eOetabetceeteteiine ghr Spar orb -ipteketan as aphs a Perse tacetea et ibrar ts 3 fr i By Syitd it a i its 1H i ik i 0 bebe Rekheee oe Se F ti lelpserenetsecRewenete 95 eREREN TSG PO: ehenes ewes: peressreregesel BESS pa ptotriedes sez8 ths sishigeedayes averet eet y! Wij , f rE md ated 4 “a SUariraied tonh Engraunrys es a SS nse one ~ wi = ; “ee AV EES. {AM iC i’ , _ \ ‘ , por o re Se Cs’, ies) jus .« | “ SANG peer X, | Aion: Nghe Ph, as They | Aw oe 402 ; ‘ae i ee ie ia atts ah a ey Ae AS 7 A JOURNAL QF NATURAL PHILOSOPHY, CHEMISTRY, AND Tee A RTS. VOL. XX. @lustrated with Enagravings. puns Sok ca BY WILLIAM NICHOLSON. LONDON : PRIINTED BY We. STRATFORD, CROWN COURT, TEMPLE BAR; FOR _ W. NICHOLSON, CHARLOTTE STREET, BLOOMSBURY, AND SOLD BY J. STRATFORD, No. 112, Hotsorw. Hixt. 1808. : 19 ye Oe veel oe Mus Bare a , wort, -gaitom pr ht: adores iM nea ae | Has: % oy eee a4 Leet a J M.. vngit 4 wad ake a Movie - as: beetles) ten obra : =) iM: re / Nisupes¥ < oUt padeag PTO our 2 ie ee Lie gdartyugatl “i>; Bev eriie Cue il zustagyat | Saat avian corset M petals). “Mi Rolo! He i wi ai el (sue ds 2 at 4 Z Be 1b = eo ies! : eee vs ei ae ye cae ath: a ae eS cM oi i RM oe eae 4 ned sito banest 38 . Ry fae: 3 pied x > GNE Piso sobuaxed TE goetrad tie gob aM: aaibhilt ignoinAl piste. ¢.0.4 7 mont mectrA. : Vatwel ON GAL MD tae ee aes - 2 Ae eemedi agiseh ae sastyps f i SARE AM iscosls letdet AL aM ped eotede OH 2.8 ae Ad Baik 2 ast spall me eign Cubreresey chien. 9S 8 pad relat a, hie ouaiaat aa ee one x ia yeah 2D - cyte RS: et é ta ¢ 7 eo ; 4 . baad ty / abere 2 siesnbine 2 5 wt. ey | prrostaotn> a tnt ao: Agluast Doe! sui? ped do Hea nedeth ou." ais ean > "yi 2 Laat Hon B®. sek ei Tab “on Sees Oe & 18708 ta ae 136 oP at 2°y boeke La eA ope ee Io tied a3 Feats) ge e wee i, proves sai Moher ek i atetondlt SE Yi: me oF wranou - lefodinie Riess ata re Polat 4 ADCs ma % 0s peQhae Balasate oy ‘pater ‘ bites BU peteeRne fic walt rsaare ‘sige sna aoe. frac ift ME ee at yatras,. 10. a 4 CR He ‘ a » a ¢ i ve Nt? t ° , - 4 oo, r rat 7 A R . Sul au \ oS Mine & 5 | . a3 4A Wa» PREFACE. Tue Authors of Original Papers and Communications in the present Volume are, R. B.; Joseph Reade, M. D.; Dytiseus; Hemerobius; Mr. Robert Banks; John Gough, Esq.; P.; A. B. C. D.; Lieutenant Henry Kater; Mr. J. Aston; Professor Vince ; Mr. Daniel Dering Mathew; Dr. Clerke; Rev. J. Blanchard ; Mr. T. Clifton; Mr. J. Wright; Mr. G. H. Willers; John Dick-, enson, Esq.; Mr. John Martin; Mr. Richard Drew; Mr. John Tatum; a Correspondent. Of Foreign Works, M. L. F. Lemaitre; M. Tonnelier; M. Theodore de Saussure; Christian Frederic Bucholz; Mr. le Li- evre; M. Margueron; Professor Lampadius; M. Vauquelin; M. G. A. Deluc; M. Perperes; M. Planche; M. Depuytren; M. Thenard; Mr. Roloff; Mr. Giulio; Mr. Bergman; Professor Wur- zer; M. Collet-Descotils; Mr. Klaproth. And of British Memoirs abridged or extracted, Sir Joseph Banks, Bart. K. B. P.R.S.; Everard Home, Esq. F.R.S.; Mr. John Middleton; Mr. Joseph Carne; Dr. Alexander Marcet; Ma- jor William Lambton; Arthur Biggs, F.H.S.; Richard Antony Salisbury, Esq. F.R.S.; C. H. Parry, M.D.; Mr. G. Irwin; Rev. Thomas Falconer ; Mr. William Hardy; Mr. James Dickson, ¥.L.S.;V.P. H.S.; H.I. Colebrook, Esq.; Mr. F. C. Daniel ; Lieutenant John Bell ; Humphry Davy, Esq. Sec. R.S. M.R.T.A.; James Smithson, Esq. F. R. 8S. ; Mr. William Garrard; Nevil Mas- kelyne, D. D. F.R.5.; Mrs. Hannah D’Oyley; Right Hon. Earl of Fife; David Day, Esq. The Engravings consist of 1. Mr. Middleton’s Mode of Print- ing; 2. Relistian Tin Mine; 3. Singular Strata in a calcareous Mountain near Cressy ; 4, 5. Ditto in the Department of Doubs ; 6. Draining of the Pond of Citis; 7. Yenite, a new Mineral Sub- stance ; 8. Mr. Hardy’s Compensation Balance; 9. Compensation Pendulum, by Mr. Henry Kater; 10. An irregular Production of the Cucumber; 11. Mr. Mathew’s Scapement ; 12. Planche’s Ap- paratus for Succinic Acid; 13. Mr, Wright’s artificial Horizon; 14, Mr. Danicl’s Life Preserver from Shipwreck ; -15. Lieutenant Bell’s Method of saving Persons from stranded Ships; 16. Com- “pound Sulphuret; 17. New Properties of Tangents; 18. Radiation and Reflection of Cold; 19. Mr. Richard Drew’s Balance Level ; 20. Mrs. D’Oyley’s Method of rearing Poultry. TABLE TABLE (OF. (CONTENTS TO THIS TWENTIETH VOLUME. MAY, 1808. Engravings of the following Objects: 1. Mr. Middleton’s Mode of Printing: 2. Relistian Tin Mine: 3. Singular Strata in a Calcareous Mountain near Chessy: 4, 5. Ditto in the Department of Doubs. I. An Attempt to ascertain the Time when the Potato (Solanum Tuberosum) was first introduced into the United Kingdom; with some Account of the Hill Whieat of India. By the Right Hon. Sir Joseph Banks, Bart. K.B. P.R.S. &c. - - = = : . 1 Ti. Observations on the Structure of the Stomachs of different Animals, with a View to elucidate the Process of ee and Vegetable Substances into Chyle. By Everard Home, Esq. F. - 5 Ilf. Description of a Machine for Printing das Hang inge. By Mr. John Middleton, of St. Martin’s Lane 21 IV. An Account of the Relistian Tin Mine. By Mr. ae Came; in a Letter to Davies Giddy, Esq. M.P. F. B.S. - 2A - V. An Analysis of the Waters of the Dead Sea and the River Jordan. By Alexander Marcet, M.D. one of the Physicians to Guy: S Bey Com- municated by Smithson Tennant, Esq. I. R.S. 25 . VI. An Account of the Measurement of an Arc on the Meridian of the Coast of Coromandel, and the Length of a Degree deduced therefrom in the Lati- tude of 12° 32”, By Brigade Major William Lambton - 40 - VIT. An Account of some New Apples, which, with many others that have been long cultivated, were exhibited before the Horticultural Society, the 2d of December, 1806. By Mr. Arthur Biggs, F. H. 5. = 50. VIIL On the Cultivation of the Polianthes Tuberosa, or bart By Richard Antony Salisbury, Esq. F.R.5. &c. = 55 1X. Geological Remarks on a Calcareous Mountain near Chessy, in the De- partment t of the Rhone.. By Mr. ae F. ene ee gi of Gun- powder and Saltpetre - 62 X. Remarks on a singular Arrangement of Strata observed in the Chain of Jura, in the Department of Doubs. By the same - 64 J. An Inquiry into the Causes of the Decay of ee and the Means of preventing it. By C. H. Parry, M.D. - 2 69 Scientific News - * - ig Pe 79 JUNE, Cz2OWNT LyNyT Ss: ¥ JUNE, 1808. ‘ Engravings of the following Objects: 1, 2,3. Draining of the Pond of Citis: 4. Yenite, a new Mineral Substance: 5. Mr. Hardy’s Compensation Balance. I. Observations en such Luminous Phenomena in the Atmosphere, as appear to _ depend on Electricity. By a Correspondent, (R. B.) - - 81 II. Account of the Draining of the Pond of Citis ts he 88 IN. Resales oa some Pseudomorphoses observed in the Substances, that form Part of the Mineralogical Collection of the Council of Mines. By Mr. Ton- nelier, Keeper of the Mineralogical Cabinet to the Council - 93 IV. An Experiment on Soap-Suds asa Manure. By Mr. G. Irwin of Taunton; ~ with Remarks by the Rey. Thomas Falconer - by 4 99 V. An Inquiry into the Causes of the Decay of Wood, and the Means of pre- so yventing.it. :By CoH. Parry, M.D.) ~~ - Zz = 102 VI. Analysis of Jade; read to the Society of Natural History and Philosophy ~~ at Geneva, Dec. 5, 1805. By Theodore de Saussure “+ 104 _VII. Remarkable Fact of an Increase of Temperature produced in Water by ~ Agitation: In a Letter from Joseph Reade, M.D. « 113 - VII. Further Remarks on Professor Vince’s Answer. By aCorrespondent 114 Tx. Calculation of the Rate of Expansion of a supposed Lunar Atmosphere. By a Correspondent - - - = ~ 117 __ X., Experiments on Molybdena. By Christian Frederick Bucholz. Translated _.. from the German - cr wt, = = a 121 XI. Construction of a Curb affording a Compensation for the Effects of Heat _...and.Cold in Time-pieces. By Mr. William Hardy, No. 29, Cold-bath Square = = = - - - 138 - XI. Of the Yenite, a new Mineral Substance. By Mr. le Lievre, Member , of the Institute, Counsellor of Mines, &c. - - 139 - XII. Memoir on the reciprocal Action of several Volatile Oils and certain Sa- line Substances. By Mr. Margueron, late Apothecary-major to the Hétel des Invalides - zi 145 - XIV. Analysis: of the Schist that accompanies the Menilite near Paris... By Prof. Lampadius a ae - . S ae 155 ' Scientific News . - - - -- 157 Meteorological Journal = - - = _ 160 vi CONTENTS. JULY, 1808. Fngravings of the following Objects: 1. Compensation Pendulum; by Mr. ~ Henry Kater: 2. Representation of an Irregular Production of the Cucumber: 3. Mr. Mathew’s Scapement: 4. Planche’s Apparatus for Succinic Acid, I, An Essay on Polygonal Numbers, containing the Demonstration of a Pro- position respecting Whole Numbers in general. In a Letter from John Gough, Esq. - - - - - - - 161 If. On a Variety of the Brassica Napus, or Rape, which has long been culti- vated upon the Continent. By Mr. James Dickson, F.L.S. V. P.H.S. 168 Itt. Comparative Analysis of some Varieties of Steatite, or Talc. By Mr. Vauquelin - c 5 he - - 170 IV. Observations on the Crystallized Substances included in Lavas. By G. A. Deluc = a - - - - - - 176 V. Experiments on Molybdena. By Christian Frederic Bucholz 188 VI. Remarks on the Formation of Acetous Acid in Cases of Indigestion. By Mr. Perperes, Apothecary, at Aziles. Communicated by Mr. Parmentier 196 VII. On the Cause of Animal Heat. In a Letter from a Correspondent 200 VIII. Description of a Species of Ox, named Gaydl. Communicated by H. T. Colebrook, Esq. - . - 201 IX. A concise Method of determining the Figure of a gravitating Body re- volving round another. By a Correspondent - = = 208 X. Description of a new Compensation Pendulum. By Lieutenant Henry Kater. Communicated by the Author - - - "214 XI. Extract of a Letter from Mr. J. Aston of Ipswich, giving an Account of a Mule Cucumber, and other Objects - = - < 221 XU. Letter from Professor Vince, in Reply to Dytiscus. —-~ aa 222 XIUT. Certain Improvements in Chronometers, by Daniel Dering Mathew, Caius College, Cambridge, In a Letter from the Author - 224 - XIV. Observations on the Possibility of collecting a certain Quantity of Suc- ‘cinic Acid, during the Preparation of Amber Varnish, without any Injury to the Quality of the Varnish. By Mr. Planche, of the Society of Apothe- caries, Paris - st! a Gen XV. An Essay on the Saccharine Diabetes, By Messrs, Dupuytren and The- nard. Abridged by the Authors : = - > 230 XVI. Letters from Mr. Roloff, of Magdebourg, on the fetid Resin of Sul- ~ phur - - - “ 2 . - - 237 Scientific News - - ~ - a - 238 Meteorologjcal Tables - a ‘ F 2 _ 240 AUGUST, CONTENTS. vib AUGUST, 1808. Engravings of the following Objects: 1. Mr. Wright’s Artificial Horizon: 2. | Mr. Daniel’s Life Preseryer from Shipwreck: 3. Lieut. Bell’s Method of sav- ing Persons from stranded Ships. I. Observations on the crystallized Substances included in Lavas. By G. A, Deluc ~ Bin = At - - - 241 i]. Experiments on Molybdena. By Christian Frederic. Bucholz 253 iif. On the native Gold Dust found in the Hills in the Environs of the Com- mune of St. George’s, in the Department of the Doire. By Mr. Giulio, Prefect of the Department of the Sesia = - - : 266 tV. Calculation of the direct Attraction of a Spheroid, and Demonstration of Clairaut’s Theorem. By a Correspondent - P 273. ¥. Reply to Professor Vince’s Ultimatum. By a Correspondent 276 VI. Question respecting the Ignition of Tinder by compressed Air. In a Let- ter from a Correspondent - - - - 278 VII. Description of a portable artificial Horizon for taking Altitudes at Sea or Land, by Mr. Wright. In a Letter from the Inventor - 279 VIII. Description of an Apparatus to secure Persons from sinking in Water, or _ to act as a Life-preserver when shipwrecked, with Instances of its Utility. By Mr. F. C. Daniel, of Wapping - - — 281 IX. Account of Experiments made by ‘Lieutenant Jobn Bell, of the Royal Ar- tillery, to ascertain the Practicability of throwing a Line to the Shore frem 2 Vessel stramded - - - - a 235 X. The Bakerian Lecture, on some new Phenomena of Chemiéal Changes pro- duced by Electricity, particularly the Decomposition of the fixed Alkalis, and the Exhibition of the new Substances which constitute their Bases; and - on the general Nature of Alkaline Bodies. By Humphry Davy, Esq. Sec. R.S. M.R.IA - 290 ‘XI. Remarks on Iron Spar. By Mr. Bergman - wht 314 | XII. Analysis of a Urinary Calculus. By Professor Wurzer—- : 317 Scientific News - . : - - | 218 Meteorological Journal ' - - > ae 320 SUPPLEMENT, viii CON TEN Ts. SUPPLEMENT TO VOL XX. Engravings of the following Objects: 1. Compound Sulphuret: 2. New Pro- aa of Tangents: 3. Radiation and Reflection of Cold: 4. Mr. Richard rew’s Balance Level: 5. Mrs. D’Oyley’s Method of rearing Poultry. I. The Bakerian Lecture on some new Phenomena of Chemical Changes _pro- duced by Electricity ; particularly the Decomposition of the fixed Alkalis, and the Exhibition of the new Substances which constitute their Bases; and on the. general Nature of Alkaline Bodies. By Humphry Davy, Esq. See. R.S. M. RTA. - - . - - 321 II. On the Composition of the Compound Sulphuret from Huel Boys, and ar Account of its Crystals. By James Smithson, Esq. F.R.S. - 32 IJ. On a new Property of the Tangents of the three Angles of a Plane Tri- angle. By Mr. William Garrard, Quarter Master of Instruction at the Royal Naval Asylum at Greenwich. Communicated by the Astronomer Royal 338 IV. Ona new Property of the Tangents of three Arches trisecting the Circum- ference of a Circle. By Nevil Maskelyne, D.D. F.R.S. and Astronomer moval c 5 ; : 3 - 340 V. On the apparent Radiation and Reflection of Cold by Means of two con- cave metallic Mirrors. In a Letter from Mr. John Martin - 34% VI. Description of a Balance Level, useful for laying out Land for Irrigation, for Roads, and other Purposes. By Mr. Richard Drew, of Great Ormond ' Street - = - = = = S++ VH. Account of 2 new Method of rearing Poultry to Advantage. By Mrs. Hannah D’Oyley, of Sion Hill, near Northallerton, Yorkshire 346 VIII. Communication from the Right Hon. the Earl of F ife, relative to his _ Plantations - - - el - - 350 IX. Remarks on the Advantages derived’ from Plantations of Ash Trees. By David Day, Esq. of West hill, near Rochester - - 252 ‘X.. Chemical Examination of a Sparry Iron Ore, sent to Mr. Guyton by Berg- - man. By Mr. Collet-Descotils - - - 3&7 Xk Chemical Examination of the Alum Ore of Tolfa, and the Earthy Alu- minous Schist of Kreienwald. By Mr. Klaproth - - 359 XII. On the Effects of Galvanism on Animals. In a Letter from Mr. John Tatum - - - - - Ot XII. On the Structure and Uses of the Spleen. By Everard Homme, Esq. F.R.S. - - EA ELON hie - - 374 XIV. On the Purification of Lemon Juice. In a Letter from a Correspondent 382 Scientific News - - - ~ 383 - A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND m THE ‘ARTS. MAY, 1808. ARTICLE I. An Attempt to ascertain the Time when the Potato (Solanum tuberosum) was first introduced inta the United Kingdom ; with some Account of the Hill Wheat of India. By the Right Hon. Sir Josern Banks, Bart. K. B.: P. ROS. &e.*- Tue notes on the introduction of the potato, which it is Notes collected hoped will not be found uninteresting, were chiefly collected panes « : by my worthy and learned friend Mr. Dryander, some of -— them from authorities not easily accessible. Those on the wheat, though not within the immediate object of this So- ciety, will, I hope, be considered as sufficiently interesting to be laid before them: could we trace the origin of any one of our cultivated plants, it may, and probably will, lead to ‘the discovery of others. The potato now in use (solanum tuberosum) was brought Potato intro- to England by the colonists sent out by Sir Walter Raleigh, Eoooeae under the authority of his patent, granted by Queen Eliza- 1586, by Sir beth, ‘for discovering and planting new countries, not pos- ba ea _sessed by christians,” which passed the great seal in 1584. * From the Trans, of the Horticultural Society, Vol. I, Part I, p. 8. « _ Vou. KX. No. 86.—May, 1808. B Some 2 INTRODUCTION OF THE POTATO. Some of Sir Walter’s ships sailed in the same year ; others, on board one of which was Thomas Herriot, afterward known as a mathematician, in 1585; the whole however re- turned, and probably brought with them the potato, on the 27th July, 1586. This Mr. Thomas Herriot, who was probably sent out, to examine the country, and report to his employers the nature First account and produce of its soil, wrote an account of it, which is mete me printed in De Bry’s collection of Voyages, Vol.I. In this account, under the article of roots, p. 17, he describes a plant called openawk : ‘‘ These roots,”’ says he, ‘ are round, some as large as a walnut, others much larger: they grow in damp soil, many hanging together, as if fixed on ropes ; they are good food, either boiled or roasted.” Gerard receive Gerard, in his Herbal, published 1597, gives a figure of rahe Virginia. the potato, under the name of potato of Virginia ; and tells us that he received the roots from Virginia, otherwise called Norembega. | First introduc-. The manuscript minutes of the Royal Society, December a. Tre- 13, 1693, tell us, that Sir Robert Southwell, then presi- dent, formed the fellows, at a meeting, that his grandfather brought potatoes into Ireland, who first had them from Sir Walter Raleigh. This evidence proves, not unsatisfactorily, that the potato was first brought into England, either in the year 1586, or very soon after, and sent thence to Ireland, without Considered as delay, by Sir ‘Robert Southwell’s ancestor, where it was a 9 cherished and cultivated for food before the good people. of gland in 1597. England knew its value; for Gerard, who had this plant in his garden in 1597, recommends the roots to be eaten as a delicate dish, not as common food. Conveyed ear- It appears, however, that it first came into Europe, at an lier from Ame- earlier.period, and by a different channel ; for Clusius, who rica to Spain, ry : : : : Fi and thence to at that time resided at Vienna, first received the potato in Italy. 1598, from the governor of “Mons, in Hainault, who had procured it the year before from one of the attendants of the pope's legate, under the name of taratoufli; and learned “from him, that in Italy, where it was then in use, no one certainly knew whether it. originally came from Spall or from America. Peter INTRODUCTION OF THE POTATO. 3 Peter Cieca; in his Chronicle, printed’in 1553, tells us, Mentioned in chap. xl, p. 49, that the inhabitants of Quito, and its vicie 1553, nity; have, beside mays, a tuberous root, which they eat, and call papas. This Clusius guesses to be the plant he received from Flanders; and this conjecture has been con- firmed by the accounts of travellers, who have since that period visited the country. From these details we may fairly infer, that potatoes were General infe- first brought into Europe from the mountainous parts’ of South America, in the neighbourhood of Quito; and, as the Spaniards were the sole possessors of that country, there is little doubt of their having been first carried into Spain, but as it would take some time to introduce them into use in that country, and afterward to make the Italians so well ac- quainted with them as to give them a name*, there is every reason to believe they had been several years in Europe, be~ fore they were sent to Clusius. The name of the root, in South America, is papas, and in Etymology ot ” Virginia, it was called openawk; the name of potato was thename. therefore evidently applied to it on account of its similarity in appearance to the battata, or sweet potato; and ‘our po- tato appears to have been distinguished from that root, by the appellative of potato of Virginia, till the year 1640, if not longer f. Some authors have asserted, that Potatoes were first dis. The sweet po- covered by Sir Francis Drake, in the South Seas; and others, tate introduced that they were introduced into England, by Sir John Haw- ine eae kins; but in both instances the plant alluded to is clearly the sweet potato, which was used in England as a delicacy, long before the introduction of our potatoes; it was imported in considerable quantities from Spain, and the Canaries, and was supposed to possess the power of restoring decayed {ts reported vigour. The kissing comfits of Falstafft, and other con- Properties. fections of similar imaginary qualities, with which our an- ‘¢€ * Taratoufli signifies also truffles, .t Gerard’s Herbal, by Johnson, p. 729, { “Let it rain potatoes, and hail eipine comfits.” Merry Wives of Windsor, Act v, Scene 5. Parkinson’s Paradisus Terrestris, p. ‘518. Gerard’s-Herbal, 1697, Pe 780, said Be cestors * Small seeds called hill wheat, Produced. spring wheat of the ordinary Size. Came from some part of India. Highly desira- ° ble to learn its origin, and whether wild. HILL WHEAT. cestors were duped, were principally made of these, and “4 eringo roots. The potatoes themselves were sold by itinerant adcaesig chiefly in the neighbourhood of the Royal Exchange, and purchased when scarce at no inconsiderable cost, by those who had faith in their alleged properties. The allusions to this opinion are very frequent in the plays of that age. Every anecdote that tends to throw light on the introduc- tion, or on the probable origin, of plants now cultivated for use, is certainly interesting, even though it is not quite per fect; I venture, therefore, to add the following. Seven or eight years ago, Mr. Lambert brought to me a small paper of seeds, on which was written, * Hill Wheat ;” I opened it, and found the seeds contained to be scarce larger than those of our wild grasses; but when viewed through @ lens, they perfectly resembled. grains of wheat. Of these seeds, he was so good as to spare me a few, which I sowed in a garden, the remainder he sowed; our crops very unexpectedly proved to be wheat of the spring kind, and the usual size, the grains of which were nearly, if not quite, as large as those of the ordinary spring wheat. On this, Mr. Lambert applied to Mrs. Barrington, from whom he had received the seeds, for information of the country from which they came; but she-had, among the multiplicity of seeds received by her about the same time, forgot the exact history of them; all she knew was, that they came from India, but from what part of India, she did not recollect. From the writing on the paper, “ Itd/ Wheat,” it is see! ble they came either from the Penmsula, or from the hilly country, far within land frem Bengal, as the province of Bengal itself is a flat alluvial soil, entirely level. The hill wheat, however, is no doubt known to some per- sons, who either are now in India, or have returned from it into this country; and it is certainly a matter of some importance to know, what they can inforn us on the -sub- ject of it; especially whether this wheat is a cultivated, ora wild plant; as we shall, if the latter is the case, ascertain two of the greatest.desiderata of cultivators; the country where wheat — STRUCTURE AND OFFICE OF THE STOMACH, $ wheat grows spontaneously ; and the nature of the grain in its original state, when unassisted by the fostering hand of man, yt err it. Observations on the Structure of the Stomachs of different Ani- mals, with a View to elucidate the Process of converting gnimal and vegetable Substances into Chyle. By Everarp Home, Esq. FP. R. S*. Tue observations on the stomachs of the porpoise}, and Fourth cavity of ruminating animals, contained in two former communi- “hg aah Cations, led me to believe, that the fourth cavity of the rumi- divided into “nant’s stomach, while the animal is alive, is always divided, ‘Y° portions, tn a greater or less degree, into two portions, in one of which is included the plicated structure, in the other, the villous, In some genera, this division is permanent, as in the camel and that tribe; in others only occasional, as in the bullock, deer, sheep, Xc. 4 If this opinion should be found to be true with respect to Thefood theres animals in gencral, it will throw considerable light on the io changesin processes carried on in the stomach, and lead us to conclude, it. » that the food undergoes two changes 1 in it, the one prepara- tory to the other, and that it is the last of these, which forms the chyle. With a view to investigate still farther this very interesting subject, I have been led to examine the internal structure of the stomachs of different animals. . In this inquiry it will be found, that the same webatibaiien A regular gra- are digested by stomachs varying considerably from each svebiehe Bees other, and many ef these varieties can at present in no other Malgees 0K way be accounted for, than by referring them to the general ! principle, which pervades the structure of animals, making them run into oneanother by a regular series of minute * Abridged from the Philos. Trans. for 1807, Part I], p. 159, “ +} See our last vol. ¢ changes § STRUCTURE AND OFFICE OF THE STOMACH, changes of form, so as to compose one connected chains from which we derive the fullest evidence of the power and wisdom of their Creator. Threedifferent ‘The stomachs of all ruminating animals have three dif- structuresin ferent structures; the first of these is cuticular; the second the stomach of ; é “ ; ruminants, has a secreting surface, thrown into folds, on which are seen the orifices of glands; and the third is smooth and more de- licate in its texture. andalsoofnon- In the following account, it will be found that three similar ruminants. structures are met with in the stomachs of quadrupeds which do not ruminate, and that the gradation between the most complex and most simple stomachs forms a uniformly connected series, of greater extent than has been hitherto supposed. To complete the view of this subject is too extensive a pursuit for an individual, whose professional duties occupy so large a portion of his time as mine necessarily do. All that can be expected from one so circumstanced is to give a general outline, leaving the minuter parts to be filled up by those who have more leisure, but by no means more zeal, for studies of this kind. Best mode of — As the object of the present inquiry is to determine with ne as much accuracy as possible the shape the stomach puts certainits | on, while performing its functions in the living body, and the oar structure, which belongs to the different parts of its internal membrane, it became necessary to consider what would be the best mode of making such examinations. It was found, that the stomach ought not to be in a distended state at the time of the animal’s death, for when this is the case, the air which is let loose, or even the shaking of the contents, elon- gates or stretches the muscular fibres, so as to enlarge the cavity, and give jt a form, by no means natural to it. This partly arises from the weakness of the muscular fibres them- Death destroys selves; but principally from the effect of death upon this pope a organ, which destroys the rigidity of its muscular dibres, so reverse of that they become easily elongated, even when much short- ae eww ened at the time death takes place. It is necessary to men- tary muscles. ~ tion this circuinstance, as it is the reverse of what happens in the voluntary muscles, which gre generally known to be- come rigid at that time, and it accounts for the real form of the STRUCTURE AND OFFICE OF THE STOMACH. 7 the stomach having been much less frequently noticed than was naturally to be expected. To come at the real form of the stomach, it must be seen n Should be ex. recently after death, before its muscles have been disturbed ; eee in this state a gentle and gradual distension with air shows - 4 both the permanent divisions of its cavity, if there be any, in the best possible manner, and also any occasional muscu- lar contractions, that are employed during life. The internal membrane is only to be met with in a natural I*s internal surface soon " state recently after death, since the secretion from the solyent acted upon ak ~ glands frequently acts upon it, and destroys the surface, and ter death, the slightest degree of putrefaction, which comes on very quickly in this cavity, prevents the nicer distinctions of struc- ture from being detected. To make an accurate examination of the different parts Best method of this membrane, it is necessary, that its folds should be ae Pra extended, and the mucus commonly found adhering to it membrane. removed; which is most readily effected, and with the least disturbance, by inverting the stomach and gradually dis- tending it; and im this state only can the relative situation of the different structures be ascertained with exactueéss. In examining stomachs, with the attention directed to Often obscured all the circumstances above mentioned, it is found, that, in °Y BYCY . a recent state, the internal membrane is often completely obscured by mucus, which in many instances is inspissated, and puts on the appearance of a cuticular covering, from which it is with difficulty distinguished ; in others it resem- bles a fine villous surface, so very tenacious is its nature; ‘and where the membraneis irregular it adheres with unusual firmness. ‘The internal membrane of most stomachs is found to be Much more extensive in considerably more extensive than any of the other coats, seneral than ‘and much more so than it appears to be on a superficial ex- the other coats, amination; for it is not, only thrown into longitudinal and transverse folds, but is subdivided by slight fissures into a pumber of small portions varying in shape and size in dif- ferent parts of the same stomach, but generally smallest near the pylorus. This appearance was at first mistaken for the real internal structure of the membrane; but when in- nevted and. distended, | so as to be put HPPA the stretch, all Pa these . of § STRUCTURE AND OFFICE OF THE STOMACH. these disappeared, and it became very thin and smooth. This is seen most readily,in the human stomach, and in those of carnivorous animals. Cannot per-’ Such distention enables us to examine the internal struc- rp a ture of parts, but this is not to lead us away from their overdistended. more natural appearance; since the functions of this mem- brane could no more go on were it unfolded to a great ex- tent, than the muscular actions of the outer coat, in an overstretched state of its fibres, © Hence a child In proof of this observation, I have known an instance of ee ae child three years old, who, being left alone at dinner, ate so large a quantity of apple-pudding, that it died, which raised suspicion of its having been poisoned. On exami- nation after death, the whole stomach was distended to its utmost extent, and rendered quite tense, which was the only apparent cause of the child’s death. Mr. Home.next proceeds to describe the stomachs of a considerable number of animals, his able and minute ex- amination of which is illustrated by several excellently en- graved plates; after which he gives the following general observations. Process of di- In the stomachs of ruminating animals, the processes the gestion most food. undergoes before it is Gonrerted into chyle are more complex in ru- 4 : C4 minating ani- Complex than in any others. It is cropped from the ground mals, ‘by the fore teeth, then passes into the paunch, where it is ‘mixed with the food in that cavity; and it is deserving of First stage of remark, that a certain portion is always retained there; for pie procter. although a bullock is frequently kept without food seven days before it is killed, the paunch is always found more than half full; and as the motion in that cavity is known to be rotatory by the air balls found there being all spherical or oval with the hairs laid in the same direction, the contents must be intimately mixed together; the food is also acted on by the secretions belonging to the first and second tavi- ties; for although they are lined with a cuticle, they have secretions peculiar to them. In the second cavity these ap- pear to be conveyed through the papilla, which in the deer AM conical ; and when examined by a lens the focns of which is 7 an inch, they are found to have three distinct orifices, ' and that part of each papilla next the point is semitransparent. These t STRUCTURE AND OFFICE OF THE STOMACH. 9 These secretions are ascertained by Dr. Stevene’s experi- ments to have a solvent power in a slight degree, since vegetable substances contained in tubes were dissolved in the paunch of a sheep*. neds The food thus mixed is returned into the mouth, where Seeond stage. it is masticated by the grinding teeth; it is then conveyed into the third cavity, in which it would appear from the gast let loose, that a decomposition takes place, and thence it is received into the upper portion of the fourth cavity. The changes which are produced on the féod in the first The 4th sto- mach the true three cavities are only such as are preparatory to digestion, <0) o¢ digs. and it isin the fourth alone this process is carried on. In tion, the plicated portion the food is acted on by the secretion of the solvent glands; and in this portion of the cavity of the deer’s stomach smail orifices are seen in the internal mem- brane leading to cavities, the size of a pin’s head, which I consider to be the openings of these glands, since they beat Formation of some resemblance to those of other stomachs. In the lower ee Fae portion the formation of chyle is completed. , ' lower portion. In birds with gizzards the food goes through very similar Birds with gir changes; it is picked up by the bill, which in smailer birds 2414s. ‘separates the husk from the seed, it then passes into’ the crop, where it is acted on by the secretions of that ‘cavity, after which it is received into the gizzard, to undergo the ” same change produced by the grinding teeth of the rumi- ants; the secretion of the solvent glands is then poured “upon it, acting upon the nutritious part before ‘it is -spread upon the glandular structure at the orifice of the gizzard, in which last situation it is formed into chyle. In the whale tribe, the first cavity, although lined with Whale tribe, a cuticle, has’ secretions peculiar to it, and therefore cor- responds with the first and second of the ruminants, and ping the aye i birds with gizzards: it answers howbver a ‘© Dissertatio Physiologica inauguralis de Wiereidlinrds concoctione, Au- ‘tere Edwardo Stevens, Edinb. 1777. “4 Mr Davy and Mr. W. Brande examined this gas, and found it to be Not the fer- inflammable, and not to contain carbonic acid; which establishes a dif- mentative pro- ference between this process and fermentation. jy COS» : farther 10 STRUCTURE AND OFFICE OF THE STOMACH, farther, pugpose, by-dissolying its conteuts sufficiently to prevent the necessity of rumination, or the use of a gizzard. The second cavity performs the same office as the plicated portion of the fourth cavity of the rummant, and the fourth _is that im which the chyle is formed. This complex struc- Different from jg the ruminating ~ ture of the stomach in. the. whale tribe, although it gives it an appearance of great similarity to that of the raminant, not at all formed on the same principle, since the ad- tribe, though a ditional cavities in the ruminant are to prepare the food for similarity in structure. Animals near- est to the ru- minants. Hare and rab- bit. Ruminate oe- casionally. the process of digestion; while in the whale tribe no sugh preparation is required ;, but as the fishes they feed upon are swallowed whole, and have large sharp bones which would injure any surface not defended by cuticle, a reservoir be- came necessary, in which they may be dissolved and con- verted into nourishment, without retarding the digestion of the soft parts. The very narrow communication between the second, third, and fourth cavities, resembles the open- ing between the cardiac and pyloric portion in fishes. The stomachs of this tribe of animals are therefore in- troduced here, as being next i erder with respect to the complexity of parts, and having by the division of them led me to the present investigation, although it is by no means their proper place, with. respect to their mode of di- gestion. | The animals, nearest allied to the ruminants in their mode of digestion, are those which, like them, retain a portion of food im the cardiac extremity of the stomach, that it may undergo a change, before it is submitted to the action of the solvent liquor; and when so hard as. to render it neces- sary, return it again into the mouth, to be masticated a second time. The hare. and rabbit are of this kind; the cardiac pertion of the stomach is never completely emptied, and they occa sionally ruminate. In proof of both these facts,, a nabbit, which had been seven days without food, died, and the car- diac portion of the stomach was found to contain more than half of its usual quantity of contents: they were rather softer than common, and a number, amounting to 50 or 60 of distinctly formed pellets, the size of shot, were collected together inthe cardiac extremity, immediately below STRUCTURE AND OFFICE OF THE STOMACH, i? below the cesophagus:. These.could not have been formed at the time of eating, since in seven days the action of the stomach would have destroyed their shape. They. must therefore have acquired it by the animal chewing the cud. This second class of ruminants have no cuticular lining Their difer- to their stomachs, which may arise from their being more ence from the cautious feeders than the others, so that they are not liable “Y® ™™ 20" to receive into the stomach any thing which can injure its internal membrane. All that portion of the stomach, which corresponds with the first cavity im the true ruminant, has one uniform structure, and is covered with a viscid mucus, but beyond this there are orifices, which I believe belong to ‘solvent glands of a very small size; and toward the pylorus, - the glandular appearance is of a different kind; so that in ‘these stomachs the changes the food goes through correspond very closely with those it undergoes in ruminants, The next order of animals with respect to digestion con- Beaver and sists of the beaver and dormouse. These, both in the shape 4°™™ovse- and general appearance of the stomach, as well as of the Wocth, bear a close affinity to the hare; but they have a glan- ‘dular structure peculiar to them, which seems to correspond ‘with the solvent glands of other animals; and as the dor- mouse empties its stomach completely, there is reason to be- lieve, that the beaver does so likewise, and that neither of them ruminates, smce the regurgitation of the food-would be probably do ‘attended with difficulty from the situation of these glandular °t ruminate. ‘structures; and it is probable, as they do not ruminate, the increased secretion of a solvent liquor renders it unne- ‘essary. ~The changes the food undergoes in these stomachs are Link between only two; it is acted upon by the secretion from the solvent ale eid glands, and afterward converted into chyle by the secretion rous. of those near the pylorus, ‘This is a less complex process than in many of the stomachs not yet taken notice of, and is exactly similar to what takes place in carnivorous animals; it may therefore be considered as a connecting link between ‘the ruminating and carnivorous stomachs. After these, which form a regular series from the rumi- Water rat. pants, are the stomachs with cuticular reservoirs, in which rhe the 12 STRUCTURE AND OFFICE OF THE STOMACH, the food is macerated, before it is submitted to the process .of digestion. Animals of this kind are the water rat, m Common rat and mouse, Horse and ass. sanguree, Occasionally ruminates. Stomach occa- sionally di- vided into a which there is a permanent division between the cuticular cavity and the digestive part of the stomach; the common rat and the mouse, in which there is only a muscular one. The cuticular lining is thick and impervious; beyond it is a glandular part, that secretes a mucus found adhering to its surface; and farther on are orifices, which appear to belong to the solvent glands. These animals do not ruminate, and there is a kind of provision ‘in nature to prevent regurgita- tion of the food, When kept without food for several days they completely empty their stomachs, The horse and the ass, although animals, in all other re- spects different, correspond so very closely in the structure of their stomachs with the rat and mouse, that their stomachs must be considered of the same kind. In these the food: is rendered easy of solution by re- maining in the cuticular reservoirs; it is then acted on by the solvent liquor, and in the pyloric portion converted into chyle. ; The stomach of the kanguroo, from the peculiarities of its structure, forms an intermediate link between the sto- amachs of animals which occasigna}]y yuminate, those which havea cuticular reseryair, and a third kind not yet noticed, with processes or pouches at their cardiac extremity, the in- ternal membrane of which is more or less glandular. The kanguroo is found to ruminate, when fed on hard food. This was observed by Sir Joseph Banks, who had several of these animals in his possession, and frequently amused him- self in observing their habits. It is not however their con- stant practice, since those kept in Exeter Change have not been detected in that act. » This occasional rumination con- nects the kanguroo with the ruminant. The stomach hav- ing a portion of its surface covered by cuticle, renders it similar to those with cuticular reservoirs; and the small pro- cess from the cardia gives it the third distinctive character; indeed it is so small, that it would appear placed there for no other purpose. The kanguroo’s stomach is occasionally divided into a greater number’ of portions than any other, since every part of STRUCTURE AND OFFICE OF THE STOMACH: 13 of it, like a portion of intestine, can be contracted separately ; greater num- and when its length, and the thinness of its coats are consi- Vongnpaie vi dered, this action becomes necessary to propel the food from ene extremity to the other. Such a structure of stomach makes regurgitation of its contents into the mouth very ea- sily performed. The food in this stomach goes through se~ veral preparatory processes ; it is macerated in the cuticular portion; it has the secretion from the pouch at the cardia mixed with it; and is occasionally ruminated.. Thus pre pared, it is acted on by the secretion of the solvent glands, which probably are those met with in clusters in the course of the longitudinal bands, .and afterward converted by the - secretions near the pylorus into chyle. : The animals, whose stomachs have processes or douches Animals with at their cardiac extremity, are the kanguroo, hog, pecari, eae” hippopotamus, and elephant. The pecari’s stomach bears the nearest. resemblance. to Pecari. those with cuticular reservoirs, having a portion of its surface lined with cuticle; but it only extends to a'small distance from the termination of the cesophagus, and is not continued ever any part of the great curvature. | The hippopotamus’s stomach I have never seen, and Dau- Hippopotamus benton’s description and engravings are taken from that of a feetus; so that the structure of its minute parts is imper- fectly known ; but there is no doubt of there being, a large pouch on each side of the cardiac portion, and there is rea- son to believe, that no part of the aren of the stomach is lined with cuticle. The elephant’s stomach is the most simple of this kind: Elephant. Tt has no euticular lining; the elongation at the cardia is only a continuation of iin general cavity, distinguished from it by the membranous septa ; and the broad one may act. as a valve, and occasionally preclude the food from: passing. In these stomachs the pouches at the cardia can jouly be connected with the preparation of the food, softening it by means of their secretions, or retaining: it within their eavi- ties; the other glandular structures are similar to those in the ass and rat, only more conspicuous. It is deserving of remark, that the internal. structure of In phytivorous the stomachs fitted for digesting vegetable substances, cor- rong oes esponds 14 SYRUCTURE AND OFFICE OF THE STOMACH. the stomach responds much less with the kind of teeth, than it has been sy Penge pinay generally supposed to do. The animals with chissel teeth teeth than have no uniformity in the structure of their stomachs; those panes tr of the beaver and dormouse being of one kind; the hare’s and rabbit’s of another; the squirrel’s of a third, resembling that of the monkey ; the guinea pig’s of a fourth, differing from that of the squirrel, im there being a greater dispropor- tion between the thickness of the coats of the cardiac and pyloric portions; the rat tribe of a fifth, which resembles the stomach of the horse and ass, animals whose teeth have a very different form. Greater anato- On the other hand, all the ruminants with horns have one SLatocant ” structure of stomach ;.all those with fighting teeth another, ‘weapons of de- as ‘has*been observed in a former paper; also all the animals patie with projecting tusks have the pouches at the cardia, which appear to be peculiar to them, although there is no connec- tion we yet know of between these weapons of defence and the stomach. Elephant. As the elephant’s grinding teeth are the best fitted for preparing vegetable food for digestion, so the stomach in its structure approaches nearer to those of carnivorous ani- mals. ‘The stomachs of which the structure has been hitherto considered belong to animals that feed on vegetables, and ehiefly on the leaves, roots, and branches of plants. In the Animals that dation towards carnivorous stomachs, we are next to take feed on fruits. ‘notice of those that belong to animals whose principal food is the fruits of trees, which appear to require less preparation for the. process of digestion; of this kind are the stomachs of the squirrel and monkey. These in their general appear- ance resemble very closely the human stomach; at least. the few opportunities, which have occurred to me of examining them, have not-enabled me to detect any circumstances in ote which they differ. Human sto- The human stomach appears to be the uniting link Ages mach. tween those that are fitted only to divest vegetable sub- tances, and those that are entirely carnivorous; and yet we _ find in its internal structure it is in every material respect similar to. those of the monkey and squirrel, which only di- gest vegetable productions, and also equally similar to those of STRUCTURE AND OFFICE OF THE STOMACH. 45 of carnivorous animals. Bein this it would appear, that many parts of vegetables are as easily digested as animal substances, and require the sarne organs for that purpose — but others again require a particular preparation, without which they cannot be converted into chyle; of these last the principal are the grasses, which the human storhach is Grasses not di- unable to digest. py Cesinle Ry it The bieaian stomach 1s divided i into’a cardiac and pyloric Divided into two portions. portion, by a muscular contraction similar to those of other animals; and as this circumstance has not before been taken notice of, it may be necessary to be more particular in de- scribing it. The first instance, in which this muscular contraction was First instance observed in the human stomach, was in a woman, who died © it observed. in consequence of being burnt. She had been unable to take much nourishment for several days previous to her death. The stomach was found empty, and was taken out of the ‘body at a very early period after death. It was carefully in- verted to expose its internal surface,.and gently distended with air. The appearance it put on has been already de- scribed. ‘The contraction was so permanent, that after the stomach had been kept in water for several days in an in- verted state, and at different times distended with air, the appearance was not altogether destroyed. Since that time I have taken every opportunity of exa- General: mining the human stomach recently after death, and find that this contraction in a greater or less degree is very gene- rally met with. The appearance which it puts on varies: but varies in sometimes it resembles that of the ass, so that this effect is 2PPS#™°° not produced by a particular band of muscular fibres, but arises from the muscular.coat in the middle portion. of +the stomach being thrown into action: and this for a greater or dess.extent, according to.circumstances, When this part of ‘the stomach is examined by dissection, the muscular fibres are not to be distinguished from the rest. If the body be arena so late as 24 hours after death, Seldom observ- this appearance is rarely met with, which accounts, for its not en Pape having before been particularly noticed. Perrault found a contraction somewhat similar ina Sion? S$ Lion’s stomach stomach, which ca vig to him extraordinary, as it was similar. only 16 STRUCTURE AND. OFFICE OF THE STOMACH. only met with’in one instance out of four, that were examined. ‘He gives a drawing of the appearance, but makes no com- ~ ments on the cause.of the contraction*. Attempt to Finding this contraction was met with, when the human at a "12 stomach was nearly empty, I endeavoured to produce it in the cat, by having the stomach emptied by means of an emetic a short time before the animal’s death: This did not however succeed; for although in the contracted state the line between the cardiac and pyloric portions was very dis- tinct, and the last mofe contracted than the former, yet upon distending the stomach with air, the middle portion Camnot be pro- relaxed equally with the rest. The contraction at this part duced artifi- is therefore only to be seen, when these fibres have acted in- Ori dependently of the others; which takes place while the func- tions of the stomach are going on, but cannot be artificially produced. _ Dog. ¥n examining the stomach of a dog in a contracted state, and afterward when it was distended, the line between the two portions could be distinctly perceived, even after the contraction was destroyed, by the longitudinal folds of the mternal membrane of the pyloric portion all terminating _there. Food disso'ved . That the food is dissolved in the cardiac portion of the poran cardiac human stomach, is proved by this part only being found ; digested after death; the instances of which are sufficiently numerovs, to require no addition being made to them. This could not take place unless the solvent liquor was deposited ‘there. Mr. Hunter goes so far as to say, in his paper on ‘this subject, ‘ there are few dead bodies in which the sto- mach at its great end is not in some degree digested.” ~ * La conformation du ventricule étoit particuliére, et bien différent en ce sujet de celle, que nous ayons trouvés aux autres lions, que nous avons dissequcs, ou le ventricule étoit semblable & celui des’ chiens et: _des chats; ayant un fond ample et large vers Vorifice supérieur qui alloit toujours en s’étrecissant vers le pylore; mais celui ci avoit le fond se paré en deux, en quelque facon comme les animaux qui ruminent. Ce forme particuliére du ventricute n’étoit qu’en un seul des quatre. ani- maux de cette espece que nous avous dissequés, scavoir deux lions et deux lionnes Mémoires pour servir & Ulistoire Naturelle des Animaux, dresséz par M., Perrault, Fol, Ed..1676, That STRUCTURE AND OFFICE OF THE STOMACH. 17 That the chyle is not formed there, and also that it is com- but the chyle pletely formed before the food passes through the pylorus, is Aig. ake proved by the result of some experiments of Mr. Hunter’s, made upon dogs in the year 1760 ; and as they were instituted for a very different purpose,—that of determining whether the gastric juice is acid or alkaline,—the results were detailed without any possible bias. _ The stomach of seven dogs were examined immediately Dogs examine after death, which took place while digestion was going on; = and among other observations the following appear among Mr, : Hunter’s notes made at the time: “ In all the dogs the food was least dissolved, or even «© mixed, towards the great end of the stomach, but became “* more and more so towards the pylorus ; and just within the ‘* pylorus it was mixed with a whitish fluid like cream, which ** was also found in the duodenum.” ‘ He afterward adds; ‘* It is plain, that digestion is com-: «* pleted in the stomach, as none of the crude food is found ‘* beyond that cavity; and even within the pylorus there is the ** same white fluid, that is met with in the duodenum.” 7 From the result of these experiments, as well as from the Glands that see analogy of other animals, it is reasonable to believe, that the tte the sol- F : 3 : : nie vent liquor, glands situate at the termination of the cuticular lining of the cesophagus, which have been described, secrete the solvent liquor, which is occasionally poured on the food, so as to be intimately mixed with it before it is removed from the cardiac portion: and the muscular contraction retains it there, till wn this takes place. : Such contraction being occasionally required in the sto- Curvature of mach, accounts for its being more or less bent upon itself, the stomach ‘ : : ae : : accounted for. which renders it more readily divided into two portions by the | action of the muscular fibres at that part where the angle is formed. It accounts for men occasionally ruminating, a process, Men occasion«- which, without such a contraction, could hardly take place. 2! Tminate That some men ruminate, the accounts of authors are suffi- ciently explicit to put beyond all doubt; particularly the in- stances collected by Peyer from Fabricius ab Aquapendente and others, as well as from his contemporaries, in all six or seven VoL. XX.—May, 1808. Cc instances, 18 An instance observed by the author, . ‘The contents not discharged by the first ef- fect of an eme- tic, Cramp of the stomach, Indigestion. STRUCTURE AND OFFICE OF THE STOMACH. | instances. Of these, two were examined after death. In one of them the esdphayus was unusually muscular, but nothing particular was met with in the stomach: in the other, nothing issaid of the esophagus, but the internal surface of the sto- mach was very rough. . The fact, however, does not rest on these authorities, since a case of this kind has come within my own observation. The instance to which I allude, is a man 19 years of age, blind, and an ideot from his birth, who is now alive. He is very ravenous, and they are obliged to restrict him in the quantity of his food, since, if he eats too much, it disorders his bowels. Fluid food does not remain on his stomach, but comes up again. He swallows his dinner, which consists of a pound and'a half of meat and vegetables, in two minutes, and 1 in about a quarter of an hour he begins to chew the cud. I was once present on this occasion. The morsel is brought up from the stomach with apparently a very slight effort, and the mus- cles of the throat are seen in action when it comes into the mouth; he chews it three or four times, and swallows it % there is then a pause, and another morsel is brought up. This process is continued for half an hour, and he appears to be more quiet at that time than at any other. Whether the re- gurgitation of the food is voluntary or involuntary cannot be ascertained, the man being too deficient in understanding, to give any information on the subject, This contraction of the stomach also explains the circum- stance of its contents not being completely discharged, by the first effect of an emetic, which only empties the cardiac por- tion: the contraction preventing the pyloric portion from be- ing. emptied till the violenge of the straining ceases, at which: time relaxation takes place. It may also enable us to account for many symptoms that oceur inthe diseases of this organ, particularly the violent cramps, to which it is liable: as from the situation of the pain- they probably arise from preternatural contractions of these ‘ muscular fibres. On thé other hand, the indigestion met within debilitated stomachs may proceed from this part hav- ing lost its proper degree of action, and therefore the food is ‘ not ‘STRUCTURE AND OFFICE OF THE STOMACH. 19 not retained in it so as'to be acted on by the different secre tions, This however is not the place to enter into these subjects ; the object of the present investigation has been to collect facts in comparative anatomy, that may throw light upon the conversion of the food into chyle, and to abstain as much as possible from all matters of opinion ;—no easy forbearance in boing over ground, that has given rise to so many theories, and which the mind cannot contemplate, without forming a variety of conjectures. _ The stomach of the truly carnivorous quadruped appears Truly camivo- ‘to be made up of the same parts as the human. In the lynx, a the different structures are more strongly marked, the solvent human. glands are more conspicuous, the pyloric portion is more bent, Thelynx. which renders the diyision between it and the cardiac more distinct, the muscular coats of the pyloric portion are much stronger, and on its internal surface glands are very obvious, which are not to be observed in the human. The stomachs of some carnivorous animals have glandular Peculiarities in structures peculiar to them; these are in the pyloric portion; oe there are alse similar glands in the stomachs of some grami- nivorous animals, as has been already explained. The follow- ing may be mentionéd as instances of this kind. In the lynx, a glandular zone surrounds the orifice of the Lynx, pylorus. - In the mole, there is a similar zone. _ Mole, In the stoat, and armadillo, there is a glandular structure aa hae = near the pylorus. i In the sea otter, there is a glandular structure extending Sea otter, from the pyloric portion into the duodenum, described in a former paper. In tracing the gradation from carnivorous quadrupeds to Gradation birds of prey, it would have been natural to expect, that the aia at bat, which has wings, and lives on animal food, should form birds of prey. an intermediate link: this, however, is not the case; the sto- Long-eared mach of the long-eared bat resembles those of small carnivo- rous quadrupeds; that of the vampyre. bat, which will be Vampyre. found to live on vegetables, has more the appearance of an intestine, and may, from its form, be mistaken for the G2 cecum 20 Ornithorin- chus, the only real link be- tween beasts and birds. Birds of prey. Snakes, turs ties, and fishes. General con- clusions. STRUCTURE AWD OFFICE OF THE STOMACH. cecum and colon; in this respect it approaches the kanguroo, and still more closely, the kanguroo rat; its cardiac portion is shorter, and its pyloric longer, than in the stomach of that animal, and there is no valvular structure at the orifice of the cardia. The only real link between the stomachs of quadrupeds and birds is that of the ornithorinchus, which, however, is more an approach to the gizzard, being lined with a cuticle, containing sand, and having the same relative situation to the esophagus and duodenum. The food of this animal is not known; it is probably of both kinds; the papille at the py- lorus, which appear to be the excretory ducts of glands, are peculiar to it. The stomachs of birds of prey are formed upon the same principle as those of carnivorous quadrupeds, but their cavity is more a continuation of the cesophagus, and the solvent glands are more conspicuous and numerous. Beth these dif- ferences may be accounted for from their swallowing their prey whole, or nearly so; which requires a more direct pas- sage into the stomach, and a greater quantity of secretion from the solvent glands, than when the food has undergone masti- eafion. The cardiac portion of these stomachs is very distinet from the pyloric. In snakes, turtles, and fishes, the stomachs have the same characters as in birds of prey, but the cardiac and pyloric portions are still more distinct from each other, and the sol- vent glands are in general distributed over a larger surface of the cardiac portion. . From the series of facts and observations which have been adduced, the following conclusions may be drawn, That the solvent liquor is secreted from glands of a some- what similar structure in all animals, but much larger and more conspicuous in some than others. That these glands are always situate near the orifice of the cavity, the contents of which are exposed to their secretion. That the viscid substance, found on the internal membrane of all the stomachs that were examined recently after death, is reduced to this state by a secretion trom the whole surface of the stomach, which coagulates albumen. This appears to be vi balla ae A a ia Rene ae Mie ert ara” rx = a QOS 4 = ay Te0dT’ d1 7d XX7 M2 7124 VO ULNOL*SOPY J SL L087 OYI) 472 PUFF D i WA oe wey fgeye me EO APPARATUS FOR PAPER-STAINING. o1- / be proved, by every part of the fourth cavity of the calf’s sto- mach having the property of coagulating milk. This property in the general secretion of the stomach leads Weak sto- : to an opinion, that the coagulation of fluid substances is ne- ot ree _cessary for their being acted on by the solvent liquor; and a food. practical observation of the late Mr. Hunter, that weak sto- machs can digest only solid food, is in confirmation of it. That in converting animal and vegetable substances into chyle, the food is first intimately mixed with the general se- cretion of the stomach, and after it has been acted on by them, the solvent liquor is poured upon it, by which the nutritious part is dissolved. ‘This solution is afterward conveyed into the pyloric portion, where it is mixed with the secretions pe- culiar to that cavity, and converted into chyle. The great strength of the muscles of the pyloric portion of some stomachs will, by their action, compress the con- tents, and separate the chyle from the indigestible part of the food. : In animals whose food is easy of digestion, the stomach consists of a cardiac and pyloric portion only; but in those whose food is difficult of digestion, other parts are superadded, in which it undergoes a preparation before it is submitted to that process, If, Description of a Machine for Printing Paper Hangings. By Mr. Joun Mippueton, of St. Martin’s-Lane.* i By this machine the printer works with greater facility and Advantages of dispatch than in the usual way; and the tereboy, who could ap ee with great difficulty serve one sieve, can by its means serve two with ease to himself. For this improvement the honorary silver medal was voted to Mr. Middleton by the Society of Arts, The following description shows the nature of this apparatus for facilitating the operations in paper-staining, and the mode of using it both for light and dark grounds. * From the Transactions of the Society of Arts, for 1807, p. 155. Method 92 APPARATUS FOR PAPER-STAINING, Method of printing Light Grounds. Description. of. PI. I, fig, 1, A, the printer’s table covered with a soft blan- the apparatus. fet BR the woollen cloth sieve on which the colour is laid, and spread by a boy (called the tere-boy) with a hair brush. This cloth sieve is laid upon a leather sieve impervious to wet, and it floats upon some gum liquor, in a wooden vessel C. D, D, two cords of 36 feet long, stretched from the table A to the other end of the room, and kept tight by a weight at B. : F, F, an endless cord, passing round a grooved wheel G.. under the table, over a pulley H, in the side of the table, and and over another I, at.the other end of the room. Its use is to carry the cross-piece K, called the traverse, which is fas- tened to it. L, is a wheel fixed on the same axis as the wheel G, but on the outside of the boarding of the table; it has three pegs projecting about four inches from its face. This wheel is moved by the printer setting his foot on one of the pegs. Fig. 2, is the traverse on a larger scale. M, M, are two pieces of wood connected by a hinge at N, and when closed are retained in that position by a ring O, put over the ends of | them: it is connected with the endless cord, by astaple P on one side, and another staple on the other side, and slides along the cords D, D, by means of two pullies R, R. Method of The operation of printing commences by putting one end printing light of the paper to be printed (which is 12 yards long and 23 oo inches wide) between the divisions of the traverse (fig. 2), and fastening it there by the ring O. ‘The other part of the paper, . except what lies on the printing table, is wound round the roller.S,. The workman takes up the printing block with his right hand, dips the face of it on tbe woollen cloth in-the sieve, which the tere boy had previously spread with colour, and then places the block upon the paper to be printed, giving it two or three smart strokes with a leaden mall held in his’ left hand; he then removes the block to supply it with more colour from the sieve; and during this operation sets his foot - upon the peg in the wheel; and as he recovers his upright po- sition to bring the block over the table, his foot presses tne Peg APPARATUS FOR PAPER-STAINING. peg down into the position 2, which, by means of the wheel G, endless cord F, and traverse K, draws the paper forward on the table just the proper distance to print again. When the whole piece is printed, the tere-boy goes to the end of the room, loosens the paper from the traverse, and hangs it up to 25 dry in folds, on loose sticks placed across racks attached to” the ceiling. Method of printing Dark Grounds. The table and sieve for the colour are the same as in print- ing light grounds. The difference of printing consists in ap- plying the colour from the block upon the table, by means of Method of printing’ dark — grounds, a lever, instead of striking the block with a mall; the pressure of the lever forcing a greater quantity of colour upon the pa- per and in a more even manner, T, the axle of the lever. Y, the arm (15 inches long) to which the power is applied by means of a rope U, fastened to , it, which has a treadle W at its end, for the workman to place his foot upon. X, another arm (6 inches long) to which is jointed Y, a long pole, the end of which is applied to the back of the block 3, when the pressure is given. Z, aii arm on the other side of the axle T, to which a weight is hung to balance the pole Y. Fig. 15! shows a section of the axle T with the arms V and a projecting from it, and the manner in which the arm X is con- nected ‘by a joint with the pole Y; the excellence of this, “principle depends upon the very great increase of power, which is given by bringing the pole near the centre of the joint or axis. i ‘The paper being placed upon the table as in printing. light grounds, and the workman having placed his block, furnished with colour, upon the paper to be printed, he puts his foot on — the treadle’'W, attached to the cord U, takes the pole from be- - hind the piece of wood 4, and applies its end upon the block | U, and pressing down his foot inakes the impression from the block upon the paper. He then lodges the pole behind the piece of wood 4, to be out of the way ; he next removes the — block to furnish it again with colour, and draws the paper for- ward for another impression, by the foot-wheel L, as described in the former mode, IV. QA RELISTIAN TIN MINE: IV. ‘An Account of the Relistinn Tin Mine. By Mr, Josern Carne, ina Leiter to Davixs Gippy, Esq. M.P. F.R.S*. DEAR Sau Penzance, April 22, 1807. Chlorite shist \ V HEN I mentioned the occurrence of pebbles of chlorite cemented by crystallized tin. shist, cemented by crystallized tin, in the Relistian mine, you expressed a wish to receive a particular account of this novel circumstance. The minedee The Relistian mine is nearly on a level with the surround. rears ing country, The lode has been seen at the depth of 12, 25, 50, 65,75, 81, and 90 fathoms from the surface. It is of different width in different parts; the extreme width is 36 feet, and in this part it is principally worked. As it extends east and west (which is its due course), its width gradually diminishes, till at the distance of 100 fathoms east it is but 5 feet wide. It is composed (excepting the metallic substances) of shist, chlorite, and quartz. In some parts the shist pre- dominates, and in others the chlorite; the quartz is through- out the smallest component part. The engine shaft (see plan A, P1.I, fig. 4) is situate 8 fathoms north of the widest part of the lode (B). In sinking the shaft a flookan (C), about 2 inches wide, was discovered, bearing a south-east course, which cut the lode at an angle of 45°; and heaved and disordered it. At the depth of 12, 25, and 50 fathoms, nothing was dis- covered in the lode but the cavities from which the ore had been taken away during the former period of working the mine. At 65 fathoms in depth were found, close to the flookan, a great number of angular fragments of shist, cemented by the same substance. Flookan di- At the depth of 75 fathoms the flookan (C) became 4 inches ca alii wide in the shaft (A), and continued of that size for 10 fa- branches, thoms; it then became divided i into 4 parts or branches (D), hei ta of each diverging from its former course, and in this state it con- €s De- Gs ther, tinued through ‘the lode (B), of which the first 3 feet were * Philos, Trans, for 1807, Part IJ, p. 298. i q composed ! ‘ WATER OF THE DEAD SEA. 2% composed of copper pyrites (EK), and then was discovered a chiefly shist, body of pebbles (1°), wearly 12 feet square, extending in Faia width to the extreme branches of the flookan. Jn this part of or oxide of the lode the shist greatly, predominates ; ; of course the pebbles oa are generally composed of shist, cemented jn some parts by the same substance or chlorite, in others by oxide of tin, which is generally crystallized, and in some of the crevices . - there is a little copper pyrites. [t is singular, that a few peb- bles (perhaps not more than half a score) were found of quite a different nature from the others; they were composed of tin in quartz coated with chlorite. ) The pebbles did not continue in a body to the height of more than 2 fathoms; but scattered bunches, and single peb- bles, were found 4 fathoms above and 6 fathoms below the place i in which they were at first discovered. It i is only ne- cessary to add, that the lode has since been worked 15 fa- thoms deeper than where the pebbles occurred ; 5 ae there con- sists for the most part of chlorite formed i ina regular manner; not the least trace of pebbles i is to be seen, nor indeed of any disturbance i in the strata. . I am, dear Sir, very sincerely yours, Penzance, Cornwall, JOSEPH CA RNE. 1 An Analysis of the Waters of the Dead Sea and the River Jor- . dan. By AuexanveR Manrcert, M.D. one of the Physi- » sians to Guy's Hospital. Communicated by Smiruson TEen- NANT, Esq. F.R.S*. Tur Dead Sea, or Lake Asphaltite, is situate it tHe Dead See. southern part of Syria, near Jerusalem, and occupies an ex- ; | tent of about 60 or 70 miles in length, and from 10 to 20 in breadth. ‘his lake has been from time immemorial cele- brated on account of the intense saltness of its waters, which % Philos. Trans. for 1807, Part I, p. 296, . is 26 Only analysis of it, ‘Water brought home by Mr. Gordon. WATER OF THE DEAD SEA. is such as to prevent either animals or vegetables from living init, a peculiarity from which it has derived its name. It appears, that this saling quality has existed in the earliest. ages; for independently of the frequent allusions made to it in the Scriptures, we find it described by several ancient au- thors, amongst ethers by Strabo*, who wrote during the reign of Augustus, by Tacitust, and by Plinyf. Amongst modern travellers, Pococke§, Volney||, and others, have noticed and described this singular spot. But although the most obvious peculiarities have for a long time been in some degree known, the only chemical analysis I have been able to find on record is that which was published in the ‘¢ Mémoires del Académie des Sciences’ for the year 1778, by Messrs. Macquer, Lavoisier, and Sage. The names of Lavoisier, and of his two distinguished associates, might appear to render any further investigation of the nature of ~ this water superfluous ; but whoever has perused the paper in question must be convinced, that these gentlemen, however correct in their general statements, neither attained that de- gree of accuracy of which modern analysis is susceptible, nor did they bestow on the subject that share of attention, which is indispensable in minute analytical experiments. The gentleman to whom I am indebted for the specimen of the water of the Dead Sea, which is the subject of this pa- per, is Mr. Gordon of Clunie, who recently travelled in that country, and undertook, not without some difficulty and dan- ger, an excursion from Jerusalem to this remarkable lake. There he himself filled and brought to Sir Joseph Banks a ~ phial, containing about one ounce and a half of this water, carefully corked, 'and in a state of perfect preservation. The same gentleman brought also in another phial, somewhat larger, a specimen of the River Jordan, which runs into the Dead Sea, without having any outlet, so that the river might : be expected to hold in solution ingredients analogous to those of the Lake itself. These specimens Sir Joseph put into the, hands of Mr. Tennant, for examination, But knowing that I * Strabonis Geogr. vol. ji, p. 1107. + Tacitus, lib. v, Hist, cap. vi. Y Plinii lib. v, cap. xv, and xvi. § Pococke’s Travels in 1743, ii, | Volney, i, 281, p. 34, was WATER OF THE DEAD'SEA, wasengaged in similar researches, Mr. Tennant was so oblig- ing as to entrust me with this. analysis, and to afford me fre- quent opportunities of availing myself of his assistance in the course of the inguiry. Being possessed but of a small quantity of this water, a further supply of which could not easily be procured, I was anxious not to waste any considerable portion of the ‘speci- men by preliminary trials. With this view, I began by making a variety of Comparative experiments on artificial solutions, in order to ascertain the accuracy of different modes of ope- rating ; and knowing by Lavoisier’s analysis, and also by the general efiects of. reagents applied to minute quantities of the water, what were the principal ingredients which I might ex- pect to find init, I. made solutions, the contents of which I Preliminary observations. had previously ascertained with precision, so that by ana~ - lysing these solutions in different ways, I had an opportunity of judging of the degree of accuracy that could be expected from a variety of methos. Some of these trials I shall briefly relate; for although not strictly belonging to the particular analysis i in question, yet I conceive, that they may be of some general use, in pointing out the most eligible method to be pursued in inquiries of this kind. Indeed it must be con- fessed, that the minute chemical examination of any indivi- dual substance requires so much time and patience, that ‘to obtain a knowledge of that substance only would seldom ap- pear ‘a sufficient inducement to such a laborious undertaking, was it not always more or —— connected with other useful] collateral objects, Secr..I. General Properties of the Dead Sea. 1. One of the most obvious peculiarities of the Dead Sea- water, is its specific gravity, which J found to be 1°211, a de- gree of density scarcely to be met with, I believe, in any other natural water. The circumstance of this lake allowing bodies of considerable weight to float upon its surface was noticed by some of the most ancient writers. Strabo, amongst others, states that men could not dive in this water, and in going into General pro- perties of the water. it, ‘would not sink lower than the navel 5 and Pococke, who | bathed 28 ‘om parative | periments. WATER OF THE DEAD SEA. bathed in it, relates that he could lie on its surface, motion- Jess, and in any attitude, without danger of sinking. “These peculiarities, which I at first suspected of being exaggerated, are fully confirmed by Mr. Gordon, who also bathed jn the » lake, and experienced all the effects just related. 2. The water of the Dead Sea is perfectly transparent, and does not deposit any crystals on standing in close vessels, 3. Its taste is peculiarly bitter, saline, and pungent. 4. Solutions of silver produce from it a very copious preci- pitate, showing the presence of marine acid. 5. Oxalicacid instantly discovers lime in the water. 6. The lime being separated, both caustic and carbonated alkalies readily throw down a magnesian precipitate. 7. Solutions of barytes produce a cloud, showing the ex- istence of sulphuric acid. 8. Noalumine can be discovered in the water by the deli- cate test of succinic acid combined with ammonia. 9. Asmall quantity of pulverized sea salt being added to a few dyops of the water, cold and undiluted, the salt was rea- dily dissolved with the assistance of gentle trituration, show- ing that the Dead Sea is not saturated with common salt. 10. None of the coloured infusions commonly used to as= certain the prevalence of an acid or an alkali, such as lit- mus, violet, and turmeric, were in the least altered by the: water. : Bren, tt. Preliminary Experiments to ascertain the Composition of the Salts concerned in this Analysis. Having satisfied myself by these preliminary experiments, that the Dead Sea contamed muriate of lime, muriate of mag- nesia, and selenite, and having nO doubt both from. the taste of the water, and from Layoisier’s statement*, that it con= » tained also common salt, I proceeded to the comparative ex- periments above mentioned, —» The first indispensable step was to ascertain with accuracy the proportions of acid and base in the three muriates just * Macquer, Lavoisier, and Sage, discovered the three muriates, but overlooked the smat! quantity of selenite. , “ named. WATER OF THE DEAD SEA. 29 named. ‘This I had already done in the course of a moré general inquiry, which I began some time ago in conjunc- tion with Mr. Tennant; and which has been of great use to me on the present occasion. But as the particulars of that series of experiments may probably be published at some future period, I shall now confine myself to such general statements as immediately belong to my subject. 1. The composition of muriate of lime was ascertained Muriate of ‘by pouring a known measure of muriatic acid on a piece of BES wd pure marble of known weight, and more than sufficient to 49:23 acidt saturate the acid. The remaining portion of marble being then weighed, and the solution evaporated and heated to redness, the proportions of acid and earth were easily de- duced. But in order to draw such an inference, it was ne-= cessary to ascertain with precision the quantity of pure lime in a given weight of marble, which, from a number of ex- periments performed with great care by Mr. Tennant and ' myself, appeared to be 56-1 parts of lime in 100 of marble. Marble con- From a great variety of trials, made with considerable atten- ‘""* naan tion, and with due allowance for any accidental circum- stances, muriate of lime appeared to consist of 50°77 parts of lime, to 49°23 of inuriatic acid. 2. To ascertain the proportions of earth and acid in mu- Muriate of riate of magnesia, required a synthetic process somewhat ™sn¢sia different. To a known weight of pure magnesia perfectly calcined, a known quantity of acid* was added, and after the whole of the magnesia was dissolved, the remaining por- tion of acid was saturated by marble. From the loss sus= contains of tained by the marble, and the known proportions of acid Magnesia 43-99 and magnesia used, the composition of muriate of magne- Re sia (supposed perfectly free from water) was deduced, and the proportions resulting from several careful trials. were 43°99 parts of magnesia, to 56-01 of muriatic acid. 3, Muriate of soda was analysed by various methods. But Muriate of " ® By a known quantity of acid is meant as much acid as will dissolve a known weight of marble. In all these experiments the quantities of - acid were not weighed, but measured by means of a peculiar appara- tus, and the real weights or intrinsic quantities of acid, corresponding to the measures in question, were easily deduced from the results above . mentioned, the soda, 54 4 soda, dhheronly one which I shall row relate consisted in precipi~ = tating the acid by a solution of silver from a known weight of muriate of soda, and inferring the proportion of acid ‘and alkali from the quantity of luna cornea obtamed. This however required a previous exact knowledge of the propor- tions of acid and silver in luna cornea. In order to ascer- tain this point, a known quantity of acid was iprecipitated Mutiate of sil. by nitrate of silver, and the weight of the luna cornea, after wer, being melted and heated to redness, indicated 19°05 parts of see sr acid to 80°95 of oxide of silver. The composition of com+ mon salt, calculated from these data, proved to be 46 parts of acid to 54.0f soda. ; Sect. iit. Comparative Analysis of artificial Solutions. Artificial sokmn 1 shall not enter into all the particulars of the variotis tons of these analyses of artificial solutions, resembling the water of the es Dead Sea, which directed me in the choice of the method which I ultimately adopted. But it may be proper to state, in a summary manner, the principal means which were tried, and their respective defeéts and advantages, These artificial mixtures all contained the three muriates above mentioned, but in each of them the small quantity of selenite was altogether disregarded. 1. The first of these solutions was evaporated to dryness, and the residue exposed for near an hour to a red heat ir a platina crucible pretty closely covered. The object of this was to drive off the acid from the magnesia (muriate of magnesia being decomposable by heat), and after separating this earth from the other salts by means of distilled water; to precipitate the lime by carbonate of amrhonia, and to ob= tain the muriate of soda by evaporation to dryness, But I Heat didnot soon found, that the complete decomposition of muriate of ae aaaR ts magnesia by heat, under these circumstances, was extremely muriate of difficult, if not impossible; and accordingly the results ob- magnesia, —_—_ tained from this method indicated considerably less magne+ sia and proportionally more lime, than the solution really contained, The quantity of common salt was tolerably ac- curate. 2, From ‘WATER OF THE DEAD SEA. sa 2. From another similar solution the lime was. precipitated by oxalate of ammonia; the magnesia was separated .by heat in an open crucible, and the common. salt was, obtamed, as before, by evaporation and exposure ,to a low red heat, The result was satisfactory both as to the lime and magne- The muriate of sia ; but as the separation of the latter could only be com- iy eee pleted. by long continued heat, in an open vessel, I found. tion. the muriate of soda materially reduced by sublimation, and was therefore obliged to abandon this mode of proceeding. g. From a third artificial solution, the lime was precipi- A 3d trial deo tated by oxalate of ammonia, the magnesia by carbonate of f*t¥e- ammonia recently prepared, and the sea salt was obtained as usual by evaporation and desiccation in a low red heat. The object of this mode of operating was to supersede the necessity of applying a red heat in the first instance. But I was again disappointed ; for the magnesia was but imper- fectly precipitated; and in order to separate the last portions of this earth, it was necessary to calcine the last residue containing the muriate of soda, which gave rise to the same objections as in the former experiments. A. The last and most successful. method consisted in di- Most succes- viding the artificial solution into two portions. From one get meee these the muriatic acid was precipitated by nitrate of silver, and its quantity ascertained. From the other the lime was separated by oxalate of ammonia, and the magnesia by caustic potash * ; and the respective portions of acids belong- ing to each of these earths being calculated, the quantity of muriate of soda was inferred from the remaining quantity of acid. This method afforded remarkably accurate results. The Only objection only objection to it seems to be, that the muriate of soda ves being only estimated, and not actually obtained, if any er- - our be made either in the estimation of the acid or in the * separatien of the lime and magnesia, these errours must also’ ultimately affect the computation of the muriate of soda, without allowing any immediate means of detecting them. * Or, by carbonate of ammonia. In this ease the precipitation of Magnesia is not so perfect; but the precipitate falls down more quickly, andthe separation of any remaining portion of this earth may be ultir mately completed by heut. , This | 39 WATER OF THE DEAD SEA. in-great mea- This objection, however, is in a great degree removed, by a ture removed. Comparison of the two portions of the solution, from one of which the common salt can be obtained undecomposed ; and the present method has this additional advantage, that the quantity of acid is.a sort of check, which, when con- nected with some other point of comparison, prevents ary pross errour in the computation of the earths from escaping notice. This plan being very similar to that which I actually fol- lowed in the analysis of the water of the Dead Sea, it may be worth while to mention the summary results of the com- parative experiments which decided ine in its favour. The artificial solution contained : Salts. Acid. Actual éci Muriate of lime-- ag? 8°17 grains 4°02 grains. tents of the so Muriate of magnesia»- 26°10 = 14:62 aloes Muriate of soda-+-+++ 25:00 = 11°50 59°27* = 30°14 And the cortents inferred by the foregoing method; were: 7 Sa 4 Ncid 3 Contents given alts Acid by the analysis, Muriate of lime-+---- 814 = 4°01 grains. Muriate of magnesia ++ 25°62 = 14:35 Muriate of soda ---.+- 25:47. = 11°72 59°23 = 30°08 oo ee Sect. IV: Analysis ef the Dead Sea. Water. Analysis of the I now come to-the actual examination of the water of the sc Sea wa- Dead Sea, the particulars of which will be found much short- - ened by the preceding observations: * These happened to be very nearly the real proportions of salts in the Dead Sea; yet this coincidence was a matter of mere accident; for when I mixed up the ingredients, 1 was led to suppose from Lavoisier’s papery, that their proportion in the Dead Sea was very different from that which I afterward ascertained. 1. 20 WATER OF THE DEAD SEA. 35 “}. 20 grains of this water (the whole supply of which By evapora- amounted only to 540 grains) were put into a glass capsule, to”: and slowly evaporated in a water bath, by means of an ap- propriate apparatus, the temperature of the capsule being constantly kept within 5 degrees of 180°. The object of this experiment was simply to know the weight of the solid ‘contents of the water, dried under various degrees of heat, and to observe the appearances produced by evaporation. After a few hours, and when the residue had ceased to lose weight, the saline mass, whilst still warm, appeared in the form of a white semitransparent incrustation, which yielded to the touch, being soft, and of a pulpy consistence. In cooling it became hard, and of a much more opaque white colour. When exammed with attention, the borders of this mass were found covered with small cubic crystals, and the same appearance was observed, though less conspicuously, in the centre under the saline incrustation, when in the state of semifusion iust described. On standing in the air for some time, the white opaque mass gradually absorbed water from the atmosphere, and returned to a liquid state. The 20 grains of the water, thus evaporated and dried at 186°, weighed, whilst still warm, 8°2 grains, 2. The same saline mass, being afterward exposed in a sand bath to the temperature of 212° Fahrenheit, was re- duced to 7°7 grains. Hitherto not the least smell of muria- tic acid was perceived, nor did any decomposition appear to take place. 3. But having raised the heat about 15° higher, the resi- due, after a few minutes, was found reduced to 7:4 grains; and on redissolving it,a few insoluble white particles appeared floating in the solution, showing an incipient decomposition in the muriate of magnesia. It appears from these experiments, that 100 parts of the Dead Sea water yield 41 of salts dried at 180°, and 38-5 dried at 212°*. What proportion these quantities bear to . the * Tf the quantity of materials upon which these results are founded should appear too small, I would observe, that, if the bulk of salt be> considerable, it is impossible to dry it accuritely, owing to the crust * which forms on the susface, and prevents the escape of moisture. But Vou. XX.—-May, 1808, D at 34 By nitrate of aparytes. By muriate of silver. Mouriate ofam- monia added. Oxalate of ame monia, WATER OF THE DEAD SEA. the same salts, when perfectly deprived of water, will Be seen frem the subsequent results. I now pass on to the che- mical examination of the water. 4. To 100 grains of the Dead Sea water a few drops of muriate of barytes being added,.a precipitate was obtained, which, after being well washed and exposed to a low red heat on a piece of laminated platina, weighed 0°09 grain, which, allowing for the unavoidable loss attending the mani- pulation of such very minute quantities, may safely be called 01 grain. ‘This residue, on being heated with fluat of lime, instantly ran into a globule, and was evidently sul- phate of barytes. 5. To another portion of the Dead Sea water, weighing 250 grains, a solution of nitrate of silver being added till it ceased to produce any precipitate, a quantity of luna cornea was obtained, which after careful edulcoration and exposure to a red heat, weighed 1632 grains, a quantity equivalent, according to the proportions above stated (sect. IT, 3), to 31°09 grains of real acid. 6. 'To the remaining solution a little muriate of ammonia was added, in order to remove the unavoidable small excess of silver, and this new precipitate was separated and well edulcorated. 7. The clear fluid, which had been much increased in bulk by these edulcorations, being concentrated to about 3 ounces, a strong solution of oxalate of ammonia, warm, but. not nearly boiling*, was tie to it, by which a precipitate was obtained, which collected and washed with the usual precautions, and after deducting 0'076 grains of limef for at any rate no perfect accuracy can be relied on réspecting this kind of limited desiccaticn, as its completion depends in a great degree on the shape of the vesse), the thickness of the stratum of salt, &e. * The precipitates of lime by gxalate of ammonia subside more readily, if the solutions be used warm; but when concentrated and heated to the boiling point, this test acts also in some degree on magne- sia, a circumstance which in the present instance was to be particularly avoided. + The proportion of lime in selenite, and of acid in sulphate of barytes, are taken from a paper of Mr. Chenevix, in Nicholson’s Journal, Vol, II, in which they are stated to be 56°4 of lime in 100 parts of selenite, and 24 parts of acid in 100 parts of sulphate of barytes, h the oe WATER OF THE DEAD SEA. es the 0136 grains of selenite belonging to 250 grains of the water, yielded 4°814 grains of pure lime = 4°66 grains acid = 9°48 grains muriate of lime. I should not omit mentioning, that the method which I used in all my experiments to ascertain the quantity of pure “lime in oxalate of lime, consisted in driving off the oxalic acid by a low-red heat, and adding to the calcareous residue, then converted into a subcarbonate, a known quantity of muriatic acid more than sufficient to dissolve the whole lime. A piece of marble of known weight was afterwards added to take up the excess of acid, and from these data the quantity of lime was calculated with great precision. 8. The clear solution containing nitrate of magnesia, nitrate of soda, and a small excess both of oxalate and mu- ‘riate of ammonia, and amounting in bulk to about 4 ounces, was éxposed to the heat of a lamp for concentration ; but in a few minutes the mixture became turbid and began to de- posit a white powder, which, from former observations, I sup- posed to be oxalate of magnesia. To this solution Concen= Subcarbonate trated to between 2 and 3 ounces, and still warm, I added of ammonia, carbonate of ammonia with excess of pure ammonia. A considerable precipitation immediately appeared, and. the mixture became opaque and milky. The next morning, however, the fluid had become quite transparent, and in« stead of a white impalpable precipitate, I found clusters of perfectly pellucid crystals spread over ‘the bottom of the vessel, with distinct interstices between them. __ This salt was no doubt an ammoniaco-magnesian carbo nate; and the remaining solution, although still containing, as will presently appear, a vestige of magnesia, was so far free from it, as not to have its transparency disturbed by caustic potash. These crystals, after being well washed in distilled water, were exposed to a gentle heat to drive off the ammonia, in consequence of which they crumbled down mto a white impalpable powder, exactly resembling common carbonate of magnesia. This powder being then treated, and its quantity estimated, in a way similar to that which had been employed with the lime; and being increased by . the addition of about 0°5 of a grain of a similar precipitate (which had escaped the action of the carbonate of ammonia D2 and 36 so°WATER OF THE DEAD SEA. and was obtained from the last remaining solution by evapor ration and calcination), amounted to 11-10 grains of pure magnesia =14°15 grains of muriatic acid = 25'25 grains of muriate of magnesia. — 9g. The muriate of soda was next estimated from the 12°28 grains: of muriatic acid found to remain after substracting the sum of the two portions (4°66 graius and 14°15 grains) belonging to the lime and magnesia, from the 31:09 grains, or sum total of acid. These 12°28 grains gave according to the proportions before mentioned (sect. HI, 3) 26°69 grains of muriate of soda. 10. From these several results brought into one view, and the salts being supposed heated to redness, 250 grains of the Dead Sea water appear to contain, Salts. ‘ Acid. Contents of Muriate of lime --++++ 9°480 grains 4°66 grains - 250 grains of oe fy NVR 23 m the wash Muriate of magnesia ++ 25°25 = 14°15 Murniate of soda -----+ 26°695 = . 12°28 ‘ Sulphate of lime «----+ 0°136 61°561 31°09 or of 100. And therefore 100 grains of the same water would contain, Grains. Mouriate of lime +--++eeeeeseses 3°792 Muriate of magnesia ---«++++++ 10°100 Muniate of soda -+--++++++++++ 10°676 Sulphate of lime -+++++seeeeee+ 0054 24°622, Srecr. V. Second Analysis of the Dead Sea Water by a Method some> what different from the former, . 2d. analysts, byasomewhat In the mode of proceeding just related some small loss different mode. . in the earths might naturally be suspected to have taken place in consequence of the previous separation of the acid and indispensable edulcorations, Besides, the muriate of soda being-nec essarily decomposed by the first part of the process, the analy sis could not have been considered as quite satisfactory, WATER OF THE DEAD SEA. satisfactory, had not the common salt been procured unal- tered by some other process. 1. In order to obtain these points, 150 grains of the water were treated, with regard to the lime and magnesia, exactly as in the former analysis; but in this case, the acid, instead of being actually separated by silver, was only calculated from the former estimation (sect. LY. 5). 2. The result proved perfectly agreeable to my expecta- tion. It yielded a little more lime aud magnesia than the former analysis, but this excess was scarcely perceptible. With regard to the muriate of soda, I was able actually to procure by evaporation as much as 13-1 grains of this salt, the actual quantity of which, inferred as in the preceding analysis, was 15°54 grains, a difference easily accounted for by the necessity of heating the salt to redness for its ulti- mate separation. 3. On summing up the contents of these 150 grains of the water, they appeared to be as follow: Salts. Acid. Muriate of lime --++++++ 5°88 grains 2°89 grains. Muriate of magnesia +--+ 15°37 = 8°6] Muriate of soda-..+--- eos oe ae ke ~ Selenite --s-eseeeeeee - 0°03 E 36°87 18°65 37 Contents of 150 grains, by this analysis, And consequently the proportions of these salts in 100 adil grains of the water would be: Grains. Muriate of lime -+ssexepeeeees 3°920 Muriate of magnesia -----+4---+ 10°246 Muriate of soda «-++++--ceee++ 10°360 Sulphate of lime Sa pace ateime arte. OS One 24°580 The coincidence of these results with those of the former analysis was such as I could scarcely have expected to in- credse by further trials, The last statement, however, I con- sider as the most accurate of the two, : It WATER OF THE RIVER JORDAN. ye General result. . It may therefore be stated in general terms, that the Dead Sea water contains about one fourth of its weight of salts supposed in a state of perfect desiccation ; while, as I ob- served before, if these salts be only desiccated at the tem-_ perature of 180°, they will amount to 41 per cent of the wa- .ter, This great difference between the two states of desic- cation depends on the great affinity which muriates, particu- larly that of magnesia, have for water. Muriate of soda is . scarcely at all concerned in this difference: for I found, not without surprise, that 100 grains of artificial cubic crystals of muriate of soda, being fused and heated to redness in a platina crucible, lost at most half a grain. Proportions of _ In the analysis of Macquer and Lavoisier,, the solid con- Macquer and tents of the Dead Sea are estimated at about 45 per cent of ome! the water, and in the proportions of nearly 1 part of com< mon salt to 4 of muriate of magnesia, and’3 of muriate of lime; proportions widely different from those which I had obtained. But their mode of operating, which they can- didly relate, was so evidently inaccurate with regard to the separation and desiccation of the salts, and in general so deficient in the estimation of quantities and proportions, that these eminent chemists cannot be considered as having aimed, in this instance, at any thing like an exact analysis, Jt may be observed alse, that these gentlemen found the specific gravity of the water 1246 instead of 1-211, as I have stated it to be; but it appears, that their specimen had suffered some evaporation previous to their experiments, since they found crystals of common salt in one of their bot- tles, which could not have happened without evaporation. — The proportie Besides, the specimen which I examined was, I understand, ons above per- haps rather too brought from a part of the lake not more than two miles small. distant from the mouth of the Jordan, a circumstance which may perhaps account for its being somewhat more diluted, than it might be found i in other parts. Secr. VI, Analysis of the Water of the River Jordan. Water of the As I had scarcely two ounces of this water, and as it con= Jordan, tained but a very small pyoportion of saline ingredients, it would ® WATER OF THE RIVER JORDAN, . * would have been in vain to aim at analysing it with strict accuracy. Yet 1 thought it worth while to endeavour to form as exact an estimation of its contents as I could, on account of its connection with the Dead Sea, into which, as was observed before, it pours. its waters, and appears to re» main in a stagnating state. Zhis specimen was brought from a spot about three miles distant from that where the a river enters the Dead Sea. | From the perfect pellucidity of this water, its softness, Apparently and the absence of any obvious saline taste, I was led to sup- P"™ pose, that it was uncommonly pure, and could i in no degree partake of the peculiar saline qualities of the Dead Sea. But I was soon induced to alter my opinion by the following results. 1. The same chemical reagents, as were used to ascer- but analogous tain the general properties of the Dead Sea water, being ada - applied to this, produced analogous effects. The same cept in three muriates and even the vestige of selenite were dise St'ength. tinctly discovered; and this raicraiane became more striking in proportion as the water was concentrated by evaporation. + 2. 500 erains of this water being evaporated at about 200°, the dry residue weighed exactly 0°S of a grain. This makes the solid ingredients amount only to 1-6 grain in 1000 grains of the water, a singular contrast with the Dead Sea, which contains nearly 300 times that portion of saline Apparently matter. As the water was concentrating, a few white par- canta sae 4 ticles were perceived on its surface, and a few others gradu- Sey rai ally subsided. When dried, the residue appeared in the form of a white incrustation, the upper edge of which exhibited great numbers of very minute aie which from their rans taste, and their cubic shape, discoverable by the aid of a microscope, were eyidently common salt. 3. Distilled water being thrown on this residue, a minute portion of it remained undissolved, and on pouring an acid on this substance, a distinct effervescence was produced, showing the presence of carbonate of lime. 4. From the clear fluid a precipitate was obtained by oxalate of ammonia, which, dried but not calcined, weighed 0 p12 of & gyain, 5. From 40 MEASURE OF A DEGREE ON THE COROMANDEL COAST. ° 5. From the remaining clear solution a magnesian prey cipitat e was produced by ammonia and phosphoric acid, which, after driving off the ammonia by heat, weighed 0:18 of a grain. 6. The solution had suffered too many alterations to allow me to separate, with any degree of accuracy, the muriate of soda; but from a variety of circumstances, I thought it not unlikely, that it would have been found pretty near)y 1 in the same proportions, with respect to the other salts, as it exists in the Dead Sea. "he Dead Sea The inference I drew from this was, that the River Jory perhaps the — qan might possibly be the source of the saline ingredients of same water concentrated the Dead Sea, or at least that the same squrce of impregna~ by evaporation. tion might be common to both. This i inquiry, hqwever, would require a much more correct knowledge both of the proportions of the salts, and of local circumstances, than J have been able to obtain. mac An Account of the Measurement of an Are on the Meridian of the Coast of Coromandel, and the Length of a Degree is deduced therefrom in the Latitude of 12° 32’, By Brigade Major Wixu1aAm Lamson, (Concluded from Vol. XIX, p- 317.) Reductions of Tue reductions from the hypothenuses to bring them tag a br pothe- the horizontal level were made by numbering the feet from the old chain as they were measured, viz, by calling 32 chains 3200 feet, which would be 3200°1}5 feet by the new chain; but this would produce no sensible errour in the versed sign of a very small angle, and on that account these decimals were not taken into the computation, which was thought less necessary, since the whole deduction did not amount to three inches. Neither was any notice taken of the different heights of the hypothenuses or levels one above another, as that difference was too trifling to affect a length of thirty or forty chains, The base has therefore heen con- sidered MEASURE OF A DEGREE QN THE COROMANDEL (COAST, Aq sidered at the same distance from the centre of the earth, before it was reduced to the level of the sea, and the per pendicular height of the south extremity, which I have cone _ sidered as nearly the general height, hag been taken for that purpose. That perpendicular height was obtained by come paring the south with the north extremity, and the height of the latter was determined by observations made at the race- stand and on the sea-beach, where allowance has been made for the terrestrial refraction. The following is the manner in which it has been determined : On the top of the race-stand, the under part of the flag Determination an of the height en the beach was observed to be depressed 9’ 30’; and at shove the sea. the beach, the top of the race-stand was elevated 7 15”. Wher the instryment was on the platform of the race-stand, the axis of the telescope was on a level with the top of the railing, which was observed from the beach. But at the beach the axis of the telescope was four feet below the part of the flag which had been observed, The horizontal distance from the station on the stand to that on the beach js = 19208 feet. Then as 19208:4:; Rad : tan, 43”, which must therefore be added to the ob= _gerved depression ofthe flag. Hence 9’ 30’ + 43” = 10’ 13” is the depression of the axis of the telescope on the beach, observed from the race-stand, Now the station on the beach is nearly at right angles to the meridian, therefore, by allowing 60957 fathoms to the degree, 19293 feet will give an are of 3’ 9” very nearly, which is the contained arc. And the difference be-. tween the depression and elevation being 2’ 58”, we have 3! 9! mn 2! GM = 5'°5 for the terrestrial refraction. Hence, ‘since the observed elevation of the stand, plus half the con- tained arc, would give the angle subtended by the perpen- —@icular height of the gtand above the telescope at the ao? 2 — 5'°5 = 8'44” for the true angle subtended by the pér- pendicular height, which being taken as tangent to the ho- tizontal distance and radius, we have R: tan. 8’ 44” :: 19208 : 48°797 feet the height required. But the axis of the telescope on the beach was determined, by levelling down beach, were there no refraction, we shall have 7°15” + t MEASURE OF A DEGREE ON THE COROMANDEL COAST. down to the water, to be 21:166 feet above the sea. Which, added to the above, give 69°963 feet for the perpendicu- lar height of the top of the stand above the level of the sea. Now the top of the race-stand was determined by level- ling to be 31°25 feet above the north extremity of the base; which, taken from the other, leaves 38°713 for the north extremity of the base above the sea, which extremity be- ing, by the table, 22°96 «feet above the south extremity, - we-shall have 15°753 feet from the perpendicular ‘height of the south extremity of the line above the level of tie ‘sea; and from this height the length of the base has been reduced. é é The angles of elevation and depression were taken by the circular instrument, from a mean of. several observations, and the errour of co!limation was corrected by turnimg the _ transit over, and the horizontal plate half round. But the Properest sta- tions selected. Theodo'ite, weather was rather dull during the whole of these opera- tions. . Major Lambton then proceeds to give the particulars of the measurement of his base line, commencing im lat, 13° 00’ 29°59” N., and extending 4000674418 feet south-west- erly, making an angle of 10 36” with the meridian. Commencement of the operations from the base. The large theodolite. After the completion of the base line, there remained nothing of importance to. be done until I received the large instrument, which arrived in the beginning of September. I had however made an excursion down the sea coast, as far as Pondicherry, for the purpose of selecting the properest stations for determining the length of a meridional are, This and the measurement of a degree at right-angles to ; the meridian I considered as the first object of this work: I accordingly lost no time in proceeding to accomplish these desiderata. The instrument above alluded to was made by Mr. Cary, and is in most respects the same as that described by Ges ’ neral Roy in the Philosophical Transactions for the year 1790, with the improvements made afterwards in the micro# . scopes, j MEASURE OF A DEGREE ON THE COROMANDEL COAST, 43 scopes, and im an adjustment to is vertical. axis, by which the circle can be moved up or let down by means of two capstan screws at the top of the axis. These are mentioned in the Philosophical Transactions for 1795, in the account of the trigonometrical survey. By sinking the circle on the axis, it is better adapted for travelling, and when the micro- scopes are once adjusted to minutes and seconds, on the limb of the instrument, the circle can always be brought _ back to the proper distance from them. Great attention however is necessary in bringing the axis down, so that the- wires in each microscope being fixed at opposite dots on the limb, they may coincide with the same dots when the circle is turned half round, or made to move entirely round, and in a contrary direction to what it had been moved before ; ‘which latter method:has been recommended by the maker. This circumstance respecting the axis should be most scru- pulously attended to before the adjustment of the microme- ters begins, so that when by arranging the lenses in such a manner that ten revolutions of the micrometer may answer to ten minutes on the limb, and therefore one division to 6 one second, the circle can always be brought to its proper height, by trying the revolutions of the micrometer. It has however been found from experience, that unless in cases of very long and troublesome marches, it is not ne- cessary to sink the axis. The carriage being performed al~ together by men, there is not that jolting which any other mode of conveyance is subject to, and as I found, that a considerable time was taken up in adjusting the axis before the revolutions of the micrometers could be brought to their intended limits, 1 therefore Jaid it aside, unless under the circumstances above mentioned. _ The semicircle of the transit telescope is graduated to 10’ Semicircie of of a degree in place of 30’, which was the case with the Wahi if semicircle described by General Roy, and the micrometer te the horizontal microscope applied to this semicircle, making one revolution in two minutes, and five revolutions for ten minutes on the limb ; .and the scale of the microme- ter being divided into sixty parts, each part is therefore two seconds of the circle. A number of experiments have been made for determin- Errour of the ine semicircle, t=] 44 Line of colli- mation, MEASURE OF A DEGREE ON THE COROMANDEL COAST. ing the errour of the semicircle, and to ascertain the place of the fixed wire in the horizontal microscope, so as to divide the errour. It has appeared in the event, that the telescope being in its right position, (that is, when the limb and mi- croscope were on the left hand,) and the fixed wire placed at zero on the semicircle, when the circle or limb of the theodolite was turned 180° in azimuth, and the telescope turned over, the fixed wire was then distant from zero on the opposite part of the ar¢ by a mean of a great many ob~ servations 2’ 57”, the half of which is therefore the errour. This half was carefully set off from zero by the movable micrometer wire, and the fixed one brought to coincide with it. On the right application of this errour, there will be 1’ 28'°5 to add to the elevations and subtract from the de- pressions, The observations for determining this quantity were repeated at different times, and under the most favour-. able circumstances; the adjustments of the whole instru- ment being frequently examined, and the level apphed to the telescope reversed at most of the observations. For the Jine of collimation, as these corrections depend on having 4 well defined object, I fixed 2 bamboo upwards of a mile dis- tant from the observatory tent, and tied round it several narrow stripes of black silk, one of which was near the ho- rizontal wire when the axis of the telescope intersected the staff after being brought to a level by the bubble, Then the instrument being adjusted, and the telescope directed to the bamboo being perfectly level, and the wire of the mi- crometer in the piece brought to the intersection of the cross wires, the angular distance to the mark on the bamboo was measured by the runs of that micrometer, and the wire brought back to the point of intersection of the other wires. The circle was then turned half round and the telescope reversed or put again into the same Ys. The levelling ad= justment was then made, and the angular distance from the intersection of the wires to the black mark again taken, half the difference between which and the former was of course the errour of collimation, This errour was repeatedly re- duced till it became very small, half by the finger screw of the clamp to the semicircle, and half by the adjusting screws to the levelling rods. After that, the remaining er- your MEASURE OF A DEGREE ON THE COROMANDEL COAST. rour was repeatedly examined and found to be 2°36 to be substracted from the elevations and added to the depressions when the telescope is in the ordinary position, or when the semicircle and microscope are on the left hand; but vice versa when in the contrary position. These errours of the semicircle and line of collimation being opposite, the result from comparison will be, «‘ That when elevations or depres- sions are taken with the semicircle, 1’ 26” must be added to the former, and substracted from the Jatter.”’ _ And that when the elevations and depressions are taken by the micrometer in the eye piece 2-36 must be deducted from the e/evations and added to the depressions. The micrometer in the focus of the eye-glass of the tran- sit telescope is the same in all respects as the one mentioned by General Roy, that is to say, the circle or scale is divided into one hundred divisions, and there is a nonius fixed to the upper part of the telescope, which defines the revolu- tions of the micrometer as far as ten for the elevations, and ten for the depressions. Several experiments were made with the same marked bamboo, for ascertaining the value ef these divisions, and it was found, that seven revolutions and 61°4 divisions were equal te ten minutes on the limb of the semicircle, so that one division was equal to *788 of a see cond. Having given tables of all the angles, Major Lambton adds. The angles have been taken with much care, and I believe with as much accuracy as the nature of such a pro- cess admits of; difficulty, however, very frequently arose from the haziness of the weather, which rendered the ob- jects. at the very distant points extremely dull, and occas sioned some irregularity in the angles.. Whenever that hap- pened, the observations were often repeated, and in ease any one, in particular, was different from the other so much ag ten seconds, it was rejected till the three angles of the tri- angle had been observed. If the sum of these angles was near what it ought to be, no further notice wag taken of it; but should the sum of the three angles be nearer the truth by taking it into the account, and that there appeared an irregularity in the other two observed angles, I have made ita rule to take each observed angle as a. correct one, and divide 45 Micrometer. Remarks on the angles taken. 46 Zenith sector. MEASURE Of A DEGREE ON THE COROMANDEL COAST. divide the excess or defect between the other two, and then compute from the given side the other two sides; and after doing the same thing with each of the angles successively, a mean of the sides thus brought out was taken, which, to certain limits, will always be near the truth. I then varied the selection of the observed angles, rejecting such as I had reason to doubt; and by correcting them, and computing “the two required sides of the triangle, those which gave the sides nearest to what had been brought out by the other method were adopted, let the errour be what it would. This, fiowever, has rarely happened; and when it did, great pre- caution was used; and no angle was rejected, a a some reason appeared to render it doubtful. In correcting the observed angles to obtain those made by the chords, I have used the formula given by the Astro- nomer Royal, in his demonstration of M. de Lambre’s pro- ° blem, which appears in the Philosophical Transactions for 1707. The spherical excess is of course had from the well ‘known method of dividing the area of the triangle in square seconds, by the number of seconds in the are equal to ra dius, where the number of feet 10 a second may be had by using the degree as has been commonly applied to the mean sphere, or the mean between the degree on the meridian and its perpendicular. This being of no farther use than to check any errour that might Habpen in computing cor= rections for the angles. Observations by the Zenith Sector for the latitude of Paudree station, and the station near Trivandeporum; and the length of the celestial arc. } , The zenith sector, with which these observations havé been taken, was made by Mr. Ramsden, and is the one al- luded to by General Roy, in the Philosophical Transactions for 1790, being then unfinished. The radius of the are is five feet, and the arc itself is of that extent to take in nine degrees on each side of the zenith. It is divided mto de- grees, and smaller divisions of 20’ each, which are num- bered. Each of these last is again subdivided into four, of 5’ each. The micrometer, which moves the telescope and ere, is graduated to seconds, and one revolution moves the arc MEASURE OF A DEGREE ON THE COROMANDEL COAST’ 47 ate over 1’ 10” 08”, but the scale being large, a small fracs | tion of a second can be easily defined. The construction, and improvements to the zenith sectors are so well known, that a minute description of it here would be unnecessary. ‘ It will therefore suffice to say, that:as far as so delicate an instrument can be managed in a portable observatory, or travelling tent, which never can offer the advantages of a fixed, well contrived building, I have every reason to be sa- tisfied with it. The time I commenced ebaenvinié 4 at Paudree station was Observations. during the heavy part of the monsoon, which occasioned ' frequent interruptions: and although I had intended ob- serving by at least three fixed stars, I only succeeded to my satisfaction in one, which was Aldebaran. With that star J had a fertunate succession for about. sixteen nights; some few of these. observations, being: less favourable than the others, were rejected. During the time I was at Trivandeporum, near Cudda- lore, the weather was settled and serene, and the nights perfectly clear, so that I had an unlimited choice of stars, but having been successful with Aldebaran, [ chose that star fer determining the length of the are, As I consider the celestial arc more likely to be erroneous Manner of obs than any terrestrial measurement, I have thought it neces- shighd Ber sary te give seme account of the manner of ohadevink and instrument. of adjusting the instrument, for, after two years experience, L have found, that, notwithstanding the great powers of the zenith sector, extreme delicacy and attention aré requisite, to render the observations satisfactory. The following me- _ thod of adjustment I have always practised. After having brought, the vertical axis nearly to its true position by the adjusting screw at the bottom, or so that the wire of the: a plummet would bisect the same dot when the telescope was. moved to the opposite side, or half round on the axis, I then examined whether the dot at the centre of the, hori- zontal axis was bisected, and whether the wire moved in the vertical plane clear of the axis; for unless it be perfectly, free, all the observations will be false. When I had. bi-> sected the dot, I either took out the microscope and looked obhiquelys:o or did the same by # magnifying glass, and by’ that 43 MEASURE OF A DEGREE OW THE COROMANDEL COASY, that nieans I could discover the smallest parallax. H it ade mitted being brought nearer to the axis, it was done; but E found from experience, that it was more eligible to leave the wire at a sensible distance, than to bring it very near. Hav- ing satisfied myself in this particular, I examined with. the microscope again in front, moved the wire freely in the ver- tical plane, and then bisected the dot. The telescope was then moved, so that the wire was brought orer the dot zero on the arc, and the same precaution used with respect to the wire moving free of the arc; and here, as well as above, I found it best to allow a sensible distance between the wire and the are. Adjustment of . The microscope by which the upper dot in the horizontal the microscope. Fixing the in- ent. axis is examined being fixed by the maker, the axis of vision is of course at right argles to the vertical plane, and wilt meet that plane in the centre of the axis; but the lower microscope is movable, and requires care to fix it so as to have the wire in the axis of vision, and be free from the ef- fects of parallax; this I have done by moving it along the brass. plate in front of the arc, till the wire appeared free from curvature, and then adjusted the dot. In these late observations, I have generally made the final adjustment by the hight of a wax taper, for the wind being sometimes high and troublesome, I found there was much irregularity in the’ observations, until I adopted that method. I therefore: closed the doors and windows of the observatory tent, so as to have a perfect stillness withm. The distance of the wire from the axis and the arc is likewise better defined by ‘a taper by noticing the shadow in moving the hght to the right and left. In fixing the instrument for the star, great care was taken to have it placed in the meridian, which was done by a mark at near the distance of a mile (generally one of my small flags), the polar’star having been previously observed by the large theodolite for this purpose. The telescope was then moved in the vertical, till the wire of the plummet was at the nearest division on either limb to the zenith distanee ’ of the star, which could always be nearly known. The mix crometer, having been put to zero, was firmly screwed, and the dot on the limb carefully bisected, the instrument was “turned MEASURE OF A DEGREE ON THE COROMANDEL COAST. 49: turned Half round ; the adjustment examined and corrected, if necessary. This being done, the degrees and minutes,’ &c., on the arc were noted down, as was also the particular division on the micrometer scale, at which the index stood, and the fractional part of a division in case there ‘Was any. In this state every thing remained to within fifteen or twenty’ minutes of the time the star was to pass, when I repaired to the tent, and again examined whether the wire bisected the’ dot; if it did not, the instrument was again adjusted to the same dot, and the horizontal axis also examined by the up- per microscope, ail this being done, the sector was placed’ in the meridian. - When the star entered the field of view, the micrometer Observation of : : yuin, the state was moved gently till the star was near the horizontal wire, but not bisected till it came near the vertical, that the mi- erometer might not be turned back, but continue moving in the same direction. ‘This I did to avoid any false motion in Caution re- the micrometer screw, and [ was led to this precaution by cma tee the repeated experiments I had made in examining the divi- sions on the arc, for it sometimes happened after moving the are Over one of the divisions till the wire bisected the next dot ; and then turning it back again, that the index of the micrometer was not at the same second, but had passed over it perhaps one, and sometimes two seconds; but by moving over the next five minutes in the same direction, the number of revolutions and seconds were always what they ought to be, to some very small fraction. This anomaly, however, only happened in some situations of the screw, and to avoid any errours arising therefrom, I adopted the above method. _ The zenith distance of the star being now had, on one part Zenith dis- of the are or limb, after the same process had been gone meta | through the next night, with regard to the adjustment, the theare. zenith distance was taken on the other part of the arc, by turning the instrument half round on its vertical axis. The mean of these two was therefore the true observed zenith dis- tance, and half the difference was the errour of collimation. For applying these to the purpose in question, the mean of the zenith distances being corrected for refraction, the decli- nation of the star for each of these nights was corrected for You. XX.— May, 1808. | nutation, 50 Degree of lat. between 12° and 13° N. 60495 fath. Deg. of long. gn 12° 32’ 61061 fath. CULTURE OF APPLE TREES. nutation, aberration, &c., to the time of observation, and the mean of the two taken for determining the latitude. In this manner has the whole series of observations been continued, by turning the sector half round every night, for the purpose of observing on opposite parts of the arc, and each compared with its preceding and succeeding one. In pursuing this method, it was unnecessary to notice the errour of collimation for any other purpose than as a test to the regularity of the observations; for until they became uniform, no notice was taken of the zenith distances, con- cluding that there had been some mismanagement, or some defect in the adjustment. After major Lambton had made out his account of the meridional arc, he completed the measurement of a degree perpendicular to the meridian in latitude 12° 32’, nearly, derived from a distance of upward of fifty-five miles, be tween Carangooly and Curnatighur, two stations nearly east and west from each other. ‘The final results of his compu- tations are, that the degree on the meridian in this latitude is 60495 fathoms nearly, and the degree perpendicular to it 61061 fathoms nearly. VII. An Account of some New Apples, which, with many others that have been long cultivated, were exhibited before the Horticultural Society, the 2d of December 1806. By. Mr. Artuur Brees, F. H. S. The apple one Or all the different fruits, that our island affords, none of our best fruits. can be brought to a higher degree of perfection, with so little care and trouble, especially in its southern counties, than the Apple. For a proof of this, I hope it will not be deemed presumptuous in me to refer to the catalogue below, every variety of which I had the honour of exhibiting to the Horticultual Society, at our meeting in December last. Hav- ing been flattered by the wishes of many gentlemen then present, CULTURE OF APPLE TREES. 5) present, to give some account of such as are new, and by what culture they have been produced in such perfection, I cannot but attempt it, though very inadequate to the task, for almost every hour of my life has been employed in fol lowing the instructions of others, and when I have deviated from them, with a view to improvement, I have seldom been able to write down the result of my experiments with any satisfaction to myself, Beside the sorts of apples lately exhibited, the garden Apple trees of Isaac Swainson, esq., my indulgent master, contains Gar eho number of others, which are less valuable. WhenI mention norther that I am cutting these away as the better trees advance, and pach an ie ' thinning the branches of the latter also as they require it, I perhaps tell all that is to be told upon the subject; for I have found nothing of more consequence to the health of the apple tree than plenty of light and air. The instructions of the late Mr. Philip Miller, on this head, are so pointed, and I’see so many apple trees smothered either by their own branches or those of other trees, that I cannot do better than quote his words. After directing the standard trees to be Large ones planted at the distance of 40 feet every way, and the dwarfs ape at that of 20 feet, he says, ‘‘ [ am aware how many enemies I feet distant. shall raise by retrenching the great demand, which must of ne- cessity be made in the several nurseries of England, if. this practice be adopted, but as I deliver my sentiments freely on every article, aiming at nothing more than the information of my readers, so I hope there will be found none of my profession of such mercenary tempers, as to condemn me for telling the truth, though it may not always agree with their interests.” I feel no fear in referring to this great gardener’s work, be- May beptanted cause all the principal nurserymen, who now supply the pub- atta lic in the vicinity of London, are men of too much liberality grow. to recommend a less distance, than the above; and in the present opulent state of this country, the original price of the trees is comparatively so trifling, that if any one plants double the number which ought to remain, he will be repaid more than a hundred fold in the few years that the alternate trees are suffered to stand. This is a practice, therefore, « E 2 ) which 52 ‘CULTURE OF APPLE TREES. which I have not scrupled to recommend: but, after all, whether a gentleman plants many or few trees, his future success and gratification depend principally upon the judg- @hould be - ment of his gardener, in choosing such trees in the nursery, grafted from as have been grafted from bearing branches; and if 1 thought aha, myself authorized to give any hints to our nursery-men, it Graftstobe would be relative to the selection of their grafts and buds, gag with not only in the apple tree, but every sort of fruit tree, about which they are in general too careless. : Apple trees I must now observe that the apple tree will grow readily by raised with ad- cuttings, and that trees raised in this way, from healthy one vantage from ; 3 : cuttings. year old branches, with blossom buds upon them, will continue to go on bearing the very finest possible fruit, ina small com- These wel] P48, for many years. Such trees are also peculiarly proper adapted to — for forcing, by way of curiosity or luxury, and I believe SPIRE» that they are less liable to canker than when raised by graft- ing, though I am unable to assign any reason for it. I have more than once experienced this in the golden pippin, cuttings and continue Of which have remained seven years in perfect health, when eee grafts taken not only from the same tree, but from the very branch, part of which was divided into cuttings, cankered in This discover. two or three years, Accident, which brings to light so many ed by accident. yseful things, first taught me this practice; some cuttings, that I had stuck into the ground for marks of annual flowers, having all made roots. ‘The soil was loamy, and the summer proved so wet and cold, that many bunches of grapes in a large greenhouse, which I could not prevail upon the gentle- man I then served to be at the expense of thinning with scissars, rotted when green. Effects ofsou The soil at Twickenham is light, and inclined to sand rr igh. rather than loam, in which the apple tree will ripen its fruit , earlier and more completely than in a stiffer soil, but it will not last so Jong. Young seedling plants will also produce ‘their blossoms and fruits in a shorter period in such soil. Our trees being originally placed too near each other, I have May be tsans- transplanted several into other quarters with very great suc- Planted large. “cess, even after they had attained a considerable magnitude. In doing this, I was careful to preserve every root possible both great and small, to have the ground where they were to be y CULTURE OF APPLE TREES. 53 be planted ready open to reccive them; .so that their roots were only exposed to the air a few minutes, disposing their fibres as horizontally as possible, and not too deep. The months of September and October should be preferred for transplanting any large tree, watering it wellif showers do not fall the same day: if the leaves are not pulled off, it will make fresh roots immediately, or at all events be more disposed to push them forth in spring. I constantly tread Treading the the ground exceeding firmly with my feet, in separate layers idan, Kev of about an inch, so as to render staking unnecessary, a ferable to stake practice which if performed so as to have any. real effect is ing. very expensive, but which too frequently does more mischief than good. Of the varieties of the apple cultivated in Mr. Swainson’s Early ripening garden, which ripen early, I can especially recommend, the 4PP!** summer pippin, Devonshire quarrington, summer traveller, bland rose, summer pearmain, red colville, marigold, Kirk’s incomparable, Evan’s valuable, nonsuch. \ Of the autumn and winter varieties, perhaps all those Autumnal and which follow are valuable, especially such as are marked ed bia with a star, and those marked with a cross are new. *Norfolk storer, *Norfolk beaufin, Norfolk paradise; Hol- land pippin, embroidered pippin, striped Holland pippin, *le- mon pippin: as this variety is beginning to canker in many gardens, there is no doubt that it is old, and has been intros duced from the continent, probably Normandy: fora gen- tleman who was at Rouen, during the last short peace, saw it there in abundance. , *Ribston pippin, New Town pippin, *golden pippin, Mar- mail pippin, French pippin, Kirten pippin; Wyken pippin, Fern’s pippin, London pippin, *Kentish pippin, New Town late pippin, mathematic pippin, +William’s pippin, Whitmore’s ippin, New York pippin, raspberry pippin, cat’s head, king of pippins, nonpareil codling, Cowring’s queening, *flower of Kent, Selleswood’s reinette, *Holland berry, golden mundi, margill, nutmeg apple, royal russet,golden russet, Pile’s russet, Clifton crab, “Minchin crab, French crab, Hereford shire —pearmain, Loan’s pearmain, Holt’s pearmain, Kentish feinette, lady’s thigh, pigeon’s egg, Tolworth court, spice apple, 54 Description of the best. William’s pip- pin, Padley’s pip- pin. Bigg’s non- such. Mirier’s pumpling. CULTURE OF APPLE TREES. apple, quince apple, hall door, *transparent pippin, *golden reinette, golden royal, +Bigg’s nonsuch, tflat green, +false beaufin, summer breeding, cceur pendu, +Minier’s dumpling, +Padley’s pippin, toval apple, tgreen pyramid. To give a complete history of each of the new apples above mentioned is out of my power: they have all been raised by other gardeners, from whom we may rather expect it: in the mean while, however, the following descriptions will perhaps suffice to make those which appear to me the best, more known, William’s pippin. Size, from 2 inches to 2 inches long. Colour, pale yellow, with a little red on the sunny side, and here and there a spot. Shape, somewhat conical, scarcely longer than broad, deeply umbilicated at the stalk, which is short, hollow at the top; the leaflets of the calyx, though black and dry, still remaining more perfect than in many. Flesh, pale, yellow, soft, excellent to eat ripe from the tree, baking and roasting well, till Christmas. Padley’s pippin. Size, from 2 to 3 inches in length. Colour, rich yellow, generally very finely laced all over with a pale rough starry bark, if I may use the term. Shape, oval, about the stalk flat, or often a little prominent on one side, not much depressed about the calyx, which is more ob+ jiterated thanin many others, perhaps from this circumstance. Flesh, firm and juicy, of a'rich perfumed and poignant fla- vour, in high perfection all December and January. Iam inclined to think this the very best of our new apples, Bigg’s nonsuch, Size, from 2 to 3 inches in length. Colour, deep yellow, striped and variegated with red on the sunny side, Shape, and general appearance, somewhat like the nonsuch, but broader at the base, moderately depressed about the foot-stalk, very hollow at the top, where the leaves of the calyx remain long and rolled back. Flesh, pale, yel- low, soft, and excellent to eat ripe from the tree ; 3 Toasts and bakes well till Christmas, Minier’s dumpling. Size, from-3 to 3 inches and a half in breadth, but not solong. Colour, deep green, and very dark . yed next to the sun; which, together with its spherical shape, qnore contracted at the top, and swelled intg @ few imperfecy : angles, CULTURE OF THE TUBEROSE. SS angles, give it some appearance of the Norfolk storer, but there are darker green lines on the north side which dis- tinguish it from all the apples1 know. It is depressed about the stalk, which is long and stout enough for so large an apple. The calyx is nearly obliterated by the time the fruit is ripe, which is not till Christmas, or after, It is most valuable for boiling or baking till April, and even to eat at the end of the season; its flesh firm, high flavoured and juicy. VIII. On the Cultivation of the Polianthes Tuberosa or Tuberose. By Ricuarp Antuony Sauispury, Esq. F.R.S. §c*. Tue charms of Horticulture, in every civilized nation, Art of gardens have been acknowledged by men of all ranks, from the é highest prince down to the lowest cottager. While the graver duty of the historian has been simply to commemo- rate the calm and innocent delights which it affords, the holy mythologist has exalted it as the sole employment of our first parents in Paradise; and poets have embellished their most enchanting verses with its productions: so that to offer a long and laboured panegyric upon any single branch of it, to a Society instituted for the express purpose of encouraging them all, would, in the émphatic language of ‘an old writer, be like vainly attempting to paint the hly, add a perfume to the violet, or gild refined gold. The field before us, moreover, is no less extensive than that of the whole globe, which is in fact one immense garden, covered with vegetables common to every animal that exists; but Providence has in infinite wisdom allotted to man the proud preeminence over all; his wants, if he is not indolent, being invariably first supplied. In those earlier stages of society, however, when the ground was first cultivated, it must have ® Abridged from the Trans. of the Horticultural Soc, vol. J, p. 41. } been 56 CULTURE OF THE TUBEROSE. been inconceivably difficult to exclude various animals, both carnivorous and herbiverous, from the immediate precincts of human habitations; driven as they now are from every populous country, we can form but a very imper- fect idea of their tremendous power and strength im warmer subsequent te elimates, while thinly inhabited. Hence the progress, even. agriculturee of Agriculture, was in all probability for a long period slow and interrupted: years and years must, have elapsed, before her younger and more delicate sister, Horticulture, ventured to appear; though, to plant a clump of bananas, which would give ma ee shade, and to perfume the surround- ing air ets the fragrance of an orange grove, independent of the fruit these two vegetables afford, must have been na~ tural, one would think, to many a savage of finer feelings, the moment his residence became fixed. Tubcrose re- To leave the language of fancy for that of fact, I know no commended deqwetsGhile: ornamental plant, which seems to me more deserving of cultivation in the warmer soils of this kingdom, or that would repay the labour attending it with greater profits, than the tuberose. First account _ The first account that I find of the tuberose, isin VEcluse’ r He Sowret History of Plants, where it appears that on the ist of De- cember 1594, he received a specimen of it, in very bad cons dition, from Bernard Paludanus, a physician at Rome, to whom it was sent by the celebrated Simon de Tovar, of Se- ville. It certainly had not then been many years in Europe, and Linné, in his Hortus Cliffortianus, on this head refers ug to Plumier’s Genera Plantarum, p, 35, who says it was first Supposed from brought by Father Minuti, from the East Indies, into the theFastindies, nator Peiresc’s garden at Boisgencier, near Toulon. It is much more probable, however, that it was introduced at More probably an earlier period, and from ‘America, for no author describes from Americ ++ 45 wild in the East Indies. Loureiro only found it culti- yated in the gardens of Cochin China, and Rumph says it was unknown in the Island of Amboyna, till the Dutch care ried it there from Batavia, in 1674. On the contrary, Ka- mel informs us, that it was brought to the Island of Luzone, by the Spaniards, from Mexico; and Parkinson, i in 1656, tells us, that the plants, which he describes as two. species, Natives of the « both grow naturally in the West Indies, whence being first CULTURE OF THE TUBERGSE, 57 fiist brought into Spain, they have from thence been dis- West Indies. persed unto divers lovers of plants.” The senator Peiresc, as may be learnt from Gassendi, was only fourteen years old in 1594, when Simon de Tovar had already cultivated it at Seville, and according to Redouté, it was not planted in his garden at Boisgencier, by Father Minuti, till 1652, whom that author makes to have brought it from Persia. I only infer, however, that he travelled from Hindostan over land. Redouté moreover asserts, that the authors of the Flora Peruviana found it wild in America, but in the work itself they say, cultivated in gardens. Hernandez’ evidence, how- ever, I think, takes away all doubt about the matter: he ‘says, *‘ provenit in frigidis et temperatis regionibus, veteri incognita mundo,” and as the agg@ve, to which the tuberose is more immediately allied, is also a native of Mexico, Iam fully of opinion that it is indigenous. there. The description given by ‘the venerable ’Ecluse, of his {’Fcfuse aa specimen, half dried and battered by the journey, with only accurate obs the lowest flower of the spike expanded, affords a memora- areal ble instance of his accuracy and discernment. The size of the stem, insertion and figure of the leaves, and their hempy texture, are particularly noticed ; the shape of the corolla, with its general similarity to that of the Asiatic hyacinth, but in consistence rather to that of the orange, is next re- marked; and having no knowledge of the root to guide his judgment, but what he derived from Simon de Tovar’s ap- pellation of Bulbus Indicus florem album proferens hyacintht Orientglis emulum, he guesses it may possibly belong, to the same genus with the bulbus ertophorus, or Peruvian hyacinth, though not without some doubts raised by its stem being co- vered with leaves, and its tubular corolla. Two years after- ward, these doubts were corroborated by his receiving roots both from Simon de Tovar, and the Comte d’ Arem berg, which by August were full of leaves; and I-think it worth poticing, that his figure of the plant appears evidently te have been made up from the original specimen sent by Bere nard Paludanus, and one of those growing roots, which he expressly sanded did not flower: he concludes with ob- ; serving, 58 Origin of the name, Fast Indian HRame, Figures of it. Vallet. Swertius. Ferrarius, Parkinson. Bauhin. Ray. Miller, CULTURE OF THE TUBEROSE. serving, that if it is still to remain in the genus, it may be called hyacinthus Indicus tuberosd radice. From this latin phrase, no doubt, our silly appellation of tuberose, and the more accurate French name, fubereuse, ori- ginated; but in the East Indies it is distinguished by the poetical title of sandal malum, or intriguer of the night ; in Spain, where at the period of this plant’s being discovered it was the fashion to give both places and things religious names, it is called vara de S. Josef. ; Soon after |’Ecluse’s figure, an excellent one by Vallét the embroiderer came out at Paris in 1608, and both these were copied and published as different species, by Swertius, in his Florilegium. An original figure, which has great me- rit for that day, though not equal to Vallct’s, next appeared in the Theatrum Flore, my edition of which, I believe the earliest, bears the date of 1622; it shows many routs flow- ering in one pot. From Ferrarius’s pompous book on the culture of flowers, we learn it was still regarded as a rarity in the Barberini gardens, at Reme, in 1633, but that it in- creased abundantly, and was taken out of the ground every year in March, to separate the offsets. Our countryman Parkinson, more than half a century after its being first de- scribed by l’Ecluse, is the next author who treats of this plant; but yaluable as many of his quaint observations still are to the horticulturist, his account of the tuberose does him little credit; he makes two species of it, saying, he thinks VEcluse never saw the first, though he owns ‘‘'some do doubt that they are not two plants several as of greater and lesser, but that the greatness is caysed by the fertility of the soil ;’’ his figures’ are wretchedly copied frem Swertius, and by his calling it the Indian knobbed jacinth, it appears not to have been known here then by its modern name. Gaspar Bauhin, with his usual carelessness, also takes it up as two species from Swertiwts, and even the learned Ray seems to have known as little about jt in 1693, adding, howeyer, to his second species, the title of tybergse. { meet with nothing moye pf any consequence respecting it, till Philip Miller, the pride of every British gardener, published the first edition of his Dictionary in 1731. He makes CULTURE OF THE TUBEROSE. 59 makes it a distinct genus from Hyacinthus, and describes the variety with double flowers, now so common, but then only to be seen in Monsieur de la Court’s garden, near Leyden, Instance of whose memory is most. justly consigned to infamy by our appieene. author, for destroying many hundreds of the rovts, rather ‘than parting with a single one to any other person; an in- stance of narrowness of mind and illnature, he adds, too’ common among the lovers of gardening. I trust no one who belongs to this Society will ever deserve a similar reproach. At this period we find the roots were aunually imported into Imported witts England, along with orange trees and myrtles from Genoa, Lon oe ’ and to the directions there given for blowing them, so as to Genoa. have a succession of flowers from June till October, nothing can be added. Though our gardens now are enriched with a profusion of Stil! much, other fragrant and beautiful flowers, the ¢uberose still conti- ‘wag nues to maintain its superiority, and we receive roots, espe- cially of the double variety, from the warmer provinces of North America, as well as Italy. There is no necessity, May be culti-’ however, to be indebted to foreign countries for this supply, 74ted at home. as I can speak from experience, having cultivated it in the open air for many years at Chapel Allerton, notwithstanding the average temperature of that hill from the month of April to October is far less than in the adjacent valley. Ifa suffi- cient degree of heat in summer can only be obtained to bring the leaves out to their full magnitude, that of the roots fol- lows of course, and very little more care than what is be- stowed upon the artichoke, will pene them from the severest frosts. For this purpose, select a piece of ground that is perfectly Method of drained, under a'south wall; or, if this cannot be spared, “ture. defend it on the north by a reed hedge. ‘The size of the bed must be proportioned to the number_of roots you want, for ‘ the same tuber never blows a second time, but only ‘the late- ral ones, which are produced in great abundance round jt: as they are to be planted at five inches distance from each other, a bed nine oh long, by three feet wide, will hold 144 ots, | The soil, in which I have found them succeed best, is light Soil, sandy a 60 Preparation of the. bed, Planting. Management after planted. CVULTURE OF THE TUBEROSE. sandy earth, mixed with a third part of very rotten cow dung: the earth should be taken about seven or eight inches deep, along with the green turf, chopping it very small with the spade, and turning it once a month for a year before it is used; if the earth is not very light, add a quantity of sea sand, or fine shelly gravel. If you are obliged to use this compost sooner, pass it through a wide screen, casting out nothing but any large stones. About the middle of April prepare the bed as fein : first, take out all the old earth, to the depth of two feet and a helf, or three feet, filling it nearly to the top with fresh stable dung, that has been cast into a heap to heat a fort- night before: lay the dung evenly in the trench, treading each layer very firmly down with a board, under your feet, and reserving the smallest and shortest for the last: upon this Jay eighteen inches in depth of the compost, sloping it well towards the south, not only for the benefit of the sun, but to throw off violent rains. In a day or two after, plant your roots at five inches dis- tance from gach other, observing to place them alternately in the rows, and that the crown or upper part of the tuber is only just covered with earth, These should be the offsets vf such as after flowering the preceding year have been pre- _ served from frost through the winter in sand, as well as the strongest remaining upoy any fresh imported ones. Till you obtain a sufficient stock, even the weakest may be planted, but as a great number are annually produced by every root, in time those which are large enough to flower the following year need only be selected. Cover the bed at night, espe- ~ cially if frosty, with a double mat, till the leaves appear, : but give little or no water, protecting it carefully from heavy raiis. When the leaves are about an inch long, add a little fresh compost to the surface, filling up any inequalities, and removing all won If the season prove dry, it will now require watering , and towards the end of June and in July, when the Ara are in full vigour, very copiously ; but this must depend upon the weather: From this period till the beginning of winter, nothing more is necessary than to weed the bed, and protect it from the autumnal rains: this may be CULTURE OF THE TUBEROSE: 6i be done by sloping the ground more up to it, or if you have ‘@ cucumber frame not in use, it may be employed for this purpose, taking care to sink the front so low as to admit all the sun possible. About the first week in December, take the advantage of a dry day, and after clearing away all the decayed leaves, thatch the bed all over, and at the sides, a foot thick with dry straw, sloping it well to throw off the wet. About the middle of February, if not prevented by se- Roots to'he vere frost, take up all the roots, preserving their fibres, and ic 3 Ng pack them in very dry sand, in cellars where the cold cannot _ penetrate till April, when they must be replanted as before, and replanted shortening their fibres more or less, as you find them de- ih cayed. If the climate was even milder than ours, I should recommend the roots to be taken out of the ground, and pre- served in dry sand, for it throws them into a complete state of rest, and disposes them to form their flower stems earlier. Many offsets will by this time have made their appearance round each root, all of which, except two or three at most of the strongest, should be cut entirely out, and this opera- tion must be in some degree repeated after they are planted ani growing, as fresh offsets are produced, for, if permitted to remain, they will rob the other buds of sufficient nourish- ment. ‘This second year some of the largest roots will probably Management ‘flower: if they send up their stems early it will only be ge- ating —T . Cessary to stick them carefully, when about a foot and a half high, and leave them to blossom in the open air; but when they appear later than July, they should either be removed _into pots, with a trowel, preserving all the fibres’ possible, _and placed in a stove, or if you have not that convenience, _ cut out the flower stem, with all the central leaves, as soon . asvit is discovered, which will strengthen the offsets. In the . succeeding winter thatch the bed, taking up the roets in Fe- _bruary, as,before, most of which will now be strong enough _ to flower, and may be selected for sale: such roots, if wanted _ for early forcing, will have a decided advantage over imported ones, for, as their fibres will not be entirely decayed, they will 62 OBSERVATIONS ON A CALCAREOUS MOUNTAIN. will push immediately upon being removed into brisk heat, and may be brought to flower as early as May. Estimate of According to the abovementioned distances, half a quar- expense and ter of an acre would contain 15,125 roots, leaving nearly as i much space for the alleys as the beds, which, at 3d. each, amounts to the sum of £189 1s. 6d. and as when a sufficient stock of offsets to select the largest was obtained, the annual return of blowing roots may be estimated at half the number planted, the profits of a bed of tuberoses, after deducting every expense of rent, dung, and labour, would be consider~ able, even if it were necessary to cover it in autumn and Places favour- Winter with three light frames. There are many places in able for it. our Island where 1 should imagine this plant might be cul- tivated with still less care and attention, especially mm the southern counties near the sea; in the vicinity of London. Ham Common, Sunbury, and Walton upon Thames; in the Isle of Wight; about Southampton; below Exeter ; General ree Bath and King’s Weston; in South Wales: and the theory ae which I would recommend any intelligent gardener to adopt in its general management is, to keep the roots growing as vigorously as possible from May to October, but in a state of complete rest and drought for the remainder of the year. t IX. Geological Remarks on a calcareous Mountain near Chessy, in the Department of the Rhone: by Mr. L. F. Lematrre, Inspector General of Gunpowder and Saltpetre.* All natural I Do not think there exists a natural fact, or an obferya- pkarinn tion however slight, that does not merit the attention of the geologist., geologist, who should study incessantly the voluminous book that Nature has laid open before his eyes. Certain pages of this book it is true may appear but little interesting; yet he should not pass over a single one if possible, would he attain an accurate knowledge of the interesting history of our globe, and the wonderful revolutions it has undergone. A mountain, * Journal des Mines, No. 106, p, 307. a mine, OBSERVATIONS ON A CALCAREOUS MOUNTAIN. 63 a mine,.2 quarry, an earthslip, are so many pictures, in which geologists may discern this history. From the-same considerations I am induced to think, that they will be gratified by the account and sketch I here pre- sent them, which appear to me to exhibit something singular, if not problematic, which it is for them to solve. See Pl. II, . fig. 1. The schistose vale, in which the village of Chessy, near vate near Lyons, is built, is bounded on the north-east by a chain of Lyons. mountains of no great height, which appears to run south- east and north-west, and in whicha well known mine of yellow sulphuret of copper is wrought. On the opposite side of the vale is achain of mountains of two’ or three hundred yards high, nearly parallel to the former chain, but not stretching so far to the north-west, and cut about three quarters of a mile from Chessy by another vale, meeting the first almost at a right angle. The last mentioned chain is calcareous from its summit Cthieess about two thirds of its height. Its base appeared to me to mountains on be composed of a schistose rock, similar to that which com- 2 baseof schist. poses probably the first chain and the whole of the interme- diate valley, since the vein of copper, which has been wrought to the depth of upward of a hundred and sixty yards, is enchased in this rock. , The extremity of the high calcareous chain, at the kind Se gh of promontory it forms where the two vales meet in an angle, top. | exhibits at its summit a large quarry of calcareous stone, which is used for building in the adjoining country. A per- pendicular section eighty or ninety feet high, made in a di- rection nearly east aud west, exhibits a series of strata from eight to fifteen inches thick, not arranged horizontally, but Strata various. 5 a i i “ ! ‘ ly inclined. with different desreés of inclination to the horizon, and ° — Copper mine, ‘crossing one another in various directions, as seen in PI, II, ‘ rm -fig. 1, which is from a drawing taken on the spot. The value of the angie I have inserted at the different arrange- ments of the strata is only estimated by sight, as I was un- able to measure it, on account of the steepness of the place. It is according to the decimal division. All the strata in each arrangement are parallel, except those marked A & B, ihe ea ae which grow wider, the first as it descends, the second as it course | follows 64 SINGULAR ARRANGEMENT OF STRATA. follows the curvature of the strata on which it rests, Each of these is very distinctly separated from that which imme+ diately follows it, or from the head or base of those it covers, or which abut against it by a kind of saalbande of the same nature as the strata, but of another colour. Stone coloured’ ‘Lhe stone of this quarry has a pretty fine grain, is. ren« by iron, and dered yellowish by oxide of iron, and contains a few shells. erie afew mere are found in it small bivalves of the chama kind, crowstones or gtyphites, anda few belemnites. The shelly and coarse strata serve for building, the fine and hard strata are used for entablatures and other ornamental parts. Mine counsellor Gillet ? Aumont has given such a satisfac- tory explanation of the angles and tortuous bendings of cer- tain veins of eeal, and other alluvial strata, such as those of bog iron ore near Sarre-Libre, that he seems to have caught Nature i in the very fact. Whether his ingenious hypothesis will account for the arrangement of the strata in the quarry at Soy I must leave to his consideration. Terenr 6s wares xX. Remarks on a singular Arrangement of Strata observed in the Chain of Jura, in the Department of Doubs : by the Same*. . Of what use is Or what equence is it, some will say, whether the the observation , ny ee ee é y ‘ : ef Nature? constituent parts of our globe be arranged in this way or ‘that ? What signify to us the causes of the regularity or dis- order they may exhibit, if the order of Nature as a whole be not disturbed; if every thing in the universe be as it ought to be? It may be No doubt the abuse of observation, for every thing has its abused, abuse; no doubt the desire of explaining every thing, not excepting what exceeds the limits of our narrow comprehen- sion; have led natural philosophers into useless researches, ‘and inte idle explanations, that frequently betray more va- nity, than desire of being useful: but I conceive there are but is certainly faets ia geology, which it is advantageous, I will not say in beneficial. - # Journal des Mines, No. 106, p. 310, all a ee i ie ANAS \ YY ie, Me 7 is ag G7 \\\ \ \\ \\\ \ \ Yi ty s |e Lis ANU ZZ ¢ ye § hie ; \\\ Ly \ y Soy \\\ i | a) \Vil iN le ANY i ee aA "| 5\\\ | | ee Ve) a Hh \\ a » H A Yip ‘) \ \ \S \ Wy . . be Oa ‘ ee Lf], \\\ AIAN 2X CQ MIS OES Ot, geen’ vs " SINGULAR ARRANGEMENT OF STRATA, 65 all cases to explain, but at least to observe accurately, and, to make known, because they are of importance to an art of essential utility, an art founded on observation, that of the miner. . The course of the strata of combustible minerals and mes Lead to a tallic veins, their various directions and inclinations, their sei of bendings, turns, faults, disappearance, and change of posi- tion, their impoverishment, &c.; all these different states, all these modifications, appear to depend on. the arrange- ment of the strata of our globe, and the concussions they may have experienced at different periods, whatever the causes may have been. Perhaps therefore it is not useless, to make known any singularities of this kind, hitherto little observed, that may offer themselves. Since it is from the bosom of the earth we derive the mae Thence useful terials of our most useful arts, minerals, to study its inter- *° the miner, nal constitution is of importance, as this would frequently lead to the solution of the difficulties that present themselves to the miner, or at least diminish their number. His pro- gress therefore, being less uncertain, would be much less b expensive, If my reasoning be just, I shall bring forward with more The author's confidence a few observations, that appear to me to claim risa aS the attention of ‘geologists, from the singularity of the facts, They may confide in what I have the honour to lay before them, since, as I am not sufficiently initiated into natural history to form systems, I have always confined myself to observation, and to observe long before I copy; and in the present instance I have the confirmation of several fellow tra- vellers, among others the senator Aboville, whose accuracy. of observation is well known. : o The table land of Jura, on which stands the city of Pon- Jura. tarlier, is furrowed by a few valleys, more or less close. One of the most interesting is that of la Loue, on account of its Vale of la wild and picturesque scenery, and the various works con- 4°" structed on the banks of the river. It is rendered particu- larly remarkable by the source of the river itself. I do not think the reader wi)l be displeased with my saying something here of this wonder of Jura, as it may be styled, which de- Vou. XX,—May, 1808. hi serves 66 SINGULAR ARRANGEMENT OF STRATA. serves on many accounts to be visited koth by the Paige and the lover of the arts. he’ wake ie The valley of la Loue begins above the village of Mon- scribed. thier-Hlaute-Pierre, between Pontarlier and Ornaus, in the subprefecture of Pontarlier, in the department of Doubs. This valley, very narrow at its origin, and very deep, and almost perpendicular throughout, exhibits in this part the. appearance of a yast well, opened on one side to let the « water flow out. Its sides are composed of compact, gray, calcareous rocks, veined with white carbonate of lime in a state of confused crystallization. At the foot of these rocks, but nine or ten yards above the bottom of the valley, a ai Cavern, from cavern, the depth of which is unknown, and the mouth of Yo ae issues @ which is about seventy yards wide and thirty-five yards high, pours out with great noise a very copious torrent of eok water, that tumbles foaming among the rocks, which it has torn off and-driven before it. The depth of the valley, the beetling cliffs that form it, the aspect of the cavern, the roar of the torrent rushing out of it, the mist it throws up, the gloom that reigns in this savage place, the bottom of which has never been illumined by the rays of the Sun con= fined to the tops of the rocks, all conspire to give an idea of the chaotic disorder, that prevailed before human industry had laid earth, water, air, and fire under contribution for ‘the benefit of the arts. Numberofma- By regulating the course of these waters, or of part of pes tcslansh 62 them; gaining by the explosion of gunpowder a few yards of surface from the adjacent rocks; and by suspending eree- tions over the torrent itself; a number of different manufac- - tories have been established at the foot of this precipice, “forming a complete contrast between art and nature. The Loue, after it issues from the cavern, is divided and turned in numberless directions to set in motion eight or ten flour tills, oil mills, mills for bruising hemp, forge bellows, large and small hammers, flatting mills, cylinders for cutting iron into bars, and saw-mills. These wonders, which are daily increasing by the addition of fresh structures, are owing to \ the iddhlctty and activity of Mr. Besson, administrator of saltworks. I had forgotten to mention, that you get to the bottom of this enchanted precipice by a flight of steps, the windings SINGULAR ARRANGEMENT OF STRATA. 67 windings of which, concealing it from your view till you reach it, render the picture more magical, and the surprise the greater. It was in the cliffs forming the walls of this narrow basin, Strata distorted, that I had an opportunity of noticing some singular arrange- ments of the strata composing it. Every thing exhibits traces of the derangement I had observed in many other parts of Jura, but here they appeared to me larger and more varied than any where else. I cannot give a better idea of them than by the drawings I mede on the spot, engravings from which are annexed. See PI. II, figs. 2and 3. It is to be remembered, that frg. 2 represents the face of Cavern, the rock to the right of the cavern, the entrance of which commences ata very little distance from the natural vault A; so that the cavern has been opened through the strata B, B, and those resting upon and parallel to them, which dip toward the centre of the mountain at an angle of about thirty degrees. This fact will give an idea of the effect and of the time required for the water, or the acting power whatever it was, thus to force its way through, immense strata of a hard and compact rock. ‘The strata A, C, &c. exhibit ‘a semicircular arch; those Naturalarches. marked D, D, an elliptical arch. sBoth appear to rest on the strata E, E, which are no doubt produced to the left un- der an ‘angle nearly similar to that of the strata B, B; and probably receive the extremity A, C, of the smaller arches. All the little veins or lamine, that compose each ‘stratum, Laminz of the have regularly undergone the same curvature; so that the strata regularly ” é curved, arcades and all the curved parts of the strata of this moun- tain exhibit the appearance of a book bent in different di- rections. ' I could not get at the knowledge of the arrangement of Part beneatn the part below, F, F, which forms the floor of a sort of yard P°t visible. belonging to the manufactory. Mr. Besson is making an excavation under the natural arch D, D, for the purpose of a storeroom or workshop. The existence of the portions'or rudiments of strata, Depositions in G, G, G, H, H, H, will perhaps appear singular, but it is - Bs 8s of -not the less real, and is very distinct. If i might be per- ors amuitted to hazard an opinion respecting them, it would he, F2 that 68 Ancther partof the mountain. Natural arch, Contorted strata, Strata inter- secting. Similar ap- pearances in other parts o the mountains; and elsewhere. SINGULAR ARRANGEMENT OF STRATS. \ that, from these depositions in the angles of the arches. we must infer, that the arches were in being before these depo- sitions were formed. Fig. 3 represents another face or precipice of the same mountain contiguous to that represented im fig. 2; so that it forms one contiguous mass, but with an obtuse saliant angle ata b. In this part too there is an arch I, of larger dimeusions than etther of the others, and much flatter. It seems to form a support for the upper strata, L, L, L, which rest on its extrados. | The singular contortion of the strata K, K, is represented exactly as it is in nature. The strata L, L, L, M, M, M, and N,N, eross and mu- tually intersect each other, without losing any of their regu- larity in this part. Though I observed them from a distanee, their general and reciprocal arrangement is too conspicuous, for me and my fellow travellers to have been deceived. In thus observing the two sides of the mountain analogous dispositions of the strata are observable. I give here the most striking, but all of them merit the attention of the geologist. The mountains of Jura however are not the only ones, in which I have noticed phenomena analogous to those I have described. I have had opportunities of observing such in the calcareous mountains of the Lyonnese, in that which overlooks the village of Chessy, seven miles north of Lyons, toward the west, in a quarry on its summit, and of which I lately sent an account and drawing to the council of mines. See the preceding article, and Pi. IT, fig. 1. In coal and other mines we every where find examples of, great disturbances happening to the surface of our globe, disturbances that must have occured at periods very remote from each other, and that excite our astonishment. “Ages to man are but moments to nature. @N PREVENTING THE DRY-ROT IN WOOD. §9 XI. An Inquiry into the Causes of the Decay of Wood, and the ‘Means of preventing it. By C. H. Parry, M.D. (Continued from Vol. XIX, p. 338.) A ise" wood decays under cover, that condition is usu- Dry-rot, ally called the dry-rot. Let us examine the circumstances in which this change takes place. ) It affects the interior doors, shelves, laths which subdivide Places where it the layers of wine, and all other wood work in certain cel- ee al ars; beams and rafters which support the roofs of close passages; joists laying on or near the earth; the wainscot« ing of large rooms, little inhabited, in old and especially _single houses; and wood in various other situations of a similar kind, which need not he particularized.- In some of these cases, while one sample or portion of wood shall suffer the dry-rot, another specimen or portion shall remain un- changed. In other instances, wood of various kinds and qualities has been successively employed, and all has alike _suffered. During the stages of change, a crop of mucor or Attended with _mould, and yery frequently of fungi, has sprung from the PAP (et poreus mass; and the decay is always attended with a wide- liar smell. spreading exhalation, the odour of which cannot well be _described, but which is sufficiently known. What then are the causes of this destruction; Precisely Cause. the same as those which I have befare described; though _their action is differently modified, and Jess obyigus to gross _ observation. The decay is produced by the putrefactiye . fermentation of the component parts of the wood, in con- _neetion with moisture, withgut which, as I have before stated, . wood cannot putrefy, Commoy air is not only combi of mixing with a con- Air loaded siderable quantity of water in form of vapour, but during With water, . every state of our atmosphere is always much loaded with _it. Water becomes vapour in consequence of being uuited _ with a certain proportion of that substance which is called heat. Ss P wis | 70 which is dee posited on any with v thing colder than tle air. Many cireum= stances @€X- plained thus, . 4 Dampness of certain walls. The wet does not come th rough the wall,” ON PREVENTING THE DRY-ROT IN WOOD. heat. If a sufficiently cold substance comes into contact apour, the superabundant heat, which was necessary to its existence in that form, passes into that cold substance, and the vapour is then immediately condensed or changed into water. Thus if in the hottest day in summer, when the vapour in our breath is totally invisible, we breathe on a looking-glass or plate of polished metal, which 1s colder than our breath, the surface is immediately dimmed; and if we continue to breathe on it, small drops of liquid appear, which gradually become larger and larger, and many of them at length uniting, run down the surface in a stream, The same thing takes place on the outside of a glass of water drawn in summer from a deep well, and of a bottle brought up into a warm room out of a cool cellar; and on the inside of our windows in frosty weather. On the other hand, we could not dim with our breath a plate of metal or glass of 100 degrees of heat, which is greater than that of our breath, and no mist is observable on the inside of our windows during the heat of a summer’s day; nor is there any condensation of moisture on the outside of a glass of cold water fresh drawn from the well, or of a bottle out of a cellar, when either is brought into the open frosty air. These circumstances will explain many appearances, by which, for want of due examination, we are often greatly puzzled. We are frequently mortified by seeing in our houses, especially in the country, the walls become stained, or the paper separated and hanging down, and often Hees ing; and as this usually happens on the side or corner which is most exposed to the weather, we conclude that the damp comes through the wall, and tax our faculties to the utmost, in order to prevent this penetration, The measures which we employ sometimes succeed. But it often happens, that casing, and plastering, and painting the devoted angle fails; , and then, as the last resource, we take off the paper and at- tach it tu canvass at the distance of one or more incheg from the wall, and thus, for the present at least,’ effect the desired purpose. Now in this case it is just gs absurd to suppose, that the wet comes through the wall, as that it comes through the glass window in a frosty day, or the glass or bottle from the well or cellar. ‘The fact is, that in an’ ex. posed ON PREVENTING THE DRY-ROT IN WooD. NI — posed house, and more especially on the most exposed cor- ner of a room seldom warmed by fire, the inner surface of the wall, by the continuance of frost, is become of a very low temperature, like the air within the room itself. So long as this state of equal temperature between the wall and internal air continues, or if the wall is warmer than that air, it is obvious that the vapour which is mixed with the air can- not part with any heat to the wall, ahd therefore will not un- dergo condensation; just as no dampness appears on our windows daring a hot day in summer. But if a thaw comes butis deposited on, and the air becomes warmer than the wall, which, from renin ay in, jts capacity of easily shifting place, it will readily do, then ; the vapour, which is mixed with it, parts with its superabun- dant beat to the colder wall, and appears on it in moisture or drops, or pours down it in streams; just as happens to the cold bottle brought into the warm dining-room. ~ This change is the greater, the more completely the ma- terials of the wall fit it for carrying the heat out of the va- pour, or, in philosophical language, the better they-eonduct heat. _ Hence a wall painted in oil condenses vapour, or runs 4 walt painted with water, sooner than one, which, being unpainted, 1S more with oil suon- porous 5 for which reason, in cities, we first perceive damp- “t ¥ ‘ness and drops or streamlets of water on the oil-painted party walls which bound our staircases, and which ave, there-. fore, absurdly said to sweat, though these walls have no ‘communication with the outward air, and, from their var- nished covering, cannot admit of the oy oa hy of moisture or perspiration through their pores, sila, this” case tKe remedy is obvious, and by its success principle of “shows the nature of the evil. Prevent your walls from ever prevention. . becoming colder than the warmest external air of winter, and you will never have this appearance of damp on their i inner surfaces. 3" This may be doue, first, by constructing the walls of such \fethod of ap- a degree of thickness, or with such a disposition or quality plying it. of iaalertits’ that they shall not, in the usual way, be greatly cooled throughout their whole substance by any temperature of the outwar fdlaie - With this view, I think that in all single Detached houses, which are not warmed by neighbouring fires, and houses require _ more sg JAP yas in situations exposed to high winds, and eycker team Pini. ble walls. : therefere ? * i “J L2 How the com- gon methods sometumes suc- ceed, Not possible te keep out the cold. Wot wholly, ON PREVENTING THE DRY-ROT IN WOOD. therefore to great evaporation from the external surface, and consequent abstraction of heat, the walls should always be double, having on the inside a thin layer of brick, with an interval of one or two inches from the outer and thicker layer of brick or stone, to which it must be united by proper binders. The porous structure of the bricks, added to the impermeableness of the intermediate stratum of air, would so ill conduct heat, that such walls would necessarily tend to keep a house dry and warm in the winter, as well as coo} in the summer. This end would be still further promoted by filling the interyal between the two layers with dry sand, fresh sifted coal-ashes, or powdered charcoal. In fact, when +he common external means before described have succeeded in curing dampness, it has been either by affording a varmsh, which has diminished evaporation by preventing absorption, or by increasing the space or changing the quality of the materials of the wall through which the heat was to pass, sp as in either of these cases to retain it more forcibly: And when the dampness has been remedied by removing the pa- per to some distance from the wall by means of strained canvas, that effect has been produced by rendering the pa- per a worse conductor of heat; and therefore indisposing it to condense the vapour in the room sv readily as when jt was in contact with the colder wall. It has been suggested, that it would be possible to keep out cold, or, in more accurate language, prevent the egress of heat from the inside of a room, and therefore from the walls surrounding it, by shutting it closely up, and prevent~ ing any admission of the cold external air. This has 5. Are the geognostic relations of the porphyry slate or clinkstone porphyry of East Lotinan the same as in ether countries ? ; 6. What are the geognostic seiabns of the claystone, compact feldtspar, and striped jasper of the Pentland Hills? 7. What is the extent and mode of distribution of the sienite of Galloway ? 8. Does the Craig of Ailsa in the Firth of Clyde and the Bass rock in the Firth of £ orth belong to the newest fletz trap forifiation : » - * Neue Thisbite von ‘der Entstehung der Gange von A.G,.Werner, 1791. “f Beschreibung des Giuben-gebaudes Himmelsfist. von F.Mohs, 1804. t Minetalog’ Bemerkungen bei gelegenheit einer Reise durch den merkwurdigsten Theil des Harzgebirges, von Friesleben, 1795. § Mineralogical Description. of Dumfrieshire, 1805, Elements of Geognosy, 1208. Q: Does. 860 Mineralogital queries. SCIENTIFIC NEWS: . 9: Does the pitchstone of Ardosputshap belong to the newest flcetz trap formation ? 10. Is the granular quartz in the islands of Isla and Jura subordinate to mica slate, or does it eonstitute a Diets formation ? 11, Are the Cullin sountaity in the isle of ie com- posed of rocks belonging to the newest floetz trap and se- cond porphyry formations ? 12. What are the geognostie characters and relations of the obscure egg in the isle of Egg one of the Hebrides ? 13. Of what rock is the isle of Staffa composed, and what its geognostic characters and relations ? as 14. Is the porphyry of the isle of Rasay porphyry slate? 15. What are the geognostic relations of the tremolite of Glen-Elg in Invernesshire ? 16. Does the ‘upper part of Ben Nevis belong to the’ se- ¢ond porphyry formation; and if this be the case on what does the porphyry rest ? 17. Does the porphyry of the Brauer near Blair in Athol belong to the first or second porphyry formation ? 18. Does the granitic rock in the vicinity of Aberdeen nie Jong to the granite or sienite formation ? 19. Does the sandstone of the Shetland islands belong to the independent coal formation, or to any of the formations described by Werner? 20. In what species of mineral repository are the ores of Sandlodge in Shetland contained, and what are the oryctog- nostic and geognostic characters and relations of these ores ? 21. Does the claystone of Papa Stour, one of the Shet- lauds, belong to the newest ficetz trap, or coal formations ? 22. Does the serpentine of the islands of Unst and Fets jar belong to the first orsecond serpentine formations? , TO: CORRESPONDENTS. F.R.S. will perceive that the communication from Professor Pince, in- serted in our Supplement, renders it less necessary to insert his favour. At the same time that his general remarks upon the spirit most desirable to be shown tn controversional writings must be allowed, tt must be admitted in behalf of the Editor of a periodical publication, that very cogent and manifest rea- sons ought to present themselves, before he can be justified, for interfering an the discussions transmitted to the Public. The Editor having been, contrary to expectation, disappointed of the Meteorological Register, is stil! obliged to postpone it; but he will take pro- per meusures to a Sarther delay, / JOURNAL NATURAL PHILOSOPHY, CHEMISTRY, . AND THE ARTS. } J UNE, 1808. -ARTICLE I. Observations on such Luminous Prenonlénc'ta ihe Atmosphere, uw as. appear to Fras on Electricity. Bya Correspondent, © (RB) Ir: a beck long since. incontrovertibly eseauiahen that echoing is lightning isthe electrical stroke between the clouds and the ery Earth, or between one cloud and another. All the differ-_ ences of opinion therefore relate at present to its attributes . or affections, which ‘philosophers have not scrupled to inves-. tigate by the assistance of the electrical machine, ,, But. there are many circumstances, for an explanation of which we mtust have recourse to the great theatre of nature, ‘ The luminous appearances seen above the surface of the Enumeration earth are, ignes fatui; lightning, shooting stars, fire balls, of luminous and the aurora borealis. Whether the ars be an electrical. ce phenomenon has. not yet been satisfactorily ascer tained, and. indeed their cause may be said to be entirely unknown; but lightoing and the aurora borealis are perfectly imitable by electricity ; and it is highly probable, that an electric spark _ would exhibit the appearance of shooting stars and fire balls, if of sufficient length and remoteness to permit its figure and angular velocity to be perceived. Itis also probable, Vou. XX. No. 85—June, 1808. G that, §2 The electric spark or fire ball. The velocity of disengaged electricity 23 miles in a se- cond tor light- ning, and also fora fire ball; but it is not likely to be constant, ON LUMINOUS PHENOMENA. that the electric explosion consists of a ball or cylinder of no great length, ignited by the compression of the air or gas, or other fluid it drives before it. Admitting this, the zigzag spark with ramifications may be considered as a fire ball continually throwing out detached pieces; the brush will be a fire ball broken to pieces, and the lightning will not differ from fire balls but in its vicinity to the Earth, and its velocity, which is perhaps greater. An artificial fire ball moving slowly has been seen once, and but once, by Warl- tire the lecturer. See Priestley’s Electricity. The magnificent experiments of Watson on Shooter’s-hill, in which the shock was transmitted through great lengths of wire, teach us nothing of the velocity of disengaged elec- tricity, as there is no proof that it has any known relation to that of the electric matter passing through conductors, Most persons think they can distinguish the direction of light- ning, but this may perhaps be a deception. M. Marat* is the only philosopher that I know of, who has made any ob-_ servation from which an inference of the velocity of light- ning may be deduced; and he himself remarks, that it is attended with various causes of uncertainty. He measured the angular distance between two clouds, from one of which ~ a horizontal flash of lightning flew to the other, and found it 30 degrees: the time was 20 thirds, and the distance de- termined from the interval of time between the flash and the report, was 10,000 toises. From these data he infers, that the velocity was 19,200 toises per second, which is somewhat more than 23 English miles. This determination, by its remarkable coincidence with that of Sir Charles Blagden, respecting the velocity of fire balls, might lead to a conclusion, that there is a settled ve- locity for luminous electric matter, if it were not credibly. ascertained, that it sometimes moves much slower, and is even nearly stationary, according to circumstances. Jn the storm which happened at Steeple Ashtont, on the 20th of June, 1772, two gentlemen being sitting in a parlour at the vicarage-house, and conversing about aloud clap of thun- * Marat, Recherches physiques sur l’Electricité, p. 226. + Ph, Trans. vol, 63, p. 282. i vi der ON LUMINOUS PHENOMENA. 83 der that had just happened, they saw on a sudden a ball of fire between. them, at about a foot distance from one of them. They described it to have been about the size of a sixpenny loaf, and surrounded with dark smoke; that it burst with an exceeding loud noise, like the firing of many cannon at once; and that they perceived a disagreeable A fire ballin a smell, resembling that of sulphur, vitriol, and that of many '0™ other minerals in fusion. One of them was exceedingly hurt. As soon as he was struck he sunk ia his chair, but _ was not stunned; his face was blackened, and his features distorted; his body was burned in several places, small holes were made in his clothes, and he lost in some measure the use of his legs for two or three days. He is positive he saw the ball of fire in the room for a second or two after he was struck. He also saw after the explosion a great quantity of fire of dilferent colours, vibrating backwards and forwards in the room, with a most extraordinary swift motion. This might perhaps be an affection of his sight. Mr. Field, a painter of Trowbridge, during the storm, seen before its observed a ball of fire vibrate backwards and forwards over ¢°5°o8" some part of Steeple Ashton, and at Jast dart down perpen- dicularly. This was in all probability the same ball as was seen to burst in the parlour of the vicarage-house. A body of fire was also seen during the same storm mov- Anotherin the ing towards a house, at some distance from the house of “@™° S0"™- Mr. Paradise, which changed its direction and passed through the last house, and afterwards burst with a prodi- gious explosion. Mr. Paradise, who was three or four feet out of its line of motion, was struck against the wall, his body covered with fire, and he thought for some time he should have been suffocated with the smoke and smell of sulphur. He escaped unhurt, and his house received no damage. To these instances of electric matter which produced the Lightning at effect of lightning, though its velocity was too sinall to pre- brecvigna vent its figure being perceived, may be added, the very se- gure was ob- vere stroke of lightning, which killed two of the servants of Scrvable Mr. Adair, at Eastbourne* in Sussex, threw himself hurt * Ph, Trans. vol. 71, p. 42. G2 and 84 Distinction be- tween light- ning and the aurora borealis. Shooting stars, aurora borealis, . and fire balls, are greatly ele- vated. ON LUMINOUS PHENOMENA. and motionless on the floor, and rendered a young lady and her servant insensible for a time, though these persons were in, different apartments of the house, et left considerable marke of its violence on the house and furniture. It hap- pened on the 17th of September, 1780. The morning was very stormy, with rain, thunder, and lightning; ; and just at nine o’clock a horrid black cloud appeared, out of which Mr. Adair saw several balls of fire drop into the sea succes- sively, as he was approaching a one pair of stairs window ; very soon after which, he was struck by a most violent flash of lightning, the effects of which may be particularly seen by consulting the original account. But what more espe- cially applies to the present purpose is, that multitudes on the seashore before the house saw the meteor dart in a right line over their heads, and break against the front of the house in different directions; and all agreed, that the form and flame exactly resembled an immense sky recket. These facts show the near resemblance between lightning and fire balls. It is probable however, that the electric mat- ter, when it passes violently through the lower regions of the atmosphere, usually has the form of a spark; that is to say, it passes with an extreme angular velocity in some definite direction. But the masses of luminous matter, which pass along the superior and more rarified parts of the air, appear either in the form of those flashes, which we produce by passing electricity through a vacuum, or in the form of balls of fire. In either case the phenomena are on a scale of astonishing magnitude. Shooting stars, the aurora borealis, and fire balls, have in general been found by the best observations to be greatly elevated in the atmosphere; and indeed, beyond the region where the action of the sun’s rays on the air occasions the twilight. Mr. Brydone* frequently observed shooting stars from the mountain St. Bernard, one of the high Alps, and also saw several from the highest region of Mount Etna, and they always appeared as high as when seen from the lowest grounds, I find however one curious instance of lights reserabling both the aurora borealis and shooting stars, at a much lower elevation. * Ph, Trans, vol. 63, p. 167. As “% ON LUMINOUS PHENOMENA. As Mr. Nicholson *, teacher of the mathematics at Wake- field in Yorkshire, was returning on horseback on the Ist of March, 1774, from Crofton, a village near Wakefield, he saw a storm approaching in the north-west quarter, from which the wind sat. It was then about half past six in the evening, and the weather was so dark and overcast, that it was with difficulty he could find his way. When the storm began, he was agreeably surprised to observe a flame of light dancing on each ear of his horse, and several others on the end of his stick, which had a brass ferule notched with using. These appearances continued till he took shelter in a turn pike-house. After having continued about twenty minutes the storm abated, and the clouds divided, leaving the northern region very clear; except, that about ten degrees high there was a thick cloud, which seemed to throw out large and exceed- ingly beautiful streams of light, resembling an aurora bo- realis, towards another cloud that was passing over it; and every now and then there appeared to fall to it such meteors as are called falling stars. These appearances continued till he came to Wakefield, but no thunder was heard. About nine o’clock a large ball of fire passed under the zenith, towards the south-east part of the horizon; and Mr. Nicholson was informed, that a light was observed on the weathercock of Wakefield spire, which is about 240 feet high, all the time the storm continued. The present state of our knowledge respecting fire balls, with observations, is exhibited in an excellent treatise writ- ten by Dr. Blagden +, now Sir Charles, on occasion of ott fiery meteors which were seen in the year 1783. The great meteor of Aug. 18, in that year, had the appearance of a luminous ball, which rose in the N. N. W. nearly round, became elliptical, and gradually assumed a tail as it ascend- ed, and in a certain part of its course seemed to undergo a remarkable change, compared to bursting; after which it proceeded no longer as an entire mass, but was apparently divided into a great number or a cluster of balls, some larger than the others, and all carrying a tail, or leaving a train * Ph, Trans, vol, 64, p. 351. + Ibid, vol. 74, p. 201. behind. 85 Appearances in a storm re= sembling the aurora borealis & falling stars, Do not these show two fluids like my sparks} Treatise of Sir pantage Biag- en Great fire ball of 1785. ’ 86 Its height 57 miles; velocity 20 miles per second; dia- meter half a mile; course 1200, miles. Sir Charles ascribes there appearances to electricity. The velocity greatly » xceeds that of planct- ary projection: ON LUMINOUS PHENOMENA. behind. Under this form it continued its course’ with a nearly equable motion, dropping or casting off sparks, and yielding a prodigious light, which illuminated all objects to a sufprising degree; till having passed the east, and verging considerably to the southward, it gradually descended, and at leneth was lost out of sight. ‘Uhe time of its appearance was gi. 16m. P. M. mean time of the meridian of London, and it continued visible about half a minute. It seems probable, that the meteor burst and umted again several times during its course; and that the great change corresponded with the period at which it suffered a deviation in its course. Its appearance was not uuilormly bright, but consisted of livid and dull paris, which were’ perpetually changing their relative position. Its height deduced by. computation from the angular elevations from various places, proves much more correspondent than might be expected from such data. One combination gives the height 542 statute miles, two give 57 miles, two 58, one 59, and one 60: the mean is 572 miles. It does not appear to have really approached the Earth in its course, which was above 1200 miles in length. Its absolute diameter across, supposing it to have been about half a degree broad, was half a mile, and its velocity was at least 20 miles in a second. A_ report was heard after its disappearance; and it is very remarkable, considering the rarity of the air at such a height, that the height of the meteor, deduced from the time of the pas- sage of the sound*, nearly agrees with the geometrical de- duction: it is 562 miles. A hissing, whizzing, or cracking, was also said to have been heard during its passage. fy After describing the phenomena of the smaller meteor, which appeared on the 4th of October in the same year, Sir Charles proceeds to consider the cause of these pheno- mena. He shows the insufficiency of Halley’s hypothesis, that they consist of a train of combustible vapours set on fire; and also of that which supposes they are terrestrial co- mets. This last position he observes is incompatible with their general appearance, which does not resewble solid bo- dies; with their exceeding great number, which could scarce- * Ph. Trans. vol,:74, p. 111. ly ON LUMINOUS PHENOMENA, ly fail. to produce some other appearances, beside a tran- sient illumination ; and more particularly with the extreme velocity of the meteor of Aug. 18, which is three times as great as a body falling from infinite space towards the Earth would have.acquired, when it came within 50 miles of the Earth’s surface. He therefore recurs to electricity, the only agent in nature with which we are acquainted, that seems capable of producing such phenomena. Its extreme and hitherto unmeasured velocity, the electric phenomena at- tending fire balls, the hissing noise, their. connection with and similarity to the northern lights, which have sometimes assumed: this form, and particularly their course, which is for the most part nearly in the magnetic meridian, are among the circumstances which are pointed out and elucidated in a perspicyous and highly interesting manner. And he con- cludes by observing, that if the conjectures he offers be just, there are distinct regions allotted for the electrical phenomena of our atmosphere. ‘Here below we have thun- der and lightning, from the unequal distribution of the elec- tric fluid among the clouds; in the loftier regions, whither the clouds never reach, we have the various gradations of falling stars; till beyond the limits of our crepuscular at- mosphere, the fluid is put into motion in sufficient masses to - hold a determined course, and exhibit the different appear- ances of what we call fire balls; and probably at a still greater elevation above the earth, the electricity accumulates in a lighter less condensed form, to produce the wonder- fully diversified streams and coruscations ofthe aurora bo- realis. » There is a fact observed by Mr. de Saussure, which seems difficult to be accounted for by the help of our present _ knowledge of electricity. He was on the Alps with some friends, while a thunder storm formed in the air beneath them. While it lightened and thundered below, they found themselves electrified, but differently, so that they drew _ sparks from each other *. - t Ph. Trans, vol. 64, p. 128, I shall finish this communication by a remark of Mr. _ Winn on the aurora borealist, that this phenomenon is * Memoirs of the Academy of Sciences for 1773, usually 37 Conclusion. A south wind follows the au- rora borealis. Draining ponds and marshes always considered a difficulty. " A successful instance given as an example Description of the pond, DRAINING OF THE POND OF CITIS. usually followed by hard southerly winds, with hazy weather or small rain; which Dr. Franklin, admitting the fact, sup poses to be a consequence of the clearness to the northward, which renders them visible, and may have been produced by long continued winds from that quarter; for when the winds have continued Jong in one quarter, the return 1s of ten violent. The later discoveries respecting ignited stones which have fallen from the atmosphere, seem also to belong to the subject of this paper; but I cannot at this time consise tently with brevity enter upon them. II. Account of the Draining of the Pond of Citis*. Tur draining of ponds and marshes has always been con- sidered as a difficult enterprise; and it has frequently hap- pened, that works begun for the purpose have been relin- quished, before the object was attained, either because the local circumstances have occasioned too many obstacles, the means employed have been inadequate, or the capital em- ployed has fallen short, before the expected benefit could be derived from the undertaking. To instruct and encourage the speculator, as far as isin our power, and enable him to furnish agriculture with new land for the plough or the sithe, we hasten to publish the particu- lars of the draining of the pond of Citis, which is now going on. We shall point out the difficulties, that have been sur- mounted; and the new mechanical means, that have been em- ployed. S The pond of Citis is to the south-west of the department of the Mouths ef the Rhone, at a short distance from an arm of the sea called the Pond cof Berre. It is near the ponds of Lavalduc, Pourra, Rassuen, &c. The different quality of the waters of these ponds, and the dissimilarity of their levels, show, that they have no subterranean communication with * Journal des Mines, No. 116, p. 137, each DRAINING OF THE POND OF CITIS. 89 each other, though they are so near. The pond of Citis is several feet lower than any of those here mentioned, and, what is very remarkable, it is near twenty-seven feet, English mea- Its level 27 sure, below the level of the sea. This pond may be consi- . sg Se dered as a spacious basin, enclosed by lofty mountains, in which the rain water has accumulated and become stagnant, having no outlet. The waters of Lavalduc are saline to sixteen degrees*. The Salt-works es- proximity of this pond to that of Citis; the facility with which tabliphqnalyerre its water might be let into it, by opening a passage through the mountain separating them ; and the decrease of the water of Citis after several years of drought, gave rise to the salt-works of Citis. These were undertaken by a company, who sub- scribed a joint stock to defray the expense. Their pian was to prevent the addition of more water, and gradually dry up the pond, by stopping on the sides of the mountains the course of the rain water, which was its sole supply. This attempt succeeded completely, and the affairs 61 the company were in a very prosperous way, when, after a memorable winter, the _ pond was completely inundated by the excessive rains, that These inun- fell for three months successively. ‘The company indeed Bein might blame themselves for this disaster; since by their neg- ligence in not keeping the cana] in repair, or rectifying its Jevel, the rain-water, being so much more abundant than - usual, could not flow with sufficient freedom through it; and thus by its weight breaking down the feeble dike that sup~ ‘ported it along the sides of the mountains, it ran into the pond. This event, of which apprehensions had always been enter= Apparently a tained, appeared to admit of no remedy to the company, who ®opeless case. had long foreseen, that, if the pond should come to fill at any time, there would be no way to preserve the salt-works, but by carrying off the water over the hills between the pond and thesea, But what méans could effect this? There appeared none but the common pump, or the screw of Archimedes; and these being too expensive or inadequate, the company Was proposed to be* about to give up the work, when Mr. Augustus de Jessé pro- drained by a steam engine, posed to drain it by employinga steam engine. Being admit- forcing the * This I believe implies, that they contain-36 per cent ofsalt, Tr. mene , ted 90 water overa hill 172 feet high. This might have been ef- fected by asuce, cession of Steam engines but a single one preferred, The canal for carrying off the rain water first repaired aud improved. A w.l] sunk, with two pumps ‘worked altcrnate ly by DRAINING OF THE POND OF CITIS. ted to present a statement of his design, he showed the prac- ticability of conveying the water into the sea over the hills, though their tops were 172 feet above the bottom of the pond; and that, by adapting the power of the machine to the quan- tity of water to be raised, he could engage to accomplish it in a very short time. . Lastly, as the company seemed,undeter- mined, he agreed to undertake it at his own expense. . His. proposals and his conditions were accepted. Mr. Jess¢ might have accomplished his purpose, by placing several steam engines on the ascent of the first hill; the wa- ter raised by the first being raised higher by the second, and 3 so on successively, till itreached the top. The power of these engines, which may be increased to any extent, assured him of a given quantity of water ina given time; but such a com- plication would have been detrimental to the general. effect, for the draining could not have gone on regularly, unless all the engines had worked with constant uniformity, which could not easily have been efigcted. ‘That he miglit have no obsta- cles of this kind, and no stoppage, he conceived the design, and carried-it into execution, of throwing the water from the pond to the top of the first hill in a single stream, and by means of asingle engine. ‘This was adding to the difficulty ; but in this the chief merit of the undertaking consists. We shall give an account of the works, by which this was accom- plished: and we apprehend the reader will be gratified by the view of them given in Plates III and IV. After having corrected the errours committed in the con- struction of the original canal, or drain for the rain-water, carried round the mountains, and encircling the pond, he raised its level considerably, so as to give it a greater descent toward the end where it discharged itself. This canal was supported in the steepest parts by stone causeways; and to prevent the fall of the water into it from being too forcible, he diverted it as much as possible from a perpendicular direc- tion, giving it different inclinations, according to local cis cumstances, ‘ At some distance from the pond,.on the slope of the hill, the steam engine is erected. A well is there sunk to a level below that of the bottom of the pond, ‘and from its bottum a horizontal DRAINING OF THE POND OF CITIS. 91 horizontal gallery is carried to the pond at the distance of 320 asteam engine, ifs and forcing the feet. . This gallery, or rather aqueduct, conveys the water water through from the pond into the well. For this purpose it was neces- @ cylinder 450 sary, to urch it over completely. Inthe well are two pumps, fe ores and close to it is the steam engine, which works them both bil. alternately by means of a double crank, - Adjoining the pumps in the well are two vertical pipes, communicating with them, and united at the mouth of the weil by means of an elbow, or fork. The part: where they unite is fitted to a cast iron cylinder, 450 feet long, carried up the slone of the hill. This hill not being so high as some of the following, it was ne- cessary to raise‘the cylinder upon supports of mason work, to form a common level. A wooden trough, supported by tres- Thence con- sels, unites the first hill to the second. ‘This is 895 feet long. vey aaa ay At the end of this trough begins a canal of 2494 feet, which is g95 feet fone cut in the rock to the mean depth of 94 feet. To unite the 5 a nore summits of all these hills it has been necessary to erect several he 3, ape tg aqueduct bridges, over which the canal is conveyed. The ee canal might have been cut to less depth, by raising higher the the sea, — cast iron cylinder, and consequently the wooden trough; but the wind already has sufficient bold of both these, and they could not fail to have been weakened, had they been raised higher. if the iron cylinder had been made to rest on the hill,’ in order to dispense with tne wooden trough, the cana] must _have been cut to an extraordinary depth, or a gallery of 2560 feet must have been cut through the rock, which would have occasioned an enormous expense. _ The steam of the engine acts upon the pumps, which draw up the water of the wel], and force it into the vertical pipes. ‘These convey the water to the ascending cylinder, in which it rises gradually to the top of the first hill, whence it flows through the trough into the canal, which discharges it into the sea. < The water contained in the cylinder acts with all its weight The engine on the valve, that separates it from the fork of the two pipes: = ge . X72 strokes ina yet such is the power of the engine, that at every stroke, of minute, rais- which it makes thirty-two in a minute, it not only raises a ig 4660 lbs. ; F : : f _ of water in the certain quantity of water into the vertical pipes, but gives it cylinder. i a pres- ‘ a 92 DRAINING OF THE POND OF CITIS. a pressure capable of raising the whole of the water in the cylinder, which is of the weight of 4660 lbs. avoisdupois. Raises 69611 ‘The engine is calculated to raise 69611 cubic feet of water | re es every twenty-four hours, making a weight of 38845 ewt. or water in aday. 19424 tuns. It is obvious, that if it were required to raise @ Adequate greater quantity of water, and at the same time to a greater | pcre) height, as of 500 feet for instance, the same steps should be greater effect, adopted, ing redsitng proportionally the diameter of the eylin- f der of the steam engine, the dimensions of which give the mea- J sure of the power, and increasing the thickness of the cast | iron pipe, so*that it might be able to resist the “Sere of the | water forced into it. Novelties of Before the draining of the pond of Citis, we do not believe a the mode. —_ steam engine has been employed for such a purpose ; ; still less pumps moved by the usual agents; or that any attempt has been made to raise a large quantity of water to a considerable height in a constant and uninterrupted stream, For this new | application of it therefore we are indebted to Mr. de Jessé, and we trust that many enterprising persons will avail them~ [ Places where ‘selves of it. In the south of France, and near the coasts of J it might be ap- plied with ad- vantage. would be of importance to drain; their vicinity being a scourge to a country in other respects so much favoured by nature. Some attempts that have been made in the depart- | ments of the Aude and Gard enable us to presume, that the. nature of the soil is in general excellent. We conceive, that no draining can be attended with more | difficulties than that of the pond of Citis; that Mr. de Jessé’s _ tnethod is applicable to any pond to be drained, attention be- ing paid to local circumstances; and that is equally applica-, ble to great morasses, the whole produce of which it would } be so advantageous to obtain, at a time when the scarcity of fire-wood cieates anxiety for the means of supplying the want of fuel. the Mediterranean, there are a great many ponds, which it } + Explanation of Pl. III, and Pl. IV, fig. 1 Explanationof A. The pond of Citis, the plate. B. ‘Thearm ot the sea, called the pond of Berre. — a. Level of the pond of Citis, 6, Level eee Oe Seana or IR AC ff faa 2 fururas @ OP PDIP BOA AT TT RK UA [OU POTN SUOSTOPANT gogr genbnp- jo © 5d » yer 2p wnbog: 1) fo Pty (Od UD MERE eA rrEmoy son ruorjeynye + ———_—_—_=__—_ — Y, fp titrtrag 72 * ¢ 1 ON SPURIOUS CRYSTALS. 93 v. Level of the pond of Berre. C D. Gallery that conveys the water from the pond of | Citis into the well. D E. The well, in which are the pumps, E F. The cast iron cylinder. F G. The wooden trough. “GH, The canal cut through the rock. oO. The steam engine. g,4. Aqueduct bridges. K KKK, Pillars of mason-work, supporting the iron cy- dinder. Km. Height of the first hill. Ii. . Remarks on some Pseudomorphoses observed in the Substances, that form Part of the Mineralogical Collection of the Councit of Mines: by Mr. Tonne ier, Keeper of the Mineralogical Cabinet to the Council”. ® M INERALES that crystallize regularly do not always ap- is. ‘pear under as ie that may be considered as appropri- ae not their ate to them. squently they assume those of organized bodies, and sometimes those of substances included like themselves in the mineral kingdom, but of a different nature. These borrowed forms have been designated under the names These called -of pseudomorphoses, or pseudocrystals; and these are the more 8 aang ‘suitable, because, if they do not always deceive us, they may pseudocry- at least under certain circumstances impose upon us with re- ‘tls. Spect to their real origin. In some cases too they present us with enigmas not easy to explain, since we cannot alw vays con- ceive what substance it is, the natural figure of which they “have borrowed, though we soon detect those that have as- sumed it, under the mask by which they are concealed. The pseudomorphoses | have chiefly in view in writing these gteatite and observations are thus far remarkable, that they appear in mi- eb ae ap- pear in the ( # Journal des Mines, No. 116, p. 155, ; nerals, 94r form of crys- tals. Different erys- talline forms assumed by steatite of Bay- reuth, Steatite fronz Carlsbad . e Serpentine, OR SPURIOUS ERYSTALS. nerals, that are commonty amorphous, as the steatite, speck- stein of Werner, and serpentine. Nature, which very rarely indeed allows the species, of which these are varieties, to as- sume its proper forms, seems to have designed to indemnify it, by placing it in situations favourable for borrowing those of certain species, which appear to yield them up with more rea- diness, in proportion as they are more susceptible of variation. The steatite of Bayreuth, of which there are many speci- mens in the collection of the Council of Mines, sent by Dr. Scheider, a physician at Heff, in Franconia, exhibits several pseudomorphoses. The chiefof these are the primitive rhom-- boid of carbonate of lime; those of the equiaxal’and inverse varieties of the same species, as well as the dodecaedron, with scalene triangular pyramids opposed base to base, the me/asta- tique of Haiiy; the hexagonal prism, terminated at each end by hexaedral pyramids, of the prismatic hyaline quartz, sometimes alternate, at others bisalternate and flattened. A steatite from Carlsbad in Bohemia has exhibited to Mr. Haiiy a remarkable pseudomorphosis, consisting inan oblique prism with a rhombic base, similar to the binary feldtspar. It forms part of a rock with base of feldtspar, which serves it for a gangue. This interesting specimen was sent by prof. Jurine of Geneva, who has aduplicate of it in his collection, — = ’ Mr. de Champeaux, to whom we are indébted for a know- ledge of the situations, in which uranium, oxide of titanium, emeralds, and graphic granite are found in the department of the Sadne and Loire, one of those which that engineer of Mines has the charge of inspecting, has found in the valley of Vidge, at Mont-Rose, a serpentine interesting for the novelty of the regular figures it exhibits. This substance, which is in the collection of the Council of Mines, is of a greenish co- lour, a little transparent on the edges, and nearly approaches the noble serpentine of Werner, Oligist iron, or specular iron ore, is disseminated in it. It exhibits, besides, 1st. the form of the prismatic hyaline quartz, their being no difference that can be appreciated between the inclinations of the faces, and values of the angles, when they are compared together: Qdly. the same form modified by facets occupying the places of the edges contiguous to the summits of the pyramids, which had neyer ye J ON SPURIOUS CRYSTALS. 95 never yet been observed in the quartz itself. All these pseudo- morphoses of steatite and serpentine are so many examples added to the well-known instances of quartz, which borrows sometimes from one species, sometimes ‘from another, forms it is incapable of assuming when left to itself. : The idea that first occurs to the mind respecting the origin Supposed ori- of such accidental forms has been to suppose, that the spe-.S' cies, which has lent its form, has had an influence on the crys-,That a portion tallization; and though mixed with.a foreign substance, often cae ha predominant in point of quantity, nevertheless acts the princi- ahha Sue pal part, and impels its companion to yield to the form it im- form of the poses on it. Thus it was at first supposed, that, in the rhom- a yen : boidal figures, similar to those of calcareous spar, exhibited : by the steatite of Bayreuth, and the same might be said of the other forms imitated from carbonate of lime, there existed originally a certain quantity of carbonate of lime, as in the crystallized sandstone of Fontainebleau, and that the steatite owed its form to this carbonate. Subsequently however the pseudocrystals of steatite have But the false been compared with the steatitic mass, by which they are ©'Ystal does : not appear te completely enveloped; and they have been found perfectly contain any similar in every respect to the gangue in which they occur, S¥ch portion. * possessing its softness, greasy appearance, soapy feel, &c. No trace of the substance, the presence of which was supposed necessary to imprint on it the regularity of form that distin- guishes it, could be perceived. These considerations, and Difficultto ex- iffic of explaining how carbonate of li valvar p iain how stea- the difficulty P Soo te of lime, hyalin tite should quartz, and feldtspar, could yield their place to the steatitic take the place particles, allowing them to arrange themselves in tle precise Ae g order required for the regularity of the figures retained, have _ appeared 2 motive sufficient to cousider these forms as proper hence suppos to the substances bearing them. Analogy, however, and the ed to a ae : ? i E s originaisteatite usual laws of crystallization, appearing to me little favoura- i ble to this opinion, I shall submit my doubts on the subject in a few words, We frequently see quartz assume the cubic or octacdral Spurious crys- form of fluate of lime, at others affect that of the metastatic 4/5 of quartz. «carbonate of lime, and again put on several of those of sul- phate $6 P-eudacrystals of quartz, of calamine, of quartz. ‘ ON SPURIOUS CRYSTALS. phate of barytes*. The origin of these forms is by no means. i equivocal. * In the coll®ction of the Council of Mines are several quartzose’ pseudomorphoses, of which I shall content myself with mentioning the most remarkable. The first is borrowed from the metastatic carbonate of lime, and was found at Montbrizon, in the department of the Loire, by Mr. Laverri¢re, engineer in chief. The origin of this accidental form is by no means enigmatical. It is even necessary, in order to account for it, to have recourse to a sort of cementation, by which the particles of quartz would gradually have taken the places of those of the carbonate of. lime, which before occupied the situation; it is sufficient, that a cavity left void by the calcareous spar, destroyed by any cause, served for a mould to the matter of the quartz, A piece of calamine, from Somerset- shire, which is in the systematic cellection of the Council of Mines, ex- hibit a pseudomorphosis similar to that of the quartz of Montbrizon. The pseudocrystals of this ore of zine are of a reddish brown colour, three inches long, and hollow within, a circumstance in which they differ from the preceding, those being full and compact. The crystals uf metastatic calcareous Spar, which are sometimes found in the interior of those of ca- lamine, and certain groupes of similar calcareous spar mentioned by Romé de VIsle, part of which is still in the state of carbonate of lime, while the rest is in that of oxidé of zinc, leave no doubt respecting the origin of this pseudomorphosis. The department of the Saéne and Loire, and that of the Nievre, visited by Mr. Champeaux, have afforded a variety of pseudomorphoses of a quartzose nature. These forms, all borrowed from acidiferous substances, derive their origin in some instances from fluate of lime, in others from sulphate of barytes. The regular forms borrowed from fluate of lime are the octaedron and the cube. These octaedrons.are either hollowed out, or in relief. The faces of the first are plane, or convex: the second.ex- hibit sometimes a regular octaedral summit, at others a simple equilateral triangle. The cubic forms, which are more numerous, ,are either solid or hollow. Ali these forms exist with the same appearances in the fluor spars found in the same place. The forms originating from the sulphate of barytes are the primitive form of that sulphate, with the trapezoid, the pointed, the laminar, the concrete, and the radiated vari- eties. The pseudomorphic quartz crystals originating from sulphate of barytes are not accompanied with this sulphate, as those indebted .0 fluate of lime for their form are with this fluate; whether because the sulphate of barytes has been subsequently destroyed, or because the pseu- domorphic quartz has been removed from its place; which must have happened sometimes, sifice it is found not only in veins, but in ravines, and on the surface of the ground. However, on proceeding but a little way from the places where these pseudocrystals of quartz are found, we soon meet with veins of sulphate of barytes, and this in sufficient abun- dance, to leave no doubt of the origin of these pseudomorphoses, If ON SPURIOUS CRYSTALS. 97 equivocal. The fluate of lime, sulphate of barytes, and car- bonate of lime, which are found in the same places, are so many faithful witnesses, which point out the source whence these forms are derived: and though we are not able to ex- plain completely every circumstance respecting them, their nature cannot be doubted. When we find steatite exhibiting Steatite. itself under several of the forms of carbonate of lime, may we not with great probability infer, that it has only imitated quartz by deriving from the same source the forms common to both? and when it presents itself under the forms that be- long to quartz, is it not highly probable, that these forms are no more peculiar to it, than those of carbonate of lime are to guartz? But it may be said, the crystals of steatite so perfectly re- semble the mass in which they are enveloped, that we must suppose them to be the same substance, differing only in re- gularity of form. Tothis I would answer, such an inference Crystals donot is contradicted by analogy: for, when a substance is regu- rence ee larly crystallized, and its crystals are enveloped in an amor- the same sub- phous mass serving as their matrix, this is commonly of a*"""" different nature. Thus fine limpid crystals of hyaline quartz Instances. with two points are found buried in white Parian marble, in certain clays or marles, and in porphyries; crystals of hema- toid quartz, or red jasper, and of borat of magnesia, are con- cealed in masses of gypsum ; crystals of sulphate of lime are commonly found in banks of clay; crystals of specular iron ore, garnet, tourmalin, and magnesian limestone, occur in micaceous schist; &c. . It may be said farther, that the steatite, which exhibits Steatite ina forms analogous to those of rock crystal, presents others, that Peculiar form: appear to be peculiar to itself; such for instance as the hex- agonal prism with hexaedral pyramids truncated on the edges contiguous to the summit, which raises the number of termi- nal faces to twelve. This observation, I confess, might have but this has been adduced as a very plausible objection, before quartz had S!"°* been If these pseudomorphoses of our departments be compared with these of Saxony, Bohemia, and Hungary, described by baron von Born, we shall find, that they present the same circumstances of form and situation, and have a similar origin. Vor. XX.—Junez, 1808. H shown 98 found in quartz. Argument from the laws of crystalliza- tion, Proof against this, Carbonate of time crystal- lized in the same figure, * but with dif- ferent angles. ON SPURIOUS CRYSTALS. shown usin the crystals of the geodes of Oberstein this very secondary form, the structure of which, as ascertained by Mr. Haiiy, is derived from the primitive rhomboid of quartz. But since this variety of form, which has not escaped the atten- tive eve of Mr. Tondi, occupies a place in the series of forms of quartz, the difficulty vanishes, analogy resumes all its weight, and the origin I ascribe to the regular forms of steatite retains it probability. The laws of crystallization have been appealed to in favour of the opinion Icombat. On breaking the steatite of Bay- reuth, we discover in it parts, which have the form. of the rhomboidal calcareous spar, Itis in fact the primitive rhom- boid of carbonate of lime, which has been mentioned above as one of the forms, under which steatite sometimes presents itself. Nowit has been said, rhomboidal molecules are capa- ble of producing the prismatic form of rock crystal, and that of the inverse calcareous spat, the muriatic calcareous spat of del’Isle: therefore, the forms observed in steatite may. be its own. It is very true, that the obtuse rhomboid of 101°, similar to that of carbonate of lime, performing the office of a nucleus and substractive molecule, may produce the hex- aedral prism of rock crystal. It does this in the prismatic carbonate of lime, by means of a decrement on the inferior angle of the nucleus in which two rows of molecules are sub- tracted; and this Jaw is general for every rhomboid. But it cannot produce the hexagonal pyramid, which terminates the prismatic hyaline quartz, with the same incidences which are constantly found in the quartz; as these require for the pri- mitive form and subtractive molecule a slightly obtuse rhom- boid only, the angle of which is about 94°. Mr. Héricart Thury, engineer of mines, has found near Grenoble-indeed carbonate of lime crystallized in a hexaedral prism with a pyramidal summit of six triangular faces; but this form has nothing in common with the prismatic quartz, the crystals being altogether different, both in respect to the incidences of the faces, and the values of their angles. It differs from the prismatic hyaline quartz, as the greenish yel- low phosphate of lime in hexaedral prisms terminated by hexagonal pyramids, the spargelstein of Werner, differs from the a eee ee. Pease aes ee ee ae eli! A ON SOAP-SUDS AS A MANURE. 99 the two former, and from the phosphate of lead, which some- times assumes an analogous form. In combating the opinion of those, who might be tempted still it is aim. to consider the regular figures under which the steatite of cuNeeceiivas Bayreuth and the serpentine of Mont-Rose present themselves guartz crystals as crystalline forms properly belonging to these substances, [ were destroy- ed, and the have not concealed the difficulties, to which the opposite opi- steatite assum- nionis obnoxious. I frankly confess the impossibility of cons 4 “ei place. ceiving, for want of local facts and observations, the means that nature can have employed for destroying the quartz crys- tals, which I suppose to have been originally included in the steatite, and fragments of which are found in neighbouring Masses of steatite, to supply their place subsequently by a mass similar to the gangue in which they are included, yet so as to retain the ancient figure. I. know not any rational explanation, to account fur what has become of the substan- ces, the forms of which alone remain. It appears to be a secret, which nature has preserved; but which farther ob-. servations, and inspection of the places, may perhaps some day enable us to penetrate. If however we believe the existence of nothing, except what we can completely ex- : plain, how narrow must be the bounds, to which we confine - our knowledge! IV. An Experiment on Soap-Suds as a Manure. By Mr. G. Ir- win, of Taunton; with Remarks by the Rev. Tuomas F ALCONER*. 4 A Few years ago my attention was attracted by the soil Soil ofa garden of a garden, reduced to a state of poverty very unfriendly rhe eka to vegetation. Interest in its future produce influenced my ote lhs for its restoration. An invigorating manure was ne- cessary ; but such a stimulus could not be easily procured. While considering which of the succedanea within my reach * From Papers of the Bath and West of England Society, vol. XI, -p. 261, H 2 had 100 enriched by soap-suds. Dr. Hunter's oil compost. ON SOAP-SUDS AS A MANURE. had the greatest probable appearance of succeeding, it oc= curred, that possibly some trivial advantage might be de- rived from the oil and alkali suspended in the waters of a washing +. Pits were immediately ordered to be made, and in them the contents of a tub, which my servant usually committed to the common sewer, were carefully deposited: ~ as washing succeeded washing, other pits were dug and filled; so that the whole garden, a small portion only ex- cepted, has in this manner been watered and enriched: that small portion remains a visible demonstration of the utility of this manure. There vegetation is still languid; while the residue of the garden, invigorated by the suds only, annually exhibits a luxuriance almost equal to any thing this fertile neighbourhood can produce. Iam, Sir, your humble servant, GEORGE IRWIN, ee em Remarks, by the Rev. T. FaLconer. i. The above important experiment may perhaps remind the reader of the principal ingredients of the oil compost, suggested by Dr. Hunter of York. In the simple fluid manure we have an animal oil, potash, and water; in the compost are the same oil and the same «lkali, but neither of them perhaps in so pure a state as in the manure, with the addition of “ fresh horse-dung.” The fresh horse-dung is added, in order to produce “ heat and fermentation ;” and a delay of “ six months” is supposed to be necessary, to make the compost “ fit for use.” All, however, that seems to be gained by the horse-dung, is the animal oil, which may be united to the alkali during the process of fer- mentation, and the straw, which in the fermentation of the compost will bind the mass together, and when decomposed on the ground will afford a small supply of vegetable mat- ter. If we make the comparison strictly accurate on the + It is the common practice of some parts at least of the west of Eng- land, to use a lixivium, made by passing water through an appropriate strainer containing wood ashes, for the purpose of washing, This was probably the case here, though not mentioned by the author. other ON SOAP-SUDS AS A MANURE. 101 other side, we may observe, that in the fluid manure there must be an increased quantity of animal matter in the wa- ter, after it has been used for the purpose of washing linen. The experiment then shows what is the advantage of the application of the oil aud alkali only, as a manure, and perhaps the delay of “ six months” in preparing the com- post would not he compensated by any superior efficacy, that may be expected to arise from the combination of the horse-dung. It also appears from the experiment, that the compost is a more useful discovery than Dr. Hunter himself could just- ly infer from his own limited experience of its effects. Q, This mixture of an oil and an alkali has been more ge- Soap-sudsare- nerally known than adopted, as a remedy against the insects medy against ee : : ° the insects that which infest wall-fruit trees. It will dislodge and destroy inj ene tate the insects, which have already formed their nests and bred trees. among the leaves. When used in the early part of the year, it seems to prevent the insects from settling upon them ; but whether by rendering the surface of the leaf disagree- able to the bodies of the animals, and thus repelling them, _or by neutralizing the acid they deposit, and thus prevent- ing the leaf from contracting into a necessary form for their reception, I cannot presume to determine. One of the modes, by which this mixture indirectly contributes to the fertility of the ground, may be by its destruction of the in- _sects, which prey upon the plants. It is also, I think, to be preferred to the lime water, or Preferable to the wood ashes and lime, which Mr. Forsyth recommends eg ns = to be used for the removal of insects. It is preferable to vium. _ _the iime water and the lime, because lime loses its causticity, and with that its efficacy, by exposure to air, and must con- sequently be frequently applied; and to the dredging the leayes with the fine dust of wood ashes and lime, because the same effect is produced by the mixture without the same labour, and is obtained without expense, | _ Mr. Speechley, in his treatise on the Vine, published in Mr. Speechley 1796, has used this mixture with great success; but he has recommendsit. applied it awkwardly and wastefully.. He directs it to be poured from a ladder out of “a watering pot ever both trees and 102 ON PREVENTING THE DRY-ROT IN WOOD. and wall, beginning at the top of the wall, and bringing it on in courses from top to bottom :” page 161. Mr. Speech. ley is not the first person who has thought of this application of the mixture. It is a fact which has been long known and neglected. Best applied A considerable extent of wall may be washed by means | Be ae of a common garden pump in a short time; and this opera- tion should be repeated as often as a supply of the mixture can be procured; or if the water of a washing cannot be had, a quantity of potash of commerce dissolved in water may be substituted*. The washing of the trees and wall twice a week for three or four weeks in the spring will be ‘ sufficient to secure them from the injuries of these insects. A valuable On the whole, then, this must be considered as a valuable Peta Shs pp manure, as it can be obtained easily, at small expense, and the garden. in large quantities ; and, when its nature 1s well understood, will probably be no less esteemed by the farmer than horse dung. To the gardener, as well as to the farmer, it is use- ful, mixed with mould, as a fertilizing compost; or, when fluid may be applied to his fruit-walls, as a wash fatal to ane noxious brood of predatory insects. THOMAS FALCONER. eS See eee! V. An Inquiry into the Causes of the Decay of Wood, and the Means of preventing it. By C.H. Parry, M.D. - (Concluded from p.78.) Would the I Do not know whether in very damp situations, surrounds varnish insome ed with stagnant air, these varnishes would in time admit sae Sd of the ee of fungi or mould. The brimstone might gi? be sufficient to preclude that effect; but, if we believe Bra- connot, seeds of the white mustard sown in pure flowers of brimstone, and well watered, became vigorous plants, which * Mr. Speechley uses his mixture warm, to soak the shreds, and wash the wall, more effectually, flowered ON PREVENTING THE DRY-ROT IN WOOD. 103 flowered and produced effective seed*. It is certain, how- ever, that the essential oi] of turpentine will act as @ poison on growing vegetables ; and perhaps the same property may exist in resin, which seems to, be a similar essential. oil, united with a certain proportion of oxigen. It is however highly probable, that the union of the brim- The brimstone stone may have another good effect, which is to prevent one 7°Y defend ‘ from insects. of the causes of the destruction of timber which I have be= fore mentioned, the depredations of insects. Whoever would learn the havoc, which certain animals of this kind are capable of making in hot countries, would do well to read Smeathman’s description of the termes, or white ant, originally published in the Philosophical Transactions, and thence abridged into the English Encyclopedia Britannica, and other collections. In this country we know little of | such ravages. Mischief however of this kind does some- times occur, and may be the work of various animals, a par- ticular account of which may be met with in the fifth volume of the Transactions of the Linnean Society. ; Tam informed, that in India, a circle of Lord Dundonald’s Coal tar. coal tar drawn on the floor round boxes and other furniture, will effectually preserve them and their contents from the depredations of the white ant. It appears, that most insects are fond of sugar and muci- Otherdefences lage; which is the probable reason why that wood is most 284Mstinsects, subject to be penetrated by worms, which is felled when it most abounds with sap. In such cases, it might be well to try the effects of washing the wood, previously to the use of the varnish, with a solution of arsenic in hot water, in, the proportion of 11b.. to 10 gallons; or with a strong de- coction of coloquintida or bitter apple, or white hellebore; after which the wood must be completely dried before the application of the varnish in the manner before directed. All these preparations are extremely cheap, and are either destructive or offensive to insects, and therefore will, proba~ bly, be an effectual defence against any injury from that cause. z C. H. PARRY. | Circus, Sept. 30, 1807. * See Joumal, vol. XVIIL -p. 18. VI. 104 ANALYSIS OF JADE. WE. Analysis of Jade; read to the Society of Natural History and Philosophy at Geneva, Dec. 5, 1805: by THEoporE DE SAUSSURE*. General cha- racters of jade, Unper the name of jade are generally comprised cer- tain stones, not crystallized, remarkable for a greasy or oily appearance; a colour between waxy white and leek green, inclining sometimes to a blue, sometimes to a gray; a dull, greasy, scaly, and not lamellar fracture ; extreme tenacity ; hardness capable of scratching rock crystal; and lastly, a density superior to that of feldtspar or petrosilex. Two stones = Two stones, which have been considered only as varieties possess these: the oriental, or Of the same species, unite all these characters in an eminent lapis nephriti- degree. One of these is the oriental jade, or lapis nephri- Wik ticus, which Mr. Haity calls jade néphrétique. This comes from China and the Levant, but we know not its situation in the earth. It is celebrated for the property ascribed to it by the Eastern nations of curing the renal colic, and allay- ing the pain of the stone, It is known in Europe only by the amulets, vases, and other pieces of ie lars brought from the places where it is native. _ and onefound The other, considered by most mineralogists as a variety peeelae ‘© of the oriental jade, is found in seyeral parts of Europe. 4 jade. : My father was the first who made it kuown, after having found it on the borders of the Leman lake (Voyages dans les Alpes, § 112), on those of the Durance, at Musinet near Turin, and in other places. From the name of the lake it was called /emanite by Mr. dela Métherie, who has well distinguished it from the oriental jade. Mr. Haiiy has called it tenacious jade; and several authors have mentioned Characters of it by the name of Saussure’s jade. This stone resembles this stone. the oriental jade in colour, hardness, tenacity, and fracture: canto but it differs in its specific gravity, which is greater; in its ; transparency, which is less; and in its fusion, which is more easy, and affords a perfect glass, with a smooth, conchojdal * Journal des Mines, No, 111, p. 205. . fracture, ANALYSIS OF JADE. ‘105 fracture, though frequently semitransparent, while the orien- tal jade produces only an opake mass, with a dull, uneven, and by no means conchoidal fracture. It differs likewise, as _ I shall show presently, in its constituent principles, It is proper therefore, that the name of jade should be taken from it; and I would propose to substitute that of Saus- Name of Sause surite, as a compliment to the memory of my father, who See ROT first directed the attention of mineralogists to this stone. Names too, like this, which have no particular signification, Names should are most convenient, because they do not lead us into er- pees de- rour. Names derived from one of the places where a stone meaning. is found are always improper, as has frequently been re- marked, because it is net peculiar to this place exclusively. Names derived from one of the characters of a fossil too, in whatever language they are framed, are not more suitable; since this character never belongs exclusively to the mineral denoted by it, which differs from others only by its general properties. ' Werner considers as a subspecies of jade the Letistein, Beilstein con- sidered as a _~ pierre de hache, or axestone, which is chiefly known to us jade by means of the hatchets fabricated with it by the Ameri- cans. But this is much inferior in hardness and density to the stones generally comprised under the name of jade, and does not easily strike fire with steel; though it has a greasy appearance and greenish colour. On this stone however I can say nothing more, as I have it not in my possession, and have been able to examine it only superficially, so that I am obliged to leave its rank undetermined. The greasy polish of jades has appeared to most mine- From their ralogists to indicate, that they are impregnated with taley Se: ae particles, and that consequently they ought to be classed magnesian: with the steatites. Mr. Hoepfner has confirmed this opimion and Hoepfner’s by the analysis he has given of the jade of Swisserland. In Bef a this he found 0;47 silex, 0°38 magnesia, 0°04 alumine, 0-02 siain the Swiss lime, and 0.09 oxide of iron. The magnesian nature of this J2¢°: stone appears the better founded, as it sometimes occurs in mountains of serpentine: but | thought it necessaty, to re- but this ques- peat the examination, partly because this was made at 5 ee. time when processes were less precise than at present; partly because 4 66 ANALYSIS OF JADE, because the identity‘of the tenacious jade and the oriental jade did not appear'to*me to be proved. Analysis of the oviental jade, jade néphrétique of Haiiy. Analysisofthe For this analysis I employed amulets cut in form of.a briental jade. : ot My 15 : 7 Fhespecimens Crescent very littie hollowed out. Their colour was a leek described, green, inclining to gray: their specific gravity 2°957. Ac- cording to Brisson the specitic gravity of this jade is 2-966 *; and according to my father between 2°970 aad 3°071. > These amulets are interiorly dull, and merely shining in small spots; they exhibit a dull fracture, with some fibres here and there, either straight or curved; they are semi- transparent, and hard enough to scratch rock crystal, but are scratched by the topaz and the emerald. Their tenacity is very great: I could not pulverise them without greatly in- juring an agate mortar, till I heated them red hot, and threw them into water. Ina red heat they lose all their transpa- rency and about 5}, of their weight, their green colour py to a dark dirty gray, aud they become fragile. ~ Exposed to a 0! OWE of these amulets, of the weight of about 6 gram- strong heat in mes [93 grains], was exposed whole for an hour in a platina a platina cru- ele, crucible to the most violent fire of a wind furnace. It there melted into a button, which was gray on the surface exposed to the air, but white interiorly ; opake, beiig merely a lit- tle translucid at the edges; of a greasy, unequal, and con- fusedly lamellar fracture; and covered here and there with smooth, shining, greasy crystals, the extremity of which only was visible. ‘This extremity exhibited very flat pyra+ mids with four faces, the two larger of which terminated at the summit of the pyramid in two obtuse angles, and the two intermediate in acute angles. ‘The upper surface of the button, when inspected with a microscope, showed a mul- titude of metallic globules of a gold colour, the nature of which I could not ascertain.’ The lower surface was covered with a row of large blebs, that did not penetrate into the substance, A small part of this button was fused before the blowpipe, but without forming a glass.’ One hundred parts of the jade by weight lost by fusion 24 parts. * In Brisson’s Mineralogy it is from 2°9502 to 2°9829, Tr. oY “boiling the solution, weighed when dry half a-part. The ANALYSI5 OF JADE. 107 «2. Texposed to a red heat for two hours a mixture of 100 Heated with parts of this jade pulverised with 450 parts of potash. The! Carat result was a deep grass green mass, not vitrified, that com- municated the same colour to cold water, in which it was and water at diffused. This colour’soon disappeared, the solution at the fused, same time letting fall a gray A opealane precipitate, which afterward became brown. ‘These defects indicated the pre- sence of oxide of manganese, which for the présent I left mixed with the other principles of the stone. 3. The preceding liquor, as well as the undissolved part, Muriatic acid was mixed with a portion of muriatic acidin excess; but 2444 this did not attack a brown or blackish flocculent residuum, which, being mixed with thrice its weight of potash, pro- duced on exposure to the fire a green glass. This dissolved entirely in water and muriatie acid. The muriatic solutions being mixed and evaporated yielded a jelly, which being re- duced to dryness, and the residuum digested in muriatic acid diluted with water, 537 parts of pure silex, distinetly characterized, were obtained. 4. The muriatic solution, separated from the silex, was The muriatie mixed with ammonia; and a yellow precipitate formed, con- S°!8tion preci: pitated by am- sisting of the metallic oxides and alumine. This precipitate, monia. : while still wet, was digested with potash twice in succession, to dissolve the alumine: but this solution, when supersatu- rated with acid and precipitated by ammonia, threw down but half a part of alumine. 5. The metallic oxides left on the filter after such a pro- Metallicoxides cess as the preceding are seldom pure, as they retain both ici ea alumine and alkali. To, separate these, they were mixed water affused. with five times their weight of potash, and heated red hot. The result was quickly diluted with cold water, and thrown on.a filter, which retained the oxide of iron; a green liquor, -holding in solution alumine and oxide of manganese, pass- Manganese ing soedush! The oxide of manganese, precipitated by giesieyated iy solution, after this oxide was separated from iit, being’ super- alumine by ° saturated with acid, and precipitated by ammonia, some alu- ¢™™onia, ‘mine was thrown down, which when dried at a red heat weird one part. ‘ ane oxide of iron, being freed from the alkali, that re- Oxide of iron recipitated, mained PreiPitat 108s ANALYSIS OF JADE. mained united with it, by dissolving it in muriatic acid, was precipitated by ammonia. After calcination it weighed six parts and half. But as its black colour indicated, that it Some more _ still retained some oxide of manganese, I digested it repeat- ane a edly with vinegar, evaporating it to dryness every time, and rated from it, Yedissolving the residuum in water. The solutions being added together, and precipitated by potash, yielded 12 part’ of oxide of manganese: the pure oxtde of iron therefore weighed but 5 parts. | Carbonate of 6. The muriatic solution (3) separated from the alumine lime precipita- a4 metallic oxides was supersaturated cold with carbonate ted by carbo- Y ] ue : nate of ammo- of ammonia. This separated 22 parts of carbonate of lime, oe which furnished after calcination 123 parts ef pure lime. The ammouiacal liquor, being filtered, let fall nothing on ebullition. No magnesia. The 123 parts of lime I dissolved in sulphuric acid, and eould be disco- divested in water: they were found to have the same de- - vered among Ane bless é it. gree of solubility as sulphate of lime, and I could not dis- cover, either by crystallization, taste, or any other sign, an atom of sulphate of magnesia. Products. Thus a hundred parts of nephritic jade yielded me on this occasion Silex ie Sie sled eine ore ee wee wisne asus 53°75 Lime - eer cess ec ccee cece ceees 1975 Pe Writs ete Weenie ae ee ae Oxide of iron cccccocersieccens § " Oxide of manganese -e+eee-++s 2 Water seqeeerecssceseeeqeees 2195 77°25 Loss eeaseseoe 22a 100. From thegreat This loss being much too great to be ascribed to an er- loss anacidsus- your in the process, I repeated the analysis in the same pected, She ays . manner, endeavouring in addition to detect the presence of any of the acids, that sometimes enter into the composition of minerals. vi . but none After this examination, which was so far fruitless, though found, in other respects it confirmed the preceding, giving nearly the ANALYSIS OF JADE. 109 the same results, though from different specimens, I sought to discover an alkali in the’ amulets, by employing nitrate eel ie for of barytes to decompose them according to Klaproth’s me- “" *“*" thod. A hundred parts of nephritic jade were mixed with five Heated with times their weight of nitrate of barytes. This mixture I ee ae divided into four parts; and after having exposed the first to the action of the fire in a platina crucible till it ceased to swell up, I added to it the second, and so on with the rest. The whole, after having been exposed to a red heat for at least half an hour, exhibited a spongy mass of the colour of goose-dung. This was pulverized, and diluted with a large Water affused, ; : 4 E and muriatic quantity of cold water. The mixture assumed a hilac red jeig gadea, colour, which disappeared by a boiling heat, but returned on adding a few drops of muriatic acid, and again disap- peared on adding a farther quantity of the acid, which gave the liquor a yellow colour. Jt contained a white insoluble powder, weighing 43 parts. This powder was exposed to . the fire with four times its weight of barytes; and the spongy white substance thus produced dissolved completely in water and in muriatic acid, without exhibiting the colours men- tioned above. The muriatic solutions having been mixed together, sul- The solution phuric acid was added in excess, which separated the ba- seen by rytes, and part of the silex. a) ae The liquor was filtered, and evaporated, till all the mu- The muriatic riatic acid was distilled off. The residuum moderately dry Pe ARR: off was digested in distilled water, which dissolved the whole, Rasa cana except the last portions of silex, and a little sulphate of solved in water lime. The solution being filtered, ammonia was added, which and precipita- precipitated the alumine and metallic oxides. vat aero These substances having been separated, the liquor re- The liquor maining after filtration was evaporated, and the residuum “7? oraied, heated to redness, This, which was of a whitish colour, and earthy sul- weighed 56 parts. Being diluted with cold water, 16 parts a a bia of calcined sulphate of lime were separated by filtration, The alkaline sulphate therefore weighed after calcination 40 — a etn The 110 ANALYSIS OF JADE. Thealkalfme . "The aqueous solution of alkaline sulphate, being left to raeeny aa crystalhze slowly, showed itself to consist of sulphate of stallization. soda and sulphate of potash. “These salts when crystallized weighed 74 parts. The sulphate of soda after calcination weighed 24°6 parts; that of potash 15°4 parts. Assuming for these’salts the proportions assigned by Kirwan, we fret that the stone contained 10°83 parts of soda, and 3°44 parts of potash. Component On putting together these results, we find, that 100 parts parts of orien- tal ornephritic jade. of nephritic jade contain Sy eb eR re Ad ARS SINE SR eiey lO iyanter toe oee he SA et ET er, 12°75 Alumine > STE Serre Siete © tty 2 yen) ® Ley Oxide of iron eeeecea eeereve seen 5 Oxide of manganese -+++s+++++ 2 Soda es a eeeeee esceeeceo ep eeere ces 10°75. Potash © in 6 fe (@ [ow isje 6 9 © 6 jeleye etele eels 8°45 Water rae ie ah ble lee 0. ape velwie es wine ere O95 96°5 Foss eeoeeorees 3°5 100. Difersfromall Vence the nephritic jade appears to have no resemblance other stones. 4, any stone hitherto analysed. Analysis of the Saussurite, tenacious jade of Hariy. Specimen of For this analysis | selected a rounded pebble, found on nr the borders of the lake of Geneva by my father, who con-~ described. sidered it asa pure and well marked jade. Its colour was a deep leek green inclining to sea green. Its surface, polished on one side by art, on the other by natural attrition, was smooth, shining, oily to the sight, and greasy to the feel. ‘Its fracture was dull, not lamellar, fine-grained, and with large scales. On the edges it was translucid. Its tenacity was very great, and similar to that of the nephritic jade. It easily scratched rock crystal, but was scratched by the topaz and the emerald. Its specific gravity was 3°261. That of specimens weighed by my father was 3-318, 3'327, and 3-389. It was free from diallage, or smaragdite, ettech 7 is almost al- ways ANALYSIS OF JADE, Lif - ways found dissemmated in it. It had no perceptible effect on the maguetic needle. | A saussurite very distinctly marked yielded: before the Fused intoa : au ahs ‘ . palesemitramse blowpipe a greasy, semitransparent glass, of a white or parent glass; greenish colour: but the same stone, which in this way pro- duced such a glass, being exposed to the most violent heat & ata greater heatiutoa pers di: ‘ fectiy transpa- alight brown glass, of the most perfect transparency, and rent brown free from blebs both within and at the upper surface. Some &'**: were seen in contact with the sides of the crucible. I thus fused about six grammes of saussurite, which did not lose by this operation any sensible portion of its weight *. of a wind-furnace in a platina crucible for an hour, yielde I shall not detail the processes I employed to analyse this Analysed as stone, since they were the same as those already described. th o'b*": I shall only mention, that, to separate the alkali, I attempted Attempt to se to treat the powdered saussurite with sulphuric acid, by a ee boiling it on it, and evaporating to dryness. I repeated this yic acid unsue- process with the residuum six times, powdering it each time, cessful, But I could not by this process extract above 0°12 the weight of the stone, or deprive it of more than 0-02 of al~ kali. I then’ treated with nitrate of barytes, assisted by heat, the insoluble part, which had retained the metailic - parts, because it had been calcined. The spongy matter procured by this operation was of a greenish gray. Cold water did not bring eut the lilac colour, which had appeared on treating the oriental jade in the same manner. This co- lour was owing probably to the oxide of manganese, which ‘ exists in some quantity im the oriental jade, but was scarcely sufficient to be weighed in the specimen of samssurite, that I analysed. / ! fw _* On this glass free from blebs I made one striking observation. atthe elace was, that the specific gravity of the stone previous to fusion is much capa softer than the stone greater than that of its glass. The specific gravity of the saussurite is itself. 3261: that of its glass is at most 2:8. The glass is softer than the stone, and easily scratched by it. : A hundred 112 Component parts of the saussurite, It is neithera magnesian stone, nora jade. The saussurite compared with feldtspar. ANALYSIS OF JADE. A hundred parts of saussurite afforded me Beil: + «as tt anein: cls ol ete Le 44 AMINE”, sie wales sis eb bieeiemninle S > OS ctigie «Sse wtsia) wteevorel siaiale iar enanetees teva 4 Csxide GF iteb ss + ccidsisis does + oes here Oxide of manganese -+-+++++++ 0°05 OCGA 8S bine & LRG whe Cees cM ks oe or MS Potash Wis vest tcecasc tans ws ee RS 96°38 Loss eer eneee 3°23 100. From these results it appears, that the saussurite 1s not a magnesian stone. It appears too, that it cannot be classed with the nephritic jade, as the alumine, which is in very small quantity in the jade, forms a considerable proportion of the saussurite; and the two stones likewise differ greatly in the alkali they contain. 3 The saussurite contains a great deal more metallic oxide than feldtspar; their earthy principles however are the same: at least they succeed each other in the same ‘order, the pro- portion of silex only being greater in the feldtspar, and the proportion of alumine less. Their external characters, if we consider the extremes of the two species, are totally dif- ferent, but there are gradations between these, that bring them almost together. ‘Thus that feldtspar, which my fa- ther called greasy (Voyages dans les Alpes, § 1304), and which is found crystallized in the green antique porphyry called ophites, and confusedly crystallized in nodules of va- riolite, does not always exhibit any signs of a lamellar struc- ture. Its hardness is so great, that it readily scratches rock erystal; and like the saussurite it has a greenish and oily aspect. If the granulous and scaly petrosilices be feldtspars, as analysis tends to show*, another link 1s added to connect them. * See the analysis and description of the petrosilex of Pisse-Vache. Voyages dans les Alpes, § 1057. Ido WATER HEATED BY FRICTION. | 113 I do not intend by these gradations to confound the two stones: their elements, and their external, characters, con- sidered in the extremes, are sufficiently marked, to consti- tute distinct species. I would only remark, that they have shades of resemblance, which tend to confirm the results of analysis. VIL Remarkable Fact of an Inerease of Temperature produced in Water by Agitation. In a Letter from JosepH Reape, - M. D: i To Mr. NICHOLSON. SIR, Cork, May 8, 1808. Since my communication on the increased capacity of water, I have been engaged with’ some experiments on heat excited by friction, one of which I beg leave to communi- cate through the medium of your Phitobophical Journal, and hope it may not be esteemed uninteresting. 1 shall confine myself to a concise recital of the experiment, which if confirmed, is in direct contradiction to received opinion, that the agitation or friction of fluids cannot excite sensible heat. ) Experiment. Z The temperature of the apartment being 40°, half a pint water at 40° of water, at a similar heat, was poured into a tin bottle- tse to 48° by agitation in a shaped vessel; into the aperture of which was inserted a closed tin ves thermometer, surrounded with chamois leather, and made sel. to fit accurately, with its bulb nearly in the axis. After briskly agitating the vessel for a few minutes, to my ex- treme surprise 1 found the temperature of the water rose § degrees; and even after the apparatus was uncovered and laid at rest on the table, the water continued to rise for se- veral minutes ; proving the origin of the heat to be inherent in the fluid, and independent of any external causes. Anx- ious however to obviate every source of fallacy or objection, - Von. XX—JUNE, 1808. L I prevented 114 ON GRAVITATION, Repetition of [ prevented the communication of caloric by my hands, or the exp. Remarks on Prof Vince’s letter upon gravitation, of radiation from my body, by coating the tin vessel with many layers of woollen cloth carefully wrapped round it; over which there was a tin case, the entire nearly two inches in thickness, and covered externally with three wet towels. In the course of the experiment I dipped my. hands fre- quently in snow water, and also sprinkled the towels. Having repeated this experiment with similar results be- fore the Rev. Mr. Hincks, Lecturer on Chemistry in the Cork Institution, I now venture to lay it before the public. Mr...dincks on repeating the experiment in a glass bottle, found the heat of the vessel, by means of »a thermometer placed between it and the covering, to be inferior to that of the enclosed fluid, and on a par with the atmosphere, which proves in a most satisfactory manner, that there could be no communication of caloric from the hands. Some-extremely interesting conclusions may be drawn from this experiment. What is the cause of the increased heat? certainly not aris- ing from a diminution of capacity. Is caloric material or immaterial? Is friction adequate to account for animal heat? Should this experiment on critical examination be found correct, these, and some other speculation on heat, will occupy a more extensive inquiry. Sir, I have the honour to remain, Your very obedient humble servant, JOSEPH READE, M, D. VIlt. Further Remarks on Professor Vincr’s Answer. By aCor- respondent. I T is not the “ mathematical,” but the literary abili- ties” of this country, that will be impeached, according to Protessor Vince's ideas, by the observations contained in his answer; since “ the errours in the works of Dytiseus”’ con- sist, if his explanation is admitted, in having first mistaken a plural number for a singular; and secondly, im having wantonly ON GRAVITATION, : 115 wantonly understood a term in its common and only correct Remarks upon acceptation. But it appears to me, that the passage, w hich Prof. Vince’s letter upon is the first subject of his critical remarks, admits, beside gravitation. the two alternatives which he discusses, a third sense, essen- tially different from them both: ‘ the two first terms of the series” may possibly allude to the two first terms of the only two.series which are to be found in the essay, these two terms having already been mentioned as sufficient for deter- mining the force: and if the author will take the trouble of reperusing the whole of his essay, instead of trusting to his “memory for its general tendency, he will probably be aware, that such must have been his original meaning. Two of the four terms thus obtained destroy each other immediately after their birth ; the other pair conspire in the production of a joint issue (p. 18); and this their offspring is precisely that which is honoured with a place in the 18th section, as the representative mot only of both its parents, but also of the whole of the unfortunate family; for we are expressly and very truly told (p. 19), that the terms omitted are so small, that they could make no sensible alteration in the result. Let them rest in peace, Let not the same hand which has bestowed on them a decent interment as dead in Philosophy, now drag forth their poor remains to stand in dumb parade under the banners of Logic. . The series which Professor Vince now introduces to our acquaintance, as willing to present us with its two first mem- bers, is not even mentioned in the essay, much less so stated as to make it possible to found any reasoning upon it. If “it was proposed”’ to take any ‘‘ second terms”’ of such a se-= ries into consideration, the proposal was wisely confined to the author’s breast: for why should they be considered, if they could “* make no sensible alteration” in the result? Y WoRsiies 5 oes i : The series = + fe +... may certainly vary as ae iv all the Greek letters after the first become inconsiderable, and our author has virtually confessed in his essay, that they do become inconsiderable. . - As to the difficulty of extending the law to the internal parts of the sun’s substance, it is perfectly obvious, that the 19 law His explana- tion notadmmise sible. Difficulty re- moved. T16 ON GRAVITATION. law of the density, as well as that of the force, must be sup- posed to change at the surface of every material body, long r | before 2 can become equal to P. Atoms to be Professor Vince’s “ two independent circumstances” are considered as separate. the medium on a material aggregate of considerable mag- nitude, which it never could have been in the contemplation of Newton to advance: it would be idle to maintain the pos- sibility of the hypothesis on any other ground, than that of the independent action of the medium on every atom of matter. Here therefore he is fighting with a shadow, and not with “ the vaunting assertions and errours of Mr. D.” Improper It is difficult to perceive the “ necessity ” of employing oT the term density, in order to convey the idea of the square ; of the cube root of the density, simply because this was the power of the density that was required for the author’s pur- pose. The density of light or heat diverging from a centre: in the form of projected corpuscles, may be very justly esti- mated by the number of particles falling on a given surface, for this simple reason, that their number is here a true mea- sure of the density; while in the case of an elastic medium it is not a true measure. Atmospheres. "The idea of the interference of different atmospheres must be considered as in some measure foreign to the question, since only one general ethereal medium of variable density’ is supposed to be concerned, and since the modifications of this medium, produced by the several celestial bodies, might easily coexist without any material interference or interrup- tion. ' Mistake of . I must beg leave to observe, on the other hand, that ano- ae “ther modern author appears to me to have been somewhat too hasty in asserting, that the law of gravitation may be derived from the supposition of an elastic medium, repelled by a force which varies inversely as the distance. If I am not mistaken, such a force would produce, according to the common laws of the operation of forces, a medium varying in density as some given power of the distance, and an ap- parent attraction increasing with the distance of the material bodies concerned, T have both dependent on the supposition of the external action of | LUNAR ATMOSPHERE. LY7, T have been informed, that the only intimation commonly Custom of the given to the author of a paper which is not to be printed in ai ese sie the Philosophical Transactions is @ simple letter of thanks, without any further notice respecting it. But the Society does not usually return thanks for a lecture read by appoint- ment: hence therefore must have arisen the omission, which Professor Vince seems to think so inexcusable. Iam sorry that any of your correspondents should, have Intentions of considered my remarks as written in an improper spirit : "e AUN: you, I believe, were not of that opinion; and I can only gay, that if that correspondent could have pointed out to me any objectionable expressions, I should most: willingly have omitted them. My only motive was the wish to repel an unjust attack; my observations tended more to impute inattention than inability to the party concerned; and I am at this moment ready to allow that a very great mathema- tician may not only be materially mistaken, but may reso- lutely defend his errour, when it is discovered by another person; and that he may even have so short a memory, as to forget, while he is defending himself, what he had before written on the same subject. Lamy; Sir, Your very obedient servant, 7 May, 13808. DYTISCUS. IX. Calculation of the Rate of Expansion of a supposed Lunar Atmosphere. By a Correspondent. To Mr. NICHOLSON. SIR, TL rhas been a subject of inquiry among some who are at- Inquiry into tached to astronomical speculations, whether or no, if the rai e eraing moon had ever been possessed of an atmosphere equally traction upon dense with that of the Earth, she could have retained it, with- the atmosphere me : ‘eile : : ,_ of the moon. out a very sensible diminution, in consequence of the Earth’s attraction, upon the supposition of the infinite dilatability of the 118 LUNAR ATMOSPHERE. Inquiry into the air, with a density always proportional to the pressure. wi Ses wet The imquiry involves a great variety of considerations, and traction upon it would be extremely difficult to make an exact calculation sneak a of all the particulars connected with it; but it may be shown . from some general principles, that the diminution would have become perceptible to a spectator situated on the Earth, in the course of a few centuries. | Equilibriumof Jf a be the distance of the moon from the earth, and « i log atmo- the distance of any other point in the line joining them, the ewe and the centrifugal force, arising from the revolution round the com- mon centre of gravity, to be added for the terrestrial atmo- sphere, and to be subtracted-for the lunar, bemg equal to the force of gravitation at the distance of the centres, the joint force f acting on the particles of the atmosphere will be as 1 1 1 1 1 1 Togo ea): horas? Ot Ge Trogg (euleeatns spectively: or, since f must be equal to unity at the Earth’s surface, whet x is equal to the Earth’s semidiameter 0; y itiores a near the Earth, without sensible errour, and 7. : 1 force of gravitation will be as —> — x ree 2 2 2 ying fon 70 om). a the density being y, which may also be called unity at the Earth’s sorhieee we have —cj = fy, and it is obvious that c must express the height of a column of air of uniform density capable of producing the pressure by its weight, in order that —c 7 “til be initially equal to #. Hence we have HL. = — Shs; but fs = 0¢ (5 — a Faces | (a—x? =); therefore HL. =—(a—4— ae —=),¢ a? y c x 70(a—«r) a? » for the lunar atmosphere. Then , . , b? f being, without sensible errour, 1 ++ an Now 6 is 3958, and e 5.28 miles, and at the moon’s surface x is about 606, and 1 4 a—x 3,6; whence H. Lig = 685.69. Again, when f va- nishes, LUNAR ATMOSPHERE, 129 1 I + ae and a 1 nishes, and the density is least, — x = 70 (a2)? x is nearly .825 a, whence H.L.— = 724.31; and this den- sity is to the density at the moon’s surface as 1 to the num- ber of which the hyperbolic logarithm is 38.62, and the common logarithm 16.773: and supposing the density to be increased in any given ratio, the proportion will remain the same, the number e still indicating the height of a co- lumn equal in density to the atmosphere, thus condensed, at the Earth’s surface. . Now the,expansion of the lunar atmosphere, supposing it General law of to be equal in density to that of the Earth, and to extend to ™°#™ the point where the force f vanishes, which is the most fa- vourable condition for its permanence, may be determined from this general principle; that the motion of the centre of gravity of any system of bodies, some of which are urged by a greater force in one direction than in another, must be the same as if the difference of the forces acted on the whole system, collected into the centre of gravity. Thus, if the pressure of the highly rarified air, at the termination of the supposed lunar atmosphere, which would have kept it in equilibrium, be removed, the elasticity of the column pressing on the moon will be by so much greater than its gravitation; and the centre of gravity of the column will be repelled, with a velocity as much smaller than that of a body falling at the Earth’s surface, as the pressure removed is smaller than the weight of the column: but this ratio is compounded of that of the densities at the opposite ends of the column, and that of the force of gravitation, or rather the force f, near the moon’s surface, to its force at the sur- face of the Earth, since the mass required to produce the given density, by its pressure, is as much greater, as the gra- vitation is smaller; and if we diminish in this proportion the space which a falling body would describe in.a century, we shall have 514 feet, for the elevation of the centre of gravity of a column of the lunar atmosphere in that time. , But in order to estimate the effect of such a change, we Centre of gra- must calculate the actual height of the centre of gravity of me ee, a given column of an elastic fluid: and for this purpose we may 120 Sensible ef- fects. LUNAR ATMOSPHERE. ray suppoee the attractive force uniform. The height of the centre of gravity is determined by dividing the fluent of zyx by the mass, or by 1—y; but, since —cy = yx, ye = —exy, x bemg =c (HL), or, according to a mode of expression lately employed by one of your corre- J 1 jee : $pondents, cm Cala 1), when m is infinite; hence —c x ¥ x =cem(j—y ™%), of which the fluent is e--+cem 1 i—= 1— * yey y a) =e he ey ae Yo an Bsaches —cy; which must vanish when y=1 and x=0; conse- quently e=c, and the height of the centre of gravity is e+ S*4 . and when y = 0, this height is equal to that of the column e, which for the Earth’s atmosphere is 5:28 miles, and for the moon’s as much greater as the force is smaller, that is, 27°75 miles. The centre of gravity being therefore elevated 514 feet, or z15 of its height, in a century, the mean density of the column must also be reduced about ‘4g but since a certain part of this elevation depends on the supposed acceleration of the more distant portions, which would produce no sensible effect in the neighbourhood of the moon, we cannot estimate the mean rarefaction of the part remaining more nearly in its original situation, at more than about 4,3; and this will be reduced to about one fourth for the mean of the whole atmosphere, surrounding the moon on all sides: so that we may take +25, for the mean rare- faction of such a lunar atmosphere in the course of the first century. So small a rarefaction as this would certainly not be di- rectly observable at the distance of the Earth. Supposing that the atmosphere would be visible untilits density became equal to a given quantity, the point, at which this density would be found, would be depressed only about 18 miles, if the whole density of the atmosphere were reduced to one half, and by a diminution of +745, only +55 of 27.75 miles, or about 120 feet. The effect of an atmosphere would how- ever EXPERIMENTS ON MOLYBDEWA. 19t ever be more perceptible in the refraction, which’ would oc- Faunar refrac: casion an alteration in the apparent place of a star about.to "°™ be eclipsed, and which would amount, in the case of the Earth’s atmosphere, to 66 minutes. But the refractive den- sity of the lunar atmosphere would vary nearly as the 134th root of the distance, instead of the 7th; and the deviation, imstead of 66 minutes, would become 13’ 50”, one 1200th of which would be only {75 of a second, which would still be imperceptible; although in two or three centuries, since the rarefaction would increase at first as the square of the time, it might perhaps be discoverable; and this would be consi- derably sooner than the decrease of the moon’s apparent dia~ meter could be observed. It is however scarcely probable, that so slow a rate of diminution could have reduced the lunar atmosphere from a density equal to that of the terrestrial at- mosphere, to its present state, in the course of 10,000 years. I am, Sir, Your very obedient servant, 16 May, 1808. HEMEROBIUS. »¢ Experiments on Molybdena: by Curistian Freperic Bu- cHoLz. ‘Translated from the German*. { T is near thirty years ago, that the immortal Scheele Metal in mo- discovered in molybdena, as it was then called, a peculiar Ce metallic substance, many of the properties of which he Scheele. made known, as well as its action on several other sub- stances. ‘Several able chemists, as Pelletier, Heyer, Ilsemann, Since examin- Richter, Hielm, Klaproth, Ruprecht, and others, have pag toler since turned their attention to the same subject: but the ledge of it im- knowledge we have acquired from their labours is by no Petect- means proportional to the number of chemists, who have examined it, and the time that has elapsed since the disco- * Journal des Mines, No. 106, p. 241. The original was published in Crell’s Journal, Vol. IV, 1805. very 123 EXPERIMENTS ON MOLYBDENA. Constitution of very of Scheele. If any one doubt of this, he has only to it in the native state doubted. Proportion of oxigen in the acid unknown, 5 First the exist- ence and quan- tity of sulphur to be ascer- tained, The native sul- phuret con- tains no excess of sulphur, & no oxigen, cast an eye over the different elementary works we have on chemistry, to be convinced of it. Who would not be sur- prised to see chemists still in doubt respecting the composi- tion of molybdena us it is found native? Some consider it as a sulphuret, ia which, the xnolybdena is in the metallic state; while others assert, that they cannot find a particle of sulphur in it, and look upon it as a native molybdena. The smell alone however is sufficient, to convince us of the pre- sence of sulphur in if. Let any one heat lamine of the purest molybdena, the sulphurous smell, that will exhale,. must prove to him, that it contains sulphur, if he have not lost the sense of smell. Farther we are ignorant of the proportion in which oxi- gen is combined with the metal to form molybdie acids though it has been so long known. The want of positive knowledge on these points has led me to think, that, if I were to undertake a series of experiments on molybdena, I should attempt a task of some utility, and that would con- tribute to augment and improve our knowledge of this sub- stance. To my friend Mr. Haberlé I am indebted for the quantity of molybdena, that has enabled me to make these experiments. The first thing to be ree was, I conceived, to remove all doubt respecting the presence of sulphur, and to determine its quantity. This [ imagined would best be effected, by oxigenizing both the sulphur and the molybdena, and sepa- rating by means of barytes the sulphuric acid formed. But it was necessary previously to ascertain, whether the molyb- dic acid, which also forms a salt of no great solubility with barytes, would not occasion some errour in this computa- tion. 1. Experiments to determine the composition of the native sulphuret of molybdena. Exp. 1. Twenty-five grains of very pure chosen molyb- dena were reduced to a fine powder, and heated quickly in a small glass matrass. No sulphur was disengaged. The matrass when cooled contained a little sulphurous acid va- pour, and the molybdena, which had been heated red hot, had scarcely EXPERIMENTS ON MOLYBDENA: jos scarcely lost an eighth of a grain. ‘This experiment shows, ist, that the molybdena contained no excess of sulphur: adly, that the heat applied was not sufficient to expel the sulphur from it: Sdly, that there was no oxigen combined with it. | Exp. 2. The molybdena of the preceding Aue Treated witia was put into half an ounce of pute nitric acid, the specific ™'* #0 gravity of which was 1:22, and made to boil on a sand heat. The acid attacked the molybdena pretty briskly, but not so much as I should have supposed. To accelerate the ope- ration, and prevent the sulphur from passing to the state of sulphurous acid, I added a drachm and half of pure muri- muriatic acid atic acid, of the weight of 1:135, and a drachm of nitric an acid. After boiling for an hour the whole was converted into a homogeneous mass of a milky whiteness, which was diluted with eight times its-weight of water; the solution was filtered; and the sulphuric acid, that had been formed, and sulphuric was separated, by washing well both the residuum and the *“4 formed, filter. Into the liquor, that had passed through the filter, a solution of muriate of barytes was poured. This occasioned which was pre- a precipitate, which, being carefully. collected, dried, and sch ee heated red hot, weighed seventy-two grains, and comported itself as pure sulphate of barytes. ‘To determine the cir- cumstances, in which this precipitate is possible, I made the two following experiments. Exp. 3. Five grains of molybdic acid were mixed with Molybdic aad two ounces of distilled water; twenty drops of muriatic acid, SSG oot of the strength mentioned above, were added ; the whole was of barytes. boiled for half an hour, and the liquor was filtered. The solution had a very rough metallic taste; and solution of muriate of barytes did not render it turbid, though a little sulphuric acid produced this effect immediately. _ Exp. 4. Five grains of molybdie acid and twenty grains Molybdate of of pure liquid ammonia were put into two ounces of water, eta and the mixture shaken, till the whole was perfectly dis- solved. A solution of muriate of barytes being added, a ang muriate of copious flocculent precipitate immediately fortac which barytes added. was afterward redissolved on adding a few drops of muriatic or uitric acid, and shaking the mixture. ; These experiments Mow: 1, that no indissoluble molyb- Inferences, date 124 Sulphuret of molybdena treated with aqua regia. Precipitated with muriate of barytes. 190 grs. sulph. of barytes con- tainS2°5ofacid: 400 of sulph. EXPERIMENTS ON MOLYBDEWA. date of barytes is formed, unless the molybdic salt be neutra- lized; and not when any free muriatic or nitric acid is pre- sent. 2, that the molybdena contains a large quantity of sul- phur; for the 72 grains of sulphate of barytes, obtained from 25 grains of molybdena in the 2d experiment, repre~ sent nearly 24 grains of dry sulphuric acid; which indicate the presence of 10°2 grains of sulphur, or 40°8 per cent. After these preliminary operations I could proceed to a more accurate analysis. Exp. 5. A hundred grains of lamine of molybdena,. picked with the greatest care, were put into a retort with six drachms of pure muriatic acid, of the spec. grav. of 1135, and 22 of nitric acid, equally pure, of the gravity of 3°22, and distilled on a sand bath with a gentle heat. After an hour’s ebullition almost the whole of the fluid had passed over into the receiver. What remained in the retort was white, some gray flocks excepted. The liquor was poured back into the retort, half an ounce of fresh nitric acid was added, and when about a third was distilled over the gray flocks disappeared. The hquor that liad passed over contained neither sulphuric nor sulphurous acid. The white mass was diluted with six ounces of water and filtered; and the residuum was repeatedly washed with the greatest care. In order to be well assured, that in precipitating the sulphate of barytes, which 1 was preparing to do, no molybdate of barytes should be thrown down with it, I added two drachms more of pure muriatic acid to the liquor, which held in solu- tion but a small quantity of molybdic acid. This being done, T added a very pure solution of muriate of barytes, and sul- phate of barytes was precipitated. The liquor being passed through a filter previously weighed, the residuum was put into eight ounces of water containing two drachms of muria- tic acid, and well shaken; after which it was filtered again, and washed. After being exposed to a red heat it weighed 284 grains, to which 6 grains must be added, as the filter, after being thoroughly dried, had gained so much in weight. As 100 grains of sulphate of barytes contain 32°5 of sul- phuric acid, this quantity must have contained 94°25 grains: and farther, as according to my experiments 100 grains of ! sulphuric EXPERIMENTS ON MOLYBDENA. ' 195 “wn sulphuric acid contain 42°5 of sulphur, it follows, that 100 acid, 42°5 of Bete Shiphiiret oP tmolybdens contain “40°86 oF'enpuae, HP, Benes grains of sulphuret of molybdena contain of sulphur, 100 of sulphu- which differs very little from the result of experiment 2. tet of molybd. t This agreement seemed to render it unnecessary for me to re- Be = thet peat the analysis: yet certain circumstances, which will ap- pear farther on, induced me to commence a new one, that no doubt might remain. I took a hundred grains of powdered eames 7 z y) * molybdena, put them into a mixture of three ounces of nitric acid and one of muridtic, and treated them as the preceding; with this difference only, that, by employing a larger quantity of acid in the first instance, it was not necessary to return into the retort the liquor that passed over into the receiver. The sulphate of barytes obtained in this instance weighéd 288 grains, which, according to the preceding computations, con- tained 93°6 grains of sulpburie acid, and 39°78 of sulphur. This gaves9-78 of sulphur. Taking a mean between this result and the preceding, we may conclude, that, 100 parts of sulphuret of molybdena contain Sulphur eeueeereves eveeeerere Af) Medium, Metallic molybdena*+-++ +++. 60 Exp.6. A hundred grains of sulphuret of molybdena, Silas aye of dissolved as the preceding, and distilled to dryness, were put nae" ao into two ounces of pure liquid ammonia, diluted with an fore, and am- monia added, equal quantity of water. The mixtpre being shaken, in the course of a quarter of an hour the whole was dissolved, ex- cept a few yellowish flocks, which, collected on a filter, scascely weighed a grain after being heated red hot. On about 1 gr. of boiling this precipitate in nyariatic acid it was decomposed, PP and yielded 0°75 of a grain of silex, with 2 of a grain of ted. oxide of iron. Thesmallness of the quantity seems to show, that these two substances were accidentally present in the * Scheele supposed, that molybdena existed in the acid state in its ore: it was the doctrine of the French chemists, says Fourcroy, that corrected this mistake, by showing Guyton, Pelletier, and all the authors or partizans of the pneumatic theory, that Scheele produced the acid by burning the molybdena, and loading it with as much oxigen, as it could take up. Fourcroy’s Chemistry, Sect. VI, art. IV, § 2. In the subsequent part of this paper of Mr Bucholz it is shown in the mo@ evident manners, that tie molybdena is in the metallic state in its ore... . molybdena, 126 To obtain the acid, native sulphu- ret roasted in an inclined crucible, The acid may be separated by boiling it with an excess of soda, or di- gesting in am- monta, and pre- ci; itating by nitric acid, or expelling the ammonia by heat. EXPERIMENTS ON MOLYEDENA, molybdena, and merely in mechanical union with the speci- mens analysed. For the subsequent experiments I was desirous of procur- ing some quantity of molybdic acid. The processes I em- ployed are mentioned in another work, here therefore I shall mention them briefly. II. Process for obtaining molybdic acid. I took 11% ounces of native molybdena, the quartz ad- hering to which was pretty well separated, and put it into a Jarge crucible, which was placed obliquely on the fire. A strong heat was first given, to kindle the sulphur, which was afterward diminished, and the matter was roasted, stirring it occasionally with a wooden spatula, A large quantity of sulphurous acid was evolved, and the mass was entirely co- vered with a crust of the purest molybdic acid, which was of a lemon colour.on the fire, and of the purest silvery white when cold. By taking a little trouble, and using some pre- cautions, the whole might thus have been converted into mo= lybdic acid: but as this would have required a great deal of time and attention, I put an end to the process, when T per- ceived, that the greater part of the sulphur was volatilized, that a considerable quantity of molybdic acid was formed, and that, on leaving it exposed to a lower degree of heat, the mass began to agglutinate, and even to become fluid near the sides of the crucible. By this operation I obtained 82 ounces of a gray shining mass, perfectly crystalline, which was of a whitish gray colour when powdered. Half an ounce remain- ed adhering to the sides of the crucible, which could not easily be separated from it. The pure molybdic acid may be separated from the mass by heating it with water, adding carbonate of soda till it ceases to occasion effervescence, and afterward boiling it with a little excess of soda: or the separation may be efiected by digesting the mass in pure liquid ammonia, the heterogeneous parts, such as the quartz and oxide of iron, remaining undis- solved. On pouring nitric acid into the neutral solution, the molybdic acid is thrown down, ‘The molybdate of ammonia might be decomposed likewise by fire; in which case some- times EXPERIMENTS ON MOLYBDENA. 127 times molybdic acid, sometimes molybdena in the metallic state, or at least approaching to it, is obtained, according to circumstances, Temployed the latter method, that with ammonia, as being The latter mo, the most advantageous. Previous trials had taught me, that aise RiPtetTted three parts of pure liquid ammonia, of the specific gravity Of g parts of am- 0°97, dissolve one of molybdic acid reduced to fine powder, Monia dissolve ; me ; 1 of molybdic and separate it from any impurity, that may be present. In acid, consequence I powdered the produce of the preceding roast- ing; put it into a bottle with ammonia closely stopped; and left it to digest for twelve hours, shaking it from time to time. The acid disappeared, and two ounces of heterogeneous mats ter remained, containing still a little molybdena not decom- posed. This residuum was boiled with two ounces of common nitric acid, and the molybdena was readily converted into acid, which was obtained perfectly pure by means of ammo- nia. . The ammoniacal liquor, in which the roasted mass had 4 little oxide se é ! ae of iron precipi- been dissolved, became a little turbid at the expiration of tated from the five hours, and assumed a yellow ochre colour. Five days ™olybdate of . 6 . ammonia, after, the matter that occasioned this turbidness had -sub- ‘sided, and comported itselé like oxide of iron, Part of the limpid solution was evaporated to dryness, and part of the residuum was heated red hoi, to obtain from it the pure mo- lybdic acid, as I had formerly done with a smaller quantity, but my expectation was frustrated. At the beginning the Effect of heat lybdate of nia turned blue; and it ended in ass ee pach molybdate of ammonia ue; and it ended in assum: gare of ammo- ing a metallic aspect throughout, even interiorly; the blue ma. colour changed to a coppery red, and it had a similar appear- ance to products J had formerly obtained, which every thing indicated to be molybdena in the metallic state, or nearly metallic. The mass became oxided anew on the surface: but it was more agglutinated in those places, where the heat had acted most strongly. MII. Experiments to ascertain the most advantageous method of reducing molybdena to the metallic state. Exps.7 and 8. By the process just mentioned having ob- Attempts to ‘ : 4 - d lyb- tained a mass, which every thing led me to suppose was in ray vee the Ammonia ex- pelled by heat: residuum co- vered with charcoal : and exposed to a strong heat. Product. Attempt to fuse it into a button, but merely ag- glutinated. Experiment repeated witha stronger heat. Product. \ EXPERIMENTS ON MOLYBDENA, the metallic state, before other experiments had given me far- ther light respecting its nature, I resolved to employ the dis- oxigenizing action of ammonia, to obtain metallic molyb+ dena, I took six ounces of liquid molybdate of ammonia, and evaporated to dryness. During the evaporation it diffused a sme]l much resembling that of vanilla, The saline residuum was pressed tight into a small glass of a convenient form, and covered with a layer of charcoal dust; the glass was bedded in sand in a crucible; and this was set on the fire. After the ammonia was volatilized, the glass was closed with a chalk stopple, the fire urged briskly, and the crucible kept for half an hourin a strong red heat, which melted the glass. After the whole had grown cold, a tolerably compact mass was found, easily reducible to powder, of a copper colour inclining in some places to blue, with a’ metallic lustre, and exhibiting crystalline laming. It weighed three drachms. ; To see whether this mass would not fuse into a button ina stronger heat, I pounded it; rammed the powder, which was of a violet colour inclining to copper red, tight into a cruci- ble lined with charcoal; covered it with a finger’s breadth of charcoal powder; closed the crucible well; and kept it for half an hour ata white heat in a forge fire. After cooling the mass was ayglutinated in places where it was most expo-- sed.to the action of the fire; but in the middle it was pul-+ verulent, and had retained its colour. Exps. 9 and 10, Desirous of repeating the preceding expe- riments with a greater heat, I put some molybdate of ammo- nia into a Hessian crucible. After the ammonia had been expelled by a moderate heat, I covered the mass with a stra- tum of charcoal, closed the crucible, increased the fire toa white heat,and kept the crucible in this state half a hour. After cooling a compact mass was found of a violet brown colour, the lower part of which, that was in contact with the bottom of the crucible, and had consequently experienced a stronger heat, was tolerably consistent; it could not be reduced to powder without difficulty. This powder was of a violet co- lour, and appeared to consist of a multitude of small crys- talline scales of a metallic brilliancy. ‘The fissures that tra- _ versed the mass in every direction exhibited on their sides a . great EXPERIMENTS ON MOLYBDENA, 129 great quantity of larger scales, likewise of a violet colour, and of a very -fine metallic lustre. The outside of the mass was in great part covered with scales also, but smaller, and exhibited a very pretty changeableness of colour. The up- per part, which had been in contact with the charcoal dust, displayed some reflections of an indigo blue. ‘The outside of the crucible was spotted with green in several places. Several circumstances in the preceding experiment indi- “eehulietiead cate, that the mass would have become more soft and com- uh.” pact, if it had been subjected to a more violent fire. In Greater heat consequence I took a similar quantity of molybdate of am- ¢™Pployed. monia, and exposed it to the action of the most violent fire for an hour. After cooling I found a mass weighing five Result. drachms in every respect similar to the preceding; except that it appeared a little more compact, and the fissures were filled with scales, which were more crystalline and in larger quantity. These scales, examined with a lens in a strong light, resembled polished false gold; as the largest did when viewed by the naked eye. _As the masses obtained in the four preceding experiments Reasons for had a specific gravity varying from 4:5 to 5°67 according to ea their different densities, and this is the specific gravity as- lic molybdena: signed by many to metallic molybdena; as besides, on heat- ing them red hot. in contact with air, or with nitric acid, in which case oxigen gas isevolved, they afforded molybdic acid ; and lastly as they had a metallic aspect; I was induced to consider them as reguli of molybdena, particularly as no one had ever yet spoken of such an oxide. But subsequent ob- but it wasa pee servations taught me, that these masses were molybdena in a er Calde. peculiar state of oxidation, and that by the processes [ had hitherto followed it would be impossible for me to obtain molybdena in the metallic state. It was necessary therefore, that I should attempt its reduction by other means, Exps. 11, 12, and 13. I took four drachms of molybdate Attempts tore of ‘ammonia, similar to the two masses obtained in the pre- aude ceding experiments; powdered it; mixed it with olive oil, so paste with oil, as to make a thick pap; putitintoacrucible; and heated it till the oil was burned. It was then pressed down; covered with a stratum of charcoal powder, and over this a little pow- Vou. XX—Juwe, 1808, K dered 130 Pyoduct dis- . solved in nitric acid, and mu- riatic added. Attempt to fuse It. Slightly agglu- tinated merely. Heated again. Agglutinated more strongly. Eagerly ab- EXPERIMENTS ON MOLYBDENA, | dered chalk; another crucible was put over it; the fire was urged to a strong white heat, and in this state it was kept for an hour and a quarter. After the combustion of the oil, the mass was pulverulent, of a deep blue colour approaching to black, and in some parts violet: and after it had undergone the strong heat to which it was exposed, it was entirely of an ash gray, and formed a mass of an earthy appearance, the parts of which had but little cohesion; the part in contact with the crucible scarcely showed the slightest indication of fusion; and thrown into nitric acid it produced a more con- siderable effervescence, than the products of the preceding experiments. The solution thus formed was at first reddish, and afterward became milkwhite. I added concentrated mu- riatic acid, and boiled to dryness, without any perceptible solution taking place. .These circumstances led me to think, that the molybdena was entirely reduced, and that nothing was wafiting, but to unite the particles into a button. To endeavour to fotm this button, the mass obtained in the preceding experiment, which weighed 32 drachms, was pressed tight into a smail crucible, and exposed anew for an hour and half to the most violent forge fire. “This heat was so gteat, that the whole of the surface was vitrified, and the iron melted and burnt in three minutes. After cooling, the stra- tum of charcoal powder, with which it had been covered, was scarcely diminished. The molybdena had ahnost entirely preserved the same form as before; it was of an ash gray co- lour; its particles were but slightly agglutinated; and no mark of fusion appeared even in the part that adhered to the sides of the crucible. Its weight was 34 drachins as before. I took the same mass a third time, powdered it with six grains of charcoal, and exposed it again for an hour and half to a forge fire, which I endeavoured to urge as far as possi- ble. After cooling, the mass had the same ash gray colour as before; on turning the crucible upside down it fell out with- out breaking; and it had a slight degree of consistency, yet notwithstanding it was friable between the fingers, and easy to pulverize.’ No mark of fusion could -be discovered in the inside of the crucible; but the mass had lost six grains of weight, from part of it adhering to the sides. ‘The mass be- ing EXPERIMENTS ON MOLYBDENA. 131 ing thrdwn into water, this fluid entered its interstices with sorbed water,, avidity. Exps. 14 and 15. To know whether the molybdic acid Molybdic acid : : : exposed toa were capable of being reduced by the action of fire alone, ctrong heat without being mixed with any carbonaceous matter, I took imbeddedin | a piece of the acid, which had been melted, and weighed 55 Bi: grains, ‘This I placed in the midst of charcoal powder ina crucible, and exposed it for an hour and half to the same de- gree of heat asin the preceding experiment. The result was a tumid mass; which had not any more consistency than that of experiments 12 and 13. It was like that of an ash gray colour, and had lost eighteen grains of its weight, or in the proportion of 32°73 per cent. In nitric acid it comported itself in the same manner as the masses obtained in the pre- ceding experiments. ‘Two hundred and seventy grains of the matter obtained from the molybdate of ammonia roasted in experiments 9 and 10, being treated in the same manner, and kept a quarter of an hour at a white heat, gave a similar product to that of experiments 12 and 13. They had lost 78 grains, or 28°89 per cent. | Ina second trial 264 grains of the viulet brown oxide, Attempt to re- having been kept only half an hour at a moderately strong Se a bakes red heat, the result was a mass but imperfectly reduced. The interior was no way changed; the surface only was gray. Re- placed in the fire, and kept at a white heat for half an hour, it was entirely reduced, and lost 74 grains, amounting to 28°03 per cent. Hence it follows, that the substance obtained from the molybdate of ammonia is very far from being in the metallic state. These experiments show, that oxigen may be separated Oxigen separa- from molybdena by the action of fire alone when in contact Here td cle with charcoal. They prove, that the reduction of the oxide tact with chara and of the acid of molybdena may be effected without great aie aeee difficulty. It remains to be seen, whether this reduction can be effected with larger quantities, and whether the molybdena cannot be obtained in a button. Exps.16 and 17. J took ten drachms of molybdate of Molybdate of “ammonia; put them into a glass which I placed in a cruci- 2™™omia heat ble, and exposed to a red heat for half an hour; and obtained ed; the brown. K@ @ mass 132 EXPERIMENTS ON MOLYBDENA. eide bedded a mass of violet brown’oxide weighing one ounce. This mass in charcoals placed in a crucible, surrounded it with powdered charcoal, and exposed it for an hour to the most violent forge fire. and reduced he result was a metallic mass, the different parts of which by a violent forge fire, were more or less frothy, and more or less tenacious, but the tenacity was in no place such, but it might be beaten to pow- . der. The exterior part was of an ash gray; in the interior, and even at the surface where cavities and depressions were formed, ‘it had a truly metallic lustre, and was of a silver blue colour. The parts that had this lustre being pressed upon and beaten in a porcelain mortar were extended a lit- tle under the pestle, and this increased their brilliancy; but on coutinuing it they were reduced to agray powder. ‘Their hardness before trituration was greater than that of silver of nine pennyweights (0°75), since they scratched it. Attempt to ob- In order to obtain this matter in small melted parts, I ig an gO? pounded six drachms, which I pressed as strongly as possible into a crucible lined with charcoal, and exposed to the most violent forge fire for an hour and half. After cooling I found, that the mass was agglutinated,and reduced in bulk one fourth. I could not getit out without breaking the crucible. Those parts which had been in contact with the button and sides had considerable tenacity, but it was not the same with the Agelutinated, surface. However, it could not be said to have been actu- ally fosed. ally fused in any place, its parts being merely agglutinated by acommencement of fusion. Every where it exhibited a large ‘quantity of scales, which were of a silvery white and a metal- lic lustre. Bruised on glass or porcelain, they acquired a medium lustre between that of tin and thatof silver; but Afew small this disappeared in twelve or fifteen minutes. At the bottom . eee eat of the crucible appeared a few grains of molybdena, of the had been size of a pin’s head, which had evidently been fluid. They fused. were all over of a metallic lustre, and silvery white, like the scales already mentioned. The lower part of the mass of metallic molybdena, when beaten with a ile ip pestle, as- sumed the same lustre*. Notwith- * Ruprecht appears to have observed something similar. He says, that tn endeavouring to reduce molybdena he obtained some small metallic grains EXPERIMENTS ON MOLY BDENS, py 133 Notwithstanding the molybdena here possessed all the pyo- perties, that characterize metals, lustre, compactness, -and even malleability, though in a slight degree, I could not ob- tain a well fused metallic button by exposing afresh to the most violent forge fire for two hours a piece of the mass al- ready obtained, that weighed forty grains. A trial I after- Most succesg- ward made with two ounces of brown oxide was attended Ao i with better success, than any I had yet obtained. I exposed this oxide to the most violent fire, well kept up, but for one hour only: and though the whole mass was not fused into a button, yet in ‘some parts appeared pieces of one, or two drachms, almost entirely fused; having a spherical surface, a white metallic lustre, and a much greater consistency than any mass I had yet obtained. On rubbing these metallic parts against a very smooth piece of porcelain, they assumed a lustre, which it would have been difficult to distinguish from that of silver. [I must observe too, that this lustre re- mained for several days; while in my other trials it did not continue an hour, probably owing to the moisture of the air, From the experiments hitherto related we may infer: ' © General con- Ist, That heat, in decomposing the molybdate of ammonia, °!45!°"* causes the acid, in consequence of the disoxigenizing action of the ammonia, to pass to a slighter degree of oxidation, ' and gives rise to a peculiar oxide, some of the external cha- racters of which have been noticed in the account of the 41th, 12th, and 13th experiments. Qdly, That the oxide and acid of molybdena are com- pletely reducible by the simple action of fire, when they are plated in the midst of powdered charcoal, .and that the metal _ then appears ofan ash gray colour: but that, this metal being X grains, the least of which had the appearance of silver; and that the sides of the crucible had a coating of the same colour. He did not ven- ture to assert however, that these grains were entirely metallic; for he observed others which were either of a whitish gray, reddish, or blueish. The following part of this essay, and what has already been said, will show, that these coloured grains belong to the oxide, which has been mentioned. Hielm, observing that molybdena rendered the colour of ~ other metals lighter, inferred, that its own colour was white. This infer- ence is confirmed by my experiments. difficult 134 Specific gravity of molybdena. About 8611. Experiment to ascertain pro- portion of oxi- gen in molyb- dic acid. EXPERIMENTS ON MOLYBDENA. difficult to fuse, the most violent fire must be employed, to obtain a more compact metallic button. The experiments related put the possibility of this out of doubt. IV. Determination of the specific gravity of molybdena. From the property, which the masses of molybdena I obtained in the metallic state possessed, of imbibing the wa- ter in which they are immersed, it is difficult to ascertain their specific gravity with accuracy. In the three trials I made, I suspended the masses by a hair to one of the arms of a very nice pair of scales; and in order to expel the air as much as possible, I boiled them for a quarter of an hour in distilled water. I afterward weighed them at the common temperature. The first trial gave a specific gravity of 8°636; the second of 8°490; and the third 8°615: we shall not be far from the truth therefore, if we take the mean term of 8°611. It is true the result differs much from that given by some.authors, who fix the specific gravity at 4°5, or at 6°5. Hielm gives 7°5 for the maximum: but it is probable, that the masses, with which these were determined, were not pure, or were full of blebs, which occasioned the specific gravity to appear less than it really is to Hielm, Ruprecht, and Heidinger. . Determination of the proportion of oxigen to metal in y . vege i molybdie ig ‘ os Exp. 18. The knowledge of the quantity of metal con- tained in the native sulphuret of molybdena affords a conye- nient mode of ascertaining this proportion. For this pur- pose I took a hundred grains of select scales of molybdena, put them into a small retort with acid as before, and distilled to dryness. ‘Toward the end of the operation sylphuric acid was extricated in gray and heavy vapours. To expel this acid entirely, I broke the retort cautiously ; put the pieces into a small glass, which was placed on a sand bath in a crucible; and kept them ina ted heat for half an hour. The whole of the sulphuric acid was thus volatilized, and the molybdic acid was left pure in the form of smal] crystals of a yellow- oh white colour inclining to gray. This residuum weighed ninety EXPERIMENTS ON MOLYBDENA» 135 -ninety grains. The pieces of glass having been weighed, they were carefully washed, and weighed again; when they were found to have lost a grain. Thus the hundred grains of sul- phuret of molybdena had yielded ninety-one grains of mo- lybdic acid: and, if we admit as above sixty parts of metal in the sulphuret, the proportion of metal to oxigen will be as sixty to thirty-one, or as 100 to 51°67; consequently 100 parts-of acid contain 34°06 of oxigen. Exp..19. Desirous of making a counter trial, I took some nadia eXpe of the substance obtained in decomposing molybdate of am- , -monia by heat, which at that time I considered as molyb- , dena in the metallic state, and endeavoured to oxigenize it. | Having poured on it nitric acid of the spec. grav. of 1°22, a brisk effervescence immediately took place, which continued -for some time, without requiring the aid of heat; but as I was drying the oxigenized mass, it was’ suddenly thrown out of the vessel, occasioning a loss, that prevented me from go- “ing on with the trial. ‘I then repeated the operation, employing a very tall glass This repeated. to contain the oxigenized mass, while I dried and melted it, A hundred grains, treated with ten drachms of nitric acid, produced a radiated mass, that weighed exactly a hundred and nine grains ;.and, if we add one grain for what may have remained adhering to the vessels employed, we shallhave110 |. , grains of acid from 100 of the metallic substance. This result differed so widely from the preceding as to con- The substance vince me, either that the substance I had taken for molyb- Solin hese ‘dena in the metallic state was not actually so, or that I had monia from the made some mistake in determining the quantity of sulphur poe ye contained, and the quantity of oxigen absorbed, by the na- ‘tive sulphuret of molybdena. I resolved therefore to repeat »my experiments. , a awl _ Ihave already given the result of the second experiment I Experiment ‘made to find the quantity of sulphur contained in the native With the sul- phuret of mo- sulphuret. What I did to verify the proportion of oxigen to jypdena, metal in the formation of the acid consisted in taking a hun- _dred grains of native sulphuret of molybdena, which I put into a mixture of one ounce of muriatic acid and. three punces of nitric acid; and, in order to prevent loss from any being + ¥ 136 EXPERIMENTS ON MOLYBDENA. - being thrown out, I conducted the oxigenation in 2 tall ves- sel, which I placed first on sand, and afterward in a cruci- ble, the sides atid bottom of which were coated with chalk. By this process I obtained-ninety grains of molybdic acid, which indicate fifty parts of oxigen to a hundred of metal; so that 100 parts of molybdic acid would consist of 66:67 metal and 33°33 oxigen. The regulus of molybdena, which J] had obtained in my preceding experiments, afforded me another mean of verify- ing the results. Experimentby Exp.20.A hundred’grainsof the metallic ssobfedene of expe- acidifying the riment13 were reduced to very fine powder, put into a porce- metal itself. : ae : ‘lain capsule, and thirteen drachms of pure uitricacid added. An extraordinary effervescence took place, and a great deal of nitrous gas was evolved. On ‘evaporating, the matter, which was at first of a brownish yellow, passed gradually to a whitish yellow.. In drying it became orange, and even blue in those places where the heat was the strongest. Af- ter it was well dried, and collected together, it was fused in q a glass; and its weight was found to be increased. thirty- four grains, which indicates 25°37 parts of oxigen in 190 of molybdic acid. It. was thoroughly crystalline, and formed ‘crystals of a silver white inclining to gray. - Variation in The change of colour just mentioned, which has not been er tern remarked - before, indicated a variation in the proportion of cated. 8 oxigen to metal. It appeared to me probable, that a por- Was itowing tion, though small, of the charcoal, which had been ‘to charcoal? yningled with the molybdena to promote its reduction, had combined with it, produced the phenomena observed during the oxigenation, and changed the proportion of the ges to the metal. Twoattempts Exp-21. To verify this suspicion, I thought it necessary pei bther this to repeat the trial, employing molybdena that I had reduced ' by simply placing the mass to be reduced in the midst of powdered charcoal, without having triturated and mixed them together. “The experiment failed twice. The first time the effervescence and swelling up on pouring the nitric ‘acid on it were so great, that the matter ran over the sides of the vessel: and the second, though the Acid had been di- \ Jated, EXPERIMENTS ON MOLYADEWA. 187 luted, explosions gook place, by which some of the molyb+ dic acid was thrown about. To prevent these accidents, I made the trial again in wide- 4 third mouthed capsules. 1 took a hundred grains of powdered metal, and poured on it an ounce of nitric acid diluted with half an ounce of water. {na few minutes a very powerful action took place, and the liquor became of a yellowish red inclining to brown. The whole of the metal not being dis- solved, when no more gas was evolved i added half an ounce ‘of acid, and placed the solution on a sand bath. The whole ‘was now dissolved, but the liquor remained of a yellowish red inclining to brown as before, only a reddish white pow- der appeared swimming in it. I evaporated the mixture to dryness, stirring it constantly. The residuum had a red copper colour, mixed with a great deal of white; on continu- ing the heat the surface acquired a grayish blue, the edges a brown red, and in some parts an orange yellow. Thus it was evident, that the difference of colour exhi- showed that hited by the oxigenized molybdena was not occasioned by charcoal was 4 charcoal mixed with it, but might be ascribed to different in [Eames degrees of oxidation of the metal. It is surprising, that the The sulphuret ‘molybdena should become oxigenized so imperfectly in this More easily manner; while its oxigenation is accomplished much more Spr ‘speedily and completely, when sulphuret of molybdena is ’ employed. To produce a perfect oxigemization, I poured half an ounce of nitric acid on the dry mass, and heated it. Finding “no perceptible change take place, 1 added two drachms of pure muriatic acid, which expedited the effect, _ -the mass became more and more compact and lighter co- loured, and at length was white. Being dried and carefully collected, it was kept at a red heat in a glavs capsule for a quarter of an hour, left to cool, and weighed. Its weight was now 146 grains, to which must be added three for what adhered to the sides of the capsule, so that in this experi- met a hundred grains of molybdena had absorbed 48 grains ‘of oxigen. In 100 parts of acid therefore there are 32°43 ‘of oxigen. | id This experiment then gives a result differing little from Exp. 14 re- . those obtained inthe 14th and 18th. Trepeated the first ened once more, Taking a piece of fused molybdic acid, that greets weighed 138 COMPENSATION CURB FOR TIME-PIECES. weighed 100 grains, I put it into a crucible in the midst of powdered charcoal, and exposed it for an hour to the most violent forge fire. The gray mass I obtained weighed ex- actly 32 grains less than the acid employed. Molybdic acid Thus we may admit, without being far from the truth, Reese pan that a hundred parts of metallic molybdena absorb forty- and 82°bof nine or fifty parts of oxigen, when this metal passes to the oxigen. acid state, and that consequently a hundred parts of molyb- dic acid contain thirty-two or thirty-three of oxigen. This confirms These experiments on molybdena in the metallic state, er alia aud on molybdic acid, confirm the proportions I have as- rete signed to the constituent parts of the natiye sulphuret of molybdena. , (Fo be continued.) ae Construction of a Curb affording a Compensation for the Effects of Heat and Cold in Time-pieces. By Mr. Wi1- L1AM Harpy, No. 29, Cold-bath Square. Compensation Iw Pl. IV, fig: 2, the circles A B denote an expansion SE SOTO aay composed externally of brass and internally of steel ; in consequence of which its curvature will be diminished by Mannerin heat, and increased by cold. The end A is fixed, and the which it acts. yest of the bar is at liberty, whence the extremity B will be affected by a motion from temperature, which will carry the pin F {between which and G the spring D E passes) a lite tle onwards when the temperature rises, and a little back- wards when it falls. But F will be scarcely at all affected in the direction of the radius, because the two semicircular parts of the bar counteract each other. CG is an arm of brass fixed to the expansion bar, in the middle of its length, It carries a pin G oppasite to F; and as C is thrown inwards by increase of temperature through a space, amounting to the whole change to which the diameter of the curved ex- pansion bar is liable, G will be carried towards F, and will The balance allow the spring less play; and by that means add ta its Tan) stiffuess, DESCRIPTION AND ANALYSIS OF YENITE. 139 stiffness, when its elastic force is diminished by the weather: spring will and the contrary effect will take place when the spring be- rigihsant nal comes more rigid by cold. An adjustment for temperature has been applied in chro- A former ad- nometers several years ago, by means of a pair of tongs, or simula? patent double expansion bar, of the same nature as if the spring ple. were to pass through the variable notch A B in the present figure. Whether Mr. Hardy’s contrivance will afford supe- rior advantages in its effect, or in the convenience of dis- posing the parts, must be referred, like all things of this | nature, to trial. | ) a) W. N. a0 Of the Yenite, a new Mineral Substance: by Mr. 1x LiryReE, Member of the Institute, Counsellor of Mines, &c.* W nen I was sent to the isle of Elba five years ago as commissary of the government, I thought I might avail my= self of the opportunity, to study and make known the mi- neralogy of a country so interesting to the naturalist. The business of my office, however, having occupied nearly the whole time I spent in that island, did not allow me to carry this design into execution: but my journey will not have ‘proved altogether fruitless to the science of mineralogy ; for, beside the mineral that forms the subject of the present pa- Minerals from per, I have brought with me some others, that may prove oe of interesting to the mineralogist. Such are 1. A. green substance, that has some resemblance to acti- A new mineral. note, and a considerable analogy to that which I am about to describe, 2. Transparent white emeralds, some of which are three white eme- centimetres [1°18 inch] long. ralds. 3. Black, yellow, and rose-coloured tonrmalins. — Tourmalins.: 4. Rose-coloured and white lepidolite, lamellar and com- Lepidolite. pact. * Journal des Mines, No.21, p. 65. Extracted from a paper read at phe meeting of the Institute, December the 29th, 1806. A a2 % one § ‘ 5. 140 DESCRIPTION AND ANALYSIS OF YENITEs« Porphyry. 5. A porphyry with base of white. compact feldspar, and containing black globular nodules, which appear to me to be a mixture of amphibole and feldspar. Diallage. 6. Green and metalloid diallage. Resiuite, 7. Resinite quartz similar to that of Musinet in Pied- mont. Fetid quartz, 8, _Fetid pseudomorphous quartz, &c. In some future papers I shall mention what I have noticed, that is peculiar, either in the characters or situations of these : but I shall confine myself for the present to that, which I now lay before the class, aud to which I have given the name Yenite. of yénite, from of one of the most memorable events of the age, the battle of Jena. Pa its physical characters. Spec. grav. This mineral weighs nearly four times as much as distilled water (3°825, 3:974, 3°985, 4°061). Hardness. Its hardness is a httle inferior to that of the aduieria feld- spar, by which it is scratched; but it scratches glass strongly, and gives a few sparks with steel. Primitive form. ‘The mechanical division leads, as wi!! be more particularly described presently, to a rhomboidal prism of 113° and 67°, which may be subdivided parallel to the shorter diagonals of its bases. Colour. The yenite is opake, and of a black colour inclining some- times to brown. Its powder is of the same hue. Surface. The surface of the crystals, when they are very black, is shining. (Those varieties represented Pl. IV, figs. 5 and 6, have commonly a dull and brownish surface.) The lateral faces of the prisms are streited lengthwise: the facets O of the summit are smooth and very shining. © Fracture. The fracture is unequal, and of a greasy lustre ‘aan like that of phosphate of manganese). Nonelectric. It is not electric, either by heat or friction. Magnetic Heated to redness in the flame of a wax candle merely, it when heated. becomes weakly attractable by the magnet. Spontaneously ~ Exposed to the action of the air it is decomposed, and decomposed. covered with an earthy yellow and brown crust, perfectly si- milar to the ochres, or oxides of iron mingled with earths, which are found native. ; Ltt Geometrical DESCRIPTION AND ANALYSIS OF YENITEs 141 Geometrical characters *, Cleaving exhibits indications of laminz parallel to the mechanicai sides of a prism with a rhombic base, the angles of which division. are 112°37'9” and 67° 22’ 51”. Mather more evident in- dications are found of a division according to the shorter diagonals of the rhombs, This section is pointed out on the crystals by the strize at the summit. The bases present no section: their fracture on the contrary is uneven conchoi- dal, &e. The primitive form, PI. IV, fig. 3, is a right prism, with a Primitiveform. rhomboidal base, the diagonals of which are to each other as 2to3. From the theory of decrements its height is to the shorter diagonal as 4 to v7. The crystals have five varieties with respect to figure. Figures of the Var. 1. Fig. 4 is the primitive form elongated, and termi- tYs!#! nated by a pyramid with four faces rising from its edges. The angle of incidence between M and OQ is 128° 28’ 59”; that between O and O, 139° 36’ 48”; and that between O and its reverse 117°38'8”. ' Var. 2. Fig. 5 is a tetraedral prism, nearly rectangular, terminated by a double bevil, obtuse, and placed on the obtuse angles. The angle of incidence between S and S$ is 83° 16’ 4”; that between R and its opposite face 113° "oo. Var. 3. Fig. 6 is the preceding form with a double trun- cature at each acute angle of the bevil. The angle of inci- dence between O and R is 159° 48 24”. Var. 4. Fig. 7 is an octaedral prism terminated by an ‘obtuse octaedral summit, four of the faces of which are at the angles of the prism, and four on the edges. The angle of incidence between X and the edge Z is 131° 24’ 37”. Var. 5. Fig. 8 exhibits the preceding variety with this dit ference, that it has at the summit a facet parallel to the base of the primitive form. The angle of incidence between P and R is 146° 31 48”; and that between P and O, 141° A ae * These characters were ascertained by Mr. Cordier, engineer of mines, who was so obliging as to undertake the examination of the crystalline forms, which he calculated accoiding to the method of our Jearned comrade Haiiy. At / 142 Differs from all others. DESCRIPTION AND ANALYSIS OF YENITE: At first view this mineral seems to approach the epidote in form: but in the first. place the regularity of the faces forms an objection ; and in the second, the measure of the angles, and the laws of decrement, totally contradict this apparent analogy. No other mineral substance has any si- milarity with this new species; at least as far as respects form. Chemical characters. Chemical chase. The yenite simply calcined becomes attractable by thé magnet, passes from black to a very dark reddish brown, and loses about two per cent of its weight. It readily fuses before the blowpipe, without any sensible ebullition; and yields an opake, black button, very readily attracted by the magnet, but without polarity, dull, and ex- racters, Component paits. hibiting a metallic aspect. with a short effervescence. With glass of borax it dissolves On continuing the fire an ena- mel is obtained, that appears black: if a larger quantity of borax be added, we have a transparent glass, of a yellow- ish green colour, without any indication of a 7stallic but- ton, or residuum; which proves, that the who.e has beer dissolved. It is attacked by the sulphuric, nitric, and ‘muriatic acids. The last dissolves it most readily: the silex remains at the bottom, and the solution acquires a fine yellow colour, with a slight tinge of green. Analysis. It has been analysed by Messrs. Vauquelin and Descotiis, and a hundred parts gave Descotils. ex te id nos \elsbeal aie wiele 983 Lime... ceccevereses Oxide of iron Oxide of manganese: - Alumine Loss aeeeveosreqaeeeee eee neesvee Vauguelin. a ey ee: eee ree eoesee 1D soeeve 12°5 55 j 7 bes sbh By Dede eh eoyle 0:6 VA vesees Q 12 100. 100. 100. ~ This DESCRIPTION AND ANALYSIS OF YENITES ’ "This agreement between the results obtained by these two: skilful chemists, who operated on the stone at the same time, and unknown to each other, gives these analyses as high a degree of certainty as could be wished ; and author- ises us to conclude, that the yenite, at least in those speci- mens analysed, contains rather more than half its weight of iron, mixed with a little manganese, and that the rest of the stone is lime and silex, the proportion of silex being consi- derably more than double that of the lime. Situation dnd local circumstances: I found the yenite in two different places in the island of Elba; at Rio-la-Marine, and at Cape Calamite. In the first of these it forms part of a very thick mass or stratum, resting on a primitive limestone mixed with tale (a kind of cipolin marble) ; the whole exhibiting a cliff, or bare perpendicular rock, about thirty yards high. It is im- bedded in the green substance, which I have mentioned as bearing considerable analogy to it, in masses that reach to the size of a few cubic decimetres [the dec. is near 4 inches}, and frequently form the sides of cracks in the rock. These masses are most frequently composed of distinct pieces, and in each of these piéces the mineral is in radii diverging from acentre. Sometimes the radii are nearly parallel, and so conjoined together, as to exhibit compact masses, which di- vide into shapeless prisms like certain basaltes. At other times the radii, particularly when their extremities are free, terminate in true crystals. Frequently the yenite appears in long pieces, or imperfect prisms, of the size of a man’s finger, and sometimes even much more slender, in the midst of the green substance ; from which it is very distinct, their limits being always decidedly marked. Frequently too it is found in cavities of this substance, in crystals sometimes with a polyedral summit at each extremity, and 3 or even 4 cent. [1 inch or 12] long; sometimes they are solitary, at others variously grouped. The stratum that has been men- tioned includes likewise epidote of a fine yellowish green, quartz, some crystals of arsenical iron, and that variety of amorphous oxidulated iron called loadstone. At a Calamite the yenite is found in the same sub- stance, 143 Where fouud. Its situation it the earth. 144 WESCURIPTION AND AVALYSIs OF YENITE, stance, but of a grayer colour, and of an aspect similar to that of certain asbestiform actinotes.. It is accompanied by oxidulated iron, garnets, aud hyaline quartz *, Anold speci- I have lately examined a specimen in my mineralogical men said to — eg|lection, which I have had several years, and which, not have come (3 4 : from Siberia. being able to refer it to any of the known minerals, I bad put into a particular place, as is my custom, for farther exa- mination. This specimen is black yenite, imbedded and. as it were disseminated in the same green'sh substance. It is accompanied with a note, that marks the part of Siberia be- tween Perm and Tobolsk for its native place. I cannot venture however to warrant the authenticity of this indica- tion. The substance of which I have given the history might perhaps be employed as 4n iron ore, and smelted for its metal, if it weve more abundant than I have yet observed, and not so near one of the richest iroa mines in Europe. Alwaysaceom- It has been seen, that the yenite, whether at Rio, at Cape nant Be! q} Calamite, or in Siberia, is always accompanied with a green resembling substance, disposed in fibres or rays like actinote. To this strahistein. —_ seglogical relation may he added, that there is a much.closer in their composition: these two mmerals differ only in this, Paiod ese * Mr. Fleuriau de Bellevue, to whom Yshowed the specimens of years ago. yenite I had, telling him I considered it as a new substance, informed me, that he himself had brought home specimens of the same mineral from Cape Calamite nine years ago, and that it was analysed by Mr, Vauquelin the year following. He at that time obtained from it Tis aindlysis. as SAGX) Diataivis ts m diarsiticeiv’e et sin s\0' sive alsin ee) (sae then given. Eade ighthe ic tine Cteiaens S90% Ria ee Go oh sie ee @Oxidergi woe!) 1. LS Se eee al A SD Oxide of manganese’ Ki caseee es 2 Alumine ..... a pialel, cigtounttielpieiele's ils biehul bf, & { oe 96°8 len Shae de Since my memoir was read, Mr, Gillet-Laumont has found in the col- Lisle’s collec- lection of Romé de Lisle, now in his possession, crystals of thé same. tion. “substance ; aud informs me, that they were placed by that learned mi- neralogist at the end of the tin ores. I believe | may venture to assert, that they came from Rio. This mineral was at Paris therefore long be- fore it was brought thither by Mr. Fleuriau de Bellevue, though it was not known. that ACTION: OF SALTS ON VOLATILE OILS. A5 that one contains a much larger proportion of iron than the ' ” ‘other. They have besides almost all the same physical and chemical characters; whence I am induced to consider them as forming but one species. Ina subsequent paper on the green substance I shall give more at large the reasons, by whieh I am led to this opinion; and I shall point out the place, which I conceive they ought to HORewny? in the classifi- cation of minerals. XIII. Memoir on the reciprocal Action of several Volatile Oils and certain Saline Substances: by Mr. Mareurron, late Apo- thecary-major to the Hétel des Invalides*. { Inserted in the 2ist vol. of the Annales de Chimie a pa- Object of the per containing some results of the action of cold on volatile sae oils, and an examination of the concretions found in several of these oils. The object of the present is, to make known the reciprocal action of several saline substances with oils of that kind, and to point out the alterations such salts are ca- pable of producing in them. Exp.1. Imadea saturated solution of acetite of lead in solution of distilled water at 15° [59° Fahr.], divided this solution 2cetite of lead with volatile equally in four phials, and added to each portion one eighth oils ef its weight of the following volatile oils; namely dios of thyme, lavender, rosemary, and sage. I shook each phial, till the oil in it was broken into globules; that the con- tact might be the more intimate. After keeping these mix- tures several months, the following were the results. The oil of thyme had undergone no alteration; but the of thyme, part in coutact with the solution contained several whitish bladders, which at the slightest motion separated in films. The oil being afterward filtered differed in no respect from what it was at first. The oils of rosemary, lavender, and sage, likewise expe- TS°™4'y, Ja- * Annales de Chimie, vol. XLVII, p. 46. Vou. XX—June, 1908. L rienced 146 ACTION OF SALTS ON VOLATILE OILS. vender,and rienced no alteration; and no flocks formed in them, as in aid the oil of thyme. TI filtered these oils, as I did the preced- ing, and assured myself, that they had not been altered by the solution of acetite of lead, which remained very clear. Into each of these oils I dropped a few drops of sulphuret of potash, which occasioned no precipitate and produced no colour. , Sulphate of Exp. 2. I mixed eight parts of a cold saturated solution ct eal of sulphate of alumine with one part of the volatile oils of der, sage, hys- lavender, sage, hyssop, and rosemary, each separately. eee rosé These mixtures having been kept four months in flint glass _ phials with ground stopples, neither the oils nor the solution of alum had undergone any change. te: ena Exp. 3. I mixed eight parts of solution of muriate of of the vulne- !ime with Gne part of the volatile oil of the vulnerary plants rary plants. ina phial, and képt the mixture for a month, shaking it now and then, without perceiving the slightest alteration. In this state I added liquid potash, to decompose the calcare- ous muriate; but I merely found, that the oil had evidently lost some of its colour, and become whiter. Oil oflemons Bey, 4. Voiatile oil of lemons, expresséd from the and sal ammo- dee rind, being’ mixed with a solution of sal ammonia, and -kept for a month, shaking it frequently, underwent- no change. Hyperoximu- Exp. 5. Into five phials I put a solution of superoxi- iate of potash : : fel ais hg tik of genized muriate of potash, made in distilled water at a tem- thyme, laven- perature of about 15° [59° F.]. In one I added an eighth rea apie 28 part of oil of thyme; in the second, an eighth of oil of and cloves. lavender; in the third, an eighth of oil of peppermint; in — -the fourth, an eighth of oil of lemons; in the fifth, an -eighth of oil of cloves. I put the bottles into a place se- cluded. from the light, and kept them thus a month, shak= ing them once every day. Neither the oils nor the solution of the salt experieuced any alteration. I then placed the five phials in a water bath, which I heated so as to make the water boil fora moment. These oils retained their colour, smell, fluidity, aid transparency ; and all of them their pro- perty of floating on water, except the oil of cloves; which sunk in it as usual. I separated each of the oils from the saline solution, evaporated each portion of the solution separately, ACTION OF SALTS ON VOLATILE OTLS. 147 separately, and obtained by crystallization the superoxigen- ized muriate of potash just as it had been before it was dis- solved. Exp. 6. Into a phial I put two parts of recently made Lime-water lime-water and one part of volatile oil of rosemary. ‘The sion hoe mixture became white on shaking it: but on standing the oil separated as fluid, and as transparent, as before, though whiter. ‘The portion in contact with the lime-water formed a light whitish coaguiam: and the lime-water had acquired a dull yellow dato) without having lost its property of be- _ ing precipitable by oxalic or carbonic acid. Exp. 7. Crystals of nitrate of mercury, obtained from a Nitrate of mer- solution of the metal made without heat in nitric acid, were aa enclosed in a phial with four times their weight of oil of rosemary, and immediately a curved tube, terminating un-. der a glass jar filled with water, was inserted intothe mouth of the phial. Ishook the mixture occasionally, leaving it thus for six days. I perceived no commotion, or evolution of gas; the oil acquired an amber colour; the quantity of crystals of nitrate of mercury was considerably diminished ; and I observed a gray powder, among which globules of fluid mercury might be distinguished. Having poured the contents of the phial on a filter, the oil passed of a reddish colour, with the thickness of a fixed oil, and with an em- pyreumatic acid smell, that was predominant over that of rosemary. It contained likewise a small portion of nitrate of mercury in solution. Copper was whitened by it. The mercurial matter remaining on the filter was gray, 4 and of laven- glutinous, and intermixed with globules of mercury. Sipiitt h of wine passed through it eave? a reddish colour, and grew milky on the addition of water, like a resinous tmc- ture. After this washing with spirit of wmea gray oxide re- mained, with which slaball es of mercury were mingled. This experiment repeated with volatile oil of lavender afforded the same results. Exp.8. I prepared a solution of corrosive sublimate in Solution of cor- the proportion. of ten grains of the salt to an ounce of dis- preter <3 tilled water, for a series of experiments, which F shall here 4 relate, ist. Into a phial I put one ounce of this solution and with oil of le- L a) some mons, 148 / oil of chervil, oil of hyssop, oil of pepper- mint, and oil of lavender, ACTION OF SALTS ON. VOLATILE OILS, some volatile oil of lemons recently rectified, and. perfectly colourless, I shook this mixture from time to time. In ten days the oil had subsided to the bottom in globules of a light amber colour, which, when separated by filtration, dis+ solved in spirit of wine. This solution being mixed with distilled water, the oil reappeared, with the property of swimming on the surface of water, being divested of the mercurial salt, which it had dissolved. The solution of corrosive sublimate separated from this oil had a somewhat acid smell, not unlike that of the residuum left after rectify< img oil of lemons, and formed a yellow precipitate with lime-water as usual. 2d. Volatile oil of chervil, that had been made two. years, treated with a solution of ,corrosive sublimate, was likewise precipitated in the form of globules, without its co- lour being lightened. I separated the oil in the same man- ner by the filter, and dissolved it in spirit of wine. Water mixed with this solution did not free the oil from the corro- sive sublimate it had dissolved, for it still remained heayier than the fluid, and kept at the bottom of the vessel. 3d. Volatile oil of hyssop, that had been long made, treated with the same solution of corrosive sublimate, sunk to the bottom of the liquid at the end of four days, with; out any change of colour. 4th. Oil of peppermint, recently distilled, with the same reagent thickened,’ became greener, was precipitated, and adhered to the sides of the phial. The solution of this oil im spirit of wine was of an emerald green; and the addition of water caused the oil to make its reappearance with its na- tural green colour. sih,. Oil of lavender, agitated i 1 a similar po PM of corrosive sublimate, was precipitated at the expiration of a few days, and became of a high amber colour approaching to red. On the sides of the phial a whitish mercurial erust was observed. , This oil, when separated from the solution, had lost its fluidity ; its smell was considerably changed, being acid and empy reumatic; its colour was reddish; and it spotted glass in the manner of empyreumatic oils. Beaten up with dis= tilled water, it first subsided to the bottom, and after some time ACTION OF SALTS ON VOLATILE OILS, 149 - time rose to the surface. Shaken afterward with lime-wa- ter, it gave signs of the presence of corrosive sublimate by the yellow precipitate it formed. It dissolved completely in spirit of wine: but on the addition of water it reappeared, in part light, in part heavy. I kept some of the solution of this oil in alcohol a considerable time: and I observed, that the sides of the phial acquired a white coating, which I found to be mild muriate of mercury. The solution of cor- rosive sublimate separated from the oil was not entirely. de- composed, it still manifesting the presence of this salt by the yellow precipitate it for Hea with lime water. Exp. 9. Into a phial I put forty grains’ of corrosive sub- Crystals of cor- limate crystallized from water, and poured on them an ounce pe para * of mercury of volatile oil of rosemary. In the course of a few days it with oil of acquired a deeper amber colour than it had before, and tosemary+ a white flocculent precipitate formed in it. I then added more corrosive sublimate, which changed the colour of the oil toa very deep green; the precipitate from white became green ; the oil lost its fluidity; and it emitted an empyreu- matic acid smell, with which that of rosemary was faintly perceptible. separated the oil from the precipitate, mixed’ it with water, and heated the mixture till it boiled. The oil did not change its colour, and still remaimed heavy. ¥ washed it several times with distilled water, which freed it from the mercurial salt it had dissolved; it again became’ light enough to swim on the surface of water; it spotted’ _ the glass in the manner of empyreumatic oils; and its solu- tion in spirit of wine was greenish. The green precipitate mentioued above had a strong smell of rosemary, and burned with a vivid flame. On adding spirit of wine to it, the resinous part was dissolved, and formed a green tinc- ture, which turned white on the addition of water, in the’ same manner as resinous tinctures. That part of the preci- pitate, which remained insoluble, was mild muriate of mer- omy mixed with a little corrosive sublimate. | ’ Exp. 10. Corrosive sublimate in powder, shaken with oil Oil of turpen- of turpentine rectified from water, had no effect on this oil, pk s though I kept the mixture a long time. The solution of of mercury, this salt, on the contrary, after a certain time produced a and with its soe lution, change; causing it to assume the consistence of turpentine, while 150 ACTION OF SALTS ON VOLATILE OILs.. while mild muriate of mercury was deposited on the sides of the phial. Calomel and Exp. 11. Oil of lavender kept several months on mild oilof laven- dav. muriate of mercury, well washed and well levigated, unHers went no alteration. - Cinnabarand =» _ Erp. 12. Factitious cmpabar in powder and oil of roses il ofrosemary. “1: . : : d ourontosem='Y* mary exhibited no reaction during or after their mixture. Sulphate of Exp.13. Oil of rosemary poured on turbith mineral, and i Ld kept some time, experienced achange. It let falla greenish ry. flocculent precipitate, and at the same time acquired the property of sinking in water, when poured on it. _ A portion of the turbith was converted into gray oxide of mercury, which retained in combimation that part of the oil, that had become resinous, Red nitrous Exp. 14. I put into a phial a drachm of red precipitate anal nae with one ounce of volatile oil of lavender, and kept the lavender,in mixture several months in the shade. . The oil had formed onsicop aad 2 whitish sediment, and the red precipitate was in part re- duced to gray oxide of mercury. The whitish sediment was soluble in spirit of wine, and this solution turned milky on the addition of water. The oil retained the fluidity, colour, and smell of oi] of lavender, swam on water, and dissolved well in alcohol. in the sun, Having exposed a similar mixture to the light of the sun, the oil lost somewhat of its transparency and deposited a whitish sediment, and the red precipitate had assumed the shining metallic colour of iron filings. Muriate of an- Exp. 15. Into a small phial I put a drachm of crystal- gun bape lized caustic muriate of antimony, and poured on it an equal equal parts. weight of oil of rosemary. On corking the phial J imme- diately perceived a great heat, the cork flew out, the oil spouted out with violence, and the inside of the phial re- mained coated with a black oil of a particular smell mixed with the smell of rosemary. This mischance induced me to repeat the experiment in a larger vessel, and with different proportions of the mpere® dients. Bpartsofthe J put into a plial eight parts by weight of oil of rose- oil to lof the mary with one of crystallized caustic muriate of antiniony. muriate. ‘The heat was scarcely perceptible; the munate of antimony ” fell ACTION OF SALTS ON YOLATILE OILS. 15] fell to pieces very slowly ; and the portion of oil that was in contact with it acquired a deep amber colour. In a few days the whole of the oil was turbid, and exhibited inte- riorly a flocculent precipitate. As soon as the oil appeared to be grown clear, I poured it out on a filter, on which a light orange coloured matter remained, that I shall notice Fresently, The oil passed through of a deep amber colour ; it liad the consistency of an expressed oil; and its smell was less sweet. Being kept a long while in a phial, it de- posited a whitish sediment. Poured into distilled water, and gently shaken, it separated into flakes, which rose to the surface of the water, and let full a silky precipitate, of a very white and silvery appearance. This was insoluble both in water and in alcohol, was not volatilized at a red heat, and resembled the silvery flowers of antimony. The oil dis- solved easily in alcohol, separated from it on the addition of water, and let fall on standing a precipitate similar to that abovementioned. The orange coloured matter left on the filter, having been washed repeatedly with spirit of wine, and dried on paper, exhibited a crystalline appearance in certain parts. Put ona slip of iron, and heated to redness, it became covered with shining needles, as muriate of anti-. mony does. | _ Exp. 16. Oil of rosemary added to a solution of nitrate Nitrate of sile of silver exhibited after some time a whitish pellicle, which. ver and oil of had a metallic aspect, and formed a separation between the oe solution and the oil. The oil did not appear to be altered, and the solution of nitrate of silver still formed muriate of silver on the addition of muriatic acid. _ The pellicle was a portion of the silver reduced to the metallic state. Exp. 17. The volatile oils in the experiments lately men~ volatile oils tioned having undergone a great deal of alteration, I thought, with sugar. it right, to continue the examination of the same oils with a less active substance, as sugar, with which they are sup-~ posed to ‘be capable of forming a perfect combination, com- pletely soluble 1 in water, without losing any thing of their properties. Such a compound is called an oleosaccharum, and is used to impart to different preparations, solid or li- seit he the smell of a fruit, flower, or some other part of a ; vegetable. 152 For an oleo- saccharum the oil should be highly recti- fied, The best oil rises first, ACTION OF SALTS ON VOLATILE OILS vegetable. Whatever be the proportion of sugar and vola- tile oil directed in different Dispensatories, the authors are agreed on the intimate. nature of the union; and conceive; that this method renders volatile oils miscible with aqueous liquors. Tk Volatile oils reduced to an oleosaccharum are the more easy to unite with aqueous liquors, in proportion as the oils are more fluid, and more highly rectified. When they are so to a sufficient degree, they even dissolve in-a large quans tity of water alone. Mr. Baumé remarks, in his Elements of Pharmacy, that essential oils, when they quit a vegeta- ble to rise in distillation with water, undergo even in this a true rectification. ‘That which rises first with the milky water is more fluid and more fragrant, than what passes af ter the receiver has been changed. The latter does not whiten the water: the former dissolves jn it in consequence of its tenuity, and gives it that milky whiteness, which is observed as long as it passes over in the distillation. Ac- cordingly an oleosaccharum made with these first oils is agreeably aromatic, does not render the aqueous liquor tar bid, and does not separate from it: while on the contrary the second, of which we have been speaking, or any other volatile oil that bas been made a certain time, or a mixture of both these oils recently made, forms an oleosaccharum that is not of a pleasing smell or taste, renders the aqueous mixture turbid, and separates from it in a very short time, We may ascertain this fact, by putting into a glass tube filled with water an oleosaccharum made with this oil. It will fall to the bottom; the air contained in the sugar will be extricated; the oil will rise through the fluid in small slobules and collect on the surface; if the mixture be shaken it will turn milky, and be ‘a long while becoming clear again; but the oil will at length reappear, having ex~ perienced a sort of thickening, so that instead of globules it will form a sort of mucilaginous flakes. The oleosaccha- ram then is an imperfect combination, when it is prepared with an oil not sufficiently rectified. It is to be observed, zie eg ne that many lozenges made by baking, and flavoured with ess 10N O) 1€ Ol J : . ¢ with the sugar Sential oils, as those of peppermint, anise; &e., are oleo- saccharums ACTION GF SALTS ON VOLATILE OLLAs. 153 saccharums that do not let the oil separate on solution in promoted by water, though commonly the makers are indifferent about baking employing: highly rectified oils; not.to mention, that the most volatile part of the oil must be dissipated by the heat, to which it is exposed during the baking of the sugar. It would seem, that in this case the heat must produce a more jntimate combination with the oil, the nature of which it would be interesting to know. Exp. 18. As I had at hand a certain number of essen- Experiments tial oils, [ thought it not amiss to make a series of experi- ide i eee ments, for the purpose of ascertaining the heat or cold they produced on would produce when shaken with water. These experiments ye pa furnished me with a new mode of detecting those adulterated ft ‘by a mixture of spirit of wine. 1. I mixed volatile oil of peppermint with thrice its Oil of pepper. weight of distilled water, and plunged a mercurial thermo- ‘eek: _ meter into the mixture. The temperature was 10° [50° F.], and no change took place. 2. Common oil of peppermint of the shops, mixed with Common oil water in the same proportion, at the same temperature raised S a the thermometer 12° [2°7°]. 3. Oil of lemons recently rectified from water on a water Oj! of lemons. bath, as limpid and as fluid as ether, being shaken with dis- tilled water, produced neither heat nor ulti 4. Oil of orange flowers-recently distilled comported it- Oil of orange self in the same manner; while the orange flower oil of the Revels. shops with the same quantity of water raibed the thermome- ter 1° [1°8°]. These experiments having taught me, that some essential When heat is oils produce neither heat nor cold by their mixture with wa- Produced, they are adulterated ter; while others on the contrary produce a sensible heat, with spirit of thouch operating with very small quantities; I conceived, wine: that the cause of this heat was ascribable to spirit of wine, employed to adulterate them. Accordingly I mixed one part of spirit of wine with two of an essential oil, kept the mixture some time, and then mixed it with thrice its weight of water, when it caused the thermometer to rise 1° ['8"). General 154 ACTION. OF SALTS ON VOLATILE OILS: General re- General conclusions. sults. . , : Fyom the experiments above related it follows: i Effects of ace- . 1. That the oils of thyme, lavender, rosemary, sage, and: tate of lead, or Jemons, undergo no alteration, even by standing, with solu-: of alum ; tion of acetate of lead, or of alum. ef muriate of 2, That the oil of the vulnerary plants with a solution of ae muriate of lime, loses its lemon yellow colour, and becomes whiter. ' ef hyperoxi. 3. That the solution of superoxigenized muriate of potash: Tee Maowhon occasions no change in the oils of thyme, lavender, pepper- 3 . mint, lemons, or cloves. of lime water; 4. That lime-water destroys in part the colour of oil of rosemary. of nitrate of 5. That nitrate of mercury 1s decomposed in oil of rose- pe le mary, which it renders high coloured. ae cbrlasive 6. That corrosive fs, a and its solution in distilled subiimate; water, increase the colour and consistency of the oils of le- mons, chervil, hyssop, lavender, and rosemary, and are partly decomposed by them, producing mild muriate of mercury. of calomel and _ 7. That mild muriate of mercury and factitious cinnabar einnabar 5 occasion neither action nor reaction with oils of lavender and rosemary. oftprbith mi- 8- That turbith mineral is partly decompesed in oil of neral; rosemary. of red precipi: 9. , That red precipitated mercury is in part converted into tate; gray oxide in oil of lavender, without causing the oil to un- dergo the least alteration. of muriateof 10. That caustic muriate of antimony is decomposed in antimony; — oil of rosemary, which it colours and thickens; while part of this muriate loses its acid, and appears to be converted into silvery flowers of antimony. of sugar; 11, That an oleosaccharum is a more or less perfect com- bination, according to the oil employed. and of water. 12. Finally, that volatile oils shaken in distilled water produce no heat, that is sensible to the thermometer, unless they have been adulterated with spirit of wine. : XIV. ANALYSIS GF ADHESIVE SLATE, 155 XIV. Analysis of the Schist that accompanies the Menihte near Paris: by Prof. Lampaprus*. Turs mineral was formerly confounded with polierfchie- a anesive and Jer, or polishing slate: but Werner has given it the name of polishing slate klebfchiefer, or adhesive slate, on account of its property of eis ai adherme strongly tothe tongue. On his return from France he gave mea certain quantity, that I might subject it to chemical examination. The following are its external characters, as given by Wer-’ Characters of ner. It adheres strongly to the tongue. Its colour is of ec land pale yellowish gray. It is without lustre. Its fracture is slaty, with straight leaves. Itis opake. Scratching gives it alittlelustre. It is very tender. It separates into leaves spontaneously, which is one of its principal characters. It is light, not being twice as heavy as water. It serves as a gangue to the menilite, with which it is found Where found. im the ‘hill of Menil-Montant near Paris. The following are the results of my chemical experiments Analysis. on it, a. Roasted for two hours im a very active wind furnace Calcined. ~ it lost 30 per cent of its weight. Its colour became a deep brown. It exhibited no sigus of fusion, either ina clay cru- cible, or in acrucible lined with charcoal: yet it had become - harder, and less friable. ‘That which had been roasted in the clay crucible was rendered very attractable by the mag- net, 6. Before the biowpipe on charcoal and with oxigen gas Treated with it melted ina few seconds into an opake glassy bead, of a Seige cad blackish brown colour, gas: c. Exposed to the flame of the blowpipe simply, it was with borax. not possible to melt it: but with borax a small portion was dissolved, and coloured of a blackish brown. These preliminary trials, and its effervescence with mu- riatic acid, led me to suspect, that it contained carbonic acid and iron, ii e '% Jnurnal de Mines, N. 106, p. $17. Extracted from a work pub- lished by prof Lampadius in 1604 under the title of Beytrage sur Erweite- sung der Chemie. scl d. A t 56 ANALYSIS GF ADHESIVE SLATE: Roasted. d. A thousand parts of the mineral roasted in a retort yielded 270 of carbonic acid. Dissolved in e. Another thousand parts dissolved i in ten times their’ muriatic acid» Wweioht of muriatic acid lost 270 parts. It contains therefore 27 per cent of carbonic acid. I afterward proceeded with the analysis i in the following manner. Treated with 1, One part of the mineral was well powdered, and put sulphuric acid. into four parts of concentrated sulphuric acid, in which it dissolved with evident effervescence ; and the solution was evaporated to dryness. Silex Q. The residuum was diffused in water, and a gelatinous matter separated, which was still a little yellowish. f his was silex. 3. The liquor was filtered. 4. The gelatinous residuum was washed with boiling water, till no farther trace of sulphuric acid was discover- able. 5. This water and the filtered liquor were evaporated to~ gether, till there remained but ten drachms. Lime. 6. Some sulphate of lime separated, which was decom- posed by an alkaline carbonate; and after it had been heated and roasted 0°08 of pure lime were obtained. Iron and mag- 7, The liquor separated from the sulphate of lime was i ins! concentrated by heat, and it yielded crystals of sulphate of iron, and of sulphate of magnesia. 8. Without separating the crystals I put the whole ists a platina crucible, and exposed tlre saline mass to a strong heat for two hours. g. After cooling, the mass had an Scio colour, and a bitter taste. On it I affused boiling water, filtered and washed the residuum. tries, 10. The oxide of iron remained on the filter. alee having been dried and roasted it weighed 0°09. Magnesia. 11. I added to the liquor carbonate of ammonia, when a white earth was precipitated, which dried and roasted ap- peared to be magnesia, and weighed 0-28. 12. The yellowish gelatinous residuum (No. 4) was. di- gested in muriatic acid, till its colour became entirely white. More iron. 13. Being filtered and washed, the liquor was of the co- lour ‘SCIENTIFIC NEWS. 157 lour of pale white wine. Being precipitated with ammonia, I obtained some more oxide of iron, which washed and roasted weighed 0°03. 14, After having redissolved this oxide of i iron, and that Silex to be de- of No. 10, there yet remained 0:008 of silex. 2, arp 15. The residuum of No. 13 was found to be pure silex, ¢;.,. which, after having been dried and roasted, weighed 0:30. Accordingly 100 parts of this mineral contain. Cries Magnesia «+++. eeoverccncessesee OR parts, TP arbouic, acid «+ 20.00 \c 000 secnegs¢ Q7 Silex eee eeereesssecccesersceseceses S()'§ Oxide of iron eoebiercccesseeveces LID Pea a aclersiads cterace wns BIS Re kine Be ce Oe Water ee ceeese re ssedicsinesecoecs§ OS ee et Deiciite ais laine) te valshelelfoie)eitisteha's)otalele 1°9 100 The most remarkable circumstance is, that this mineral Contains no contains no alumine, and includes a large quantity of iron. pena ari B The outward appearance of the mass would lead us to sus- expected. pect the former substance, and its light colour by no means indicates so large a quantity of the second. Probably the carbonic acid combining with the oxide of iron conceals its presence*. SCIENTIFIC NEWS. Wernerian Natural History Society. Ar the last meeting of the Wernerian Natural History Wernerian Society (14th May), Mr. P. Walker read an account of fae Poly * Mr. Klaproth, who had before analysed a specimen of this “chit, Klaproth’s feund in it: analysis of it. RUELGSE ccprage sje 'e,.5'« Lialare et (o.sleteactie itaurela ts sis UGS PRUAIUIEIEcie eta nic iset n'sis ealereade aie. esis Swann Magnesia..... lis ens\ St case, olathe alana e mpet 90 ASS LAME 6 ies» poems ough ahs AN aiaraiba ts He cistia ial etal HL Oxide ofiron..........- ie Die iaratans clase Uva 2°5 Water es oration as tiint « piMeke Shane a 19 97°75 BsGSSesice ae sein ereeierrere ee eeee re 2:25 158 Minetalocical queiies. i SCIENTIFIC NEWS. birds that frequent the vicinity of Edinburgh. He enume~ rated 178 species; of which J1 belong to the genus falco, 4 to strix, 1 to lanius, 8 to corvus, 1 oriolus, 1 cuculus, 1 picus, 1 alcedo, I upupa, 1 certhia, 2 sturnus, 6 tur dus, 1 ampelis, 2 loxia, 7 emberiza, 8 fringilla, 1 musci« capa, 3 alauda, 15 motacilla, 4 parus, 4 hirundo, 1 cae primulgus, 2 columba, 1} phasianus, 6 tetrao, 3 ardea, 6 scolopax, 7 tringa, 4 charadrius, 1 hematopus, 3 rallus, 3 fulica, 4 podiceps, 4 alca, 6 colymbus, 2 sterna, 12 larus, 1 procellaria, 5 merganser, 20 anas, 4 pelecanus. This ac- count was accompanied with interesting observations on the distinctions of several of the species, their changes of plum- age at different ages and times of the year, and their kind of food; and specimens of some of the dubious species were exhibited. . Mr. Jameson, at the same meeting, read the following mineralogical queries, and stated the reasons, that induced him to consider the objects pointed out by them as desery- ing the particular attention of mineralogists. : Mineralogical queries. 1. In what species of rock are the metalliferous veins of Tyndrum situated, and what are the minerals they con- ‘tain ? 2. Are the leadglance veins of Strontian situated in sien- ite, and what are their geognostic relations? 3. Are the trap-veins, that traverse the mining field at Strontian, basalt, porphyry slate, or greenstone, or do all these different species of rock occur in that district ? 4. Does the quartz-rock of Seuraben and Morven in Caithness, and of Portsoy in Bamffshire, occur in an un- conformable and overlying position, or does it belong to» the comformable primitive rocks,-as clay slate or mica slate? 5. Does not the granular rock of Ben Nevis rather belong to the sienite than to the granite formation ? 6. Does the rock of the hill of Kinnoul near Perth be- long to the floetz-trap or newest floetz-trap formation? 7. Is the mountain of Cairnsmuir in Galloway composed of old granite ? . 8. What SCIENTIFIC NEWS. 159 8. What is the extent and» particular geegnostic rela- tions of the black pitchstone of Eshdale Muir in Dumfries- shire? 9. Does the black pitchstone of tie Chavet hills belong to the newest floetz-trap formation ? . 10. On what formation does the porphyry slate of Braid Hills near Edinburgh re what are the venigenous and tinbedded fossils it contains ? ‘11. What are the geognostic characters and relations of - -the edge and Hadumssl. beds or-seams in. Mid. Lothian ? 12. On what formation does the Calton Hill near Edin- _burgh rest? 13. Does the greenstone of Corstorphine Hill belong to the independent “cual formation ? 14. Does the hill on which the town of Stirling is built belong to the coal fermation : > 15. What are the geognostic characters and relations of the veins that traverse or are included in the greenstone of the independent coal formation ? 16. What are the characters of the transition greenstone of the south of Scotland? 17. What are the particular species of petiifactions that eccur ‘in the transition limestone near the Crook, on the road from Edinburgh to Moffat > mee Mr. Parkinson’s second volume of organic remains of a Parkinson’s or- former world is intended to be published in June. Tt will g2mic remains, contain twenty plates, representing the figures of nearly two hundred different fossils of the remains of zoophytes, coloured after nature; among which are the mineralized re- mains: of upwards of twenty ‘species of the encrinus. It cannot but be gratifying to our readers to know, that of these remains the greater number have been found in dif- ferent parts of this island. SE a Dr. Satterley and Dr. Young propose to give two courses Medical lece of Medical Lectures next winter at the Middiesex Hospital, t'>- Dr. Satterley’s will be Clinical lectures, and auy of the pu- pils of the hospital attending them will have the privilege of seeing the patients whose cases are discussed. He will be assisted in the department of morbid anatomy by Mr. Cart- wright. Dr Young’s course will be on the Elements of the Medical Sciences in general, and on the Practice of Physic in particular. It has been erroneously stated in ‘several periodical publications, that Dr. Young had a large medica! work nearly ready for the press; the errour arose from his having been for somé time ewgaged in the preparation of these lectures. METEOROLOGICAL JOURNAL ° For MAY, 1808, Kept by ROBERT BANKS, Mathematical Instrument Maker, in the Strand, Lonpon. N.B. The apparatus and its relative situations will be described in our next. | THERM ORE THB, wah daaaaeal s |s [2 1} 2 1 BAROME- MAY: | Aob™ i hottie Day of} < | & | 5 | | Night. Day. Sl ae es Se 2 | 57158} 62156} 29,93 Cloudy Fair 3 | 60)61 | 60} 52} —,85 Moonlight | Do. Rain at 4 |61}60|76}56| —,81 | Ditto Do. [9 4.M. 5 |62160]68|56| —,83 | Ditto Do. 6 | 62|61 170/56} —,77 Ditto Do. 7 |64{60|69/ 52] —,62 Rain Rain 8 53153 158/48 | —,57 Cloudy Fair 9 149148 | 56/45} —,54 Moonlight | Ditto 10 | 54/49!159/47 | —,79 Ditto Ditto. 11 54150} 60] 51 —,95 Ditto Ditto 32 §8 162) 56] 54] 30,17 Cloudy Ditto 13° | 61/}61167)59} —,26 Ditto Ditto 14 168)63 174/61} —,18 Ditto * Ditto: 15 |70|}72|177166} —,16 Fair Ditto 16 | 74169 {| 80] 61} 30,00 Ditto Ditto 17. | 68/64|74/ 56] —, 8 Cloudy Ditto 18 581514, 59| 44) —,11 Ditto Rain 19 | 54|501571/46); —,22 Fair Fair 20. | 571 55 1 05 | 54 30,00 Cloudy Ditto 21 | 57465158) 54 | PORE Ditto Rain 292 158157 159/541 —,50 Ditto: Ditto 23 | 58| 54 163|)491 - —,66 Fair Ditto 94 159157 |651491 —,84 Cloudy Fair 25 158162 |66} 50] .—,93 Ditto Ditto 26 | 60159 160/53! —,73 Ditto Rain 97 “4°591560) 61.1 ST) 2Os74 Fair Ditto 28 | 61}55|64/53} 30,00 Ditto Fair 29 | 61/60 |64156] 30,18 Ditto Ditto A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. JULY, 1808. ARTICLE I. An Essay on Polygonal Numbers, containing the Demonstra- tion of a Proposition respecting Whole Numbers in general. In a Letter from Jounxn Goueu, Esq. SIR, Middleshaw, May 26, 1808. Tue design of the present essay is, to demonstrate the Proposition to following general propositions : every whole number is either pears a polygonal number of a given denomination m; or it may be divided into polygons of that denomination, the number | of which does not exceed m. This singular property of num- bers was discovered by Mr. de Fermat, who I believe gave it to the world without a demonstration. .Should the pre- sent attempt to supply the defect obtain your approbation, the publication of it will oblige , | 3 Yours, &c. JOHN GOUGH. a Definitions. 1st. The sum of any arithmetical progres Definitions. sion, beginning with unity, is called a polygonal number, and a polygon at times in the present essay. Vout, XX. No. 88—JuLy, 1808. M ad, 162 Prop. 1. Corollary. Table, Prop.2, ON POLYGONAL NUMBERS. ad. The difference of two adjacent terms in the generate ing series increased by two is cailed the denomination of the polygonal number ; and the number is said to be di« gonal, Higa tetragonal, &c., accordingly as the denomi< nation m — 2, 3,4, &c. 3d. The number of terms a, which are added together to form any polygonal number, is called its index; and the polygon is said to be of the first, second, or third order, &e., accordingly as @ = 1, 2, 3, &e. Proposition-ist. - Lemma. -Let-b be-the greater of two adjacent terms, @ 6, in a series of digonal or natural num- bers; then wWithavg Eee =~ +b—1. Ford =—a2-+1, and 6—1 =a; but li Rass ymca 2 2 ee ps again" +bo—1= » ecm eo are, QED. Corollary. Herice if we gh a=1, 2, 3, &c. sticcessively, each succeeding value of “——% may be found, by adding - x 5 Z: Bas the next value of @ in succession to that of es last found, and subtracting unity from the sum; where it is evident, ee that when a= 1, 2 UTD ae Ui Tn this manner the annexed “table is constructed, the use of which will appear in the sequel. fa ee PL Re Se. YL Be ON IO. LE ee at SOT. 8 20 10% to 6 St . 28) SGuee. oe ~ Proposition 2d. fk be a polygonal number, of which the denomination =m, and index"= a, we have k =a + m—2 X% a*—a. For the first term of the generating se- ries =1 (by Def: ist); and the common difference of the terms —=m—2 (by. Def. 24); but the term of which the nuinber ON POLYGONAL NUMBERS. 16. number is @, =14+ m— 2 X% a—1 (Emerson’s proportion, prop. 6) =m—2 X @ + 3—m; moreover the sum of a terms of the series =k (by Def. 1) = <4 m—2 x “ “i on x > (proportion prop. 7); therefore k= a+ m—2 x a*—a gira T QED. | Cor. 1st. Every polygon of the first order #41; and every Cor, 1. one of the second order =m} this is proved by substituting a? —a 1 and 2 for a in the expression a + m—2 X z= ke Cor. 2d. All polygons of higher orders may be found by Cor. 2, the table in prop. ist, thus: to the given index a, add the product of the corresponding number o°=*, multiplied by m—2, and the sum is the polygon. Example—Thus the sixth decagon = 6 + 15 x 8= 1926. Prop. 3d. Let g,h,l, &c. be polygonal numbers of a Prop. 9. common denomination m, the indices of which are 6, ¢, d, &e. respectively ; also put.64+c+d, &c. =a, and let k be the polygon of which the denomimation =m and index =a; then gth+l, &. +m—2X be+ bd+ecd, &. =k. For by addition and prop. 2, g+A+/, &. =b+c+d, Ate te — n=3) x bel oe Wat 2 2 2 2 j ats pe = “. — (b¢+6d+ cd) by involution; a*-—@ es hence by substitution g + kh+/= 4+ m—2 x m—2 xX be + bd + cd; therefore gthil + m—2 x bc + bdted=atm—2x2 lak (by prop. 2) QED. Scholjum. Put m= 4, and we have (by def. 2 and prop. scholiuzn. 2 ea 0, h=oe?, I=d?; therefore g++ h+l+m—2X M 2 ic 164 Theorem con- fined to squares here general- ized. Prop. 4, For e+ m—2 X » pees (by prop. 3) =a+ m—2 xX Eas Cor. t. Cor. 2. Prop. 5. Cor. 1. \ ; ON POLYGONAL NUMBERS. be+bd+ced= be pct +d? +exbetbdted= k= at. Thus it appears, that the present proposition generalizes a theorem formerly confined to squares, and extends it to polygons of all denominations. f Prop. 4th. Put e and » respectively equal to g i h+4, a’—a. a—éeé &e., and bie 1 ee ae 3; secwmilion al m—2Z a*—a ~ a*—a C—-- (by prop. 2); hence v aie gh 4 QED. m—2. Cor. 1st. Since 6, c, d, &c., are integers, vw is an inte- 2a - . : C= =e : ger; but fF 45 an integer, therefore ¢ is an integer ; 2 m—2 ; will exis ake ‘ hence if ap Sew quotient s and a remainder p, a = p m —— 9 Wiis. ; ) ; or ——— gives a quotient r and a remainder p; from which ee we have the following general sn Se singin e=p+m—2Xs; ee a> ——¢ a=p+m—2Xr; v= RAED ger Cor. 2d. Put p=0, 1, 2,3...m—3 successively, then e will be expressed as in the following table. ip ° e= |O0=m—2 =2m—4 =3m—6, &e. p=|lje= 1=m—241=2 m—4+1=—3 m—6+1, Ke. 1 = 1 eae or m—4+2=—3 m—6+2, &e. a e= |83=m—24+-3=2 m—443=3 m—6+4+38, &c. It appears from the table, that the values of e, taken vertically, constitute the series of natural numbers ; there- tore every integer 1s ‘either a polygon of a given denomina- tion m, or it may be resolved into nets gons of that denomi- nation. Prop. 5th. b?+-c?4+ d*, &e. a+ 2s —2n’ For b* +c? + d*? + 2v=a* by involution; but 2» =a? —a +-2r—2s (cor. 1, prop. 4); therefore b? + c?+4+d*=a+4 9s—2r QED. Cor,1st. b* —6-4+-e*—c f. d?—-d=2%s—2r, idcuate b+cec+d=a. - Cote. ON POLYGONAL NUMBERS. 164 Cor. 2d. Since a is any term of an arithmetical pros Cor. 2, gression, bounded by p and e, and having m—2 for its common difference, prop. 4. cor. 1; it will be easily under- stood, that r is also a corresponding term of an arithmeti- cal progression, of which the extremes are o and s, and common difference 1; hence it follows, that, 2s5—-27 me creases, while r and a diminish; therefore 62— 6+ ¢2—e + d?—d increases, while the sum of the roots 6+ e+ d diminishes; consequently, the number of the parts 6, ¢,; d, into which a is divided, decreases at the same time, . . \ Cor. 3d. If a can beso taken that a+ 2s—2r—=.a%,Cor,§ b= a; and e is a polygon to the index a and denemina- tion m. ° Prop. 6th. If e be an aggregate of polygons of any de- piop'g.. nomination m, and y that polygon, which is less thawe, but. greater than any polygon of. an inferior order and the same Seton : then the polygons, into which e can be re-_ solved, are equal to y or less than y. For the next superior polygon is greater than y (by prop. 2); it is therefore greater than e by hypothesis, and cannot constitute a part. of it. Q E D. Cor. If e= y+m—1,.it may be resolved into m po= Cor. lygons of the denomination m; namely, into y and, m—1 units; again, if e=y-+m it may be resolved into poly- -gons, the number of which is less than m -{ 1; this is evi- dent from cor. 2, prop. 4: lastly, if e, = y + t, can be re- solved ito polygons, the number of which = m—f, e+ may be resolved into m polygons of the same denomination, It is evident, from the properties of polygonal numbers contained in this corollary, that every whole number. may- be resolved ito polygons of the denomination Ms the nume ber of which does not exceed m U9 Prop. 7. Problem. 'To resolve a given number e into Prop. 7, polygons of a given denomination m, by help of the table - m prop. 1. meh ‘ ied ome Method. ist; Write down all the successive values of a; beginning with e and diminishing them progressively. by m—-2, until the series termmates with 0, or with p?less . than m—2; 2d,. under each value of a place the corres KISS sponding 166 Example 1. Example 2. ON POLYGONAL NUMBERS. sponding value of s—r, making the series begin with’ 0, and increase by unity, until it ends with s; 3d, these pre= peratory steps being completed, take any value of s—r in the work, and find what numbers in the second column of the table will produce the same when added together ; then if the indices of these numbers, when added in like man- ner, give the index of s—r im the work, they are also the jadices of the constituent polygons; but if the sum of the numbers taken from the table prove = to the given value of s~—r, while the sum of their indices is less than the corresponding valne of a in the work, the deficiency may. be made up in the latter sum by the addition of units, be- cause one is the index of 0 in the table. Example \st. Resolve 14 into pentagons. According to the directions given above, the work will stand thus: e= 14; a—14.11. S115 -1 s—r= Ge ts 8 a Here the first value of s—r = 0 resolves ¢ into 14 units, because 9 in the table has 1 for its index; and 0x14=0 —s—r,and1x14=14=4a. The second value of s—r = 1 resolves 14 into 9 pentagons of the first, and 1 of the second order, for 1 in the table has 2 for its index, denoting a polygon of the second order; but 2+ 9=11 =a in the work, The third value of s—r= 2 resolves 14 into 4 pen- tagons of the first and 2 of the second order, for 2x 1 in the table = 2, the double of the index of which = 4 and 44+1%4=>8=>46 The fourth value of s— r= 3 resolves 14 into 3 pentagons, namely, into 2 of the first and-1 of the third order, for 3 in the table has 3 for its index, and $41x%2=5=4. The last value of s—r=4 will not resolve 14, because 3 + 12> 4 and the sum of their indices =3+2=5, which ts greater than 2 or a in the work, Example 2d. To resolve all the numbers from 16 to 24 into tetragons or squares, which shall not in any case ex~ ceed 4 in number. It is evident from cor, 2, prop. 5, and the last example, that all the values of @ may be re= jected i in the present instance, which are greater than the index of 16, namely 4, m the table to prop. 1, when this number ON POLYGONAL NUMBERS. number is considered separately ; consequently, the cores responding values of @ in all the remaining numbers, 17, 18... 24 may also be rejected, and the collateral va- lues of s—r placed under the last series; which being done, the work will stand thus. 16; V7} 18; ° e NIA PP © 9 to 29 © 39 ft thet Sar ste: tf == — Qvorotl onan anzn aan % HF BH BD BH to co 1 Heat SESE ee Ks) x) eek eeeaaeneaae, NOC @ SOXATA SOHO ive) x | Here the first index of 16 = 4, and s—r=6; therefore 16 = a square of the fourth order by table; first index of hese ahd 1; $—r=6— 64 0; first index of 18= 6=44+141; s—r—640-+ 0: first index of 19=7 Serials 1; s—r=640+40+40; hence 19 1s resolved into 4 squares, 18 into 3, and 17 into 2: again; second mdex of 20=-6=44+2, s—r=7=—6+1; therefore, 20 is resolved into two squares, namely, one of: the second and one of the fourth order: second index of M=-7=-44+2+4+1, S— p27 0 ick O: second Men 06 02 — 8 — 4-4 2 41-4 4, s— 7 = 7 0 FT 0+ 0; therefore 22 is resolved into 4 squares, and 21 into 3: again, second index of 23 =9=3+4+3+2+41, SF —/—3+3.4+1-+ 0; that is, 23 "is resolved into 4 squares : lastly, third index of 24 = 8 — 4 fo 2! ox s—r=s=6+1 +13 that is, 24 is resolved into 8 squares. on In the same manner any other number’ may be resolved into polygons of any denomination m, so that the number of these polygons. shall not exceed m, denoting the deno- mination, TW 167 168 NEW ESCULENT ROOTs II. On aVare iety of the Brassica Napus, or Rape, which has long been cultivated upon the Continent. By Mr. James Tex. son, F.0D. SOVUPS HES *, 3 Great improve- I N the report drawn up by our worthy member, T.A. Knight, ae om Esq., at the request of a Committee of this Society, and culture, printed by their orders, it is remarked, that nature appears to have put no limits to the success of our labours in ime ° proving vegetables, if properly applied: that thus our wild crab has been converted into the-golden pippin, and that our most delicious plums have originally spryng from the sloe, The vegetable which I have now the honour of laying upon your table, gentlemen, is one more among many instances of the truth of the above remark; which I have quoted, be- cause [ think it cannot be too frequently repeated, and in- stilled into the minds of young gardeners. Nature has yn- doubtedly done much in furnishing our table with a variety of esculents spontaneously, but when we aid her efforts to befriend us, by industry on our part, she, like a kind mother, ’ never disappoints us. Who would suppose, that the hard acrid root of the brassica napus, or common rape, ‘might be rendered so mild and palette by cultivation, as to be pre- ferred to the common turnip? yet this has actually heen the case, and in France as well as Germany few great dinners are served up without it in one shape or other. I am unable to trace its first coming into such common use there; but, as it is distinguished pe Gaspar Bauhin, who published his Pinax in 1671, it must have been well Syaonimes. known at that period. The only synonyms J dare put | down as certainly belonging to it are, brassica napus, B. Linn. Sp. Pl, ed. 2, p. 931; napus sativa, C. Bauh. Pin. p. 953 le navet; Gallis; Teltow riiben, Ger mants ; French tur- Dip, Anglis. For above twelve years I have seen this plant brought to our own market in Covent Garden, but only by one perfon: Use of them. and I believe it has been chiefly sold to foreigners, though, * Transact, of the Horticultural Society, Part I, p. 26, when “NEW ESCULENT ROOT. 169 when once known, it will be a very acceptable root'in most families. It is much more delicate in flavour than our com- mon turnip, and is to be used in the same way. In ‘Ger- many, it enriches all their soups, and there is no necessity ; to cutaway the outer skin, or rind, which is thinner than that of the common turnip, but only to scrape it. Stewed in gravy, it forms a most excellent dish, and, being white; and of the shape of a carrot, when mixed alternately with _ those roots upon a dish, is very ornamental. The following different receipts for dressing: vip ing are by an eminent French cook. «< "Take your roots, and wash them very clean with a pjish prepared brush; then scrape them, cutting a thin slice away from the from them. top, and as much from the bottom as will make them all of equal lengths: boil them in water, with a little salt, till they are tender; then put them into a stewpan, with a gill of veal gravy, two tea spoonfuls of lemon pickle, one of mushroom ketchup, a little mace, and salt, and let them just simmer, but not boil, for a quarter of an hour; thicken the gravy with flour and butter, and serve them up hot.” . “Take your roots, and after preparing and boiling them Another. as before, put them into a stewpan, with a little water, work- i ing in as much flour and butter as wi!l make it as thick as cream; Jet them simmer five minutes, then ‘place the stew- pan near the stove to keep hot: just before you dish them, add two large spoonfuls of cream, mixed with the yolk of ‘an egg, and a little mace beat very fine, shaking the pan over the fire for two or three minutes, but do not let them boil. Put white sippets of French bread round the dish.” <* Take your largest roots, clean them as before, and cut A third. them in slices as thick as a crown piece; thea fry them till they are of a pale brown colour on both sides; after which, put them into a stewpan, with as much water as will cover them, to simmer for ten minutes; then add a large spoonful of Madeira or Xeres wine, the same of browning, afew blades of mace shred, two tea spoonfuls of lemon pickle; thicken the liquor with a little flour and butter, and serve , them up with toasted sippets round the dish,” One great adv antage attending the cultivation of this ve- Requires no eta i is, that it requires no manure whatever; any soil “net unt is bestina poor that san ly soil, i70 Mode of cul- ture. Saving the seed. Tnactuosity of steatites suppo- sed owing to” magnesia. ANALYSIS OF SOME STEATITES. that is poor and light, especially if sandy, suits it, where i+ seldom exceeds the size of one’s thumb or middle finger; in rich manured earth it grows much larger, but is not so sweet or good in quality. The season for sowing the principal crop is any time from the middle of July to the end of Au- guit, or even later in this country, where our frost seldom sets in before Christmas. If the season. should prove dry, it will be necessary to water the beds regularly, till the plants have got three or four leaves, otherwise they will be deftroyed by the fly; and this crop will supply the table till April, If wanted during the whole year, a little seed may be sown the latter end of October, and these plants, if they do-not miscarry, will be fit for usein April or May. The Jast crop may be sown from the middle of January to the middle of February, which will also come in the end of May and June, but in July and August they will not be very good, and as at that season of the year there is an abundance of other vegetables, it is of less consequence; upon a north border, however, and in a sandy moist soil, it is possible to have them sweet and tender during the whole summer. To save good seeds, you should, in February, or the be- ginning of March, transplant some of ‘the finest roots, placing them two feet asunder, and keeping the ground re- peatedly hoed: when the seedpods are formed, they should be guarded from the birds, either with nets, or shooting some, and hanging them up upon sticks. As soon as they change colour, cut the heads, and spread them to dry in the sun, ike which beat out the seed, and lay it up for use. IU. Comparative Analysis of some Varieties of Steatite, or Talc; by Mr. V AuQUELIN*.- Ir has commonly been supposed, that the smoothness and unctuosity of the stones called steatites were owing to the pre- sence of magnesia, because this earth had been found in every one analysed, 4nd in consequence all the stones that had these “@ Annales de ‘Chimie, vol, XLIX, p. 74. ° if, external ANALYSIS OF SOME STEATITES. 171 external characters were classed together. “But the pierre Bildstein con- de lard, or speckstein, which in some respect may be con~ saiilgemioes sidered as the prototype of the species, having been analysed by Klaproth, and no magnesia found in it, has changed the opinions of mineralogists on this subject, and led them to wish, that some ef these substances should be analysed anew. With a view to remove this uncertainty, Mr. Haiiy gave Three varieties mé three varieties of talc, that I might make a comparative ee analysis of them. The first of these is termed in Haiiy’s Mineralogy lami- !@minar talc; nar tale. It is of a greenish white colour when seen in the mass, very smooth to the touch, and divides into exceedingly thin, flexible lamine of a silvery white. The second is called in the same work tale glaphique, bild:tein. because it is employed in sculpture; but commonly pierre de lard, lt is the bildstein of the Germans*. This is compact, very greasy to the touch, and of a colour varying between gray, yellowish, and greenish. Its fracture is dull, uneven, and at the same time scaly. Of this species Mr. Haiiy sent me two specimens; one of a yellowish white, from a broken Chinese image; and the other of a light rose colour, but in every other respect perfectly similar to the preceding specimen. Analysis of the flexible laminar tale. i aininiar tie 1. I calcined in a strong fire a hundred parts of this catcinea; stone. By this operation it acquired a yellow colour, with a light rosy tint, was deprived of its flexibility, and lost six parts of its weight. Its lamime bemg thus rendered very fragile, I could easily reduce it to powder. . 2. The hundred parts thus calcined I heated with twice heated with their weight of caustic potash. The mixture did not melt; potash ; | but its tumneRintion indicated, that a combination between the substances had taken place. 3. The mixture diluted with water was afterward dis. treated with solved in muriatic acid, and evaporated to dryness in a gen- ee ee tle heat. Toward the end of the operation the liquor formed a jelly. 4. The residuum, being lixiviated with distilled water, }ixiviated; * Agalmstolite of Klaproth, pagodite of Napione, steatite pegodite of pepegtian. Tr. left 172 ANALYSIS OF SOME SYTTATITES.’ left a white powder, which when ‘calcined in a red heat weighed 62 parts. It was pure silex. piers 5. Ammonia, mixed with the liquor separated from the with ammonia, silex, formed in it a yellow precipitate of little bulk, from which a part and half of alumine were separated by means of caustic potash. ‘The remainder was oxide of iron, weigh-~ mg three parts and half, plana i 6. “After having precipitated the iron es alumine by siita, _ means of ammonia, I put into the liquor a solution of car~ bonate of soda, and ‘set it to boil. As soon as the mixture began to grow hot, it grew turbid and deposited a large quantity ofa white powder, which when washed and cal- cined weighed 27 parts. This substance was magnesia, for with diivuitié acid it formed a salt, that had all the charac- teristics of common sulphate of magnesia. Flexible laminar talc therefore is cea dell of Results of the Silex secsscecceereeecerscasesee GQ, : ae Magnesia sec cece eee errsernsscee QF CO) eile: attr iin is! spe toca: ohh! =, 05a > cchke eye ais: 3°5 "A Lista cabeadlie Treccow's cate, fades» chattel eae 15 Wistetiaialave bis pdrivese ante tle oct SnaLe ,oises ee 100 Considering the smallness of the quantity of the iron and alumime, [ think these substances may be presumed not. to be essential to the formation of the stone; so that perfectly pure laminar tale may be deemed a compound of. silex and magnesia, Analysis of compact rose-coloured tale. Compact rose. In the analysis of this variety | pursued the same pro- coloured talc. eegses as in that of, the preceding; I therefore need not enter into the particulars, but the following are its results, Results of its Silex e's vec ct ere snesecsccvcee HY analysis. Magnesia + estpeeet eee ees sce renes 22 A Parties RE Re he ds SRE Og Tron mixed with magnesia++++e+eres 5 Wrteaters vo6 aia Els Ae pe - 100. Analysis ANALYSIS OF SOME STEATITES. 173 _° Analysis of the yellowish compact talc (speckstein.) a Bildstein i. A hundred parts’of this stone strongly calcined lost 5 parts. 2. Heated afterward with twice its weight of potash im jcteq with a silver crucible no fusion took place, but the matter was potash ; greatly increased in bulk, and had become homogeneous. 3.. This was diffused in water, and dissolved in muriatic nha Bh mL ayia j : treated with acid, The solution, being evaporated, became gelatinous muriatic acid ; toward the end of the operation. 4. The matter being dried, and washed, a white powder remained, which, after calcination, weigned 56 parts. 5. . The silex having been separated by lixiviation, the... . ey a nie ‘ : 1 4,79) precipitated liquor was mixed with a small quantity of muriatic acid, with ammonias and ammonia was afterward poured in, which formed in it a copious white flocculent precipitate. 6. The liquor being filtered, the precipitate was washed j.oated with and dried. This was alumine, and weighed 30 parts. The sulphuric acid; alumine dissolved entirely in sulphuric acid, and its solu- tion, saturated with the requisite quantity of potash, af- forded very pure alum: but the mother water, evaporated afresh, yielded 52 parts of sulphate of lime crystallized in needles. Thus with the assistance of the alumine the am- monija precipitated the lnne from its solution in mnuriatic calcined s lixiviated ; acid. 7. The liquor from which the alumine had been separa- ,_ 5 ie) j ¥ and carbonate ted gave no precipitate with carbonate of soda, even assisted of soda, but by long beiling. The speckstem therefore contains no nothing Lex ier é pu thrown down. magnesia, like the two preceding varieties. ut in recapitulating the products of this analysis w B p g p this analysis We p a ites of this find only 93 parts; namely analysis. ‘ PNR dee aia! win sng 0) oe eh 5'n/ x lgiinlay seal eile: oye 56 —Alumine-+- ee ccccew ces ceeeesnes 99 ROE er iot cl cot ctrl o) sa\ « xJ0)\e yea. ed obeber or eieny che MIGESTN ou ey eeateiatia stele elara leo reciente ecleteln ohare ? r I RE ALEPA Marais me cabo en sray cae soe iy A loss so considerable, which is not common in such y 655 too gicate analyses carefully executed, led me to suspect,: that the t equn pact 174 ANALYSIS OF SOME STEATITES. compact talc contained some other principle, which the pro- Treated with cesses employed did not enable me to discover. In conse~ sulphuric acid, yence I treated a hundred parts, reduced to fine powder, with concentrated sulphuric acid. 1. After boiling for two hours I dried the enitclii cs lixi« viated the residuum with distilled water, and boiled the Cubic crystals lixivium. At the expiration of a few days I obtained 36 ofalumob- parts of alum crystallized m cubes: and by a second evapo~ bcs ration I procured from the mother water 15 parts more of the same salt, mixed with a few needly crystals of sulphate of lime. Treated with 2. ‘As the stone appeared to me but imperfectly ibieeas pte sulphuric nosed, I powdered it afresh, and treated it as’ before. .On : adding the acid employed in this operation to the mother and more alum water of the preceding, I obtained 15 parts more of alum, produced. = making in all 60 parts. Then, as I employed for this opera« tion very pure sulphuric acid, and added no potash to the solution, it is evident, that the stone contained a certain portion of this alkali, and that this substance was the occa= sion of the loss I had in the first analysis, pa bo of — Sixty parts of alum however do not require seven of pot- bably not ex. ash, the quantity of loss; but as the stone is very siliceous, tracted, it is probable, that the whole of the potash was not ex- tracted by the sulphuric acid, though I boiled the stone twice in it. The speckstein thoretore 6 composed of Its true compo. nent parts, Silex «cece. Ce ereecccreccscoeres 5G Alumine--«..s. tee receneseseeerss WWD Lime coccecvcccsscscvscvecccesee BF Trotn' its «shes sa aie Pee eine tan RTE WHIRHEIMs: «n'y « wlstn'ss se hw wie ass oie ale 5 Potash scccccscccccccsccsccecves F 100 Klaproth Mr. Klaproth, im his analysis of speckstein, found no reckons too potash: but the quantity of water, which according to him much water. ? amounts to 10 per cent, and the loss of 27, which he ex- perienced, will just balance the deficiency I found. It is probable, that Mr, Klaproth estimated the water by com- putation, \ ANALYSIS OF SOME STEATITES. 175 putation, and not by direct. experiment; for, to whatever heat I exposed the stone, it never lost more than 5 per cent. - Frem the analyses here given it follows, that of the pitdstein shape varieties of talc here mentioned, two only must con- therefore an tinue to be so called; namely the laminar talc, and -the niacin compact rose-coloured talc. The third, the speckstein, should be removed to the genus of alkaliniferous stones. Tt is particularly remarkable, that those two varieties, Minerals which most resemble each other, and which have always “saat Ape been classed together, should now be separated by analysis: external cha- which shows, that minerals should never be classed accord- "¢***+ jing to their external appearance, since the most. striking analogies in this respect are the most deceitful. In fact, the speckstein and compact rose-coloured tale have the same softness, the same fineness of particles, the same fracture, nearly the same specific gravity; and cer- tainly, if there were any room to suppose, that one of the three substances ought to be separated from the talc species, we should be more inclined to suppose it the laminar, than either of the others. Note. On this occasion T analysed that species of talc thant known by the name of craie de Briangon, or French chalk, French chalks. and I found it to contain the same principles, and nearly in the same proportions, as the laminar tale, and the compact rose-coloured talc. These proportions were, Bs «a6 teiRiarbwikba Ss ecient end HORDE Magnesia wible BEE D6 cleo emns oo! DDS AV ateTee dale covecciecserteses. & Alumine --cseseeeceeseseeeccs 1 Oxideofiron---s-sesecessecces 1 UMC lec tt tween ge ghene es O75 Losseccrecererecssecores 3°95 ee 100 176, _ON THE CRYSTALS IN LAVAS. og WT AMA Gi Observations on the C) ystalttzed Swhstnces ineluded in Lavas: by G. A. Deer: det wy at Oo sures Various con- V otcanoxrs occupy such a striking place among ter~ ethos “ne, Testrial phenomena, that they have petdane the subject of causes and ef. numerous conjectures respecting their origi, their influ- pi of volea- ence; and the geological, consequences deducible from them. Wherever natural philosophers or geologists have imagined nie oe they might be called in to found a system, they have made “te to geoio- them act whatever part appeared most suitable to their pur- By: pose; sv that from a:simple, and solitary. fact,) single of its kind, and influencing only the ground occupied. by. the vol- cano and its vicinity ; and although . the volcano resembles only mountains ofits own kind,. and i ain no respect other “qnauntains,” either, ai ‘shape, constr uction,, or. component parts; they have nevertheless concluded, that: the strata and mountains on the sux face of the Earth owe their: origin | to the action of fire: fire, say they, daily exhibiting to us pro- ? ductions identical with the primitive rocks of our globe. Crystalsinlava _ Flence. itis, that these naturalists consider the different Pitcairn Pe ery stals included in lava, not as products i in the humid way anterior to the ‘Tava, | that, existed ‘i in the strata which the volcanic fires brought into a state of fusion, bat as crystal- lizations formed in "ene lava itself, and from “tg! ‘substance, by the slow refrigeration: of the mass.--.+: 9) 4 This the foun- On this.opinion chiefly is founded a4 sishis hich; Mr. te Saag Fleuriau de Bellevue has adopted, and lately .publishedt, system. respecting the action of the fire of volcanoes, and the for- mation of the terrestrial globe, its strata,-and its mountains. Simple state- This question, reduced to its most simple terms, is this: ment of the saci tion have the crystals included in lava been formed in the lava, and fiom its substance; or are they foreign to it, and formed anteriorly, in the humid way, in the strata or substances which the volcanic fire reduced to the state of fusion? And * Journal des Mines, No, 115, p. 5, + Journal de Physique, May, 1805, an ON THE CRYSTALS IN ‘LAVAS. D | 77 an exdmination of this question, deduced from the true state of things, and carried by facts to a degree of evidence that excludes all doubt, would decide one of the most im- portant poimts in geology, by exhibiting a just idea of vol canoes and their phenomena. ; The principal argument of Mr. Fleuriau de Bellevue is Crystals of glass drawn from the analogy he finds between the formation of bi ihe gi the crystals coritained in lava, and that kind of crystalliza- alg sti: tion, which has been called crystallites,'and is formed in the pots in glass-houses, when the glass that wasin fusion is suf fered to cool slowly. Let us now examine what these crystallites of glass- These crystals houses are. The whole mass of cooled glass exhibits a con- assay fused crystallization, all of the sanre tint, in which we see small compact bars confusedly imterlaced, some slightly striated, and others disposed in the form of stars, equally confused. At other times a number of threads are formed at the bottom of the pot, which cross and intermingle with each other, and exhibit likewise stellate figures. ~ In the first case these crystallites compose the substance of the glass, and are distinguished only in some places. In - the second we see at the bottom, through the transparent glass, these bundles of nets, and starry figures, which have some resemblance in shape to the little icy stars, that fall with snow in very cold weather. Perhaps some instances of more decided vitreous crystallizations may occur: but these, which are rare, only prove, that there may be some circum- stance favouring this crystallization in a very small space. Mr. Fleurieu de Bellevue conceives, that these crystal- These said to lite figures singularly resemble tremolite. This opinion, that ee. . wna there exists a striking resemblance between two substances, one of which is the product of a glass-house, the other of a mineral stratum, appears to me astonishing I confess; for but they have in this way there is no substance, which we may not reckon peepee similar to another, provided they have some similarity in shape, form, Thus we may say, that the capillary schoerls, or mineral byssus, resemble hairs; and that the fibres of the amianthus, or stone-flax, resemble those of flax or hemp; though these substances merely resemble each other in form, without there being any real similarity between them. Vor. XX.—JuLy, 1808. N This 178 Tremolite de- ° scribed. Cannot have been crystal- lized from fue SiGe Crystals in lavase ’ Several kinds of them, dif- ferent from ON THE CRYSTALS IN LAVAS. This remark was necessary, as it might be supposed, from. the expression singularly resemble, that it was something more than in appearance, and this not very close. The tremolite, which derives its name from the vale of Tremola near St. Gothard, one of the principal places in which it is found, is a radiated mineral substance, the threads of which, most commonly of a shining white, are united in sheaves or bundles. These bundles issue from a common centre, and diverge around it, which gives them the figure of a radiated star; and these centres being varie ous, they give different directions to the radii, which are from half an inch in length to three inches or more. This mineral substance is one of the most curious and pleasing to the eye. It is sometimes intermixed with tale and calca- reous spar; that is with two substances, one of which is vitrifiable but of difficult fusion, and the other calcinable: a circumstance of itself sufficient to exclude the least re- semblance between tremolite and the products of glass- houses. And if we compare these products with theslender and brilliant threads of the tremolite, each of which taken separately has the form of a quadrilateral prism, we shall be surprised, that they were ever compared with each other. The tremolite is vitrifiable; but it is not and_ never was vitrified. . Let us now turn our attention to the crystallized sub- stances included in lavas, to which the vitreous crystallites have been compared. ‘This comparison I am able to make on a great number of pieces which I have collected from burning and from extinct volcanoes. The lavas that include leucites, or white garnets, fre- quently include hkewise volcanic schoerls, augites or pyrox- each other,and ¢ties*, and chrysolites or olivines. Here are three spedies of from the lava, crystals, very distinct from each other both in figure and co- lour, contained in the same lava; enveloped in the same paste, which has no resemblance to either of them in nature, colour, or chemical properties, as will soon appear. ® J shall mention these in future by the name of pyroxene schoerls, because the denomination of pyroxene does ‘not belong to them exclu- sively, all the substances contained in lavas being equally py roxene, of strangers to fire. The ON “THE CRYSTALS IN LAVAS. 179 “ The form of the leucites and volcanic schoerls is perfectly Their figure determinate; there is nothing in it confused, but all is. bie orig precise and well marked. The leucite is constantly of a tained, round figure, cut with twenty-four trapezoid faces, and of a gray white colour. The volcanic or pyroxene schoerl isan octaedral prism with two diedral pyramids, of a deep olive colour, and sometimes black. The chrysolite has its peridot ‘ colour, and its three crystais are found in the cellular and spongy lava, as well as in the compact, ' The schce | is strongly adherent to the lava, so that it can= The schoerl not be de:ached, and appear with its faces polished and United to the angles entire, but by a chemical operation, the effect of the sulphurous acid fumes of the volcano. The leucite is Leucites more more easily separable, leaving impressed on the lava its ¢sily separa ted, leaving round form, with the shapes of its facets as clearly marked {heir imprege as they are on the leucite itself. Its impressions in the lava sion on the may be compared to those left by garnets, cubic martial aig pyrites, and several other crystallized substances, on the , rocks that include them; with this difference, that the im- pressions of the leucite were made on a substance in fusion, and those of the garnet aid pyrites on a rock that was soft from humidity. Hence we may draw this inference, that the leucites were Formed before no more produced in the lava at the time of its cooling, Papers. as than the garnets and pyrites were formed from the substance found in rocks, of the rock, which encloses them now it is dried and hardened. Both are equally foreign to the matter that contains them, - and existed before it; the leucites before the lava, and the garnets and pyrites before the rock in which they are im bedded. Leucites are also found separate, and in great numbers, among volcanic ashes. In this exact statement of facts, can we perceive any re= No analogy j between thes semblance, any analogy, between the crystallised substances ora the cryg- included in lava, and those confused heaps of vitreous crys- tals of glass. tallites formed of the substance of the glass in the pots ia glass-houses? or between those fantastic forms of cooled glass, and the crystals in the strata of our mountains, all of a constant and regular form, each in its kind? The pyroxene schoerls too are found separate, and somes Loose pyroxe times in multitudes innumerable. The crater that opened eres in great numbers on. N ~ IN Etna: 180 ON THE CRYSTALS IN LAVAS. in the base of Etna in 1659, which raised a cone 4300_ paces in circumference at its base, whence issued the enor- mous lava that we see in existence, and the bulk of which astonishes us, exhibits a singularly striking example. The thos* wthout summit of this crater 1s covered with these schoerls mixed hpi ns with small scorie; and this remarkable circumstance at- lava ; tends them, the schoerls on the outside of the crater have those within, all without exception retained on their surface a crust of a the lava that included them, while those within exhibit their . native polish. Thisaccounted I will here explain the cause of this difference, and I be- bes esate lieve I am the first who have attended to it. The sulphu- canicfumeson. rous acid fumes of the volcano penetrate and decompose the the crust. surface of the lavas and scorie, that are exposed to it; and the schcerls, which these fumes do not attack, then appear in relief, and entire throughout, being perfectly cleaned from the lava that surrounded them; as rock crystals, when they are covered, as they are sometimes, with a calcareous tufa, are freed from it’ by nitric acid, and appear with all their brilliancy. This operation proves, that there is no chemical affinity between the lava and the pyroxene schoerl it includes, since the one is attacked and dissolved, and the other is not. The effect of this is sometimes a pleasing sight, as it exhibits schoerls of all sizes, even microscopic, fixed on the lava, the surface of which has been decompo- sed, shining with their native polish and their angles per- feetly sharp. Sometimesthe It sometimes happens, that the schoerls themselves are pyroxenes — attacked, and their colour altered to such a degree, as to themselves at- 3 : : : tacked, appear like small crystals of sulphur, or still whiter. This effect is produced, no doubt, when the fumes contain a mix- ture of acids, that act on schoerl when combined, which they could not do separately: a chemical operation of which we have a well-known instance in the aqua regia, composed of the nitric and muriatic acids. Inthevolcanic + To these facts, which evidently prove, that these crystal- one rie lized substances were anterior and foreign to the lava in- united toa cluding them, I shall add asa superabundant proof a singu- ors ohio larity, found among the ashes that covered Pompeii, and ) now in my collection of volcanic substances. This is a so- litary ‘ Nicholsons Philos. Journal, VoUXXPU. 5 pee. ee Trreqgular production of the 7 i Wee * tf in, i. ies ey e igh eee wie ba ps soa nai" in i at pit we ce Sala anti wet Niutholsons: Philos, Journal, VoL AES UC. P00, ner ionoledp ‘ % pe aN a ‘ a Brent { > Ht ~ , Pare sy & vo i: ; f betas | ek alt se 2 x pa - = <4 = ; and = a Sako a e ‘ i ae eee oe oes 4 Pi shah = ay Bm eng nee . ae ie pent ze « ' : 5 ‘ eae J . 63 4d (agen wae Bd \ F i ab 8 a : ei shi BAT PO abe Bp a | 4 rh 3iey rt Ck ng wt - ha ced "t t + ‘ | yn Whi Bae dF pa: ite se sypier Ly ; Avid: Wastrvin 991-11 f t 4 | : a ‘a Pr iy i” ee hare ON THE CRYSTALS IN LAVAS. 18] litary leucite of three or four lines diameter throughout its whole crystallization, united to a schoerl, the greater part of the prism of which it embraces. This schoerl too is per- fectly crystallized, and each of these crystals retains its pro- per colour. It appears by some vestiges still adhering to the schoerl, that these two crystals were enveloped in a red- dish spongy lava. . This is not the only singularity I possess. I have another A leucite en- that caine from the same place, though not so well defined, Neil because it has retained more of the lava. This too is a leucite of the same size, perfectly distinct, and including a small groupe of schoerls, one of which is larger than the other two united with it. Are not these instances similar to those that frequently Similar to rock éccur to crystals of strata formed in the humid) way? to f™™stons- those green schoerls, or epidotes, we see included in rock crystals; those micas, those pyrites, included in the same kind of crystal; and this in its turn enveloped in crystals of calcareous spar: unions that indicate a succession of for= mations. The green schoerls, micas, and pyrites, have pre- ceded the rock crystal ; and the rock crystal the caleareous spar. We find also combinations of these three crystals in- cluding each other in the same order, whence this natural consequence follows, that the pyroxene schoerl preceded the leucite in formation. I would likewise remark, that spongy lavas exhibit in Leucitesinth | - their fissures leucites in part isolated, the greater part soli- a “ tary, but some in groups, as happens with crystals of all kinds. Is this the course, is this the appearance, of these confused heaps of crystallites of glass cooled in the glass- houses ? - We are not acquainted with any lava of Etna that con- No leucites in, tains leucites; or any of Vesuvius that encloses those ee af xen whitish crystalline laminz, which are so abundant in the crystalline la- lavas of Etna. This is a fact, to which the naturalist, that eee supposes these crystals to be formed in the lava, ought to yet both con- pay some attention. If the leucites were really formed in eas a it, why do the lavas of Etna contain none, while they are ites, d filled with pyroxene schoerls and chrysolites, which they possess in common with the lavas of Vesuvius? Is not this difference 182 ON THE CRYSTALS IN LAVAS, difference accounted for much more naturally by the ab- sence of leucite in those strata, from which the layas of : Etna proceeded? Lavas of He- - The same variations are observed in the lavas of different a, volcanoes. Those of Hecla, of which I have considerable specimens brought home by Sir Joseph Baaks, contain neither pyroxene schoerls, nor leucites, nor chrysqlites, but a great many small, white, cracked, crystalline substances, from the size of a grain of hempseed to that of a pea, of an irregular figure, having the appearance and hardness of and Mont- quartz, of which they appear to be fragments. The lavas d’Or. of Mont-d"Or, an ancient volcano.of Auvergne, contain large crystals of amphibole, or hornblende, and feldspar, which, show by their cracks and vitreous refiections, that they have experienced the action of incandescent lava; and.in, other ancient volcanoes in Auvergne we find pyroxene schoerls without leucites. Leucites in The smail gravel of the volcanic lake of Andernach, is shauna filled with loose pyroxene schoerls, whole and in pieces, ; Should we find in this state the coafused radu of cooled glass, which formed part of the mass, and could only. be separated from it in shapeless fragments? Eruption of Among the facts | adduced against the opinion of Six ola in James Hall, quoted by Mr. Fl. dé Bellevue, whose opinion, ne is the same, I mentioned a singular eruption of Vesuvius, that happened in 1754. © A mouth opened nearly at the le- vel. of the valley, which separates the present cone from, Grotto lined Mount Somma. At the rise of the lava this mouth formed: ne a grotto, which it lined by its spirtings with a quantity of scorize in a stalactitical form, the intertwined jets of which are from three to six lines in diameter, of a reddish colour, _ eontaining py- and full of blebs. In the fragments of these jets L have TOKENS, 7 found pyroxene schoerls in a state of perfect crystallization, and with their deep olive colour. These spirtings indicate, that the lava was in a high degree of fusion, and such sleny der jets must have cooled and hardened the moment nh were separated. a No slow cool: 44 We have here no slow refrigeration to form crystals, nor inghee. - yaass sufficient to give rise to crystalline forms by this mean; yet we find in these jets pyroxene schoerls, and for: | the ON THE CRYSTALS IN. LAVAS. 183 the most part even on their surface. Is not this a farther proof, that these crystals were preexistent to the lava? Mr. Fl. de Bellevue does not admit this conclusion : yet, if we attend to the fact, it will be found very convincing. The surface of the jets of this singular stalactite, and that Sublimed iron of the interior of the blebs, are covered with a multitude of peat shining points, which are perceptible only by the reflection jets. of the light. When viewed by a lens with a high magni- fying power; they appear to be very slender bundles of sub- limed iron,. I will mention another remarkable fact, the discovery o which required all the attention, with which I have exa- mined volcanic phenomena. The branches that separate from a stream, of lava, or the When lava lava itself when it is not abundant, break into fragments nar into be _at their extremity, which m this case have no progressive i eT motion, but by the flowing of these fragments pushed for- below redness, : 5 . : /pyroxenes are ward or to the sides by an impulse from the interior. These seen in it, fragments heaped up retain their heat a long time. This is seen when they are viewed by night; and felt in the day _by the heat they diffuse, as well as by the sulphurous and .mephitic gasses they exhale. These fragments broken off from the lava itself, which have not ceased for a moment to be red hot, exhibit at their surface pyroxene schoerls, I possess two such fragments, which I took from the spot myself, and which have several. What can reasonably be objected to so many facts? Yet I abridge the enumeratien of them. ‘* Mr. Salmon and Mr. de Buch,” says Mr. Fl. de Bel- Opinion of ' Jevue, “‘ have demonstrated, to all those who are acquainted sayings with existing volcanoes, that the erystals of leucite could att only have been formed during the slow refrigeration of the _ lava.” I am acquainted with existing volcanoes, of which I Contradicted. have just given proofs; yet from my observations I draw a quite opposite conclusion. The facts I have cited, which are true and exact, decide the question. With regard to the opinion of these two naturalists I Why should will add, that it sins in an essential point. What ground abkar - Gu is there for distinguishing the leucites frem the pyroxenemore than the schoerls the cysts * ~ 184 ON THE CRYSTALS IN LAVAS. schoerls and chrysolites, since these three crystals are found together in the same lava, separated from each other, and from the matter of the lava, by a line as clear and distinct as separates the small pebbles, that compose a pudding- stone, from the cement that envelopes them? If one of these crystals be foreign to the lava, so are the other two: this is a natural consequence. The fact assuredly is, that they are all three foreign to it. | Argument | The two instances I have mentioned of isolated leu- salen cites enveloping pyroxene schoerls are inexplicable facts, tion. on the hypothesis of these crystals having been formed in the igneous way: while nothing is more common, or more easy to conceive, than such combinations between crystals of different kinds formed in the humid way. | Pas ae I should never have done,” says Mr. Fl. de Bellevue, ral History. ‘¢ if I were'to bring forward all the objections, that offer themselves to the system of the preexistence of crystals in lava. -Several will be found at the articles Lavas and Leu- cites, im the new Dictionary of Natural History, in which Mr, Patrin has strongly combated these suppositions.” We should re- | am sorry to learn this, since the readers of that Dic- gard facts, not |. ; ; suppositions, tonary, who are desirous of knowing what lavas and leu- cites are, will be led into errour. JT have exhibited facts, and not suppositions. In the physical phenomena of our globe, the accurate knowledge of which depends always on matters of fact, I never was fond of suppositions, ing seldom fail to lead us into some mistake. ka + a ie Let me remind Mr, Fleuriau de Bellevue of a very re- cites calcined, Markable lava of the ancient volcanic mountain of Viterbo. | This lava contains a multitude of leucites from the size of a large pea to that of a rapeseed. These leucites have ‘undergone a kind of calcination, which renders them very white, and the lava that includes them is black, which oc- -casions a striking contrast between these substances. No- thing more strongly marked can be conceived. Now is it not evident, that all these leucites existed before the lava’? If we dispute this conclusion, we may as well deny, that any foreign substance whatever, included in a rock, has existed before the rock. J Leucites acted Leucite does not resist the action of volcanic fires and | vapours ON THE CRYSTALS IN LAVAS. 185 vapours im the same degree as schoerl ; as their effects upon upon by vol- it appear to be not inferior to those upon the lava. At least 1" ee none of the pieces I possess, that have been exposed to than schoeri, their action, afford any leucite in good preservation ; though it retains its characteristic form in the midst of red hot fava. When the heat is carried higher, it is capable of softening it, and occasioning it to undergo a sort of calci- nation. It then cracks, and the matter of the lava pene- trates these cracks in the leucite ; whence we perceive within it particles of lava, which are distinguishable by their black or brown colour, aud little blebs: but the form of the leu- cite is preserved, because, as the lava entirely surrounds it, no part of its surface can separate from it. This is the case with the leucites of the aicient lava of Viterbo; and on the piece in my possession there are several niches of leucites, with the impression of their facets. The lava and jeucites coming together out of the fires of the volcano, as the lava there must be more perfectly fused than when it flows exposed to the open air, and in its subterranean course must meet with narrow passages in which it is compressed, its matter must penetrate more easily into the cracks of the lencites, It has been said, that no leucites are found in lavas that Not easy to de- have flowed with rapidity, but that they are confined to i ae such as have flowed slowly. This is a mere ideal distinc- flowed slowly. tion: for by what signs can we determine, whether a lava haye flowed slowly or rapidly? I faney it would puzzie any man, to determine this with certainty: and besides, what change can the less or greater velocity or slowness of its course occasion in the substance of a lava? The following is a very remarkable fact related by Mr. Loose leucites Dolomiev. * Loose leucites are so abundant in the vicinity ound caro of Rome, that the road from Rome to Frescati may be said to be covered with them. The rain washes them away, and collects them in vast quantities in the ditches by the road+ side,” To this fact Mr. Dolomieu subjoins some conjec- tures respecting the origin and formation of the leucites, in which I think he is mistaken, though he is far from sup- osing them to have been formed of the matter of lavas. I have not seen this singular place, but I possess a pretty They come large 186 ON. THE. CRYSTALS IN LAVAS, from decom- large number of these very leucites, from the smallest size posed lava. +5 that of a little cherry. They must have come from spongy lava at no great distance, that has been decomposed. I have seen some of the same nature near Civita Castel~ . Similar ones Jana; the whole surface of which was spotted with a multi- Kal ie tude of white grains. Unfortunately, and to my great re gret, it rained very hard at the time, which prevented my alighting from my earriage. How ean we conceive, that the multitude of loose leucites at Frescati were formed from the substance of the lava that included them? They are a little transparent, and of a slightly yellow colour: is there in this any analogy with the colour or matter of lava? Indeed we might as well’ maintain, that the garnets in= cluded in a rock have been formed of the substance of that rock. Crystalssaidto Mr. Fl. de Bellevue imagines, that the crystals thrown ible out separately by the crater ‘* are new products, formed in the crater itself by a first cooling.” None but by _ Nothing is formed. in the crater, or to speak more accu- sublimation. ~ rately on its sides, but crystals of salts and sulphur by sub- limation; and never any crystal of solid matter like those contained in lava. The lava said Fo support this opinion he fixes two epochs: the first of » a of Moy which, according to him, takes place in the crater itself, A ie eruption, first cooling in the crater! But let us admit this supposi- tion. Thus we have a lava cooled and hardened: but from a lava come to this state none of the substances contamed in it could be separated so as to appear loose: for this it must be plunged again into the fire of the velcano; and would it not there enter again into fusion ? The crystals The erystals that are found detached on the cone of a merely thrown crater have been separated in the crucible of the volcano out by the ex- ; ‘ plosions. itself by the ebullition of the melted lava, and the jets of ‘Crater on Etna tts explosions, ‘The crater that opened on Etna in 1669 of 1669. exhibits a very instructive example. The very large cone raised. by this opening is covered with an innumerable mul- titude of pyroxene schoerls, all without exception covered by a slight crust of the lava that contained them, mixed among the small scoriz in which some are included. This lava cannot have been cooled for a moment from the first » imstant _ the successive impulses given by the matter that issues from: ) i ON THE CRYSTALS IN LAVAS. instant of its fusion; yet we here find a multitude of crys~ tals, that issued from the crater ready formed. Can these have been produced by a first cooling of the lava? The enormous. mass of this lava; that. issued from the foot of the cone, contains itself a prodigious quantity of these _ schoerls: ali their edges are distinguishable on the surface of the fractures. ‘This same ‘ava, and the jets of its explosions, exhibit another interesting fact. It includes, beside the pyroxene ‘ih schoerls, a plticude of small crystalline lamine ofa whitish colour, that have no regular form, and appear to be seales from some substance splintered by the heat. These laminee are found detached likewise, mingled with the schoerls and little scoriz. Can we discover here that play _ Of affinities, to which the formation of the crystals included ‘in lava is ascribed, since here is no regular form? Besides, ( the play of affinities can take place only when the mole- cules, on which they act, are at liberty to unite, which they cannot be, except in a mass perfectly fluid: and this is not the state of lava, in which it is asserted to occur. They are in fusion, no doubt; but it is a dull, heavy fusion, that has no progressive motion but on steep descents, or from the voleano, and pushes before it, while at the same time it spreads at the sides, that which preceded it. How can affinities be exerted in such a mass ?- The burning matters thrown up by the explosions of the crater, some of which are drops of compact lava, others fragments torn from the mass in fusion, contain likewise pyroxene: schoerls, which show themselves entire, whea these fragments have been exposed to the corrosive action of the vapours of the crater. This action is sometimes car- ried so far, as to reduce these fragments to a degree of soft- ness little less than that of dough: and the schoerls there being in perfect preservation, they are well distmmguished _ by their black colour on the yellow sulphurous tint of this paste, which acquires some consistency in drying, but is 187 Another fact respecting this Cannot arise from the action of affinity. Matters thrown up by the ex- plosions con- tain pyroxenes easily broken. I have collected several pieces in these dif- - ferent states, which are now before me. We cannot sup- Poses that there was a moment of first cooling in this case: since 188 EXPERIMENTS ON MOLYBDENA. since these pieces were thrown from the focus of the vol- cano, at the very moment when its contents were in the. highest fusion. . piso lai “One of the most natural ideas, that present them- should becom. Selves, to solve so many difficulties,” says Mr. Fl. de Bel- . with Jevue at the outset, “ must be carefully to compare the ose of art. : products of volcanoes, and the circumstances in which they are found, with the results of those large bodies of fire, by means of which man separates, dissolves, brings together, end combines minerals, and produces in them a change of Fhisdone. form.” This I have just done. I have compared the pro- ducts: of our glass-house furnaces with those included in Java, and the result ef my comparison is, that they are to- tally different. (To be concluded in our next.) Vs Experiments on Molybdena: by CurtstiAN FREDEBIC Bucuouz. (Continued from p. 138.) VI. Phenomena presented by molybdena exposed to the action of fire in contact with atmospheric air. Molybdena Fexp. 22. A Piece of molybdena in the metallic state, calcined. weiching fifty-three grains, of a moderate consistency, and an ashen gray colour, was put into a Hessian crucible, and the heat raised gradually. Scarcely had the heat reached a deep red, when the surface of the metal became of a brown- ish yellow, and soon changed to a fine violet, inclining to indigo, The metal being withdrawn from the fire and broken, its central part was still gray, and had undergone Oxided in dif- no alteration, From this nucleus to the surface the colour ferent degrees: poceeded in gradation throngh a yellow and brownish yel- low to blue. The metal having been again exposed to the same degree of fire for a sufficient time, it became entirely. blue; » EXPERIMENTS ON MOLYBDENA. 189 blue: but many precautions were necessary to attain this Blue oxide. result, because the surface passed very readily to a higher degree of oxidation, and quickly reddened. On this blue mass I poured cold water, which partly dissolved it; and by Dissolved in boiling I completed the solution, which was equally of a “7° blue colour. | When the crucible, in heating it more strongly, passed Exposed to a to a deep red, the metal quickly began to burn, putting on 8*te! heat. likewise a deep red appearance. At this degree of heat it kept its deep blue colour. The fire being increased, the metal was brought nearly te a white heat, and after cooling, its surface, te the depth of a few lines, was of a blueish white; nearer the centre it was of a blue inclining to vio- let; and the nucleus was violet inclining to brown, like the matter obtained in decomposing molybdate of ammonia by heat. The metallic mass, which had little consistency till the action of the fire had given its surface a white colour, became more compact and tenacious, so that it was diffi- cult to crumble it between the fingers. On urging the fire Acid formed. the whole surface became enveloped by the molybdic acid that was formed ; and this acid gradually increased in quan- tity, till at length it entered into fusion. These phenomena evidently imdicate different degrees of Difterent de- oxidation. The brownish oxide may be considered as the 8° Ot ne first degree. The violet brown oxide is very probably at the same degree of oxidation, as that obtained by exposing the molybdate of ammonia to a red heat. The blue oxide so- Iuble in water seems to contain a larger quantity of oxigen ; while the blueish white oxide may be considered as a mix~ ture of the blue oxide with white oxide, the last of which is probably nothing but molybdic acid, that fuses and sub- limes at a higher heat. Thus these different oxides may be Theig order. arranged in the following order: the light brown, the violet brown or violet, the blue, and the white. ‘Of these oxides the blue chiefly attracted my attention, Blue chiefly more particularly on account of the different manners, in etced. which it may be produced by oxidation and disoxidation, in . « the treatment of molybdena by acids, alkaline sulphurets, ‘metallic solutions, &c. 190 Experiments on this. Not so soluble as in the pre- ceding experi- ment. Residuutn. Heated again. N EXPERIMRNTS ON MOLYBDENA. Experiments on the blue oxide of molybdena. Exp. 23. Fifty grains of metallic molybdena powdered were put into a porcelain crucible, placed in a sloping di- rection on the fire, and heated till the surface acquired a blue colour. On first heating the powder became of a brownish yellow, which soon changed to a copper brown. This colour remained some minutes, till the crucible ac- quired a greater heat. The metal burned in a part where the crucible scarcely began to be of a dull red. Imme- diately on this I drew back the crucible, and kept it for a quarter of an hour exposed to a moderate heat, constantly stirring the powder. The brown colour thus changed com- pletely to a grayish blue, and the powder carefully collected and weighed had gained an addition of five grains, or one tenth. Having poured on it an ounce of water, and shaken it a few minutes, a very small portion only was dissolved. On keeping the mixture for two hours at a heat of 30° [86° F.] the solution assumed a deep sapphire blue colour, and a bitter metallic taste. Having decanted the solution, and poured a fresh quantity of water on the residuum, I proceeded as before, and obtained a very pale blue soletion.~ The residuum I boiled with two ounces of distilled water in a china cup till half the fluid was wasted; and when the powder had subsided, I had a fine deep sapphire blue solu- tion. The same thing took place on repeating this process. Thus the oxide formed in this experiment did not comport itself like that obtained in the preceding (Exp. 22.) where the blue oxide obtained by the calcination of metallic mo- lybdena dissolved in water completely. In this present case the blue oxide appears to have penetrated the rest of the mass, and prevented the whole from being oxided to this point, by which it bad become itself less soluble. The residuum when dried weighed twenty grams, and was of a dark gray inclining to brown, which led me to believe it was a mixture of brown oxide and metal. I then put it again into the cup, and roasted it cautiously; and im fact, as soon as I began to heat it, its colour changed to brown inclining to blue, till by degrees it became entirely blue. After having boiled it three different times with two ounces of EXPERIMENTS ON MOLYBDENA. 19% of water till half was evaporated, 1 obtained a blue solu- tion. Still I had a residuum of fifteen grains, which was Still a resi- of a copper brown inclining to blue. This I set aside fer the present, and made a trial with a large quantity of metal, in order to find a readier method of obtaining the blue oxide, Exp. 24. I reduced two hundred grains of metallic mo- Exp, 24. jybdena to as fine a powder as possible, and treated this as in the preceding experiment. A copper brown oxide was formed, which became blue on continuing the heat. When it was nearly of an indigo blue, with a tint of gray, and be- gan to burn in different places, I withdrew it from the fire, put it into two ounces of water, and boiled it till half was evaporated. A blue solution was thus obtained, and the re- siduum was treated three times in the same way. The last residuum had entirely lost its blueness, and acquired a cop- per colour: however, ! boiled it thrice more, and the solu- tion was still blue. This is an evident proof, that simple Boiling boiling in water changes the brown oxide into blue oxide, vans pes a and consequently that the latter is more oxided. blue. _. T now attempted actually to convert the brown oxide that Attempts to ' remained into blue oxide by continued ebullition in water, Cae ar tye _ and for this purpose I put it into a large vessel with sixteen one ounces of distwiled water, which I boiled till it was reduced to two. The solution was blue it is true, but not te such a degree as I expected from so long boiling. I therefore tried whether the brown residuum would not be more easily changed into blue oxide, if I merely moistened it and af- terward dried it repeatedly. This I did ten times; and each time I poured an ounce of water on the residuum, which I boiled for five minutes. The solution was still blue, and in this way I reduced the brown oxide to eleven grains. This mode of preparing the biue oxide is very trouble- Trials to pro- some, I was sensible of the defect, and I sought by several oe peat ia methods to find a better. I had observed, that, when a so- trouble. lution of molybdena in sulphuric acid is decomposed by an With sulphuric alkaline sulphuret, and that afterward a little sulphuric acid acid. is added, the precipitate, that was formed in the first in- stance, is decomposed, and a blue solution is produced. But 192 Could not be collected onac- ; count of its so- hubility. Blue colour destroyed by an alkali. Other acids turn the mo- ly bdic blue. Miuriatic acid. Could not be entirely sepa- rated. Most metals change the molybdic acid bine. 42 gers. of mo- ly bdena and 24 of its acid zn water form blue oxide, EXPERIMENTS ON MOLYBDENA- But T could discover no method of collecting the blue oxide in its pure state; for, after 1 had evaporated the solution of this oxide, [ could not separate the residuum, on account of its great solubility, either from the sulphuric acid, or from the alkaline sulphate formed by means of the sulphu- retted alkali. A portion of sulphur too remained in this residuum. It is true the alkalis separated a small quantity of oxide, when the solution was concentrated, but its solu- bility did not permit me to wash what was on the filter. I must observe too, that an excess of alkali destroyed the blue colour; consequently it is probable, that it occasioned a higher degree of oxidation. To eit the separation sought, I endeavoured to avail myself of the experiment of Scheele and other chemists, namely, that molybdic acid, when dissolved in other. acids, affords a blue liquor. The muriatic acid appeared to me most proper, on account of its volatility. Accordingly I dissolved two drachms of brown oxide, obtained by cal- cining molybdate of ammonia, in moderately concentrated muriatic acid. The solution during ebullition changed from brownish yellow to yellowish green, and lastly to a deep blue. I evaporated to dryness, and obtamed a mass of a dull blue, but I could not free it entirely from the acid that adhered to it. On washing it, it was partly dis- solved, and what passed through the filter, as well as what remained on it, contained muriatic acid. If I heated the blue mass more strongly, it became gray, and was deprived of its solubility in water as well as of its muriatic acid. After several unsuccessful trials varied in different ways, I was at length led to the object I sought by the consideration -of a simple fact, namely, that a solution of molybdic acid assumes a blue colour by the contact of most metals. I conceived it would be the same with molybdena itself, and that this metal, participating in the oxigen of the molybdic acid, would change it to the state of blue oxide. Exp. 25. In consequence I took twelve grains of metal- lic molybdena and twenty-four of molybdic acid, reduced the whole to a very fine powder, and put this into seven ounces of water. After standmg ten minutes the liquor assumed a blue colour, which grew deeper and deeper. On ; boiling EXPERIMENTS ON MOLYBDENA. 193 boiling for half an hour the solution was found to be much stronger than in any of the preceding trials; and on boile ing it a second time the whole of the acid and metal had disappeared, except two or three grains, being converted, into blue oxide. I was now desirous of trying, whether I could not obtain the blue oxide in a still simpler and cheaper manner, by employing the brown oxide obtained from the décomposie tion of molybdate of ammonia instead of metallic molybe dena. Exp. 26. A hundred grains of molybdic acid and eighty 100 grs. of acié of brown oxide were triturated together, and reduced to a ets a very fine powder. This powder being wetted, after some did the same, time a blue colour appeared, but much more tardily than Petal e when metallic molybdena was employed. After triturating | this mass. however for a quarter of an hour, the magma was very blue.. It was then boiled four times, with four ounces of water each time, and the whole was dissolved ex« cept a few grains. The solutions were blue. Several other trials convinced me, that molybdena in the metallic state acts more powerfully than the brown ox ide in converting molybdic acid into blue oxide. I found Molybdena too, that by long triturating a mixture of metallic molyb- cpiaeabed => dena and brown oxide, and adding water from time to time, into blue by so as to keep the mixture of the consistence of pap, the great- (oynvon = er part of the mass might be converted into blue oxide. 3 When the mixture was dry, I poured extremely pure Extraordinary water on it, when a smell nearly resembling that of oil of S™ell fom it. rosemary, faintly inclining to that of camphor, was very sensibly emitted. This is a very extraordinary circumstance; ~ but if any one should doubt the fact, I can appeal to the ‘testimony of Messrs. Trommsdorff and Haberlé, who were with me when I made the experiment. Perhaps the cause of this might be discovered by operating with a larger quan- tity of materials. Exp.27. I took all the solutions of blue oxide in pure The blue soly- water produced in the preceding experiments, poured them — nl into a porcelain capsule, and boiled them down to the con- sistence of asirup. As the liquor boiled it grew lighter coloured, till at length it appeared. of 2 deep steel gray ; Vou. XX—Juxy, 1808. 0 and 194 5 EXPERIMENTS ON MOLYBDENA. and after it was cold it resembled altogether a concentrated solution of acetite of copper inclining a little to blue, in other words, it was of a deep blueish green; it was of a metallic and bitter taste; and no precipitate was formed. The addition of a little muriatic acid appeared to restore the original blue colour. ‘This experiment evidently shows, that the blue oxide is capable of passing to a higher degree of oxidation by the effect of simple boiling in water; and that this degree of heat must if possible be avoided, when we wish to obtain blue oxide. Severa) other experiments, which it would be superfluous to detail here, taught me, that the following process is best adapted to produce a pure and permanent bine oxide. Best process for Take one ‘part of metallic molybdena and two parts of obtaining pure é ; . andpermanent pure molybdic acid {or three parts of brown oxide and four blue oxide. of acid), triturate them aconsiderable time in a poreelain or glass mortar, moistening the mixture with distilled water, either at the beginning or after it is reduced to a fine pow- der, so as to give it the consistency of pap. Continue the trituration with a moderate heat, till the matter is very blue. Then add eight or ten parts of water, and boil for a few minutes. After the liquor has stood a little while, filter it, and continue to triturate and lixiviate the residuum, till no more blue solution is obtained. All the solutions being poured into a porcelain capsule, they are to be evaporated at a heat of 30° or 40° of R. [100° or 122° F.], when the co- four will undergo no sensible change, and a very fine blue residuum will be obtained, which is soluble in a very Fvapcration Small quantity ef water, Care must be taken, that the mustnotbetoe evaporation does not go on too slowly; for I think I have ae observed, that in consequence of being in contact with the oxigen of the atmosphere, the blue oxide passed gradually to green, yellow, and lastly even to white molybdic acid. At least I have remarked these phenomena, when potash or am- monia was present in the blue solution. Means of pre This accident however may be prevented effectually, by Sich evista Jeaving a little metallic molybdena or brown oxide in contact 5 ‘ with the solution evaporated, till the liquor has attained the consistence of asirup. This will prevent the oxigen present — from producing a higher degree of oxidations 9 50. ; From EXPERIMENTS ON MOLYBDENA, 195 From the experiments on the blue oxide, that have been General re- related, we may deduce the following results. sults. 1. Several of the degrees of oxidation before observed have been confirmed, and some others discovered. Inthe experiments made on metallic molybdena I have frequently remarked, that its surface lost its splendour, and seemed to become coated with a gray matter. This is certainly a commencement of oxidation, and is Different the first stage : the brown oxide is the next: and this passes, oa oe as has been said, by boiling to the blue; which may likewise be produced by heating the metal, or by heating the brown oxide obtained by the decomposition of the molybdate of ammonia; and it appears, that the substance produced by these two different operations may be considered as identi- cal. After the blue oxide we have the blueish green, which may be produced by boiling the blue, or leaving it exposed _ some time to the air: and the contact of metallic molyb- dena, or the action of pure ammonia, will bring this back again to the state of blue oxide. Lastly the blueish green oxide passes to yellow, and afterward to white, which is the molybdic acid. The transmutation of the blue oxide into Alkali pro- the last two is singularly promoted by the presence of an PP oie alkali. 2. The white molybdic acid placed in contact with the Molybdic acid brown oxide, or with metallic molybdena, divides its oxigen converted to with them, and thus passes to the state of blue oxide. The siaiabale oi. blue colour, that molybdie acid acquires on the addition of a metallic solution, as remarked by Scheele, Heyer, and ~Tisemann, is an effect of a similar disoxigenation. Other disoxigenizing circumstances may occasion the conversion of the molybdic acid to the state of blue oxide, as for instance the passing of ammoniacal gas over it. -After having discovered these different degrees of oxida- Proportions of tion, it appears an object to ascertain he proportion of "shit ee oxigen to the metal in each. This I shall pursue with some inquirys other inquiries, when I have procured a sufficient quantity of the ore of molybdena. The principal subjects of my research will be the blue and the brown oxide, as they are the most stable, and are most easy to procure in large quan- tity and unmixed: but what renders them particulatly in- O02 teresting 196 ON INDIGESTION. teresting is, that they frequently occur in various operations on notin I shall confine myself here to a few of the Blue oxide acts principal properties of the blue oxide. 1. It comports | leer ec itself altogether as an acid. It reddens blue paper more than the acid Quickly and more powerfully than the white acid; and it itself, produces a brisk effervescence on combining with alkaline carbonates, with which it furnishes a blue solution. Wesee here a base combined with. a certain quantity of oxigen manifesting a stronger acidity, than when it contams a greater quantity of the acidifying principle; a very re- markable anomaly.. 2. This acidity still remains when the Blueish green blue oxide has passed to the state of blueish green oxide oxidealso acid. (which reverts to its former state on the addition of an alka- line corbonate). Its preparation shows its solubility in water, but I have not yet ascertained the quantity water will take up. Molybdena Exp. 28. The manner in which metallic molybdena com- converted into ts ; e blue oxide by Portsitself, when heated in the open air, has already been water atthe seen. Some phenomena, that occurred when I was ascer- ~ Se inconsiderable, they must be increased to 2°024 and 5°042 ackeantyiFaas for an imaginary planet of uniform density ; but since n is : : 3 Pe in reality about 53, and = nearly 3, the ellipticity must be to the primitive disturbing force only as 1 to & or 9 to 8, and the height of the sides in equilibrium °911 and 2-269 respectively, and the joint height 3:18 feet. And when the surface assumes any other form than that which affords the equilibrium, the force tending to restore that form is always less by one ninth than it appears to be when the attraction of the elevated parts is neglected. The theory of the tides must therefore be very materially modified by these consi- derations, although they do not affect the general method of explaining the phenomena. These calculations are also immediately applicable to the Ellipticity from figure of an oblate spheroid: for it may easily be shown, ee aie: 3 that the difference of the elevations in the opposite halves sity of the sue “of each semicircle is precisely the same in an oblate as in See -an oblong spheroid of equal ellipticity: so that the ellipti- city must here also be to the disturbing force, where it is greatest, as 1 to 1——, or to the centrifugal force at the ~ : 6 : equator as 1to2— =. Thus, the centrifugal force being zh» if the density were uniform, the ellipticity would be a yee’ 4s : 6 a7; but since it is in reality about +5, 2 —Z, = hh and nN s=ri"32, O1 A NEW COMPENSATION PENDULUM. m = 1°32, implying here the mean density of the earth compared with the mean density of the elevated portion of the spheroid, which heace appears to be about three fourths of that of the whole earth. It is obvious that, in this case as well as in the/former, if the density of the sea were two thirds greater than that of the earth, the slightest dis- turbing force would completely destroy the equilibrium, and the whole ocean would be collected on one side of the earth. TI am, Sir,. Your very humble servant, A. B.C. D. xX. Description of a new Compensation Pendulum; by Lieute- nant Henry Karer. Communicated by the Author. a deal Sin ‘CE the first application of the pendulum to clocks, Oe 7 numerous attempts have been made, to correct the errour clocks from arising from a variation of temperature, which, by contract- Bast see ene ing or dilating the substance of which the pendulum rod is oatapectti occasions the clock to go faster in cold than 1 in warm weather, and consequently to vary ‘considerably in its rate at different seasons of the year. Defe-ts of the The gridiron pendulum, now used in almost all regular giver P Mode of ad- justment. Objection to this compensa~ tion. Its advantages, The compen- gation may be divided. Advantages of this pendu- lum, NEW COMPENSATION PENDULUM. ried: adding this to one inch, the length of the spring by which the pedulum is suspended, we have three inches of steel; and the expansion of steel to zinc being as 147 to 1] 353, we have sl lsat = 1°25 inches nearly for this part of the correction. _ The deal rod will be about 44°5 inches long; and its expansion being to that of zinc as 49 to 353, we have BRAS Pig ly inches nearly for the length of zine neces- sary to counteract the expansion of the deal, which being added to 1°25 inches, before found, gives 7°42 inches for the whole compensation sought. . The adjustment is effected in the same manner as before described by means of the screw E F, by which the length of the zinc is either increased or diminished; and below the large weight is a smaller one, for the purpose of regulating the pendulum tothe greatest nicety. This small weight may have a tube of zinc attached to it, on the same princr+ ple as that of the larger, to correct the expansion of the steel screw, if it be thought necessary. The chief objection to this pendulum appears to be, that the compensation is partly enclosed in the weight, and con- sequently is not likely to be so soon affected by any sudden variation of temperature, as it would be if it were exposed to the immediate influence of the atmosphere. But it has the advantage of being much shorter, and far more simple in its construction, than the one first described, and is there- fore on the whole perhaps preferable. If it be thought more convenient, the compensation may be divided, and half placed between the weight of the pen- dulum, and the other half on the cock of the time-piece; and the nut for regulating it may be either above or below. _ Experiments in regular observatories can alone determine’ the relative merits of this pendulum; It certainly possesses the superior advantages of economy, simplicity, and ease of adjustment, and there appears every reason to believe, that it may be found at least equal in point of accuracy to any that has hitherto been described. * Exeter, April, 1808. - bai XI MULE CUCUMBER. © 991 Xi. Extract of a Letter from Mr. J, Aston of Ipswich, giving an Account of a Mule Cucumber, and other Objects. I Have taken the liberty of sending you a curious produc- Curious natural tion of nature, which was produced in the following man- sg ner; Mr. Chapman, the proprietor of very extensive pineries in this town, had growing in one of his hot houses a plant of the cucumis colocynthis (coloquintida, or bitter apple), ae which happened to put forth a male blossom a day or two impregnated a before it was removed into the open air. In the same house Common there were also growing some plants of the common cucum- ber also in blossom at ‘some distance from the other plant: It is supposed some of the farina was carried by a bee from the blossom of the coloquintida to a female one of those on the cucumber, which thus became impregnated, and pro- duced the fruit I send yous Mr. Chapman says he noticed the cucumber when about an inch and a half or two inches long, and it had every appearance of becoming a very fine fruit, but soon afterward it began to swell, and continued to . do so till the other day, when he gathered it and presented it to me. I had some thoughts of sending you a drawing of it, but, as I am a very indifferent botanist, it struck me, that you would not be able so well to understand its nature either by delineation or description, as by seeing the fruit itself. Mr. Chapman is an intelligent man, and has been for many years engaged in horticultural pursuits*. You will perceive it is what is called a mule fruit partaking of the nature of both the parent plants. See Pl. V, fig. 5. If you should be of opinion, that it is a circumstance worth mentioning in your Journal, I beg you will do it ia any manner you please, and in a way that you think will be most easily comprehended by botanists, to whom most pro- bably the communication will be found acceptable. * This Effect, I am informed is not unfrequent, and is ascribed to bees. Whole beds of melons have in some instances been thus spoiled. N. When 299 ON GRAVITATION. Pyriteson the = When I was in London you may perhaps recollect I men- en Har- tioned to you, that considerable quantities of iron pyrites were to be found upon the sea shore at Harwich. I have embraced the preseut opportunity of sending you a small specimen for your inspection. It would be curious to as- Seawater ap- certain the true theory of its formation. From the little = pik ae observation I have had an opportunity of making, | am per- en, converting suaded its formation is considerably aided by the seawater. wood, &c. into pieces of wood, bone, &c. become converted into it by time, pytites. 5 AANA and lose every trait of their origin, except the shape of the grain, which in many specimens is nicely preserved. The cliff above the shore appears to be almost entirely composed of a blueish soft clay, which is continually crumbling and falling down upon the beach, and is washed by the waves, and I think a curious observer conversant in mineralogy might easily trace the formation of the pyrites by gradation from the clay, as pieces may be found in several different states, - and it appears to be influenced by the alternate action of the air and sea water, but in what way I am entirely at a loss at present to conjecture. . Ipswich, 6th of June, 1808. XII. Letter from Professor Vince, in Reply to Dytiscus. To Mr. NICHOLSON. SIR, Two mistates I Shall esteem it a favour, if you will insert a few remarks asians on the observations of Dytiscus in your last Journal, en- Dytiscus. gaging not to trouble you again on this subject. In the first paragraph there are two unaccountable misre= presentations, for I would not charge Dytiscus with doing it wilfully. He says, ‘‘ the two first terms of the series very possibly allude to the two first terms of the on/y Two series which are to be found in the essay, these two terms having been already mentioned as sufficient for determining the force.” Now 1| have put down the first terms of THREE of the ON GRAVITATION. 23s the series, with + &c., meaning, of course, that the other series and terms were to be supplied, as I before remarked, and which it is strange Mr. D. should have forgotten, And secondly, I have never mentioned, nor was it possible I could mention, that the two terms alluded to are sufficient to determine the force: a further proof with what little ate tention Dytiscus has read the essay. g Bi pits . | a ~ Again, he says, “the series — 4 —-+ = + &c. may cer- Anassertion of ee REE his erroneous, lie ie fainly vary as —, if all the Greek letters after the first be- come inconsiderable, and our author has virtually confessed in his essay, that they do become inconsiderable.” The se- : 4 1 Sipe ries certainly can not vary as—-- The quantities 6, y, &c. a? _ are very small, but still finite, and can only be rejected in an approximation to the law of force. The law of gravity . 1 , . varies accurately as —-, and the series can never give that p law, as I have proved in Art. 11. Farther: “« As to the difficulty of extending the law to Another con- the internal parts of the sun’s substance, it is perfectly ob- “44 vious, that the law of density, as well as that of the force, must be supposed to change at the surface of every material body, long before = can become equal to P.” Wot per- fectly obvious. When we discover sudden variations of the laws of nature, it is not that the primary cause is necessarily altered, but that some of the circumstances under which it acts are changed, as in the present instance, Without con- sidering the cause, we know, that the attractions of every two particles of matter composing the sun’s body vary in- versely as the squares of their distances, and at the same time constitute a whole force, which, to a body external to : 1 , : the sun, varies as —, and to an internal body, as a. It is a not therefore necessary, that the law of attraction of the constituent particles should vary, in order to produce these different laws of force. According to Newton, any two par- ticles 224 which would involve New- ton ina contrae diction. Chronometers have been greatly im- proved, IMPROVEMENTS IN CHRONOMETERS. ticles of matter, either both within a body, or one within and the other without, tend toward each other by the same law of force, and therefore the cause of that tendency, that is, in our present consideration, the variation of the density of the fluid, must in both cases be regulated by the same law. If we were to admit the position advanced by Dytis- cus, it would involve Newton in a contradiction, and instead of affecting the truth of my proposition, would further tend to confirm it. To change the law of density émmediately, would be to substitute two fluids instead of one, such a change necessarily implying a change of the fluid; for what better criterion have we of different fluids, than that their constitutions are regulated by different laws? To defend his objections, Dytiscus makes an assumption totally incon sistent with Newton's hypothesis. . I do not think it necessary to make any farther remarks on the observations of Dytiscus, and I must make an apo- Jogy to mathematicians for having said so much; but I was induced to do it upon this consideration, that they might not mislead those who are ignorant of the subjeet. Iam, Sir, Your obliged humble servant, Cambridge, 9 June, 1808. S. VINCE, XIII. Certain Improvements in Chronometers, by Danie, DeRING Martnew, Caius College, Cambridge. In a Letter from the Author, SIR, Tae degree of accuracy, to which chronometers have been brought within these few years, may appear to be the utmost to which, in a machine so complicated, human art could extend; but as navigation has derived great advan- tages from improvements made in them, I have been tempted to make some alterations in their construction, the ws : | superiority IMPROVEMENTS IN CHRO NOMETERS. 9295 superiority of which 1 leave for your candid readers to de- cide. The principle of Mr. Mudge’s free escapement (see 4to Mudge’s seapee- Journal, vol. ii, p. 56) is, I believe, allowed’to be the best ™*"t- “that was ever offered to the public; but its performance has” not | been found to be superior to the others, most 1i kely ‘on account of there being so many pivots and springs, and on account of its tripping, whence it cannot be depended upon. Mr. Arnold says, be has made his pendulum spring Arnold's. so, that the vibrations are performed in the same time when the main spring is weak, as when it is strong. This pér- haps may be in some degree accomplished by very fine workmanship, and a great many trials, but the main spring is not detached from the balance; and on this account I think the title of being detached is not correct, as the main spring keeps up the action of the balance. My alterations and improvements, if I may so call them, Principles of consist, Ist, In reducing the wear and friction of Mr, ‘he author's. Mudge’s escapement, and putting it into a more simple form. _@dily, In applying my equalizing maintaining powets im ‘.such a manner, that tension does not alter their strength. ' Sdly, In securing the locking of the tooth against the de- tent. 4thly, In stopping the holes with hard platina. For these purposes I have two escapement wheels, equal Description of and similar in all respects, as seen in Pl. VI, fig. 1. a@ A, it. 6B, cC, dD, e E, f F, represent the teeth of the two wheels, which are so placed, that the tooth A of the upper wheel is exactly between the two teeth a6 of the lower whee]. "These teeth are prevented from revolving round ‘by 7 the two detent pallets GH, which turn on a pin, and con- centric with these detent pallets the pivots of the verge turn, which is in the form of a crank as at M, or more plainly at fig.2. y y are two joints at the ends of each of the arms of the pallets GH, in which the pieces x x are screwed, so as to allow a free motion. These pieces are - fixed to the ends of two springs K L, which are made simi# lar to the main spring in a gun lock. Each of these springs turns upon.a stud m, as seen at K, fig. 3; and the spring is made stronger or weaker by the regulating screw n. The stud m is made of brass and the screw is steel, = VoL. XX.—JuLy, 1808. ~ Q * the 2. }ts, manner of acting. Sin IMPROVEMENTS IN CHRONOMETERS. the greater expansion of the stud will in some measure counteract the alterations of the ne by heat and cold. N N is the potance. The action of the escapement is thus. The wheel being propelled by the main spring in the diyection of the arrow V, and prevented from revolving by the detent of the pal- let H, the balance by its vibration knocks out the detent at d, and at the same time the tooth E raises the pallet G, till it comes to its detent. In the mean time the balance carries the pallet H through its semivibration, and is fol- lowed back by the pallet as far as the rim of the wheels between the teeth de, this gives the balance force sufficient to knock out the detent of the pallet G, and the same ac- tion and reaction will continue so long as the moving power acts. To prevent any estan of the wheel tripping, I put two _ banking pins as at g on the arm of each pallet, hah: pre- Advantages of th.s scapement. Objections an- swered. vent the pallet from going farther back than is necessary to allow the tooth to raise up the pallet to its detent, by means of the catches p p, the end of which is a fine tender spring ; and I make a circular piece to project out from the catch, so that the crank in its vibration first raises up this catch, and keeps it up while it knocks out the detent. Having explained the action of my scapemeut, I will now state a few of the advantages, which appear to me to arise from these alterations. 1st. By making use of a double wheel, I not only reduce the wear of the teeth, but I can in this way place my detent pallets and back springs so as not to interfere with one another, and I can have the pallets to turn upon the same centre. 2d. Straight springs are al- ways preferable to a spiral one, where they can be used, because they are not so dificult to make, and their strength can be altered by adjusting screws, which cannot be done when spiral springs are used. Another advantage pained by using straight springs is, that the compensation may be put to the springs themselves, which is preferable to a compen- sation on. the balance. In using a gun lock spring, the pressure of the tooth against the inclined plane is equal, and will therefore wear _the face of the pallet equally. I am aware, that many objections _ON AMBER VARNISH AND ACID. 2907 objections will be made to these springs on account of there being so many joints; but as there must be either the rub of the spring up and down the back of the pallet, or a dou- ble joint: the latter method is certainly preferable to the former. In Mr. Mudge’s watches, the adjusting of his auxiliary Defect in spring to prevent tripping was one reason, why they fre- Mudge’s, quently stopped ; for when clean, the main spring was ad- justed just to raise up the pallets to their detent, and there- fore; when the oil got more tenacious, and the works got dirty, the main spring had not power to raise the pallet ; the consequence of which was, the watch stopped. The pendulum spring ts generally allowed by workmen Pendulum to be the most difficult part of a chronometer to make and ‘Pts. adjust well. The two back springs answer the purpose of the regulating power, as well as the maintaining power. As platina is the closest grained metal we have, and it Preference of can be drawn very hard, I prefer stopping the holes with Platina. it. It burnishes very fine, and oil has no chemical action on it. If you think these improvements worthy a place in your Philosophical Journal, by inserting them you will oblige Your sincere friend, DAN. DERING MATHEW. XIV. Observations on the Possibility of collecting a certain Quan- tity of Succinic Acid, during the Preparation of Amber Varnish, without any Injury to the Quality of the Varnish: by Mr. Puancue, of the Society of Apothecaries, Pa- rts *. Havine had occasion lately to assist in the fabrication gyccinic acid of a large quantity of amber varnish, I remarked, that sublimesin Sains ‘ i be during the process, and till the heated substance had ac- abe 4 pipe: * Annales de Chimie, vol. XLIX, p. 40. Q 2 quired 928 ON AMBER VARNISH AND ACID. quired the proper degree of fluidity, a great deal ‘of succi- nic acid was given out. No advantage ‘Every person, who has ‘made it, must have had’ the op- Osea 7 portunity of observing the same thing; but whether from not knowing the true nature and properties of this salt, or from considering it as essential to the goodness of the var- nish, no one, at least that I know of, has thought of turn- Amber in var-tug it te advantage. It would be a mistake however to =a ead conclude, that good varnish ought to be free from succinic prived of its acid: on the contrary it is very probable, that at the time =e when the drying oil ‘and oil of turpentine are added, to in- crease the fluidity of the amber, this substance js still capa- ble of furnishing it, and even im some quantity. Much of the ‘I’should be wandering from the purpose of this notice, if Sena Fwere to detail the various processes employed for the pre- of making. paration of this varnish. I shall only say, that, as the process is most commonly conducted on an open fire, and in an open glazed earthen vessel, the mouth of which is four or five inches in diameter, when the matter is suffi- ciently heated, part of the acid set free is carried off and Yost inthe air, while a tolerable quantity adheres to the sides of the matrass in ‘the form of very slender: needles, . sufficiently white ‘to require no ‘purification *. Viib. of amber Every matrass contaming 24 0z., which is the common 90 g's. of acid quantity, may furnish 80 or 90 grains of acid, without any without detri- lajury.to the quality of the varnish: a fact of which I have a satisfied myself by several trials made in my own labora- tory, as wel] as in that of Mr. Tonnelier, coach painter, Propér time of who is well skilled in the subject. It is proper to observe collecting it. here, that we ought to collect the succinic acid as it is sub- limed, which takes place a little before the addition of the oxigenized or drying oil. If this operation were deferred, the greater part ‘of it would be lost. In fact, the motion - of the spatula necessary to mix the oil with the ‘amber would separate a great deal of the acid: and there is no Acid pure in a * The acid obtained is sufficiently pure when the vessel is new, but new vessel. _—it is more coloured in subsequent operations. It may then be purified according to the method indicated by Pott. The artists who use cops per matrasses will find an advantage in it, for these vessels being more easily cleaned, they will continue te #-mish the same product. hope Copper best, ON AMBER VARNISH AND ACID. 999 hope of collecting any after the oil of turpenti».e is added, as this oil, partly converted imto vapour by the heat of the mixture, so as to make it swell up or even boil over, occa- sions the acid to disappear entirely. ‘However minute the means I have employed for collect= Method of do- ing the siccinic acid may appear, I think it indispensable oe ee to describe them. At frst I thought of taking it off with a card. This answered pretty well, but there is danger of burning the fingers, if from inattention they should: pom: the geated matter. I found a much more convenient in- Instrument de strument was a tin spoon, made as represented in Pi. VI, St where fig. 4 is a side view of it, and fig. 5 a front view. + This spoon differs from others only in the form of its bewl, whichis but, little concave, the front of it forming a seg= ment of| a circle, and adapted to the size of the matrass ; which is represented at fig. 6, but on a much smatier scale, not to occupy too much room im the plate. The bowl of the spoouw is terminated behind by a thin plate of. iron, which rising a few lines above its edges forms a sort of neck, and to this is jomed a handle of the same material, stxteen inches long, forming. a right angle with the bowl, The shape of this spoon appeared to me the most convenient, be- cause, Ist, as it adopts itself accurately to the sides of, the vessel, it prevents the sublimed acid, which is scraped off . by drawing up the spoon, from mixing with the melted am- ber: and adly, it allews the operator to collect it without be- ing incommoded by the vapours emitted. From, what has been said it appears, that artists em- Vamrish makers _ ployed in making amber varnish, without, any alteration in TARR PUES! B their usual processes or apparatus, may farnish us im future quantity of the with a pretty large quantity of succimic acid, which. has 2¢i2. hitherto been confined to medical uses, but may soon. be found beneficial in other arts. Some trials already give Useful for imi- _ me room to hope, that its solution in aleohol may be em- ame ployed. to imitate the colour of some valuable woeds, ~ Ch ANALYSIS OF DIABETIC URINE. XV. An Essay on the Saccharine Diabetes; by Messrs. Duruy- TREN and THunaRp. Abridged by the Authors. Urine changed Ir has long been known, that the nature of the urine is so in diabetes; much changed in the disorder called diabetes, as, instead of - being pungent and in small quantity, like that of a healthy person, it is on the contrary saccharine and very coprous. but its analysis The first attempts at its analysis however are not to be dated ar farther back than thirty years. For this three reasons may be assigned: first the rarity of the disease; secondly the little certainty of the chemical means of analysis formerly employed; and thirdly the common neglect of animal che: mistry. Sugar demon- a It was not till 1778 that the existence of sugar in diabetic strated in it. urine was actually demonstrated. This discovery, made by Cauley, and confirmed i in 1791 by Franck, was conjectured by Willis in the beginning of the 17th century, and in some measure perceived by Poole and Dobson. But'it must be confessed, that Cauley, attending only to the saccharine mat- ter of this sort of urine, left much to be desired. It was necessary to inquire into the other principles it might con- tain, and particularly those that enter into the composition of healthy urine. ‘This was done in 1803 by Messrs. Nico- General state las and Quendeville of Caen. From their researches it ap- soma pears, that diabetic urine contains no sensible portion of uree or of lithic acid; that the most sensible tests scarcely indicate any traces of phosphate or sulphate ; that it is im- possible to discover in it any free acid; and lastly that we find in it only a large quantity of sugar with more or less common salt. Objects of the Our object in this essay is not merely to confirm the’ re- sorrnee. sults we have mentioned, but farther to make known 1. The medical observations we have made on the patient, whose urine we analysed ; ® Annaleside Chemie, vol. LIX, p. 41, 2, The . AN ALYSIS OF DIABETIC URINE, CSt 2. The very peculiar nature of the saccharine substance we found in this urine: and ; 3. The various changes this urine underwent before it was brought back to its primitive composition. Parr I. Observations made on the patient, whose urine Observations ; . on the disease. we examined. From these observations it follows; 1. That the saccharine May continue diabetes may continue several years, and even as long as sgn Sa the digestive powers can maintain themselves, and supply the excessive waste occasioned by the urine. 2, That this disease 1s not incurable at any period, not Curable at any eyen when the impaired digestion appears unable to supply Bee the materials of the secretion that exhaust the animal eco- nomy. ‘3. That the seat of thie affection appears to be im the Itsseat the kid- kidneys, not in the intestinal canal. ait han In fact neither the appetite nor thirst of a diabetic patient is any way depraved: they both, as well as the digestive » powers, appear merely to be proportional to the want of re- paration; in the next place the aliment undergoes the same preparation in the stomach of a diabetic patient as in that of aman in health; and what completely proves, that the digestive faculty is not altered, but simply increased, in diabetic patients, is the quantity of food they take, the quickness with which it is digested, the large proportion of it conveyed into the circulation, and the small quantity of feces to which it is reduced; and lasily, from the digestion of: the food till the secretion of the ure, we find no fluid at all saccharine, or that has under gone any. change in its joe aie _ 4. That the cause of the saccharine diabetes appears to {ts cause their _be an increased and depraved action of the kidneys; that Scere the saccharine matter of the ure is produced in conse- : quence of this action; and that to it all the symptoms of the disease are to be traced. | 5. That the excessive loss, which takes place in this Superficial ab- q sorption in- creased. - disease, seems under some circumstances to occasion pretty considerable absorption at the surface of the body. 6. That the new proportions established by the saccharine gecretions af- diabetes > ~ O35 ANALYSIS oF DIABE TC URINE. fected as by | diabetes between the food and the secretions in ant and 1s ag between their several kinds in particular, are analogous to those occasioned by any evacuation in excess, whateyer its nature may be. | Dr. Rollo’s 7. That the mode of treatment recommended by Dr. ae PeNL ine Rollo, and since so successfully employed by our country 1bD1ic men, Messrs. Nicolas and Quendeville, and which consists especially in a purely animal diet, is as effectual as the bark in intermittent fevers. Does not alter 8. Lastly, that the saccharine diabetes produces no change thestate of the in the state of the organs, but an exertion of the digestive ote and urinary organs, both of which are in a state of great activity during this Seas: one to prepare and the other to expend the materials of nutrition. Analysis of the Parr Il. Analysis of the urine of a diabetic patient, from ene. the fifteenth day after his admission into the Hotel Dien, till he left that place jor the vee of the Medical School. Itsappearance. This urine, very remarkable for the largeness of its quan- tity, emitted a smell, that was not disagreeable. It was limpid, perceptibly yellow, of greater specific gravity than water, and scarcely reddened infusion of litmus. Its taste was slightly saccharine, and at the same time it had some- thing of that of common salt. Changoby . Left to itself at the temperature of 18° [59° F.], it be- Keeping. came turbid in five or six days: bubbles of carbonic acid gas were disengaged on the slightest agitation: the urinous smell it had at first was gone, and it had acquired a smell resembling that of newly made wine: it likewise afforded alcohol by distillati tion, and became very sour by exposure to the air, so that it exhibited i in a slight degree all the marks of a spirituous | fermentation, _, Distilled i in a retort, or evaporated i in a a capsule, the phe- Di aglled. nomena it exhibited were ‘the same. Ii did not become tur- 27 Nr. eenehines Ate) to a enor. sometimes to a twen- tieth, and never to less than a thirtieth of its weight. From the, urine we examined we thus obtained near thirty pounds of sirup, which on cooling always dried into a mass, com-~ posed ANALYSIS OF DIABETIC URINE, 233 posed of a multitude of small grains void of consistency, These soft granulous crystals being scarcely sweet, it was natural to suppose, that the substance which formed them was not homogeneal, and included but a very smal] quan- tity of the saccharine principle. To ascertain this the fol- lowing experiments were made, A hundred parts of this substance were distilled in a re- Saccharine tort, the neck of which entered into a receiver kept con- ™tter dis- stantly cool, The products were a great deal of water, but 66 little oil, no ammonia, a larger quantity of gasses that were but slightly fetid, and a tolerably bulky coal, easy to in- Cinerate, and when completely incinerated: yielding two parts and half of common salt, and half a part of phosphate of lime. : From this result we may deduce the following consequen- General con- ces: 1. that this substance contained no animal matter, since clusions. - it yielded no volatile alkali on calcination: 2. that it con- tained very little saline matter, since when reduced to ashes it afforded only a residuum equal to a few hundredths of its weight: 3. that it was formed of vegetable principles, since it afforded all their products on distillation. Presuming ‘sugar to be one of these principles, and not Fermented being able to form any conjecture respecting the nature of with water aad shoe with which we considered it to be mixed, we deter- 7°** mined to have recourse to fermentation, to destroy the first . without altering tne others, so that by filtration bee evapo- ration we staph obtain them very pure. We put into a large Jay 100 gram. [1544°5 grs.] of the substance to be analysed, 25 gr. [386-125 grs.] of yeast, and 500 gr. [7722°5 grs.] of water: to the tubulure of this jar we fitted a tube terminating under a jar filled with water: and the tem- ‘perature being raised to 18° [64°4° F.], the whole was left to itself. Some hours after these matters had been thus left together, a movement was apparent in some parts of the fluid, which soon became general. A great deal of floccu- lent matter, from which a considerable number of bubbles issued, was raised up, and carried to some height in the fluid. These bubbles passed rapidly into the jars filled _ with water, but the flocks fell to the bottom of the vessel, and, giving birth to new bubbles, rose again, to be precipi- tated 234 Fermentation ‘active. Carbonic acid evolved, alcohol pro- duced, and a residuum left. Resembled su-, gar in its pro- ducts, and its habits with reagents. Yet differs from sugar in taste, Different spe- cies of sugar, Manna fer- mented with yeast and wa- ter, Fermentation brisk, but soon over, Left asweet ynatter incapa- ble of fer- Menivg. This mater examined, of the faculty of fermenting. \ x ANALYSIS OF DIABETIC URINE. tated as before. This phenomenon, which did not cease for three days, indicated a very active fermentation, and conse~ quently the presence of a large quantity of saccharine prin- ciple. In fact near thirteen quarts of pure carbonic acid gas were evolved: the liquor.was very spirituous, and con- tained near 48 parts of alcohol at 40°: and on evaporating to dryness only 23 parts of extract were obtained, formed of 3 parts of seasalt, and 20 parts of a brown viscous matter, Now we know, that 100 gr. [1544°5 grs.] of sugar pro-~ duce 12 gr. [185'34 grs.] of a similar residuum, 56 gr, [864°92 grs.] of alcohol, and 36 gr. [556°62 grs.] of carbo- nicacid., “The substance obtained from diabetic ure there- fore gave us by fermentation the same products, and nearly in as large quantity, as the best crystallized pure sugar: and if to this we add, that with nitric acid, alcohol, and other reagents, it comports itself like sugar, we must neces- sarily consider these two substances as being in some mear sure identical, woke Bey -We must recollect however, that it is scarcely sweet, and © that at any rate it is much less so than sugar. Hence we are led to conclude: 1. that, as chemists have lately begun to imagine, there are different species or varieties of sugar: for here the differences are so striking, that they must con- vert to a certainty what was only probable. But as the taste is not a certain mdication of the existence of the saccharine principle, it became necessary to inquire, whether, among the substances that have hitherto been confounded with su- gar on accountiof their taste, there were not some, that dif+ fered from it essentially. We were thus led to examine manna. Our first care was to mix it with yeast and water at the temperature of 18°[64-4° F.], and observe with atten- tion all the phenomena arising from thismixture. The fer- mentation quickly took place: it was at first brisk, but soon abated: and at the expiration of two days it was at at end, The liquor however had a very strong vinous smell; but, far from being spirituous, it was on the contrary very saccha- rine; and on evaporation it deposited in the form of crys- tals almost all the matter that had been employed, divested Though persuaded -by these results, that manna contained but ‘ ANALYSIS OF DIABETIC URINE. 935 “puta very small quantity of sugar, we still deemed it ne- cessary, to compare it with this substance in all its proper- ‘ties, in order to place the fact in the strongest light, and thus discover all the characters proper to the peculiar pria- ciple, of which it appears to be almost wholly formed, For this reason we examined the action of alcohol on it, which does not attack the saccharine principle, and that of nitric acid, which does not convert any portion of this principle into mucous acid; The first of these reagents, at the tem- fot alcohol perature of 0° [140° F.] dissolved so large a quantity of Sbhsteyd of manna, that on cooling it formed a mass of crystals in tiny spre _» groups,’ the crystals in bath group issuing from a common cooling. centre. The second produced in it by long continued boil- Nitric acid con- ing such a large deposit of mucous acid, that the weight plese was nearly equal to half that of the manna employed. | ~ Here then we have two more characters, that stnikin$ly These charae- distinguish sugar properly so called from the peculiar prin- ters distingu’sh ciple of manna. Sry | ARIE ~ No doubt farther research would exhibit many others and perhaps more or less striking; but as those we have related are suf- others. ficient, to make those two substances be considered as per- fectly distinct from each other, we did not think it neces- sary to push our examination farther, Hence it follows, that it will always be an easy matter to This principle discover and to separate manna, or rather the pecutiar prin- cae ng ciple of manna, whatever be the substances with which it is cohol, mingled. All that is necessary is to treat the matter con- taining it with hot alcohol, and it will be almost entirely precipitated by cooling. Indeed there are other vegetable substances, that possess this property even in a striking de- gree; but as these substances are found only in this class of acids, it is always practicable to deprive it of these, by com- bining it with an alkaline or earthy salifable base, or a me- tallic oxide, according to the nature of the acid; and con- sequently this mode "se separation may be generally em- ployed. ’ Thus we may ascertain, whether the honeydew observed tioneydew ? on the leaves of certain trees, particular ly those of the line, be really a species of manna; and if it be the same with aq saccharine the saccharine prince: iple that exists in asparages, apd which principle in as- Messrs. Bre 236 ANALYSIS OF DIABETIC URINE. Messrs. Vauquelin and Robiquet have found there mixed. with a peculiar principle. Parr Il. Analysis of the urine of the diabetic patient, from ‘the time of his admission into the hospital of the Medica? School till he quitted it. Medicine with- During the time the patient was m the Hétel-Dieu, he ri" a ie could not be confined to any regimen. He lived nearly as entheurine, he pleased ; his disorder remained stationary, and his urme, which was still very abundant, had not altered its nature. It was then determined, to remove him to the hospital of the Medical School, where, being almost always under the eye of Mr. Dupuytren, who had the care of him, or of some one of his pupils, it was much more easy, to oblige him to do whatever was desired. Vegetable food At the expiration of a few days all kinds. of vegetables being withheid Were refused him, and nothing was given him but animal food, The quantity of this he took, as well as ef what he ‘ _ drank to satisfy an unquenchable thirst, was accurately weighed. , For the first three or four days no change im the urine ima few days a was observed ; but in five or six it was less white, more ee: vee acrid, more acid, and: less saccharme. Subjected to eva- poration, instead of remaining limpid as before, it became Albumen ap- turbid, and was covered with a tolerably thick pelliele of Raieg ineity albuminous matter. When I perceived this change, par- ticularly the presence of animal matter in his urine, though the state of the patient was completely unknown to me, and J was unacquainted with the manner in which he had been treated, I concluded, that the disorder had begun te and increased abate: and then finding, that this animal matter became mn quantity. daily more abundant, i ene ed the cure as approaching. Mentioning my opinion to Mr. Dupuytren, he said it was probable, but appeared surprised at it, till I informed him on what it was founded. From that time the patient continued te amend, His arine grew daily more animelized, and less, saccharine. The albumen The lightens animal matter soon began to diminish dimini-hed, & adually, and the uree and lithic acid as gradually reap- uree and lithic acid beganto peared, At eee it became perfectly similar to that of @ @p pear. man ‘ ANALYSIS OF DIABETIC URINE. 237 man in health, and the patient was cured. Immediately _ on this however he indulged in excesses of various kinds, Excesses when the diabetes returned, complicated with other disor- pe ie Lys ders, under which he soon sunk, ik BS Fy now we take a review of all the inductions that may General cone, be made from the experiments just related in the second “usious. and third part of our memoir, we may afirm 1. That the diabetic urine we examined was composed State of the almost wholly of a substance but ‘little saccharine: and U@e- , that nevertheless it possesses ail the properties that charac- terize sugar; for it is converted into alcohol and carbonic acid by fermentation, affords a great deal of oxalic acid and no mucous acid when treated with nitric acid, is very little soluble in alcohol at 36°, and produces when calcined but little oil, and a great deal of water and carbonic acid. And thus it is demonstrated, that there are different varie- ties of sugar. | %. That manna is not a species of sugar: that it contains yanng notsue but asmall quantity, which may be destroyed by fermen- ger. tation: and ‘that, on the contrary, it contains a great deal of a peculiar principle, the taste of which is very sweet, and the chief characteristics of which are not to ferment with yeast, to yield a great deal of mucous acid with nitric acid, and to be mere soluble in hot than cold water, but particularly iu alcohol, so that the solution on cooling be- comes a crystalline mass. 3. That if nothing but animalized food be given to diabetic An animal diet patients, their urine changes its nature pretty quickly: that pc pate at first we find in it an albuminous matter; that this albu- minows matter the quantity of which continues increasing for some days, appears to be an unequivocal sign of a cure: that afterward the albumen gradually disappears ; that the kidneys then begin to secrete uree, lithic acid, and no doubt acetous acid also: and that the urine soon becomes similar to that of a person in health: but that pu: must he nevertheless, to prevent a relapse, the patient ought stil] coatinued long te continue his regimen of an animal diet for a consider- 4 aa ny able time, and take nothing that might bring on the dia!:ctes afresh, XVI. 238 SCIENTIFIC NEWS. XVI. Letter from Mr. Rouorr, of Magdebourgh, on the fetid © Resin of Sulphur *. Fetit! resin of I lately had an opportunity of detecting Mr. Westrumb’s sulphur fetid resin of sulphur in an unexpected manner. : obtained in Mr. Michaelis, after having precipitated the golden sule making golden phur of antimony from the mdroguretted sulphuret of an- ere of an- ¢imoniated potash by means of sulphuric acid, evaporated F the supernatant liquor, which held the sulphate of potash in solution. ; Heated smells) When the solution began to be concentrated, a vapour like buming arose, by which the artist who was stirring it was singularly asafcetida incommoded. At the same time an insufferable stench was emitted, resembling that of burning asafcetida. The saline mass, being evaporated to dryness, was of a gray colour, and had the remarkable smell just mentioned. Gives to alco. Being digested with alcohol, it imparted to it the smell hol the taste & and taste of garlic. smell of garlic. The alcoholic solution, left to evaporate spontaneously, yielded a gray, glutinous mass, having a similar taste and smell. Easily procura- _ 1 was desirous to impart the knowledge of this fact, as I blein quantity. know not whether Mr. Westrumb be acquainted with the formation of a large quantity of the fetid resin, which may . easily be procured by this process. Formedinde- Since the smell displays itself before any alcohol is add- pendently of _ ed, we may conclude with Mr. Westrumb, that the alcohol alcohol. does not contribute to its formation. - : SCIENTIFIC NEWS. Wernerian Natural History Society. : Wrernerian So. At thelast meeting of the Wernerian Natural History Society, June the ciety. 11th, Dr. Thomas Thompson, one of the Vice-Presidents, read a very in- teresting and valuable paper on the chemical nature of fluor-spar. Cap- Pinna ingens. tain Laskey also read a paper on the pinna ingens of Pennant : from his observations, it appears, that the pinna ingens of Montague, pinna corea- lis of Stewart, and pinnaingens of the Linnean Transactions, are thesame species, and identical with the pinna ingens of Pennant. At the same Geognosy of meeting, Charles Anderson, Esq., read some observations on the geognosy Lifer Kea of the island of Inch Keith, in the Bi ith of Forth. It appears from the * interesting details which he communicated, that the whole island is com- posed of rocks belonging to the independent coal formation; aud that the gr enstene,which there occurs, is traversed by true veins filled with quartz, chalcedony, calespar, &c ,and also contains numerous contemporanéous veins of different kinds. Mr. Anderson intimated his intention of laying before the Society, at a future meeting, a more particular desciiption of the island, illustrated by drawings and a series of specimens. * ¥xtracted from Gehlen’s new Chemical Journal. Annales de-Chi- mié, Vol. LMI, p. 190, + Sec Journal, vol, XVIII, p. 41. TWO TWO METEOROLOGICAL.-TABLES for 1867, Communicated by Dr. CLARKE, of Nottingham. QUANTITY OF RAIN, ‘WHICH FELL AT THE FOLLOWING PLACES IN THE YEAR 1807, In Inches and Decimals. By the Rev. J. annie NotTinGHam, who solicits Communications. ‘ a t e gal E “ vs og iy fat Sat ~ 3 x : | ae “lg SsleS{Ztisct . 1s. ire nes : = S Seles | ab. bth Sobeek al et] Hey SofSeiis SPs res) |S 1s 2 | 2 1807. Sis) 4 (Ch lSQpe sree! isda a ed S WJANUARY,. 1 2°41] 0644 1°57 1-40] 1*D0 oral O35 O33 caked | 2°92} 2:38} O75 FEBRUARY, | 2°44) 1:48] 1°66, 1°79} 2°77] 2°64] 2°09] 3:59] 4:59) 5°58] 4-00] 1-23 MARCH, 0°23] 0°50| 1-36} 0-44] 1°69 eo 2-60 a 1°52] 2°21] 0°57] 0°73 APRIL, ...-~| 0°00]. 1:02] 0:81} 0°67| 2°56]. 1-77] 1:17] 3°19] 3°66] 2:90] 1-72] 0-94 MAY, .....-| 5°47] 3:26] 3-47] 5°26] 2°80] 2°55] 4°70} | 3:75] 3:97) 4-471 2-86] 5-08 TUNE, ......| 0°56] 1-74] 1-92} 2°81! 2°52} 1°13} 2-65} 12a] 2-26] 2-27] 4-00} 8-00 ITULY, ......| 1°62] 0-38} 1°54] 2°26] 2°25] 1°11] 2:43] 5°50] 3-74! 4-48] 3-43] 2-55 JAUGUST, .2.! 3:13} 1-94] 1:64} 1°57] 1°27] 3°31}, 2°18 2991 S49] 4°53] 1-40 SEPTEMBER] 3°22] 2-18] 2:17] 1-27] 1-45) 2-86] 3-34| > 10-08]10-27) 7-921 6-86) 1-70 JOCTOBER,..| 2°48] 0-94) 0-90; 3:13] 1°78] 1°93] 4-60 6°08} 7°02] 515! 1-70 NOVEMBER | 7:54] 3:36] 2-27] 1-18] 3°83] 6-02] 5-57) 4-00] 4-981 5°07 5501 3-39 DECEMBER | 0°83| 0:76] 1:06] 2°67} 0°91} 1°62! 0°86] 3:20] 3°26} 4°53] 2-64} 0-95 Total. -.+ [29 98 | 18-20/20°17|24"45|25: 13]26-95|30-04] SHOT aSs [52° 93/43-69|23°32 A Meteorological Table, from June to December, 1807, “By Dr. CLARKE, of NotrincHamM. (-= The following observations on the Thermometer are made at 8 A.M., 2P.M., j and 11 P M.; and on the Barometer at 2.P, M. The former instrament is placed in the open air, exposed to th: west, but in a situation surrounded by buildings, which prevent any alteration of temperature ‘from currents of air. The direction of the Wind is taken from the vane of St. Peter’s Church; and the numbers state how often it has been ob- '} served in agy particular quarter during the month. THER SOMETER, BAROMETER. |/WEAJ| WINDS. * ee an sell le sf a |= sit f Bay aNd ? > = ; oS « ai n S| 3 = 2: | S| 3 x {S-S]] 2] Sites 1807 Sf aoe os e lee | 2] 2 ellgis & Shoe besiege lS lela JUNE, .....---| 75°| 46°] 57°88) 10°(130°31/29-53]29°95) “35 |] 2ol10 [5031 26°53]29°95) “35 |] 20/10) |24] 9 JULY, ..... 80 | 52 | 64:00 | 8 rae 25: 52129°90) °56 ff A714 HL} 8 AUGUST, ..... 78 | 53 | 64-98 } 9 }/S0-18}29-59}29-85! +34 4} 22) siftit1a] SEPTEMBER..| 67 | 40 | 51°93 | 10 |,30-15|29-21]29°69| 55 |] 15/15] 5] 1 JOCTOBER,....| 65 | 40 | 53-29 | 14 130715) 29-19:29-83] °51 |, 25} Bi}. 8] 8 JNOVEMBER,..| 50 | 26 { 98:93 | 11 |[s0-10128-45)29-44) -B0 | 14,161 16; 2 4 {DECEMBER,..! 50 | 24 | 58-14 | 13 30°24129°11129: gal +: “53 | 2 25] elf al 9 9} 43] : Avr. for7 Mouths | — | — | 52°75 | — \| me ete [[14 rte es [445 15/206 METEOROLOGICAL JOURNAL — For JUNE, 1808, Kept by ROBERT BANKS, Mathematical Insttument Maker, in the Stranp, Lonpon. N.B. For want of room in thé present number, the apparatus and its relative situations will be described in our next, | THERMOMETER. bee tireca: MAY.) S| Mt 4, os | BAROME- ° oj} o TER. , Day of} < | & | S 3 | | Night. Day. lh (gains Hikst I 30- | 64163170) 56] 30,30 Fair Fair 31 69 | 641741 55 31,30 Rain Ditto JUNE. 1 | 60/}56|64149! 29,76 Fair Rain 2 | 62/58 166/48] 30,4 Ditto Fair 3 | 63160167157 | 29,79 Rain Ditto A 61 | 56 | 63] 52 29,71 Fair Rain 5 | 62] 56] 64) 51} 29,68 Ditto Fair 6 | 53152157149] 29,72 Rain Rain 7 |58|56162} 51] 29,84 Fair Ditto 8- 160] 55} 63} 51] > 29.82 Rain Fair Q | 54) 55)62/52|] 29,66 | Cloudy Rain 10 | 58156}64149] 29,87 Fair ~ Fair 11 |63)58 | 67|53| 30,4 Ditto Rain 12 |60}59 169/52) 30,18 Ditto Fair 13. | 66163170} 55 | 30,15 Ditto Ditto 14. | 67.}63 |70155| 30,7 Rain Ditto 15 |64/62168} 50} 29,92 Fair Ditto 36 | 62161 165,156 |" 30,12 Ditto Ditto 17 | 64}62})70/ 59] 30,14 | Cloudy Ditto 18 671681741621 30,6 Fair Ditto 19 | 68} 67 |74) 62] 30,11 Ditto Ditto 20 167166171! 60! 30,6 Ditto Ditto 21 | 67 }62}70} 58} 30,—~ Cloudy | | Ditto 22 | 091621721561 29,83 Rain Ditto 23 | 02/58 168)54| 29,72 | Fair Rain -94 |63|62|}68) 55}. 29,89 Ditto Fair 25 163162169) 56{° 30,4 Ditto Rain — 26 | 63/61/69] 55} 30,6 Ditto. Fair 27 «|. 61 +60 | 62] 54 30,6 Cloudy Ditto 28 [| 58158 ; 62154! 80,9 Yair Ditto A JOURNAL ‘OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. i eigen. TR . ree 4 Ahoom AUGUST; 1808. en oe re ARTICLE I. Observations on the crystallized Substances included in Lavas3 by G. A. Deuce. (Concluded from p. 188.) 66 very thing in volcanoes indicates, that the depth - of their foci is immense.” These are the words of Mr. Fleuriau de Bellevue, and he adds, “ This is the opinion of Mr. Deluc and several naturalists.”’ I have said, and I believe, that the foci of the volcanoes Foc: of goleas are at very great depths, contrary to the opinion of those noes very deepy naturalists, who imagine the foci to be very near the base of the volcano, and even place them in the cone, that rises above the ground: an opinion so repugnant to all the phe- nomena, that I cannot conceive how it could enter into any one’s head. I do not think however, that I have used the but not ofan word immense, which would imply a depth below the reach quate of conjecture, and this is far from my idea. A league per- ae pendicular is a very great depth, and I do not suppose the foci of volcanoes can be much deeper; but every thing in- dicates, that they have ramifications. The fragments of Ramify among natural rock they throw out can come only from these late- the strata. Vou. XX. No, 39—-Ava, 1808, R ral 942) ON THE CRYSTALS IN LAVAS. ral galleries, from which they are broken off and carried along by the lava that flows through them. Another phe- nomenon indicates the same thing: this is the burning places that manifest themselves at the bottom of the sea in the environs of a volcano during an eruption, and which are at the same time a sign, that the focus is not at a depth to be called-immense. I particularly remark this expression, because from this presumed depth have been deduced theo-~ ries respecting the formation of the globe, that are destitute of foundation. Some deeper What in fact is the depth that may be inferred from vol- sa se eanic phenomena, compared with the diameter and solidity of the globe? This-depth is no doubt more or less, accord ing to the mass raised up by the volcano. Thus it is proba- ble, that the foci of Etna, the peak of Teneriffe, and the volcanoes of Peru, are deeper than those of Vesuvius, Vul- cano, and Stromboli. This is all we can conclude; and no- thing respecting the origin of our globe, or the events that : have concurred in its formation. We alterthe ** Man separates, dissolves, brings together, and come- ag of mine 1, yes minerals, ahd causes theni to change their form.” Alt this is true: he does it by his solvents, and the fire of his but cannot re furnaces; but it is not added, that there is no method, no storethem to fre whatever, by which he can reftore them to their state of their primitive , apy 4 : : state. mineralization. He is no more capable of doing this, than libs of regenerating the plants he has burned and reduced te ashes. We are very far indeed from being able to produce any thing similar to the rocks, the crystals, the minerals of our mountains. This single reflection overturns every sys- tem, that ascribes the formation of these substances to fire, -since all the operations of natural and artificial fire that we know, and we can reason only from these, produce nothing *. «4+. Similar to them. We should be -! nese limits, which human means cannot pdss, should cautious there- render us very circumspect concerning the rseults ascribed selena oo" * them, since no one of the natural substances, that man ring our means with those of . destroys or alters the nature of, can reappear again, but by _hature, | following the laws and order established by the Creator from the origin of all things. Limestone ; Mr. Fl. de Bellevue, mentions a nde production of a Jime« ON THE CRYSTALS IN LAVASY 943 limé-kiln, which he quotes as an example in favour of his supposed tobe system. This production,” says he, ‘* resembles inter- pen Shay nally certain hornblendes of the Alps, and compact and lava ina kiln homogeneous lavas. Its external part is puffed out like that of lavas, its surface is covered with a yellow glaze, and its éavities are lined with little crystals.” In a note he adds: « let not the reader suppose, that the stones of this kind had fallen accidentally into the kiln, as this was impossi- ble? a2) >. a - [shall offer no direct objection to the fact; as this would But pieces of require 4 knowledge of the production itself, and particu- thet stone get : ere ; te into. limekilns larly of the vicinity of the lime-kiln: but I shall offer a accidentally. general temark, that may throw some light on its origin: It is a very common circumstance, for fragments of other stonés, which the workmen have overlooked, to get among the broken limestone, with which the kiln is filled, and not - to be observed till the lime is taken out. In this-case, in- stead of a piece of lime we find a stone covered on its sur- face with a vitreous glaze, which being broken appears to be granite; serpentine, or some other vitrifiable stone. In- stances of this are frequent in the lime-kilns in my neigh- bourhood. To be certain, that such fragments could not be introduced, there must be tothing but calcareous rocke in the country, these must even be free from quartzose or siliceous nodules, and there must be no other kind of stone either belonging to the soil or adventitious. Thus it is very probable, and from a great number of instances I am per- suaded it was the fact, that the product of the lime-kiln’ aboyementioued was originally a stone of a different kind from that commonly burned in the kiln. «¢ Naturalists,” continues Mr. Fl. de Bellevue, who That lavas are still believe, that rocks on which volcanic fires have acted areas have experienced only an imperfect fusion, and that their meets erystals have remained intact amid their fluid paste, are obliged to have recourse to a multitude of suppositions, to explain the state in which the lavas are found when cold.” s These naturalists have recourse to no supposition: they But it isa facts find it not necessary. Nothing in the lava changes its form of nature when it cools. The foreign substances it contain a Re in O44 ON THE CRYSTALS IN LAVAS. im its incandescent paste retain their form! no changé takes place, the fire of volcanoes not being sufficiently intense, to» fuse them or alter their nature. I have adduced a, great many. instances of this. Voleanie fires | On this occasion J shall recal to the reader’s mind the cr spteg ay idea I suggested respecting the probable state of the sub- terranean strata, from which the lavas issue. We see, that to reduce stones or minerals to a state of fusion, they must be broken into very small pieces: but there are neither pese. tles nor stampers in the strata from which the lava originate ; and volcanic fires are as incapable as those of our furnaces,: to fuse rocks in a solid mass, These strata then must ‘be in a pulverulent and muddy state, to be capable of bemg fused. In such a state we can easily conceive chemical af= finities. may exert themselves, and form crystals either soli- tary or. in groupes, that would’ remain enveloped im the matter in fusion. How is this fusion effected? whence In these fires arise the fires that occasion it? We perceive from its ema- ee nations, that sulphur is the principal ingredient, that irom gtedient, with enters mto the mixture, and that muriatic acid and sal = pate es ammoniac likewise form a part of it. But what cireum- monia. stance, what combination is necessary, to excite the fer- mentations, that produce the fires, the fusion, and all the phenomena of volcanoes? On this we shall never be able to do more than form conjectures, some of which may ap- proximate to the truth, and others be very wide of it. But as no means we are capable of employing can prevent any of them, it is of little importance, whether our conjectures en the erigin of these fires, and the manner in which they act, be just or erroneous. ‘All that is essential is not to ascribe to them a greater extent, more activity, and a wider influence, than they really have; that we may not be led to form systems on mistakes or exaggerations. Sea-water said Mir. Fl. de Bellevue does not admit, that sea-water is ab- pont 5 ne. Solutely necessary to produce volcanoes; and he quotes in canic fires, Opposition to this opinion, which at first appeared to him as an eruption yery plausible, a volcanic eruption mentioned by Messrs: gp tite ae oo von Humboldt and’ Bonpland, ‘which took place in 1759, Seasi! x ‘¢in a plain in Mexico, forty leagues from the sea in a di- rect me; an eraption that in one night threw up a volcano” of GN THE CRYSTALS IN LAVAS, 24§ ef 1494 feet [1592 Eng.] high, surrounded by more than two thousand mouths, which are still smoking.” If burning volcanoes could manifest thetiisélves any But the contig» where, without being within reach ef the influence of the ry appears from sea, we should not have a single instance of the kind quoted, a anal a for numbers would exist: and if this had been the case, [ of volcanoes, should not even have thought of the opinion I have ad- vanced. But after having attended to this general fact, that there is no burning volcano in an inland country, and that no extent of fresh water, however large, has produced one; all being near the sea, or surrounded by its waters; and having observed, that the vapours of volcanoes deposit abundance of muriatic acid: I hence deduced this indispu- table inference, that sea water is absolutely necessary, by the salts it holds in solution, to produce the fermentations that raise and feed volcanoes. This conclusion has since been confirmed by the erup- Sea-water tions of water from the volcanoes in Iceland, which depo- pete up by sited common salt in large quantity ; and lately by an ob- servation of Messrs. von Humboldt and Buch, who were Clefts inVesu- witnesses of the eruption of Vesuvius in August 1805, and Say perceived the sides of a cleft in its crater lined with a a ckust ai of sea salt two or three inches thick. Hence it follows, that the fact quoted by Mr. FI. de The Mexican Bellevue proves nothing more, than that there may be sub- volcano ac. terranean channels extending forty leagues frpm the sea, rlaidealideai and that on some occasion its waters ENTS into them; ; or perhaps their influence was merely extended gradually to that distance. -It is even very probable, that, if all the circumstances accompanying this fact were fully known, a more precise explanation of it might be given. In 1538 an equally sudden eruption raised up the Monte-nuovo near Naples. << All those who have seen volcanoes in a state of activi- Fires of yolca- ty,” says Mr. FI. de Bellevue, “ assert, that nothing is POs sc to be equal to the violence and immensity of their fires ; and yet immense. some appear without hesitation, to rate the power of vol- canoes even below that of our paltry furnaces.” _ A volcano during an eruption exhibits such a grand and But this ima- awful sight, that it lays hota of the spectator’s imagination, &9'Y- " aud 946 ON THE CRYSTALS IN LAVAS. and throws him into amazement. This is the effect’ of the extent of its fires, the noise with which they are accompa- fe nied, and the sight of the streams of burning lava, But te fala if he examine it with inquisitive attention, he will soon our furnaces ; judge from its effects, that this vast furnace has in no part a heat so intense as may be produced in our iron works ; and must be and it is easy to perceive, why our furnaces have this greater pres nea intensity of heat: it is produced by the continual eurrent of air blown into them, which by its extreme rapidity i is mcessantly bringing’ fresh air, the presence of which im- parts greater activity to the fire; but this cannot happen to the fire of a volcano, which has no such’ communication with the air. This is the reason why the pyroxene schoerl, which is unalterable by the fire of volcanoes, is reduced to the state of glass in a crucible in our iron furnaces, and fragments of lava exposed to a similar trial are more com- pletely vitrified. Of all volcanic substances the obsidian, or compact glass of volcanoes, has been exposed to the greatest heat, The vitrification of this is complete. None of the pieces I pos- ba sess, or have seen, exhibits any thing but glass. All the substances that compose it have been reduced ‘to perfect ! ) fasion. These vitiifications therefore come from a part of the focus, where the heat has been’ urged to a higher degree by some particular circumstance. Andthisine | Now why is it that. these obsidians, which must have os cr¥S- cooled as slowly as other lavas, do not exhibit any erystal~ ed line figuye within them ; if it be not for this reason, that, all the substances in them having been fused, there can 1 be’ no~ thing but glass throughout their mass? — We must not I will say in my turn, that it is much more extraordinary reason from _ for men to set out from the operations of our petty manus our operations | fo nature’s, factories, to determine the force of the fires of volcanoes, and assign them an unlimited extent; and still more extra- ordinary thence to deduce the origin and formation of rocks and primordial mountains. Let us confine ourselves to the effects, that our narrow means can produce ; and not plunge ourselves into a labyrinth of illusions, by reasoning from small to great; for, as our means are merely arkificlals they are not those that operate in nature, Obsidian a perfect glass. * fe Nataratiets,” ON THE CRYSTALS IN LAVAS. 247 « Naturalists,” says Mr. Fl. de Bellevue, ‘* who imae Lava said tobe gine, that the crystals contained in lava have remained in- Nee 5 i tact amid their fluid lava, pass by without notice the obser- vation of those, who, as Spallanzani and Hubert relate, have seen the lava spout up at different times like water: issuing from a fountain, form a number of very brisk streams, and possess a degree of fluidity sufficient to insinuate itself ‘into the smallest interstices of the bodies it penetrates :” 4 ‘and he adds in a note: “ Mr. Faujas has in his collection Piece of palin, ‘a piece of a palm-tree from the Isle of Bourbon, which Takei ‘proves, that the fluidity of the lava has been very great, has penetrated. ‘since it has insinuated itself into the very fibres of the “wood. This fact, if it were real, would prove an impossibility, This an impos ‘namely, that lava might be in a state of fusion’ without be- %>4'Y- ‘ing red hot: for a substance as combustible as a piece of a ‘palm-tree, or any other vegetable, would have been burned and consumed, or reduced to a coal at the first contact of ‘the lava. It must be an illusion therefore; and either the ‘substance surrounding the palm is not lava, or the matter “surrounded is not a vegetable substance. This illusion, Others have ‘strange’ as it is, is not single in its kind. In an account of rt ans ‘a tour to Iceland; translated and published at Paris in 1802, 5 ‘J have read, that the Danish travellers imagined they dis- cerned wood in a piece of lava of Hecla. Cadin Borch made ‘the same mistake, and even greater, for he says he saw ** pieces of wood slightly scorched” in whole rocks of the -— ‘Tava of Etna, I have in my possession a large piece of vitreous lava, Vitreous. lavas “that 1 brought from the island of Vulcano, which may serve sometimes ‘td explain this illusion. It has very large blebs, which are alla drawn out considerably in length by the flowing of the lava, wood. 1 and their surface is streaked with threads, mihi have the ; “appearance of woody fibres; and this appearance is height- éned by the tint they have derived from the vapours, that “are continually exhaling from the matter in fusion, Seve- ‘yal persons, who have seen this fragment, have taken it at “first view for wood. I have another piece of vitreous matter from Lipari, which is drawn out into such fine and close threads, that no fossile agatized wood, let its fibres be ever o . . ’ ° 7 *~ gO 943 ON THE CRYSTALS IN LAVAS. so distinct, would have a stronger resemblance of wate than this, were it not for its glassy Picire I have another piece, vitreous likewise, one of the surfaces of which, that was exterior, is marked with a multitude of very small threads, arranged in some places i in undulations resembling 1 the woody fibres round a knot. This the case From these examples I am Jed to believe, that the spe- with the sup- cimen from thg Isle of Bourbon is wholly lava, with a woody posed piece of , palm, " appearance on one of its faces; for at all events a vegeta- ble, even in the state of wood, could leave nothing after jts combustion, which must be inevitable, but a vacuity in the lava, and traces of charcoal; and by no means the impression of woody fibres, still less the fibres themselves, In support of his principal opinion Mr. Fl. de Bellevue adduces several arguments, which I shall pass ov eT because our business is with facts, not conjectures. One of them Grand erup: js the following. “The great volumes of lava, that act wang like the principal part in volcanic eruptions, burst out from the : crater, from the sides of the mountain, or from its base. ‘They proceed with rapidity from the yery focus of the vol- cano, possessing an incomparably greater degree of heat _than the matter that rests in the crater. This heat, this -rapidjty, cause them to spout forth and flow like water, and therefore the Cannot permit any crystals to form in them. All that are crystals form- found in it afterward are produced during its tepaae and ed in it while cooling. refrigeration.”’ Flowing like I must first remark, that these expressions frequently re- water a metas heated, that lava spouts out and flows like water, are merely phorical éx- ‘ : , pression. metaphorical ; for lava, far from flowing like water under any circumstances, leaves in succession, by hardening, all its matter on the ground it flows over. © Eruption of Mr. FI. de Bellevue did not recollect the lava of Etna of Etna of 1669. 1669, which I have already mentioned. This lava, issuing from the base of that great volcano, traversed a space of _ten miles in length, and advanced into the sea, where it accumulated in prodigious heaps, after having covered ifs route with its matters to a vast extent in breadth and thick- ness. This certainly was to be reckoned among the lavas, that act the principal part in volcanic eruptions. Now thjs Java, of which I have piecss before my eyes, I again assert is ON THE CRYSTALS IN LAVAS. 849 is filled throughout its whole extent, from the extremity of its destructiye course to the place where it issued from the crater, with a multitude of pyroxene schoerls, of those whitish crystalline lamine I have described, and of small chrysolites; and the crater, from which it issued, threw ‘up myriads of the same substances. Can we discern here formations produced at the time of the cooling of this lava, since all these crystals existed there at the moment of its greatest fusion and heat, the focus of the eruption itself having thrown up loose ones from its crater in multitudes innumerable 5 The naturalists who have remarked, that leucites and Leucites and pyroxene s schoerls are crystals not to be found in the strata Poa ae coming under our observation; and who have hence infer- strara we have - red, that they would have remained for ever unknown to Liat pa us, if volcanic eruptions had not brought them to light; otheis beneath. are certainly well founded in their opinion. Mr. Fl. de Bel- levue however terms it a supposition. But nothing is more true than the observation, and nothing can be more natural than the consequences deduced from it. _ * We have seen,” continues he, “‘ that there is no ex- Rocks of the ample to prove, that aqueous solutions now form, or are Primitive kind not now form- capable of forming, rocks similar to the primitive ones; and ed in water: that fire on the contrary daily exhibits to us productions, that are not simply analogous, but even identical with them.” On the contrary we have seen, that the productions of fire have only an apparent, not a real resemblance to pri- mitive, or, to speak with more accuracy, primordial rocks. > The fires of volcanoes, like those of our furnaces, have ae not produced and never will produce any taing like them, : because these primordial strate) da mbe daeethieie origin to fire. Neither will aqueous solutions form such rocks; for they pee their were produced by precipitation from the primordial fluid Py iS? aaa at periods not remote from the origin of the globe, and in the primi- every thing indicates, that they no longer continue to be cota ‘al formed. The water of the present sea ‘does not now con- funds in the tain. the requisite elements, for of these it has been de- °° prived. The mud of rivers, of which some imagine they The deposi- may 256 ON THE CRYSTALS IN LAWAS. tions of rivers may be formed, but which cannot form them, does not.reach eae form the bottom of the sea: its waves drive it back, and keep it on the shore, where it adds daily to the first boundaries of the continents. and are too On this occasion I shall repeat a riaaek I have several eae to affect times made. These additions are so trifling, compared level of the ‘ocean, with the extent of the sea, that they cannot produce any perceptible change in its level. It 1s these additions to the land that have been so often mistaken, and quoted as proofs of the retiring of the sea. Widleanees By what signs can we know ancient vulcanoes wherever could not be they exist remote from the sea, if not by their form, and distinguished from other. the nature of the substances that distinguish them? They mountains, if must then be different from all other mountains, or they ek would be confounded together, and these could not be them, distinguished from volcanoes. The truth is then, that all the mountains we know, the Alps, the Jura, the Pyrenees, and all those of our continents, have no relation to volcanic mountains; that their strata, and the matters that compose them, have been formed in water, and fire has had no cons cern in their production. Valley of Qui. It was from these distinguishing and invariable characters oy of volcanoes, and of the soil around them, that in my pres ceding observations I employed the following expressions, AS When the valley of Quito, ¢nd the mountains that border it, shall be observed by naturalists experienced in the know- ledge of volcanoes and volcanic substances, I have no doubt they will perceive, that the state of things is as I have said.” I should have been far from thus expressing myself, if other and the volca- lands and other mountains had been the subject. But the ho ee great mountains that skirt that celebrated valley on either hand being certainly volcanoes, three of which are not yet extinct, and iis soil being composed of their vast eruptions, I could venture ta give this opinion without apprehensign of going too far, er of wanting that proper diffidence a man ought to have.in his own knowledge. Ancient volca~ The ancient volcanoes obseryed en the surfaces of conti- ye ig as- Bents are not so numerous as Mr. Fl. de Bellevue imagines, sert, when he says, that volcanoes, either burning or extinct, are seen every where on the face of the globe. This is 3 “great ON THE CRYSTALS IN LAVAs. | great exaggeration. Many are seen in various places, no doubt ; but the space they occupy bears no comparison with that where there are none. I include ancient and extinct | volcanoes, ; for those still burning are very few. ‘There are Burning ones only four in Europe: those of ieebaud arein a distant lati- Very rare tude. * This reminds me of a similar opinion of Mr. Patrin, Patrin’s misre- srhich he gave of Italy. Itis in his Recherches sur les Vo'- ae af cans, a Thatity” concerning Volcanoes according to the respett, Principles of the pneumatic Chemistry.” He says, “ Italy is full of volcanoes, and covered from one end to the other with lavas and tufas of. enormous thickness.” Yet the true fact with respect | to Italy is, that the Apeunines, which traverse it from one extremity to the other, all the ramifications of that chain, and all the eastern shore of that peninsula, have nothing volcanic in them; and that the soil of this kind lies only on the western coast, where it is fr equently interrupted by | aqueous strata. ' When explanations of the manner, in which a fact in 'ter- When peorle restrial physics, that is in some degree obscure, may have picks ac. happened, deviate from the most natural, and that which often support is most conformable to all the phenomena, they may be i apa ets very different from each other, or even opposite. Thus it tradictory ar happens, that the naturalist I have just quoted, being S87 equally « of opinion, that the pyroxene schoerls did net pre- exist in the laya, separates them from the matter of the lava, aud makes’ them arise “ from an aeriform fluid, which has passed to a solid consistence by the effect of attraction.’ This question I have already discussed with precision, and to some extent, founding all I have said on facts, in my Ob- servations on Pyroxenes, or voleanic Schoerls, in the Jour- nal de Physique for March, 1801. ' From all the facts I have adduced the following conclu- General con- sions“may be considered as established. clusions.- *-That every volcano, whether burning, extinct, or ancient, Volcanic whatever its height or extent, and wheels situate, is a ee mountain of a class distinct from all others: that it is and diferent forméd by no n¢ptunian strata: that all the solid substances foma!l others. constituting it are the products of fire: that it has been raised up, fbb its base to its summit, by the accumulation ih of 952 ON THE CRYSTALS IN LAVAS. of matters successively thrown up by its eruptions, the fos cus of which is beneath all the strata with which we are ac+ quainted. Crystalsinlava. That the crystalline substances included in lava are for foreign to it. reign to it: that they haye been formed anteriorly i in the humid way in strata, which the voleanic fires have reduced to fusion leaving their crystals untguched, because those fires had not sufficient intensity to fuse them. The whole That we should cease to say volcanoes manifest. thems she og isa selyes on the suramits of mountains, because volcanic ; mountains entire constitute volcanoes, This is the reason why new mouths frequently open in their sides, or at their base, Sea waterne- That sea water is absolutely necessary, by the salts it cessary tot. holds jn solution, to excite the fermentations that pienies volcanoes. All other That all the strata and substances, which compose Ciliens eae pea reous, schistous, or granitic mountains, and_all their varies ills produced by water. ties, as well as sandy, gypseous, and argillaceous hills, are the work of water, All ancient That all the ancient volcanoes, which are nqw inland volcanoes have haye burned underneath the waters of the sea. The schists burned under ined. and granites which appear around some of them are foreign to them, belonging to strata through which the eruption forced a passage, and which have remajned bare. They would have been buried under the volcanic matter, to be seen no more, if those volcanoes had been longer active, Those which were burning at the time when the sea retired from our continents ceased to burn at that period: a period beyond the memory of the mhabitants of the country, because there could be no inhabitants of the land round those voleanoes, when it formed part of the bottom of the sea. Volcanic sand Among the numerous facts that prove this truth, count pate ips Marzari of Vicenza has furnished me with a very remark- strata. able one, on his return from a touy in Auvergne, At Sanz | tourgue there is a stratum of volcanic sand, about six inches thick, between two calcareous strata. After a calca- ‘reous deposition had been formed therefore on the sides of base of the volcano, an eruption must have thrown out and spread ; EXPERIMENTS ON MOLYBDENA. 943 spread this sdnd, upon which a fresh calcareous deposition took place; and these operations could have occurred only in the sea. Count Marzari has had the goodness to present the a specimei: of this sand, which is similar to what was thrown out of the superior aperture of Etna in the eruption of 1763, which I have mentioned above, ‘I shall remind the reader here of what F have said seve-~ Distinction be= yal times, that to distinguish the different periods when a: een volcanoes have been binmninig, and not to confound them yolcanoes. together, it is proper, to call those ancient, which have burned i in the sea before our continents were laid dry; and those only extinct, which by their situation are still capable of burning, if the inflammable matters that gave rise to them were not consumed. But this necessary distinction will never be made, as long as it is believed, in spite of the dictates of observation and experience, that burning _ ¥oleanoes may exist independent of the waters of the sea. Mr. 'Fi. de Bellevue must be convinced, that my sole 7). author's object, in making these observations, is to illustrate in a object. more precise manner the grand. phenomenon of volcanoes, that we may not ascribe to them etfects in which they have fo concern, er deny them those they have really produced. These limits, grounded on well established facts, can alone free us from systems founded on contrary netions, and af- ford more certain bases to geology, that interesting and im- portant branch of terrestrial physics. Bri il. | “Experiments on Moiybdena. By CaristTian Freperic Bucuoxz. Py ' wi’ - ,! ‘(Concluded from p. 196.) YUI. Manner in which molybdena comports itself with cer- Tort tt: , tain acids. Te: 29. Ten grains of powdered ihabibllieee were put With sulphu- into half a drachm of arenas acid of the specific gravity "> ci#- of 254 Converted ints a yellow oxide. With nitric acid, EXPERIMENTS: ON MOLYBRENA: - of 1°86, and left for twenty-four hours at an ordinary tein perature! The acid did not exert the slightest action on the metal; Ata moderate heat a large quantity of, sulphur- ous acid was evdlved, the liquor became of a yellowislt brown colour, and it assumed a sirupy consisténcé. It was then diluted with four times as much water, and became of a brownish yellow. After standing somé time a little mo+ lybdena was deposited, which had not been dissolved. The. liquor having remained some hours in contact with the me= tal, it gradually turned green, and afterward blue: but the most remarkable circumstanée was, that part of the blue oxide precipitated itself in the form of a very fine powder. The cause of this phenomenon deserves inquiry, This experiment teaches us, that the molybdena had been changed by the action of sulphuric acid into a yellow oxidey containing more oxigen than the green and the blue; which passed.to the state of green Oxidé in consequence of a dis- oxidation produced by the contact of metallic melybdenas Evp. 30. In treating on the oxigenation of molybdena, I have already had occasion to say something of the action of nitric acid on this metal. The experiments I shail ré4 late will serve as a continuation. Ten grains of powdered | molybdena were put into two drachims of nitric acid diluted with an equal quantity of water, At the expiration of a quarter of an hour there was a slight evolution of nitrous gas, and a pale red solution was formed: To accelerate the action of the acid I employed a gentle heat, when the mo- lybdena soon disappeared, and the liquor assumed a yel- lowish brown colour with a tinge of red. I added ten grains of molybdena two different times; and when I had added the last ten grains, the liquor, which had been clear, grew turbid, and became of a carnation red. This, added to a slight evolution of nitrous gas, led me to conclude, that the acid was completely saturated. . After standing a little while, blue oxide was perceived to form at the bottom of the vessel, where a little molybdena still remained undis- solved: a phenomenon similar to that observed in the solution by sulphuric acid. Twenty-four hours after,.the matter that rendered the liquor turbid was separated, and it coms ported itself in all respects like molybdic acid. 4 A solu- EXPERIMENTS ON MOLYBDEN A. A solution of molybdena by nitric acid, made without fieat, became perfectly clear in a few hours, and: of yellowish brown inclining to red. It had a slightly acid taste, that left behind it a bitterness with somewhat metal line. Part having evaporated by a gentle heat in a porce- lain capsule, it left a pulverulent residuum of a dirty reds QhS. Solution in ni- tric acid with- * out heat.’ dish yellow, which, being put into a small quantity of was ter and shaken, was entirely dissolved, except 2 small por- tien, that was molybdic acid. The solution was yellow in+ clining to red: and on being digested with metallic molyb< dena it became blue. Twenty grains of powdered molybdena having been put into a drachm of fuming nitric acid, an extremely vivid effervescence took place, attended with ‘an extrication of red vapours, and the mixture became consolidated into a mass of a light brownish red colour. Another drachm of the same acid being poured on this, and moderately heated, white molybdic acid was very readily produced. . Exp. 31. The reddish solutions obtained in the pre- ceding experiments being filtered, ammonia, cautiously added, produced a flocculent precipitate of a brownish red colour, which, having been washed and dried, yielded a powder of a lighter hue interspersed with white and shin- ing crystalline particles. Some of this powder was put into a small quantity of water, at a moderate temperature, and shaken, in which it all dissolved except a few small white crystals. These crystals however were not molybdic acid, for they were much more soluble, and had a much stronger acerb taste. The solution of the brown powder was of a vi- nous yellow colour inclining to red. The water, with which this powder was washed after its precipitation, had-a deeper colour, because the precipitate was more soluble after being wetted. On adding ammonia, or potash, to the solu- tion, a brown red precipitate fell down slowly once more. This precipitate being treated with a solution of alkaline carbonate, it was not attacked, but the white crystals were dissolved with effervescence. Farther experiments are ne- cessaty, to determine the nature of the products formed in this process. I shall here confine myself to the remark, that the brown precipitate cannot be taken for the brown oxide The nitric s@- lutions ex- amined. 256 With muriatic acid. Wetted mo- Iybdena not oxided by the ‘ water, but by the air. Oxigenized munatic acid. Arsenic acid. EXPERIMENTS ON MOLYBDENA. - oxide obtamed by the decomposition of molybdate of am- monia, for this oxide appears to be insoluble in water: and. besides, the precipitate does not furnish blue oxide with ’ modlybdic acid, but only with molybdena in the metallic state, which indicates a higher degree of oxigenation than that of the blue oxide. \ Exp. 32. Ten grains of powdered molybdena were put into a drachm of muriatic acid of the specific gravity of, 1°135, and left for twenty-four hours: The acid exerted no action ov the metal, it remained in the same state: and even after it had been boiled to dryness, a second drachn of acid ddded, and this boiled on it a few minutes, no effect was preduced. : | ; This fact appearing to me inconsistent with the property I had observed in metallic molybdena of being converted into blue oxide after having been simply wetted, I tried muriatic acid diluted with water: The metal however was not at« tacked, whether I employed one, two, or three parts of waa ter to one of acid, and digested the metal m it for a long time, or boiled it. Thus it appears, that, when powdered molybdena is sim ply wetted, the oxidation is not preduced bythe water, but by the oxigen of the atmosphere; the water serving: only to conduct the oxigen, and dissolve the oxide formed, so that_ the metal continually presents a fresh surface to the action of the air. sa and as Exp. 33. Ten grains of metallic molybdena were put ‘nto three ounces of water saturated with vapour of oxigen= ized muriatic acid: the mixture was shaken a little, and 4 blue solution void of smell was produced. But the greater part of the metal was not dissolved: nor was it by the ad-= dition of six ounces of acid. The liquor when filtered was of a fine blue colour; but on adding liquid oxigenized mu- atic acid, the solution became as clear as water; and when more molybdena in the metallic state. was put into it, the blue colour reappeared. Exp. 34. Ten grains of molybdena were put into a drachm of liquid arsenic acid contaiming half its weight of dry acid, and left to stand twenty-four hours in a closely stopped bottle. At the expiration of this time a thin stra- tum — EXPERIMENTS ON MOLYBDENAs tum of the liquor, about half a line thick, was of a brown yellow colour. Having boiled the mixture and evaporated ’ to dryness, diluted the residuum in half an ounce of wa- ter, and shaken it slightly, [ had a fine blue solution, and but little of the metal appeared to be left unaltered. Thus the metal had here been oxided at the expense of the arsenic acid, and converted into blue oxide. 257 Exp. 35. ‘Ten grains of molybdena, half a drachmn of Fhesphecs phosphoric acid, and a drachm of water, were put into gs phial, which was stopped close, and left to stand twenty. four hours. No effect was produced, and the mixture was boiled to dryness. When the residuum was nearly dry, a ¥apour, exhaled, which had a little of the smell of phospho- rus, accompanied with something like that of an alkaline lixiviam when boiling. down, The flame of lighted paper held over it assumed a greenish yellow em The resie duum was heated red hot, but no stronger smell was given out, that ceuld lead me to suppose the phosphoric acid had - acted on the molybdena; and in fact when the mass was _ eooled and diffused in half an ounce of water, the greater \ part of the metal remained at the bottom, without having undergone any alteration. The supernatant liquor was. of a yellowish brown colour, had a strongly acid taste, and left ' a metallic taste on the palate. A similar quantity of water was evaporated from the metal several times, but I did not observe the least change, and no blue oxide was formed, A small quantity of this solution was evaporated to dryness, and a grayish blue matter remained, which, on dissolving it again, to my great surprise assumed a yellowish brown co- Your. Ammonia added to the solution gave it a dull colour, without producing any precipitate: it was not till after the expiration of four and twenty hours, that a few brown flocks parated. Exp. 36. Having treated molybdena in the same mane Boracic acid. ner with boracic acid, at the end of a few hours the liquor assumed a slight blueish tint, which did not increase after- ward, even when evaporated and the residuum again dis- solved. Thus it appears, that boracic acid has no action - on molybdena, and was not the cause of the slight blue cue Bloor observed. Vou. XX.—-Ave. 1808. S I had 258: Succinic, tar- tarous, citric, and acetic acids, General con- clusions on the action of acids. EXPERIMENTS ON MOLYSBDENA. ¥ had similar ‘results with the succinic; tartarous, and citric acids: only I observed, that, in treating molybdena with succinic acid, the liquor became green during evapora- tion. Acetic acid produced no effect on it cold; but when boiled, and the liquor reduced to about half, it assumed a brownish yellow colour. . Ammonia scarcely rendered the solution turbid. From what has been said it appears : 1st. That, whenever molybdena is dissolved by acids, it becomes oxided at their expense, and consequently can be dissolved only by those acids, which, like the nitric, sulphu- ric, oxigenized muriatic, phosphoric, and arsenic, are sus- ceptible of several degrees of oxidation, and capable of parting with oxigen, either at the common or a higher tem=_ perature. Potash with the native sul phuret of moe ly bdena. Qdly. That by the action of acids molybdena may be brought to the state of blue oxide, and sometimes of brown, the nature of which is yet to be examined. The phospho- ric alone appears to produce a different state. 3diy. . That these'solu ions can searcely be considered as salts, on account of the acid nature of the oxide of molyb- . _ dena. ; IX. Action of potash on the native fulphuret of molybdena.. Exp. 37.. On fifty grains of pure sulphuret of molyb- “ dena I poured a lixivium containing two hundred grains of pure caustic alka, evaporated to ae oe! diluted the resi- duum in water, and ‘evaporated again. After repeating this several times, [| separated the undissolved part by filtration,” washed, and dried it. The loss amounted to scarcely four grains, and what remained had the same appearance as be-_ fore. On this I poured sulphuric acid diluted in water, but no sulphuretted hidrogen gas was evolved. The filtered liquor has a sirong taste of sulphurous acid; diluted sul phuric acid expelled from this a large quantity of ‘sul- ‘phuretted hidrogen gas; its colour, which was a- pale brownish yellow, changed to brownish red; and at the end of a féw minutes a ‘fine Hee ceed red precipitate was formed, which gradually changed brown, and thence to a yellowish brown ; the Tiqnor becoming a pale reddish brown. “The precipitate. ees - « ’ EXPERIMENTS ON MOLYBDENA. 259 precipitate when dried wasof a chocolate: colour, and : weighed 31 grains. This appeared to be a simple hidro- thianat [hidrosulphuret] of molybdena: for when heated with muriatic acid a small quantity of sulphuretted hidro- gen gas is evolved, and when heated redhot in a crucible it does not give out the blue flame of sulphur, but simply a smell of sulphurous acid. On decomposing it with nitric acid, it immediately gave out sulphuric acid, which was rendered evident by barytes. | . * Exp.38. Twenty-five grains of sulphuret of molybdena Heated redhot were put into a lixivium containing’ a hundred grains of caustic alkali, evaporated, and heated redhot for a quarter of an hour. As soon 4s the alkaline mass began to flow, the alkali acted so powerfully on the molybdena, that the whole of the metal seemed to be fused by it. The mass had and fused. assumed a cherry red, which soon passed to a deep crimson. The water in which this was diffused acquired a deep green Part dissolved. colour, which it lost in a few hours by mere exposure to the air, and became of a blackish gray. The residuum, after Residuum, being washed and dried, was of a light gray colour, and weighed twenty grains. Its nature ill soon appear. Sulphuric acid and muriatic acid diluted with water, and Solution ex- added in excess to the solution that had passed the filter, Kes extricated from it sulphuretted hidrogen gas, and occasioned a precipitate similar to that of the preceding experiment. A part of the molybdena formed with the free acid a blue solution above the precipitate. Nitric acid occasioned a similar precipitate: but the blue liquid, that contained it,’ became greenish, and afterward of a reddish yellow, in con- sequence of the progressive oxidation. - ‘The expériments related indicate, that the alkali (potash) potashacts but exerts but little action on molybdena in the dry way, and little onit. still less in the wet. I thought, that, if the quantity of ‘sulphur were increased, the action might be more consider- able, and accordingly I made the following experiment, __ - Exp. 39. I took ten grains of powdered molybdena, Treated with which I put into half an ounce of an alkaline lixivium Potash and y : sulphur. holding i in solution twenty grains of sulphur. ThisI boiled q and evaporated almost to dryness twice. The matter, asin me 3st experiment, was of a cherry red round the edge. 5 2 ae 260 EXPERIMENTS ON MOLYBDENA. On diffusing it in water the solution was of a fine deep green. The molybdewa however did not appear to be at- tacked in any sensible degree. Forty grains of sulphut were added, and the process as above was repeated three times. The molybdena was still found to be bat little al- tered, and had lost oaly two grains. The solution being decomposed by sulphuric acid, it yielded only a grayish - blue precipitate, the aspect of which was perfectly like what is called /ee sulphuris, and contained a few flocks of a yellowish gray. Inthedry way. Fyp, 40. I then took two poke of alkaline ( peming thirty grains of sulphur, and ten grains of molybdena; put the whole into a Hessian crucible; evaporated to dry« nefs; and left it in a red heat for a quarter of an hour. The mass being diffused in eight ounces of water, and fils tered, the undissolved tesiduam weighed three grains. The solution was of a fine yellowish red, en sulphuric acid produced i in it a blackish brown precipitate, which was in no respect altered by an excess of the same acid: the liquor gave no sign of a blue appearance: and the precipitate, af- ter being separated, washed, and dried, was of a brownish black, and. weighed forty -five grains. Precipitateex- This, precipitate was not altered by boiling in sulphuric sy acid, and afterward with muriatic: but when nitric. acid was added to the muriatic, and it was boiled again, it was decomposed and dissolved, with the exception of a little sulphur. A solution of barytes indicated the presence of sulphuric acid: Five grains of the precipitate, having been, heated redhot in a small glass, gave out about two grains of sulphur. The residuum was speedily oxided by nitric acid, but still a little sulphuric acid was found in the solu~ tion, which proves, that the action of the fire had not se- pazated all the sulphur. From what has been said it fol- lows, that the precipitate was composed of molybdena in the metallic state, or approaching to it, of hidrothianat of sulpbur, and of a slight excess of sulphur; while the pre= cipitates in the 86th experiment were composed of oxide of nolybdena combined solely with sulphuretted hidrogen,. or at most with a little sulphur. This experiment having been repeated with four times the quantity of molybdena, and the ESPREIMENTS ON MOLYBDENA. 261 the roasting continued a quarter of an hour longer, gave the same results, v x. Action of hidrothianates of athaline sulphurets, and r pure hidrothian acid, on'molybdic acid. ~~“ Exp. 41. I dissolved molybdate of ammonia in twenty Solution of times its weight of water, and added sulphuric acid, till the ™°'y>“ena in Te ; ; ea : sulphuric icid: precipitate formed was entirely redissolved. I then poured treated with in hidrothianate of ammoniacal sulphuret, and a reddish hidroguretted brown precipitate was formed, which was more or less con- sei 2 siderable, and the supernatant liquor was more or less blue, according as the quantity of sulphuric acid and of water employ ed to dissolve it was greater or less. I found too, that on adding a small quantity of hidrothianate of ammoniacal sulphuret to the solution ‘of molybdate of ammonia, the sulphuric acid produced no precipitate, but merely rendered the solution blue; while a precipitate took uneele if there were a larger quantity of hidrothianate of ammoniacal inka phuret: thus in one case all the hidrothianate of sulphur i is employ yed in disoxiding the molybdic acid. _ Exp. 42, Five grains of sublimed molybdic acid dissolved Mulybdic acid. in ten drops of concentrated sulphuric acid were put into five ounces of water. Hidrothianate of sulphuret of am- monia ‘occasioned in this a ‘chocolate coloured precipitate, which was almost black when dried. An excess of acid did not decompose it, or produce a blue colour: thus it was similar to the native ‘sulphuret of molybdena. _ Exp. 43. Molybdate of ammonia was dissolved i iu twelve Molybdate of times its weight of water, sulphuric acid added in excess, ammonia with sulphuret and and solution of sulphuret of potash poured in. This ocea~ hidoguretted sioned a light reddish brown precipitate, and the liquor be- i “i came blue. Sulphuric acid being added to a solution = molybdate of ammonia merely to saturation, hidrothianate of sulphuret of potash occasioned a flesh coloured red pre=. cipitate inclining toa copper colour. In a solution to which no sulphuric acid had been added, no precipitate was occa- . sioned by the hidrothianate, the liquid merely becoming a little milky, which might be expected from the property I have already observed the sulphuret of potash possesses of Geet molybdena. The acid added afterward produced anew 262 EXPERIMENTS ON MOLYBDENA. anew a precipitate of a reddish brown colour. All these precipitates were decomposed by an excess of acid, a blue ~ solution was formed, and nothing remained at bottom but Sulphuretted hidrogen gas passed into a solution of mo- lybdic acid. Brown resi- duum examin ed, 3 sulphur of a brownish gray colour containing a little molyb- dena. Exp. 44. Two phials were connected together as in Woulfe’s apparatus. In one, which served as a receiver, there was a solution of one drachm of molybdic acid in eight ounces of water: in the other there was an ounce of sulphuret of lime with eight ounces of water, and sulphuret- ted hidrogen gas was evolved. As soon as the gas began to pass through the solution, this assumed a reddish brown co- lour, ici became deeper and deeper, but still continued clear. I took a little, which smelled strongly of sulphuret- ted hidrogen, added to it some muriatic acid, and a blackish precipiiate was formed. At the expiration of four and twenty hours the whole of tbe solution became a little turbid; and after exposure to the air for twelve hours in shallow vessels it was completely turbid, opake, and of the colour of mud. Heated afterward to ebullition, it resumed its clearness and. colour, except that it was a little more inclining to yellow. The froth that formed during the boiliug was of a fine red- » dish yellow, like tincture of saffron. While it was evapor- ating to dryness bya inoderate heat, a smell of sulphuretted Wdronest RRR to be given'out, and toward the end a great deal of ainmonia was evolved, The residuum, weighing fifty-five grains, was of a light brown chocolate colour, and exhibited the following proper~ ties. 1. Yen’ grains bemg exposed to a moderate heat, a pretty large quantity of ammonia was evolved, accompanied with a smell of sulphuretted hidrogen. This smell alone was perceived when the heat was increased: at length sulphu- rous acid was given out, and the matter assumed a blueish’ black colour. . It now weighed eight grains, was insoluble jn water, avd in the acid a little concentrated bya mean temperature. “Thrown into aredhot crucible, it imnyediately became red, sulphurous acid vapours were expelled, and it melted. ‘Ths was molybdic acid. 2. Ten grains of the residuum put into a drachm of muriatic acid, and heated to” ebullition, eave out but little sulphuretted hidrogen; and formed, EXPERIMENTS, ON MOLYBDENA. formed a browaish yellow solution, which on dilvtion with water assumed at first a blueish green colour, and afters ward becaine completely green. A similar quantity having been previously shaken in water, and afterward put into mu- riatic acid, gave rise to a pretty considerable evolution of sulphuretted hidrogen, and produced a blue solution, which soon assumed a tinge of green, and let fall a blue precipi- tate insoluble ia water. This [had an opportunity of ob- serving in several experiments. Its external appearance greatly resembles that of the blue oxide of molybdena, from which it differs however, since it is not soluble like it in water, It requires farther examination therefore, to de- termine its nature. 3. Five grains of the dried residuum were put into half an ounce of cold water, and shaken; but no effect was produced. Being boiled for a quarter of an hour, part was dissolved, | foe two grains of a fine red- dish yellow colour. The solution had the same colour as the preceding: it emitted a strong smell of sulphuretted hidrogen: the sulphuric acid increased this smell, and as sill the solution at first blue, afterw ard green, From all these circuinstances it appears, that the residuum is a triple compound of hidrothian acid, ammonia, and mo- ‘lybdena. With respect to the acids 1t comports itself like the precipitates obtained in the experiments 38, 41, and 43. After being roasted to redness it approaches the native sul- phuret of molybdena, from which however it appears to dif- fer still’ by retaining a small portion of sulphuretted hidro- gen. It is much more quickly converted into acid by the action of fire than the sulphuret of molybdena. Exp. 45. Ten grains of very pure molybdic acid, first fused, then powdered, and afterward boiled in ten ounces of water, which dissolved but a very smail part, weré put into the same apparatus as tbat ‘of the preceding experiment, and subjected to the same treatment. As soon as the sul- phuretted hidrogen gas began to pass over, the liquid be- came brown: the colour grew deeper and deeper, and the ‘greater part of the molybdie acid, vhie ‘h swan in’ the solu- tion, was dissolved: nothiug remawet at the bottom but gome brownish black flocks. At the conclusién the Hig ‘assumed the same colour as in the preceding experiments, and A compound of su) phuret- ted hidrogen, ammonia, and molybdena, Sulphuretted hidrogen gas passed i into Wae ter in which undissolved mol) bdic acid was diffused. 264 EXPERIMENTS ON MOLYBDENA. and had a strong smell and taste of sulphuretted hidrogen, At the end of four and twenty hours it became turbid, and deposited a pretty considerable quantity of a yellowish brown powder, which was separated and dried, when it be- came of a brownish black. The filtered liquor was of a yellowish brown: when made to boil, sulphuretted hidrogen gas was evolved; a larger quantity of powder was precipita~ ted; and it retained but a slight smell of sulphuretted hi- drogen, which the addition of a few drops of muriatic acid rendered stronger, at the same time producing a blue co- Jour. The precipitated powder, put into muriatic acid and exposed to a moderate heat, comported itself like the resi- duum of the preceding experiment; but boiling it ulti- mately produced a solution of a brownish yellow colour, A little of this powder, being thrown into.a redhot crucible, burned immediately with a sulphurous flame, which soon disappeared. Pure molyb- This experiment shows, that pure molybdie acid is like« dic acid will ise capable of combining with hidrothian acid; but this combine with 5 : sulphuretted combination is not,as constant as that of the preceding ex- hidrogen. periment, in' which ammonia toois present. It proves the variations, that the less limited disoxigenizing action of the hidrothian acid must produce. Thus by dessication simply _ it passes to the same state, to which the compound of the preceding experiment is not to be brought but by a much stronger heat; and by the oxidation of a part’ of the hi- drogen it forms a hidrothianate of sulphuret of molybdena, that gives out in roasting a vivid sulphurous flame, which the native sulphuret of molybdena does ig aud is vane into molybdic acid, ets It remains for me yet to examine the action of hidrothian acid on molybdena in He same e sspece as in’ the 4ist ex * periment, 7 i. Molybdate of Exp. 46. Sulphuretted hidrogen was pesepie in the man ammonia de- ner already mentioned through a solution of a drachm of br baa molybdate of ammonia in four ounces of water, which had sulphuricacid, been decomposed and redissolved by three drachms of rece mache has tified sulphuric acid. In two or three minutes the solution; retted hidroe which was before like water, assumed a blue colour. Five gene minutes after a light chocolate brown matter was deposited on EXPERIMENTS ON MOLYBDENA. 255 on its surface, and on the wet sides of the vessel; but this disappeared after a few minutes. The fine blue colour of the solution changed to a black, and a precipitate of the same colour fell down. The liquor having been filtered, and set on the fire, became again of a fine blue by boiling, The ‘water with which the precipitate was several times washed was also blue, but the colour had little intensity. The precipitate, having been dried, was of a blueish black, and exhibited the following results, 1. Boiled in mo- derately concentrated muriatic acid, it yielded a brownish yellow solution. @. Thrown into a crucible at a dull red heat, it burned with a fine blue flame; which in a crucible at a bright red heat was quickly over, but there was a very considerable extrication of sulphurous acid after the flaine had ceased. The residuum left after the combustion with flame was of a blackish brewn, insoluble in water, and re- ducible to molybdic acid by increasing the heat. Put inte water and shaken it gave a light blue tinge after some time. The résiduum separated by the filter had lost its brown bue, and appeared almost entirely bleck. These experiments in- dicate, that the molybdic acid had been at first disoxigenized, and that afterward it entered into combination in the brown- ish black precipitate, which appeared to contain a littie blue ‘oxide; a circumstance that ‘seems peculiar in this case, and merits investigation ; but which in other respects comported itself as in experiment 45. From all the experiments repeated sci the 9th and 10th General re- heads it follows: Ist, That potash exerts scarcely any.action marks on the on sulphuret of molybdena in the humid. way; that this er ial ial action is more considerable in the dry way; and that in dis- solving afterward in water a greater or less combination of iene hidrogen with sulphur takes place. ‘Qdly.. That Bie sulphuret of potash comports itself in Tachi a the'same manner. From compounds formed in the dry way ?°%bs acids precipitate a matter, which is a sulphuret of molyb- dena containing a small portion of sulphuretted hidrogen, and which comports itself with acids nearly as native sul- . of molybdena. « Sdly. . The hidroguretted alkaline sulphurets precipitate hidrovuretted Sbiacthe. solution of molybdic acid a matter of a colour si- aa aie ey ~ milar 246 and sulphu- retted hidro- gen. Conclusion. } Farther expe- riments pro- mised, Native gold found in the sands of rivers. » NATIVE GOLD DUST. milar to that of chocolate, which imparts a blue colour to” the acids in which it is dissolved, and appears to differ from the preceding in the oxidation of the molybdena, and in - containing more sulphuretted hidrogen and less sulphur, Thus we-have two compounds of this kind; and the latter appears capable, under certain circumstances, of being cons verted into the former. 4thly, Puresulphuretted hidrogen gas equally combines with molybdena, exhibiting phenomena that indicate a dis- oxigenation, and forms products similar to those resulting from their combinations. The passage of this gas through a solution of molybdate of ammonia gives rise to a triple compound, which is soluble in water, decompofable by heat, and rendered by it similar to the native sulphuret of molybdena. I here conclude the publication of my experiments on molybdena. Iam free to confess, that they do not exhibit a complete work; but I flatter myfelf, that some conclusions may be drawn from my labours not altogether unimportant to the science of chemistry. Besides it was necessary, that such experiments should be some time made; and I can aver, that I employed all the care and attention possible, so that complete reliance may be placed on their accuracy. Farther experiments will complete what I have begun. These I shall undertake, as soon as 1 have procured a suf ficient quantity of molybdena, and my occupations will af- ford me leisure. ITT. On the native Gold Dufi found in the Hills in the Environs of the Commune of Si. George's, in the Department of the Doire: by Mr. Grutio, Prefect of the Department — of the Sesia*. Ir has long been known, that a great number of rivers and brooks carry with them particles of native gold, af * Journal des Mines, No. 116, p. 145. larger NATIVE GOLD DUST. 807 Jarger or smaller size: that independently of the places where this metal is found in its native situation, it is disses minated in grains in their sands, as those of the Rhone, the Arriége, and the Céze in France, and with us in those of the rivers Doire, Balthée, Cervo, Elbo, Mallon, and Orba, and of the rivulets Oropa, Orémo, Evancon,, Vison, &c, It is equally known, that there are persons, who make it their whole business, to search for this gold. Mineralogists are not perfectly sitet respecting the ori- Its origin dis- gin of this gold dust; for the oldest, os among the moderns puted. Brochant, suppose this gold was originally Brought from mines, commonly situate in. primitive mountains, from which it has been washed down by the water of the rivers. “ Na- tive gold,” says Brochant*, ‘is found chiefly in primitive Brochaat. mountains, where it is met with in veins, and sometimes disseminated in the rock----it occurs also in alluvial strata, where it is frequently wrought with advantage.. The sand of several rivers is mixed with grains of gold, which are se~ parated from it by washing. It is unquestionably evident, that the gold here is met with accidentally; and that it is deposited by the water, that has washed it away from its original situation, which was probably the same as is indi- cated above.” Others on the contrary think, that these metallic parti- Supposed to be cles were originally disseminated in auriferous strata, in the Bre: oes very places where they are exposed to view by great floods, or overflowings of the rivers, or that they have been washed into the Jatter by torrents in storms oc» heavy rains. I do not intend to enter into the question generally, or at large. This I leave to the learned, whose chief study is the improvement of the science of mineralogy. My induc- tions go no farther than the small number of researches I have made: yet I think I may venture to.say, from the ob- At least not servations I am about. to present the reader respecting) the Parser ee 2 a Tocality and situation of the native gold dust in the com- mines. mune of St. George's, that such dust is not always washed down from mines in the mountains by rivers. And if such ‘ * Elementary Treatise on Mineralogy, according to tlie Principles of Prof. Werner. Vol. Il. were 268 This the opi- nion of many. De Robillant. Balbo, NATIVE GOLD Dust. were the primitive origin of their dissemination amid the strata, it certainly could have happened only at some very remote period of the grand distuptions, that have taken place on the surface and exterior strata of our globe. But these revolutions, of which we have bo records, are buried in the night of time. For we shall see, that stratd, which furnish gold dust, are found at a considerable depth jn some hills, equally remote from mountains capable of furnishing it, and from rivers that could force it from its native situa- tion. Consequently it could have mingled in them only at a very distant period, when ‘the strata of the hills assumed the arrangement they have at present, namely, a at the time of their formation. Such too has been the opinion of several naturalists of our country, and I should be guilty of injustice to them, if, i in collecting fresh proofs tending to support their hypo- thesis, T omitted the mention of their valuable works. Ac- cordingly I shall quote “Ir. de Robillant, who, speaking of the gold dust found in the sands of the Orco, says very positively: ‘ this river carries along gold, which the people of the country observe only below the bridge down to the Po: which confirms the opinion held by the people best ac- quainted with the natural history of the country, that it is from the gullies and hills that this gold dust is washed down into the river by the rapidity of the water during storms---*, This valuable metal does not come from the high mountains, since none is found above the bridge, but it originates from the washing of the red earth, of which most of these hills and plains are composed, and which in stormy weather 't is carried down into the principal river ft. Mr. Balbo generally adopts the explanation of Mr, de Robillant respecting this species of native gold, in his learned Memoir on the auriferous sand of the Orco. * Every one,” says he, “ knows, that gold dust is collected’ in the Orco------But I do not believe it is equally known, that gold is found, not in the bed of the river alone, ‘but to the * See a geographical Essay on the continental Territories of the King of Sardinia, by de Robillant, in the Memoirs of the Royal Academy of Sciences of Turin for the years 1784,5, Part HW, p. 234. + Ib. p.268. distance NATIVE GOLD DUST: 269 distance of several thiles, every where mingled more or less Found in the with, the sand.....-It ia very positively asserted, that it oc« ase hts gl curs in all the little rivulets between Valperga and Rivara river. seeeesd endeavoured to discover, whether all the waters tise sufficiently near to each other, to lead us to suppose, that they equally derive their gold from the same mine: as it is in this way that the vulgar, and even most of the jearned, generally account for the gold found in rivers. But I was completely convinced, that the waters of which I t, speak arise from different heights at some distance from one another, so that, as we cannot suppose all these places to contain mines, from which the gold may be derived, we _ must, necessarily admit, that the particles of gold are not _ separated daily by the action of the water, and carried along _ by its streams, but that the water finds them in the soil it- self over which it flows-.s.«- Aad it ts farther confirmed by the ebservation, that the anriferous strata disappear as we proceed up the Orco; that we find them at. farthest only as high as the bridge ; that above this all traces of them are lost, though this is very far from the springs, while as we descend into the plain these strata are every day exe posed by the action of the water, and particularly in. floods *.”” In a second part I shall speak of the theory proposed by Supposed to Mr. Napion, in his Memoir on the Mountains of Canavaist, © shee from py= who, having observed that all the pyrites of those mountains. are auriferous, attributes the particles of gold to their de- " eomposition or attrition.. This is the opinion of our worthy egileague, Dr. Bonvoisin. 4 . The « observations I am now about to communicate appear Further proof 4 , to ine still more decisive, than the proofs alleged by these wl period to _ authors; and if the earths of which I shall speak do not furnish, so large a quantity of gold dust, they afford indis-. table arguments, to convince us, that the gold certainly. does not proceed from avy mine traversed by water, at least baits present day. . “* Mem. of the Roy. Ac. of Turin for 1784,5, on the auriferous Sand of Orco, Part IT, p. 404, 407. +t Ib, for 1785,6, p. 945,6. On 270 NATIVE GOLD DUST. Hills in the On the north of the commune of St. George’s, in the cir- department of , : : the Doire, Cle of Chivas, in the department of the Doire, we find fer-. tile rising grounds, and hills almost wholly covered with vineyards, which continue till we come to the highest of them, the hill of Macuenano, part of which is cultivated, part covered with wild chestnut trees; a distance of about three miles. | Three distinct In proceeding from the outer and upper surface of these — hills to the bottom of the valleys, which intersect them in. different directions, we find in general three very distinct strata. The upper. The upper stratum is for the most part argillaceons, as it furnishes an excellent earth for making bricks and tiles. The thickness of this stratum varies in different places from The middle. three or four feet to twenty-five or thirty. The second stra- tum, which stretches likewise horizontally beneath the stra- tum of clay, is a few feet thick. It is composed of a con- siderable portion of sand, of gravel, and of pebbles of different natures, argillaceous, calcareous, and quartzose. Of these I shall speak more particularly in the second part, as well as of the fragments produced by their being broken Thelower. or decomposed. The third or lower stratum, which forms the bed of the valleys, and of the rivulets that run through them.in rainy weather, ‘is composed in great measure of the’ fragments of the argillaceous and calcareous stones’ of the second stratum. ok ‘Walleys pro- The rains gradually produced little gullies in different: besa direetions; which by the falling of fresh rain, and the quan- tity and rapidity of the water, have in the course of time been extended and converted into. valleys, more or less broad and deep, in different places. ' Part of the water of? several gullies accumulates particularly in one valley, where during storms and leng rains it forms a torrent, called in’ and gold found the country the MEc#de nizones Now the gold dust is found in them, chiefly among the sands of this torrent, and of the small la-- teral rivulets, that flow into the Merdanzone or other simi-~' lar valleys. " : But does this ald proceed Paley from the different: strata I have mentioned above, or from one of them only ? None in the [ first examined the brick earth, that of the upper stratum, in NATIVE GOLD DUST. 971 od in different places and at various depths: I also examined upperstratum considerable depositions of this earth accumulated in the shallow valleys: but I never discovered the smallest particle of geldin it. The searchers for gold knows this so well by long experience and a great number of fruitless trials, ' that they never pay any regard to this stratum. It is the pe the mid. stratum beneath this, that composed of gravel, sand, and” ime. broken sfones, in which the particles of gold are found. Of this I have convinced myself by repeated trials: and Most in the though in general, if equal quantities of earth be taken aes from this stratum, and from the bottom of the torrent or ri- vulets flowing idto it, the latter will yield most gold, it scarcely ever happens, that no gold is found in the latter upon trial. The particles of gold obtained from the auri- This distin- | ferous stratum itself, which have not yet been rolled along euighable ga 5 the others with the sand by the rains, have a duller and deeper yellow _eolour than those collected in the bed of the torrent, or of the rivulets, which are of a more shining yellow, no doubt in consequence of the attrition. "They are generally found amid a sand, that is more or less fine and blackish, and apparently ofa siliceous and ferruginous nature. The earth 6f the same nature, which reaches to some distance, equally contains gold. Thus a brook that runs on the east of the commune of Aglie, between the mansion and the park, and receives the rain water that washes down an earth composed of different strata of the same nature as‘ those of the auri- ferous hills of St. George's, equally rolls along particles of gold disseminated beneath the argillaceous stratum, which in certain places 1 is of very considerable thickness, Fifteen or twenty j years ago several persons in the com- Formerly col- mune of St. George's made it their principal employment, lected to search for gold in the sand of the torrents and rivulets that I have mentioned. This they did particularly after or during heavy rains, and after storms. i he quantity of gold they collected in a day was very vas \ +4, some friable. Sometimes each of them would gain eight or ten profit, shillings a day, at other times scarce a fourth or fifth of this sum. ‘The size of the particles too varied much, as from an almost invisible atom to the weight of nine or ten grains or more e772 Cs WATIVE GOLD DUST: more. They were afterward sold to merchants, who sent thera to the mint. Gold found in 1am not speaking here, as is obvious, of gold dust dis~ other stiua- — seininated in arable land. Earth of this kind in the territory tions, : : ‘of Salussole, as I am informed by my colleague Giobert, contains particles of gold. The earth of gardens is known to contain them. It has been proved in our days by the ex- periments of Sage, Berthollet, Rouelle, Darcet, and Deyeux, that there are particles of gold in vegetables, Berthollet has. extracted about 2°14 gram. [83 grs.] from 45000: gram, or 2 hundred wei ight of ashes. Here not on Hitherto gold has not been found in the arable land in euasen the environs of St. George’s, but only in the stratum be- sometimesio neath the clay, the surface of. which is cultivated. The @ considerable Gepth. j : t ; feet deep below the argillaceous stratum in some places. We have nothing to do here with particles of gold mixed. with the surface mould by the decomposition of plants, or which plants have derived from the earth, I have no doubt, Every where it that the particles of gold found in the environs of St. has 2 common George’s have the same origin as those met with from Pont. rub, _ to the entrance of the Orco and of the Mallon into the Po, from Valperga and Rivara to Aglie and St. George's; as well as of those, which Dr. Bonvoisin observed i in the envi- rons of Challant in the valley of Aoste. The famous piece. of native gold preserved in the arse: al was found there. In that space pieces of gold of the weight of a louis have sometimes been found; and other pieces are mentioned of. the value of more than 1001. [£4 3s. 4d.]. It is probable, that the gold found in the earth i in the valley of Brozzo, and in other places, has the same. origin. I shall propose my conjectures on this subject 1 in the second part of this memoir, where I shall enter more at large into the nature of the earths and stones of the auriferous strata, as well as the nature of the land in which they are contained... — auriferous stratum, as I have observed, is more than thirty. IV. Es tl DIRECT ATTRACTION OF A SPHEROID. | O78 IV. Calculution of the direct Attraction of « Spheroid, and De-_ monstration of CiuatrauT’s Theorem. By a Correspondent. foads iv . To Mr, NICHOLSON. SIR, Tue same mode of calculation, by which the figure of spatecsin of @ gravitating body, differing but little froma foes has ae been determined (p. 208 of "his volume), is also applicable to the magnitude of its immediate attraction, or the com- parative Veueth of a pendulum in different latitudes. ‘Suppose a sphere to be inscribed in the spheroid, and Attraction of _ another to be circumscribed about it; I shall first show, oe that the attraction at the pole is equal to that of the smaller sphere increased by ;*; of that of the shell, and at the equa- _ tor equal to that of the larger diminished by 32. If we call _ the attraction of this shell 2, its surface beiag equal to the curved surface of a circumscribing cylinder, the attraction of a narrow ring of this cylinder, or of the elevated portion of the ashen at the equator, supposed to act at the dis- _ tunce of the radius, or unity, may be expressed by its breadth: but in its actual situation its attraction in the. di- ; rection of the axis is reduced in the ratio of the cube of the chord of half a right angle to the cube of the radius; and the attraction of any other ring will be to this in the ratio of the quantity of matter, or the cube of the sine of the distance from the pole, and of the versed sine directly, and _ in the ratio of the cube of the chord inversely; that is in the joint ratio of the cube of the cosine of half the angie and the versed sine: thus, if we call the cosine of half the angle.xs. 1a tee sine being 2—2*, and the fluxion of the arc ——, the fluxion of the force at the equator 7 —F ra) vi be ware a, rater and elsewhere as much less as ii Vex. XX—Auc. 1908. rt z? Polar & equar. torial attrac- tion, DIRECP ATTRACTION OF A SPHEROID, F ATF 2/2 / Gaerne , of which the fluent is found as before (¢ x* 3 (2—2-2*) is less than Ax? x Cait aa A te of? — 44.) / (1— 2x); and this becomes <8; while increases from 0 to 1, being to 2, the attraction of the’ whole shell, as 4, to 1; but if the radius of the sphere be 1, and the ellipticity e, the attraction of the shell will be’ 3 é f : oe to that of the sphere as —— to 1, » being the mean’ den- 2, sity of ae Bap aa Cots pelt ed ith that of the Te artedl j parts, and the attraction of the spheroidal prominence will 4é Ft 5 : be. expressed by EF that of the sphere being unity. The depression below the circumscribed sphere is. equal, on the meridian, to the elevation above the inscmbed spherez but vanishes’ at the equator, being every where propor tional to the square of the sine/of the latitude; so that the mean depression of each of an infinite number of rings; of which any point of the equator is the pole, must be half as: great asthe elevation of the corresponding rings parallel to the equator; and the whole deficiency is equal to half of nt AP 7 4 : i; 2°@ ; the whole excess, that is, to Pe: consequently, the re-: n ‘ . oi}. ! } SS etie Meds 2 PG maining attraction of the shell is Bat from which we grid te 2" must deduct the diminution of the attraction of the in-’ 13 e sctibed sphere Ze, and. th e whole will become F ms a bas s Fie : rie eee : 2e, which subtracted trom 1 ty ae leaves 2 poses for’ the excess of the immediate attraction at the pole above’: the equatorial attraction; to whieh if we add the centrifu- gal force f, the whole diminution of gravity g will be 2.e— € oe —~++ f; >but since e was before found to f-es-1 to 2 wig® 50 ‘ Fm 457 5n On-—9 = 10n—9Q oOrgs> ~ mee hese 2as-———+-¢ ae ee Dy 16 2 ert 3. its “10-1 = 6° Ss DIRECT ATTRACTION OF A SPHEROID. 975 207m —15 and sie se . J, to which if we add e, we find e+¢ = AE = f= 4/; and this is the celebrated theorem: Tw of Clairaut. Tt remains to be shown, that the diminution of the at- Variation of tractive force at different par‘s of the spheroid varies as: the gravity. square of the cosine of the latitude. The elevation, being eyery: where proportional to the square of the distance from the axis, may be divided into two parts; one proportional to. the square of the sine of the distance from the meridian of the place, nnd the other to the distance from the plane of another meridian perpendicular to it: but the first, of these being constant, whatever may be the position of, the place | to be con: sidered, the second only produces the varia- tion, Now if we take in the second. portion the mean. of the elevations ; at any two points of a legs circle, equidistant the squares, of the distanc e of the centre of the la Hm the axis, and of the cosine of the distance from, the meri- dian in the same circie, reduced to a sitnilar direction, that | ig, | diminished 1 in the ratio of the radius to the sine of the . * latitude, since twice the sum of the squares of any two : quantities is equal to the sum of the squares of their sum and their difference. We have, therefore two quantities, varying as the square of the cosing, and as the square of the sine of the latitude respectively : but the square of the. * sine may be represented by a constant, quantity diminished by. the square of the cosine : and the decrease of the attrac- tion of the. inscribed sphere is as the elevation, which is as the square of the cosine; the centrifugal force reduced to a vertical ‘direction is also as the square of the cosine. We have therefore, beside ‘two constant quantities, two negative forces. and a positive one, all vary ing as the squares of the cosine of the ‘latitude ; and itis obvious, that the joint re< sult, of the whole, or the upper real diminution of gravity, niust also vary in the same proportion. a _A. B.C. D, 99 Pine’ 1808. To Vs 27 Silence not to be allowed as am argument. Series not mentioned. REPLY TO PROF. VINCE. Reply to Professor Viicr’s Ultimatum. By a Correspondent. To. Mr. NICHOLSON: Sir, 4 fl Tr; is no unusual expedient with an expert dispufant, to affect a contempt for his antagonist, which he does not feel ; and to decline a contest, to which he is unequal, on the pretence, that it is superfluous to engage in it. 1 am far from wishing, to protract a controversy with Professor Vince; but I protest against his right to excuse himself from the necessity of replying to any future observations of mine on the ground of his engagement not to trouble you further on the subject. If however the Professor thinks my remarks undeserving of any additional notice from him- self, it is to be presumed, that some person will be found among the numerous disciples of that illustrious school, in which he holds so distinguished a situation, who will uns dertake the easy task of confuting me, and vindicating the - honour of the university from the slightest shade, that the publicity of such a mistake as I have einai to’ Professor Vince could possibly cast on it. I grant, that three quantities are “ put down” in hd essay, which the Professor now calls the first terms of three series ; but I still shall deny, that these series are to be found, or are any where mentioned, in that work. It is not a Httle re- ntarkable, that a man, whose hfe is devoted to the seience of réasoning with accuracy, should adduce so weak a proof of my being guilty of misrepresentation. With respect to the sufficiency of each of these ie ties for determining its share of the force, Professor Vince’s words are, p. 19: ‘* Now the terms omitted in the Quantities em- series are comparatively so extremely small, that if they ployed said to be sufficient, were pot considered, they could make no sensible alteration in the result” And now he accuses me of _@ seeond ** une accountable misrepresentation,” for saying, that he has men- tioned / PEPLY TO PROF. VINCE. {77 tioned the terms actually employed “ as sufficient” for his Purpose. , In the third place, he does nut appear to be aware of the Law of gravita- distinction between physical and mathematical accuracy. FEMA age Physically speaking, the series * may certainly” vary as truth. 1 : : . ae = with as little sensible errour as the law of gravitation: mathematically speaking, we have not the slightest evidence, pe. 5 col that the law of gtavitation “ varies accurately” as ~ and in this sense the Professor's assertion is totally void of foun- @ation. ; ) flay The change of the law of density of the medium at the Law of density surface of a planet, instead of being * inconsistent with cece Newton’s hypothesis,” is the simple and unavoidable conse- in a planet. quence of it; Each particle of matter being supposed’ to induce a certain state of the medium around it indepen« dently of all others, so that the attraction may be produced alike in all circumstances, the state of the medium withia the planet must necessarily be such, as to producé*he joint effect of all the attractions; that is, the force must vary as x, and the density as xx or aa; the square of the distance ' from the centre; and this must be the immediate conse- ' quence of the same cause, that produces the usual variation of density with respect toa single particle. It may be said, that the operation of this cause is equally obscure with the ultimate effect of gravitation considered as independent of it; and 1 am perfectly ready to admit the objection. [am not defending the Newtonian hypothesis; I am only en= deavouring to show, that Professor Vince has attacked it unsuccessfully, and has heaped errour upon errour in ate tempting to support his arguments. I am, Sir, Your yery obedient servant, 8th July, 1908. DYTISCUS. Vi, 278 IGNITION BY COMPRESSED AIR, VI. Question respe ecting the Ignition of Tinder by compressed Ai ite ae wey @ Letter Srom a Correspondent.” . “To Mr. NICHOLSON. PERy , | | ahaa Ay MONG the mumnber of philosophical apparatus of mo~ nited by con- dern inyéntion, there are perhaps f few which involve move densed.air, interesting matter of inquiry, than ap instrument lately con= trived si setting ‘fire to cOnanas pth e a by the agency of compressed air. a c ina syringe of »: The little apparatus, which I have seen for this purpase, — sae was in the possession of Mr. Accum, who ‘showed me its surprising e ‘ects 11 igniting common tinder, and different “species of fungi. ‘This singular mode of producing fire is accomplished by the quick compression of the small quan- tity of air contained in’ a ‘condensing’ syringe of small size. Tt might perhaps be matter'of considerable importance, in a plosophical point ‘of view, to'ascertain what’ change the air undergoes during this operation; ‘whether the effect | produced is to be ascribed to the ‘rhechanical action of the air, or toa Toner of ae induced by the ee cons densation ? | Your remarks may tend to dhe elucidation of this ver oy curious fait. f pus sa gente A ge What is the cause 2. iat Sir, Yours respectfully, Titieale S * ditt, doly isth, 1808. a T, CLIFTON, Eiiahs RLY andes Apparently This pivicrnene, which is now be some standing, seems diminution of capacity. to ee on the diminution of P capacity, preduced by thé , : "eaayen Nicholsons Phulbs, Journal, Vol.20P1: 7. pZ / ‘9: TT Hy MN / oc TITLIMnINDPILLDODILLLLLLLLL (i ITH il i (s) ARTIFICIAL HORIZON. | 279 ogi peegenia From Mr, Dalton’s experiments, (see our Journal, vol. ITI, p. 160) it appears, that the con- -densation answering to the pressure of our atmosphere af- fords an increase of temperature upwards of 50 degrees; and, if we suppose this augmentation to be in the simple ratio of the compression, aesuath it is probably higher, a compression of 18 atmospheres would give ‘the temperature of PgpiHOn, WaN,. VII. Deseription of a portable artificial Horizon for taking Al titudes at Sea or Land, by Mr. Wricur. In a Letter from t the Inventor. Srr, I Beg leave to transmit you a déséription and delineation Artificial hori. of an artificial horizon, which I conceive will be found pre- 700 described. ferable to any other in use. , Plate VIL, fig. 1, represents the horizon with all its parts complete: fig. 2 Q,a cylindric vessel of brass, to be filled with water when in use: fig. 3, the upper part of the horizon taken from the vessel, to show its internal. parts. AA are vo uprights of brass and a horizontal axis on the top, ith twe ite edges 4 at BB, on ‘which the brass frame CC is : ded. ’ At the bottom of the frame are an index and- two. sights; the nearest sight E having a fine horizontal edge on its top, and on the farthest sight Fis a fine black line in a piece of transparent ivory. The index i 18 adjusted to a horizontal position by two screws, which fasten it also to the frame when adjusted; on the index 1s a conyex glass to magnify the line on theivory sight F, and throw its image on the edge of the sight E; and under the index, im its | gentre, is screwed a thin brass blade H, to be immersed i in the water in the vessel, fig. 2, for the purpose of preventing the herizen from getting any vibrating ex pendulous motion’ to , 280 Method of t taking an alti- tude with it. ARTIFICIAL, HORIZON, ° to disturb its gravity, or divert the sights.from. their hevieau- tal direction, when in use. If the ship have.a considerable motion, it is bh a tn to suspend the box bya small brass gimmal at the top toa por- table stand; and to prevent the wind’s affecting it, a glass slides into each end of the box, through which the observa- ‘tion is taken; their surfaces being parallel, you adjust it by the sea horizon, or by meridian altitudes of the'sun, the la- titude being known, or by any other method observers make use of, or allow the index errour, as is done with the octants and sextants. D is asmall brass pin, to prevent the index from getting any motion in carriage; and is to be taken out, when the horizon is in use. . i, In observing the moon, planets, or stars, by night, a small lanthorn with a lamp is necessary, to be placed behind the box, so that the light may fall on the ivory, to show the line distinctly ; and to prevent its spreading too much when you are observing the stars, the glass is to be taken out, and the brass with a small square hole, G, slid into its place. To take an altitude with the octant and artificial horizon, bring the eye as near to the horizon i in the box as the frame of the octant will admit of, and in a horizontal line look at the fine edge of the sight E, which by the least motion of the head you may bring into contact with the line on the ivory sight F, and move forward the index on the frame of the octant with your hand, to bring the object you are ob- serving to a coincidence with the ivory lme also, For “altitudes of the sun or moon, and for all terrestrial objects, an octant of the usual construction will answer every purpose; but for observing the stars, one with a larger horizon glass, and its silvered sur intace aap. larger, with a dit; missing or mistaking a star when near to others, or its getting out of the glass in bringing mto contact with the horizon, With sucha quadrant and this horizon, the me~ ridian altitudes of all bright stars, as they come to the me- ridian, may be taken, by which means the latitude might be frequently found by observations at night, and with as much ease as by the sun at agonday also, the altitudes of the moon ‘MACHINE TO PREVENT DROWNING. 228i moon and stars, to correct the lunar problem for the ae tude, will ig more correctly and easily taken with it i I am, Sir, ‘ Your very obedient humble servant, : J. WRIGHT, VIL. Description of an Apparatus tosecure Persons from sinking in Water, or to act as a Life-preserver when shipwrecked, with inftances of’ tts Utility: by Mr. F, C. Danten, of Wapping*. ‘ gs 4 I HAVE taken the liberty of sending one of my life pre- Life-preserver servers, and am proud to say, they nove realized the name; ard I shall feel myself obliged if you will cause it to be brought before the Society for their approbation. I beg to say, Sir, though I have given it publicity >it has never been before any committee. I have enclosed a copy of a letter, which I received from has already the only surviving officer of the Alert private ship of war, = a and, independent of that document, I have had information from respectable authority, that the machines have saved several lives. It is not, Sir, a pecuniary reward I look for, although I have sunk near £1500 in the undertaking; yet, I must con- fess, to have the sanction of the Society of Arts would be highly flattering, and the world from that moment must be gees of their utility. I have the honour to be, Sir, r 2 ONE sg - Your obedient servant, F.C. DANIEL. ‘* Abridged from Transanctions of the Society of Arts for 1807. The gold medal was voted to Mr. ‘Daniel for this invention. Copy 282 MACHINE TO PREVENT DROWNING. ; oo @9 4a 1 Ogg Copy of a Letter from’Mr. Georce. Waiters; late Surgeon of the Alert, private Ship of War, lost off the Western dslands. Sir, Privateer i AM happy in having it in my power to say, I owe my life to your invaluable invention, the life preserver; and the circumstances relative thereto are as foilow :—I shipped as surgeon on board the Alert, private ship of war, mounting wrecked near 18 guns, and 98 mea, commanded by James Desormeaux, decemaam esq., belonging to: Mewar: Ww right aad Birch, W albrook. pie We sailed frou Falmouth, April 1805, and, aiter cruising five months, on the 22d of September, we unfortunately struck on a rock among the Western Islands, and the ship went to pieces in five minutes; at that time we had eighty~ four men on board: I witnessed the loss of every officer, six in number, and six ty-four foremast men ; thirteen of the - ‘The surgeon crew were saved, by clinging to pieces of the wreck, spars, al i &e. which drifted’ from the wreck ; and J have the happiness to say, by possessing’ one of your life preservers (though I cannot swiin,) I was suppor ted for some time, the sea run- ning mountains high, but providentially a large Portuguese boat put off'to my assistance, being then near a mile from the shore; and Iwas thus saved, by the hand of Providence and your invention, from a watery grave.” I beg, Sir, you will permit me to ackiowledge how much . TP feel myself obliged to you; aud you are at full liberty ta make this case known for the benefit of mankind. I am, Sir. Your most obedient servant, G. H. WILLERS. - \ rr diners sete R Copy of a Letter from Joun Drexenson, Esq. of the City of Norwich, to Mr. Dawiet. rf Sir, TINTENDED myself the pleasure of calling on you, ; and acquainting you personally of a singular incident, whem j the MACHINE TO PRUVYEN'T DESWNING 283 the excellence of your machine, or hife preserver, was most conspicuously manifested. J went from the city of Norwich, ina pleasure-boat that A pleasure I keep for the amusement of sailing, in company with ae gentleman and two ladies. As our return to Norwich in the evening was-indispensible, and the direction of the wind favouring us both ways, a few hours would effect it, the distance being only thirty miles: accordingly we set sail aboyt four o'clock, it being moon-light during the night; and forturiately eked | in case of accident’ (the wind blowing hard at south-east) one of your life preservers, through the interest of a friend, of’ captain, who had pure chased one at Newcastle. ‘The precaution proved, in a short time after sailing, to have been a fortunate one indeed. On tacking to enter. Norwich river, at the extremity of a broad water, two miles over, known by the name of Braydon, * rok a sudden gust overset ‘the boat, precipitating myself, com- side panion, aud two ladies, into as agitated a water as I have ever seen at sea, (except in hard Lbluiiing weather). You 4 may judge my situation at such a juncture. Your machine was jokingly filled as we came aloug, to which I aseribe {though very unexpected by us) our preservation, The Two pale gentleman, whose name is Goring, was inexpert at swim- Galles toile ming, and with ‘difficulty kept himself up, till I reached Up by one life hin; and then ‘directing him to lay hold of the collar of eee ‘my coat, over which the machine was fixed, I proceeded towards the ladies, whose clothes kept them buoyant, but — jn a.state of fainting when I reached them: then taking one of the ladies under each arm, with Mr, Goring hasten ‘ing from the collar of the coat; the violence of the wind drifted us on shore upon Burgh Marshes, where the boat had already been thrown, with what belonged to her. We got the assistance of some countr ymen directly, (after tak- ing refr eshment at a marsh farmer’s house, where we pro- cured some dry clothing for the ladies, who were now pretty well recovered,) and by their endeavours put the boat in sailing trim, and prosecuted our voyage to Norwich, which we effected by eleven o'clock that night. - From this smgular escape, on my return from Birming- ham, I shall be induced to inspeet your warehouse, and The machine described. MACHINE TO PREVENT DROWNING. procure the various prices of your invention, anxious to recommend it in even sailing excursions, in which its utility has been so evidently demonstrated, and its use ascertained, You are at liberty, Sir, to make whatever use you please of this account, and | beg to subscribe miyself, Sir, Ae Your most obedient humble peer J OHN DICKENSON, Swan with Two Necks, Lad Lane, Jan. 30, 1807, — Reference to the figure of Mr. Danie? s Machine, ealled a Life Preserver when Shipwrecked, Pl. VIE, Fig. 1.. A, represents the body of the inachine, which is double throughout, made of pliable water-proof leather, large enough to admit its encircling the body of the wearer, whose head is to pass betwixt the two fixed straps, BB, which rest upon the shoulders; the arms of the wearer pass through the spaces on the outside of the straps; one on each side, admitting the machine under them to encircle the body like a large hollow belt; the strap, C, on the lower part of the machine, is attached to the back of it, and by passing betwixt the thighs of the wearer, and buck- Ting at D, holds the machine sufficiently firm to the body, without'too much pressure under the arnis: The machine, being thus fixed, is inflated with air by the wearer blowing Method of making it. in from bis lungs, through the cock E, a sufficient quantity of air to fill the machine, which air is retained by tutning the stop-cock. The machine, when filled with air, will dis- place a sufficient quantity of water, to prevent four = from sinking. ' . Mr. Daniel recommends his life pibseteied: to be prepared as follows: viz. To select sound German horse-hides, and to cut a piece six feet long, and two feet six imches wide, free from blemish or shell; it is first to be curried, and then sess ‘ed water-proof by Mollerstein’s patent varnish, of Os- * born. (inn HUTT i it CC = “7 o 2 ao sic CL BAp9 7 PIOVUD FZ Vi A mm MO WIATHI4 fy ¥ OY) 290V PUMLIN Pomsnog soynyg suosprpyy Fa EE * oe PE ke Sx BT : x é 7 Ms 2 are as ARNE ae j y “ iy "y A. Ww Ai a Wk te iy io ee i ru rs ial > ae, Ae ; os ~ Sy ‘f vy Ss ps 4 ae es ey a ne es J ‘<“ yy * : . : } ent ' Jeet % My. ‘ a . } 4 7 . \ SAVING LIVES IN CASE OF SHIPWRECH. 28% born street, Whitechapel, which preserves the leather more supple; and admits it to be easier inflated than any other watet-proof leather. Theleatheris to be nailed ona board, and the varnish applied upon it; it is then to be passed into an oven several times; the varnish being each time repeated, till the leather is com pletely covered; it is then cut in the form of a jacket, as above described, and neatly and firmly stitched ; the seams and stitches are afterwards to be perfectly secured by the following black elastic varnish. Take of gum asphaltum, two pounds ; amber, halfa pound; Varnish for the gum benzoin, six ounces; linseéd-oil, two pounds; oil of *"* turpentine, eight pounds; and lamp-black, half a pound; unite them together in an earthen vessel with a gentle heat. ‘The machine, when properly made according to the draw= ing and description, resenibles a broad belt, or circular girdle; composed of two folds of pliable leather attached together, and perféctly impervious to waters IX. Account of Experiments made by Lieut. Joun Beur, of the. Royal Artillery, to ascertain the Practicability of throwing a Line to the Shore from @ Vessel Stranded*. Tue several trials made before a Committee of the Society at Woolwich, on the 29th of August 1791, ef throwing a line on shore on this principle; were as follow. Experiments. From * Trans. of the Society of Arts for 1807, p. 136. A publicity having been recently given to some experiments off the eastern coasts of this island, for preserving lives in cases of shipwreck, by means of a ropeat- tached toa shell thrown from a mortar; the Society deemed it incum- bent on them to remind the public, that, su far back as the year 1792, a bounty of fifty guineas was given to Mr. John Bell, then sergeant, afters wards lieutenant of the Royal Regiment of Artillery, for his invention of throwing a rope on shore, by means of a shell from a mortar, on board the vessel in distress; the particulars of which were published in the tenth volume of the Society’s Transactions, page 204; but a descriptive engraving 286° _ SAVENG LIVES IN CASE OF SHTPWRECE” Abzllcarrying © Frey a boat moored about 250 yards from shore, the’ oh abieaebed shell was thrown 150 yardson shore, with the rope attached » 2 boat. to it; the shell was of cast iron, filled with lead, it weighed” 75 Ibs., its diameter 8 inches; the rope inthe trial was a deepsea-line, of which 160:yards-werghed 18 lbs; the angle of the mortar, from which the shell wag fired; was 45 de-) grees. By means of the line; Mr. Bell and another man worked themselves on shore upon his raft of casks; there were many kinks im the rope, which were with ease cleared by Mr. Bell, in wh uch he was much assisted by his snatch ® blocks: = a Tota . A second trial ‘The second trial was repeated iu a similar manner, and) agg with equal success, the shell falling within a few yards of? the former place, the gale of wind was brisk, and the water ’ rough, The direction of the shell was nearly front north toi south, and the wind blew nearly north-west? bint ipo Inch and half . In the third trial, the mortat was elevated to 70 iris o, rope throw the rope attached to the shell was an inch and half tarred B60 yards. Si Fi : rope, of which every 50 yards weighed fourteen pounds and a half; the shell of the kind above mentioned: It fell 160° yards from the mortar, and buried itself about two thirds in the ground; the line or rope ran out was about 200 yards, and it required the force of three men to draw the shell eut of tlre ground at that distance. Two men The grommet, in all these trials, wes.of white three aa worked them- b f +I selves on shore TOPe; aud in all the above trials, by means of the line, two by it. men worked themselves on shore upon the raft: each re of powder was fifteen ounces. art A grapnel not =A fourth e: speriment was made by firing, from, the sD) i moortar, a grapnel in a wooden case; it. en not retain its hold in the ground so well as the shell, but amongst thé crevices of rocks, or where the vesseliis near shore, . ail ig \ : useful. Grapnel with ~*~ A’ grapnel of this kind may be fired from a common ean: an endless rope. non with an endless rope, 1 nauning ima pulley or small block r - engraving having been omitted at that time, it was thought expedient’ to insert it in the Banger: publication, with some further particulars then omitted.” Models and Drawings of the whoie apparatus are reserved in the 5 “ect ciety’s Repository, for the inspection of the public. pins fixed eee ——e ae SAVING LIVES EN CASE OF SHIPWRECK. . 2B7 fixed. thereto, by which,a raft may be successively drawi to and from the, vessel either by the persons on board the ves~ sel,-or those jon shore. as Observations made by Lieutenant Bell, upon throwing a Line on Shore’t in Case of a Ship being stranded. in 4 hse From the aati construction the piece of ord- Weicht of the nance, intended to throw the shot and Itne on shore, I sup~ ™°"#" pose it will be between five and six hundred weight. The chamber is to contain one pound of powder, and the Dimensions. bore to admit a leaden ball of sixty pounds or upwards; the length of range, or distance, will depend upon the size of the line made use of; 1 suppose it will carry a deepsea-line “between three and four hundred yards distance. 2d. All ships that have iron ballast may use this. piece May be used as a part of it, and then there would be only the trifling * ballast. difference of casting so much of the ballast into the form of the piece; the leaden balls may likewise be used as bal- last. 3d. Iam of opinion, there are various ways, on board of May be used a ship, that the mortar may be placed in a proper position . a Cai for firing without a carriage expressly made for it; it may vg be Bisced upon a coil of rope, or its trunnions Laie upon coins, or any thing else, whereby the muzzle can be raised so high, that the groove upon the trunnion appears vertical, ag the piece in that position would be elevated nearly 45 degrees. 4th. As I imagine all ships carry deepsea-lines,, on that Line. account I made use of it in the experiments at Woolwich ; but if it should be thought too short for the distance, any other light line may be added to the length of it. “Sth, Supposing a ship’s owner to purciiase such a piece Cost, of ordnance with the leaden balis, and a biock carriage ; me do not think the whole would amount to more than ten or eleven pounds expense. 6th. Where a ship is driving or unmanageable near the The line to be shore, it would be proper to haye the piece loaded, the line Soiled on poles. reeled upon handspikes or poles, and laid upon the deck ready ry The mortar would answer for signals, ot defence, ~ Not Hable to SAVING LIVES IN CASE OF SHIPWRECK. ready for firing at any time it might be judged necessary. The handspikes-or pokes the Jine is reeled upon preserve it in a horizontal form; and they aré not to be drawn cut- until the instant of firing: in this manner the line will deli- ver itself freely. The five water casks should also be prepared in readiness, by lashing them together, and.a seaman’s chest fixed upon the top of them, having part of its ends or sides cut out; in order to let out such water as may be thrown into it by the surf. I dare undertake to land with such a float upon’ a lee shore any where upon the coast, when it might be deemed unsafe for a bodt to make good its landing. 7th. There is every reason to conclude, that this contrivs ance would be very useful at all ports of difficult access both at home and abroad, where ships are liable to strike ground before they enter the harbour, as Shields Bar, and~ other similar situations, when a line might be thrown over the ship, which might probably be the means of saving both lives and property; and moreover, if a ship was driven on shore near such a place, the apparatus might easily be res moved to afford assistance; and the whole performance Is 80 exceedingly simple, that any person, once seeing it ih would not want any further instructions, | ial JOHN BELL. Woolwich; Aug. 29, 1791. Some farther Observations meade by Lieutenant Bell, upon the Application of the Mortars intended for throwing a@ Line ow Shore, in case of a Ship being stranded: ist. In trading ships, this piece adel answer for making signals of daktees, by filling the chamber with powder, and well wadding it, as the report would be heard some miles distance at sea. 2d. Such a gua, being accompanied with a few rounds of round and grape shot, would defend a ship much better than a longer gun, against any piratical or other hostile” intentions, as, from its shortness, it would be more anny loaded and fired with a layzer charge each time. 3d, Accidents. frein”a gun’ bursting, which may’ arise SAVING LIVES IN CASE OF SHIPWREOK. 289: from an unskilful person loading with too great a proportion purse. of powder, are in this piece effectually guarded against, by the chamber being constructed to contain but one pound of powder, a‘quantity which is only about one-third of the usual charge of a cannon. 4th. From the small size of such a gun and carriage, it Not inconve- might be kept upon deck, without much inconvenience in age te key working the ship, in order to be ready if necessity required ;: site and ‘chon the ship is out at sea, it might then be put below. But from the number of dreadful wrecks, which so fre« quently happen along the coast, it certainly would be pru=' dent to have it alviate upon deck when within sight of land, and particularly in stormy weather. “Si JOHN BELL: ‘Woolwich, Sept. 30, 4791. " To C. Taytor, M.-D. Sec. we Reference to the Engraving of Lieutenant Bell's Method of throwing a Rope on Shore, from a stranded Vessel, Pl. V. IT. I, a, Q—7. , a, Represents the mortar on its carriage; 5, the. shell, Description of shown within the mortar by dotted lines; c, te grommet, the apparatus, ot double rope, which connects the shell and line; dd, the line to be thrown on shore, now ready wound on the poles or, hand-spikes, pp, which are to be withdrawn when the ‘mortar is fired. Fig. 3 Is a separate view of the shell, with the grommet and end of the line attached thereto, aba by the samé — detters.: Fig. 4 Sires another invention, ' Ghisiegiated instead of a shell, and to be fired from a.common cannon, in which e, is an iron pin; f, an iron collar and rope sliding upon it; g> an iron ring which turns upon two pins in the collar; h, is the grommet or double rope, attached to the ring, to which the line to be thrown on shore is fastened, This plan may be used where sn em on shore, to assist when a line is thrown. Fig. 5 Shows a grapnel, which may also be fired from a Vou. RRX—Ave. 1908. U common ‘390. NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. common cannon; the collar slides along it in the same man- ner as that in fig. 4, to allow the head of the pin to go down to the wadding within the cannon; 2i, are two pins on which the ring & is movable; J, the block or pulley fas- tened to the ring; m, the endless. or double line running “through it. This method maybe used with great advantage, where a ship is stranded»near the shore; but where a mortar is on board, the,use of the shell and line is the most certain: Fig. 6 Shows the method of forming a raft, by lashing together with ropes five empty water casks belonging to the ship... Fig. 7. Repr satin the raft ready for use; the arta m, to hold the person upon it, is made fram a seaman’s chest with holes cut in the sides of it, to allow the person within it firmer hold, and to let out the water that may be thrown into it from the waves; 00 are two pulleys attached to the ends of the chest, and through which the line is to run; the raft is to be ballasted underneath, to prevent it from upsetting. The whole apparatus is So arranged as to be enclosed in a small box, as may be seen by a reference to that in the So- ciety’ 5 possession. a” po The Bakerian Lecture, on some new Phenomena of chemical Changes produced by Electricity, particularly the De- composition of the fixed Alkalis, and the Exhibition of the new Subsiances which constitute their Bases; and on the general Nature of alkaline Bodies. By FLuMPHRY Davy, Esq. Sec. R.S. M.R.L.A.* Read November 19, 1807. I. Introduction. Electricity pre- Iw the Bakerian Lecture which I had the honour of pre- sumed capable of extending Se sahicd to the Royal Society last year, I described a num * Philos, Trans, for 1808, Part I, p. 1. 7 * ber NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 291 ber of decompositions and chemical changes produced in our knowledge of the elements substances of known composition. by electricity; and I ventured to conclude, from the general principles on which the phenomena were capable of being explained, that the new methods of investigation promised to lead to a more intimate knowledge than had hitherto been obtained, con- cerning the true elements of bodies *. ‘This conjecture, then sanctioned only by strong analogies, I am now happy'to be able to support by some conclusive facts. In the course of a laborious experimental applica- tion of the powers of electro-chemical analysis to bodies, which have appeared simple when examined by common chemical agents, or which at least have never been decom- posed, it has been my good fortune to obtain new and sin gular results. i - Such of the series of experiments as are in a tolerably mature state, and capable of being arranged in a connected order, I shall detail in the following sections, particularly those which demonstrate the decomposition and composition _of the fixed alkalis, and the production of the new and-ex- traordinary bodies that constitute their bases. of bodies, This conjece ture verified. ) In speaking of novel methods of investigation, I shall Novel process not fear to be minute. When the common means of che- & only descri- bed minutely. mical research have been employed, I shall mention only. results. A historical detail of the progress of the investiga- tion, of all the difficulties that occurred, and of the man- ner in which they were overcome, and of all the manipu- lations employed, would far exceed the limits assigned to this lecture. It is proper to state, however, that when ge- neral facts are mentioned, they are such only as have been deduced from processes carefully performed and often re- peated. Il. On the Methods used for the Decomposition of the fixed Alkalis. The researches I had made on the decomposition of acids; The powers of and of alkaline and earthy neutral compounds, proved, that the powers of electrical decomposition were proportional to # See Journal, Vol. XVIII, p. 321; amd XIX, p. 97. T U2 the electrical de- composition. 909 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. the strength of the opposite electricities in the circuit, aud to the conducting power and degree of concentration of the materials employed. Cee a ‘ In the first attempts that I made on the decomposition of kalis, the fixed alkalis, I acted upon aqueous solutions of potash and soda, saturated at common temperatures, by the highest electrical power I could command, and which was produced ~ by acombination of Voltaic batteries belonging to the Royal “Institution, containing 24 plates of copper and zinc of 12 inches square, 100 plates of 6 inches, and 150 of 4 inches square, charged with solutions of alum and nitrous acid ; but in these cases, though there was a high intensity of ac+ tion, the water of the solutions alone was affected, and hi- drogen and oxigen disengaged with the production of much heat and violent effervescence. } Potash infu- © The presence of water appearing thus tu prevent any de- ai composition, I used potash in igneous fusion. By means of a stream of oxigen gas from a gasometer applied to the flame of a spirit lamp, which was thrown on a platina spoon containg potash, this alkali was kept for some mmutes in a connected with strong red heat, and in a state of perfect fluidity. The spoon sehne hy was preserved in communication with the positive side of the battery of the power of 100 of 6 inches, highly charged ; and the connection from the negative side was made by a platina wire. Appeared to —-_ By this arrangement some brilliant phenomena were pro- A ih duced. The potash appeared a conductor in a high degree, and as long as the communication was preserved, a most intense light was exhibited at the negative wire, «nd a co- Flameemitted. lumn of flame, which seemed to be owing to the develope- ment of combustible matter, arose from the point of con- tack,” ) Connected When the order was changed, so that the platina spoon aes, nega- was made negative, a vivid and coustant light appeared ‘at the opposite pomt: there was no effect of inflammation round it; but aeriform globules, which inflamed in the at- mosphere, rose through the potash. The platina The platina, as might have been expected, was consider- acted upons ably acted upon: and in the cases when it had been nega- tive, in the highest degree. The NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 293 »» The alkali was apparently dry in this experiment; and it Inflammable seemed probable, that the inflammable matter arose from Peg tie od its decomposition. The residual potash was unaltered ; it sition of the contained indeed a number of dark gray metallic particles, 2*44-_ but these proved to be derived from the platina,. . I tried several experiments on the electrization of potash rendered fluid by heat, with the hopes of being able to col- Ject the combustible. matter, but without success; and I only attained my object, by employing electricity as the common agent for fusion and decomposition. Though potash, perfectly dried by ignition, is a nongon- A slight addi- Rasen, yet itis rendered a conductor by a very slight ad- ts = et dlition of moisture, which does not perceptibly destroy its aggregation ; and in this state it readily fuses and decom- poses by strong electrical powers, ~ A small piece of pure potash, which had been exposed Potash expose for a few seconds to the atmosphere, so as to give conduct- agileatn mag ing power to the surface, was placed upon an insplated disc of platina, connected with the negative side of the battery _ of the power of 250 of 6 and 4, ip a state of intense acti- vity ; and a platina wire, communicating with the positive side, was brought in contact with.the upper sarface of the alkali. The whole apparatus was in the open atmo- Oe lour; and by repeatedly distilling: and heating the substance jna close tube of this kind, it finally loses its metallic form, aiid a thick brown crust, which slowly decomposes water, and which combines with oxigen when exposed to air, form- ing ‘alkali, lines the interior of the tube, and in many parts in ound meprtahog through its sabstance*. | i a “a hes we * This i is the obvious explanation in the present state of our know- Perhaps the sie Vox. XX—Ave, 1808, x ledge; 366 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS, In my first experiments.on the distillation of the basis of potash, f had great difficulty in accounting for these pheno- -mena; but the knowledge of the substance it forms in its ‘first degree of union with oxigen afforded a satisfactory ex- planation. “ V. On the Propertics and Nature of the Basis of Soda. Waste Of'seda, The basis ef soda, as I have alreafly mentioned, is a solid at common temperatures. It is white, opaque, and when examined under a film of naphtha, has the lustre and general appearance of silver. It is exceedingly malleable, ‘and is much softer than any of the common metallic sub- stances. When pressed upon by a platina blade, with a small force, it spreads into thin leaves, and:a globule of the Poth, or 3;th of an inch in diameter is easily spread over a surface of a quarter of an inch*, and this property does not ‘diminish when it is cooled to 32° Fahrenheit. Conducts heat; It conducts electricity and heat in a similar manner to and clectricit¥* she basis of potash; and small globules of it inflame by the voltaic electrical spark, and burn with bright explosions. Specific gravity, [ts specific gravity is less than that of water. It swims du in oilvof sassafras of 1-096, water being 1, and sinks in -naphtha of specific gravity *861. This circumstance en- ‘abled me to ascertain the point with precision.. 1 mixed to- ‘gether oil of sassafras and naphtha, which combine very per- -fectly, observing the proportions till I had composed a fluid, -ya which it remained at rest above or below; and this fluid “consisted of nearly twelve parts naphtha, and five of oil of -sassafras, which gives a specific gravity to that of water “nearly as nine to ten, or more accurately as "9348 .to 1. Perfectly fluid. The basis of ‘soda has a much higher point of fusion than at 180°. — «the basis of potash; its parts begin, to lose their cohesion at lex of the glass.ledse; but it is miore than probable, that the ‘silex of the glass likewise altered, suffers some change, and probably decomposition. This subject I hope to, be able to-resume on another occasion. &. ty Sh Lt & , : ; . # a © - W7 elds at com- Globules may be ae ho to adhere and form one mass by strong mon tempera- pressure: so that the property of welding, which belongs to iron and pla- tures. tina at a white heat only, is possessed by this substance at common tem- peratures, ~ »-9eert 4 j seh about « NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 307 about 120°. Fahrenheit, and it.is a perfect fluid at about 180°, so. that it readily fuses under boiling naphtha. _d have not yet been able to ascertain at what degree of Not easily vos heat it is volatile; but it remains fixed in a state of ignition oe at the point.of fusion of plate vlass. The chemical phenomena produced by the basis of soda Its pronerties are analogotts to those produced by the basis of potash ; 27#!ogous to thuse of th . but with such characteristic differeaces as might be well ex- ‘oe of aciaete pected. - When the basis of soda is exposed to the atmosphere, it Action-of the lnmediately tarnishes, and by degrees becomes covered with 2! 00 it. . a white crust, which deliquesces much more slowly than the substance which forms on the ‘basis of potash. It proves, on minute examination, to be pure soda. . The basis of soda combines with oxigen slowly, and with- of oxigen. out any luminous appearaace, at all common temperatures; and when heated, this combination becomes more rapid; but no light is emitted, till it has acquired a temperature near that of ignition. _ The fiame that it produces in oxigen gas is white, and it sends forth bright sparks, occasiouing a very beautiful ef- fect ; in common air, it burns with light of the colour of that produced during the nhs grees of charcoal, but much brighter. The basis of soda when heated in hidrogen, seemed to ‘Of hidrogen. ihe no action upon it. When introduced into oximuriatic of oximuriatic acid gas, it burnt vividly with numerous scintil'ations of a acid gas. bright red colour. Saline matter was formed in this coin- bustion, which, as might have been expected, proved to be muriate of soda. . Its operation. upon water offers most satisfactory evidence Of water. of its nature. When thrown upon this fluid, it produces a violent effervescence, with a loud hissing noise; it combines with the oxigen of the water to forin soda, which is dissolved, and its hidrogen is disengaged. | In this operation there is no luminous appearance; and it seems probable, that even in the nascent state hidrogen is capable of combining with it*. When the basis of soda is thrown into hot water, the de= of hot water. * The more volatile metals only seem capable of uniting with hidro- fen; a circumstance presenting an analogy, i mo. tyes XQ composition 308 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. Composition is mére violént, dnd in this case a few scintillas tions are genérally observed at the surface of thé fluid; but _ this is owing to small particles of the basis, which are thrown out of the water suificiently heated, to burn in pass- ing through the atmosphere. When, however, a globule is brought into contact with a small particle of water, or with - rhoistened paper, the heat produced (there being no medium to éarry it off rapidly) is usually sufficient for the accension _of the basis. Ofalconetant The basis of soda acts upon alcohol and ether precisely ether. @£ acids. Of oils and naphtha. Of oxigen. Of inflammae bles, in a similar manner with the basis of potash. The water that they conta is decomposed; soda is Pies formed, and hidrogen disengaged. The basis of soda, when thtown upon the strong acids, aéts ‘upon them with great energy. When nitrous acid is émployed, a vivid inflammation is produced; with muriatic and sulphuric acid, there is mach heat generated, but no light. When plunged, by proper means, beneath the surface of the acids, it is rapidly oxigenated ; soda is produced, and the other educts are similar to those generated by the action of the basis of potash. With respect to the fixed and volatile oils and sei in their different states, there is a perfect coincidence between the effects of the’two new substarices, except in the difference of the appearancés of the saponaceous compounds formed ¢ those produced by the oxidation and combination of the ba= sis of soda being of a darker colour, and apparently less soluble. The basis of soda, in its degrees of oxidation, 9 pres cisely similar habits with the basis of potash. When it is fused with dry soda, in certain quantities; there is a division of oxigen between the alkali and the base; and a deep brown fluid is produced, which becomes a dark gray solid on cooling, and whieh attracts oxigen from thé air, or which didaiivtionds water, and becomes soda. The same body is cften formed in the analytical pros cesses of decomposition, and it is generated when the basis of soda is fused in tubes of the purest plate glass. - There is scarcely any difference in the visible phenomena ii of NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 309 of the agencies of the basis of soda, and that of potash, on giilphur, phosphorus, and the metals. It combines with sulphur in close vessels filled with the Of sulphur, vapour of naplitha with great vividness, with light, heat, and often with explofion from the vaporization of a portion of sul- phur, and the disengagement of sulpburetted hidrogen gas. -The sulphuretted basis of soda is of a deep gray colour. The phosphuret has the appearance of lead, and forms Of phospho- phosphate of soda by exposure to air, or by combustion.’ _™* The basis of soda in the quantity of 4, renders mercury Of mercury. -@ fixed solid of the colour of silver, and the combination is attended with a considerable degree of heat, It makes an alloy with tin, without changimg its colour, of tin, -and it acts upon lead and gold whea heated. I have not lead, and gold examined its habitudes with any other metals; but in its state of alloy it is soon converted into soda by exposure to vair, or by the action of water, which it decomposes with the evolution of hidrogen. _ _ The amalgam of mereury and the basis. of soda. seems to Its. amalgam ‘form triple compounds with other metals. I have tried iron ain re and platina, which I am inclined to believe remain in com- bination with the mercury, when it is.deprived of the new - gubstance by exposure to air. The amalgam of the basis of soda and mercury likewise and with sul- “combines with sulphur, and forms a triple compound of a ?* dark gray colour. YI. On the Proportions of the peculiar Bases and Oxigen in Potash and Soda. . ‘The facility of combustion of the bases of the alkalis, Proportions of and the readiness with which they decompesed water, ofiered the bases means fully adequate for. determining the propertious of as oad form -their ponderable constituent paris. I shall mention the general methods of the experiments, -and the results obtained by the different series, which ap- _proach as near to each other as can be expected in operas “tions performed on such small quantities of mat terials. For the process in oxigen gas I employed glass tubes Process to de- containing small trays made of thin Jeayes of silyer, or other te'™mine these. noble metals, on which the substance to be burnt, after being 310 Difficulties. ‘NATURE AND DECOMPOSITION OF THE FIXED ALKALIS, being accurately weighed or compared with a globule of mercury equal in size*, was placed: the tube was’smail at one end, curved, and brought to a fine point, but suffered to remain open; and the other end was fitted to a tube communicating with a gasometer, from which the oxigen gas was introduced, for neither water nor mercury could be*used for filling the appara us. The oxigen gas was car- ried through the awe till it was found thet the whole of the common air was expelled. The degree of its purity was ascertained by suifering a small quautity to pass-iuto the mercurial apparatus. The lower orifice was then he?- metically sealed by a spirit lamp, and the upper part diawn out and finally closed, when the aperture was so sinall, as to render the temperature employed incapable of mate- terially influencing the volume of the gas; and when the whole arrangement was made, the combination was efiected by applying heat to the glass in contact with the metallic tray. . In performing these experiments many difficulties occur- red. When the flame of the lamp was immediately brought to play upon the glass, the combustion was very vivid, so as sometimes to break the tube; and the alkali generated partly rose in white fumes, which were deposited upon the glass. When the temperature was slowly raised, the bases of the alkalis acted upoa the metallic tray and formed alloys, and in this state it was very difficult to combine them with their ‘full proportion of oxigen; glass alone could not be em- ployed on account of its decomposition by the alkaline’ bases; and porcelain is so bad a conductor of heat, that it was not possible to raise it to the point required for the’ Pro: cess, without softening the glass. In all cases the globules of the alkaline bases were care fully freed from naphtha before they were introduced ; of course a slight crust of alkali was formed before the coms * When the globules were very small, the comparison with mercury, which may be quickly made by means of a micrometer, was gejerally employed as the means of ascertaining the weight; for in this case the globule could be immediately introduced into the tube, and the weight of mercury ascertained at leisure, bustion, NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. $1] ‘bustion, but this could not materially affect the result; and when such a precaution was not used, an explosion generally took place from the vaporization and decomposition of the . film of naphtha surrounding the globule. After the combustion, the absorption of gas was ascer- tained, by opening the lower point of the tube under water or mercury. In seme cases the purity of the residual air was ascertained, in others the alkali formed in the tray was weighed. | : From several experiments on the synthesis of potash by Two syntheti- combustion, I shali select two, which were made with every satis a possible attention to accuracy, and under favourable cir- ash selected, cumstances, for a mean result, . In the first experiment 0°120f a grain of the basis were em- ist experi- ployed. The combustion was made upon’platina, and was ™*" rapid and complete; and the basis appeared to be perfectly saturated, as no disengagement of hidrogen took place, when the platina tray was thrown into water. The oxigen = gas absorbed equalled in volume 190 grain measures of quicksilver ; barometer being at 29°6 inches, thermometer 62° Fahrenheit; and this reduced to a temperature of 60° Fahrenheit, and under a pressure equal to that indicated by 30 inches *, would become 186-67 measures, the weight of which would be about ‘0184 grain troyt; but -0184: 21384 :: 13°29: 100; and according to this estimation 100 parts of potash will consist of $6°7 basis, and 13'3 oxigen nearly. _ In the second experiment ‘07 grains of the basis ab- 2d experiment. sorbed at temperature 63° of Fahrenheit, and under pres- sure equal to 30°1 barometer inches, a quantity of oxigen * In the correction for temperature, the estimations of Dalton and Gay Lussac are taken, which make gasses expand about 4$o0 of the pri- mitive volume for every degree of Fahrenheit. + From experiments that I made in 1799, on the specific gravity of oxigen gas, it would appear, that its weight is to that of water as 1 to 748, and to that of quicksilver as 1 to 10142. Researches Chem. and Phil. p- 9; and with this estimation, that deducible from the late accurate re- searches of Messrs. Allen and Pepys on the Combustion of the Diamond almost precisely agrees, Phil, Trans, 1807, poge 2753 or our Journal, vol, XIX, p. 223, ‘equal 31S NATURE AND DECOMPOSITION OF THE FINED ALKALTS. ‘equal in volume to 121 grain measures of mercury, and the proper corrections being made as in the former nk this gas would weigh *01189 of a grain. Mean 86 1base But *07 + °01189. = *08189 : 07 :: 100 : 85:48 nearly, may parts of potash will consist of 85°5 of basis and 14:5 of oxigen nearly. And the mean of ‘the two experiments will be 86:1 of basis to 13°9 of oxigen for 100 parts, Experiment In the most accurate experiment that I made on the com- with soda, 'hustion of the basis of soda ‘08 parts of the basis absorbed a quantity of oxigen equal to 206 grain measures of mer- cury; the thermometer being at 56° Fahrenheit, and the barometer at 29°43 and this quantity, the corrections being made as before for the mean temperature and pressure, equals about: ‘02 grains of oxigen. 80 base to 20 And as *08 ++ °02 = °10: °08, :: 100: 80, 100 parts of Se soda, according to this estimation, will consist of 80 basis’to 20 of oxigen. Increase of In all cases of slow combustion, in which the alkalis weight indicat- Natasa . bait es . ed more oxi. Were not carried out of the tray, I found a considerable in- gen - -ereasé of weight; but as it was impossibie to weigh them except im the atmosphere, the moisture attracted rendered but less to be the results doubtful; and the proportions from the weight depetdelt on. of the oxigen absorbed are more to be depended on. In the ‘experiments in which the processes of weighing were. most speedily performed, and in which wo alkali adhered to the tube, the basis of potash gained nearly 2 parts for 10, and that of soda between 3 and 4 parts. . Decomposition © The.résults of the’ decomposition of water by the bases of ie hoo by Ne the alkalis were much more readily and perfectly obtamed hae than those of their combustion. Amalgam of — To check the rapidity of the process, and, in the case of mas ty potash syotash, to prevent anyof the basis from being dissolved, I employed the amalgams with mercury. IT used a known weight of the bases, and made the amalgams under ees tha, usitg about two parts of mereury mm volume to one of ‘basis. | Tn the first instances T placed the amalgams under tubes filled with naphtha, and inverted i in glasses of naphtha, and slowly admitted water to the amalgam at the bottom of the glass; bui this precautioa I soon found unnecessary, for the r action y NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 313 action of the water was not so intense, but that the hidro- gen gas could be wholly collected, ; I shall give an account of the most accurate experiments made on the decomposition of water by the bases of potash and soda. {nan experiment on the basis of potash conducted with Experiment. every attention that I could pay to the minutiz of the ope- Fations, hidrogen gas, equal in volume to 298 grains of mercury, was disengaged by the action of -03 of a grain of the basis of potash, which had been amalgamated with about 8 grains of mercury. The thermometer at the end of the precess indicated a temperature of 56° F abrenheit, and the barometer an atmospheric pressure equal to 29-6 inches. Now this quantity of hidrogen* would require for its tombustion a volume of oxigen gas about equal to that oc- cupied by 154°9 grains of mercury, which gives the weight of oxigen required to saturate the ‘08 of a grain of the basis of potash at the mean temperature and pressure nearly ‘0151 of a grains. And ‘08 + 0151 = ‘0951:+08:: 100: 84°2 nearly. — | And according to these indications 100 parts of potash Gave 84 base consist of about 84 basis and 16 oxizen. fo 16 ox\gcm. ~ Jn an experiment on the decomposition of water by the Sa basis of soda, the mercury in the barometer standing at pny 3 30°4 inches, and in the thermometer at 52° Fahrenheit, the volume of hidrogen gas evolved by the action of -054 of a grain of basis equalled that of 326 grains of quicksilver. Now this at the mean temperature and pressure would require for its conversion into water, 0172 of oxigen, and -054 + *0172 = °0712 : 054 :: 100: 76 nearly; and according to these indications, 100 parts of soda consist of nearly 76 ba sis, and 24 oxigen. . Wap another-experiment made with very great care, *052 Another expo of the basis of soda were used; the mercury in the baro- oe meter was at 29°9 inches, and that in the thermometer at 58° Fahrenheit. The volume of hidrogen evolved was equal ‘to that of 302 grams of mercury ; which would demand for Gave 76 base to 24 oxigen. * Researches Chem. and Phil. poge 287. ~ 7 its whens S14 gave 77 base to 23 oxigen. . : i i i - g ‘according to this proportion, would consist nearly of 77 ba- \ Several other experiments made, From a com- parison of the whole 6 base to 1 ox- igen for potash ! and 7 base to 2 oxigen for soda probably near the truth, Mr, Bertixer found no per- € eerie por- tion of lime in iron spar. Component parts of black iron \spar, ac- cording to the author: ANALYSIS OF IRON SPAR. its saturation by combustion at the mean temperature and pressure ‘01549 of a grain of oxigen; and 100 parts of soda, sis, and 23 oxigen. The experiments, which have been just acne ure those in which the largest quantities of materials were em- ployed; T have compared their results, however, with the results of several others, in which the decomposition of wa- ter was performed with great care, but “in which the pre- portion of the bases was still more minute: the largest quantity of oxigen indicated by these experiments was, for potash 17, and for soda 26 parts in 100, and’ the smallest 13, and 19; and comparing all the estimations, it will pro-= bably be a good approximation to the truth, to consider potash as composed of about 6 parts basis and t of oxigen ; and soda, as consisting of 7 basis and 2 oxigen. - teh (To be concluded in our next.) XI. Remarks on Iron Spar: by Mr. Brncman*. ~ Mr. Haiiy, having been informed i in a letter from Mr. Elassenfratz, that Mr. Berthier, in his analysis of i iron spar, had found merely inperceptible traces of the presence of lime, sent to the laboratory of investigation belonging to the Museum two pieces of this ore, one of which was black, tne other white, both regularly crystallized and free from any gangue, that they might be examined for the existence of lime. The following are the results of this preliminary examination. Black iron spar. - oe Tron, at a minimum --+-eeeeseeeee G2 Carbonic acid united with the iyon-- 16:9 Carbonate of lime++sseeeeceseeeee 5 Water of crystallization +++sssseses 16°1 100 * Journal des Mines, No, HI, p. 241. White ANALYSIS OF TRON SPAR. ' $15 White iron spar. fron, ata minimum pesereedoresne BS and of white Carbonic acid united with the iyon -- 6-8 fron spar, a re ritip ny tk tacoma: » . . Water of crystailization-+...0++..66 17 Pe PATGES Us {slaie 0 nieve wpm sine, (es @ees ee a 100 After the publication of Mr. fad a on the same sub- Mr Drappier's ject, whose results were so different from mine, [ examined alae pane ‘anew pi products, which [ had carefully preserved : and Seana were accordingly I treated the 48 parts of carbonate of the, bonate of lime found in the w hite iron spar, with weak sulphuric acid. A C*@muned., very brisk effervescence took place, and a very bulky wag- ma was formed, which had all tne characters of sulphate of lime. This ma‘ter, having been heated with the usual pre- cautions to expel the moisture, was slizhtly calcined to drive 7 parts ofitnot off the excess of acid; diluted with a very small quautity lime, of water; and filtered. ‘The liquor had a bitter taste siun- larto that of sulphate of magaesia, bat slightly metullic. The residuum, separated from the filter, and calcmed, was perfectly white aud insipid. It weighed 37 paris. If we admit 32 parts of lime in 100 of crystallized sulphate, there will be 23 in the 57 calcined: and if there be 44 parts of -garbonic acid jn 100 of carbonate, there must have been only 41 per cent of carbonate of lime, instead of 48 per : gent mentioned above. The liquor mentioned above was left to evaporate slowly in the open air. After a few days the whole was crystallized into a white salt, that weighed 26 parts. The solution of this, salt in water was very bitter, and still retained its nieta!- Tie taste. ‘On caustic potash being added, a bulky white precipitate was formed, which had ee appearance of mag~ nesia. When separated, dried, and calcined, it was of a put carbonate light violet colour, owing to the presence of oxide of man- of magnesia, ganese, and weighed 5 parts. These being added to the 41 of carbonate of lime give but 2 of loss, which may be as- cribed to carbonic acid belonging to the magnesia. Thus we must admit 7 per cent i carbonate of magnesia, the quantity of manganese being but very small. The magnesia ‘colourdd with manganese was treated with radical with a minute 316 ANALYSIS OF JRON SPAR. portion ofmane radical vinegar a little diluted, and the whole was dissolved, OO except some traces of black oxide of manganese, The so- lution was slightly coloured. On heating it, it became co- lourless; and though the precipitate was a little increased by this ebullition, it could not be yi on account of the smallness of its quantity, The supposed As the iron might contain manganese, it was calcined with hamiadi g caustic potash, which thus acquired a very deep green co- ‘of manganese. lour, The calcination with potash was repeated, till the in- tensity of the colour was so far diminished, as to render it alinost certain, that the whole of the manganese was separ~ ated. The alkaline liquor being saturated by an acid, the manganese was precipitated by ammonia. It weighed 4 parts. The true results therefore of the analysis of white iron spar are Réalt compo~ Tron..ss eee eeresrccccaceecseeoves 20° nent parts of Manganese++++eesseceecesecccnes A°5 honaicdin sarki Carbonic aud waited with the wee Oe Carbonate of lime--++-ssseeeeneee Al ; Carbonate of magnesia--+-+++eeeees 7 Loss and water of crystallization+-++ 17:2 Pyrites ++ ee ceceee seen cece necece S$ 100 Examination of the products of analysis of black iron Spar. Precedinganae The five parts of carbonate of lime mentioned above, be= lysis of bluck ing treated in the same manner, were found to contain 3ron Spar €xa- merely an atom of lime, the quantity of which was too rained. -small to be estimated. They consisted almost wholly of magnesia, with a httle manganese. The iron too contained a perceptible quantity of manganese, which could not be separated from it completely but by repeated calcination wrth canstic potash. The following alterations therefore must be, made i in the results of the analysis of the black iron spar. Sts real compo- Oxide of iron and of manganese++++ 64 pent parts. Carbonicacid united with the2 metals 16 9 Carbonate of magnesia a lar as arco Soar Loss and water of crystallizations «++ 164 160 XII. ay) Penk | ANALYSIS OF A CALCULUS. XI. Analysis of a Urinary Calculus: by Professor Wurzer *. For the stone I have now analysed I am indebted to Mr. Michaelis, who extracted it from a patient by the ope- ration. It was nearly oval, but a little flattened: brown exterior= Physical cha- ly, and of a yellowish white within. It weighed exactly (tS Fey 870 grains German weight [834 grs. Eng.]. Its specific gravity was 1°572. Its surface was irregular, and a little rough. It was of the consistence of hard chalk, was with- dut a nucleus, and composed of layers. \ 2. PE macerated 300 grains of this concretion, previously Chemical exe- powdered, in distilled water at the temperature of 12? R, mination. {69° F.] for two days. Having filtered the liquor, it was Water took up without colour; and neither afforded any precipitate, nor 2otbing- was perceptibly changed, by nitrate of mercury, nitrate of silver, muriate of barytes, barytes-water, lime-water, oxalic acid, potash, or ammonia. It is evident therefore, that the distilled water had taken up none of the constituent parts of this urinary concretion. - The powder when dried weighed as much as at first. 2. This powder I left fur two days in muriatic acid of the Muriatic acid specific gravity of 1°181, at a temperature of 15° R. [65-75° » cid F.j, and then added to it distilled water. After filtering, I dried the residuum thoroughly, which then weighed 248 grains, and was of a reddish brown colour. . 8. The filtered liquor, precipitated by lime-water, af- phosphate of forded a powder, which when collected and examined was ™* found to be phosphate of lime. It weighed 52 grains. 4. The 248 grains that remained from the second experi- Potash dissol- _ ment were put into a solution of potash a little diluted, and gamely left im it for two days at a tenrperature of 18° R. [72°5° F.]. matter. - I then filtered off the liquor, from which acetous acid threw down a precipitate weighing 230 grains. This, carefully examined, consisted of 226 prains of uri¢ acid, easily dis« tinguishable by its properties and characteristics, and about 4 grains of animal matter. * Annales de Chimie, vol LX, p, 310, | 5, What Si8 , - . SCTENTIFIC NEWS: Vndissolved 5. What remained on the filter weighed 18 grains. This aninial matter : : z : : E hausnek I heated to incaudescence ima SHver crucible. During this process a very disagreeable fetid smell was emitted; resem- Reft Sgiains = bling that of horn or hair burning. The residuum weighed searcely 3 grams. - G. These 3 grams were nat soluble in sulphuric, tctaie, or muriatic acid, even when heated with them in succession to ebuilit.on. tex j : : Z ash, and melted the mixture in a suitable heat. The whole dissolved in’ water, and I precipitated pure silex by adding an acid in excess. ; Thisarareoc- ‘This earth was found but twice by Messrs. Fourcroy and ea Vanqguelin in urinary calculi, though they analysed a very great number; which induced. me to repeat my operauon Found again. with the 570 grains | had reserved. As I again found silex, the anifyin and in a similar proportion, in these, [ felt assured, that there had been no mistake in my analysis. From these experiments it follows, that 100 parts of this calculus contained ; Uric acid te ercceersescees F533 Phosphate of lime -+-+-++e+ 19°35 Animal matter «++-eeeeeees 632 TIEN ia) « etbie we caine ele'pe ele ateve- onto 100. SCIENTIFIC NEWS. Wernerian Natural History Society. Wemerian A f : “ x mt Bataccal Eicne T the last meeting of the Wernerian Natural History: ry Society. Society (July16), the. President laid before. the Society. . three communications from Col. George Montague, F.LAS., of Knowle House, Devon. Two of these communications were read at this meeting, The first part of the first com< munication contained an interesting view of the natural Gannet. habits and more striking external appearances of the gannet: or soland goose, pelicanus bassanus. The second part con= tained an account of the internal structure of this bird, a of the distribution of its air-cells, which the anggmens author showed to be admirably adapted to its : mode which were si- 7, [ then mixed them with four times their weizht of pot- ecco Segaige: ——_s SCIENTIFIC: NEWS. mode of life, and continued residence on the water, even iti the most turbulent sea, and during the most rigorous seasons. ‘The second communication was the deacuasuinin and » erawing of a new genus of insect, which inhabits the cellular Ae of the gannet, and to which Col. Mon- tague gives the name of cellularia bassani.—At the samé meeting, Mr, P. Neill laid: before the Society a list of such Bchelonging to the four Linnean orders, apodes, jugu- lares, thoracici, and abdominales, as he had ascertained to be natives of the waters in the neighbourhood of Edinburgh, - accompanied with valuable remarks, and illustrated by spe- cimens of some of the rarer species. Of the apodes he enumerated 4 species belonging to 3 genera: 2 td murena, 1 anarhichas, and 1 ammodytes. Of the jugulares he mentioned 13 species, belouging to 3 genera: 1 calliony- “mus (the gemmeous dianaet: Pais from examining many “specimens, the author had concluded, that the sordid dra- gonet of Mr. Pennant and Dr. Shaw is not a disiinct spe- cies, but merely the female of the gemmecus dragonet), 9 of the genus gadus, and 2 blennius. Of the thoracici he stated 229 species, belonging to 9 genera: I gobius, 2 cot- tus, 2 zeus, the doree and the opah (a specimen of this last most resplendent fish having been taken off Cramond in the Firth of Forth some years ago, and being still pre- served in the musenm of P. Walker, Esq.), 7 pleuronectes, ‘1 sparus, the toothed gilt head (a rare fish, of which only two specimens have‘oceurred. in the Frith of- Forth), 2 perca, 3 gasterosteus, with 1 trigla. Of the abdominales he had ascertained 14 species, belonging to 7 genera: 1 -eobitis, 4 salmo, 3 esox, the pike, garpike, and the saury or gandanook (which last, though rare in England, is not, the stated, uncommon at Edinburgh, but arzives in the Frith almost every autumn in large shoals), 3 clupea. Of the genus cyprinus, of which no fewer than ten species inhabit the rivers and ponds of England (including the carp, teneh, gudgeon, dace, roach, bream, &c.), only one insignificant species, the author remarked, is found near Edinburgh, _wiz.. the common minow.. Of the genus scomber, the _mackarel is got in the entrance of the Frith of Forth. Mr. Neill reserved the notice of the amphibia nantes of Linneus, including the ray tribe, to a future meeting. 319 New insect, Fishes near Edinburgh, Sordid drago net, the female of the gemme- ous. METEOROLOGICAL JOURNAL. For JULY, 1808, Kept by ROBERT BANKS, Mathematical Instrument Maker, in the Srranp, Lonpon. . | zee MOMET a ee JUNE, abet? | 3 | BA ROME. | ——____ ° wr at hag TER. : Day of si * |S Katie ge ag Night. Day. 29 | 681647 717 56} * S0°14 Fair Fair 30: 1634601 69155} 30°23 Ditto Ditto JULY: Io] 63.460 | 70'|36 |. 30°16 Ditto Ditto 2 162161) 69|456] 30:06 Ditto Ditto 3 | 63/60|69| 51} 80:02 | Ditto Rain 4 |60159167/521 30°01 Ditto Fair 5° + 6b} 62 (67 | 56 | 29°07 Ditto Ditto 6 61164]}68160} 3°10 Ditto Ditto 7.1 G8.\.05 | 724 5 80°14 Ditto Ditto 8.108.165 +72 | 62). 30205 Vitto Ditty 9 | 64|66/71/ 62; 30°04 Ditto Ditto 10 | 65} 65 72 | 60 30:07 Ditto Ditto i 68/72 1760) 66] 30°17 Ditto Ditto 12 74.}78 | 83" 70 30°12 Ditto Ditto 13°04. 90) 84 1-87 DiRie los S001 = Ditto ‘| Ditto 14. |824-82 | 871701. 30°02. } Ditto Ditto 15 76168 | 81173 30 Ditto* Ditto 16 eA Te | 8a1OS.| 29-96 Ditto Ditto ¥7° | 7h) Pa | BP 165 S808 Ditto Ditto 418° 174175 | 80166] 30°05 Ditto Ditto 19 | 76/73 |82/64| 29°94 Ditto Ditro 20% Ab Fo} GS | 75162 | | 20°85 Ditto Rain 21 ¢ +60) D5 POON 20°75 Ditto Fair | QF ok AGB Wt dee TSO: Fin Ditto Ditto 2 70| 68 |'77.| 64 29°84 tain Ditto 24° 773 |} 65 | 81161 29°83 Cloudy +. | Raint 25 165|161}68|60} 29:78 Ditto Ditto * Lightning in the W. t Lightning in the S.E. t Thunder. (> I have lately seen in the Papers several accounts of the great height of the thermometer in various places; atid as there appears much difference in the temperatures, | conceive there must have been more or less reflected heat in the different situations. The thermometers, from whichI register, hang a few feet from the ground, against a wall that has nearly an eastern aspect, and © is completely sheltered from the sun both at its back and front the whole day, in such a manner, that it cannot be affected by its heat, either direct or reflected. i conclude therefore, that the highest temperature liere stated is a near approxi- snation to truth, é A JOURNAL OF NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. SUPPLEMENT TO VOL. XX. ARTICLE I. The Bakeriun Lecture on some new Phenomena of Chemi- cal Changes produced by Electricity; particularly the De- composition of the fixed Alkalis, and the Exhibition of the new Substances which constitute their Bases; and on the general Nature of Alkaline Bodies. By Humpury Davy, Esg. Sec. R.S. M. R. 1. A. (Concluded from Page 314.) VII. Some general Observations on the Relations of the Bases of Potash and Soda to other Bodies. SHOULD the bases of potash and soda be called metals? Are these base; The greater number of philosophical persons, to whom this AN aa question has been put, have answered in the affirmative. They agree with metals in opacity, lustre, malleability, conducting powers as to heat and electricity, and in their qualities of chemical combination. Their low specific gravity does not appear a sufficient 7)... tiple . reason for making them a new class; for among the metals not a sufficient themselves there are remarkable differences in this respect, °J¢*tion. platina being nearly four times as heavy as tellurium*; and in * Tellurium is not much more than six times as heavy as the bases of soda. There is great reason to believe, that bodies of a Vou. XX.—SUPPLEMENT. X¥ similar $22 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. in the philosophical division of the classes of bodies, the. analogy between the greater number of properties must al. ways be the foundation of arrangement. Nomenclaturee | On this idea, in naming the bases of potash and soda, it will be proper to adopt the termination, which, by common consent, has been applied to other newly discovered metals, and which, though originally Latin, is now naturalized in our language. Potasium and Potasium and sodium are the names, by which [I have Sins ventured to call the two new substances: and whatever changes of theory, with regard to the composition of bodies, may hereafter take place, these terms can scarcely express an errour; for they may be considered as implying simply the metals produced from potash andsoda. Ihave consulted with many of the most eminent scientific persons in this country upon the methods of derivation, and the one I have adopted has been the one most generally approved. It is perhaps more significant than elegant. Butit was not pos- sible to found names upon specific properties not common to both; and though a name for the bases of soda might have been borrowed from the Greek, yet an analogous one could not have been applied to that of potash, for the ancients do not seem to have distinguished between the two alkalis. The terms The more caution is necessary in avoiding any theoretical should beun- expression in the terms, because the new electro-chemical connected with : < : Adige theory. phenomena, that are daily becoming disclosed, seem distinctly to show, that the mature time for a complete generalization of chemical facts is yet far distant; and though, in the ex. planations of the various results of experiments that have been detailed, the antiphlogistic solution of the phenomena has been uniformly adopted, yet the motive for employing it has been rather a sense of its beauty and precision, than a conviction of its permanency and truth. The discovery of the agencies of the gasses destroyed the hypothesis of Stahl. The knowledge of the powers and effects of the ethereal substances may at a future time possibly similar chemical nature to the bases of potash and soda will be found of intermediate specific gravities between them and the lightest of the common metals. Of this subject I shall treat again in the text in some of the following pages. act NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. act a similar part with regard to the more refined and inge. nious hypothesis of Lavoisier; but in the present state of our knowledge, it appears the best approximation that has been made to a perfect logic of chemistry. 323 Whatever future changes may take place in theory, there Metals not like- seems however every reason to believe, that the metallic bases ly to be separat- ed, and no rea- of the alicalis, and the common metals, will stand in the same 50M yet to sup- arrangement of substances; and as yet we have no good reasons for aSsuming the compound nature of this class of bodies *, pose themcom- The experiments in which it is said, that alkalis, metallic Air and water oxides, and earths may be formed from air and water alone, in processes of vegetation, have been always made in an in- conclusive manner +; for distilled water, as I have endea- not free from solid matters, * A pblogistic chemical theory might certainly be detended, on Phlogistic the- the idea, that the metals are compounds of certain unknown bases 7% with the same matter as that existing in hidrogen; and the metallic oxides, alkalis, and acids, compounds of the same bases with water;—but in this theory more unknown principles would be as- sumed than inthe generally received theory. It would be less ele- gant and less distinct. In my first experiments on the distillation of the bases of potash, finding hidrogen generally produced, I was led to compare the phlogistic hypothesis with the new facts, and I found it fully adequate to the explanation. More delicate researches however afterward proved, that in the cases when inflammable gasses appeared, water, or some body in which hidrogen is admit - ted to exist, was present. + The explanation of Van Helmont of his fact of the produc- Van Helmont’s tion of earth in the growth of the willow was completely overturned **Pemment. by the researchesof Woodward. Phil. Trans. Vol. XXI. page 193. The conclusions which M. Braconnot has very lately drawn from Braconnot’s ex- his ingenious experiments, Annales de Chemie, Fevrier 1807, page Perments. 187, [see our Journal, vol. XVII, p. 15.] are rendered of litle avail in consequence of the circumstances stated in thetext. In the only case of vegetation in which the free atmosphere was ex- eluded, the seeds grew in white sand, which is stated to have been purified by washing in muriatic acid; but such a process was insuf- ficient to deprive it of substances, which might afford carbon, or various inflammable matters. Carbonaceous matter exists in seve- ral stones, which afford a whitish or grayish powder; and when in a stone the quantity of carbonate of lime is very small in proportion to the other earthy ingredients, it is scarcely acted on by acids. Y2 youred 324 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. voured to show *, may contain both saline and metallic im- pregnations; and the free atmosphere almost constantly holds in mechanical suspension solid substances of various kinds, » the pro- In the common processes of. nature, all the products of eee living beings may be easily conceived to be elicited from Sy from known combinations of matter. The compounds of iron, ee of the alkalis, and earths, with mineral acids, generally abound in soils. From the decomposition of basaltic, por- phyritic +, and granitic rocks, there is a constant supply of earthy, alkaline, and ferruginous materials to the sure face of theearth. In the sap of all plants, that have been examined, certain neutrosaline compounds, containing pot- ash, or soda, or iron, have been found. From plants they Organization may be supplied to animals. And the chemical tendency rather combines f seats 1s fest bi ict than decompo- Of organization seems to be rather to combine substances ses. into more complicated and diversified arrangements, than to reduce them into simple elements. VIII. On the Nature of Ammonia and alkaline Bodies ir general; with Observations on some Prospects of Disco- very offered by the preceding Facts. Composition of Ammonia is a substance, the chemical.composition of Sige ee which has always been considered of tate years as most per- certained. fectly ascertained, and the apparent conversion of it into hidrogen and nitrogen, in the experiments of Scheele, Priestley, and the more refined and accurate experiments of Berthollet, had left no doubt of its nature in the minds of the most enlightened chemists. * Bakerian Lecture, 1806, page 8. + In the year 1804, for a particular purpose of geological in- quiry, I made an analysis of the porcelain clay of St. Stevens, in Cornwall, which results from the decomposition of the feldspar of fine-grained granite. I could not detect in it the smallest quantity of alkali. In making some experiments on specimens of the un- decompounded rock taken from beneath the surface, there were evident indications of the presence of a fixed alkali, which seemed. to be potash. Sothat it is very probable, that the decomposition depends on the-operation of water and the carbonic acid of the at- mosphere on the alkali forming a constituent part of the chrystal- line matter of the feldspar, which may disintegrate from being de~ prived of it. j All . ‘NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 325 All new facts must be accompanied however by a train of But conjectured analogies, and often by suspicions with regard to the accuracy oh a ter of former conclusions. As the two fixed alkalis contain a small quantity of oxigen united to peculiar bases, may not the volatile alkali likewise contain it? was a query which soon occurred to me in the course of inquiry ; and in perusing the accounts of the various experiments made on the subject, some of which I had carefully repeated, I saw no reason to consider the circumstance as impossible. For supposing hidrogen and nitrogen to exist in combination with oxigen in low proportion, this last principle might easily disappear in the analytical experiments of decomposition by heat and electricity, in water deposited upon the vessels employed or dissoived in the gasses produced. Of the existence of oxigen in volatile alkali I soon satis. This proved. fied myself. When charcoal carefully burnt and freed from moisture was ignited by the Voitaic battery of the power of 250 of 6 and 4 inches square, in a small quantity of very pure ammoniacal gas*: a great expansion of the aeriform matter took place, and a white substance formed, which collected on the sides of the glass tube employed in the pro- cess; and this matter, exposed to the action of diluted mu- riatic acid, effervesced, so that it was probably carbonate of ammonia. A process of another kind offered stiil more decisive re. ae decisive proof, sults. In this the two mercurial gazometers of the inven- tion of Mr. Pepys, described in No XIV of the Phil. Trans. for 1807+, were used with the same apparatus, as that * The apparatus in which this experiment was made is described in page 214 Journal of the Royal Institution. The gas was con- fined by mercury, which had been previously boiled to expel any moisture that might adhere toit. The ammonia had been exposed to the action of dry pure potash, and a portion of it equal in vo- Jume to 10980 grains of mercury, when acted on by distilled water, left a residuum equal to 9 grains of mercury only. So that the gas, there is every reason to believe, contained no foreign aeriform mat- ‘ter; for even the minute residuum may be accounted for by sup- posing it derived from air dissolved in the water. ¢ See Journal, vol, XIX, p. 217. employed 326 A more deci- Sive proof. NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. employed by Mrs. Allen and Pepys for the combustion of the diamond, and these gentlemen kindly assisted in the ex- periment. Very pure ammoniaca) gas was passed over iron wire ignited in a platina tube, and two curved glass tubes were so arranged, as to be inserted into a freezing mixture; and through one of these tubes the gas entered into the platina tube, and through the other it passed from the platina tube into the airholder arranged for its reception. The temperature of the atmosphere was 55°; and it was observed, that no sensible quantity of water was deposited in the cooled glass tube transmitting the unaltered ammonia, but in that receiving it after its exposure to heat moisture was very distinct, and the gas appeared in the airholder densely clouded. This circumstance seems distinctly to prove the formation of water in this operation for the decomposition of ammo- nia; unless indeed it be asserted, that the hidrogen and ni- trogen gasses evolved hold less water in solution or suspen. sion than the ammonia decomposed, an idea strongly op- posed by the conclusions of Mr. Dalton* and the PARR ments of Messrs. Desormes and Clement +. After the gas had been passed several times through vo ignited tnbe from onegazometer to the other, the results were examined. The iron wire became converted superficially into Kiam and had gained in weight 44% parts of a grain, about “4, of a grain of water were collected from the cooled glass tubes by means of filtrating paper, and 33°8 cubic inches of gas were expanded into 55-3 cubic inches, and by detonation with oxigen it was found, that the hidrogen gas in these was to the nitrogen as 3-2 to 1 in volume. Tt will be useless to enter into the more minute details of this experiment, as no perfectly accurate data for proportions can be gained from them ; for the whole of the ammonia was not decomposed, and as the gas had been prepared by being sent from a heated mixture of sal ammoniac and quicklime into the airholder, it was possible, that some solution of * Manchester Memoirs, Vol. V, Part Il, page 535, 1785. + Annales de Chemie, Vol. XLII, p. 125. ammonia . NATURE AND DECOMPOSITION OF THE FIXED ALKALIS, 327 ammonia might have been deposited, which, by giving out new gas during the operation, would increase the absolute quantity of the material acted upon. In examining the results of Mr. Berthollet’s* elaborate Berthollet’s de- experiments on the decomposition of ammonia by electricity, eee o I was surprised to find, that the weight of the hidrogen and electricity. nitrogen produced rather exceeded than fell short of that of ee iia the ammonia considered asdecomposed, which was evidently contradictory to the idea of its containing oxigen. This cir- cumstance, as well as the want of coincidence between the results and those of Priestley and Van Marum on the same subject, induced me to repeat the process of electrization of ammonia, and I soon found, that the quantities of the Quantities of products in their relations to the apparent quantity of gas ee eye destroyed were influenced by many different causes. teuseataae Ammonia procured over dry mercury from a mixture of dry lime and muriate of ammonia, I found, deposited moisture upon the sides of the vessel, in which it was collected, and in passing the gas into the tube for electrization, it was not easy to avoid introducing some of this moisture, which must have been a saturated solution of ammonia, at the same time. Ta my first trials, made upon gas passed immediately from the vessel in which it had been collected into the apparatus, I found the expansion of 1 of ammonia vary in different in stances from 2°8 to 2:2 measures, but the proportions of the nitrogen and hidrogen appeared uniform, as determined by detonation of the mixed gas with oxigen, and nearly as 4 to 3 in volume. To exclude free moisture entirely, I-carefully prepared ammonia in a mercurial airholder, and after it had been some hours at rest, passed a quantity of it into the tube for decom- position, which had been filled with dry mercury. In this case 50 parts became 103 parts by electrization, and there was still reason to suspect sources of errour. I had used iron wires not perfectly free from rust for taking thespark, anda black film from themercury appeared on the sides of the tube. It was probable, that some ammo- nia had been absorbed by the metallic oxides both upon the * Mémoires de? Académie, 1785, page 324. iron 328 Specific gravity ef ammonia. NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. iron and the mercury, which might again have been given out in the progress of the operation. I now used recently distilled mercury, which did not leave the slightest film on the glass tube, and wires of platina. The ammonia had been exposed to dry caustic potash, and proved to be equally pure with that mentioned in page 326. 60 mea- sures of it, each equal to a grain of water, were electrized till no farther expansion could be produced, the gas filled a space equal to that occupied by 108 grains of water. The thermometer in this experiment was at 56°, and the barom- eter at 30°1 inches. The wire of platina transmitting the spark was slightly tarnished *. The 108 measures of gas, carefully analyzed, were found to consist of 80 measures in volume of hidrogen, and 28 measures of nitrogen. The results of an experiment.that I made in 1799 + give the weight of 100 cubic inches of ammonia as 18-18 grains at themean temperature and pressure. I had reasons however for suspecting, that this estimation might be somewhat too low, and on mentioning the circumstance to Messrs. Allen and Pepys, they kindly undertook the examination of the subject, and Mr. Allen soon furnished me with the following data. ‘In the first experiment21 cubic inches of ammonia weighed 4:05 grains; in a second experiment the same quart. tity weighed 4:06 grains, barometer 30°65, thermometer 54° Fahrenheit.” Now if the correctness for temperature and pressure be made for these estimations, and a mean taken, 100 cubic inches of ammonia will weigh 18°67 grains, barometer being at 30, and thermometer at 60° Fahrenheit: and if the quantity used in the experiment of decomposition be calcu- Jated upon as cubic inches, 60 will weigh 11-2 grains. But the hidrogen gas evolved equal to 80 will weigh 1°93 + grains, and the nitrogen equal to 28§, 8:3. And 1:9+ ; 8°3 * This most probably was owing to oxidation. When platina is made positive in the Voltaic circuit in contact with solution of am- monia, it israpidly corroded. ‘This is an analogous instance, + Researches Chem. and Phil. p. 62. } Lavoisier’s Elements, p. 569. A’cubical inch of hidrogen is considered as weighing ‘0239, § R essaycChem. and Phil. page 9. From my experiments 100 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 3829 8-3=10°2; and 11-2—10-2=1; all the estimations being made according to the standard temperature and pressure. So that in this experiment on the decomposition of Promce only ammonia, the weight of the gasses evolved is less by nearly #1? therefore zz than that of the ammonia employed; and this loss can ** °'E* only be ascribed to the existence of oxigen in the alkali; part of which probably combined with the platina wires employed for electrization, and part with hidrogen. After these ideas the oxigen in ammonia cannot well be Ammonia pro- estimated at less than 7 or 8 parts in the hundred; and ae gee og possibly exists in a larger proportion, as the gasses evolved may contain more water than the gas decomposed, which of course would increase their volume and their absolute weight *. In supposing ammonia a triple compound of nitrogen, Supposing ita ] triple com- pound, the account of the phenomena of its production and decompo- phenomena easily accounted for. hidrogen, and oxigen, itis no less easy to give a rationa sition, than in adopting the generally received hypothesis of its composition. Oxigen, hidrogen, and niirogen are always present in cazes in which volatile aikali is formed; and it usually ap- pears during the decomposition of bodies in which oxigen is loosely attached, as in that of the compounds of oxigen and nitrogen dissolved in water. At common temperatures under such favourable circum- Ammonia stances, the three elements may be conceived capable of srg eel combining, and of remaining in union: but at the heat of compound ignition the affinity of hidrogen for oxigen prevails over the ca complex attraction, water is formed, and hidrogen and nitrogen are evolved; and according to these conclusions, ammonia will bear the same relations to the fixed alkalisy as the vegetable acids with compound bases do to the mineral ones with simple bases. 100 cubical inches of nitrogen weigh, at the standard temperature and pressure, 29°6 grains, * Jn the present state of our knowledge, perfectly correct data pare = “ for proportions cannot probably be gained in any experiments on ede the decomposition of ammonia, as it seems impossible to ascertain only by elec- the absolute quantity of water in this gas; for electrization, ac- tization. cording to Dr. Henry’s ingenious.researches, offers the only means known of ascertaining the quantity of water in gasses. 5 Oxigen 330 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. ee Oxigen then may be considered as existing in, and as rincipte o . ° ‘ . . Micaiinity. forming an element in all the true alkalis; and the prin- ciple of acidity of the French nomenclature might now likewise be called the principle of alkalescence. yl Sapa? From analogy alone it is reasonable to expect, that the oxidized metals. 2ikaline earths are compounds of a similar nature to the fixed alkalis, peculiar highly combustible metallic bases united to oxigen. I have tried some experiments upon Barytes and _ barytes and strontities ; and they go far towards proving, that oa gail thismust bethecase. When barytesand strontites, moistened with water, were acted upon by the power of the battery of 250 of 4 and 6, there was a vivid action and a brilliant light at both points of communication, and an inflammation at the negative point. In these cases the water might possibly have interfered, Other experiments gave however more distinct results. Barytes and strontites, even when heated to intense whiteness in the electrical circuit by a flame supported by oxigen gas, are nonconductors; but by means of combina- tion with a very small quantity of boracic acid, they Infammable become conductors; and in this case inflammable matter, “on ee which burns with a deep red light in each instance, is pro. them. duced from them at the negative surface. The high tem. perature has prevented the success of attempts to collect this substance; but there is much reason to believe, that it is the bases of the alkaline earth employed. Probably other Barytes and strontites have the strongest relations to the Blea ere fixed alkalis of any of the earthy bodies*; but there is a electricity. chain of resemblances, through lime, magnesia, glucina, alumina, and silex. And by the agencies of batteries suffi- ciently strong, and by the application of proper circum- Earthslong ago * The similiarity between the properties of earths and metallic considered ana- 4.ides was noticed in the early periods of chemistry. The logous to metal- ~~. : < 3 lic oxides. poisonous nature of barytes, and the great specific gravity of this substance as well as of strontites, led Lavoisier to the conjecture, that they were of a metallic nature. ‘That metals existed in the fixed alkalis seems however never to bave been suspected. From their analogy to ammonia, nitrogen and hidrogen have béen sup. posed to be amongst their elements. It is singular, with regard to this class of bodies, that those most unlike metallic oxidés are the first which have been demonstrated to be such, stances & NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 331 stances, there is no small reason to hope, that even these refractory bodies will yield their elements to the methods of analysis by electrical attraction and repulsion. In the electrical circuit we have a regular series of powers Powers of clec-’ of decomposition, from an intensity of action, so feeble as wi lad x scarcely to destroy the weakest affinity existing between the ~ wv parts of a saline neutral compound, to one sufficiently energetic to separate clements in the strongest degree of union in bodies undecomposable under other circumstances. When the powers are feeble, acids and alkalis, and acids Their action. and metallic oxides, merely separate from each other; when they are increased to a certain degree, the common metallic oxides and the compound acids are decomposed ; and by means still more exalted, the aikalis yield their elements. Andas far as our knowledge of the composition Oxigen at- of bodies extends, all substances attracted by poling (98° PY Dest electricity are oxigen, or such as contain oxigen in excess ; combustible vs matter by and al] that are atiracted by negative electricity are pure ¢ ¥ negative, combustibles, or such as consist chiefly of combustible matter. : The idea of muriatic acid, fluoric acid, and boracic acid containing oxigen, is highly strengthened by these facts. And the general principle confirms the conjecture just stated concerning the nature of the earths. In the electrization of boracic acid moistened with water, Boracic acid. I find, that a dark coloured combustible matter is evolved at the negative surface; but the researches upon the alkalis have prevented me from pursuing this fact, which seems however to indicate a decompositicn. Muriatic acid and fluoric acid in their gaseous states are Muriatic and nonconductors: and as there is every reason to believe, Wore acid. that their bases have a stronger attraction for oxigen than water, there can be little hope of decomposing them in their aqueous solutions, even by the highest powers. In the electrization of some of their combinations there is how- ever a probability of success. An immense variety of objects of research is presented New metals af- in the powers and aflinities of the new metals produced righ from the alkalis. research. In 332 NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. eer In themselves they will undoubtedly prove powerful ane Bhi agents for analysis; and having an affinity for oxigen stronger than any other known substances, they may possibly supersede the application of electricity to some of the undecom pounded bodies. Base of potash The bases of potash I find oxidates in carbonic acid and decomposes decomposes it, and produces charcoal when heated in con- carbonic acid. E ? p tact with carbonate of lime. It likewise oxidates in mu- riatic acid; but Ihave had no opportunity of making the experiment with sufficient precision to ascertain the results. Geology. In sciences kindred to chemistry, the knowledge of the mature of the alkalis, and the analogies arising in con- sequence, will open many new views; they may lead to the solution of many problems in geology, and show, that — agents may have operated in the formation of rocks and earths, which have not hitherto been suspected to exist. It would be easy to pursue the speculative part of this inquiry to a great extent, but I shall refrain from so oc- eupying the time of the Society, as the tenour of my ob- ject in this lecture has not been to state hypotheses, but to bring forward a new series of facts. II. On the Composition of the Compound Sulphuret from Huel Boys, and an Account of its Crystals. By James Smiruson, Esq. F. KR. S.*. Compound sul- Ir is but very lately, that I have seen the Philosophical arenas Transactions for 1804, and become acquainted with the two papers on the compound sulphuret of lead, antimony, and copper contained in the first part of itt; which circum. stance has prevented my offering sooner a few observations on Mr. Hatchett’s experiments, which I deem essential towards this substance being rightly considered, and indeed the principles of which extend to other chemical com- pounds ; and also giving an account of this compound sul * Philos. Trans. for 1807, Part 1, p. 55. + See Journal, vol. IX, p. 14. phuret, A . ‘. oN if c bs a, ; 5 7. Ghadiitin 4 ‘EE Up, a 72 ae SO) sd iis Sf Y f Fig lt oiftow nd Sdfebore Wicholoons Philas Journal: Vola Pg pp.332 fig. 2. 1\ / ; 4 a / | 2 are iy | | | | <<, Ae eee tt SULPHURET OF LEAD, ANTIMONY, AND COPPER. 833 phuret, as that which had been laid before the Society is very materially inaccurate and imperfect. We have no real knowledge of the nature of a com- To know the pound substance, till we are acquainted with its proximate er ie elements, or those matters by the direct or immediate union must find its ef which it is produced; for these only are its true elements. x ines Thus, though we know that vegetable acids consist of oxigen, hidrogen, and carbon, we are not really acquaint- ed with their composition, because these are not their proximate, that is, are not their elements, but are the elements of their elements, or the elements of these. It is evident what would be our acquaintance with sulphate of iron, for example, did we only know that a crystal of it consisted of iron, sulphur, oxigen, and hidrogen; or of carbonate of lime, if only that it was a compound of lime, carbon or diamond, and oxigen. Im fact, totally dis- similar substances may have the same ultimate ele- ments, and even probably in precisely the same proportions 5 nitrate of ammonia, and hydrate of ammonia, or crystals of caustic volatile alkali*, both ultimately consist of oxigen, hydrogen, and azote. It is not probable, that the present ore is a direct qua- The ore pro- druple combination of the three metals and sulphur, and that Dahle compares these, in their simple states, are its immediate component phurets. parts; it is much more credible, that it is a combination of the three sulphurets of these metals. On this presumption I have made experiments to deter- mine the respective proportions of these sulphurets in it. I have found 10 grains of galena, or sulphuret of lead, 10 grssulphuret , of lead produce to produce 12:5 grains of sulphate of lead. Hence the y2.5 suiphate. 60:1 grains of sulphate of lead, which Mr. Hatchett obtained, correspond to 48-08 grains of sulphuret of lead. I have found 10 grains of sulphuret of antimony to af- 10 grssulphuret ford 11 grains of precipitate from muriatic acid by water. orale “ Hence 31:5 grains of this precipitate are equal to 28°64 grains of sulphuret of antimony. The want of sulphuret of copper has prevented my de- termining the relation bétween it and black oxide of copper, * Fourcroy, Syst. des Con. Chem. t. 1. p. lxxxviii. Transl. 1, — ut 334 SULPHURET OF LEAD, ANTIMONY, AND COPPER, but this omission is, it is evident, immaterial, as the quan tity of this sulphuret in the ere must be the complement of the sum of the two others. But as the iron is a foreign adventitious substance in thi¢ ore, it follows that the foregoing quantities are the products of only 96°65 grains of it. 100 parts cf the ore are there- Component © ore compesed of parts of the ore: Sulphuret of Icad 4 49°7 Sulphuret of antimony 29°6 Sulphuret of copper - 20°7 100-6 -ar probably in» Tt is impossible not to be struck with the trifling alter. Se ae ation which these quantities require, to reduce them to very simple proportions, or to think it a very great violation of probability to suppose that experiments, affected with no errours, would have given them thus: Sulphuret of lead - 50: Sulphuret of antimony - 30. Sulphuret of copper. - 20. But perhaps no However, I doubt the existence of triple, quadruple, &c. webine compounds; I believe, that all combination is binary; that mate elements. no substance whatever has more than two proximate or true elements; and hence I should be inclined to consider the present compound as a combination of galena and fahl- ertz; and if 30, it will be accurately represented, as far as chemical annalysis has yet been able to go by the follow. ing figure : True nature of 2 sulphur the compound. Compound 2 galena = 3 lead sulphuret of lead, -» 2 antimony, 2 sulphuret of __ : 4 sulphur. and copper 2 fahlertz— § antimony ~~? gantimony. (3 ¢sulphuret of __ § tsulphur. copper ~~ ( #copper. Ultimate ele- Its ultimate elements are therefore, satiate Sulphur « 20:7 1\eaes Leads A412, ce28 Antimony - 25 «. m5 Copper - 132 a ee and , SULPHURET OF LEAD, ANTIMONY, AND COPPER. $35 and it is not a little remarkable, that here, as was the case In sexagesimal with the calamine*, they are sexagesimal fractions of it. tons. When in a former paper I offered a system on the pro- portions of the elements of compounds, I supported it by the results of my own experiments, which might be sup- posed influenced, even unconsciously to myself, by a fa- vourite hypothesis, and I made the application of it prin- | cipally to a substance, the nature of which was not very clear. But the present case is not liable to these objections : here no fondness to the theory can be suspected of having led astray, nor did even the experiments, as they came from their author’s hands, bear an ‘appearance in the least favourable to it, and yet when properly considered, they are found to accord no less remarkably with its principles. lt is evident, that there must Lea precise quantity, in Elements of which the elements of compounds are united together in Pace them, otherwise a matter, which was not a simple one, precise quan. would be liable, in its several masses, to vary from itself, “U°> according as one or other of its ingredients chanced to pre- dominate; but chemical experiments are unavoidably: at. tended with too many sources of fallacy for this precise quantity to be discovered by them ; it is therefore to theory, that we must owe the knowledge of it. For this purpose Hypothesis nes an hypothesis must be made, and its justness tried by RCO: strict comparison with facts. If they are found at variance, by facts. the assumed hypothesis must be relinquished with candour as erroneous: but should it on the contrary prove, on a multitude of trials, invariahly to accord with the results of observatien, as nearly as our means of determination authorise us to expect, we are warranted in believing, that the principle of nature is obtained; as we then have ali the proofs of its being so, which men can have of the justness of their theories; a constant and perfect agreement with the phenomena, as far as can be discovered. | The great criterion in the present case is, whether on the Do the simple conversion of a substance into its seyeral compounds, and ae ee of these into one another, the simple ratios always obtain, aiways obtain ? which the principles of the theory require. Amongst the * Phil. Trans. 1803, p. 12. or Journal, yol. VI, p. 83. multitude 336 SULPHURET OF LEAD, ANTIMONY, AND COPPER: multitude of instances which I could adduce, in support of such being the fact, I will for ihe sake of brevity confine myself to a few, in the substances which have come under consideration above, as they will likewise give the grounds, on which some of the proportions in the table have been assigned, and every chemist, by a careful repetition of the experiments, may easily determine for himself to what at- tention the present theory is entitled. Instances, Lead - “ = 2 of sulphate of lead i ete = of sulphuret of lead Sulphuret of lead = of lead j = of sulphate of lead Sulphate of-lead a ee of lead ’ 4 of sulphuret of lead A nitimony) 4/9) 2" = é of powder of algaroth - wom £ of sulphuret of antimony Sulphuret of anti- mony - ©2242 of powder of algaroth. In the experiments by which these relations were ascer- tained, the portion of powder of algaroth and sulphate of lead dissdlved in the precipitating an Wwashigg waters was scrupulously collected. : Perhaps the The importance of a knowledge of the true quantity in quantity of an which matters combine is too evident, to require to be prone: Wis sce dwelt upon; but this importance will be greatly augmented, of attraction. if it should prove, that this quantity is, as has been suge gested, expressive of the forces with which they attract each other. Itis perhaps in the form of matters, that we shall find the cause of the proportions in which they unite, and a proof, a priorz, of the system here maintained. adiaiemeg TEE eal Gray copper I have examined some of the gray ores of copper in te- aa traedral crystals; but the notes of my experiments are in England. I can however, say, that they do contain anti- mony, and that they do not contain iron in any material quantity. With respect to the proportions of the consti« tuent parts, I canirot now speak with any certainty; but, I think, that at least some species of fahlertz contain a smaller portion of sulphuret of antimony, than the fahlertz does which exists as an element in the foregoing compound: one. Of SULPHURET OF LEAD, ANTIMONY, AND COPPER, 337 Of the Form of this Substance. Of the seventeen figures which have been given, as of the Form of the crystals of this compound sulphuret, in Part II of the yo- a — lume of the Transactions for 1804, great part are acknow- ledged to have no existence, nor are indeed any of them consistent with nature. This substance seems to have yet offered but one form, which is represented in Plate 9 under its two principal appearances; that is, having the primitive faces the pre- dominant ones of the prism; and having the secondary ones such, and which will be fully sufficient to make it known. In the first infancy of the study of crystals, it might be ne- cessary to attend to every, the most trifling, variation of them, to trace each of their changes step by step, to spell as it were, thesubject; but in the state to which the science has now attained, to continue to do so would be not only superfluous, but most truly puerile. I have a very small, but very regular, crystal of the form of Fig. 1. By mensuration the faces @ and m appear to form together an angle of about 135°, and.the faces c and 6 an angle of about 125°. It is said in the account above quoted, that the primitive Dimensions of form of this matter is a rectangular tetraedral prism, but no sen prem proofs of this have been offered ; nor have the dimensions of mine the primi- this prism been given, a circumstance of the first moment to Ye f"™- the determination of true or primitive form, nor have any quantities been assigned to the decrements supposed. I will, therefore, supply these very important omissions. ; That the atom of this substance is a rectangular tetraedral It is a cube. prism, is inferable, not from the striz on the crystals, for strie are by no means invariably indicative of adecrement in the direction of them; but from the angles which the faces a and c make with the faces m and }; and these angles also prove, that the height of this prism is equal to the side of its base, that is, that it is a cube. Hence the face ais produced by a decrease of one row of Its decrements. atoms along the edge of the cube, and the angle it forms with the face m is really of 135°. ~ Vou. XX.—SurrLsement. Z The 338 NEW PROPERTY OF TANGENTS. The face c is produced by a decrease of two rows of atoms at the corners of the cube, and the angle it forms with the face b is = 125° 15’ 52”. The face b being produced like the face a, forms the same é angle with the face m. No crystal I possess has enabled me to measure the incli- nations of the faces g, d, or f; should the face g, as is presum- able, result from a decrease of one row of atoms at the cor- ners of the cube, it will form with the face 4 an angle of 144° 44’8’; and if the facesd and f are, as is also proba- ble, produced by a decrease of two rows of atoms along the edges of the cube, the first will form an angle of 116% 33’ 54”, and the latter one of 153° 26’ 6”, with the face m. This differs The angles assigned here differ considerably from those Sega given in the former account of these crystals; but the angles crystals, there given have not only appeared to me to be contradicted by observation, but, crystaillographically considered, are in- consistent with each other, as the tetraedral prism of dimen- sions to produce an angle of 135° by a decrement along its edge would not afford angles of 140° and 120° by decre- ments at its corners. ‘The sum of the faces of these crystals is 50. Mil. On a new Property of the Tangents of the three Angles of a Plane Triangle. By Mr. Wituiam Garrarp, Quarter Master of Instruction at the Royal Naval Asylum at Greenwich. Communicated by the Astronomer Royal*. Sum of three Proposition I. In every acute angled plane tri- tangents of 2 anole, the sum of the three tangents of the three angles plane triangle multiplied by multiplied by the square of the radius is equal to the conti- square of radius nued product of the tangents. equal to their continued pro Demonstration.—Let AH, HI, and IB, Plate 9 Fig. 3, duct. z i . Daonstrated De the arches to represent the given angles ; and AG, HK, in anacute an- and BT be their tangents, put 7 the radius, AG=a, and gied triangle: BT=3, * Philos, Trans. for 1807, Part I, p. 120, Then NEW PROPERTY OF TANGENTS. 839 : 2 2 Then — and" will be the tangents of HD and DI. Now by Prop. VIII, Sect. I, Book I, Emerson’s Trie gonometry, As radius square—product of two tangents Is to radius square, So is the sum of the tangents To the tangent of their sum, aeyhe rt igh ha edi A HK HG ih eet Oe >) ies Rae : rea+7r?b_ a*b-+ab* therefore a + b + Tape Tals = —r == the sum of the three tangents, a*b-+-ab? r7a+r2b r xr?*=abx om ab—r* a duct. Q. E. D. = their continued pro« Proposition If. In every obtuse angled plane triangle, the sum of the three tangents of the three angles multiplied by the square of the radius is equal to their continued pro- duct. Demonstration.—Let AH, Fig. 4, be an obtuse arc, and in anobtuse and HE, EB the other two. angled. tiaugies ‘Then BF, ED, and AG are the three tangents. Put BF =¢ and DE =~ radius =7, then per trigonome- t+-u as before, 7? x - = ‘ i aaa r>—tu ; . But— BT = AG = - a2 ——— >< Toe r?*—tu Wherefore ¢ + wu — — x r? =the sum of the three r? —tu - tangents, which being reduced is = — tux ame and multiplied into r? is equal to ra r?—tu té+u tux wy x r? = the product. Q. E. D. 2 IV. On Sum of three tangents of three arches tri- secting a circle, multiplied by radius, equal to their product. Preliminary remark, NEW PROPERTY OF TANGENTS. IV. On a new Property of the Tangents of three Arches trisect. ing the Circumference of a Circle. By Nevin Maskt- tyng, D. D. F.R.S. and Astronomer Royal *. Mra. William Garrard having shown me a curious pro- perty of the tangents of the three angles of a plane trian- gle, or in other words, of the tangents of three arches tri- secting a.semicircle, in a paper which I have communicated to this Society, I was led to consider, whether a similar pro- perty might not belong to the tangents of three arches tri- secting the whole circumference; and, on examination, found it to be so. Let the circumference of a circle be divided any how into three arches A, B, C; that is, let A +-B--C be equal to the whole circumference. I say, the square of the radius mul- tiplied into the sum of the tangents of the three arches A,B,C, is equal to the product of the tangents multiplied together. I shall demonstrate this by symbolical calculation, now com. monly called (especially by foreign mathematicians) analytic calculation. It may be proper to premise, that the signification of the symbolical expressions of the tangents of an arc, whether with respect to geometry or numbers, are to be understood according to their position as lying on one side, or the other side of the radius, passing through the point of commence. ment of the arc of the circle; those tangents which belong to the first or third quadrantvof the circle being considered as positive, and those belonging to the second and fourth qua- drant, being of a contrary direction, as negative; in like manner as the sines in the first semicircle are considered as positive, and in the second semicircle as negative; and the cosines in the first and fourth quadrant are considered as po sitive, and in the second and third quadrants as negative; they lying, in the second case, on the contrary side of the diameter. passing through the point of ninety degrees, to what they do in the former. Henceit easily follows, that the tan- Thid, p, 122, , gent SUPPOSED RADIATION AND REFLECTYON OF CoLp. 341 gent of any arch and of its supplement to the whole circum. ference, or 360 degrees, are equal and contrary to one ane. = other, or the one negative of the other. , Fe? Let ¢, u, w, be put for the tangents of the three arches A, Demonstrationa B, C respectively, and r for the radius, and © for the whole ¢ circumference. Then A +B+C=60,andC=@ —A+B. 7? xé+Lu By trigonometry, ¢, A+-B= 35 sand the tang. C=tang. 72 (OQ —-A + B)=—tang. A+ B, by what has been said above. Thereforet, A-+-t, B+-t, Cort --u pot +u——% — ' r?—ty oo =t2x — > but #and ware the expressions for the tan- —tu r?>xttu , 2 + is the expres. gents of A and Brespectively, and — sion for the tangent of C, orfor w. Therefore, 7? x ttutw, or the square of the radius multiplied into the sum of the three tangents of A, B, and C=¢uw, or the product of the tangents. Q. E. D. —————————— Ws On the apparent Radiation and Reflection of Cold by means — of two concave metallic Mirrors. In a Letter from Mr. Joun Martin. To Mr. NICHOLSON, SIR, ‘Tuere are many phenomena, exhibited to the notice Some chemica} i i her in th f his arduous ‘2's not sufi- of the chemical philosopher in the course o ciently explain- research, that are not so well understood as perhaps the ed. present state of science might lead him to expect. Some of these phenomena have hitherto been totally inexplicable ; others have not been explained with all the clearness and perspicnity that could be wished. Among the number of Apparent radi- ation and re- the latter may be ranked the apparent radiation and reflec- flection of cold. tion of cold by means of two concaye metallic mirrors. This 342 SUPPOSED RADIATION AND REFLECTION OF COLD. This curious fact, notwithstanding we are so well ac. quainted with the laws that govern heat during its passage through and impingency upon bodiés, has never, I be- lieve, been illustrated with sufficient clearness. The cold body The explanations that have hitherto been given rest prin- ule te cipally for support on the supposition, that the thermome- from the ther- ter placed in the focus of one mirror acts as a heated body, eas and that the heat radiating from it is transmitted to the cold But this cannot body in the opposite focus. The thermometer, however, ae out radiant +. in fact not a heated body, since it is not hotter than the surrounding atmosphere, and consequently cannot radiate caloric: but it is said, the surrounding air becomes cooled, and consequently the thermometer in respect to it is a hot body, and radiates caloric accordingly. This however does not explain clearly why the thermometer should be reduced to a temperature lower than the air which surrounds it, which will be found to be the case; or at least, it leaves too much to be supplied by the imagination. I trust I shall be able to render this matter clearer. Another mode There are only two ways, in which heat can be made to ae move in one direction through any given body, we will rit. suppose a wire A_” Y * _B; one is the application of a superior temperature to B, causing the heat to move on towards A by the conducting power of the wire, and the tendency of the caloric to establish an equilibrium; the other is, to reduce the temperature at A, and thus cause a partial vacuity of hcat, which must of necessity be filled up by a fresh quantity from toward a, which will receive again a fresh supply from toward y, and that from towards zx, &c., and by this means induce a current of heat from B to A, till an equilibrium is established. It is upon this principle, the filling up of partial vacuities of heat (if I may be allowed the expression), that the rational explana. tion of the phenomenon in question can be grounded. Fact puts this sufficiently beyond a doubt, and it now remains to show how it is effected. Fees tenia It will scarcely be necessary to mention in this place, effected, that, when a particle of heat impinges upon a plane re~ flecting surface, itis thgown off in an angle equal to that with SUPPOSED RADIATION AND REFLECTION OF COLD. with which it is thrown upon it. Now, on the contrary, if a cold body, b, Fig. 5, Pl. 9, be brought near a plane refiecting surface, as particles of heat are entering into that body in all directions from the surrounding air, some par. ticles of heat must be entering into it in the direction ad, consequently the point a of the reflecting surface must be. come cooler, or, to use my former expression, a vacuity of heat will be there formed: now it may be demonstrated, that this vacuity or space will not be supplied by heat mov- ing in the direction xa, ya, or za, but will be supplied by heat moving in no other direction than ca, which heat, striking against the point a, will be thrown off into the body 6; the angle cad being equal to the angle dae, and bodies will move in the direction in which they meet with the least resistance; for if heat were to come from any other direction but ca, it would not be reflected towards the body b, but elsewhere, and consequently, to join the current of heat ab, it must again change its course. Hence it follows, that, when a cold body is brought near a plane reflecting surface, in proportion as the surrounding air be- comes cool, heat will enter into that body in right lines tending toits centre; the plane reflecting surface will have -its temperature lowered, and particles of heat will strike upon every part of it in such directions, as to be thrown off in right lines to the cool body. 343 The application of this fact to the explanation of the This appliedto tuting concave reflecting surfaces instead of plane ones: the heat enters into the cold body placed in the focus of one mirror (B. fig. 6) from the surrounding air in all di- rections, consequently every point of the surface of the mirror, a,b, c, d, &c., becomes cooled, and those points can only receive a fresh supply in parallel rays, in a direct course from the opposite mirror, because only such rays (striking against so many imaginary tangents a, b, c, d, of that mirror) can. be thrown off towards the body B; the opposite mirror therefore becomes cool, and for the same reason the whole surface of it must be expoliet by heat from the thermometer T, which consequently must become cooler than a body placed any where in its neighbourhood- te a concave sur~ phenomenon in question will be readily perceived, substi- face. 344 Balance Jevel useful in drain- ing and water- ing land, BALANCE LEVEL. If you think proper, an insertion of this explanation in your valuable Journal will greatly oblige, Sir, Your most obedient Servant, Old Broad Street, JOHN MARTIN. 19 July, 1808. VI. Description of a Balance Level, useful for laying out Land for Irrigation, for Roads, and other Purposes. By Mr. Ricuarp Drew, of Great Ormond Street *. SIR, Herewira you will receive a Balance Level, of my invention, which-I have satisfactorily used on several gentle. , * . ae men’s estates in Devonshire, where I have been employed . to drain and carry water to irrigate meadow land. I have made several for persons in that county, whose employment is to drain and irrigate land, and they have found jt to‘an- - swer their purpose better than the spirit or water level, it Method of using it. being more portable and ready to the sight. I have lately used it on Mr. Satterley’s farm, at Hastings, to carry the water of his closes over several acres of dry ground. Dr. De Salis, who has seen it, advised me to send it to the Society of Arts, &c., that they might judge of its merits. | Jam, Sir, Your obedient Servant, RICHARD DREW. Explanation of the Method of using the Instrument. Set it on a triangular staff, and point it at the object staff, which is held by another person at a distance; move the level on the joint, until the inner tube plays clear within * Trans. of the Society of Arts for 1807, p.22, The Society voted Mr. Drew ten guineas for this invention, the SSS >> >>> SSS LN KK: SSS SS SO i 7 es / CO —_——— Za S SSS (iat SS << a cee SS > cAI | < L Y WS Ol ___ a / Ze Lae < SQ ale alll — Zee SSS S > > SSS = SS TTS ———— a TWO 2 SSS —_ = a ————— b << ZZ SS ——> pen nee, oe WSS et Aa SS i ESS IN SHE HS Sy NAN Tw V7 MTSSSSiS SSSI aE PDS S=S=S= OTISJJ UN SSS TT SSIS 2E¢ TSS TIS S LUOUOLUTAUULLNAETTZZ, ITTV TTT << Sz SS Ze S Za | CALLA, SI SS Se SS ZEA ZZ KK | | | SS Z << oe SS ZZ nt | SS Ww SS AAAI ep AP SS SS ZL LD SS St S S> (A i ——=\7 $$} i $= /\\ TZ SaaS TTT f \\ m7 =IN LN NX SMM Ly IN) ! AIR i if IU NY = =") Mis Yes Y VA y PID KK Leper es LILLE Wen SSS CLZLL LLL SS YEAS ba Zz = Za2 SAL Ls Mt $<} {TT iN Tie /; \\ SPL: 7 y IN —=\/| TT ’ if ____— i y = —————SSSS=ZN'; SaaS / LY 0 LL0Y) ra (WE / Wd f ff C JIU Ya V1, a7 5, ATdALTA TPUMit SOM IT SUISTIYINAT eed rey = See Se as ' << eT ae Big tt Sateen joan BALANCE LEVEL. 3A5 the outer tube. Look through the sights, and observe the object staff which the person holds, let him move the slide on the staff, until you see the hair cut the middle of the slide, on which there is a black line; then turn the level round, look through the sights, and see if the hair cuts the middle of the slide as before; if it does, it will be level ; but if there be a difference in both ends, the person who holds the staff must set the slide to half that difference. You are then to adjust the level by turning with a key the screw, which moves the balance contained in the bottom of the inner tube. Certificates from Mr. J. W. Gooch, Mr. Charles Lay- 5 ne with : ton, and Mr. Benj. Holmes, testify, that they have seen in Seer -. use the level invented by Mr. Richard Drew, and that the business is done by it with accuracy and dispatch. Reference to the Engraving of Mr. Richard Drew’s Balance Level. Plate X, Fig. 1, 2, 3, 4. Fig. 1. The balance level, mounted on a ball and socket The instrument joint, with a tube, a, to fix on a stand. cerca, Fig. 2. A section, bcc two tubes of tin, which slide on a short tube, dd, placed in the middle, and having an iron wire soldered round it to stiffen it, and to serve as a shoulder. ee Two eye pieces, with glass in both, one at each end, and sliding into the tubes 6 and c. ff The balance level, hanging by a sort of staple g, on a point fixed upright on the middle of the bar h (shown in Fig. 3), which is fastened across the tube d. i Two eye pieces sliding into the ends of the level f ts and having a narrow slit horizontally across the middle, “with a hair before each, shown by the dots hh. k An adjusting screw, which acts by drawing the piece m, (which moves in a dove-tail slide), in one end of the tube. n The key-hole through which the screw is turned. Fig. 4. An end view of the case and level, showing the eye pieces 7 ande, one within the other. VII. Accouné 346 NEW METHOD OF REARING POULTRY. Vil. Account of a new Method of rearing Poultry to Advantage. By Mrs. Hannan D’Ovtey, of Sion Hill, near North. allerton, Yorkshire *. SIR, Cheap and easy { BEG leave to communicate a most desirable method of method of rear- ing poultry. Yoed. Poultry house. Breeding: Rearing chick- €ns. Artificial mo- ther. rearing poultry, which [ have proved by experience; the economy and facility, with which it may be performed, would, if generally adopted, lower the price of butchers” meat, and thereby be of essential benefit to the community at large. I-keep a large stock of poultry, which are re- gularly fed in a morning upon steamed potatoes chopped. small, and at noon they have barley; they are in high con- dition, tractable, and lay a very great quantity of eggs. In the poultry yard is a small building, similar to a pigeon cote, for the hens to lay in, with frames covered with net to slide before each nest; the house is dry, light, and well ventilated, kept free from dirt by having the nests and walls white-washed two or three times a year, and the floor covered once a week with fresh ashes. When I wish to pro- cure chickens, I take the opportunity of setting many hens together, confining each to her respective nest; a boy at- tends morning and evening to let any off that appear restless, and to see that they return to their proper places. When they hatch, the chickens are taken away, and a second lot of eggs allowed them to set again, by which means they produce as numerous a brood as before: I put the chickens into long wicker cages, placed against a hot wall at the back of the kitchen fire, and within them have artificial mothers for the chickens to run under ; they are made simi- | Jar to those described by Monsieur Reaumur, in “his Art de faire éclore et d’éleser en toutes Saisons des Oiseaux domes- © tiques de toutes Eispéces,’? &c., in two volumes, printed at Paris, 1751. They are made of boards about ten inches * Trans. of the Society of Arts for 1807, p. 24. The silver medal was voted to Mrs, D’Oyley. broad, NEW METHOD OF REARING POULTRY. 3SAzT broad, and fifteen inches long, supported by two feet in the front, four inches in height, and by a board at the back two inches in height. The roof and back are lined with lamb’s skins dressed with the wool upon them. ‘The roof is thickly perforated with holes for the heated air to escape ; they are formed without bottoms, and have a flannel cur- tain in front and at the ends for the chickens to run under, which they do apparently by instinct. The cages are kept Cages. perfectly dry and clean with sand or moss. The above is a proper size for fifty or sixty new hatched chickens, but as they increase in size, they of course require a larger mother. When they area week old, and the weather fine, Airing. the boy carries them and their artificial mother to the grass. plot, nourishes and keeps them warm, by placing a long narrow tin vessel filled with hot water at the back of the mother, which will retain its heat for three hours, and is then renewed fresh from the steamer. In the evening they are driven into their cages, and resume their station at the hot wall, till they are nearly three weeks old, and able to go into a small room, appropriated to that purpose. The room is furnished with frames similar to the artificial mo- thers, placed round the floor, and with perches conveniently arranged for them to roost upon. When I first attempted to bring up poultry in the above Numbers lost way, I lost immense numbers by too great heat and suffoca- eae aes tion, owing to the roofs of themothers not being sufficiently ness. yentilated, and when that evil was remedied, I had another serious one to encounter; I found chickens brought up in this way did not thrive upon the food I gave them, and many Food. of them died, till I thought of getting coarse barley-meal, and steaming it till quite soft. The boy feeds them with this and minced potatoes alternately ; he is also employed rolling up pellets of dough, made of coarse wheat flour, which he throws to the chickens to excite them to eat, thereby caus- ing them to grow surprisingly. I was making the above experiments in the summer for In two months about two months, and during that time my hens produced 42 '2"¢% me upwards of five hundred chickens, four hundred of which T reared fit for the table or market. I used a great many made into pies for the family, and found'them cheaper than butchers’ 348 NEW METHOD OF REARING POULTRY. Might be sold butchers’ meat. Were I situated in the neighbourhood of ct oe peg London, or any.very populous place, Iam confident I could butchers’ meat. Make an immense profit, by rearing different kinds of poultry in the above method for the markets, and selling them on an average at the price of butcher’s meat. A child might A young person of twelve or fourteen years of age might aed prea bring up in a season some thousands, and by adopting a season. fence similar to the improved sheep-fold, almost any num- ber might be cheaply reared, and with little trouble. Hens kept as mine are, and having the same conveniences, will een readily set four times ina season, and by setting twice each chickens a year. time, they would produce at the lowest calculation, eighty chickens each, which would soon make them very plen- tiful. If this information should be so fortunate as to merit the approbation of the Society, I shall consider myself highly honoured, and my time as having been usefully employed. T am, Sir, Your most obedient Servant, HANNAH DOYLEY. Farther account “Lhe most convenient size of .an artificial mother for forty of the mode of or fifty young chickens is about fifteen inches long, ten managing them. deep, four high in front, and two at the back; it is placed Ps § ’ 5 p in a long wicker cage against a warm wall, the heat at about eighty degrees of Fahrenheit’s thermometer, till the chickens © are a few days old, and used to the comfort of it, after which time they run under when they want rest, and ac. quire warmth by crowding together. I find it advisable, to have two or three chickens among them of about a week old, to teach them to peck andeat. ‘The meat and water is given them in small troughs fixed to the outside of the cage, and a little is strewed along from the artificial mother, asa train to the main deposit. It would have given me great plea- sure, to have been able to send aspecjmen of my superior feed and management, if the season had been rather more advanced, for I think it is not possible for turkies and chickens to weigh heavier, to be whiter, or altogether better fed than mine are, After NEW METHOD OF REARING POULTRY. 349 After a certain age, they are allowed their liberty, living chiefly on steamed potatoes, and being situated tolerably secure from the depredations of men and foxes, are per- mitted to roost in trees near the house. According to your request, I herewith send you a rough Apparatus sketch of the apparatus I use, which probably will con. vey an idea of the business, and not be too complicated for persons employed in poultry yards, fully to understand ; but to prevent trouble and prejudice in the first onset, I think it necessary to remark, that if the chickens do not readily run under the artificial mother for want of some educated ones to teach them, it will be proper to have the curtain in front made of rabbit or hare skin, with the fur side outwards, for the warmth and comfort to attract them, afterwards they run under the flannel ones, which are pre- ferable for common use, on account of cleanliness, and not being liable to get into the mouths of the chickens, I have had great amusement in rearing poultry in the above way, and if my time was not occupied with my chil- dren and other family concerns, I should most assuredly farm very largely in poultry. Reference to the Engravings of Mrs. D’Oyley’s Method of breeding Poultry, Plate X, Fig. 5, 6, 7. Fig. 5. The apparatus called the artificial mother, with described, acurtain of green baize in front and at each end, and holes through the top to allow the circulation of air. Fig. 6. Another view of the artificial mother, but with- out the curtain, in order to show its sloping direction, and interior lining of woolly sheep-skin. Fig. 7. A wicker basket four feet long, two feet broad, and fourteen inches high, with a lid to open, and a wooden sliding bottom similar to a bird cage: the artificial mother is shown, as placed within it. Q. A trough in front to hold food for the chickens, Remark. As the cheapness with which fowls can be reared in this way is an object of primary consideration, it is to be re- gretted, that Mrs, D’Oyley has not added an account of the 390 Plants above 100 acres a ytare Trees should be very sparing- ly pruned, Oaks. Larch wood Randsome. PLANTATIONS OF TIMBER TREES. the quantity of food consumed by a certain number of chickens in a given time; as on this must depend the price at which they could be sold, and the profit that might be made of them. This would have been attended with another ad- vantage, it would have been a guide with respect to the quantity of the different kinds of food, with which the chickens ought to be supplied in the several stages of their growth, to those who have not been in the habit of rearing poultry; and this must necessarily be the case with many persons in the vicinity of London in particular, to whom the adoption of Mrs. D’Oyley’s plan might be very desirable. Mrs. D’Oyley does not say whether the turkeys she men- tions were reared in the same way. VII. Communication from the Right Hon. the Ear. or Firr, relative to his Plantations *. SIR, I request you will lay this letter before the Society for the Encouragement of Arts, &c. as I feel it my duty to cons vey any information to them, respecting my plantations, from the grateful sense of the honour they have done me. I have continued every year, since I last wrote to the Society, to plant above one hundred acres: my plantations now, in the counties of Banff, Aberdeen, and Murray, amount to about thirteen thousand acres. I haye always re- commended to planters to be very sparing in pruning trees. Ihave the pleasure to observe, that on the highest grounds in Duff-House Park, even where exposed to the sea, by cutting down firs and other trees, where they interfere with each other, the oaks and other close-grained timber trees rise vigorous and healthy, and will be very valuable, the oaks in particular. The silver fir and larch also grow to a great size. I was under the necessity of cutting down two silver firs and larches, where they prevented the growth of other trees; I directed them to be sawed up—The boards of the larch have been made into tables, and are * Trans. of the Society of Arts for 1807, p. 1. very PLANTATIONS OF TIMBER TREES. 35) very handsome. Those of the silver fir have been used as sityor fr flooring to two rooms in Delgany Castle, where the fir had Planks. decayed, and are remarkably white and finely polished. The trees in question were about forty years old. There was a very high wind the 25th of December last, Dimensions of which blew down a great many trees upon my estate. Par. 2 S/¥er Sr at 50 ticularly a silver fir in the woods on the low grounds near Duff-House, which appeared to be well sheltered. It was planted by me in the year 1756, and had a most venerable appearance. The dimensions were as follow, as attested to me, Viz. Ft. In. Length of the trunk from the surface of the ground, until divided in five limbs - RE EE Girth at surface of ground - - - a Girth immediately below where the limbs set off 8 6 The five limbs are all of the same height, except No. 1, which divides into two branches before it reaches the top. ‘These are only a few inches shorter than the others, which are 42 feet 6 inches from where they leave the trunk, the length of which is 7 feet, therefore, when added together, the height of the tree, is - 2, 40606 No. 1. Measure of girth where it sets off from the trunk - - - - - - 5 $ And at the distance of 8 feet divides itself into two large branches. No. 2. Girth where it sets off from the trunk 4 0 And at the distance of 23 feet 4 inches from starting, measures 2 feet. No. 3. Girth at starting : - 4 - 3 10 This, and the two other branches, No. 4 and 5, gradually decrease towards the top. No. 4. Girth at starting from trunk - - 3 No. 5. Girth at ditto ditto - - - - 3 The tree alluded to has a great deal of wood in it, which I have ordered to be manufactured for different purposes. There are pineaster larger, but their wood I conceive not Pineaster. to be so fine, The other trees are thriving and well-fenced. Little to “I 352 “eedling larch. Scotch firs. Hard woods. PLANTATIONS OF TIMBER TREES. Little trouble is occasioned by keeping the fences in repair: I do not recommend the planting of acorns, but rather’ procure them from nurseries, at two or three years old. I think seedling larch thrives best when planted in moors, and this also thins the seed beds, from which so many may be taken and transplanted into nurseries, arid planted out the second year after. — I raise very few Scotch firs, as I buy them from nursery- men, at ten-pence per 1200. I continue to have rurseries of all the different hard woods, near my plantations, and which I find answer better than what are purchased from nurserymen. In general they are planted too near each other in their nurseries, and not being removed in time, the roots are seldom so good, which I think I have stated in my former letters. Tam, Sir, Your most obedient humble servant, FIFE. a {X. Remarks on the Advantages derived from Plantations of Ash Trees, by Davin Day, a of West-hill, near Rochester *. Formeraccount In the first volume of the Society’s Transactions for 1783, ef planting ash, trees, page 109, will be found a detailed account of the experi- ments which Mr. Day had made to the years 1779 and 1780 in planting Ash trees; the present account points out their subsequent management. Mr. Day has deposited with the Society a minute account of the expenses to which the following statements refer, and which may be inspected at the Seciety’s house. * Abridged from Trans. of Society of Arts for 1807, p. 4 The silver medal of the Society was voted to Mr. Day. SIR, PLANTATIONS OF ASH TREES. 353 Ip you think the following information, relative to my plantations of ash trees, likely to be of advantage to the public, I wish to lay it before the Society of Arts, &c. The Rewards F received from the Society have stimulated Stimulated to me to exertions in this line, and I have been very successful. Searle I have declined all business but that of raising ash trees for the society. my own amusement, and for improvement of the landed in- terest; and I flatter myself, that I know it as well as any man in the kingdom. I am so certain of the success at- tending ash plantations, that I am willing, on landed se- curity being given me, to advance any sum as far as thirty thousand pounds, on having the execution of such improve- ments under my own inspection, either jointly, or on the owner’s account. I have travelled over a considerable part sof England, and was sorry to see such a waste.tract of land as Bagshot Heath, when I know it might be improved by Bagshot heath cultivation or planting, as has really been done at Farnham, sche 5 ne and many other commons in the kingdom. Where there are, at present, wild or uncultivated woods, I would re- Wild or un- ‘commend to grub up the old wood, and either put the land ie in tillage, or plant it properly with fresh wood, which _ would produce four times as much both in timber and un- derwood. I have made from the underwood of some of my plania- Profit of plan- tions 94J. per acre, at only ten years growth, and I am ‘tions of ash. now falling some plantations, of which the underwood alone will produce me 150/. per acre, exclusive of the ex- pense of falling. It cannot be expected that noblemen or gentlemen, brought up in expectation of possessing large estates, can have a knowledge of improvements like the executive man, and they are deterred from them by the im- positions they meet with in attempting their execution. Few servants will exert themselves properly in improve- ments without having an interest in it themselves: But my plan is no speculation; I know from long experience it “will yield an ample profit to the persons who engage in it with attention. When the plantations are once put im Valuable por- | order, they require but little to be dong afterwards, and, tions for ? daughters, Vou. XX. SuppLement. 2A therefore, 354 PLANTATIONS OF ASH TREES. therefore, are good estates for parents to give their female _ children, as the wood will always find its value from the buyers, when ready for falling, without any trouble or ex- pense to the owner. Iam, Sir, Your obedient servant, DAVID DAY. Statements and Mr. Day next proceeds to a detailed account of the ex- profits. penses and receipts on various plantations, of the profits from which the following is a summary. 2 acres in 30 years produced a clear profitof 135 1 8 - - - - - ° > - 254 1 4 1; - 20 - = - - - 121 16 3 7 - 10 - . = = - - 8814 9 BX seh. 82, es ep? adh De eae Cea eI Bea mi BA hm Lelie mb aes eh ge 5 - 23 = © = 2 ° 50t 2 7 z . 9A ” - ° - - 1914 5 OT) oo us “tt apiclealan hat sae 23:19 3 ff ee Oe Pen reer EINE | tie ae Ceca yb Net 73 8 1 PE pa 2 1Gse ay acinewaoe Jhon ae 6 a 8 Er ire ea ee 56 6 Q These 6 acres were planted with ash and chesnut; and the 11 acres mentioned in the preceding line were in the hands of a farmer as a tenant, whose cattle, being per. mitted to graze among the plants, did them much damage. Method of The following is Mr. Day’s method of raising ash trees, raising ash + ¥ 3 trees. given in his own words. Methods of raising Ash Trees. Choice of seed. I carefully procure, from good straight well-proportioned ash trees, the ash keys, as they are commonly called, or pods containing the seed, betwixt Christmas and the middle Keepingit. of February. Having, as soon as the ash keys are collected, prepared a hole in the ground, about ‘three or four feet deep, I lay a bed of sand, a few inches deep, at the bot. tom of the hole; upon that I place a layer of ash keys, i ' about “ PLANTATIONS OF ASH TREES. 355 about two inches thick; these I cover with sand about the same thickness, to preserve the keys from heating, and then proceed with alternate layers of the keys and sand till the hole is full. They are suffered to remain in this state till the beginning of the month of March of the following year, when they should be taken out for sowing. The Sowing, keys will be found in a swelled state, ready for vegetation. The land being properly prepared, drills should be made in it as for sowing pease, and the keys laid regularly therein, and covered up with earth. In about six weeks the young plants will appear above Hoeing. ground, and should be kept perfectly clear from weeds by hoeing. In the month of March of the next year they should Planting out. be planted out in rows, a foot wide, and the plants placed three or four inches asunder in the row. In this state they are to remain for two or three years, when they will be in @ proper condition for planting out into the land, where they are to remain. For planting out where they are to remain, the land be- Final planting. ing previously well ploughed the preceding autumn, and a good loamy soil, not too wet or stiff, the ground is to be opened by the plough into drills about two feet apart, and the plants placed in each other drill or row, so that the rows of ash are four feet apart, and the plants in the drill two feet asunder. The drills should be 10 or 12 inches deep. A man, who sets the plants, places each upright in the drill, draws the earth to it with his foot, and treads it well in. Where a plant with a larger root than common is found, the man with a small hoe or pricker makes a hole - within the drill, a little deeper than usual, to hold the plant, but this is not often necessary. A statute acre will contain 5400 ash plants, and one man can plant 1000 or 1200 plants in a day. The intermediate row between the plants may be either set with beans or potatoes, or may be left open advantage- ously to serve as a drain to keep the young plants dry. In the second year the plants should be stubbed, or cut Stubbing the élose to the ground with a bill; the produce serves for paee. bavins or fire wood, and pays the expense of rent and cut- 2A ting 356 Crops. Uses of the ~ wood, Other uses. Nurseries. Cheapness of planting. PLANTATIONS OF ASH TREKS. ting. from the stubs thus left in the ground the regular crops of ash are produced, and are fit for falling every ten years. The ash plants are usually fallen betwixt Christmas and March, and the wood sorted into poles of three denomina= tions; viz. best, second, and third hop-poles; beside stakes, edders, and bavins. The bavins will amply pay the expense of falling. The best hop-poles are worth, at present, forty shillings per hundred, the second quality twenty-five shillings, and the third ten shillings. Stakes and edders are about two shillings and sixpence the hundred. . When the plants remain uncut for twelve or fourteen ‘years, the ash plants are fit for other purposes, such as wood proper for wheelrights, and broad hoops for coopers, beside hop-poles, &c. as before-mentioned. When the plants have been two years in the nursery beds, and ready for planting out, they are worth from six shillings to ten shillings the hundred according to their quality. The ash plants I raised from 1763 to 1778, were 442484 I raised and sold from 1778 to 1807 & 156320 I have now ready for sale _- - - 126096 Total of plants I have raised 724900 I will engage, provided the land is prepared by my direc- tions, to plant ash for one third less money than by any other mode of cultivation yet known; and for all plants that die in such a case, provided they are in new plan- tations, I will give plapts gratis to replace them the suc. geeding year. X. Chemical ANALYSIS OF IRON SPAR. S57 D5 Chemical Examination of a Sparry Iron Ore, sent to Mr. Guyton by Bereman. By Mr. Cottet-Derscorits *. Tue analyses of iron spar, that have been lately pub- Recent analyses lished, having exhibited results considerably different from connate “ those obtained by Bergman, it was to be wished, that some Bergman's. of the species on which that celebrated chemist had operated might be subjected to a fresh examination. In fact this was the only method by which it could be known, whether these differences arose from the composition of the ores them- selves, or from mistakes in the analysis. Mr. Guyton, who had received from the Swedish chemist a small specimen of the very ore, that had been the principal subject of his examination, having the goodness to break off some pieces A piece of the from it, and entrust them to me to analyse, I have executed PE se the task with all the attention I could possibly pay to it. The small quantity of iron spar I had at my disposal, it being only 388 cent. [60 grs.], and the method I employed, not allowing me to ascertain the proportion of the volatile principles, I confined myself to the investigation of the nature and quantity of the fixed; and I conceive it neces- sary, to relate at large the means I employed, that the che- mical reader may be enabled to judge of the degree of con- fidence to be placed onmy results; previously giving a brief description of the specimen on which I opemted. Its specific gravity, taken by Mr. Guyton, was 3°693. _ Its physical Its colour was brownish yellow. iapiaiie It was scarcely translucid. Its crystallization was a little confused: its lamine very small, and a little twisted. This ore, reduced to powder, was dissolved with effer- Dissolved in vescence in sulphuric acid diluted with water; and I took sulphuric seid. care to employ no more than was necessary, so that the li- quor was without excess of acid. Some insoluble matter re- mained, weighing 1 decig. [1-544 grs.], which was found to be silex. * Annales de Chemie, Vol. LVIII, p. 149. The ee 358 ANALYSIS OF IRON SPAR. Ewaporatedand The solution, on several successive evaporations, afford. eee ted crystals of green sulphate. Only a few small scales of suJphate of limewere formed. Thelast portions of liquor, affording no more crystals, were added to the crystals that had been separated, and the whole diluted with a quantity of water more than sufficient for their complete solution. Sulphuretted Water of sulphuretted hidrogen occasioned no precipitate hidrogen added. in this solution: it merely destroyed its transparency, as is _ the case in solutions of iron that contain but a small quantity of red oxide. Precipitated by The hidrosulphuret of ammonia, afterward added, oc~ hidrosulphuret casioned a very copious black precipitate, which was scpa- of ammonia. an rated by the filter, and washed in cold water. Precipitatedis- | The precipitate detached from the filter was treated with ea aqua aqua regia. I neglected to burn the filter, and treat the ashes in the same way, which may have occasioned a little loss of the metallic principles; for this very fine precipitate easily insinuates itself into the paper. Solution de- The nitromuriatic solution diluted in water and filtered vet bia by was decomposed by saturated carbonate of potash. The ate of potash. ferruginous sediment was redissolved, while still wet, by weak acetic acid, and by successive evaporations the ace- tate of iron was entirely decomposed. The sediment, col- lected on a filter, was dried with a red heat, and weighed 188 cent. [29 grs.]. The colourless liquor, separated by the filter, was decomposed by saturated carbonate of pot- ash: it did not become turbid, and it was added to that, which arose from the decomposition of the nitromuriatic solution. From this carbonate of manganese was soon thrown down by boiling, which, when washed, and dried at a red heat, was converted into brown oxide, and weighed 7 cent. [1-08 gr. ]. Oxalate of am- The liquor separated from the metallic precipitate ob- meme Bide a nod by the hidrosulphuret of ammonia was mixed with a smal! quantity of oxalate of ammonia, which did not occa. sion in it any sensible precipitation. On evaporating after- ward, a white sediment formed, which was separated. 'This sediment, heated in a small porcelain capsule, burned with a blue flame, and left a residuum, which, after being heated red hot, was found to weigh 2 cent. [0°308 gr.]. It had . all the characters of lime. The ANALYSIS OF ALUM ORES. 359 _ The clear liquor was then evaporated to dryness in a pla. Solution eva- tina crucible, and the residuum heated red hot. The am- agape Se moniacal salts being expelled, there remained a salt of the weight of 21 cent. [3243 grs.], which was sulphate of magnesia. This quantity of 21 cent. gives at least 77 milli. [1:189 gr.] of earth, supposing the crystallized sulphate to contain 19 per cent of base; for that which has been heat- _ ed red hot must have lost some of its acid, and it is neces- sary to add a little to the solution, to make it crystallize. | On reducing the products above-mentioned to hundredth parts, we shall have Fragments of quartz - - an B58 Component Red oxide of iron a te 48°45 pari Brown oxide of manganese - - 1:80 Lime .- = & - - 0°52 Magnesia - 2 De OR - 1°98 55°33 The remainder is carbonic acid, water, and loss. From this result it appears, that Bergman did not ex- Magnesia mit ‘ ey 3 . . taken for lime. amine with sufficient care the nature of the earthy princi- ples contained in the iron spars he analysed; and it is very probable, that he examined other ores, in which magnesia was contained in still larger proportion, and mistaken by him for lime *. XI. Chemical Examination of the Alum Ore of Tolfa, and the Earthy Aluminous Schist of Freyenwalde. By Mr. Ktaprotu +. A\vum, a substance so indispensable in dyeing and se- re = —_ ° ° . i on veral other arts, is a triple salt, composed of sulphuric fea anes acid, alumine, and potash, with an excess of acid. It is ® In the last number of our Journal, p. 314, an analysis of two varieties of iron spar was given, which corroborates the fact of magnesia having been mistaken for lime. + Journal des Mines, No. 117, p.179. First published in the Berlin Chemical Journal, vol. V1. obtained 360 ANALYSIS OF ALUM ORES. obtained from various earths and stones, which contain the elements necessary to its formation in a more or less perfect state, and are included under the name of alum ores. Thus the alum of the shops is an artificial production. Native. Nature it is true presents us with alum completely formed in some volcanic countries, but it is in so small a quantity, as to be altogether insignificant compared with the great demand for it. Among the native alums of volcanic coun- At Cape tries that of the alum grotto at cape Miseno, near Naples,, Miseno. 5 : hates , “tei . is particularly to be distinguished. This is continually efflorescing on the inside of the cavern in small tufts, coms posed of little, short filaments of a silky lustre, sometimes intermixed with granular crystals. From the results of my examination, which have been published some years, it is well known, that the greater part of this native salt is a perfect alum, that is to say, it has from nature not only the sulphuric acid and earthy base, but likewise the third essential constituent principle, potash. Alum of the It appears, that the alum we now use was not known to ancients: the ancients; and that the alumen of the Romans, as well as the surlngiw of the Greeks, was a native sulphate, arising from the decomposition of pyrites, and consequently not differing from their misy and sory. Pistmade in The art of extracting and preparing alum came to us theLevant. from the Levant. The most ancient of the alum works known to us is that of Rocca in Syria, now called Edessa ; whence the term alumen Rocce, vulgarly rock alum. All} the alum used in Europe in the middle ages was brought from the Levant. ot into Jn the fifteenth century some Geroese, who had learned e in the Levant the mode of fabricating it, were fortunate enough to discover ores of it in Italy, and to extract it from them. John of Castro is recorded in history as the Holly abundant first, who discovered the ore of Tolfa. To this discovery oo Raa rag he was led by the large quantity of holly growing there; as he-had observed in the Levant, that the mountains from which alum was taken there were covered with this shrub. The manufactures of this salt succeeded so well and so. speedily in Italy, that pope Julius II prohibited its impor- tation Rochalum. ee ¢ ANALYSIS OF ALUM ORES. 361 tation from the Levant, because it annually drew large sums of money to Turkey. This prohibition increased the prosperity of the Roman alum works. The following is a brief account of the method employed Method of at Tolfa, near Civita Vecchia. The ore is blown up with Tole nae . gunpowder: it is separated from the pieces of the rock, that adhere to it: it is calcined in furnaces, nearly in the same manner as lime is burned: in six or seven hours, being sufficiently calcined and friable, it is taken out, and laid on pavements of a long shape, surrounded with walled trenches : on these it is laid in heaps of a moderate height, which are watered for forty days with water from the trenches. The ore being thus decomposed, it is boiled in large caldrons ; and when the water is saturated to a certain point, it is poured into the crystallizing pans; where, after itis cold, it deposits the alum in large crystalline masses. Alum is obtained in avery different manner at Solfa- and at Solfater terra, near Puzzuola. Here nature acts synthetically. ™ Fumes pregnant with sulphurous and sulphuric acid are continually issuing from little crevices in the volcanic soil of this place, the former of which deposit a concrete sulphur ; the second gradually penetrate the ancient lavas, which are of an argillaceous nature, combine with their alumine, and thus form an alum ore, which afterward affords by lixivia- tion and crystallization a very pure alum. In the sixteenth century the art of fabricating alum Introduced inte spread into several parts of Europe; after it had been dis- roger % covered, probably by accident, that various sorts of argil- laceous schists, impregnated with carbon or bitumen, and subsequently termed aluminous schists, would furnish alum when properly treated; and the alkali, which did not na- _turally exist in them, was added during the process. The “first works of this kind established in Germany appear to Germany. have been those of Commotau in Bohemia, and Schwensal in Saxony. - Subsequently, that is in the beginning of the last century, Manufactory at _ an alum manufactory was commenced at Freienwald, in Freienwald. Brandenburg. At present it belongs to the grand Orphan School at Potsdam, and furnishes annually four hundred tons of alum. 5 The 362 Preparation of the OTee ANALYSIS OF ALUM ORES. The aluminous schists, from which alum may be obtained, ‘must undergo a process preparatory to their lixiviation. In Lixiviation. Oxidation of the iron. Potash added. This obtained from soap-boil- ers refuse. Other matters might be used. the aluminous schists properly so called, which are hard, of a stony texture, and contain a great deal of pyrites, the preparatory process consists in roasting. But for the softer alum ores, such as that of Freienwald, exposure to the air is sufficient. When the ore is extracted from the mine, it is placed in large heaps, sloping to a ridge like the roof of a house, and left exposed to the open air for a year or more. When its decomposition, which is particularly pro- moted by damp air, is sufficiently advanced, it is distributed into long flat troughs, and lixiviated. When the water is sufficiently saturated with the salts, which are sulphate of alumine and sulphate of iron, it is carried to the manufac- tory, and boiled in leaden caldrons, till the, proof liquor taken out becomes on cooling acrystalline mass of the con- sistence of honey. During the long boiling of the lixivium, the greater part of the sulphate of iron is decomposed, the tron passes to a higher degree of oxidation, in which state so much of it cannot be dissolved in sulphuric acid, and it is deposited in the form of brown oxide. When the lixivi- um is sufficiently boiled down, it is carried to the settling troughs, and as soon as it has grown clear by standing a little, it is drawn off into other troughs, where it is mixed with the quantity of potash necessary for making it into alum. | At Freienwald, as at most alum works, they use for supplying the alum with this potash the saline mass obtained from soap manufactories, where soap is made with an alka- line lic and muriate of soda, by boiling the spent lie to dry- ness. ‘The muriate of potash contained in this saline mass is decomposed ‘the instant it is mixed with the aluminous > lixivium: the potash unites with the sulphate of alumine, and forms alum, which can no longer continue in solution in the concentrated lixivium, and is precipitated in the form of small crystalline grains, known by the name of alum meal. The muriatic acid, thus set free, lays hold of the oxide of iron, and prevents its falling down with the alum. Instead of the saline mass from the soap-makers, matters containing sulphate of potash might be employed, as the residuum ANALYSI8 OF ALUM ORES. 363 residuum left after the distillation of nitric acid, glass gall, &c. The alum meal is washed with cold water, redissolved Crystallization. afterward in a small quantity of boiling water, and lastly drawn off into large wooden vessels, where it is left to cry- stallize slowly. I shall now proceed to the proper object of this essay, Analysis namely, the chemical analysis of the alum stone of Tolfa, ot maeeke oe and of the earthy aluminous schist of Freienwald. 3 I. The Alum Ore of Tolfa. The alum stone of Tolfa in its natural state contains the Contains all the three essential constituent principles of alum, considered capo Parts as a triple salt; sulphuric acid, alumine, and potash. The earth in which it is found is probably of volcanic origin, and has been altered and whitened by the vapour of sul. phuric acid. In this it exists in irregular veins, and in no- dules. The harder and heavier it is, the richer in alum it is presumed to be. Some naturalists, as Monnet and Berg« man, have supposed it contained sulphur, which was after- ‘ward converted into sulphuric acid by the process of roast- ing. But Dolomieu and Vauquelin have shown, that this Acid ready acid is ready formed in the ore, which will be farther con- ag in the firmed by what I shall say. ’ The alum stone employed in my analyses was of a pearl Physical charac- gray, that is, gray with a violet tinge; in amorphous ‘™°% this ore. masses; dull, with afew shining points, or having very lit. tle lustre; of an unequal fracture approaching to shelly; a little translucid on the edges; hard, not adhering to the tongue, and heavy. A. Two hundred grains were strongly roasted in a small Roasted. retort with its proper apparatus. An aqueous liquor passed over, highly loaded with sulphuric acid, and accompanied with a smell of sulphurous acid, but without a particle of sulphur. Theloss of weight was twenty nine grains. B. Two hundred grains were gently heated, so that the Water expel- loss of weight could proceed only from water expelled. led. This loss was six grains. C. a. Two hundred grains were reduced to fine powder, Fused with mixed with twice as much carbonate of soda, and the whole ym subjected to the action of a fire, at first moderate, but af- terward 364 muriatic acid added, and diluted with water. Purt of the so- lution precipi- tated by muri- ate of barytes; the other by ammonia. The ore heated with nitrate of barytes, dilute sulphuric acid added, and pre- with sulphuric acid. cipitated by ammonia. Its component parts. These as given by Vauquelin, ANALYSIS OF ALUM ORES. terward increased so as to fuse it. The mass when cold had the appearance of a white enamel. It was well pow- dered, muriatic acid poured on it to supersaturation, and evaporated to dryness. Theresiduum, mixed with water and diluted, left behind silex, which after being heated red hot weighed 113 grains. 6. The muriatic solution was aided into two parts. Into one of these was poured a solution of muriate of barytes, and sulphate of barytes was precipitated, which after being heated red hot weighed 50 grains; indicating 16:5 grs. of concrete sulphuric acid. c. The other half was precipitated by ammonia, which threw down the alumine. This when purified, washed, and roasted, weighed 19 grains. D. A hundred grains of the ore were mixed with 200 grs. of crystallized nitrate of barytes, and heated red hot. The pounded, mixed with water, and supersaturated After evaporating till the saline mass was moderately dry, it was diluted in water, boiled, neu- tralized with ammonia, and filtered. The liquor being eva= porated, and the residuum heated red hot in a platina cru. cible, left seven grains of sulphate of potash, which in. cluded four grains of pure potash. According to this 100 parts contain » mass was Silex - - * = OS Alumine 28 f Ls 19 Sulphuric acid = = = 16:5 Potash * 4 e 40 Water = e “ EP 1g 99° These component parts are the same in kind as those found by Mr. Vauquelin, who gives them as follows: Silex “ -, - > 24 Alumine . « ° 43:92 .. Sulphuric acid - - = 25 Potash | 5 - 3:08 Water - « . - 4 100° The ANALYSIS OF ALUM. ORES. 365 The difference between these analyses in regard to the re- differ in their spective quantities of the several component parts must 2022t%tes- have arisen, no doubt, from a difference in the composition ef the specimens. I]. Earthy Aluminous Schist of Freienwald. The mineral that furnishes the alum of Freienwald owes Alum ore of its origin unquestionably to the vegetable kingdom, and ap- Dione neal pears to be produced by an alteration of brown coal. Itgin. forms a considerable stratum amid the alluvial formation at Freienwald, which is traversed by galleries for its extrac- tion. At coming out of the mineit is of a brownish black, tender or friable, and very slightly shining. Its fracture in the great is imperfectly slaty; in the small, earthy. When rubbed it takes a lustre inclining to that of wax. It belongs to that species of the argillaceous genus, that is ‘designated in the systems of mineralogy by the term alumi- nousearth (alaunerde). 'This mineralogical term must not occasion it to be confounded with the simple substance known by chemists under the name of earth of alum (alaun- erde), and it is to prevent this mistake I here employ the denomination of earthy aluminous schist. Hitherto this mineral, as well as the true aluminous Mistakenly sup- schist, has been considered as a clay impregnated with bi- \ sient tumen and pyrites. It is indeed true, that the earthy schists, pyrites. and still more those that have the consistence of stone, very frequently contain pyrites: but such ores afford only a very ferruginous alum, and are consequently less fit for the fa- brication of this substance, than for that of vitriol. The following experiments, made on alum ores of the The sulphur first quality, will show, that the sulphur they contain is ite es ‘not combined with the iron in the state of pyrites; but that with carbon. it appears to form a peculiar combination with carbon. A. a. A thousand grains of the ore, in the state in which The ore boiled it was extracted, were put into a phial with twenty ounces” ***" of distilled water, and boiled for an hour; when the liquor was filtered off, and the residuum lixiviated. What passed ‘through the filter was colourless, did not perceptibly change blue vegetable tinctures, and had a vitriolic taste. b. Half 366 Half the solu- tion decompo- sed by muriate of barytes, the other half by oxalate of ammonia. Proportions of the sulphates of lime and iron determined. The ore boiled with carbonate of soda and pre- cipitated by muriatic acid. ANALYSIS OF ALUM ORES. 6. Half of this was decomposed by a solution of muriate of barytes, and sulphate of barytes was formed, which, after being heated red hot, weighed 23 grains. This pre- cipitate being separated from the liquor, prussiate of am- monia threw down another of prussiate of iron, weighing AO grains. c. To the other half oxalate of ammonia was added. It became a little turbid, and assumed a pale yellow colour, which probably arose froma small quantity of oxalate of iron. It then gradually grew clear again, a precipitate falling down, which, after having been heated red hot, weighed 2°5 grains, and was found to be lime contaminated with iron. Thus what the ore had yielded to the water, in which it had been boiled, consisted of sulphate of lime and sulphate of iron, the proportions of which may be determined as follows. A thousand parts of ore produced 46 parts of sulphate of barytes, which contain 15°18 parts of concrete sulphuric acid. Of these 7 parts are required to neutral. ize the 5 parts of lime; and thus, including the water of crystallization, we may admit 15 parts of gypsum, or sul. phate of lime, in the ore. The 8°18 remaining parts of sulphuric acid with 8-5 parts of iron will give about 18 parts of vitriol of iron at the state of decomposition. B. Two hundred grains of ore, and 400 grains of dry carbonate of soda, were put into water, and boiled. The liquor when filtered was of a very deep blackish brown co- lour. Muriatic acid was gradually poured in, which af- forded no indication of sulphuretted hidrogen gas; but a muddy sediment was formed, of a blackish brown colour, and occupying considerable space, which, when collected on a filter and dried, weighed twelve grains. Heated in a platina crucible, it burned, without emitting any sensible “smell of sulphur, and Jeft behind one grain of white alu- Ore digested in muriatic acid. mine. . C. Two hundred grains were digested in muriatic acid. The slightest indication of sulphuretted hidrogen gas was not observable, either by the smell, or by holding against the mouth of the vessel paper, on which I had written with solution of acetate of Jead. The acid appeared to display ‘ but ANALYSIS OF ALUM ORES. 367 but little action on the ore. On pouring nitric acid on it Nitric acid drop by drop, nitrous gas was evolved, and the black co- wee lour of the ore changed to brown. The filtered solution was of a golden yellow; and muriate of barytes threw and mutiate of down from it a copious precipitate. This, which was sul- >**/t* phate of barytes, being collected and heated red hot, weigh- ed 54 grains. D.a. A thousand and two grains of the ore, not yet Ore distilled, freed from the humidity it contains in the mine, were pat 8*¥¢ out sul- " ; phuretted and into a glass retort furnished with a pneumato-chemical ap- carburetted hi- paratus. ‘Two hundred and twenty cubic inches of gas were drogen, evolved, which was a mixture of sulphuretted hidrogen gas and carburetted hidrogen gas. If a candle were bronght into contact with it, it took fire, and burned with a blue flame. When shaken in a vessel containing water, half of it was absorbed. A solution of lead, poured into the wa- ter impregnated with it, afforded a precipitate of a deep brown, which was sulphuret of lead. b. The fluid that passed over weighed 133 grains. It was The fluid con- aqueous, yellowish, and turbid with slight flocks of sul. ‘ine? sulphu- phuretted carbon. Its smell was that of sulphuretted am. nia. monia, diluted with a great deal of water. Litmus paper, that had been reddened by an acid, it turned blue, and it emitted a white vapour, on bringing near it a glass rod wet. ted with fuming muriatic acid. A drop was let fall into a solution of lead, and the metal was precipitated brown. It was neutralized by a few drops of muriatic acid, and be- came slightly milky. On being filtered and evaporated two grains of sal ammoniac were obtained. c. The residuum left in the retort weighed 750 grains. Residuum con- It had the appearance of a black coally powder. Being “"¢4 carbon. burned on a test it left 90 grains, which were the carbon - gonsumed. d. The fifth part of the remaining 660 grains, or 132 Silex precipi- ° Mens Bic ; : tated from a grains, was roasted with twice its weight of caustic soda. portion of it. The mass when cold was of a greenish brown, and gave a light green tinge to the water with which I mixedit. I su- persaturated it with muriatic acid, evaporated, diluted it again with water, and filtered. The silex was left behind. This, after being heated red hot, weighed 80 grains. he e. The 368 ANALYSIS OF ALUM ORES: Alumine. e. The solution that had passed through the filter I prés cipitated by carbonate of potash, washed the precipitate, and boiled it in a lixivium of potash, which became loaded with alumine. This earth being precipitated by muriate of ammonia, washed, and heated red hot, weighed 32 grains. Sulphate of Jf. The brown residuum, that remained in the alkaline hime. See : ; ; . lixivium, was dissolved in sulphuric acid, and evaporated to dryness. During the evaporation sulphate of lime was deposited, which, carefully collected, weighed two grains. The dry mass was strongly roasted, and then lixiviated. Oxide of iron. The oxide of iron, collected on the filter, was dried, moist« ened with a little oil, and heated red hot in a Close vessel, when it yielded 14°5 grains of oxide of iron attractable by Magnesia. the magnet. The remaining liquor, decomposed during ebullition by carbonate of potash, gave some slight indi- cations of carbonate of magnesia. Waterexpelled EK. a. One hundred grains* were put into a small glass i retort, which was placed on a sand heat, and the fire cau- tiously increased, lest any gas should be evolved, or any perceptible decomposition occasioned, .and that nothing but water might be raised fromit. The quantity expelled was 21°5 grains. It had-a very slight opal tinge, and a very faint smell of sulphuretted hidrogen. A very slight coating of sulphur too was deposited in the neck of the retort. Theore burned 9. The ore being dried was burned ona test; when the without flame combustion proceeded without flame or smoke, and emitted aah but a slight sulphurous smell. - The loss in weight, which was 45 grains, represents the quantity of sulphur and char- coal burned, and perhaps too a small portion of water, that was left in the ore. Magnesia preci- © The residuum was dissolved in a mixture of 200 grains pitated, ‘of sulphuric acid, and 400 of water, evaporated to dry- ness, and kept at a strong red heat for half an hour. The residuum was lixiviated, filtered, and precipitated with am- monia, when 0*5 of agrain’of magnesia were obtained. * This is apparently an errour of the press. According to the proportions of the constituent principles given at the end, it must have been two hundred grains. F. Ed. . d. The ANALYSIS OF ALUM ORES. 369 d. The liquor was evaporated to dryness, and the resi- Sulphate and duum heated till no more white fumes were expelled. What eh er remained weighed 4:5 grains, It was a neutral salt, formed of amixture of sulphate and muriate of potash. As this last salt must necessarily have been completely formed in the ore, we may admit too, that the potash of the former was not free in it, but formed a real component part of it in the neutral state. Till experiments on a larger scale shall have enabled me to determine more accurately the propor- tions of these two salts, I shall reckon that of sulphate to that of muriate as three to one. F. The results of the experiments above given will serve Corrections of to rectify some of our chemical ideas respecting the earthy vag sn aluminous schist of Freienwald, and those of a similar nature. . 1. In their composition there is carbon only, but not The ore con- bitumen; for they afford no bituminous oil by distillation, Hager and when roasted in open vessels they burn like charcoal men. without flame or smoke. 2. The sulphur of the ore, which becomes oxigenized The sulphur . > ° + united with car- during its exposure to the air, and thus forms the sulphuric hoy in a pecu- acid necessary for the production of alum, is not combined liar mr: and in it in the state of pyrites, exclusively of any pyrites mixed alee s with the ore accidentally, but is intimately united with the carbon, and this in a manner with which we are not yet well acquainted. With the best lenses we cannot discover the smallest atom of pyrites in the ore, either in its natural state, or after it has been triturated and washed through the ‘sieve with care*. In this state of combination with carbon the sulphur is protected against the solvent power of alka- Vis, and gives no sulphuretted hidrogen gas with muriatic acid. G. As to the determination of the respective proportions Difficult - de- wile ts . aa . termine the of the constituent principles mentioned, there is some difl- a oneal as “* I have observed in several coal-mines, particularly those of Fire damp not Anzin, a fact, that has probably some connexion with this men- from pyrites. tioned by Mr. Klaproth. The coal that produces fire damps does not contain any pyrites, at least perceptible to the eye; and in the same places the coal that contains a great deal of pyrites is wrought without the least danger. Vor, XX.—SuPppLemMeENT. 2B culty 370 Sulphur and carbon. Alumine. Sulphur. Carbon: 1000 p. ore might produce 216 alum. Less obtained from defects in the process. ANALYSIS OF ALUM ORES. culty in it, arising chiefly from the intimate union between the earbon and the sulphur; as these two substances cati- not be separated in the dry way, without new gaseous com. pounds being formed. . me The essential parts of the mineral, as an alum ore, are alumine and sulphur. The aadientee processes of analysis give us directly 160 parts as the quantity of alumine in 1000 of the ore. The sulphur not being obtainable ina separate state, we must deduce its quantity from that of sulphate of barytes obtained in treating the ore by nitric acid. Accor- ding to what has been said (in C), 1000 parts of the ore produced 270 of this sulphate. From this quantity 46 parts are to be subtracted, which were furnished by the vi- triol and gypsum, and 20 by the sulphate of potash, ad- mitting 15 of this sulphate in 1000 of theore. Thus there remain but 204 parts of sulphate of barytes produced by ~ this sulphur: but 204 parts of this salt contain 90°75 of sulphuric acid of the specific gravity of 1:85, or 67:5 of concrete acid, which are produced by, the oxigenation of 28°5 of sulphur. And if (according to E }) the sum of the sulphur and carbon may be taken at 225, on deducting 28-5 for the sulphur we shall have 196-5 for the quantity of carbon. H. Admitting that 1000 parts of eaetenpen alum, de» composed by muriate of barytes, produce at a mean 945 of sulphate of barytes, we shall find, that the 28°5 of sulphur contained in 1000 of ore may afford 216 parts of afim, provided the proper quantity of potash be added. The component parts of the ore, that produce them, are not a fifth part of the mass. If the quantity of alum obtained, or even that might be obtained in the manufactories, be much less than I haye mentioned, this arises from the imperfection of the process employed to produce the efflorescence of the ore during its exposure to the air. The oxigenation of the sulphur, and Component parts of the aluminous “schist. consequent formation of sulphate of alumine, takes place only on the surface of thelumps, and of course the greater part of the ore remains undecomposed. J. From the preceding experiments jwe may infer, that 1000 parts of the earthy aluminous ‘schist of Preienwald q contain Sulphur 73 eee EFFECTS OF GALVANISM ON ANIMALS. 371 Sulphur - «. G. - - 28:5 Carbon. - G. - 196°5 Alumine - hat 3 a - 160 Silex - - D. d. = 400 Black oxide of iron, with a slight trace of _ manganese Peet hy Ae #rom which subtract for the vitriol 8-5 64 - 64 Vitriol of iron EY lle Wess ok a Sulphate of lime . Rca oe 15 Magnesia- = ae oe ee Sulphate of potash - Lo ae 15 ~ Muriate of potash =i Ed. Le Water - “es E. @. = 107°5 1012: ‘Itis very possible however, that the quantity of some of these component parts may be capable of being determined with more accuracy. As to the excess of about one per cent, which the sum total shows, this may be considered as of little importance in an analysis like the present. XII. On the Effects of Galvanism on Animals. Ina Letter from Mr. Joun Tatum. Dear Srp, My two papers on galvanism having met with an inser- Galvanic expe- tion in your Journal, induces me to send a third, contain- riments. ing galvanic experiments, some of which I presume will be new to most of your readers, as I believe no one has per- formed them but myself. After having killed two frogs, one by electricity, and Two frogs kill- the other by immersion in carbonic acid gas, and dissected’ a armghelime c5 tricity, the _ them in the usual manner, I endeavoured to excite them by other by fixed i a-galvanic trough of 50 plates, containing 350 inches sur- wy Pex ae face, but no muscular contractions ensued. I did not (as 2B2 a 379 EFFECTS OF GALVANISM ON ANIMALS. is generally the case) confine my experiments to the inferior parts only of the frog, but made them on the superior also. The first moist- I then moistened both upper and lower extremitics of ened with oxi the frog killed by electricity with oximuriatic acid, and im- muriatic acid, i Z an i f . without effect. mediately applied the positive and negative wires of the above trough, but with as little success. But six hours Having left them on the table, to attend to some other after it was con- experiment in another room, I did net return to remove egal "them till about six hours after the experiment, when £ was plates. much surprised to observe the head of the latter frog appear ° more healthy than when I left it. It being late in the even-' ing, I began to lament, that I had emptied afd cleaned my trough, as I wished to try its effects a third time; but from the appearance I was tempted to try the effect of a pair of zinc and silver plates of 17 in. diameter, and the convul- sive motion produced by this small power far exceeded my most sanguine expectation. Two mice {also killed two mice, one by dividing the vertebre of killed. the neck, the other by confining it under a bell glass: con- taining about a pint of atmospheric air. The first mouse was powerfully excited by a pile of 60 pairs of zinc and copper plates moistened with solution of muriate of soda. The one by suf- But the same pile produced so small a degree of motion in focation not ex- the second mouse, that I can scarce say whether it moved cited. A or not. Two frogs gal- | Afier having performed a variety of experiments before vanized i 5 x = tana ap a numerous company with four troughs of 106 pairs of plates, containing 5360 inches surface, I placed the posi- tive and negative wires in a glass jar of water, in which were two large frogs. The instant both the wires touched the water, the frogs betrayed the greatest signs of uneasi.« ness, so much that some gentlemen requested me to remove the wires. I complied with their request, but observed, £ had every reason to believe they would not survive. The died in two result was, that on the next day (being left in the water) a they appeared very languid, and on the ‘second day they were dead. Perhaps, Sir, I may presume ‘too far, in submitting my ‘theory or opinion on the above experiments; but if I ‘err, ‘Lam open to conviction, and shall esteem it a particular fa vour to be corrected by any of your scientific readers. I concerre;* »- EYFECTS OF GALYANISM ON ANIMALS. 373 I conceive, Sir, that animals possess a certain portion of Accounted for excitability, which, by the application of various powerful re Lik in stimuli, such as galvanism and electricity, produce muscu- ed irritability. lar motions both in the living and dead animal; and if too great a portion be applied, it finally exhausts the excitabi- lity, and produces death. But the excitability may also be destroyed by depriving the animal of those things, which are calculated to increase or replenish it: I farther conceive, that the excitability is in proportion to the oxigen the ani-« mal or parts of an animal may possess; and if animals are deprived of life by the above means, I am inclined to think little or no motion can be produced by the most powerful stimuli with which we are acquainted. This theory, Sir, I think will account for the results of the experiments I have detailed. Thus with respect to the two frogs killed, one by elec- tricity, the other by depriving it of oxigen; the excitabi- lity being destroyed in both, it could not be exerted. But the excitability, I conceive, was in some measure restored in the first by its absorbing oxigen from the oximnriatic acid or the atmosphere, after being a few hours expased to their action. ‘The first mouse, being suddenly deprived of life, still possessed a greater quantity of oxigen than the second, which was killed by depriving it of the vital prin« ciple by degrees; and thus it was easily excited, while the _jJatter was not. The two frogs killed by galvanism may be accounted for en the same principle as tlie frog killed by electricity. _ __ As this is counmitted to paper in a hurry, I flatter myself the candid reader will draw a veil over any imperfections. Permit me, Dear Sir, to subscribe myself, re Yours truly, 53, Dorset Street, JOHN TATUM. July 21, 1808. Remark. si These experiments appear by no means sufficient to prove, -thatdeath is caused by the deprivation of a peculiar prin- _siple.of excitability, according to the ingenious theory of Brown} BIA €ommunica- tion between the stomach and circulation through the e spleen. Stomach during digestion sepa- rated into two poruions. Fluids chiefly contained in the cardiac por- tion, and car- ried out of the stomach with- out reaching the pylorus, STRUCTURE AND USES OF THE SPLEEN. Brown; still less, that oxigen is that principle, an hypo- thesis I believe first broached by Girtanncr. Much indeed must be done, before we can venture to establish any theory on so abstruse a‘subject, as that of vitality still remains: a subject on which it is not of so much importance to multi. ply facts, as to describe those that present themselves with accuracy, and with attention to every concomitant circum. stance even of the minutest kind. C. XIII. On the Structure and Uses of the Spleen. © By Everarp Home, -Esq. F. R.S.* In bringing forward a fact of so much importance, as a communication between the cardiac portion of the stomach, and the circulation of the blood, through the medium of the spleen, J shall not take up the time of the Socicty by offering any preliminary observations, but state the circum. stances which led to the discovery, and the experiments by which the different facts have been ascertained. During the investigation of the functions of the stomach, (in which [J have been lately engaged,) it was found, that, while digestion is going on, there is a separation between the eardiac and pyloric portions, either by means of a permanent or muscular contraction +. This fact placed the process of digestion in a new light, and led me to consider in what way the quantities of different liquors, which are so often taken into the stomach, can be prevented from being mixed with the half digested food, and interfering with the formation of chyle. Pursuing this inquiry, I found, that the fluids are princi- pally contained in the cardiac portion, and the food that * Philos. Trans. for 1807, p. 45. ‘The president and council of the Royal Society adjudged the medal on Sir Godfrey Copley’s donation, for the year 1807, to Mr. Home, for his various papers on anatomy and physiology, printed in the — Trans- actions. + See our Journal, p. 15 of the present vol. 5 as a STRUCTURE AND USES OF THE SPLEEN. 375 has reached the pyloric portion is ‘usually of one uniform consistence, so that the fluids, beyond what are necessary for digestion, would appear to be carried out of the sto- mach, without ever reaching so far as the pylorus. To siberian the truth of this opinion is the object of the pre- sent paper. The lymphatic vessels of the stomach are numerous, but Lymphatics ap they are equally or more so in the other viscera. Many cir- a aE aia cumstances appeared to render it probable, that the spleen is dani by the the route by which liquids are conveyed. The more I con- ae sidered the subject, new reasons in favour of this opinion crowded on my mind, so as almost to enforce conviction, and made me set about devising various methods, by which its truth or falsehood might be established. The first point to be decided was, whether the liquids Fluids can received into the stomach do escape in any considerable Lae quantity, when prevented from passing out at the pylorus. out passing the _ This was ascertained by the following experiment, made ny i October 31, 1807, with the assistance of Mr. Brodie, Mr. W. Bette, and Mr. Clift. The pylorus of a small dog was secured by a ligature, and 3 This proved on a few minutes afterwards five ounces by measure of an — fusion of indigo in water, of the temperature of the atmos. _ phere, were injected by the mouthinto the stomach. At the end of half an hour the dog became sick, and brought up by vomiting 2 ounces of a nearly colourless fluid. Thedog was immediately killed, and the different parts were examined. The pylorus was found compietely secured by the ligature, so that nothing could pass in thatdirection. The pyloric por- tion of the stomach was found empty and contracted; the cardiac portion contained about two ounces of solid con. tents, enveloped in a gelatinous substance, and one ounce of water with little or no colour, the indigo being com- pletely separated from it, and spread over the surface of the internal membrane. Of the five ounces of water thrown into the stomach, two were brought up by vomit. ing, and one only remained; two ounces had therefore escaped in the course of half an hour. As the stomach contained two ounces of solid food at the time the experi- ment was made, it is reasonable to suppose, that there was . also 376 STRUCTURE AND USES OF THE SPLEEN. also some liquid in it, and in this case the whole quantity Not bythe — that escaped must have excecded two ounces. On examin- lymphatics. : : ing the external covering of the stomach, and along the course of the vasa brevia, where the absorbents usually pass, mone were discovered, so that these vessels were not at that time carrying any liqnid. N The spleen tur-. Fhe spleen was turgid, unusually large, and its external Seca aia. surface very irregular; when cut into, small cells wereevery where met with containing a watery fluid, and occupying & considerable portion of its substance. This appearance, which [ had never seen before, made me inquire, if it had been taken notice of by others, and endeavour to ascertain the circumstances, under which it is produced. The. fol- lowing statement contains the information, which J have received on this subject. Malpighi’s no-. Malpighi appears to be the first anatomist, who had any oleae the particular knowledge of the structure of the spleen. He describes its capsule, and a network which pervades every part of the substance. He mentions a number of-smail glands, which are hollow, and surrounded by arterial zones, but he had never been able to trace any venal branches into them. He believed, that there was a cellular structure: in the spleen containing red blood, interposed between the ar- teries and veins; this led him to adopt a theory, that the network was shane ells and by its action asf) the blood, so that there was a systole and diastole in the spleen, as in the heart. Stukely. _Stukely, in his Gulstonian lecture, has very tee copied Malpighi, without giving any additional information. - Cuvier. _ Cuvier, the latest writer on this subject, in his Legons ad’ Anatomie comparee, corrects the errour of Malpighi: re- specting the nature of the network, which he states to be composed of elastic ligament, and says, that there are small corpuscles, the use of which is unknown, and which dis. appear when the blood vessels are minutely injected. ee In the course of the present investigation, I have examined glands of ‘Mal. the spleen after death, under the ordinary circumstances, pighi, contain and have found the appearances described by Cuvizr.. 11 a fluid, after drinking large- have also examined it fr equently immediately after the sto- ly. mach had received unusnal quantities of liquids, andin that state STRUCTURE AND USES OF THE SPLEEN. 377 state have found invariably, that the corpuscles of Cuvier, which were the glands of Malpighi, are distinct cells, cons taining a fluid, which escapes when the cells are punctured, and renders their membranous coat visible; so that itwould appear, that the distension of these cells is connected with the state of the stomach, and therefore only takes place occasionally; and that the elastic capsule, by which the — spleen is surrounded, adapts the organ to these changes im its volume. On examining further into the structure of the spleen, in Farther exami. which I have been materially assisted by Mr. Brodie, olen —- fellowing facts have been ascertained. In the spleen of the bullock, horse, and hog, the cells, Arteries ramify when the arteries and veins are injected with coloured size, en of are seen to have numerous arterial branches ramifying in their coats, but no venal ones, which confirms the state. ment of Malpighi; aud when the cells are empty and con~ tracted, and the blood-vessels filled to a great degree of mi- nuteness, the appearance of cells is entirely lost, as stated by Cavier: When the cells were in a distended state, their cavities in Intermediate a great many instances were very distinct, having been laid een =e open in making a section of the spleen. The intermediate parts of the spleen are but sparingly supplied with arterial branches, and the smaller ones do not appear to have any particalar distribution. When the veins only are injected, their branches appear Veins more 5 numerous than more numerous, aud larger than those of the arteries, mak- the arteries, and ing the whole substance of the spleen of a red colour. — from the They appear to arise from the outside of the cells, going off — * at right angles to their circumference, like radii. Where the injection has not been very minute, they are seen to _arise at so many points of the capsule; but where the in- jection has got into smaller branches, their number is so much increased, that they appear to form plexuses round the cells. : isive: The trunk of thesplenic vein, compared with that - the aaa on ne artery, when both are filled with wax, is found to be in the jhe artery. proportion of five to one in its size. This was aseertained both by an accurate measurement of their diameters, and by » 378 STRUCTURE AND USES OF THE SPLEEN. by weighing half an inch in length of cach in a very nice balance; the disproportion between them is greater, than between corresponding veins and arteries, in other parts of the body. Experiment Having acquired this knowledge of the internal structure with madder. oF the spleen, I made the following experiment witha de. coction of madder. This substance was employed, from the animals who feed on it having their bones tinged red, so that there can be no doubt of its colouring matter being carried into the circulation of the blood. I was much disappointed on seeing the colour of the decoction, which, instead of being a bright red (the tinge communicated to the bones), ‘was of adirty brown. The same gentlemen assisted me, as in the former experiment. Decoction in- . Nov. 8, 1807, seven eunces of a strong decoction of ee madder were injected into the stomach of a dog, immedi- dog, with the ately after the pylorus had been secured. At this time the pylorus tied uP- dog voided some urine, which was limpid and colourless. In 42 minutes, two ounces of a yellowish fluid were brought, up by vomiting. In 18 minutes more the dog vomited again; what came up proved to consist of 34 ounces of solid matter, and 3 ounces of liquid. In 15 minutes after. wards, 5 ounces of the decoction were injected, which re- mained quietly on the stomach for two hours and a quarter, After 1; hour at the end of which period the dog was killed. In the act urine resembled ~ ae x : Auid inthe sto- Of dying he made water, in the quantity of two ounces, of mache a'dark muddy colour. This was saved, and afterwards compared with the remaining liquid in the stomach, which State of the in- it exactly resembled. On examining the connections be- ternal parts. ‘tween the stomach and spleen, none of the absorbent ves- sels were apparent, more than in the former experiments, The pyloric portion of the stomach contained about two ounces of half digested food, but no liquid. The cardiac - portion contained four ounces of liquid, and half an ounce of solid food, so that the act of vomiting, which appeared, at the time, a sufficient exertion to have completely emptied the stomach, had brought up no part of the contents of the pyloric portion, and had not even completely emptied the Xth of the liquid cardiac portion. In’ this experiment, without making al- had escaped. Jowance for any liquid'in the stomach, prior to the decoc. tion STRUCTURE AND USES OF THE SPLEEN. 379 tion of. madder being injected, one fourth part of the quan- tity thrown in had escaped. The cells of the spleen were ore distinctly seen than in the former experiment, parti-' cularly at the great end. , Although there was every reason to believe, that the co- Madder not louring matter of the madder had been conveyed into the Ma gous urinary bladder, yet so muddy and indistinct was the colour, meat. that it was by no means completely ascertained. I there- fore resolved in my future experiments, to make use. of some colouring substance, the presence of which could be detected in a very diluted state, by means of a chemical test; and I requested Mr. W. Brande, of whose assistance I have before availed myself, to point out the substances best fitted for this purpose. He immediately suggested, that Rhubarb sug- rhubarb was a substance, which he’ had made use of as est a test to ascertain the presence of alkali, and, therefore had no doubt, that the caustic alkali would prove a test-of rhubarb. This substance has also another advantage; it is well known to pass very readily by the kidneys, without being decomposed. The following are the results of experiments made with bb et its rhubarb, to ascertain the best modes of detecting it in the ms urine and blood, and the time it takes to pass from the sto- mach to the urinary bladder. ° Five drops of tincture of rhubarb, added to 3 ounces of In water. water, are found to strike an orange tint when the test is added, which does not take place when the rhubarb is more diluted, Six drops of tincture of rhubarb, added to three ounces of In serum. serum, are readily detected by the eye, but the colour is not heightened by applying the test; the alkali contained in the serum being sufficient to strike as bright a tint, as that quan- tity of rhubarb can receive from the addition of alkali. When tincture of rhubarb is mixed with blood just taken In blood. from the arm, its colouring matter is afterwards found both in the serum and in the coagulum. When blood is drawn from the arm of a person, who has Gets into the taken rhubarb in sufficient quantity to affect the urine, the se- aheaie es rum is found to have a slight tinge from it, equal to that, which one drop of tincture of rhubarb gives to half an cunce of serum when added to it. Half S80 STROCTURE AND USES OF THE SPLEEN. | iis cfects on ” ideal f an ouned/of tincture of rhubarb, diluted in 12 ounce Sale of water, taken in the interval between meals, did not pass off by urine in Jess than an hour, and even then was not in sufficient quantity to be discovered, till the test was ap. _ - plied. WR The same quantity was taken immediately before a break. fast consisting of tea. In 17 minutes, half an ounce of urine was voided, which when tested had a light tinge. In 30 minutes another half ounce was made, in which the tinge was stronger ; and in 41 minutes a third half ounce was made, im which it was very deep. In an hour and ten minutes 7 ounces were voided, in which the tinge of rhubarb was very weak, and in two hours twelve ounces were voided, in which it was hardly perceptible. and faces, In 62 hours the rhubarb acted on the bowels, and gave a decided tinge to the feces; the urine made at the same time had amuch stronger tinge, than what was voided at one hour and ten minutes. Gets into the In this experiment, the rhubarb appeared to have escaped usine by tvo from the cardiac portion of the stomach; and in two hours di ferent chan- mead ceased to pass through that channel; but was afterwards carried mto the system from the intestines, and again ap- peared in the urine. Fxperiment re- This experiment was repeated. on another person; the ee rhubarb was detected in the urine in 20 minutes. In 2hours ; the tinge became very faint; in 5 hours-it was scarcely per- ceptible ; in seven hours the rhubarb acted on the bowels; and the urine made after that period became again as highly tinged as at first. ; Prussiate of It was suggested by a chemical friend, that the prussiate o mar Sugeest’ potash might bea better substance than rhubarb, for the pre- sent experiments, since the solution of one quarter of.a grain in two ounces of water becomes cf a blue colour on the ads dition of the acidulous muriate of iron. Nat tobe te To determine this point, one quarter of a grain was dis sc see ise solved in two ounces of sernm, but no blue colour was pro. ouanbiies, duced by the addition of the test, nor did this effect take : place till the quantity of the prussiate was increased. to a grain; so that minute quantities of the prussiate of potash, or at least of the prussic acid, may exist in the blood, -with- out being detected by adding solution of iron. ' ‘The STRUCTURE AND USES.OF THE SPLEEN. red | The effects of rhubarb on the wine, and the different Experie parts of the blood, having been thus ascertained, a third“? ™ experiment was made, in which that substance was em- ployed, and I had the assistance of the same gentlemen as in the ethers. ~ On November 17, 1807, at 35 minutes past 11 o’clock, ona dog, five drams of a mixture of tincture of rhubarb and water, in the proportion of a dram to an ounce, were injected into the stomach of a dog, the pylorus of which was se- cured. At 20 minutes past one, two ounces of fluid were brought up by vomiting: ten minutes afterwards, another ounce of the mixture was injected, as were nine drams more at half past four o’clock. The two last pertions were re. tained, and at eight o’clock in the evening the dog was killed, On examining the partsafter death, the pylorus was found None of the to be completely secured; the stomach contained about two oe ounces of fluid; none of the absorbent vessels passing from distended, its great curvature were in a distended state, soas to be ren- dered visible. The spleen was turgid as in the former ex- but the spleen periment, and the urinary bladder full of urine. si pigen This urine, tested by the alkali, received a deeper tinge Rhubarb in the of rhubarb than the human urine, after rhubarb had been “"°3 taken three hours by the mouth, and in other respects re- - sembled it. ~ When the spleen was cut into, the cells were particularly and in the ‘large and distinct. A portion of it was then macerated fat Pieen two drams of water for ten minutes ina glass vial. All the parts were exposed to the water, by its being divided in all directions. The water thus impregnated was strained off and tested by the alkali, and immediately the reddish brown colour was produced in the centre, and no where else, but im less than a minute it began to diffuse itself, and extended over the whole. A similar portion of the liver was treated in the same way, None in the and the alkali was added to the strained liquor, bat no livers change took place in it whatever. In this experiment the rhubarb was detected in the juices Could not hay of the spleen as well as in the urine; and as there was no papi het. Re appearance of it in the liver, it could not have arrived there absorbent sy: 5 through *°" 382 PURIFICATION OF LEMON JUICE. through the medium of the common absorbents carrying it into the thoracic duct, and afterwards into the circulation: of the blood. The inquiry to The discovery of this fact I consider to be of sufficient be pursued- importance to be announced to the Society, that, when it is thifs made public, I may be at liberty more openly, and ona more extensive scale of experiments, to prosecute the inquiry. XIV. On the Purification of Lemon Juice. In a Letter from @ Correspondent. a To Mr. NICHOLSON, SIR, : Purification of A READER. of your valuable publication submits to temon juice: your judgment the following methods of purifying lemon juice, which should you think worthy of a place therein, it will oblige Yours, &c. PHILOCHEMICUS, Ist, Take of nitromuriate of tin, (prepared by dissolving "by nitromuriate the rietial in a mixture of two parts nitric, and one muriatic atte acid) one dram, lemon juice one quart; after te forty eight hours filter through white paper. or charcoal. 2nd, Take of finely pounded and well burned chnittael one ounce; lemen juice one quart; mix, and after standing twelve hours filter through white paper. Second method The latter method seems preferable, as there is nothing perhaps prefer- employed, which can in any degree injure the juice, the charcoal being perfectly insoluble. In the former, perhaps some of the solution of tin may pass the filter, though it is most probable it precipitates along with the mucilage and extractive matter, which are so combined, that one cannot be precipitated without the other ; however should any pass, the quantity must be so small, as to render it of little consequence. SCIENTIFIC SCIENTIFIC NEWS. SCIENTIFIC NEWS: I AM informed by Dr. Forbes of Edinburgh, that he is New translation : : . L : Pliny’s Na- engaged on a translation of Pliny’s Natural History, which tural Hi “a is to be accompanied with such notes and illustrations, as may be necessary to elucidate the context, a Life of the Author, and a Preliminary Dissertation on the Origin of Natural History, and on its progress and gradual improve- ment, from its infancy to its present state of comparative maturity. He observes, that the thirty-seven books of the Natural History of Caius Plinius Secundus may with propriety be regarded as the Encyclopedia of antiquity, since its very inquisitive and industrious author has collected 2!1 the facts recorded by every Greek and Roman writer previous to his own time, concerning the animal, the vegetable, and the tnineral kingdoms, and detailed in a clear and luminous arrangement all that the accumulated experience of past ages had ascertained, relative to the nature of animals and vegetables, to meterology, astronomy, botany, medicine, chemistry, &c. Pliny’s. work may be divided into three parts, geography, natural history, and materta medica. Of his geographical inquiries his strictures on the interior parts of Africa are perhaps the most important. He de- rived the sources of his information on this subject from the Carthaginians ; and from what he has recorded respect- ing the natives and productions of those regions, it is evi- dent, that the ancients were much better acquainted than the moderns are with this quarter of the globe, which from recent events, and from the consequences likely to arise from a great act of national justice, deservedly excites in this country no small share of public interest. The mate. ria medica exclusively occupies fifteen books of the Historia Naturalis, and constitutes a very curious and instructive department of the author’s investigations. It cannot be ‘denied, that Pliny discovers his ignorance in particular points, and that he has recorded with solemn gravity many absurd 383 | History. i 384 SCIENTIFIC NEWS. New translation absurd fables and anile stories. But perhaps he might hare of Pliny’s Na- tural History. used the language of Quintus Curtius, ‘** Mgquédem plura transcribo quam credo ;” and we know, that he occasion- ally discovers a proper degree of scepticism on various points, which came under his review, and severely rebukes the vanity and self confidence of the Greek authors, from whom he derived his information. Yet, notwithstanding all the censure to which he is obnoxious on the score of credulity, his eloquent and instructive history will-ever be regarded as an imperishable monument of its author’s inde- fatigable industry and Roman spirit. Pliny’s Natural His. tory is indeed to be considered an invaluable treasure, more especially on account of its containing an infinite number of excerpts and observations illustrative of the various sub- jects of which the author treats, extracted from the books of many ancient writers, whose works have perished through the injuries of time. It may therefore appear surprising, - that no English translation of this admirable performance has been offered to the public for more than two centuries. It is the present translator’s object to supply, to the best of his abilities, this deséderatum in English literature. One great object, which the translator will keep in view in his notes and illustrations, will be, to accommodate Pliny’s descriptions of animals, plants, and minerals to the no- menclature of the Systema Nature Linnai. This, he is abundantly aware, will prove by much the most difficult part of his labours; and he despairs of executing it with full satisfaction cither to the public or to himself. But as in the present state of natural history a translation of Pliny would not be well received without some account of the synonyms, he enters on the task in the hope of being able to contribute in some measure toward its accomplish- ment. The translation thus enlarged must extend to six or seven volumes in octavo, and will be published either im se- parate volumes successively, or when the whole shall have been finished, as future circumstances may-render it ad- visable. . P xt) Tak. ‘ A. A. B. C. D. on a concise method of détermining the figure of a gravita- ting body revolving round another, 208—On the direct attraction of a spheroid, and demonstration of Clai- raut’s theorem, 273 ; ‘Accum, Mr. his apparatus for igniting light combustible substances by means of compressed air, 278 Acetous acid, formation of, in cases of indigestion, 196 Alkalies, fixed, nature of, and their ~ decomposition by electricity, 290, 321 Allen, Mr. 326 Altitudes; artificial portable horizon for taking, 279 Alum ore of Tolfa, analysis of, 359 Amber varnish and acid, 227 Ammonia, nature of, 324 Analysis—of the water of the Dead Sea, 32— Of the water of the river Jor- dan, 38—=-Of jade, 104—Of yenite, _ 142—Of the schist that accompanies the menelite near Paris, 155—Of some varieties of steatite, or talc, 170 =-Of diabetic urine, 232—Of iron . Spar, 314, 357——Of an urimary cal- _culus, 317—Of alum ore, 359 Anderson, Charles, Esq. on the geog- ' nosy of the island of Inch Keith, in the Frith of Forth, 238 Animal heat, cause of, 200 Apple-trees, culture of, 50 Arc of the meridian measured in India, 740 Aremberg, Comte de, 57 Ames pendulum spring, 225 Ash-trées, improved method of raising, 354 Asphaltite, lake, analysis of its water, 25 , Vou, XX. Aston, Mr. J. extract of a letter from, giving an accountof a mule cucum- ber, and other-cbjects, 221 Atmospheric phenomena, 81 Atmosphere, lunar, 117 Attraction, direct, of a spheroid, 273 Attraction of the earth upon the atmos- vere of the moony 117 Aumont, Gillet, 64 Aurora borealis, see Phenomena E. Bakerian lecture, 290, 521 Balance level, for laying out land for irrigation, &c. 344 Balbo, M. on native gold dust, 268 Banks, Sir J. on the time when the potato was first introduced into the United Kingdom; with some account of the hill wheat of India, 1-On the rumination of the kanguroo, 12— On the lava of Mount Hecla, 182 Bauhin, Gaspar, on the tuberose, 58, 168 Beilstein, a species of jade, 105 Bell, Lieut. John, his account of ex- periments made to ascertain the prac- ticability of throwing a line to the shore from a vessel stranded, 285 Bellevue, M. Fleuriau de, on volcanie agency, 176, 241 Bergman’s analysis of iron spar, 314, 057 Berthier, M. his analysis of iron spar, 514 Berthollet, M. on hative gold dust, 272 —His decomposition of ammonia by electricity, 327 . Besson, M. 67 Biggs, Mr. his account of some new apples, which, with many others that have been long cultivated, were exhi- b bited INDE X. bited before the Horticultural Society, 50 Bildstein, analysis of, 171, 173 Blagden, Sir C. on the velocity of fire- balls, 82, 85 Bonpland, see Humboldt Borch, Count, mistake of, in his de- scription of the lava of Aitna, 247 Bonvoisin, Dr. on pysites and native gold dust, 269 Braconnot’s experiments, controverted, - 102, 323 Brande, Mr. 375, Biassica napus, a new variety of, 168 Brisson, M 106 Brochant, M. on native gold dust, 267 * Brodie, Mr. his experiment on the structure and uses of the spleen, 375 Brydone on shooting stars, 83 Bry, De, extract from his ‘‘ Voyages,” 2 Buch, M. De, on the crystals included in volcanic lava, 183, 245 Buchanan, Dr. his description of the . gay4l, or Indian ox, 203 Bucholz, C.F. his'experiments on mo- __dybdena, 121, ii 258 c. “C. on the effects of galvanism on ani- mals, 379 Calcareous mountain, geological re- marks on, 62 Calculus of the urinary passages, ana- lysis of, 317 Carne, Mr. J. his aecount of the Relis- _ tian tin mine, 24 Caulcy, M. on the saccharine diabetes, 230 /€ellularia bassani, a new genus of in- ‘sect, 319. Chalk, French, analysis of, 175 Champeaux, 94, 96 Chapman, Mr. 221 - Chen.vix, Mr. 34 —€bronometers, improvements in, 224 ie Cieca, Peter, i Bate ts Chro- _-) Bicley” 3 ae Citis, pord of, how drained, 88 Clairaut’s system of gravitation, 208 Clement, M. 326 Clift, Mr. 375 Clifton, Mr. T. question by, respecting the ignition of tinder by compressed air, 278 Clusius, on the introduction of the po- tato to Spain and Italy, 2 Colebrook, H. T. Esq. his description of a new species of ox, named Gay- a), 201 Cold, supposed radiation and reflection of, 341 Compensation curb for timepieces, 188 Compensation pendulum, 214 Cordier, M. on the geometrical charac- ters of yenite, 141 Coromandel coast, measure of a degree at, 40 Court, M. De la, 49 Crystals in lavas, 176, 242 Crystals, spurious, 93 Cucumber, a mule, described, 221 Cuvier, on the structure and offices of the spleen, 376 Mi D. Dalton, Mr. his experiments on com- presssed air, 279, 326 Daniel, Mr. F. C. his description of: an apparatus to secure persons from sink. ing in water, or to act asa life-pre- server when shipwrecked, 28% Darcet, 272 Daubenton’s description of the stomach of the hippopotamus, 13 Davy, H. Esq. on some new pheno- mena of chemical changes produced by electricity, particularly the de- composition of the fixed alkalies, and ' the exhibition of the new sabatanids which constitute their. bases; and on the general nature of alkaline wig 290, 321 Day, David, Esq. on the advantage de, rived from plantations of ash-trees, 352 | "Dead Se a IN DEX. Dead Sea, aintivei: of the waters of, 32 Decay of wood, prevention of, 69, 102 Deluc, G. A. on the crystallized sub- stances included in lavas,.176, 242 Déscotils, M. Collet, his chemical ex- amination of a sparry iron ore, 357 Desormes, M. 326 Deyeux, 272 Diabetes, essay on, 230—Cured by ani- mal food, 232, 236 Dickson, Mr. J. on a variety of the brassica napus, or rape, which has long been cultivated on the continent, 168 Digestion, process of, 8 Dobson, on diabetes, 230 Dolomieu, M. on volcanic productions, 185 D’Oyley, Mrs. Hannah, her new me- thod of rearing poultry to advantage, 346 Draining the pond of Citis, 88 Drappier, M. on iron spar, 315 Drew, Mr. Richard, description of his balance level, useful for laying out land for irrigation, for roads, and for other purposes, 344 Drowning, machine to prevent, 281 Dry rot, inquiry into its causes, and the means of prevention, 69, 102 Dryander, Mr. on the time when the potato was introduced to the British Isles, 1 Dundonald, Lord, 103 Dupuytren and Thenard, on the sac. charine diabetes, 230 Dytiscus on gravitation, in reply to Professor Vince, 114, 276—<—Answer- ed, 222 E. Ecluse’s “‘ History of Plants,” 56 Electricity, new phenomena of chemi- cal changes produced by, 290 Eliott, Mr. his description of the Gay- 4], or Indian ox, 207 Esculent root, new, described, 168 b2 F, Falconer, Rey. Thos. his. rémarks oh the experiment of Mr. Irwin on soap- suds as a manure, 100 Faujes, M. mistake of, as to the pos- sibility of lava insinuating itself into the fibres of wood without consuming it, 247 Ferrarius on thé culture of flowers, 5% Fife, Earl of, communication from, re- lative to his plantations, 550 Fire-balls, atmospheric, 81 Fishes near Edinburgh, 519 Fixed alkalies, see Alkalies Fluor spar, 238 Forbes, Dr. his new translation of Pli- ny’s Natural History, 385 Forsyth, Mr. 101 Fourcroy on molybdena, 125 Franck on diabetes, 230 Franklin, Dr. on the southerly winds which follow the aurora borealis, 8& French chalk, analysis of, 175 French turnips, see Turnips Friction communicates heat to water, 113 Cu Galvanism, effects of, on animals, 371 Gannet, or Soland goose, camer his- tory of, 318 Gardening, 55 Garrard, Mr. Wm. on a new property of the tangents of the three angles of a plane triangle, 338 Gay4l, a new species of ox, 201 Geological remarks on a calcareous mountain near Chessy, 62 Gerard’s “ Herbal,” 2 Giddy, D. Esq. 24 Gillet Laumont, M. 144 Giobert, M. 272 Giulio, MZ on the native gold dust found in the hilsin the environs of the commune of St. George’s, in the department of the Doire, 266 Gold dust, see Giulio Gordon, PN DP ERA. Gordon, Mr. of Clunie, 26 Gough, J. Esq. his essay on polygonal numbers, containing demonstration of a propasition respecting whole numbers in general, 161 Gravitation, farther remarks on Profes- sor Vince’s answer, 114, 276, 208, 222—(See Vol. XTX. p. 304, 344 ) Guyton, M. his chemical examination of a sparry iron ore, 357 Hi. Haberlé, M. 122 Hall, Sir James, on volcanoes, 182 Halley’s hypothesis of meteors, not sa- 'tisfactory, 86 Hardy, Mr. W. his curb for time- pieces, affording a compensation for the effects of heat and cold, described, 138 Hassentratz, M. 314 Hatchett, Mr. 533 Hauy, Mr 94, 98, 104, 171, 314 Heat in animal bodies, cause of, 200 Heidinger, 134 Helmont, Van, his experiment of his production of earth in the growth of the willow, oyerthrown, 823 Aemerobius’s calculation of the rate of expansion of a supposed lunar atmos- phere, 117 Hernandez, 57 Herriot, Mr. Thos. the first who de- scribed the solanum tuberosum, or potato, 2 Heyer’s experiments on molybdenaj 121, 195 Hielm’s experiments on molybdena, 121, 133 Hill wheat of India, 4 Hoepfner, Mr. his analysis of the jade of Swisserland, 105 Home, Everard, Esq. on the structure ‘4nd office of the stomachs of differ- ent animals, with a view to elucidate the process of, converting animal and vegetable substances into chyle, 5, 874 Horizon, artificial, ares e795" Huberlé, M. 193 Huel Bovs, composition of the sulphu- ret from, and its crystals, 352 Humboldt and Bonpland on volcanic eruptions, 244 Hunter, on the human stomach, 16 Hunter, Dr. his oil compost, 100 I. Ignition by compressed air, 278 Ilsemann’s experiments on molybdena, Ue ws) Indigestion, 196 Jron spar, analysis of, 314, 357 Irwin, Mr. G. his experiment on Soap suds as 4 manuse, 99 J. Jade, analysis cf, 104 Jameson, Mr. Ties, 78, 158 Jessé, Mr. Augustus De, lis ingénious contrivance for diaining the pond of Citis, 89 Jordan, river, analysis of its waters, 38 Jura, Mount, remarks on a singular ar- rangement of strata in the chain of, 64 J urine, his mineralogical que- Ss Professor, 94 K. Kamel, 56 Kater, Lieut. H. his new compensation pendulum, 214 ; Kerr, Mr. mistake of, 207 Klaproth’s experiments on molybdena, _121—His analysis of the schist that accompanies the Menelite near Paris, 157—Of bildstein, 171—Of speck- stein, 174—His chemical examina- tion of the alam ore of Tolfa, and the earthy aluminous schist of F rey- enwalde, 359 Knight, T. A. Esq. 168° Knox, 202 Lamberé, ON D8 BS L. Lambert, Mr. 4 kambton, Brigade Major W. his ac- count of the measurement of an arc of the meridian on the coast of Co- romandel, and the length of a degree deduced therefrom, in the latitude of 12° 82’, 40 Lampadius, Professor, his analysis of the schist that accompanies the me- nelite near Paris, 155 Laskey, Capt. on the pinna ingens of Pennant, 258 Lava, crystallized substances found in, 176, 242 Laverriére, M. 96 Lavoisier, M. his analysis of the water of the Dead Sea, inaccurate, 27, 32 Lectures at the Middlesex Hospital for the ensuing winter, 159 Lemaitre, M. on a calcareous mountain near Chessy, in the department of the Rhone, 62—On a singular arrange- ment of strata observed in the chain of Jura, in the department of Doubs, 64 Lemon juice, purification of, 382 Liévre, M. Le, his description and ana- lysis of a new mineral substance, called yenite, 159 Life-preserver, described, 281 | Lightning, observations on, 81 Linné’s “ Hortus Cliffortianus,” 56 Loureiro, M. 56 Lunar atmosphere, calculation of the _ rate of expansion of, 117 M. Maclaurin on gravitation, 208 “Macquer, M. 26 Malpighi’s notion of the spleen, 576 “Manures, 99 Marat on the velocity of lightning, 82 Marcet, Dr. Alex. his analysis of the water of the Dead Sea, and the ri- ver Jordan, 25 . Margueron, M. his memoir on the re ciprocal action of several volatile oils, and certain saline substances, 145 Martin, Mr. John, on the apparent ra- diation and reflection of cold by means of two concave metallic mirrors, 341 Marum, Van, 327 Marzari, Count, 252 Maskelyne, Dr.N. on a new property of the tangents of three arches tri- secting the circumference of a circle, 840 Mathew, Mr. Daniel Dering, on im- provements in chronometers, 224 Medical lectures, 159 Meridian, measurement of an are of, on the Coromandel coast, 40 Meteorological journal for May, 159—« for June, 240—for July, 320 Meteorological table for 1807, 239 Meteors, see Atmospheric phenomena Métherie, M. Dela, 104 Michaelis, Mr. on the fetid resin of sulphur, 238, 317 Middleton, Mr. John, his machine for printing paper hangings, described, 21 Miller on the culture of apple-trees, 51 --Of the tuberose, 58 Mineralogical queries, 78 Mineralogy, 158 Minuti, F. 56 Molybdena, experiments on, 121, 188, 253 Moon, supposed atmosphere of, 117 Montague, Col. George, on several sub- jects of natural history, 318 Mudge, Mr. his scapemeut for time- pieces, 225 Mule cucumber, 221 N. Napion, M.°on native gold dust, 269 Neill, Mr. P. on the fishes, natives of the waters near Edinburgh, 319 Newton, Sir I. deficiency in his re- searches on the figures of gravitating bodies, 208 Nicholson, IN DEX Nicholson, Mr. his account of appear- ances in a storm, resembling the au-~ rora borealis and falling stars, 85 Nicolas on d abetes, 250 Numbers, polygonal, essay on, 16% oO. Oils, volatile, and salts, reciprocal ac- tion of, 145 ‘Ox, new species of, 201 P. P. on the cause of animal heat, 200 i Paludanus, Barnard, 56 Paper-staining, apparatus for, 21 Parkinson on the culture of the tube- rose, 58 id Parkinson’s ‘‘ Organic Remains,” 159 Parmentier, M. 196 Parry, Dr. on the causes of the decay of wood, and the means of prevent- ing it, 69, 102 Patrin, Mr. his inquiry concerning vol- canoes, 184, 251 Peirsc, 57 Pelletier’s experiments on molybdena, 121 Pendulum, to correct the errors arising from 4 variation of temperature, 214 Pennant, Mr. correction of a mistake of, in natural history, 319 Pepys, Mr. his mercurial gazometers, 825 Perperes, M. on the formation of ace- tous acid in cases of indigestion, 196 Perrault on the stomach of the lion, 15 Phenomena, Juminous, which appear to depend on electricity, 81 Philochemicus on the purification of lemon juice, 382 Pinna ingens, 258 Planche, M. on the possibility of col- lecting a ¢ertain quantity of succinct acid, during the preparation of am- ber varnish, without any injury to the quality of the varnish, 227 Plantations, improvement for, 350, 352 Pliny’s natural history, a new transla- tion of, 383 Plumier’s ‘* Genera Plantarum,” 56 Pococke, 27 Polygonal numbers, essay on, 161 Poole on diabetes, 230 Potash and soda, general observationg on the relations of their bases to other bodies, 321 Potato, when introduced to the British isles, 1 Poultry, new method of rearing, 346 Priestley’s electricity, 82, 327 Pseudocrystals, 93 Pyrites on the shore at Harwich, 222 Q. Quendeville on diabetes, 230 R. R. B. on such luminous pheriomena im the atmosphere as appear to depend on electricity, 81 Raleigh, Sir W. brought the potato to England, from Virginia, 1 Rape, a new variety of, 168 Ray, on the tuberose, 58 Reade, Dr. J. his account of a remark- able fact of an increase of temper- ature produced in water by agitation, 113, 200 Redouté, 57 Relistian tin mine, 24 Resin of sulphur, 238 Richter’s oe on molybdene, 121 Robillant, M. hd on native gold dust, 268 Rollo, Dr. his mode. of treating the dis abetes infallible, 232 Roloff, Mr. on the fetid resin of sul- phur, 238 Root, esculent, a new one, described, 168 Rouelle, 27% : ‘Roxburgh, INDE X. Roxburgh, Dr. his description of the Gay4l, or Indian ox, 202 Roy, General, 43 Rumph, 56 Ruprecht’s experiments on molyhdena, 121, 132 S. Sage, M. Le, his analysis of the Dead Sea water, 26, 272 Salisbury, R. A. Esq. on the cultiva- tion of the polyanthos tuberosa, 55 Salmon, Mr. on volcanic crystals, 183 Salts, action of, on volatile oils, 145 Saussure, M. De, on electric clouds, 8 7—eeHis analysis of jade, 104 Saussurite, see Jade Scheele’s discovery of metal in molyb- dena, 121, 125, 192 Scheider, Dr. 94 Schist, see Slate ‘Scientific News, 78, 17, 238, 318, 383 Shaw, Dr. mistake of in natural his- tory, corrected, 319 Shipwreck, lives saved in cases of, by means of Mr. Daniel’s life-preserver, 282, 285 Slate, adhesive, analysis of, 155 _ Smeathman, 103 - Smithson, James, Esq. on the compo- sition of the compound sulphuret from Huel Boys, and an account of its crystals, 332 Soap-suds used as manure, 99 Soda, see Potash Solanum tuberosum, 1 Southwell, Sir Robert, his notice of the introduction of the potato to Ire- land, 2 Speckstein, analysis of, 173 Speechley, Mr. on the culture of the vine, 101 Spheroid, direct attraction of, 273 Spleen, structuyse and uses of, 374 Stahl’s hypothesis of gasses overthrown, 322 Steatite, or talc, comparative analysis of some varieties of, 170 Stevens, Dr. ondigestion, 9 Stomach, structure and office of in dif- ferent animals, 5 Strata, singular arrangement of in the chain of Jura, 64 Stukely’s notion of the spleen, 376, Sulphureous resin, 238 Sulphuret of lead, antimony, and cop- per, 332 Swainson, Isaac, Esq. 51 Swertius’s “ Florilegium,” 58 T. Talc, see Steatite Tangents, new property of, 388, 340 Tatum, Mr. J. on the effects of gal- vanism on animals, 371 Tennant, S. Esq. 25 Thenard, M. see Dupuytren Thompson, Dr. Thos. on the chemical nature of fluor spar, 258 Thury, M. Héricart, 98 Timber trees, plantations of, 350, 352 Time-pieces, compensation curb for, 138 Tinder, ignition of, 278 Tondi, M. 98 Tonnelier, M. on some pseudomorpho- ses in substances that form part of the mineralogical collection of the Coun- cil of Mines, 93, 228 Tovar, Simon de, 56 Transit telescope, error in the semi-circle of, 43 Tremolite of St. Gothard, described, 178 Trommsdorff, M. 193 Tuberose, culture of the, 55 Turner, Capt. 202 = « Turnip, French, 168 Turton, Dr. mistake of, 208 Vallét, a ee INDEX. Vv. Wallét, 58 ‘Vauquelin, M. his analysis of yenite, 144—-Of some varieties of steatite, or tale, 170 Vegetables, wild, improved by culture, 168 Wince, Professor, on gravitation, 114, 222, 276 U. Urinary calculus, analysis of, 317; Ww. Walker, Mr. ‘his account of the birds that frequent the vicinity of. Edin- burgh, 157 Walker, P. Esq. 319 Watrltire, on fire-balls, 82 Water heated by friction, 113 Watson’s electrical experiments, 82 Werner, M. 105, 155 Wernerian Society of natural history, 78, 157, 238, 318 : Westrumb, Mr. 238 Winn, Mr. on the aurora borealis, 87 W.N. on the construction of a curb affording a compensation for the ef- fects of heat and cold in time-pieces, by Mr. Wm. Hardy, 1388—-On the cause of animal_heat, 201—On the ignition of tinder by compressed air, ee ee Wood, decay of, inquiry into the causes of, and the means of preventing it, 69, 102 Woodward, Mr. 323 Wright, Mr. description of his port- able artificial horizon, for taking ‘al- titudes by sea or land, 279 Wurzer, Professor, his analysis of an urinary calculus, 317 Ne Yenite, description and analysis of, 139 HOM, END OF THE TWENTIETH VOLUME: TT RET EE Stratford, Printer, Crown-Court, Temple-Bare ute ‘ { ( } d q q : z : Ligasoes ee: peeene pesososeeess repays moe 2: pavedererey bo: eesrres pegs es ithe peyrts ehh eeeeee precremers>