the oxygen of the lime and the hydrogen of the hydro-chloric acid. If the subcarbonate which results from the direct condensation of the two gases yield water by being heated along with dry lime, or if it afford no more sal-ammoniac by satu- ration with muriatic acid than the sublimed subcarbonate does, then the whole doctrine of gaseous combination will need revision. That carbonic acid gas hygrometrically dry contains no water, is held to be demonstrated by the fact of its decomposition by potassium affording no hydrogen. We must next turn our attention to the ammonia. This gas was submitted to the action of potassium by Messrs. Gay-Lussac and Thenard, as well as by Sir H. Davy. The results of their experi- ments were, however, more calculated to astonish than to instruct. We may hence judge of the intricacy of the subject; for these philosophers are not only the most brilliant discoverers, but the most luminous writers, of the age. Potassium was found to absorb 120 times its bulk of ammoniacal gas, becoming in consequence olive-green, and heavier than water. On distilling this substance in a tube of wrought platina in a very intense heat, potash was found with a quantity of potassium, and the gas was hydrogen with only a small proportion of azote.* The remarkable circumstance of this experiment is the disappearance of the principal constituent of ammonia, the azore. Now I apprehend that an analogous de- struction of ammonia took place in my ignition of sal-ammoniac * Recherchps Physico-Chimiques, par MM. Gay-Liissac et Thenard ; and Phil. Trans. ISOD. 18170 ^^ ^'^^ Ammoniacal Salts. 211 and quick-lime ; and that the product was also analogous, namely, water. For the hydrogen in Sir H. Davy's experiment would pro- ceed from the action of the potassium on the water, or its element oxygen, whence potash was formed. Ammonia consists, as already stated, of three volumes of hydrogen and one volume of azote condensed into two volumes, or into one lialf of the total volume. If we shall suppose that azote is a deutoxide of hydrogen, a volume of it miglit uniie to a volume of hydrogen to constitute water, while a greater or smaller part might remain, according to the circum- stances of the experiment, in the condition cf ammonia. It may be conceived that the joint influence of the chlorine, lime, and high temperature, determine this decomposition of the ammonia, as sulphuret of potash decomposes cold water, which neither of its constituents can effect. In the dry sulphate, nitrate, carbonate (and in the old view, also the muriate), one-third of the ammoniacal liase is water. To those who wish to repeat my experiments on the decomposi- tion, by quick-limcj of the ammoniacal salts, I may mention that at these high temperatures there are considerable difficulties to be encountered ; for on the slightest relaxation of the heat, the water rushes back from the Woolfe's bottles into the apparatus, and breaks it to pieces. In the fourth volume of the Annals of Philosophy, when treating of the composition of the chlorides, you have expressed your con- viction that sal-ammoniac is a chloride of ammonium. It is with diffidence that I venture to controvert an opinion resting on such authority. You tliere state its composition to be 97*14 chlorine + 2'J'5II ammonium. From the preceding experiments, 100 parts of sal-ammoniac contain from 50 to 5 1 of dry muriatic acid, equi- valent to 65 or G6 of chlorine, as inferred from the chlorides of potassium, sodium, and calcium. These 65 or 66 parts of chlorine may be united with 35 or 34 of ammoniacal base to constitute 100 of sal-ammoniac. But by your ratio of 97" 14 to 24 '5 II, 65 or 66 of chlorine should take only 16*4 or 16-6 of a base to constitute 82 of saline product, instead of 100 parts. We must add no less thaa 18 parts of water to 82 of chloride to make up the product of sal- ammoniac. Or, more exactly, 100 parts of ammonia unite with 209-0 hydro-chloric acid, consisting of 20293 chlorine + 6'07 hydrogen. To constitute your chloride, these 607 parts of hydrogen must quit the chlorine ; and, since they do not escape as hydrogen, must find 46-0 parts of oxygen, their saturating quan- tity, whence 52'07 parts of water will result. Of ammoniacal base there remain 54*0 parts, of which IS'47 are its original hydrogen, as deduced from Gay-Lussac's theory of volumes; but by your weights of the atoms {Annals of Philosophy, vol, iii.) 100 am- monia contain only 6*82 parts of hydrogen and 93* 1 8 azote. Assuming Gay-Lussac's numbers from their correspondence with the analysis of ammonia by Bertliollet and Davy, the 54 parts of basis unite with 202-93 chlorine to form 256 93 sal-ammoniac or o 2 212 On the Ammoniacal Salts. [Sept. chloride of ammonium ; and 100 parts will consist of 79 chlorine + 21 ammonium, containing 7*2 hydrogen and 13'8 azotium. But by your view of ammonia, the composition of these 21 parts of ammonium is 2-65 hydrogen + 18*35 azotium, using this term to denote the azotic base which remains when the oxygen has been withdrawn by the hydrogen of the muriatic acid gas. If we take the water into the account of the composition of the salt, then the numbers will stand correctly, Chlorine 65*67 Ammonium 17*48 Water 16*85 100*00 We know how speedily the amalgam of ammonium is decom- posed by a drop of water, and we also know that five parts of chlo- rine can resolve one part of ammonia into its ultimate constituents, though ammonia in this view, being an oxide, should be less readily acted on than its metallic radicle. How then can we conceive the existence of ammonium in the midst of chlorine and water, all together forming one of the least destructible of compounds ? Be- sides, the presence of water is, I believe, considered to be incom- patible with the existence of metallic chlorides. It converts them into hydro-chlorates of the metallic oxides. Sal-ammoniac, regarded as such, is no less an anomaly, being, I imagine, the only dry liydro-chlorate, and is composed in 100 parts of 66 chlo- rine, 2 hydrogen, and 32 ammonia. These 2 of hydrogen will take 15 oxygen from the lime to form the water obtained in my experiments. If it be called a dry chloride of ammonium, then to account for the 16 or 17 parts of water so procured, we must ex- pend ■§- of the 2*65 parts of hydrogen, which on your statement 21 parts of ammonium contain, and consequently only ^ of the am- monia should be recoverable, instead of from i to -f-. According to MM. Gay-Lussac and Thenard, when three parts of ammoniacal gas and one of chlorine are mixed together, they condense into sal-ammoniac, and azote equal to -j^ the whole volume is given out. This statement merits examination. Taking ihe composition of ammonia given by the same distinguished che- mists, this alkaline gas contains in a condensed state half its volume of azote and li its volume of hydrogen. Hence 15 volumes, when they condense with five of chlorine, and leave -^ of the whole volume, or two of azote, retain of the 74- azote present in 15 of ammonia, 5-|-. These 6 J- require 164- of hydrogen, together equal to 22 in volume, but condensed into 1 1 of the ammonia. But 15 of ammonia contain 22i of hydrogen, 16^ of which are now con- densed, leaving 6 to convert the chlorine into hydro-chloric acid. There are, however, only five of chlorine altogether, which take five of hydrogen to form 10 volumes of hydro-chloric acid. Hence one volume of hydrogen is unoccupied ; and as 10 grains of hydro- chloric acid take 10 grains of ammonia to constitute sal-ammoniac. 1817.] ^^ ^^^ Ammoniacal Salts. 213 a volume of the alkaline gas will be also insulated. Thus there will remain unprovided for, or in a gaseous state, one volume of hydro- gen, one volume of ammonia, and two of azote, heing -i of the original bulk, instead of -^ of azote alone. As 15 of ammonia are here reduced to 11, 100 would become 73tj 26f of ammonia being destroyed in this combination. And if 15 volumes of am- monia be mixed with 18^ of chlorine, or 100 with 125, tlie de- composition of the alkali will be total. The phenomenon of com- bustion is to be ascribed to the condensed state of the hydrogen. I shall conclude with describing an easy method of separating carbonic acid gas and chlorine from muriatic acid gas. When the two former are subjected to dry quick-lime at ordinary temperatures, there is no condensation. I exposed carbonic acid gas, previously dried by muriate of lime, to dry lime over mercury, for 20 hours, using occasional agitation; but the bulk of gas continued the same. This phenomenon surprized me; for since water is foreign to the constitution of carbonate of lime, nay since it aids the expulsion of the gas from the ignited carbonate of lime and barytes, or weakens its affinity for the calcareous base, I could not expect that water would, on the contrary, render their affinity efficacious, or be essential to their re-union. On admitting a little of the pulverulent hydrate to the gas which had resisted the action of dry lime, ab- sorption speedily took place. Chlorine unites very readily also with the calcareous hydrate. Muriatic acid gas, on the other hand, I found speedily to condense by exposure to dry lime. Hence in the controversial experiments of Dr. Murray and Dr. John Davy, where chlorine, carbonic oxide, and hydrogen, were mixed, the muriatic acid generated will be detected and withdrawn by dry lime, and metallic laminae will condense the chlorine ; when the carbonic acid, if it be a product, will remain to be examined in the usual way. These phenomena at the first aspect might lead one to believe that, since dry gases will not unite with dry lime, there must be water in muriatic acid gas to favour its combination. We may, however, regard it as a case of complex affinity, in which chlorine and calcium, hydrogen and oxygen, by the sum of their respective attractions, determine the combination. Several important branches of the above inquiry, particularly that relative to the results of mixing chlorine and ammonia ia various proportions, I have been unfortunately prevented from entering upon, in consequence of the only apartment of the Insti- tution where such experiments can be safely made having beei) alienated to other uses for some time. I am, dear Sir, your most obedient servant, Andrew Ubb. 214 Report on Hachette's Second Memoir [Sept. Article IX. Report made to the Academy of Sciences, Oct. 14, 1816, on a second Memoir of M. Hachette, relative to the running of Fluids through Orifices with thin Sides, through cylindrical or conical Pipes, and through capillary Tubes. Thk Academy has charged MM. Poissoii, Ampere, and myself (M. Cauchy), to give an account of the new memoir of M, Hachette on the flowing of liquids through orifices with thin sides, and through pipes applied to these orifices. It will be recollected that M. Hachette has already presented a set of experiments on this subject, which, in consequence of the report* of M. Poisson, has gained the approbation of the Academy. Some of the new expe- riments confirm the conclusions established in the first memoir ; others offer new results. We shall give an account of both sets, and show how the author has ascertained the influence on the flow of water produced by the size of the orifice, its shape, that of the surface in which it is placed, the addition of a cylindrical or conical pipe, th'e height of the liquid, the kind of liquid, and the nature of the surrounding medium. Size of the Orifice, All other things being equal, the contraction f of the vein which issues from an orifice with thin sides diminishes with the dimensions of the orifice. This proposition, which M. Hachette had established in his first paper, is confirmed in the present by new experiments. These experiments, however, induce him to augment the contrac- tion of the vein, which he had at first given for a circular orifice of a millimetre in diameter, and to raise it from 0'22 to 0-31. The contraction is reduced to 0'23 when the orifice has a diameter of -/jyV of a millimetre. Tn the apparatus employed to measure running water by inches of the engineer, it is 0-31, as in the first * See ^nnais of Philosophy for 3u\y, 1817, vol. ix. p. 31. + We call contracted section the smallest section made in a vein parallel to the plane of ihe orifice; and contraction of the vein, the ditference between the area of the orifice and the area of ihe contracted section, when the area of the orifice is taken for unity. As the common velocity of al! the points of the contracted section is nearly ihe velocity due to the height of Ihe fluid above the orifice, it follows that the real waste does not differ sensibly from what would be furnislied by the theorem of Torricelli for an orifice equal in surface to the contracted sec- tion. Hence if we compare the theoretic expense calculated for the given orifice with the real expense, the difference between the two referred to the theoretic expense taken for unity will be the measure of the contraction of the vein. It is likewise, in some measure, the contraction of the expense. On this account we shall hereafter distinguish by the name of contraction the excess of the theoretic expense above the observed expense, referred to the first of these expenses, even in the case when the velocity of the contracted section is no longer that determiiied by the theory of Torricelli,— (Note of the Reporters.) 18170 071 the running of Fluids through various Orifices. 215 of the two preceding cases. For diameters above 10 millimetres, the contraction becomes almost constant, and is included between the heights 0-40 and 0-37. In considering what is the size of orifices employed to obtain a contraction of from 0-31 to 0*23, we have inquired whether thick- nesses of the sides of the vessel which might be neglected relatively to orifices of JO millimetres in diameter ought still to be considered as thin witli respect to orifices whose diameter is one millimetre, or below it. We conceive that we cannot leave that thickness out of consideration whenever it is such as to be comparable to the diameter of the orifice. In that case, under certain pressures at least, it ought to act on the fluid vein like a cylindrical pipe ; tiiat is to say, increase the expense, as we shall see afterwards. Perhaps we ought to ascribe in part to this cause the diminution of the con- traction observed in the flow from orifices of a very small diameter, and probably it would be possible, without varying the diameter, to obtain different contractions by varying the thickness. This con- jecture will explain why orifices of a millimetre in diameter have not always given the same product. But new experiments are requisite to determine the point with certainty. Form of the Orifice. The form of tlie orifice, when the sides arc thin, has no sensible influence on the expenditure, unless it contains re-entering angles; but it has a marked influence upon the exterior surface of the fluid vein. As the contraction increases with the dimensions of the orifice, it was natural to think that when a fluid vein escapes between the two sides of a sallant angle, the contraction ought to increase in proportion to the distance from the summit of the angle; so that a section made at a little distance from the plane of the orifice, and parallel to that plane, shall be terminated, not by two straight lines, but by two curve arches convex to each other. This is what actually happens. Hence when the contour of the orifice is a regular polygon, each side of the polygon becomes the base, not of a plane, but of a surface, wliich, viewed externally, is convex from the orifice to the contracted section. The concavity of the surface, after having reached its maximum between these two sections, dimi- nishes as we approach the contracted section, and even changes beyond it, in consequence of the velocity acquired, into a very evident convexitv, so as to show a sallant edge when there was a hollow before. This hollow, and the saliant e^^gc that succeeds it, are produced on the middle of the side which we examine, and are situated in a perpendicular plane on the same side. When the contour of the orifice presents a re-entering angle, an edge hollow at first, and convex afterwards, passes by the summit of this angle. Form of the Surface on ivhich the Orifice is placed. According as this surface turns its concavity or convexity towards the interior of the vessel which contains the liquid, tlie expenditure 3 216 Report on Hachette's Second Memoir [Sbpt. increases or diminishes. M. Hachette confirms this assertion by the example of an orifice whose contour presents a re-entering angle, and which is situated at the extremity of a pyramid concave towards the interior of the vessel. By simply turning the pyramid, the expenditure is varied from 100 to 71. This effect ought to be ascribed, like the phenomena of capillary tubes, to the adhesion of the liquid to the sides cf the vessel, and of the liquid to itself. It is the same cause which produces the phenomena of pipes, as we are going to explain. Addition of a cylindrical Pipe. When a cylindrical or conical pipe is added to an orifice, it may happen that the fluid vein adheres to the inside of the pipe, and fills up Its whole capacity, or it may detach itself from the sides. In the last case the flow takes place exactly as if no pipe were added. But on the other hypothesis, the action exercised on the interior molecules of the vein by those which are in contact with the inside of the pipe, produces the double effect of dilating the vein or of diminishing its velocity. When the length of the pipe is not sufficient to render the last of these two effects sensible, the dilatation of the vein produces a considerable increase in the expenditure. Thus when a circular orifice of 9J millimetres in diameter has given, under a pressure of 142 millimetres, a contraction of 0-37, it is sufficient to add to this orifice a pipe of equal diameter, and of six millimetres of length, to obtain under a pressure of 30 millimetres a contraction of 0-07 only. When the length of the pipe becomes very considerable relatively to its diameter, the velocity of the fluid molecules is sensibly re- tarded by the action of those which are in contact with the inside of the pipe. The consequence is a diminution of the expenditure, which destroys a part, and sometimes even surpasses the whole augmentation, produced by the dilatation of the vein. For ex- ample, if in the last example we increase considerably the length of the pipe, the expenditure will become much less: the contrac- tion, according to the calculation of Poleni, will increase from 0*07 to 018. If we fit a pipe to a given orifice, so that a portion of the pipe penetrate through the orifice into the inside of the vessel in which the liquid is confined ; if, besides, the pipe be very thin towards the extremity at which the liquid is introduced, the effect will be the same as when the orifice is made in a surface convex towards the inside of the vessel; that is to say, the expenditure will be dimi- nished. Borda has observed that when large pipes with thin sides, and entirely plunged into the liquid, are employed, the expendi- ture is reduced to one-half.* When we employ a capillary tube * I proposed io diminish this expenditure by placing in the inside of a cylin- tlrScal pipe another parallel pipe of a smaller diameter. The lower bases of these 18170 "" ^^^ riinn'mg of Fluids through various Orifices. 217 with a thin end, the cause just announced, joined to the diminution of the velocity, from the length of the tube being always very great when compared with its diameter, ought to produce a consi- derable diminution in the expenditure. M. Hachelte verified this conjecture by means of a capillary tube whose length was 49*3 millimetres, and its diameter 1*19 millimetre. This tube termi- nated in a cone towards its extremity, occasioned under a pressure of 24 centimetres a diminution of 0*60 in the expenditure, calcu- lated according to the theorem of Torricelli. When we increase indefinitely the length of a capillary tube, we at last reach a limit beyond which the liquid flows out only drop by drop ; but this limit varies with the height of the liquid above the orifice, as we shall see immediately. Height of the Liquid above the Orifice. The contraction of the vein diminishes with the heiglit, or which is the same thing, with the pressure resulting from it. Thus, for example, while an orifice of 27 millimetres of diameter gives, under a pressure of 15 centimetres, a contraction of about 040; the same orifice, under a pressure of 16 millimetres, gives only a contraction of 0"31. Since the fluid vein has a tendency to contract in proportion as the pressure increases, it was natural to think that when a pipe is employed, the fluid, by pressures always increasing, ought to tend more and more to detach itself from the inside of the pipe, and at last to separate itself altogether. This accordingly actually happens. The pressure necessary to produce the separation dimi- nishes, as was to be expected, as the length of the pipe increases. It is less for a conical pipe than for a cylindrical one, and decreases at the same lime as the angle at the summit of the cone, which is under consideration. M. Hachette found that for a pipe of six millimetres in length and 9i in diameter, it was still superior to 30 millimetres. He destroys, therefore, an opinion supported by Mr. Vince,* an English philosopher, that the flow cannot take place with the tube full in pipes shorter than six millimetres. When the height of the liquid above the orifice becomes very small, the fluid vein at last acquires a particular form, very different from that which it had before, and which seems independent of the form of the orifice. M. Hachette calls this kind of veins secondary veins. He has observed them alike with orifices and pipes of all figures and sizes. If we make the height of the liquid decrease indefinitely after having obtained secondary veins, we at last reach a limit beyond which the flow ceases to be uninterrupted. M. Hachette has par- two tubei were iu the same plane, and tlie first rose above the sccobH. Instead •f diminiehin)^ the expenditure from I to ^, as Borda had done, I diminished it aoly in the ratio of 1 to 0-62. • See bis memoir, Phil. Trans. Ixxxt, for 179^. 218 Report on Hache tie's Second Memoir [Sept. ticulaily examined the laws of this last phenomenon in the case when cylindrical capillary tubes are employed as pipes. Six expe- riments* made upon similar tubes of different lengths, and of the same diameter, appear to prove that the limit in question is propor- tional to the length of the tubes. When the vessel containing the water has a very small size rela- tive to the orifice, the form of the vein is sensibly altered, and be- comes very irregular ; but we can always make this irregularity disappear by increasing sufficiently the height of the liquid, f Nature of the Fluid. The experiments above related were made with water. Most of the phenomena remain the same when mercury is substituted for water. Thus, for example, the contraction relative to an orifice of one millimetre in diameter with thin sides, and that which under a pressure of 24 centimetres, a capillary tube of 49"3 millimetres in length, and 1*19 millimetre in diameter, gives, will be for mercury as for water, the first 0*3 1 , and the second O'6'O. Alcohol, whose molecules adhere less to each other than those of water, flows out more readily. For the sane reason, the pressure necessary to detach a fluid vein from the inside of a pipe is smaller for alcohol than for water. :|: When oil is substituted for water, the viscosity of the oil increases considerably the duration of the flow of the fluid through small ori- * These experiments were made upon a glass capillary tube, 053 millimetre in diameter. Having put it in a vertical po^jition, water was made to flow from it by means of pressures measured exactly by means of tlie apparatus described in p. 219 of this report. The leiiijih of the tiibe was at first 980 millimetres ; and having successively diminished this length, five other tubes were obtaintd of the same diameter, and of th« following lengths: — 780, 5S0, 380, 180, 90, millimetres. The constant flow ceased in each under the following pressures: — 586, 464, 342, 233, 120, 52 nsillimetres. The pressures, calculated on the hypothesis that they are proportional to the lengthi. of the tube, would be 466, 346, 227, 107, 53, millimetres. The small differences between the results of calculation and observation may be owing to a slight curvature in the tube, to the inequality of its interior sections, or to the uncertainty under which all tlic^e observations labour. This experiment may be repeated with capillary tubes of different diameters', taking care that for water, for example, the diameters are below a millimetre ; otherwise the thread would be constant, how small soever the height of the liquid above the inferior orifice of the tube. — H. C + I avoided by the same means the helical motions in the capillary tubes which I used to study the motions of liquids in these tubes. — H. C. ■^ This result agrees with the f.)llowing experiment of M. Gay-Lussac. which M. de Laplace has related in his Rlecauique Celeste, supplement to book x. p. 54, A disc of glass of the diameter 118'3ti6 millimetres was moistened successively ■with water and alcohol, and placed in contact with the surface of these liquids: the weights of the liquid column raised at the instant that it detaches itself from the disc are equal to 69"4 grammes and 31'147 grammes.— H, C. 18170 °^ ''''^ running of Fluids through various Orijices. 2\9 fices. Through an orifice of one millimetre in diameter, the time of the flow of these two liquids was in the ratio of one to three. The nature of the fluid is one of the principal causes on which depend the continuity or discontinuity of the jet in the flow througli capillary tubes. VViien water was employed, the thread remained continuous at all pressures for a tube with a diameter equal to or greater than a millimetre. But when oil was used, the flow through a similar tube, whose length did not exceed five centimetres, was only drop by drop under a pressure of a column of oil more than a metre in height. Siirroimding Medium. In experiments on the flow of a fluid by a given orifice or pipe, the surrounding air may influence in two ways: I. By modifying the pressures on the orifice by the liquid under consideration. 2. By opposing a certain resistance to the emission of the liquid, or to its motion. That the first of these two effects may become sensible, it is necessary that the vertical pressure exercised from the top to the bottom on the upper surface of the liquid, and the pnssure in a contrary direction on the exterior surface of the orifice or pipe should be very different from each other. This happens when we leave the upper part of the vessel containing the liquid exposed to the open air, and place the orifice or the pipe through which the liquid flows under the receiver of an air-pump, in which the air may be rarefied at pleasure. By means of this artifice, and by dimi- nishing progressively the elastic force of the air under the receiver, we observe the same phenomena which are produced in the open air by the gradual augmentation of the height of the liquid. We have even the advantage of being able to determine a very considerable pressure at little expense. It was by this method that M. Hachelte was able to determine the diminution of tlie expenditure under a pressure equivalent to 10 metres of water, for capillary pipes ter- minated in cones towards the orifices — a diminution which was found the same as for pipes with thin sides and of a large diameter entirely plunged into a liquid. If, instead of increasing the pressure, we wish to diminish it, it obviously would i^e sufficient to leave the given orifice or pipe ex- posed to the free air, and to put the upper surface of the liquid in contact with air rarefied under the receiver of an air-pump. It remains for us to speak of the resistance opposed to the issue and to the motion of the fluid vein by the surrounding medium. Some philosojjhers have thought that we ought to ascribe to that resistance the changes of form which the vein experiences under variable pressures; but this conjecture is destroyed l)y the experiments of M. Hachettc. He ol)served no difterencc in ilie form of the fluid veins produced by the flow of water and mercury througli a trian- gular orifice in the air and in a vacuum. The flow of a liquid through small cylindrical tubes seems entirely 220 On the running of Fluids Ihrough various Orifices. [Sept. to depend uport the resistance and density of the surrounding medium. Mr. Matthew Young* had already remarked that in this case, if we place the apparatus under the receiver of an air-pump, the flow continually decreases with the density of the air, and that in the open air the vein runs in a full stream tilling the pipe, while in a vacuum it detaches itself from the sides of the pipe. But that philosopher does not appear to have suspected the difference which exists in this respect between tubes of a great and of a small diameter. M. Hachette has ascertained that a tube of 6-6 milli- metres in diameter only gave two different products for all densities of the air, according as the fluid vein filled or did not fill the pipe. But when he employed a tube whose diameter was reduced to three millimetres, he obtained, like the British philosopher, an expendi- ture varying with the density of the air. Mr. Young concluded from his experiments that this expenditure reaches its maximum when the elastic force of the air is equivalent! to the weight of the liquid contained in the pipe, and that in this case the liquid fills the pipe ; but this conclusion appears very doubtful. AH that we can be sure of is, that for tubes of a very small diameter, when we diminish the elastic force of the air beyond a certain limit, the ex- penditure continually decreases. M. Hachette supposes with much probability that in that case the vein fills only a part of the pipe, and he ascribes this effect to the compression coming from the air, which endeavours to enter into the pipe to replace that which the motion of the liquid has necessarily carried off. When the diameter of the tube augments, a double current of air may be established, and the effect of which we are speaking ceases to take place. It is evident from what has been said that M. Hachette has de- termined with much care the principal circumstances of the pheno- mena which the motion of fluids presents, and sometimes even the laws of these phenomena. Still some questions relative to this sub- ject remain to be resolved ; as, for example, what ought to be the thickness of the walls of an orifice in order that it may exercise a marked influence on the expenditure ? According to what law, when this influence is abstracted, does the contraction vary with the height of the liquid and the diameter of the orifice? Supposing the diameter given, what is the pressure at which the fluid vein changes into a secondary vein, and that at wiiich the flow ceases to be con- stant ? How does the pressure capable of separating a fluid vein from the sides of a cylindrical tube vary with the diameter, the length of the pipe, and the elastic force of the surrounding air ? Finally, what length must we give to a cylindrical pipe of a deter- • See his papers. Memoirs of the Irish Academy, vol. vii. + I demoostrated in the first memoir on the flow of liquids through pipes, that when we increase the velocity of the liquid which issues from a pipe which it fills, the liquid vein detaches itself from the inside of the pipe, even when the elastic force of the medium in which the flow takes place is very superior to the weight of the liquid contained in the pipe. — (Note of M. Hachette.) 1817.] Proceedings of Philosophical Societies. 221 tninate diameter to obtain the maxitnutn of expense ? These are so many problems which we will propose with confidence to M. Hachette. We think that, in engaging him to continue this kind of researches, the Academy ought to approve of his memoir, and order it to be printed in the Recueil des Savans Etrangers.* Article X. Proceedings of Philosophical Societies. ROYAL ACADEMY OF SCIENCKS. Analysis of the Labours of the Royal Academy of Sciences of the Institute of France during the Year 1816. Physical Part. — By M. le Chevalier Cuvier, Perpetual Secretary. (Continued from p. 148.) BOTANY AND VKGETABLE PHYSICS. One of the most important botanical considerations, and which connects it more than any other branch of natural history with the physical sciences in general, is vegetable geography, or the science of the laws of the distribution of plants according to the height of the pole, the elevation of the soil, the temperature, and the dryness or moisture of the climate. M. de Humboldt, whose travels have advanced so remarkably this branch of knowledge, as well as several others, has just pub- lished a kind of complete treatise of it, under the title of Prolego- mena de Distributione Geographica Plantarum secundum Coeli Temperiem et Altitudine Montium,t a work in which he gives at the same time profound researches on the distribution of heat, whe- ther relative to the position of places, or to the seasons of the year. For not only the lines under which the mean annual temperature is the same are far from being parallel to the equator ; but the places which have their whole mean heat equal are far from having their summers and winters similar. This mean heat may be more or less unequally spread through the whole of the year, and it is obvious • In a third memoir I shall examine the motion of viscid liquids, I shall com- pare with each other the liquids of this kind which we obtain by dissolving in water gum, sugar, soap, glue, mucilage, &c. Bringing all these liquids to the nme drnsity, 1 shall measure the velocity of their flow, the ditference of which Will depend in that hypotheiis on the adherence of the particles of liquid (o each other, and to the sides of the vessel. M. Petit and myself have ascertained, by an observation on the refraction, that when a liquid flows in a glass prism, taking care that the sides of the prism are cot altered by the motion, the density of the liquid is the fame, whether in a • late of rest or motion. — H. C. t Paris, 1817, one volume, 8vo. 5 222 Proceedhigs of Philosophical Socielies, [Sbpt^ that all these differences ought to have considerable influence on the propagation of plants. The author then passes to the differences which result from tlie elevations, which differ considerably, and follow different laws in different places. Finally, M. de Humboldt comes to a consideration quite new, on which he has likewise pub- lished a dissertation in French ; namely, that of the distribution of vegetable forms. On comparing in each country the number of plants of certain well-determined families with the whole number of vegetables, we discover numerical ratios of a striking regularity. Certain forms become more common as we advance towards the pole ; while others, on the contrary, augment towards the equator. Others acquire their maximum in the temperate zones, and dimi- nish equally by too much heat and cold : and, what is remarkable, this distribution remains tlie same round the whole globe, following not the geographical parallels, but those which M. de Humboldt calls isoihermic ; that is, lines of the same mean temperature. These laws are so constant, that, If we know in a country the number of species of one of the families, of which M. de H. has given a table, we may nearly conclude from it the total number of plants, and that of the species of each of the other families. The prolegomena of which we have just spoken are placed at the licad of the great work which M. de H. is at present publishing with MM. Bonpland and Kunth, on the new plants which he dis- covered in South America. This augmentation, the richest perhaps and most brilliant which botany has received at any one time, will be explained in six quarto volumes, which will contain 600 plates, and descriptions of more than 4000 species. MM. de Humboldt and Bonpland have published at the same time the conclusion of their description of the Melastomes, a work externally more magni- ficent, but which could not be followed for the remaining plants without inducing an expense and a delay prejudicial both to the science and to those who cultivate it. In collecting thus without interruption the immense products of the great and laborious enterprise of this illustrious traveller, the friends of the sciences are in doubt whether they owe more gratitude to the courage which supported him amidst so many reverses and fatigues, or the perseverance which he has shown in communicating the result of his acquirements. Even at present M. de Humboldt is publishing in London, along with Mr. Horner, a quarto volume, which will exhibit 300 species of mosses, lichens, and other cryptogamous plants. He has pre- sented one of the plates to the Academy. M. de Beauvois, whose perseverance is equally deserving of praise in publishing the plants and insects collected in his travels, has given this year the 14th and 15th parts of his Flora of Owara and Benin ; and not satisfied with these ancient collections, he has taken advantage of the remarkable and disagreeable wetness of this year to prosecute the study of the fungous family of plants. The constant rains brought so many of them forward, that several pre- 1817.3 B.oyal Academy of Sciences. 223 sented themselves which had escaped preceding botanists, even the roost successful in that kind of study. For example, a variety of sclerotiiim, winch reduced the crop of kidney beans vvitliout branches to nearly a third of the usual quantity ; a new species of spheria, which injured the onions very much ; a new species of uredo, which was still more pernicious to them ; and, what is remarkable, and offers few examples in the vegetable kingdom, a new species of parasitical plant, which grows upon another parasitical plant, and injures the vegetable considerably, which is obUged to nourish them both. It is a species of tubercle, which fixes itself above the root of the orobanche racemosa, which is known to grow parasitically upon hemp. This tubercle possesses characters which makes it ap- proach to trufles and to sclerotium ; but with distinctions, which constitute it a new and intermediate genus. As M. de Beauvois proposes next year to repeat his observations on this very remarkable plant, he has deferred assigning it a name till he has more accu- rately determined its manner of growing, and all the details of its organization. It is known that the family of dipsaceae, such as the scabiosa, are very near the composite plants in several characters of their flower and their fruit. The most obvious mark of distinction is, that their antherae are entirely free. Botanists have discovered some plants with flowers formed equally of several smaller flowers, whose an- therae are united by their lower part only. It was doubtful in what place to arrange them. M. Henry de Cassini, who examined them as a sequel to his great work on the family of synanthercce, or com- posite plants, of wiiicli we have had occasion to speak several times, has found that they difler from the synanthereee, because their an- therae have no appendices at the summit, because their style and stigma have a different formation ; because the seed is suspended at the summit of the cavity of the ovarium, and contains a thick and fleshy albumen. They differ from the dipsaceae by having their antherae united below, and by their alternate leaves ; but the most part of their other characters are common with these two families. In consequence M. de Cassini thinks that a distinct family may be made of them, which will serve lo connect the two others, and which he distinguishes by the name of hoopidece. It will compre- hend the genus calycera of Cavanilles, boopli and lackarpha of M. de Jussieu. We announced last year the opinion of M. de Candolle respecting that injurious substance called ergot (the spur), and which shows itself upon the spike of rye, and of some other corns, especially in moist countries and seasons. The year 1816", unfortunately, pro- duced a great deal of it ; and M. Virey has made some researches •on it, which lead him to consider the ergot, according to the old opinion, as a degenenicy in tlie grain, and not as a fungus of the genus sclerotium, as is the opinion of M. de Candolle. He says that he has ohserved grains infected with the s/jiir, which not only preserved their natural form, but which still continued to display 224 Proceedings of Philosophical Societies. [Skpt, the remains of stigmata ; and he mentions the assertion of M. Tessier, that we often observe grains one half of which only is in- fected, and sometimes tlie half towards the summit, sometimes to- wards the base. M. Vauquelin has made a comparative analysis of healthy rye, infected rye, and of a sclerotium well defined as such. In the infected grain we Snd neither starch nor gluten in their natural state, though it contains a mucous matter, and abundance of a vegeto-animal matter disposed to putrefaction. It contains a fixed oil quite formed. The principles of sclerotium are very diffe- rent. These experiments, without being decisive, have induced some persons, as well as M. Virey, to hesitate whether the ergot be a fungus. M. Gail, Member of the Academy of Belles Lettres, has com- municated to us some critical inquiries relative to the plants men- tioned by Theocritus. The object of them is not so much to deter- mine the species as to explain why Theocritus came to give them certain epithets, or to make certain comparisons respecting them. They are of course as much philological as botanical ; and the public will know them more in detail by the analysis of the Academy to which that celebrated Greek scholar belongs. ZOOLOGY, ANAT03IY, AND ANIMAL PHYSIOLOGy. Animals have likewise their geography ; for nature confines each species within certain limits, by ties more or less analogous to those which confine vegetables. Zimmerman formerly published a work on the distribution of animals, which was not destitute of celebrity. Latreille has just published one on the distribution of insects. It is obvious that it must be intimately connected with that of plants ; and in reality we find upon the mountains of a warm country the insects that inhabit the plains of colder countries. The difference of 10 or 12 degrees of latitude occasions always at an equal height particular insects ; and when the difference amounts to 20 or 24 degrees, almost all the insects are different. We observe analogous changes corresponding to the longitude, but at distances much more considerable. The old and new world have different genera of insects which are peculiar to each. Even those which are common to both present appreciable differences. The insects of the countries surrounding the bason of the iVIediterranean, and those of the Black Sea and of the Caspian ; those likewise of a great part of Africa have much analogy with each other. Tiiese countries constitute the especial domain of the coleoptera, which have five articulations in the four anterior tarsi, and one less in the two that are situated behind. America presents, besides the insects that are peculiar to her, a great number of herbivorous insects, such as chrysomeles, charan- sonSf cassides, capricornes, hutiei-flies, &c. Those of Asia beyond the Indus have a great affinity both in the families and genera of which they constitute a part. The species of New Holland, though 1817-] Royal Academy of Sciences. 225 near the Moluccas, differ notwithstanding in essential characters. The islands of the South Sea and of South America appear to show in this respect some general relations, while the entomology of Africa exhibits an essential contrast in several points with that of South America. In the western parts of Europe the domain of southern insects appears very distinctly as soon as in going from north to south we come to a country favourable to the cultivation of the olive. The presence of the lousier sacre and of scorpions announces this re- markable change of temperature. But it does not take place in North America till we approach four or five degrees nearer the equator. The form of the new continent, the nature of its soil and climate, produce tliis effect. M. Latrellle then explains a new division of the earth by climates. Greenland, though very near America, appears from the fauna given by Otho Fabricius, to approach more in this respect to northern and western Europe. We may at least consider Green- land as a country intermediate between the two worlds. On this account M. Latreille takes it as a position for his first meridian, which, passing 34° west from that of Paris, proceeds into the Atlantic Ocean, and terminates at Sandwich Island, in the 60th degree of south latitude, the ne plus ultra of our discoveries towards the ant- arctic pole. This meridian, setting out at 84° of north latitude, the last approximative term of vegetation, and proceeding to 60° of south latitude, is cut at every 12 degrees, by circles parallel to the equator. The intervals form as many climates, which M. Latreille distinguishes by the names oi polar, subpolar, superior, intermediatey supertropical, tropical, and equatorial. But as the insects of America differ specifically from those of the ancient continent, and as the insects of Eastern Asia (beginning at the bason of the Indus) appear distinct in several general relations from those of the western parts, M. Latreille in the first place divides the two hemispheres by an- other meridian, which he places at 182° east from that of Paris, and then divides each continent into two great portions by means of two other meiidians; the one is 62° further west than Paris, and passes on the western limits of the bason of the Indus ; the other cuts America 106° west from Paris, and cuts off that part of the continent which lies nearest Asia, and perhaps approaches it most in the nature of its productions. The two hemispheres are thus divided longitudinally into two zonts, the one oriental, the other occidental. All Paris had it in its power to see a woman brought from the Cape of Good Hope distinguished by the name of the Hottentot Venus. She belongs to a nation in the interior of Africa celebrated among the colonists at the Cape for its ferocity, and which the barrenness of the country that they inhabit, and the persecutions of the people in their neighbourhood, contribute equally to render miserable. The smallness of their size, the peculiar sliape of their Vol. X. N° IH. P 226 Proceedings of Philosophical Societies. [Sept heads, the yellowness of their skin, and particularly the enormous size of the hips in the women, seem to render them a very distinct race from the negroes and caflFrees by whom they are surrounded. A great deal has been said about the apron of these women, which the first travellers described very inaccurately, while recent voyagers have gone so far as to deny its existence altogether. The woman of whom we have spoken having died in Paris, M. Cuvier had an opportunity of dissecting her, and of determining the peculiarities of her structure. She possessed the apron ; but it was neither a fold of the skin of the belly, nor a peculiar organ. It was only a considerable prolongation of the upper part of the nymphae, which fell over the opening of the vulva, and covered it entirely. The protuberance of the hips is composed of a cellular matter, filled with fat, nearly similar to the bunch on the hack of camels and dromedaries. The skeleton preserves no traces of it, unless it be a somewhat greater size of the edges of the pelvis. The head exhibited a singular mixture of the characters of the negro and of those of the Calmuc. Finally, the bones of the arm, re- markable for their smallness, exhibit some distant relations with those of certain apes. One of the most formidable serpents after the rattlesnake Is the yellow viper, or fer-de-lance, of Martinique and St. Lucia, or> which M. Moreau de Jonnes has read to the Academy an interest- ing memoir. Naturalists at present place it among the trigono- cephali, characterized by the pit situated behind the nostrils. It fills the principal of the colonies that remain to us. Some afBrm that it was formerly brought there out of hatred to the Carabees by the Arrouages, a little people on the borders of the Oronoko — a tradition which might explain why it has remained unknown in the other Antilles. From the sea shore to the top of the Mornes we are exposed to its attacks ; but its principal refuge is among the sugar-canes, where multitudes of rats serve it for food, and where it is propagated with a rapidity proportional to the number of its young, which amounts to 50 or 60 at a time. Its length is some- times more than six feet. Vain attempts have been hitherto made to destroy these vipers by pursuing them with English terriers. M. Jonnes proposes to try against them that bird of prey with long legs called messager or secretaire [falco serpentariiis, L.), which devours so many serpents in the neighbourhood of the Cape of Good Hope; and the administration has already thought of transporting this useful species to Martinique. Probably the mangouste would not render less important seivices. {To be continutd.) 1817.] Scientific Intelligence. 227 Article XI. SCIENTIFIC intelligence; and notices of subjects CONNECTED WITH SCIENCE. I. Lectures. Medical School, St. Bartholomew's Hospital. — The following Courses of Lectures will be delivered at this hospital during the en- suing winter, to commence Oct. 1 : — On the Theory and Practice of Medicine; by Dr. Hue. — On Anatomy and Piiysiology; by Mr. Abernethy. — On the Theory and Practice of Surgery; by Mr. Abernethy. — On Chemistry and Materia Medica ; by Dr. Hue. — On Midwifery; by Dr. Gooch. — Practical Anatomy, with Demonstrations ; by Mr. Stanley. St. Thomas's and Guy's Hospitals. — The usual Courses of Lec- tures given at these Hospitals will commence the beginning of October, viz. : — ^t St. Thomas's. — Anatomy, and Operations of Surgery ; by Mr. Astley Cooper and Mr. Henry Cline. — Principles and Practice of Surgery ; by Mr. Astley Cooper. At Guy's. — Practice of Medicine ; by Dr. Curry and Dr. Cholmeley. — Chemistry ; by Dr. Marcet and Mr. Allen. — Experi- mental Philosophy; by Mr. Alien. — Theory of Medicine, and Materia Medica; by Dr. Curry and Dr. Cholmeley. — Midwifery, and Diseases of Women and Children ; by Dr. Haighton. — Phy- siology, or Laws of the Animal Economy ; by Dr. Haighton. London Hospital. — Lectures on the following subjects will be given at this hospital, to commence in October : — Anatomy and Physiology; by Mr. Headington. — Surgery; by Mr. Headington. — Midwifery ; by Dr. Ramsbottom. — Chemistry ; by Mr. R. Phillips. — Materia Medica and Pharmacy; by Mi. R. Phillips. Middlesex Hospital. — Dr. P. M. Latham and Dr. Southey will begin their Lectures on the Practice of Physic and the Materia Medica at this hospital, in the first week of October.— Dr. Merri- man and Dr. Ley will commence their Lectures on Midwifery, and the Diseases of Women and Children, as usual, early in the month of October. Mr. Clarke will commence his Course of Lectures on Mid- wifery, and the Diseases of Women and Children, on Monday, Oct. 6. The Lectures are read every morning, from a quarter past ten to a quarter past eleven, for the convenience of students attending the hospitals. Dr. Davis will commence his first winter Course of Lectures on the Theory and Practice of Midwifery, and on the Diseases of Women and Children, Oct. 7, at six o'clock in the evening. Dr. Clutterbuck will begin his Autumn Course of Lectures on p 2 228 Scientific Intelligence, [Sew, the Theory and Practice of Physic, Materia Medica, and Chemistry, on Friday, Oct. 3, at ten o'clock in the morning, at No. 1, in the Crescent, New Bridge-street, Blackfriars. — Pupils are admitted, as . usual, to attend the medical practice of the General Dispensary, Aldersgate-street, and, when qualified, to visit the patients at home. — Clinical Lectures on the most interesting cases that occur will be given at the Dispensary by the Physicians in rotation. Mr. Good's Course of Lectures on Nosology, Medical Nomen- clature, and the Theory and Practice of Medicine, will commence on Monday, Sept. 29, 1817, at the Crown and Rolls Rooms, Chancery-lane. The Course will extend to rather more than three months, and be repeated three times a year. From the compre- hensiveness of the subject, a Lecture will be given daily, instead ot every other day, as is the common practice. The Introductory Lecture will commence at half past three o'clock in the afternoon; the subsequent Lectures at eight in the morning. Dr. Adams will commence his Course of Lectures on the Insti- tutes and Practice of Medicine early in October, at No. 17, Hatton Garden. Mr. R. Phillips will commence a Course of Lectures on Che- mistry at No. 66, Cheapside, on Oct. 6, at seven o'clock in the evening. II. Ores of Cobalt. The principal ores of cobalt, known in Germany by the names of kobaltglanz and speiskohalt, are of a very complicated nature ; and the analyses of them by different chemists differ so much from each other, that there is reason to suspect them not to be chemical compounds, but rather mechanical mixtures. Cobalt glance crys- tallizes in cubes, and appears to contain about seven per cent, of iron pyiites. Bernhardi announced long ago his opinion that this small portion of pyrites gave its crystalline form to the cobalt ore ; for it is universally known that the primitive form of iron pyrites is a cube ; and it has been repeatedly observed that a very small quan- tity of one mineral gives its crystalline form to a very large quantity of another. Thus the gres de Fontainbleau has the crystalline form of calcareous spar, though sometimes the quantity of carbonate of lime which it contains is very small. In like manner it was observed by Bucholz that about three parts of proto-sulphate of iron give their own crystalline form to 1 00 parts of sulphate of zinc. Stro- meyer and Gehlen have announced that arragonite owes its crystal- line form to the small quantity of carbonate of strontian which it usually contains. Stronieyer has lately subjected glance cobalt and speiscobalt to a new and very careful analysis, in order to determine their constitu- tion. He found a specimen of tliis ore from Skutterud, in Modum- kirchspiel, Norway, of the specific gravity 6*2316, composed as follows :— 1317.] Scientific Intelligence, 229 Arsenic 43*4644 Cobalt 33-1012 Iron 3-2324 Sulphur 20'0H40 99-8820 or of — Sulphuret of cobalt 49-3852 Persulphuret of iron 7-0324 Arsenic 43*4644 99-8820 If the sulphuret of cobalt be a compound of one atom cobalt and two atoms sulphur, then tbe above analysis indicates seven atoms of sulphuret of cobalt, one atom of persulphuret of iron, and about eight atoms of arsenic. According to Stromeyer's analysis, crystallized speiscobalt from Riegelsdorf, in Hesse, of the specific gravity 6-149, contains the following constituents : — Arsenic 74-2174 Cobalt 20-3135 Iron 3-4257 Copper 0-1586 Sulphur 0-8860 99-0012 or — Arseniuret of cobalt 51-6978 Arseniuret of iron 9-1662 Persulphuret of iron 1 -5556 Sulphuret of copper 0-2046 Arsenic 36-3770 99-0012 I suspect that Professor Stromeyer's statement of the proportions in which cobalt and iron unite with arsenic are rather hypothetical. Arsenic is one of the substances which requires further elucidation before it can be made to accord properly with the atomic theory. Our present knowledge indicates 4-75 as its weight ; but on that supposition the oxygen contained in both its acids must be repre- sented by fractionable numbers ; for arsenious acid is a compound of Arsenic 4-75 Oxygen 1'5 and arsenic acid is a compound of Arsenic 4*75 Oxygen 2-3 Now to make tiiese numbers accord with the atomic theory, we might suppose that arsenious acid is a compound of two atoms 230 Scientific Intelligence. [Sept. arsenic and three atoms oxygen, and arsenic acid of two atoms arsenic and five atoms oxygen. But from the constitution of arseiiiate of lead and arseniate of lime, both of which are accurately known, there can be no doubt that the equivalent number for the weight of an atom of arsenic acid is 7'25. As these determinations do not accord with the above numbers given by Stromeyer, 1 may state here what the composition of speiscobalt ought to be according to his experiments: — Arseniuret of cobalt 46'*92 Arseniuret of iron 6*36 Persulphuret of iron 1*55 8iilphuret of copper 0*20 Arsenic 44*35 99-38 In the course of his experiments Stromeyer satisfied himself that the best mode of separating arsenic from iron is by a current of sul- phureted hydrogen gas. When the arsenic is acidified, and thrown down by means of a salt of lead, it carries along with it some arseniate of iron. He satisfied himself, likewise, that cobalt can- rot be freed from iron, either by means of caustic ammonia or car- bonate of ammonia. The best process for separating these two metals is the addition of some oxalic acid, a method first employed by Tupputi. The whole of the oxalate of cobalt is thrown down, while the oxalate of iron remains in solution. III. Register of the Weather at New Malton, in Yorkshire. March, I817.— Mean pressure of barometer, 29-60; max. 30-30; min. 28-10. Range, 2-20 in. Spaces described by the curve, 8-92 in. Number of changes, 20. — Mean temperature, 4050°; max. 58°; min. 24°. Range, 34°.— Amount of rain and snow, 0-81 in. Wet days, 5. Prevailing winds, S and W. N, 2. SE, 1. S, 7. SW, 7. W, 10. NW, 2. Var., 2. Number of brisk winds, 5. Boisterous, 3. — Character of the period : clear, dry, and cold. April. — Mean pressure of barometer, 30-221; max. 30-65; min. 29-60. Range, 1-05 inch. Spaces described by the curve, 6-27 in. Number of changes, 19. — Mean temperature, 44-66°; max. 62° ; min. 27. Range, 35°. — Amount of rain and snow, p-41 inch. Wet days, 2. Prevailing wind, N. N, 14. NE, 2. E, 1. SE, 1. S, 1. SW, 1. W, 5. NW, 4, Var., 1. Number of brisk winds, 3. Boisterous, 1.— Character of the period : dense, fair, and dry, with a very low temperature. Maij. — Mean pressure of barometer, 29-630 ; max. 30-34 ; ihin. 29-15. Range, ]-19 in. Spaces described by the curve, 6-14 in. Number of changes, 13. — Mean temperature, 48*75°; max. 64°; min. 33°. Range, 31°— Amount of rain, 1-88 in. Wet days, 8, Prevailing wind, northerly. N, 8, NE, 5, SE, 2. 18170 Scientific Intelligence. 231.' jS, 3. SW, 6. W, 2. Var., 5. Number of brisk winds, 5- Boisterous, 3. — Character of the period : cold and changeable, with a thick and cloudy atmosphere for the most part. June. — Mean pressure of barometer, 29'6B4 ; max. 30*32; min. 28*85. Range, VA'J in. Spaces described by the curve, 7'46 in. Number of changes, 15. — Mean temperature, 69-50°; max. 82°; min. 42°. Range, 40°. — Amount of rain, exactly 4 in. Total this year, 9*75 in. Wet days, 15. Winds, light and varialile. NE,3. E,3. SE, 3. S, 5. SW, 8. W, 3. NW, 1. Var., 4. Number of brisk winds, 3. Boisterous, 2. From the commencement of this month to the new moon (the 14th) the weather was uncommonly wet, with scarcely an interval of a fair day ; and, the temperature having twice risen a little above the regular maximum, was followed by thunder storms. On the 10th the lightning was extremely vivid; and the thunder, which almost instantly followed it, was the loudest that has been heard here for several years. The wind during this storm veered to every point of the compass in less than an hour. From the 13th to the 18th there was a regular increase of temperature, and a similar de- crease of pressure. On the 19th the thermometer, from one to nearly four, p. m. indicated 80° ; and from seven to eleven in the evening the lightning, which at this place was not accompanied with thunder or rain, was vivid and incessant. The thermometer indicated 82°, the maximum of the period, on the 20th ; 80° on the three following days ; and 7*-*° on the 25th. In the afternoon of this day we had another thunder storm, with a few flashes of vivid lightning, and the greatest fall of rain, for the time it continued, perhaps every remembered here, the amount, as measured from the gauge in about 35 minutes, being equal to a full inch and a quarter. The temperature and pressure again decreased ; and heavy showers, with distant thunder at intervals, closed the period. JfewMaUon,Juli/l, 1817. J. S, IV. Explosion in a Durham Coal-pit.* It is with feelings of the most painful nature that we this week find it our melancholy duty to record one of those awful calamities under which this part of the country has so severely suiFered, but from which we had fondly hoped that the discoveries of science had nearly relieved us. On Monday last, the 30th ult. about eleven o'clock in the forenoon, the carbureted hydrogen gas in the Row Pit, at Harraton Colliery, on the River Wear, unfortunately ignited, when, our readers will learn with regret, that no fewer than 38 men and boys lost their lives from the violence of the blast. It is described to us as one of the most violent explosions • Copied from the Newcastle Chronicle of July 5. 5 232 Scientific Intelligence. [Sept. which has happened for years ; corves, trams, and several utensils used at the bottom of the pit, being blown into the air, together with the bodies of two of the unfortunate workmen, one with the head off, and the oiher cut in two in tl)e middle. There were 41 workmen down the pit at the time of the explosion ; 38 of these have perished, as we have stated ; the remaining three are expected to recover. All the sufferers, except one from Fatfield, belonged to New Painshaw, and were l)uried there on Wednesday afternoon. Amongst them were ten belonging to one family, viz. the grand- father, his two sons, and seven grand-sons. On Tuesday a Coro- ner's Inquest was held upon the bodies, when, after a patient inves- tigation, the Jury returned a verdict, " that the deceased had got their deaths by an explosion of fire-damp, occasioned by the using of candles instead of the safety lamps, contrary to orders given." — Upon so delicate a subject as the origin of this melancholy accident, we feel ourselves unwilling to say much ; but as some notice of it may be expected by our readers, we shall merely state that we un- derstand, from the best authority, it appeared to the Jury that the part of the pit in which some of these men had been set to work that day was not clear of fire-damp. This circumstance was parti- cularly impressed upon them, and they were expressly ordered to use their safety lamps ; and to show to them more clearly the neces- sity of using them, one of the overmen went with a lamp a little in advance of where they were to work, to prove to them that some portion of fire-damp was in their neighbouihood. One man, how- ever, was found who would not attend to these directions, but used a lighted candle, for the workmen prefer a candle to the safety lamps, on account of its giving a greater light. When perceived by the overman, he was instantly ordered to extinguish his candle and light his lamp, which he did. A short time after he was found by the overman again using his candle ; for this he was most severely repiimandcd, and ordered to light his lamp. This he did, but the overman had not long left him when the explosion took place in that part of the pit where this man was working ; he was one of the sufferers, and it is therefore only conjecture that he had again re- verted to the use of his candle. But the painful narrative does not close here : on Wednesday afternoon some of the workmen went into the Nova Scotia Pit of the same colliery, to repair some part of the pit which had been injured by the explosion in the Row Pit on Monday; and not re- turning in time, another party of the men went down to seek them, but were obliged to return without effecting their object, being un- able to proceed, on account of the great quantity of choke-damp which had entered the workings, supposed from the Row Pit, sub- sequent to the explosion. The eight workmen who had first gone down were obliged, therefore, to be left to their fate. Their bodies wert' got out late on Thursday evening; six of them were quite dead j two were still alive, but there were little hopes of recovery. 18170 Scientific Intelligence. 233 V. Explosion on Board a Coal Vessel.^ On Friday night, July 4, as ihe master of a Scotch sloop lying in theTyne, and just laded with coals, was going to bed, his candle unfortunately ignited a quantity of gas which had collected in the state room, and produced a slight explosion, by which his face and hands were much burnt, and the curtains of his bed set on fire, but they were soon extinguished ; another person was also, we under- stand, much burned. What renders this circumstance the more curious is, the coals were by no means fresh from the pit. VI. Coal in Russia. An attempt to raise coal is now about to be made in Russia, under the immediate patronage of the Emperor. The spot fixed upon for this purpose is in the vicinity of Tula, celebrated for its extensive iron-works. Tula is the capital of the government of that name, distant from Moscow 115 miles, and situated on the river Upha, in long. 37° 24' E. and lat. 54° 10' N. All the measures were con- certed in London with his Excellency Count Lieven, the Russian Ambassador ; and on June 20 Mr. Loiigmire, of Whitehaven, came to London, with an assistant draughtsman, and four pitmen, be- longing to Whitehaven, and two borers, previously engaged at Newcastle. They sailed from Gravesend, for St. Petersl)urgh, on July 1 — all their equipments for the voyage being on the most liberal scale. They are to winter at Moscow, excepting a few occasional visits to Tula, as the season may allow, and to commence operations as early after that as the climate will permit. VIL Query respecting the Matter concreted at the Bottom of Coppers. (To Dr. Thomson.) SIR, As I have observed with pleasure that your Annals of Philosophy is open to inquiries, however apparently tiivial, if at ail connected with science, allow me to request the favour of you, or any of your scientific readers, to say by what process can the concreted matter usually formed, in the course of time, at the boitom of coppers in general domestic use, and known by the name of ^er, or J ur, be dissolved, so as to leave the metal clear and open for the common methods of polishing and cleaning. With much respect, yours, July 24, 1817. A CONSTANT ReADEK. VIIL Experiment of Lampadius. I am indebted to M. Von Mons for an account of the following experiment of Lampadius, which he says is a decomposition of • From the Newcastle Chronicle of July 12. 234 Scientific Intelligence. [Sept. muriatic acid. Not being master of the particular views and opinions of M. Von Mons and M. Lampadius, I do not pretend to understand the drift of the experiment ; but I think it right to give it to my readers as I received it : — Into a forged iron tube he puts a mixture of two ounces of iron filings and one ounce of calcined charcoal. To the tube is adapted a Hessian retort containing a mixture of one ounce of fused common salt and two ounces of calcined sulphate of iron. The tube is con- nected with a pneumatic trough. He heats in the first place the tube to incandescence : then he raises the retort to a white heat. The products are carbonic acid, carbonic oxide, and carbureted hydrogen. The gases are extricated with such violence that they resemble an explosion. IX. Note respecting the Sugar of the Acer Pseudoplatanus. By VV. A. Cadell, F.R.S. At Carronpark, in the county of Stirling, on March J and 8, 1816, incisions were made through the bark of a great maple tree, the acer pseudoplatanus of Linnaeus, in Scotland called the plane. The tree was about 42 years old. The incisions were made in the bark of the trunk, five feet from the ground. The sap was quite transparent and colourless, and flowed freely, so as to fill in two or three hours a bottle capable of containing a pound of water. At night, the weather being cold, the sap froze, and liung from the bark in icicles. Three bottles and a half were collected, weighing in all S lb. 4 oz. Some days after this the flow of the sap from the incisions ceased entirely. In a few weeks after the tree was cut down. The sap was evaporated by the heat of a fire, and gave 214 grains of sugar, in colour resembling raw sugar; in taste sweet, with a peculiar flavour. After being kept 15 months, this sugar was slightly moist on the surface. The quantity of sap employed in the evaporation was 2496"0 gr. (3 lb. 4oz.) ; the quantity of sugar obtained from it was 214 gr. : therefore in smaller numbers 1 1(> parts of sap yielded by evapora- tion one part of sugar. July 25, 1817. W. A. CaDELL. X. Mineralogy and Geology. Part I. of a most extensive collection of minerals, consisting of numerous instructive duplicates collected during the last two years on the Continent, for the express purpose of advancing these sciences in this kingdom, by Professor H., a disciple of Werner's (in the suite of the Emperor) who has consigned them to be sold at 1*., 25. 6d., and 5^. each ; several hundred will be exposed to view at once, to obviate the trouble of opening drawers, and those of one price will remain separate from those of another. By Mr. Mawe, No. 14y, Strand. Persons desirous to add to their collections have, therefore, an opportunity of obtaining these rare substances at a very moderate expense. 18170 Scientific InlelUgence. 235 XI. Correction of a Mistake in the Epitonie of Mr. SoUi/'s Paper given in the Account of the Meetings of the Geological Society in the last Number of the Annals of Philosophy. By S. Solly, Esq. (To Dr. Thomson.) SIR, In transcribing your extract from the transactions of the Geolo- gical Society, an error has occurred, which I hope the following statement will enable you to correct. The short account of Finbo, which I drew up by desire of M. Suedenstierna, does not (as stated in your last number) assert that the granite containing the pyrophysalite, gadolinite, yttrotantalite, yttrocerite, thoride, &c. &;c. is situated in one of the ridges of granite gravel or sand oasen, but that it is surrounded by tiie usual varieties of the gneis, which I do not consider as a stratified rock. When the mica is very abundant, it generally runs in a particular direction ; but this appearance of stratification is continually inter- rupted by a granitic structure rising through the gneis, and crossing it in every direction. For a long time I considered the mica as indi- cating a dip of the gneis, as it very frequently rises towards the S.E. I expected to meet with older and lower strata in that direction; but these distinctions seem scarcely admissible among the crags of Scandinavia. The headland in which Finbo is situated terminates one of the southern ramifications of the granitic ridge which sepa- rates the basin of Lal 1 8h 35' 24° 31' 04" _h / o 1 (/ 7h 10' 24" 34' 27" 2 8 40 24 30 02 35 24 41 22 6 55 24 35 42 3 8 40 24 28 34 35 24 41 52 6 45 24 37 09 4 8 35 24 29 36 35 24 41 26 6 55 24 34 -6 5 8 35 24 31 00 35 24 43 28 6 55 24 35 05 6 — — — — — 35 24 40 55 6 55 24 33 35 7 S 35 24 31 32 35 24 42 06 6 55 24 35 00 8 8 35 24 30 38 35 24 39 32 6 55 24 34 09 9 8 30 24 30 50 35 24 40 49 6 55 24 35 05 10 8 35 24 31 26 40 24 39 42 6 55 24 35 52 11 8 45 24 31 33 40 24 43 07 6 55 24 35 23 12 8 40 24 30 34 35 24 41 39 6 55 24 34 53 13 8 35 24 32 13 40 24 42 52 6 55 24 37 33 14 8 30 24 34 03 30 24 42 12 6 55 24 35 34 15 8 40 24 32 46 35 24 42 09 6 55 24 34 44 16 8 35 24 30 34 40 24 36 52 6 55 24 35 41 17 8 35 24 33 05 40 24 42 14 6 55 24 35 19 18 8 35 24 30 42 ^ 35 24 40 34 6 55 24 36 05 19 8 40 24 32 01 45 24 38 55 6 55 24 33 28 20 8 35 24 30 28 35 24 43 31 6 55 24 35 45 21 8 40 24 31 12 40 24 43 02 6 55 24 36 09 22 8 35 24 31 16 30 24 44 26 6 55 24 35 09 23 8 35 24 32 08 40 24 42 44 6 55 24 34 18 24 8 35 24 32 57 40 24 42 35 6 55 24 34 09 25 8 35 24 31 55 35 24 43 28 7 05 24 34 13 26 8 35 24 28 SO 30 24 43 17 6 50 24 34 24 27 8 35 24 31 42 35 24 43 06 6 50 24 33 55 28 8 40 24 32 09 35 24 43 17 6 50 24 33 44 29 8 30 24 30 57 40 24 42 42 6 55 24 34 33 30 8 35 24 31 17 35 24 44 46 7 00 24 34 35 31 8 30 24 30 28 35 24 44 25 7 00 24 37 16 Mean for Month. JS 36 24 31 14 1 36 24 42 06 6 55 24 35 45 July 1. — ^The needles vibrated 21 '00' between the noon and evening observation. July 27. — The needles at the morning observation vibrated 12" 30", which was followed by thunder and rain. 1817.] and Meteorological Talks. Meteorological Table. 237 Month. Time. Barom. Ther. Hyg. Wind. Velocity. Weather. Six's. Inches. Feet. Morn 29-302 60° 63=" SE [lazy 52 July 1 \ Voon. . . . 29-163 57 88 SE 14-657 [tain 59 / Even .... 28-985 58 65 S\V Drizzle :-55 Morn. . . . 29-153 57 66 wsw Showery "\ JJoon. . . . 29-305 63 51 w 40-410 Cloudy 6S Even 29-412 61 49 W bv S Very fine \- Morn. . . . 29-478 58 64 sw Cloudy s) Noon. . . . 29-456 60 53 ssw 10-963 Cloudy 6S Even .... 29-345 61 60 E Showery ■ 55 Morn 29-157 57 88 SW by S Showery 4) Noon 29-173 f.3 61 SW by S 14-855 Fine 63 Even 29-1.58 59 63 WSW Showery I 54 Morn.... 29-107 58 70 NW by W Cloudy 5^ Noon. . . . 29 150 63 58 NW 10-628 Showery 63 Even .... 29-230 51 73 W Showery }M Morn .... — — — — — oi Noon.. . . 29-255 66 54 SW by W 17-569 Fine 6T Even .... 29-263 59 63 W by S Showery |50 Morn. . . . 29-323 59 60 WbyS Fine ') Noon. . . . 29-317 66 49 W 15-26S Fine 6T Even .... 29 325 61 53 WbyS Fine |50 Morn. . . . 29-400 60 52 W by N Fine s] Noon. . . . 29-402 65 44 W by N 13-619 Fine 6T Even .... 29-414 61 47 WNW Cloudy 5=3 Morn .... 29-430 61 55 W Fine 9-| Noon, . . . 20-430 68 44 W 7-027 Sultry 70 Even .... 29-423 63 52 WSW iSuItiy |55 Morn.. . . 29-400 63 50 SE Very fine lO-J Noon 29-370 71 41 Var. 7-034 Cloudy 75 Even . . . . 29-355 64 62 SW by W Showery I 56 Morn. . . . 29-345 61 74 SW S:iowery J "1 Noon... . 29-337 67 54 SW 16-477 ICIoudy 67 Even . . . . 29-335 62 57 WSW [Shovpcry |56 Morn 29-423 57 80 NWby N Showery 12^ Noon 29-490 63 62 N 5-154 Cloudy 66 Even . . . . 29 520 63 58 Calm V^ery fine }" Morn.... 29-544 61 54 SSW Fine 13-| Noon. . . . 29-527 63 52 W 17-548 Cloudy 66 Even . . . . 29-443 58 68 WSW ■showery J50 Morn 29-380 56 69 SW by W Cloudy u-j Noon. . . . 29-165 63 58 Var. 9-511 Sliowery 63 Even . . . . 29-150 57 60 WbyS IShowery }» Morn 28-800 54 78 WSW Fine 15< Noon 28-784 61 57 SW 13-033 Showery 63 Even ... 28-765 56 65 NNR Showery }« Morn 29172 54 59 NNW Fine 16< Noon. . . 29-263 59 49 NWbyN 19-800 Cloudy 62 Even . . . 29-323 58 rA NW by N Fine (40 Morn . . . 29-400 56 57 NW Cloudy 17S Ncion... 29-425 61 48 WNW 14-133 Fine " 61 Rven . . . 29-407 57 55 WSW (yloudy f- f \lo-n... 29-365 59 63 NNW Fine I8< Voon. ■ • 29-400 61 .52 NW 15-691 Fine 65 I l-ven . . 29-435 58 54 NW Fine 238 Col. Beaufoy's Meteorological Talk. [Sbpt. Meteoroloo'ical Table continued. Month. Time. Barom. Ther. H.Yg. Wind. Velocity, Weather. Si.-t's. July Inches. Feet IMorn 29-500 58° 55° NW Fine 49» 19 ) Noon,... 29'50() 63 50 WNW 12-124 Fine 65 Even . . . . 29-500 61 50 WNW Very fine }" Morn 29-545 60 50 WNW Fine SO^ Noon .... 29-540 64 47 W 14-500 Cloudy 65 Even . . . . 29540 57 65 sw Rain }54 Morn 29-468 58 79 SW by S Shovfcry 21 ^ain, " It is probable that the coarse and finer cinnamon, or the laurus cinnamomum and casia, are merely different varieties, arising from tlie climate, and especially from the soil." Mr, Forbes, in his Oriental Memoirs, seems to have also con- founded the two plants, and applies the term casia to the laurus cinnamomum. His words are : " The leaves of the casia are smaller than the laurel, and more pointed. Those of the cinnamon still more delicate ; the blossoms of both, like the flowers of the arbutus, hang in bunches, white, and fragrant ; the fruit resembles an acorn. The young leaves and tender shoots are of a bright red, changing to green as they approach maturity ; they taste of cinna- mon," &c. This is an exact description of the cinnamon-tree, not of the laurus casia. The dried leaves of the cinnamon-tree have an olive-yellow colour. They are shining and glossy ; thick, crisp, and durable ; the three nerves are protuberant on the inferior side of the leaf; they endure for several weeks the heat and rains of a tropical cli- mate, without losing their spicy aromatic taste; they have in a con- siderable degree the acridity and flavour of cloves. Commelinus informs us that they afford oil of cloves by distillation. They give an excellent simple, and spirituous water, and an essential oil, according to Dr. Dancer. In Cayenne they are employed in the distillation of rum, to improve its flavour. Is the leaf of the cinnamon-tree the malabathrum folium or folium indicum of the ancients ? Tamala patra is the Sanscrit appellation for cinnamon, of which term malabathrum seems to be only a varied pronunciation, or slight corruption. I am aware that some authors are of opinion that the malabathrum folium is the produce of the laurus caryophyllus, laurus kulit cawang, and that others assert that it is the leaf of the piper betel. The leaf of the piper betel does not possess the qualities ascribed to the folium indicum. When fresh pulled the betel leaf is soft and succulent, and very soon loses its acrid quality. By drying, it be- comes thin, flexible, tasteless, and inodorous. The natives rarely use it when more than two or three days pulled. The malabathrum was held in high estimation by the Greeks and Romans as a perfume, and it entered into the composition of their aromatic unguents. The casia bud of commerce is the fleshy hexangular receptacle of the seed of the laurus cinnamomum. When gathered young, the receptacle completely envelopes the embryo seed, which pro- gressively protrudes, but continues firmly embraced by the recep- tacle. The buds have the appearance of nails, with roundish heads of various sizes. If carefully dried, the receptacle becomes nearly black, and the point of the berry light-brown. The seeds contract by drying, and often fall out; the receptable is then cup-shaped. When long kept they have a dirty-brown colour, and possess very 5 246 Description of the Laurus Cinnamomiim. [Oct. little of the aromatic flavour of cinnamon. The Tamul name for casia buds is sirnayapoo or siniahapoo; Cingalese, kurunclu ettej Dutch, kassia bloemen ; French, fleurs de la cannelle. Casia buds possess the same properties with cinnamon, though in an inferior degree. By distillation they yield an essential oil, not inferior to that which is prejiaied from cinnamon. The confectioners use them in the composition of conserves. Casia buds are not prepared in Ceylon. By decoction, the ripe seeds yield a suety substance, which is perfectly inodorous, and has no very considerable degree of inflam- mability. The natives sometimes extract this substance, and employ it as a liniment for external bruises, &c. Cinnamon thrives best in a situation rather elevated, and in a sandy loam, mixed with the earthy remains of decayed vegetables. In the lubbisl.y soil near houses it is uncommonly succulent. The shelter afforded by buiUliugs appears to contribute to its luxuriance. '1 he gionnd tor plintiiig cinnamon is in the first instance pre- pared, by cutting down the low brush-wood and young trees. The lofty trees aie allowed to remain, as the cinnamon is observed to thrive better under their shade, when not too close, than when it is exposed to the direct rays of the sun. The brush-wood is collected into heaps, and burned. The planting commences when the seeds are ripe, generally during the months of June, July, and August. The workmen stretch a line upon the ground, along which they with a mammettee (hoe) turn up about a foot square of earth, at intervals of six or seven feet. The ashes of the burned shrubs and branches of trees are then spread upon the spots of friable earth ; and into each of them four or five cinnamon berries are planted with a dibble Branches of trees are spread upon the ground, to prevent the friable earth from being scorched, and to protect the young shoots. The young shoots appear above the ground in about 15 or 20 days. Sometimes the berries are sown in nurseries, and the shoots transplanted in the months of October and November. In favourable situations the shoots attain the height of five or six feet in about six or seven years; and a healthy bush will then afford two or three shoots fit for peeling. Every second year from four to seven shoots may be cut from a bush in a good soil. Thriving shoots of four years' growth are sometimes fit for cutting. As four or five seeds are sown in one spot, and as in most seasons many of the seeds germinate, the plants grow in clusters, not unlike a hazel bush. Jn seasons with little rain many of the seeds fail, and a great number of the yotmg shoots die; so that it is frequently necessary to plant a piece of ground several times successively. A plantation of cinnamon, even on good ground, cannot be expected to make much return before eight or nine years have elapsed. The plantations from which a considerable part of the cinnamon is procured are Kaderang, Ekele, Marendahn (Colombo), and Morutta. These are styled protected plantations, to distinguish them frojq^ 1817.] Descriptmi of the Lauras Cinnamomum. 247 a number of extensive fields that were planted with cinnamon by the Dutch, and which have since been permitted to be overrun with creepers, brush-wood, &c. and many of the cinnamon plants rooted up by the natives. Kaderang is situated in the neighbourhood of Negombo, and contains about 4,106 acres. A few small pieces of ground belong- ing to private individuals are included in this statement. A very considerable portion of this plantation is marshy and unproductive. There are about 1623 acres which bear cinnamon; and this number is annually increasing. Kaderang, on an average of ten years, pro- duces annually about 535 bales of cinnamon. Ekele is situated 10 miles north from Colombo, and contains about 1598 acres of ground of an excellent soil, which is not en- tirely planted; but the cinnamon is reckoned to be of the finest quality. The annual produce is about 341 bales. Marenrlahn is situated in the immediate vicinage of Colombo, and contains (including a number of small fields belonging to pri- va e individuals) about 3S24 acres of giound well adapted for the cultivation of cinnamon. More attention has been paid to this plantation than to any of the others : it is nearly completely planted, and produces annually about 1124 bales. Morotta lies seven miles south from Colombo; and is about the same extent as Ekele. Little attention is paid to the cultivation of this plantation. It yields annually about 2 IS bales. The jungle and neglected plantations in the neighbourhood of Colombo and Galle afford a large quantity of excellent cinnamon. The Candian country has continued to furnish annually a quan- tity of cinnamon. The King did not grant permission for the chaliahs to enter his territory; but they contrived to make short excursions into it ; and by stealth, bribery, or sufferance of the headmen, succeeded in obtaining a considerable quantity of bark, which they prepared at their leisure, after leaving the Candian limits : occasionally they suffered for their temerity, but not often. On an average of 10 years the quantity of cinnamon deposited annually in the magazine at Colombo from the jungles and aban- doned plantations of our own territory, including what has been collected in the Candian country, amounts to 1184 bales; and at Galle, during the same period, 935. The peeling commences early in May, and continues until late in October. The rains which precede, and occur during the south- west monsoon, produce such a degree of succulency in the shoots as to dispose the bark and wood to part easily. The setting in of the rainy weather immediately produces a fresh crop of scarlet or crimson-coloured leaves. The cinnamon harvest begins by dividing the peelers into small parties, which are placed under the directions of an inferior super- intendant. When they are to peel in the plantations, each party has a certain extent of the plantation allotted to it. A few of the party cut shoots ; while the remainder are employed in the wad* 248 Description of the Laurus Cimamomum. [Oct. (or peeling shed) to remove the bark and to prepare the cinnamon. When the chaliah perceives a bush with shoots ot a proper age, he strikes his ketta (which resembles a small bill-hook) obliquely into a shoot ; he then gently opens the gash, to discover whether the bark separates easily from the wood. Should the bark not separate easily, the shoot or branch is not deemed fit for cutting. The chaliahs seldom trust implicitly to any external mark of the proper condition of the plant, and rarely try a shoot until the scarlet leaves have assumed a greenish hue. Some plants never acquire a state fit for decortication. Shoots of many years' growth often bear the marks of numerous annual experiments to ascertain their condition. Un- healthy, stunted plants, are always difficult of decortication ; and the cinnamon procured from them is generally of an inferior quality. The peelers do not cut shoots or branches whose diameter is much less than half an inch, or more than from two to three inches. To remove the bark, the peeler commences by making with his lokette, or peeling knife, through the bark, a longitudinal incision, of which the length is determined by the figure of the shoot. A similar incision is made on the opposite side of the shoot, and when the branch is thick the bark is divided in three or four places. The kokette is next introduced under the bark, which is gradually sepa- rated from the wood, and laid aside. When the bark adheres firmly to the wood, the shoot is strongly rubbed with the handle of the liokette. These sections of bark are carefully put one into another, the outer side of one section being placed in contact with the inner side of another, and are then collected into bundles, and firmly pressed or bound together. In this state the bark is allowed to remain for 24 hours, or some- times more ; by which means a degree of fermentation is produced that facilitates the subsequent operation of removing the cuticle. The interior side of each section of bark is placed upon a convex piece of wood, and the epidermis, with the greenish pulpy matter under it, is carefully scraped oft' with a curved knife. During the operation the peeler sits upon the ground, and keeps the bark steady upon the piece of wood with his heel or toes. The bark dries, contracts, and gradually assumes the appearance of a quill or pipe. In a few hours from the time the cuticle is removed, the peeler commences to put the smaller tubes into the larger, and in- troduces also the small pieces. By this means a congeries of quills is formed into a pipe, which measures about 40 inches long. The cinnamon is suspended in the vvadu upon open platforms for the first day. The second day it is placed in the sun, on wicker shelves, to dry. When sufficiently dry, it is collected into bundles of about 30 lb. weight each, and in this state deposited monthly in the Government magazines at Colombo or Galle,* * From Baldeus's print of the manner of peeling cinnamon, and also from his description, it would appear (hat during liis residence in Ceylon the bark was removed from large trees, and the trunii allowed to remain uncut. Captain Per- •ival, who published his account of Ceylou nearly 20Q years afterwards, has only 18170 Descrif)tion of the Laurus Clnnamomum. 24D When newly prepared, cinnamon has a most delicious odour : this odoriferous quality becomes gradually fainter. Cinnamon is at first a light-orange colour, which becomes a shade darker by ex- posure to the air. The bark of old trees acquires a reddish-brown colour. Shortly after the cinnamon is deposited in tlie store-houses, the inspection of it commences. The East India Company employ an inspector and two assistants to superintend the sorting and baling of the cinnamon. The manipulation is performed by natives. Each bundle is placed on a table or l.irge bench; the bundle is untied, and the cinnamon examined quill by quill. It is divided into a first, a second, and a third, or rejected sort. The first and second sorts are alone deemed of a quality fit to form the Company's investment. T he sorting of cinnamon consists chiefly in detecting cr separating what is coarse, and otherwise of a bad quality, including the impo- sitions of the peelers. This is chiefly performed by inspection. Habit soon enables the people employed to discover by a single glance of the eye what is considered defective. Tasting is very rarely had recourse to. The bark of the large shoots, or thick branches of trees, pro- duces coarse cinnamon, which is generally rejected by the sorters. This cinnamon is thick, and has a reddish-brown colour, rough surface, loose texture, and is coarse-grained. It breaks short, shivery, and crumbling. When chewed it is disagreeably pungent, feels gritty, ligneous, and sandy, in the mouth. The peelers occasionally scrape off the external pellicle of this quality of cinnamon. This operation thins the cinnamon and im- proves the colour, but leaves it with a coarse, rough surface. This quality of cinnamon is always rejected. Cinnamon prepared from the bark of very young and succulent shoots is rejected. It is light straw-coloured, thin, and almost without flavour or taste ; and what little aroma it possesses is very evanescent. Mildewed or half-rotten and smoky cinnamon is rejected. When the peelers are overtaken with rain at a distance from sheds, the bark they have previously collected ferments, becomes decayed, and inodorous. In such situations they frequently retire to caves, or very confined huts, where they kindle fires, to procure warmth and to dress their food. The smoke arising from these fires often greatly injures the bark, and renders it unfit to be manufactured into good copied and reduced the Rev. Gentleman's prini, and rendered it confused, by in- chidiiip; in the same plate another print from tiie same author, showing the costume of the native women, and their manner of making butter. Many authors subse- quent to Hiiideus have asserted that tlie decorticated stnmp regained a new bark, I was, however, surprised to find t!ie following passage in a manuscript memoir on the cultivation of cinnamon, addressed to Mr. North, while Governor of Ceylon, by Mr. Jonville, Superintendant of Cinnamon Plantations: " Your Excelleiicv remembering that some travellers had advanced that the bark of the Cinnamon is taken olF the tiranch growing from the trunk, and that it grows again, ordered me to try that: 1 did so on several plants; but they all died." 250 Description of the Ltiurus Cinnamommn. [Oct. cinnamon. To increase the weight, the peelers sometimes stuff the quills of cinnamon with sand or clayey earth, thick ill-prepared pieces of bark, &c. &c. When these impositions are suspected, the quills are undone, often broken, and the foreign mixtures remoTcd. This is one of the many causes which prevents the cinnamon from being in quills of nearly equal length. Cinnamon produced beyond the river Keymel on the north, and the Wallawey on the south,* is generally condemned. It is light-coloured, greatly de- ficient in aromatic flavour, astringent, bitter, and has sometimes a taste similar to the rind of a lemon. Even between these limits the cinnamon produced differs greatly in quality. Differences of soil, and exposure, are very evident causes of a difference in the quality of cinnamon. Shoots exposed to the sun are more acrid and spicy than the bark of those which grow under a shade. A marshy soil rarely affords good cinnamon. It has often a pale yellow shade, approaching to the colour of turmeric. It is loose, friable, and gritty, and its texture coarse-grained. It possesses little of the spicy taste of cinnamon. Very often, however, the cause of the inequality of this spice is not apparent ; the bark of different shoots of the same bush have often very different degrees of spiciness. That which is considered in Ceylon as of the best quality is of a light yellow colour, approaching nearly to that of Venetian gold; thin, smooth, shining; admits of a considerable degree of pressure and bending before it breaks ; fracture splintery ; has an agreeable, warm, aromatic flavour, with a mild degree of sweetness. When chewed, the pieces become soft, and seem to melt in the mouth.f The first nnd second sorts are weighed, and put up into bundles, each weighing 92^ lb. English. Each parcel or bale is firmly bound round with ropes, and then put into double gunnies. The outside of the bale is marked with the number of the quality of the cinnamon, and the initial letter of the name of the protected plantation from whence it is procured. The bales of cinnamon which are procured in the neglected plantations, the woods of our own territory, or in the Candian country, are marked A. G. (Aban- doned Gardens.) The Company export their cinnamon from Colombo or Galle. • Good cinnamon is found on the southern portion only of the island. The dis- trict which uffords it appears to lie to the south of a line stretching from a few miles of Negombo to Panama, a station 18 miles north of Kandy, and from Panama to the neighbourhood of Hanibangtolte. + On an average of 10 years, it appears that about one-sixth of the cinnamon collected has been rejected as unlit to form a part of the Company's investment. The specimens of cinnamon from China which I have seen differ from good Ceylon cinnamon in being darker coloured, rougher, and not so well prepared, denser, and breaks shorter, but without crumbling. It is more pungent, and has a flavour easily distinguishable from Ceylon cinnamon. The taste is harsher; and, when chewed, is more ligneous. Ceylon cinnamon has a delicious sweetness, which is not very perceptible in China cinnamon. Some of the tubes are de6cient of the spicy qualities of cinnamon; and sometimes pieces are found which have an astringent and bitter taste. 6 18 17-] Description of the Laurus C'lnnamomum. 251 The interstices between the hales are filled with black pepper. Tliis mode of packing was gc'ierally practised by the Dutch, and has been scrupulously adhered to by the English. Thunberg attributes pecu- liarly useful qualities to the packing with pepper. Accident and economy of tonnage very probably induced the Dutch to adopt this mode of stowing. The ships belonging to the Dutch East India Company appointed to take in cinnamon arrived at Ceylon often half filled with pepper from the Malabar coast. As the cinnamon bales are nearly circular, a considerable saving of tonnage was effected, by removing the pepper, and strewing it among the bales. When pepper happened not to be readily procured, the spaces between the bales were filled with cotlee. The Dutch were less careful in sorting the cinnamon. Thun- berg's ludicrous account of the medical men of the colony being employed for several days together in chewing cinnamon has been orally confirmed by the people who had been employed in this duty. At ail the stations where cinnamon was deposited "■ two Doctors" were appointed to " taste the cinnamon." As the in^pectois did not unbind the bundles, they had a very limited opportunity of ascertaining the quality of the cinnamon, and none of detecting the im|)ositions and adulterations of the peelers. With the Dutch the peelers incurred blame, and were frequently punished, when the monthly collection of cinnamon was considered defective in quan- tity ; and for successful industry they sometimes received a small premium; hence it became the interest of the peelers to attempt impositions, to increase the weight of their collections. The same practice is followed by the English. The Directors of the Dutch East India Company complained frequently, in their communications to the Colonial Government, that the cinnamon sent from Ceylon yvas coarse, and ill-prepared. Sometimes it was so bad that they did not dare to expose it to sale, lest the credit of the Ceylon cinnamon should suffer; and, to pre- vent its being employed in adulterating cinnamon of a good quality, they were on some occasions obliged to burn it. On some occasions the Ceylon Government has directed oil to be extracted from the cinnamon, whose quality did not permit it to form part of the Company's investment. The process is sirtiple : the bark is grossly powdered, and macerated for two days in sea- water, when both are put into the still. A light oil comes over with the water, and swims upon its surface, and a heavy oil, which sinks to the bottom of the receiver. The light oil separates from the water in a few hours ; but the heavy oil continues to precipitate for 10 or 1:2 days. The heavy oil, which separates first, is about the same colour as the light oil ; but the portion which separates last has a browner shade than the supernatant oil. In future distil- lations the saturated cinnamon-water is advantageously used, added to sea-water, to macerate the cinnamon. SO lb. of newly-prepared cinnamon yield about '2{- oz. of oil, which floats upon the water, ^nd b\ of heavy oil. The same quantity of cinnamon, if kept in 252 Description of the Lavrus Cinnmnomuyn, [Oct. store for several years, yields about 2 oz. of light oil, and 5 oz. of heavy oil. The prepared bark of the laurus cinnamomum has received a variety of appellations. It has, however, been chiefly known by the terms casia and cinnamon. The derivation of neither of these terms is well ascertained. It has been asserted that the term casia, joined with the Hebrew word khenah (which signifies a pipe), is the original of what has been rendered cinnamon in the 30th chapter of Exodus, and that the word rendered casia by our trans- lators is kiddah, from khadh, to split or divide longways. We read in Herodotus that casia grew in Arabia, but that cinnamon was brought thither by birds from the country where Bacchus was born, that is, India. The term used by Herodotus to specify the last of these substances indicates the cinnamon we now have, for it sig- nifies the rind separated from a plant,* and evidently points out the bark, under which form we still receive this spice. Galen was of opinion that casia and kinnamomum were the pro- duce of different species of plants. He, however, finds great diffi- culty in marking the distinctions. He says that cinnamon resembles the best casia ; and avows that they are so much alike that it is not an easy matter to distinguish them. The cinnamon mentioned by Galen appears to have been small shoots or branches, which were sold wood and bark together, xylo casia, casia lignea. The ancients enumerate a variety of sorts of casia. Some of the terms employed to denominate this spice specify the mart, or port, where it was to be found ; some a particular character, or quality ; the origin and import of others are undetermined. Ten different sorts are mentioned in the Periplus: — 1. Mosylitick, from Mossy- Ion, a port to which it was brought. 2. Gisi ; small, esteemed the best. 3. Ordinary. 4, Aroma; sweet-scented. 5. Mayla. •* Vincent's Periplus of the Erythrcan Sea. — The extreme ignorance of tlie an- cients respecting cinnamon may be guessed by the account Herodotus has given of the manner casia and cinnamon were collected. He tells us that casia grows in a shallow lake ; and that round the borders of this lake there are a number of ■winged animals reseniMing bats, which are very strong, and utter the most piercing and dismal cries. The Arabs take great care to defend their eyes from the attacks of these animals, and drive them away : after this precaution, they collect the casia. Cinnamon is collected in a still more surprising manner. The Arabs them selves do not know from whence it comes, nor the country which produces it. Some people assert that it grows in the tountry where Bacchus was born ; and their opinion is supported by strongly probable circumstances. They relate that some very large birds collect quantities of the sprigs and small branches of tha plant which we call cinnamon, a name we have borrowed from the Phenicians. These birds construct their nests with the cinnamon twigs upon mountains inac- cessible to man. To procure the cinnamon twigs, it is asserted that the inhabitants been successfully cultivated in the island of Dominica by a Mr Bu^e. The »ani« Gentleman hat succeeded in propagating tbe clove-tree \u Domiaica. 1817.] Description of the Laurus Cinnamomum. 255 Ribeiro, on the autliority of the Portuguese historians, states that they imported spices into Ormus, and other ports in the Arabian Gulph. He tells us, also, that the Arabians give the appellation of dar Chini Seylane (the China wood of Ceylor)) to the cinnamon produced in Cevlon ; while they apply the term kerfah to the cin- namon produced on the coast of Malabar, and other countries. The Persian appellation for this commodity is dar Chini. The Hindoostannee term for it is dar Chinie. This term might have been applied in consequence of the Chinese importing cinnamon into distant ports; or perhaps, more probably, from merely supply- ing the merchants with it when they arrived at any of the ports of China. Cinnamon was for a long time imported into Europe under the appellation of China wood. Herodotus tells us that the term used by him to specify cinnamon was adopted by the Greeks from the Plienicians. Their country, however, did not produce cinnaaion ; but as they were industrious merchants, and extensive navigators, they may have imported it from the countries where it gi^ew, either in their own ships, or in those of other nations. " Traders from the Arabian coast had pro- bably in all ages frequented the eastern seas, although no record of their voyages of an earlier date than the ninth century has been preserved." * In Cochin China the cinnamon plant is termed cay que. The Chinese appear to have adopted this term, but in some degree modified ; they call it kuei chau, which, when pronounced by a native of China, sounds like the word qui sheu or qui chou : chou in the Chinese language signifies a tree. That the term employed by the Chinese to specify cinnamon has a foreign derivation, is ex- tremely probable; as it appears that cinnamon is not indigenous in China. It appears very probable that the term casia has been de- rived from either the Cochin Chinese or Malay languages, f The Malays specify cinnamon by the term kayu manis (sweet wood). Marsden renders it kulet manis (sweet bark or rind), which may be the appellation employed by the higher classes. The vulgar, however, term it kayu manis. There is a considerable consonance in the pronunciation of the terms casia, cay, and kayu, all indicative of the same substance. The Malays were in early ages an active, enterprizing, and com- mercial people. Their language is very generally employed in the * Marsden's Introduction to a Grammar of ttie Malay Languages. + Valeiityn derives the term casia from Casia, the name of an island in the Persian Gulpli, which was for a long period a depot for the productions of India. Here the merchants from Europe found cinnamon, which, according to this author, was by the physicians termed casia lignea (casia wood). According to Dodoneus, Galen once saw a branch of a tree, one end of which yielded cinnamon, and the other casia. The same author informs us that Theophrastus and Pliny confidently believed that casia and cinnamon were the produce of the same species of plants, and that whatever difference existed between them, they supposed arose from the circumstance of the former being procured from trees which grow on the hills, and •he latter from those which grow iu the valleys. 256 On the Constniction of Skips, &c. [Oct. districts bordering on the sea coasts of the islands of the eastern Archipelago, the Malay peninsula, Sumatra, Java, &c. These countries abound with cinnamon, vvhicli the Malays exported pro- bably in their own ships, or furnished the merchants of other coun- tries with it, in the ports of the districts where it is found most abun- dant. This they now do; and foreigners would very probably adopt the Malay term for the article ; and by this means, through a suc- cession of traders, the Phenicians, and eventually the Greeks, may have received the terms casia and cinnamon. Casia is not impro- bably a corruption, or foreign pronunciation, of the Malay term kayu (wood), omitting the qualitive adjunct manis (sweet); and the kinamon of the Greeks may be derived from kayu manis, altered by incorrect pronunciation, or erroneous transcription. The vowel y in kayu has the power of a consonant, and in this word has a soft nasal sound, resembling in no inconsiderable degree the usual enun- tiation of the letter s in casia. Orally the Malays frequently con- found the sounds of the vowels o, u, and a. They often pronounce the term kayu manis as if it were written kaynomanis or kainamanis, which terms do not differ materially from the ancient kinnamon, or the modern cinnamon, either in the letters, or in the mode of utter- ance : and they certainly specify the same substance. It is worthy of observation that Moses employs the term sweet (manis) cin- namon. Plate LXXI. Fig. 1, exhibits the Laurus Casia with ripe berries. The Cingalese designate this plant by three different names — Dawul Kurundu, Nika Dawulu, and Nika Kurundu. Fig. 2 is a traced outline of Burman's 28th Plate, which is a delineation of the Kurundu Gaha, or Cinnamon-tree, in a state of florescence, Burman has erroneously stated this to be a print of the Dawul Kurundu of the Cingalese. Article II. Suggestions for luilding experimental Vessels fw the Improvement of the Navy, with Remarks on the present Mode of Construction, and some Experiments on the comparative Resistance of Water on differently shaped Solids. By Col. Beaufoy, F.R.S. (To Dr. Thomson.) MY DEAR SIR, Bushey Heat/i, Slanmore, July 22, 1817. It is reasonable to suppose that in a maritime country like the United Kingdom of Great Britain any endeavour to promote the science of naval architecture will meet with a candid and favourable . .„ ouppusc iiuu in a maritime country like the United Kingdom of Great Britain any endeavour to promote the science of naval architecture will meet with a candid and favourable 18170 ^ ^^^ Consf.ruclhn of Ships, &c. 257 reception, especially from those to whom the planning, huilding, and sailing of our ships and vessels are entrusted. Various have been the plans submitted, from time to time, to the directive Boards of Admiralty and Navy, for the improvement of our ships of war; many of which possessed great science, skill, and ability. But while some were probably not carried into execution on account of the expense of building large ships for the purpose of experiment, others were alike disregarded because of the comparative uncertainty of success attendant on all new plans, and the possibility that the expectations of the projector might not be fulfilled, the too sanguine speculations of the most scientific having but too frequently plunged them into the mass of what are commonly termed schemers. The science of naval architecture is not likely to be benefited in any very material degree but by experiments reduced to practice : con- sequently should any mode be suggested for the building of experi- mental vessels without subjecting Government to additional expense, the chief objections which have been made to any intended innova- tions will be removed. There is a class of vessels belonging to his Majesty's dock-yards, of an unseemly shape and clumsy construc- tion, called lighters. It is proposed that, when any of those now in use require to be replaced, instead of moulding the new after the model of its predecessor, it shall be converted to the purpose of experimental inquiry; because as their fitness for sailing is of no immediate moment in the service in which they are employed, they may be rendered, without detriment to the service, not only ade- quate to all the purposes for which they were originally intended, but may ultimately lead to important practical advantages. It is proposed that these lighters shall partake of some geometrical figure, or rather of three geometrical figures, under varied combi- nations and arrangements ; namely, the cylinder, sphere, and seg- ment, of a prolate spheroid. We will suppose, in the first experi- ment, the middle or midships to partake of the cylinder, the bow of the globe, and the stern of the prolate spheroid. In the second, instead of forming the bow of a spherical shape, let it be made more acute, and formed by the revolution of a circular segment: in other words, the fore part will be a portion of a circular spindle In a third, let the bow be still more acute, by adopting a circulai spindle whose length bears a greater proportion to its breadth than ill the first instance; proceeding thus until the most advantageous bow is ascertained. In this plan the length, breadth, and depth, of every vessel is to be the same ; and the only variable parts of the vessel will be the middle and bow ; the length of the cylindrical part decreasing in proportion as the foremost is rendered more acute. When the most advantageous bow has been determined, the nest alteration to be made is in the stern part. This extremity, like the fore part, is to Vol. X. N° IV. R 258 On the Construclmi of Ships, &c, [Oct. undergo similar changes till the maximum be obtained.* The reason for not altering the two extremities at the same time is ob- vious ; for should this be done, it would be impossible to say what proportional part of the effect is to be attributed to the altering of the fore part, and what is to be set down to changing the shape of the stern. Another most materiar circumstance must also be attended to ; that is, the masts, booms, gaffs, bowsprit, and sails, must be the same in each vessel, and the masts stopped at the same distance from the bow of each, measured on the load water-line. By using the above simple and easily drawn figures in the con- struction of vessels, the water will not form those numerous eddies and whirls which take place when the vessel's hull is composed of an infinite variety of curves, which cause those particles of the fluid, which, after having acted against the hull, and are perhaps descend- ing, to meet with others moving in a different direction, and thus form innumerabl. vortices, which impede both the sailing and steering ; for, as has been before mentioned in the An?ials of Philosophy, water meeting with an obstacle in its course endeavours to escape by the shortest road, as shot would do, supposing a vessel suspended by the stem, and a quantity poured on the bow. Vessels built in the present irregular form, when sailing, are con- tinually exposing a different surface (and frequently an unfair curve) to the action of the fluid, unless the water be perfectly smooth, and the vessel remain upright, or be inclined an invariable angle (cir- cumstances not likely to occur in practice) ; but these proposed ex- perimental vessels will in all cases expose nearly the same surface and shape to the impulse of the fluid ; conditions, it is thought, highly advantageous for facilitating their progress. Should this paper merit the consideration of those connected with the marine, my intention in writing it will be fulfilled. Having made these preliminary observations, a draft of two vessels proposed to be built when new lighters are wanted is in- serted. (See Plate LXXII. Fig. 1,2.) The length of the vessel from the fore part of the rabbit of the stem to the after part of the rabbit on the stern post, measured at the height of the extreme breadth, is 60 feet ; the extreme breadth, 20 feet ; the draught of water, exclusive of the keel, eight feet, or two-fifths of the beam ; the breadth of the keel is nine inches, or •75 parts of a foot, of which ■37», deducted from 10, leaves 9"6:35, ♦ The sailing, particularly the steering, depends in great nieasuie on the shape of that part of the stern called the run ; for a vessel full abaft may steer suffi- ciently well when sailing tive knots in an hour, and become ditficult to manage when running eight or nine. This is to be attributed to the water not closing in behind, and flowing to the rudder in lines parallel to the keel. The Kast India ships belonging to the Company would be much improved by atlending to this circumstance, and sailing them so much by the head unnecessary, excepting what is caused by the stowing of the provisions and water. i:utf3Sii Vefsel ] \\'tii.r Diij/Zacxl 273 firJunj Kn4ftvv*afhT2>rThi>m.sm^jtiuuatfirBiadwin.CnuUcktsJoy.RiUnuisUr'Si)w.OctTJJia7 \ 181 7-] On tlie Construction of Skips, ^c. 259 the radius of the midship bend, or greatest vertical section, and also that of the stem, reckoning from the heigi)t of the extreme breadth. The height of the gunvvhale above the extreme breadth amidship is two ieet, and at each extremity four feet. Tlie vertical curve, or sheer, as ii is termed, is described in tlie following manner. The distance, two feet ; the beight of each extremity above the middle part of the vessel is divided into as many equal parts as the half length, 30 feet; then, by drawing intersecting lines, a number of points are formed, through which the curve is drawn. The draught of water abaft exceeds that forward by two feet. This difference is caused by making the after part of the keel that quantity deeper, or, as the shipwrights term it, giving so much more skeg. The dimensions of the three component parts of the first vessel stand thus: length of the fore part, 9625 feet; midship part, 31*125; and stern part, 19'25. The quantity of water displaced by the vessel is 173*32 tons, a cubical foot of sea water weighing ()4"1875 lb. Avoirdupois, and a ton containing 34*897S cubical feet. The next point to be considered is the stability of the proposed vessels, and to investigate t' is most important property. Suppose the vessel, when laden, has its centre of gravity at the load water- line ; not that I think it will be so much elevated ; but that it is safer, in calculating the stability, to be under the mark than in excess. The centre of gravity is considered to be elevated eight feet above the under side of the garboard strake, or that plank in- serted in the keel. It is also taken for granted that the main-sail exposes to the action of the wind ]582'82 square feet; the fore- sail, 339"29; and the large jib, 5'J4'5G superficial feet ; * that the vessel is upon a wind ; and that the sails make an angle of 35° with the wind's direction. By calculation, the centre of pressure of the three sails is found to be 29-6 1 feet above the load water-line, by examining the experiments on tiie resistance of air in the Annals of Philosophy, vol. viii. the resistance of a superficial foot exposed to the action of the wind moving with a celerity of 20*29 feet per second, and making an angle of 35° with its direction, is 6*1514 oz. .... , 61514 X 2496-67 . , ^ ,.__ ,^,- „ ^, Avoirdupois, then is equal to 959-89 lb., the force of the wind on the sails, which, multiplied by 29*61, the product, 28422 lb., or 12*689 tons, is the effort of the wind to incline the vessel. To find what inclination the vessel receives by this impulse, we have 959-89 lb., or 0-42852 part of a ton, which, multiplied by 29-61, and divided by 173*32, the tons of salt water displaced by the vessel, the quotient 073209 is the length of lever on which the displaced water acts to counterbalance the effort of the wind. Tlie vertical sections or frames, so called by the builders, being * The quantity of canvas exposed to the impulse of the wind iu the $n\U of the lighters now in use. K 2 260 On the Cotutruction of Ships, &lc. [_Oct. segments of circles, the metacentre is in the centre of those circles, and the centre of all the circles being elevated l'G'25 foot above the load water-line, 1-625 : radius :: -073209 : S 2° 35', the inclina- tion of ihe vessel. As the vessel is supposed on a wind, it is evident the power to heel it will be greater tlian what it was when the vessel remained at rest : it is not improbable this vessel, when under sail, will gain three knots per hour to windward, which is equal to 4*029 feet per second. This number, added to 20*29, gives 24*3 19, the velocity of the apparent wind, which exerts an inclining power of 18*357 tons. To balance this effort, the vessel must incline 3° 41', and the lee side will be immersed 15f inches. Two other causes, not taken into account, will further incline the vessel, viz. the action of the wind on the mast, rigging, and hull; and the re- sistance of the water from the lee way acting against that part of the vessel's body immersed in the water, and situated beneath the vessel's centre of gravity ; but the inclination of the sails from a vertical position will diminish the effort of the wind. Vessel I. — Bow is the fourth part of a globe at the height of the extreme breadth, and the top sides of the vessel are formed by con- tinuing the curvature of the different circles to the gunwhale. Vessel II.* — The horizontal section of this vessel, at the height of the extreme breadth, is the same as the curve of the stem up to that point ; but as the sweep of the stem above that projects for- ward, and the stern post rakes aft, the upper works, unless the breadth of the vessel be augmented, can no longer be formed by continuing the curvature of the frames or vertical sections of the vessel's hull. Therefore that part of the body above the extreme breadth is formed in the middle or cylindrical part by straight lines, tangents to the midship bend, and other frames of the same dimen- sions, and the upper works of the fore and after bodies will be thrown outwards, commencing at what may be termed the balance frames, A and 1, and gradually increasing till the line terminates in the rabbit of the stem and stern post. By giving the stern an arched form, it is rendered as strong as the bow ; and, by contracting the after part, the vessel is better adapted for turning to windward ; for the common construction of square sterns and large quarter galleries, by holding a great deal of wind, much impede the ship's progress when turning to windward; and a vessel of this shape is better adapted either for offence or de- fence, as guns may be run aft, and pointed more than half round the compass. The dimensions of the three component parts of Vessel II. will be as follows: length of the fore part, 145 feet; midship part, * Vessel II., fo have the same stability as Vessel I., must have the centre of {gravity lowered 1()3 iiieb. The stem of Vessel II. projecting more than that of Vessel I., this cxct-ss of length should be considered as so much bowsprit : conse- quently it becomes requisite to have more canvas in the fore-sail, and proportion- ally less in the jib, of Vessel II., that each may contain in the three sails 2496*67 feet of canvas. Wodels of Vessels I. ar.i IT. have beeu made, and look well. 181/.] On the Comtruction of Ships, &c. 261 26*25 feet; and the stern part, 19"25 feet. The capacity of Vessel II. is 16"l-59 tons, or S'^S tons less than Vessel I. I i de- termitiing the power of a machine, it is usual to muhiply the weight into the velocity ; therefore the momeotuin of Vessel I. will exceed the momentum of Vessel II., when running with the same velocity ; but the increased rate of sailing of Vessel II. will more than counterbalance the diminution of tonnage. For in- stance, if Vessel I., with a certain breeze, sails with a velocity of 113 ; and Vessel II., with the same strength of wind, with a velo- city of 1 19 J or, what is nearly the same thing, if Vessel II. can make 20 voyages whilst Vessel I. performs 19 ; both vessels will be equally useful. In other words, the same quantity of freight will be carried the same distance in the same space of time; but should the sailing of Vessel II. exceed this piopoition, it is to be preferred to Vessel I. The builders' tonnage of the King's sailing lighters is 104^1-. Being ignorant of the weight of the hull, I am unable to state what is the actual displacement of water. If it be supposed, which probably is not far from the truth, that the weight of each of the vessels proposed to be built is 69 tons, the cargo that may be placed on board will amount to 10i"32 tons, nearly the same tonnage as the present lighters. Should it be asked why the force of the wind is calculated with the celerity of 20*29 feet per second in preference to any other velocity, the answer is, that from observation, and by experiment, I found that with that wind square-rigged vessels between 200 and 300 tons burthen under sail, and upon a wind, can just carry top- eallant sails. These experiments are the more strongly recommended, as it is likely and requisite that some classes of the English navy should undergo considerable alteration ; for the large American frigates have taught, by sad experience, how unequal (notwithstanding the desperate braver}' of the crews) small vessels are to contend with large ones; and as tlie Americans of all classes, merchant ships included, are, generally speaking, far superior in point of sailing to our own, it behoves every well-wisher to his country to contribute, as far as he is able, to the improvement of naval architecture and maritime science in general ; for such arts and sciences are not only most essential, but absolutely necessary, to the welfare, prosperity, and glory, of Great Britain. Little doubt can be entertained that a rising floor, in point of sailing, has many advantages over a flat one. Why could not the different tenders that are attached to Admirals, as well as the yachts belonging to the various Boards and dock-yards, also when new ones are wanted, be built as vessels of experiment, making the floors tangents to the cur\-ature of the different frames. By such experiments it appears feasible to expect much valuable and useful information would be obtained, and the groundwork laid for build- ing ships oii unerring principles. No doubt the loss of stowage may 262 On the Construction of Ships, &c. [Oct. be urged against building large vessels with rising floors ; but this loss of capacity is readily made up by giving so much more length of midship body as is equal to the capacity lost by acuteness of the floor timbers. It may be also remarked that sharp bottom vessels will not take the ground * so well as flat bottom ones, which cer- tainly is a disadvantage ; but it should be recollected that men-of- war are not intended to ground; and taking the ground maybe considered like running against a rock, a circumstance to be re- gretted, but never designed. To conclude, unless ships are con- structed with curves of some known properties, it will be in vain to search for the particular parts in a vessel's hull wherein the good or bad qualities they possess are situated. Probably to the hetero- geneous curves used in the construction of ships may be traced the shipwright's axiom " that no man can tell how a vessel will sail before it is tried." It is to be regretted that no experiments on the resistance of fluids, as far as I can learn, are likely to be made in this country ; for much remains to be done. Even the elaborate memoir of M. Zaccarie Nordmark, Professor of the University of Upsal, and Knight of the Pole Star, which gained the prize offered by the Royal Marine Department of Russia, is incomplete, as the effect of the friction and minus pressure is not taken into the account : ard as the Emperor Alexander, to his great honour, is not only an encourager of travels for promoting the science of geography, but also sends vessels to the most distant parts of the globe on discovery, and at the same time patronizes, in a manner worthy of himself, those arts connected with the marine, why should not a series of experiments be made at our Royal Naval College at Portsmouth ? This would enable those students who are to be our future ship- tuilders to compare the present pneumatical and statical theory with matters of fact. The Committee of the House of Commons recommended that no false economy miglit impede continuing the admirable trigono- metrical survey so ably conducted by Col. Mudge and Capt. Colby ; and the same scientific spirit of liberality would unquestionably encourage an undertaking, the professed object of which is to train up for the public service practical and scientific builders, a class of men no less an ornamental than a valuable acquisition to the king- dom of Great Britain. It is worth recollecting that the building of a single bad vessel will cost five times more money than probably any intended set of experiments will come to. A comparative set of experiments on the resistance of water is easily made by means of a pendulum ; it being only requisite, in the first place, to make each of the solids to be tried of the same specific gravity as water, and then attaching them to the lower ex- tremity of the rod. The pendulum being drawn aside to a certain * In case of a ship's grounding and bilging, see Annals of Philosaphr), vol. ii. p. 356, 1817-3 On the Construction of Skips, &'c. 263 point, and then let go, it is evident the less the resistance of the attached body, the greater the ascending arc described by the pen- dulum, and vice vena : consequently the greater or less resistance will be measured by the arc of vibration. Two disadvantages attend this mode of experimenting; the slowness and inequality of the motion, and the passage of the figures through the water not being rectilineal. Subjoined are experiments made in this manner with a pendulum 5 feet 5*85 inches long, the lower extremity being immersed 12'7 inches. The solids were two inches in diameter, and as much in length, with the exception of the double cone, which was four inches long, when lengthened by a cylinder, it measured six inches (the same remark is applicable to the elliptical spindle) ; and the sphere, when cut in halves, and separated by a cylinder, measured four inches. Table I. Resistance of a cube the angle being opposed to the fluid 1000 Resistance of the side 877 Resistance of a cylinder 1000 Resistance of a sphere 574 Resistance of a sphere cut in halves, and length- ened by a cylinder 238 Resistance of the base of a cone 1000 Resistance of the vortex, its angle being 53'OS . . 46/ Resistance of the base of a wedge 1000 Resistance of the vortex, its angle being 53*0S . . 512 Resistance of a double cone 1000 Resistance of the same lengtliened by a cylinder . . 380 Resistance of an elliptical spindle 1000 Resistance of an elliptical spindle lengthened by a cylinder * 735 The follovving table contains experiments made with six different solids, the diameter of each being two inches, and the length seven inches. Table II. 1. An elliptical spindle 1000 2. A circular spindle 847 3. A double circular spindle, greatest breadth ^ from the foremost end 648 4. A ditto, ditto, greatest breadth -^ from the fore- most end 603 * It ig remarkable that the simple aitditioii of length should so much diminish the resistance, a circumstance fully corroborated by other experiments made in a different manner. 26 i Elementary Ideas on the First Principles of Oct.] 5. A ditto, ditto, greatest breadth l from the fore- most end 587 6. A ditto, ditto, greatest breadth -S- from the fore- most end ., 540 The experiments were compared with each other in the following manner. The ascending arc of the pendulum, before any body was fixed to it, was found by measuring the chord, and calculating the angle to be 19° 5' 39", the elliptical spindle being attached to the rod, the ascending arc was found to be 18° 42' 35"; the difference between those two numbers is 13S4". This solid being detached, and the circular spindle substituted, the arc of ascension was found to be 18° 46' Of, which, deducted from 19° 5' 39", leaves 1172. Then 1384 : 1000 :: 1172 : 897, the comparative resistance of the circular spindle. In the same manner the other comparative resistances are calculated. From these experiments it appears that the extreme breadth should be placed ^ from the bow ; but whether this will hold good in all velocities remains to be de- termined. It was my intention to have made some remarks on the method of cutting sails ; but lest I should intrude too much on your time, 1 beg leave to subscribe myself, My dear Sir, very sincerely yours, Mark: Be.\ufoy. Article III. Elementary Ideas on the First Principles of Integration, by Finite Differences. By Mr. George Harvey, of Plymouth. I. Since A is the symbol which denotes the process of differen- tiation, let A~' be the symbol of the converse operation, by which the integral is obtained. Now, it u be any function whatever, since A (w) = A w, therefore A"' . A u = A~' A (a) = ?^, the primitive function. Again, since A (u^) = 2u A u + A u\ and that 2u A u + A u^ is a function of u, let it be denoted by O w, and therefore A (a^) = O ?/; hence A~' O ii — A~' A (zr) = u", the primitive function. To present, however, a more general and comprehensive view of the subject, let u denote, as before, any function whatever j then since 1817.] Integratinn, by Finite Differences. 265 f one differentiation, , . J -. ^i • V- I two differentiations, IS derived from the primitive ., ..^ ■ . r ^- . *^ < three differentiations, lunction M by j \ji differentiations, A u therefore A zi "I fone integration, A-u \ 1^ ^ 1 ^t • •.• two integrations, ^3 ^ l^ ought to rj^roduce^the primitive ^ ^^^^^ integrations, (A). A" M J {.n integrations. Hence, as A~' has been adopted to represent the converse ope- ration of A, so let A""", A~', - - - - - A~" denote the converse operations of A'-, A' ----- A"; and tlierefore as A, A*, A' - - - - - A" indicate the first, secortd, thirdy and 7i}^ differences of the primitive function u, so will A~ ', A~-, A~^, ------ A~" represent the first, second, third, and n^^ integrals of the same function. According to these principles, the formulae (A) will become A-' . A 7i A-^ . A^ u A~^ . A* M I - u ------- - (B). A-" . A" M J Geometers, however, have adopted the symbols S, %-, ^', _____ 2" as characteristics respectively equivalent to A"', A~-, A~^, - - - - - A~", and hence the equations denoted by (B) will be transformed into •^ A u -) ^- A' u \ 2^ A' w J> = ti. - - - I %" A^ u J Corollary. — Hence it appears that the «"* integral of the n^ differential of any function is the primitive function from which the differential was derived. II. It is moreover evident, from the preceding principles, that since A* may be considered as composed of the two factors'" A, A, and is termed the second difference, A' may be considered as composed of the three factors of the A, A, A, and is termed the third difference, ^ primitive function. A" may be considered as composed of the n factors A, A, A, A and is termed the 7i*'' difference. 266 Elementary Ideas on the First Principles of [Oct* so A~ * may be regarded as composed of the two factors'^ A" ', A"" ', and is termed the second integral, A"^ may be regarded as composed of the three factors A- ', A- ', A- and is termed the third in- tegral, of the y pr'rnitive function ; A"" may be regarded as composed of tlie ?i factors A~ ', A~ ', A~ ', A" ' and is termed the n* integral, or by adopting the characteristic 2, as before, %^ may be considered as composed of the two factors^ 2, "^f and is termed tin- second integral, S' may be considered as composed of the three factors of the 2, 2, %, and is termed the third integral, }► primitive ---------------- function. S" may be considered as composed of the n factors 2, 2, S, S and is termed the ?«*'' integral, ^ Corollary. — Hence it appears that any differential, by the process of integration, may be clianged into different forms ; and also an integral may undergo corresponding variations by the process of differentiation : thus u representing any function, as before, its second integral may be denoted by either of tlie forms 2- u = A- - 7< = A- ■ A- ' u = A- 3 A' ?< = A- ^ A' u = &c. j and its third integral by either of the forms %^ u = A-^i = A- ' A- ' A- • M = A- 2 A- ' 7< = A-- A" u = A' A~ " ?/, &c. III. By similar operations we may obtain %- Au = A-- A'u = A-' u = "^ u, 2^ A^ u= A-« A- u = A" u =z '^' u, 2* A^ u = A~^ A^ u = A' u = "^ A- ?/, 2" A"" 21 = A-" A"" 7c = A'"~" u = &c. These combinations, it is obvious, may be varied without end. Corollary. — If in the latter form rti be greater than n, the result will be a differential of the function u ; but if m be less than w, then an integral of u will be obtained. Suppose, for example, m = 4, and n = 2, then 2" A" u = 2' A* ii = A° u, the second difference of the primitive function u ; but if m = 3, and n = 5, then 2" A™ M = %^ A^ u = %- u, the second integral of the pri- mitive function u. 18170 Integration, ly Finite Differences. 26/ IV. A facility in the management and transformation of these symbols will be of great advantage to the student : and the follow- ing examples are therefore added to exercise his ingenuity: — EXAMPLES ON DIFFERENTIATION. The first difference of S A" z< = A S A" m = A A" ' A" e^ = A" 7/ = ^ A" "*"'?< = &c. The first difference of S'^ A" ?< = A T' A" 7^ = A A" "~ A" zi = 2 A" u, = &c. The second difference of %' A" u = A« %' A" ?i = A= A" ' A" « =s A- ' A" M = 2 A" u, = &c. The ««" diflerence of S A" ?/ = A" :S A" 7t, = A" A" » A" M ^ A- ' A= " 7 7i Carbonate of strontian 4*885 .... 30*221 In other specimens of strontianite 30*000 The above arragonite seems a compound of DJ'6 carbonate of lime and 2*4 carbonate of strontian. 5 Magnesian lime-stone 4*952 .... 45*954 5 Crystals adhering to magnesian lime. . 4*700 .... 43*f>lG 5 White Antrim lime-stone 4*(J50 .... 43*152 5 Pearl spar 4*20 38*97G 5 Gall-nut Hme-stone , 4'()8 ..., 43*430 5 Carrara marble , 4*69 43*523 74- Ignited subcarbonate of potash .... 5*075 .... 31*40 5 Subcarbonate of soda 4*403 40*86 4 Dense subcarbonate of ammonia .... 4*69 .... 54*404 Remarks on the precedivg Table. The crystals adhering to the pieces of magnesian lime-stone I found, by a common analysis, to contain no magnesia. I precipi- tated by subcarbonate of ammonia, from the acidulous muriate of lime, 99 grains of carbonate from 100 grains of Antrim lime-stone ; and 43*152 is to 43*616 as 99 to 100, which is a perfect accord- ance between the two distinct modes of analysis. The lime-stone in the form of gall nuts clustered together is from the vicinity of Sunderland. It contains a very little oxide of iron, and has a spe- cific gravity of 2*700. It is not a magnesian lime-stone, as some have supposed. The gaseous product shows the absence of mag- nesia. These gall nuts are denser than common lime-stone, of which the Antrim is of 2585 specific gravity ; the spar is 2*70; the Cultra magnesian lime-stone varnished is 2- 157. The subcar- bonate of potash was from Tartar ; the subcarbonate of soda from ignited bicarbonate, which was found by the ordinary chemical tests to be nearly free from all contamination of muriatic and sulphuric salts, the nitrate of silver giving with its nitrate a scarcely percep- tible milkiness. It is a substance, however, difficult to get absolutely pure. The best way of obtaining it which I have yet practised is to boil a solution of pure sea salt with a large quantity of yellow oxide of lead, till no more muriatic acid remains undecomposed. To lilier, add a little carlionate of ammonia to the liquid, evaporate, and ignite. The crystallized subcarbonate of commerce, even when found in regular rhomboids, is very far from being pure. It yields, when ignited, only 37,} or .iS per cent, of carbonic acid. White lead or carbonate will not answer the purpose. I have digested it on a sand-bath with solution of sea salt for many hours without the liquid aL-quiriiig the power of reddening litmus paper; but after the wliite lead is ignited, it begin? immcliiitelv to decern- 272 On the Quantihj of Real Acid [Oct. pose the salt with great force. The joint affinities of carbonic acid, oxygen, and lead, and hydrochloric acid and soda, are here shown to be stronger than those of chlorine and lead, oxygen and hydrogen, carbonic acid and soda, which are the divellent forces, opposed to the former as quiescent. A very pure subcarbonate of soda may also be got from the crys- tallized acetate by ignition. Thus accurately acquainted with the composition of the car- bonates which I was to employ, the instrument and balance being both of equal delicacy, I next diluted with distilled water at G0° of Fahr. some pure liquid hydrochloric or muriatic acid, in the follow- ing proportions. Acid of 1-192 specific gravity, at 60° of Fahr. was employed, equal in dry acid per cent, to 28-3 : — Acid. Water. Sp. Gr, Temp, on Dry acid Grains. Grains. Proportions. at 60°. mixture. per cent. lOSO + 120 = = 90+10 1-1730 80° 25-47 yeo 240 80 + 20 1-1536 82° 22-64 8^(0 360 70 + 30 1-184 i 85° 19-81 720 480 60 + 40 1-1150 90° 16-98 600 600 50 + 50 1-0960 88° 14-15 480 720 40 + 60 1-0765 83° 11-32 360 840 30 + 70 1-0574 79° 8-49 240 960 20 + 80 1-0384 75° 5-76 120 1080 10 + 90 1-0192 69° 2-83 The calculated and experimental specific gravities at 60° exactly coincide. The mixture of acid and water was made 24 hours before the density was determined, in which interval of time it was fre- quently agitated. In round numbers we may reckon the addition of -pi-g^ of water to acid of any specific gravity as diminishing this by two in the third decimal figure. 1 shall be able presently to demonstrate, by a series of accurate experiments, that the propor- tion of dry acid is exact as given above. Hence preceding tables must be wide of the truth. We may here remark, in the first place, that we have two phe- nomena somewhat singular in the dilution of this acid. First the evolution of heat from the mixture of two liquids, not saline, with- out any condensation of their volume. This fact completely dis- proves the notion, too common in chemical books, that the evolu- tion of heat, in the dilution of alcohol and of sulphuric acid with water, is due to the mechanical effect of the diminution of the pores or interstices which formerly lodged the caloric. The maximum rise of temperature appears above in the mixture of six parts of acid with four of water, which consists nearly in bulk of five of the former to four of the latter. Equal volumes, when mixed, evolve a heat somen-hat greater ; or by weight, six of acid to five of water. The second fact is, that v,e have here a true chemical combina- tion without any change of density. It is curious that the same rsi7.] i'i Liquid Hydrochloric, ^c. 2"3 proposition holds with gaseous hydrochloric acid, formed hy equal volumes of chlorine and hydrogen, which chemically combine while the density is the mean of its components. What is the origin of the heat in this case ? The following ex- periments will give a satisfactory answer to this question : — A thin glass globe capable of holding 1800 grahis of water was successively filled witii this liquid, vvith the strong acid sp. gr. I'iy2, and with that of l-USii; and being in each case heated to the same degree, was suspended with a delicate thermometer im- mersed in it, in a large room of uniform temperature. The com- parative times of cooling through an equal range of the thermo- metric scale was carefully noted by a watch in each case. The fol- lowing were the results : — Globe with water cooled from 12 1° to 66° in 122 minutes Dilute acid 124 to 66 in 102 Strong: acid 12-4 to 66 in 8S o The glass itself had a capacity for heat equal to that of 150 gr. of water. Hence in the three cases we have the following relations between the quantities of matter cooled and the times of cooling : ... 1^2' X 100 ^ , ^, ,., .J 102' X 100 ^,., ^^^^"" 1800 -^ 150 = ^'^'^ 5 dilute acid ,,,, ^ ,,o = 46 ; strong acid ''' ^ '"'^ = 36./. 2154 + 250 J If water be called unity, or TOOO, then the dilute acid is 0*735, and the strong acid 0*586. These numbers represent the specific heats by experiment. But the dilute acid ought, from calculation, to have the mean capacity for heat corresponding to 6 strong acid 6 X 0-386 + 4 X i-ilO ^^,„ ttt i e + 4 water, = -^ = "/oie. We see, therefore, that the capacity is diminished in the ratio of '735 to •7''' 16, to which cause the evolution of heat is due. Conceiving that I observed in the successive stages of cooling of the several liquids indications of the relative specific heats varying at different temperatures, I made the following experiments to decide this interesting point. The samie glass globe and thermo- meter were employed : — Water cooled from 210° to 150° in 21-5' Concentrated oil of vitriol 210 150 17'0 ' Spermaceti oil, sp. gr. 0-915. ... 210 150 12-75 Oil of turpentine sp. gr. 0-875.. 210 J 50 11-25 Water 150 90 57 Concentrated oil of vitriol 1 50 90 39J Spermaceti oil, sp. gr. 0-915 .... 150 90 29 Oil of turpentine, sp. gr. 0-875 . . 150 90 25-83 Hence, including the specific heat of the vessel, and the differ- ence of density of the liquids, wc get the following equations : — Vol. X. N° IV. S 3 27*4 On the Quantity of Real Acid [Oct. Upper Range. Under Range. Water ^ = ^^' W = ^9-2' Sulphuric acid ....^ = 4-6' |^ = 10-64' Spermaceti oil • • • . 4|^ = 6-57' ^ = 15-0' Oil of turpentine . . . -pg^ = 6-0' -p^^ = 13-h' And reckoning water to be unity, or 1*000, Upper Range. Under Range, Water 1-000 1-000 Sulphuric acid 0-418 0-364 Spermaceti oil 0'597 0-513 Oil of turpentine 0-545 0*472 The ratios of the sulphuric acid, and of the two oils, are ob- viously proportional to one another in both ranges ; but the specific heat of the water, compared with these bodies, increases in a re- markable ratio as its temperature falls. Had I continued the expe- riments to still lower degrees of the thermometer, this difference would probably have become greater. But when the substance operated on approached the temperature of the atmosphere, which was then from 55° to 60° Fahr., the cooling was too slow to permit the intervals of time to be marked with the requisite precision. Hitherto the specific heats of bodies have been compared with that of water either at the freezing temperature, as in the calori- meter of Lavoisier and Laplace, or by admixture, or rate of refrige- ration, at very moderate heats. In all these cases the capacity of water, being at a maximum, has caused other bodies to stand rela- tively low in the capacity scale. The mean capacity of water, be- tween that of freezing and boiling, is probably to be placed at about the hundredth degree of Fahrenheit's scale. By thus possessing at ordinary atmospherical heats its maximum specific caloric, water is peculiarly fitted for performing its important function of a magazine and equalizer of temperature to the terres- trial globe. In describing the experiments performed with the view of deter- mining the composition of the chlorides, and the quantity of dry acid in liquid hydrochloric of a certain density, I shall make use of the old language and hypothesis at first, after which the substitution of the new may be readily made. The point of neutralization between acid and alkali was ascer- tained in the usual way by litmus paper; but it was occasionally found that a combination would appear neutral by this test when the solution was very dilute, which on concentration gave evident marks of an alkaline or acid excess. To this cause chiefly must we ascribe 18170 in Liquid Hi/drochloric, &c. 275 a very considerable error, vvhicli the celebrated Dr. Black has com- mitted, in his analysis of the Geyser water, as I demonstrated in a memoir on Alkali-metry, subjected about a year ago to the inspec- tion of Dr. Henry, of Manches'er. When a saline mixture ap- proaches the neutral state, it is advantageous to touch with the point of a glass rod dipped in pure water, a spot of the paper continuous to that where the combination is applied. The practical philosopher knows well what difficulties attend the actual analysis and synthesis of the salts, when the ultimate precision demanded by the doctrine of multiple proportions is sought for. * The following experiments are the results of at least a hundred trials. The evaporations were conducted on a nicely regulated sand-bath, in platina capsules, and the dry matter was ignited with a cover, to prevent loss by decrepitation j but very gently, so as to avoid the volatilization of the salt. Chloride of Potassium. ExPER. I. — 50 grains of recently ignited subcarbonate of potash from tartar, containing 34*3 grains of potash, took for neutralization 700 grains of a diluted muriatic acid, equivalent to 70 grains of that whose specific gravhy is 1-192. 54 grains of muriate gently ignited were obtained. As 54 contain 34-3 of potash, 100 grains will consist of 63*52 potash and 3(>-48 acid. And if 70 grains of liquid acid be equivalent to 197 t>f dry, 100 will contain 28*14. 100 grains of subcarbonate take 140 of the above strong liquid acid for saturation, and yield 108 grains of muriate. ExPER. II. — 50 grains of pure bicarbonate of potash in crystals, equal to 34' 5 subcarbonate and 23*67 potash, took 480 grains of dilute acid, equal to 48 of the strong. 37*25 grains of muriate were obtained. As 37"25 is to 23*67 of potash, so is 100 to 63*54 base and 36*46 acid. Here also 100 grains of subcarbonate yield 108 of salt. 100 grains of subcar- bonate take in this experiment 139 grains of the strong acid, which gives 28*3 per cent, of dry acid. A hundred parts of muriate of potash will yield by decomposition with sulphuric acid 129-^ of liquid muriatic acid, specific gravity 1*192. Fifty grains of subcarbonate of potash contain 28*6 potassium, which constitute the basis of 54 of chloride, leaving 25*4 of chlo- rine. Hence 100 chlorine take 112*6 potassium j or in 100 parts we have 53 potassium +17 chlorine. Chloride of Sodium. ExPER. I. — 100 grains subcarbonate of soda, from a recently Ignited pure bicarbonate, took for neutralization I8V6 grains of the strong liquid muriatic acid ; and 1 1 1*7 grains of muriate were ob- • This is usually, but I humbly apprehend too vaguely, called the doctrine of definite proportions. Definite proportions have been inculcated ever niece tbr fact of luline neutralisation wat known. S 2 27^ On the Quanlily of Real Acid [Oct. tained. 100 of this subcarbonate contain 40*9 grains carbonic acid and 59-1 soda. Hence 100 parts of muriate are composed of 52-9 soda + 47'1 acid. Here we have 28-G grains of dry acid in 100 oi' the liquid. ExPKH. II. — 50 grains of a similar subcarbonate took 9 r4 of the above liquid acid, and 5r>-4 of gently ignited muriate were obtained. In 100 parts 53-34 soda + 46*66 acid. Here we have 28-3 of dry acid in 100 of the liquid. The proportion of dry acid in this last experiment, compared with that deduced from the muriate of potash, shows it to be the more correct of the two experiments on muriate of soda. 100 parts of this salt should yield by careful decomposition 165 parts of liquid muriatic acid of the density 1*190 formerly required by the London College. Extraordinary errors on this subject are to be found in some chemical compilations. Contemplated as a chloride, we have 53-3 soda, equivalent to 39*98 sodium. Hence 39*98 sodium + 60*02 chlorine = 100 chloride. And 100 chlorine combine with €6*61 sodium. Chloride of Calcium. Exi'KR. I. — 50 grains of rhomboidal calc spar dissolved in mu- riatic acid, in a long necked glass vessel, such as was employed also in the above experiments, to prevent loss by effervescence, afforded after careful evaporation and ignition, 55*1 grains of muriate. ExPER. II. — 50 grains of a similar spar yielded 55*4 grains of gently ignited salt. ExpEK. III. — 100 grains of pure lime took for neutralization 340*0 grains of the strong liquid muriatic acid, of which 100 grains contain 28*3 of dry acid in the muriates, corresponding to 36*5 of chlorine, as deduced from the preceding chlorides. It may here be remarked, that to discharge the water, which adheres so forcibly to the muriate of lime, without partial decom- position, is a very nice process. A bright red heat speedily disen- gages so much of the acid as to enable the watery solution made from that muriate to darken litmus paper. I have repeated the syn- thesis of muriate of lime more than 50 times, particularly in my researches on magnesian lime-stone, and could not obtain a de- sirable uniformity of results with a strong heat. Hence Mr. Ten- nant's process for separating magnesia from lime, by igniting the mixed muriates, is incapable of giving final precision, because the muriate of magnesia requires such an intense heat for its entire de- composition as to affect, more or less, the muriate of lime. I believe that the mean of the two preceding experiments must be very nearly exact. We may, therefore, consider 100 grains of calc spar equivalent to 110-5 of ignited, but perfectly neutral, mu- riate. From the above experiments we may deduce, not only the composition of the chloride, but the weight of the atom of calcium. The atom of carbonic acid is assumed 27*51, oxygen being 10. Now as 43*6 of it combine with 56*4 of lime to form the carbonate, the atom of lijne weighs 35*58, and that of calcium 25*58. I con- 181 7.] in Liquid Hijdrochloric, &c. S77 ceive that the number 36*20, given by you, is much too great. In round numbers, 35'f; is very near the truth. Therefore 56-4 lime will consist of 15-85 oxygen and 40-55 calcium. Hence 110-5 chloride contain 40-55 calcium, and the remainder 69-95 is chlo- rine. Or 100 chlorine combine with 58 calcium. The atom of chlorine thence deduced is 44- IS. A hundred grains of calc spar take for saturation or solution \9Q grains of the above liquid hydrochloric acid. Chloride of Silver. From the mean of several experiments, I find this to be composed of 100 chlorine and 307-5 silver. In one experinient, very care- fully conducted, 100 parts of pure silver, sp. gr. lO-Ji;, revived from the muriate, gave 157*66 of dry nitrate, and afterwards of gently fused luna cornea, 132-41. Here 100 parts of chloride contain 24-476 chlorine + 75'524 silver. Or if we state it in the old language, as an oxide of silver, we have 75-523 silver + 18'03 muriatic acid + 5-547 oxygen. Hence 100 oxide contain 7-34 oxygen. This experiment gives 100 chlorine to 303-5 silver. If we compare together the whole of these experiments, we shall find that muriatic acid, of the sp. gr. 1*192, contains 2S-3 parts in the hundred of dry acid. In the first two experiments on chloride of calcium we have an unexceptionable means of verifying the accuracy of the third. As their mean gives the relation of dry acid and lime as the numbers 54*1 to 56*4; then 96*22 of dry acid, present in the 340 grains of the third experiment, should neutralize 100*3 of lime; and the actual number by experiment is 100, a coincidence of the most satisfactory nature. Mr. Dalton, in the second volume of his new System of Chemical Philosophy, gives a modified copy of Mr. Kirwan's table of muriatic acid, which, he says, is nearly correct. Acid of the sp. gr. 1*192, according to this table, contains only 24-75 of dry acid by weight, instead of 28*3. Having repeated my experiments, with every precaution to ensure accuracy, I am certain that the number 28-3 does not differ from the truth by more than the decimal fraction, provided it differ so much. And in a note to p. 454 of Dr. Henry's valuable System of Chemistry (edition of 1810, vol. i.), we are led to believe that 100 parts of common salt should afford 414 parts of liquid acid, sp.gr. 1*160. Now 100 parts of salt will yield no more, 1 apprehend, than 186*3 of that density. He takes his data from Berthollet. The difference is no less than 55 per cent. In the last edition of this deservedly popular work the above note is properly suppressed, and the quantity of acid to be obtained from 100 parts of salt is said to be about equal weights, the acid liaving a specific gravity of 1142, that lately prescribed by the London College. Now as this acid contains 21 per cent, of dry acid, we ought to have 220 parts of it from 100 parts of the muriate of soda. If the table of muriatic acid given by Mr. E. Davy, as deduced 278 Mode of exploring the Interior of Jfrica. [Oct. from condensation of the gas, be compared with mine, a near ac- cordance will be found. His acid of 1"190 contains 38'38 of mu- riatic acid gas in the 100 grains of liquid. At the same density 100 of mine contains 3G'5 of chlorine + 1'09 hydrogen = 37*59 of hydrochloric or muriatic acid gas. I remain, dear Sir, your most obedient servant, Anderson's Institution, Slasgoa, AnDRBW UrB July 17, 1817. P.S. Id my Experimental Researches on the Ammoniacal Salts, published in the last ciiimber of the Annals, two typographical errors of importance occur. The first, p. 207, linr 7, members is printed instead of numbers. The secend, p. 212, near the bottom, where I endeavour to show the incompatibility of M. Gay-Liis^ac's experimental results with his theory of volumes, the word grains has been improperly inserted after 10. Now, not grains, but volumes, is obviously meant, on the proportions of which, indeed, the wholi; reasoning of the paragraph hinges. I do not think the word grains existed in the copy : the sense is complete without it. Article V. Memoir on the Mode of exploring the Interior of Africa. By H. Edmonston, Esq. Surgeon, Newcastle-upon-Tyne. (Concluded from p. 112.) The ingenious Editor considers the practicability of penetrating beyond the kingdom of Bambarra as not finally settled by the re- sult of Park's journey. If he mean the general point of practica- bility, he is right. It is not settled. But if Amadou Fatou ma is to have credence, and the respectable writer in question inclines that way ; and if the reasoning I have employed be correct, the practicability of penetrating much beyond Bambarra by forcible means has, one should think, been well nigh settled in the negative for ever. So far from the danger, as this writer alleges, *' dimi- nishing as he (Paik) advanced," every consideration of prudence, reason, and testimony, lead us to draw an opposite conclusion. It is doubtful how far inward the Moorish dominion extends in Africa. It would seem from the evidence already cited of Amadou Fatouma, that as soon as Park passed the frontier of Bambarra, the country was every where on the alert against him. Of this he must have been too feelingly aware, for he pushed on as if afraid of delay, till at last he was overpowered by numbers, and said to have perished by leaping into the Niger. Indeed, it was scarcely possible that any better termination could ensue from an enterprise so commenced and so constructed. The only wonder is, that it was suffered to proceed so far. But even allowing, for the sake of those who are determined to shut their eyes to all obstacles and all dangers, that Park and his 50 armed followers had reached the disemboguement of the Niger, an event of which there is some reason to imagine the bare possibility, had it not been for the rainy season taking him at a disadvantage; and supposing also, as has been done by one of the first authorities. Major Kennel, that this disemboguement takes place in a lake or IS 170 Mode of exploring the Interior of Africa. 279 morass in the interior of the African continent ; it by no means follows as a certain consequence that this military expedition could have accomplished its final purpose. Granting that he passed in safety on the Niger, through the territories of Tombuctoo and Houssa, which are conjectured to be the districts to which the Moorish sovereignty is chiefly confined in that quarter, the Moors would be placed between him and the coast, and would not fail to exert all their influence to render ultimate success abortive. In passing rapidly down the Niger, as Park did, it would be impossible to pay tribute to all ; and if not to all, the disappointed would, when the opportunity occurred, revenge the omission. In fact, the dissatisfaction of the natives was beginning to manifest itself shortly after his embarkation. Having, however, as we may admit, attained the great object of all their search, the termination of the majestic Niger, in a lake or morass in the heart of Africa, the expedition must, I presume, find its way back. How this is to be done in a most difficult country, against a current running six miles an hour, I do not well perceive, nor have the advocates for military escort been at pains to explain. It must occupy a considerable time, even admitting the utmost celerity of motion, and the most perfect exemption from every sort of accident, interruption, or molestation. Shall it be said that the pestilential season may not overtake them, in the midst of this labo- rious navigation ? Where and how they are to pass this period of rain and sickness does not clearly appear. If, on the other hand, we view the whole country as inimical, the canoe to be damaged, and various other casualties, not very un- likely to happen, I suspect, to say the least of it, we shall have but too good grounds for fearing that, even with their fire-arms and their superior intelligence, the individuals composing such an expe- dition would find great difliculty in extricating themselves from their perilous situation. In fact. Park himself considers the return by the Niger as a thing impossible. But in truth, even the expectation of ultimate good fortune to such an expedition as Park undertook, and indeed to every military expedition, must proceed upon two assumptions, which, if they do not at last turn out to be absolutely false, are in the mean time so perfectly unfounded in fact, that no enterprize which has the smallest atom of prudence for its basis can be hazarded on the sup- position of their stability. The first of these assumptions is, that the River Niger empties its mighty and continuous stream into the sea ; a fact of which there is not yet the slightest shadow of proof, whatever the presumptions in its favour may be. The second is, that this immense body of water is easily navigable throughout the whole extent of its course. The direct reverse of this is presumptively, if not directly proved, both by the existence uf numerous rapids between Bambakoo and Sansanding, mentioned 2S0 Mode of explor'nig the tntenor of Africa. [Oct. by Park himself, and also by the account given by Amadou Fatouma. For all these reasons, I am afraid we dare not permit ourselves to anticipate any other result than defeat to every enterprize conducted upon similar principles ; and extreme danger, if not absolute de- struction, to all immediately concerned in it. While I thus have expressed myself in strong terms of disapproval of all military expeditions to Africa, let me not be denounced br persons who cannot or will not see danger any where, as one of those whom Dr. Johnson has characterized as " of narrow views and grovelling conceptions, who, without the instigation of per- sonal malice, treat every new attempt as wild and chimerical, and look upon every endeavour to depart from the beaten track as the rash effort of a warm imagination, or the glittering speculation of an exalted mind, that may please and dazzle for a time, but can produce no lasting advantage. These men value themselves upon a perpetual scepticism, upon inventmg arguments against the success of every new undertaking, and where arguments cannot be found, upon treating it with contempt and ridicule." Life of Sir Francis Drake.) I trust I am neither so wilfully obstinate nor stupid as not to be aware that the accomplishment of every thing great must be at- tended with great hazard. But I apprehend where the object is interesting to science, and to mankind at large, and especially when the lives of men are to be put in imminent danger, causes of diih- culty, even the most insignificant, are not to be overlooked. The evil consequences of miscalculation, and of the want of due deli- beration, have been already too fatally experienced. Having enumerated what appears to me to be insurmountable objections to the attempt of penetrating into the interior of Africa by force of arms, I shall next take the liberty of offering some suggestions, calculated, I hope, to effect the purpose of discovery, upon easier, safer, and less costly terms. I take it as a matter agreed upon by all, that the intellectual qualifications required for a first explorer of Africa are by no means of the highest order. The leading facts to be ascertained in the first instance are the course and termination of the river Niger. To these may be added a few of the principal geographical features, the natural productions, and something of the inhabitants of the country. These particulars are within the compass of any capacity raised a little above mediocrity. A slight talent of observation, good common sense, an expertness at taking the latitude and longitude of places, the altitude of mountains, and a few other requisites, comprise, I should suppose, all that is necessary. To determine where and how the Niger terminates, whether the face of the country be mountainous or flat, the soil moist or dry, the people dark or fair, mild or ferocious, demands not the varied study and complete apparatus of a Bruce, the philosophic research of « 18170 Mode of exploring the Interior of Jfrica. 281 Volney, the knowledge of architecture and antiquity of a Denon, the zoological discrimination of a Pallas, or the profound and ex- tensive science of a Humboldt.* For any immediate purpose, all these points may be as satisfactorily ascertained, and as accurately described by a traveller ot moderate abilities, as by any of the cele- brated personages whose names have just been cited. The attain- ments of Hearne, Mackenzie, and Park, were far from being splendid ; yet the one determined the course of the copper-mine river, at Hudson's Bay; the other settled the long agitated question of a north-west passage ; and the third ascertained the existence and direction of the Niger. I am the more desirous of directing attention to these things, because, if an imaginary excellence is to be held indispensable, the difficulty of procuring properly qualified persons will be increased to such a degree as to forbid tiie hope of ever finding them. Indivi- duals of exalted rank in science will not sacrifice their valuable time and labour, unless for such recompence as neither the funds of the African Association, nor the views of Government, will admit of being acceded to. I notice it for another important reason ; namely, to show the little necessity which there is for a first explorer taking with him a complicated geographical apparatus ; an incumbrance tending not only to increase tlie bulk of the baggage, and the difficulty of locomotion, but likewise the dangers of the route, by awakening the jealousies and cupidity of the natives. In fact, it is not required to take any other instruments than a few quadrants and pocket compasses. This was the plan adopted, though imperfectly, by Horneman, who avoided as much as ))ossible every appearance that miglu give cause of offence or suspicion to the people. On this part of the subject it was with much satisfaction I found the following opinion given by Jackson in his Account of Morocco. •' If their (the African Association's) emissaries have not always been successful, or have obtained information only of minor importance, compared with the great object of their researches, it is to be attri- buted to their want of a sufficient knowledge of the country, and the character and prejudices of its inhabitants, without which, science to a traveller in these regions is comparatively of little value." In selecting individuals for the undertaking, it might not be without advantage to descend to minutic-e. Of two persons cqu;illy well qualified, one of a dark should be preferred to one of a light complexion. * Of all men, probably Park was, with one exception, the best fir(c(l for an original explorer. Endowed with a liardv cotistittitinn, iiiKDoqutralile intre- pid itj, wnshaken iierieveranec, great penetration and prp>eiK'e of mind. il\s pnly di'fert w;is wlial, nnder almost any other circntnstanco', \ronld have been held to be a virtue — an e.vtrerne ardour in regard to ihc sueress of the enterprise, >yhith prevented liis .jnd{:ineMt from exercising its due inllucnce in regulating hia plans, and anticipatiinj tlie diOicultiet rcaioniibly to be ovpcited. 282 Mode of exploring the Interior of Africa. [Oct. These and other preliminary matters being settled, one, two, or three young men (or whatever number the government appoint) should be chosen. Wliethei- the stations whence the journey is to commence be the Gambia or the Congo, or both, or any other, there should be but one traveller to each. This is the more necessary when we recollect that Park's life on hh first yonxnty was never in danger, unless from physical and otiier casualties, to which every traveller is liable. He encountered no difficulties, no perils, from which numbers could have saved him, but which would have been augmented fifty fold had he been accompanied by fifty armed men ; nor from Isaaco's Journal does it appear that his progress was ever seriously impeded, or his life put to any imminent danger. Each voyager being provided with every necessary on the smallest portable scale, he is to repair to his post. His first object should be to conciliate the favour of the Moorish authorities in the neighbour- hood, to form an acquaintance with, and to gain, if possible, the entire confidence of, one or two intelligent Moors ; if merchants or priests, so much the better. With their, and such other aid as may be obtained, he should begin to study the language of the country, and the different dialects which may be most necessary on his route,* making himself intimately acquainted with the manners and customs of the inhabitants, and with every particular that may be in the least interesting or important. On his first arrival, it would be advisable to assume the Moorish dress, and to expose himself to the influence of the sun, so as to cause his face, and those parts of the body that are geneially exposed in those climates, to put on a tanned appearance. In regard to the subject of dress, on which so much depends, and on which I have dwelled at large in another place, I have again great pleasure in bringing forward the author already quoted: — " When we consider the disadvantages under which Mr. Park laboured in this respect [viz. knowledge of the country and its inhabitants], and that he travelled in a European dress, it is really astonishing that that gentleman should have pene- trated so far as he did in his first mission ; and we are not so much surprised at the perils he endured, as that he should have returned in safety to his native country. Had he previously resided a short time in Barbary, and obtained there a tolerable knowledge of the African Arabic j and, with the mstorns, adopted the dress of the * Of all the languages to be leained, the Arabic secm.s to be the most useful. Park on iimrc occasions llian one experienced the disadvantages of his deficiency tn this nx)5t essential point ; and even Hornemann, though better versed in it, found that a greater pnificience would have been in his favour. It is this accom- plishment which, more (han any other, tends to allay the suspicions of the Moors on the score of religion, by convincing them that the person possessing it can read the Koran, tliat great ;.nd indispensable criterion of Islamism : and it is this also that, by working on the religious fears and superstitions of the inferior classes, eives a character of sanctity and imj)orfance which notliing else can bestow. — Quaere: would it be an unjusliSuble breach of morality to practise a few of the external and minor ceremooies of Islumism, in order to mislead the faoaiical Moors ? J 8170 Mode of exploring the Interior of Africa. 2S3 country, what might we not have expected from his perseverance and enterprising spirit? Whatever plans future travellers may adopt, I would recommend to them to lay aside the dress of liurope; for besides its being a badge of Christianity wherever he goes, it inevitubly exposes him to danger; and it is so indecent in the eyes of the Arabs and Moors, that a man with no other clothing than a piece of linen round his middle would excite in them less indig- nation." (Jackson.) In order to acquire these preparatory requisites, it is obvious that a prolonged residence will be necessary. During this residence he should, in company with his Moorish friends, make occasional ex- cursions lo different parts in the neighbourhood, investigating points of natural history, and other circumstances connected with the objects of his journey. The knowledge of these points, if nothing else should be gained, would be valuable. But, what is of more consequence, he would thus, on tlie small scale, habituate his mind to the duties of his mission, to the difficulties, and the means by which they are to be successfully met. His constitution would be- come inured to the climate and food, his plans would be gradually unfolded, and all unfavourable suspicions of his designs removed. This, it is well known, is a matter of some moment. Horneman experienced much annoyance on account of it; and Jackson informs us that *' no people under heaven are more jealous or more sus- picious of every thing which they do not comprehend than the Africans." Having remained a sufficient time to acquire all the previous qualifications ; having estimated the characters of his Moorish friends, and ascertained in whom confidence is to be placed, the next point of importance is to determine what form the expedition is to assume. Perhaps it may be advisable for him to choose one or two Moors as guides, or part interpreters, or rather as attendant merchants or priests, for the purpose of engaging the attention of the natives, particularly the Moors, and leaving the traveller at leisure to make his observations.* Some such arrangement will appear the more necessary, for we find Park, instead of having time to pursue the objects of his journey, continually occupied with measures for the preservation of his property and life. • Jackson does not approve of the confidence which Horneniann placed in his African fellow travellers; and he thinks that he was too sanguine in his expecla- tions. But it is not the casual acquaintance of a Shereef in a caravan, as in the case of Hornemann, that is here insisted on. Jackson says that he had written " several remarks on Mr. Hornemann's Journal, which he intended to g ve in an Appendix; but as they might create ill-will, and involve him in useless contro- ■versy, he had suppressed thera." It is hardly to be granted him that the contro- versy would have been a useless one. The remarks of so Intt'llijeiit an observer must have been valuable ; and if they had relat'd to Hornemann's mo'le of ex- ploring the country, it is l.i be regretted that they were not given. They might have been some guide to ihe leaders of the last expeditii ns. However, it is to be hoped that «o competent an authority as Air. Jackson has not been left uncon- •ulted on such an occasion. — From what he says, Morocco would appear to be a favourable point from which to proceed on a journey to the interior. 284 Mode of exploring the Interior of Africa. [Oct. Hornemann assumed the character of a Turkish merchant ; and had he shown sufficient address in supporting the character, there is reason to believe that it would have saved him from all interruption. As it was, he was only once in danger, and then from his indiscreet curiosity in examining some ruins, which led the ignorant and bigotted Mahometans to suspect that he was in reality a different person from what he gave himself out. Probably the most eligible plan would be for the traveller to appear in some subordinate capacity, and leave the distribution of tribute, and in general the economy of the coffle, to his Moorish companions. In the history of Hearne's journey in North America there are many apposite illustrations of the advantage of this mode of travelling among barbarous tribes. Of all these arrangements, however, the traveller himself will be best able to judge correctly, from his own observation on the spot. Since tJovcinment patronizes these expeditions, they should be carried on upon a scale worthy of a great country. Every exploit which has in view to extend the sphere of natural knowledge, and to enlarge the stock of national wealth, is deserving of liberal en- couragement. Frugality ceases to be a virtue when it is exercised in starving exertions which are intended to benefit both the present age and posterity. Every department of the expedition ought to be furnished with a munificence that should leave nothing to be desired. Those Moors who may be induced to accompany the mission should be encouraged by the assurance of rich rewards for their services. Articles of agreement should be entered into conformably to the legal forms of the countrj', by which provision should be made for the permanent support of their families in case of death, or any other misfortune, and an increase of remuneration in case of success. In short, no expense should be spared, when it is considered that a fortunate result must depend chietiy on their fidelity ; and if they fail in their duty from any mistaken parsimony in the previous ar- rangements, the whole expense may be regarded as thrown away. While other preparations are going forward, it would be well for Government, through its Ambassadors and Consuls at all the Turkish and Moorish States in Europe, Asia, and Africa, to obtain every sort of recommendation necessary to ensure, as far as that can be done, a favourable reception from the Moorish authorities in the interior. Political influence, religious prejudices, every means should be laid hold of to promote the object in view. It was in this way, and this alone, that Bruce succeeded in Egypt and Abyssinia. Had he not been supplied with letters and rescripts from religious and civil authorities, which at the time of receiving them he re- garded as superfluous, in all likelihood he must have fallen a victim to the barbarity of those among whom he travelled. " His mode of travelling was peculiar to himself. He omitted no opportunity of securing the means of safety in foreign countries, by methods whicii other travellers have often neglected, to their great disadva,q-r tage." (Preface to Bruce's Travels.) 1817.] Mode of exploring the Interior of Jfiica. 285 The -party, consisting of as small a number as possible, sliould caiTv with them such arms only as are required for their defence, in case' of any sudden attack of men, or wild beasts, or for procuring food ; and it would seem highly expedient that they lay in no other kind of tribute than what the' JMoorish coffles or the slatees are in the daily habit of taking. Much caution will be required, when the party sets off, to prevent its departure and its intentions from being bruited abroad. Sonie idea may be formed of the celerity with which news spreads in Africa, for we are told of Karfa Taura, tlie hospitable friend of Park in his first mission, performing a six days' journey to meet him on his second expedition, " having just heard that a cofHe of white men was travelling the country." Every requisite provision having been thus previously made, the traveller may set out with some reasonable hopes of success. But, above all things, he should be prepared for spending a considerable time on the journey. He is not to traverse the country as if he were running a race against time, or against the elements. If the un- healthy season overtake him, he is to remain where he is, and not to attempt to vanquish physical impossibilities. He is occasionally to take up his abode with the natives, when iUness, or the necessity of removing suspicion from their minds (as happened to Isaaco) shall render it prudent. The proposal of Park's Editor of employing Mahometan traveller! to explore Africa seems to be very unfeasible. They have none even of the elementary points of science; a long time would be neces- sary for their instruction, and consequently the expense would be great ; nor could tlie same dependance be placed on their narrative* which tiiose of Europeans claim. Besides, we are already in pos- session of all the information which Mahometans can give us, and still it is considered unsatisfactory. Travellers have on different occasions derived advantage from appearing in the character of physicians. Bruce studied physic for the express purpose, with Mr. Ball, surgeon to the consulship at Algiers, and with Dr. Patrick Russell at Aleppo, and found it of the greatest service. Sonnini, who was a captain in the French navy, and knew nothing of medicine, gave himself out for a phy- sician, with the greatest advantage to his pursuits. Park already possessed this qualification, and found it serviceable. It is therefore advisable that those who may be fixed upon in future should make themselves acquainted with some of the principles of this science. And this naturally suggests the propriety of making our military stations on the African coast in some measure sul)servient to the purpose of exploring the interior of that vast continent. The sur- geons and assistant surgeons of corps in our garrisons there should seem to be the fittest for this destination, and they should be selected with this view. The situation presents every facility and ample leisure for perfecting themselves in all the preparatory steps. 286 Extraordinary Case of a Blind Woman [Oct. But it is sufficiently evident that some considerable inducement should be held out to invite men to the enterprise. It is not the temptation of a small piece of money that ought to be considered sufficient ; but such a sura as should, if the adventurous individual be successful, constitute a comfortable provision for his after life, or for that of his family should he perish. Newcastle-upon-Tyne, June, \^n. HeNRY EdMONSTON, Article VI. Extraordinanj Case of a Blind Young Woman who can read ly the Points of her Fingers. By the Rev. T. Glover. (To Dr. Thomson.) SIR, Being lately on a visit at Liverpool, I had a favourable oppor- tunity of witnessing the exercise of an extraordinary faculty pos- sessed by a blind young woman, named Margaret M'Evoy ; and I have been induced, by the request of my friends, to send the results of my experiments for insertion in your journal. Without pretending to give a medical report of this singular case, which an abler pen is preparing for the public, I shall briefly pre- mise that Miss M'Evoy is a native of Liverpool, and about 17 years of age. She became blind in the month of June, 1816, from a disorder in the head, which was supposed to be water on the brain, and which was treated as such : she was partially relieved by a dis- charge from the ears and nostrils. She has since experienced two returns of the same disease, and each time has been relieved by a similar discharge of fluid. A portion of this fluid has, I believe, been analyzed by Dr. Bostock. She has remained completely blind from the time of the first attack. She first discovered by accident, about the middle of October, 1816, that she could read by touching the letters of a book. Having blindfolded her in such a manner that I was certain not a ray of light could penetrate to her eyes, I made the following experiments, most of which had not been tried before. 1 copy the results from notes taken on the spot, and nearly in the order in which they were made : — ExPKR. 1. — I presented to her six differently coloured wafers fastened between two plates of common window glass. She accu- rately named the colour of each. She pointed out, unasked, the cracks and openings in the wafers. Being asked, while touching the surface of the glass above the red wafer, if the substance under mipht not be a piece of red cloth or paper, she answered, " No, I think it is a wafer." 1 18170 ^^^^^ <^^^ '■^'^^ ^y ^^'^ Points of her Fingers. 287 ExPER, II.— She described the colour and shape of triangular, square, and semicircular wafers, fastened in like manner between two plates of glass. ExPKR. 111. — To the seven prismatic colours, painted on a card, she gave the following names : scarlet, buff, yellow, green, light blue, dark blue or purple, lilac. As the orange paint was much faded, the term buff was correctly applied to it. ExPER. IV.— The solar spectrum being thrown by a prism, first on the back, and then on the palm, of her hand, she distinctly de- scribed the different colours, and the positions which they occupied, on her hands and fingers. She marked the moments when the colours became faint, and again vivid, by the occasional passage of a cloud. Oq one occasion she observed that there was something black upon her hand : hut perceiving it to move, she said it was the shadow of her own fingers, which was correct. The prismatic colours have afforded her the greatest pleasure which she has expe- rienced since her blindness ; the violet rays were the least pleasant. She never saw a prism in her life. ExPER. V. — ^The prism being put into her hands, she declared it was white glass ; but, on turning it, she immediately said, " No, it is not; it is coloured; it has colours in it : " and she traced with her finger what she called " bent stripes of colours." She could discover no colours on that side of the prism on which the direct rays of light fell. ExPER. VI. — She perceived the coloured rings formed by press- ing together two polished plates of glass. She said she felt them at the edge of her fingers flying before them. ExPER. VII. — Several attempts were made to ascertain whether she could discover colours in the dark, by presenting differently coloured objects to her hands, concealed under a pillow. She always failed; every thing appeared black. On one occasion she said a green card was yellow. ExPER. VIII. — She read a line or two of small print by feeling the letters. She next read through a convex lens at the distance of nine inches from the book. I'iie principal focal length of the lens is 14 inches. While reading, she gently rubs the upper surface of the lens with the tips of her fingers ; she leads much easier through the lens than without it; she says the letters appear larger, and as If they were printed on the glass. A penknife was laid on the line which she was reading, and she immediately perceived and named it. ExPER. IX. — A concave lens being put into her hands, she tried to read through it at the distance of seven or eiglit inches, but said that the letters were all confused. As she moved the lens gradually towards the book, she at length perceived the letters, but observed that they were very small. She could not read easily until the glass was laid on the paper. ExpER. X.— She read common print by feeling on the upper surface of a piece of common window glass held 12 inches from t^ 288 Extraordinary Case of a Blind JVoman [Oct. book. At a greater distance she coulrl not read ; but could read much easier when the glass was brouglit nearer to the book. In like manner she perceived through the glass several coins spread out before her; told which had the head, which tiie reverse upwards j pointed out the position of the arms, crown, &c. ; read the dates j and observed, unasked, that one half-guinea was crooked. ExPER. XI. — On applying her fingers to the window, she per- ceived two newly cut stones, of a yellow colour, lying one on the other, at the distance of 12 yards. She described a workman in the street, two children accidentally passing by, a cart loaded with barrels of American flour, another with loaves of sugar, a third empty, a girl with a small child in her arms, &c. One of the company being sent to place himself in different poiiitions, she marked every change of position as soon as any one with his eye- sight could have done. A middle-sized man at the distance of 1 2 yards did not appear, she said, above two feet high. As he ap- proached nearer, she observed that she felt him grow bigger. All objects appear to her as if painted on the glass. ExPER. XII. — A stone ornament in the shape of an orange she took for a real orange, feeling through the plane glass, at the dis- tance of two or three inches; at tlie distance of 15 inches, it ap- peared no larger than a nut ; at 30 inches distance, it was dimi- nished to the size of a pea, the brightness of the colour remaining undiminished. ExPER. XIII. — On touching a plane glass mirror, she said that she felt the picture of her own fingers, and nothing else. ExpEU. XIV. — Holding a plate of plane glass three or four inches before the mirror, she was then enabled to perceive the re- flected image of herself. When the mirror was gradually removed further off, she said her face diminished. All objects constantly appear as a picture on the glass, which she touches. ExpER, XV. — She perceived through a plane glass, as before, the image of the sun reflected from a plane mirror ; also the sun itself. She said that she was not dazzled with it, but found it very pleasant. ExPER. XVI. — She accurately described the features of two persons, whom she had never seen before, holding the plane glass at the distance of three or four inches from the face. ExPER. XVII. — Several small objects were held over her head. She perceived them all through her plane glass. On one occasion slie asked, doubtingly, if a three-shilling piece was not a guinea; but raising the glass, and bringing it nearer to the object, she cor- rected her error. ExPER. XVIII.— She was unable to distinguish colours by the tongue; but holding between her lips the red, yellow, blue, and white petals of different flowers, she told the colour of each accu- rately. ExpER. XIX. — She accurately distinguished polished glass from natural crystals by the touch. She declared three several trinkets 2 1817.] ii'ho can read by I he Points of her Finger si 280 to be glass, which were believed to be stone : being tried by a file afterwards, they proved to be paste. She also distinguished between gold, silver, brass, and steel; likewise between ivory, tortoise-shell, and horn. " Gold and silver," she said, " feel finer than the other metals : crystals feel more solid, more firm, than glass." ExPKR. XX. — She could not discover, by feeling, any difference between pure water and a solution of common salt in water. These experiments were frequently repeated and varied, during the space of three days that I had the opportunity of seeing her, with the same results. 1 must observe that this faculty of distinguishing colours and objects is more perfect at one time than at another: sometimes it suddenly and entirely fails; then every thing, she says, appears black. This sudden change seems like to what she remembers to have experienced when a candle has been extinguishedj leaving her in the dark. She says that she has not been taught by any one to distinguish colours by her fingers ; but that, when she first perceived colours by this organ, she felt convinced that they were such and such colours, from the resemblance of the sensations to those which she had formerly experienced by means of the eye. From the preceding facts, it appears evident that Miss M'Evoy has perceptions, through the medium of her fingers, similar to those which are usually acquired through the medium of the eye. With respect to the manner how she acquires them, and the neces- sity of an intermediate transparent substance when she does not actually touch the object, I shall offer no conjecture. I have only further to add, that she has no apparent motive for attempting to impose upon those who visit her, were such an impo- sition practicable. She receives no remuneration from visitors. On the contrary, the mere presence of a stranger agitates her consider- ably for a time ; so very weak and delicate is her state of health. Any noise or bustle affects her still more painfully : and I am ashamed to say that some of her visitors have showed a great and culpable disregard for her feelings, and subjected her to much unnecessary inconvenience. I remain, Sir, &c. StonyhuTSt, Aug. 25, 1817. T. GlOV£R. Vol. X. N° IV. 290 Proceedings of Philosophical Societies. [Oct. Article VII. Proceedings of Philosophical Societies, ROYAL ACADEMY OF SCIENCES. Analysis of the Labours of the Royal Academy of Sciences of the Institute of France during the Year 1816. Physical Part. — By M. le Chevalier Cuvier, Perpetual Secretary. ZOOLOGY, ANATOMY, AND ANIMAL PHYSIOLOeY. (Continued from p. 226.) M. Cuvier has terminated the work on which he has been so long employed on the anatomy of the molusca by a long memoir on the poulpe, the seiche, and the calmar. The genera which we have just named are the most remarkable of that numerous class of animals, by the complication and the singularity of their structure. Provided with three hearts, with a very extensive nervous system, with large eyes as well organized as those of any animal with ver- tebrae, with very singular excretory viscera, formed upon a plan of which nature affords no other example. They deserve well the attention of naturalists. The author has added this memoir to all those which he had pre- viously read to the Institute on animals of the same class, in order to form a quarto volume, with 36 copper plates, which has just appeared under the title of Memoirs to serve as a History of the Anatomy of Mollusca. While making these anatomical researches on the seiches, M. Cuvier had an opportunity of ascertaining the nature of a fossil pretty common in our calcareous beds, and which had hitherto pre- sented an inexplicable enigma to geologists. It consists of a bony substance, concave on one side, with a radiated edge, convex on the opposite side, and furnished with a long spine between the con- vexity and the edge. It is now demonstrated that this is the lower extremity of a bone of a seiche. It is astonishing that so evident a resemblance was not sooner recognized. The fresh water in some parts of the south of France breeds a very small shell similar to a shield, terminated by a pointed and re- **urved needle. It had been considered as a univalve, and had been called the ancyle epine de rose. But M. Marcel de Serres has just satisfied himself that it is one of the valves of a regular bivalve shell, the hinge of which possesses peculiar characters. He has therefore formed a genus of it, which he calls acanthis. The animal of this hell has not hitherto been observed. Animals without vertebrae in general, considered with regard to 1817.] Royal Academy of Sciences. 291 their classification, and the enumeration of their species, form the object of a great work, of which Lamark has just pubHshed the first three volumes in octavo, beginning with microscopic animals. The author then proceeds to the polypi, whether at liberty, or supported by the masses more or less solid, to which the name of corals has been given. He then comes to the radiated animals, a class under which he comprehends the soft beings commonly called sea nettles^ and those to which their envelope, often spiny, has given the name of echinodermes. He makes a fourth class, which he calls tunicies, of those com- pound raollusca, of which M. Savigny has made us about a year ago acquainted with the singular history ; and likewise of the simple moUusca analogous to those the re-union of which forms them. The fifth class comprehends the intestinal worms, to which the author joins some fresh water worms, which ought, it would seera, to have remained among the annelides. His third volume terminates with a portion of the insects. The great details into which M. Lamark has entered, and the new species of which he gives a description, render his book pre- cious to naturalists, and ought to cause the prompt continuation of it very desirable, especially from our knowledge of the means which that skilful professor possesses of carrying to a high degree of per- fection the enumeration which he will give us of shells, that im- mense department of natural history. As to the history of corals, it has just been enriched by the great work of M. Lamouroux, on those genera whose solid parts are flexible — a work which we have announced several times in our preceding analyses, and which has appeared this year in an octavo volume with 18 plates. A prodigious number of genera and species are recognized, several of which under other names are the same as those established by M. Lamark. The public possess likewise now the history of the crustaceous animals of Nice by M. Risso, and the fine investigations of M. Savigny on the mouth of insects, and on compound mollusca. These last researches especially, which open to science views en- tirely new, are well worthy the attention of naturalists. But as both had been previously communicated to the Academy, and as we have already given the analysis of them, we shall dispense with re- suming the subject again. This continued multiplication of animated beings which natu- ralists observe, the necessity of giving them from time to time a convenient arrangement, and of accurately characterizing them, has determined M. Cuvier to exhibit a collected view of them in four octavo volumes, with 18 plates, which he has just published under the title of the Animal Kingdom arranged according to its Organi- zation. His object, at the same time, is to make this work serve as an introduction to the great Comparative Anatomy, which he is pre- paring; and in that point of view he has given equally the internal T 2 292 Proceedings of Philosophical Societies. [Oct. and external characters. His classes are those of which we gave a table two years ago ; but what we could not mention then, and still can only mention in a general way, is the extreme division of the genera into subgenera, and other lower subdivisions ; by means of which the author conceives he has obtained so much precision, that it is scarcely possible to hesitate any longer about the position of a species. This was chiefly necessary when treating of the animals with vertebra:, and has been executed by the author with great care. New observations have been made on the confusions of synonymes, and upon the double application of words, so common with those authors who have not employed extreme critical attention. M. de Barban^ois, corresponding member, proposes likewise some changes, or rather some further subdivisions, in the methodi- cal distribution of animals. He does not think it proper that man should remain confounded with the mammiferous animals, and is even of opinion that a fourth kingdom of nature might be consti- tuted on purpose for him, under the name of the moral kingdom. He conceives that viscous reptiles, or hatricians, ought to constitute a distinct class from scaly reptiles ; that the cephalodes should be separated from the other mollusca; that the cirrhipedal moUusca should be placed at the head of the annelides ; and that some other analogous changes should be introduced into the old classes, which he in other respects adopts. The great object of this kind of research is less to establish op multiply subdivisions than never to omit classing in those which are admitted animals which resemble each other, nor to place together animals which do not resemble each other. In this point of view M. de Barban9ois does not contest any of the relations recognized by the naturalists who have preceded him. One of the most interesting questions in physiology is the origin of the azote which constitutes an essential element of the human body. It was suspected that respiration, which carries off tlie carbon and hydrogen from the blood, and leaves the azote, contri- butes in that way to increase the relative proportion of that sub- stance. But it was not positively known whether this azote came entirely from the food, or whether the atmosphere likewise furnished a part, either by means of respiration or by absorption, over the whole surface of the body, or whether it was not produced by the action of life itself. M. Magendie wished to determine the point by experiment ; and for that purpose he fed animals with substances that contain no sensible quantity of azote; namely, sugar, gum, olive oil, and butter, to which he added distilled water. These animals all died; but with very singular phenomena, particularly with an ulcer in the cornea, which sometimes pierced that membrane so that the humours of the eye were emptied. Their secretions assumed the characters of those of herbivorous animals. The principles con- taining azote gradually diminished in them ; the volume of the muscles was reduced to one-sixth ; and these consequences did not 1817.] Royal Academy of Sciences. 293 proceed from want of digestion ; for food destitute of azote fur- nishes chyle, and fills the lacteals, and sustains life a much longer time than if the animal were entirely deprived of nourishment. Azote is an essential constituent of urea and uric acid. These elements of the urinary calculus diminish sensibly in the urine of animals fed upon food destitute of azote. M. Magendie concludes from tliis that by means of a vegetable diet the progress of the dreadful disease of the stone might be at least retarded. It is true that a regimen entirely vegetable sometimes occasions a disease of an opposite kind; namely, diabetes, or an excessive flow of urine, containing a saccharine matter, a disease cured by feeding the patient on animal food. These facts may become useful in medicine, and furnish impor- tant dietetic indications. M. Magendie has likewise, in conjunction with M. Chevreul, made experiments to determine the nature of the gases which are evolved during digestion in different parts of the alimentary canal. In four felons, who had taken a little before their death a determi- nate quantity of food, the stomach contained oxygen, carbonic acid, hydrogen, and azote. The small intestines contained the last three gases ; but no oxygen ; and the large intestines, besides car- bonic acid and azote, contained likewise carbureted and sulphureted hydrogen. These last two, therefore, belong only to the large in- testines. The oxygen is found in the stomach only. The azote and carbonic acid exist in the whole canal, and the quantity of the latter increases as we proceed downwards. MEDICINE AND SURGERY. If ignorance is often dangerous in medicine, it is perhaps never more terrible than in those cases, when, called to the support of justice, it misleads by incautious analogies, which may draw upon innocence the disgrace and the punishment due to crimes. The work, therefore, which M. Chaussier has undertaken on medical jurisprudence, and which is intended to unite the information de- rived from anatomy, chemistry, and physiology, in order to deter- mine the cause of death from an inspection of the dead body, is of the greatest importance to society. To the general rules which he prescribes, he adds, by way of example, several reports made to courts of justice relative to remarkable cases, and joins his remarks upon the omissions, errors, and obscurities, and the false reasoning, which too frequently occur in these important pieces. All this part corresponds perfectly to the epigraph of the book : — Sontibus inde tremor; civibus inde salus. But the author has not confined himself to what his title promises. He has pointed out, likewise, the mistakes in the ordinary way of opening dead bodies for the purposes of pathological anatomy- mistakes which have often lead to false conclusions respecting the nature and seat of maladies. Physiology itself will profit by a great 294 Proceedings of Philosophical Societies. [Oct. number of delicate remarks on functions little studied, which this skilful physiologist communicates by the bye. M. Moreau de Jonnes, who observed with so much care the geology of the Antilles, has not employed himself less zealously in investigating their climate, its fatal effects on the health of Euro- peans, and the means of preventing or curing a part of the evils which it occasions. In particular he has examined by what rules of regimen it would be possible to preserve the troops there. The precautions which he points out for the disembarkation, lodgment, food, and marching of the soldiers, are dictated by a wise medical theory ; and most of them have been already confirmed by expe- rience. His work has been sent into the colonies by order of the Ministers of War and of the Marine. M. Boyer has given a valuable memoir on a cruel disease of which he first found out the method of cure. It consists in certain fissures which occur at the anus, and which, being accompanied by a spasmodic state of that part, occasion dreadful pains and insupport- able anguish. An incision of the sphincter, made carefully, always makes them cease in a short time. M. Larrey is one of those surgeons who have exercised their art on the vastest and most varied theatre. Attached to the French armies during 25 campaigns, he has followed them through the four quarters of the world, and directed as chief the surgical service in Egypt and in Russia, as well as in all the intermediate climates; during epochs of the most brilliant victories and the greatest pros- perity, as well as of defeats the most frightful, and the most com- plete final reverses. Every kind of experience, therefore, came in his way, and he took advantage of them all. To the results of his experience already consigned in his books, he has this year added important observations on the effects of foreign bodies introduced into the thorax, and on the operations undertaken to extract them. When collections of pus and blood have forced the iungs to contract, the extraction of these matters occasions in the thorax a vacuum, which nature endeavours to fill up either by the production of a new substance, or by displacing the ribs and some other of the neighbouring parts. M. Larrey has shown these changes in individuals whom it was in his power to open, because, after their cure, they fell victims to other accidents. He has given an example of a person perfectly cured of the ex- tirpation of the superior articulation of the thigh bone, an operation respecting the possibility of which M. Larrey first fixed the opinion of practitioners, by making known the method by means of which it may be performed with certainty. RURAL ECONOMV AND TECHNOLOGY. The hair of the castor, so necessary in the fabrication of fine hats, becoming more and more scarce and dear, several other kinds of hair have been tried, without finding any that can be entirely substituted for it. M. Guichardier, hat-maker in Paris, has just 18170 Royal Academy of Sciences, 295 employed successfully the hair of the sea otter and the common otter. It is true that hats made entirely in this way would be a great deal too dear ; but we may with profit sprinkle, or, as the hatters say, gild with this hair hats the body of which is composed of a more common stuff. This has been long done with the hair of the castor. We ought likewise to place in the rank of useful works which have occupied the members or correspondents of the Academy during the year 1816, the instructions of M. Huzard on the mea- sures to be taken by feeders in order to disinfect their stables, and preserve their cattle from the epizootic ; several articles of agricul- ture inserted by M. Yvart in the New Dictionary of Natural His- tory ; and especially the article on the copulation of domestic ani- mals, which v/as read to the company ; and the history of French agriculture, by M. Rougier de la Bergerie. Mathematical Part. — By M. le Chevalier Delamlrcy Perpelt/ul Secretary. Never perhaps was the zeal of mathematicians better supported. Never perhaps have they devoted themselves with more constancy to their accustomed labours, to the developement of their first ideas, to the completion of works already published in part, and yet we have never experienced so many difficulties in drawing up the annual history of the Academy. Reduced almost to our bare re- collections of memoirs, which the authors have withdrawn in order to revise or extend them, or which they have already sent to the press, in order to accelerate by every means in their power the pub- lication of the volume, which will be the commencement of a new series, under the title of New Memoirs of the Royal Academy of Sciences, we can only briefly point out the different objects which have occupied our meetings during the year which has just elapsed. Besides, the more progress that mathematics have made, the more difficulty will there be to make them advance further, and the more impossible it will be to render striking the new results obtained. The problems become complicated; even the annunciations of theorems require continued attention, in order to understand their meaning ; the applications of analysis to physics, which, after the complete explanation of the system of the world, constituted the hopes of mathematicians, has hitherto offered only problems sur- rounded with difficulties. Even the experiments are far from being as simple as those which made us acquainted with the nature and principal phenomena of light and electricity. It is requisite to repeat them, and to study the necessary apparatus, in order to form an idea of the new truths which are the fruit of these researches j and this requires an equal degree of patience and sagacity. Hence, though to philosophers by profession the quantity of labour be always the same, yet the portion of which we are able to give an account must diminish every day. Our readers, then, will not be much surprised if we confine our- 296 Proceedings of Philosophical Societies. [Oct. selves merely to the titles of several memoirs, notwithstanding the importance of the subjects, and the merits of the execution. Among these are — 1. A long memoir of M. Poisson, on the Variation of arbitrary constant Quantities. 2. The Formulas of M. Cauchy relative to the Determination of Definite ^ Integrals, and the Conversion of Finite Differences of Powers into Integrals of the same Species ; and his demonstration of a curious theorem relative to numbers, in which he draws as a simple corollary a remarkable property of common fractions ob- served by Mr. Farey. Likewise a memoir on particular solutions ; and another on the imaginary roots of equations. 3. Two long memoirs, with notes, on diffraction, by MiVT. Pouillet, and Biot who has inserted them in his Traite de Piiysique, to which we will devote a particular article. 4. Different memoirs of M. Biot on the Sound of the Strings (Aiiches) in Musical Instruments, on the Intonation of the Pipes\f an Organ filed with different Gases, on the Pile and on Electri- city, the desciiption of a Colorigraph, and his New Experiments on the Polarization of Light. (It is known that M. Arago is employed in researches relative to this last object, witii which he has repeatedly occupied the attention of the Academy, and which he proposes to unite in a particular work as soon as he has completed them.) 5. Lastly, the notices read by Count Laplace on the Velocity of Sound in different Substances, on the reciprocal Action of Pen- dulums, and on a Precaution hitherto neglected in the Experiments ivhich serve for the Determination of the Length of the simple Pendulum. Of all the experiments of this kind tried at different times by the most distinguished mathematicians, astronomers, and philosophers, those of Borda are generally considered as the most certain and conclusive, both on account of the attention bestowed, the inge- nious processes followed, 'the size of the apparatus, and the well- known skill of this excellent observer. It is admitted that he very properly preferred the suspension on a thin edge, which he considered as more susceptible of precision than suspension from pincers; because in these last there is always some uncertainty with respect to the true point round whicli the oscilla- tions are made ; while in the other, the edge of suspension being very fine, the centre of motion may be conceived to be on the plane itself on which it rests. This supposition, which Borda adopted, and which was long granted without any hesitation, at length gave rise to some doubts. It has been thought that the edge could never be sufficiently sharpened to be considered as a mathematical line. That it ought rather to be considered as a small cylinder, the centre of which was more elevated than the line of contact ; so that the radius of this cylinder would require to be added to the length pleasured. Tlie question deserved to be examined, and if wc 18170 Royal Academy of Sciences, 297 could not flatter ourselves with being able to determine the radius of this cylinder, and the correction which it would require, the amount at least might be estimated, and the limits of the error known. M. Laplace has just submitted this question to calculation, and the result no doubt surprized himself; as he found that this radius, whatever it be, must be subtracted from, and not added to, the length measured. But this length is about four times that of the pendulum. This is sufficient perhaps to legitimate the supposi- tion of Buida ; but it is at the same tiuie a piece of knowledge useful to those philosophers who propose to repeat the experiment with much shorter pendulums. Besides these different notices, all of them happy applications of the general principles which he has established in his Mecanique Celeste, M. Laplace lias given supplements and useful additions to his Analytical Theory of Probabilities, and to the Philosophical Essay on the same subject, the third edition of which appeared a few montlis ago. The author terminates that work with this reflection, that there is no science more worthy of' our meditations, and that it would he useful to make it a part of the system of public instruction. This philosophical view has been seized by M. Lacroix, who perhaps might have found it in the writings of a celebrated mathematician, who has repeatedly exercised himself on that difficult subject, and it has given birth to the following work, which will complete the mathematical course of this author. Traite elementaire du Calcul des Probalilites, par S. F. Lacroix. Paris, Madame Feuve Courcier, 1816. When genius has created a new science, or when by a skilful analysis it has extended the limits of science, it is the duty of every one employed in the public instruction, and to whom all parts of modern geometry are equally familiar, to read and comment on original works, to extract from them every thing that can be rendered intelligible to ordinary readers, to seek for direct and particular demonstrations of the most useful theorems, which the inventor has found by methods more general and rich, but more difficult to comprehend. This is the case with the new work of M. Lacroix, who has given the subject all the interest of which it is susceptible, by well-chosen examples, by numerous quotations from original writers, by his care in assign- ing to each the part which he can legitimately claim, and by a de- tailed history of the labours of this kind performed by the greatest of mathematicians, from the age of Pascal and Fcrmar, to our own times. From the time of the suppression of the Academy of Sciences, which is nearly when Legendre pul)lished his first memoir on Ellip- tical Transccndentals, this profound niathematiciim has not ceased every year to extend this theory, which he had in some measure created, and which he has explained in his Exercises on the Integral Calculus, to which he has already publisiied several sui)i)lements. 2 298 Proceedings of Philosophical Societies. [Oct. The last of these, which appeared in July, 1816, has for its object the construction of elliptical tables. In pointing out to mathematicians all the advantage which they might draw from transcendentals of this species, the author had announced that his solutions would not become truly useful but by means of tables in which these fractions could be valued in all cases to a convenient degree of approximation, and without requiring too fatiguing calculations — tables which should do for analysis nearly the same thing as tables of the sines, and tangents, and the loga- rithms of numbers, do for astronomy. The construction of these tables constitutes the principal object of the new supplement of Legendre. The first of these tables gives 900 values of the quadrants of the ellipse, and an equal number of values of the analogous function F', 420 of which at least have been calculated directly as far as 14 places of decimals ; the remainder have been calculated as far as 12 places. These transcendentals, then, are now known more exactly than the circumference of the circle was before the calcula- tions of Ludolph Van Ceulen. To this have been joined the first, second, and third dififerences, and the whole has been reduced to 12 decimals. As far as 70" of the arguvient, the third differences, which at first contained only a single significant figure, has increased progressively, so as to become 6778 for E' and 25284 for the func- tion F'. It was then necessary to add the fourth differences, which are then 49 and 362, and increase afterwards to 485160 and 5706908015, which are the last numbers of these two columns. The second table gives the values of the functions E calculated to 12 decimals for all the amplitudes

At the end of this memoir we find a very elegant formula for calculating the latitude of a planet in seconds, and in the function of the tangent of the demi-inclination. The author deduces it from a more general formula, demonstrated in the 11 6th article of the fifth part of his Exercises of the Integral Calculus. It may be deduced still more simply from the series which Lagrange has given for the angle which the ecliptic makes at any point wita the parallel to the equator. This series may be transported to the declination of the sun, as we have remarked. (Astronomic, n. 239 ) In this case, to have the declination of the sun in a function of the right ascension A, it is sufficient to put (90° - A) m place of the longi- tude L of the formula of Lagrange, and we have tor the declination D the formula D = 2 tang, i w sin. A + f tang.' i iv sin. 3 A + f tang.* -• w sin. 5 A + &c. We have even calculated, in the place quoted, the numerical coeffi- cients of the first terms, the fifth of which may be always neglected. The only inconvenience of that formula is, that it gives the declina- tion in a function of the right ascension, or the latitude in a func- tion of the argument reduced to the ecliptic, whereas we generally want them in a function of the longitude, or of the argument not reduced from the latitude. This made us seek for a series which has not this inconvenience. Wc found one still more converging, but the coefficients have not the same simplicity. 300 Proceedings of Philosophical Societies. [Oct, M. Legendre has likewise published a supplement to hb Theory of Numbers, second edition, February, 1816", .: This supplement is divided into three chapters. The first shows the means of dividing a given number into four squares, such that the sum of their roots is equal to a number given comprehended between certain limits. This problem serves as an introduction to the next chapter, the object of which is a general demonstration of the theorem of Fermat respecting polygonal numbers. This demonstration is founded on the same principles as the one recently discovered by M. Cauchy, But it differs from it in some respects, and it supposes nothing de- monstrated but the theorem relative to triangular numbers, which is the first case of the general theorem. In giving an account last year of the discovery made by M. Cauchy of a demonstration hitherto sought in vain by all mathema- ticians, we expressed some doubts respecting the reality or the generality of the demonstration which Fermat had announced in the most positive terms, which he had never given, and no vestige of which could be found among his papers, although from its nature that demonstration must have been long. It appeared, therefore, unlikely that Fermat should have wrhten nothing on a subject which required so much developement ; and we had sus- pected that Fermat, after having more carefully examined his de- monstration, had been himself dissatisfied with it, and had resolved to suppress it entirely. M. Legendre, on the contrary, has no doubt that Fermat was in possession of the general demonstration of his theorem. He thinks merely that Fermat's demonstration was quite different from the one which he himself has given. Fermat knew only two cases at most of the trinary form of numbers, without which he would not have restrained to the form (8 »— 1), a property which extends generally to all odd numbers. In fine, Fermat did not perceive a thing which gives more precision and elegance to his theorem, namely, that in the {m + 2) polygons of the order (in + 2) which compose a given number^ there are always (m — 2), which may be supposed equal to 0, or unity. This condition, added by M. Cauchy, will show that Fermat himself had not a very precise idea of his theorem. But M. Legendre goes still further; he demonstrates that beyond a certain limit easily assigned for each, order of polygons, every given immber may be decomposed into four polygons, or five at most. These two limitations, added to the theorem of Fermat, appear to us sufficiently important to enable us to say that, after it is de- monstrated this theorem is not quite the same, and that without ceasing from being true, according to the more general enunciation of the author, it has received two modifications useful to be known. The third chapter of this supplement contains new methods for approximate solutions of numerical equations. One of these methods requires merely that we should know a 1817.J Koyal Academy of Sciences. SOl superior limit to the greatest of the roots, and this limit is found by a very simple formula. The author gives the name of omale, that is, without irregulardy, to every function of x which possesses the property of being always increasing or decreasing in proportion as x augments in a positive sense from x equal to zero to x infinite. He determines, then, the greatest of the roots, and, dividing the equation by that root, he reduces it one degree, and seeks again the greatest root of the equation thus prepared. Here the limit is known, since the second root is necessarily less than the first. The same process will give successively all the roots in the order of the greatness, all decreasing. The second method consists in dividing the proposed equation into two simple omale functions. The curves of these two equations are constructed, and the different intersections of these curves, give us the positive roots which can be determined. The author, finally, employs himself in the more difficult inves- tigation of imaginary roots ; but it is obvious that this last part must be much less susceptible of extract than the former. He concludes by announcing to the lovers of the theory of num- bers two important works, and almost indispensable in researches of this nature. The first is the Cibrum Arithmeticum of M. Chenac, Professor of Philosophy at Deventer, in which we find all the prime numbers, and all the divisors of the other numbers from one to one million, and further. This work has already proved that the rule of M. Legendre, to find in what quantity prime numbers occur between two given limits, is an uncommonly exact approxi- mation. The other is that of M. Burckhardt, who, in order to extend this table much further, has invented a sure and easy method, which has furnished him in a short time the smallest divisor of any number comprehended between two millions follow- ing each other. Before going further, M. Burckhardt thought that he ought to give the first million in the same form as the second and third. This first part has just appeared under the title of Tahle of the Divisors of all the Numbers of the First Million^ or more exactly from 1 to 1020000, with the Prime Numbers found among them^ by J. Cli, Burckhardt. Paris, Madame Feuve Courcier, 181 7. The preface announces the comparison of the million of M. Chernac with a manuscript of M. Schenmark, which the Institute possesses, and gives a table of the typographical errors which this comparison has enabled him to discover in the cribrum of M. Chernac. Nobody will be surprized that several typographical errors should have made their way into a work of this kind ; and M. Burckhardt himself requests us to state that a fault of this kind has escaped him in p. 2, in the example which he gives of the use of that tal)le. He makes choice of the number 7*^4241, and the object is to find its smallest divisor 53. The number, by mistake, has been printed 764241. But the error is easily observed, and 302 Proceedings of Philosophical Societies. [Oct. will deceive nobody; for in p. 88, which is correctly pointed out, it will he perceived at once that the number ought to begin with 78, and not with 7fc>. Besides, all those who have been employed in the disagreeable labour of the publication of tables, whether astrono- mical or arithmetical, have learned by experience that the mistakes left in them seldom occur in the most difficult places, which have been examined with the most severe attention, but most commonly in those places where they might have been most easily avoided, so that they at once strike the eyes of the reader less engaged with them, even when he does not look for them. M. Burckhardt then explains the methods which he has con- trived to extend the use of these tables of divisors. He finishes by announcing that, if the sale of the first three millions gives any hope of enabling him to publish the following ones, that little labour is wanting to complete the fourth, fifth, and sixth millions. Let us point out to calculators another typographical error. It occurs in those tables which it is customary to employ with confi- dence— those of Schulze and of Vega. The hyperbolic logarithm of 1853 is S'968 imtead of 8"9C7. The number, we conceive, ought to be 7853, and not 1853. In fact, the logarithm of 7^53 begins in both tables with the figures 8'967, and it is evident that the 7 is too small. An easy calculation shows that in reality we ought to read 8'968 ; a new proof of what we just now said, that errors exist always in those places where they are most easily per- ceived, and over which the tired eye of the reviser passes in a care- less mannefi Article VIII. SCIENTIFIC intelligence; and notices of subjects CONNECTED WITH SCIENCE. I. Curious Effect of Paste on Iron. At Deanston, near the village of Down, in the county of Perth, there is a manufactory where cotton is woven by machinery. Iron cylinders were used in order to apply the weaver's dressing to the cloth. This dressing, as is well known, is nothing but common paste made of wheat flour or barley meal. The cast-iron cylinder was in a short time rendered quite soft, and similar to plumbago, by the action of the paste. This corrosion took place repeatedly; and it was so rapid that the proprietors of the manufactory were obliged to substitute wood in place of the iron. I conceive that the paste employed was usually sour, and that it was the acid developed which, by dissolving the iron, produced this curious effect. A similar effect is produced upon cast-iron by the action of muriate of magnesia, and probably other salts. 5 18170 Scientific Intelligence* 303 II. Further Improvements in the Oxygen and Hydrogen Blow-pipe. (To Dr. Thomson.) DEAR SIR, Since my last, in which I proposed a zigzag pipe, I have been led to consider the best mode of forming Dr. Clarke's fagot of tubes, from the very great difficulty, not to say impossibility, of obtaining any thing similar to his proposition. Both the cane and wire one of Mr. Beale are, I think, objectionable : the cane must be liable to be burned, from the return of the oxy-hydrogen flame: the wire, though ingenious, would, if made of iron, be liable to oxidation ; and if of copper, would, I think, be too flexible, and easily put out of order. The one I shall propose will, I think, remedy both these objections, besides giving an advantage that neither Mr. B.'s nor Dr. C.'s can very easily allow of; namely, that of giving passage to any quantity of gas, and thereby being ren- dered applicable to manufacturing purposes — a desideratum of the highest importance. The form of the tube that I now propose is briefly this: — A number of brass or copper plates laid one on the other, the edges of which are slightly thickened, so as to allow of a very small space between each plate. It is evident that this sort of tube may be extended to any size, without either inconvenience or greater liability to explosion, and that any volume of flame may be used, provided the gazometer be of sufficient capacity. The blow-pipe might by this means be peculiarly adapted to the pur- poses of smelting ores, a use of the utmost importance, since the saving in fuel would be incredible, from the comparatively light expense attending the production of the gases, particularly where the metal is difficult of reduction. The oxygen might perhaps be obtained from the ores themselves. Instead of condensing the gases into a gazometer, as in the small blow-pipe, they might be driven out of a reservoir into the tubes by means of a double bellows worked by a steam-engine (which would materially lessen the danger of explosion), the superfluous steam of which might be employed to form the hydrogen. In order to render these tubes safer, I should recommend each end being covered with a piece of wire-gauze ; and the cap at their end, for gathering together the gases, when used for large purposes, might, to prevent fusion, be made of platinum, without much greater expense. I should also recommend another piece of gauze being placed within the safety cylinder, just above the oil. Should any, or all, of these specula- tions be in your opinion either idle, or in any other way unworthy of insertion, you will suppress them accordingly. — A (PI. LXXII. Fig. 4) represents the safety cylinder : B, the tube made of copper plates, the two ends, a, a, of which are capped with wire-gauze : C, another piece of gauze extending over the whole surface of the safety cylinder, just above the oil; this might be double: D, a 304 Scientific Intelligence. [Oct, tube with a stop- cock perforating the gauze, in order to fill the cylinder with greater ease : E, the cap for collecting the gases, which in large works should be made of platinum : F, the tube viewed in front : h, the spaces through which the gas passes. 1 am, Sir, your obedient servant, Worcesttr Tything, Jug. 8, 1817. F. G. SpiLSBURY. III. On a Lactometer. By Mr. Johnson, Surgeon, Lancaster. (To Dr. Thomson.) SIR, In Mr. Holt's Agricultural Survey of Lancashire there is deli- neated a lactometer, constructed by Mr. Dicas, on the principle that if the specific gravity of milk be taken before and after the separa- tion of the cream, the difference will indicate the proportion of cream and the relative value of the milk. This instrument is expensive, and liable to the objections of un- certainty, because of the saline constituents of milk, and difficulty of application, in consequence of the ver}- slight change produced on the specific gravity of milk by abstracting the cream. The de- sired results may be obtained more correctly in an easier way. "' When new milk has been set aside for a few hours in a cylindrical vessel, the column of cream may be seen floating on the surface of the milk, and, if the vessel be 10 inches deep, and properly gra- duated, every tenth of an inch on the scale will indicate one per cent, of cream. Early last year, having again met with the description of Dicas' lactometer in Dr. Dickson's new edition of the Agricultural Survey of this country, I transmitted to the Board of Agriculture a drawing like the annexed (Plate LXXII. Fig. 5), with some such remarks as the foregoing. My paper was ordered to be published in the next volume of Communications, which, I believe, has not yet appeared. About the same time I requested Mr. Newman to make the instrument for sale. I am informed, by a very respectable Vice-President of the Board of Agriculture, that he caused some of the instruments just described to be fitted up in stands, and sent them to the President of the Royal Society, and other patrons of agricultural inquiry, some of whom described the instrument in the public papers. Having no interest in the sale of these instruments, I should have waited for the next volume of Communications to the Board of Agriculture, had 1 not seen a notice on this subject in the last number of the Journal of Science and the Arts. May I request you to give this paper a place in the Annals of Philosophy, and to inform your readers that Mr. Newman con- structs these instruments accurately, and at a very moderate price ? I am. Sir, your very obedient servant, Lancaster, July 10, 1817. C. JoHNSON. 18170 Scientific liUeUigence . 305 (To Dr. Thomson.) SIR, Lancaster, Jug. 5, 1817, A few weeks ago I sent you a note on the subject of a lactometer. 1 have subsequently met with an extract from the Report of a Com- mittee of the Highland Society on the use of aerometric beads; and as some passages in tliat Report seem to he founded on a cur- sory estimate of the specific gravity of milk and its constituents, I beg leave to mention a iew facts which appear to me at variance with some conclusions of the Committee. Although the butter is lighter than water, yet cream is specifically heavier; so that no combination of the cream and curd can so counteract each other as to afford rich milk with a low specific gravity ; neither will the abstraction of the cream cause any consi- derable variation in the specific gravity of the remaining skimmed milk. If, for instance, the specific gravity of cream be 1024,* and that of skimmed milk be 10J3,t and if good milk contain 15 per cent, of the former, and 85 of the latter, its specific gravity ought to be 1031*5, and tlie difference between new and skimmed milk only TS. Experiment has indeed afforded me a difference somewhat greater, viz. three, four, or five degrees in 1000, but not proportioned to the quantity of butter in any regular manner. The curd bears a considerable proportion to the entire milk, and is comparatively heavier; % yet when milk is coagulated by rennet, the curd mostly floats in the whey. I found the specific gravity of new milk and its whey to be 1031 and 1030 ; that of some skimmed milk and its whey 1032 and 1029. Muschcnbroeck and Brisson § observed or calculated a much greater difference; but their whey had only a specific gravity of 1016 or 1019, which is much lower than any I ever met with. In the separation of cream, of butter, and of curd, changes are constantly going on ; these as yet are little understood ; but the evolution and absorption of gaseous matters have been noticed, and must contribute to render the specific gravity of milk a very uncer- tain test of its relative value. I remain, Sir, your obedient servant, C. Johnson. IV. On a Rain-guage. By the Same. Some years ago Mr. C. Seward, of this town, made me a rain- gauge, which I should not have ventured to mention, but that it seems to be an improvement of those described in the Manchester Memoirs, vol. iv. ; and in Nicholson's Encyclopaedia, Article Rain- gnuge. It is merely a funnel, the area of which is 100 inches at top, sur- * Berzelius, Medico-Chir. Trans, vol. iii. + Ibid. X Tlie curd of skimmed milk, dried until it becanae brittle, liad a specific gravity of 1 150. The crust of a clicese was about tlie same. A slice of good clifese was 1063 : some inferior cheese was 1087. ^ Nicholson's Fourcroy; ix, 497. Vol. X. N° IV. U 306 Scientific Intelligence, [Oct. mounted with a hoop about I4- inch deep. The rain collected in this funnel being measured, every cubic inch will indicate -^^ of an inch of rain. A funnel 11 -3 inches in diameter is very nearly of the proper size. V. On preparing Extracts, &c. By the Same. In the preparation of vegetable extracts, in evaporating diabetic urine, &c. the last portion of water is expelled with most difficulty, and the last stage of the process seems most injurious to the product. If small quantities of rectified spirit be added occasionally, this stage is shortened, and less injury is sustained. VI. Observations on the Nomenclature of Clouds. (To Dr. Thomson.) SIR, The cloud which Mr. Johnson, of Lancaster, has described in your 5 1st number, p. 216, and which he would term a lanceolate cloud, is a thick linear Cirrus, which I have seen three times within the last month (June) ; and when at about 50° or 60° above the horizon, it has^ gradually changed, by the gentle pressure of an upper current, into a beautiful Cirrocumulus : and fine weather for many subsequent days was twice the result. Indeed, I have often remarked that the ramified Cirrus is a more certain harbinger of approaching storms of wind and rain than the thick linear Cirrus. The other modification, which Mr. J. compares to the shape of a man's hand, is simply the Cumulus cloud, raised from the surface of the water in a dense hemispherical body by the heating effects of caloric downwards in its neighbourhood; and the long tufts ex- panding like fingers often belong to a vapour of the same density, sometimes in the front, and at odier times in the rear of that cloud. I have observed that this modification, in whatever shape it may present itself, is generally attended with the most fertilizing weather, it being more frequently seen in the summer than in the winter months, from the abundant evaporation. Seeing lately an explanation of the nomenclature of clouds, in the first volume of your ^mmZi of Philosophy, as used by Luke Howard, Esq. in his remarks on the weather ; and also some acute objections by Mr. Johnson on the compound terms of the nomen- clature, in the 51st number, p. 21 7, I beg to suggest the propriety of your obtaining a correct engraving of the various modification* of clouds. The drawing, I think, could be comprised in a 4to size, divided into seven perpendicular parts, and in as many divisions lengthways as the appearances of each modification require, pre- serving narrow spaces !)efore them for the appellations. The Cirrus, or first highest and lightest modification in the atmosphere, agree- ably to this plan, would occupy /ye horizontal divisions of li- inch deep, in squares, ellipses, circles, or semicircles, whichever may be found most convenient; namely, the ramified, linear, curled lock, plumose^ and the light z'e//— the first four to be drawn on an 1817.] Scientific Intelligence. 307 azure ground, and so on with the rest of the modifications. But if this space should be found too small to draw them in to advantage, the depth might be increased to 2^ inches : in that case the plate would be double, and the impression therefrom would fold twice. The drawing might be prepared by, or under the superintendance of, the projector of the nomenclature, and by him only it could be done in a masterly manner; and a proof impression should be sub- mitted to his inspection, lest any touches be omitted by the en- graver. If some such engraving as this were CKecuted for the Annals of Philosopliy, as a general reference, I am fully persuaded that no future endeavour to extenuate Mr. Howard's merits as a first-rate meteorologist would be attempted; nor would there be any more cavilling on the supposed abstruseness of the nomenclature : for by these means it would soon become more generally known, and more practically useful to the lasting credit of the projector — not that I think he has the least ambition for any superfluous meed on that score. I am. Sir, yours respectfully, Glosterian. VII. On the Hedgehog. (To Dr. Thomson.) SIR, The strong prejudices which are in many parts of this kingdom entertained against that harmless animal the hedgehog, or urchin, and the erroneous information respecting it which has in some par- ticulars been given by naturalists, induce me to offer you the follow- ing observations, which are the result of near two years' acquaint- ance with its habits. The hedgehog subsists entirely on snails, slugs, worms, milli- pedes, and other insects, and is consequently the best assistant the horticulturist can have in clearing his plants from those destructive vermin. It never eats fruit, as it has been asserted by most zoolo- gists that it does ; nor, as far as I have been able to ascertain, does it make roots or any vegetable substance a part of its food. It is too gentle and timid to attack young hares, partridges, or pheasants, as the ignorant gamekeeper will assert, to justify his persecution of a defenceless animal : and the vulgar idea that it will suck a cow is too absurd to require refutation. If put into a garden, it will in the course of two or three nights entirely clear it of slugs ; but of course it can only be confined within a walled one, and it will be necessary to feed it after the first few days, as it will not find a suffi- cient supply of insects for its support. For this purpose a little raw meat, or entrails, should be placed near its nest every other night ; and it will also require a little water in a shallow pan. It will secrete itself by day in the most retired spot it can find, making its nest partly in the ground, and covering it over with leaves. If dis- turbed, it generally forsakes the place, and forms another habita- tion, whence it rarely stirs but in the night. As far as I can judge, V 2 308 Scientific Intelligence. [Oct the confinement of even a tolerably sized garden does not agree with the constitution of the hedgehog, as I have generally found it prove fatal to him in the course of five or six months. It would consequently be advisable to keep him only for a limited time, then restore him to liberty, and have his place supplied by a fresh one. In winter he remains in a torpid state, seldom coming from his nest unless the weather is very mild. It is, therefore, of little use to detain him from his wild haunts, except in spring and summer. Should you think the above worthy a place in the Annals of Phi- losophy, you may perhaps rescue a few of the harmless hedgehog tribe from persecution and torture. I am, Sir, your humble servant. E. B. C. G. VIII. Prizes of the Royal Academy of Sciences and Belles Lellres of Brussels for the Year 1818. The Royal Academy of Sciences and Belles Lettres had proposed on June IS, 1793, for the prize question for 1794, the following problem : — What Places in the 17 Provinces of the Netherlands, and in the Country of Liege, could be considered as Cities between the seventh and the twelfth Century exclusively ? Two Latin memoirs had been sent on this question : but when the French armies entered in the year 179 ', the Academy, being obliged to separate, was unable to decide upon their merits, or award the prize. Being re-established by the care and munificence of the King, it made a point of again proposing the same question, in hopes of receiving answers still more satisfactory ; permitting at the same time the memoirs already sent to come in competition with those that were expected. A single memoir, written in French, has been received since that period, with the following inscription : — Centum habitant urbes magnas uberrima regna.— VnsG. ^i«. I. 3. But this memoir, far from surpassing those already sent, is much inferior to them ; the author having seldom consulted contemporary authors and original sources of information. He has shown but little critical sagacity in discussing facts, and has drawn most of his proofs from modern books, by means of which he has frequently been misled. The Academy was obliged, in consequence, to return to the old memoirs, and the gold medal was voted to the Latin memoir with the following motto : — Quot post excidiumTrojae sunt erufa castra ? This memoir, though it has not answered all the objects of the Aca- demy, exhibits much discernment, considerable critical sagacity, and an intimate acquaintance with the history of the provinces. Aa accessit has been given to the memoir with the inscription— Quot pagos olim, claras nunc ceruimus urbes. 6 1817.] Scientific Intelligence. 309 The letters containing the names, which had accompanied these two memoirs, not having been found, the authors are requested to make themselves known, by sending to the Secretary the requisite information. The Academy has received no memoir on the state of the sciences and literature in the Low Countries during the few last years. It has resolved, in consequence, to propose again this question for the year 1818, in the following terms : — To trace a historical Picture of the State of the Sciences and Literature in the Low Countries from the Year 1792 to 1815, pointing out carefully the different Causes ivhich contributed either to promote or retard the Cultivation of the Scienoes and Literature. The Academy proposes for the same time the two following historical questions : — What was the State of Slavery in the Low Countries from the most remote Period till towards the End of the l^th Century? How was that State gradually abolished ; and what Remains of it still continued till the Time of the Introduction of the new French Laws P What was the State of the Population, Arts, and Manufactures and Commerce, of the Low Countries during the I5th and idtk Centuries P The subject of this second question has been treated in a superior manner by M. Verlioeven for the two preceding centuries in a memoir crowned and published by the Academy in 1777 5 a memoir to which M. Des Roches has made important additions.* The 15th and I6th centuries furnish materials by no means less interesting than those that preceded them. The progressive increase of the population, of the arts and manufactures, and their different vicis- situdes, the flourishing state of the commerce of the city of Bruges, and its decline towards the end of the 15th century, the consider- able portion that remained to it during the first three quarters of the following century, and its almost total destruction during the last quarter of tliat century ; the progress, successful commerce, and immense wealth of the city of Antwerp, during the greatest part of the 16th century, will present facts equally interesting for their object, and glorious for the nation. The Academy had proposed at the sitting of the 20th November last this question : — IFhat are the Applications which may be made in our Manufac- lures, and in Domestic Economy, of Steam employed as a Vehicle of Heat P Three memoirs on that question have been received. The Academy is of opinion that the memoir with this motto — Tbe true method of improving tlie arts consists less in describing their processea with accuracy than in bringing all their operations to general principles. CuAPTAL, Chimie Jppl. Aw. Arti. containing many researches, experiments, and enlightened views, • In the analysis of the memoir ai the end of it, and torn. iii. of the Memojrei de I'Acad, Jourp, dcs Seauces, p. 27 — 32. 310 Scientific Inlellige?ice. [Oct. both theoretical and practical, was worthy of the prize. Accord- ingly the gold medal was voted to its author, M. A. de Hemptine, apothecary at Brussels, An accessit was voted to the memoir No. 3, with the motto— Inventio fructus ingenii, perfectio temporis. the author of which is M. Charles Delaveleye, manager of the water-mills at Tournay. The Academy received 11 memoirs on the following question : — As for some Years past the Orolanche has made great Ravases in our Provinces on the Clover, the Academy ivishes to know jckat are the Lest Means of destroying that parasitical Plant, and of prevent- ing its Reproduction? Some of these memoirs exhibit botanical knowledge and good observations ; but as none of them has solved the problem, it has been impossible for the Academy to adjudge the prize ; and ob- serving that the experiments hitherto made on the subject leave much to be desired, it does not think that at present the question could be proposed a second time with any chance of success : it thinks proper merely to vote a silver medal, by way of encourage- ment, to the author of the memoir. No. 5, with the motto — Agriculturae amator, quo nibil homioe libero dignius ; which gives experiments useful for diminishing the multiplication of this plant. On opening the letter, it was found that the author of this memoir is M. F. Schaumans, an old farmer, who resides at present in Ghent. The Academy proposes for the year 1S18 the three following questions : — First Question (already proposed in 1793). — What are the Faidts to which our different Bricks are subject P What are the Means of making them more perfect P What are the Materials and the Processes employed in the Northern Provinces of the Kingdom for certain Species of Bricks of which we are destitute P Second Question. — Can we from satisfactory Experiments, or from the Doctrine of determinate Proportions, establish with Cer- tainty that the Radical of Muriatic Acid is a compound Body, or is it more probable that this Radical is a simple Substance P Supposing the Question incapable of being decided, which of the tivo Ways of viewing its Nature is most proper for simplifying the Theory of chemical Facts P Third Question. — French Printing Paper and English Paste- board (Cartons) having an acknoivledged Superiority over those of other Countries, it is demanded in wliat that Superiority consists, and on what Causes it depends, whether locaU or derived from the Materials or the Process; and how the same Manufacture might be extended in this Kingdom P The Academy proposes for the year 1819 this question : — To determine in a giveyi Place, and during a given Time, the Expejiditure of the JFater of a River, whose Breadth, Depth, and Descent) is known. To determine at the same Place, and during 1817.] Scientific Intelligence. 311 the same Time, the Variations which take place in this Expenditure tvhsn the Breadth of the River is gradualli/ diminished by any 01^ strnctions whatsoever. The prize for each of these questions will be a gold medal weigh- ing 25 ducats. The memoirs, written legibly in Latin, French, Dutch, or Flemish, must be sent post paid before Feb. 1, 1818 ; and those written in answer to the last question before Nov. 1, of the same year ; to M. Van Halthem, Register of the Second Chamber of the States General, and Provisional Secretary to the Academy. The Academy requires the greatest accuracy in the citations : for this purpose the authors must take care to mark the editions and the pages of the books which they quote. They will not put their name to their works, but only a motto selected at pleasure. They will write it, likewise, upon a sealed letter, containing their name and address. Those who shall make themselves known in any way what- ever, and those likewise whose memoirs come to hand after the limited time is expired, will not be allowed to stand. IX. Translator of Euler's Algelra. — Heat generated ly the Rupture of' Iron Bars. (To Dr. Thomson.) SIR, R. M. Academy, Aug.2\, 1817. I find from the number of your Journal for August, which I saw but to-day, that there appears to have been some question respect- ing the translator of Euler's Algebra. This task was accomplished by the Rev. Mr. Hevvlet ; I merely superintended the printing of the second edition, and added the notes given at the end as illus- trative of certain properties of numbers not demonstrated in the body of the work. It is, therefore, Mr. H. who has to claim the " honour of having introduced the excellent treatise in question to English readers," While I am writing to you, I take the opportunity of proposing a query, which you, or some of your ingenious correspondents, may be disposed to answer : — I have been for some time caiTying on experiments with a view to establishing a correct theory of the strength and stress of wood and other materials ; and was lately present at an experiment performed at the Iron Cable Manufactory of Capt. Brown, when a cylindrical bar of iron IJ- inch in diameter was drawn asunder by a force of 43 tons. Before the rupture the bar lengthened about five inches, and the section of fracture was reduced about -iths of an inch ; and about this part a degree of heat was generated which rendered it unpleasant, if not in a slight degree painful, to grasp the bar in the hands. I have been very handsomely furnished by Mr. Telford with many accurate and valuable experiments of a similar kind ; also others by Capt. Brown ; in many of which the same phenomena of the gene- 312 Scientific Intelligence. [Oct. rated heat is noticed, although in others it is said no heat was ob- served. There is, however, 1 should imagine, but little doubt that a certain quantity of heat takes place in all cases, although it is in some more perceptible than in others : and I should esteem it a particular favour if you, or any of your correspondents, could suggest a satisfactory explanation of the phenomena. There is no external friction on the bar ; and the only probable reason that I can assign is the internal friction amongst the panicles, which how- ever some persons to whom I have mentioned the circumstance do not seem to consider sufficiently conclusive. 1 have the honour to be, Sir, Your obedient servant, P. Barlow. X. External Application of Sulphurous Acid as a Remedy. Dr. De Carro, of whose ardent and successful attempts to pro- pagate the vaccine inoculation in Austria we lately made honour- able mention in a biographical sketch which appeared in our Journal, is now eagerly employed in prosecuting a set of experi- ments at Vienna to ascertain the value of sulphurous acid fumes externally applied, according to the method of Dr. Gales, of Paris, as a remedy in different diseases. Dr. de Carro has distributed amongst his friends the following short account of his insthution : — " Although the utility of sulphur, taken internally, applied by friction, and mixed with natural and artificial baths, in many chronic diseases of the skin, the joints, the glands, and the lymphatic system, has been acknowledged from time immemorial, the most enlightened physicians have long desired some mode of administering the vapour of this mineral rendered acid, and more penetrating by combustion ; and this wish was particularly expressed by a great physician of this capital, J. P. Frank, in his Epitome de curandis Hominum Morbis, Cap. Psora. " Many contrivances, more or less perfect, have been adopted at different times for the employment of the sulphurous acid fumi- gation ; but none of them till the present have been so managed as to admit of being used without affecting the respiratory organs. " At length, however. Dr. Gales, of Paris, has invented and brought to perfection a Boete Fumigatoire, which appears to answer every purpose; and the success of which, since the year 1813, •would appear almost incredible, were it not attested by the prin- cipal civil and medical authorities of Paris, and fully detailed in a memoir * published in 1816, and distributed by order of the French Government. " Dr. Gales, who has obtained an exclusive privilege for this • Memoire et Rapports sur fes Fumigations Sulfiireuses appliquees au Traite- ynent des Affections cutanees et de plusieiirs aiitres Maladies. Par J. C. Gales, Docteiir en Medecine de la Faculte de Paris, &c. Imprimes par Ordre du Gou- verneineut. De I'Imprimerie Royal. Paris, 1816. 1817.] Scientific Intelligence. 313 practice in the capital, and, as a national recompense, a pension for life of 6000 francs, has in his own house 26 sets of apparatus, for all of which he finds employment ; and similar estabUshments, public and private, are daily multiplying throughout France. " Struck with the great advantages of this remedy, I have esta- blished an institution for its exhibition, after having obtained the consent of the Imperial Government of Lower Austria, who have inspected the situation and the plan. I have devoted four chambers, containing two sets of apparatus, one for females, and the other for males, provided with proper attendants for each sex. The number of chambers, and the extent of the apparatus, will be increased according to its success. In order to be the more secure, and to avoid the difficulties inseparable from an imitation, I have procured the apparatus from Paris, constructed under the direction of Dr. Gales. " The employment of the fumigation will never be left to the discretion of the patient ; and no one will be admitted until he has consulted me, either alone, or in concert with other medical men. " Wishing to facilitate beyond the capital, and in foreign coun- tries, the adoption of this remedy, I shall always have, according to the example of Dr. Gales, sets of apparatus, made under my own eye, for those who require them; and these will be accompanied with small explanatory models, capable of being taken to pieces, in order to point out exactly the disposition of the diiferent parts." (Signed) Dii Carro, M.D. Vienna, July 15, 1817. XI. Expanding Rigger. (To Dr. Thomson.) SIR, Through the medium of your Aniials, I beg leave to inquire whether a smooth wheel of variable radius, or what mechanicians term an expanding rigger, has ever been applied to any machine, in connexion with a centrifugal regulator, for the purpose of equal- izing the velocity of the working part of the machine when the driving power is subject to sudden and considerable variation ? An answer to this inquiry, by any of your readers possessing the requi- site information, will be esteemed a favour, by, Sir, your obliged and obedient servant, Srimscomb, Aug. 15. A. M. XII. Mill-stones. (To Dr. Thomson.) ♦SIR, What description of stone is that which is commonly employed for constructing flour mill-stones, called French burs ? Each mill- Stone is formed of several burs, hewn into shape, and cemented together. They are also hooped with iron. A pair of stones pf this 314 Scientific Intelligence. [Oct. kind, which are considered the best in use, cost upwards of 20/, Have we no stones equally fit for the purpose in England ? Churn Cottage, S. WeBB. The French bur-stone is a kind of vesicular quartz, found in the formations round Paris. No stone answering the purposes of a mill-stone so well has ever been found in Britain. Tolerable mill- stones are made in Scotland from green-stone. — T. XIII. Inverted Rainbow. (To Dr. Thomson,) SIR, ^Perhaps you may think the following notice deserving a place in a less perishable record than the one from which it is extracted : — " We hear from Canterbury that on Friday last, about noon, a large ball of fire was seen to pass over that city, which was followed by a storm that broke almost all the windows in the town ; and the next morning three suns appeared in the sky, attended with a rain- bow inverted, which lasted from nine till twelve, to the great asto- nishment of the inhabitants." (The Cirencester Flying Post, Dec. 2S, 1741, No. 54.) A. M. XIV. Chemical Equivalents. (To Dr. Thomson.) SIR, If not inconsistent with your plan, I request, in behalf of several chemical students, that you will do us the favour to insert in a number of the Annals a table of chemical equivalents, for the purpose of laying them on slide-rules. Stating what you consider the most accurate numbers would render a reference to the autho- rities unnecessary. Z. In the new edition of my System of Chemistry, which will be published in a few weeks, I have been at considerable pains to de- termine the weights of the atoms of bodies according to the best data at present in the possession of chemists, I refer my Corres- pondent to that work for the table which he desires to have. — T. XV, On impregnating Water with Carbonic Acid by the Syringe of Mr. Brooke's Blow-pipe. (To Dr, Thomson.) SIR, It appears to me that the condensing syringe of Mr. Brooke's blow-pipe may be applied with advantage to the purpose of im- pregnating water with carbonic acid. A (Plate LXXII, Fig. 6) represents an urn to contain the water. B, the condensing syringe. C, a silk bag to contain 1817,] Scientific Intelligence. 315 the gas. D, a funnel, furnished with a stop-cock, to replenish the urn with water. When fresh water is to be introduced, the syringe is to be removed, and the silk bag connected with the stop-cock, E, in order that the expelled gas may not be lost. When the gas is to be introduced, the syringe may be screwed on to either of the stop-cocks, E or F, as may be found most convenient. If the idea has sufficient novelty to find a place in your Journal, by inserting it you will oblige your humble servant, T. Glovkr. XVI. Lectures. Dr. Marcet proposes to give a Course of Clinical Lectures at Guy's Hospital during the next winter. And Mr. Bell will give a Course of Lectures on the Treatment and Diseases of the Teeth. Mr. T. J. Pettigrew, F.L.S. Surgeon Extraordinary to their Royal Highnesses the Dukes of Kent and Sussex, will commence his Winter Course of Lectures on Anatomy, Physiology, and Pathology, on Friday, Oct. 17, at eight o'clock in the evening precisely. The Lectures will be continued every succeeding Wed- nesday and Friday, at the same hour, until completed. Mr. Guthrie, Deputy Inspector of Military Hospitals, will com- mence his Autumn Course of Lectures on Surgery on Monday, Oct. 6, at eight in the evening, in the Waiting Room of the Royal Westminster Infirmary for Diseases of the Eye, Mary-le-bone- street, Piccadilly. Mr. Clarke will begin his Lectures on Midwifery, and the Diseases of Women and Children, on Friday, Oct. 10, at No. 10, Saville-row, Burlington Gardens. Mr. Gaulter will deliver in the ensuing season two Courses of Lectures on the Physiology of the Human Body, at No. 10, Frith- street, Soho-square. The Lectures will be given on Monday and Thursday evenings, at a quarter past eight o'clock, after the Surgical Lectures are concluded. The Introductory Lecture of the First Course will be on Thursday, Oct. 9. The following arrangements have been made for Lectures at the Surry Institution during the ensuing season : — 1. On Ethics; by the Rev. W. B. Collyer, D.D. F.S.A. To commence on Tuesday, Nov. 4, at seven o'clock in the evening precisely, and to be continued on each succeeding Tuesday. 2. On Chemistry ; by James Lowe Wheeler, Esq. To commence on Friday, Nov. 7, and to be continued on each succeeding Friday. 3. On the British Poets, from Chaucer to Cowper, by Wm. Hazlitt, Esq. To commence early in January, 1818. 4. On Music ; by W. Crotch, Mus. D. Professor of Music in tlie University of Oxford. To commerce early in February, 1818. 316 Colonel Eeaufoy's Magnetical [Oct. Article IX. Magnetical and Meteorological Olservations. By Col. Beauloy, F.R.S. Bushey Heath, near Stanmore. Latitude 31° 37' 42" North. Longitude west in time 1' 20'7". w. 'ag7i eiic al Observations , 1817 . — Variation West. Morning Observ. Noon Observ. Evening Observ. Month. He ur. 1 Variati on. Hour. Variation. Hour. Variation. .Ang. I 8h 35' 24° 31' 09' Iti 40' 240 42' 04" e"! 55' 24^ 35' 20" 2 8 35 24 29 50 35 24 43 10 6 55 24 33 32 3 8 35 24 33 56 33 24 43 58 6 55 24 34 03 4 8 35 24 30 58 40 24 42 00 6 55 24 33 50 5 8 35 24 31 08 35 24 43 52 6 55 24 34 10 6 S 35 24 30 55 45 24 40 39 6 55 24 33 54 7 8 40 24 30 35 45 24 43 50 6 55 24 33 56 8 8 35 24 31 15 40 24 42 42 7 00 24 32 27 9 8 35 24 30 38 30 24 42 40 7 00 24 33 41 10 8 40 24 30 45 35 24 41 04 6 55 24 33 -M 11 8 35 24 31 37 35 24 43 19 — — 12 8 35 24 SO 57 35 24 43 56 6 53 24 33 36 13 8 35 24 31 32 35 24 43 03 7 00 24 33 03 14 — — — — — 55 24 43 15 6 55 24 34 13 15 8 35 24 29 40 35 24 41 35 6 55 24 34 31 16 8 35 24 31 42 35 24 43 54 — — 17 8 40 24 30 25 30 24 41 30 6 53 24 34 00 18 8 35 24 28 29 35 24 44 44 — — — — — _ 19 8 35 24 34 20 55 24 41 42 6 55 24 29 38 20 8 30 24 32 46 35 24 43 30 6 55 24 34 47 21 9 10 24 31 38 40 24 41 01 6 55 24 34 26 22 8 40 24 30 42 45 24 42 39 6 55 24 33 58 23 8 35 24 31 32 45 24 43 36 6 55 24 35 16 24 8 35 24 31 22 45 24 43 51 6 55 24 34 26 25 8 30 24 32 47 — — — 6 55 24 33 26 26 8 40 24 SO 10 40 24 42 23 6 55 24 34 13 27 8 35 24 32 12 35 24 41 58 6 55 24 34 26 28 8 40 24 37 25 — . ^^ — 7 15 24 31 20 29 8 40 24 29 30 55 24 43 ,47 — — -. , . 30 8 40 24 30 28 25 24 43 14 6 50 24 33 37 31 8 35 24 32 39 50 24 43 31 6 50 24 34 06 Mean for Month. }» 37 24 31 26 1 39 24 42 51 6 57 24 33 45 Aug. 19. — In the morning Busliey Heath was immersed in ^ cloud. 18170 mid Meteorological Talks. MetearoloQical Table. 317 Month. Ans. 1 Morn. . Noon. . Rveu . . Morn., Noon., Even .. 10 11< 12^ 13^ Time. Barom 16^ 17' L hven . . . r Morn... \ Noon... L Even ... Thar. 18 I Inches. 29 334 29-377 29-400 ■29-510 29-517 29-585 29-305 29-288 29-295 29-345 29-325 29-310 29-523 29 605 29-600 29650 29-645 29-595 29-485 29-435 29-363 29-095 29-110 29-200 29-270 29-300 29-375 29-400 29-400 29-412 29-390 29-300 29-173 29-973 29973 29-973 28-800 29 034 29-180 29-250 29-234 29-200 29-283 29-357 29-410 29 450 29-360 29-267 29-293 29-337 29-315 29-520 Hyg. 56° 66 61 58 66 62 56 63 69 55 60 60 58 66 63 61 68 62 60 71 65 60 61 58 58 62 59 57 60 59 57 63 59 57 63 56 57 64 59 60 65 65 58 65 59 61 65 57 62 58 56 61 Wind. 63° 46 48 57 41 45 70 51 50 68 50 52 60 45 47 66 44 45 54 43 47 84 5S 50 59 53 52 65 55 50 61 56 63 60 49 63 74 47 53 85 70 60 73 49 52 63 46 60 52 55 68 52 Velocity. W by N NW W bv N W WNW W ssvv w W by S WbyS W w NNE N C:ilm SSB SSW SSE ESE Sby W SSE SSVV W byS WSW WSW WSW W by N WSW WNW WNW S by W SSW SSE SW by W svv SW by S Wby N W WbyS SW SSW SSW WSW WbvS SW SSW SSW WSW w w w SW by S Feet. 12-704 9-225 21-675 22-931 6-566 10-977 5-636 Weather. Six's. 26-399 25-189 10-934 13-939 17-715 28-624 23-326 28-404 11-625 26-627 Fine Showery Fine Very fine Very fine Cloudy Drizzle Showery Very fine Sm. rain Showery Fine Fine Fine Fine Fine Cloudy Fine Cloudy Fine Cloudy Rain Showery Fine Fine Showery Fine Cloudy Showery Very fine Cloudy Cloudy Rain Fine Showery Showery Showery Fine Fine Rain Showery Showery Showery Fine Fine Fine Fine Fine Showery Showery Cloudy Cloudy 47" 66 [49 69 \ 54 6T 49 6G 55 63 54 70 53 71 58 65 50 64 52 65 43 66 54 65 54 65 56 6T 56 66 52 66 50 63 49 62 } } } \ } } } } } } } S18 Col. Beaiifoy's Meteorological Table. [Oct. Meteorological Table contimwd. Month. Time. Barom. Ther. Hyg. Wind. Velocity. Weather. Six's. Aug. Inches. Feet ( Morn 29-277 600 83° WSW Cloudy 55 • 19 j Noon... . 29-257 64 81 SW Sliowery 66 f Even .... Morn. . . . 29-217 29-190 61 60 83 61 ssw W by S Cloudy Cloudy |5f> 20^ Noon.. . . 29-200 64 51 SW by W Cloudy 66 I Even .... 29-200 59 58 SW Cloudy |53 f Morn 29-300 54 75 NNE Raiu 21 { Noon. . . . 29-400 56 70 NNE Showery 60 I Even .... 29-500 55 61 N Fine |44 r Morn .... 29-657 52 65 NNE Very fine tzl Noon, .. , 29-663 60 45 Var. Cloudy 62 I Even .... 29-660 55 60 Calm Fine }45 c Morn.... 29-592 53 59 ESE Very fine 23^ Noon 29-526 62 45 SSE Cloudy 63 (_ Even .... 29-480 56 58 E Cloudy jsi r Morn 29-335 57 55 Eby S Cloudy 24 < Noon 29-275 57 64 ESE Showery 62 (. Even 29- 160 57 57 ESE Showery }- J Morn 28-843 57 80 SSE Showery 25< Noon. . . . 28-700 59 80 SSE — 64 I Even .... 28-660 61 73 SSW Fine |56 r Morn 28-624 61 71 SSE Showery 26< Noon.. . . 28-565 65 65 S Showery 65 L Even ... 28-540 55 73 SSW Showery }- r Morn 28-720 60 70 W Fine 27 < Noon. . . . 28-815 62 61 w Showery 64 Even .... 28.910 57 66 Wby N Showery }53 s Morn 29-205 59 61 WNW Fine 28 ■( Noon. . . . — Cloudy 63 (. Even .... 29-285 57 61 WSW Cloudy }m „J Morn. . . . 29-178 57 70 w Cloudy 29 < Noon. . . . 29-223 63 60 w Showery 66 L Even .... — — — — — }« f Morn 29-460 56 68 w Fine S0<{ Noon 29-462 63 58 Sby W Drizzle 66 I Even .... 29-445 59 64 Sby E Cloudy |55 r Morn 29-400 58 66 WSW Fine 31 <^ Noon 29-427 64 51 SW Showery 67 I Even 29-483 68 58 SW Fine Aug. 17. — The wind machine was spoiled by the breaking of the pivot. 1SI7.3 Mr. Howard's Meteorological Table, MS) Article X. METEOROLOGICAL TABLE. Barometer. Thermometer. rly^r. al 1817. Wind. Max. Min. Med. Max. Mill. Med. 9 a. m. Rain. 8tb Mo. Aug. 3 N E 30-05 3000 30025 70 48 59-0 47 C / 6 N E 30-00 29-85 29-925 74 40 370 44 1 7 N W 29-8329-45 29-640 73 55 65-0 44 \ 8 s w 29-58I29-45 29-515 67 48 57-5 S5 9 w 29-7229-59 29-655 71 45 58-0 44 1 1.0 s w 29-72 29-71 29-715 71 34 52-5 30 10 11 s w 297229-33 29-525 71 48 69-5 52 — 12 s w 29-33i29-17 29-250 68 52 600 30 45 9 13 s w 29-55'29-33 29-440 67 54 60-5 55 14 w 29-61 29-55 29-530 71 54 62-5 62 3 13 w 29-78 29-33 29-665 68 46 57-0 48 4 16 s 29-38 29-33 29-565 70 48 59-0 45 22 17 w 29-87 29-59 29-730 66 45 33-5 30 6 18 S W 29-64 29-59 29-615 66 34 60-0 49 28 19 S W 29-64 29-55 29-^9^ 68 54 61-0 60 6 ^ 20 w 29-64 29-55 29-595 69 50 39-5 50 — 21 N W 30-02 29-64 29-830 59 42 50-5 64 12 22 E 30-02 29-94 29-980 63 35 49-0 50 23 S E 29-94'29-68 29-810 67 4S 57-5 58 24 S 29-68 29-20 29-440 65 50 57-5 45 — 25 S W 29-20:29-00 29-100 62 48 55-0 63 29 26 S 29-082890 28-990 64 44 54-0 55 15 1 ^ 27 s w 29-55,29-08 29-315 68 31 59-5 48 3 I 28 s w 29-64 29-54 29-390 68 51 59-5 30 12 29 w 29-8O 29-64 29-720 69 47 58-0 33 3C s w 29-8O 29-75 29-775 71 54 62-5 53 IS 31 s w 29-95 29-73 2983C > 67 41 34-0 53 9 th Mo Sept. 1 N I - 29-9S 29-95 29-.965 69 37 530 64 c ! E 29-9? 30-0^ 29-85 28-9C 29-905 ) 29-63] 69 48 58-5 58 75 34 57.6: . 32-3 2-ia The observations in each line of the table apply to a period of twenty-four hours, beginning at 9 A. M. on the day indicated in the first column. A ilusli doiKiles, that the result is included in the next following observation. 320 Mr. Howard's Meteorological Journal, [Oct. 181 7. REMARKS. Eighth Month. — 21. A wet morning: windy at N: p.m. cloudy, with wind about NNW: pretty calm at night. 22. Fair, with Cirrostratus beneath Cirrus: gold-coloured moon : calm at night. 23. Fine morning: there is s^d to have been hoar frost : a few Cumuli appeared, which soon became heavy Cumulostratus : and in the evening it was quite overcast, with a few drops of rain. 24. Fine, a.m.: the wind SE: a little rain, p.m.: during the day a singular anomalous veil of cloud overspread the sky, in which the Cirrostratus on the whole predominated : the lower surface of these clouds put on fine crimson and grey tints at sun-set, and the lights formed by the moon shining through them were peculiarly soft and pleasing. 25. Cloudy, a. m. : small rain : the wind gentle, veering to S : it rained much of the day at intervals : afterwards appeared groups consisting of Cumuto- stratus and Cirrocumuhis, with Nimbi: hazy moonlight. 20, Cirrostratus in the morning : then Nimbus, and some rain : the wind gone back to SE, and moderate: many sudden showers of small amount from ill-defined clouds amidst haze: a bow soon after three, p.m.: windy night. 27. Fine morning: much dew: calm: Cumulostratus tending to OVrocumu/us above : some rain at mid-day. 28. Fine morning: Cumulus passed to Cumulostratus: a very few drops fell, p.m.: and there followed wind, succeeded by calm, with Cirrostratus and haze: rain in the night. 29. F;iir: brisk wind, with various clouds. 30. A veil of Cirrostratus \ti flocks, a. m., with this Cumulus rapidly inosculating, formed Cumulostratus, which was heavy through the day : in the evening much Cirrostratus, succeeded by small rain: in the night a heavy shower. 31. Fine, with Cumuli, carried by a strong breeze. Ninth Month. — 1. Misty morning, with Cirrostratus above, to which succeeded Cumulostratus. 2. Fine morning : wind NE, with C!>ros5 ; and as it does not appear that Bergman arrived at a perfect knowledge of the acid properties of fixed air before 1770, the priority of the learned Professor's claim. to tlie discovery can by no means with justice be admitted. The labouis of Dr. Brovvnrigg in this extensive field of chemistry, which had hitherto been crowned with such surprising success, were afterwards continued with undiminished zeal and perseverance. For many years it was his design to ofter to the world an explanation of the causes of some curious phenomena which occuired in his expe- riments upon tlie Pouhon water ; a description of the diflFeient metiiods of disengaging the air of that water; additional proofs of the dissolving power of fixed air, and of effecting its re-absorption, with illustrations of those doctrines which be had originally ad- vanced. Wlicther the result of his inquiries had been anticipated by the progressive improvement of science, or for reasons which it would be as difficult as it would be useless to discover, this design was never put in execution ; a circumstance which the friends of Dr. Brownrigg, and of mankind, must equally regret. In the year 174^1 Dr. Brownrigg published his valuable work, entitled, The Art of making common Salt, as now practised in most Parts of the World, with several Improvements in that Art, for the Use of the British Dominions. He was prompted to under- take this arduous task from a general desire which at that period prevailed in the nation to promote and extend the British fisheries, and by this measure to find a profitable employment, not only for great numbers of seamen, who, on the restoration of peace, had been discharged from the service of their country, but also for the natives of the north of Scotland. The active exertions of the Highlanders during the late rebellion had roused the attention of the Legislature to that remote part of the" kingdom, which had hitherto been treated with neglect or indifference. An inquiry into their situation discovered that the inhabitants of a portion of the British empire were sunk into a state of barbarity and ignorance scarcely paralleled in the annals of mankind ; and the voice of humanity, as well as of policy, called loudly for the adoption of some expedient calculated to improve and ameliorate their condi- tion, and to introduce amongst them the blessings of civilization. The establishment of fisheries, for which the north of Scotland is conveniently situated, seemed particularly adapted to facilitate * See Dr. Brownrigg's lelter to Sir John Pringle, prefixed to ihe continuation. + It was tlioiight proper to disregard llie clironological order of Ur. Browu- r'SS's publications, for the salje of giving an uninterrupted detail of his discoveries and inquiries relative to fixed and inflammable air. 1817.] Dr. William Broivnrigg, 333 the accomplishment of so desirable an event. It was naturally ex- pected that a more enlarged intercourse with the world would con- tribute to enlighten their minds, soften their manners, expand their views, and remove tiieir political prejudices. The nation moreover indulged the hope that such a measure would become a powerful obstacle to future insurrections; that, exciting a spirit of industry, it would have a direct tendency to weaken, if not destroy, the in- fluence of the disaffected chieftains ; as it would rescue the vassals from that state of slavish dependence on their masters to which they bad hitherto been subjected by their poverty and indolence ; whilst the enjoyment of comforts and pleasures before unknown would strengthen their attachment to the existing government. It was justly supposed, also, that could this fishery be conducted with the same skill and success vvhich attended the indefatigable exertions of our continental neighbours on the coasts of Great Britain, the strength and opulence of the state would in consequence be consi- derably increased. An inquiry being made by the British Legislature, it was found that salt of a proper quality was wanted in this kingdom for the use of fisheries ; and that if salt could be prepared in England of the same ])urity as in some adjacent countries, the wealth of those who were frequently our enemies would no longer be supported by the money which was expended in purchasing it from them, our fisheries would become more flourishing, and the nation, as well as its colo- nies, would not on any future occasion be liable to the same difli- culties which, from this necessary article of life being the exclusive property of the French, Spaniards, Portuguese, and other foreigners, they had in time of hostilities experienced. In order to remove these inconveniencies, a premium of 10,()OOZ. was granted by the House of Commons to Mr. Lowndes, for communicating to the public his method of making brine salt, which he asserted was greatly superior to any salt that could be prepared, either from sea water, or by refining rock salt, and would answer every requisite purpose, being as well adapted for the use of the table as for the preservation of provisions. Dr. Brownrigg, on examining Mr. Lowndes's publication, though iar from depreciating his labours and endeavours, was of opinion that the method proposed was too partial and confined, that it would not fully accomplish the intentions of the Legislature, and that a better, less expensive, and purer salt might be obtained, even from brine, than could be procured according to the plan which that gentleman had recommended. He therefore took a more general and comprehensive view of the subject ; and, without soliciting any reward, has given rules for preparing a pure and strong muriatic salt in various ways, as well from sea water and rock salt, as from springs of brine, fit for all culinary uses, and for preventing the putrefaction of animal food. This publication on the art of making common salt, in which profound and ingenious remarks are united to valuable information, 334 Biographical Accou7it of [Nov. reflects distinguished lustre on Dr. Brownrigg's talents,, whilst his application of philosophical inquiries to the interests and necessities of mankind entitle him to the highest praise and admiration Having mentioned in the introduction many particulars with respect to the uses, the abundance, and the natural history of common salt ; and having laid down a distinction of its different kinds, founded on their origin and mode of preparation, not on those adventitious qualities which result from some heterogeneous admixture, he pro- ceeds in the first place to the consideration of bay salt. The methods of extracting it, either from the brine of ponds and lakes, or by a total evaporation of the water impregnated with it, and its preparations, as practised in France, Spain, Portugal, the Cape de Verd Islands, Salt Tortuga, and Turk's Island, are ex- plained in a full and satisfactory manner. After an enumeration of the several kinds of white salts. Dr. Brownrigg gives an accurate and comprehensive relation of the processes adopted by various nations for obtaining and preparing them. In describing the arti- ficial mode of procuring salt from sea water by coction, he enters upon an examination of the principles and ingredients of sea water. This analysis, replete with important observations relative to the substances of vvhicii it is compounded, their characteristic qualities, their comparative difficulty of separation, and their salutary or dele- terious effects upon the human body, has contributed much to the elucidation and improvement of a subject which, though intimately connected with medicine and general science, yet had hitherto been neglected by the experimentalist and the philo^opher. The Dutch method of preparing salt upon salt, which, by the artful policy of that nation, had been carefully concealed from the inquisitive eye of the curious or the interested, was first communi- cated to the public by Dr. Brownrigg. In consequence of the superior excellency of this refined salt in the preservation of provi- sions, the Dutch had gained such advantages over their competitors in the herring fishery, as to preclude all expectations of adequate success ; and the Doctor, therefore, has an indisputable right to the thanks and praises of his country for the removal of an obstacle which had retarded the prosecution, and even threatened the exist- ence, of that trade. Unrestrained by obligations of secrecy, and convinced that such a discovery would be productive of the most beneficial consequences to the nation, he discloses without reserve whatever information, deserving of credit, he had an opportunity of collecting upon the subject during his residence in Holland. The Dutch refined salt is white salt boiled from a solution of bay salt in sea water, or any other kind of salt water. The only essen- tial difference of the process consists in the addition of half a pint of whey, kept for a considerable space of time, until it has acquired a very powerful degree of acidity. The addition is made on the first appearance of granulation ; and to this single circumstance, as the grand arcanum of their art, the Dutch attribute the superior purity, strength, and durability, of their salt. 1817.] ^' William Broivnrigg. 335 To this history of the various kinds of bay and white salt are annexed some useful remarks concerning their respective advan- tages, and the peculiar qualities which they derive from their diffe- rent mode of preparation. The several methods also of preserving provisions, whether designed for immediate consumption or for ex- portation, and the properties of that species of salt which is best calculated to resist putrefaction, are enumerated and explained. Without exaggeration, it may be observed that this part of the work claims to itself no inconsiderable degree of credit and praise for a strict conformity to truth, and a faithful adherence to facts, for accuracy of detail, and perspicuity of language. And as it exhibits in a conspicuous point of view the author's versatility of talents, and just discrimination of evidence, his extensive reading, and intimate acquaintance with the manners and customs of various nations, so the remainder of it is eminently distinguished for inge- nuity of sentiment, originahty of observation, and solidity of judg- ment. Sincerely regretting, from disinterested and patriotic views, that the art of preparing salt had not arrived at that degree of perfection in the British dominions as in other countries, and impressed with a conviction that this circumstance was not to be ascribed to any local disadvantage, but solely to the ignorance and unskilfulness of the manufacturers. Dr. Brownrigg proceeds to show that active, laborious, and well-directed exertions, assisted by parliamentary encouragement, would introduce the most important improvements in the preparation of this useful article ; and that supplies of it might be obtained, at a moderate price, from the British salterns, in quantity sufficient for our domestic consumption, and in quality even superior to any foreign salt. This opinion he supports, as well by authentic and incontrovertible facts, as by irrefragable and unso- phisticated reasoning. Previous to the explanation of his own pro- cesses. Dr. Brownrigg, in four lemmas, constituting in a great measure the foundation of the future superstructure, determines with accuracy the annual quantity of rain which falls in different counties of the kingdom, and gives a comparative estimate of the proportion of water ascending from the sea and lakes in exhalations, and descending in rain. The improvements proposed in the art of making bay salt are described and recommended in six propositions. 1. From exact calculations, it appears that during the hottest months of the year the usual evaporation from a pond whose watery particles are exposed to the action of the sun and winds exceeds by 17 inches' depth of water the quantity which it receives by rain. By parity of reason, therefore, a pond filled with sea water to the depth of l(j inches in May, will by the end of August, in conse- quence of the exhalation arising from it, contain nothing but a crust of salt deposited at its bottom, which crust is determined, by proper calculations, to be equal to 1245 bush. 0*4 lb. upon every statute acre. As this method is tedious, and liable to many incon- veniences ; as its success depends on the casualties of the season. 336 Biographical Account of [Nov. and the vicissitudes of the weather ; and more particularly as the salt, from its thickness, being only about J- of an inch, must be injured by an unavoidable mixture of mud, calcareous earth, and other impurities adhering to it, in a very large proportion, its actual practice is not recommended. Dr. Brownrigg endeavours to demonstrate, in the second propo- sition, that the preparation of bay salt in England may be conducted with equal convenience, expedition, and certainty of success, as in France, Spain, and Italy; and that the sea coast, from Dover to Yarmouth, is well adapted to this purpose. He thinks that as the French can prepare, in a fortnight of favourable weather, a supply of salt adequate to their annual consumption, and that of their commercial allies; so it would be by no means impracticable to obtain here, in the course of the summer, considerable quantities by the method which they have adopted. In the latitude, in the climate, in the temperature of the atmosphere, in the operation of the winds, in the frequency or quantity of rain, and in the acci- dental circumstances which may retard and interrupt the process, no remarkable or material difference can be discovered at some parts of the French and English coasts. Even on the supposition that in the former country a double quantity of water would evapo- rate in equal spaces of time, in consequence of a more intense heat, yet Dr. Brownrigg conceives that this inconvenience might be obviated in such a manner as that the French manufacturers of salt should possess no advantage over our own, either in the quantity prepared, or in the inferiority of its price. The introduction in this place of his ingenious arguments and accurate calculations is incompatible with the nature and design of the present work : the inference, however, which natuially arises from them, is, that a greater extent of surface must be exposed at an English salt-marsh to the influence of the sun and air, which extent must be deter- mined and regulated by the proportion of the sun's heat in England to that in France. The English salt-pit will also require a more enlarged surface, on account of the rain received into it during evaporation. The exact extent it must be obvious can only be ascertained by suitable and repeated experiments. From a due consideration, however, of every circumstance, the following con- clusion appears reasonable : that an equal quantity of salt may be obtained from an English as from a French salt-pond, when the surface of the former exceeds that of the latter by one-fifth part. Although the practicability and convenience of this method must be admitted, yet it is attended with these disadvantages, that it is liable to interruption from rain, that the preparation of any consi- derable quantity is prevented, and that the formation of large crys- tals cannot be effected. The plan, therefore, explained in the third proposition, is deserving of preference. It consists of im- provements in the construction of the French salt-marsh ; the object of which is to prevent the dilution of the brine with rain, to add force to the heat of the sun, and to accelerate the exhalation of 18170 Dr. William Brownrrgg. 33? the water. Dr. Brownrigg recommends certain covers of thin board, or of coarse canvas stretched on frames of wood, as useful on two accounts : first, when hanging down, as a protection for the ponds from rain ; and, secondly, when erected, as reflectors of the sun's rays. He also thinks it advisable to raise the salt water by the assistance of a small fire-engine, which must be suffered to return into the reservoir by means of a diverger, as the evaporation will thus be increased, and consequently completed in a much shorter space of time. By these contrivances, and some others which are descrilied, he apprehends that at an English work of equal size and dimensions with one in France a double quantity of salt might be procured. The fourth proposition relates to the preparation of bay salt from the natural brine of salt springs, and also from rock salt dissolved in sea water or weak brine. In those places where natural brine is perfectly saturated with salt, no further process is requisite for ob- taining it, except the separation of its impurities ; and a complete impregnation of weak brine with salt may be produced by exposure to the action of the sun and air, increased by reflectors. Large quantities of bay salt may also be procured, either from weak brine, or sea water saturated with rock salt. . From exact calculations. Dr. Brownrigg concludes that, on the most moderate computation, 18 pits of three inches depth, and 16 feet square, filled with brine completely saturated, will contain more than 21177 Ih. of salt, and that the time requisite for its preparation may be estimated at six days. He next proceeds, in the fifth proposition, to an examination of the quality and quantity of the salt obtained by the above-mentioned processes, and of the expenses connected with its preparation. He first proves that, notwithstanding the acknowledged superiority of the French bay salt, its price is only one-third of that for which white salt can be prepared in those parts of England which are most favoured by nature, and improved by art. He next shows that the expenses of making a salt-marsh in England, after the French construction, would not much exceed tliose incurred by the French mitnufacturers, and that the additional expenses occasioned by the improvements described under the third proposition would be amply compensated by more than a proportional increase of profit. If, however, any difference in the price of English salt should exist, this disadvantage would be sufficiently counterbalanced by its exemption from certain duties and customs imposed upon salt im- ported from France, and by certain indulgences and encourage- ments afforded by the Legislature to British manufacturers. From the nature of the processes recommended, and from actual expe- rience, he thinks himself justified in concluding that the British salt would be by no means interior in its qualities and uses to that of foreign preparation; suggesting, at the same time, a method for a more perfect purification of the brine. Vol. X. K° V. Y 338 Explanation of the Characteristics d and ?■. [Nov. Under the sixth proposition he considers the practicability of obtaining in North America, from sea water, a supply of bay salt adequate to its consumption. From the comparative situation of France and North America ; from the natural and artificial advan- tages of the latter, from the intensity of its heat, from the early maturity of its fruits ; from all these considerations the necessary inference, as he conceives, is, that by inconsiderable exertions, and at a moderate expense, the inhabitants of that portion of the globe might prepare salt in such abundance, as not only to satisfy the demand of their fisheries, but even render their commerce more flourishing by its exportation. (To be continutd.) Article II. Explanation of the Characteristics d and J. By Mr. Adams, (To Dr. Thomson.) SIR, Stoneltouse, near Plymouth, July 6, 1817. Being of opinion that the following explanation of the charac- teristics d and S", together with the general formula derived there- from, may be useful to youths just entering upon the differential and integral calculus, your inserting them in the Annals of Philo- sophy will much oblige, Sir, your most obedient servant. Jambs Adams. On the Characteristics d and ^. Since by differentiating with the characteristic d, we have d [x) = d X d {x-) = 2 X d X d (x^) = 3 x^ d X d{x'') = n x""' dx d^ {x") = n{n — I) a;"-* dx"" &c. &c. d X being constant. So by differentiating with the characteristic 3", we have d.v dx •(a;) = ^x =^^.^x ?(x«) = 2x^x = t±l^I± = ^*. Jx ^ ' ax dx 18170 Explanation of the Characteristics d and J". 337 Vox -. » V 3 i'' J X rf X d ^3 - ? (X") = 7Z X"- • ? :C = r = -r— . 0- X d X d X X"- f^ (X-) = W (7Z - 1) X"-^ JX^ = -^ ^-^^5 = 7^ Jx"-. &c. &c. ^ X constant. Hence we conclude that 3'" (x") = -^^-^ . Jx", therefore c?"' x" J>» x" J x" Jx" From whence, if V be a function of y, we may easily arrive at this fundamental theorem, For by the preceding And d- (JV) = d- {i^ ^y) = '-^^iy Therefore J J'" V = J"" J V (A) Otherwise thus : since the variation of any quantity depends upon that quantity, it is evident that the variation of any primitive must be a function of that primitive. Therefore ^ y = (p y = function of y And ^ y' = 'P y' = function of y' Hence ^ y' — ^y ■=

r + M >re = M N + N n; that is, ^y -\- d{rj + ^y) = l{y + d y) + dy; or, ly + dy + d^y = ^y + ^dy + d y .'. d ^ y = i d ff. COROLLART In any two curves. The difference of the variations of two consecutive ordinates is equal to the difference of their diffe- rentials. For V r + Mw = MN+Nn.'. v/ — MNsMtJi - N «. The expression "/JV = 3""/ V, may be proved as follows:— Let IV = 'fY = n^^ integral of V. Then d" IV = Y .'. ^ d'' V = ^Y = d" ^ w (by the foregoing) Therefore "/J V = "/J" ? m' = i""" ^w = ^w = $''fY That is, yJV = J-/V (B). Suppose (p and & to represent two variable functions ; and let it be required to find the variation of "f^ d'" L From the theorems marked (A) and (B), we have J {"f

J 9. Then, by substitution, J ("/^ d"" 9) = y {d" (^ J 9) - <^" ^ 3-9 + 3"^ d'^ 9} t= "-"/f J9 + "/(^^ i"'9 - c?" ^ J9). If m = n = I, then J(/^{/* 9 = 9] must be deduced from that of the equation F {S, n^ S, %!.- % 4' S} = O." I cite these words from Mr. B.'s concluding observations, in the Journal just mentioned, on the solution oi ■^'^ x = x, which is contained in the formula X = <2 ~ ' ■< i-^ + c» I And, with all the deference due to this gentleman's profound science, I cannot help attributing his hesitancy in this instance to his having overlooked a principle which he has so happily applied to functions of the first order in Prob. VIII. of his Essay. It is by no means restricted to such expressions, but adapts itself with the evidence of an axiom to pure functional equations of all orders. I refer to the principle that the arbitrary constants in such equations may be exchanged for any symmetrical functions of all the inferior functions of the variable concerned. In the formula just quotedj for example, we are at liberty to make a = a {x, i!l> X, ^^ X, •>J/' x} I = i {x, 4. X, i'- X, iP x} c = y {x, 4* X, •«}/* X, \|/' x} And when these substitutions are made, nothing — as it appears ta Bie — can be added to tlie generality of the solution. By this methodj it is true, we arrive frequently at implicit func- 342 Solution of the Equation 4-" a; = x. [Nov. tions ; but this circumstance does not detract from the perfection of the solution, since the results are placed within the reach of known processes. The proof and illustration of these remarks will be attended with no difficulty, as far as they regard the simple case whose solution Is y = ^^ = \in-7vi) In fact, by taking

x(py-\- b f y = a n symmetrical function of x and y, which can be readily identified, by means of the arbitrary constants, with any proposed function similar to W{t, y} = O, and, therefore, a fortiori, with any particular solution of the case. ExPER. I. — When a = b = \, c = O, and

COS. 2 & » we shall have «" — ' X sin. n & " ~ sill. & X (2 COS. 3)"- •' a function which becomes null when S = — , k being any integer. The connexion in which it appears will show that k in the sub- sequent formulae must be interpreted 1, 2, 3 . . . . i ^^ — 1, or -^ (n — 1), as 71 is even or odd. In other vvords, ^ < i-n. Restoring then the values of s, z, 9, our investigation gives - (ft + c)" a d — I c ■=■ ^ „ %kir 2 + 2 COS. n and consequently 2 fc w — (6« — 2 COS. 4 c + c') d — 77. — ^ (2 + 2 COS. 1 a n J If this be substituted for d in the value of /x, the equation/* x = a; is solved ; and as Mr. Babbage has shown (Essay, Prob. XI.) that r}." X will be = ^f"'/" f x^, if 4^ x = says that an annual quantity of 1,000,000 lb. of cinnamon is said to be exported from this coast to the Gulf of Persia and to the Red Sea. A small quantity is likewise sent to Europe. This quantity is incredible. Fra Paolino da San Bartolomeo had, from his long residence, profession, and studies, an infinitely better opportunity of learning the internal state of the country, as well as the export trade, than Stavorinus, who was only an occasional visiter. He arrived in India in 1776, where he resided 13 years. He tells us that the English purchased cinnamon from the King of Travancore, at the rate of about SO rupees a candy, or about 500 lb. Avoirdupois, which is nearly two fans per lb., and that Malabar supplied at least 500 candys, amounting to 250,000 lb. He adds, that " the Dutch do not wish the cinnamon to thrive, and extirpate the trees in Malabar wherever they find them, in order that their cinnamon which grows on Ceylon may not become of less value." Tlie statements of the learned Carmelite appear in general to deserve belief, except re- lating to the subject of religion, and then his opinions and conduct seem to be at variance with his usual good sense. Mr. VVilcocke, the translator of the Voyages of Stavorinus, in his note to the work, says, that in 1 77^, 600,000 lb. of cinnamon were disposed of at the Europe sale, at about 1 Is. sterling per lb., being part of the imports from Ceylon. In an appendix to that work, he gives a statement of the quantities of cinnamon and cin- namon oil sold at the Dutch East India Company's sales from 177^ to 1 779 :— Pounds of cinnamon in 1775, 400,000— 1776, 400,000— 1777, 400,000—1778, :^50,000— 1779, 300,000. Ounces of oil of cinnamon, in 1775, 240—1776, 160—1777, bO— 177s, 160—1779, 160. Being an annual average of 370,000 lb., which, if sold at lis. per lb., the rate stated above for the year 1778? amounts to 203,500/. The encroachments of other nations into the cinnamon trade continued to give the Dutch great alarm. These encroachments, which were never regarded with indifference, had been making gradual, but steady, advances. A letter from the Dutch India Directors, addressed to the Supreme Government, bearing date 1817.] Of Cinnamon as an Article of Commerce. 351 Dec. 29, 1787> expressly states, that " We have great need of a considerable quantity of the best cinnamon to put a stop to the con- sumption of the Chinese, and the cinnamon imported by other nations ; and by that circumstance, to occasion their not yielding a profit any longer, prevent their importation ; and by these means ours will retain that general estimation which alone can ensure its high price, and consequently our profit." Their fears were too well grounded : the cinnamon importations into Holland gradually declined. The following is an account of the cinnamon imported and sold at the Dutch India Company's sales from the years 1785 to 17^1 inclusive, with the sale amount of each year : — Years. lb. £, 17B5 309,040 1.09,470 17^6 453,920 280,605 1757 144,000 82,470 1788 485,600 273.765 1739 463,400 252,785 1790 375,920 205,045 1791 183,765 100,235 The average quantity imported into Holland in each year of the preceding period is 345,092 lb., and the average annual amount 199,195/. Us. being about \\s. 6d. per lb. This statement evinces that the exportation of cinnamon was on the decline : it still, however, retained its price. The rivalship of the China cinnamon trade, and the difficulties and impediments occasioned by the King of Kandy to the collecting of cinnamon in his territories, may be assigned as the chief causes of the diminu- tion of the cinnamon commerce in Ceylon. The Kandian Court, although unsuccessful in the resistance it made against the Dutch, remained unconquered, and entertained a proud spirit of independ- ence, a constant enmity, and deep resentment, against its invaders, tor the many attempts they had made to humiliate and subdue its power. The misfortunes of both parties occasionally led to a cessa- tion of hostilities, sometimes to mutual concessions, but never to amity. To check the rivalship of the Chinese cinnamon, and to render themselves independent of the King of Kandy, the Dutch adopted means which experience has evinced to have been extremely prudent. The plan they adopted was the cultivation of cinnamon in their own country. Cinnamon began to be cultivated in very small quantity on Ceylon about the year 1765 ; the propriety and necessity of the measure became more evident ; and succeeding circum- stances rendered it more and more imperious to extend the cultiva- tion by all the means of which they were in possession. Dr. Thun- berg, who visited Ceylon in 1778, informs us, that "by the un- wearied exertions of Governor Falck, exceedingly large plantations 852 Of Cinnamon as an Article of Commerce. [Nov. of cinnamon had been formed, and that the shoots of some of the plantations had been already three times barked." He particularly mentions large plantations of cinnamon being cultivated at Sita- wake, a place situated near to the Kandian border, and about 30 miles from Colombo, at Grandpass, Marendahu, Matura, and Caltura. Governor Falck died in February, 1 785 ; and was succeeded in the colonial government by W. J. Vande Graaf, a zealous promoter of the cultivation of cinnamon. He prosecuted Governor Falck's undertaking with zeal, judgment, and perseverance. The district or portion of the belt of territory possessed by the Dutch, which affords good cinnamon, is bounded on the north by the Reymel river, a few miles to the northward of Negombo, and on the east by the river Wallaway, near Hambantotte. Beyond these boundaries few cinnamon plants grow ; and their bark, when pre- pared, is not only deficient in the cinnamon odour and flavour, but sometimes bitterish, and unpleasantly tasted. Between these two rivers, but particularly between Negombo and Matura, many extensive fields were cleared, and planted with cinnamon. This must have been a work of infinite labour. In Ceylon trees and low brushwood rise with great rapidity, and cover the ground with a dense luxuriance of wood and foliage which is unequalled, except in the richest of the tropical islands. The business appears to have been entered upon with spirit, zea- lously prosecuted, and conducted with economy. The labour of clearing and planting the government plantations was performed chiefly by the native Cingalese, as personal service. By exciting a rivalship among the native headmen, liberally feeding their vanity with praise, and sometimes conferring high-sounding titles upon a few of them, and occasionally bestowing upon some of the most active a gold chain, a medal, or a silver hiked hanger, the labour seems to have, on their part, been executed with some degree of alacrity. Permanent situations, with a small monthly salary, were given to some of the headmen, who cultivated cinnamon ex- tensively. Many spots of ground were planted, particularly in the Aloet Roer Corle, near to Negombo, by granting lands to the natives, who bound themselves and their heirs to plant one-third of the lands with cinnamon, and to guard the plants from being overgrown with brushwood, or destroyed by cattle. For every pingo (GO lb.) of good cinnamon produced on these plantations the owner was allowed two rix dollars (about 3s. 6d. sterling). The shoots were cut, and the bark prepared, by the government peelers. Severe penalties were inflicted upon persons cutting, or otherwise destroying, cinnamon plants. On conviction, the culprit was severely fined, sentenced to hard labour in chains for a period of years, or banished to the Cape of Good Hope for a term of 25 years. These laws are still in force. Political altercations between the Colonial Government and the Court of Kandy occurred in 1/82, and also in 179ii« During these 181 7-] Of Cinnamon as an Arlicle of Commerce. 353 altercations the peeling of cinnamon in the King's territory was greatly interrupted. These interruptions appear to hhve constantly increased ; for we find that, on March I'f!, 1 793, a letter was ad- dressed to the King of Kandy, by order of Governor Vande Graaf, *' to inquire if, although no embassy was sent, tlie King would allow cinnamon to be peeled in his territories." The King's letter in reply stated, " that the peeling of cinnamon in his territories was usually allowed when the Company's ambassadors asked for leave to do it ; and that it was in this, and in nc other manner, that it could be done." The Governor declined sending an ambassador on this occasion, and avows that he entertained fears that leave would not have beea granted, and was afraid to risk the chance of a refusal, which might have prejudiced the respectability of the Company. It appears, however, to have been customary to send annually a messenger to the King of Kandy to request permission to cut cinnamon in his territory. To render this petition apparently less supplicatory and degrading, they dignitied the bearer with the title of Ambassador, and used, after the treaty of I7(>t>, to make a voluntary offer to the King of Kandy of leave for his subjects to collect salt in the neigh- bourhood of Chilan and Putlam, as an equivalent for his permissioa to cut cinnamon. This proposal was generally received by his Kandian Majesty with strong maiks of disdain and indignation: on one occasion his reply was, " My subjects shall continue fo collect salt on the coast as usual ; and you have my permission to cut cin- namon, as formerly." These embassies were expensive, and the ambassadors necessitated to submit to the most degrading and humi- liating formalities. By the treaty of J7'i6, the ceremony of kneel- ing before his Majesty by the Dutch ambassadors was to be dis- pensed with. Subsequent events rendered it expedient for the Dutch to yield to the renewed request of the King of Kandy to comply with the ancient usages of his Court. Neither the expense attending the embassies, nor the indignities offered to the ambas- sadors, or even the violation of right, would have alone or conjoin- edly operated successfully in preventing the customary annual n)essage. The chief cause was, that the Kandian Court received all the embassies and presents as a homage due to their monarch, who conducted himself with such an overbearing, haughty de- meanour, even while the ambassadors wete performing the de- grading and al)ject ceremonies, which inveterate custom had ren- dered indispensably requisite to approach his presence, that the Coh)nial Government beiame alarmed less the native Cingalese should sup|)Ose that they were dependant upon the Kandian Court; in fine, that they would entertain the same opinion as the King did himself. By the year 1793, Governor Vande GraaPs exertions in extend- ing the propagation of the cinnamon plant had so far succeeded that he was enabled to furnish the annual investment from ihe ter- ritory of the Company, including the plantations. In a memorial Vol.. X. N° V. Z 354 Of Cinnavion as an Article of Commerce, [Nov. addressed to Gerard Van Angelbeek, his successor, bearing d^^te July 15, 175^4, lie congratulates him that in future they would not be under the necessity of flattering the Court of Kandy any longer. G. Van Angelbeek's government was short, but destructive to the labours of the two preceding Governors in the cultivation of cinnamon. During his government little care was taken to defend it from cattle, or to prevent the plants from being overgrown with creepers and underwood. Ceylon was reduced by a British force in February, 17%. The cinnamon found in the storehouses was sold by the captors to the English East India Compai.y for 180,000/. 1 have not been able to ascertain the number of bales captured by the army. In the latter end of 1/97 t'^*^ quantity of 13,893 bales was brought to England. Mr. North assumed the government of Ceylon in October, 17'^S, but was under the controul of the Governor-General in India until the year 1802. The English Company, like the Dutch, engrossed the exclusive privilege of trading in Ceylon cinnamon : the natives of Ceylon, and all other persons, were debarred from the smallest participation ill the commerce of this article. In December, 17-^S, a regulation was issued by the President in Council, Fort St. George, directing that every ship, &c. on board which a quantity of cinnamon above 20 lb. might be found, without authority from Government, should be confiscated, with all her cargo ; and that for every pound of cinnamon, tlie quantity being less than 20 lb., a penalty of 50 star pagodas shall be paid. This prohibition continues in force. The same year a number of chalias were sent to the Malabar coast by the Ceylon Government to bark and prepare casia. On proceeding to the forests, they discovered the cinnamon-tree grow- ing in great abundance, which they divided into the fanciful sorts, or varieties, that they had been accustomed to do with the cinna- mon produced in their own island. Specimens of the j>rep3red bark were forwarded to Ceylon for the inspection of Governor North. Mr. Brown, the agent of the East India Company on the Malabar coast, considered this a most im|)ortant discovery. I have aot learned that any notice was taken of Mr. Brown's report. In 1799 the Company exported from Ceylon 5642 bales. During the same year Mr. Jonville, a French gentleman, who held an appointment in the Cinnamon Department, addressed a memorial to Governor North, wherein he sets forth that he had discovered that a cinnamon plant, when well taken care of, ought to produce 23 oz. of cinnamon every second year ; whereas those at present in the Marandhan produce, in the same space of time, no more than four-tenths of an ounce per tree. These comparative calculations appear to have been made in a very unequal manner. The first is most probably the amount of the produce of a choice plant, or bush : the second is admitted to be the average produce of each plaot iii the plantation. No allowance is made for bad 181 70 Of Cinnamon as an Jrlicle of Commerce. 355 soil, although there are many spots in the Marandhan so steril, or otherwise ill adapted for the cultivation of cinnamon, that the plants barely live, become stunted, and never afford cinnamon of a qualify fit for the Company's investment. Governor North, whose desire to promote and to ene:ross the monopoly of the cinnamon trade appears to have been ardent, was evidently much influenced by the misrepresentations and sophistical arguments of M. JonviJle. In 1799 he addressed an elaborate memoir respecting the cultivation and trade of Ceylon cinnamon to the Governor-General in Council. In this memoir we find that he had three grand objects in view : first, to obtain a sufiicient quan- tity of cinnamon annually ; secondly, at a cheap rate; and, thirdly, to preserve entire the Company's monopoly of this article. The annual consumption of cinnamon throughout the world he esti- mated at 5200 bales. In suggesting the means of obtaining this quantity he enters into an elaborate calculation, founded on the statements of M. Jonville, to ascertain how much cinnamon the Marandhan plantation could be made annually to produce. Tiie conclusion he draws is, that this plantation alone would yield annually 13,618 bales. In prosecuting this subject, he strongly and precipitately recommends the immediate grubbing up of the cinnamon plants in tiie Kaderane plantation, and in the innu- merable small plantations which were found in the private property of individuals, and eventually the plantations of Ekele and Morotto. The enormous, exaggerated estimation of the eventual produce of the Marandhan plantation, consequential to an improved mode of cuhivation, led to unfortunate results, and afford a strong instance of the propriety of much caution being used before a mere specu- lative theory should be adopted. Among the causes which induced Governor North to recommend the uprooting of the cinnamon growing in the plantation of Ekele and Morotto, he mentions their proximity to the sea. His imagi- nary fears respecting smuggling contributed greatly to his entertain- ing an opinion that the cinnamon produced in these plantations might be cut, and exported in a contraband manner. In this memoir the annual expense incurred on account of the Cinnamoa Department is estimated at pagodas 30,409 29 52. It does not appear that Governor North's suggestions were much attended to, or that his recommendations were adopted by the Governor in Council. The cinnamon was permitted to remain in the plantations which were recommended to he grubbed up, and the Marandhan continued to be cultivated- but with no extraordi- nary care. The discordant opinions of Governor North and M. Jonville probably contributed to prevent the immediate adoption of any important measure. In September, 1800, we find M. Jonville, in a memorial ad- dressed to the Governor, strongly recommending the rooting up of all the cinnanwn plants, not only in the plantations of Ekele and z 2 355 Of Cinnamon as an Article of Commerce. [Nov. Morotto, but even in that of tlie Marandhan, and suggesting the propriety of cultivating the Kaderane plantation alone, which he deemed adequate to furnish the usual annual investment. By the treaty of Amiens, concluded in Maich, 1802, the Bata- vian Republic ceded to his Britannic Majesty all their possessions in the Island of Ceylon which belonged before the war to the United Provinces. His Majesty's Ministers, deeming it prudent to permit the Company to continue to enjoy the monopoly of the Ceylon cin- namon trade, entered into an agreement with the Directors, which agreement stipulated that the Ceylon Government should furnish to the agent of the Company, who was to reside at Colombo, 400,000 1b. of cinnamon, or about 4,324 bales of 92i lb. each; for which they engaged to pay at the rate of Ss. sterling per lb. What cinnamon happened to be collected beyond this quantity w&s to be burned; and the Company agreed that whenever the cinna- mon furnished was disposed of at a higher rate than to afford five per cent, profit, after defraying all expenses, the surplus was to be placed to the credit of the Ceylon Government. The Company was to be allowed five per cent, upon the value of all cinnamon sold by the Ceylon Government for the supply of the markets in India, but none was to be disposed of in India at a rate lower than 55. per lb. This agreement was concluded for the year 1802 ; and I am not aware that any very material alteration in the terms of the contract has since been adopted. The dispatch which announced to the Ceylon Government the conclusion of this agreement recommended that the cinnamon plantations should be limited, so as not to produce, one year with another, a quantity larger than that contracted for by the Com- mittee ; and should the island be able to afford a surplus quantity, the Minister recommended that a part of the cinnamon plantations should be converted into cocoa-nut gardens, and, where the soil would permit, into rice grounds. This recommendation appears to have been made in consequence of an erroneous opinion respecting the ease with which cinnamon could be collected, and the facility with which it might be cultivated. It is impossible to say how far Governor North's memoir contributed to the Minister's mistake. The contracting parties, eager to retain the monopoly, and appa- rently ignorant that cinnamon was produced in many other parts of the world, as well as Ceylon, adopted the most effectual means to frustrate their own views, by limiting the cultivation of cinnamon, and by restricting its exportation considerably within the annual consumption of the inhabitants of the whole world. By these re- strictive measures, a premium was offered to the rice merchants of other countries to endeavour to procure cinnamon at a cheap rate, and consequently to undersell the Ceylon cinnamon. The Ceylon Government appears to have entertained serious alarms that the market would be overstocked with cinnamon the produce of Ceylon; and, anxious to prevent a reduction of the price of tlie article, 1817.] Of Cinnamon as an Article of Commerce 557 adopted a most extraordinary measure, which was to employ work- men to root up the cinnamon in many of the plantations. On Feb. 19, 1802, the Chief Secretary to Government addressed a letter (from which the following is an extract) to the President of the Board of Revenue and Commerce. " It being the intention of his Excellency the Governor that all the cinnamon gardens belonging to Government, except those of the Marandhan, Kaderane, Morotto, and Ekele, should be disposed of, his Excellency requests that you would give directions to the Agents of Revenue and Commerce in whose districts there are any cinnamon gardens, to advertise that they will be sold by public out- cry on the first of May next : the purchasers to bind themselves to root out all the cinnamon trees, and destroy them ; and all such trees belonging to private persons must likewise be destroyed." This measure conduced the rooting up the cinnamon in many of the plantations. In all those which were doomed to destruction the plants were entirely neglected, and allowed to be overgrown with creepers and brushwood, or browsed upon by cattle. No unusual activity was exerted to promote the cultivation of the four unde- stroyed plantations. Fortunately, however, the business of uproot- ing the plants was a work of great labour ; and the purchasers of a number of the plantations failed to perform their agreement to its completion. Notwithstanding the unforeseen aid of these planta- tions, the usual investments became greatly reduced, and were ob- tained with infinite labour. In July, 1805, General Maitland assumed the government of Ceylon. One of the first acts of this government was to arrest the progress of the dispolialion of the cinnamon plantations. He readily saw the propriety of encouraging and increasing the cultiva- tion of cinnamon, and adopted means which have been followed with great success. During his government the annual investments continued gradually to increase, and many hundred acres of new ground were planted. Less dependance was now placed on the supply from the Kandian territory, which was always uncertain, and subject to many impediments. His successor has, with un- abated zeal, prosecuted the same policy : he has been particularly attentive to improve the situation of the cast of people employed in its cultivation and preparation. The following is an account of the quantities of cinnamon be- longing to the East India Company sold at their sales in the years 1803 to IvSlO inclusive, with the sale amount thereof; likewise the quantities retained for home consumption : — Retained for Year. Quantity sold. Amount. Home ConsumptioR. 1803 287,267 lb. . . 63,504/. . . . 8,762 lb. 1804 357,683 78,659 9,830 1805 200,962 52,565 6,672 1806 ..,. 261,196 .... 61,216 .... 10;389 35? Of Cinnamon as an Article of Commerce. [NoV. Retained for Yfar. Quantity sold. Amount. Home Consumption, 1807 366,74fJ lb. . . 116,501/. ... 7,947 1b. 180S .... 334,631 .. .. 114,974 . . .. 13,116 1S09 433,624 153,626 . ... 10,267 1810 303,954 125,558 . . .. 11,564 being, on an average of eight years, 318,258 1b.; and the sale amount 95,825^. per annum, or about 65. per lb. The small quantity retained for home consumption is not included in this calculation. This statement, when compared with the account of the cinna- mon imported and sold at the Dutch East India Company's sales in the years 1785 to 1791 inclusive, proves that the annual quantity of cinnamon imported from Ceylon was considerably reduced, and that the prii e was diminished to nearly one- half the sum for which it was sold by the Dutch. The large importations of cinnamon which have, under the denomination of casia, for some time past been exported from Canton into Great Britain, America, as well as the British settlements in India, are the chief apparent causes of the diminished demand for Ceylon cinnamon, as well as of its re- duced price. I have not been able to discover a good reason for supposing that this traffic is of long standing. The Dutch about the year 17^7 began to apprehend a formidable rivalship in the monopoly of the cinnamon trade from the Chinese. As the exportation of cinnamon from Canton has increased, the demand from that produced on Ceylon has been on the decay, and the price reduced. The cin- namon exported from Canton, although in general of an inferior quality, can be purchased at a comparatively low rate, and may be sold, even with a large profit, far under the Ceylon cinnamon. The following are the quantities of casia imported and sold at the Company's sales from 1804 to 1808 incltjsive, with the sale amount and average price : — Year. Cwt. Average price per cwt, 1804 1,507 ...... 17,433Z. )1/. 11*. Ad. 1805 4,282 4.V)02 10 0 10 1806 1,588 7,881 4 19 4 IS07 911 3,781 4 3 0 1808 381 3,891 10 4 5 The greater part of these quantities of casia came from China. Under the denomination of casia buds, the following quantities of the receptacle of the cinnamon berry were imported and sold at the East India Company's sales in the years 1804 to 1808 inclusive, together with the sale amount, and average price per cwt. :— 6 £8170 Of Cinnamon as an Article of Commerce. 359 Year. 1804 1805 1806 1807 1S08 Cwt. 678 .520 292 0 54 Average price per cwt. 4783/. 7Z. \S. \d. 4200 8 1 6 17;i7 5 18 U 0 0 0 0 628 11 9 0 China exported in the year 1805 into the British settlements in India the product of the cinnamon plants, under the denomination of casia and casia buds, to the value of 7^j670 rupees : — Calcutta imported to the value Of rupees ... 19,134 Bombay 51,190 Madras 2,346 Some part of this casia was exported from Calcutta to London. Bombay supplies the market of Massuah, Judda, Aden, BushitJ, &c. and a great part of the consumption of this article in the Arabian Gulph. In 1810 and 1811 China exported from Canton in country ships to the British settlements casia to the amount of 3019 piquels, or 401,527 lb. : in regular ships, 6 peculs 998 lb. In the sarile season were exported from Canton in American ships 1604 peculs, or 199,977 lb. This quantity of casia is imported into Canton from the Sooloo, Archipelago, and other islands in these seas, and the different ports of Cochin China. We have no good authority for believing that any of it is produced in China. The following is a statement of the quantity of cinnamon pre- pared in Ceylon, the quantity rejected on inspection, and the number of pounds exported annually on account of the East India Company, from the year 1804 to 1814 inclusive, with the annual expense of the Cinnamon Department from I8O7 to 1814 in- clusive : — Year, Quantity Quantity Quantity Annual Expense. prepared. rejected. exported. lb. lb. lb. 1804 318,251 70,536 247,715 1805 258,144 21,159 236,985 1806 399,171 l'i,816 385,355 Rix Dollars. £ s. a. 1807 447,45.3 72,888 374,625 122,270 .... 13,049 2 8 1808 405,541 52,251 413,219 132,021 .... 14,082 4 10 1809 5-^2,358 208,783 313,575 155,845 16,623 9 4 1810 4^2,928 12,690 410,237 130,728 .... 13,944 6 5 I8II 407,803 36,3:3 371,480 135,397 .... 14,444 6 11 1812 454,562 31,189 42.3,373 145,443 .... I5,5I.«I 18 5 1813 .'r7''a/th\-t/f,(^u./<'r7.' "k J^x JtJl-rno.'^'ter R.'w.S'M'H^l j^j^^ 1817.] Improvement in the Gas Blow-pipe. S73 Article VIII. Account of an Improvement made in the Gas Blow-pipe; with some additional Remarks tipon the Revival of Met&\s from their Oxides, and of the Fusion of refractory Bodies, by Means of the same Instrument. In a Letter to the Editor by Edward Daniel Clarke, LL.D. Professor of Mineralogy in the University of Cambridge, Member of the Royal Academy of Sciences at Berlin, &c. (To Dr. Thomson.) SIR, I HAVE the satisfaction of making known to you and to your chemical readers an improvement which I have lately made in the gas hlow-pipe ; by which the safety of the operator, and its powers of fusion, have been considerably increased. It has already enabled me to extend the use of this blow-pipe in some measure to the arts; and has tended greatly to facilitate a number of experiments, wliich before were attended with difficulty, owing to the interruption caused by the necessity of replenishing the gas reservoir, as often as it became exhausted. In explaining the nature of this improvement it will be proper to refer to a form^ number of your Annals,* in which there is an engraved representation of a screen which I had adopted as a pre- caution of safety in using the gas hlow-pipe in the common way. The same screen is again represented in the drawing which accom- panies this article (Plate LXXIII. Fig. 1) ; only the spectator, in- stead of being placed opposite to it, is supposed to view its edge only ; that the whole apparatus, which is very simple, may be ex- hibited at the same time. No. 1 represents a bladder containing the usual gaseous mixture of hydrogen and oxygen.f No. 2, the syringe ; the handle of the piston being placed on the outside of the screen, so that it may not be necessary to open the door of the screen after the bladder has been fixed, as at No. 1. No. 3 is a brass tube conducting gas from the syringe into the reservoir at No. 5. No. 4 is another tube of brass, by which means the bladder, instead of being fixed close to the piston, is held at such a conve- nient distance, as not to incommode the operator, or to interfere with the rest of the apparatus. The piston at No. 2 is worked horizontally, instead of vertically, as in the former mode of using this blow-pipe. For the purpose of using this apparatus, the stop-cocks are all to • See No. XLIX. plate facing p. 91. + To obtain tlie greatest degree of heat, I have lately altered the proportioa between tlie two gases; and find that a mixture, by bulk, of seven parts of hydrogen, witli ihm parts of oxngen gas, ansvfers better than that of two to one. 374 Improvement in the Gas Blow-pipe, [Nov. be opened, excepting the small one of the jet at No. 6 ; and after 40 or 50 strokes have been given with the piston, the operator gently opening the jet by means of No. 6, applying his ear at the same time to the reservoir, No. 5, is to listen, and thereby to ascertain, by the bubbling noise of the oil in the safety cylinder, whether that fluid be in its proper place. Finding this to be the case, he is to close the jet, and all is ready for use. As soon as the gas has been ignited at the mouth of ihe jet, the syringe at No. 2 is to be kept working; continual strokes being made with the piston during the whole time that the gas is suffered to escape and to undergo combustion; by which means an uninter- rupted stream of ignited gas may be maintained so long as any of the gaseous mixture remains in the bladder at No. 1. I had the good fortune to procure a bladder capable of containing 41 gallons of gas ; owing to which circumstance I maintained an uninter- rupted stream of ignited gas during S' 30"; the gas being consumed nearly at the rate of 4^ pints, in a minute : whereas with the original apparatus the reservoir became so speedily exhausted, that the experiments were constantly liable to interruption, owing to the necessity of its being replenished. And if, instead of using a llndder to contain the gas, a silk balloon varnished with a solution of caoutchouc* could be substituted, it might be made of such magnitude as to allow of a constant current of ignited gas for almost any given time requisite during the most protracted experiments. The apparatus which I have described was constructed for me by Mr. Newman, of Lisle-street, Leicester- sqnare ; who entertained some doubts as to the practicability of using it, grounded upon the idea that the gas would escape faster than it could be supplied by the p'Slon ; and that a retrograde movement of the flame from the jet might thereby ensue : but I have not found this to be the case : on the contrary, the success of it has surpassed my most sanguine expectations; for the action of the piston, by its distance from the reservoir, has never afl'ected the presence of the oil in the safety cylinder; which sometimes happened with the former apparatus ; whereby an explosion was more than once occasioned. Both the safety of the blow-pipe, and its power of fusion, have been, there- fore, greatly increased by its present mode of construction ; and the results which it has enabled me to obtain shall now be stated. I began by placing a cnpel beneath the jet, and using a bent tube above it, like that which is represented in the plate; so that the current of ignited gas might act perpendicularly upon any substance placed within the cnpd. A small quantity of pla- tinum was thus melted ; and, while the metal remained in a state of perfect fusion and ebullition, more platinum was added ; until half an ounce of the metal was rendered perfectly liquid; and this, being suffered to cool, was obtained in the form of a * Mr. Sadler, sen. informed me that the balloon with which be ascended from DeTonsbire House, in Piccadilly, was thus coated, with a solution of caouteliouc. 1817.] improvement in the Gas Blow-pipe. 375 bullet. It was then rolled out, and made into wheels, with a view of being used for chronometers by a mechanist of this town. I have sent to you a wheel of this description. Very curious alloys of difterent metals have also been obtained ; and especially a small ingot of pure precipitated gold alloyed with rather less than ten percent, oi platinum ; of whicli some beautiful works have been •wrought ; possessing a fine gold colour, without being liable to become tarnished. Messrs. Rimdell and Bridge have lately polished some of this alloy : which had been coarsely wrought in this place. The extended use, therefore, of the gas hlow-pipe to the arts, may be said to have commenced ; it will remain for others, more interested in this application of it, to further its progress. I will now recur to its more philosophical application. As soon as I had observed that all metals might be revived from their oxides by means of this I'low-pipe, I endeavoured to obtain pure precipitates of those which are the least known in the metallic form ; beginning with uranium. Following the rules suggested by Klaprolh, in his analysis oi peclihlende,* I endeavoured to obtain a pure oxide of this metal. He considers the phaenomenon of its acid solution yielding a deep brown red precipitate to the prussiate of potash as " one of the most characteristic properties by which this metallic substance is distinguished." I obtained this precipitate : and the same acid solution which afforded it, yielded also a yellow precipitate, when, instead of the prussiate of potash^ a caustic alkali had been added. In fusing these precipitates, after they had been carefully washed and dried, and mixed with oil, a metal was revived, resembling iron; he'mg sAso magnetic ; and when re- dissolved in acids yielding a Hue precipitate to prussiate of potash; hence it was evidently contaminated at least with iro?i. I then ex- posed to the ignited gas a crystal of the pure yellow oxide of uranium in a charcoal crucible ; and in this manner obtained a metal resembling iron which was not magnetic; and which had all the characteristic properties ascribed to uranium. Afterwards I proceeded in a course of experiments with some of the other semi- metals, and with similar success. At this time (Oct. 10) Prifessor Kidd, of Oxford, paid a visit to Cambridge, with a view of being present at my experiinents ; in- tending to introduce the use of the gas hlow-pipe at his own lec- tures. Several Cientlemen of this University were present when I exhibited to the Professor some of the most remarkable results which 1 bad before ol)tained ; especially the 'metal of burytes ; and the pbaenomenon deciding its metaUtc nature ; of which he repeat- edly ex|jressed bis conviction.* Professor Hailstone, being also present, had brought with him a small quantity of that yellow pre- cipitate, which is by some considered as an acid, and by others as * Analytical F.ssays, vol. i. p. 476, Lond. 1801. + I nave received a letter from Professor Kidd since his arrival in Oxford; in which lie expresses af;aiii his conviction that this " metal, which he filed himself, was the melal of l/ari/tcs." 3 3/6 Improvement in the Gas Blow-pipe. [Nor. an oxide, of tungsten.^ We made it, as usual, into a paste, with a little olive oil; and then placing it in a charcoal crucible beneath the jet of the blow-pipe, we suffered the igjiittd gas gradually to act upon it. Fusion ensued; accompanied by the partial volatilization of the metal ; depositing first a fine deep blue oxide, and afterwards a yelloiu oxide upon the iron forceps used as a support for the crucible. Its further volatilization was now checked ; and upon examining the crucible, all who were present had the satisfaction to witness the perfect revival of the metal ; appearing as a superficies investing the surface of the charcoal. It was surrounded by globules of a highly limpid glass. We afterwards repeated the same experiment, and with the same success. Judging from the appearance exhibited by tungsten, when thus revived upon charcoal, which however may aifect its colour superficially, this metal has a cupreous aspect, intermediary between that of gold and copper. Our next experiments related to the fusion of the most refractory native compounds of the metals of the earths ; but as 1 have before circumstantially described the changes which such bodies undergo when exposed to the ignited gas, 1 shall not now repeat my former observations. While Professor Kidd remained with me, two erne- raids discovered by the Rev. Mr. Mandell in Cumberland, at the foot of Carrach Fell, were, by his desire, submitted to the action of the gas blow-pipe ; when their fusion being instantaneous, they ran together in a liquid state. These emeralds were supported in a small charcoal crucible. As soon as their fusion had taken place, the mass began to boil ; and it was so liquid that a slight detonation taking place at the mouth of the jet, a portion of the liquid matter was scattered out of the crucible, and fell in minute globules upon a sheet of white paper. The Peruvian emerald is known to be fusible with difficulty before the common blow-pipe ; but the berr/l emerald was often considered as one of the most infusible bodies; and in all my own experiments with the common blow-pipe 1 have found it to be utterly infusible. Before I conclude this article, it will be satisfactory to your readers to add, that as the experiments for the exhibition of the metallic nature of barytes have been attended here with such complete success, and constantly exhibited to scientific men, in whose minds no doubt remains as to the fact, the cause of failure elsewhere may be attributed to the nature of the barytes used for the experiment. For some time I received from Messrs. JJllen a sub- stance under the name of pure barytes, which never exhibited any metallic appearance after fusion; but I have now obtained, by means of the same chemists, barytes answering perfectly, in all its charac- ters, to that which I had originally employed; exhibiting, after fusion and the action of the file, a metallic lustre equal to any that 1 have before witnessed. Some barytes which I formerly received from Messrs. Accnm has the same character ; the only difference, as far * See Thomson's Chemibtry, fifth edition, vol. i. p. 552, Lond. 1817. 1817.] Proceedings of Philosophical Societies. 377 as I am able to determine, between the two substances ; namely, that which deliquesces before the gas blow-pipe, and that wliich fuses into a jet-black substance exhibiting metallic lustre, is this; that the first has not been entirely divested of water. It is, ia fact, a hydrate ; and therefore any experiment made with it, for the purpose of exhibiting the metallic nature of barytes, must be attended with failure. I have the honour to be. Sir, yours, &c. Cambridge, Oct. 13, 1817. EdwARD DaNIEL ClARKB. Article IX. Proceedings of Philosophical Societies. ROYAL ACADEMY OF SCIENCES. Analysis of the Labours of the Royal Academy of Sciences of the Institute of France duiivg the Year 1816. Mathematical Part. — By M. le Chevalier Delamlre} Perpetual Secretary. {Continued from p. 302.) URANUS. The surprise of astronomers in 1781 will be recollected when it was announced that a planet hitherto unknown had been discovered by Herschel, the care with which they examined this new planet, and their efforts to form tables capable of representing its apparent motion. Scarcely were these tables sketched out, when astronomers discovered unexpected resources. It appeared singular that a planet which by common glasses could not l)e distinguished from stars of the fifth magnitude, except by a light somewhat less brilliant, should have escaped the eyes of those who have given numerous catalogues of stars even much smaller than the planet. M. Bode conceived the happy idea of looking for it in the catalogues of Flamsteed and Mayer, and of ascertaining that twice already the planet had been observed, but mistaken for a common star. The same examination into the observations of Lacaille was unsuccess- ful, because that astronomer made his list beforehand of the stars whose position he wished to verify from the old catalogues. Besides, he died before he had completed his catalogue of zodiacal stars, which was not published till some years afterwards. Besides these two observations of 1G90 and 17^5, Lemonnier published three others, one of 17^4, and two of 17<>S. These last would have given him the honour of the discovery, if he had taken the trouble of comparing them with each other, for they were made in the 378 Proceedings of Philosophical Societies. [Nov, most favourable circumstances. With the assistance of these obser- vations, and joining a series of chosen ol)serv:itions macle during an interval of eight years posterior to the discovery, tables were con- structed into which tiie perturbations produced by Jupiter and Saturn were introduced ; and these tables, which have been in the hands of all astronomers for 15 years, represented the motions of Uranus with a precision of which none could have hoped that it was susceptible, and much superior to what could hitherto be given to the theory of planets that had been long known. But it was very unlikely that this exactness could last much longer ; and astro- nomers waited patiently till the progress of years should furnish a sufficient number of observations to confirm or rectify a theory not hitherto sufficiently tried. The journal of M. Lindenau informs us that Bessel had found in the collection of Bradley another observation, still more ancient than that of Mayer. The journal says nothing more on the sub- ject. M. Lindenau, at our request, demanded of M. Bessel the information which we desired. A letter of M. Bessel has informed us that the observation was made on Due. 3, 17"*3, but that it is incomplete, because it was only made with a transit. The sidereal time of the passage is 22'' 2'i' 21-828"; and therefore Dec. 3, at 5'^ 32' 31-8" T. M. the right ascension was 330° 50' 27-1" the declination 10-55' A Our tables give 50° 39-9' the declination 10-53' 32-9" Thus the error of the tables is only 12'5". M. Bessel has likewise calculated anew the observation of Mayer; and on Sept. 25, 1756, at 10'' 51' 52-8" T. M. he has found The right ascension . . 348° 0' 52-9" declination G° 1' 49-l"A According to our tables 348 14-5 6 1 35*4 Excess of calculus ... . +11-6 —12-7 Hence M. Bessel concludes that " these two valuable observations agree perj'bctly." Long before we received this answer, and without even knowing that we had put the question, M. Burckliardt set himself to look for the observation, which he easily found. He had likewise calculated it, in order to compare it with the tables, and he had read the results at one of our meetings. 'J'his first success had encouraged him to make new researches. It was by means of the catalogue of Flamsteed that M. Bode had found the observa- tion of 1G90. Since that time Miss Caroline Herschel had printed a complete catalogue of all the stars which Flamsieed had observed, and which he had not put into his catalogue. This was a new mine to explore ; and M. Burckliardt discovered in it five observations all equally important. He calculated them with all possible care, employing even the motions of the stars as far as they could be ascertained. In this manner he has deduced the opposition of 181?.] Royal Academy of Sciences. 379 Uranus in 1715, 15 years after tlie first observation, and 41 years before that of Mayer. He iias obtained the following results : — 4M;irch, right ascen. 170° 40' 18-0" declin. 4° 54' 227" 10 March I70 25 45-0 5 0 38-G The mean result is an error in the tables of +C5'7'" in longitude, and -f ]*2" in latitude. Besides the three observations employed above, M. Burckhardt has likewise found two others ; the first, of Apiil 2, 1/12; and the other of April 2'.), 1715. The tliree observa- tions of Lemonnier are, Jan. 15, 1764, and Dec. 27 and ^0, I768. The opposition of 1799, compared vvith that of Flamstecd, gives 60"9" more tlian the tables for the motion in 84 years ; for after an entire revolution, the error of the aphelion, and that of the eccen- tricity, are the same. We must, thertfore, add 0"725" to the annual motion, which will be 4° \Y 55". This result is the more important, because it has been hitherto impossible to separate the two indeterminate quantities. M. Burckhardt remarks, likewise, that the observations of 1715 and 1753 are very well situated for determining the place of the aphelion ; those of 16y0 and I78I are very proper for rectifying the equation of the centre. The observations of 1690, 1715, and 1753, bave given the fol- lowing corrections for the tables : — ' Epochs of 1799— + 34-1" aphelion + 6' 41" equat. — 55-3". The observations of 1715, 17^3, and 17^1? have given— + 27-5 + ()'25 + 3-6 The mean of which is — + 30-8" + 6' 33-5" — 26-8" A change of six minutes in the aphelion may in certain cases change the longitude 3(»". As for the observation of Flamstecd of 1G90, which entered into the composition of the tables, the new elements represent it as only 1' wrong. Unfortunately, it is solitary; and it would be suffi- cient to read in the passage 44" instead of 49" to make the whole agree. But the manuscripts of Flamstecd are preserved at the Observatory of Greenwich. It would be easy, therefore, to deter- mine whether the conjecture of M. Burckhardt be well founded. M. Burckhardt then gives an easy method of comparing the new elements vvith all the observations which we wish to calculate. It is to add to the mean longitude of the tables 0725" /, t being the number of years since I7GI ; to add 6' 2(i" to the aphelion, and to suppose that the tables of the equation and radius vector are for the year 1813. The stars which Flamsteed observed at the same time with Uranus are 3" Lconis and b Virginis. 5S0 Proceedings of Philosophical Societies. [Nov. COMETS OF 1783 AND 1793. The first of these comets was observed by M. Mechain, on Nov. 26, and observed by himself, as well as by M. Messier, to Dec. 21. Mr. Pigott had seen it in England from Nov. 20, and could only follow it till Dec, 3. He had only estimated the declinations, so that the uncertainty with regard to them may amount to two minutes. Mechain, the President, Saron, and the Chevalier d'Angos, could find no parabola which came nearer than 5' or 6' of the observa- tions at a time when the diurnal motion was only 4\'. Such con- siderable errors in an arc of 25 days indicated an orbit different from a parabola, for it is proved that the observations of M. Messier agreed perfectly with those of M. Mechain. After having tried parabolas in vain, M. Burckhardt tried an ellipse, and he found the elements as follows : — Half the larger axis, 3-15854; sidereal revolution, five years, 7-^ months, or 2050-4 days. Eccentricity, 0 5395345; distance of the perihelion, 1*4544. Passage over the perihelion in 1783, 19-50013 November, astro- nomical time. Place of the perihelion, 50® 3' 8" ; ascending node, 55° 45' 20". Inclination, 44° 53' 24" direct motion. With this ellipse, the errors scarcely amount to a minute and a half. The comparison of this ellipse with known orbits leads to the opinion that the come: of 1783 may be the same as that of 1793. It was necessary, therefore, to examine if the above ellipse would agree with this last comet. On the supposition that the two ellipses were a little different, it would be proper to examine the effects of the attraction of Jupiter, to which the comet must have approached very near towards its aphelion. M. Burckhardt has not yet had leisure to undertake this task; but. in the mean time he gives the errors of the places of the comet, calculated in an ellipse of five years, and in an ellipse of 10 years, the elements of which are as follows : — Passage over the perihelion, 1783, Nov. 19-5G868 ; node, 65° 12^; inclination, 47° 43'. Perihelion, 'JL»° 31' 55"; eccentricity, 0-6784; distance of the perihelion, 1-49532. Log. 4- greater axis, 0-6674185; log. (1^)* 9-6412103 ; log. parameter, 0-3996300. Half the greater axis, 4-64963. The two ellipses correspond well; slight changes might still diminish the errors of the longitude ; but the errors of the latitude are greater in the ellipse of 10 years. But the difference is not sufficient to prevent great uncertainty with respect to the greater iSlf.] Uoyal Acadeimj of Sciences. 381 axis. Hence there is no hope of determining the perturbations with certainty. The comet of 1793 exhibits much more troublesome uncer tainties. In the first place, that comet was very weak. Chance discovered it to M. Perny when he was not looking for it. M. Messier could not see it at first with liis night glass ; he was obliged to employ his large achromatic telescope. He explains the reasoa why the comet has not been seen since, if it actually returns every 10 or every five years. The period of the observations is 75 days. It was only 55 in 1783. About the same time, M. Messier had himself discovered another comet, which interested him more, and to which he applied exclu- sively his best telescope. To observe the comet of M. Perny, he employed a telescope with a very defective micrometer, and only gave the declination within two minutes, as was afterwards known. M. Perny had a better glass, and a more exact micrometer ; but he appears to have been rather negligent with respect to the passage across the wire. Hence we have good reasons for distrusting the observations of both, and it would be very difficult to decide upon the true orbit. The astronomers who were then in Paris not having leisure to calculate these ol)servations, the President Saron, ivho was in prison, undertook the task, and Lalande gave him the necessary data. The parabola determined by Saron was the last labour of this respectable and unfortunate magistrate. In a note which still remains he expresses his surprise that he could only re- present the observed longitudes within IG' or 17', and the latitudes within 2' or 4'. We have just seen the causes; but it is just to remark, that the comet was very near the pole of the ecliptic, and that these errors reduced to the paraHel of the comet become much less considerable. It is evident that errors in latitude are sufficient to ascertain that the orbit cannot be parabolic. On the supposition that the orbit is entirely unknown, M. Burck- hardt has found an ellipse, of which the elements are as-follows : — Passage, 1793, November, 28-60631; place of perihelion, ?5° 58' 58". Inclination, 47° 35' 5"; node, 359° 4' 48". Logarithm of half the greater axis, 07225030; log. of the parameter, 0-3853764. Log. of the dist. of perihelion, 0*146 1360; eccentricity, 07347635. Revolution, nearly 12^- years. This ellipse represents the last longitude only v.'ithin 47-^', and the latitude within 1-i-'. If we suppose half the greater axis known, and the revolution of 10 years, we have Kccentricity, 0701355; distance of perihelion, r3S859; peri- helion, 75° 49'; inclination, 46° 55'. 382 Proceedings of Philosophical Societies. [Nov. This ellipse does not represent better the observation of the 8th of December. These observations, calculated by the method of M. Gauss, lead to a hyperbolic orbit. The conclusion of M. Burckbardt is, that with observations so uncertain, and under similar circumstances, it is impossible to pro- nounce on the identity of the two comets, however probable it may have appeared at first. If the two comets con>titute only one, we must suppose a consideralile motion both in the node and in the perihelion of the orbit. Future observations alone can decide the question ; but there are many chances that so feeble a comet may return many times to its perihelion without being perceived. Memoir on the Agrarian Measures of the Ancient Egyptians. By M. Girard. It is well known that the inundations of the Nile, by destroying the boundaries of estates, obliged the Egyptians to cultivate geo- metry. They are even said to have been the first masters of the Greeks. It is related, indeed, that Thales taught the Egyptian priests to determine the height of the pyramids by the length of their shadows. If this be true, the geometrical science of the Egyptians was probably confined to some coarse practices of land measuring. Let us see if this new memoir throw any light on this difficult question. " What is at present practised in Egypt is a faithful representa- tion of what has been practised from the earliest times of civiliza- tion." Hence the present practices will give us an idea of the knowledge that must be ascribed to the priests of that country. " It is obvious that in the measurement of lands much time would have been lost if they had measured the aroi/ra (this was a square whose side was 100 Egyptian cubits in length, and whose surface was the space that two oxen could labour in a day) by applying successively a cubit measure along the length of tliat line. They replaced the cubit by one of its multiples. The land measurer, holding in his hand a long reed, places himself at the extremity of the line which he is going to measure. He traces with this reed a slight transverse furrow, to point out the place of that extremity. He places one end of the reed as near as possible to the ground, and traces with the other end a second transverse furrow. He places the end of the cane upon this second furrow; and thus he goes on till he has gone over the whole line. We see that this mode of measuring is as simple as possible, and scarcely requires more time than is necessary to pace over the distance to be mea- sured ; but it is obvious that it is not rigorously exact. " Since the unit of agrarian measurement was a square of 100 cubits the side, it is obvious that the length of the cane employed in measuring must be one of the factors of this number. A reed of five cul)its satisfies the essential conditions. The unity of agrarian measure of 10,000 cubits was thus transformed into anotheiof 400 square canes. 1817.J Royal Academy of Sciences. 383 " To render the operations of measurement more expeditious was to solve a problem of the highest importance. The priests contrived a new cane, equally easy to employ, and having the ad- vantage over the former of abridging the labour, without sensibly altering the value of the primitive agrarian measure." Such are the facts stated by the autlior. The following are his conjectures. On constructing upon the diagonal of a square a new square, we see that by prolonging the sides of the primitive square, we have the diagonals of the second, and that the second was exactly double the first. We see easily that the diagonal contains more than 28 canes, and less than 29 — more than 141 cubits, and less than 142. They pitched upon 28 canes. The error was only 16 superficial canes in 800 ; that is, a .50th part ; and this error was favourable to government, because it increased the impost. The number 28 has 7 for a divisor. On that account the cane was made seven cubits long, still with the view of abridging. It is true that we do not find in antiquity any positive evidence of the employment of the cane of seven cubits. But we can supply the place of this want of positive proof by other circumstances nearly equally strong. The author has made several observations in his memoir on the Nilometer of Elephantine, which demonstrate that the builders of the great pyramid intended to give to the different parts of this monument a round number of linear measures. It is natural to think that the base of this pyramid ought to contain a round number of superficial measures. According to the lai^t measure- ment, the surface of the base is 51135 metres, which mukes exactly 10 of these septennary arouras, and gives for the cubit 0 525 metre, exactly what is deduced from the sepulchral chamber, and likewise from the nilometer at Elephantine, We may admit very readily the singular exactness of these coin- cidences ; but if we adopt the whole hypothesis, it would only follow from it that (he Egyptian priests were acquainted with the most simple case of the famous problem of the square of the hypothenuse, which would not indicate a very advanced state of the science. The second and third sections of the memoir treat of the agrarian measures in Egypt under the Persians and under the Romans. We see that the jiigbrum of Hero is nothing else than the Roman jugerum. We find it proved by a passage of Didymus of Alexan- dria that the Italian foot was the same as the Roman foot. All the modifications introduced into the agrarian measures are explained by this principle, which has always regulated the conduct of con- querors, to augment the sum of the impositions, attending as much as possil)le to the habits of the conquered people. From calcula- tions which it is impossible for us to extract, it appears that the real size of the base of the great pyramid is only -f^^ different from the value which Pliny has assigned it. 384 Proceedings of Philosophical Societies. [Nov. The object of the fourth section is to prove that the Arabians i ntroduced no sensible aheration ; and the memoir terminates with the following table, which is an epitome of the whole : — I. Primitive Aroura. Primitive cubit 0*525 metres Cane of five cubits 2*625 Side of 20 canes 52*50 Surface of 400 canes 2756-00 Surface of the double aroura 5512*1 2 II. Double Aroura of the Great Pyramid. Cubit 0*525 metres Cane of seven cubits 3*675 Side of 20 canes 73*50 Surface of 400 canes 54 1 3*00 III. Dovlle Roma?! Jtigertim. Cubit 0*527 metres Cane of 6f cubits 3*5133 Side of the double jugerum 70*-t) Surface of 400 canes 4937*00 IV. Socarion of Hero. Cubit 0*527 metres Koyal Spirhame 0*2035 Orgye of 9-1- spir 2*435 1 Side of 10 orgyes 24*3510 Surface of the socarion 502*9710 Deusple surface 5929*7100 Y. Present Feddan of the Cidtivators. Pik beledy 0*5775 metres Cane of 6-| pik beledy 3*8500 Side of 20 canes 77*0000 Surface of 400 canes 5929*00 VI. Prese7it Feddan of Zoltes. Pik beledy 0*5775 metres Cane of 6-} pik beledy 3*658 Side of 20 canes 73*16 Surface of 400 canes 5353*00 Theory of the Motion of Water in Capillary Tubes at different Temperatures. By M, Girard. In presenting to the Academy an account of his experiments on the motion of water in capillary tubes, M, Girard had announced a theory capable of explaining all the phenomena. It was observed that experiments of the same nature liad been made at Prague in 1796, and published in 1800, by Professor Gerstner. The memoir 1817.] Royal Academy of Sciences. 385 of this philosopher having been communicated to M. Girard, he begins his new memoir by an analysis of the labours of the Pro- fessor of Prague. He describes his apparatus, explains the object which he had in view, and the principal results which M. Gerstner obtained. It results from this comparison, that if the two memoirs have some resemblance in certain parts, the differences between them are much more numerous,and occur inthe most essential points. M. Gerstner employed merely the empirical formula of the Chevalier Dubuat. M. Girard employs a formula, the first member of which, taken directly from a formula of Euler, expresses the accelerating forces; while the second, according to the ideas of Coulomb, expresses tiic retarding forces. From the equality be- tween these two members results the uniformity of motion. The second member au + h v?- h composed of two terms, one of which depends upon the simple velocity u, the second upon the square of that velocity ; a and h are constant quantities to be de- termined by experience. In certain circumstances, the term proportional to the square disappears. Then the formula becomes linear, as well as the mo- tion. The term a u represents the resistance from the adhesion of the fluid to the surface along which it flows ; the term h u^ depends upon the asperities with which that surface is covered. After these preliminaries, M. Girard undertakes the explanation of the 10 phenomena which he has observed. All that we can do is to transcribe here the enunciation of these phenomena. 1. Under any charge whatever, when the capillary tube through which the liquid runs has acquired a certain length, the term pro- portional to the square of the velocity disappears from the general formula of uniform motion. 2. The limit of the length at which this square disappears is so much the further from the origin of the tube the greater the charge of water above it is. 3. Every thing else being equal, the limit of the length is so much the further from the origin of the tube the greater its diameter is. 4. When the motion of the water has become linear, variations of the temperature have such an influence on the products of the flow that in the interval between 0 and 84° of the centigrade ther- mometer these products vary in the ratio of one to four. 5. Within the limits at which the movement begins to be linear, and when by the diminution of its length it is reduced to a simple ajutage, the produce of the flow varies only in the ratio of five to six for a thermometrical interval between 0° and 87°. 6. The coefficient u of the first power of the velocity varies with the diameter of the tubes employed in the experiment. 7. The coefficients a, which for tubes of different diameters have different expressions at a given temperature, approach so much the nearer to identity the higher the temperature is. 8. Whatever is the diameter of the capillary tube, the variations in the products . ' the flow from one degree of temperature to another are so nmch the more considerable the lower the temperature is. Vol. X. N°V. 2B 386 Proceedings of Philosophical Societies. [Nov. 0. The law of variability which expresses the ratio of the pro- ducts of the flow to the degrees of temperature is manifested with so much the greater regularity the smaller the diameter of the tube is in which the experiments are made. 10. The temperature which exercises so great an influence on the products of uniform flow ceases to have a sensible influence when the motion takes place in open canals, or in ordinary tubes whose diameter is too great to be capillary. The author parses to the application of his experiments to the determination of the ratio of the temperature, and the thickness of the coat of fluid adhering to the sides of the tube. The superficies of the transverse section of the tube is diminished by a circular crown, the thickness of which varies with the tempe- rature of the fluid. He expresses the surface of this crown by a series of this form : — S=A + BT+CT^ + DT* + &c. T being the temperature. He seeks the value of the coefficients from experiment, either confining himself to TS or in proceeding as far as T^. He deduces from this the formula of the thickness e : and by means of these two formulas he calculates the whole of the experiments made with diflferent series of tubes, which enables him to compare these for- mulas with each other, and with the quantity of water which really flows out. The result of these comparisons for the first series of tubes is, that the product calculated by the formula, employing the first three powers, is greater than the product observed ; and that •when the third power is suppressed, and we confine ourselves to the first two, the calculated product is a little too small. But all these differences are extremely slight. From experiments made witli the second series of tubes, it results that we may neglect the third power, so that the curve is only of the second degree. These conclusions may be verified by the simple inspection of the tables, which exhibit all the circumstances of each experiment. The author then discusses the different causes of the errors which could influence the results, and produce the slight differences re- marked in them. He thinks that we may always assign the ratio which exists be- tween the diameter of a capillary tube, its size, and the depression of its lower orifice below the surface of the fluid in the reservoir from which it flows, and between the temperature and the flow per second when the motion has become linear. He makes similar calculations for the thickness e of the coating for the same two series, and in the double hypothesis of the equa- tion of the second degree and that of the third. He determines this thickness for every five degrees of fche thermometer from the freezing to the boiling point. The results of these new calculations are likewise exhibited in two tables, where we remark easily that the thickness of the fluid coats which cover the inner surface of the tubes is less in the small tube than in the large. Hence the author concludes that these thicknesses do not depend solely upon the temperature, but likewise upon the radius of curvature, and the 18170 Sclenlijic Intelligence. 378 transverse section of the tube, which would not be the case if the action of the tube did not extend to a finite distance from the sur- face. Tiiis remark will occasion new researches, which will be the subject of another memoir. (To be continued.) Article X. SCIENTIFIC intelligence; AND NOTICES OF SUBJECTsS CONNECTED WITH SCIENCE. I. Arragonite. It has been long known to mineralogists that the crystalline forms of calcareous spar and arragonite are different ; and Haiiy demon- strated that no admissible decrements could reconcile their primitive forms. In the year 1813 Stromeyer announced that he had disco- vered In the arragonite of France 4^ per cent, of carbonate of strontlan ; and in the arragonite of Spain, 2^ per cent, of the same salt. He stated, at the same time, that he considered the crystal- line shape of arragonite as the same with that of carbonate of strontian. It has been known for some years that certain substances, when they amount only to a small proportion of a compound, im- press upon the whole, notwithstanding their own crystalline form. Thus two or three per cent, of sulphate of iron is capable of in- ducing its own form upon sulphate of zinc. White cobalt ore owes its cubic form to a small portion of iron pyrites which it contains. Gres de Fontainbleau has the crystalline form of calcareous spar, of which it contains only a small portion, Stiomeyer conceived that in like manner the small proportion of carbonate of strontian in arragonite influenced the crystalline form. A short time before his death, Gehlen announced that he had met with very well-defined crystals of carbonate of strontian, and that the form was precisely the same as that of arragonite. This question has been lately dis- cussed at great length by Professor Fuchs, of Landshut. The re- sult of his examination is, that the crystals of carbonate of strontiaa have a considerable resemblance to those of arragonite, but that they are by no means the same (Schweigger's Journal, xix. 1 13). The crystals of carbonate of strontian found lately near Saltzburg are regular six-sided prisms. Those of arragonite are likewise six- sided prisms, but not regular; for four of the angles are of 11G% and the two others of 128°. Now M. Haliy has demonstrated that the primitive furm of arragonite cannot pass into the regular hexa- hedron in virtue of any admissible law of decrement. Besides this, Bucholz and Meisner analyzed different specimens of arragonite, which were destitute of carbonate of strontian ; and Laugier found only -i-^Vro-th part of this salt in the arragonite of Bastenes. From these facts we may consider it as demonstrated that the opinion of Stromeyer is inaccurate. It follows, therefoje, that the cause of 2 JB 2 3S8 Scientific Intelligence. [Nov. the discordance between the crystals of arragonite and calcareous spar is as problematical as ever. II. Bar lei/. According to Proust, the constituents of barley-meal are as follows : Yellow resin 1 Gummy and saccharine extract 9 Gluten 3 Starch 32 Hordein 55 100 The resin is obtained by digesting the meal in alcohol. It is a pitchy substance, which seems to me better entitled to the name of oi! than of resin. I examined it many years ago, and was much struck with its flavour, whicii is precisely similar to that of spirits made from unfermented barley. Hence I was disposed to consider that flavour as owing to the presence of this oily substance. The gummy and saccharine matter are obtained by digesting the barley-meal in cold water. The gluten precipitates in flocks when this aqueous infusion is heated. The starch and hordein constitute the powder that remains after the preceding processes. By boiling this powder in v;ater, the starch is taken up, while the hordein remains. The substance to which Proust has given the name of hordein has much the appear- ance of the sawings of wood, and possesses, according to him, the properties of Ugnin ; or at least it approaches very closely to that vegetable principle in its properties. III. Malt. According to Proust, the constituents of malted barley are as follows : — Resin 1 Gum 15 Sugar 15 Gluten 1 Starch 5G Hordein 12 100 He affirms that barley in malting loses a third of its weight (Ann. de Chim. et Phys. v. 342) ; but I can assure the reader that the whole of his account of malt and malting is very far from accurate. The average loss in more than 50 malting processes on a pretty large scale, which I myself superintended, and during which much care was taken to ensure accuracy, vv^as only 20 per cent. The malt in these cases was weighed just when taken off the kiln, and the barley had been weighed just before it was put into the steep. 1 found that if the barley was kiln-dried, it lost 12 per cent, of its weight ; and that the malt, when kept for some time in a granary, recovered the same proportion of weight. Hence I conceive it follows that the true loss of weig^it in malting does not exceed 1817.] Seienlific Intelligence. 389 eight per cent., or rather less than -^ih.. One half of this loss is to be ascribed to matter dissolved from the husk of the grain by the steep-water, and to grains of barley bruised and destroyed by the malster while turning the malt upon the floor ; so that the real loss in malting does not, I believe, exceed four per cent. I leave it to M. Proust to decide whether it is likely that so very remarkable a change should be produced in the composition of barley-meal by malting, and yet so small a change in the weight. The hordein of Proust I consider as starch in a particular state, somewhat similar to the fibrous matter of potatoes. The malting partly converts it into the state of sugar, and partly into that of common starch, by destroying a certain unknown glutinous substance which glues the particles of it so firmly together. IV. Brewing. M. Proust's notions of brewing by means of barley and malt are obviously very imperfect. He says the great product of the fermen- tation is carbonic acid. The fact is, as I have determined by numerous experiments upon a large scale, that the portion of malt which is dissolved is resolved by fermentation into nearly equal weights of carbonic acid and alcohol of the specific gravity 0"825. When raw grain is employed by the distillers, it undergoes, while in the mash tun, a change similar to that induced on barley by malting ; for the wort is just as sweet- tasted as the wort from malt. V. Effect of Lightning on a Tree. (To Dr. Thomson.) SIR, George-street, Edinburgh, July 23, 1817. In my walk two days ago I happened accidentally to step into Craiglockart Garden, near the village of Slateford, about two miles west of Edinburgh, where, after inspecting the garden, hothouses, and romantic grounds, upon the wooded banks of the water of Leith, the keeper informed me that the thunder-storm of the 10th ult. had been particularly terrible at that spot, that the lightning had struck a tree on the side of the highway to the north of the garden wall, and had afterwards struck a man who had taken shelter in a neighbouring outhouse attached to the back of the garden, near the tree. Wishing to ascertain the appearance of a tree struck with electric fluid (having often observed large blotches on the bark of trees said to have been caused by the lightning), I requested the keeper (Mr. Robertson) to show me the tree. I found it to be an English elm. The lightning had struck it at a small decayed knob about 15 feet above the ground, on the north side of the tree. It descended all round in a spiral form, and went off from the ground, destroying a large quantity of nettles and grass at the root of the tree in a south- west direction, towards the house where the man had taken shelter, where at the root of the tree I observed it had torn up the earth, which is still quite apparent, from the root of the tree, in the shape nearly of a large grooved wheel track, diminishing in size as it ex- 390 Scientific Intelligence. [Nor. tends outward. From this it entered the outhouse where the men were, and struck one of them so much that he was quite stupified for some time; and afterwards, as the men relate, the lightning went otf by a skylight, altliough there is no visible mark of its course after quitting the root of the tree, and the grooved way, which does not extend above two feet from the tree, but is in the direction of the door of the house. In this house there was a con- siderable quantity of iron. Thus it would appear that leading a conductor to the earth is no certain rule of safety — the lightning does not descend into the ground. The appearance of the effects of the fire upon the tree is quite different from the blotches which, in my ignorance, had frequently been pas-ed upon me for the effects of lightning, and which pro- bably is some disease of the tree, or animalculse. The appearance of this tree is as if the top knobs of the outer cortex had been touched with a wright's plain, having a white glistening colour, as if after friction. No black traces remained upon the tree, and nothing bore the resemblance of burning, except some lateral branches, and the nettles and brushwood at the bottom of the tree. The most surprising fact, however, is, that four years ago two trees (within a few yards of the elm that was struck) were in like manner successively struck with lightning. The one tree was a beech, and is now cut down, having decayed by the effects of the lightning : the otl)er a fir, I believe, which remains a wretched spectacle to this day. This led me to inquire as to the contiguous metals imbedded in the ground under the spot. Fortunately a well about 18 feet deep is sunk close by, which a man informed me he had been at the bottom of, and he assured me that the only mineral cut through in that depth was a greyish free- stone. I have thought it proper to set down this information for you as I received it, and saw it. And if it can throw any light, or afford any hints to your learned friends, upon this most awful phenomenon of nature, 1 shall be happy. The shape of the groove by which the electric fluid escaped from the tree may perhaps be some foun- dation for ascertaining the form of the forked lightning. And from the direction as marked on the ground, and the circumstance of the man being so sensibly affected in the outhouse, it would appear to have been the same flash that did both. 1 have the honour to be, Sir, Your most obedient, humble servant, John Govan. VI. Register of the Weather at New Malton, in Yorkshire. July, 18] 7. — Mean pressure of barometer, 29-518; max. 29*83 ; min. 28*75. Range, 0*88 in. Spaces described by the curve, 5*00 in. Number of changes, 13. — Mean temperature, 58-92*'; max, 70° ; min. 48°. Range, 22°.— Amount of rain, 4-05 in. Wet days, 22. Prevailing winds. Westerly. N, 3. NEj 2. E, 1, 181 7.] Sdenlific Inlelligence. 35)1 SE, 1. S, 6. SW, 7. W, 7. NW, 3. Var., 1. Brisk winds, 3. Cliaracter of the period : wet, cold, and cloudy. August. — Mean pressure of baroraeter, 2y-492; max. 2992; m in. 28 '80. Range, 1*12 inch. Spaces described by the curve, 7'30 in. Number of changes, 20. — Mean temperature, 5G-60°; max. 70° J min. 42. Range, 28°.— Amount of rain, 5'47 inch. Wet days, 25. Prevailing wind, SW. NE, 3. SE, 2. S, 6. SVV, 13. VV, 1. NWi 2. Var., 4. Brisk winds, 12. Bois- terous, 6". Tiiis period was so uncommonly wet, that scarcely a single day elapstd witliout rain, either in greater 01 less quantities, and often accompanied with very heavy gales, the amount being equal to nearly 54- inches. The barometrical column, as may be seen from tiie number of changes in its direction, was in continual fluctuation, and the mean lower than for some time past. Seplember. — Mean pressure of liarometer, 29*772 ; max. 30*14; min. 28*G9. Range, 1*45 in. Spaces described by the curve, 6*12 in. Number of changes, 15. — Mean temperature, 55"43°j max. 71°; min. 30°. Range, 4 1°— Amount of rain, 1-05 in. Total quantity this year, 20*32 in. — Prevailing wind, easterly. N, 4. NE, 7. SE, 5. S, 8. SW, 1. W, 3. NW, 1. Var., 1. Brisk winds, 3. Boisterous, 2. A violent storm of thunder, vivid lightning, and heavy rain, between three and four, a. m. on the 4th, closed a series of wet and changeable weather of above three months' duration. The air now become serene and mild, with very little rain for the remainder of the period. When the moon attained her full on the 25tb, a suc- cession of heavy equinoctial gales from the S and SW were expe- rienced, which considerably depressed both the pressure and tem- perature ; the thermometer indicating 32° on the 30th, and 30*^ oa the following morning. New Mallon, Oct. 3, 181 T. J« S. VII. Kidney Bean and Common Bean Perennials. (To Dr, Thomson,) SIR, Should you deem the following facts worthy a place in your Journal, I shall feel myself much honoured, And am, with due respect. Sir, your very obedient servant, Cork, Sept. IS, 1817. Thomas Holt. It is a generally received opinion, supported by the authority of all the botanical and horticultural works I have had oppoituiiity of consulting, that the phaseolus vulgmis. or common kidney bean, and the pkasmlus nanus, or dwarf kidney bean, are annual plants. Experience has taught me that they are both perennials, as well as the j'aha vicia, or common garden bean, with its varieties. Hovv the fact could have escaped the penetrating eye of the late Philip Millar, I cannot determine 3 but in lus Botanical Dictionary they 392 Scientific Intelligence. [Nor. ?ire all pronounced annual plants. Of course the botanical works of more recent date, being chiefly abridgments, selections, and improvements, of that book, have maintained the same opinions. The fact is readily proved. In the month of September or October, on the appearance of any sharp frosts, or when the beans have done bearing, let them be cut down within two inches of the soil ; shake over the roots some litter from a stable ; and about the May following the roots will throw up fresh shoots, whicli will be stronger, and more vigorous, than those of the first year's growth. This I have repeated with never-failing success for these six years past, in the course of which I have observed that the bean pods do not come to maturity so early by about three weeks in the second or succeeding years as they do the first year's growth ; but that the second year's crop is not so liable to be injured by variable weather, frosts, or wet, as the fresh sown plants ; and that the roots are more in danger of injury from cold rains in winter than by hard frosts. At the same time I must request permission to correct a mis- statement of a fact which appeared in Mr. Sym's paper on Flame^ which appeared in the yinnals of Philosophy for November last. The author observes, " forjiame is an opake substance, as any one may satisfy himself by trying to read a book through the upper part of the flame of a candle." (Vol. viii. pp. 322, 323.) I have re- peatedly tried tlie experiment; and have satisfied myself that a book of very small print may be easily read through any part of the flame of a candle, and indeed of any other not intensely bright fiamCj if held a short time behind it, with the eye fixed oa it. VIII. Rmjal Geological Society of Cornwall. Annual Report of the Council. — In performing this annual duty, the Council acknowledge with pleasure the liberal contributions of mineral specimens, to which the increased splendour of the cabinets is so greatly indebted ; and they contemplate with peculiar satisfac- faction the spirit of investigation, and activity in research, which continue to aniqiate the members of the society, and to augment that interesting department of the collection which is calculated to illustrate the geological structure of the county. In consequence of such an increase in the number of specimens, as well as in that of the members of the society, the present room has been found inadequate to its purposes, a museum has therefore been erected, which will prove better adapted for the meetings, and more favourable to the enlarged views and increasing prosperity of the institutiori. The Council have to lament the unfavourable state of the weather during the preceding year, as it has unfortunately rttaided the pro- gress of those investigations which are necessary for the conipletion of the geological map of the county; and tfit-y beg to remind tiie membors of the society that to obtain this desirable object, their social and united exertions are required, and they more especially solicit the co-operation of those gentlemen who are resident in th§ more remote districts of the county. 181 7.] Scientific Intelligence. S93 The Council beg to direct the attention of the Society to the very interesting and instructive series of specimens collected liom the different mines, at different levels, by Joseph Carne, Esq. in illustration of the history of that rock to which tlie name of Elvan has been provincially given. It is hoped that similar suites of the other metalliferous rocks will be collected, with a view to discover their geological relations. Mr. Chenhalls reports that the safety bar continues in use in all the western mines, without any objection ; and that not a single accident has occurred for two years. This testimony of its value, together with the strong address of Mr. Justice i^bbot, and the resolution of the Grand Jury at the last Lent Assizes, in favour of its speedy and general introduction, cannot fail to eradicate any prejudice which might exist against it. Comparative View of the Number of Members at the last avd on the present Anniversary. — Last anniversary, 153; withdrawn and dead, 5; elected this year, 18; total, IGO. The Secretary reports that the first volume of Transactions is in the progress of printing. The following papers have been read since tlie last Report : — 1. On the Processes for making the different Preparations of Arsenic which are practised in Saxony, and on those for preparing Smalt or Cobalt as pursued in Bohemia ; presented to the Society in the hope of introducing similar establishments in Cornwall ; by John Henry Vivian, Esq. M.G.S.C. 2. Notice relative to the Formation of a mineral Substance known by the Name of Swimming Quartz ; by Joseph Carne, Esq. M.G.S.C. 3. On the Discovery of Gregorlte in large Quantities in a Stream at Lanarth, in the Parish of St. Keverne ; by John Ayrton Paris, M.D. F.L.S. Hon. Mem. G.S.C. &c. 4. A Sketch of the Plan of the Mining Academies of Freyburg and Schemnitz, and on the Advantages which would attend the Establishment of a School of Mines in Cornwall ; by John Henry Vivian, Esq. M.G.S.C. 5. On the Nature and Quantity of tlie different Rocks and Clays annually exported from the County of Cornwall, for the Purposes of Architecture, Manufactures, and the Arts; by John Ayrton Paris, M.D. F.L.S. Hon. Mem. G.S.C. &c. G. On the Circulation of printed Queries respecting Lodes through the Mines of Cornwall ; by John Hawkins, Esq. F.R.S. M.G.S. L. and C. 7. On the History of Sub-marine Mines; by John Hawkins, Esq. F.R.S. M.G.S. L. and C. 8. On the Salt Minos of Poland ; by John Henry Vivian, Esq. M.G.S.C. 9. On the Lodes of Polgooth Mine ; by John Hawkins, Esq. F.R.S. M.G.S. L. and C. 10. On the Introduction of the Steam Engine, and a Corps of fCornish Miners, into the Silver Mines of South America, with an 394 Scienllfic Intelligence. [Nov. Account of the Arrival and singular Reception of Mr. Trevithick, the Bngiueer ; by Henry Boasc, Esq. Treasur'^r. 11. A Notice respecting the Discovery of Piiosphate of Iron, at Huel Kine, in St. Agnes, and on the Circumstances under which it was discovered ; by Joseph Came, Esq. M.G.S.C. 12. On the Art of refining Tin; by John Hawkins, Esq. F.R.S. M.G.S. L. and C. 13. An Account of the Quantity of Tni produced in Cornwall in the Year ending with Midsummer Quarter, 1817; by Joseph Came, Esq. M.G.S.C. 14. An Account of the Produce of the Copper Mines in Corn- wall, in Ore, Copper, and Money, for the Year ending June iiOth, 1817; by Joseph Carne, Esq. M.G.S.C. 15. An " Eioge " upon the Life and Scientific Labours of the late Rev. William Gregor ; by John Ayrton Paris, M,D. F.L.S. Hun. Mem. G.S.C. At the anniversary meeting, Sept. 16, 1S17. Davies Gilbert, Esq. M.P. F.R.S. President, in the Chair, the Report of the Council being read, it was resolved, That it be printed and circulated : That the thanks of the Society be presented to John Hawkins, Esq. John Henry Vivian, Esq. Joseph Carne, Esq. Henry Boase, Esq. and John Ayrton Paris, M.D. for their communications; and that the Eloge upon the Rev. William Gregor Le immediately printed. The following Resolutions, proposed by Davies Gilbert, Esq. M.P. President, and seconded by Sir Christopher Hawkins, Bart. were unanimously passed : — Resolved — That Dr. Paris is entitled to the warmest thanks of this Society, and of the county of Cornwall, for originating the plan, and promoting the institution, of the Royal Geological Society, which renders our home the school of science, and our native riches increasing sources of prosperity, whilst it has cleared the laborious path to them of its peculiar perils. Resolved — That, as he has left in this institution so ample a memorial of himself, he ought not to be permitted to depart with- out a lasting memorial of us. Resolved — That a valuable piece of plate, with an inscription expressive of his merits, and of our grateful sense of them, be presented to him ; and that Davies Gilbert, Esq. M.P. Sir Rose Price, Bart, the Rev. C. V. Le Grice, Thomas Bolitho, Esq. and Joseph Carne, Esq. be appointed a Committee for carrying the said Resolution into effect. IX. Remarkable Actio?! of Paste on Cast-iron. (To Dr. Thomson.) SIR, In the Annals of Philosophy of last month (p. 302) you have noticed the remarkable action of paste on the cast-iron cylinders IS 170 Scienlific InleUigejice. 395 employed in weaving cotton; and you conjecture that the substance resembling in appearance plumbago is formed by the development of an acid — unquestionably acetic. In confirmation of this opinion, I beg to observe that the very same kind of substance is produced by distilling pyroligneous acid (which is identical with vinegar) in cast-iron vessels. 1 have remarked that, after the vessels have been some time in use, their interior becomes so very soft, that with a common pocket knife they may in a few minutes be almost entirely cut through. In this instance, and in that related by you, as men- tioned above, the formation of fictitious plumbago may be regarded as proceeding from the action of vinegar; but, in the instance re- lated by Dr. Henry, in an early number of your Annals, the partial conversion of iron into this substance has undoubtedly a different origin. 1 am. Sir, yours most respectuilly, Chester, Oct. 14, 1817. S. LeET. Article XI. Scientific Books in hand, or in the Press. Dr. Armstrong, of Sunderland, is about to publish a work on Scarlet Fever, Measles, Consumption, &c. His volume on Typhus Fever is also reprinting, with considerable additions. Dr. Adams is about to publish a New Edition of his Life of Mr. John Hunter. Mr. Thomas Forster has just published a work, entitled, Observa- tions on the casual and periodical Influence of peculiar States of the Atmosphere on Human Health and Diseases, particularly Insanity. Tlie object of this work is to point out and illustrate the connexion between the periodical changes in the electricity of the atmosphere and the periods of diseases. The same Author has likewise published Observations on the Phe- nomena and Treatment of Insanity, being a Supplement to the former. In this work the Author has shown the particular application of the foregoing doctrine to the treatment of madness, and has adduced numerous proofs of the safety of the lowering regimen in that disease. The Manuscripts of the late Mr. Spence, of Greenock, were some time ago submitted to Dr. Herschel, who has selected the most com- plete Tor publication. The students of pure mathematics will be gratified to hear that the volume now preparing for publication con- tains, besides the ingenious Essay on Logarithmic Transcendants, unpublished Tracts on the same class of the science, equally new and elegant. A Biographical Sketch of the Author, by his friend Mr. Gait, will be prefixed to the volume. Mr. Jones, Optician, is about to publish the late Mr. Ferguson's Astronomical Planisphere of the Heavens ; showing the Day of the Month ; Change and Age of the Moon; Places of the Sun and Moon, and Stars of the first, second, and third Magnitude ; likewise his Astronomical Rotula, showing the Change and Age of the Moon, the Motion of the Sun, Moon and Nodes, with all the Solar and Lunar Eclipses, from 1817 to ]86i-, with Descriptions of their Uses. The Calculations are cou tinned by the Kev. L. Evans, R. M. A. 396 Colonel Beaufoy's Magnetical [Nov. Article XII. Magnetical and Meteorological Observations. By Col. Beaufoy, F.R.S. Bjishey Heath, near Sianmore. Latitude 51° ST 42" North. Longitude west in time 1' 20-7". Magnetical Observations, 181 7. — - Variation West. Morning Observ. Noon Observ Evening Observ. Month. H [)ur. Variation. H our. Variation. Hour. Variation. Sept. 1 8i 35' 24° 32' 50' Ih 35' 24° 42' 32' _h _' o ' " 2 8 35 24 32 56 30 24 42 32 6 35 24 33 60 3 8 40 24 32 25 40 24 42 04 6 40 24 35 17 4 8 35 24 31 59 45 24 42 31 6 35 24 34 64 5 8 40 24 33 30 30 24 41 58 6 45 24 34 26 6 8 45 24 33 12 35 24 40 53 6 40 24 35 05 7 8 40 24 33 40 40 24 41 43 6 30 24 34 34 8 8 40 24 32 52 35 24 42 36 6 40 24 35 IS 9 8 35 21 32 52 35 24 41 41 — — — — — 10 8 40 24 34 02 45 24 40 00 6 30 24 35 32 11 8 35 24 33 58 35 24 40 53 6 30 24 35 27 12 8 35 24 33 39 35 24 42 07 6 30 24 35 00 13 8 35 24 33 06 35 24 43 42 6 30 24 35 24 14 45 24 40 04 6 20 24 35 12 15 8 30 24 32 54 35 24 43 39 6 20 24 35 21 16 17 18 8 8 8 Afi O/l 41 55 33 45 34 19 35 40 40 24 44 24 42 24 41 16 53 23 411 35 35 24 24 6 10 24 34 25 19 8 35 24 32 10 30 24 41 37 6 20 24 46 51 20 8 35 24 33 26 35 24 38 18 6 15 24 34 43 21 9 36 24 33 14 40 24 38 58 C 10 24 35 21 22 8 35 24 32 20 — — — — — 6 05 24 34 20 23 8 35 24 34 56 35 24 40 38 6 05 24 32 45 24 8 35 24 32 10 35 24 41 58 6 05 24 34 35 25 — — 35 24 41 54 5 50 24 33 64 26 8 35 24 31 54 35 24 40 SO 5 55 24 33 06 27 8 35 24 32 02 — — — — — 5 55 24 35 03 28 29 8 8 35 40 24 24 34 14 31 14 50 40 24 41 24 40 51 21 5 50 24 33 35 30 8 35 24 32 13 55 24 40 58 5 65 24 34 27 Mean for ") the r 36 24 33 02 1 38 24 41 36 6 19 24 34 38 Month. J The morning observation on tlie 16th, and the evening observa- tion on the 19th, are rejected in taking the mean, being so much in excess, for which there was no apparent cause. 5 18170 and Meteorological Tables. 3^7 Meteorological Table. Month. Time. Barom. Ther. Hyg. Wind. Velocity. Weather. Six's. Sept. Inches. Feet. C Morn.. . . 29 '608 570 72° SSE Cloudy 4T I ] Noon. . . . 29-630 63 45 wsw Fine 65 ( Even .... — __ — •50 f Morn 29-628 58 60 E Very fine 2) Noon 29-590 66 50 ESE Hazy 67 ( Even 29-535 61 70 Eby S Cloudy js, r Morn 29-500 63 65 ESE Very fine H Noon 29-480 74 46 SEbv E Clear 75 I Even 29-515 68 52 ESE Clear 1 5S r Morn .... 29-620 59 73 NW Cloudy 4-j jNoon.... 29-66T 69 43 NW Very fine 70 (_lEver! .... 29-745 63 52 Why N Vcy fine 554 r iMorn.... 29-765 61 65 NNE Very fine ii Noon.... 29-7T0 71 47 NW Very fine 72 t Even 29-755 62 57 Calm Very fine |55 flMorn.. . . 29-713 62 54 SSW Very fine «1 Noon. .,, 29-700 70 44 WSW Very fine ^72 1 Even .... 29-700 62 51 Calm Very fine |56 f Morn,... 29-713 62 63 E Very fine ^^ Noon. . . . 29-700 71 49 E Very fine 72 I Even 29-662 63 48 E Very fine |5S f Morn. . . . 29-585 62 75 E Very fine ^\ Noon 29-555 73 47 Var. Very fine 75 I Even .... 29-555 60 52 E Very fine 1 s Morn .... 29-643 57 75 N Foggy ^\ Noon ... 29-650 62 66 N Foggy 65 I Even .... —^ |55 f Morn.... 29-630 56 76 NNE Foggy 10< Noon.... 29-600 60 68 NNE Cloudy 61 L Even .... 29-585 56 73 N Fine |53 f 'Morn 29-625 56 92 ENE Foggy *M Noon... . 29-625 61 77 ENE Foggy 63 I Even .... 29-600 60 72 NE Cloudy }M ,ol Morn 29-525 56 83 ESE Foggy 12<^ Noon... . 29-473 65 54 SW by S Cloudy 66 L Even 29-510 60 59 WSW Cloudy }49 .A Morn. .. . 29-583 54 60 NE Fine \sl Noon. . . . 29-583 62 50 ENE Cloudy 63 f Even . . . . Morn. . . . 29-564 56 67 ENE Rain |55 14^ Noon. . . . 29-490 59 78 NE Rain 60 L Even . . . . 29-507 59 79 NE Misty |58 r Morn 29-594 61 86 ENE Drizzle 15S Noon 29-634 65 74 ENE Moist 65 I- Even 29-653 62 79 ENE Moist jeo r Morn. . . . 29-660 62 82 ESE Foggy 16< Noon.... 29-660 65 69 . E Cloudy 67 V r>ven . ■ • . f Morn.. . . 29-600 58 78 ENE Fog^y 17\ Noon... 29-534 68 55 ENE Fine 1 (. Even . . . — — 1 - 398 Col. Beaufoy's Meleorological Table, [Nov. Meteorohaical Table continued. Month. Time. Barom. Ther. Hyg. Wind, Velocity. Weather. Six's. Sept, inches. Feet r Morn 29-S73 58° 74° NE Showery 55» 181 Noon.. . . 29-257 62 60 NK Fine 62 I Even .... 29-2{>0 57 75 N Showery I55 Morn. . . . 29-430 57 75 Wby N Foggy 19^ Noon. . . . 29-485 60 60 W Cloudy 62 ( Even .... 2955J 57 70 W Fine |51 r Morn .... 29-605 56 64 NW Fine 20<^ Noon. . . . 29-610 61 57 Wby N Cloudy 63 1 Even .... 29-625 57 60 WNW Cloudy }54 r Morn .... 29-575 55 76 NEby N Cloudy «'i Noon 29-564 61 56 NE by N Cloudy 63 I Even .... 29-530 56 58 NE Fine |45 r Morn, . . . 29-465 51 69 NE Very fine 22-^ Noon _ — 60 I Even 29-437 54 53 NE Cloudy |49 r Morn 29-438 54 70 NNE Cloudy 23 < Noon. . . . 29-466 62 52 NE Fine 64 I Even .... 29-480 68 63 NE Fine |50 f Morn 29-548 54 73 Caira Cloudy 24 <{ Noon. . . . 29-540 61 55 S Hazy 62 L Evf n .... 29-468 55 57 S Fine |52 1 Morn, . . . — _ — ^ -^ — — 25<( Nocn. . . . 29-110 61 51 sw Cloudy 63 (. Even . . . 29 050 58 58 SW by S Drizzle |54 f Morn .... 28-787 57 67 SSW Stormy 26< Noon. , . . 28-790 60 49 SSW Stormy 61 (. Even 28-840 51 55 wsw Stormy S-48 f Morn 28-958 53 55 sw Cloudy I 27^ Niion. . . . — — — 55 I Even .... 28-985 48 65 Wby S Cloudy }45 f Morn.... 29-285 47 65 W by S Cloudy 28< Noon. . . . 29-367 56 43 W by N Fine 57 L Even . . . . — — — — — 1 39 r Morn 29-580 46 63 W Cloudy 29< Noon. . . . 29-580 56 43 W by N Fine 67 L Even .... 29-580 51 60 SSW Cloudy |45 f Morn 29-518 47 58 NE Shoivery 30< >foon 29-537 55 46 ENE Fine 56 ' I Even .... 29-537 49 49 ENE Clondy 1S17.] Mr. Howard's Meteorological Table, 39:> Article XIII. METEOROLOGICAL TABLE. 1 Barometer. Thermometer. aygr. at 1817. Wind. Max. Min. Med. Max. MiD. Med. 9 a. m. Rain. 9th Mo. Sept. 3 S E 29-96 29-79 29-875 75 53 64-0 65 c 4 Var. 30-10 29-96 30-030 69 43 56-0 63 5 Var. 30-10 30-03 30065 73 46 59-5 60 6 Var. 30-{;3 30-00 300 15| 63 47 55-0 59 7 S E 3003 C9-91 29-970 71 44 57-5 60 S E 30-07 29-94 30005 76 47 61-5 58 9N El 29-96 2;) 94 29950 66 54 60-0 63 10 N 129-97 29-02 29-94-) 65 50 575 59 11 N Ei29-92 29-87 29-895 68 49 58-5 65 0 12 Var. '20 93 29 80 :9-86:, 68 49 58-5 62 — 13 S t 29-93,-29 85 N E,29'93i?9-83 29-890 66 53 59-5 56 — 14 29-88O 63 56 5.9-5 63 0-17 ]5!N Ei29'98l29'9-^ 29-955 66 60 63-0 64 l6iS E 29-98,29-94 29960 72 51 61-5 63 17|N E ^29-94 2961 29775 70 54 62-0 60 D 18; N 29-7f''29-56 29-660 62 55 58-5 62 4 19 W 29-95:29-76" 29-855 67 47 57-0 57 20 N W 2995i29-9i 299^0 64 55 59-5 53 21 N E|29-9> '29-83 29-870 60 42 52-5 61 22 iN Ej29-83,29-80 29-815 59 47 53-0 53 23 'N E;29-90;29-80 29*850 64 47 55-5 52 24 S E29-9* 2952 ■29710 66 47 56-5 51 25,8 W'29 5-2 29- 6 29-34' 6-t 55 59-5 65 — 0 26 'S W 29-31 29 H' 292.35 60 47 53-5 53 0-20 27 S W 29-63 •id-'d I 2948C 58 44 510 48 7 28 W 29 9o 29-65 298OC 59 S3 46-0 55 29 N W 29-95 29 8S 29-92( 58 43 50-5 54 30 N E - 29-8i > 2975 29-82C ) 55 42 48-5 53 10th Mo. Oct. 1 N "W ' 30-0? !29-7' .29-88i ) 56 30 43-0 57 2 N 300i 30- H ) ^0-05 J29i( ! ,0-03.; )29 8-t^ , 46 > 76 24 24 35-0 48 0-4t^ 55-7^ ) 58 The observations in each line of the table apply to a period of twenty-four hours, bej;inimi{i; at 9 A M. on tlie day indicated in the first column. A dasli (IcDulcs, that the result is included in the next following ohservutiun. 6 400 Mr. Howard's Meteorological Journal. [Nov. 181 T'. REMARKS, Ninth Month. — 3. Much dew : very fine day, with Cirrus only, in horizontal striffi: temp. 72° after sun-set. 4. Dew: fine morning: Cirrocumulus, followed by cloudiness from S about nine: clear afterwards, save a line of low thunder clouds in the NE. 5. Fine, after raisty morning : large Cumuli : at night the IJoating dust and smoke assumed the horizontal arrangement usual before the Stratus. C. Misty morning: afterwards large plumose Cirri, passing to Cirro- cumulus: p. m. some delicate streaks of Cirrostratus, with two currents near the earth at sun-set, SW above E. 7. Serene day, after misty morning: a very luminous, yellowish, evening twilight, with crimson streaks of Cirrocumu/«s, and a dewy haze round the horizon. 8. As yesterday, with Cirri, finely tinted in orange at sun-set, 9. Overcast, a.m. : at sun-set, Cirrostrati from SE. 10. Over- cast morning: then Cumuli, and with an electrical character : a fine breeze these three days. 11. Calm, misty morning : then lightly clouded till evening. 12. Misty morning: after a little rain, the sky exhibited a veil of clouds moving from the SW. 13. Cumulostratus through the day. 14. Rain very early: temp. 63° at nine, a.m.: mild and damp air. 15. Cloudy, close, damp, day and uight. 16. Overcast, with a breeze. 17. Misty morning: then sunshine and flying clouds. IS. Slight showers, with wind. 19. Cloudy morning : luminous evening twilight, orange, with rose colour above. 20. Clear dewy morning : the temp, scarcely varied from 55° through the night: Cumulus. 21 — 23. Fine, with breeze pretty strong, and various clouds. 24. The approach of the westerly current from the southward was indicated to-day by the southing of the wind, by heavy Cumuli and Cumulostrati in the SE, and by a lurid haze, with greenish streaks of Cirro- strati, before the moon. 25. A gale from SW, with light rain : in the evening a lunar corona with the JVimjMs; heavier showers in the night. 26. Showery morn, ing : then Cumuli carried in a fine blue sky ; evening showery: night windy. 27. Wind and showers. 28. The morning gradually cleared up, with Cirrorfra/us passing to Cirrocumulus, and some very elevated Cirri : at sun-set these showed red, stretching SW and NE. 29, 30. The wicd, after going to SW for a short time, came round by N to NE, with fine weather. Tenth Month. — 1. Fine: very red Cirri at sun-set. 2, Hoarfrost, with ice. RESULTS. Winds Easterly, interrupted after the full moon by a gale from the westward. Barometer: Greatest height 30" 10 inches. Least 29*16 Mean of the period 29-842 Thermometer: Greatest height 76° Least 2-1 Mean of the period 55'76 Mean of the Hygrometer 58 Rain 0-48 inch. Tottenham, Tenth Month, 23, 1817. L. HOWARIX ANNALS OF PHILOSOPHY. DECEMBER, 1817 Article I. Biographical Account of IVilliam Browmigg, M.D. F.R.S, By Joshua Dixon, M.D; {Concluded from p. 338.) IN four lemmas, introductory to his account of the improvements proposed in the art of preparing white salt, Dr. Brownrigg shows, by indisputable facts and arguments, that white salt obtained by the usual methods is inadequate to the purposes to which it should be applied ; that it is not calculated for the preservation of provisions ; and that it assists, rather than prevents, putrefaction. The dissi- pation of the volatile acid in large quantities, in consequence of the violent heat used in the process ; the mixture of calcareous and ferruginous earths, of lieterogeneous salts, of sulphureous sub- stances, and of impurities occasioned by the several additions to white salt ; appear, from accurate experiments, the sole cause to which its evident defects can be ascribed. As a remedy for these defects. Dr. Brownrigg proposes two methods of obtaining salt superior in strength and purity to every other kind : first, by a more complete impregnation of it with its acid ; and, secondly, by a more perfect separation of its impurities. According to the plan which he suggests, a kind of white salt may be prepared, either from sea water, natural brine, or rock salt dissolved in weak brine, or sea water. The construction of the salt marsh should correspotid to that adopted in France, and the size of the boiler should be the same as what is used by the Dutch ; the clarification of the brine is to be effected by the mixture of whites of eggs, and the alkaline Vol. X. N° VI. 2 C 402 Biographical Account of [Dec. salt of the brine to be neutralized by the addition of a proper quan- tity of sour whey. The violent boiling which he reconomends in this part of the process cannot occasion any considerable dissipation of the acid, as experiments discover that no portion of it is separated until one-third of the water is exhaled. The salt thus prepared, though sufficiently adapted to culinary purposes, may yet further be improved by the following expedients. By the addition of such a quantity of pure spring water as may be sufficient to dissolve the salt and produce a strong brine, a sediment will be deposited at the bottom of the vessel. A slow evaporation of this clear solution of white salt must then be promoted by a gentle, equal, and regular heat ; and, on the first appearance of crystallization, such a pro- portion of muriatic acid must be mixed with the salt as may prevent the ascendancy of either the acid or alkali. The salt remaining after the evaporation is completed will surpass in purity, strength, and efficacy, every other preparation. Though the expenses attend- ing this process can only be ascertained and determined by proper experiments ; yet, from Dr. Brownrigg's calculations, it is probable that the price of this refined salt would be less than that of common bay salt, and would not exceed that of common white salt. He concludes this ingenious and elaborate publication by recommending the interference of the Legislature in directing a more compre- hensive inquiry into the practicability of the improvements pro- posed ; in erecting salt-works for the puipose of making additional and more accurate experiments ; in appointing skilful and judicious persons to the inspection and superintendance of them ; and in regulating the price and quality of salt by one common and esta- blished standard. The superior advantages of the processes which have been ex- plained over that of Mr. Lowndes must be sufficiently obvious, inasmuch as the latter is confined entirely to boiled brine salt, whilst Dr. Brownrigg suggests improved methods of obtaining both bay and white salt. Mr. Lowndes's process, likewise, can neither be admitted as perfect and unexceptionable, nor, whh justice, can it be considered as his exclusive discovery. Tlie addition of the alum, which constitutes its chief peculiarity, had long before been practised in Cheshire ; and, in all probability, the uniform and moderate heat used in the preparation of the salt was solely instru- mental in producing those effects which were improperly attributed to the alum. This work was so highly approved by the Royal Society, that they conferred upon Dr. Brownrigg the singular honour of directing an abridgment of it to be made by Mr. William Watson, a most worthy member of that establishment, which they published in the 46th volume of their Transactions. His improvements in the salt- pans and furnaces have been adopted in the Cheshire and Droitwich salterns, and in many other parts of the kingdom. In consequence, a stronger and purer boiled salt than that which was formerly made is now prepared at all the British salt-works, and the demand for 1817-] -Dr. William Brownrigg. 403 their salt was greatly increased, especially before the North Ameri- can war. To this judicious and valuable publication the late celebrated Professor of Chemistry in the University of Edinburgh, Dr. Joseph Black, when explaining in his lectures the art of preparing and preserving common salt, always made a particular reference, re- spectfully intimating that the ample instructions there given super- seded the necessity of expatiating on the subject. Subsequent writers, also, who have pursued the same track of inquiry, whilst they unanimously acknowledge their obligations to Dr. Brownrigg, mention his labours in terms of praise which reflect equal honour on his talents and their own judgment.* The metal platina di pinto, juan bianco, or white gold, was the next object of Dr. Brownrigg's attention. The first specimens of this article, having been originally carried from Carthagena, in New Spain, to Jamaica, were brougiit to England in 1741, by Mr. Charles Wood, a skilful and inquisitive metallurgist. They were given by him to his relation Dr. Brownrigg, who presented them to the Royal Society in 1750, accompanied with an accurate and in- genious account of its origin and properties, which was inserted in the 46'th volume of their Philosophical Transactions, under the title of Several Papers concerning a new Semimetalf called Platina. The specimens were, first, those of its ore in a natural state ; secondly, when purified; thirdly, when fused ; and, lastly, as form- ing part of the pummel of a sword. Don Antonio d'Ulloa, a Spanish mathematician, had in the year 174s slightly mentioned this intractable metallic stone, as he im- properly terms it ; which is represented as preventing the separation of gold from its ore. Dr. Brownrigg, however, is entitled to the credit of having communicated to the public the earliest scientific information respecting it. He introduces the subject with observing that naturalists yet remain unacquainted with a great variety of mineral substances; and that, of those already discovered, there are many species whose properties are imperfectly known. After comparing the specific gravity of gold with that of mercury and platina, he notices the singular qualities of the latter, and proves from them that it is in many respects an exception to certain axioms admitted in metallurgy. Platina, he observes, is not found in the form of a pure ore, but in the state of dust or grains, blended with ferruginous impurities, which are easily attracted and separated by the magnet. He next mentions the manner of obtaining it, its • Dr. Campbell, in his Political Survey of Great Britain, noticing Dr. Brown- ilgg's treatise upon salt, calls it " a very learned, ingenious, and solid perform- ance; than which," he adds, " there is not pertiaps any thing more concise or more correct in any language." This eulogium from the pen of one who was as well qualified lo form a proper estimate of merit as he was incapable of con- ferring undeserved praise, is not less flattering than it isjust. + Platina has been improperly stiled a semimetal : for, when all extraneous substances are removed, it possesses the distinguishing qualities of a metal, viz. malleability and fixitv. 2 C 2 401 Biographical Account of [D£c. abundance in the Spanish West Indies, the method of fusing it, and the difficulty of effecting the process even by saline additions. From its being specifically heavier than other metals, and from its ready combination with them, arose the practice among the Spa- niards of adulterating gold with it; in consequence of which the mines were closed, and the metal became much scarcer. The in- ference which Dr. Brownrigg draws from his experiments and re- searches is, that platina has a great affinity to gold in its qualities of fixedness and solidity, to which in other respects it is nearly allied. He concludes with intimating that, similar to many metallic sub- stances, it may probably be possessed of several wonderful proper- ties, and may on some occasions be productive of very important advantages to mankind. Mr. Wood had, with great accuracy and sagacity, previously subjected this metal to various experiments, wliich Dr. Brownrigg purposed to repeat, intending at the same time to make further experiments upon it with sulphureous and other cements, as also with mercury, and many corrosive menstrua. In performing these experiments, he remarked that platina does not wholly resist the action of lead in cupellation, as he had before supposed. The extraordinary nature of this newly-discovered metal has long excited the curiosity and attention of philosophers ; but the prohi- bition of its sale has hitherto prevented its application to practical uses. It is, however, to be hoped that regard to their own interests, if not to the improvement of the arts and sciences, will no longer suffer the Spaniards to continue the interdiction of this valuable article. Their apprehensions lest it should be employed in the adulteration of gold are now groundless, since the fraud may, with- out difficulty, be detected by the methods which chemists have proposed. When we consider that in this metal the fixity of gold is joined to the hardness of iron, that it cannot be acted upon by acids, that it is not injured by water or air, and that it is incapable of being corroded and impaired by rust, we are led to indulge the sanguine expectation that, if its commerce was subject to no restric- tions, benefits would result to society of which we can at present form only an imperfect conception. Mankind will then pay a just tribute of gratitude and veneration to the memory of that person who gave to the world the first intelligence of its existence and properties. Long were the miners of Peru acquainted with this metal before its introduction into Europe ; and if Dr. Brownrigg had not brought it forward to public notice, the knowledge of it might, even in the present age, have been confined to that illiterate class of men. In some explanatory notes to A descriptive Poem addressed to two Ladies at their Return from viewing the Mines near White- haven,* published in 1755 by John Dalton, D.D. is contained a * This poem, and its explanatory notes, are inserted in Pearch's Oxford Cellec- tioa of Poems. 1S17.] Dr. William Brownr/gg. 403 short account of those mines, which proceeded from the pen of Dr. Brownrigg. These notes are not intended to form a history of collieries, or a philosophical treatise upon their peculiarexhalations ; but merely to illustrate and confiim the poet's description of the operations and appearances in the mine^. An accurate relation is given of the various expedients which attentive observation and melancholy experience have at different periods suggested for the purpose of preventing the explosions of the fire-damp, and the fatal effects of the choak-damp. The scenes exhibited in those subterraneous regions, which fill the mind with awe, surprise, and terror, are delineated with equal elegance and perspicuity. The circumstances which are mentioned relative to the strata of coal, the depth of the mines, the uses of the steam-engine, the origiiial establishment of the collieries, and their influence on the prosperity of Whitehaven, are curious in themselves, and must to many persons, from their local residence, be particularly interesting.^ These notes are deserving of praise, as being a valuable specimen of topography, and as containing a faithful description of mines, the most extraordinary of any hitherto discovered, and concerning which no authentic information had appeared before the public. An indubitable proof of their merit is, that those writers who have noticed the coal-works at Whitelmven are, in a great measure, in- debted for their accounts of them to Dr. Brownrigg. In tlie 49th volume of the Philosophical Transactions, for the year 175(>, is inserted a paper written by Dr. Brownrigg, which is intituled. Thoughts on the Rev. Dr. Hales's new Method of Distil- lation by the united Force of Air and Fire. The following circum- stance gave occasion to this publication. Dr. Hales, who has enriched philosophy by many ingenious and valuable discoveries, had proposed a new method of distillation, by which, from the combined power of air and heat, a greater quantity of steam was raised than by any former process. The perfect separation of fresh water, in a large proportion, from sea water, was the immediate advantage which he expected from this discovery ; and the benefit of navigators was his particular object. Desirous, however, of rendering its uses more extensive and important, he requested Dr. Brownrigg to consider its application to the improvement of those mechanical operations which depend on the action of steam. Dr. Brownrigg, in compliance with his friend's solicitation, carefully and attentively examined whether this discovery was adapted to increase the power and fiicilitate the motion of the steam-engine. Convinced that Dr. Hales's method of exciting so violent an agita- tion of the water was inapplicable to that machine, and prompted by the interesting nature of the subject to extend his inquiries, he considered what other expedients, unaccompanied with similar in- conveniences, were calculated to produce the same effects. The improvements which he suggests in the construction and operations of the steam-engine were the result of this investigation. Although the Doctor, with that modesty which is the inseparable attendant, Q 406 Biographical Account of [Dec. and best criterion, of intrinsic merit, expresses a doubt of their success in practice, and regards them merely as conjectures, not sanctioned and established by experience ; yet, when submitted to the inspection oi" Mr. Carlisle Speddiiig, at that time superinten- dent of the coal-mines at Whiteiiaven, they received the approba- tion of that eminent engineer. The quantity of steam was in- creased, in Dr. Hales's process, by a current of air introduced into the still ; which, either by the rapidity of its motion, or by its attraction of the watery particles, accelerated the distillation. From a just consideration of the nature and principle of the steam-engine, it must be obvious that such a method of promoting evaporation would impede, rather than assist, the operations of the machine. When the regulator, or valve, which stops the commu- nication between the boiler and cylinder, is opened, the steam rushes with impetuosity from the boiler into the cylinder, and overcoming by its superior force the pressure of the atmosphere, elevates the piston. As one extremity of the lever, or beam, is attached to the piston, and the pump-rod is fixed to the other ex- tremity, whilst the former is thus raised, the latter will be propor- tionably depressed. The steam being next condensed by a jet of cold water, a vacuum is made in the cylinder ; the external air, experiencing little or no resistance, presses down the piston ; the pump rod, in consequence, is elevated, and the water ascends from the same cause as in the common pump. From this brief account, it appears that the ascent of the water depends on a vacuum being produced in the cylinder. Supposing, therefore, that a great in- crease of steam was obtained by forcing into the boiler a stream of air, although the piston would be raised, and the pump rod descend, yet a portion of air entering into the cylinder, and re- maining after the condensation of the steam, would, by its elas- ticity, counteract the weight of the incumbent atmosphere, and prevent the depression of the piston. The engine, in consequence, would be deprived of that regularity and uniformity of motion which arise from the alternate action of the steam and the atmos- phere. Sensible of this disadvantage. Dr. Brownrigg directed his thoughts to the discovery of some other method, calculated to in- crease either the quantity or the elasticity of the steam. The im- provements which he proposes consist, first, in assisting evaporatioti by a mechanical agitation of the water in the boiler; and, secondly, in rarefying the steam by heat. For producing the former effect, to a wheel placed in the boiler motion should be communicated by the exertions of a labourer, by the force of the water which the engine raises, or by a crank suspended from the beam. But the introduction of elastic steam into the boiler is more particularly recommerided, as being better adapted to promote evaporation. For this purpose strongly elastic steam, contained in an eolipile, or small boiler, is to be conveyed, by means of a tube, into the large boiler, at the bottom of which the tube must be divided into several 18170 Dr. William Broivnrigg. 407 smaller tubes, perforated with holes. The steam being thus con- fined within a narrow compass, and being prevented from escaping through any aperture, except the holes, will pass with considerable violence into the large boiler; and from the commotion thus excited in the water, the evaporation will be much accelerated. From certain facts and experiments, Dr. Brownrigg concludes that steam is capable of a greater degree of expansive force, by means of heat, than it usually possesses, when applied in the steam-engine. He therefore suggests two methods for increasing the heat of the steam ; first, by carrying through the fire of an air furnace the pipe which forms a communication between the boiler and the cylinder ; or, secondly, by fixing it in the flue of the common furnace. It is necessary to observe, that neither the heat of the same quantity of steam which is commonly employed in steam-engines, nor the quantity with the same degree of heat, can be increased in the manner proposed; since if the steam was above one pound per square inch stronger than the pressure of the atmosphere,* the danger of its bursting the boiler would be very great. If, however, the steam raised in a smaller vessel will, in consequence of its quan- tity or its heat being increased by these contrivances, possess the same degree of force as the steam now used, the expenses which arise from the size of the boiler, the consumption of fuel, and the price of labour, would be much contracted. Of this publication it may with justice be observed that it affords an additional evidence of Dr. Brownrigg's inventive talents and comprehensive mind. And as it displays his knowledge of subjectsf not immediately connected with professional studies, so it proves the subserviency of his inquiries to the real interests of society. The gratification of curiosity, the desire of popular applause, or mere intellectual pleasure, never prompted him to degrade the dignity of reason by idle and unprofitable speculations. It was his opinion that the noblest powers of the human mind were best applied when directed to the uses of mankind, and that the merit of literary labours could only be appreciated and determined by their reference to this end. In the year 1771 the appearance of the plague in some distant * To prevent such an accident, there is a pipe fixed in the boiler, with a valve loaded with lead, equal to about one pound per square inch. When the steam is so powerful as to lift about 16 lb. upon every square inch, this valve rises, and suffers the steam to pass into the open air until its force is less than 16 lb. per square inch; then the valve drops down, and permits no more steam to escape. + This reraarii. is not intended to convey the most distant insinuation that mechanics can have no influence on the improvement of medicine. A previous acquaintance with this useful part of natural philosophy, hitherto too much neg- lected by medical practitioners, is essentially requisite to a right knowledge of myology, and to the success of many operations, which it is the province of the surgeon to perform, and which the physician has frequent occasion to superintend. It must, however, be obvious that, amidst the multiplicity of important objects which have a claim to serious consideration, an attention to this particular branch of mechanics might, without impropriety, be omitted. 408 Biographical Account oj [Dice. parts of Europe had produced a general apprehension lest It should, as was formerly experienced, very widely extend its fatal ravages. In consequence, his Majesty, whose reign has been distinguished by an anxious and unremitting attention to the welfare and happi- ness of his subjects, had displayed his prudence and affectionate regard in taking suitable precautions to prevent its introduction into this country ; and had expressed, in a speech from the throne, his firm confidence in the immediate concurrence of his Parliament at any future period, when more imminent danger should dictate the necessity of making additional provisions for the security of these kingdoms. In answer to this gracious communication, the two Houses of Parliament respectively declared their perfect coinci- dence of opinion with regard to the propriety of adopting preventive measures, and their disposition to comply with his Majesty's bene- volent wishes. The expediency of amending the laws now established as a barrier against this destructive malady is thus intimated by his Majesty and the whole British Legislature. Upon which occasion Dr. Brown- rigg, observing their defects, and actuated by principles of duty and humanity, was prompted to offer to the public a treatise, inti- tuled. Considerations on the Means of preventing the Communica- tion of pestilential Contagion, and of eradicating it in infected Places. Tlie danger at that time threatening the nation from the near approacli of so dreadful a calamity, and the desire to mitigate in future the virulence, and suppress the baneful influence of con- tagious fevers, long prevalent in this country, were the laudable motives which excited his attention to this interesting inquiry. He therefore collected many well-attested facts concerning the origin, progress, and nature, of pestilential contagion ; and the methods by which it is conveyed from place to place, and from one person to another. The practicability of preventing its propagation in highly infected situations was the next object of his consideration. On a review of the laws relating to this disease, he shows the instances in which they are defective, or are capable of iinprovement, and what is the most easy and certain manner of carrying them into execution. He then enumerates those measures the efficacy of which, in arresting the progress of pestilential contagion, has been confirmed by expe- rience. The laws of quarantine, as first introduced by the Vene- tians, and improved by subsequent alterations, are strongly recom- mended, from their obvious tendency to preclude its importation ; and some useful additions aje suggested respecting the restriction of clandestine trade, and the erection of lazarettos. From the im- portance of the subject, a particular account is given of bills, or manifests of health, the plan of conducting them as adopted by different nations, the intimations which they convey with regard to the degree of infection in the country whence they are transmitted, and the means of obviating those impositions which are frequently practised. In consequence of the establishment of these bills, and 1817.] Dr. J'Villtam Brownrigg. 409 of a strict attention to the information contained in them, this kingdom has been long preserved from the ravages of the plague, which formerly almost depopulated its metropolis, and has often raged with violence upon the continent. Of these salutary provisions, the most essential consist, first, in a constant communication of intelligence relative to the state of salubrity among foreign nations ; the names of those vessels which have omitted, by neglect or evasion, the necessary precautions ; and the number of seamen who have been lately afflicted with the distemper : secondly, in destroying the bed-clothes, wearing ap- parel, and every article qualified to imbibe or retain the infection : thirdly, in thoroughly washing and ventilating the ship : fourthly, in receiving no merchandize until perfectly purified : lastly, in the exact obedience of the commander of the vessel to his directions, and a punctual discharge of every requisite obligation. For his instruction, therefore, a brief abstract should be made of the laws and regulations now in force which relate to the prevention of the disease, wuh rules of conduct respecting it, and an accurate de- scription of its characteristic symptoms. Where the danger of its rapid extension is much to be appre- hended, it would be expedient to interrupt every source of con- nexion, to restrain the commerce, to prohibit the importation of goods capable of conveying the infection, and even to preclude all intercourse with the objects of it, and with the places which it infests, by inclosing them with lines, and by appointing proper guards for their defence. This last method has been adopted in Hanover, Marseilles, Messina, Reggio, Istria, and Dalmatia, with repeated success ; and, under similar circumstances, by the Hot- tentots, in preventing the progress of the small-pox. The Doctor nest expatiates on the advantage of giving speedy information of the first appearance of the disease to proper officers, constituting a board of health, in order that every exertion may be used for its eradication. The support and cure of the sick at the public expense are recommended, both from political considerations, and as the dictate of humanity. To these respective heads a very judicious and circumstantial attention is paid, the various customs of other nations being explained, and positive evidence given of their efticacy. The conclusions drawn from the facts related are highly im- portant ; and demonstrate that the contagion is received by imme- diate contact, or by morbid effluvia, which cannot be carried through the medium of the air to any great distance; and that the inhabitants of adjacent houses, if unconnected with infected situa- tions, will be unsu3ceptil)]e of it. Of this consolatory assurance several well-attested proofs arc introduced, which evince this to be the best prophylactic measure ; one tliat is not only most agreeable to our feelings and desires, but to which we are prompted by the irresistible impulse of that first law of nature — self preservation. The former practice of secluding the sick is shown to be cruel and 410 Biographical Accuimt of [Dec, insecure. The safety of the public cannot be endangered by the allowance of proper assistance to the unfortunate victims of that distemper, or by the attendance of those who have recovered upon such as may afterwards suffer it, if the precaution be used of obliging them to occupy separate and detached houses. This mode of treatment, in its application to every class of the community, is justified by its propriety and humanity; whilst the hazard and occasional inconvenience arising from its omission are powerful arguments in its favour. Should this nation be ever again afflicted with so dreadful a visi- tation, these provisions must be strictly executed, carefully pre- cluding all connexion with the house, street, or lane, in which the contagion prevails; and we may rest assured that their influence will be efficacious and extensive. With regard to the eradicatioo of this exotic contagion, which appears to have been imported by war or commerce, the means already directed will be sufficient for the purpose ; and it is earnestly recommended to admit no inter- course with the infected persons, goods, or habitations, until they are entirely purified. Of the numerous notes, and references to facts and authorities, which confirm the doctrines advanced, it may be briefly remarked that, collected with accuracy and judgment, they contribute to elucidate the important subject, and prove the utility of the pre- ventive plan deduced from them. Not only to the plague, but to every nervous, putrid, or bilious fever, these obstructions are strictly applicable. VVhilst the observations of practical writers are, with this view, copiously introduced, the Doctor very properly avails himself of that experience which he had derived from a long and diligent performance of professional duties. He has hence, as intimately connected with the immediate object of this publication, given a particular account of the rise and progress of an epidemic, corresponding to the jail fever, which prevailed at Whitehaven in 1757 and 1758. This contagion, assimilating to its own nature that of all other acute diseases, and associating their symptoms, appeared under a different form, and with increased virulence. Not only the adjacent, but very distant situations, have long deplored its fatality ; and since that period this country has never been per- fectly free from its destructive influence.* • In the summer of 1773 this malignant fever returned with unusual violence. Its first appearance was early in the preceding winter ; and in this stage it was accompanied by some degree of phlogistic diathesis. Such, however, was onlj' a temporary and contingent circimistaocc, which the influence of the season, or exposure to cold, produced in particular constitutions. The disease then proved neither so contagious nor so fatal as in its subsequent progress. Its duration wai generally from 7 to 14 or 20 d,iys, and always shorter in proportion as there was a greater degree of inflammatory combination. As the spring advanced, casting off the mask of inflammation, it assumed a more purely nervous aspect, rarely uuited with any septic tendency. During the summer, which was distinguished by intensity of heat, and dryness of weather, the virulence of its symptoms wa» powerfully increased. When tracing the disease from its origin, in its progress, a loss was perceived of 1 in 20, then 1 in 10 and 6 patients ; whereas now it wai 1817.] ^''' William Brownrigg. 411 As the apprehension of danger at the time above-mentioned was happily soon removed, this treatise and its prophylactic advice did not receive from the Legislature that attention which they will probably obtain on some future emergency, when it may be deemed eligible to revise the laws now in existence, in order to provide a more effectual security against t' z introduction and coramunicatioa of pestilential contagion. In the year 1772, Dr. Brownrigg, in the presence of Dr. Franklin and Sir John Pringle, who were then upon a visit at his house, performed an experiment of a very curious nature upon Derwent Lake, near Keswick. On pouring a small quantity of oil into the lake, during a great commotion of the water, the surface in a short time became perfectly smooth. This e;itraordinary effect having been originally noticed by Dr. Franklin, was suggested by him to Dr. Brownrigg. Soon after his departure from Ormathwaite, Dr, Franklin transmitted to Dr. Brownrigg a letter, dated London, Nov. 7j 1773, in which he gave a full and circumstantial relation, not only of every experiment which he had made at different periods for ascertaining this remarkable property of oil, but also of the various incidents which had led to the discovery. An extract of this letter, and also of two letters on the same subject, one from Dr. Brownrigg to Dr. Franklin, dated Ormathwaite, Jan. 27, 177'; the other from the Rev. Mr. Farish, of Carlisle, to Dr. Brownrigg, was inserted in the 64th volume of the Philosophical Transactions, for the year 1774.* Although the influence of oil in allaying the agitation of water is expressly mentioned by Aristotle, Plutarch, and Pliny ; f and although a knowledge of it, derived from tradition, had contributed much to the advantage of divers and fishermen in their respective occupations, yet it had not hitherto attracted the attention of any experimental philosopher. Accidentally observing in 17^7 a partial stillness of the waves found that tlie deaths and recoveries were nearly equal, and unhappily on sorae- occasions that the former exceeded the latter. At this period, and during the lemaioder of its continuance, miliary in many, and even petechial eruptions in some cases, appeared generally about the 7 tii or 11th day. With regard to the duration of this disease, it did not finally recede, Bor were its symptoms sensibly mitigated, before the following spring. * It is entitled, On the stilling of Waves by Means of Oil. + This circumstance suggests a useful lesson to modern philosophers. It teaches ns (hat the opinions of the ancients on philosophical subjects are entitled to sorae degree of deference and respect, and that a general ridicule and contempt of wliat juccessive ages have preserved with religious care are the characteristics rather of sciolism and pedantry than of solid learning. To select one instance from the many pretended discoveries of the moderns: the effects of boiling upon water, which Dr. Black ascertained, in rendering its congelation more easy and rapid than be- fore it has undergone that operation, were known to Aristotle, Hippocrates, Athe- nxus, Galen, and Pliny. The pridennd incredulity of thepresent generation should also be repressed, by the confirmation which the accounts of Herodotus respecting many curious phenomena in the interior parts of Africa, and in other countries, have received from the representations of subsequent travellers. Instead of being the fictions of romance, or the suppositions of a visionary speculatist, they are now proved neither to deviate from truth, nor to be heightened by exaggeration. 412 Biographical Account of [Dec. near some ships, Dr. Franklin was struck with the singularity of the circumstance ; and, upon inquiry, was informed that it was occasioned by water which had been thrown into the sea after being apph'ed to culinary purposes. Dissatisfied with this solution of the difficulty, but recollecting at the same time the remark of Pliny, his mind fluctuated between the apparent inadequacy of the cause assigned, and the credibility of what had been asserted by that sagacious writer. He resolved, therefore, at some convenient opportunity, to determine by careful experiments whether oil was qualified to moderate the violence of agitated water. By the general success of these experiments, which are related in his letter to Dr. Brownrigg, this wonderful property of oil is now firmly established. In the preservation of ships during tempestuous weather, and in facilitating a landing where there is a dangerous surf, this method of calming the sea will probably, as has already been proved by some instances, be found particularly useful. As a chemical philosopher, Dr. Brownrigg has not confined his attention to the different gases which arise from the substances, or impregnate the waters, contained in the earth, but has also endea- voured to discover its numerous saline productions. In a letter to Sir John Pringle, President of the Royal Society, inserted in the 64th volume of the Philosophical Transactions, for i'J'i^, he de- scribes 20 specimens of native salts, which were found in the coal- mines near Whitehaven. They were inspected at a meeting of the Royal Society, June 23, I'J'J'^, and were afterwards deposited in the British Museum. To this subject he directed his thoughts with a view to account for the generation of such bodies, and to detect their properties and component parts. 1. Sal Cathariicus Amarus. — Having noticed its remarkable abundance in sea water, and in several mineral springs and lakes, he justly ascribes their peculiar qualities to this ingredient. It is found adhering, in immense quantities, to subterraneous stones and other substances ; and hence arises a satisfactory explanation of the mode by which fountains, and the ocean, receive continual and plentiful supplies of it. In the Howgill colliery it is observed to germinate in long, bright, and polished fibres, from grey free- stone. The free-stone discovered in the neighbourhood of Wliite- haven, and in all coal countries, is not possessed of cohesion and durability when applied to the purposes of building ; which circum- stance is to be imputed to the separation of this salt, or of vitriol when in contact with the external air. 2. Another species of bitter salt, similar to the former, which had been taken out of an old coal-work. By a gradual germination from grey free-stone it had at length been formed into a compact mass. Alum, green vitriol, and several other salts, from the spe- cimens presented, had been produced in the same manner. " "3; Small, transparent, firm, but irregular pieces of the same salt, very abundant in the Howgill and VVhingill collieries. Specimens 1817.] -D'"' I'Villiar}:. Brownrigg. 413 of bitter salt in this form were transmitted by Dr. Brownrigg to the celebrated naturalist Sir Hans Sloane, 30 years prior to the date of this letter. 4. The same as No. 3, in a crystallized state, and purified from all extraneous matters. This salt is in a great measure the same as the bittern, the Scarborough salt and the ingredient, which gives to saline purgative waters their essential properties. It resembles also, in its form and medicinal uses, the common Epsom salt. The figure of the crystal is that of a quadrilateral prism terminating in a quadrilateral pyramid. These crystals are diaphanous, and of a beautiful colour. If the action of the air is not entirely excluded, they long retain their natural appearance. This is the case with all the saline incrustations which are produced upon any calcareous or mineral substance. 5, 6, 7. Depurated Epsom salt, in large and regular crystals. The process for obtaining them is accurately described. 8. Sal catharticus amarus, prepared from the bittern of the salterns near Whitehaven. The purity and cheapness of this medi- cine recommend it as a useful substitute for the common Epsom salt. 9, 10. A saline substance procured from the same bittern, dis- tinguished by the rhomboidal shape of its crystals, and by its un- usual bitterness. 11. Scarborough salt, similar to Nos. 7 and 8. 12. Pieces of green vitriol, collected in grant abundance from crevices in the pillars of a long-deserted coal-work at Howgill. 13. A very singular specimen of the same. These last two germinating from metallic ores, combine their filaments into com- pact masses ; and hence appears the cause of the curious texture of such saline bodies. 14. Another specimen of the same, exhibiting a clearer proof of this state, and of the natural operations producing it. 15. Green vitriol shooting from pyrites of iron, found near coal, in thin and interrupted strata. 16. Several specimens of the same mineral substance, where the vitriol appears in the interstices of the pyrites ; which, from the gradual accretion and separation of the saline matter, is reduced into a powder. This state of decomposition, and consequent decay, in sulphureous and metallic ores, arises from the united power of air and moisture. IT. Native alum, of that species which the ancients called alumen plumosum. Fibrous efflorescences of it were found on the surface of some bituminous stones in the collieries at Whitehaven. 18. Purer alum. 19. An aluminous earth, discovered in large quantities near the former salt ; very similar, from its astringent qualities, to burned alum. 20. A species of argillaceous schistus, or stony clay, with a smooth and bright surface^ which abounds in all collieries, and is 414 Biographical Accouni of [Dec* called generally by rainers shale, and by those of this country sill. Alum sometimes slioots from it, and it undergoes little change from the action of fire. Such were the laudable and beneficial pursuits of Dr. Brownrigg; and in taking a retrospective view of them, we are impressed with equal admiration of the vigour of his genius, and the versatility of his talents. The most successful efforts of the most active mind have seldom terminated in more important discoveries. Dr. Brownrigg was the first who proved that the existence either of the choak, or of the fire-damp in mineral waters, is the cause of their singular qualities ; that they may be imitated, in consequence of the solubility of these damps in water ; that the presence of fixed air occasions the suspension of iron and calcareous earths in the acidulse, and that it is entitled to a place among the other acids. To him we are indebted for our knowledge of the valuable metal platina, for various improvements in the preparation of common salt, and in the construction of the steam-engine ; for several judi- cious directions with regard to the prevention of pestilential disease; and some curious information respecting the production and ap- pearance of native salts; the mode of analyzing the Pouhon water; and the precise quantity of fixed air which it contains. By accurate and repeated experiments, he attempted to disclose the latent opera- tions of nature ; and the present well-established doctrines relative to carbonic acid gas and hydrogen gas may in a great measure be imputed to his discoveries, which constituted the basis whereon the permanent system of chemical philosophy is now erected. His attainments in every branch of science were acknowledged not only by the literati of this kingdom, but by the most eminent professors on the continent, with many of whom he was either personally intimate, or supported a regular correspondence. The style which he has adopted for transmitting to the world his opinions upon any philosophical or medical subject is remarkably distinguished for its energy and perspicuity, and is equally remote from affectation, vulgarity, and bombast. His ideas are conveyed in the clearest and most intelligible terms ; and the simple narrative of facts is accompanied with that originality of remark, and dignity of expression, which both illustrate and adorn their useful applica- tion. In imitation of the example, and in conformity with the advice of Sir Isaac Newton, he made experiments the foundation of all his inquiries. Instead of forming in his imagination some plausible theory, and accommodating to it the phenomena of nature, as had been the practice of several illustrious philosophers, he en- deavoured, by an attentive observation of the effect, to arrive at a knowledge of the cause. Reasoning a priori is, indeed, little adapted to the limited faculties of man: assuming the delusive appearance of truth, it leads us into an inextricable labyrinth ot error. The celebrity which Dr. Brownrigg deservedly obtained, in the exercise of his profession during a period of 30 years, might have 3 1S17.] Dr. WiUiani Br wnrtgg. 415 been predicted by the favourable circumstances connected with his primary attachment to it. From a careful perusal of the Greek and Roman classics, he was perfectly acquainted with their various beauties, which few have the judgment to perceive, or the taste to relish ; and so great was his proficiency in the Latin language, that he wrote it with facility, purity, and elegance. Prompted by the impulse of genius, and the united motives of utility and pleasure, to direct his attention to the mathematics, their most abstruse branches soon became familiar to his comprehensive mind. Con- versant, moreover, with many of the modern languages, he was well qualified to prosecute the general literary and philosophical studies which are requisite preliminaries to those of the science of medicine. As an experienced and skilful physician. Dr. Brownrigg attained the highest estimation. Zealous were his exertions to suppress and eradicate contagion, whilst he displayed an equal degree of discernment and assiduity in alleviating the pains of chronic infirmities and distempers. Of his medical consequence, the surest proof may be deduced from the frequent application which was made to him by his opulent friends in all cases of diffi- culty and danger, long after he had relinquished actual practice, with a view to enjoy the otmm aim dignitate. His removal to London was repeatedly solicited by those who were capable of esti- mating his professional abilities, and whose influence in the metro- polis, and respectability of station, would have rendered their patronage the certain road to immediate honour and opulence. A predilection for his native county prevented him, whilst he resided at Whitehaven, from accepting their flattering invitations ; and after his retirement to Ormathwaite, a fondness for rural scenery confirmed him in his resolution. In this retirement, among other chemical studies, mineralogy was by no means neglected. His cabinet contained several rare metallic and fossil substances ; and he was well acquainted with all the subterraneous productions of Cumberland, which in number, value, and curiosity, are not inferior to those cf any other county. To the minerals found in the neighbourhood of Keswick he paid particular regard. Having judiciously selected, he carefully ana- lyzed, the ores of black jack and black lead, extracted from the mines at Borrowdale, in order to discover their original properties and adventitious qualities ; and the public was much disappointed in not receiving the result of his accurate inquiries. Many of his leisure hours were occupied in agricultural improve- ments, which contributed not only to his private advantage in ren- dering his own estates more productive, but also to that of the inhabitants of Keswick and its vicinity; as in consequence of the methods which he suggested of draining and cultivating lands, the fertility of the soil has been considerably increased. In this retirement also he indulged that passion for polite litera- ture which iiad never been entirely sacrificed to more interesting pursuits. Much of his time was devoted to the perusal of the 416 Biographical Account of [Dec. attfcient and modern poets, which had often been to him a source of relaxation and amusement, when engaged in severer studies. By an extemporary application of their descriptions, he was wont to express the ideas which rushed upon his mind when contemplating the scenery of Keswick, where nature exhibits in a collective view the beauties of Italy and the horrors of Switzerland; but influenced by religious motives^ and admiring sublimity of conception, he read with serious care the sacred poets, whose compositions are far superior in unaffected grandeur of style, in genuine pathos, and in elevation of sentimentj to the most celebrated productions of un- assisted reason. From this general statement, it may be properly inferred that Dr. Brownrigg was possessed of every qualification necessary to form a chemical philosopher, a dogmatic physician, and an elegant scolar. By his conduct in a civil capacity, which required difTerent talents, he acquired additional honour. Long in the commission of the peace, an acting magistrate for the county of Cumberland^ he discharged the duties of that important station with not less credit to himself than advantage to the community. To this, the public, may be briefly annexed the private character of the man justly estimated not less good than great.* That modesty which ever accompanied his inquiries into the secret works of nature, and which was the result of deep investigation and long research, disposed him to doubt the sufficiency of human reason, and to admit the consequent expediency of a revelation. Convinced also, by frequent experience in the prosecution of his studies, that even objects which are daily presented to the inspection of our senses are yet surrounded by impenetrable darkness, he was not surprised at the mysterious doctrines of the Christian religion. To refuse assent to them because they relate to things which mortal eye has never seen, and wiiich must evidently exceed the limits of our compre- hension, was in his opinion disingenuous, as constituting an excep- tion-to our general mode of conduct in the common concerns of life. A firm believer in the truth and reasonableness of Christianity, lie regulated his actions according to the precepts and the example of its divine author. Impressed with just ideas of the attributes of the Creator, and the dependance of man, his piety was at an equal distance from frigid indifference and presumptuous enthusiasm. By a practice conformable to his faith, it was his endeavour to vindicate his name from that imputation of infidelity and irreligion with which the medical profession has been undeservedly stigmatized, f ♦ Thetaneuage of TuUy maj, with peculiar propriety, be introduced upon the present occasion : " Gratuhr, quod eunt, quern necesse erat diligere qualiscunque tssety tahm hcibemus, ut lubiniir quoque dUigamus." + The injustice of this ignominious aspersion is proved not only by the deduc- tions of ri'ason, but also by the powerful evidence of examples. The tendency of philosophical and medical pursuits to inspirelhe mind with suitable notions of the Supreme 15eing, and to restrain the pride of human wisdom, seems to be ad effectual antidote to the poison of infidelity. The steady attachment of Hotfman to the christion religion is displayed in various parts of his publications. — ^Tbat rial. Fiq.U. >l 1 II M ! jc. J'y*- feet Seconds 2 i — reet. 16^ l.SeconM. B- ZySeeorviU 3 Seeoixd^ ErLyraved.JbrJl':Tlu)rwcni-^ln>uiU-fS 0 0 268 7 6 Cabin allowances, presents for Indians, extra liquor, and other encouragement for the people, cannot be estimated at less than 31/. 125. (id. per month, making a total uf 300/. Brig Lyon one-tlurd less expense. As experiments are making on the length of the pendulum in the Orkneys, it is highly desirable that scientific men be sent for the same object in one of the Greenland ships to Spitzbergen ; and at the conclusion of the fishery they might return in the same vessels. Every Greenland vessel should be furnished with an artificial horizon ; of which the first and best is a shallow cylinder of wood four inches diameter in the clear, and three-tenths and a half deep, into which, by means of an ivory funnel, is pouied quicksilver. To prevent the mercury from being ruffled by the wind, two glass planes are placed over it, whose surfaces are parallel, and forming an angle with each other of 90° ; and if this be not sufficient pro- tection when the mercury is agitated by wind, or any heavy object * A vessel of the above tonnage with a rising floor is the best adapted for this service, as it has a sufficient momentum among the loose ice, anU is eosilx managed. IS 17.] 07id the Insular Form of Greenland, 427 passing near, a circular piece of glass is floated on the quicksilver. The second (invented, I believe, by the late Mr. Adams, of Ed- monton) is a plane concave glass four inches in diameter, and ground to a long radius. It is fitted into a metallic box, with its concave side downwards. This bos, when wanted, is nearly filled with spirits, leaving a bubble ; and by means of three screws, this bubble is brouglit into the centre of the glass. On one side of the box is a small thumb-screw, to be taken out when filling, that the air may escape. This screw should not be made of iron, because it will corrode. If this instrument be well made, and pains taken in the levelling, it may be depended on to two minutes, which gives an error of one minute of altitude. Neither of these artificial horizons can be used when the altitude of the object exceeds 67°. It would be extremely curious to ascertain the extent of the varia- tion of the compass in Baffin's Bay. Captain Brown found it to be 79° 42' West in latitude 72° 46' N. (see the Amials of Philosophy, vol. vii. p. 14) ; and there being an increase from Cape Farewell to this latitude, it is not impossible that in higher latitudes the aug- mentation may continue, until the needle loses its polarity ; which extraordinary declination of the compass (peculiar to this part of the world) is so remarkable, that, were a vessel sent for no other pur- pose than of making raagnetical observations, both the time and money which might be bestowed on the expedition would be advan- tageously employed for the advancement of science. The variation of the compass in latitude 70° 17' N. and longitude 163° 24' W. is 30° 28° E. ; and in latitude 7U° 58' and longitude 54° 14' W. is 74° W. ; whence it appears that in nearly the same parallel of latitude, and in a difference not exceeding 10'J° 10', or about 16S5 geographical miles of longitude, there is a ditference in the varia- tion amounting to 84° 42'. It would also be a desirable discovery to ascertain whether on going to the westward it would be found that the variation gradually decreases to the point of no variation, and afterwards gradually increases ; or whether its return be not by a sudden jump from W. to E. Observations on points of this de- scription, accompanied with remarks on the depth, temperature, and saltness of the sea, and with a meteorological journal, would contain much interesting and valuable information, and throw great light on the natural phenomena of these unexplored regions. The depth of the sea in Baffin's Bay has been determined beyond doubt by Brown to be more than a mile. It is not unusual in April (the time the Greenland vessels arrive in Davis's Straits) for Fah- renheit's thermometer to stand at 10° or 22° below freezing. Considerable diversity of opinion prevails respecting the form of Greenland, which is conjectured by some to bend to the westward, and, joining the continent of America, to form the vast and sup- posed gulf of Baffin's Bay ; by others, to be one large island ; and by a third class, to be a cluster of islands intersected by a variety of channels running from sea to sea, but so blocked up with ice as to render the passage between them irapracticable. In a journal 428 On the Cells of Bees. [Dec, before me it is mentioned that a strong current sets round Cape Farewell to the north-west, and that the water breaks for several miles. It appears probable, therefore, from this circumstance, that Greenland does not consist of a multitude of islands ; because in that case the current would have taken its direction between them, instead of flowing round the extremity of the land. The junction of Greenland with North America appears to me to be likewise improbable, from the following reasons : first, that Brown (as already mentioned) never saw the western land : next, that Hearn in his travels arrived at the sea, seals having been seen by him: and, thirdly, that Mackenzie, whose travels lie to the westward of Hearn's course, came to the mouth of a large river, which also emptied itself into the Arctic Ocean : and, lastly, from the great -probability that the immense quantity of drift wood found in Baffin's Bay, on the coast of Labrador, and on the north-west coast of America, has been deposited there after being brought down by Mackenzie's River, and driven to the east and west, and afterwards southward, according to the direction of the winds and currents : all which circumstances combine, in my opinion, to furnish a ground of belief that North, as well as South America, is sur- rounded by the ocean ; and that the north-west passage is to be sought about latitude ^2°. That Greenland is an island seems also to be highly probable, from the quantity of drift wood found on the coast of Iceland ; for it is much more natural to suppose the trunks of trees found in that part of the world are carried off from the northern extremity of America, and driven round the north of Greenland, than that, being floated from the mouths of the Obe, Lena, and other great rivers of Russia, they should pass Nova Zembla round the North Cape to the prodigious distance of 20° west longitude. Cape Farewell, the southern extremity of Greenland, according to the Requisite Tables, is in latitude 59° 38' 00" N. and longitude 42'^ 42' 00" VV. By observations in my possession, it is in latitude 59° 42' N., and longitude 45° 16' W. I remain, my dear Sir, very sincerely yours, Mark Beaufoy. Article IV. On the Cells of Bees. By Mr. Barchard. (To Dr. Thomson.) DEAR SIR, In the 55th number of the Annals of PJiilosophy 1 was much pleased by seeing that a previous paper of mine had drawn the atten- tion of Dr. Barclay, who, notwithstanding the light way in which he 5 15^17.] On the Cells of Bees. 42y treats what he calls my hj'pothesis, still finishes his letter in a way that appertains to a man of science : for, although our ideas on the subject differ, why should we descend to personal scurrility, at all times hostile to the advancement of tlie object in view. I shall in the present paper endeavour to show Dr. B. by some new experi- ments, as well as by the explanation of my former ones, the result of my reasoning, and the truth of my inference. In the first place, I must beg to put Dr. B. right with regard to what he calls my hypothesis. I have none : if possessed by either, it is by him, as he stated the case in the first instance, and I only replied. I must impute to Dr. B. some want of knowledge of the domestic economy of the bee, by asking wliy (if the bees are so sparing of their time and labour) one large cell might not suffice instead of so many small ones. That they are so sparing, we see by the shape of the cells, (the shape being that which admits of most space with the least quantity of material, the angle of the rhombuses terminating the bottom), containing, according to Kirby and Spence's Introduc- tion to Entomology, the exact number of degrees tiiat a skilful mathematician would adopt for the purpose of strength and space. Dr. B. candidly acknowledges the comb he broke before the Wer- nerian Society was dark-coloured, had been exposed to the weatlier, and to every appearance had contained brood — the certain symptoms of old comb ; the consequence of which would be that on breaking or cutting, it certainly to a superficial observer would appear double; that is, each cell exhibiting the appearance of its own party wall (if I may be allowed the expression) ; the reason of which we shall immediately see, if we consult Huish's second edition, p. 42, in which he expressly names the lining of the cells : " The bees which are bred in the first combs of a hive will be larger than those which are bred in an old stock hive : for this reason, the cells in an old stock hive having had repeatedly young brood in them, are each time diminished in their capacity by a small film which the bee on quitting the cell leaves behind it," &c. Again, p. 129, "The larva continues to grow for five or six days, and then weaves a whitish, silky film, which is found to be firmly attached to the inside of the cell, and is the cause of its appearing of a different colour from that of new or virgin comb." I shall now proceed to my own experiments on both old and virgin comb. Dr. B. laughs at the idea of putting the comb into hot water. What other menstruum could be employed, so cheap and simple ? He says the cells are stuck together with a peculiar animal glue. I wanted something to dissolve it, and therefore put a piece of old comb with a piece of virgin comb into water, and gradually raised it to near the boiling point; the consequence of which was, that tiie heat just sufficient to dissolve the virgin comb was also sufticient to dissolve the wax composing the original struc- ture of the old comb. Now virgin comb is very nearly pure wax, therefore, by the heat of the water, it dissolves, and floats on the sur- 430 Demomlrat'ioii of a Mathemal'ical Theorem. [Dkc. face : the old comb being full of the films left by the young ones, the wax melts and floats, but the comb still retains its cellular ap- pearance, which while in the water may be separated into single cells ; but these single cells are not the original formation, but aa animal matter, and formed by the larvae or young bees ; for we may in a hive of observation see the same comb repeatedly filled with honey; that is, for two or more years; but it still retains the property of virgin comb : but directly this comb has had brood, its appear- ance is changed; and as soon as put into hot water, separates into the filmy cellular appearance. Now what other conclusion can we draw from this, than that the cells are all built alike; but those which have contained brood are lined by the larvje, and thus mis- lead by their double appearance. Anotiier way in which 1 have succeeded is to cut a piece of old brood comb into this shape AAA/ by which means both sides of the same cell can easily begot at; when, by careful dissection, several layers of film or lining may be taken off, and the comb brought to the state it was before it had had brood in it. Being one day at Guy's Hospital, I took the opportunity of dissecting some comb before some of the gentlemen that were present, and who expressed themselves perfectly satisfied with the result. Having now stated my method of experimenting, 1 should be happy to hear or see Dr. B.'s method. At any time that he is in the neighbourhood of London, 1 should feel much pleasure in personally explaining the business, and Remain, Sir, yours with respect, Waddon, Sept.^l, 1817. R- W. BaRCHARD. P. S. The comb of the hornet is determinately single, being built of wood in a peculiar state of decay, the pieces of vv-hich are sufficiently large to be distinctly seen on both sides of the same cell. Article V, Demonstration of a Mathematical Theorem. By Mr. J. Adams. (To Dr. Thomson.) STR, Slonehouse, Aug. 7, 1S17, Should you consider the following proposition and demonstra- tion to merit a place in your Annals of' Philosophy, your inserting them therein will oblige, Sir, your most obedient servant, James Adams. 1S17.] Demonstration of a Mathematical Theorem. 431 Proposition. In the series A + B x + C x"- + Dx' + &.c. where the coeffi- cients A, B, C, D, &c. are supposed constant, and x arbiirary, x may be so taken that the sum of all the terms except the fir=t shall be less than any finite quantity. Demonstration. Let « be any finite quantity whatever, Q x" the greater term ia the proposed series, and Q :c"' =

B x" ~) Where J '?' ^ ^^l > continued to n terms. L &c. J Therefore cp +

+ &c. to 7i terms = n (p is greater than B x' + C x' 2 + D x' 3 + &c (1). But since f may be any finite quantity whatever, let therefore f = —> '"■ denoting any finite number of terms except the fiist, and q any whole number. Then substitute for (p in expression 1), and we have y greater than B x' + C X ' + D X ' + &c. Therefore x may be so taken that the sum of all the terms, except tU first, shall be less than any finite quantity. In the same manner it may be shovn that x may be so taken that any term of the series shall be indefinitely greater than the sum of all the other terms which contain higher powers of x. For B X + C x« + Dx^ + E X* + &c. = x (B + C x + D x"- + E x^ + &c.) But it has been demonstrated that — nay be greater than C x + D x« + E x' + &c. Therefore B x > 9 (C x^ + D x^ + E x^ 4- &c.) ; that is, x may be so taken tiat B x may be indefi- nitely greater than the sum of all the othor terms of the series which contain higher powers of x. The principles contained in the preceding demonstration are similar to those in Mr. Cresswell's Maxima aid Minima. .-,. , . fsr = A-Bx+Cx2-Dx+Ex^-&c.\ ,„x Ifm the equations "j^2^^^£j^.^CxHDaf+Ex'+&c./-^^^- .432 On soifie Points relating to Vision. [Dec. X be so taken that tlie sum of all the terms wiiich follow B x shall be /ei5 than that quantity, however small it may be ; let then B x be consideret! as indefinitely, or incomparably small; and smce the sum or difference of two indefinitely small quantities are likewise indefinitely small, we may conclude that on this supposition the above equations would become x' = A — 0, and x = A + 0 j in which state z will become a maximutn, and z a minimum. Now since B j; is considered greater than the sura of all the succeeding terms, it is evident that if B a: becomes nothing, the said sum will necessarily become less than nothing, to represent which the signs of each of the succeeding terms must be changed. The proposed equations would in this case become fx' = A - C X- + D x^ - E X* + &c. \ ._. \x; = A - (C a;"- + D x^ + E a;* + &c. J v^> If in these last equations x he so taken that C x'^ shall be greater than the sum of all its succeeding terms, and C x^ conceived to become nothing ; on this supposition the sura of all the succeed- ing terms must evidently become bss than nothing, and therefore the signs of each of the terms must be changed j equations (3) will now becoihe s;' = A - D x* + E X* - F X* + &c. ■At a; = A + D x^ + E X* + F x3 + &c. which are manifestly similar to equations , (2). In like manner may D x^ E x"*, &c. be made to vanish, and the greatest and least values cf «;' and x exhibited at each change. Article VI. On some Points relating to Vision. ALTHOurtH the physblogy of vision has met with considerable attention from philosophers, it is yet in many respects but imper- fectly understood ; andwhilst it may be pretty satisfactorily ex"- plained upon general principles, the use of the individual parts composing the delicatf organ by which it is accomplished is still involved in much obscarity. For illustrating some points connected with the healthy ani abnormal state of some of these, more especially of the iris, the following experiments and observations are submitted to the nspection of your scientific readers. A portion of the rewly prepared extract of belladonna, for the sake of experiment, .vas inserted between, and applied to, the eye- lids ; in consequencr, in the space of about 20 minutes, the pupil was so much dilated, that the iris was almost totally invisible. From the time that the pipil attained to three times its natural dimen- 1817-] On some Points relating to Vision. 433 slons, objects presented to this eye with the other closed were seen as through a cloud ; and as it proceeded to the point of extreme dilatation, this effect gradually increased, so that minute and near objects, as letter-press, &c. could not be at all distinguished. By means of a double convex lens, the focus of this eye was found to be at twice the distance of that of the sound eye : the iris, how- ever, dilated * upon the- sudden admission of light ; and although the pupil approached by almost imperceptible degrees for six daj's to its natural size, yet at the end of that time it was dilated to twice the extent of the other; and, in proportion as the contraction took place, the sight became more distinct, and the focus nearer the natural. In the open air all objects except those near were dis- tinctly seen, but immediately on entering a room all was again enveloped in mist. From the preceding experiment it appears that the iris certainly holds a very important part in the physiology of vision. It will be seen that as soon as it had contracted to a certain extent, indistinct sight was produced, of the same nature as happens in the eyes of presbyopic or aged people ; and the same sort of glass was required by the affected eye as is necessary in advanced life. The cause of this can scarcely be looked for in a diminished convexity of the cornea, from a decrease of the humors, as the effect took place so soon after the cause was applied, as not to allow time for that occurrence. It seems to me much more satisfactorily explained by the increased size of the pupil permitting too great a quantity of the rays of light to be thrown upon the crystalline lens, and these when again refracted by the last-mentioned body, not being thrown so as to impress the image of the object accurately upon the retina, but at some distance behind it, as may be more readily understood by the annexed figures (Plate LXXIV.); where Fig. 1 represents the vision in its natural state, the inverted image being exactly im- pressed upon the retina ; and Fig. 2, that with the dilated pupil, where it will be seen that the rays of light are thrown so near the extremities of the crystalline lens that, when refracted, they do not converge sufficiently to impinge the object correctly upon the retina, but at a considerable distance behind it. This principle of refraction in the crystalline lens may be familiarly illustrated by that of a common convex lens, where, if the rays of light from any object are allowed to occupy the whole circumference of the glass, the object is seen indistinctly through it. It would appear, therefore, that one great use of the iris is for allowing only a certain proportion of the rays of liglit to be tlirown upon the lens, and that, when the pupil is preternaturally dilated, indistinct vision, analogous to what takes place in a diminished convexity of the cornea, is the conse- quence, from too great a divergence of the rays proceeding from • It may b<* proper to remark, in order to prevent misconception, that I have ased the term dilatation of the iris to iiguify that itate ie which the pupil U cub- traded, and vice versa. Vol. X. N° Vh 2 E 434 Regisler of the Weather in Flymouth. [Dec. any object : and thus the dilated pupils of myopes, or short-.slghted people, would appear to consist in an efl'ort of nature to remove thedeiect; for if, along with the greater degree of convexity in these cases, the pupil retnained of the same dimensions, too few of the rays of light would fall upon the retina ; but when the pupil is dilated, it admits a greater quantity, and in all probability pre- vents the increased degree of short-sightedness which otherwise might have occurred. One curious anomaly with respect to the iris remains to be noticed, viz. that it should be so long in dilating, after it had been once contracted, a space in this instance of more than 10 days, although the sensibility was not taken away by the narcotic, as was evident from its dilating perceptibly on exposure to liglit. London, Nov. 4, 1817. RoBLKY DcNGLISON. Article VII. Register of the Weather in Pbjmouth for the last Six Months of 1816. By James Fox, jun. Esq. (With a Plate, LXXV.) JULY. Dale. 1816. July 1 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Wiud. WNW WNW W w NW SE to NW S ESE S sw NW NW WSW SW SW NW Rain. 035 015 0-65 023 125 0 16 0-28 0'68 0-51 Observations. Hail showers during the clay ; fair at night. Siiowers early morn ; cloudy and fair afternoon Sliowers, morn ; cloudy afternoon. Showers, uiorn ; cloudy and fair after- noon. Cloudy and fair. Cloudy morn ; heavy rain, afternoon. Cloudy aud fair morn ; showers, after-. noon. A gale of wind, and heavy rain. High wind and heavy rain, morn; cloudy and fair, afternoon. Cloudy and fair morn ; thunder and lishtninj;, afternoon. Cloudy morn; misty afternoon. Misty morn ; high wind ; cloudy and fair afternoon. Cloudy and fair. Thick weather. Cloudy and fair day ; cloudy at night. Heavy rain, morn ; cloudy and fair afternoon. Heavy rain. 1817 •] Register of the Weather in Ply fnoiifli. 4^5 Date. Wind. Rain. Observations. ISI6. July 18 WSW 0-24 Heavy showers. 19 S 1-35 A truly wet day; high wind, and thick weather. 20 S to E 0-04 Misty morn ; cloudy and fair afternoon. 21 SE to SW 0-47 Heavy showers. 22 SW to S 0-33 Cloudy morn ; rain and high wind, after- noon. 23 WNW to S 005 Light showers, morn ; cloudy and fair afternoon ; cloudy at night. 24 Var. 018 Cloudy and fair morn ; shower?, after- noon. 25 WNW Cloudy and fair. 26 Var. Cloudy morn ; ditto and fair day ; cloudy at night. 27 NW Cloudy and fair; cloudy at night. 28 NW Cloudy and fair. 29 NW 0'26 Cloudy morn ; thunder and showers, afternoon ; distant lightning at night. 30 Var. Cloudy and fair. 31 Var. 0-26 Ditto morn ; rain, afiernoon. 7"44 inclies. Barometer: Highest 29'94 inches Lowest 29-20 Mean 29574 Thermometer: Highest 70'^ Lowest. 44 Mean 55-822 Wind. Var. S W^SW Var. AUGUST. A iigust 1 NW Cloudy and fair. 2 Var. 0'32 Ditto morn ; heavy rain, afternoon. 3 Ditto. Fog, morn ; cloudy and fair day. 4 Ditto. 006 Ditto, ditto; shower, afternoon ; cloudy and fair eve. 5 WNW Fair. 6 S 0-41 High wind, and heavy rain. 7 S 066 Ditto, ditto. 8 WNW 0'07 Misty morn ; cloudy and fair day. 9 WNW 0-04 Showers early, morn; ditto, ditto, day. 10 WNW to SSW Cloudy and fair morn ; cloudy, and high wind, afternoon. 11 SSW to W 0-13 High wind; thick weather; small rain. 12 W to W N W 0-09 Small rain, early; cloudy day; fair at intervals. 13 W to S Cloudy and fair morn; fair afternoon ; cloudy at night. 14 ESE to S 0-15 High wind, and showers. 15 SW (0 WNW 0-3S Heavv showers. 16 NW 012 High wind, and showers. 17 W 017 Ditto, ditto. 18 WNW Ditto j cloudy and fair. 2 £ 2 436 Register of tlie Weather in Plymouth. [Dze. Date. ■Wind. Rain. Observations. ,,,, ■ 1816. August 19 Var. Cloudy and fair. 20 NW Ditto, ditto; a slight shower. 21 S to WNW Cloudy and fair. 22 NW Ditto; cloudy at night. 23 NW to S Ditto, ditlo. 24 Sto W Cloudy and fair. 25 Var. Fair day ; cloudy at night. 26 NW to E Fair. 27 ENE Cloudy and fair ; cloudy at night. S8 ENE Cloudy morn ; fair day. 29 NW Fair morn ; cloudy and fair afternoon ; cloudy at night. 30 NW to SSW Cloudy and fair morn ; cloudy afternoon. SI NW 0-44 High wind, and heavy showers ; a bois- terous day. 307 inc hes. Barometer: Highest 30-22 inches Lowest. 29' 18 Mean 29923 Thermometer: Highest 71° Lowest 42 Mean 58451 Wind. Var. Ditto Ditto NW SEPTEMBER. Sept. I NW 0-08 High wind ; cloudy and fair morn ; showers, afternoon ; a truly cold day. 2 NW 0-05 Showers, morn ; cloudy and fair day. 3 4 NW NW i 0-31 Cloudy and fair; showers, afternoon. Showers early, morn ; high wind ; cloudy and fair day. 5 NW Cloudy and fair day ; fair at night. 6 Var. ) < 0-07 Fog, morn ; misty day. 7 Ditto. Ditto, ditto ; cUudv day ; misty at night. 8 SW to NW Cloudy and fair; cloudy at night. 9 SW to SSW 0-76 Thick weather ; heavy rain ; a gale at night. 10 wsw i 018 Cloudy and fair, with showers. 11 wsw Ditto, ditto. 12 SW Ditto. 13 S to E Fair morn; cloudy and fair afternoon. 14 s 0 45 Heavy showers early, morn : thick wea- ther during the day. 15 S to 9SE A misty day. 16 NE Ditto. 17 ENE Fair morn ; cloudy and fair afternoon. 18 W to S Fog, morn ; fair afternoon ; cloudy at night. 19 £ Cloudy morn ; ditto and fair afternoon j fair at night. 20 E High wind ; cloudy. 1817.] Register of ike Weather in Plymmth. 4S7 Date. 1816. Sept. 21 22 23 24 25 26 27 28 29 30 Wind. Rain. S to NW ENE ENE Var. Ditto. SW to NW NW W SSW to WNW W 0-30 }o 18 0-10 Observations. Heavy showers, morn ; cloudy aud fair afternoon ; cloudy at night. Cloudy and fair morn ; fair day. Fair. Ditto and clondy. Ditto, ditto. Ditto, ditto ; cloudy afternoon. Thick weather, morn ; cloudy aud fair afternoon. Showers, morn ; cloudy day. A gale, and showers ; cloudy and fair at night. High wind, and showers. 2*48 inches. Barometer Thermometer Highest 30-22 inches Lowest 29"43 Mean 29-816 Highest ]1° Lowest Ti.,R Mean 56-416 Wind. Var. NW Var, NW OCTOBER. Oct. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 13 16 17 18 19 20 21 22 23 SW to WNW SSW to WNW NW to S SSW SSW to SE SE to E E ESE E E to WXW NW to NNW ENE to ESE E to SSF, NW to SW SSE SSE to S NW NW NW to W NW NW 0-54 0-12 0-20 0-64 0-28 0-24 } 0-20 Oil ENE to S }„. 08 High wind, and heavy showers, morq ; thick weather, afternoon. A gale, and showers, morn; cloudy day. Cloudy morn ; misty day. Misty, small rain. Heavy rain. Cloudy morn ; showers during the day. Showers. Cloudy day ; high wind at night. High wind, and showers. Cloudy and fair morn ; cloudy afternoon. Cloudy and fair. Fair day ; cloudy at night. Misty morn ; cloudy day. Fog, morn ; cloudy aad fair day. Fair day ; cloudy and fair at night. Cloudy day ; showers at night. Fair morn ; showers, afternoon. Showers early, morn; fair day. Cloudy and fair morn ; misty afternoon ; cloudy eve. Cloudy morn ; cloudy and fair afternoon ; showers, eve. High wind, morn; cloudy and fair day ; a calm at night. Cloudy and fair morn; showers after- noon. Fair morn; showers, afternoon; high wind at night. 488 Register of the Weather in Thjmoulh. [Dec. Date. 26 27 28 89 30 SI Wind. W WNW S to E E ENE to SSW E E to S SSE Rain. } 99 62 ■25 •07 }0 0 i-29 62 Observations. High wir.d, and heavy rain. A jrale early, mom; iieavy showers of hail and rain during the day. High nind, with ditto. Ditto, with ditto of rain. Occasional rain; a heavy gale at mid- night from SSW for half an hour only, ■which drove two vessels on shore in the harbour, ivhen it abated, and veered round to the E. Showers. Ditto. Heavy ditto. 5-25 inches. Barometer: Highest 30-15 inches Lowest 290a Mean 29770 Thermometer: Highest 67° Lowest 35 Mean 52-935 Wina. SSE E to S Var. Ditto NOVEMBER. Nov. 1 NW 0-C7 Cloudy and fair morn ; showers, after- noon ; cloudy at night. 2 Eto W 0-79 Heavy rain. 3 Var. Fair morn: cloudy and fair afternoon. 4 NE Cloudy and fair morn; fair afternoon. 5 Var. Fair morn ; cloudy and fair afteruoon. 6 NW 0-20 Showers. 7 NW Cloudy and fair ; some sleet at noon. 8 ENE ? 0-39 Ditto, ditto, day; high wind, and heavy showers, at night. 9 SW to W 5 A gale early, morn ; high wind, and snow showers, during the day. 10 NW I 0-65 Ditto, ditto, ditto. 11 E to W Snow showers (lay on the ground from six to eleven, a. m.) ; heavy rain, after- noon and night. 12 NW A violent storm. 13 WNW High wind, and thick weather. 14 WNW \ 0-33 Ditto ; showers. 15 NW Ditto; ditto of rain, hail, and sleet. 16 NW A verv while frost; fair day. 17 WNW to SSW I 0-30 Ditto ; misty at nisht. 18 WNW Showers early, morn; cloudy .ind fair day. Cloudy day ; showers, and high wind, at 19 WNW to 8 ^ L 017 ni!;ht. 20 S to SSE ^ CI. udy morn; high wind, and showers, afternoon. . ISl/.U Register of the Weather in Plymouth. 439 Date. Wind. Rail). Observations. 1816. Kov. 21 ESE Ili^h wind ; cloudy and fair. 22 E Ditto, ditto. 23 E Ditto; fair. 24 E Hoar frost ; fair morn ; cloudy and fair aftprnoon. 25 Sto W 1 0-51 Cloudy morn ; misty afternoon. 26 ISVV Verj' heavy showers early, morn ; cloudy and fair day. 27 F.NE to W Cloudy and fair day ; cloudy at night. 28 WiWV toNE Cloudy day ; fo^ at night. 29 ENE Fo;, morn ; fair day. 30 ENE Fair day ; cloudy, and a halo, at night. 3-41 incites. Barometer: Highest 30'67 inches Lowest 2S'91 Wean 29778 Thermometer: Highest 54° Lowest 26 Mean 41-666 Wind. ENE SW Var. KW DECEMBER. Dec. 1 2 3 4 5 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 NE NW ENE SE SE to WNW WNVV WNW to WS NW SE to NW Var. W ENE, WSW W W toS w Var, W WNW to ENE WNW to E E to N NNW to ENE ENE to WNW W to WNW 0-40 0-28 0'20 0-64 0-28 0-26 0-48 0-24 0-95 012 0-45 0-04 010 Cloudy morn ; cloudy and fairafternoon; fair at night. Ditto, ditto; ditto, ditto; fog at night. Cloudy. Ditto. A gale, and cloudy morn ; heavy rain, afternoon. Cloudy and fair morn ; heavy rain, and high wind, afternoon. Heavy showers of rain and hail. Cloudy and fair. High wind, and heavy rain. Ditto; ditto showers. Ditto; ditto hail ditto. Heavy rain, and a violent storm. Heavy showers of hail and rain; high wind. Showers, morn; a storm, and heavy rain, afternoon and night. High wind, and hail showers. Cloudy and fair; a light shower. Heavy rain, morn ; cloudy and fair after- noon. Showers, morn ; fair afternoon ; cloudy eve. Fair. Ditto. Ditto ; high wind. Ditto morn ; cloudy afternoon and eve. Ditto, ditto; misty afternoon and eve. 440 Biographical Sketch of Ventenal. [JDec Date. ^ ><' viw^.sxL Rain. Observations. 1816. Dec. 24 WNW to W 012 Hi^h wind ; floudv, and light rain.>llX3 25 SW to S 005 Fair morn ; lijrbt showers, afternoon. 26 S to SSW 0-45 A gale, w ith showers of hail and rain. 27 NW Oil Hail showers. 28 SW to WNW 0-39 Heavy showers, and a gale of wind. i'i. W 0'28 Cloudy and fair morn; heavy rain, after« noon and eve. 30 s 1-40 Heavy rain ; high wind. 31 SW to NW 0-38 Cloudy morn; heavy showers, afternoon and evening. 7-62 inches. •';)fiJO 3 Wind. Barometer: Hisrhest.. 30-64 inches NE Thermo Lowest. . 28-80 WSW, a Mean. . , 29-751 great storm meter : Hishest 710 Var. Lowest. 25 NW Mean . . 39-96T Article VIII. Biographical Sketch of Fentenat. VfiNTENATwas bom at Limoges on March 1, 1757. His parents destined him for the ecclesiastical state, and placed him, at the age of J 5 years, in the congregation ot the canons of St. Genevieve, where he pursued his studies with so much ardour, and at the same time possessed so many advantages of voice and person, that his superiors predicted that he would have risen to distinguished emi- nence in the clerical profession. But he soon found the situation in which he was placed little adapted to his scientific and inquiring turn of mind ; and, renouncing the advantages of interest which it held put to him, he resolved to devote his life to study, and parti- cularly attached himself to that of botany. In the year 1/88 he came to London, for the purpose of pro- curing books; and on his return was wrecked on the coast of France, and escaped from the most imminent danger. He was the only one of the crew that was saved; and he owed his life to his dexterity as a swimmer, and to his presence of mind, which never forsook him in the utmost extremity. It seems that his health never entirely recovered from the violent exertion whicli he was obliged to use on the occasion. He continued, however, diligently to pro- secute his favourite study, and indeed seems to have devoted his time and attention almost exclusively to it. His first botanical essay 1^170 Biographical Sketch of Venlenai.' XhX was published in 17^2, in the first volume of the Magasin Ency- clopedicjue, in which he ventured to combat the theory of Hedwig on the fecundation of mosses. His first work of any considerable size was published in I797j under the title of Principles of Botany, extracted from a course of lectures which he delivered at the Lyceum. This work he afterwards considered so imperfect, that he took great pains to have it suppressed ; but, notwithstanding all his exertions, it was translated into German, " a language into which they translate every thing." Two years afterwards he remodelled the work, and published it in an improved form, under the title of View of the Vegetable Kingdom. It is professedly founded upon the Genera Plantarum of Jussieu; but by retrenchments in some parts, and additions in others, it assumed altogether a more popular cast, and was better adapted for general use. It was, however, more by works on descrip- tive botany that the great reputation of Ventenat was raised, and on which it must ultimately rest. In his splendid publications of the figures ofplants are united all the elegances of the arts of paintingand engraving, accompanied by exact descriptions and learned observa- tions. In productions of this kind he decidedly surpassed all his predecessors, and has scarcely been equalled by any of his contem- poraries. The first of Ventenat's magnificent works was his account of the plants in the garden of Cels. The reputation which it ac- quired obtained for the author the patronage of the Empress Josephine, who engaged him, in connexion with Redoute, to describe and figure the rare plants in the gardens of Malmaison. The result of their united labours produced a work still more superb than the former. Ventenat's health, however, which had never recovered the shock of the shipwreck, now began seriously to de- cline ; and various incidental circumstances, probably aggravated by an excessive ardour in all his pursuits, and a degree of natural irritability of temper, acted unfavourably upon his constitution, and produced a disease of the spleen, of which he died the 13th of August, 1808. Ventenat must be considered as holding a distinguished place among the botanists of his age ; and in the figuring and describing of plants will perhaps never be excelled. His merit, however, was rather that of a very able artist, and an accurate observer, than of a profound scientific botanist ; and it is probable that his reputation with posterity will scarcely maintain the rank which it bore among his contemporaries. Oiiii :.•«■ ^'i2 Account of the Ballston Waters, [Dec. Article IX. Account of the Ballston IVaters. The waters of Ballston have been long famous in America for their powerful medicinal effects; and we have been favoured ,by a correspondent witii some account of them, from which we extract the following particulars : — At the request of Mr. Livingston, a quantity of the water was sent him, during his residence in France, which he gave for exa- mination to "one of the most celebrated chemists " of that country, whose name, however, is not mentioned. The following is the result of the examination : — " L' Analyse de I'Eau que M. L. ma donne a analiser, contenant par Boulcille de 25 Onces. SAVOIR. 1. Acide carbonique (air fixe) 3 fois son volume 2. Muriate de sonde (sel marin) 31 grains 3. Carbonate de chaux sursature 22 grains 'J. Muriate de magnesie (sel inarin a base de magnesie) 12-1- grains 5. Muriate do chaux (sel marin a base de chaux) 5 grains 6. Carbonate de fer 4 grains *' Aucune eau minerale de notre continent n'est aussi riche en substances salines de ce genre j celle de Vichy, qui a une grande reputation, ne contient par bouteille qu'un dixieme de grain de carbonate de fer, tandis que celle dort nous donnons Tanaiyse en con- tient 4 grains. C'est au fer que ces especes d'eaux acidulees doivent leur qualites toniques et de>obstruantes, " A la dose de deux bouteilles I'eau d'Amerique doit etre un leger purgatif qui convient dans tous les cas, ou il est necessaire d'evacuer la bile, et donner du ton au systeme vasculaire; cette eau veritablement precieuse pour une infinite des maladies, semble avoir ete formee par la nature, dans les meilleures proportions, pour guerir les pales coulcurs, et les suppressions. On ne doute point que cette eau ne devienne un objet important de commerce.'* With respect to the constituents of the water, we may conceive that the above account of them refers to the substances which were obtained by analysis, and not to the state in which they actually exist in the water. Its chief peculiarity consists in the large quantity of iron which it contains, according to this analysis, the carbonate composing -^^ part of the whole of the solid contents. Jf we estimate the composition of this saltj in round numbers, at 6 1817.] Analyses of Booh. 4^3 about two parts of acid to three of the protoxide, -j?^ of the resi- duum will consist of the protoxide of iron, and the residuum being about 93 grains in a wine pint, this quantity of the water contains about three grains of the protoxide. The medical virtues attributed to these waters are those of a powerful tonic and deobstruent, and may be supposed to depend principally upon the great quantity of iron which they contain, and in some degree also on the neutral and earthy salts. The quantity of the muriate of lime in these waters is so considerable as to in- duce us to attribute some important etfects to this ingredient, inde- pendent of the general purgative quality which will result from the combined operation of the whole. Article X. Analyses ov Books. I. An Essay on the Chemical History and Medical Treatment of . Calculous Disorders. By Alex. Marcet, iM.D. F.R.S. &c. &c. Thk formation and deposition of various kinds of calculi, in difterent parts of the living body, constitute a series of actions that form an immediate connexion between the sciences of chemistry and medicine. An analysis of this work will, therefore, properly belong to the Annals of' Philosophy ; and it will be the more necessary to give an account of it, as the author has not merely afforded us a very correct and perspicuous view of what had been previously done by others in this department, but has also furnished us with some new facts, and described some new substances, which had not been before noticed. After detailing an account of the symptoms which characterize the presence of calculi in the different organs where they are usually found, and some curious facts respecting the comparative prevalence of calculous complaints in various districts, we come to the chemical part of this work, in which the author gives a descrip- tion of the difierent species of urinary calculi, of their external characters, and chemical nature, and afterwards forms a classifica- tion of tliem. Many writers on this subject had arranged calculi according to the parts of the body in which they were deposited ; but there seems to be no proper ground for forming any division of them from this circumstance. In whatever organ they are deposited, they probably all originate from the same cause, and it seems in a great measure accidental whether they are lodged in one part or another. The only correct principle of classification is their che- mical composition ; and this is the only mode which can be of any utility, either as affording us any chance of arriving at a correct theory of tiieir formation, or any probable means of removing tliem ^44 .tt^litoiiCl ■ Analyses of Books.''^^-i^^'^ o*^ [ttetl by the aid of medicine. The external characters of calculi affe' described in detail : tlieir form, size, colour, the nature of their surfaces, their specific gravity, odour, internal structure, the nucleus upon which the bulk of the calculus is often deposited, and the ahernation of layers which tliey generally exhibit. We have next a sketch of the discoveries that have been successively made on these bodies, from the first rude attempts of V^anhelmont to ascertain their nature, to the more correct experiments of Scheele, Fourcroy, and Wollaston. The author has shown a proper anxiety to render to each chemist his due degree of merit ; and has in a spirited, but certainly very correct manner, vindicated the fame of his friend Dr. Wollaston against the encroachments of Fourcroy, who most unaccountably published as his ovvn discovery a nuRjber of important facts respecting urinary calculi which had heen most explicitly announced two years before in the Philosophical Transactions by the English chemist. The substances which have been hitherto discovered in urinary calculi arc five: lithicor uric acid, phosphate of lime, ammoniaco- magnesian phosphate, oxalate of lime, and cystic oxide. These substances are, however, many of tliem at least, seldom found in a separate or pure state, but they afford certain combinations suffi- ciently constant to enable us to form our arrangement. Proceed- ing upon these principles, Dr. Marcet forms them into nine classes, under the following titles and designations : — 1. The liihic cal- culus. 2. The bone-earik calculus, principally consisting of phos- phate of lime. 3. The aiumoniuco-magnesian phosphate, or calculus in which this triple salt obviously prevails. 4. The fusible calculus, consisting of a mixture of the two former. 5. The mulberry cal- culus, or oxalate of lime. 6. The cystic calculus, consisting of the substance called by Dr. Wollaston cystic oxide. 7« The ulter- nalin^ calculus, or concretion composed of two or more different species, arranged in alternate layers. 8. The compound calculus, the ingredients of which are so intimately mixed as not to be separable without chemical analysis. 9. Calculus from the prostate gland. Each of these species is then accurately described : we have an account of their discovery, of the circumstances under which they are most frequently generated, and of the action of chemical re- agents upon them, in the review of these substances wliich is thus presented to us we cannot but be forcibly struck with the great obligations under which we lie to Dr. Wollaston. To him we are: indebted for our knowledge of the existence of phosphate of lime,'* as constituting a distinct species of calculus; and the same remark" applies to the triple calculus. With respect to the fusible calculus, although the late Mr. Tennant first discovered that it differed from the lithic acid of Scheele, yet it is to Dr. Wollaston that we are to ascribe our correct knowledge of its nature; and the same remark applies to the mulberry calculus and the cystic oxide. Except, therefore, the original discovery of Scheele, respecting the lithic 18170 ^^' MarceCs Essay on Calculous Disorders. 445 acid, we owe to our learned countryman the correct knowledge of all the primary compounds of the calculi that are as yet distinctly known. Dr. Marcet may seem to have deviated from his plan in forming the ninth species, the calculus of the prostate gland, from its situa- tion; but we learn that the calculi which are found in this organ possess a peculiar composition, or rather always exhibit the same chemical properties. For this fact we are again indebted to Dr. VVoUaston, who found " that they all consist of phosphate of lime, not distinctly stratified, and tinged by the secretion of the prostate gland." Like the cystic calculi, which consist of phosphate of lime, the earthy salt is in its neutral state, without the redundance of lime which exists in the earth of bones. .n niw. I fjjThe author has hitherto been principally occupied in conveying to us, under a correct and commodious form, the information that had been previously afforded by others ; but in the next chapter we enter upon new ground. We have "an account of two calculi, which cannot be referred to any of the species hitherto described." The first of these seems to have the most analogy or resemblance to the, cystic oxide, but it possesses sufficient marks of distinction : for we are informed that the new substance forms a bright lemon resi- duum on evaporating its nitric solution, and is formed of lamina?, whereas the cystic oxide is not laminated, and leaves a white residue from the nitric solution. Although they are each of them soluble both in acids and alkalies, yet the proportion of effect is different in the two cases, the oxide being rather more soluble in alkalies, and considerably more so in acids, than the new substance. Upon the whole, there seems no doubt of its being really a calculus of a new and peculiar nature. On this account Dr. Marcet has conceived it necessary to give it an appropriate name, and he has chosen the property which it possesses of forming the yellow residuum from the nitiic solution as one of its most specific and distinguishing proper-^ ties, and has accordingly denominated it xanthic oxide. The other new calculus was found to possess properties exactly similar to those of the fibrine of the blood, was no doubt formed by a deposit from this fluid, and accordingly has received the appellation oi' Jibrinous calculus. The sixth chapter is on the analysis of urinary calculi, in which the object of the author is not so much to propose any new methods of examining these bodies, or to detail any discoveries which he has made upon the subject, as to point out to medical practitioners a few simple tests and easy processes by whicb they may ascertain the prevailing nature of the concretion, so far as concerns the kind of remedies to be employed. Tests are therefore given for each of the species above enumerated, and directions given for their applica- tion, which seem to be well adapted to the proposed object. We have a number of interesting facts in the seventh chapter, on some other kinds of animal concretions, which do not belong to the urinary passages. These have been occasionally found in most of I 446 Analyses of Books. [Dec. the viscera, the salivary glands, the pancreas, the spleen, the lungs, and other parts ; but those of the most frequent occurrence, and most importance in medical practice, are concretions in the intestinal canal. Of these many varieties are described, obviously consisting, in a great measure, of substances taken into the sto- mach, and detained, or accidentally mixed with other matters, and moulded into the round form by the action of the bowels. One of the most remarkable of the intestinal calculi is a species, which appears not to be uncommon in Scotland, consisting of con- centric layers of a brown velvety substance and a white earthy matter. The white matter appeared to be composed of a mixture of the two phosphates, but the brown substance was more puzzling: its nature, however, was discovered by fhe sagacity of Dr. Wol- laston, wlio found it to be formed of minute vegetable fibres, de- rived from a kind of beard, which exists at one extremity of the seed of the oat. It would be scarcely consistent with the nature and object of the Annals to follow Dr. Marcet through his remarks on the medical treatment of calculous disorders. Enough has been said to point out the nature of the work, and the manner in which it has been executed : it may be characterized as exhibiting a correct and elegant view of the present state of our knowledge on the subject of calculi, and likewise as affording some valuable additions to it. It is accompanied by some very excellent places, representing the diffe- rent species of concretions, and the apparatus employed in their analysis. II. FhilosoplilcahTransacthns of the Royal Society of London, for the Year 181 7, Part I. This Half- Volume contains the following Papers. 1. An Account of the Circulation of the Blood in the Class Vermes of Linnaeus, and the Principle explained in which it differs from that in the higher Classes. By Sir Everard Home, Bart. V. P. R. S. 2. Observations on the Hirudo Vulgaris. By James Rawlins Johnson, M.D. F.L. S., &c. 3. On the Effects of Galvanism in restoring the due Action of the Lungs. By A. P. Wilson Philip, Physician in Worcester. 4. An Account of some Experiments on the Torpedo Electricus, at La Rochelle. By John T. Todd, Esq. 5. A Description of a Process, by which Corn tainted with Must may be completely purified. By Charles Hatchett, Esq. F.11.S. G. Observations on an Astringent Vegetable Substance from China. By William Thomas Brande, Esq. Sec. R. S. 7. Some Researches on Flame. By Sir Humphrey Davy, LL. D. F. R. S. V. P. R. I. 8. Some new Experiments and Observations on the Combustion J817.] Philosophical Trmsaclions for IS\7, Part I. Wj of gaseous Mixtures, witli an Account of a Method of pre- serving a continued Light in a Mixture of inflammable Gases and Air without Fiame. By Sir Humphrey Davy, LL. D. F.R.S. V. P. R. I. 9. De la Structure des Vaisseaux Anglais, consideree dans ses dernievs Perfectionnements. Par Charles Dupin, Correspondant de rinstitut de France, &c. 10. On a new fulminating Platinum. By Edmond Davy, Esq. Professor of Chemistry, and Secretary to the Corlv Institution. 11. On the Parallax of the fixed Stars. By John Pond, Esq. Astronomer Roval, F. R. S. Appendix to Mr. Pond's Paper on Parallax. 12. An Account of some Fossil Remains of the Rhinoceros, discovered by Mr. Whitby, in a cavern inclosed in the lime-stone Rock, from which he is forming the Break-water at Plymouth, By Sir Everard Home, Bart. V. P. R. S. Some account of the contents of these Papers has already been given, in the History of the Proceedings of the Royal Society ; * the papers of Sir H. Davy, however, are so interesting, and con- tain so much curious and important matter, that it will be proper to give a more complete analysis of them. In his former researches, the results of which have been laid before the public, the author has shown that the explosion of gaseous mixtures, however inflammable, may be prevented, by any circumstance which tends to reduce their temperature ; and it was from this consideration that he was led to his beautiful discovery of the wire gauze lamp, as a safe method of illuminating coal-mines. In a subsequent train of experiments he established the position that the intensity of the light of flame chiefly arises from the igni- tion of particles of solid matter, which are thrown ofl^ from the burning body, and from this he infers that the light and heat gene- rated in this process are, to a certain degree, independent phe- nomena. In detailing the account of his recent labours on the subject of flame, the author proposes to arrange his observations under four heads. In the first section he considers " The Efl^ect of Rarefac- tion by partly removing the Pressure of the Atmosphere upon Flame and Explosion." This point has lately been examined by M. de Grotthus ; but it is unnecessary to dwell upon his conclusions, because the experiments of Sir H. Davy have conducted him to very different results. It was found that a small jet of hydrogen, proceeding from a fine glass tube, and forming a fiame of about \ of an inch in height, wiicn introduced into a receiver, contain- ing from 200 to 300 cubic inches of air, had tiie flame enlarged as the receiver was gradually exhausted, until the pressure was between four and five times less than that of the atmospiiere ; and that when it became between seven and eight times less, it was ♦ AmaUt yiii, 458 j ix. 149, 229, 323. 448 Analyses vf Books. [Dec* extinguished. When a larger jet was used, the flame continued until the atmosphere was rarefied ten times, and it was observed that, in this case, the point of the tube was raised to a white heat. It therefore occurred to the author that the continuance of the combustion, under a great degree of exhaustion, in the latter ex- periment, depended upon the higher temperature to which the gas was subjected on issuing from the orifice of the tube; and this con- jecture was confirmed by observing the effect that was produced by coiling a platinum wire round it, for with this addition, the small jet continued to burn until the pressure was reduced 13 times. Hence it follows, that hydrogen is extinguished in a rarefied atmo- sphere, not froit) the deficiency of oxygen, or at least not directly from this cause, but in consequence of the heat produced not being sufficient to support the combustion. The necessary degree of heat seems to be that which communicates visible ignition to metal ; and this is also the temperature which hydrogen requires for its combustion at the ordinary pressure of the atmosphere. From this fact respecting hydrogen. Sir H. Davy was induced to form tiie general conclusion, that combustible bodies which re- quire the least heat for their combustion, as well as those which generate the most heat during this process, should be capable of burning in the most rarefied air; and he found this conclusion to be justified by every experiment which he performed for the pur- pose of putting it to the test. The experiment was tried upon defiant gas, which, with the small jet and the platinum wire, burned until the pressure was diminished between 10 and 11 times, the flame of alcohol and a wax taper only until the pressure was diminished seven or eight times ; light carburetted hydrogen, when the pressure was reduced to -^ ; carbonic oxide when it was ^; and sulphuretted hydrogen when it was -i-. Sulphur, on the contrary, requiring a lower temperature for its combustion, bore a diminu- tion of pressure equal to i^. Van Marura has shown that phos- phorus will burn in an atmosphere rarefied 60 times, and phos- phuretted hydrogen produces a (flash of light in the most perfect vacuum of an air pump. On the same principle it was found that oxygen and chlorine, which explode at a lower temperature than oxygen and hydrogen, and evolve more heat, would bear a greater degree of rarefaction ; the latter will not explode by the electric spark when rarefied 18 times, whereas the former combine when the exhaustion is ~. Various experiments are then detailed, which prove that by sufficiently heating substances, they may be caused to burn in air rarefied to a degree which would not other- wise support their combustion, and this appeared to be the case in whatever way tiie heat was communicated. The author next performed a series of experiments, the object of which was to determine the quantity of heat generated by the combustion of the different inflammable gases. For this purpose similar quantities of the gases in question were burned in an appa- ratus so contrived, that the heat was applied to the bottom of a 1817 J Philosophical Transactions for I8I7, Part I. 449 small cup filled with olive oil, and the increase of temperature in the oil, during a given time, was carefully noted. Calculating from the elevations of temperature actually produced, and the quantities of oxygen consumed, the heat produced by the com- bustion of the gases was found to coincide with the conclusions deduced from the former set of experiments. Hydrogen was found to be the gas which produced most heat, and the gaseous oxide of carbon the least, in the proportion of about 26 to 6. The second section is " On the Effects of Rarefaction by Heat on Combustion and Explosion." M. de Grotthus, in the experi- ments which have been already alluded to, states that rarefaction by heat destroys the combustibility of gaseous mixtures, a state- ment which is indirectly opposed by the facts and experiments that have already been brought forward, but which Sir H. Davy made also the direct subject of experiment. He found that he was not able to produce a greater degree of expansion by heat in a glass vessel than 2"5, whereas M. de Grotthus speaks of a mixture of air and hydrogen being expanded to four times its original bulk. But it is inferred that this extraordinary degree of expansion depended upon a portion of steam being mixed with the gases, and to this, rather than to the expansion of the air, it is that we ought to attribute its not exploding, as was the case in this experiment. Sir H. Davy, however, found that the rarefaction of a gaseous mixture rendered it explosive at a lower temperature, a result which might naturally be expected as less of the communicated heat would be expended in rais- ing the temperature of the substance. In the course of his experi- ments he found that mixtures of oxygen and hydrogen confined in tubes, and exposed to a heat between that of the boiling point of mer- cury, and what makes glass luminous in the dark, combined silently and without emitting any light. By a proper management of the temperature it seems probable that all substances, which are capable of combustion, may be made to combine in this gradual manner. T'he author takes occasion to controvert an opinion, which has been supported by Dr. Higgins, M. Berthollet, and others, that the electric spark causes the explosion of gaseous bodies, in conse- quence of the sudden expansion of that part to which the electri- city is immediately applied. He found by a direct experiment, that an increased temperature, and not compression, produced the explosion of these mixtures ; and from this he draws the general conclusion, that " the heat given out by the compression of gases is the real cause of the combustion which it produces, and that at certain elevations of temperature, whether in rarefied or com- pressed atmospheres, explosion or combustion occurs ; i. e. bodies con>I)ine with the production of heat and light." The third head is " On the Effects of the Mixture of different Gases in Explosion and Coml)ustion." In order to ascertain these effects he procured a mixture of two parts hydrogen and one part oxygen by measure, and diluting them with various proportions of Vol.. X. N° VI. 2 F i50 Analyses of Books, [Dec. different gases, he tried their inflammability by the electric spark. The general result is, that very different quantities of the gases employed prevented the inflammation of the mixture ; it required 1 1 parts of nitrous oxide, and only i of defiant gas ; and in ge- neral the author observes, they show that other causes, besides den- sity and capacity for heat, are concerned in the operation. An observation of Mr. Leslie's is alluded to, in which he found that hydrogen has a much greater power in abstracting heat from solids than air or oxygen have ; Sir H. Davy verified this by his own expe- riments, and extended his researches to various other gases, and he concludes from them that elastic fluids abstract heat from solids ** in some inverse ratio to their density ; " that gases have different powers of conducting heat, which seem to be specific or peculiar to themselves ; and it is inferred that those which are the best con- ductors of heat act the most powerfully in preventing explosion, by carrying off the heat, and thus diminishing the temperature below the necessary degree. This abstraction of heat in gaseous mixtures cannot depend, as it does with respect to solids, merely upon the mobility of the particles, but upon the " power which they possess of rapidly abstracting heat from the contiguous par- ticles, depending upon the simple abstracting power by which they become quickly heated, and their capacity for heat, which is great in proportion as their temperatures are less raised by this ab- straction." This abstracting power of the different elastic fluids is found to operate uniformly with respect to the different species of combus- tion, so that those explosive mixtures, which require least heat for their combustion, also require larger quantities of the different gases to prevent the effect. It is observed that the cooling power of gases in preventing combustion must necessarily increase with their condensation, and diminish with their rarefaction ; at the same time the quantity of matter entering into combustion in given spaces is relatively increased and diminished. By a direct experi- ment the author found that the condensation of atmospherical air does not materially increase the heat of flame, as it was before ob- served that rarefaction did not materially diminish it ; from which the general inference may be drawn, that in all degrees of atmos- pherical pressure in which life can be maintained, the atmosphere still retains the same relation to combustion. The fourth part of the paper is entitled, " Some general Obser- vations, and practical Inferences." The author remarks that all his subsequent researches tend to confirm his former ideas concerning the operation of the wire-gauze coverings of the lamps, that it depends upon the gauze cooling each portion of the elastic matter that passes through it, so as to reduce its temperature below the exploding point. The diminution of the temperature must be in proportion to the smallness of the mesh and the mass of the metal; and ihe power of the tissue to prevent explosion must depend upon the degree of heat required to produce the combustion compared J 81 7.] Philosophical Transactions for 1817, Part I. 451 with tliat acquired by the metal. These principles are illustrated in a variety of ways ; and a number of experiments are adduced in support of them; but as they principally refer to what has been already stated, it will not be necessary to give an abstract of them in this place. Sir H. Davy's second paper may be regarded as an appendix to the one which has been analyzed, and is principally founded upon the fact stated above, that combustible bodies may be made to combine silently, at a temperature below ignition, and produee the same chemical compounds as when exposed to the temperature necessary for combustion. But although in these combinations there was no rapid evolution of caloric, it occurred to the author that heat must be extricated; and the quantity was in fact found to be considerable enough to preserve a wire of platinum in a state of ignition, and to keep up the further combustion of the gases. The first experiment of this kind was made with a mixture of air and coal gas, which the author was examining for the purpose of find- ing out the degree in which different proportions of these bodies were affected by an increase of temperature. It v.as found that as long as the metallic wire remained at a temperature which produced a visible ignition, the combination of the gases went on, and that, after the wire was extinguished, the gaseous mixture was no longer inflammable. It also appeared that a degree of heat much below ignition was sufficient for producing this phenomenon, and conse- quently that the wire might be taken out of the mixture, and cooled in the atmosphere, until it ceased to be visibly red, and yet that when it was again introduced to the gases, it instantly acquired the red heat. A variety of other inflammable compounds, besides that originally made use of, were capable of producing the same effect j and Sir H. Davy mentions one very beautiful way of performing the experiment, in which the vapour of ether is the substance em- ployed. If a drop of this fluid be thrown into a glass, and a portion of platina wire, heated by a poker or a candle, be suspended in the upper part of the vessel, the wire will acquire a glowing heat, and retain it as long as the glass continues to be filled with the vapour. During this silent combustion of the ethereal vapour, it would appear that a peculiar acrid volatile substance is generated, which is possessed of acid properties. The only metals with which this effect can be produced are platinum and palladium ; it is remarked that they have low conducting powers, and small capacities for heat, compared with other metals, which properties seem to be the principal causes of the phenomena. The practical application of the experiment is no less interesting than the fact itself. The author observes that, by suspending coils of wire, or a fine sheet of platinum, above the wick of the lamp in the wire-gauze cylinder, the miner may be supplied with light after the flame is extinguished by the quantity of the fire-damp ; and by removing the lamp into different situations, he will be able, by the degree of brilliancy which the metal exhibits, to judge of the con- 2 V 2 452 Proceedings of Philosophical Societies. [Dec. dition of the atmosphere. It is important to know that while the wire continues ignited, the air is in such a state as to be capable of supporting respiration. We are assured that there is no danger attached to the use of this apparatus, for that if the heated platinum should produce an explosion, the effect will be confined to the space within the wire-gauze cage. Article XL Proceedings of Philosophical Societies. ROYAL ACADEMY OF SCIENCKS. Analysis o/" the Labours of the Royal Academy of Sciences of the Institute of France during the Year 181b". Mathematical Part. — By M. le Chevalier DelamlrCf Perpetual Secretary. (Concluded from p. 3S7.) On the Relation of the Measure called Pouce de Fontainier with the modern Roman Ounce of IVater and the undent Quinarius ; and on the Determination oj a new Unity nf Measure for the Dis- tribution of Waters, adapted to the French Metrical System. By M. de Prony. It is some years since the author was invited to present his views on the determination of a new unity of measure, applied to the distribution of water, and proper to replace that known by the name of pouce de fontainier, or inch of ivater. To make the ex- periments which this determination required, he contrived a new apparatus, with which he could undertake the most delicate obser- vations, and the most useful to mechanics and the philosophy of fluids. The distribution of water in different quarters, and among the inhabitants of a city, reduces itself to make determinate quantities of water arrive at different points in times equally determined. The notion of measure, when applied to the distribution of water, is composed of the idea of a certain volume of fluid, and of that of the time during which that fluid can escape from a reservoir by a determinate mode of flow. This type of measure is wanting in the new French metrical system, and the addition of it is necessary to render it complete. There are three things to determine to obtain the suitable rela- tion between the volume of the water and the time of its flow j namely, the diameter of the circular orifice to be made in a plane or vertical vvall, the constant charge of water on the centre of that Orifice, and the length of the ajutage. 18170 Royal Academy of Sciences. 45S The inch of water, or of the fontainier, is the quantity of water furnished by a circular orifice of an inch in diameter, pierced in a vertical wall, with a charge of water of seven lines on the centre of the orifice, or of one Hne on the summit of the orifice. This type of measure has the material fault of leaving undetermined the length of the ajutage, or the thickness of the wall ; for tlie product varies sensibly with this length and thickness. Another fault, no less serious, is the smaliness of the charge, which it is almost im- possible to regulate according to its just value, and which, however, when altered, has a sensible influence on the produce. This pro- duce being nearly 14 pints (French) in the minute, and the pint containing about 48 cubic inches, it has been pretty generally the custom to make of the inch of water a measure purely nominal of 672 cubic inches per minute, equivalent to 560 cubic feet, or 19*2 cubic metres, in 24 hours. During an abode of more than two years by the author in the Roman States, he was a good deal occupied with the waters and aqueducts of Rome. The water of the ancient aqueduct is called Aqua Virgo ; that of the aqueduct constructed or restored by Pope Sixtus Quintus is called Aqua Felice; that of Trajan's aqueduct supplies the fountain Paulina. The ounce of water derived from the first of these aqueducts is twice as great as that furnished by the two others. The price of the waters of Paulina and Felice, sup- posing tiie quantity equal, is double that of the Aqua Virgo. To preserve a nominal value to the price of the unity of the distributioa of the water common to the three fountains, the absolute value of these unities has been established inversely as the money values of these waters. The great ounce of the Aqua Virgo, or of the fountain of Trevi, is furnished by an orifice of -Lj- of a Roman palm, a subdivision which is called ounce. The palm is equivalent to 0'2234 metre, and the ounce to 0*0186. To this orifice is fitted a pipe of ^ of a palm, with a charge of water at the centre, which is likewise ^ palms, or 0*2792 metre. The ounce of the water of Trevi gives a produce of 41*16 cubic metres in 24 hours. The produce of the ounce of water from the other two fountains, then, is 20*58 cubic metres in the same time. It exceeds by I*H8 cubic metre, or by about -^V, the produce of the French inch of -A'ater. Here the author indulges some conjectures on the comparison between the Roman ounce of water and the ancient measures of the same kind. In the different aqueducts which distributed water to ancient Rome we see orifices of 25 different sizes. The most common is circular; and it had a diameter of five-fourths of the finger, which made it be called quinquarius. But from the distance between the mile-stones of the Appian Way, the ancient Roman foot was 0*29461 metre. Hence the finger, or the 16th of the foot, amounted to 0*01841 metre. The length of the pipe, accord- ing to Frontinus, ought not to be less than 12 fingers, or 0*221 454 Proceedings of Philosophical Societies. [Dec. metre. He says nothing respecting the charge of water on the orifice. If we compare the modern Roman ounce of water with the ancient quinarius, we find the orifice was nearly the same for both ; that is to say, 0*0186 metre for the one, and 0-0 184 metre for the quinarius. The respective lengths of the ajutages are 0*28 metre and 0*22 metre ; but in the modern modulus the charge upon the centre of the orifice is equal to the length of the ajutage. Hence we may conjecture that this ratio of equality existed also in the ancient quinarius. On this hypothesis, and considering the orifices as equal, the modern Roman ounce would be to the ancient quina- rius in the ratio of 53 to 47. Setting out from these determina- tions, which probably are not far from the truth, we find great mistakes in certain valuations of the Roman waters which have been given to the public. The ounce of water, then, is an imitation of the ancient quina- rius. The pouce de J'ontainier seems to be a less fortunate imita- tion of the little Roman ounce. The diameter of the orifice was the 12th part of the Roman linear unit. Hence from analogy they chose to take for diameter the 1 2th part of the French foot. This analogy, extended to the charge on the centre of the orifice, would have given 15 inches, which was impracticable, on account of the enormity of the product. Hence the product was preserved, and they endeavoured to find what charge would furnish this product. This explains the small difference which exists between the pouce de Jontainier and the little Roman ounce. But the French engineers misunderstood these principles, paying no regard to the length of the ajutage, wisely fixed in the Roman modulus. From augment- ing considerably the orifice, in consequence of a misunderstood analogy, they obliged themselves to have a charge a great deal too small ; so that the French method of gauging is in every respect very inferior both to the ancient and modern Roman method. The absolute value of the modulus depends upon the quantity of water for each inhabitant which it is agreed upon to supply. This quantity varies according to situation and custom. At Rome, under Trajan, the nine aqueducts supplied 14,018 quinarii of water, which makes in 24 hours 24,868 pouces de Jfbntoiniei; or 477,466 cubic metres per day — a quantity about double of that which is supplied by the canal ot'Ourq. Five other aqueducts were constructed soon after. Rome had then 14 .-aqueducts; and the progressive augmentation of the waters was rn)ich greater than that of the population. Modern Rome, with its thiee aqueducts, and some other resources, receives at present a produce of about 150,000 metres per day. It has been ascertained that in Paris each inhabitant consumes about seven litres of water per day : which at the rate of 600,000 souls makes a total consumption of ',200 metres per day. But from an examination of the different sources or machines which furnish water to Paris, it appears that the supply amounts to 8,314 cubic metres per day ; that is, nearly double what is strictly necessary. Desparcieux re- i8l7.] Rmjal Academy of Sciences. 455 quired 20 litres per head. The author conceives that 10 are suffi- cient ; and the rule of Desparcieux might be a limit which would fix the maximum of distribution applicable to private wants. In these determinations are not included emissions in great quantities for objects of utility and decoration, for the arts and manufactures. If, then, we take 20 cubic metres in round numbers in 24 hours for the value of the inch of water, we come to the small modern Roman ounce ; and we shall have this advantage, that in intro- ducing into the decimal system of measures the new unity which was wanting, the different numbers composed of this unity will correspond nearly to the same numbers of the pouce de fontainier. It remains, then, to find the size of the orifice, the charge upon the centre, and the length of the ajutage, which will give the most convenient apparatus. Calculation gives 20 millimetres for the diameter of the orifice, and about 1 7 millimetres for the length of the ajutage. This small length will permit the ajutage to be con- tinued in the thickness of the border which surrounds the reservoir, and none of those accidents which result from the jetting out of the ajutage is to be feared. It will be much more easy to keep the flow perfectly free, and unconnected with the matters which may ob- struct tubes of a certain length. The charge on the centre is re- duced to five millimetres. To this unity the author thinks that the name of modulus of water may be given. Instruction respecting the IVork of M. de Sept-Fontaines^ and on the Cubature of fVood in general. By M. de Prony. " We have, and probably shall long have, many things which will require a comparison of the old and new results deduced from calculations, of which we may desire to make the proof by doubling them according to the ancient measures. The metrical foot, equal to the third of the metre, being a measure admitted, and submitted to the duodecimal division, if we make a beam equal to three metrical cubic feet, subdivided in the same way as the ancient beam, the first tables of M, de Sept- Fontaines will be immediately applicable to that manner of measuring wood. The last five will be the only useless ones." These tables having been republished in the Encyclopedic Me- thodique, it has been thought proper to place before them the in- formation which we have just given. But what extent soever we give to these tables, there are questions so complicated that the use of the tables, whhout ever giving the exactness of direct calcula- tion, will have the disadvantage of leading to operations still more troublesome. For these cases the author gives particular rules, which he facilitates by tables of the factors that enter into the operations. But of all these helps, none is comparable to a table of logarithms. The author points out the advantages of it, and re- commends particularly the use of negative characteristics for the fractions. Astronomers usually prefer positive and complementary characteristics ; but if the practice of them is more simple and uniform, the rules for them are perhaps less easy to understand. In other respects the two processes are perfectly identical. 456 Proceedings of Philosophical Soclelies, [Dec. The author, in tracing this piece of information, which has ap- peared in the dictionary Des Bois et Forcts, has had no other view but that of rendering it useful ; but in tlie smallest things we always perceive a hand accustomed to labours of another order. .)>a81!v-^ O71 the Height of the Mountains of India. By M. Alexander de Humboldt. " The exact measurement of mountains whose summits we can- not attain presents difficulties which depend in a great measure upon the elevation of the grounds surrounding their bases. The plat- forms on which the chains are elevated are usually too far from the coasts to be able to determine their elevation either by the angles of jdepression or by levelling. The consequence is, that every mea- surement of a high mountain is almost always in part barometrical, in part trigonometrical." When M. de Humboldt measured the height of Chimborazo on the j^latforra of Tapia, where he had taken his base, he was elevated 2,890 metres above the sea, and the summit of the mountain only rose 6° 40' above that horizon. The distance from the mountain was 30,437 metres. More near, in the plains of Sisgun, the base would liave had an elevation of 3,900 metres, and the portion determined geometrically would have been only 2,630. Thus travellers are often reduced to point out only the height of mountains above plains of the absolute elevation of which they are ignorant, or to take their measures in plains at a great distance, from which the height is not seen, except under a very small angle, which the refraction may sensibly alter. These are the obstacles which have deprived us during so long a time of an exact knowledge of the height of the mountains of India. The eastern part of Himalaya (the abode of snows, the Imaiis of the ancients) is visible from the plain of Bengal, at the distance of 150 English miles. Its height above the plains, then, is not less than 2020 toises. A very high peak of the Himalaya, visible from the town of Patna, was estimated by Col. Crawford at 20,000 English feet above the plains of Nepaul, which he supposed elevated 5,000 feet above the level of the sea. Though these mea- surements are only approximations, we may conclude from them that the mountains of India attain or surpass the elevation of the Cordillieras at Quito. Mr. Elphinstone informs us that Lieut. Macartney found some peaks of the Hindou Coosh (black mountain, in Persian) elevated 20,493 English feet. Above what valley was the elevation estimated? If it was above the plains of Peshawer, it is probable that but little remains to be added to the height measured by Mr. Macartney. The angle of height was only 1° 30'; the distance was 100 miles. The author himself does riot put much confidence in results ob- tained from such data. Mr. VVebb, Lieutenant to the Corps of Infantry in Bengal, to whom we owe more exact information respecting the course of the Ganges, was charged vyith making a survey of Kuraaon, and of the 181 7.j Hoyal Academy of Sciences. ''«f57 province of Nepaul. He measured the height of 2/ peaks covered with perpetual snow : 20 of these exceeded 20,000 English feet ; the lowest is 15,733 feet; the most elevated, 25,669 feet, or 4,012 toises. Mr. Webb adds, that this last is a mile higher than Chim- borazo, which he estimates at only apparently 3,014 toises. The following are the heights of the four most elevated peaks of Himalaya : — Peak. Feet. Toises. Metres. llth 25669 4013 7821 12th 23263 3637 7088 3d 22810 3571 6959 23d 22727 3553 5925 Chimborazo, according to Humboldt ... . G530 The 12th volume of the Asiatic Researches will give us impor- tant information on this subject. Already, from an extract pub- lished in the Journal of Science and the Arts, we learn that the peak of Chamalasi is seen from different parts of Bengal at 232 miles' distance, which indicates, admitting a mean refraction, a height of 28,000 English feet. Another peak of the Himalaya appears under an angle of 1° 1', at a distance which, from Major Rennel's map, cannot be less than 150 miles. Hence its height is at least 26,000 feet. Lieut. Col. Colebrooke has taken from two stations the angles of the height of a peak, which, if we suppose .yij- of refraction, is 22,291 feet higher than the plains of Rohil- khund, and nearly 22,800 feet above the level of the ocean. From some observations of Major Lambton, it appears that the terrestrial refraction in the climate of India is i : it varies from i to ^. According to the measures of Col. Crawford, Mount Dhaihun is 20,140 feet higher than Cathmaudu, which is elevated 4,500 feet above the ocean. Other peaks are 17,819, 20,025, 18,662 feet high. The nearest is at the distance of I70 miles; the farthest of 226 miles. The Dhawalager (white mountain of Hima- laya) measured from four different points, and taking three angles of height, was found 26,784, or 27,551 feet, according as we reckon the refraction i- or -^4-. The President of the Society of Calcutta finds that, if we suppose the errors of observation and re- fraction a maximum, and both on the side of excess, this peak is still 26,462 feet above the plains of Gorakhpur, and 26,862 above the ocean. The Yamunavatari or Jamoutri is 20,895 feet above Nagunghari, which is 5,000 feet above the ocean, making a total of 25,900 feet. A mountain, supposed to be the Dhaibun, is 24, 7 10 feet above the level of the sea. Another peak, visible at Pilibhit and Jethpur, is 22,786 feet above the level of the sea. Another, seen at Cathmandu, in the direction of the Calabhairavi, is 24,625 feet high. The valley of Nepaul itself, in which several bases have been measured, is 4,600 feet above the level of the sea. 458 Proceedings of Philosophical Societies. [Dbc. The highest peak of Himalaya, which, according to the calcula- tions of Lieut. Webb, is only 4,013 toises, or 7,821 metres, is, according to the calculation of the President, 4,201 toises, or 8,187 metres. It is not accurate to judge of the height of a chain of mountains merely from that of some of the most elevated peaks. One peak of Himalaya exceeds Chiniborazo by 1,300 metres; Chimborazo exceeds Mount Blanc by J, 700 metres; Mount Blanc exceeds Mount Perdu by 1 ,300 metres. But these heights do not give us the ratio of the relative heights of the chains ; that is to say, the height of the backs of the mountains upon which the peaks are raised. The parts of these backs which form the passages of the Andes, the Alps, and the Pyrenees, furnish us with a very exact measure of the minimum of height to which mountain chains reach. By comparing these measures with those of Saussure and Raraond, the author estimates the mean height of the back of the Andes of Peru at Quito and in New Granada at 3,600 metres, while the backs of the Alps and Pyrenees rise to 2,300 metres. The mean difference of the Alps and the Cordellieras is, therefore, 500 metres less tlian would have been believed from the height of their peaks. It would be interesting to know the mean height of the chain of the Himalaya between the meridians of Patna and Lahore. The snow line does not commence near the equator, in the Andes, below the height of 4,800 metres. In Himalaya, in the latitude of 30°, it is probably as low as 3/00 metres. Hence in the New World vegetation extends over a greater space than it does on the Cordillieras of India. As the snows harden in the temperate zones, while they remain soft in the Andes of Quito, it will be possible, in all probability, to traverse tlie snows of the Himalaya without being obliged, as was the case with Humboldt and Bonp- land to follow the narrow summits of the rocks which appear at a distance like black lines in the midst of these eternal snows. But these fatiguing excursions, the recital of which excites the interest of the public, present but few facts which are useful to the progress of the sciences. The traveller finds himself on a soil covered with snow, and surrounded by an atmosphere the chemical composition of which is the same as that of the plains, and in a situation in which delicate experiments cannot be made with the requisite pre- cision. (See the Ann. de Chim. et Phys. November, 1816.) The same number contains the memoir on the velocity of sound by M. Laplace, of which we could only give the title. It contains the following theorem : — " The real velocity of sound is equal to the velocity given by the Newtonian formula multiplied by the square root of the specific heat of the air subjected to the constant pressure of the atmosphere, and at different temperatures to its specific heat when its volume remains constant." According to this rule, M. Laplace finds 345*35 metres for the Telocity of sound in a second when the temperature is 43°. The 1817.] Uoyal Academy of Sciences. 459 French Academicians found S37-18 metres. By tlie experiments of Lacaille. given in the third volume of the Base de Systeme Metrique Decimal, p. 342, the velocity is 34'!'42 metres. We do not know what was the temperature when these observations were made. They were performed in October, and in the neighbourhood of Marseilles. Setting out from the experiments of Canton, M. Laplace found the velocity of sound in rain-water and in sea-water equal to 1525*8 and 1620'9 metres ; so that the velochy of sound in fresh-water is about 44- times greater than in air. Traite de Physique Experimenfale et Mathematique. Par M. Biot. Four octavo volumes of more than 2450 pages. Paris, Deterville, 181G. In his dedication to Berthollet, the author draws a picture of the present state of physics. " Every one who has had occasion to make extensive researches has seen with regret the scattered state of the materials of this fine science, and the uncertainty under which it still labours. One result is admitted in one country, and another in another. Here one numerical value is constantly em- ployed, while in another place it is regarded as doubtful or inaccu- rate. Even the general principles are far from being universally adopted." The .author gives as an example the three diflferent systems of electricity, the different opinions respecting the New- tonian theory of the fits of easy transmission of light. " Hence it eomes that, not being agreed about the principles of the science, we are in the situation of persons who speak in different languages which are not mutually understood. Good methods are not ex- tended ; the most fertile considerations remain long unknown, and of course barren ; some parts of the science advance rapidly in one country, and remain stationary, or even retrograde, in another ; not certainly that well qualified men are wanting to cultivate physics — for in the short interval of 40 years how many important results have been ascertained, how many new facts discovered ! " In this place occurs a concise enumeration of the labours of Coulomb, Galvani, Volta, Malus, and several other modern philosophers. " This rapid glance over science shows us the vastness of its riches. What it wants is union. It is the junction of the parts that makes a single body of it ; it is a fixing of the data and the principles which gives the same direction to all efforts. This is what I have attempted to do. The task was difficult : the public will judge of the success." The author then enters into a detail of the valuable assistance which he obtained j and he explains the plan which he thought it requisite to follow. " Some are of opinion that physics should be presented under a purely experimental form, without any algebraic formulas. It has been said, that the precision which we conceive that we attain by its assistance is purely imaginary, because it far surpasses the limits of the errors to which the exjieriments are un- avoidably subject. But when we have observed with precision the 3 460 Proceedings of Philosophical Societies. [Dec, different modes of the same phenomenon, and have obtained the numerical measures, what inconvenience is there in connecting them by a formula which embraces them all ? If they are reducible to some simple law, though not perceptible at first sight, is not this the only way to discover it ? To perceive the certainty of this method, and how productive it may be, we have only to ol)serve the use that Newton made of it in his examination of the most subtile properties of light. If the book of the Optics in which these results are found has been but little understood, and in general so ill appreciated, the fault is not to be ascribed to the use of alge- braic formulas, but to Newton's employing, instead of formulas, a synthesis but little adapted to so many details. We shall see in the work that, by means of the present mode of analytical calculation, I have been able to express all the principles of that theory by means of a small number of formulas, so simple that we can deduce from them with the utmost facility all the cases resolved or pointed out by Newton, and even extend them to many others. It will be seen how much neatness the theory of fits acquires under this new view, how certain its foundation is, and with what fidelity it represents in their minutest details a great number of phenomena which Newton did not suspect when he established it. This manner of proceed- ing, which I have always endeavoured to follow, is the one that Newton has taught us in his works, and which, Jiince the time of this great man, has been perhaps but too little followed. It is the only one that can lead us to solve this general question, compre- hending under it all physics : The circtirnstances which determine a phenomenon being defined to assign exactly in numbers ail the par- ticularities ii'hich will result from them." Such, likewise, was the question which the ancient astronomers proposed, and wbich has been since so completely resolved by modern astronomers. After so clear and precise an exposition, it only remains to point out as briefly as possible the objects of which the author treats in the different parts of his work. He first describes the instruments which are employed in all ex- periments ; he ascertains the laws of the condensation of air and of gases, those of their dilatation by heat, and at all temperatures, those of the dilatation of solids and liquids ; he treats of the forces which determine the different states of bodies, of vapours, of their mixture with gases, of evaporation, of hygrometry ; of the specific gravity of gases, of liquids, and solid bodies ; finally, of elasticity. In the second book, which is consecrated to acoustics, will be found the new experiments of the author and M. Hamel. The third book on electricity gives the analysis of the principal theories, that of Volta's pile, the discoveries of Coulomb, and the skilful calculations of M. Poisson. The fourth book exhibits the magnetical experiments of Coulomb, Gay-Lussac, and Humboldt ; and the observations of travellers on the laws of magnetism in different parts of the world. The fifth book, on light, is one of the most ccnsiderable of the 1817.] Royal Academy of Sciences, 4Gl treatise. It contains a description and calculation of the heliostate of S'Gravesend, very much improved by M. Charles : the methods and formulas necessary to determine the laws of refraction for solids, liquids, and aeriform bodies : finally, a very detailed theory of refraction, both ordinary and extraordinary ; and on the con- struction of micrometers with double images, which had never been explained in so luminous and complete a manner. In his analysis of light he states, comments on, and explains, the researches of Newton ; he gives the exact formulas of achro- matism, and describes the apparatus which he employed in the ex- periments that he made to company with M. Cauchoix. We in- vite philosophers to consider the developments which he has given of the theory of fits of transmission and easy reflection, " all the phenomena of which may be represented with the greatest fidelity by ascribing to the molecules of light two poles, the one attractive, the other repulsive, which they present alternately to the surface of bodies by turning with a uniform motion round their centre of gravity. The particles of light would then be in the same situation as two magnets approaching each other by their two poles, either similar or dissimilar. On this view of the matter the time of the fit would be the period elapsing during the revolution of a luminous particle, and the length of the fit would be the space described by the particle during that revolution. Newton appears to have had that idea ; but not to have explained it, no doubt to avoid mixing an uncertain, though probable notion, with the certainty which he had ascertained of the existence of the fit. Being at present pos- sessed of more facts than Newton had been, we though it right to develope it farther, stating it always as what it is." The polarization of light is the subject of the sixth book. It is needless to say that the author has collected and classified the dis- coveries of Malus, his own discoveries, and those of the philoso- phers, both foreign and French, who have most successfully culti- vated this new branch of physics. The seventh book treats of caloric, both radiant and latent. We find in it the experiments of Herschel, WoUaston, Ritter, Boeck- man, Berard, Leslie, Rumford, and De la Roche ; the experiments which the author made along with M. de CandoUe, the analytical inquiries of MM. Fourier and Poisson, and the labours of MM. Lavoisier and Laplace. The last chapter treats of steam-engines. The work terminates with the memoir of MM. Pouiliet and Biot on the diffraction of light. Note respecting several Memoirs of M. Poisson. The author has continued the researches which he presented some years ago to the Academy, the general object of whicii is the theory of the order and arrangment of different things without any consideration of their size — a theory still little known, which may be regarded as the foundation of algebra, and of the principal properties of numbers. 462 Proceedings of Philosophical Societies. [Dec. The author showed first how the system of all the possible per- mutations of several things may be divided into different groupes of permutations, associated so that in spite of all the changes that may be made, the permutations of the same group can never separate. He likewise divides each of these principal groups into secondary groups of permutations equally inseparable ; and so in succession for the successive groups, which are subdivided according (o the divisors of the total number of permutations. He thus forms tables, which exhibit at once several remarkable consequences. We know, in algebra, that if we seek to determine any function of the roots of a proposed equation, the result is elevated to the degree marked by the number of all the permutations which the roots can offer under the function considered. But it results from the preceding theory that this elevated equation is not more difficult than the one proposed itself; and that it may be actually resolved by means of equations of degrees marked by the divisors of its exponent. Tins first manner of connecting permutations furnishes no data for their further reduction. But the author is enabled to group permutations in another manner, by making them proceed from each other by the same law. He can assemble in the same way the different groups which result from this. In the tables thus formed we see, without any calculation, why the equations of the first four degrees can be resolved ; why the reduced equation of the fifth dt'gree, which rises to the 1 20th by means of fifth radicals, and of a peculiar equation of the sixth degree, may be reduced to an e(jnation of the fourth, as Lagrange and Vandermonde observed ; but we see further that this last equation will not in reality possess tlie difficulties of the fourth degree, but only those of the second. The four roots of this equation give occasion for 24 transmutations, which may be connected two and two. These 12 unite, likewise, two and two. The six groups resulting, likewise, unite two and two; which reduces the whole system to three principal groups. Hence it follows that the equation of the fourth may be actually resolved by equations of the second and third degree, without assuming any particular hypothesis respecting that function which reduces these 24 values to three, considering them as equal, eight and eight. There is likewise another remarkable table of the 24 permuta- tions of four things, in which we see the permutations united by four to be reciprocals of each other at pleasure. This singular table contains all the ways of dividing by two and two the system of 24 permutations. The essential point in speculations of this nature, being the simplicity of the representation of so many for- mulas, the author finds in the new polygons which he has made known a means of reducing them and expressing them with an extreme facility. This theory conducts naturally to that kind of numbers which Euler called primitive roots, and the demonstration of which ap- 1817-3 Royal Academy of Sciences. 4GS peared to hlro one of the most difficult problems of the theory of numbers. (Opuscules Analyliques.) The author has obtamed their analytical expression, by following a singular analogy, on which the bounds of this notice prevent us from dwelling, and which led the author to conclude that the imaginary roots of the equation of the degree p — 1, which are not primitive roots, ought to be the analytical representation of the primitive roots of the first number treated of; that, vieived simply as residues relative to this prime numher, they ought to be equivalent to it ; and that if to the numbers under the radical sign suitable multiples of this prime number be added (which can never change the residual values), these imaginary expressions become real, rational, and entire, give exactly the primitive roots, and produce only these numbers. This is what the author has established in different ways, and confirmed by a number of curious examples. From these imaginary expres- sions we may, says the author, deduce a variety of theorems on whole numbers. The theorems of Fermat and Wilson are the first consequences of them. This analysis leads to the demonstration of this new theorem respecting the formula which expresses the roots of the binomial equation of any prime degree whatever /;. That the number p must necessarily enter every where as a factor under the radicals of this formula. Thus in the formula of the cube roots of unity, the number 3 must of necessity occur under the square radical. In the formulas of the fifth roots the number 5 is every where a factor of the numbers which are under the different radicals. The same holds with the 7th, 1 1th, 13th, I7ih, &c. roots, as may be verified in the general expressions of these roots. Euler first studied and discovered the principal properties of residues. M. Legendre simplified this theory by the consideration of indeterminate equations, and by the omission of the multiples of the prime number in the successive operations. M. Gauss simplified it still further by the new signs of these equations, which he names congruent. Finally, the amhor, occupying himself less with num- bers themselves than their forms, changes these equations, or con- gruents, into true equations, and thus reduces the whole of this analysis;under common algebra. This idea may lay open new routes. It is the' first example of the application of algebra to the theory of numbers. 'Die primitive roots being very useful in analysis and in geometry, the author has endeavoured to find in arithmetic an easy method of finding them all at once for any given prime number. Suppose the prime number to be 31, as the next lowest number 30 is decom- posed into the three simple factors 2, 3, 5, it Is clear that the pri- mitive roots of 31 can neither be squares, cubes, nor fifth po were ; for on account of the factors 2, 3, 5, the squares would bring unity at least to the fifth power, the cubes to the tenth, and the others to the sixth. It is sufficient, then, to exclude from the 30 numbers that precede SI those that are squares, cubes, or fifth powers, or rather the pro J7 8 25 24 29 38 1 20 24 41 11 u 18 8 20 24 30 00 — — — — 19 8 25 24 29 58 1 25 24 40 08 20 8 25 24 30 58 1 25 24 42 08 V 21 8 20 24 32 50 1 50 24 43 53 •5 22 8 30 24 34 47 1 25 24 40 12 23 8 25 24 31 52 1 30 24 38 21 ss 24 8 25 24 32 08 1 45 24 37 53 25 8 30 24 31 25 1 30 24 39 45 H 26 8 35 24 29 44 1 35 24 41 16 27 — _ — 1 25 24 43 33 28 8 40 24 31 46 1 15 24 38 28 •5 29 1 8 30 24 30 16 1 25 24 39 07 o 30 1 1 20 24 38 46 ■*rf 31 1 30 24 37 13 a fe Mean for Moiitli. l8 31 24 31 06 1 31 24 40 46 O Oct. 31. — At the commencement of the noon observations the variation was 24° 37' 23" W., the wind being to the south of the west. As the wind became more westerly, in a few minutes the variation decreased to 24° 27' 45", and then increased to 24° 37' 13". This was followed by a hard squall, with rain, from west by north. 18170 and Meteorological Tables, 471 Meteorological Table. Monl*. Time Oct. Morn. Barom. 11- 12< 13< 16-! IR^ Ther, Inches, 29-376 29-345 29-630 29-650 29-645 29-758 29-758 29-844 29-840 29-853 29-818 29-734 29-731 29-700 29-658 29-565 29-535 29-485 29-485 29-530 29-550 29-610 29-600 29-778 29-808 29-817 29-783 29-625 29-558 29-423 29-472 29-658 29-648 29-500 Hyg. Wind. Velocity. Weather.'Six's. 450 51 39 40 50 45 54 44 52 42 53 48 56 48 54 46 53 46 54 42 47 43 51 44 51 42 49 44 48 44 44i 42 48 40 65° 54 53 60 45 56 44 55 48 57 44 58 44 53 46 64 46 60 46 59 53 63 60 64 54 65 50 74 72 84 75 63 58 63 Feet. NNE N N NNW NE I Eby N Eby N ENE ENE ENE £ ENE ENE EbyN E E E NNE NNE NbyE N N N NEby N NE NNW NNW NNW NWbyN NE E ENE EbyN NE by N 41 55 I 35 48 35 52 33 5i 37 55 33 54 40 56 44 55 1 39 54 Very fine J Cloudy I 55 }4l Showery | 49 Cloudy }^^ Showery I 50 Cloudy Fine Very fine Clear Very fine I Very fine iFine Clear Cloudy Fine Fine Fine Clear Cloudy Fine Fine Clear Very fine Showery Very fine Cloudy Mizzle Showery Showery Showery Showery (Showery Cloudy J37 } } } 52 36 51 42 49 38 45i 37 49 38 44 472 Col. Beaufoy*s Meteorological Table. [Dec. Meteorological Table continued. Month. Time. Barom. Ther. Hyg. Wind. Velocity. Weather. Six's. Oct. Inches. Feet C Morn 29-483 43° 750 NNE Cloudy 38* 19-^ Noon.,.. 29-465 45 59 NNE Cloudy 45^ L Even.... ._ — — — }43 f Morn 29-510 43 68 NNE Mizzle 20 ^Noon 29-510 47 56 NNE Cloudy 4T r Even .... Morn .... 29-467 43 75 NE Cloudy ■ 42 2 J Noon. . . . 29-432 48 60 Eby S Cloudy 49 I f Even Morn .... 29-385 43 72 N by W Foggy }« 22< Noon.... 29-400 48 69 N Cloudy 48 l Even Morn. . . . 29-510 44 79 NbyE Cloudy |40 23-! Noon. . . . 29-512 49 55 NE Showery 50 > Even .... Morn 29-485 42 72 NEby E Mizzle }" 24west passage, 424. Bcanvais, M. Flora of Ovvara and Be- nin, by, 222. Bees, on the combs and cells of, 14, 428. Berger, Dr. on the specific gravity and temperature of sea water, 139. Berzelins, Professor, on tellurium in sulphuric acid, 464. Belladonna, effects on vision, 432. Beudant, M. on salt and freshwater shell-fiih, 144. Bigge, Mr. on the mineralogy of the Cheviots, 140, Riot, M. Traite de Physique, par, 459. Bi tartrate of potash, primary form of, 37. Blainville, Dr. on the spur of the orni- thorhiiichus paradoxus, 112. Blind woman who can read by the points of her fingers, account of, 286. Blow-pipe, Brooke's, improvement in, 66. Bonnard, M. observations by, on the position of granite, 143. Booth, Mr. improvement in Brooke's blow-pipe, by, 67. Boy, blind and deaf, observations on, .50. Braconnot, M. analysis of rice by, 186. Brewing, 388. Brewster, Dr. on the action of transpa- rent bodies on the differently coloured rays, 49 — description by, of a dark- ening glass for solar observations, 50 — on the optical properties of calca- reous spar, 51 — of common salt, fluor spar, diamond, 52. Brewster, Rev. James, on the remark- able case of Margaret Lyall, 53. Brochant, M, on transition rocks, 142, Brownrigg, Dr. biographical account of, 321, 401. Brugnatelli, M. method of detecting arsenious acid or corrosive sublimate, by, 151. Buckland, Rev. W. on the plastic clay formation, 58. Butter of antimony, 149. CadcU, W. A. Ksq. on the sugar yielded by the acer pseudoplatanus, 234. Calculous disorders, Marcet's account of, 443. Campbell, John, Esq. on vision, 17. Carro, Jean de, M. D. account of, 1. Cassini, M., on certain compound flowers, 2-i3. Clerasin, 147. Chaussicr, M., on medical jurispru- dence, 293. Cheviots, mineralogy of, 140, I 476 Index. Chlorides, composition of, 275. Christison's application of fluxions, 417. Cinnamon of, as an article of com- merce, 346. Clarke, Dr., fusion of wood-tin by, 70. — New experiments by, 133. Im- provement in the gas blow pipe by, 373, Clouds, on the nomenclature of, 308. Coal found in Russia, 233. — New spe- cies of, 61. Coal pit, explosion in, 231. Coal vessel, explosion on board a, 233, Cobalt, analysis of the ores of, 228. Comets of 1783 and 1793,380. Comet, new one discovered by M. Pons, 464. Common salt, optical properties of, 52. Compass, variation of in the northern ocean, 427. Corrosive sublimate, method of detect- ing, 151. Cremation, on the origin of, 50. Cubature of wood, Proney's remarks on, 455, Cuvier, M., account of his Regne Ani- mal distribue d'aprcs son Organiza- tion, 127, 291. On the anatomy of tlje molusca, 290, U. Dalton, Mr. John, on the chemical compounds of azote and oxygen, 38, 83. Darkening glass for solar observations, 50. Davy, Sir H., researches on flame, 447 — service of plate presented to, 464. Davy, Dr. John, on the temperature of the ocean and specific gravity of the sea in tropical climates, 54. Deliquescent substances, on the preser- vation of, 29. Deutosulphuret of copper, 148. Dewar, Dr., on the method of pre- serving volatile and deliquescent sub- stances, 29— on the blind and deaf boy, 50. Diamond, optical properties of, 51. Dick, Thomas Lauder, Esq., on dif- ferent currents of wind at the same time, 16. Differential equations, table of, 116, Dixon, Dr. his biographical account of Dr. Brownrigg, 321, 401. Donovan, Mr, essay by on galvanism, 129. Dunglisson on vision, 432. Edmonston, H. Esq., on the mode of exploring the interior of Africa, 103. Egg singularly formed, 69. Emetin, 150. Ether, silent combustion of its vapour, • 451. Euler's algebra, translator of, 152, 3H. Extracts, on preparing, 306. Explosion in a coal-pit, 231 — on board a coal vessel, 233. Fibrinous calculus, account of, 445. Fluorspar, optical properties of, 51, Fluxions, applied to lines of the second order, 417. Fox's account of the weather at Ply- mouth, 434. Freyberg, sketch of the Mining Aca- demy at, 61, G. Galvanism, essay on, 129. Garden, Mr. account of a remarkable mineral water by, 72. Garthshore, Dr. Maxwell, biographical account of Dr. Ingenhousz by, 161 Gas blow-pipe, experiments with, 133 — improvements in, .303, 367, 373. Geological Society, meetings of, 58, 139. Girard, M, on the theory of the motion of water iu capillary tubes, 384. Glover, Rev. T. account by of a blind woman, who cau read by the points of her fingers, 286. Gordon, Dr. John, ou the blind and deaf boy, 50. Gorham, Dr. examination by of sugar supposed to be poisoned, 197. Govan, Mr. on the effect of lightning ou a tree, 389. Granite, on the positions of, 143. Gregor, Mr. new species of coal dis- covered by, 61 — death of, 153. Greenland supposed to be an island, 427. Grotthiis, his experiments on flame re- ferred to, 447, 449. Gum from the Congo, 147. H. Hatchette, M. on the running of liquids through small orifices, 31, 214. Harvey, Mr. George, elementary ideas by, on the first principles of integra- tion, 264, Hedge-hog, on, 307, Herschell, Sir W, on the distribution of the stars, 55. 5 Index. 477 Himalayar mountains, observations on the height of 456. Holt, Mr. experiments by, to show that the bean is perennial, 391. Holmite, 71. Home, Sir Everard, on the difference between the sepia and shell vermes, 55. Hordein, 388, 389. Horner, Mr. solution of the equation, 4" x = X by, 341. Howard, Luke, Esq., meteorological tables, by 79, 159, 239, 319, 399, 473 — Description of a descending land spout by, 146. Humboldt, M., on the distribution of plants, 221 ; on the Indian moun- tains, 456. Hydrochloric acid, liquid, quantity of real acid in, 269, 369, I. Jackson, Dr., elementary demonstra- tion by, of the composition of pres- sures, 53. Jamieson, Dr. John, on the origin of cremation, 50. Ice, formed by means of oatmeal, 61. Indian mountains, Humboldt's remarks on, 456. Ingenhousz, Dr., biographical account of, 161. Insects which live in a vacuum, 151. Integration, on the first principles of, 264. Jonn^s, M. Moreau de, on the geology of Martinique, 145— on the yellow viper, 226. Johnson, Mr., on a lactometer, 304 — on a rain gage, 305 — on preparing extracts, 305. Iron, curious eflfect of paste on, 302. Kidney bean, a perennial, 391, Lactometer, on a, 304. Lamark, M., on animals without ver- tebras, 291. Lamouroux, M.,on corals, 291. Laplace, M., on determining the length of the pendulum, 296 — on the velo- city of sound, 458 Latreillc, M., on the distribution of iu- sects, 224. Laugier, M., experiments by, on arra- gonite, 152 — analysis of the meteo- ric iron of Siberia, by, 152. Laurus cinnamomum, description of, 241. Leach, Dr., on the genus ocythoae, 55. Lect, Mr. on the action of vinegar on cast-iron, 394. Leslie, Professor, produces ice by means of oatmeal, 61. Lichnis dioica, on the red and white varieties of, 56. Licoperdon solidum, 56. Licopodium denticulatura, seeds of. Lightning, eiTecl of, on a tree, 389. Ligurlan mountains, on the mineralogy of, 59. Linnaean Society, meetings of, 66. — Office bearers in, 56. Lyall, Miugaret, remarkable case of, 33. M. M'Avoy, Miss, an account of, 268, 465. M'Niven, Dr., on the water of Schoo- ley's mountain, 465. Macbritle, Dr., on the licoperdon soli- dum, 56. Magendie, M., on emetin, 150, — Expe- riments by, on feeding animals with food destitute of azote, 292. M.Tgnetical observations 76, 156, 236, 316,396,470. Malaxis, new species of, 56. Malt, constituents of, 388. — Patent 465. Marcel's essay on calculous complaints, 443. Marshall, Henry, Esq., on the laurus cinnamomum, 241. — On cinnamon, as an article of commerce, 346, Massa, S. Giovanni, on the mineralogy of the Ligurlan mountains, 59. Meteorological tables, 77, 157, 237, 217, 397, and 470. Mineral water?, general formula for the analysis of, 93, Mitchell, James, the blind and deaf boy, on, 50. Morphium, 153. Moyle, Mr., machine for raising heavy weights by, 65. Murray, Dr. John, on the analysis of sea water, 51. — General formula by, for the analysis of mineral waters, 93. Murray, Hugh, Esq. on the ancient geo- graphy of central Asia, 51. N. Naphtha of Amaino, composition of, 1 18. pro]>erties aud 478 Index. New Malton, weather at, 230, 390. North-west passage, Beaufoy's remarks on, 424. O. Ornlthorhinchus paradoxu?, on the spur of, 112. Obbrey, Mr. improvement by on the oxygen and hjdrogen blowpipe, 366. Paris, Dr., on tests fur ar'ienic, 60. Patents, list of, 73, 154, 468. Pelletier, M., on einetin, l.)0. Permutations, system of, 462. Persnlphates of iron, on, 98. Philosophical Sociely of London, oOice bearers in, 62. Plastic clay formation, on, 58. Plymouth, account of weather at, 434. Poisson, M., report by, on the running of liquids through small orifices, 31, 214 — Notice respecting his memoirs, 461. Pole, North, on sailing to, 63, Pons, M,, new comet discovered by, 464. Pouce de Fonlainier, Prony's remarks on, 452. Pressures, elementary demonstration of the composition of, 53. Primitive roots, remarks on, 462 Prony, M., on the measure of water, 452 — on the substance of wood, 455. R. Rainbow, inverted, 314. Rain -gage, on, 305. Rhiziniorpha, account of, 56, Rice, analysis of, 186. Risso, M., on the crustraccous animals of Nice, 291. Robiouct, M., on the butter of antimo- ny,'l49. Rochon, M., biographical account of, Si. Rocks, effects of, on the magnetic needle, 69. Roman ounce, Prony's remarks on, 452. Royal Academy of Brussels, prizes by, 308. Royal Academy of Sciences, labours of, 141, 221.290, .377,452. Royal Geological Society of Cornwall, meetings of, .59,392. Royal Medical Society of Edinburgh, prize by, 63. Royal Society, meetings of, 51, 139 — - analysis of the Transactions of, for 1817, Part 1. 446. Royal Society of Edinburgh, analysis of the transactions of, 49. S. Safety lamp, farther improvement of, 451. Salisbury, Mr., on the seeds of lycopo- dium deiiticutatum, 56. Saturn's ring, on the disappearance of, 148. Saussurc, M. Theodore dc, on the naphtha of Amiano, 118. Schooly's mountain, water of, 465. Sea water, analysis of, 51 — ■ipecific gravity and temperature of, l.'j9. Seaton, Mr., nn the red and white vari- eties of lychnis dioica, 56. Scniple, Mr., register of the weather at Malone house by, 11 — on an absence barometer, 47. Sept-Fontaine's work, Prony's remarks on, 455. Serpentine from America, 58. Serres, M. Marcel de, on fresh water beds, 144. Sewell, Mr., new mode of curing lame- ness in the foot of a horse, by, 54. Smith, Sir I. E., on a rhizimorpha, 50. Soda, method of determining the quan- tity of, 114. Sodalite found in Vesuvius, 141, 192. Solly, S. Esq. on the mineralogy of certain parts of Sweden, 141, 235. Sound, Laplace on the velocity of, 458. Spout, descending land, 146. Spur in rye, on, 223. Standard barrow, improper, 61. Stars, on the distribution of, 55. Stevenson, Mr. en the waters in the mouth of the Dee, Thames, &c. 57. Stromever, Mr. experiments by, on the ores "of cobalt, 228. Strult, Mr. on a singularly formed egg, 69. Sugar, supposed poisoned, chemical examination of, 197 — yielded by the acer pseudoplatanus, 234. Sulphurous acid, external application of, as a remedy, 313. T. Tellurium in sulphuric acid, 404. Tennnant, Charles, Esq. table by. to determine the quantity of soda, 114. Thibet, mountains of, height of, 145. Thomson, Dr. Thomas, on the salts composed of sulphuric acid and per- Index. 479 •side of iron, 98 — on gum from the Congo, 147 — on the hydrate of tin, 149 — analysis of tins by, 166. Time keeper, description of, 365. Tin, hydrates of, 147 — analysis of dif- ferent specimens of, 166— nature of the black powder left when it is dis- solved in muriatic acid, 71. Transition rocks, observations on, 142. Transparent bodies, action of, on the different coloured rays, 49. Turkey oil stone, 71. U. Vapour of ether, silent combustion of, 451. Ventenat, biographical sketch of, 440. Venus, Hottentot, dissection of, 225. Vessels of plants, on, 177. Villefos.-e, M. Heron de, on mines, 143. Vinegar, action of, on iron, 394. Viper, yellow, account of, 226. Viney, M. on the spur in rye, 223. Vision on, 17, 432. Vivian, J. H. Esq. on the Mining Aca- demies of Freyberg and Schemoitz, 61. Volatile substances, on the preservation of, 29. Uranus, on the construction of tables of, 377. Ure, Dr. A. on ammonincal salts, 20.'i — on the quantity of real acid in liquid hydrochloric, 269, 369. W. Wahlenberg, Dr., on the vessels of plants, 177. Water, mineral, remarkable, 72— the- ory of its motion in capillary tubes, 384 — Prony's remarks on the mea- sures of, 452. Weather at Mai one-house, 11 — at New Malton, 230—390. Webster, Mr., on the effects of different rocks on the magnetic needle, 69. Weights, machine for raising great, 65. Wheeler's patent malt, 465. Wind, different currents of, at the same time, 16. Wollaston, Dr., on the primitive form of bitartrate of potash, 37 — discove- ries on calculi, 444, Wood-tin, fusion of, 70. Wynn, Mr. W., time-keeper by, 365. X. Xanthic oxide calculus, account of, 443. END OF VOL. X. <'. Baldnin, Prinlrr, Ne» Uriil^e-alfevt, London. ■f'-